Analysis of factors that influence the maximum number of repetitions in two upper-body resistance exercises: curl biceps and bench press.

Science.gov (United States)

Iglesias, Eliseo; Boullosa, Daniel A; Dopico, Xurxo; Carballeira, Eduardo

2010-06-01

The purpose of this study was to analyze the influence of exercise type, set configuration, and relative intensity load on relationship between 1 repetition maximum (1RM) and maximum number of repetitions (MNR). Thirteen male subjects, experienced in resistance training, were tested in bench press and biceps curl for 1RM, MNR at 90% of 1RM with cluster set configuration (rest of 30s between repetitions) and MNR at 70% of 1RM with traditional set configuration (no rest between repetitions). A lineal encoder was used for measuring displacement of load. Analysis of variance analysis revealed a significant effect of load (pbench press and biceps curl, respectively; pbench press and biceps curl, respectively; p>0.05). Correlation between 1RM and MNR was significant for medium-intensity in biceps curl (r=-0.574; pvelocity along set, so velocity seems to be similar at a same relative intensity for subjects with differences in maximum strength levels. From our results, we suggest the employment of MNR rather than % of 1RM for training monitoring. Furthermore, we suggest the introduction of cluster set configuration for upper-body assessment of MNR and for upper-body muscular endurance training at high-intensity loads, as it seems an efficient approach in looking for sessions with greater training volumes. This could be an interesting approach for such sports as wrestling or weightlifting.

Accelerated high-frequency repetitive transcranial magnetic stimulation enhances motor activity in rats

NARCIS (Netherlands)

El Arfani, Anissa; Parthoens, Joke; Demuyser, Thomas; Servaes, Stijn; De Coninck, Mattias; De Deyn, Peter Paul; Van Dam, Debby; Wyckhuys, Tine; Baeken, Chris; Smolders, Ilse; Staelens, Steven

2017-01-01

High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) is currently accepted as an evidence-based treatment option for treatment-resistant depression (TRD). Additionally, HF-rTMS showed beneficial effects on psychomotor retardation in patients. The classical HF-rTMS paradigms however

Dual-Comb Coherent Raman Spectroscopy with Lasers of 1-GHz Pulse Repetition Frequency

OpenAIRE

Mohler, Kathrin J.; Bohn, Bernhard J.; Yan, Ming; Hänsch, Theodor W.; Picqué, Nathalie

2016-01-01

We extend the technique of multiplex coherent Raman spectroscopy with two femtosecond mode-locked lasers to oscillators of a pulse repetition frequency of 1 GHz. We demonstrate spectra of liquids, which span 1100 cm$^{-1}$ of Raman shifts. At a resolution of 6 cm$^{-1}$, their measurement time may be as short as 5 microseconds for a refresh rate of 2 kHz. The waiting period between acquisitions is improved ten-fold compared to previous experiments with two lasers of 100-MHz repetition frequen...

Validity of one-repetition maximum predictive equations in men with spinal cord injury.

Science.gov (United States)

Ribeiro Neto, F; Guanais, P; Dornelas, E; Coutinho, A C B; Costa, R R G

2017-10-01

Cross-sectional study. The study aimed (a) to test the cross-validation of current one-repetition maximum (1RM) predictive equations in men with spinal cord injury (SCI); (b) to compare the current 1RM predictive equations to a newly developed equation based on the 4- to 12-repetition maximum test (4-12RM). SARAH Rehabilitation Hospital Network, Brasilia, Brazil. Forty-five men aged 28.0 years with SCI between C6 and L2 causing complete motor impairment were enrolled in the study. Volunteers were tested, in a random order, in 1RM test or 4-12RM with 2-3 interval days. Multiple regression analysis was used to generate an equation for predicting 1RM. There were no significant differences between 1RM test and the current predictive equations. ICC values were significant and were classified as excellent for all current predictive equations. The predictive equation of Lombardi presented the best Bland-Altman results (0.5 kg and 12.8 kg for mean difference and interval range around the differences, respectively). The two created equation models for 1RM demonstrated the same and a high adjusted R 2 (0.971, Ppredictive equations are accurate to assess individuals with SCI at the bench press exercise. However, the predictive equation of Lombardi presented the best associated cross-validity results. A specific 1RM prediction equation was also elaborated for individuals with SCI. The created equation should be tested in order to verify whether it presents better accuracy than the current ones.

Effects of different strength training frequencies on maximum strength, body composition and functional capacity in healthy older individuals.

Science.gov (United States)

Turpela, Mari; Häkkinen, Keijo; Haff, Guy Gregory; Walker, Simon

2017-11-01

There is controversy in the literature regarding the dose-response relationship of strength training in healthy older participants. The present study determined training frequency effects on maximum strength, muscle mass and functional capacity over 6months following an initial 3-month preparatory strength training period. One-hundred and six 64-75year old volunteers were randomly assigned to one of four groups; performing strength training one (EX1), two (EX2), or three (EX3) times per week and a non-training control (CON) group. Whole-body strength training was performed using 2-5 sets and 4-12 repetitions per exercise and 7-9 exercises per session. Before and after the intervention, maximum dynamic leg press (1-RM) and isometric knee extensor and plantarflexor strength, body composition and quadriceps cross-sectional area, as well as functional capacity (maximum 7.5m forward and backward walking speed, timed-up-and-go test, loaded 10-stair climb test) were measured. All experimental groups increased leg press 1-RM more than CON (EX1: 3±8%, EX2: 6±6%, EX3: 10±8%, CON: -3±6%, Ptraining frequency would induce greater benefit to maximum walking speed (i.e. functional capacity) despite a clear dose-response in dynamic 1-RM strength, at least when predominantly using machine weight-training. It appears that beneficial functional capacity improvements can be achieved through low frequency training (i.e. 1-2 times per week) in previously untrained healthy older participants. Copyright © 2017 Elsevier Inc. All rights reserved.

Impact of visual repetition rate on intrinsic properties of low frequency fluctuations in the visual network.

Directory of Open Access Journals (Sweden)

Yi-Chia Li

Full Text Available BACKGROUND: Visual processing network is one of the functional networks which have been reliably identified to consistently exist in human resting brains. In our work, we focused on this network and investigated the intrinsic properties of low frequency (0.01-0.08 Hz fluctuations (LFFs during changes of visual stimuli. There were two main questions to be discussed in this study: intrinsic properties of LFFs regarding (1 interactions between visual stimuli and resting-state; (2 impact of repetition rate of visual stimuli. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed scanning sessions that contained rest and visual stimuli in various repetition rates with a novel method. The method included three numerical approaches involving ICA (Independent Component Analyses, fALFF (fractional Amplitude of Low Frequency Fluctuation, and Coherence, to respectively investigate the modulations of visual network pattern, low frequency fluctuation power, and interregional functional connectivity during changes of visual stimuli. We discovered when resting-state was replaced by visual stimuli, more areas were involved in visual processing, and both stronger low frequency fluctuations and higher interregional functional connectivity occurred in visual network. With changes of visual repetition rate, the number of areas which were involved in visual processing, low frequency fluctuation power, and interregional functional connectivity in this network were also modulated. CONCLUSIONS/SIGNIFICANCE: To combine the results of prior literatures and our discoveries, intrinsic properties of LFFs in visual network are altered not only by modulations of endogenous factors (eye-open or eye-closed condition; alcohol administration and disordered behaviors (early blind, but also exogenous sensory stimuli (visual stimuli with various repetition rates. It demonstrates that the intrinsic properties of LFFs are valuable to represent physiological states of human brains.

Effect of Training Frequency on Maximum Expiratory Pressure

Science.gov (United States)

Anand, Supraja; El-Bashiti, Nour; Sapienza, Christine

2012-01-01

Purpose: To determine the effects of expiratory muscle strength training (EMST) frequency on maximum expiratory pressure (MEP). Method: We assigned 12 healthy participants to 2 groups of training frequency (3 days per week and 5 days per week). They completed a 4-week training program on an EMST trainer (Aspire Products, LLC). MEP was the primary…

The relationship between muscle action and repetition maximum on the squat and bench press in men and women.

Science.gov (United States)

Flanagan, Shawn D; Mills, Matthew D; Sterczala, Adam J; Mala, Jesse; Comstock, Brett A; Szivak, Tunde K; DuPont, William H; Looney, David P; McDermott, Danielle M; Hooper, David R; White, Mark T; Dunn-Lewis, Courtenay; Volek, Jeff S; Maresh, Carl M; Kraemer, William J

2014-09-01

The relationship between muscle action and fatigue is not well understood, especially in terms of potential sex-specific differences. The purpose of this investigation was to determine whether a different number of repetitions could be performed on the individual muscle actions of the bench press and squat in men and women. Ten resistance-trained men (n = 10; age, 25.2 ± 1.2 years; height, 178.6 ± 8.8 cm; weight, 91.4 ± 18.1 kg; body fat, 12.7 ± 3.6%) and women (n = 10; age, 25.4 ± 2.4 years; height, 164 ± 4.0 cm; weight, 58.45 ± 3.3 kg; body fat, 20.8 ± 1.5%) participated in this balanced and randomized within-group study. Using 85% of a 1 repetition maximum, over the course of 3 visits, subjects performed 1 eccentric (ECC), concentric (CON), or combined (COMB) set to failure on the squat and bench press. Differences in muscle action and sex-specific number of repetitions to failure were compared on the squat and bench press, where significance was p ≤ 0.05. Across both exercises and sex, we observed significant differences between each of the 3 muscle actions, where the number of repetitions decreased from ECC to COMB to CON. While no sex-specific differences were observed in the squat, women performed significantly more repetitions on the ECC and CON muscle actions of the bench press. Men performed more combined repetitions, however, indicating a greater reliance on the stretch-shortening cycle. Different muscle actions contribute uniquely to the successful performance of a lift and fatigue. These contributions appear to differ in men and women.

Femtosecond pulse with THz repetition frequency based on the coupling between quantum emitters and a plasmonic resonator

Science.gov (United States)

Li, Shilei; Ding, Yinxing; Jiao, Rongzhen; Duan, Gaoyan; Yu, Li

2018-03-01

Nanoscale pulsed light is highly desirable in nano-integrated optics. In this paper, we obtained femtosecond pulses with THz repetition frequency via the coupling between quantum emitters (QEs) and plasmonic resonators. Our structure consists of a V -groove (VG) plasmonic resonator and a nanowire embedded with two-level QEs. The influences of the incident light intensity and QE number density on the transmission response for this hybrid system are investigated through semiclassical theory and simulation. The results show that the transmission response can be modulated to the pulse form. And the repetition frequency and extinction ratio of the pulses can be controlled by the incident light intensity and QE number density. The reason is that the coupling causes the output power of nanowire to behave as an oscillating form, the oscillating output power in turn causes the field amplitude in the resonator to oscillate over time. A feedback system is formed between the plasmonic resonator and the QEs in the nanowire. This provides a method for generating narrow pulsed lasers with ultrahigh repetition frequencies in plasmonic systems using a continuous wave input, which has potential applications in generating optical clock signals at the nanoscale.

Closed-cycle 1-kHz-pulse-repetition-frequency HF(DF) laser

Science.gov (United States)

Harris, Michael R.; Morris, A. V.; Gorton, Eric K.

1998-05-01

We describe the design and performance of a closed cycle, high pulse repetition frequency HF(DF) laser. A short duration, glow discharge is formed in a 10 SF6:1 H2(D2) gas mixture at a total pressure of approximately 110 torr. A pair of profiled electrodes define a 15 X 0.5 X 0.5 cm3 discharge volume through which gas flow is forced in the direction transverse to the optical axis. A centrifugal fan provides adequate gas flow to enable operation up to 3 kHz repetition frequency. The fan also passes the gas through a scrubber cell in which ground state HF(DF) is eliminated from the gas stream. An automated gas make-up system replenishes the spent fuel gases removed by the scrubber. Total gas admission is regulated by monitoring the system pressure, whilst the correct fuel balance is maintained through measurement of the discharge voltage. The HF(DF) generation rate is determined to be close to 5 X 1019 molecules per second per watt of laser output. Typical mean laser output powers of up to 3 watts can be delivered for extended periods of time. The primary limitation to life is found to be the discharge pre- ionization system. A distributed resistance corona pre- ionizer is shown to be advantageous when compared with an alternative arc array scheme.

Effect of parallel magnetic field on repetitively unipolar nanosecond pulsed dielectric barrier discharge under different pulse repetition frequencies

Science.gov (United States)

Liu, Yidi; Yan, Huijie; Guo, Hongfei; Fan, Zhihui; Wang, Yuying; Wu, Yun; Ren, Chunsheng

2018-03-01

A magnetic field, with the direction parallel to the electric field, is applied to the repetitively unipolar positive nanosecond pulsed dielectric barrier discharge. The effect of the parallel magnetic field on the plasma generated between two parallel-plate electrodes in quiescent air is experimentally studied under different pulse repetition frequencies (PRFs). It is indicated that only the current pulse in the rising front of the voltage pulse occurs, and the value of the current is increased by the parallel magnetic field under different PRFs. The discharge uniformity is improved with the decrease in PRF, and this phenomenon is also observed in the discharge with the parallel magnetic field. By using the line-ratio technique of optical emission spectra, it is found that the average electron density and electron temperature under the considered PRFs are both increased when the parallel magnetic field is applied. The incremental degree of average electron density is basically the same under the considered PRFs, while the incremental degree of electron temperature under the higher-PRFs is larger than that under the lower-PRFs. All the above phenomena are explained by the effect of parallel magnetic field on diffusion and dissipation of electrons.

Maximum-likelihood methods for array processing based on time-frequency distributions

Science.gov (United States)

Zhang, Yimin; Mu, Weifeng; Amin, Moeness G.

1999-11-01

This paper proposes a novel time-frequency maximum likelihood (t-f ML) method for direction-of-arrival (DOA) estimation for non- stationary signals, and compares this method with conventional maximum likelihood DOA estimation techniques. Time-frequency distributions localize the signal power in the time-frequency domain, and as such enhance the effective SNR, leading to improved DOA estimation. The localization of signals with different t-f signatures permits the division of the time-frequency domain into smaller regions, each contains fewer signals than those incident on the array. The reduction of the number of signals within different time-frequency regions not only reduces the required number of sensors, but also decreases the computational load in multi- dimensional optimizations. Compared to the recently proposed time- frequency MUSIC (t-f MUSIC), the proposed t-f ML method can be applied in coherent environments, without the need to perform any type of preprocessing that is subject to both array geometry and array aperture.

Terahertz repetition frequencies from harmonic mode-locked monolithic compound-cavity laser diodes

International Nuclear Information System (INIS)

Yanson, D. A.; Street, M. W.; McDougall, S. D.; Thayne, I. G.; Marsh, J. H.; Avrutin, E. A.

2001-01-01

Compound-cavity laser diodes are mode locked at a harmonic of the fundamental round-trip frequency to achieve repetition rates of up to 2.1 THz. The devices are fabricated from GaAs/AlGaAs material at a wavelength of 860 nm and incorporate two gain sections with an etched slot reflector between them, and a saturable absorber section. Autocorrelation studies are used to investigate device behavior for different reflector types and reflectivity. These lasers may find applications in terahertz imaging, medicine, ultrafast optical links, and atmospheric sensing. [copyright] 2001 American Institute of Physics

Global Repetition Influences Contextual Cueing

Science.gov (United States)

Zang, Xuelian; Zinchenko, Artyom; Jia, Lina; Li, Hong

2018-01-01

Our visual system has a striking ability to improve visual search based on the learning of repeated ambient regularities, an effect named contextual cueing. Whereas most of the previous studies investigated contextual cueing effect with the same number of repeated and non-repeated search displays per block, the current study focused on whether a global repetition frequency formed by different presentation ratios between the repeated and non-repeated configurations influence contextual cueing effect. Specifically, the number of repeated and non-repeated displays presented in each block was manipulated: 12:12, 20:4, 4:20, and 4:4 in Experiments 1–4, respectively. The results revealed a significant contextual cueing effect when the global repetition frequency is high (≥1:1 ratio) in Experiments 1, 2, and 4, given that processing of repeated displays was expedited relative to non-repeated displays. Nevertheless, the contextual cueing effect reduced to a non-significant level when the repetition frequency reduced to 4:20 in Experiment 3. These results suggested that the presentation frequency of repeated relative to the non-repeated displays could influence the strength of contextual cueing. In other words, global repetition statistics could be a crucial factor to mediate contextual cueing effect. PMID:29636716

Vibrational sum-frequency generation spectroscopy of lipid bilayers at repetition rates up to 100 kHz

Science.gov (United States)

Yesudas, Freeda; Mero, Mark; Kneipp, Janina; Heiner, Zsuzsanna

2018-03-01

Broadband vibrational sum-frequency generation (BB-VSFG) spectroscopy has become a well-established surface analytical tool capable of identifying the orientation and structure of molecular layers. A straightforward way to boost the sensitivity of the technique could be to increase the laser repetition rate beyond that of standard BB-VSFG spectrometers, which rely on Ti:sapphire lasers operating at repetition rates of 1-5 kHz. Nevertheless, possible thermally induced artifacts in the vibrational spectra due to higher laser average powers are unexplored. Here, we discuss laser power induced temperature accumulation effects that distort the BB-VSFG spectra of 1,2-diacyl-sn-glycero-3-phosphocholine at an interface between two transparent phases at repetition rates of 5, 10, 50, and 100 kHz at constant pulse energy. No heat-induced distortions were found in the spectra, suggesting that the increase in the laser repetition rate provides a feasible route to an improved signal-to-noise ratio or shorter data acquisition times in BB-VSFG spectroscopy for thin films on transparent substrates. The results have implications for future BB-VSFG spectrometers pushing the detection limit for molecular layers with low surface coverage.

Decomposition of methane to hydrogen using nanosecond pulsed plasma reactor with different active volumes, voltages and frequencies

International Nuclear Information System (INIS)

Khalifeh, Omid; Mosallanejad, Amin; Taghvaei, Hamed; Rahimpour, Mohammad Reza; Shariati, Alireza

2016-01-01

Highlights: • CH 4 conversion into H 2 is investigated in a nanosecond pulsed DBD reactor. • The absence of CO and CO 2 in the product gas is highly favorable. • Effects of external electrode length, applied voltage and frequency are examined. • The maximum efficiency of 7.23% is achieved at the electrode length of 15 cm. • The maximum CH 4 conversion of 87.2% is obtained at discharge power 268.92 W. - Abstract: In this paper, the methane conversion into hydrogen is investigated experimentally in a nanosecond pulsed DBD reactor. In order to achieve pure hydrogen production with minimum power consumption, effects of some operating parameters including external electrode length, applied voltage and pulse repetition frequency have been evaluated. Results show that although higher CH 4 conversion and H 2 concentration can be obtained at longer electrode lengths, higher applied voltages and pulse repetition frequencies, these parameters should be optimized for efficient hydrogen production. Actually, the maximum CH 4 conversion of 87.2% and maximum hydrogen percentage of 80% are obtained at the external electrode length, discharge power, voltage and frequency of 15 cm, 268.92 W, 12 kV and 10 kHz, respectively. However, the maximum efficiency of 7.23% is achieved at the external electrode length of 15 cm, applied voltage of 6 kV, pulse repetition frequency of 0.9 kHz and discharge power of 4 W. Furthermore, at this condition, due to low temperature of discharge zone very little amount of solid carbon was observed on the inner electrode surface of the reactor.

Repetition and Translation Shifts

Directory of Open Access Journals (Sweden)

Simon Zupan

2006-06-01

Full Text Available Repetition manifests itself in different ways and at different levels of the text. The first basic type of repetition involves complete recurrences; in which a particular textual feature repeats in its entirety. The second type involves partial recurrences; in which the second repetition of the same textual feature includes certain modifications to the first occurrence. In the article; repetitive patterns in Edgar Allan Poe’s short story “The Fall of the House of Usher” and its Slovene translation; “Konec Usherjeve hiše”; are compared. The author examines different kinds of repetitive patterns. Repetitions are compared at both the micro- and macrostructural levels. As detailed analyses have shown; considerable microstructural translation shifts occur in certain types of repetitive patterns. Since these are not only occasional; sporadic phenomena; but are of a relatively high frequency; they reduce the translated text’s potential for achieving some of the gothic effects. The macrostructural textual property particularly affected by these shifts is the narrator’s experience as described by the narrative; which suffers a reduction in intensity.

Influence of previous experience on resistance training on reliability of one-repetition maximum test.

Science.gov (United States)

Ritti-Dias, Raphael Mendes; Avelar, Ademar; Salvador, Emanuel Péricles; Cyrino, Edilson Serpeloni

2011-05-01

The 1-repetition maximum test (1RM) has been widely used to assess maximal strength. However, to improve accuracy in assessing maximal strength, several sessions of the 1RM test are recommended. The aim of this study was to analyze the influence of previous resistance training experience on the reliability of 1RM test. Thirty men were assigned to the following 2 groups according to their previous resistance training experience: no previous resistance training experience (NOEXP) and more than 24 months of resistance training experience (EXP). All subjects performed the 1RM tests in bench press and squat in 4 sessions on distinct days. There was a significant session × group effect in bench press (F = 3.09; p reliability of the 1RM test is influenced by the subject's previous experience in resistance training. Subjects without experience in resistance training require more practice and familiarization and show greater increases in maximal strength between sessions than subjects with previous experience in resistance training.

Modulation of N400 in Chronic Non-Fluent Aphasia Using Low Frequency Repetitive Transcranial Magnetic Stimulation (rTMS)

Science.gov (United States)

Barwood, Caroline H. S.; Murdoch, Bruce E.; Whelan, Brooke-Mai; Lloyd, David; Riek, Stephan; O'Sullivan, John D.; Coulthard, Alan; Wong, Andrew

2011-01-01

Low frequency Repetitive Transcranial Magnetic Stimulation (rTMS) has previously been applied to language homologues in non-fluent populations of persons with aphasia yielding significant improvements in behavioral language function up to 43 months post stimulation. The present study aimed to investigate the electrophysiological correlates…

High-frequency maximum observable shaking map of Italy from fault sources

KAUST Repository

Zonno, Gaetano

2012-03-17

We present a strategy for obtaining fault-based maximum observable shaking (MOS) maps, which represent an innovative concept for assessing deterministic seismic ground motion at a regional scale. Our approach uses the fault sources supplied for Italy by the Database of Individual Seismogenic Sources, and particularly by its composite seismogenic sources (CSS), a spatially continuous simplified 3-D representation of a fault system. For each CSS, we consider the associated Typical Fault, i. e., the portion of the corresponding CSS that can generate the maximum credible earthquake. We then compute the high-frequency (1-50 Hz) ground shaking for a rupture model derived from its associated maximum credible earthquake. As the Typical Fault floats within its CSS to occupy all possible positions of the rupture, the high-frequency shaking is updated in the area surrounding the fault, and the maximum from that scenario is extracted and displayed on a map. The final high-frequency MOS map of Italy is then obtained by merging 8,859 individual scenario-simulations, from which the ground shaking parameters have been extracted. To explore the internal consistency of our calculations and validate the results of the procedure we compare our results (1) with predictions based on the Next Generation Attenuation ground-motion equations for an earthquake of M w 7.1, (2) with the predictions of the official Italian seismic hazard map, and (3) with macroseismic intensities included in the DBMI04 Italian database. We then examine the uncertainties and analyse the variability of ground motion for different fault geometries and slip distributions. © 2012 Springer Science+Business Media B.V.

High-frequency maximum observable shaking map of Italy from fault sources

KAUST Repository

Zonno, Gaetano; Basili, Roberto; Meroni, Fabrizio; Musacchio, Gemma; Mai, Paul Martin; Valensise, Gianluca

2012-01-01

We present a strategy for obtaining fault-based maximum observable shaking (MOS) maps, which represent an innovative concept for assessing deterministic seismic ground motion at a regional scale. Our approach uses the fault sources supplied for Italy by the Database of Individual Seismogenic Sources, and particularly by its composite seismogenic sources (CSS), a spatially continuous simplified 3-D representation of a fault system. For each CSS, we consider the associated Typical Fault, i. e., the portion of the corresponding CSS that can generate the maximum credible earthquake. We then compute the high-frequency (1-50 Hz) ground shaking for a rupture model derived from its associated maximum credible earthquake. As the Typical Fault floats within its CSS to occupy all possible positions of the rupture, the high-frequency shaking is updated in the area surrounding the fault, and the maximum from that scenario is extracted and displayed on a map. The final high-frequency MOS map of Italy is then obtained by merging 8,859 individual scenario-simulations, from which the ground shaking parameters have been extracted. To explore the internal consistency of our calculations and validate the results of the procedure we compare our results (1) with predictions based on the Next Generation Attenuation ground-motion equations for an earthquake of M w 7.1, (2) with the predictions of the official Italian seismic hazard map, and (3) with macroseismic intensities included in the DBMI04 Italian database. We then examine the uncertainties and analyse the variability of ground motion for different fault geometries and slip distributions. © 2012 Springer Science+Business Media B.V.

Gravitational Waves and the Maximum Spin Frequency of Neutron Stars

NARCIS (Netherlands)

Patruno, A.; Haskell, B.; D'Angelo, C.

2012-01-01

In this paper, we re-examine the idea that gravitational waves are required as a braking mechanism to explain the observed maximum spin frequency of neutron stars. We show that for millisecond X-ray pulsars, the existence of spin equilibrium as set by the disk/magnetosphere interaction is sufficient

Gyromagnetic nonlinear transmission line generator of high voltage pulses modulated at 4 GHz frequency with 1000 Hz pulse repetition rate

International Nuclear Information System (INIS)

Ulmasculov, M R; Sharypov, K A; Shunailov, S A; Shpak, V G; Yalandin, M I; Pedos, M S; Rukin, S N

2017-01-01

Results of testing of a generator based on a solid-state drive and the parallel gyromagnetic nonlinear transmission lines with external bias are presented. Stable rf-modulated high-voltage nanosecond pulses were shaped in each of the four channels in 1 s packets with 1000 Hz repetition frequencies. Pulse amplitude reaches -175 kV, at a modulation depth of rf-oscillations to 50 % and the effective frequency ∼4 GHz. (paper)

Optically stabilized Erbium fiber frequency comb with hybrid mode-locking and a broad tunable range of repetition rate.

Science.gov (United States)

Yang, Honglei; Wu, Xuejian; Zhang, Hongyuan; Zhao, Shijie; Yang, Lijun; Wei, Haoyun; Li, Yan

2016-12-01

We present an optically stabilized Erbium fiber frequency comb with a broad repetition rate tuning range based on a hybrid mode-locked oscillator. We lock two comb modes to narrow-linewidth reference lasers in turn to investigate the best performance of control loops. The control bandwidth of fast and slow piezoelectric transducers reaches 70 kHz, while that of pump current modulation with phase-lead compensation is extended to 32 kHz, exceeding laser intrinsic response. Eventually, simultaneous lock of both loops is realized to totally phase-stabilize the comb, which will facilitate precision dual-comb spectroscopy, laser ranging, and timing distribution. In addition, a 1.8-MHz span of the repetition rate is achieved by an automatic optical delay line that is helpful in manufacturing a secondary comb with a similar repetition rate. The oscillator is housed in a homemade temperature-controlled box with an accuracy of ±0.02  K, which not only keeps high signal-to-noise ratio of the beat notes with reference lasers, but also guarantees self-starting at the same mode-locking every time.

A high pulse repetition frequency ultrasound system for the ex vivo measurement of mechanical properties of crystalline lenses with laser-induced microbubbles interrogated by acoustic radiation force

International Nuclear Information System (INIS)

Yoon, Sangpil; Emelianov, Stanislav; Aglyamov, Salavat; Karpiouk, Andrei

2012-01-01

A high pulse repetition frequency ultrasound system for an ex vivo measurement of mechanical properties of an animal crystalline lens was developed and validated. We measured the bulk displacement of laser-induced microbubbles created at different positions within the lens using nanosecond laser pulses. An impulsive acoustic radiation force was applied to the microbubble, and spatio-temporal measurements of the microbubble displacement were assessed using a custom-made high pulse repetition frequency ultrasound system consisting of two 25 MHz focused ultrasound transducers. One of these transducers was used to emit a train of ultrasound pulses and another transducer was used to receive the ultrasound echoes reflected from the microbubble. The developed system was operating at 1 MHz pulse repetition frequency. Based on the measured motion of the microbubble, Young’s moduli of surrounding tissue were reconstructed and the values were compared with those measured using the indentation test. Measured values of Young’s moduli of four bovine lenses ranged from 2.6 ± 0.1 to 26 ± 1.4 kPa, and there was good agreement between the two methods. Therefore, our studies, utilizing the high pulse repetition frequency ultrasound system, suggest that the developed approach can be used to assess the mechanical properties of ex vivo crystalline lenses. Furthermore, the potential of the presented approach for in vivo measurements is discussed. (paper)

Generation of tunable, high repetition rate frequency combs with equalized spectra using carrier injection based silicon modulators

Science.gov (United States)

Nagarjun, K. P.; Selvaraja, Shankar Kumar; Supradeepa, V. R.

2016-03-01

High repetition-rate frequency combs with tunable repetition rate and carrier frequency are extensively used in areas like Optical communications, Microwave Photonics and Metrology. A common technique for their generation is strong phase modulation of a CW-laser. This is commonly implemented using Lithium-Niobate based modulators. With phase modulation alone, the combs have poor spectral flatness and significant number of missing lines. To overcome this, a complex cascade of multiple intensity and phase modulators are used. A comb generator on Silicon based on these principles is desirable to enable on-chip integration with other functionalities while reducing power consumption and footprint. In this work, we analyse frequency comb generation in carrier injection based Silicon modulators. We observe an interesting effect in these comb generators. Enhanced absorption accompanying carrier injection, an undesirable effect in data modulators, shapes the amplitude here to enable high quality combs from a single modulator. Thus, along with reduced power consumption to generate a specific number of lines, the complexity has also been significantly reduced. We use a drift-diffusion solver and mode solver (Silvaco TCAD) along with Soref-Bennett relations to calculate the variations in refractive indices and absorption of an optimized Silicon PIN - waveguide modulator driven by an unbiased high frequency (10 Ghz) voltage signal. Our simulations demonstrate that with a device length of 1 cm, a driving voltage of 2V and minor shaping with a passive ring-resonator filter, we obtain 37 lines with a flatness better than 5-dB across the band and power consumption an order of magnitude smaller than Lithium-Niobate modulators.

Geodesic acoustic eigenmode for tokamak equilibrium with maximum of local GAM frequency

Energy Technology Data Exchange (ETDEWEB)

Lakhin, V.P. [NRC “Kurchatov Institute”, Moscow (Russian Federation); Sorokina, E.A., E-mail: sorokina.ekaterina@gmail.com [NRC “Kurchatov Institute”, Moscow (Russian Federation); Peoples' Friendship University of Russia, Moscow (Russian Federation)

2014-01-24

The geodesic acoustic eigenmode for tokamak equilibrium with the maximum of local GAM frequency is found analytically in the frame of MHD model. The analysis is based on the asymptotic matching technique.

Word Recognition and Nonword Repetition in Children with Language Disorders: The Effects of Neighborhood Density, Lexical Frequency, and Phonotactic Probability

Science.gov (United States)

Rispens, Judith; Baker, Anne; Duinmeijer, Iris

2015-01-01

Purpose: The effects of neighborhood density (ND) and lexical frequency on word recognition and the effects of phonotactic probability (PP) on nonword repetition (NWR) were examined to gain insight into processing at the lexical and sublexical levels in typically developing (TD) children and children with developmental language problems. Method:…

Transitions between corona, glow, and spark regimes of nanosecond repetitively pulsed discharges in air at atmospheric pressure

Science.gov (United States)

Pai, David Z.; Lacoste, Deanna A.; Laux, Christophe O.

2010-05-01

In atmospheric pressure air preheated from 300 to 1000 K, the nanosecond repetitively pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and interelectrode gap distance) of each discharge regime. In particular, the experimental conditions necessary for the glow regime of NRP discharges have been determined, with the notable result that there exists a minimum and maximum gap distance for its existence at a given ambient gas temperature. The minimum gap distance increases with decreasing gas temperature, whereas the maximum does not vary appreciably. To explain the experimental results, an analytical model is developed to explain the corona-to-glow (C-G) and glow-to-spark (G-S) transitions. The C-G transition is analyzed in terms of the avalanche-to-streamer transition and the breakdown field during the conduction phase following the establishment of a conducting channel across the discharge gap. The G-S transition is determined by the thermal ionization instability, and we show analytically that this transition occurs at a certain reduced electric field for the NRP discharges studied here. This model shows that the electrode geometry plays an important role in the existence of the NRP glow regime at a given gas temperature. We derive a criterion for the existence of the NRP glow regime as a function of the ambient gas temperature, pulse repetition frequency, electrode radius of curvature, and interelectrode gap distance.

A feasible repetitive transcranial magnetic stimulation clinical protocol in migraine prevention.

Science.gov (United States)

Zardouz, Shawn; Shi, Lei; Leung, Albert

2016-01-01

This case series was conducted to determine the clinical feasibility of a repetitive transcranial magnetic stimulation protocol for the prevention of migraine (with and without aura). Five patients with migraines underwent five repetitive transcranial magnetic stimulation sessions separated in 1- to 2-week intervals for a period of 2 months at a single tertiary medical center. Repetitive transcranial magnetic stimulation was applied to the left motor cortex with 2000 pulses (20 trains with 1s inter-train interval) delivered per session, at a frequency of 10 Hz and 80% resting motor threshold. Pre- and post-treatment numerical rating pain scales were collected, and percent reductions in intensity, frequency, and duration were generated. An average decrease in 37.8%, 32.1%, and 31.2% were noted in the intensity, frequency, and duration of migraines post-repetitive transcranial magnetic stimulation, respectively. A mean decrease in 1.9±1.0 (numerical rating pain scale ± standard deviation; range: 0.4-2.8) in headache intensity scores was noted after the repetitive transcranial magnetic stimulation sessions. The tested repetitive transcranial magnetic stimulation protocol is a well-tolerated, safe, and effective method for migraine prevention.

Laser-diode pumped self-mode-locked praseodymium visible lasers with multi-gigahertz repetition rate.

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Zhang, Yuxia; Yu, Haohai; Zhang, Huaijin; Di Lieto, Alberto; Tonelli, Mauro; Wang, Jiyang

2016-06-15

We demonstrate efficient laser-diode pumped multi-gigahertz (GHz) self-mode-locked praseodymium (Pr3+) visible lasers with broadband spectra from green to deep red for the first time to our knowledge. With a Pr3+-doped GdLiF4 crystal, stable self-mode-locked visible pulsed lasers at the wavelengths of 522 nm, 607 nm, 639 nm, and 720 nm have been obtained with the repetition rates of 2.8 GHz, 3.1 GHz, 3.1 GHz, and 3.0 GHz, respectively. The maximum output power was 612 mW with the slope efficiency of 46.9% at 639 nm. The mode-locking mechanism was theoretically analyzed. The stable second-harmonic mode-locking with doubled repetition frequency was also realized based on the Fabry-Perot effect formed in the laser cavity. In addition, we find that the polarization directions were turned with lasing wavelengths. This work may provide a new way for generating efficient ultrafast pulses with high- and changeable-repetition rates in the visible range.

Criteria for formation of low-frequency sound under wide-aperture repetitively pulsed laser irradiation of solids

International Nuclear Information System (INIS)

Tishchenko, V N; Posukh, V G; Gulidov, A I; Zapryagaev, V I; Pavlov, A A; Boyarintsev, Ye L; Golubev, M P; Kavun, I N; Melekhov, A V; Golobokova, L S; Miroshnichenko, I B; Pavlov, Al A; Shmakov, A S

2011-01-01

The criteria for merging shock waves formed by optical breakdowns on the surface of solids have been investigated. Targets made of different materials were successively irradiated by two CO 2 -laser pulses with energies up to 200 J and a duration of ∼1 μs. It is shown that the criteria under consideration can be applied to different targets and irradiation regimes and make it possible to calculate the parameters of repetitively pulsed laser radiation that are necessary to generate low-frequency sound and ultrasound in air.

Preliminary Evidence of the Effects of High-frequency Repetitive Transcranial Magnetic Stimulation (rTMS) on Swallowing Functions in Post-Stroke Individuals with Chronic Dysphagia

Science.gov (United States)

Cheng, Ivy K. Y.; Chan, Karen M. K.; Wong, C. S.; Cheung, Raymond T. F.

2015-01-01

Background: There is growing evidence of potential benefits of repetitive transcranial magnetic stimulation (rTMS) in the rehabilitation of dysphagia. However, the site and frequency of stimulation for optimal effects are not clear. Aims: The aim of this pilot study is to investigate the short-term effects of high-frequency 5 Hz rTMS applied to…

Technique for long and absolute distance measurement based on laser pulse repetition frequency sweeping

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Castro Alves, D.; Abreu, Manuel; Cabral, A.; Jost, Michael; Rebordão, J. M.

2017-11-01

In this work we present a technique to perform long and absolute distance measurements based on mode-locked diode lasers. Using a Michelson interferometer, it is possible to produce an optical cross-correlation between laser pulses of the reference arm with the pulses from the measurement arm, adjusting externally their degree of overlap either changing the pulse repetition frequency (PRF) or the position of the reference arm mirror for two (or more) fixed frequencies. The correlation of the travelling pulses for precision distance measurements relies on ultra-short pulse durations, as the uncertainty associated to the method is dependent on the laser pulse width as well as on a highly stable PRF. Mode-locked Diode lasers are a very appealing technology for its inherent characteristics, associated to compactness, size and efficiency, constituting a positive trade-off with regard to other mode-locked laser sources. Nevertheless, main current drawback is the non-availability of frequency-stable laser diodes. The laser used is a monolithic mode-locked semiconductor quantum-dot (QD) laser. The laser PRF is locked to an external stabilized RF reference. In this work we will present some of the preliminary results and discuss the importance of the requirements related to laser PRF stability in the final metrology system accuracy.

Repetition and the Concept of Repetition

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Arne Grøn

2013-11-01

Full Text Available This paper offers a description of the meaning of the category of repetition. Firstly, it is pointed out that Constantin uses repetition as a concept that means the creation of epochs; the passing from Greece to Modernity is accomplished distinguishing between recollection, a concept that looks back to the past, and repetition, a concept that looks forward to future. Secondly, it is showed that the category of repetition, as a religious category, relates with what Climacus calls “ethic despair” and with what Vigilius calls “second ethics”; it is through repetition that it can be understood that sin finds its place in ethics and these shows the tension between it and dogmatics. And thirdly, it is showed that the descovery of the new category of repetition is a rediscovery of what Kierkegaard calls category of spirit; repetition has for its object the individuality, and coming to be oneself is what Kierkegaard undertands as liberty. At the end of the paper it is questioned if the category of repetition is inconsistent with the book Repetition.

The effect of electric field maximum on the Rabi flopping and generated higher frequency spectra

International Nuclear Information System (INIS)

Niu Yueping; Cui Ni; Xiang Yang; Li Ruxin; Gong Shangqing; Xu Zhizhan

2008-01-01

We investigate the effect of the electric field maximum on the Rabi flopping and the generated higher frequency spectra properties by solving Maxwell-Bloch equations without invoking any standard approximations. It is found that the maximum of the electric field will lead to carrier-wave Rabi flopping (CWRF) through reversion dynamics which will be more evident when the applied field enters the sub-one-cycle regime. Therefore, under the interaction of sub-one-cycle pulses, the Rabi flopping follows the transient electric field tightly through the oscillation and reversion dynamics, which is in contrast to the conventional envelope Rabi flopping. Complete or incomplete population inversion can be realized through the control of the carrier-envelope phase (CEP). Furthermore, the generated higher frequency spectra will be changed from distinct to continuous or irregular with the variation of the CEP. Our results demonstrate that due to the evident maximum behavior of the electric field, pulses with different CEP give rise to different CWRFs, and then different degree of interferences lead to different higher frequency spectral features.

Effects of low-frequency repetitive transcranial magnetic stimulation on event-related potential P300

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Torii, Tetsuya; Sato, Aya; Iwahashi, Masakuni; Iramina, Keiji

2012-04-01

The present study analyzed the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity. P300 latency of event-related potential (ERP) was used to evaluate the effects of low-frequency and short-term rTMS by stimulating the supramarginal gyrus (SMG), which is considered to be the related area of P300 origin. In addition, the prolonged stimulation effects on P300 latency were analyzed after applying rTMS. A figure-eight coil was used to stimulate left-right SMG, and intensity of magnetic stimulation was 80% of motor threshold. A total of 100 magnetic pulses were applied for rTMS. The effects of stimulus frequency at 0.5 or 1 Hz were determined. Following rTMS, an odd-ball task was performed and P300 latency of ERP was measured. The odd-ball task was performed at 5, 10, and 15 min post-rTMS. ERP was measured prior to magnetic stimulation as a control. Electroencephalograph (EEG) was measured at Fz, Cz, and Pz that were indicated by the international 10-20 electrode system. Results demonstrated that different effects on P300 latency occurred between 0.5-1 Hz rTMS. With 1 Hz low-frequency magnetic stimulation to the left SMG, P300 latency decreased. Compared to the control, the latency time difference was approximately 15 ms at Cz. This decrease continued for approximately 10 min post-rTMS. In contrast, 0.5 Hz rTMS resulted in delayed P300 latency. Compared to the control, the latency time difference was approximately 20 ms at Fz, and this delayed effect continued for approximately 15 min post-rTMS. Results demonstrated that P300 latency varied according to rTMS frequency. Furthermore, the duration of the effect was not similar for stimulus frequency of low-frequency rTMS.

Electrical strength of vacuum gap at repetitive breakdown

International Nuclear Information System (INIS)

Dubinin, N.P.; Chistyakov, N.P.

1983-01-01

The investigation of repetitive pulse breakdown of vacuum space, which electrodes have been subjected to various treatment in vacuum and inert gas, is carried out. In case of electrode warm-up in vacuum up to 400 deg C as well as electronic heating up to 900 deg C the voltage in case of repetitive breakdown hasncreased approximately twice and in case of a through treatment, which is accomplished by a high-current glow discharge in inert gas, the maximum high voltage in case of the first breakdown at repetitive breakdown has decreased by 30...40%, remaining 2-3 times higher than in the first case

Transduction of Repetitive Mechanical Stimuli by Piezo1 and Piezo2 Ion Channels

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Amanda H. Lewis

2017-06-01

Full Text Available Several cell types experience repetitive mechanical stimuli, including vein endothelial cells during pulsating blood flow, inner ear hair cells upon sound exposure, and skin cells and their innervating dorsal root ganglion (DRG neurons when sweeping across a textured surface or touching a vibrating object. While mechanosensitive Piezo ion channels have been clearly implicated in sensing static touch, their roles in transducing repetitive stimulations are less clear. Here, we perform electrophysiological recordings of heterologously expressed mouse Piezo1 and Piezo2 responding to repetitive mechanical stimulations. We find that both channels function as pronounced frequency filters whose transduction efficiencies vary with stimulus frequency, waveform, and duration. We then use numerical simulations and human disease-related point mutations to demonstrate that channel inactivation is the molecular mechanism underlying frequency filtering and further show that frequency filtering is conserved in rapidly adapting mouse DRG neurons. Our results give insight into the potential contributions of Piezos in transducing repetitive mechanical stimuli.

The 1 Repetition Maximum Mechanics of a High-Handle Hexagonal Bar Deadlift Compared With a Conventional Deadlift as Measured by a Linear Position Transducer.

Science.gov (United States)

Lockie, Robert G; Moreno, Matthew R; Lazar, Adrina; Risso, Fabrice G; Liu, Tricia M; Stage, Alyssa A; Birmingham-Babauta, Samantha A; Torne, Ibett A; Stokes, John J; Giuliano, Dominic V; Davis, DeShaun L; Orjalo, Ashley J; Callaghan, Samuel J

2018-01-01

Lockie, RG, Moreno, MR, Lazar, A, Risso, FG, Liu, TM, Stage, AA, Birmingham-Babauta, SA, Torne, IA, Stokes, JJ, Giuliano, DV, Davis, DL, Orjalo, AJ, and Callaghan, SJ. The 1 repetition maximum mechanics of a high-handle hexagonal bar deadlift compared with a conventional deadlift as measured by a linear position transducer. J Strength Cond Res 32(1): 150-161, 2018-The high-handle hexagonal bar deadlift (HHBD), a variation of the conventional deadlift (CD), is said to reduce the lift range of motion, which may change the mechanics of the lift. However, no research has investigated this. This study compared the mechanics between a 1 repetition maximum (1RM) CD and HHBD. Thirty-one strength-trained subjects (21 men, 10 women) completed a 1RM CD and HHBD. A linear position transducer measured lift distance, duration, and work; and peak and mean power, velocity, and force. The presence of a sticking region (SR) was determined for each lift. A repeated-measures analysis of variance (ANOVA) calculated differences between 1RM CD and HHBD mechanics. A one-way ANOVA compared the mechanics of each lift between subjects who exhibited an SR or not, and the SR between the CD and HHBD. Significance was set at p mechanics between subjects with or without an SR, and no differences in SR region distance or duration between the CD and HHBD. Greater force can be generated in the HHBD, which could have implications for strength-training adaptations over time.

High-repetition-rate short-pulse gas discharge.

Science.gov (United States)

Tulip, J; Seguin, H; Mace, P N

1979-09-01

A high-average-power short-pulse gas discharge is described. This consists of a volume-preionized transverse discharge of the type used in gas lasers driven by a Blumlein energy storage circuit. The Blumlein circuit is fabricated from coaxial cable, is pulse-charged from a high-repetition-rate Marx-bank generator, and is switched by a high-repetition-rate segmented rail gap. The operation of this discharge under conditions typical of rare-gas halide lasers is described. A maximum of 900 pps was obtained, giving a power flow into the discharge of 30 kW.

High-power 355 nm ultraviolet lasers operating at ultrahigh repetition rate

International Nuclear Information System (INIS)

Chen, H; Liu, Q; Yan, P; Gong, M

2013-01-01

In this letter, we demonstrate a novel 355 nm ultraviolet (UV) laser operating at ultrahigh repetition rate from 300 kHz to 1 MHz. The hybrid fiber-MOPA–bulk amplifiers based IR source exhibits a high average power of 105 W with near-diffraction-limited beam quality, narrow linewidth and high polarization extinction ratio. Two-cascaded LBO crystals are employed for high efficiency frequency tripling, and a maximum 43.7 W of average UV power is achieved at 400 kHz, corresponding to a conversion efficiency as high as 41.6%. The pulse duration of the UV pulse can be tuned from 5 to 10 ns with good pulse peak stability (better than 2.2% (RMS)). (letter)

Repetitively pulsed, double discharge TEA CO/sub 2/ laser

Energy Technology Data Exchange (ETDEWEB)

Hamilton, D C; James, D J; Ramsden, S A

1975-10-01

The design and operation of a repetitively pulsed TEA CO/sub 2/ laser is described. Average powers of up to 400 W at a repetition frequency of 200 pulses/s have been obtained. The system has also been used to provide long pulses (over 20 ..mu..s) and tunable single axial mode pulses.

The application of low frequency repetitive transcranial magnetic stimulation in rehabilitation of Parkinson's disease patients

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WU Zhuo-hua

2013-07-01

Full Text Available Objective To explore the application value of low frequency repetitive transcranial magnetic stimulation (rTMS in Parkinson's disease (PD patients and electrophysiological research. Methods Fifty-six PD patients treated in the Department of Neurology of our hospital from September 2010 to September 2012 were randomly divided into 2 groups, group A (N = 28 and group B (N = 28. Patients in group A were given conventional drug treatment and rehabilitation training, while patients in group B were given low frequency rTMS on the basis of conventional drug treatment and rehabilitation training. After 3 weeks, the scores of Unified Parkinson's Disease Rating Scale (UPDRS, resting threshold (RT, cortical latent period, nerve root latent period, central motor conduction time (CMCT and the incidence of adverse reactions were compared between 2 groups. Results After intervention, the emotion, ability of daily living and motor function of patients in group B was obviously improved, and the scores of UPDRS in group B were significantly lower than that in group A (P 0.05. Conclusion The effect of low frequency rTMS in the treatment for PD is evident, safe and reliable, and with less adverse reaction. It can be used as a noninvasive physical treatment measure for PD.

Shoulder muscle fatigue during repetitive tasks as measured by electromyography and near-infrared spectroscopy.

Science.gov (United States)

Ferguson, Sue A; Allread, W Gary; Le, Peter; Rose, Joseph; Marras, William S

2013-12-01

The objective of this study was to quantify shoulder muscle fatigue during repetitive exertions similar to motions found in automobile assembly tasks. Shoulder musculoskeletal disorders (MSDs) are a common and costly problem in automotive manufacturing. Ten subjects participated in the study. There were three independent variables: shoulder angle, frequency, and force. There were two types of dependent measures: percentage change in near-infrared spectroscopy (NIRS) measures and change in electromyography (EMG) median frequency. The anterior deltoid and trapezius muscles were measured for both NIRS and EMG. Also, EMG was collected on the middle deltoid and biceps muscles. The results showed that oxygenated hemoglobin decreased significantly due to the main effects (shoulder angle, frequency, and force). The percentage change in oxygenated hemoglobin had a significant interaction attributable to force and repetition for the anterior deltoid muscle, indicating that as repetition increased, the magnitude of the differences between the forces increased. The interaction of repetition and shoulder angle was also significant for the percentage change in oxygenated hemoglobin. The median frequency decreased significantly for the main effects; however, no interactions were statistically significant. There was significant shoulder muscle fatigue as a function of shoulder angle, task frequency, and force level. Furthermore, percentage change in oxygenated hemoglobin had two statistically significant interactions, enhancing our understanding of these risk factors. Ergonomists should examine interactions of force and repetition as well as shoulder angle and repetition when evaluating the risk of shoulder MSDs.

An Improved Clutter Suppression Method for Weather Radars Using Multiple Pulse Repetition Time Technique

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Yingjie Yu

2017-01-01

Full Text Available This paper describes the implementation of an improved clutter suppression method for the multiple pulse repetition time (PRT technique based on simulated radar data. The suppression method is constructed using maximum likelihood methodology in time domain and is called parametric time domain method (PTDM. The procedure relies on the assumption that precipitation and clutter signal spectra follow a Gaussian functional form. The multiple interleaved pulse repetition frequencies (PRFs that are used in this work are set to four PRFs (952, 833, 667, and 513 Hz. Based on radar simulation, it is shown that the new method can provide accurate retrieval of Doppler velocity even in the case of strong clutter contamination. The obtained velocity is nearly unbiased for all the range of Nyquist velocity interval. Also, the performance of the method is illustrated on simulated radar data for plan position indicator (PPI scan. Compared with staggered 2-PRT transmission schemes with PTDM, the proposed method presents better estimation accuracy under certain clutter situations.

Effective treatment of narcolepsy-like symptoms with high-frequency repetitive transcranial magnetic stimulation

Science.gov (United States)

Lai, Jian-bo; Han, Mao-mao; Xu, Yi; Hu, Shao-hua

2017-01-01

Abstract Rationale: Narcolepsy is a rare sleep disorder with disrupted sleep-architecture. Clinical management of narcolepsy lies dominantly on symptom-driven pharmacotherapy. The treatment role of repetitive transcranial magnetic stimulation (rTMS) for narcolepsy remains unexplored. Patient concerns: In this paper, we present a case of a 14-year-old young girl with excessive daytime sleepiness (EDS), cataplexy and hypnagogic hallucinations. Diagnoses: After excluding other possible medical conditions, this patient was primarily diagnosed with narcolepsy. Interventions: The patient received 25 sessions of high-frequency rTMS over the left dorsolateral prefrontal cortex (DLPFC). Outcomes: The symptoms of EDS and cataplexy significantly improved after rTMS treatment. Meanwhile, her score in the Epworth sleep scale (ESS) also remarkably decreased. Lessons: This case indicates that rTMS may be selected as a safe and effective alternative strategy for treating narcolepsy-like symptoms. Well-designed researches are warranted in future investigations on this topic. PMID:29145290

Efficacy of the National Football League-225 Test to Track Changes in One Repetition Maximum Bench Press After Training in National Collegiate Athletic Association Division IA Football Players.

Science.gov (United States)

Mann, J Bryan; Ivey, Pat A; Stoner, Josh D; Mayhew, Jerry L; Brechue, William F

2015-11-01

Numerous investigations have attested to the efficacy of the National Football League (NFL)-225 test to estimate one repetition maximum (1RM) bench press. However, no studies have assessed the efficacy of the test to track changes in strength across a training program. The purpose of this study was to determine the accuracy of the NFL-225 test for determining the change in 1RM bench press in National Collegiate Athletic Association Division IA college football players after training. Over a 4-year period, players (n = 203) were assessed before and after a 6-week off-season resistance program for 1RM bench press and repetitions completed with 102.3 kg (225 lbs). Test sessions typically occurred within 1 week of each other. Players significantly increased 1RM by 4.2 ± 8.6 kg and NFL-225 repetitions by 0.9 ± 2.3, although the effect size (ES) for each was trivial (ES = 0.03 and 0.07, respectively). National Football League 225 prediction equations had higher correlations with 1RM before training (intraclass correlation coefficient [ICC] = 0.95) than after training (ICC = 0.75). The correlation between the change in NFL-225 repetitions and change in 1RM was low and negative (r = -0.22, p bench press strength after short-term training.

Speech-evoked brainstem frequency-following responses during verbal transformations due to word repetition.

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Galbraith, G C; Jhaveri, S P; Kuo, J

1997-01-01

Speech-evoked brainstem frequency-following responses (FFRs) were recorded to repeated presentations of the same stimulus word. Word repetition results in illusory verbal transformations (VTs) in which word perceptions can differ markedly from the actual stimulus. Previous behavioral studies support an explanation of VTs based on changes in arousal or attention. Horizontal and vertical dipole FFRs were recorded to assess responses with putative origins in the auditory nerve and central brainstem, respectively. FFRs were recorded from 18 subjects when they correctly heard the stimulus and when they reported VTs. Although horizontal and vertical dipole FFRs showed different frequency response patterns, dipoles did not differentiate between perceptual conditions. However, when subjects were divided into low- and high-VT groups (based on percentage of VT trials), a significant Condition x Group interaction resulted. This interaction showed the largest difference in FFR amplitudes during VT trials, with the low-VT group showing increased amplitudes, and the high-VT group showing decreased amplitudes, relative to trials in which the stimulus was correctly perceived. These results demonstrate measurable subject differences in the early processing of complex signals, due to possible effects of attention on the brainstem FFR. The present research shows that the FFR is useful in understanding human language as it is coded and processed in the brainstem auditory pathway.

All-fiber interferometer-based repetition-rate stabilization of mode-locked lasers to 10-14-level frequency instability and 1-fs-level jitter over 1  s.

Science.gov (United States)

Kwon, Dohyeon; Kim, Jungwon

2017-12-15

We report on all-fiber Michelson interferometer-based repetition-rate stabilization of femtosecond mode-locked lasers down to 1.3×10 -14 frequency instability and 1.4 fs integrated jitter in a 1 s time scale. The use of a compactly packaged 10 km long single-mode fiber (SMF)-28 fiber link as a timing reference allows the scaling of phase noise at a 10 GHz carrier down to -80  dBc/Hz at 1 Hz Fourier frequency. We also tested a 500 m long low-thermal-sensitivity fiber as a reference and found that, compared to standard SMF-28 fiber, it can mitigate the phase noise divergence by ∼10  dB/dec in the 0.1-1 Hz Fourier frequency range. These results suggest that the use of a longer low-thermal-sensitivity fiber may achieve sub-femtosecond integrated timing jitter with sub-10 -14 -level frequency instability in repetition rate by a simple and robust all-fiber-photonic method.

Repetitive transient extraction for machinery fault diagnosis using multiscale fractional order entropy infogram

Science.gov (United States)

Xu, Xuefang; Qiao, Zijian; Lei, Yaguo

2018-03-01

The presence of repetitive transients in vibration signals is a typical symptom of local faults of rotating machinery. Infogram was developed to extract the repetitive transients from vibration signals based on Shannon entropy. Unfortunately, the Shannon entropy is maximized for random processes and unable to quantify the repetitive transients buried in heavy random noise. In addition, the vibration signals always contain multiple intrinsic oscillatory modes due to interaction and coupling effects between machine components. Under this circumstance, high values of Shannon entropy appear in several frequency bands or high value of Shannon entropy doesn't appear in the optimal frequency band, and the infogram becomes difficult to interpret. Thus, it also becomes difficult to select the optimal frequency band for extracting the repetitive transients from the whole frequency bands. To solve these problems, multiscale fractional order entropy (MSFE) infogram is proposed in this paper. With the help of MSFE infogram, the complexity and nonlinear signatures of the vibration signals can be evaluated by quantifying spectral entropy over a range of scales in fractional domain. Moreover, the similarity tolerance of MSFE infogram is helpful for assessing the regularity of signals. A simulation and two experiments concerning a locomotive bearing and a wind turbine gear are used to validate the MSFE infogram. The results demonstrate that the MSFE infogram is more robust to the heavy noise than infogram and the high value is able to only appear in the optimal frequency band for the repetitive transient extraction.

Frequency-Domain Maximum-Likelihood Estimation of High-Voltage Pulse Transformer Model Parameters

CERN Document Server

Aguglia, D; Martins, C.D.A.

2014-01-01

This paper presents an offline frequency-domain nonlinear and stochastic identification method for equivalent model parameter estimation of high-voltage pulse transformers. Such kinds of transformers are widely used in the pulsed-power domain, and the difficulty in deriving pulsed-power converter optimal control strategies is directly linked to the accuracy of the equivalent circuit parameters. These components require models which take into account electric fields energies represented by stray capacitance in the equivalent circuit. These capacitive elements must be accurately identified, since they greatly influence the general converter performances. A nonlinear frequency-based identification method, based on maximum-likelihood estimation, is presented, and a sensitivity analysis of the best experimental test to be considered is carried out. The procedure takes into account magnetic saturation and skin effects occurring in the windings during the frequency tests. The presented method is validated by experim...

Effects of Navigated Repetitive Transcranial Magnetic Stimulation After Stroke.

Science.gov (United States)

Chervyakov, Alexander V; Poydasheva, Alexandra G; Lyukmanov, Roman H; Suponeva, Natalia A; Chernikova, Ludmila A; Piradov, Michael A; Ustinova, Ksenia I

2018-03-01

The purpose of this study was to test the effects of navigated repetitive transcranial magnetic stimulation, delivered in different modes, on motor impairments and functional limitations after stroke. The study sample included 42 patients (58.5 ± 10.7 years; 26 males) who experienced a single unilateral stroke (1-12 months previously) in the area of the middle cerebral artery. Patients completed a course of conventional rehabilitation, together with 10 sessions of navigated repetitive transcranial magnetic stimulation or sham stimulation. Stimulation was scheduled five times a week over two consecutive weeks in an inpatient clinical setting. Patients were randomly assigned to one of four groups and received sham stimulation (n = 10), low-frequency (1-Hz) stimulation of the nonaffected hemisphere (n = 11), high-frequency (10-Hz) stimulation of the affected hemisphere (n = 13), or sequential combination of low- and high-frequency stimulations (n = 8). Participants were evaluated before and after stimulation with clinical tests, including the arm and hand section of the Fugl-Meyer Assessment Scale, modified Ashworth Scale of Muscle Spasticity, and Barthel Index of Activities of Daily Living. Participants in the three groups receiving navigated repetitive transcranial magnetic stimulation showed improvements in arm and hand functions on the Fugl-Meyer Stroke Assessment Scale. Ashworth Scale of Muscle Spasticity and Barthel Index scores were significantly reduced in groups receiving low- or high-frequency stimulation alone. Including navigated repetitive transcranial magnetic stimulation in a conventional rehabilitation program positively influenced motor and functional recovery in study participants, demonstrating the clinical potential of the method. The results of this study will be used for designing a large-scale clinical trial.

RELIABILITY OF THE ONE-REPETITION MAXIMUM TEST BASED ON MUSCLE GROUP AND GENDER

Directory of Open Access Journals (Sweden)

Dong-il Seo

2012-06-01

Full Text Available The purpose of the present study was to examine the influence of muscle group location and gender on the reliability of assessing the one-repetition maximum (1RM test. Thirty healthy males (n = 15 and females (n = 15 who experienced at least 3 months of continuous resistance training during the last 2 years aged 18-35 years volunteered to participate in the study. The 1RM for the biceps curl, lat pull down, bench press, leg curl, hip flexion, triceps extension, shoulder press, low row, leg extension, hip extension, leg press and squat were measured twice by a trained professional using a standard published protocol. Biceps curl, lat pull down, bench press, leg curl, hip flexion, and squat 1RM's were measured on the first visit, then 48 hours later, subjects returned for their second visit. During their second visit, 1RM of triceps extension, shoulder press, low row, leg extension, hip extension, and leg press were measured. One week from the second visit, participants completed the 1 RM testing as previously done during the first and second visits. The third and fourth visits were separated by 48 hours as well. All four visits to the laboratory were at the same time of day. A high intraclass correlation coefficient (ICC > 0.91 was found for all exercises, independent of gender and muscle group size or location, however there was a significant interaction for muscle group location (upper body vs. lower body in females (p < 0.027. In conclusion, a standardized 1RM testing protocol with a short warm-up and familiarization period is a reliable measurement to assess muscle strength changes regardless of muscle group location or gender

High-Frequency Repetitive Sensory Stimulation as Intervention to Improve Sensory Loss in Patients with Complex Regional Pain Syndrome I.

Science.gov (United States)

David, Marianne; Dinse, Hubert R; Mainka, Tina; Tegenthoff, Martin; Maier, Christoph

2015-01-01

Achieving perceptual gains in healthy individuals or facilitating rehabilitation in patients is generally considered to require intense training to engage neuronal plasticity mechanisms. Recent work, however, suggested that beneficial outcome similar to training can be effectively acquired by a complementary approach in which the learning occurs in response to mere exposure to repetitive sensory stimulation (rSS). For example, high-frequency repetitive sensory stimulation (HF-rSS) enhances tactile performance and induces cortical reorganization in healthy subjects and patients after stroke. Patients with complex regional pain syndrome (CRPS) show impaired tactile performance associated with shrinkage of cortical maps. We here investigated the feasibility and efficacy of HF-rSS, and low-frequency rSS (LF-rSS) to enhance tactile performance and reduce pain intensity in 20 patients with CRPS type I. Intermittent high- or low-frequency electrical stimuli were applied for 45 min/day to all fingertips of the affected hand for 5 days. Main outcome measures were spatial two-point-discrimination thresholds and mechanical detection thresholds measured on the tip of the index finger bilaterally. Secondary endpoint was current pain intensity. All measures were assessed before and on day 5 after the last stimulation session. HF-rSS applied in 16 patients improved tactile discrimination on the affected hand significantly without changes contralaterally. Current pain intensity remained unchanged on average, but decreased in four patients by ≥30%. This limited pain relief might be due to the short stimulation period of 5 days only. In contrast, after LF-rSS, tactile discrimination was impaired in all four patients, while detection thresholds and pain were not affected. Our data suggest that HF-rSS could be used as a novel approach in CRPS treatment to improve sensory loss. Longer treatment periods might be required to induce consistent pain relief.

Low-Frequency Repetitive Transcranial Magnetic Stimulation and Intensive Occupational Therapy for Poststroke Patients with Upper Limb Hemiparesis: Preliminary Study of a 15-Day Protocol

Science.gov (United States)

Kakuda, Wataru; Abo, Masahiro; Kobayashi, Kazushige; Momosaki, Ryo; Yokoi, Aki; Fukuda, Akiko; Ishikawa, Atsushi; Ito, Hiroshi; Tominaga, Ayumi

2010-01-01

The purpose of the study was to determine the safety and feasibility of a 15-day protocol of low-frequency repetitive transcranial magnetic stimulation (rTMS) combined with intensive occupational therapy (OT) on motor function and spasticity in hemiparetic upper limbs in poststroke patients. Fifteen poststroke patients (age at study entry 55 [plus…

Effect of high-frequency repetitive transcranial magnetic stimulation on chronic central pain after mild traumatic brain injury: A pilot study.

Science.gov (United States)

Choi, Gyu-Sik; Kwak, Sang Gyu; Lee, Han Do; Chang, Min Cheol

2018-02-28

Central pain can occur following traumatic brain injury, leading to poor functional recovery, limitation of activities of daily living, and decreased quality of life. The aim of this study was to determine whether high-frequency (10 Hz) repetitive transcranial magnetic stimulation, applied over the primary motor cortex of the affected hemisphere, can be used to manage chronic central pain after mild traumatic brain injury. Prospective randomized feasibility study. Twelve patients with mild traumatic brain injury and chronic central pain were randomly assigned to transcranial magnetic stimulation (high-frequency stimulation, 10 sessions) or sham groups. Diffuse tensor tractography revealed partially injured spinothalamocortical tracts in all recruited patients. A numerical rating scale (NRS) was used to evaluate pain intensity during pre-treatment and immediately after the 5th transcranial magnetic stimulation session (post1), 10th transcranial magnetic stimulation session (post2), and 1 (post3), 2 (post4), and 4 weeks (post 5) after finishing treatment. Physical and mental health status were evaluated using the Short Form 36 Health Survey (SF-36), including physical and mental component scores (PCS, MCS). The NRS score of the repetitive transcranial magnetic stimulation group was significantly lower than the sham group score at all clinical evaluation time-points during and after transcranial magnetic stimulation sessions. The transcranial magnetic stimulation group's SF-36 PCS score was significantly higher at post2, post3, post4, and post5 compared with the sham group. High-frequency transcranial magnetic stimulation may be used to manage chronic central pain and improve quality of life in patients with mild traumatic brain injury. However, this is a pilot study and further research is needed.

Versatile mid-infrared frequency-comb referenced sub-Doppler spectrometer

Science.gov (United States)

Gambetta, A.; Vicentini, E.; Coluccelli, N.; Wang, Y.; Fernandez, T. T.; Maddaloni, P.; De Natale, P.; Castrillo, A.; Gianfrani, L.; Laporta, P.; Galzerano, G.

2018-04-01

We present a mid-IR high-precision spectrometer capable of performing accurate Doppler-free measurements with absolute calibration of the optical axis and high signal-to-noise ratio. The system is based on a widely tunable mid-IR offset-free frequency comb and a Quantum-Cascade-Laser (QCL). The QCL emission frequency is offset locked to one of the comb teeth to provide absolute-frequency calibration, spectral-narrowing, and accurate fine frequency tuning. Both the comb repetition frequency and QCL-comb offset frequency can be modulated to provide, respectively, slow- and fast-frequency-calibrated scanning capabilities. The characterisation of the spectrometer is demonstrated by recording sub-Doppler saturated absorption features of the CHF3 molecule at around 8.6 μm with a maximum signal-to-noise ratio of ˜7 × 103 in 10 s integration time, frequency-resolution of 160 kHz, and accuracy of less than 10 kHz.

Versatile mid-infrared frequency-comb referenced sub-Doppler spectrometer

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A. Gambetta

2018-04-01

Full Text Available We present a mid-IR high-precision spectrometer capable of performing accurate Doppler-free measurements with absolute calibration of the optical axis and high signal-to-noise ratio. The system is based on a widely tunable mid-IR offset-free frequency comb and a Quantum-Cascade-Laser (QCL. The QCL emission frequency is offset locked to one of the comb teeth to provide absolute-frequency calibration, spectral-narrowing, and accurate fine frequency tuning. Both the comb repetition frequency and QCL-comb offset frequency can be modulated to provide, respectively, slow- and fast-frequency-calibrated scanning capabilities. The characterisation of the spectrometer is demonstrated by recording sub-Doppler saturated absorption features of the CHF3 molecule at around 8.6 μm with a maximum signal-to-noise ratio of ∼7 × 103 in 10 s integration time, frequency-resolution of 160 kHz, and accuracy of less than 10 kHz.

Low- vs high- frequency Repetitive Transcranial Magnetic Stimulation as an add-on treatment for refractory depression

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julien eeche

2012-03-01

Full Text Available Objectives: Repetitive transcranial magnetic stimulation (rTMS seems to be effective as an antidepressant treatment, however, some confusion remain about the best parameters to apply and the efficacy of its association with pharmacological antidepressant treatments.Method: In a single blind randomized study14 patients with unipolar resistant depression to one antidepressant treatment were enrolled to received, in combination with venlafaxine (150 mg, either 20 sessions of 10Hz rTMS (2 000 pulses per session applied over le left dorsolateral prefrontal cortex (DLPFC or 20 sessions of 1 Hz rTMS (120 stimulations per sessions applied over the right DLPFC. Results: A similar antidepressant effect was observed in both groups with a comparable antidepressant delay of action (2 weeks and a comparable number of patients in remission after 4 weeks of daily rTMS sessions (66 vs 50 %.Conclusion: Low- and high- frequency rTMS seem to be effective as an add-on treatment to venlafaxine in pharmacological refractory major depression. Due to its short duration and its safety, low frequency rTMS may be a useful alternative treatment for patients with refractory depression.

Efficient high-peak-power and high-repetition-rate eye-safe laser using an intracavity KTP OPO

International Nuclear Information System (INIS)

Guo, J; Jiao, Z X; Wang, B; He, G Y

2015-01-01

An efficient high-peak-power and high-repetition-rate intracavity KTP optical parametric oscillator pumped by a Q-switched Nd:YVO 4 laser is demonstrated. We achieved 1.5 W output power of 1.5 μm at 10 kHz repetition rate with the pulse duration of 6 ns. The maximum peak power of 25 kW and the maximum pulse energy of 150 μJ have been obtained. The maximum conversion efficiency of 9.5% is achieved with respect to a laser diode power of 10.5 W. (paper)

Effect of high-frequency repetitive transcranial magnetic stimulation on chronic central pain after mild traumatic brain injury: A pilot study

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Gyu-sik Choi

2018-01-01

Full Text Available Objective: Central pain can occur following traumatic brain injury, leading to poor functional recovery, limitation of activities of daily living, and decreased quality of life. The aim of this study was to determine whether high-frequency (10 Hz repetitive transcranial magnetic stimulation, applied over the primary motor cortex of the affected hemisphere, can be used to manage chronic central pain after mild traumatic brain injury. Design: Prospective randomized feasibility study. Methods: Twelve patients with mild traumatic brain injury and chronic central pain were randomly assigned to transcranial magnetic stimulation (high-frequency stimulation, 10 sessions or sham groups. Diffuse tensor tractography revealed partially injured spinothalamocortical tracts in all recruited patients. A numerical rating scale (NRS was used to evaluate pain intensity during pre-treatment and immediately after the 5th transcranial magnetic stimulation session (post1, 10th transcranial magnetic stimulation session (post2, and 1 (post3, 2 (post4, and 4 weeks (post 5 after finishing treatment. Physical and mental health status were evaluated using the Short Form 36 Health Survey (SF-36, including physical and mental component scores (PCS, MCS. Results: The NRS score of the repetitive transcranial magnetic stimulation group was significantly lower than the sham group score at all clinical evaluation time-points during and after transcranial magnetic stimulation sessions. The transcranial magnetic stimulation group’s SF-36 PCS score was significantly higher at post2, post3, post4, and post5 compared with the sham group. Conclusion: High-frequency transcranial magnetic stimulation may be used to manage chronic central pain and improve quality of life in patients with mild traumatic brain injury. However, this is a pilot study and further research is needed.

High frequency repetitive sensory stimulation as intervention to improve sensory loss in patients with complex regional pain syndrome (CRPS I

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Marianne eDavid

2015-11-01

Full Text Available Achieving perceptual gains in healthy individuals, or facilitating rehabilitation in patients is generally considered to require intense training to engage neuronal plasticity mechanisms. Recent work, however, suggested that beneficial outcome similar to training can be effectively acquired by a complementary approach in which the learning occurs in response to mere exposure to repetitive sensory stimulation (rSS. For example, high-frequency repetitive sensory stimulation (HF-rSS enhances tactile performance and induces cortical reorganization in healthy subjects and patients after stroke. Patients with complex regional pain syndrome (CRPS show impaired tactile performance associated with shrinkage of cortical maps. We here investigated the feasibility and efficacy of HF-rSS, and low-frequency rSS (LF-rSS to enhance tactile performance and reduce pain intensity in 20 patients with CRPS type I. Intermittent high or low frequency electrical stimuli were applied for 45min/day to all fingertips of the affected hand for 5 days. Main outcome measures were spatial 2-point-discrimination thresholds and mechanical detection thresholds measured on the tip of the index finger bilaterally. Secondary endpoint was current pain intensity. All measures were assessed before and on day 5 after the last stimulation session. HF-rSS applied in 16 patients improved tactile discrimination on the affected hand significantly without changes contralaterally. Current pain intensity remained unchanged on average, but decreased in 4 patients by 30%. This limited pain relief might be due to the short stimulation period of 5 days only. In contrast, after LF-rSS, tactile discrimination was impaired in all 4 patients, while detection thresholds and pain were not affected. Our data suggest that HF-rSS could be used as a novel approach in CRPS treatment to improve sensory loss. Longer treatment periods might be required to induce consistent pain relief.

2-Step Maximum Likelihood Channel Estimation for Multicode DS-CDMA with Frequency-Domain Equalization

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Kojima, Yohei; Takeda, Kazuaki; Adachi, Fumiyuki

Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can provide better downlink bit error rate (BER) performance of direct sequence code division multiple access (DS-CDMA) than the conventional rake combining in a frequency-selective fading channel. FDE requires accurate channel estimation. In this paper, we propose a new 2-step maximum likelihood channel estimation (MLCE) for DS-CDMA with FDE in a very slow frequency-selective fading environment. The 1st step uses the conventional pilot-assisted MMSE-CE and the 2nd step carries out the MLCE using decision feedback from the 1st step. The BER performance improvement achieved by 2-step MLCE over pilot assisted MMSE-CE is confirmed by computer simulation.

Abdominal crunch exercise analysis performed with maximum and submaximum loads: An electromyographic study

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M.L. Moura

2011-01-01

Full Text Available The purpose of this study was to verify the electromyographic activity of the rectus abdominis and obliquus externus abdominis during abdominal crunch exercise performed with maximum and submaximum loads. Thirteen male and female university students participated in this investigation (18-23 years old. The subjects completed abdominal crunch exercise until exhaustion with 20, 40, 60 and 80% of the maximum load. The root-mean-square (RMS from electromyography activity of the rectus abdominis and obliquus externus muscles from the first and last three repetitions from each workload performed was analyzed. RMS for the last repetitions increased in relation to the first repetitions for the 20% workload, first two repetitions on 40% workload and first repetition on the 80% workload. There was no difference for the 60% workload. Results showed that external load on abdominal crunch exercise might be an alternative to increase intensity while performing abdominal crunch exercise, which on its turn can be a practical tool for subjects that aim to increase abdominal strength level.

A copper bromide vapour laser with a high pulse repetition rate

International Nuclear Information System (INIS)

Shiyanov, D V; Evtushenko, Gennadii S; Sukhanov, V B; Fedorov, V F

2002-01-01

The results of an experimental study of a copper bromide vapour laser with a discharge-channel diameter above 2.5 cm and a high pump-pulse repetition rate are presented. A TGU1-1000/25 high-power tacitron used as a switch made it possible to obtain for the first time a fairly high output radiation power for pump-pulse repetition rates exceeding 200 kHz. At a maximum pump-pulse repetition rate of 250 kHz achieved in a laser tube 2.6 cm in diameter and 76 cm long, the output power was 1.5 W. The output powers of 3 and 10.5 W were reached for pump-pulse repetition rates of 200 and 100 kHz, respectively. These characteristics were obtained without circulating a buffer gas and (or) low-concentration active impurities through the active volume. (active media. lasers)

Measurement of the Maximum Frequency of Electroglottographic Fluctuations in the Expiration Phase of Volitional Cough as a Functional Test for Cough Efficiency.

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Iwahashi, Toshihiko; Ogawa, Makoto; Hosokawa, Kiyohito; Kato, Chieri; Inohara, Hidenori

2017-10-01

The hypotheses of the present study were that the maximum frequency of fluctuation of electroglottographic (EGG) signals in the expiration phase of volitional cough (VC) reflects the cough efficiency and that this EGG parameter is affected by impaired laryngeal closure, expiratory effort strength, and gender. For 20 normal healthy adults and 20 patients diagnosed with unilateral vocal fold paralysis (UVFP), each participant was fitted with EGG electrodes on the neck, had a transnasal laryngo-fiberscope inserted, and was asked to perform weak/strong VC tasks while EGG signals and a high-speed digital image of the larynx were recorded. The maximum frequency was calculated in the EGG fluctuation region coinciding with vigorous vocal fold vibration in the laryngeal HSDIs. In addition, each participant underwent spirometry for measurement of three aerodynamic parameters, including peak expiratory air flow (PEAF), during weak/strong VC tasks. Significant differences were found for both maximum EGG frequency and PEAF between the healthy and UVFP groups and between the weak and strong VC tasks. Among the three cough aerodynamic parameters, PEAF showed the highest positive correlation with the maximum EGG frequency. The correlation coefficients between the maximum EGG frequency and PEAF recorded simultaneously were 0.574 for the whole group, and 0.782/0.717/0.823/0.688 for the male/female/male-healthy/male-UVFP subgroups, respectively. Consequently, the maximum EGG frequency measured in the expiration phase of VC was shown to reflect the velocity of expiratory airflow to some extent and was suggested to be affected by vocal fold physical properties, glottal closure condition, and the expiratory function.

Effective treatment of narcolepsy-like symptoms with high-frequency repetitive transcranial magnetic stimulation: A case report.

Science.gov (United States)

Lai, Jian-Bo; Han, Mao-Mao; Xu, Yi; Hu, Shao-Hua

2017-11-01

Narcolepsy is a rare sleep disorder with disrupted sleep-architecture. Clinical management of narcolepsy lies dominantly on symptom-driven pharmacotherapy. The treatment role of repetitive transcranial magnetic stimulation (rTMS) for narcolepsy remains unexplored. In this paper, we present a case of a 14-year-old young girl with excessive daytime sleepiness (EDS), cataplexy and hypnagogic hallucinations. After excluding other possible medical conditions, this patient was primarily diagnosed with narcolepsy. The patient received 25 sessions of high-frequency rTMS over the left dorsolateral prefrontal cortex (DLPFC). The symptoms of EDS and cataplexy significantly improved after rTMS treatment. Meanwhile, her score in the Epworth sleep scale (ESS) also remarkably decreased. This case indicates that rTMS may be selected as a safe and effective alternative strategy for treating narcolepsy-like symptoms. Well-designed researches are warranted in future investigations on this topic.

Effects of lifting tempo on one repetition maximum and hormonal responses to a bench press protocol.

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Headley, Samuel A; Henry, Kelley; Nindl, Bradley C; Thompson, Brian A; Kraemer, William J; Jones, Margaret T

2011-02-01

This study was carried out in 2 parts: part 1 was designed to measure the 1 repetition maximum (1RM) bench press with 2 different moderate-velocity tempos (2/0/2) vs. (2/0/4) in male lifters while part 2 compared the hormonal responses at the same tempos as described in part 1. In both parts 1 and 2, the 1RMs (lbs) were higher on the 2/0/2 tempo than on the 2/0/4 tempo. The change in plasma volume (PV) was greater after the 2/0/4 tempo (-5.7 ± 1.7% vs. 0.96 ± 1.2%, p < 0.05). All blood parameters were significantly (p < 0.05) higher post-exercise compared with baseline. With PV corrected, insulin-like growth factor 1 (IGF-1) (ng·mL⁻¹) was higher with the 2/0/2 tempo only (pre-exercise: 277.4 ± 21.8, post-exercise: 308.1 ± 22.9; 2/0/4 tempo pre-exercise: 277.2 ± 17.6, post-exercise: 284.8 ± 21.2). In conclusion, heavier loads can be lifted and more total work can be performed using a (2/0/2) tempo compared with a slower (2/0/4) tempo, but with the exception of IGF-1, the hormonal responses are similar. Individuals may get the same metabolic responses to training by using different tempos, but they will need to use less weight at a slower tempo.

Radio Frequency Transistors Using Aligned Semiconducting Carbon Nanotubes with Current-Gain Cutoff Frequency and Maximum Oscillation Frequency Simultaneously Greater than 70 GHz.

Science.gov (United States)

Cao, Yu; Brady, Gerald J; Gui, Hui; Rutherglen, Chris; Arnold, Michael S; Zhou, Chongwu

2016-07-26

In this paper, we report record radio frequency (RF) performance of carbon nanotube transistors based on combined use of a self-aligned T-shape gate structure, and well-aligned, high-semiconducting-purity, high-density polyfluorene-sorted semiconducting carbon nanotubes, which were deposited using dose-controlled, floating evaporative self-assembly method. These transistors show outstanding direct current (DC) performance with on-current density of 350 μA/μm, transconductance as high as 310 μS/μm, and superior current saturation with normalized output resistance greater than 100 kΩ·μm. These transistors create a record as carbon nanotube RF transistors that demonstrate both the current-gain cutoff frequency (ft) and the maximum oscillation frequency (fmax) greater than 70 GHz. Furthermore, these transistors exhibit good linearity performance with 1 dB gain compression point (P1dB) of 14 dBm and input third-order intercept point (IIP3) of 22 dBm. Our study advances state-of-the-art of carbon nanotube RF electronics, which have the potential to be made flexible and may find broad applications for signal amplification, wireless communication, and wearable/flexible electronics.

Repetitive Stress Injuries

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... Safe Videos for Educators Search English Español Repetitive Stress Injuries KidsHealth / For Teens / Repetitive Stress Injuries What's ... t had any problems since. What Are Repetitive Stress Injuries? Repetitive stress injuries (RSIs) are injuries that ...

Acute Frontal Lobe Dysfunction Following Prefrontal Low-Frequency Repetitive Transcranial Magnetic Stimulation in a Patient with Treatment-Resistant Depression

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Guilhem Carle

2017-05-01

Full Text Available The potential of repetitive transcranial magnetic stimulation (rTMS to treat numerous neurological and psychiatric disorders has been thoroughly studied for the last two decades. Here, we report for the first time, the case of a 65-year-old woman suffering from treatment-resistant depression who developed an acute frontal lobe syndrome following eight sessions of low-frequency rTMS (LF-rTMS to the right dorsolateral prefrontal cortex while also treated with sertraline and mianserin. The pathophysiological mechanisms underlying such an unexpected acute frontal lobe dysfunction are discussed in relation to the therapeutic use of LF-rTMS in combination with pharmacotherapy in depressed patients.

Repetition of Attempted Suicide Among Immigrants in Europe

Science.gov (United States)

Lipsicas, Cendrine Bursztein; Mäkinen, Ilkka Henrik; Wasserman, Danuta; Apter, Alan; Kerkhof, Ad; Michel, Konrad; Renberg, Ellinor Salander; van Heeringen, Kees; Värnik, Airi; Schmidtke, Armin

2014-01-01

Objectives To compare frequencies of suicide attempt repetition in immigrants and local European populations, and the timing of repetition in these groups. Method: Data from 7 European countries, comprising 10 574 local and 3032 immigrant subjects, were taken from the World Health Organization European Multicentre Study on Suicidal Behaviour and the ensuing Monitoring Suicidal Behaviour in Europe (commonly referred to as MONSUE) project. The relation between immigrant status and repetition of suicide attempt within 12-months following first registered attempt was analyzed with binary logistic regression, controlling for sex, age, and method of attempt. Timing of repetition was controlled for sex, age, and the recommended type of aftercare. Results: Lower odds of repeating a suicide attempt were found in Eastern European (OR 0.50; 95% CI 0.41 to 0.61, P Europe stands in contrast to their markedly higher tendency to attempt suicide in general, possibly pointing to situational stress factors related to their suicidal crisis that are less persistent over time. Our findings also raise the possibility that suicide attempters and repeaters constitute only partially overlapping populations. PMID:25565687

Design and development of repetitive capacitor charging power supply based on series-parallel resonant converter topology.

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Patel, Ankur; Nagesh, K V; Kolge, Tanmay; Chakravarthy, D P

2011-04-01

LCL resonant converter based repetitive capacitor charging power supply (CCPS) is designed and developed in the division. The LCL converter acts as a constant current source when switching frequency is equal to the resonant frequency. When both resonant inductors' values of LCL converter are same, it results in inherent zero current switching (ZCS) in switches. In this paper, ac analysis with fundamental frequency approximation of LCL resonant tank circuit, frequency dependent of current gain converter followed by design, development, simulation, and practical result is described. Effect of change in switching frequency and resonant frequency and change in resonant inductors ratio on CCPS will be discussed. An efficient CCPS of average output power of 1.2 kJ/s, output voltage 3 kV, and 300 Hz repetition rate is developed in the division. The performance of this CCPS has been evaluated in the laboratory by charging several values of load capacitance at various repetition rates. These results indicate that this design is very feasible for use in capacitor-charging applications. © 2011 American Institute of Physics

The repetition timing of high frequency afferent stimulation drives the bidirectional plasticity at central synapses in the rat medial vestibular nuclei.

Science.gov (United States)

Scarduzio, M; Panichi, R; Pettorossi, V E; Grassi, S

2012-10-25

In this study we show that high frequency stimulation (HFS, 100Hz) of afferent fibers to the medial vestibular nucleus (MVN) can induce opposite long-term modifications of synaptic responses in the type B neurons depending upon the stimulation pattern. Long burst stimulation (LBS: 2s) and short burst stimulation (SBS: 0.55s) were applied with different burst number (BN) and inter-burst intervals (IBI). It results that both LBS and SBS can induce either N-methyl-d aspartate receptors (NMDARs)-mediated long-term potentiation (LTP) or long-term depression (LTD), depending on temporal organization of repetitive bursts. In particular, the IBI plays a relevant role in guiding the shift from LTP to LTD since by using both LBS and SBS LTP is induced by shorter IBI than LTD. By contrast, the sign of long-term effect does not depend on the mean impulse frequency evaluated within the entire stimulation period. Therefore, the patterns of repetitive vestibular activation with different ratios between periods of increased activity and periods of basal activity may lead to LTP or LTD probably causing different levels of postsynaptic Ca(2+). On the whole, this study demonstrates that glutamatergic vestibular synapse in the MVN can undergo NMDAR-dependent bidirectional plasticity and puts forward a new aspect for understanding the adaptive and compensatory plasticity of the oculomotor responses. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Evaluating Annual Maximum and Partial Duration Series for Estimating Frequency of Small Magnitude Floods

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Fazlul Karim

2017-06-01

Full Text Available Understanding the nature of frequent floods is important for characterising channel morphology, riparian and aquatic habitat, and informing river restoration efforts. This paper presents results from an analysis on frequency estimates of low magnitude floods using the annual maximum and partial series data compared to actual flood series. Five frequency distribution models were fitted to data from 24 gauging stations in the Great Barrier Reef (GBR lagoon catchments in north-eastern Australia. Based on the goodness of fit test, Generalised Extreme Value, Generalised Pareto and Log Pearson Type 3 models were used to estimate flood frequencies across the study region. Results suggest frequency estimates based on a partial series are better, compared to an annual series, for small to medium floods, while both methods produce similar results for large floods. Although both methods converge at a higher recurrence interval, the convergence recurrence interval varies between catchments. Results also suggest frequency estimates vary slightly between two or more partial series, depending on flood threshold, and the differences are large for the catchments that experience less frequent floods. While a partial series produces better frequency estimates, it can underestimate or overestimate the frequency if the flood threshold differs largely compared to bankfull discharge. These results have significant implications in calculating the dependency of floodplain ecosystems on the frequency of flooding and their subsequent management.

Suppression of motor cortical excitability in anesthetized rats by low frequency repetitive transcranial magnetic stimulation.

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Paul A Muller

Full Text Available Repetitive transcranial magnetic stimulation (rTMS is a widely-used method for modulating cortical excitability in humans, by mechanisms thought to involve use-dependent synaptic plasticity. For example, when low frequency rTMS (LF rTMS is applied over the motor cortex, in humans, it predictably leads to a suppression of the motor evoked potential (MEP, presumably reflecting long-term depression (LTD -like mechanisms. Yet how closely such rTMS effects actually match LTD is unknown. We therefore sought to (1 reproduce cortico-spinal depression by LF rTMS in rats, (2 establish a reliable animal model for rTMS effects that may enable mechanistic studies, and (3 test whether LTD-like properties are evident in the rat LF rTMS setup. Lateralized MEPs were obtained from anesthetized Long-Evans rats. To test frequency-dependence of LF rTMS, rats underwent rTMS at one of three frequencies, 0.25, 0.5, or 1 Hz. We next tested the dependence of rTMS effects on N-methyl-D-aspartate glutamate receptor (NMDAR, by application of two NMDAR antagonists. We find that 1 Hz rTMS preferentially depresses unilateral MEP in rats, and that this LTD-like effect is blocked by NMDAR antagonists. These are the first electrophysiological data showing depression of cortical excitability following LF rTMS in rats, and the first to demonstrate dependence of this form of cortical plasticity on the NMDAR. We also note that our report is the first to show that the capacity for LTD-type cortical suppression by rTMS is present under barbiturate anesthesia, suggesting that future neuromodulatory rTMS applications under anesthesia may be considered.

Predicting a 10 repetition maximum for the free weight parallel squat using the 45 degrees angled leg press.

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Willardson, Jeffrey M; Bressel, Eadric

2004-08-01

The purpose of this research was to devise prediction equations whereby a 10 repetition maximum (10RM) for the free weight parallel squat could be predicted using the following predictor variables: 10RM for the 45 degrees angled leg press, body mass, and limb length. Sixty men were tested over a 3-week period, with 1 testing session each week. During each testing session, subjects performed a 10RM for the free weight parallel squat and 45 degrees angled leg press. Stepwise multiple regression analysis showed leg press mass lifted to be a significant predictor of squat mass lifted for both the advanced and the novice groups (p squat mass lifted for the novice group and 55% of the variance in squat mass lifted for the advanced group. Limb length and body mass were not significant predictors of squat mass lifted for either group. The following prediction equations were devised: (a) novice group squat mass = leg press mass (0.210) + 36.244 kg, (b) advanced group squat mass = leg press mass (0.310) + 19.438 kg, and (c) subject pool squat mass = leg press mass (0.354) + 2.235 kg. These prediction equations may save time and reduce the risk of injury when switching from the leg press to the squat exercise.

High efficiency single frequency 355 nm all-solid-state UV laser

International Nuclear Information System (INIS)

Xie, Xiaobing; Wei, Daikang; Ma, Xiuhua; Li, Shiguang; Liu, Jiqiao; Zhu, Xiaolei; Chen, Weibiao

2016-01-01

A novel conductively cooled high energy single-frequency 355 nm all-solid-state UV laser is presented based on sum-frequency mixing technique. In this system, a pulsed seeder laser at 1064 nm wavelength, modulated by an AOM, is directly amplified by the cascaded multi-stage hybrid laser amplifiers, and two LBO crystals are used for the SHG and SFG, finally a maximum UV pulse energy of 226 mJ at 355 nm wavelength is achieved with frequency-tripled conversion efficiency as high as 55%, the pulse width is around 12.2 ns at the repetition frequency of 30 Hz. The beam quality factor M 2 of the output UV laser is measured to be 2.54 and 2.98 respectively in two orthogonal directions. (paper)

Understanding work related musculoskeletal pain: does repetitive work cause stress symptoms?

Science.gov (United States)

Bonde, J P; Mikkelsen, S; Andersen, J H; Fallentin, N; Baelum, J; Svendsen, S W; Thomsen, J F; Frost, P; Kaergaard, A

2005-01-01

Pain in the neck and upper extremity is reported with high frequency in repetitive work. Mechanical overload of soft tissues seems a plausible mechanism, but psychological factors have received considerable attention during the past decade. If psychological factors are important for development of regional pain in repetitive work, stress symptoms would likely be on the causal path. To examine whether objective measures of repetitive monotonous work are related to occurrence and development of stress symptoms. In 1994-95, 2033 unskilled workers with continuous repetitive work and 813 workers with varied work were enrolled. Measures of repetitiveness and force requirements were quantified using video observations to obtain individual exposure estimates. Stress symptoms were recorded at baseline and after approximately one, two, and three years by the Setterlind Stress Profile Inventory. Repetitive work, task cycle time, and quantified measures of repetitive upper extremity movements including force requirements were not related to occurrence of stress symptoms at baseline or development of stress symptoms during three years of follow up. The findings do not indicate that repetitive work is associated with stress symptoms, but small effects cannot be ruled out. Thus the results question the importance of mental stress mechanisms in the causation of regional pain related to repetitive work. However, the findings should be interpreted with caution because the stress inventory has not been validated against a gold standard.

Direct comparison of phase-sensitive vibrational sum frequency generation with maximum entropy method: case study of water.

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de Beer, Alex G F; Samson, Jean-Sebastièn; Hua, Wei; Huang, Zishuai; Chen, Xiangke; Allen, Heather C; Roke, Sylvie

2011-12-14

We present a direct comparison of phase sensitive sum-frequency generation experiments with phase reconstruction obtained by the maximum entropy method. We show that both methods lead to the same complex spectrum. Furthermore, we discuss the strengths and weaknesses of each of these methods, analyzing possible sources of experimental and analytical errors. A simulation program for maximum entropy phase reconstruction is available at: http://lbp.epfl.ch/. © 2011 American Institute of Physics

The effects of training with loads that maximise power output and individualised repetitions vs. traditional power training.

Directory of Open Access Journals (Sweden)

J M Sarabia

Full Text Available It has been suggested that strength training effects (i.e. neural or structural vary, depending on the total repetitions performed and velocity loss in each training set.The aim of this study is to compare the effects of two training programmes (i.e. one with loads that maximise power output and individualised repetitions, and the other following traditional power training.Twenty-five males were divided into three groups (optimum power [OP = 10], traditional training [TT = 9] and control group [CG = 6]. The training load used for OP was individualised using loads that maximised power output (41.7% ± 5.8 of one repetition maximum [1RM] and repetitions at maximum power (4 to 9 repetitions, or 'reps'. Volume (sets x repetitions was the same for both experimental groups, while intensity for TT was that needed to perform only 50% of the maximum number of possible repetitions (i.e. 61.1%-66.6% of 1RM. The training programme ran over 11 weeks (2 sessions per week; 4-5 sets per session; 3-minute rests between sets, with pre-, intermediate and post-tests which included: anthropometry, 1RM, peak power output (PPO with 30%, 40% and 50% of 1RM in the bench press throw, and salivary testosterone (ST and cortisol (SC concentrations. Rate of perceived exertion (RPE and power output were recorded in all sessions.Following the intermediate test, PPO was increased in the OP group for each load (10.9%-13.2%. Following the post-test, both experimental groups had increased 1RM (11.8%-13.8% and PPO for each load (14.1%-19.6%. Significant decreases in PPO were found for the TT group during all sets (4.9%-15.4%, along with significantly higher RPE (37%.OP appears to be a more efficient method of training, with less neuromuscular fatigue and lower RPE.

A Frequency Splitting Method For CFM Imaging

DEFF Research Database (Denmark)

Udesen, Jesper; Gran, Fredrik; Jensen, Jørgen Arendt

2006-01-01

The performance of conventional CFM imaging will often be degraded due to the relatively low number of pulses (4-10) used for each velocity estimate. To circumvent this problem we propose a new method using frequency splitting (FS). The FS method uses broad band chirps as excitation pulses instead...... of narrow band pulses as in conventional CFM imaging. By appropriate filtration, the returned signals are divided into a number of narrow band signals which are approximately disjoint. After clutter filtering the velocities are found from each frequency band using a conventional autocorrelation estimator......, a 5 MHz linear array transducer was used to scan a vessel situated at 30 mm depth with a maximum flow velocity of 0.1 m/s. The pulse repetition frequency was 1.8 kHz and the angle between the flow and the beam was 60 deg. A 15 mus chirp was used as excitation pulse and 40 independent velocity...

Multi-parametric study of temperature and thermal damage of tumor exposed to high-frequency nanosecond-pulsed electric fields based on finite element simulation.

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Mi, Yan; Rui, Shaoqin; Li, Chengxiang; Yao, Chenguo; Xu, Jin; Bian, Changhao; Tang, Xuefeng

2017-07-01

High-frequency nanosecond-pulsed electric fields were recently introduced for tumor or abnormal tissue ablation to solve some problems of conventional electroporation. However, it is necessary to study the thermal effects of high-field-intensity nanosecond pulses inside tissues. The multi-parametric analysis performed here is based on a finite element model of liver tissue with a tumor that has been punctured by a pair of needle electrodes. The pulse voltage used in this study ranges from 1 to 4 kV, the pulse width ranges from 50 to 500 ns, and the repetition frequency is between 100 kHz and 1 MHz. The total pulse length is 100 μs, and the pulse burst repetition frequency is 1 Hz. Blood flow and metabolic heat generation have also been considered. Results indicate that the maximum instantaneous temperature at 100 µs can reach 49 °C, with a maximum instantaneous temperature at 1 s of 40 °C, and will not cause thermal damage during single pulse bursts. By parameter fitting, we can obtain maximum instantaneous temperature at 100 µs and 1 s for any parameter values. However, higher temperatures will be achieved and may cause thermal damage when multiple pulse bursts are applied. These results provide theoretical basis of pulse parameter selection for future experimental researches.

Illusory sensation of movement induced by repetitive transcranial magnetic stimulation

DEFF Research Database (Denmark)

Christensen, Mark Schram; Lundbye-Jensen, Jesper; Grey, Michael James

2010-01-01

Human movement sense relies on both somatosensory feedback and on knowledge of the motor commands used to produce the movement. We have induced a movement illusion using repetitive transcranial magnetic stimulation over primary motor cortex and dorsal premotor cortex in the absence of limb movement...... and its associated somatosensory feedback. Afferent and efferent neural signalling was abolished in the arm with ischemic nerve block, and in the leg with spinal nerve block. Movement sensation was assessed following trains of high-frequency repetitive transcranial magnetic stimulation applied over...... premotor cortex stimulation was less affected by sensory and motor deprivation than was primary motor cortex stimulation. We propose that repetitive transcranial magnetic stimulation over dorsal premotor cortex produces a corollary discharge that is perceived as movement....

The development of a repetition-load scheme for the eccentric-only bench press exercise.

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Moir, Gavin L; Erny, Kyle F; Davis, Shala E; Guers, John J; Witmer, Chad A

2013-01-01

The purpose of the present study was to develop a repetition-load scheme for the eccentric-only bench press exercise. Nine resistance trained men (age: 21.6 ± 1.0 years; 1-repetition maximum [RM] bench press: 137.7 ± 30.4 kg) attended four testing sessions during a four week period. During the first session each subject's 1-RM bench press load utilizing the stretch-shortening cycle was determined. During the remaining sessions they performed eccentric-only repetitions to failure using supra-maximal loads equivalent to 110%, 120% and 130% of their 1-RM value with a constant cadence (30 reps·min(-1)). Force plates and a three dimensional motion analysis system were used during these final three sessions in order to evaluate kinematic and kinetic variables. More repetitions were completed during the 110% 1-RM condition compared to the 130% 1-RM condition (p=0.01). Mean total work (p=0.046) as well as vertical force (p=0.049), vertical work (p=0.017), and vertical power output (p=0.05) were significantly greater during the 130% 1-RM condition compared to the 110% 1-RM condition. A linear function was fitted to the number of repetitions completed under each load condition that allowed the determination of the maximum number of repetitions that could be completed under other supra-maximal loads. This linear function predicted an eccentric-only 1-RM in the bench press with a load equivalent to 164.8% 1-RM, producing a load of 227.0 ± 50.0 kg. The repetition-load scheme presented here should provide a starting point for researchers to investigate the kinematic, kinetic and metabolic responses to eccentric-only bench press workouts.

Syllable frequency and word frequency effects in spoken and written word production in a non-alphabetic script

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Qingfang eZhang

2014-02-01

Full Text Available The effects of word frequency and syllable frequency are well-established phenomena in domain such as spoken production in alphabetic languages. Chinese, as a non-alphabetic language, presents unique lexical and phonological properties in speech production. For example, the proximate unit of phonological encoding is syllable in Chinese but segments in Dutch, French or English. The present study investigated the effects of word frequency and syllable frequency, and their interaction in Chinese written and spoken production. Significant facilitatory word frequency and syllable frequency effects were observed in spoken as well as in written production. The syllable frequency effect in writing indicated that phonological properties (i.e., syllabic frequency constrain orthographic output via a lexical route, at least, in Chinese written production. However, the syllable frequency effect over repetitions was divergent in both modalities: it was significant in the former two repetitions in spoken whereas it was significant in the second repetition only in written. Due to the fragility of the syllable frequency effect in writing, we suggest that the phonological influence in handwritten production is not mandatory and universal, and it is modulated by experimental manipulations. This provides evidence for the orthographic autonomy hypothesis, rather than the phonological mediation hypothesis. The absence of an interaction between word frequency and syllable frequency showed that the syllable frequency effect is independent of the word frequency effect in spoken and written output modalities. The implications of these results on written production models are discussed.

Novel fast-neutron activation counter for high repetition rate measurements

International Nuclear Information System (INIS)

Mahmood, S.; Springham, S. V.; Zhang, T.; Rawat, R. S.; Tan, T. L.; Krishnan, M.; Beg, F. N.; Lee, S.; Schmidt, H.; Lee, P.

2006-01-01

A fast-neutron beryllium activation counter has been constructed for neutron measurements on a high repetition rate deuterium plasma focus. Beryllium activation is especially suitable for measurements of DD neutron yields. The cross section for the relevant reaction, 9 Be(n,α) 6 He, results in a maximum sensitivity at the characteristic energy of the DD neutrons (∼2.5 MeV) and practically no sensitivity to neutrons with energies 6 He enabled the shot-to-shot neutron yield from the plasma focus to be measured for repetition rates from 0.2 to 3 Hz (and for a range of deuterium gas pressures). With careful analysis, the shot-to-shot yield can be measured up to a maximum repetition rate of 3 Hz, beyond which the pileup of counts from the previous shots reduces the accuracy of the measurements to an unacceptable level. This new beryllium activation counter has been cross-checked against an indium activation counter to obtain absolute neutron yields. At a charging voltage of 12.5 kV (bank energy of 2.2 kJ), the average neutron yield was found to be (7.9±0.7)x10 7 per shot (standard deviation of 4x10 7 ). It was found that activation of the plasma focus construction materials (especially aluminum) must be taken into account

Optimizing strategy for repetitive construction projects within multi-mode resources

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Remon Fayek Aziz

2013-03-01

Full Text Available Estimating tender data for specific project is the most essential part in construction areas as of a contractor’s view such as: proposed project duration with corresponding gross value and cash flows. Cash flow analysis of construction projects has a long history and has been an important topic in construction management. Determination of project cash flows is very sensitive, especially for repetitive construction projects. This paper focuses on how to calculate tender data for repetitive construction projects such as: project duration, project cost, project/bid price, project cash flows, project maximum working capital and project net present value that is equivalent to net profit at the beginning of the project. A simplified multi-objective optimization formulation will be presented that creates best tender data to contractor comparing with more feasible options that are generated from multi-mode resources in a given project. This mathematical formulation is intended to give more scenarios which provide a practical support for typical construction contractors who need to optimize resource utilization in order to minimize project duration, project/bid price and project maximum working capital while maximizing its net present value simultaneously. At the end of the paper, an illustrative example will be presented to demonstrate the applications of proposed technique to an optimization expressway of repetitive construction project.

Longer repetition duration increases muscle activation and blood lactate response in matched resistance training protocols

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Hugo Cesar Martins-Costa

2016-03-01

Full Text Available Abstract This study analyzed the effect of different repetition durations on electromyographic and blood lactate responses of the bench press exercise. Fifteen recreationally trained male volunteers completed two training protocols, matched for intensity (% one-repetition maximum; 1RM, number of sets, number of repetitions, and rest intervals. One of the protocols was performed with a repetition duration of 4 s (2 s concentric: 2 s eccentric; 2:2 protocol, whereas the second protocol had a repetition duration of 6 s (2 s concentric: 4 s eccentric; 2:4 protocol. The results showed higher normalized integrated electromyography (pectoralis major and triceps brachii for the 2:4 protocol. Blood lactate concentration was also higher in the 2:4 protocol across all sets. These results show that adding 2 s to the eccentric action in matched training protocols increases muscle activation and blood lactate response, which reinforces the notion that increasing repetition duration is an alternative load progression in resistance training.

Recency, repetition, and the multidimensional basis of recognition memory.

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Buchsbaum, Bradley R; Lemire-Rodger, Sabrina; Bondad, Ashley; Chepesiuk, Alexander

2015-02-25

Recency and repetition are two factors that have large effects on human memory performance. One way of viewing the beneficial impact of these variables on recognition memory is to assume that both factors modulate a unidimensional memory trace strength. Although previous functional neuroimaging studies have indicated that recency and repetition may modulate similar brain structures, particularly in the region of the inferior parietal cortex, there is extensive behavioral evidence that human subjects can make independent and accurate recognition memory judgments about both an item's recency and its frequency. In the present study, we used fMRI to examine patterns of brain activity during recognition memory for auditory-verbal stimuli that were parametrically and orthogonally manipulated in terms of recency and number of repetitions. We found in a continuous recognition paradigm that the lateral inferior parietal cortex, a region that has previously been associated with recollective forms of memory, is highly sensitive to recency but not repetition. In a multivariate analysis of whole-brain activation patterns, we found orthogonal components that dissociated recency and repetition variables, indicating largely independent neural bases underlying these two factors. The results demonstrate that although both recency and repetition dramatically improve recognition memory performance, the neural bases for this improvement are dissociable, and thus are difficult to explain in terms of access to a unitary memory trace. Copyright © 2015 the authors 0270-6474/15/353544-11$15.00/0.

The effects of training with loads that maximise power output and individualised repetitions vs. traditional power training

Science.gov (United States)

Moya-Ramón, M.; Hernández-Davó, J. L.; Fernandez-Fernandez, J.; Sabido, R.

2017-01-01

Background It has been suggested that strength training effects (i.e. neural or structural) vary, depending on the total repetitions performed and velocity loss in each training set. Purpose The aim of this study is to compare the effects of two training programmes (i.e. one with loads that maximise power output and individualised repetitions, and the other following traditional power training). Methods Twenty-five males were divided into three groups (optimum power [OP = 10], traditional training [TT = 9] and control group [CG = 6]). The training load used for OP was individualised using loads that maximised power output (41.7% ± 5.8 of one repetition maximum [1RM]) and repetitions at maximum power (4 to 9 repetitions, or ‘reps’). Volume (sets x repetitions) was the same for both experimental groups, while intensity for TT was that needed to perform only 50% of the maximum number of possible repetitions (i.e. 61.1%–66.6% of 1RM). The training programme ran over 11 weeks (2 sessions per week; 4–5 sets per session; 3-minute rests between sets), with pre-, intermediate and post-tests which included: anthropometry, 1RM, peak power output (PPO) with 30%, 40% and 50% of 1RM in the bench press throw, and salivary testosterone (ST) and cortisol (SC) concentrations. Rate of perceived exertion (RPE) and power output were recorded in all sessions. Results Following the intermediate test, PPO was increased in the OP group for each load (10.9%–13.2%). Following the post-test, both experimental groups had increased 1RM (11.8%–13.8%) and PPO for each load (14.1%–19.6%). Significant decreases in PPO were found for the TT group during all sets (4.9%–15.4%), along with significantly higher RPE (37%). Conclusion OP appears to be a more efficient method of training, with less neuromuscular fatigue and lower RPE. PMID:29053725

Hypersonic wave drag reduction performance of cylinders with repetitive laser energy depositions

International Nuclear Information System (INIS)

Fang, J; Hong, Y J; Li, Q; Huang, H

2011-01-01

It has been widely research that wave drag reduction on hypersonic vehicle by laser energy depositions. Using laser energy to reduce wave drag can improve vehicle performance. A second order accurate scheme based on finite-difference method and domain decomposition of structural grid is used to compute the drag performance of cylinders in a hypersonic flow of Mach number 2 at altitude of 15km with repetitive energy depositions. The effects of frequency on drag reduction are studied. The calculated results show: the recirculation zone is generated due to the interaction between bow shock over the cylinder and blast wave produced by energy deposition, and a virtual spike which is supported by an axis-symmetric recirculation, is formed in front of the cylinder. By increasing the repetitive frequency, the drag is reduced and the oscillation of the drag is decreased; however, the energy efficiency decreases by increasing the frequency.

Repetition suppression and repetition enhancement underlie auditory memory-trace formation in the human brain: an MEG study.

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Recasens, Marc; Leung, Sumie; Grimm, Sabine; Nowak, Rafal; Escera, Carles

2015-03-01

The formation of echoic memory traces has traditionally been inferred from the enhanced responses to its deviations. The mismatch negativity (MMN), an auditory event-related potential (ERP) elicited between 100 and 250ms after sound deviation is an indirect index of regularity encoding that reflects a memory-based comparison process. Recently, repetition positivity (RP) has been described as a candidate ERP correlate of direct memory trace formation. RP consists of repetition suppression and enhancement effects occurring in different auditory components between 50 and 250ms after sound onset. However, the neuronal generators engaged in the encoding of repeated stimulus features have received little interest. This study intends to investigate the neuronal sources underlying the formation and strengthening of new memory traces by employing a roving-standard paradigm, where trains of different frequencies and different lengths are presented randomly. Source generators of repetition enhanced (RE) and suppressed (RS) activity were modeled using magnetoencephalography (MEG) in healthy subjects. Our results show that, in line with RP findings, N1m (~95-150ms) activity is suppressed with stimulus repetition. In addition, we observed the emergence of a sustained field (~230-270ms) that showed RE. Source analysis revealed neuronal generators of RS and RE located in both auditory and non-auditory areas, like the medial parietal cortex and frontal areas. The different timing and location of neural generators involved in RS and RE points to the existence of functionally separated mechanisms devoted to acoustic memory-trace formation in different auditory processing stages of the human brain. Copyright © 2014 Elsevier Inc. All rights reserved.

Photovoltaic High-Frequency Pulse Charger for Lead-Acid Battery under Maximum Power Point Tracking

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Hung-I. Hsieh

2013-01-01

Full Text Available A photovoltaic pulse charger (PV-PC using high-frequency pulse train for charging lead-acid battery (LAB is proposed not only to explore the charging behavior with maximum power point tracking (MPPT but also to delay sulfating crystallization on the electrode pores of the LAB to prolong the battery life, which is achieved due to a brief pulse break between adjacent pulses that refreshes the discharging of LAB. Maximum energy transfer between the PV module and a boost current converter (BCC is modeled to maximize the charging energy for LAB under different solar insolation. A duty control, guided by a power-increment-aided incremental-conductance MPPT (PI-INC MPPT, is implemented to the BCC that operates at maximum power point (MPP against the random insolation. A 250 W PV-PC system for charging a four-in-series LAB (48 Vdc is examined. The charging behavior of the PV-PC system in comparison with that of CC-CV charger is studied. Four scenarios of charging statuses of PV-BC system under different solar insolation changes are investigated and compared with that using INC MPPT.

Effect of Intermediate-Frequency Repetitive Transcranial Magnetic Stimulation on Recovery following Traumatic Brain Injury in Rats

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Leticia Verdugo-Diaz

2017-01-01

Full Text Available Traumatic brain injury (TBI represents a significant public health concern and has been associated with high rates of morbidity and mortality. Although several research groups have proposed the use of repetitive transcranial magnetic stimulation (rTMS to enhance neuroprotection and recovery in patients with TBI, few studies have obtained sufficient evidence regarding its effects in this population. Therefore, we aimed to analyze the effect of intermediate-frequency rTMS (2 Hz on behavioral and histological recovery following TBI in rats. Male Wistar rats were divided into six groups: three groups without TBI (no manipulation, movement restriction plus sham rTMS, and movement restriction plus rTMS and three groups subjected to TBI (TBI only, TBI plus movement restriction and sham rTMS, and TBI plus movement restriction and rTMS. The movement restriction groups were included so that rTMS could be applied without anesthesia. Our results indicate that the restriction of movement and sham rTMS per se promotes recovery, as measured using a neurobehavioral scale, although rTMS was associated with faster and superior recovery. We also observed that TBI caused alterations in the CA1 and CA3 subregions of the hippocampus, which are partly restored by movement restriction and rTMS. Our findings indicated that movement restriction prevents damage caused by TBI and that intermediate-frequency rTMS promotes behavioral and histologic recovery after TBI.

Maximum physical capacity testing in cancer patients undergoing chemotherapy

DEFF Research Database (Denmark)

Knutsen, L.; Quist, M; Midtgaard, J

2006-01-01

BACKGROUND: Over the past few years there has been a growing interest in the field of physical exercise in rehabilitation of cancer patients, leading to requirements for objective maximum physical capacity measurement (maximum oxygen uptake (VO(2max)) and one-repetition maximum (1RM)) to determin...... early in the treatment process. However, the patients were self-referred and thus highly motivated and as such are not necessarily representative of the whole population of cancer patients treated with chemotherapy....... in performing maximum physical capacity tests as these motivated them through self-perceived competitiveness and set a standard that served to encourage peak performance. CONCLUSION: The positive attitudes in this sample towards maximum physical capacity open the possibility of introducing physical testing...

Test-Retest Reliability of Rating of Perceived Exertion and Agreement With 1-Repetition Maximum in Adults.

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Bove, Allyn M; Lynch, Andrew D; DePaul, Samantha M; Terhorst, Lauren; Irrgang, James J; Fitzgerald, G Kelley

2016-09-01

Study Design Clinical measurement. Background It has been suggested that rating of perceived exertion (RPE) may be a useful alternative to 1-repetition maximum (1RM) to determine proper resistance exercise dosage. However, the test-retest reliability of RPE for resistance exercise has not been determined. Additionally, prior research regarding the relationship between 1RM and RPE is conflicting. Objectives The purpose of this study was to (1) determine test-retest reliability of RPE related to resistance exercise and (2) assess agreement between percentages of 1RM and RPE during quadriceps resistance exercise. Methods A sample of participants with and without knee pathology completed a series of knee extension exercises and rated the perceived difficulty of each exercise on a 0-to-10 RPE scale, then repeated the procedure 1 to 2 weeks later for test-retest reliability. To determine agreement between RPE and 1RM, participants completed knee extension exercises at various percentages of their 1RM (10% to 130% of predicted 1RM) and rated the perceived difficulty of each exercise on a 0-to-10 RPE scale. Percent agreement was calculated between the 1RM and RPE at each resistance interval. Results The intraclass correlation coefficient indicated excellent test-retest reliability of RPE for quadriceps resistance exercises (intraclass correlation coefficient = 0.895; 95% confidence interval: 0.866, 0.918). Overall percent agreement between RPE and 1RM was 60%, but agreement was poor within the ranges that would typically be used for training (50% 1RM for muscle endurance, 70% 1RM and greater for strength). Conclusion Test-retest reliability of perceived exertion during quadriceps resistance exercise was excellent. However, agreement between the RPE and 1RM was poor, especially in common training zones for knee extensor strengthening. J Orthop Sports Phys Ther 2016;46(9):768-774. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6498.

High-frequency resistance training is not more effective than low-frequency resistance training in increasing muscle mass and strength in well-trained men.

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Gomes, Gederson K; Franco, Cristiane M; Nunes, Paulo Ricardo P; Orsatti, Fábio L

2018-02-27

We studied the effects of two different weekly frequency resistance training (RT) protocols over eight weeks on muscle strength and muscle hypertrophy in well-trained men. Twenty-three subjects (age: 26.2±4.2 years; RT experience: 6.9±3.1 years) were randomly allocated into the two groups: low frequency (LFRT, n = 12) or high frequency (HFRT, n = 11). The LFRT performed a split-body routine, training each specific muscle group once a week. The HFRT performed a total-body routine, training all muscle groups every session. Both groups performed the same number of sets (10-15 sets) and exercises (1-2 exercise) per week, 8-12 repetitions maximum (70-80% of 1RM), five times per week. Muscle strength (bench press and squat 1RM) and lean tissue mass (dual-energy x-ray absorptiometry) were assessed prior to and at the end of the study. Results showed that both groups improved (ptrained subjects when the sets and intensity are equated per week.

Comparison on different repetition rate locking methods in Er-doped fiber laser

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Yang, Kangwen; Zhao, Peng; Luo, Jiang; Huang, Kun; Hao, Qiang; Zeng, Heping

2018-05-01

We demonstrate a systematic comparative research on the all-optical, mechanical and opto-mechanical repetition rate control methods in an Er-doped fiber laser. A piece of Yb-doped fiber, a piezoelectric transducer and an electronic polarization controller are simultaneously added in the laser cavity as different cavity length modulators. By measuring the cavity length tuning ranges, the output power fluctuations, the temporal and frequency repetition rate stability, we show that all-optical method introduces the minimal disturbances under current experimental condition.

Muscle power output properties using the stretch-shortening cycle of the upper limb and their relationships with a one-repetition maximum bench press.

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Miyaguchi, Kazuyoshi; Demura, Shinichi

2006-05-01

The purpose of this study was to examine the output properties of muscle power by the dominant upper limb using SSC, and the relationships between the power output by SSC and a one-repetition maximum bench press (1 RM BP) used as a strength indicator of the upper body. Sixteen male athletes (21.4+/-0.9 yr) participated in this study. They pulled a load of 40% of maximum voluntary contraction (MVC) at a stretch by elbow flexion of the dominant upper limb in the following three preliminary conditions: static relaxed muscle state (SR condition), isometric muscle contraction state (ISO condition), and using SSC (SSC condition). The velocity with a wire load via a pulley during elbow flexion was measured accurately using a power instrument with a rotary encoder, and the muscle power curve was drawn from the product of the velocity and load. Significant differences were found among all evaluation parameters of muscle power exerted from the above three conditions and the parameters regarding early power output during concentric contraction were larger in the SSC condition than the SR and ISO conditions. The parameters on initial muscle contraction velocity when only using SSC significantly correlated with 1 RM BP (r=0.60-0.62). The use of SSC before powerful elbow flexion may contribute largely to early explosive power output during concentric contraction. Bench press capacity relates to a development of the above early power output when using SSC.

Robustification and Optimization in Repetitive Control For Minimum Phase and Non-Minimum Phase Systems

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Prasitmeeboon, Pitcha

Repetitive control (RC) is a control method that specifically aims to converge to zero tracking error of a control systems that execute a periodic command or have periodic disturbances of known period. It uses the error of one period back to adjust the command in the present period. In theory, RC can completely eliminate periodic disturbance effects. RC has applications in many fields such as high-precision manufacturing in robotics, computer disk drives, and active vibration isolation in spacecraft. The first topic treated in this dissertation develops several simple RC design methods that are somewhat analogous to PID controller design in classical control. From the early days of digital control, emulation methods were developed based on a Forward Rule, a Backward Rule, Tustin's Formula, a modification using prewarping, and a pole-zero mapping method. These allowed one to convert a candidate controller design to discrete time in a simple way. We investigate to what extent they can be used to simplify RC design. A particular design is developed from modification of the pole-zero mapping rules, which is simple and sheds light on the robustness of repetitive control designs. RC convergence requires less than 90 degree model phase error at all frequencies up to Nyquist. A zero-phase cutoff filter is normally used to robustify to high frequency model error when this limit is exceeded. The result is stabilization at the expense of failure to cancel errors above the cutoff. The second topic investigates a series of methods to use data to make real time updates of the frequency response model, allowing one to increase or eliminate the frequency cutoff. These include the use of a moving window employing a recursive discrete Fourier transform (DFT), and use of a real time projection algorithm from adaptive control for each frequency. The results can be used directly to make repetitive control corrections that cancel each error frequency, or they can be used to update a

A vacuum-sealed, gigawatt-class, repetitively pulsed high-power microwave source

Science.gov (United States)

Xun, Tao; Fan, Yu-wei; Yang, Han-wu; Zhang, Zi-cheng; Chen, Dong-qun; Zhang, Jian-de

2017-06-01

A compact L-band sealed-tube magnetically insulated transmission line oscillator (MILO) has been developed that does not require bulky external vacuum pump for repetitive operations. This device with a ceramic insulated vacuum interface, a carbon fiber array cathode, and non-evaporable getters has a base vacuum pressure in the low 10-6 Pa range. A dynamic 3-D Monte-Carlo model for the molecular flow movement and collision was setup for the MILO chamber. The pulse desorption, gas evolution, and pressure distribution were exactly simulated. In the 5 Hz repetition rate experiments, using a 600 kV diode voltage and 48 kA beam current, the average radiated microwave power for 25 shots is about 3.4 GW in 45 ns pulse duration. The maximum equilibrium pressure is below 4.0 × 10-2 Pa, and no pulse shortening limitations are observed during the repetitive test in the sealed-tube condition.

A Practical Scheme for Frequency Offset Estimation in MIMO-OFDM Systems

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Morelli Michele

2009-01-01

Full Text Available This paper deals with training-assisted carrier frequency offset (CFO estimation in multiple-input multiple-output (MIMO orthogonal frequency-division multiplexing (OFDM systems. The exact maximum likelihood (ML solution to this problem is computationally demanding as it involves a line search over the CFO uncertainty range. To reduce the system complexity, we divide the CFO into an integer part plus a fractional part and select the pilot subcarriers such that the training sequences have a repetitive structure in the time domain. In this way, the fractional CFO is efficiently computed through a correlation-based approach, while ML methods are employed to estimate the integer CFO. Simulations indicate that the proposed scheme is superior to the existing alternatives in terms of both estimation accuracy and processing load.

A Practical Scheme for Frequency Offset Estimation in MIMO-OFDM Systems

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2009-03-01

Full Text Available This paper deals with training-assisted carrier frequency offset (CFO estimation in multiple-input multiple-output (MIMO orthogonal frequency-division multiplexing (OFDM systems. The exact maximum likelihood (ML solution to this problem is computationally demanding as it involves a line search over the CFO uncertainty range. To reduce the system complexity, we divide the CFO into an integer part plus a fractional part and select the pilot subcarriers such that the training sequences have a repetitive structure in the time domain. In this way, the fractional CFO is efficiently computed through a correlation-based approach, while ML methods are employed to estimate the integer CFO. Simulations indicate that the proposed scheme is superior to the existing alternatives in terms of both estimation accuracy and processing load.

Nonword repetition in adults who stutter: The effects of stimuli stress and auditory-orthographic cues.

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Geoffrey A Coalson

Full Text Available Adults who stutter (AWS are less accurate in their immediate repetition of novel phonological sequences compared to adults who do not stutter (AWNS. The present study examined whether manipulation of the following two aspects of traditional nonword repetition tasks unmask distinct weaknesses in phonological working memory in AWS: (1 presentation of stimuli with less-frequent stress patterns, and (2 removal of auditory-orthographic cues immediately prior to response.Fifty-two participants (26 AWS, 26 AWNS produced 12 bisyllabic nonwords in the presence of corresponding auditory-orthographic cues (i.e., immediate repetition task, and the absence of auditory-orthographic cues (i.e., short-term recall task. Half of each cohort (13 AWS, 13 AWNS were exposed to the stimuli with high-frequency trochaic stress, and half (13 AWS, 13 AWNS were exposed to identical stimuli with lower-frequency iambic stress.No differences in immediate repetition accuracy for trochaic or iambic nonwords were observed for either group. However, AWS were less accurate when recalling iambic nonwords than trochaic nonwords in the absence of auditory-orthographic cues.Manipulation of two factors which may minimize phonological demand during standard nonword repetition tasks increased the number of errors in AWS compared to AWNS. These findings suggest greater vulnerability in phonological working memory in AWS, even when producing nonwords as short as two syllables.

GPI-repetitive control for linear systems with parameter uncertainty / variation

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John A. Cortés-Romero

2015-01-01

Full Text Available Robust repetitive control problems for uncertain linear systems have been considered by different approaches. This article proposes the use of Repetitive Control and Generalized Proportional Integral (GPI Control in a complementary fashion. The conditioning and coupling of these techniques has been done in a time discrete context. Repetitive control is a control technique, based on the internal model principle, which yields perfect asymptotic tracking and rejection of periodic signals. On the other hand, GPI control is established as a robust linear control system design technique that is able to reject structured time polynomial additive perturbation, in particular, parameter uncertainty that can be locally approximated by time polynomial signal. GPI control provides a suitable stability and robustness conditions for the proper Repetitive Control operation. A stability analysis is presented under the frequency response framework using plant samples for different parameter uncertainty conditions. We carry out some comparative stability analysis with other complementary control approaches that has been effective for this kind of task, enhancing a better robustness and an improved performance for the GPI case. Illustrative simulation examples are presented which validate the proposed approach.

Short-Pulse-Width Repetitively Q-Switched ~2.7-μm Er:Y2O3 Ceramic Laser

Directory of Open Access Journals (Sweden)

Xiaojing Ren

2017-11-01

Full Text Available A short-pulse-width repetitively Q-switched 2.7-μm Er:Y2O3 ceramic laser is demonstrated using a specially designed mechanical switch, a metal plate carved with slits of both slit-width and duty-cycle optimized. With a 20% transmission output coupler, stable pulse trains with durations (full-width at half-maximum, FWHM of 27–38 ns were generated with a repetition rate within the range of 0.26–4 kHz. The peak power at a 0.26 kHz repetition rate was ~3 kW.

Modulation of the Left Prefrontal Cortex with High Frequency Repetitive Transcranial Magnetic Stimulation Facilitates Gait in Multiple Sclerosis

Directory of Open Access Journals (Sweden)

Amer M. Burhan

2015-01-01

Full Text Available Multiple Sclerosis (MS is a chronic central nervous system (CNS demyelinating disease. Gait abnormalities are common and disabling in patients with MS with limited treatment options available. Emerging evidence suggests a role of prefrontal attention networks in modulating gait. High-frequency repetitive transcranial magnetic stimulation (rTMS is known to enhance cortical excitability in stimulated cortex and its correlates. We investigated the effect of high-frequency left prefrontal rTMS on gait parameters in a 51-year-old Caucasian male with chronic relapsing/remitting MS with residual disabling attention and gait symptoms. Patient received 6 Hz, rTMS at 90% motor threshold using figure of eight coil centered on F3 location (using 10-20 electroencephalography (EEG lead localization system. GAITRite gait analysis system was used to collect objective gait measures before and after one session and in another occasion three consecutive daily sessions of rTMS. Two-tailed within subject repeated measure t-test showed significant enhancement in ambulation time, gait velocity, and cadence after three consecutive daily sessions of rTMS. Modulating left prefrontal cortex excitability using rTMS resulted in significant change in gait parameters after three sessions. To our knowledge, this is the first report that demonstrates the effect of rTMS applied to the prefrontal cortex on gait in MS patients.

Roles of repetitive sequences

Energy Technology Data Exchange (ETDEWEB)

Bell, G.I.

1991-12-31

The DNA of higher eukaryotes contains many repetitive sequences. The study of repetitive sequences is important, not only because many have important biological function, but also because they provide information on genome organization, evolution and dynamics. In this paper, I will first discuss some generic effects that repetitive sequences will have upon genome dynamics and evolution. In particular, it will be shown that repetitive sequences foster recombination among, and turnover of, the elements of a genome. I will then consider some examples of repetitive sequences, notably minisatellite sequences and telomere sequences as examples of tandem repeats, without and with respectively known function, and Alu sequences as an example of interspersed repeats. Some other examples will also be considered in less detail.

Comparison of concentric and eccentric bench press repetitions to failure.

Science.gov (United States)

Kelly, Stephen B; Brown, Lee E; Hooker, Steven P; Swan, Pamela D; Buman, Matthew P; Alvar, Brent A; Black, Laurie E

2015-04-01

Eccentric muscle actions (ECC) are characterized by muscle lengthening, despite actin-myosin crossbridge formation. Muscles acting eccentrically are capable of producing higher levels of force compared with muscles acting concentrically. The purpose of this study was to determine whether ECC bench press yields greater strength than concentric (CON) as determined by 1 repetition maximum (1RM). Additionally, a comparison was made examining differences in the number of repetitions to failure at different relative intensities of 1RM. Thirty healthy men (age = 24.63 ± 5.6 years) were tested for 1RM in CON and ECC bench press and the number of repetitions completed at 60, 70, 80, and 90% 1RM. For CON repetitions, the weight was mechanically lowered to the chest, and the participant pressed it up until the elbows were fully extended. The ECC bench press consisted of lowering a barbell from a fully extended elbow position to the chest in a continuous controlled manner for 3 seconds as determined by electronic metronome. Paired t-tests showed that ECC 1RM (115.99 ± 31.08 kg) was significantly (p ≤ 0.05) greater than CON 1RM (93.56 ± 26.56 kg), and the number of repetitions completed at 90% 1RM was significantly (p ≤ 0.05) greater in ECC (7.67 ± 3.24) as compared with CON (4.57 ± 2.21). There were no significant differences in number of completed repetitions during CON and ECC bench press at 60, 70, and 80% 1RM. These data indicate that ECC actions yield increased force capabilities (∼120%) as compared with CON in the bench press and may be less prone to fatigue, especially at higher intensities. These differences suggest a need to develop unique strategies for training eccentrically.

Novel high-frequency energy-efficient pulsed-dc generator for capacitively coupled plasma discharge

Science.gov (United States)

Mamun, Md Abdullah Al; Furuta, Hiroshi; Hatta, Akimitsu

2018-03-01

The circuit design, assembly, and operating tests of a high-frequency and high-voltage (HV) pulsed dc generator (PDG) for capacitively coupled plasma (CCP) discharge inside a vacuum chamber are reported. For capacitive loads, it is challenging to obtain sharp rectangular pulses with fast rising and falling edges, requiring intense current for quick charging and discharging. The requirement of intense current generally limits the pulse operation frequency. In this study, we present a new type of PDG consisting of a pair of half-resonant converters and a constant current-controller circuit connected with HV solid-state power switches that can deliver almost rectangular high voltage pulses with fast rising and falling edges for CCP discharge. A prototype of the PDG is assembled to modulate from a high-voltage direct current (HVdc) input into a pulsed HVdc output, while following an input pulse signal and a set current level. The pulse rise time and fall time are less than 500 ns and 800 ns, respectively, and the minimum pulse width is 1 µs. The maximum voltage for a negative pulse is 1000 V, and the maximum repetition frequency is 500 kHz. During the pulse on time, the plasma discharge current is controlled steadily at the set value. The half-resonant converters in the PDG perform recovery of the remaining energy from the capacitive load at every termination of pulse discharge. The PDG performed with a high energy efficiency of 85% from the HVdc input to the pulsed dc output at a repetition rate of 1 kHz and with stable plasma operation in various discharge conditions. The results suggest that the developed PDG can be considered to be more efficient for plasma processing by CCP.

Novel high-frequency energy-efficient pulsed-dc generator for capacitively coupled plasma discharge.

Science.gov (United States)

Mamun, Md Abdullah Al; Furuta, Hiroshi; Hatta, Akimitsu

2018-03-01

The circuit design, assembly, and operating tests of a high-frequency and high-voltage (HV) pulsed dc generator (PDG) for capacitively coupled plasma (CCP) discharge inside a vacuum chamber are reported. For capacitive loads, it is challenging to obtain sharp rectangular pulses with fast rising and falling edges, requiring intense current for quick charging and discharging. The requirement of intense current generally limits the pulse operation frequency. In this study, we present a new type of PDG consisting of a pair of half-resonant converters and a constant current-controller circuit connected with HV solid-state power switches that can deliver almost rectangular high voltage pulses with fast rising and falling edges for CCP discharge. A prototype of the PDG is assembled to modulate from a high-voltage direct current (HVdc) input into a pulsed HVdc output, while following an input pulse signal and a set current level. The pulse rise time and fall time are less than 500 ns and 800 ns, respectively, and the minimum pulse width is 1 µs. The maximum voltage for a negative pulse is 1000 V, and the maximum repetition frequency is 500 kHz. During the pulse on time, the plasma discharge current is controlled steadily at the set value. The half-resonant converters in the PDG perform recovery of the remaining energy from the capacitive load at every termination of pulse discharge. The PDG performed with a high energy efficiency of 85% from the HVdc input to the pulsed dc output at a repetition rate of 1 kHz and with stable plasma operation in various discharge conditions. The results suggest that the developed PDG can be considered to be more efficient for plasma processing by CCP.

High-frequency strontium vapor laser for biomedical applications

Science.gov (United States)

Hvorostovsky, A.; Kolmakov, E.; Kudashev, I.; Redka, D.; Kancer, A.; Kustikova, M.; Bykovskaya, E.; Mayurova, A.; Stupnikov, A.; Ruzankina, J.; Tsvetkov, K.; Lukyanov, N.; Paklinov, N.

2018-02-01

Sr-laser with high pulse repetition rate and high peak radiation power is a unique tool for studying rapidly occurring processes in time (plasma diagnostics, photoablation, etc.). In addition, the study of the frequency characteristics of the active medium of the laser helps to reveal the physics of the formation of an inverse medium in metal vapor lasers. In this paper, an experimental study of an Sr-laser with an active volume of 5.8 cm3 in the pulse repetition frequency range from 25 to 200 kHz is carried out, and a comparison with the frequency characteristics of media with large active volumes is given. We considered the frequency characteristics of the active medium in two modes: at a constant energy in the excitation pulse CU2 / 2 and at a constant average power consumed by the rectifier. In the presented work with a small-volume GRT using the TASITR-5/12 TASITRON switch, a laser was generated for Pairs of strontium at a CSF of 200 kHz. The behavior of the characteristics of the generation lines of 6.456 μm, 1 μm, and 3 μm at increased repetition frequencies is considered. Using the example of large-volume GRT, it is shown that tubes with a large active volume increase their energy characteristics with the growth of the CSF. The possibility of laser operation at pulse repetition rates above 200 kHz is shown.

A Nonword Repetition Task for Speakers with Misarticulations: The Syllable Repetition Task (SRT)

Science.gov (United States)

Shriberg, Lawrence D.; Lohmeier, Heather L.; Campbell, Thomas F.; Dollaghan, Christine A.; Green, Jordan R.; Moore, Christopher A.

2009-01-01

Purpose: Conceptual and methodological confounds occur when non(sense) word repetition tasks are administered to speakers who do not have the target speech sounds in their phonetic inventories or who habitually misarticulate targeted speech sounds. In this article, the authors (a) describe a nonword repetition task, the Syllable Repetition Task…

Independent and additive repetition priming of motion direction and color in visual search.

Science.gov (United States)

Kristjánsson, Arni

2009-03-01

Priming of visual search for Gabor patch stimuli, varying in color and local drift direction, was investigated. The task relevance of each feature varied between the different experimental conditions compared. When the target defining dimension was color, a large effect of color repetition was seen as well as a smaller effect of the repetition of motion direction. The opposite priming pattern was seen when motion direction defined the target--the effect of motion direction repetition was this time larger than for color repetition. Finally, when neither was task relevant, and the target defining dimension was the spatial frequency of the Gabor patch, priming was seen for repetition of both color and motion direction, but the effects were smaller than in the previous two conditions. These results show that features do not necessarily have to be task relevant for priming to occur. There is little interaction between priming following repetition of color and motion, these two features show independent and additive priming effects, most likely reflecting that the two features are processed at separate processing sites in the nervous system, consistent with previous findings from neuropsychology & neurophysiology. The implications of the findings for theoretical accounts of priming in visual search are discussed.

DC-driven plasma gun: self-oscillatory operation mode of atmospheric-pressure helium plasma jet comprised of repetitive streamer breakdowns

Science.gov (United States)

Wang, Xingxing; Shashurin, Alexey

2017-02-01

This paper presents and studies helium atmospheric pressure plasma jet comprised of a series of repetitive streamer breakdowns, which is driven by pure DC high voltage (self-oscillatory behavior). The repetition frequency of the breakdowns is governed by the geometry of discharge electrodes/surroundings and gas flow rate. Each next streamer is initiated when the electric field on the anode tip recovers after the previous breakdown and reaches the breakdown threshold value of about 2.5 kV cm-1. One type of the helium plasma gun designed using this operational principle is demonstrated. The gun operates on about 3 kV DC high voltage and is comprised of the series of the repetitive streamer breakdowns at a frequency of about 13 kHz.

A long-pulse repetitive operation magnetically insulated transmission line oscillator

International Nuclear Information System (INIS)

Fan, Yu-Wei; Zhong, Hui-Huang; Zhang, Jian-De; Shu, Ting; Liu, Jin Liang

2014-01-01

The improved magnetically insulated transmission line oscillator (MILO) is a gigawatt-class L-band high power microwave tube. It has allowed us to generate 3.1 GW pulse of 40 ns duration in the single-pulse operation and 500 MW pulse of 25 ns duration in the repetition rate operation. However, because of the severe impedance mismatch, the power conversion efficiency is only about 4% in the repetition rate operation. In order to eliminate the impedance mismatch and obtain repetitive long-pulse high-power microwave (HPM), a series of experiments are carried out and the recent progress is presented in this paper. In the single-pulse operation, when the diode voltage is 466 kV and current is 41.6 kA, the radiated microwave power is above 2.2 GW, the pulse duration is above 102 ns, the microwave frequency is about 1.74 GHz, and the power conversion efficiency is about 11.5%. In the repetition rate operation, under the condition of the diode voltage about 400 kV, beam current about 38 kA, the radiated microwave power is about 1.0 GW, the pulse duration is about 85 ns. Moreover, the radiated microwave power and the pulse duration decline little by little when the shot numbers increase gradually. The experimental results show that the impedance matching is a vital factor for HPM systems and one of the major technical challenges is to improve the cathode for the repetition rate operation MILO

A long-pulse repetitive operation magnetically insulated transmission line oscillator

Energy Technology Data Exchange (ETDEWEB)

Fan, Yu-Wei; Zhong, Hui-Huang; Zhang, Jian-De; Shu, Ting; Liu, Jin Liang [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2014-05-15

The improved magnetically insulated transmission line oscillator (MILO) is a gigawatt-class L-band high power microwave tube. It has allowed us to generate 3.1 GW pulse of 40 ns duration in the single-pulse operation and 500 MW pulse of 25 ns duration in the repetition rate operation. However, because of the severe impedance mismatch, the power conversion efficiency is only about 4% in the repetition rate operation. In order to eliminate the impedance mismatch and obtain repetitive long-pulse high-power microwave (HPM), a series of experiments are carried out and the recent progress is presented in this paper. In the single-pulse operation, when the diode voltage is 466 kV and current is 41.6 kA, the radiated microwave power is above 2.2 GW, the pulse duration is above 102 ns, the microwave frequency is about 1.74 GHz, and the power conversion efficiency is about 11.5%. In the repetition rate operation, under the condition of the diode voltage about 400 kV, beam current about 38 kA, the radiated microwave power is about 1.0 GW, the pulse duration is about 85 ns. Moreover, the radiated microwave power and the pulse duration decline little by little when the shot numbers increase gradually. The experimental results show that the impedance matching is a vital factor for HPM systems and one of the major technical challenges is to improve the cathode for the repetition rate operation MILO.

A long-pulse repetitive operation magnetically insulated transmission line oscillator.

Science.gov (United States)

Fan, Yu-Wei; Zhong, Hui-Huang; Zhang, Jian-De; Shu, Ting; Liu, Jin Liang

2014-05-01

The improved magnetically insulated transmission line oscillator (MILO) is a gigawatt-class L-band high power microwave tube. It has allowed us to generate 3.1 GW pulse of 40 ns duration in the single-pulse operation and 500 MW pulse of 25 ns duration in the repetition rate operation. However, because of the severe impedance mismatch, the power conversion efficiency is only about 4% in the repetition rate operation. In order to eliminate the impedance mismatch and obtain repetitive long-pulse high-power microwave (HPM), a series of experiments are carried out and the recent progress is presented in this paper. In the single-pulse operation, when the diode voltage is 466 kV and current is 41.6 kA, the radiated microwave power is above 2.2 GW, the pulse duration is above 102 ns, the microwave frequency is about 1.74 GHz, and the power conversion efficiency is about 11.5%. In the repetition rate operation, under the condition of the diode voltage about 400 kV, beam current about 38 kA, the radiated microwave power is about 1.0 GW, the pulse duration is about 85 ns. Moreover, the radiated microwave power and the pulse duration decline little by little when the shot numbers increase gradually. The experimental results show that the impedance matching is a vital factor for HPM systems and one of the major technical challenges is to improve the cathode for the repetition rate operation MILO.

Frequency-agile dual-comb spectroscopy

OpenAIRE

Millot, Guy; Pitois, Stéphane; Yan, Ming; Hovannysyan, Tatevik; Bendahmane, Abdelkrim; Hänsch, Theodor W.; Picqué, Nathalie

2015-01-01

We propose a new approach to near-infrared molecular spectroscopy, harnessing advanced concepts of optical telecommunications and supercontinuum photonics. We generate, without mode-locked lasers, two frequency combs of slightly different repetition frequencies and moderate, but rapidly tunable, spectral span. The output of a frequency-agile continuous wave laser is split and sent into two electro-optic intensity modulators. Flat-top low-noise frequency combs are produced by wave-breaking in ...

Repetitive transcranial magnetic stimulation modulates the impact of a negative mood induction

NARCIS (Netherlands)

Möbius, M.; Lacomblé, L.M.T.; Meyer, T.; Schutter, D.J.L.G.; Gielkens, T.; Becker, E.S.; Tendolkar, I.; Eijndhoven, P.F.P. van

2017-01-01

High frequency repetitive Transcranial Magnetic Stimulation (rTMS) over the left dorsolateral prefrontal cortex (DLPFC) has been found to alleviate depressive symptoms. However, the mechanisms driving these effects are still poorly understood. In the current study, we tested the idea that this

Repetition frequency scaling of an all-polarization maintaining erbium-doped mode-locked fiber laser based on carbon nanotubes saturable absorber

Energy Technology Data Exchange (ETDEWEB)

Sotor, J., E-mail: jaroslaw.sotor@pwr.edu.pl; Sobon, G.; Abramski, K. M. [Laser and Fiber Electronics Group, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Jagiello, J.; Lipinska, L. [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland)

2015-04-07

We demonstrate an all-polarization maintaining (PM), mode-locked erbium (Er)-doped fiber laser based on a carbon nanotubes (CNT) saturable absorber (SA). The laser resonator was maximally simplified by using only one passive hybrid component and a pair of fiber connectors with deposited CNTs. The repetition frequency (F{sub rep}) of such a cost-effective and self-starting mode-locked laser was scaled from 54.3 MHz to 358.6 MHz. The highest F{sub rep} was obtained when the total cavity length was shortened to 57 cm. The laser allows ultrashort pulse generation with the duration ranging from 240 fs to 550 fs. Because the laser components were based on PM fibers the laser was immune to the external perturbations and generated laniary polarized light with the degree of polarization (DOP) of 98.7%.

Topic Repetition in Conversations on Different Days as a Sign of Dementia.

Science.gov (United States)

Shinkawa, Kaoru; Yamada, Yasunori

2018-01-01

Detecting early signs of dementia in everyday situations becomes more and more important in a rapidly aging society. Language dysfunctions are recognized as the prominent signs of dementia. Previous computational studies characterized these language dysfunctions by using acoustic and linguistic features for detecting dementia. However, they mainly investigated language dysfunctions collected from patients during neuropsychological tests. Language dysfunctions observed during regular conversations in everyday situations received little attention. One of the dysfunctions associated with dementia which is frequently observed in regular conversations is the repetition of a topic on different days. In this study, we propose a feature to characterize topic repetition in conversations on different days. We used conversational data obtained from a daily monitoring service of eight elderly people, two of whom had dementia. Through the analysis of topic extraction with latent Dirichlet allocation, we found that the frequency of topic repetition was significantly higher in people with dementia than in the control group. The results suggest that our proposed feature for identifying topic repetition in regular conversations on different days might be used for detecting dementia.

Maximum permissible voltage of YBCO coated conductors

Energy Technology Data Exchange (ETDEWEB)

Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z. [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Hong, Z., E-mail: zhiyong.hong@sjtu.edu.cn [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Wang, D.; Zhou, H.; Shen, X.; Shen, C. [Qingpu Power Supply Company, State Grid Shanghai Municipal Electric Power Company, Shanghai (China)

2014-06-15

Highlights: • We examine three kinds of tapes’ maximum permissible voltage. • We examine the relationship between quenching duration and maximum permissible voltage. • Continuous I{sub c} degradations under repetitive quenching where tapes reaching maximum permissible voltage. • The relationship between maximum permissible voltage and resistance, temperature. - Abstract: Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (I{sub c}) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the I{sub c} degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

Macrophage and tumor cell responses to repetitive pulsed X-ray radiation

Science.gov (United States)

Buldakov, M. A.; Tretyakova, M. S.; Ryabov, V. B.; Klimov, I. A.; Kutenkov, O. P.; Kzhyshkowska, J.; Bol'shakov, M. A.; Rostov, V. V.; Cherdyntseva, N. V.

2017-05-01

To study a response of tumor cells and macrophages to the repetitive pulsed low-dose X-ray radiation. Methods. Tumor growth and lung metastasis of mice with an injected Lewis lung carcinoma were analysed, using C57Bl6. Monocytes were isolated from a human blood, using CD14+ magnetic beads. IL6, IL1-betta, and TNF-alpha were determined by ELISA. For macrophage phenotyping, a confocal microscopy was applied. “Sinus-150” was used for the generation of pulsed X-ray radiation (the absorbed dose was below 0.1 Gy, the pulse repetition frequency was 10 pulse/sec). The irradiation of mice by 0.1 Gy pulsed X-rays significantly inhibited the growth of primary tumor and reduced the number of metastatic colonies in the lung. Furthermore, the changes in macrophage phenotype and cytokine secretion were observed after repetitive pulsed X-ray radiation. Conclusion. Macrophages and tumor cells had a different response to a low-dose pulsed X-ray radiation. An activation of the immune system through changes of a macrophage phenotype can result in a significant antitumor effect of the low-dose repetitive pulsed X-ray radiation.

Repetitive transcranial magnetic stimulation for hallucination in schizophrenia spectrum disorders: A meta-analysis.

Science.gov (United States)

Zhang, Yingli; Liang, Wei; Yang, Shichang; Dai, Ping; Shen, Lijuan; Wang, Changhong

2013-10-05

This study assessed the efficacy and tolerability of repetitive transcranial magnetic stimulation for treatment of auditory hallucination of patients with schizophrenia spectrum disorders. Online literature retrieval was conducted using PubMed, ISI Web of Science, EMBASE, Medline and Cochrane Central Register of Controlled Trials databases from January 1985 to May 2012. Key words were "transcranial magnetic stimulation", "TMS", "repetitive transcranial magnetic stimulation", and "hallucination". Selected studies were randomized controlled trials assessing therapeutic efficacy of repetitive transcranial magnetic stimulation for hallucination in patients with schizophrenia spectrum disorders. Experimental intervention was low-frequency repetitive transcranial magnetic stimulation in left temporoparietal cortex for treatment of auditory hallucination in schizophrenia spectrum disorders. Control groups received sham stimulation. The primary outcome was total scores of Auditory Hallucinations Rating Scale, Auditory Hallucination Subscale of Psychotic Symptom Rating Scale, Positive and Negative Symptom Scale-Auditory Hallucination item, and Hallucination Change Scale. Secondary outcomes included response rate, global mental state, adverse effects and cognitive function. Seventeen studies addressing repetitive transcranial magnetic stimulation for treatment of schizophrenia spectrum disorders were screened, with controls receiving sham stimulation. All data were completely effective, involving 398 patients. Overall mean weighted effect size for repetitive transcranial magnetic stimulation versus sham stimulation was statistically significant (MD = -0.42, 95%CI: -0.64 to -0.20, P = 0.000 2). Patients receiving repetitive transcranial magnetic stimulation responded more frequently than sham stimulation (OR = 2.94, 95%CI: 1.39 to 6.24, P = 0.005). No significant differences were found between active repetitive transcranial magnetic stimulation and sham stimulation for

Low-frequency repetitive transcranial magnetic stimulation (rTMS) affects event-related potential measures of novelty processing in autism.

Science.gov (United States)

Sokhadze, Estate; Baruth, Joshua; Tasman, Allan; Mansoor, Mehreen; Ramaswamy, Rajesh; Sears, Lonnie; Mathai, Grace; El-Baz, Ayman; Casanova, Manuel F

2010-06-01

In our previous study on individuals with autism spectrum disorder (ASD) (Sokhadze et al., Appl Psychophysiol Biofeedback 34:37-51, 2009a) we reported abnormalities in the attention-orienting frontal event-related potentials (ERP) and the sustained-attention centro-parietal ERPs in a visual oddball experiment. These results suggest that individuals with autism over-process information needed for the successful differentiation of target and novel stimuli. In the present study we examine the effects of low-frequency, repetitive Transcranial Magnetic Stimulation (rTMS) on novelty processing as well as behavior and social functioning in 13 individuals with ASD. Our hypothesis was that low-frequency rTMS application to dorsolateral prefrontal cortex (DLFPC) would result in an alteration of the cortical excitatory/inhibitory balance through the activation of inhibitory GABAergic double bouquet interneurons. We expected to find post-TMS differences in amplitude and latency of early and late ERP components. The results of our current study validate the use of low-frequency rTMS as a modulatory tool that altered the disrupted ratio of cortical excitation to inhibition in autism. After rTMS the parieto-occipital P50 amplitude decreased to novel distracters but not to targets; also the amplitude and latency to targets increased for the frontal P50 while decreasing to non-target stimuli. Low-frequency rTMS minimized early cortical responses to irrelevant stimuli and increased responses to relevant stimuli. Improved selectivity in early cortical responses lead to better stimulus differentiation at later-stage responses as was made evident by our P3b and P3a component findings. These results indicate a significant change in early, middle-latency and late ERP components at the frontal, centro-parietal, and parieto-occipital regions of interest in response to target and distracter stimuli as a result of rTMS treatment. Overall, our preliminary results show that rTMS may prove to

The relationship between executive functioning, central coherence, and repetitive behaviors in the high-functioning autism spectrum.

Science.gov (United States)

South, Mikle; Ozonoff, Sally; McMahon, William M

2007-09-01

This study examined the relationship between everyday repetitive behavior (primary symptoms of autism) and performance on neuropsychological tests of executive function and central coherence (secondary symptoms). It was hypothesized that the frequency and intensity of repetitive behavior would be positively correlated with laboratory measures of cognitive rigidity and weak central coherence. Participants included 19 individuals (ages 10-19) with high-functioning autism spectrum disorders (ASD group) and 18 age- and IQ-matched typically developing controls (TD group). There was partial support in the ASD group for the link between repetitive behavior and executive performance (the Wisconsin Card Sorting Task). There was no support for a link between repetitive behavior and measures of central coherence (a Gestalt Closure test and the Embedded Figures Test). Further research on repetitive behaviors in autism may benefit from a focus on narrow behavioral and cognitive constructs rather than general categories.

Factor Analysis of Low-Frequency Repetitive Transcranial Magnetic Stimulation to the Temporoparietal Junction for Tinnitus

Directory of Open Access Journals (Sweden)

Hui Wang

2016-01-01

Full Text Available Objectives. We investigated factors that contribute to suppression of tinnitus after repetitive transcranial magnetic stimulation (rTMS. Methods. A total of 289 patients with tinnitus underwent active 1 Hz rTMS in the left temporoparietal region. A visual analog scale (VAS was used to assess tinnitus loudness. All participants were interviewed regarding age, gender, tinnitus duration, laterality and pitch, audiometric parameters, sleep, and so forth. The resting motor thresholds (RMTs were measured in all patients and 30 age- and gender-matched volunteers. Results. With respect to different factors that contribute to tinnitus suppression, we found improvement in the following domains: shorter duration, normal hearing (OR: 3.25, 95%CI: 2.01–5.27, p=0.001, and without sleep disturbance (OR: 2.51, 95%CI: 1.56–4.1, p=0.005 adjusted for age and gender. The patients with tinnitus lasting less than 1 year were more likely to show suppression of tinnitus (OR: 2.77, 95%CI: 1.48–5.19, p=0.002 compared to those with tinnitus lasting more than 5 years. Tinnitus patients had significantly lower RMTs compared with healthy volunteers. Conclusion. Active low-frequency rTMS results in a significant reduction in the loudness of tinnitus. Significant tinnitus suppression was shown in subjects with shorter tinnitus duration, with normal hearing, and without sleep disturbance.

Factor Analysis of Low-Frequency Repetitive Transcranial Magnetic Stimulation to the Temporoparietal Junction for Tinnitus

Science.gov (United States)

Li, Bei; Wang, Meiye; Li, Ming; Yin, Shankai

2016-01-01

Objectives. We investigated factors that contribute to suppression of tinnitus after repetitive transcranial magnetic stimulation (rTMS). Methods. A total of 289 patients with tinnitus underwent active 1 Hz rTMS in the left temporoparietal region. A visual analog scale (VAS) was used to assess tinnitus loudness. All participants were interviewed regarding age, gender, tinnitus duration, laterality and pitch, audiometric parameters, sleep, and so forth. The resting motor thresholds (RMTs) were measured in all patients and 30 age- and gender-matched volunteers. Results. With respect to different factors that contribute to tinnitus suppression, we found improvement in the following domains: shorter duration, normal hearing (OR: 3.25, 95%CI: 2.01–5.27, p = 0.001), and without sleep disturbance (OR: 2.51, 95%CI: 1.56–4.1, p = 0.005) adjusted for age and gender. The patients with tinnitus lasting less than 1 year were more likely to show suppression of tinnitus (OR: 2.77, 95%CI: 1.48–5.19, p = 0.002) compared to those with tinnitus lasting more than 5 years. Tinnitus patients had significantly lower RMTs compared with healthy volunteers. Conclusion. Active low-frequency rTMS results in a significant reduction in the loudness of tinnitus. Significant tinnitus suppression was shown in subjects with shorter tinnitus duration, with normal hearing, and without sleep disturbance. PMID:27847647

[Polish guidelines of 2001 for maximum admissible intensities in high frequency EMF versus European Union recommendations].

Science.gov (United States)

Aniołczyk, Halina

2003-01-01

In 1999, a draft of amendments to maximum admissible intensities (MAI) of electromagnetic fields (0 Hz-300 GHz) was prepared by Professor H. Korniewicz of the Central Institute for Labour Protection, Warsaw, in cooperation with the Nofer Institute of Occupational Medicine, Łódź (radio- and microwaves) and the Military Institute of Hygiene and Epidemiology, Warsaw (pulse radiation). Before 2000, the development of the national MAI guidelines for the frequency range of 0.1 MHz-300 GHz was based on the knowledge of biological and health effects of EMF exposure available on the turn of the 1960s. A current basis for establishing the MAI international standards is a well-documented thermal effect measured by the value of a specific absorption rate (SAR), whereas the effects of resonant absorption imposes the nature of the functional dependency on EMF frequency. The Russian standards, already thoroughly analyzed, still take so-called non-thermal effects and the conception of energetic load for a work-shift with its progressive averaging (see hazardous zone in Polish guidelines) as a basis for setting maximum admissible intensities. The World Health Organization recommends a harmonization of the EMF protection guidelines, existing in different countries, with the guidelines of the International Commission for Non-Ionizing Radiation Protection (ICNIRP), and its position is supported by the European Union.

Characterization and comprehension of corona partial discharge in air under power frequency to very low frequency voltage

Science.gov (United States)

Yuanxiang, ZHOU; Zhongliu, ZHOU; Ling, ZHANG; Yunxiao, ZHANG; Yajun, MO; Jiantao, SUN

2018-05-01

For the partial discharge test of electrical equipment with large capacitance, the use of low-frequency voltage instead of power frequency voltage can effectively reduce the capacity requirements of test power supply. However, the validity of PD test under low frequency voltage needs to be evaluated. In order to investigate the influence of voltage frequency on corona discharge in the air, the discharge test of the tip-plate electrode under the frequency from 50 to 0.1 Hz is carried out based on the impulse current method. The results show that some of the main features of corona under low frequency do not change. The magnitude of discharge in a positive half cycle is obviously larger than that in a negative cycle. The magnitude of discharge and interval in positive cycle are random, while that in negative cycle are regular. With the decrease of frequency, the inception voltage increases. The variation trend of maximum and average magnitude and repetition rate of the discharge in positive and negative half cycle with the variation of voltage frequency and magnitude is demonstrated, with discussion and interpretation from the aspects of space charge transportation, effective discharge time and transition of discharge modes. There is an obvious difference in the phase resolved pattern of partial discharge and characteristic parameters of discharge patterns between power and low frequency. The experimental results can be the reference for mode identification of partial discharge under low frequency tests. The trend of the measured parameters with the variation of frequency provides more information about the insulation defect than traditional measurements under a single frequency (usually 50 Hz). Also it helps to understand the mechanism of corona discharge with an explanation of the characteristics under different frequencies.

Compact frequency-modulation Q-switched single-frequency fiber laser at 1083 nm

International Nuclear Information System (INIS)

Zhang, Yuanfei; Feng, Zhouming; Xu, Shanhui; Mo, Shupei; Yang, Changsheng; Li, Can; Gan, Jiulin; Chen, Dongdan; Yang, Zhongmin

2015-01-01

A compact frequency-modulation Q-switched single-frequency fiber laser is demonstrated at 1083 nm. The short linear resonant cavity consists of a 12 mm long homemade Yb 3+ -doped phosphate fiber and a pair of fiber Bragg gratings (FBGs) in which the Q-switching and the frequency excursion is achieved by a tensile-induced period modulation. Over 375 MHz frequency-tuning range is achieved with a modulation frequency varying from tens to hundreds of kilohertz. The highest peak power of the output pulse reaching 6.93 W at the repetition rate of 10 kHz is obtained. (paper)

Reliability of the Load-Velocity Relationship Obtained Through Linear and Polynomial Regression Models to Predict the One-Repetition Maximum Load.

Science.gov (United States)

Pestaña-Melero, Francisco Luis; Haff, G Gregory; Rojas, Francisco Javier; Pérez-Castilla, Alejandro; García-Ramos, Amador

2017-12-18

This study aimed to compare the between-session reliability of the load-velocity relationship between (1) linear vs. polynomial regression models, (2) concentric-only vs. eccentric-concentric bench press variants, as well as (3) the within-participants vs. the between-participants variability of the velocity attained at each percentage of the one-repetition maximum (%1RM). The load-velocity relationship of 30 men (age: 21.2±3.8 y; height: 1.78±0.07 m, body mass: 72.3±7.3 kg; bench press 1RM: 78.8±13.2 kg) were evaluated by means of linear and polynomial regression models in the concentric-only and eccentric-concentric bench press variants in a Smith Machine. Two sessions were performed with each bench press variant. The main findings were: (1) first-order-polynomials (CV: 4.39%-4.70%) provided the load-velocity relationship with higher reliability than second-order-polynomials (CV: 4.68%-5.04%); (2) the reliability of the load-velocity relationship did not differ between the concentric-only and eccentric-concentric bench press variants; (3) the within-participants variability of the velocity attained at each %1RM was markedly lower than the between-participants variability. Taken together, these results highlight that, regardless of the bench press variant considered, the individual determination of the load-velocity relationship by a linear regression model could be recommended to monitor and prescribe the relative load in the Smith machine bench press exercise.

Haben repetitive DNA-Sequenzen biologische Funktionen?

Science.gov (United States)

John, Maliyakal E.; Knöchel, Walter

1983-05-01

By DNA reassociation kinetics it is known that the eucaryotic genome consists of non-repetitive DNA, middle-repetitive DNA and highly repetitive DNA. Whereas the majority of protein-coding genes is located on non-repetitive DNA, repetitive DNA forms a constitutive part of eucaryotic DNA and its amount in most cases equals or even substantially exceeds that of non-repetitive DNA. During the past years a large body of data on repetitive DNA has accumulated and these have prompted speculations ranging from specific roles in the regulation of gene expression to that of a selfish entity with inconsequential functions. The following article summarizes recent findings on structural, transcriptional and evolutionary aspects and, although by no means being proven, some possible biological functions are discussed.

Low-Frequency Repetitive Transcranial Magnetic Stimulation Ameliorates Cognitive Function and Synaptic Plasticity in APP23/PS45 Mouse Model of Alzheimer’s Disease

Directory of Open Access Journals (Sweden)

Zhilin Huang

2017-09-01

Full Text Available Alzheimer’s disease (AD is a chronic neurodegenerative disease leading to dementia, which is characterized by progressive memory loss and other cognitive dysfunctions. Recent studies have attested that noninvasive repetitive transcranial magnetic stimulation (rTMS may help improve cognitive function in patients with AD. However, the majority of these studies have focused on the effects of high-frequency rTMS on cognitive function, and little is known about low-frequency rTMS in AD treatment. Furthermore, the potential mechanisms of rTMS on the improvement of learning and memory also remain poorly understood. In the present study, we reported that severe deficits in spatial learning and memory were observed in APP23/PS45 double transgenic mice, a well known mouse model of AD. Furthermore, these behavioral changes were accompanied by the impairment of long-term potentiation (LTP in the CA1 region of hippocampus, a brain region vital to spatial learning and memory. More importantly, 2-week low-frequency rTMS treatment markedly reversed the impairment of spatial learning and memory as well as hippocampal CA1 LTP. In addition, low-frequency rTMS dramatically reduced amyloid-β precursor protein (APP and its C-terminal fragments (CTFs including C99 and C89, as well as β-site APP-cleaving enzyme 1 (BACE1 in the hippocampus. These results indicate that low-frequency rTMS noninvasively and effectively ameliorates cognitive and synaptic functions in a mouse model of AD, and the potential mechanisms may be attributed to rTMS-induced reduction in Aβ neuropathology.

Cortical activity, ionic homeostasis, and acidosis during rat brain repetitive ischemia.

Science.gov (United States)

Matsumoto, T; Obrenovitch, T P; Parkinson, N A; Symon, L

1990-08-01

Recent data strongly suggest that repetitive ischemic episodes have an adverse cumulative effect on development of edema and tissue damage. We wanted to assess further whether special risks such as exacerbation of extracellular acidification reflecting progressive exhaustion of the capacity to buffer H+ in the extracellular space are associated with repeated short ischemic insults. We monitored spontaneous electrical activity, extracellular direct-current potential, extracellular H+ activity, and tissue PCO2 in the cerebral cortex of rats subjected to four cycles of 3-minute ischemia produced by four-vessel occlusion with 27-minute reperfusion after each insult. Except for electrical activity, which failed to recover fully from the first ischemic insult, all parameters returned to a level close to normal after each reperfusion. Changes during ischemia did not evolve with repetition of the insult. Electrical silence occurred within approximately 20 seconds after the onset of each ischemic episode and always preceded the steep drop of direct-current potential, indicating ischemic depolarization. Each four-vessel occlusion immediately initiated a steep rise of tissue PCO2 and extracellular H+ activity, with extracellular H+ activity reaching a maximum within approximately 145 seconds. Changes in extracellular H+ activity during each recirculation period consistently included an additional and short-lasting increase associated with repolarization, a rapid decrease closely related to that of tissue PCO2, and a slow progressive return to normal. These results suggest that short, repetitive ischemic episodes severe enough to produce cell membrane depolarization and maximum acidosis of the neuronal microenvironment do not have a deleterious cumulative effect on the studied parameters, in particular, on interstitial acidosis.

Electrode patterning of ITO thin films by high repetition rate fiber laser

International Nuclear Information System (INIS)

Lin, H.K.; Hsu, W.C.

2014-01-01

Indium tin oxide (ITO) thin films are deposited on glass substrates using a radio frequency magnetron sputtering system. As-deposited ITO thin film was 100 nm in thickness and a transmittance of ITO film on glass substrate was 79% at 550 nm. Conductive electrodes are then patterned on the ITO films using a high repetition rate fiber laser system followed by a wet chemical etching process. The electrical, optical and structural properties of the patterned samples are evaluated by means of a four-point probe technique, spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that the samples annealed with a pulse repetition rate of 150 kHz or 400 kHz have a low sheet resistivity of 21 Ω/□ and a high optical transmittance of 90%. In addition, it is shown that a higher pulse repetition rate reduces both the residual stress and the surface roughness of the patterned specimens. Therefore, the present results suggest that a pulse repetition rate of 400 kHz represents the optimal processing condition for the patterning of crack-free ITO-coated glass substrates with good electrical and optical properties.

Electrode patterning of ITO thin films by high repetition rate fiber laser

Energy Technology Data Exchange (ETDEWEB)

Lin, H.K., E-mail: HKLin@mail.npust.edu.tw; Hsu, W.C.

2014-07-01

Indium tin oxide (ITO) thin films are deposited on glass substrates using a radio frequency magnetron sputtering system. As-deposited ITO thin film was 100 nm in thickness and a transmittance of ITO film on glass substrate was 79% at 550 nm. Conductive electrodes are then patterned on the ITO films using a high repetition rate fiber laser system followed by a wet chemical etching process. The electrical, optical and structural properties of the patterned samples are evaluated by means of a four-point probe technique, spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that the samples annealed with a pulse repetition rate of 150 kHz or 400 kHz have a low sheet resistivity of 21 Ω/□ and a high optical transmittance of 90%. In addition, it is shown that a higher pulse repetition rate reduces both the residual stress and the surface roughness of the patterned specimens. Therefore, the present results suggest that a pulse repetition rate of 400 kHz represents the optimal processing condition for the patterning of crack-free ITO-coated glass substrates with good electrical and optical properties.

Repetitive transcranial magnetic stimulation for hallucination in schizophrenia spectrum disorders A meta-analysis***

Institute of Scientific and Technical Information of China (English)

Yingli Zhang; Wei Liang; Shichang Yang; Ping Dai; Lijuan Shen; Changhong Wang

2013-01-01

OBJECTIVE: This study assessed the efficacy and tolerability of repetitive transcranial magnetic stimulation for treatment of auditory hal ucination of patients with schizophrenia spectrum disorders. DATA SOURCES: Online literature retrieval was conducted using PubMed, ISI Web of Science, EMBASE, Medline and Cochrane Central Register of Control ed Trials databases from January 1985 to May 2012. Key words were “transcranial magnetic stimulation”, “TMS”, “repetitive transcranial magnetic stimulation”, and “hal ucination”. STUDY SELECTION: Selected studies were randomized control ed trials assessing therapeutic ef-ficacy of repetitive transcranial magnetic stimulation for hal ucination in patients with schizophrenia spectrum disorders. Experimental intervention was low-frequency repetitive transcranial magnetic stimulation in left temporoparietal cortex for treatment of auditory hal ucination in schizophrenia spectrum disorders. Control groups received sham stimulation. MAIN OUTCOME MEASURES: The primary outcome was total scores of Auditory Hal ucinations Rating Scale, Auditory Hal ucination Subscale of Psychotic Symptom Rating Scale, Positive and Negative Symptom Scale-Auditory Hal ucination item, and Hal ucination Change Scale. Secondary outcomes included response rate, global mental state, adverse effects and cognitive function. RESULTS: Seventeen studies addressing repetitive transcranial magnetic stimulation for treatment of schizophrenia spectrum disorders were screened, with controls receiving sham stimulation. Al data were completely effective, involving 398 patients. Overal mean weighted effect size for repeti-tive transcranial magnetic stimulation versus sham stimulation was statistical y significant (MD =-0.42, 95%CI: -0.64 to -0.20, P = 0.000 2). Patients receiving repetitive transcranial magnetic stimulation responded more frequently than sham stimulation (OR = 2.94, 95%CI: 1.39 to 6.24, P =0.005). No significant differences were found

Transitions between corona, glow, and spark regimes of nanosecond repetitively pulsed discharges in air at atmospheric pressure

OpenAIRE

Pai , David ,; Lacoste , Deanna ,; Laux , C.

2010-01-01

International audience; In atmospheric pressure air preheated from 300 to 1000 K, the nanosecond repetitively pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and interelectrode gap distance) of each discharge regime. In particular, the experimental conditions necessary for the glow regime of NRP discharges have been determine...

Feasibility of the Two-Point Method for Determining the One-Repetition Maximum in the Bench Press Exercise.

Science.gov (United States)

García-Ramos, Amador; Haff, Guy Gregory; Pestaña-Melero, Francisco Luis; Pérez-Castilla, Alejandro; Rojas, Francisco Javier; Balsalobre-Fernández, Carlos; Jaric, Slobodan

2017-09-05

This study compared the concurrent validity and reliability of previously proposed generalized group equations for estimating the bench press (BP) one-repetition maximum (1RM) with the individualized load-velocity relationship modelled with a two-point method. Thirty men (BP 1RM relative to body mass: 1.08 0.18 kg·kg -1 ) performed two incremental loading tests in the concentric-only BP exercise and another two in the eccentric-concentric BP exercise to assess their actual 1RM and load-velocity relationships. A high velocity (≈ 1 m·s -1 ) and a low velocity (≈ 0.5 m·s -1 ) was selected from their load-velocity relationships to estimate the 1RM from generalized group equations and through an individual linear model obtained from the two velocities. The directly measured 1RM was highly correlated with all predicted 1RMs (r range: 0.847-0.977). The generalized group equations systematically underestimated the actual 1RM when predicted from the concentric-only BP (P <0.001; effect size [ES] range: 0.15-0.94), but overestimated it when predicted from the eccentric-concentric BP (P <0.001; ES range: 0.36-0.98). Conversely, a low systematic bias (range: -2.3-0.5 kg) and random errors (range: 3.0-3.8 kg), no heteroscedasticity of errors (r 2 range: 0.053-0.082), and trivial ES (range: -0.17-0.04) were observed when the prediction was based on the two-point method. Although all examined methods reported the 1RM with high reliability (CV≤5.1%; ICC≥0.89), the direct method was the most reliable (CV<2.0%; ICC≥0.98). The quick, fatigue-free, and practical two-point method was able to predict the BP 1RM with high reliability and practically perfect validity, and therefore we recommend its use over generalized group equations.

FPGA implementation of high-frequency multiple PWM for variable voltage variable frequency controller

Energy Technology Data Exchange (ETDEWEB)

Boumaaraf, Abdelâali, E-mail: aboumaaraf@yahoo.fr [Université Abbès Laghrour, Laboratoire des capteurs, Instrumentations et procédés (LCIP), Khenchela (Algeria); University of Farhat Abbas Setif1, Sétif, 19000 (Algeria); Mohamadi, Tayeb [University of Farhat Abbas Setif1, Sétif, 19000 (Algeria); Gourmat, Laïd [Université Abbès Laghrour, Khenchela, 40000 (Algeria)

2016-07-25

In this paper, we present the FPGA implementation of the multiple pulse width modulation (MPWM) signal generation with repetition of data segments, applied to the variable frequency variable voltage systems and specially at to the photovoltaic water pumping system, in order to generate a signal command very easily between 10 Hz to 60 Hz with a small frequency and reduce the cost of the control system.

Effects of Repetitive Transcranial Magnetic Stimulation in Performing Eye-Hand Integration Tasks: Four Preliminary Studies with Children Showing Low-Functioning Autism

Science.gov (United States)

Panerai, Simonetta; Tasca, Domenica; Lanuzza, Bartolo; Trubia, Grazia; Ferri, Raffaele; Musso, Sabrina; Alagona, Giovanna; Di Guardo, Giuseppe; Barone, Concetta; Gaglione, Maria P.; Elia, Maurizio

2014-01-01

This report, based on four studies with children with low-functioning autism, aimed at evaluating the effects of repetitive transcranial magnetic stimulation delivered on the left and right premotor cortices on eye-hand integration tasks; defining the long-lasting effects of high-frequency repetitive transcranial magnetic stimulation; and…

Repetition blindness for natural images of objects with viewpoint changes

Directory of Open Access Journals (Sweden)

Stephane eBuffat

2013-01-01

Full Text Available When stimuli are repeated in a rapid serial visual presentation (RSVP, observers sometimes fail to report the second occurrence of a target. This phenomenon is referred to as repetition blindness (RB. We report an RSVP experiment with photographs in which we manipulated object viewpoints between the first and second occurrences of a target (0-, 45-, or 90-degree changes, and spatial frequency content. Natural images were spatially filtered to produce low, medium, or high spatial-frequency stimuli. RB was observed for all filtering conditions. Surprisingly, for full-spectrum images, RB increased significantly as the viewpoint reached 90 degrees. For filtered images, a similar pattern of results was found for all conditions except for medium spatial-frequency stimuli. These findings suggest that object recognition in RSVP are subtended by viewpoint-specific representations for all spatial frequencies except medium ones.

Mixed-frame and stationary-frame repetitive control schemes for compensating typical load and grid harmonics

DEFF Research Database (Denmark)

Loh, P.; Tang, Y.; Blaabjerg, Frede

2011-01-01

In this study, repetitive current controllers operating in either the mixed or stationary frame are proposed for high-precision reference tracking and disturbance rejection of power converters. Both controllers use a proportional-resonant regulator in the stationary frame for regulating...... the positive- and negative-sequence fundamental currents, which are known to directly influence the flow of active and reactive power in most energy conversion systems. Moreover, for the tracking or compensation of harmonics, the controllers include a repetitive control path in either the synchronous...... or stationary frame, whose inherent feedback and feedforward structure is proven to resemble a bank of resonant filters in either reference frames. Unlike other existing controllers, the proposed repetitive controllers function by introducing multiple resonant peaks at only those harmonic frequencies typically...

Repetition and lag effects in movement recognition.

Science.gov (United States)

Hall, C R; Buckolz, E

1982-03-01

Whether repetition and lag improve the recognition of movement patterns was investigated. Recognition memory was tested for one repetition, two-repetitions massed, and two-repetitions distributed with movement patterns at lags of 3, 5, 7, and 13. Recognition performance was examined both immediately afterwards and following a 48 hour delay. Both repetition and lag effects failed to be demonstrated, providing some support for the claim that memory is unaffected by repetition at a constant level of processing (Craik & Lockhart, 1972). There was, as expected, a significant decrease in recognition memory following the retention interval, but this appeared unrelated to repetition or lag.

New tool to assemble repetitive regions using next-generation sequencing data

Science.gov (United States)

Kuśmirek, Wiktor; Nowak, Robert M.; Neumann, Łukasz

2017-08-01

The next generation sequencing techniques produce a large amount of sequencing data. Some part of the genome are composed of repetitive DNA sequences, which are very problematic for the existing genome assemblers. We propose a modification of the algorithm for a DNA assembly, which uses the relative frequency of reads to properly reconstruct repetitive sequences. The new approach was implemented and tested, as a demonstration of the capability of our software we present some results for model organisms. The new implementation, using a three-layer software architecture was selected, where the presentation layer, data processing layer, and data storage layer were kept separate. Source code as well as demo application with web interface and the additional data are available at project web-page: http://dnaasm.sourceforge.net.

Muscle activation strategies during strength training with heavy loading versus repetitions to failure

DEFF Research Database (Denmark)

Sundstrup, Emil; Jakobsen, Markus D; Andersen, Christoffer H

2012-01-01

. Electromyographic (EMG) amplitude and median power frequency (MPF) of specific shoulder and neck muscles was analysed and the Borg CR10 scale was used to rate perceived loading immediately after each set of exercise. During the failure set normalized EMG was significantly lower during the first repetition...

The frequency attenuation effect in identity and associative priming.

Science.gov (United States)

Nievas, Francisco

2010-05-01

Three lexical decision experiments were carried out, where the masked priming paradigm is used to study the role of the frequency attenuation effect (more priming in low-frequency target words than in high-frequency target words) in repetition and associative priming, manipulating Prime Duration (PD) and Stimulus Onset Asynchrony (SOA). A new concept was introduced, Minimum Time Threshold (MTT), this is, the minimum time interval of exposure to the masked word in order to become aware of it. Results support the notion that MTT is a key to the appearance of the frequency attenuation effect when enough word processing time is allowed. Results do not support the unified explanation of masked priming and long-term priming as proposed by Bodner and Masson (2001). Moreover, information feedback from the semantic level was not the reason for the frequency attenuation effect in repetition priming.

If you negate, you may forget: negated repetitions impair memory compared with affirmative repetitions.

Science.gov (United States)

Mayo, Ruth; Schul, Yaacov; Rosenthal, Meytal

2014-08-01

One of the most robust laws of memory is that repeated activation improves memory. Our study shows that the nature of repetition matters. Specifically, although both negated repetition and affirmative repetition improve memory compared with no repetition, negated repetition hinders memory compared with affirmative repetition. After showing participants different entities, we asked them about features of these entities, leading to either "yes" or "no" responses. Our findings show that correctly negating an incorrect feature of an entity elicits an active forgetting effect compared with correctly affirming its true features. For example, after seeing someone drink a glass of white wine, answering "no" to "was it red wine?" may lead one to greater memory loss of the individual drinking wine at all compared with answering "yes" to "was it white wine?" We find this negation-induced forgetting effect in 4 experiments that differ in (a) the meaning given for the negation, (b) the type of stimuli (visual or verbal), and (c) the memory measure (recognition or free recall). We discuss possible underlying mechanisms and offer theoretical and applied implications of the negation-induced forgetting effect in relation to other known inhibition effects. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Factors Associated with Choking During Meals; a Risk Indicator for Repetitive Fevers in The Elderly Community

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Takeshi Nishiyama

2017-04-01

Full Text Available Background: Choking during meals is a common symptom in the elderly, however the factors associated with it have not been fully clarified. In this study, we examined the factors associated with choking during meals. Methods: The oral health status and practices that promote oral health conditions was surveyed in 1305 community dwelling elderly using a self-administered questionnaire. Eight items including satisfaction with their oral condition, denture fit, chewing ability, tooth brushing frequency, dental visits, exercises to train muscles for chewing and swallowing, choking during meals, and repetitive fever were selected for analysis. Results: 25.1% of the subjects experienced choking during meals, which was significantly associated with repetitive fever occurrence. Differences in satisfaction levels with their oral condition, denture fit, chewing ability, and tooth brushing frequency were observed between groups with and without choking. Age, satisfaction level, and chewing ability were significantly associated with choking during meals. Conclusions: This study demonstrated that choking during meals is a risk indicator for repetitive fever in the elderly living in community settings. Poor chewing ability and dissatisfaction with their oral condition were risk factors associated with choking. These results suggest that training the elderly to eat efficiently and safely and improving oral conditions is necessary for those who suffer from choking during meals to prevent repetitive fever.

Effects of Menstrual Phase-Dependent Resistance Training Frequency on Muscular Hypertrophy and Strength.

Science.gov (United States)

Sakamaki-Sunaga, Mikako; Min, Seokki; Kamemoto, Kayoko; Okamoto, Takanobu

2016-06-01

The present study investigated how different training frequencies during menstrual phases affect muscle hypertrophy and strength. Fourteen eumenorrheic women performed 3 sets of arm curls (8-15 repetitions) until failure for 12 weeks. Depending on the menstrual cycle phase, each subject trained each arm separately after either a 3- or a 1-d·wk training protocol during the follicular phase (FP-T) and a 3- or 1-d·wk training protocol during the luteal phase (LP-T). Cross-sectional area (CSA), 1 repetition maximum, and maximum voluntary contraction significantly increased 6.2 ± 4.4, 36.4 ± 11.9, and 16.7 ± 5.6%, respectively (p ≤ 0.05 vs. before training), in the FP-T group and 7.8 ± 4.2, 31.8 ± 14.1, and 14.9 ± 12.7%, respectively (p ≤ 0.05 vs. before training), in the LP-T group. Changes in CSA between the FP-T and the LP-T groups significantly and positively correlated (r = 0.54, p ≤ 0.05). There were no major differences among the different training protocols with regard to muscle hypertrophy and strength. Therefore, we suggest that variations in female hormones induced by the menstrual cycle phases do not significantly contribute to muscle hypertrophy and strength gains during 12 weeks of resistance training.

Repetitive Interrogation of 2-Level Quantum Systems

Science.gov (United States)

Prestage, John D.; Chung, Sang K.

2010-01-01

Trapped ion clocks derive information from a reference atomic transition by repetitive interrogations of the same quantum system, either a single ion or ionized gas of many millions of ions. Atomic beam frequency standards, by contrast, measure reference atomic transitions in a continuously replenished "flow through" configuration where initial ensemble atomic coherence is zero. We will describe some issues and problems that can arise when atomic state selection and preparation of the quantum atomic system is not completed, that is, optical pumping has not fully relaxed the coherence and also not fully transferred atoms to the initial state. We present a simple two-level density matrix analysis showing how frequency shifts during the state-selection process can cause frequency shifts of the measured clock transition. Such considerations are very important when a low intensity lamp light source is used for state selection, where there is relatively weak relaxation and re-pumping of ions to an initial state and much weaker 'environmental' relaxation of the atomic coherence set-up in the atomic sample.

Direct Frequency Comb Spectroscopy of Alkali Atoms

Science.gov (United States)

Pradhananga, Trinity; Palm, Christopher; Nguyen, Khoa; Guttikonda, Srikanth; Kimball, Derek Jackson

2011-11-01

We are using direct frequency comb spectroscopy to study transition frequencies and excited state hyperfine structure in potassium and rubidium using 2-photon transitions excited directly with the frequency-doubled output of a erbium fiber optical frequency comb. The frequency comb output is directed in two counterpropagating directions through a vapor cell containing the atomic vapor of interest. A pair of optical filters is used to select teeth of the comb in order to identify the transition wavelengths. A photomultiplier tube (PMT) measures fluorescence from a decay channel wavelength selected with another optical filter. Using different combinations of filters enables a wide range of transitions to be investigated. By scanning the repetition rate, a Doppler-free spectrum can be obtained enabling kHz-resolution spectral measurements. The thermal motion of the atoms in the vapor cell actually eliminates the need to fine-tune the offset frequency and repetition rate, alleviating a somewhat challenging requirement for spectroscopy of cold atoms. Our investigations are laying the groundwork for a long-term research program to use direct frequency comb spectroscopy to understand the complex spectra of rare-earth atoms.

The effects of combined elastic- and free-weight tension vs. free-weight tension on one-repetition maximum strength in the bench press.

Science.gov (United States)

Bellar, David M; Muller, Matthew D; Barkley, Jacob E; Kim, Chul-Ho; Ida, Keisuke; Ryan, Edward J; Bliss, Mathew V; Glickman, Ellen L

2011-02-01

The present study investigated the effects of training combining elastic tension, free weights, and the bench press. Eleven college-aged men (untrained) in the bench press participated in the 13-week study. The participants were first given instructions and then practiced the bench press, followed by a one-repetition maximum (1RM) test of baseline strength. Subjects were then trained in the bench press for 3 weeks to allow for the beginning of neural adaptation. After another 1RM test, participants were assigned to 1 of 2 conditions for the next 3 weeks of training: 85% Free-Weight Tension, 15% Elastic Tension (BAND), or 100% Free-Weight Tension (STAND). After 3 weeks of training and a third 1RM max test, participants switched treatments, under which they completed the final 3 weeks of training and the fourth 1RM test. Analysis via analysis of covariance revealed a significant (p ≤ 0.05) main effect for time and interaction effect for Treatment (BAND vs. STAND). Subsequent analysis via paired-samples t-test revealed the BAND condition was significantly better (p = 0.05) at producing raw gains in 1RM strength. (BAND 9.95 ± 3.7 kg vs. STAND 7.56 ± 2.8 kg). These results suggest that the addition of elastic tension to the bench press may be an effective method of increasing strength.

Gate-Recessed AlGaN/GaN MOSHEMTs with the Maximum Oscillation Frequency Exceeding 120 GHz on Sapphire Substrates

International Nuclear Information System (INIS)

Kong Xin; Wei Ke; Liu Guo-Guo; Liu Xin-Yu

2012-01-01

Gate-recessed AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors (MOSHEMTs) on sapphire substrates are fabricated. The devices with a gate length of 160 nm and a gate periphery of 2 × 75 μm exhibit two orders of magnitude reduction in gate leakage current and enhanced off-state breakdown characteristics, compared with conventional HEMTs. Furthermore, the extrinsic transconductance of an MOSHEMT is 237.2 mS/mm, only 7% lower than that of Schottky-gate HEMT. An extrinsic current gain cutoff frequency f T of 65 GHz and a maximum oscillation frequency f max of 123 GHz are deduced from rf small signal measurements. The high f max demonstrates that gate-recessed MOSHEMTs are of great potential in millimeter wave frequencies. (cross-disciplinary physics and related areas of science and technology)

Repetitive Transcranial Magnetic Stimulation in Patients with Hereditary Spastic Paraplegia

Directory of Open Access Journals (Sweden)

Mehmet Ağırman

2011-06-01

Full Text Available Hereditary spastic paraplegia (HSPP is a heterogeneous genetic disease characterized by progressive spasticity of lower extremities. Spasticity is a major cause of long-term disability in HSPP and significantly affects the functional life of patients. Repetitive transcranial magnetic stimulation (rTMS is widely used in diagnosis and treatment of many neurological and psychiatric diseases. Although the positive impacts of rTMS for spasticity have been reported, no study has been found on HSPP. We present two HSPP patients treated with low frequency rTMS (20 minutes at a frequency of 1 Hz (1200 pulses, for a period of 10 treatment sessions.

Repetitive Transcranial Magnetic Stimulation in Patients with Hereditary Spastic Paraplegia

Directory of Open Access Journals (Sweden)

Mehmet Ağırman

2011-06-01

Full Text Available Hereditary spastic paraplegia (HSPP is a heterogeneous genetic disease characterized by progressive spasticity of lower extremities. Spasticity is a major cause of long-term disability in HSPP and significantly affects the functional life of patients. Repetitive transcranial magnetic stimulation (rTMS is widely used in diagnosis and treatment of many neurological and psychiatric diseases. Although the positive impacts of rTMS for spasticity have been reported, no study has been found on HSPP. We present two HSPP patients treated with low frequency rTMS (20 minutes at a frequency of 1 Hz (1200 pulses, for a period of 10 treatment sessions

REPETITION AS A SPECIAL TYPE OF SYNTACTIC RELATIONS IN REPRESENTED SPEECH: BASED ON THE PROSE BY MARINA TSVETAEVA

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Olga Pavlovna Puchinina

2017-03-01

Full Text Available The author studies the peculiarities of repetition, being one of the ways to build syntactic relations in the represented speech structure, based on the prose by Marina Tsvetaeva. The article describes the different types of repetitions, their distinctive features and frequency of usage in the studied tests. The author describes different types of repetitions in the studied cases of represented speech from the point of view of their position. Repetition occurs at the beginning, end of sentences, beginning and end of a statement or paragraph, end of a statement and beginning of the next one; lexical items may be repeated in the middle of a statement. The morphology of repetitions, i.e., the way by what parts of speech the repeated words and structures are expressed, is of interest from the point of view of functional grammar. The author notes that Tsvetaeva repeats different parts of speech: conjunctions, prepositions, particles, nouns, pronouns, adverbs, numerals, verbs, modal words or a combination of two words. Moreover, due to her special intention, Tsvetaeva intensifies repetition through particular phonetic devices, such as alliteration, rhyme and rhythm, which make her prosaic works sound poetic. Purpose. The article is devoted to the topic of rendering another person’s speech, as it continues to be one of the most important issues of modern linguistics. The subject of analysis is repetition and its different types in the structure of represented speech on the material of prose texts by Marina Tsvetaeva. The author’s aims is to reveal the way these types of repetition (lexical, syntactic, semantic ones function in the structure of represented speech and what effect is achieved with their help. Methodology. The research has been conducted using the continuous sampling method and the quantitative estimation method, aimed to identify the frequency of using different types of repetition and repeated parts of speech and constructions in the

The effect of posture and repetition on urodynamic parameters: A prospective randomized study

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Ho Joon Jeon

2017-01-01

Full Text Available Purpose: To evaluate the effect of posture and repetition of filling cystometry on urodynamic parameters. Materials and Methods: Seventy-one men with benign prostatic hyperplasia participated in a urodynamic study between September 2015 and August 2016 and were randomly assigned to a supine to supine (group SS, n=16, erect to erect (group EE, n=16, supine to erect (group SE, n=19 or erect to supine (group ES, n=20 group. The patients underwent filling cystometry twice. We evaluated the effect of posture and the effect of repetition on filling cystometric parameters. We also evaluated the correlation between overactive bladder (OAB and detrusor overactivity (DO and between maximum voided volume (MVV and maximum cystometric capacity (MCC for each posture and filling cystometry time. Results: There was a decrease in bladder sensation and occurrence of DO, and an increase in bladder compliance and MCC in the supine posture group compared to that in the erect posture group. A more significant decrease in bladder sensation and occurrence of DO as well as an increase in MCC was seen during the second filling cystometry than the first one. The supine posture during first filling cystometry showed a better correlation between OAB and DO and between MVV and MCC than erect posture. Conclusions: There were clear effects of posture and filling cystometry repetition on urodynamic parameters. The supine posture and repeated filling cystometry caused the bladder to be less sensitive and less overactive. The supine posture showed a better correlation to OAB symptoms than erect posture during first filling cystometry.

Sands subjected to repetitive vertical loading under zero lateral strain: accumulation models, terminal densities, and settlement

KAUST Repository

Chong, Song Hun

2016-08-09

Geosystems often experience numerous loading cycles. Plastic strain accumulation during repetitive mechanical loads can lead to shear shakedown or continued shear ratcheting; in all cases, volumetric strains diminish as the specimen evolves towards terminal density. Previously suggested models and new functions are identified to fit plastic strain accumulation data. All accumulation models are formulated to capture terminal density (volumetric strain) and either shakedown or ratcheting (shear strain). Repetitive vertical loading tests under zero lateral strain conditions are conducted using three different sands packed at initially low and high densities. Test results show that plastic strain accumulation for all sands and density conditions can be captured in the same dimensionless plot defined in terms of the initial relative density, terminal density, and ratio between the amplitude of the repetitive load and the initial static load. This observation allows us to advance a simple but robust procedure to estimate the maximum one-dimensional settlement that a foundation could experience if subjected to repetitive loads. © 2016, Canadian Science Publishing. All rights reserved.

Effect of Bench Press Load Knowledge on Repetitions, Rating of Perceived Exertion, and Attentional Focus.

Science.gov (United States)

Beaudoin, Christina M; Cox, Zachary; Dundore, Tyler; Thomas, Tayler; Kim, Johnathon; Pillivant, Daniel

2018-02-01

Beaudoin, CM, Cox, Z, Dundore, T, Thomas, T, Kim, J, and Pillivant, D. Effect of bench press load knowledge on repetitions, rating of perceived exertion, and attentional focus. J Strength Cond Res 32(2): 514-519, 2018-Few studies have examined the role of the teleoanticipation during resistance training. The purpose of this study was to examine the effect of bench press (BP) load knowledge on repetitions completed, ratings of perceived exertion (RPEs), and attentional focus (% associative). Thirty-six recreationally active resistance-trained men (n = 25) and women (n = 11) participated in this study (age = 20.97 ± 1.87 years; ht = 174.12 ± 9.41 cm; and mass = 80.14 ± 14.03 kg). All subjects completed 3 testing sessions: (a) 1 repetition maximum (1RM) BP determination; (b) submaximal BP repetitions to fatigue known load (KL); and (c) submaximal BP repetitions to fatigue unknown load (UL). Known load and UL sessions were randomized and counterbalanced and both completed at 70% 1RM. An estimated weight ratio was computed using the subject's estimate of the UL weight relative to the KL weight. An independent samples t-test revealed no significant testing order difference for the estimated weight ratio. Two-way repeated-measures analysis of variances revealed no significant differences in the number of repetitions (p = 0.63), RPE (p = 0.18), or attentional focus (% associative) (p = 0.93) between the KL and UL conditions. Pearson correlations found a moderate positive association between KL repetitions completed and % associative focus when the UL was completed before the KL. Load knowledge did not influence the number of repetitions, RPE, or attentional focus while completing the BP. Further research examining the use of pacing strategies, RPE, and attentional focus during KL and UL conditions are warranted.

Repetitive Questioning Exasperates Caregivers

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R. C. Hamdy MD

2018-01-01

Full Text Available Repetitive questioning is due to an impaired episodic memory and is a frequent, often presenting, problem in patients with Alzheimer’s disease (amnestic type. It is due to the patients’ difficulties learning new information, retaining it, and recalling it, and is often aggravated by a poor attention span and easy distractibility. A number of factors may trigger and maintain repetitive questioning. Caregivers should try to identify and address these triggers. In the case discussion presented, it is due to the patient’s concerns about her and her family’s safety triggered by watching a particularly violent movie aired on TV. What went wrong in the patient/caregiver interaction and how it could have been avoided or averted are explored. Also reviewed are the impact of repetitive questioning, the challenges it raises for caregivers, and some effective intervention strategies that may be useful to diffuse the angst that caregivers experience with repetitive questioning.

Evolution of repetitive explosive instabilities in space and time

International Nuclear Information System (INIS)

Wilhelmsson, H.

1984-01-01

A nonlinear rate equation describing nonlinear, explosive type interaction of waves in plasmas is studied, assuming that amplitude saturation occurs due to nonlinear frequency shifts. Emphasis is put on the space dependence of the solution caused by the assumption of a given initial amplitude distribution in space. An analysis is given of the problem of repetitive peaks governed by the nonlinear rate equation for the time development of the amplitudes of plasma waves and by a Lorentzian shape distribution of the initial amplitudes. For the one-dimensional case, the peaks developed by explosive instability move in the direction of lower initial amplitude values, and the speed and the repetition rate of the peaks are determined. The possible forms of equilibria for the nonlinear rate equation in the explosive case are also studied, including, in addition to the quadratic nonlinearity, diffusion and linear damping effects. A solution to the nonlinear rate equation including diffusion is also given for the case where the quadratic nonlinearity represents recombination. (Auth.)

Computer-Related Repetitive Stress Injuries

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Computer-Related Repetitive Stress Injuries KidsHealth / For Parents / Computer-Related Repetitive Stress Injuries What's in this article? ...

The role of short-term memory impairment in nonword repetition, real word repetition, and nonword decoding: A case study.

Science.gov (United States)

Peter, Beate

2018-01-01

In a companion study, adults with dyslexia and adults with a probable history of childhood apraxia of speech showed evidence of difficulty with processing sequential information during nonword repetition, multisyllabic real word repetition and nonword decoding. Results suggested that some errors arose in visual encoding during nonword reading, all levels of processing but especially short-term memory storage/retrieval during nonword repetition, and motor planning and programming during complex real word repetition. To further investigate the role of short-term memory, a participant with short-term memory impairment (MI) was recruited. MI was confirmed with poor performance during a sentence repetition and three nonword repetition tasks, all of which have a high short-term memory load, whereas typical performance was observed during tests of reading, spelling, and static verbal knowledge, all with low short-term memory loads. Experimental results show error-free performance during multisyllabic real word repetition but high counts of sequence errors, especially migrations and assimilations, during nonword repetition, supporting short-term memory as a locus of sequential processing deficit during nonword repetition. Results are also consistent with the hypothesis that during complex real word repetition, short-term memory is bypassed as the word is recognized and retrieved from long-term memory prior to producing the word.

Estimations of One Repetition Maximum and Isometric Peak Torque in Knee Extension Based on the Relationship Between Force and Velocity.

Science.gov (United States)

Sugiura, Yoshito; Hatanaka, Yasuhiko; Arai, Tomoaki; Sakurai, Hiroaki; Kanada, Yoshikiyo

2016-04-01

We aimed to investigate whether a linear regression formula based on the relationship between joint torque and angular velocity measured using a high-speed video camera and image measurement software is effective for estimating 1 repetition maximum (1RM) and isometric peak torque in knee extension. Subjects comprised 20 healthy men (mean ± SD; age, 27.4 ± 4.9 years; height, 170.3 ± 4.4 cm; and body weight, 66.1 ± 10.9 kg). The exercise load ranged from 40% to 150% 1RM. Peak angular velocity (PAV) and peak torque were used to estimate 1RM and isometric peak torque. To elucidate the relationship between force and velocity in knee extension, the relationship between the relative proportion of 1RM (% 1RM) and PAV was examined using simple regression analysis. The concordance rate between the estimated value and actual measurement of 1RM and isometric peak torque was examined using intraclass correlation coefficients (ICCs). Reliability of the regression line of PAV and % 1RM was 0.95. The concordance rate between the actual measurement and estimated value of 1RM resulted in an ICC(2,1) of 0.93 and that of isometric peak torque had an ICC(2,1) of 0.87 and 0.86 for 6 and 3 levels of load, respectively. Our method for estimating 1RM was effective for decreasing the measurement time and reducing patients' burden. Additionally, isometric peak torque can be estimated using 3 levels of load, as we obtained the same results as those reported previously. We plan to expand the range of subjects and examine the generalizability of our results.

A simple sub-nanosecond ultraviolet light pulse generator with high repetition rate and peak power.

Science.gov (United States)

Binh, P H; Trong, V D; Renucci, P; Marie, X

2013-08-01

We present a simple ultraviolet sub-nanosecond pulse generator using commercial ultraviolet light-emitting diodes with peak emission wavelengths of 290 nm, 318 nm, 338 nm, and 405 nm. The generator is based on step recovery diode, short-circuited transmission line, and current-shaping circuit. The narrowest pulses achieved have 630 ps full width at half maximum at repetition rate of 80 MHz. Optical pulse power in the range of several hundreds of microwatts depends on the applied bias voltage. The bias voltage dependences of the output optical pulse width and peak power are analysed and discussed. Compared to commercial UV sub-nanosecond generators, the proposed generator can produce much higher pulse repetition rate and peak power.

Synergy Repetition Training versus Task Repetition Training in Acquiring New Skill.

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Patel, Vrajeshri; Craig, Jamie; Schumacher, Michelle; Burns, Martin K; Florescu, Ionut; Vinjamuri, Ramana

2017-01-01

Traditionally, repetitive practice of a task is used to learn a new skill, exhibiting as immediately improved performance. Research suggests, however, that a more experience-based rather than exposure-based training protocol may allow for better transference of the skill to related tasks. In synergy-based motor control theory, fundamental motor skills, such as hand grasping, are represented with a synergy subspace that captures essential motor patterns. In this study, we propose that motor-skill learning through synergy-based mechanisms may provide advantages over traditional task repetition learning. A new task was designed to highlight the range of motion and dexterity of the human hand. Two separate training strategies were tested in healthy subjects: task repetition training and synergy training versus a control. All three groups showed improvements when retested on the same task. When tested on a similar, but different set of tasks, only the synergy group showed improvements in accuracy (9.27% increase) compared to the repetition (3.24% decline) and control (3.22% decline) groups. A kinematic analysis revealed that although joint angular peak velocities decreased, timing benefits stemmed from the initial feed-forward portion of the task (reaction time). Accuracy improvements may have derived from general improved coordination among the four involved fingers. These preliminary results warrant further investigation of synergy-based motor training in healthy individuals, as well as in individuals undergoing hand-based rehabilitative therapy.

Repetition Performance And Blood Lactate Responses Adopting Different Recovery Periods Between Training Sessions In Trained Men.

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Miranda, Humberto; de Freitas Maia, Marianna; Paz, Gabriel Andrade; de Souza, João A A A; Simão, Roberto; de Araújo Farias, Déborah; Willardson, Jeffrey M

2017-02-08

The purpose of this study was to examine the effect of different recovery periods (24h, 48h, and 72h) between repeated resistance training (RT) sessions for the upper body muscles on repetition performance and blood lactate responses in trained men. Sixteen recreationally trained men (age: 26.1 ± 3.1 years; height: 179 ± 4.5 cm; body mass: 82.6 ± 4.0 kg, 4.5 ± 2.2 years of RT experience) participated in this study. Eight-repetition maximum (8-RM) loads were determined for the bench press (BP), 30° incline bench press (BP30), and 45° incline bench press (BP45) exercises. To assess the effects of different recovery periods between repeated training sessions, three protocols were performed in randomized order, including: 24 hours (P24); 48 hours (P48); and 72 hours (P72). Each RT session consisted of performing four repetition maximum sets of BP, BP30, and BP45 with 8-RM loads and 2-minute rest intervals between sets. Blood lactate levels were measured pre-session (PRE), immediately post-session (POST), 3 minutes post-session (P3), and 5 minutes post-session (P5). For the P24 protocol, significant decreases in repetition performance were found between sessions for the BP, BP30, and BP45 exercises, respectively. When considering session 2 only, the total work (repetition x sets) was significantly higher in P48 and P72 versus P24 for the BP30 and BP45 exercises. Blood lactate levels (i.e. POST, P3, and P5) significantly increased for session 2 under the P24 compared to the P48 and P72 protocols, respectively. Therefore, coaches and practitioners who need to accomplish a higher training volume for the upper body muscles should adopt recovery periods longer than 24 hours between sessions that train the same or similar muscle groups.

Preparation of hydrogenated amorphous carbon films using a microsecond-pulsed DC capacitive-coupled plasma chemical vapor deposition system operated at high frequency up to 400 kHz

Science.gov (United States)

Mamun, Md Abdullah Al; Furuta, Hiroshi; Hatta, Akimitsu

2018-06-01

Hydrogenated amorphous carbon (a-C:H) films are deposited on silicon (Si) substrates using a high-repetition microsecond-pulsed DC plasma chemical vapor deposition (CVD) system from acetylene (C2H2) at a gas pressure of 15 Pa inside a custom-made vacuum chamber. The plasma discharge characteristics, hydrocarbon species, and the microstructure of the resulting films are examined at various pulse repetition rates from 50 to 400 kHz and a fixed duty cycle of 50%. The optical emission spectra confirmed the increase in electron excitation energy from 1.09 to 1.82 eV and the decrease in the intensity ratio of CH/C2 from 1.04 to 0.75 with increasing pulse frequency, indicating the enhanced electron impact dissociation of C2H2 gas. With increasing pulse frequency, the deposition rate gradually increased, reaching a maximum rate of 60 nm/min at 200 kHz, after which a progressive decrease was noted, whereas the deposition area was almost uniform for all the prepared films. Clear trends of increasing sp3 content (amorphization) and decreasing hydrogen (H) content in the films were observed as the pulse repetition rate increased, while most of the hydrogen atoms bonded to carbon atoms by sp3 hybridization rather than by sp2 hybridization.

High-Frequency Repetitive Transcranial Magnetic Stimulation (rTMS Improves Functional Recovery by Enhancing Neurogenesis and Activating BDNF/TrkB Signaling in Ischemic Rats

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Jing Luo

2017-02-01

Full Text Available Repetitive transcranial magnetic stimulation (rTMS has rapidly become an attractive therapeutic approach for stroke. However, the mechanisms underlying this remain elusive. This study aimed to investigate whether high-frequency rTMS improves functional recovery mediated by enhanced neurogenesis and activation of brain-derived neurotrophic factor (BDNF/tropomyosin-related kinase B (TrkB pathway and to compare the effect of conventional 20 Hz rTMS and intermittent theta burst stimulation (iTBS on ischemic rats. Rats after rTMS were sacrificed seven and 14 days after middle cerebral artery occlusion (MCAO, following evaluation of neurological function. Neurogenesis was measured using specific markers: Ki67, Nestin, doublecortin (DCX, NeuN and glial fibrillary acidic protein (GFAP, and the expression levels of BDNF were visualized by Western blotting and RT-PCR analysis. Both high-frequency rTMS methods significantly improved neurological function and reduced infarct volume. Moreover, 20 Hz rTMS and iTBS significantly promoted neurogenesis, shown by an increase of Ki67/DCX, Ki67/Nestin, and Ki67/NeuN-positive cells in the peri-infarct striatum. These beneficial effects were accompanied by elevated protein levels of BDNF and phosphorylated-TrkB. In conclusion, high-frequency rTMS improves functional recovery possibly by enhancing neurogenesis and activating BDNF/TrkB signaling pathway and conventional 20 Hz rTMS is better than iTBS at enhancing neurogenesis in ischemic rats.

Study and realisation of a high frequency analyzer; Etude et realisation d'un analyseur de signaux a haute frequence

Energy Technology Data Exchange (ETDEWEB)

Bourbigot, J [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

1966-07-01

This device is designed for the amplitude and frequency analysis of electric or electromagnetic signals in the frequency range of 0 to 55 MHz. The frequency spectrum of a preset bandwidth is displayed on the screen of an oscilloscope. Conceived to analyse the electromagnetic oscillations that can be generated in a plasma, its main characteristics are the following: extended bandwidth of analysed frequencies, on both sides of the ion cyclotron frequency in a magnetic field up to 20 kGs; linear amplitude and frequency response; possibility of analysing a narrow band; high sensitivity; analysis repetition rate of 25 per second. The different parts of the analyzer are described after a discussion of the choice of the techniques used in their design. In addition to its present use, the device can be applied to perform all the functions of a commercial spectral analyzer. (author) [French] Cet appareil est destine a l'analyse en frequence et amplitude de signaux electriques ou electromagnetiques dans une gamme de frequences de 0 a 55 MHz. Couple a un oscillographe, il permet de faire apparaitre sur l'ecran, le spectre de frequences dans une gamme choisie. Etudie dans le but d'analyser les oscillations electromagnetiques pouvant apparaitre dans un plasma, ses principales caracteristiques sont les suivantes: une bande etendue de frequences analysees, de part et d'autre de la frequence cyclotronique des ions dans un champ magnetique pouvant atteindre 20 kGs (valeur maximum 55 MHz); une reponse lineaire en amplitude et en frequence; la possibilite d'analyser, une bande restreinte de frequences; une grande sensibilite La frequence d'analyse est de 25 periodes par seconde. Les diverses parties de l'analyseur sont decrites apres l'expose des motifs ayant guide le choix des solutions adoptees pour sa realisation. Les schemas electriques sont egalement presentes. En dehors du but precis qui a motive la realisation de cet appareil, son usage peut s'etendre a toutes les applications

Pulse repetition frequency effects in a high average power x-ray preionized excimer laser

International Nuclear Information System (INIS)

Fontaine, B.; Forestier, B.; Delaporte, P.; Canarelli, P.

1989-01-01

Experimental study of waves damping in a high repetition rate excimer laser is undertaken. Excitation of laser active medium in a subsonic loop is achieved by means of a classical discharge, through transfer capacitors. The discharge stability is controlled by a wire ion plasma (w.i.p.) X-rays gun. The strong acoustic waves induced by the active medium excitation may lead to a decrease, at high PRF, of the energy per pulse. First results of the influence of a damping of induced density perturbations between two successive pulses are presented

Tunable, high-repetition-rate, dual-signal-wavelength femtosecond optical parametric oscillator based on BiB3O6

Science.gov (United States)

Meng, Xianghao; Wang, Zhaohua; Tian, Wenlong; Fang, Shaobo; Wei, Zhiyi

2018-01-01

We have demonstrated a high-repetition-rate tunable femtosecond dual-signal-wavelength optical parametric oscillator (OPO) based on BiB3O6 (BiBO) crystal, synchronously pumped by a frequency-doubled mode-locked Yb:KGW laser. The cavity is simple since no dispersion compensators are used in the cavity. The wavelength range of dual-signal is widely tunable from 710 to 1000 nm. Tuning is accomplished by rotating phase-matching angle of BiBO, and optimizing cavity length and output coupler. Using a 3.75 W pump laser, the maximum average dual-signal output power is 760 mW at 707 and 750 nm, leading to a conversion efficiency of 20.3% not taking into account the idler power. Our experimental results show a non-critical phase-matching configuration pumped by a high peak power laser source. The operation of the dual-signal benefits from the balance of phase matching and group velocity mismatching between the two signals.

Rotated balance in humans due to repetitive rotational movement

Science.gov (United States)

Zakynthinaki, M. S.; Madera Milla, J.; López Diaz De Durana, A.; Cordente Martínez, C. A.; Rodríguez Romo, G.; Sillero Quintana, M.; Sampedro Molinuevo, J.

2010-03-01

We show how asymmetries in the movement patterns during the process of regaining balance after perturbation from quiet stance can be modeled by a set of coupled vector fields for the derivative with respect to time of the angles between the resultant ground reaction forces and the vertical in the anteroposterior and mediolateral directions. In our model, which is an adaption of the model of Stirling and Zakynthinaki (2004), the critical curve, defining the set of maximum angles one can lean to and still correct to regain balance, can be rotated and skewed so as to model the effects of a repetitive training of a rotational movement pattern. For the purposes of our study a rotation and a skew matrix is applied to the critical curve of the model. We present here a linear stability analysis of the modified model, as well as a fit of the model to experimental data of two characteristic "asymmetric" elite athletes and to a "symmetric" elite athlete for comparison. The new adapted model has many uses not just in sport but also in rehabilitation, as many work place injuries are caused by excessive repetition of unaligned and rotational movement patterns.

Acute Alcohol Effects on Repetition Priming and Word Recognition Memory with Equivalent Memory Cues

Science.gov (United States)

Ray, Suchismita; Bates, Marsha E.

2006-01-01

Acute alcohol intoxication effects on memory were examined using a recollection-based word recognition memory task and a repetition priming task of memory for the same information without explicit reference to the study context. Memory cues were equivalent across tasks; encoding was manipulated by varying the frequency of occurrence (FOC) of words…

Effect of high-frequency repetitive transcranial magnetic stimulation on motor cortical excitability and sensory nerve conduction velocity in subacute-stage incomplete spinal cord injury patients.

Science.gov (United States)

Cha, Hyun Gyu; Ji, Sang-Goo; Kim, Myoung-Kwon

2016-07-01

[Purpose] The aim of the present study was to determine whether repetitive transcranial magnetic stimulation can improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients. [Subjects and Methods] This study was conducted on 20 subjects with diagnosed paraplegia due to spinal cord injury. These 20 subjects were allocated to an experimental group of 10 subjects that underwent active repetitive transcranial magnetic stimulation or to a control group of 10 subjects that underwent sham repetitive transcranial magnetic stimulation. The SCI patients in the experimental group underwent active repetitive transcranial magnetic stimulation and conventional rehabilitation therapy, whereas the spinal cord injury patients in the control group underwent sham repetitive transcranial magnetic stimulation and conventional rehabilitation therapy. Participants in both groups received therapy five days per week for six-weeks. Latency, amplitude, and sensory nerve conduction velocity were assessed before and after the six week therapy period. [Results] A significant intergroup difference was observed for posttreatment velocity gains, but no significant intergroup difference was observed for amplitude or latency. [Conclusion] repetitive transcranial magnetic stimulation may be improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients.

Optimizing strategy software for repetitive construction projects within multi-mode resources

Directory of Open Access Journals (Sweden)

Remon Fayek Aziz

2013-09-01

Full Text Available Estimating tender data for specific project is the most essential part in construction areas as of contractor’s view such as: proposed project duration with corresponding gross value and cash flows. This paper focuses on how to calculate tender data using Optimizing Strategy Software (OSS for repetitive construction projects with identical activity’s duration in case of single number of crew such as: project duration, project/bid price, project maximum working capital, and project net present value of the studied project. A simplified multi-objective optimization software (OSS will be presented that creates best tender data to contractor compared with more feasible options generated from multi-mode resources in a given project. OSS is intended to give more scenarios which provide practical support for typical construction contractors who need to optimize resource utilization in order to minimize project duration, project/bid price, and project maximum working capital while maximizing its net present value simultaneously. OSS is designed by java programing code system to provide a number of new and unique capabilities, including: (1 Ranking the obtained optimal plans according to a set of planner specified weights representing the relative importance of duration, price, maximum working capital and net present value in the analyzed project; (2 Visualizing and viewing the generated optimal trade-off; and (3 Providing seamless integration with available project management calculations. In order to provide the aforementioned capabilities of OSS, the system is implemented and developed in four main modules: (1 A user interface module; (2 A database module; (3 A running module; (4 A connecting module. At the end of the paper, an illustrative example will be presented to demonstrate and verify the applications of the proposed software (OSS to an optimization expressway of repetitive construction project.

Study on the mode-transition of nanosecond-pulsed dielectric barrier discharge between uniform and filamentary by controlling pressures and pulse repetition frequencies

Science.gov (United States)

Yu, Sizhe; Lu, Xinpei

2016-09-01

We investigate the temporally resolved evolution of the nanosecond pulsed dielectric barrier discharge (DBD) in a moderate 6mm gap under various pressures and pulse repetition frequencies (PRFs) by intensified charge-coupled device (ICCD) images, using synthetic air and its components oxygen and nitrogen. It is found that the pressures are very different when the DBD mode transits between uniform and filamentary in air, oxygen, and nitrogen. The PRFs can also obviously affect the mode-transition. The transition mechanism in the pulsed DBD is not Townsend-to-streamer, which is dominant in the traditional alternating-voltage DBDs. The pulsed DBD in a uniform mode develops in the form of plane ionization wave, due to overlap of primary avalanches, while the increase in pressure disturbs the overlap and DBD develops in streamer instead, corresponding to the filamentary mode. Increasing the initiatory electron density by pre-ionization methods may contribute to discharge uniformity at higher pressures. We also find that the dependence of uniformity upon PRF is non-monotonic.

Repetitive Questioning II

Directory of Open Access Journals (Sweden)

R. C. Hamdy MD

2018-02-01

Full Text Available Repetitive questioning is a major problem for caregivers, particularly taxing if they are unable to recognize and understand the reasons why their loved one keeps asking the same question over and over again. Caregivers may be tempted to believe that the patient does not even try to remember the answer given or is just getting obnoxious. This is incorrect. Repetitive questioning is due to the underlying disease: The patient’s short term memory is impaired and he is unable to register, encode, retain and retrieve the answer. If he is concerned about a particular topic, he will keep asking the same question over and over again. To the patient each time she asks the question, it is as if she asked it for the first time. Just answering repetitive questioning by providing repeatedly the same answer is not sufficient. Caregivers should try to identify the underlying cause for this repetitive questioning. In an earlier case study, the patient was concerned about her and her family’s safety and kept asking whether the doors are locked. In this present case study, the patient does not know how to handle the awkward situation he finds himself in. He just does not know what to do. He is not able to adjust to the new unexpected situation. So he repeatedly wants to reassure himself that he is not intruding by asking the same question over and over again. We discuss how the patient’s son-in-law could have avoided this situation and averted the catastrophic ending.

High-energy, high-repetition-rate picosecond pulses from a quasi-CW diode-pumped Nd:YAG system.

Science.gov (United States)

Noom, Daniel W E; Witte, Stefan; Morgenweg, Jonas; Altmann, Robert K; Eikema, Kjeld S E

2013-08-15

We report on a high-power quasi-CW pumped Nd:YAG laser system, producing 130 mJ, 64 ps pulses at 1064 nm wavelength with a repetition rate of 300 Hz. Pulses from a Nd:YVO(4) oscillator are first amplified by a regenerative amplifier to the millijoule level and then further amplified in quasi-CW diode-pumped Nd:YAG modules. Pulsed diode pumping enables a high gain at repetition rates of several hundred hertz, while keeping thermal effects manageable. Birefringence compensation and multiple thermal-lensing-compensated relay-imaging stages are used to maintain a top-hat beam profile. After frequency doubling, 75 mJ pulses are obtained at 532 nm. The intensity stability is better than 1.1%, which makes this laser an attractive pump source for a high-repetition-rate optical parametric amplification system.

Effect of current on the maximum possible reward.

Science.gov (United States)

Gallistel, C R; Leon, M; Waraczynski, M; Hanau, M S

1991-12-01

Using a 2-lever choice paradigm with concurrent variable interval schedules of reward, it was found that when pulse frequency is increased, the preference-determining rewarding effect of 0.5-s trains of brief cathodal pulses delivered to the medial forebrain bundle of the rat saturates (stops increasing) at values ranging from 200 to 631 pulses/s (pps). Raising the current lowered the saturation frequency, which confirms earlier, more extensive findings showing that the rewarding effect of short trains saturates at pulse frequencies that vary from less than 100 pps to more than 800 pps, depending on the current. It was also found that the maximum possible reward--the magnitude of the reward at or beyond the saturation pulse frequency--increases with increasing current. Thus, increasing the current reduces the saturation frequency but increases the subjective magnitude of the maximum possible reward.

Emotional response to musical repetition.

Science.gov (United States)

Livingstone, Steven R; Palmer, Caroline; Schubert, Emery

2012-06-01

Two experiments examined the effects of repetition on listeners' emotional response to music. Listeners heard recordings of orchestral music that contained a large section repeated twice. The music had a symmetric phrase structure (same-length phrases) in Experiment 1 and an asymmetric phrase structure (different-length phrases) in Experiment 2, hypothesized to alter the predictability of sensitivity to musical repetition. Continuous measures of arousal and valence were compared across music that contained identical repetition, variation (related), or contrasting (unrelated) structure. Listeners' emotional arousal ratings differed most for contrasting music, moderately for variations, and least for repeating musical segments. A computational model for the detection of repeated musical segments was applied to the listeners' emotional responses. The model detected the locations of phrase boundaries from the emotional responses better than from performed tempo or physical intensity in both experiments. These findings indicate the importance of repetition in listeners' emotional response to music and in the perceptual segmentation of musical structure.

Challenges in comparing the acute cognitive outcomes of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) vs. electroconvulsive therapy (ECT) in major depression: A systematic review.

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Kedzior, Karina Karolina; Schuchinsky, Maria; Gerkensmeier, Imke; Loo, Colleen

2017-08-01

The present study aimed to systematically compare the cognitive outcomes of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) and electroconvulsive therapy (ECT) in head-to-head studies with major depression (MDD) patients. A systematic literature search identified six studies with 219 MDD patients that were too heterogeneous to reliably detect meaningful differences in acute cognitive outcomes after ECT vs. HF-rTMS. Cognitive effects of brain stimulation vary depending on the timeframe and methods of assessment, stimulation parameters, and maintenance treatment. Thus, acute and longer-term differences in cognitive outcomes both need to be investigated at precisely defined timeframes and with similar instruments assessing comparable functions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of movement velocity on the relationship between training load and the number of repetitions of bench press.

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Sakamoto, Akihiro; Sinclair, Peter J

2006-08-01

This study investigated the effect of movement velocity on the relationship between loading intensity and the number of repetitions of bench press. Thirteen healthy men (age = 21.7 +/- 1.0 years; weight = 76.8 +/- 2.5 kg; 1 repetition maximum [1RM] = 99.5 +/- 6.0 kg), who were involved in regular weight training, voluntarily participated in the experiment. Subjects performed bench presses on a Smith machine at 5 different intensities (40-80% 1RM), repeated for 4 velocity conditions (slow: 0.15 +/- 0.03 m.s(-1); medium: 0.32 +/- 0.07 m.s(-1); fast: 0.52 +/- 0.12 m.s(-1); ballistic: maximum velocity), which were randomly assigned over 5 experimental sessions after a 1RM test. Velocity significantly changed the relationship between intensity (%1RM) and the number of reps performed (p velocities producing a higher number of reps. A significant interaction between intensity and velocity meant that velocity had a much greater effect on repetitions at lower intensities. These results suggest that the benefits of using a stretch-shortening cycle during faster movements outweigh the associated disadvantages from the force-velocity relationship. The practical applications of this study are that, when trainees are assigned a resistance training with specific RM values, the lifted intensity (%1RM) or weights will not be consistent unless velocity is controlled during training.

Ultrafast, high repetition rate, ultraviolet, fiber-laser-based source: application towards Yb+ fast quantum-logic.

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Hussain, Mahmood Irtiza; Petrasiunas, Matthew Joseph; Bentley, Christopher D B; Taylor, Richard L; Carvalho, André R R; Hope, Joseph J; Streed, Erik W; Lobino, Mirko; Kielpinski, David

2016-07-25

Trapped ions are one of the most promising approaches for the realization of a universal quantum computer. Faster quantum logic gates could dramatically improve the performance of trapped-ion quantum computers, and require the development of suitable high repetition rate pulsed lasers. Here we report on a robust frequency upconverted fiber laser based source, able to deliver 2.5 ps ultraviolet (UV) pulses at a stabilized repetition rate of 300.00000 MHz with an average power of 190 mW. The laser wavelength is resonant with the strong transition in Ytterbium (Yb+) at 369.53 nm and its repetition rate can be scaled up using high harmonic mode locking. We show that our source can produce arbitrary pulse patterns using a programmable pulse pattern generator and fast modulating components. Finally, simulations demonstrate that our laser is capable of performing resonant, temperature-insensitive, two-qubit quantum logic gates on trapped Yb+ ions faster than the trap period and with fidelity above 99%.

Repetitive learning control of continuous chaotic systems

International Nuclear Information System (INIS)

Chen Maoyin; Shang Yun; Zhou Donghua

2004-01-01

Combining a shift method and the repetitive learning strategy, a repetitive learning controller is proposed to stabilize unstable periodic orbits (UPOs) within chaotic attractors in the sense of least mean square. If nonlinear parts in chaotic systems satisfy Lipschitz condition, the proposed controller can be simplified into a simple proportional repetitive learning controller

Novel porcine repetitive elements

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Nonneman Dan J

2006-12-01

Full Text Available Abstract Background Repetitive elements comprise ~45% of mammalian genomes and are increasingly known to impact genomic function by contributing to the genomic architecture, by direct regulation of gene expression and by affecting genomic size, diversity and evolution. The ubiquity and increasingly understood importance of repetitive elements contribute to the need to identify and annotate them. We set out to identify previously uncharacterized repetitive DNA in the porcine genome. Once found, we characterized the prevalence of these repeats in other mammals. Results We discovered 27 repetitive elements in 220 BACs covering 1% of the porcine genome (Comparative Vertebrate Sequencing Initiative; CVSI. These repeats varied in length from 55 to 1059 nucleotides. To estimate copy numbers, we went to an independent source of data, the BAC-end sequences (Wellcome Trust Sanger Institute, covering approximately 15% of the porcine genome. Copy numbers in BAC-ends were less than one hundred for 6 repeat elements, between 100 and 1000 for 16 and between 1,000 and 10,000 for 5. Several of the repeat elements were found in the bovine genome and we have identified two with orthologous sites, indicating that these elements were present in their common ancestor. None of the repeat elements were found in primate, rodent or dog genomes. We were unable to identify any of the replication machinery common to active transposable elements in these newly identified repeats. Conclusion The presence of both orthologous and non-orthologous sites indicates that some sites existed prior to speciation and some were generated later. The identification of low to moderate copy number repetitive DNA that is specific to artiodactyls will be critical in the assembly of livestock genomes and studies of comparative genomics.

Document retrieval on repetitive string collections.

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Gagie, Travis; Hartikainen, Aleksi; Karhu, Kalle; Kärkkäinen, Juha; Navarro, Gonzalo; Puglisi, Simon J; Sirén, Jouni

2017-01-01

Most of the fastest-growing string collections today are repetitive, that is, most of the constituent documents are similar to many others. As these collections keep growing, a key approach to handling them is to exploit their repetitiveness, which can reduce their space usage by orders of magnitude. We study the problem of indexing repetitive string collections in order to perform efficient document retrieval operations on them. Document retrieval problems are routinely solved by search engines on large natural language collections, but the techniques are less developed on generic string collections. The case of repetitive string collections is even less understood, and there are very few existing solutions. We develop two novel ideas, interleaved LCPs and precomputed document lists , that yield highly compressed indexes solving the problem of document listing (find all the documents where a string appears), top- k document retrieval (find the k documents where a string appears most often), and document counting (count the number of documents where a string appears). We also show that a classical data structure supporting the latter query becomes highly compressible on repetitive data. Finally, we show how the tools we developed can be combined to solve ranked conjunctive and disjunctive multi-term queries under the simple [Formula: see text] model of relevance. We thoroughly evaluate the resulting techniques in various real-life repetitiveness scenarios, and recommend the best choices for each case.

REPETITIVE STRENGTH AMONG STUDENTS OF AGE 14

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Besim Halilaj

2014-06-01

Full Text Available The study involved 82 male students of the primary school “Qamil Ilazi” in Kaçanik-Kosovo.Four movement tests, which test the repetitive strength, were conducted: 1. Pull-up, 2. Sit-Up, 3. Back extension, 4. Push-up.The main goal of this study was to verify the actual motor status, respectively the component of the repetitive strength among students of age 14 of masculine gender. In addition to verifying the actual motor status, another objective was to verify the relationship between the variables employed.Basic statistical parameters show a distribution which is not significantly different from the normal distribution, yielded highly correlative values among the repetitive strength tests. Space factorization resulted in extracting two latent squares defined as repetitive strength of arms factor, and repetitive strength of body factor.

Primed low-frequency repetitive transcranial magnetic stimulation and constraint-induced movement therapy in pediatric hemiparesis: a randomized controlled trial.

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Gillick, Bernadette T; Krach, Linda E; Feyma, Tim; Rich, Tonya L; Moberg, Kelli; Thomas, William; Cassidy, Jessica M; Menk, Jeremiah; Carey, James R

2014-01-01

The aim of this study was to determine the feasibility and efficacy of five treatments of 6 Hz primed, low-frequency, repetitive transcranial magnetic stimulation (rTMS) combined with constraint-induced movement therapy (CIMT) to promote recovery of the paretic hand in children with congenital hemiparesis. Nineteen children with congenital hemiparesis aged between 8 and 17 years (10 males, nine females; mean age 10 years 10 months, SD 2 years 10 months; Manual Ability Classification Scale levels I-III) underwent five sessions of either real rTMS (n=10) or sham rTMS (n=9) alternated daily with CIMT. CIMT consisted of 13 days of continuous long-arm casting with five skin-check sessions. Each child received a total of 10 hours of one-to-one therapy. The primary outcome measure was the Assisting Hand Assessment (AHA) and the secondary outcome variables were the Canadian Occupational Performance Measure (COPM) and stereognosis. A Wilcoxon signed-rank sum test was used to analyze differences between pre- and post-test scores within the groups. Analysis of covariance was used to compute mean differences between groups adjusting for baseline. Fisher's exact test was used to compare individual change in AHA raw scores with the smallest detectable difference (SDD) of 4 points. All participants receiving treatment finished the study. Improvement in AHA differed significantly between groups (p=0.007). No significant differences in the secondary outcome measures were found. Eight out of 10 participants in the rTMS/CIMT group showed improvement greater than the SDD, but only two out of nine in the sham rTMS/CIMT group showed such improvement (p=0.023). No serious adverse events occurred. Primed, low-frequency rTMS combined with CIMT appears to be safe, feasible, and efficacious in pediatric hemiparesis. Larger clinical trials are now indicated. © 2013 Mac Keith Press.

Efficacy Of The Repetitions In Reserve-Based Rating Of Perceived Exertion For The Bench Press In Experienced And Novice Benchers.

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Ormsbee, Michael J; Carzoli, Joseph P; Klemp, Alex; Allman, Brittany R; Zourdos, Michael C; Kim, Jeong-Su; Panton, Lynn B

2017-03-13

Autoregulation (AR) is the practice of adjusting training variables in response to athlete feedback. One component of AR postulated to enhance resistance training adaptations involves implementing a resistance training-specific rating of perceived exertion (RPE) scale measuring repetitions in reserve (RIR). The purpose of this study was to examine the efficacy of this method using the bench press exercise. Twenty-seven college-aged men were assigned to one of two groups based upon training age: experience benchers (EB) (n=14, training age: 4.7±2.0 yrs) and novice benchers (NB) (n=13, training age: 1.1±0.6 yrs). Subjects performed one-repetition maximum (1RM) followed by single-repetition sets with loads corresponding to 60, 75, and 90% of 1RM and an 8-repetition set at 70% 1RM. Subjects reported a corresponding RPE, based on RIR, for every set. Average velocity was recorded for each single-repetition set along with the first and last repetitions of the 8-repetition set at 70% 1RM. Average velocity at 100% of 1RM in EB was slower (0.14±0.04 m[BULLET OPERATOR]s) compared to NB (0.20±0.05 m[BULLET OPERATOR]s) (pvelocity or RPE at any other intensity. Both EB (r=0.85, pvelocity and RPE at all intensities. Our findings suggest that the RIR-based RPE scale may be an efficacious approach for AR of bench press training load and volume in college-aged men.

Repetitive Transcranial Magnetic Stimulation (rTMS) Treatment in Enduring Anorexia Nervosa: A Case Series.

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McClelland, Jessica; Kekic, Maria; Campbell, Iain C; Schmidt, Ulrike

2016-03-01

This case series examined the therapeutic potential of repetitive transcranial magnetic stimulation in five women with enduring anorexia nervosa. Participants received ~20 sessions of neuronavigated high-frequency repetitive transcranial magnetic stimulation to the left dorsolateral prefrontal cortex. Body mass index, eating disorder (ED) symptoms and mood were assessed pre-treatment and post-treatment, at 6-month and 12-month follow-up (FU). Qualitative feedback regarding the intervention was obtained from participants and carers. From pre-treatment to post-treatment, ED and affective symptoms improved significantly, and body mass index remained stable. Further improvements in ED symptoms/mood were seen at 6-month FU with 3/5 and 2/5 participants deemed 'recovered' on the Eating Disorders Examination Questionnaire and Depression, Anxiety and Stress Scale, respectively. However, most participants had lost some weight, and therapeutic effects on psychopathology had waned by 12-month FU. Qualitative feedback regarding the intervention was encouraging. Repetitive transcranial magnetic stimulation was well tolerated, and preliminary evidence is provided for its therapeutic potential in anorexia nervosa. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

Stereotyped high-frequency oscillations discriminate seizure onset zones and critical functional cortex in focal epilepsy.

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Liu, Su; Gurses, Candan; Sha, Zhiyi; Quach, Michael M; Sencer, Altay; Bebek, Nerses; Curry, Daniel J; Prabhu, Sujit; Tummala, Sudhakar; Henry, Thomas R; Ince, Nuri F

2018-01-30

High-frequency oscillations in local field potentials recorded with intracranial EEG are putative biomarkers of seizure onset zones in epileptic brain. However, localized 80-500 Hz oscillations can also be recorded from normal and non-epileptic cerebral structures. When defined only by rate or frequency, physiological high-frequency oscillations are indistinguishable from pathological ones, which limit their application in epilepsy presurgical planning. We hypothesized that pathological high-frequency oscillations occur in a repetitive fashion with a similar waveform morphology that specifically indicates seizure onset zones. We investigated the waveform patterns of automatically detected high-frequency oscillations in 13 epilepsy patients and five control subjects, with an average of 73 subdural and intracerebral electrodes recorded per patient. The repetitive oscillatory waveforms were identified by using a pipeline of unsupervised machine learning techniques and were then correlated with independently clinician-defined seizure onset zones. Consistently in all patients, the stereotypical high-frequency oscillations with the highest degree of waveform similarity were localized within the seizure onset zones only, whereas the channels generating high-frequency oscillations embedded in random waveforms were found in the functional regions independent from the epileptogenic locations. The repetitive waveform pattern was more evident in fast ripples compared to ripples, suggesting a potential association between waveform repetition and the underlying pathological network. Our findings provided a new tool for the interpretation of pathological high-frequency oscillations that can be efficiently applied to distinguish seizure onset zones from functionally important sites, which is a critical step towards the translation of these signature events into valid clinical biomarkers.awx374media15721572971001. © The Author(s) (2018). Published by Oxford University Press on

Improved Maximum Strength, Vertical Jump and Sprint Performance after 8 Weeks of Jump Squat Training with Individualized Loads

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Marián, Vanderka; Katarína, Longová; Dávid, Olasz; Matúš, Krčmár; Simon, Walker

2016-01-01

The purpose of the study was to determine the effects of 8 weeks of jump squat training on isometric half squat maximal force production (Fmax) and rate of force development over 100ms (RFD100), countermovement jump (CMJ) and squat jump (SJ) height, and 50 m sprint time in moderately trained men. Sixty eight subjects (~21 years, ~180 cm, ~75 kg) were divided into experimental (EXP; n = 36) and control (CON, n = 32) groups. Tests were completed pre-, mid- and post-training. EXP performed jump squat training 3 times per week using loads that allowed all repetitions to be performed with ≥90% of maximum average power output (13 sessions with 4 sets of 8 repetitions and 13 sessions with 8 sets of 4 repetitions). Subjects were given real-time feedback for every repetition during the training sessions. Significant improvements in Fmax from pre- to mid- (Δ ~14%, psquats with loads that allow repetitions to be performed ≥90% of maximum average power output can simultaneously improve several different athletic performance tasks in the short-term. Key points Jump squat exercise is one of many exercises to develop explosive strength that has been the focus of several researches, while the load used during the training seem to be an important factor that affects training outcomes. Experimental group improved performance in all assessed parameters, such as Fmax, RFD100, CMJ, SJ and 50 m sprint time. However, improvements in CMJ and SJ were recorded after the entire power training period and thereafter plateau occurred. The portable FitroDyne could serve as a valuable device to individualize the load that maximizes mean power output and visual feedback can be provided to athletes during the training. PMID:27803628

Effect of loading on unintentional lifting velocity declines during single sets of repetitions to failure during upper and lower extremity muscle actions.

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Izquierdo, M; González-Badillo, J J; Häkkinen, K; Ibáñez, J; Kraemer, W J; Altadill, A; Eslava, J; Gorostiaga, E M

2006-09-01

The purpose of this study was to examine the effect of different loads on repetition speed during single sets of repetitions to failure in bench press and parallel squat. Thirty-six physical active men performed 1-repetition maximum in a bench press (1 RM (BP)) and half squat position (1 RM (HS)), and performed maximal power-output continuous repetition sets randomly every 10 days until failure with a submaximal load (60 %, 65 %, 70 %, and 75 % of 1RM, respectively) during bench press and parallel squat. Average velocity of each repetition was recorded by linking a rotary encoder to the end part of the bar. The values of 1 RM (BP) and 1 RM (HS) were 91 +/- 17 and 200 +/- 20 kg, respectively. The number of repetitions performed for a given percentage of 1RM was significantly higher (p bench press performance. Average repetition velocity decreased at a greater rate in bench press than in parallel squat. The significant reductions observed in the average repetition velocity (expressed as a percentage of the average velocity achieved during the initial repetition) were observed at higher percentage of the total number of repetitions performed in parallel squat (48 - 69 %) than in bench press (34 - 40 %) actions. The major finding in this study was that, for a given muscle action (bench press or parallel squat), the pattern of reduction in the relative average velocity achieved during each repetition and the relative number of repetitions performed was the same for all percentages of 1RM tested. However, relative average velocity decreased at a greater rate in bench press than in parallel squat performance. This would indicate that in bench press the significant reductions observed in the average repetition velocity occurred when the number of repetitions was over one third (34 %) of the total number of repetitions performed, whereas in parallel squat it was nearly one half (48 %). Conceptually, this would indicate that for a given exercise (bench press or squat) and

Investigation of monolithic passively mode-locked quantum dot lasers with extremely low repetition frequency.

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Xu, Tianhong; Cao, Juncheng; Montrosset, Ivo

2015-01-01

The dynamical regimes and performance optimization of quantum dot monolithic passively mode-locked lasers with extremely low repetition rate are investigated using the numerical method. A modified multisection delayed differential equation model is proposed to accomplish simulations of both two-section and three-section passively mode-locked lasers with long cavity. According to the numerical simulations, it is shown that fundamental and harmonic mode-locking regimes can be multistable over a wide current range. These dynamic regimes are studied, and the reasons for their existence are explained. In addition, we demonstrate that fundamental pulses with higher peak power can be achieved when the laser is designed to work in a region with smaller differential gain.

Investigation of Fatigability during Repetitive Robot-Mediated Arm Training in People with Multiple Sclerosis.

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Deborah Severijns

Full Text Available People with multiple sclerosis (MS are encouraged to engage in exercise programs but an increased experience of fatigue may impede sustained participation in training sessions. A high number of movements is, however, needed for obtaining optimal improvements after rehabilitation.This cross-sectional study investigated whether people with MS show abnormal fatigability during a robot-mediated upper limb movement trial. Sixteen people with MS and sixteen healthy controls performed five times three minutes of repetitive shoulder anteflexion movements. Movement performance, maximal strength, subjective upper limb fatigue and surface electromyography (median frequency and root mean square of the amplitude of the electromyography (EMG signal of the anterior deltoid were recorded during or in-between these exercises. After fifteen minutes of rest, one extra movement bout was performed to investigate how rest influences performance.A fifteen minutes upper limb movement protocol increased the perceived upper limb fatigue and induced muscle fatigue, given a decline in maximal anteflexion strength and changes of both the amplitude and the median frequency of EMG the anterior deltoid. In contrast, performance during the 3 minutes of anteflexion movements did not decline. There was no relation between changes in subjective fatigue and the changes in the amplitude and the median frequency of the anterior deltoid muscle, however, there was a correlation between the changes in subjective fatigue and changes in strength in people with MS. People with MS with upper limb weakness report more fatigue due to the repetitive movements, than people with MS with normal upper limb strength, who are comparable to healthy controls. The weak group could, however, keep up performance during the 15 minutes of repetitive movements.Albeit a protocol of repetitive shoulder anteflexion movements did not elicit a performance decline, fatigue feelings clearly increased in both

Electrical and magnetic repetitive transcranial stimulation of the primary motor cortex in healthy subjects.

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Gilio, Francesca; Iacovelli, Elisa; Frasca, Vittorio; Gabriele, Maria; Giacomelli, Elena; De Lena, Carlo; Cipriani, Anna Maria; Inghilleri, Maurizio

2009-05-08

Repetitive transcranial magnetic stimulation (rTMS) delivered in short trains at 5Hz frequency and suprathreshold intensity over the primary motor cortex (M1) in healthy subjects facilitates the motor-evoked potential (MEP) amplitude by increasing cortical excitability through mechanisms resembling short-term synaptic plasticity. In this study, to investigate whether rTES acts through similar mechanisms we compared the effects of rTMS and repetitive transcranial electrical stimulation (rTES) (10 stimuli-trains, 5Hz frequency, suprathreshold intensity) delivered over the M1 on the MEP amplitude. Four healthy subjects were studied in two separate sessions in a relaxed condition. rTMS and anodal rTES were delivered in trains to the left M1 over the motor area for evoking a MEP in the right first dorsal interosseous muscle. Changes in MEP size and latency during the course of the rTMS and rTES trains were compared. The possible effects of muscle activation on MEP amplitude were evaluated, and the possible effects of cutaneous trigeminal fibre activation on corticospinal excitability were excluded in a control experiment testing the MEP amplitude before and after supraorbital nerve repetitive electrical stimulation. Repeated measures analysis of variance (ANOVA) showed that rTES and rTMS trains elicited similar amplitude first MEPs and a similar magnitude MEP amplitude facilitation during the trains. rTES elicited a first MEP with a shorter latency than rTMS, without significant changes during the course of the train of stimuli. The MEP elicited by single-pulse TES delivered during muscle contraction had a smaller amplitude than the last MEP in the rTES trains. Repetitive supraorbital nerve stimulation left the conditioned MEP unchanged. Our results suggest that 5 Hz-rTES delivered in short trains increases cortical excitability and does so by acting on the excitatory interneurones probably through mechanisms similar to those underlying the rTMS-induced MEP facilitation.

Gigahertz repetition rate, sub-femtosecond timing jitter optical pulse train directly generated from a mode-locked Yb:KYW laser.

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Yang, Heewon; Kim, Hyoji; Shin, Junho; Kim, Chur; Choi, Sun Young; Kim, Guang-Hoon; Rotermund, Fabian; Kim, Jungwon

2014-01-01

We show that a 1.13 GHz repetition rate optical pulse train with 0.70 fs high-frequency timing jitter (integration bandwidth of 17.5 kHz-10 MHz, where the measurement instrument-limited noise floor contributes 0.41 fs in 10 MHz bandwidth) can be directly generated from a free-running, single-mode diode-pumped Yb:KYW laser mode-locked by single-wall carbon nanotube-coated mirrors. To our knowledge, this is the lowest-timing-jitter optical pulse train with gigahertz repetition rate ever measured. If this pulse train is used for direct sampling of 565 MHz signals (Nyquist frequency of the pulse train), the jitter level demonstrated would correspond to the projected effective-number-of-bit of 17.8, which is much higher than the thermal noise limit of 50 Ω load resistance (~14 bits).

Repetition and Emotive Communication in Music Versus Speech

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Elizabeth Hellmuth eMargulis

2013-04-01

Full Text Available Music and speech are often placed alongside one another as comparative cases. Their relative overlaps and disassociations have been well explored (e.g. Patel, 2010. But one key attribute distinguishing these two domains has often been overlooked: the greater preponderance of repetition in music in comparison to speech. Recent fMRI studies have shown that familiarity – achieved through repetition – is a critical component of emotional engagement with music (Pereira et al., 2011. If repetition is fundamental to emotional responses to music, and repetition is a key distinguisher between the domains of music and speech, then close examination of the phenomenon of repetition might help clarify the ways that music elicits emotion differently than speech.

Feature-based motion control for near-repetitive structures

NARCIS (Netherlands)

Best, de J.J.T.H.

2011-01-01

In many manufacturing processes, production steps are carried out on repetitive structures which consist of identical features placed in a repetitive pattern. In the production of these repetitive structures one or more consecutive steps are carried out on the features to create the final product.

Cathode follower RF system with frequency modulation

International Nuclear Information System (INIS)

Irie, Y.; Yano, Y.; Kaneko, N.; Kobayashi, Y.

1994-01-01

A model RF system with a cathode follower was tested under frequency modulation in the 1-3.5 MHz range. The repetition rate was 40 Hz. The oscillation was stable, and the output impedance was measured to be around 20 ohm. (author)

The Effects of Gender and Age on Repetitive and/or Restricted Behaviors and Interests in Adults with Autism Spectrum Disorders and Intellectual Disability

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Hattier, Megan A.; Matson, Johnny L.; Tureck, Kimberly; Horovitz, Max

2011-01-01

Frequency of repetitive and/or restricted behaviors and interests (RRBIs) was assessed in 140 adults with autism spectrum disorders (ASDs) and severe or profound intellectual disability (ID). The associations of gender and age range were analyzed with RRBI frequency which was obtained using the Stereotypies subscale of the "Diagnostic…

Grade Repetition and Primary School Dropout in Uganda

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Kabay, Sarah

2016-01-01

Research on education in low-income countries rarely focuses on grade repetition. When addressed, repetition is typically presented along with early school dropout as the "wasting" of educational resources. Simplifying grade repetition in this way often fails to recognize significant methodological concerns and also overlooks the unique…

Influence of air flow parameters on nanosecond repetitively pulsed discharges in a pin-annular electrode configuration

KAUST Repository

Heitz, Sylvain A

2016-03-16

The effect of various air flow parameters on the plasma regimes of nanosecond repetitively pulsed (NRP) discharges is investigated at atmospheric pressure. The two electrodes are in a pin-annular configuration, transverse to the mean flow. The voltage pulses have amplitudes up to 15 kV, a duration of 10 ns and a repetition frequency ranging from 15 to 30 kHz. The NRP corona to NRP spark (C-S) regime transition and the NRP spark to NRP corona (S-C) regime transition are investigated for different steady and harmonically oscillating flows. First, the strong effect of a transverse flow on the C-S and S-C transitions, as reported in previous studies, is verified. Second, it is shown that the azimuthal flow imparted by a swirler does not affect the regime transition voltages. Finally, the influence of low frequency harmonic oscillations of the air flow, generated by a loudspeaker, is studied. A strong effect of frequency and amplitude of the incoming flow modulation on the NRP plasma regime is observed. Results are interpreted based on the cumulative effect of the NRP discharges and an analysis of the residence times of fluid particles in the inter-electrode region. © 2016 IOP Publishing Ltd.

Influence of air flow parameters on nanosecond repetitively pulsed discharges in a pin-annular electrode configuration

KAUST Repository

Heitz, Sylvain A; Moeck, Jonas P; Schuller, Thierry; Veynante, Denis; Lacoste, Deanna

2016-01-01

The effect of various air flow parameters on the plasma regimes of nanosecond repetitively pulsed (NRP) discharges is investigated at atmospheric pressure. The two electrodes are in a pin-annular configuration, transverse to the mean flow. The voltage pulses have amplitudes up to 15 kV, a duration of 10 ns and a repetition frequency ranging from 15 to 30 kHz. The NRP corona to NRP spark (C-S) regime transition and the NRP spark to NRP corona (S-C) regime transition are investigated for different steady and harmonically oscillating flows. First, the strong effect of a transverse flow on the C-S and S-C transitions, as reported in previous studies, is verified. Second, it is shown that the azimuthal flow imparted by a swirler does not affect the regime transition voltages. Finally, the influence of low frequency harmonic oscillations of the air flow, generated by a loudspeaker, is studied. A strong effect of frequency and amplitude of the incoming flow modulation on the NRP plasma regime is observed. Results are interpreted based on the cumulative effect of the NRP discharges and an analysis of the residence times of fluid particles in the inter-electrode region. © 2016 IOP Publishing Ltd.

Analogous selection processes in declarative and procedural working memory: N-2 list-repetition and task-repetition costs.

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Gade, Miriam; Souza, Alessandra S; Druey, Michel D; Oberauer, Klaus

2017-01-01

Working memory (WM) holds and manipulates representations for ongoing cognition. Oberauer (Psychology of Learning and Motivation, 51, 45-100, 2009) distinguishes between two analogous WM sub-systems: a declarative WM which handles the objects of thought, and a procedural WM which handles the representations of (cognitive) actions. Here, we assessed whether analogous effects are observed when participants switch between memory sets (declarative representations) and when they switch between task sets (procedural representations). One mechanism assumed to facilitate switching in procedural WM is the inhibition of previously used, but currently irrelevant task sets, as indexed by n-2 task-repetition costs (Mayr & Keele, Journal of Experimental Psychology: General, 129(1), 4-26, 2000). In this study we tested for an analogous effect in declarative WM. We assessed the evidence for n-2 list-repetition costs across eight experiments in which participants switched between memory lists to perform speeded classifications, mental arithmetic, or a local recognition test. N-2 list-repetition costs were obtained consistently in conditions assumed to increase interference between memory lists, and when lists formed chunks in long-term memory. Further analyses across experiments revealed a substantial contribution of episodic memory to n-2 list-repetition costs, thereby questioning the interpretation of n-2 repetition costs as reflecting inhibition. We reanalyzed the data of eight task-switching experiments, and observed that episodic memory also contributes to n-2 task-repetition costs. Taken together, these results show analogous processing principles in declarative and procedural WM, and question the relevance of inhibitory processes for efficient switching between mental sets.

The Golden Ratio of Gait Harmony: Repetitive Proportions of Repetitive Gait Phases

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Marco Iosa

2013-01-01

Full Text Available In nature, many physical and biological systems have structures showing harmonic properties. Some of them were found related to the irrational number known as the golden ratio that has important symmetric and harmonic properties. In this study, the spatiotemporal gait parameters of 25 healthy subjects were analyzed using a stereophotogrammetric system with 25 retroreflective markers located on their skin. The proportions of gait phases were compared with , the value of which is about 1.6180. The ratio between the entire gait cycle and stance phase resulted in 1.620 ± 0.058, that between stance and the swing phase was 1.629 ± 0.173, and that between swing and the double support phase was 1.684 ± 0.357. All these ratios did not differ significantly from each other (, , repeated measure analysis of variance or from (, resp., t-tests. The repetitive gait phases of physiological walking were found in turn in repetitive proportions with each other, revealing an intrinsic harmonic structure. Harmony could be the key for facilitating the control of repetitive walking. Harmony is a powerful unifying factor between seemingly disparate fields of nature, including human gait.

Research on transient thermal process of a friction brake during repetitive cycles of operation

Science.gov (United States)

Slavchev, Yanko; Dimitrov, Lubomir; Dimitrov, Yavor

2017-12-01

Simplified models are used in the classical engineering analyses of the friction brake heating temperature during repetitive cycles of operation to determine basically the maximum and minimum brake temperatures. The objective of the present work is to broaden and complement the possibilities for research through a model that is based on the classical scheme of the Newton's law of cooling and improves the studies by adding a disturbance function for a corresponding braking process. A general case of braking in non-periodic repetitive mode is considered, for which a piecewise function is defined to apply pulse thermal loads to the system. Cases with rectangular and triangular waveforms are presented. Periodic repetitive braking process is also studied using a periodic rectangular waveform until a steady thermal state is achieved. Different numerical methods such as the Euler's method, the classical fourth order Runge-Kutta (RK4) and the Runge-Kutta-Fehlberg 4-5 (RKF45) are used to solve the non-linear differential equation of the model. The constructed model allows during pre-engineering calculations to be determined effectively the time for reaching the steady thermal state of the brake, to be simulated actual braking modes in vehicles and material handling machines, and to be accounted for the thermal impact when performing fatigue calculations.

Periodic structures on germanium induced by high repetition rate femtosecond laser

Science.gov (United States)

Lin, Xiaoming; Li, Xiaohong; Zhang, Yanbin; Xie, Changxin; Liu, Kaijun; Zhou, Qiang

2018-05-01

Laser-induced periodic surface structures (LIPSS) are studied on germanium surface in air by the femtosecond pulsed laser with repetition frequency of 76 MHz and wavelength λ of 800 nm. Three types of LIPSS were found and they are low-spatial-frequency LIPSS (LSFL), high-spatial-frequency LIPSS (HSFL), and LSFL superimposed with HSFL. The period ΛLSFL of LSFL shrinks quickly from approximately 650 nm to 400 nm (∼λ/2) when lowering the scanning speed. Comparatively, the period ΛHSFL of HSFL keeps almost constant between 90 and 100 nm (∼λ/8) when the scanning speed and the laser pulse energy vary. LSFL and HSFL coexist when the laser pulse energy is around 3.3 nJ/pulse and the scanning speed ranges between 3 and 8 mm/s. The surface plasmon polariton waves make a contribution to the formation of LIPSS and the fourth harmonic generation (FHG) might be involved in the formation of HSFL.

A strategy for improving worker satisfaction and job attitudes in a repetitive industrial task: application of production standards and performance feedback.

Science.gov (United States)

Shikdar, Ashraf A; Das, Biman

2003-04-15

Worker satisfaction improved significantly as a consequence of the provision of the assigned and participative standards with performance feedback in a repetitive industrial production task. The maximum improvement in worker satisfaction was found for the participative standard and feedback condition. Only this condition had a significant positive effect on worker job attitudes. Monetary incentive, when provided with an assigned or participative standard with feedback, added no incremental worker satisfaction or job attitudes gain. The participative standard with feedback condition emerges as the optimum strategy for improving worker satisfaction and job attitudes in a repetitive industrial production task.

High frequency energy measurements

International Nuclear Information System (INIS)

Stotlar, S.C.

1981-01-01

High-frequency (> 100 MHz) energy measurements present special problems to the experimenter. Environment or available electronics often limit the applicability of a given detector type. The physical properties of many detectors are frequency dependent and in some cases, the physical effect employed can be frequency dependent. State-of-the-art measurements generally involve a detection scheme in association with high-speed electronics and a method of data recording. Events can be single or repetitive shot requiring real time, sampling, or digitizing data recording. Potential modification of the pulse by the detector and the associated electronics should not be overlooked. This presentation will review typical applications, methods of choosing a detector, and high-speed detectors. Special considerations and limitations of some applications and devices will be described

Subjective duration distortions mirror neural repetition suppression.

Science.gov (United States)

Pariyadath, Vani; Eagleman, David M

2012-01-01

Subjective duration is strongly influenced by repetition and novelty, such that an oddball stimulus in a stream of repeated stimuli appears to last longer in duration in comparison. We hypothesize that this duration illusion, called the temporal oddball effect, is a result of the difference in expectation between the oddball and the repeated stimuli. Specifically, we conjecture that the repeated stimuli contract in duration as a result of increased predictability; these duration contractions, we suggest, result from decreased neural response amplitude with repetition, known as repetition suppression. Participants viewed trials consisting of lines presented at a particular orientation (standard stimuli) followed by a line presented at a different orientation (oddball stimulus). We found that the size of the oddball effect correlates with the number of repetitions of the standard stimulus as well as the amount of deviance from the oddball stimulus; both of these results are consistent with a repetition suppression hypothesis. Further, we find that the temporal oddball effect is sensitive to experimental context--that is, the size of the oddball effect for a particular experimental trial is influenced by the range of duration distortions seen in preceding trials. Our data suggest that the repetition-related duration contractions causing the oddball effect are a result of neural repetition suppression. More generally, subjective duration may reflect the prediction error associated with a stimulus and, consequently, the efficiency of encoding that stimulus. Additionally, we emphasize that experimental context effects need to be taken into consideration when designing duration-related tasks.

Subjective duration distortions mirror neural repetition suppression.

Directory of Open Access Journals (Sweden)

Vani Pariyadath

Full Text Available Subjective duration is strongly influenced by repetition and novelty, such that an oddball stimulus in a stream of repeated stimuli appears to last longer in duration in comparison. We hypothesize that this duration illusion, called the temporal oddball effect, is a result of the difference in expectation between the oddball and the repeated stimuli. Specifically, we conjecture that the repeated stimuli contract in duration as a result of increased predictability; these duration contractions, we suggest, result from decreased neural response amplitude with repetition, known as repetition suppression.Participants viewed trials consisting of lines presented at a particular orientation (standard stimuli followed by a line presented at a different orientation (oddball stimulus. We found that the size of the oddball effect correlates with the number of repetitions of the standard stimulus as well as the amount of deviance from the oddball stimulus; both of these results are consistent with a repetition suppression hypothesis. Further, we find that the temporal oddball effect is sensitive to experimental context--that is, the size of the oddball effect for a particular experimental trial is influenced by the range of duration distortions seen in preceding trials.Our data suggest that the repetition-related duration contractions causing the oddball effect are a result of neural repetition suppression. More generally, subjective duration may reflect the prediction error associated with a stimulus and, consequently, the efficiency of encoding that stimulus. Additionally, we emphasize that experimental context effects need to be taken into consideration when designing duration-related tasks.

The Developmental Trajectory of Nonword Repetition

Science.gov (United States)

Chiat, Shula

2006-01-01

In line with the original presentation of nonword repetition as a measure of phonological short-term memory (Gathercole & Baddeley, 1989), the theoretical account Gathercole (2006) puts forward in her Keynote Article focuses on phonological storage as the key capacity common to nonword repetition and vocabulary acquisition. However, evidence that…

Neural dynamics during repetitive visual stimulation

Science.gov (United States)

Tsoneva, Tsvetomira; Garcia-Molina, Gary; Desain, Peter

2015-12-01

Objective. Steady-state visual evoked potentials (SSVEPs), the brain responses to repetitive visual stimulation (RVS), are widely utilized in neuroscience. Their high signal-to-noise ratio and ability to entrain oscillatory brain activity are beneficial for their applications in brain-computer interfaces, investigation of neural processes underlying brain rhythmic activity (steady-state topography) and probing the causal role of brain rhythms in cognition and emotion. This paper aims at analyzing the space and time EEG dynamics in response to RVS at the frequency of stimulation and ongoing rhythms in the delta, theta, alpha, beta, and gamma bands. Approach.We used electroencephalography (EEG) to study the oscillatory brain dynamics during RVS at 10 frequencies in the gamma band (40-60 Hz). We collected an extensive EEG data set from 32 participants and analyzed the RVS evoked and induced responses in the time-frequency domain. Main results. Stable SSVEP over parieto-occipital sites was observed at each of the fundamental frequencies and their harmonics and sub-harmonics. Both the strength and the spatial propagation of the SSVEP response seem sensitive to stimulus frequency. The SSVEP was more localized around the parieto-occipital sites for higher frequencies (>54 Hz) and spread to fronto-central locations for lower frequencies. We observed a strong negative correlation between stimulation frequency and relative power change at that frequency, the first harmonic and the sub-harmonic components over occipital sites. Interestingly, over parietal sites for sub-harmonics a positive correlation of relative power change and stimulation frequency was found. A number of distinct patterns in delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz) and beta (15-30 Hz) bands were also observed. The transient response, from 0 to about 300 ms after stimulation onset, was accompanied by increase in delta and theta power over fronto-central and occipital sites, which returned to baseline

Imbalance between abstract and concrete repetitive thinking modes in schizophrenia.

Science.gov (United States)

Maurage, Pierre; Philippot, Pierre; Grynberg, Delphine; Leleux, Dominique; Delatte, Benoît; Mangelinckx, Camille; Belge, Jan-Baptist; Constant, Eric

2017-10-01

Repetitive thoughts can be divided in two modes: abstract/analytic (decontextualized and dysfunctional) and concrete/experiential (problem-focused and adaptive). They constitute a transdiagnostic process involved in many psychopathological states but have received little attention in schizophrenia, as earlier studies only indexed increased ruminations (related to dysfunctional repetitive thoughts) without jointly exploring both modes. This study explored the two repetitive thinking modes, beyond ruminations, to determine their imbalance in schizophrenia. Thirty stabilized patients with schizophrenia and 30 matched controls completed the Repetitive Response Scale and the Mini Cambridge-Exeter Repetitive Thought Scale, both measuring repetitive thinking modes. Complementary measures related to schizophrenic symptomatology, depression and anxiety were also conducted. Compared to controls, patients with schizophrenia presented an imbalance between repetitive thinking modes, with increased abstract/analytic and reduced concrete/experiential thoughts, even after controlling for comorbidities. Schizophrenia is associated with stronger dysfunctional repetitive thoughts (i.e. abstract thinking) and impaired ability to efficiently use repetitive thinking for current problem-solving (i.e. concrete thinking). This imbalance confirms the double-faced nature of repetitive thinking modes, whose influence on schizophrenia's symptomatology should be further investigated. The present results also claim for evaluating these processes in clinical settings and for rehabilitating the balance between opposite repetitive thinking modes. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of a mobile device optimized cross platform-compatible oral pathology and radiology spaced repetition system for dental education.

Science.gov (United States)

Al-Rawi, Wisam; Easterling, Lauren; Edwards, Paul C

2015-04-01

Combining active recall testing with spaced repetition increases memory retention. The aim of this study was to evaluate and compare students' perception and utilization of an electronic spaced repetition oral pathology-radiology system in dental hygiene education and predoctoral dental education. The study employed an open-source suite of applications to create electronic "flashcards" that can be individually adjusted for frequency of repetition, depending on a user's assessment of difficulty. Accessible across multiple platforms (iOS, Android, Linux, OSX, Windows) as well as via any web-based browser, this framework was used to develop an oral radiology-oral pathology database of case-based questions. This system was introduced in two courses: sophomore oral pathology for dental students and sophomore radiology for dental hygiene students. Students were provided free software and/or mobile tablet devices as well as a database of 300 electronic question cards. Study participants were surveyed on frequency and extent of use. Perception-based surveys were used to evaluate their attitudes towards this technology. Of the eligible students, 12 of 22 (54.5%) dental hygiene and 49 of 107 (45.8%) dental students responded to the surveys. Adoption rates and student feedback were compared between the two groups. Among the respondents, acceptance of this technology with respect to educational usefulness was similar for the dental and dental hygiene students (median=5 on a five-point scale; dental hygiene interquartile range (IQR)=0; dental IQR=1). Only a minority of the survey respondents (25% dental, 33% dental hygiene) took advantage of one of the main benefits of this technology: automated spaced repetition.

Repetitive Transcranial Magnetic Stimulation for Wernicke-Korsakoff Syndrome: A Case Report.

Science.gov (United States)

Chung, So Won; Park, Shin Who; Seo, Young Jae; Kim, Jae-Hyung; Lee, Chan Ho; Lim, Jong Youb

2017-02-01

A 57-year-old man who was diagnosed with Wernicke-Korsakoff syndrome showed severe impairment of cognitive function and a craving for alcohol, even after sufficient supplementation with thiamine. After completing 10 sessions of 10 Hz repetitive transcranial magnetic stimulation (rTMS) at 100% of the resting motor threshold over the left dorsolateral prefrontal cortex, dramatic improvement in cognitive function and a reduction in craving for alcohol were noted. This is the first case report of the efficacy of a high-frequency rTMS in the treatment of Wernicke-Korsakoff syndrome.

Semantic priming increases word frequency judgments: Evidence for the role of memory strength in frequency estimation.

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Woltz, Dan J; Gardner, Michael K

2015-09-01

Previous research has demonstrated a systematic, nonlinear relationship between word frequency judgments and values from word frequency norms. This relationship could reflect a perceptual process similar to that found in the psychophysics literature for a variety of sensory phenomena. Alternatively, it could reflect memory strength differences that are expected for words of varying levels of prior exposure. Two experiments tested the memory strength explanation by semantically priming words prior to frequency judgments. Exposure to related word meanings produced a small but measurable increase in target word frequency ratings. Repetition but not semantic priming had a greater impact on low compared to high frequency words. These findings are consistent with a memory strength view of frequency judgments that assumes a distributed network with lexical and semantic levels of representation. Copyright © 2015 Elsevier B.V. All rights reserved.

Measures of maximum magnetic field in 3 GHz radio frequency superconducting cavities; Mesures du gradient accelerateur maximum dans des cavites supraconductrices en regime impulsionnel a 3 GHz

Energy Technology Data Exchange (ETDEWEB)

Thomas, Catherine [Paris-11 Univ., 91 Orsay (France)

2000-01-19

Theoretical models have shown that the maximum magnetic field in radio frequency superconducting cavities is the superheating field H{sub sh}. For niobium, H{sub sh} is 25 - 30% higher than the thermodynamical H{sub c} field: H{sub sh} within (240 - 274) mT. However, the maximum magnetic field observed so far is in the range H{sub c,max} = 152 mT for the best 1.3 GHz Nb cavities. This field is lower than the critical field H{sub c1} above which the superconductor breaks up into divided normal and superconducting zones (H{sub c1}{<=}H{sub c}). Thermal instabilities are responsible for this low value. In order to reach H{sub sh} before thermal breakdown, high power short pulses are used. The cavity needs then to be strongly over-coupled. The dedicated test bed has been built from the collaboration between Istituto Nazionale di Fisica Nucleare (INFN) - Sezione di Genoa, and the Service d'Etudes et Realisation d'Accelerateurs (SERA) of Laboratoire de l'Accelerateur Lineaire (LAL). The maximum magnetic field, H{sub rf,max}, measurements on INFN cavities give lower results than the theoretical speculations and are in agreement with previous results. The superheating magnetic fields is linked to the magnetic penetration depth. This superconducting characteristic length can be used to determine the quality of niobium through the ratio between the resistivity measured at 300 K and 4.2 K in the normal conducting state (RRR). Results have been compared to previous ones and agree pretty well. They show that the RRR measured on cavities is superficial and lower than the RRR measured on samples which concerns the volume. (author)

Repetitive thinking, executive functioning, and depressive mood in the elderly.

Science.gov (United States)

Philippot, Pierre; Agrigoroaei, Stefan

2017-11-01

Previous findings and the depressive-executive dysfunction hypothesis suggest that the established association between executive functioning and depression is accounted for by repetitive thinking. Investigating the association between executive functioning, repetitive thinking, and depressive mood, the present study empirically tested this mediational model in a sample of older adults, while focusing on both concrete and abstract repetitive thinking. This latter distinction is important given the potential protective role of concrete repetitive thinking, in contrast to the depletive effect of abstract repetitive thinking. A sample of 43 elderly volunteers, between 75 and 95 years of age, completed tests of executive functioning (the Stroop test, the Trail Making test, and the Fluency test), and questionnaires of repetitive thinking and depression. Positive correlations were observed between abstract repetitive thinking and depressive mood, and between concrete repetitive thinking and executive functioning; a negative correlation was observed between depressive mood and executive functioning. Further, mediational analysis evidenced that the relation between executive functioning and depressive mood was mediated by abstract repetitive thinking. The present data provide, for the first time, empirical support to the depressive-executive dysfunction hypothesis: the lack of executive resources would favor a mode of abstract repetitive thinking, which in turn would deplete mood. It suggests that clinical intervention targeting depression in the elderly should take into consideration repetitive thinking modes and the executive resources needed to disengage from rumination.

Directed PCR-free engineering of highly repetitive DNA sequences

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Preissler Steffen

2011-09-01

Full Text Available Abstract Background Highly repetitive nucleotide sequences are commonly found in nature e.g. in telomeres, microsatellite DNA, polyadenine (poly(A tails of eukaryotic messenger RNA as well as in several inherited human disorders linked to trinucleotide repeat expansions in the genome. Therefore, studying repetitive sequences is of biological, biotechnological and medical relevance. However, cloning of such repetitive DNA sequences is challenging because specific PCR-based amplification is hampered by the lack of unique primer binding sites resulting in unspecific products. Results For the PCR-free generation of repetitive DNA sequences we used antiparallel oligonucleotides flanked by restriction sites of Type IIS endonucleases. The arrangement of recognition sites allowed for stepwise and seamless elongation of repetitive sequences. This facilitated the assembly of repetitive DNA segments and open reading frames encoding polypeptides with periodic amino acid sequences of any desired length. By this strategy we cloned a series of polyglutamine encoding sequences as well as highly repetitive polyadenine tracts. Such repetitive sequences can be used for diverse biotechnological applications. As an example, the polyglutamine sequences were expressed as His6-SUMO fusion proteins in Escherichia coli cells to study their aggregation behavior in vitro. The His6-SUMO moiety enabled affinity purification of the polyglutamine proteins, increased their solubility, and allowed controlled induction of the aggregation process. We successfully purified the fusions proteins and provide an example for their applicability in filter retardation assays. Conclusion Our seamless cloning strategy is PCR-free and allows the directed and efficient generation of highly repetitive DNA sequences of defined lengths by simple standard cloning procedures.

Repetitive Solid Spherical Pellet Injection and Irradiation toward the Repetitive-mode Fast-Ignition Fusion miniReactor CANDY

International Nuclear Information System (INIS)

HANAYAMA, Ryohei; KOMEDA, Osamu; NISHIMURA, Yasuhiko; MORI, Yoshitaka; ISHII, Katsuhiro; NAKAYAMA, Suisei; OKIHARA, Shinichiro; FUJITA, Kazuhisa; SEKINE, Takashi; SATO, Nakahiro; KAWASHIMA, Toshiyuki; KAN, Hirofumi; KURITA, Takashi; NAKAMURA, Naoki; KONDO, Takuya; FUJINE, Manabu; AZUMA, Hirozumi; HIOKI, Tatsumi; KAKENO, Mitsutaka; MOTOHIRO, Tomoyoshi

2016-01-01

Pellet injection and repetitive laser illumination are key technologies for realizing inertial fusion energy [1-4]. Neutron generator using lasers also requires a repeating pellet target supplier. Here we present the first demonstration of target injection and neutron generation[5]. We injected more than 1300 spherical deuterated polystyrene(C 8 D 8 ) bead pellet targets during 23 minutes at 1 Hz(Fig. 1). After the pellet targets fell for a distance of 18 cm, we applied the synchronized laser-diode-pumped ultra-intense laser HAMA. The laser intensity at the focal point is 5 x 10 18 W/cm 2 , which is high enough to generate neutrons. As a result of the irradiation, we produced 2.45-MeV DD neutrons. Figure 2 shows the neutron time-of-flight signals detected by plastic scintillators coupled to photomultipliers. The neutron energy was calculated by the time-of-flight method. The maximum neutron yield was 9.5 x 10 4 /4π sr. The result is a step toward fusion power and also suggests possible industrial neutron sources. (paper)

Variable frequency iteration MPPT for resonant power converters

Science.gov (United States)

Zhang, Qian; Bataresh, Issa; Chen, Lin

2015-06-30

A method of maximum power point tracking (MPPT) uses an MPPT algorithm to determine a switching frequency for a resonant power converter, including initializing by setting an initial boundary frequency range that is divided into initial frequency sub-ranges bounded by initial frequencies including an initial center frequency and first and second initial bounding frequencies. A first iteration includes measuring initial powers at the initial frequencies to determine a maximum power initial frequency that is used to set a first reduced frequency search range centered or bounded by the maximum power initial frequency including at least a first additional bounding frequency. A second iteration includes calculating first and second center frequencies by averaging adjacent frequent values in the first reduced frequency search range and measuring second power values at the first and second center frequencies. The switching frequency is determined from measured power values including the second power values.

The influence of low-frequency left prefrontal repetitive transcranial magnetic stimulation on memory for words but not for faces

Czech Academy of Sciences Publication Activity Database

Škrdlantová, L.; Horáček, J.; Dockery, C.; Lukavský, Jiří; Kopeček, M.; Preiss, M.; Novák, T.; Höschl, C.

2005-01-01

Roč. 54, č. 1 (2005), s. 123-128 ISSN 0862-8408 Institutional research plan: CEZ:AV0Z70250504 Keywords : face memory * verbal memory * repetitive transcranial magnetic stimulation Subject RIV: AN - Psychology Impact factor: 1.806, year: 2005 http://www.biomed.cas.cz/physiolres/pdf/54/54_123.pdf

Improved Maximum Strength, Vertical Jump and Sprint Performance after 8 Weeks of Jump Squat Training with Individualized Loads

Directory of Open Access Journals (Sweden)

Vanderka Marián, Longová Katarína, Olasz Dávid, Krčmár Matúš, Walker Simon

2016-09-01

Full Text Available The purpose of the study was to determine the effects of 8 weeks of jump squat training on isometric half squat maximal force production (Fmax and rate of force development over 100ms (RFD100, countermovement jump (CMJ and squat jump (SJ height, and 50 m sprint time in moderately trained men. Sixty eight subjects (~21 years, ~180 cm, ~75 kg were divided into experimental (EXP; n = 36 and control (CON, n = 32 groups. Tests were completed pre-, mid- and post-training. EXP performed jump squat training 3 times per week using loads that allowed all repetitions to be performed with ≥90% of maximum average power output (13 sessions with 4 sets of 8 repetitions and 13 sessions with 8 sets of 4 repetitions. Subjects were given real-time feedback for every repetition during the training sessions. Significant improvements in Fmax from pre- to mid- (Δ ~14%, p<0.001, and from mid- to post-training (Δ ~4%, p < 0.001 in EXP were observed. In CON significantly enhanced Fmax from pre- to mid-training (Δ ~3.5%, p < 0.05 was recorded, but no other significant changes were observed in any other test. In RFD100 significant improvements from pre- to mid-training (Δ ~27%, p < 0.001, as well as from mid- to post-training (Δ ~17%, p < 0.01 were observed. CMJ and SJ height were significantly enhanced from pre- to mid-training (Δ ~10%, ~15%, respectively, p < 0.001 but no further changes occurred from mid- to post-training. Significant improvements in 50 m sprint time from pre- to mid-training (Δ -1%, p < 0.05, and from mid- to post-training (Δ -1.9%, p < 0.001 in EXP were observed. Furthermore, percent changes in EXP were greater than changes in CON during training. It appears that using jump squats with loads that allow repetitions to be performed ≥90% of maximum average power output can simultaneously improve several different athletic performance tasks in the short-term.

Evaluation of maximum voided volume in Korean children by use of a 48-h frequency volume chart.

Science.gov (United States)

Kim, Sun-Ouck; Kim, Kyung Do; Kim, Young Sig; Kim, Jun Mo; Moon, Du Geon; Park, Sungchan; Lee, Sang Don; Chung, Jae Min; Cho, Won Yeol

2012-08-01

Study Type - Diagnostic (validating cohort). Level of Evidence 2a. What's known on the subject? and What does the study add? The relationship between the maximum voided volume followed a linear curve. The formula presented, bladder capacity (mL) = 12 ×[age (years) + 11], is thought to be a reasonable one for Korean children. Korean children have a smaller bladder capacity than that reported in previous Western studies. • To develop practical guidelines for the prediction of normal bladder capacity in Korean children measured by a frequency volume chart (FVC), maximum voided volume (MVV) is an important factor in the diagnosis of children with abnormal voiding function. • In all, 298 children, aged 3-13 years, with no history of voiding disorders volunteered for the study. The MVV was determined in 219 subjects by use of a completely recorded FVC. • Linear regression analysis was used to define the exact relationship between age and bladder capacity. An approximate formula related age to bladder capacity as follows: bladder capacity (mL) = 12 ×[age (years) + 11]. • The relationship between the MVV measured by a FVC by age (3-13 years) of Korean children followed a linear curve. • When applied to normal voiding patterns, the formula presented appears to be a reasonable one for Korean children. © 2011 BJU INTERNATIONAL.

Performance of continuous wave and acousto-optically Q-switched Tm, Ho: YAP laser pumped by diode laser

Science.gov (United States)

Li, Guoxing; Xie, Wenqiang; Yang, Xining; Zhang, Ziqiu; Zhang, Hongda; Zhang, Liang

2018-02-01

A two-end-pumped a-cut Tm(0.5%), Ho(0.5%):YAP laser output at 2119nm is reported under cryogenic temperature. The maximum output power reached to 7.76W with the incident pump power of 24.2W in CW mode. With the acousto-optically Q-switch, an average power of 7.3W can be obtained, when the pulse repetition frequency was 7.5 kHz. The corresponding optical-to-optical conversion efficiency was 30.2% and the slope efficiency was 31.4%. Then, the laser output characteristics in the repetition frequency of 7.5 kHz and 10kHz were researched. The output power, the optical-to-optical conversion efficiency and slope efficiency were increased with the increase of the repetition frequency. In the same repetition frequency, the pulse duration was decreasing with the growth of the incident pump power.

Influence of repetitive mechanical loading on MMP2 activity in tendon fibroblasts.

Science.gov (United States)

Huisman, Elise; Lu, Alex; Jamil, Sarwat; Mousavizadeh, Rouhollah; McCormack, Robert; Roberts, Clive; Scott, Alex

2016-11-01

Matrix metalloproteinase2 has been implicated in tendon pathology caused by repetitive movements. However, its activity in the early stages of the tendon's response to overuse, and its presence in the circulation as a possible indicator of tendon degradation, remain unknown. Human tendon cells were repetitively stretched for 5 days, and the rabbit Achilles tendon complex underwent repetitive motion 3× per week for 2 weeks. Quantitative polymer chain reaction analysis was performed to detect matrix metalloproteinase2/14 and tissue inhibitor of matrix metalloproteinase2 messenger ribonucleic acid of cells and rabbit tissue, and matrix metalloproteinase2 protein levels were determined with an enzyme linked immunoassay. Matrix metalloproteinase2 activity was examined using zymography of the conditioned media, tendon and serum. Immunohistochemistry was used to localize matrix metalloproteinase2 in tendon tissue, and the density of fibrillar collagen in tendons was examined using second harmonic generation microscopy. Tendon cells stretched with high strain or high frequency demonstrated increased matrix metalloproteinase2 messenger ribonucleic acid and protein levels. Matrix metalloproteinase2 activity was increased in the rabbit Achilles tendon tissue at weeks 1 and 2; however, serum activity was only increased at week 1. After 2 weeks of exercise, the collagen density was lower in specific regions of the exercised rabbit Achilles tendon complex. Matrix metalloproteinase2 expression in exercised rabbit Achilles tendons was detected surrounding tendon fibroblasts. Repetitive mechanical stimulation of tendon cells results in a small increase in matrix metalloproteinase2 levels, but it appears unlikely that serum matrix metalloproteinase2 will be a useful indicator of tendon overuse injury. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1991-2000, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Lingual Kinematics during Rapid Syllable Repetition in Parkinson's Disease

Science.gov (United States)

Wong, Min Ney; Murdoch, Bruce E.; Whelan, Brooke-Mai

2012-01-01

Background: Rapid syllable repetition tasks are commonly used in the assessment of motor speech disorders. However, little is known about the articulatory kinematics during rapid syllable repetition in individuals with Parkinson's disease (PD). Aims: To investigate and compare lingual kinematics during rapid syllable repetition in dysarthric…

Bystander Effect Induced by Electroporation is Possibly Mediated by Microvesicles and Dependent on Pulse Amplitude, Repetition Frequency and Cell Type.

Science.gov (United States)

Prevc, Ajda; Bedina Zavec, Apolonija; Cemazar, Maja; Kloboves-Prevodnik, Veronika; Stimac, Monika; Todorovic, Vesna; Strojan, Primoz; Sersa, Gregor

2016-10-01

Bystander effect, a known phenomenon in radiation biology, where irradiated cells release signals which cause damage to nearby, unirradiated cells, has not been explored in electroporated cells yet. Therefore, our aim was to determine whether bystander effect is present in electroporated melanoma cells in vitro, by determining viability of non-electroporated cells exposed to medium from electroporated cells and by the release of microvesicles as potential indicators of the bystander effect. Here, we demonstrated that electroporation of cells induces bystander effect: Cells exposed to electric pulses mediated their damage to the non-electroporated cells, thus decreasing cell viability. We have shown that shedding microvesicles may be one of the ways used by the cells to mediate the death signals to the neighboring cells. The murine melanoma B16F1 cell line was found to be more electrosensitive and thus more prone to bystander effect than the canine melanoma CMeC-1 cell line. In B16F1 cell line, bystander effect was present above the level of electropermeabilization of the cells, with the threshold at 800 V/cm. Furthermore, with increasing electric field intensities and the number of pulses, the bystander effect also increased. In conclusion, electroporation can induce bystander effect which may be mediated by microvesicles, and depends on pulse amplitude, repetition frequency and cell type.

The effect of load reductions on repetition performance for commonly performed multijoint resistance exercises.

Science.gov (United States)

Willardson, Jeffrey M; Simão, Roberto; Fontana, Fabio E

2012-11-01

The purpose of this study was to compare 4 different loading schemes for the free weight bench press, wide grip front lat pull-down, and free weight back squat to determine the extent of progressive load reductions necessary to maintain repetition performance. Thirty-two recreationally trained women (age = 29.34 ± 4.58 years, body mass = 59.61 ± 4.72 kg, height = 162.06 ± 4.04 cm) performed 4 resistance exercise sessions that involved 3 sets of the free weight bench press, wide grip front lat pull-down, and free weight back squat, performed in this exercise order during all 4 sessions. Each of the 4 sessions was conducted under different randomly ordered loading schemes, including (a) a constant 10 repetition maximum (RM) load for all 3 sets and for all 3 exercises, (b) a 5% reduction after the first and second sets for all the 3 exercises, (c) a 10% reduction after the first and second sets for all the 3 exercises, and (d) a 15% reduction after the first and second sets for all the 3 exercises. The results indicated that for the wide grip front lat pull-down and free weight back squat, a 10% load reduction was necessary after the first and second sets to accomplish 10 repetitions on all the 3 sets. For the free weight bench press, a load reduction between 10 and 15% was necessary; specifically, a 10% reduction was insufficient and a 15% reduction was excessive, as evidenced by significantly >10 repetitions on the second and third sets for this exercise (p ≤ 0.05). In conclusion, the results of this study indicate that a resistance training prescription that involves 1-minute rest intervals between multiple 10RM sets does require load reductions to maintain repetition performance. Practitioners might apply these results by considering an approximate 10% load reduction after the first and second sets for the exercises examined, when training women of similar characteristics as in this study.

Negative effects of item repetition on source memory.

Science.gov (United States)

Kim, Kyungmi; Yi, Do-Joon; Raye, Carol L; Johnson, Marcia K

2012-08-01

In the present study, we explored how item repetition affects source memory for new item-feature associations (picture-location or picture-color). We presented line drawings varying numbers of times in Phase 1. In Phase 2, each drawing was presented once with a critical new feature. In Phase 3, we tested memory for the new source feature of each item from Phase 2. Experiments 1 and 2 demonstrated and replicated the negative effects of item repetition on incidental source memory. Prior item repetition also had a negative effect on source memory when different source dimensions were used in Phases 1 and 2 (Experiment 3) and when participants were explicitly instructed to learn source information in Phase 2 (Experiments 4 and 5). Importantly, when the order between Phases 1 and 2 was reversed, such that item repetition occurred after the encoding of critical item-source combinations, item repetition no longer affected source memory (Experiment 6). Overall, our findings did not support predictions based on item predifferentiation, within-dimension source interference, or general interference from multiple traces of an item. Rather, the findings were consistent with the idea that prior item repetition reduces attention to subsequent presentations of the item, decreasing the likelihood that critical item-source associations will be encoded.

A mode-locked external-cavity quantum-dot laser with a variable repetition rate

International Nuclear Information System (INIS)

Wu Jian; Jin Peng; Li Xin-Kun; Wei Heng; Wu Yan-Hua; Wang Fei-Fei; Chen Hong-Mei; Wu Ju; Wang Zhan-Guo

2013-01-01

A mode-locked external-cavity laser emitting at 1.17-μm wavelength using an InAs/GaAs quantum-dot gain medium and a discrete semiconductor saturable absorber mirror is demonstrated. By changing the external-cavity length, repetition rates of 854, 912, and 969 MHz are achieved respectively. The narrowest −3-dB radio-frequency linewidth obtained is 38 kHz, indicating that the laser is under stable mode-locking operation. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

The Role of Low-Spatial Frequencies in Lexical Decision and Masked Priming

Science.gov (United States)

Boden, C.; Giaschi, D.

2009-01-01

Spatial frequency filtering was used to test the hypotheses that low-spatial frequency information in printed text can: (1) lead to a rapid lexical decision or (2) facilitate word recognition. Adult proficient readers made lexical decisions in unprimed and masked repetition priming experiments with unfiltered, low-pass, high-pass and notch…

An optical parametric chirped-pulse amplifier for seeding high repetition rate free-electron lasers

International Nuclear Information System (INIS)

Höppner, H; Hage, A; Tanikawa, T; Schulz, M; Faatz, B; Riedel, R; Prandolini, M J; Teubner, U; Tavella, F

2015-01-01

High repetition rate free-electron lasers (FEL), producing highly intense extreme ultraviolet and x-ray pulses, require new high power tunable femtosecond lasers for FEL seeding and FEL pump-probe experiments. A tunable, 112 W (burst mode) optical parametric chirped-pulse amplifier (OPCPA) is demonstrated with center frequencies ranging from 720–900 nm, pulse energies up to 1.12 mJ and a pulse duration of 30 fs at a repetition rate of 100 kHz. Since the power scalability of this OPCPA is limited by the OPCPA-pump amplifier, we also demonstrate a 6.7–13.7 kW (burst mode) thin-disk OPCPA-pump amplifier, increasing the possible OPCPA output power to many hundreds of watts. Furthermore, third and fourth harmonic generation experiments are performed and the results are used to simulate a seeded FEL with high-gain harmonic generation. (paper)

High voltage nanosecond generator with pulse repetition rate of 1,000 p.p.s.

Energy Technology Data Exchange (ETDEWEB)

Gubanov, V P; Korovin, S D; Stepchenko, A S [High Current Electronics Institute, Tomsk (Russian Federation)

1997-12-31

A compact high voltage nanosecond generator is described with a pulse repetition rate up to 1000 p.p.s. The generator includes a 30-Ohm coaxial forming line charged by a built-in Tesla transformer with a high coupling coefficient, and a high voltage (N{sub 2}) gas gap switch with gas blowing between the electrodes. The maximum forming line charge voltage is 450 kV, the pulse duration is about 4 ns, and its amplitude for a matched load is up to 200 kV. (author). 3 figs., 9 refs.

Control method of Three-phase Four-leg converter based on repetitive control

Science.gov (United States)

Hui, Wang

2018-03-01

The research chose the magnetic levitation force of wind power generation system as the object. In order to improve the power quality problem caused by unbalanced load in power supply system, we combined the characteristics and repetitive control principle of magnetic levitation wind power generation system, and then an independent control strategy for three-phase four-leg converter was proposed. In this paper, based on the symmetric component method, the second order generalized integrator was used to generate the positive and negative sequence of signals, and the decoupling control was carried out under the synchronous rotating reference frame, in which the positive and negative sequence voltage is PI double closed loop, and a PI regulator with repetitive control was introduced to eliminate the static error regarding the fundamental frequency fluctuation characteristic of zero sequence component. The simulation results based on Matlab/Simulink show that the proposed control project can effectively suppress the disturbance caused by unbalanced loads and maintain the load voltage balance. The project is easy to be achieved and remarkably improves the quality of the independent power supply system.

Diagnostic for a high-repetition rate electron photo-gun and first measurements

Science.gov (United States)

Filippetto, D.; Doolittle, L.; Huang, G.; Norum, E.; Portmann, G.; Qian, H.; Sannibale, F.

2015-05-01

The APEX electron source at LBNL combines the high-repetition-rate with the high beam brightness typical of photoguns, delivering low emittance electron pulses at MHz frequency. Proving the high beam quality of the beam is an essential step for the success of the experiment, opening the doors of the high average power to brightness-hungry applications as X-Ray FELs, MHz ultrafast electron diffraction etc.. As first step, a complete characterization of the beam parameters is foreseen at the Gun beam energy of 750 keV. Diagnostics for low and high current measurements have been installed and tested, and measurements of cathode lifetime and thermal emittance in a RF environment with mA current performed. The recent installation of a double slit system, a deflecting cavity and a high precision spectrometer, allow the exploration of the full 6D phase space. Here we discuss the present layout of the machine and future upgrades, showing the latest results at low and high repetition rate, together with the tools and techniques used.

Optimization of graffiti removal on natural stone by means of high repetition rate UV laser

International Nuclear Information System (INIS)

Fiorucci, M.P.; López, A.J.; Ramil, A.; Pozo, S.; Rivas, T.

2013-01-01

The use of laser for graffiti removal is a promising alternative to conventional cleaning methods, though irradiation parameters must be carefully selected in order to achieve the effective cleaning without damaging the substrate, especially when referring to natural stone. From a practical point of view, once a safe working window is selected, it is necessary to determine the irradiation conditions to remove large paint areas, with minimal time consumption. The aim of this paper is to present a systematic procedure to select the optimum parameters for graffiti removal by means of the 3rd harmonic of a high repetition rate nanosecond Nd:YVO 4 laser. Ablation thresholds of four spray paint colors were determined and the effect of pulse repetition frequency, beam diameter and line scan separation was analyzed, obtaining a set of values which optimize the ablation process.

Optimization of graffiti removal on natural stone by means of high repetition rate UV laser

Energy Technology Data Exchange (ETDEWEB)

Fiorucci, M.P., E-mail: m.p.fiorucci@udc.es [Centro de Investigacións Tecnolóxicas, Universidade da Coruña, 15403 Ferrol (Spain); Dpto. Enxeñaría dos Recursos Naturais e Medio Ambiente, E.T.S.E. Minas, Universidade de Vigo, 36200 Vigo (Spain); López, A.J., E-mail: ana.xesus.lopez@udc.es [Centro de Investigacións Tecnolóxicas, Universidade da Coruña, 15403 Ferrol (Spain); Ramil, A., E-mail: alberto.ramil@udc.es [Centro de Investigacións Tecnolóxicas, Universidade da Coruña, 15403 Ferrol (Spain); Pozo, S., E-mail: ipozo@uvigo.es [Dpto. Enxeñaría dos Recursos Naturais e Medio Ambiente, E.T.S.E. Minas, Universidade de Vigo, 36200 Vigo (Spain); Rivas, T., E-mail: trivas@uvigo.es [Dpto. Enxeñaría dos Recursos Naturais e Medio Ambiente, E.T.S.E. Minas, Universidade de Vigo, 36200 Vigo (Spain)

2013-08-01

The use of laser for graffiti removal is a promising alternative to conventional cleaning methods, though irradiation parameters must be carefully selected in order to achieve the effective cleaning without damaging the substrate, especially when referring to natural stone. From a practical point of view, once a safe working window is selected, it is necessary to determine the irradiation conditions to remove large paint areas, with minimal time consumption. The aim of this paper is to present a systematic procedure to select the optimum parameters for graffiti removal by means of the 3rd harmonic of a high repetition rate nanosecond Nd:YVO{sub 4} laser. Ablation thresholds of four spray paint colors were determined and the effect of pulse repetition frequency, beam diameter and line scan separation was analyzed, obtaining a set of values which optimize the ablation process.

Towards a frequency-dependent discrete maximum principle for the implicit Monte Carlo equations

Energy Technology Data Exchange (ETDEWEB)

Wollaber, Allan B [Los Alamos National Laboratory; Larsen, Edward W [Los Alamos National Laboratory; Densmore, Jeffery D [Los Alamos National Laboratory

2010-12-15

It has long been known that temperature solutions of the Implicit Monte Carlo (IMC) equations can exceed the external boundary temperatures, a so-called violation of the 'maximum principle.' Previous attempts at prescribing a maximum value of the time-step size {Delta}{sub t} that is sufficient to eliminate these violations have recommended a {Delta}{sub t} that is typically too small to be used in practice and that appeared to be much too conservative when compared to numerical solutions of the IMC equations for practical problems. In this paper, we derive a new estimator for the maximum time-step size that includes the spatial-grid size {Delta}{sub x}. This explicitly demonstrates that the effect of coarsening {Delta}{sub x} is to reduce the limitation on {Delta}{sub t}, which helps explain the overly conservative nature of the earlier, grid-independent results. We demonstrate that our new time-step restriction is a much more accurate means of predicting violations of the maximum principle. We discuss how the implications of the new, grid-dependent timestep restriction can impact IMC solution algorithms.

Towards a frequency-dependent discrete maximum principle for the implicit Monte Carlo equations

International Nuclear Information System (INIS)

Wollaber, Allan B.; Larsen, Edward W.; Densmore, Jeffery D.

2011-01-01

It has long been known that temperature solutions of the Implicit Monte Carlo (IMC) equations can exceed the external boundary temperatures, a so-called violation of the 'maximum principle'. Previous attempts at prescribing a maximum value of the time-step size Δ t that is sufficient to eliminate these violations have recommended a Δ t that is typically too small to be used in practice and that appeared to be much too conservative when compared to numerical solutions of the IMC equations for practical problems. In this paper, we derive a new estimator for the maximum time-step size that includes the spatial-grid size Δ x . This explicitly demonstrates that the effect of coarsening Δ x is to reduce the limitation on Δ t , which helps explain the overly conservative nature of the earlier, grid-independent results. We demonstrate that our new time-step restriction is a much more accurate means of predicting violations of the maximum principle. We discuss how the implications of the new, grid-dependent time-step restriction can impact IMC solution algorithms. (author)

Pre-Lexical Disorders in Repetition Conduction Aphasia

Science.gov (United States)

Sidiropoulos, Kyriakos; de Bleser, Ria; Ackermann, Hermann; Preilowski, Bruno

2008-01-01

At the level of clinical speech/language evaluation, the repetition type of conduction aphasia is characterized by repetition difficulties concomitant with reduced short-term memory capacities, in the presence of fluent spontaneous speech as well as unimpaired naming and reading abilities. It is still unsettled which dysfunctions of the…

Repetitively pulsed power for meat pasteurization

International Nuclear Information System (INIS)

Patterson, E.L.; Kaye, R.J.; Neau, E.L.

1994-01-01

Electronic pasteurization of meat offers the potential for drastically reducing the incidence of food poisoning caused by biological pathogens accidentally introduced into meat products. Previous work has shown that γ-rays are an effective method of destroying E. coli 0157:H7, Salmonella, C. jejuni, L. monocytogenes, Listeria, and S. aureus bacteria types. The concern with the use of γ-rays is that radioactive material must be used in the pasteurization process that can lead to some market resistance and activist pressure on the meat industry. The use of accelerator generated high average power electron beams, at energies less than 10 MeV, or X-rays, with energies below 5 MeV, have been approved by the FDA for use in pasteurizing foods. Accelerator produced electronic pasteurization has the advantage that no radioactive material inventory is required. Electronic pasteurization has the additional benefit that it removes bacterial pathogens on the meat surface as well as within the volume of the meat product. High average power, repetitively-pulsed, broad-area electron beam sources being developed in the RHEPP program are suitable for large scale meat treatment in packing plant environments. RHEPP-II, which operates at 2.5 MeV and 25 kA at pulse repetition frequencies up to 120 Hz has adequate electron energy to penetrate hamburger patties which comprise about half of the beef consumption in the United States. Ground beef also has the highest potential for contamination since considerable processing is required in its production. A meat pasteurization facility using this size of accelerator source should be capable of treating 10 6 pounds of hamburger patties per hour to a dose of up to 3 kGy (300 kilorads). The RHEPP modular accelerator technology can easily be modified for other production rates and types of products

Evidence for the involvement of a nonlexical route in the repetition of familiar words: A comparison of single and dual route models of auditory repetition.

Science.gov (United States)

Hanley, J Richard; Dell, Gary S; Kay, Janice; Baron, Rachel

2004-03-01

In this paper, we attempt to simulate the picture naming and auditory repetition performance of two patients reported by Hanley, Kay, and Edwards (2002), who were matched for picture naming score but who differed significantly in their ability to repeat familiar words. In Experiment 1, we demonstrate that the model of naming and repetition put forward by Foygel and Dell (2000) is better able to accommodate this pattern of performance than the model put forward by Dell, Schwartz, Martin, Saffran, and Gagnon (1997). Nevertheless, Foygel and Dell's model underpredicted the repetition performance of both patients. In Experiment 2, we attempt to simulate their performance using a new dual route model of repetition in which Foygel and Dell's model is augmented by an additional nonlexical repetition pathway. The new model provided a more accurate fit to the real-word repetition performance of both patients. It is argued that the results provide support for dual route models of auditory repetition.

Study of 1 MW neutron source synchrotron dual frequency power circuit for the main ring magnets

International Nuclear Information System (INIS)

McGhee, D.G.

1993-01-01

This paper describes the proposed design of the resonant power circuits for the 1-MW neutron source synchrotron's main ring magnets. The synchrotron is to have a duty cycle of 30 Hz with a maximum upper limit of operation corresponding to 2.0 GeV and a maximum design value of 2.2 GeV. A stability of 30 ppM is the design goal for the main bending and focusing magnets (dipoles and quadruples), in order to achieve an overall stabffity of 100 ppm when random field and position errors of the magnets are included. The power circuits of this design are similar to those used in Argonne's Intense Pulsed Neutron Source (IPNS) where the energy losses during each cycle are supplied by continuous excitation from modulated multiphase DC power supplies. Since only 50% of the 30-Hz sinewave is used for acceleration, a dual-frequency resonant magnet circuit is used in this design. The 30-Hz repetition rate is maintained with a 20-Hz magnet guide field during acceleration and a 60-Hz reset field when no beam is present. This lengthens the guide-field rise time and shortens the fall time, improving the duty factor for acceleration. The maximum B dot is reduced by 33% during acceleration and hence, the maximum rf voltage/turn is reduced by 56%

Identification of multiple modes of axisymmetric or circularly repetitive structures

International Nuclear Information System (INIS)

Kopff, P.

1983-01-01

The axisymmetric structures, or those composed with circularly repetitive elements, often display multiple modes, which are not easy to separate by modal identification of experimental responses. To be able to solve in situ some problems related to the vibrational behaviour of reactor vessels or other such huge structures, ELECTRICITY DE FRANCE developed a few years ago, experimental capabilities providing heavy harmonic driving forces, and elaborate data acquisition, signal processing and modal identification software, self-contained in an integrated mobile test facility. The modal analysis techniques we have developed with the LABORATOIRE DE MECANIQUE Appliquee of University of BESANCON (FRANCE) were especially suited for identification of multiple or separation of quasi-multiple modes, i.e. very close and strongly coupled resonances. Besides, the curve fitting methods involved, compute the same complex eigen-frequencies for all the vibration pick-ups, for better accuracy of the related eigen-vector components. Moreover, the latest extensions of these algorithms give us the means to deal with non-linear behaviour. The performances of these programs are drawn from some experimental results on axisymmetric or circularly repetitive structure, we tested in our laboratory to validate the computational hypothesis used in models for seismic responses of breeder reactor vessels. (orig.)

Understanding work related musculoskeletal pain: does repetitive work cause stress symptoms?

DEFF Research Database (Denmark)

Bonde, J. P.; Mikkelsen, S.; Andersen, JH

2005-01-01

for development of regional pain in repetitive work, stress symptoms would likely be on the causal path. AIMS: To examine whether objective measures of repetitive monotonous work are related to occurrence and development of stress symptoms. METHODS: In 1994-95, 2033 unskilled workers with continuous repetitive...... Profile Inventory. RESULTS: Repetitive work, task cycle time, and quantified measures of repetitive upper extremity movements including force requirements were not related to occurrence of stress symptoms at baseline or development of stress symptoms during three years of follow up. CONCLUSIONS......: The findings do not indicate that repetitive work is associated with stress symptoms, but small effects cannot be ruled out. Thus the results question the importance of mental stress mechanisms in the causation of regional pain related to repetitive work. However, the findings should be interpreted...

Inverted U-shaped model: How frequent repetition affects perceived risk

OpenAIRE

Xi Lu; Xiaofei Xie; Lu Liu

2015-01-01

We asked how repeated media reports on technological hazards influence an individual's risk perception. We looked for two contradictory effects, an increasing effect of repetition on perceived risk with the first few repetitions and a decreasing effect with later repetitions, leading to the inverted U-shaped pattern. In an experiment, we demonstrated the inverted U-shaped relationship between the repetition and perceived risk in the context of food risk. The finding broaden...

Evidence for Separate Contributions of High and Low Spatial Frequencies during Visual Word Recognition.

Science.gov (United States)

Winsler, Kurt; Holcomb, Phillip J; Midgley, Katherine J; Grainger, Jonathan

2017-01-01

Previous studies have shown that different spatial frequency information processing streams interact during the recognition of visual stimuli. However, it is a matter of debate as to the contributions of high and low spatial frequency (HSF and LSF) information for visual word recognition. This study examined the role of different spatial frequencies in visual word recognition using event-related potential (ERP) masked priming. EEG was recorded from 32 scalp sites in 30 English-speaking adults in a go/no-go semantic categorization task. Stimuli were white characters on a neutral gray background. Targets were uppercase five letter words preceded by a forward-mask (#######) and a 50 ms lowercase prime. Primes were either the same word (repeated) or a different word (un-repeated) than the subsequent target and either contained only high, only low, or full spatial frequency information. Additionally within each condition, half of the prime-target pairs were high lexical frequency, and half were low. In the full spatial frequency condition, typical ERP masked priming effects were found with an attenuated N250 (sub-lexical) and N400 (lexical-semantic) for repeated compared to un-repeated primes. For HSF primes there was a weaker N250 effect which interacted with lexical frequency, a significant reversal of the effect around 300 ms, and an N400-like effect for only high lexical frequency word pairs. LSF primes did not produce any of the classic ERP repetition priming effects, however they did elicit a distinct early effect around 200 ms in the opposite direction of typical repetition effects. HSF information accounted for many of the masked repetition priming ERP effects and therefore suggests that HSFs are more crucial for word recognition. However, LSFs did produce their own pattern of priming effects indicating that larger scale information may still play a role in word recognition.

Model-free iterative control of repetitive dynamics for high-speed scanning in atomic force microscopy.

Science.gov (United States)

Li, Yang; Bechhoefer, John

2009-01-01

We introduce an algorithm for calculating, offline or in real time and with no explicit system characterization, the feedforward input required for repetitive motions of a system. The algorithm is based on the secant method of numerical analysis and gives accurate motion at frequencies limited only by the signal-to-noise ratio and the actuator power and range. We illustrate the secant-solver algorithm on a stage used for atomic force microscopy.

The effect of high frequency steep pulsed electric fields on in vitro and in vivo antitumor efficiency of ovarian cancer cell line skov3 and potential use in electrochemotherapy

Directory of Open Access Journals (Sweden)

Zheng Fei-Yun

2009-04-01

Full Text Available Abstract Background Patients received electrochemotherapy often associated with unpleasant sensations mainly result from low-frequency electric pulse induced muscle contractions. Increasing the repetition frequency of electric pulse can reduce unpleasant sensations. However, due to the specificity of SPEF, frequency related antitumor efficiency need to be further clarified. The aim of this study was to compare in vitro cytotoxic and in vivo antitumor effect on ovarian cancer cell line SKOV3 by SPEF with different repetition frequencies. Explore potential benefits of using high frequency SPEF in order to be exploitable in electrochemotherapy. Methods For in vitro experiment, SKOV3 cell suspensions were exposed to SPEF with gradient increased frequencies (1, 60, 1 000, 5 000 Hz and electric field intensity (50, 100, 150, 200, 250, 300, 350, 400 V/cm respectively. For in vivo test, SKOV3 subcutaneous implanted tumor in BALB/c nude mice (nu/nu were exposure to SPEF with gradient increased frequencies (1, 60, 1 000, 5 000 Hz and fixed electric field intensity (250 V/cm (7 mice for each frequency and 7 for control. Antitumor efficiency was performed by in vitro cytotoxic assay and in vivo tumor growth inhibition rate, supplemented by histological and TEM observations. Data were analyzed using one-way ANOVA followed by the comparisons of multiple groups. Results SPEF with a given frequency and appropriate electric field intensity could achieve similar cytotoxicity until reached a plateau of maximum cytotoxicity (approx. 100%. SPEF with different frequencies had significant antitumor efficiency in comparison to the control group (P 0.05. Histological and TEM observations demonstrated obvious cell damages in response to SPEF exposure. Furthermore, SPEF with 5 kHz could induce apoptosis under TEM observations both in vitro and in vivo. Conclusion SPEF with high frequency could also achieve similar antitumor efficiency which can be used to reduce

Translation of Syntactic Repetitions as Formal-Aesthetic Marker in Das Brot

Directory of Open Access Journals (Sweden)

Rosyidah

2017-03-01

Full Text Available Translating repetition as a formal-aesthetic marker in a literary text is a hard task and challenge for translators. The topic of this study is translation of syntactic repetition as formal-aesthetic marker in literary text. The problems examined include: (1 the syntactic repetitions in the source text and (2 the strategies to translate these repetitions carried out by the students. This is a case study with a qualitative approach which is aimed to describe the syntactic repetitions as formal aesthetic markers in the German short story Das Brot written by Wolfgang Borchert and to explain the strategies used by Indonesian students to translate the syntactic repetitions. The research data are repetitive sentences gained from the German short story and from the translated versions done by 60 students. The analysis was carried out interactively and sociosemiotically. The results show that there were repetitions at the sentence level including sentence parts, sentences and content repetition in the source text. The strategies used by the students to translate the repetitions of sentence part and sentence were exact preservation and modified preservation with reduction, implicitation and addition of extra words, avoidance with deletion, explicitation, implicitation, nominalization, and synonymy. In the meantime, content repetitions were translated using the strategy of exact preservation and preservation with modification by adding extra words and using role-based terms of address. Thus, the results lead to two new variations of modified preservation, namely preservation by adding extra words and by changing addressing terms and one new variation of avoidance that is explicitation.

Grade Repetition in Queensland State Prep Classes

Science.gov (United States)

Anderson, Robyn

2012-01-01

The current study considers grade repetition rates in the early years of schooling in Queensland state schools with specific focus on the pre-schooling year, Prep. In particular, it provides empirical evidence of grade repetition in Queensland state schools along with groups of students who are more often repeated. At the same time, much of the…

Genesis of multipeaked waves of the esophagus: repetitive contractions or motion artifact?

Science.gov (United States)

Sampath, Neha J; Bhargava, Valmik; Mittal, Ravinder K

2010-06-01

Multipeaked waves (MPW) in the distal esophagus occur frequently in patients with esophageal spastic motor disorders and diabetes mellitus and are thought to represent repetitive esophageal contractions. We aimed to investigate whether the relative motion between a stationary pressure sensor and contracted peristaltic esophageal segment that moves with respiration leads to the formation of MPW. We mathematically modeled the effect of relative movement between a moving pressure segment and a fixed pressure sensor on the pressure waveform morphology. We conducted retrospective analysis of 100 swallow-induced esophageal contractions in 10 patients, who demonstrated >30% MPW on high-resolution manometry (HRM) during standardized swallows. Finally, using HRM, we determined the effects of suspended breathing and hyperventilation on the waveform morphology in 10 patients prospectively. Modeling revealed that relative movement between a stationary pressure sensor and a moving contracted segment, contraction duration, contraction amplitude, respiratory frequency, and depth of respiration affects the waveform morphology. Retrospective analysis demonstrated a close temporal association with the onset of second and subsequent contractions in MPW with respiratory phase reversals. Numbers of peaks in MPW and respiratory phase reversals were closely related to the duration of contraction. In the prospective study, suspended breathing and hyperventilation resulted in a significant decrease and increase in the MPW frequency as well as the number of peaks within MPW respectively. We conclude that MPW observed during clinical motility studies are not indicative of repetitive esophageal contraction; rather they represent respiration-related movement of the contracted esophageal segment in relation to the stationary pressure sensor.

RPERT: Repetitive-Projects Evaluation and Review Technique

Directory of Open Access Journals (Sweden)

Remon Fayek Aziz

2014-03-01

Full Text Available Estimating expected completion probability of any repetitive construction project with a specified/certain duration including repetitive identical activities by using program evaluation and review technique is the most essential part in construction areas since the activities were had optimistic, most likely and pessimistic durations. This paper focuses on the calculation of expected completion probability of any repetitive construction project within a specified/certain duration (contract duration by using Line Of Balance technique (LOB in case of single or multiple number of crews integrated with Program Evaluation and Review Technique (PERT. Repetitive-Projects Evaluation and Review Technique (RPERT, which is a simplified software, will generate the expected project completion probability of a specified/certain duration (contract duration. RPERT software is designed by java programming code system to provide a number of new and unique capabilities, including: (1 Viewing the expected project completion probability according to a set of specified durations per each identical activity (optimistic time, most likely time, and pessimistic time in the analyzed project; (2 Providing seamless integration with available project time calculations. In order to provide the aforementioned capabilities of RPERT, the system is implemented and developed in four main modules: (1 A user interface module; (2 A database module; (3 A running module; and (4 A processing module. At the end, an illustrative example will be presented to demonstrate and verify the applications of proposed software (RPERT, by using probabilistic calculations for repetitive construction projects.

Evidence for Transdiagnostic Repetitive Negative Thinking and Its Association with Rumination, Worry, and Depression and Anxiety Symptoms: A Commonality Analysis

Directory of Open Access Journals (Sweden)

Daniel E. Gustavson

2018-05-01

Full Text Available Recent theoretical advances have emphasized the commonality between rumination and worry, often referred to as repetitive negative thinking. Although not studied extensively, repetitive negative thinking may not only account for a substantial overlap between depression and anxiety symptoms but also encapsulate other constructs including one’s tendency to experience unwanted intrusive thoughts or have low levels of mindfulness. In this study, 643 college students completed self-report questionnaire measures of repetitive negative thinking (the Habit Index of Negative Thinking and other relevant constructs including rumination, worry, depression and anxiety symptoms, intrusive thoughts, and mindfulness. To analyze the data, we conducted systematic commonality analyses, which algebraically decomposed shared variances among these measures into various unique components. Results in Study 1 indicated that individual differences in repetitive negative thinking were explained largely by the overlap between rumination and worry, but also by some rumination-specific and worry-specific variance. Moreover, the shared variation in rumination and worry explained the frequencies of depression and anxiety symptoms and their overlap. We also found in Study 2 that repetitive negative thinking was positively related to intrusive thoughts and negatively related to mindfulness. These associations were mostly explained by shared variance with rumination and worry, but there was also some mindfulness-specific variance. These results suggest that repetitive negative thinking may indeed lie at the core of the comorbidity between depression and anxiety symptoms, but that it is also a broader construct that encompasses intrusive thoughts and low levels of mindfulness.

Gating circuit for single photon-counting fluorescence lifetime instruments using high repetition pulsed light sources

International Nuclear Information System (INIS)

Laws, W.R.; Potter, D.W.; Sutherland, J.C.

1984-01-01

We have constructed a circuit that permits conventional timing electronics to be used in single photon-counting fluorimeters with high repetition rate excitation sources (synchrotrons and mode-locked lasers). Most commercial time-to-amplitude and time-to-digital converters introduce errors when processing very short time intervals and when subjected to high-frequency signals. This circuit reduces the frequency of signals representing the pulsed light source (stops) to the rate of detected fluorescence events (starts). Precise timing between the start/stop pair is accomplished by using the second stop pulse after a start pulse. Important features of our design are that the circuit is insensitive to the simultaneous occurrence of start and stop signals and that the reduction in the stop frequency allows the start/stop time interval to be placed in linear regions of the response functions of commercial timing electronics

The risk of musculoskeletal disorders due to repetitive movements of upper limbs for workers employed in hazelnut sorting

Directory of Open Access Journals (Sweden)

Andrea Colantoni

2013-09-01

Full Text Available In the agro-industrial sector there are many activities whose urgent rhythms can cause a considerable exposure to bio-mechanical risk factors. In the hazelnut sorting, the workers are subject to several biomechanical risks, with repetitive movements, and operations that require a remarkable degree of strength. A thorough study of the workers’ exposure to repetitive manual movements has been carried out, with the aim of setting up the necessary measures to reduce the risk factors. The aim of the research is to assess the risk of work-related musculo-skeletal disorders (WMSDs due to repetitive work, for workers employed to hazelnut shells sorting. The research was carried out in an agricultural cooperative in the Viterbo’s area. For risk assessment authors used a method (Occupational Repetitive Actions “OCRA” index according to ISO 11228- 3:2009, Ergonomics - Manual handling - Part 3: Handling of low loads at high frequency which keeps into consideration several risk factors (such as repetitiveness, prehension force, posture. The risk was assessed for 16 female workers (in eight workplaces and in two different shifts through this classification: workers with experience less than 1 year, from 1 to 10 years and more than 10 years. This classification is very important for knowing if the professional experience could be considered a “prevention measure” for the risk reduction. The results show a high risk level for the right and left limb. The factors which more have contributed to reach such risk level are the great number of movements and the lack of recovering time.

Repetition rates in heavy ion beam driven fusion reactors

Science.gov (United States)

Peterson, Robert R.

1986-01-01

The limits on the cavity gas density required for beam propagation and condensation times for material vaporized by target explosions can determine the maximum repetition rate of Heavy Ion Beam (HIB) driven fusion reactors. If the ions are ballistically focused onto the target, the cavity gas must have a density below roughly 10-4 torr (3×1012 cm-3) at the time of propagation; other propagation schemes may allow densities as high as 1 torr or more. In some reactor designs, several kilograms of material may be vaporized off of the target chamber walls by the target generated x-rays, raising the average density in the cavity to 100 tor or more. A one-dimensional combined radiation hydrodynamics and vaporization and condensation computer code has been used to simulate the behavior of the vaporized material in the target chambers of HIB fusion reactors.

Repetition rates in heavy ion beam driven fusion reactors

International Nuclear Information System (INIS)

Peterson, R.R.

1986-01-01

The limits on the cavity gas density required for beam propagation and condensation times for material vaporized by target explosions can determine the maximum repetition rate of Heavy Ion Beam (HIB) driven fusion reactors. If the ions are ballistically focused onto the target, the cavity gas must have a density below roughly 10 -4 torr (3 x 10 12 cm -3 ) at the time of propagation; other propagation schemes may allow densities as high as 1 torr or more. In some reactor designs, several kilograms of material may be vaporized off of the target chamber walls by the target generated x-rays, raising the average density in the cavity to 100 tor or more. A one-dimensional combined radiation hydrodynamics and vaporization and condensation computer code has been used to simulate the behavior of the vaporized material in the target chambers of HIB fusion reactors

Two-way shape memory effect induced by repetitive compressive loading cycles

International Nuclear Information System (INIS)

Kim, Hyun-Chul; Yoo, Young-Ik; Lee, Jung-Ju

2009-01-01

The NiTi alloy can be trained by repetitive loading or heating cycles. As a result of the training, a two-way shape memory effect (TWSME) can be induced. Considerable research has been reported regarding the TWSME trained by tensile loading. However, the TWSME trained by compressive loading has not been investigated nearly as much. In this paper, the TWSME is induced by compressive loading cycles and the two-way shape memory strain is evaluated by using two types of specimen: a solid cylinder type and a tube type. The TWSME trained by compressive loading is different from that trained by tensile loading owing to the severe tension/compression asymmetry as described in previous research. After repetitive compressive loading cycles, strain variation upon cooling is observed, and this result proves that the TWSME is induced by compressive loading cycles. By performing compressive loading cycles, plastic deformation in NiTi alloy occurs more than for tensile loading cycles, which brings about the appearance of TWSME. It can be said that the TWSME is induced by compressive loading cycles more easily. The two-way shape memory strain increases linearly as the maximum strain of compressive loading cycles increases, regardless of the shape and the size of the NiTi alloy; this two-way shape memory strain then shows a tendency towards saturation after some repeated cycles

Maximum nondiffracting propagation distance of aperture-truncated Airy beams

Science.gov (United States)

Chu, Xingchun; Zhao, Shanghong; Fang, Yingwu

2018-05-01

Airy beams have called attention of many researchers due to their non-diffracting, self-healing and transverse accelerating properties. A key issue in research of Airy beams and its applications is how to evaluate their nondiffracting propagation distance. In this paper, the critical transverse extent of physically realizable Airy beams is analyzed under the local spatial frequency methodology. The maximum nondiffracting propagation distance of aperture-truncated Airy beams is formulated and analyzed based on their local spatial frequency. The validity of the formula is verified by comparing the maximum nondiffracting propagation distance of an aperture-truncated ideal Airy beam, aperture-truncated exponentially decaying Airy beam and exponentially decaying Airy beam. Results show that the formula can be used to evaluate accurately the maximum nondiffracting propagation distance of an aperture-truncated ideal Airy beam. Therefore, it can guide us to select appropriate parameters to generate Airy beams with long nondiffracting propagation distance that have potential application in the fields of laser weapons or optical communications.

Repetitive exposure: Brain and reflex measures of emotion and attention

Science.gov (United States)

Ferrari, Vera; Bradley, Margaret M.; Codispoti, Maurizio; Lang, Peter J.

2010-01-01

Effects of massed repetition on the modulation of the late positive potential elicited during affective picture viewing were investigated in two experiments. Despite a difference in the number of repetitions across studies (from 5 to 30), results were quite similar: the late positive potential continued to be enhanced when viewing emotional, compared to neutral, pictures. On the other hand, massed repetition did prompt a reduction in the late positive potential that was most pronounced for emotional pictures. Startle probe P3 amplitude generally increased with repetition, suggesting diminished attention allocation to repeated pictures. The blink reflex, however, continued to be modulated by hedonic valence, despite massive massed repetition. Taken together, the data suggest that the amplitude of the late positive potential during picture viewing reflects both motivational significance and attention allocation. PMID:20701711

Is perfectionism associated with academic burnout through repetitive negative thinking?

Science.gov (United States)

Garratt-Reed, David; Howell, Joel; Hayes, Lana; Boyes, Mark

2018-01-01

Academic burnout is prevalent among university students, although understanding of what predicts burnout is limited. This study aimed to test the direct and indirect relationship between two dimensions of perfectionism (Perfectionistic Concerns and Perfectionistic Strivings) and the three elements of Academic Burnout (Exhaustion, Inadequacy, and Cynicism) through Repetitive Negative Thinking. In a cross-sectional survey, undergraduate students ( n  = 126, M age = 23.64, 79% female) completed well-validated measures of Perfectionism, Repetitive Negative Thinking, and Academic Burnout. Perfectionistic Concerns was directly associated with all elements of burnout, as well as indirectly associated with Exhaustion and Cynicism via Repetitive Negative Thinking. Perfectionistic Strivings was directly associated with less Inadequacy and Cynicism; however, there were no indirect associations between Perfectionistic Strivings and Academic Burnout operating through Repetitive Negative Thinking. Repetitive Negative Thinking was also directly related to more burnout Exhaustion and Inadequacy, but not Cynicism. It is concluded that future research should investigate whether interventions targeting Perfectionistic Concerns and Repetitive Negative Thinking can reduce Academic Burnout in university students.

Repetition code of 15 qubits

Science.gov (United States)

Wootton, James R.; Loss, Daniel

2018-05-01

The repetition code is an important primitive for the techniques of quantum error correction. Here we implement repetition codes of at most 15 qubits on the 16 qubit ibmqx3 device. Each experiment is run for a single round of syndrome measurements, achieved using the standard quantum technique of using ancilla qubits and controlled operations. The size of the final syndrome is small enough to allow for lookup table decoding using experimentally obtained data. The results show strong evidence that the logical error rate decays exponentially with code distance, as is expected and required for the development of fault-tolerant quantum computers. The results also give insight into the nature of noise in the device.

Repetitive transcranial magnetic stimulation as a neuropsychiatric tool: present status and future potential.

Science.gov (United States)

Post, R M; Kimbrell, T A; McCann, U D; Dunn, R T; Osuch, E A; Speer, A M; Weiss, S R

1999-03-01

Repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising therapeutic intervention in the treatment of affective disorders. The differences in the type of electrical stimulation required for therapeutic efficacy by rTMS and electroconvulsive therapy (ECT) are discussed. In contrast to ECT, rTMS would not appear to require the generation of a major motor seizure to achieve therapeutic efficacy. Accordingly, it carries the potentially important clinical advantages of not requiring anesthesia and of avoiding side effects such as transient memory loss. Preclinical studies on long-term potentiation (LTP) and long-term depression (LTD) in hippocampal and amygdala slices, as well as clinical data from neuroimaging studies, have provided encouraging clues for potential frequency-dependent effects of rTMS. Preliminary evidence from position emission tomography (PET) scans suggests that higher frequency (20 Hz) stimulation may increase brain glucose metabolism in a transsynaptic fashion, whereas lower frequency (1 Hz) stimulation may decrease it. Therefore, the ability of rTMS to control the frequency as well as the location of stimulation, in addition to its other advantages, has opened up new possibilities for clinical explorations and treatments of neuropsychiatric conditions.

Nanosecond radar system based on repetitive pulsed relativistic BWO

International Nuclear Information System (INIS)

Bunkin, B.V.; Gaponov-Grekhov, A.V.; Eltchaninov, A.S.; Zagulov, F.Ya.; Korovin, S.D.; Mesyats, G.A.; Osipov, M.L.; Otlivantchik, E.A.; Petelin, M.I.; Prokhorov, A.M.

1993-01-01

The paper presents the results of studies of a nanosecond radar system based on repetitive pulsed relativistic BWO. A pulsed power repetitive accelerator producing electron beams of electron energy 500-700 keV and current 5 kA in pulses of duraction 10 ns with a repetition rate of 100 pps is described. The results of experiments with a high-voltage gas-filled spark gap and a cold-cathode vacuum diode under the conditions of high repetition rates are given. Also presented are the results of studies of a relativistic BWO operating with a wavelength of 3 cm. It is shown that for a high-current beam electron energy of 500-700 keV, the BWO efficiency can reach 35%, the microwave power being 10 9 W. A superconducting solenoid creating a magnetic field of 30 kOe was used for the formation and transportation of the high-current electron beam. In conclusion, the outcome of tests of a nanosecond radar station based on a pulsed power repetitive accelerator and a relativistic BWO is reported

BANSHEE: High-voltage repetitively pulsed electron-beam driver

International Nuclear Information System (INIS)

VanHaaften, F.

1992-01-01

BANSHEE (Beam Accelerator for a New Source of High-Energy Electrons) this is a high-voltage modulator is used to produce a high-current relativistic electron beam for high-power microwave tube development. The goal of the BANSHEE research is first to achieve a voltage pulse of 700--750 kV with a 1-μs pulse width driving a load of ∼100 Ω, the pulse repetition frequency (PRF) of a few hertz. The ensuing goal is to increase the pulse amplitude to a level approaching 1 MV. We conducted tests using half the modulator with an output load of 200 Ω, up to a level of ∼650 kV at a PRF of 1 Hz and 525 kV at a PRF of 5 Hz. We then conducted additional testing using the complete system driving a load of ∼100 Ω

Transgenerational effects of environmental enrichment on repetitive motor behavior development.

Science.gov (United States)

Bechard, Allison R; Lewis, Mark H

2016-07-01

The favorable consequences of environmental enrichment (EE) on brain and behavior development are well documented. Much less is known, however, about transgenerational benefits of EE on non-enriched offspring. We explored whether transgenerational effects of EE might extend to the development of repetitive motor behaviors in deer mice. Repetitive motor behaviors are invariant patterns of movement that, across species, can be reduced by EE. We found that EE not only attenuated the development of repetitive behavior in dams, but also in their non-enriched offspring. Moreover, maternal behavior did not seem to mediate the transgenerational effect we found, although repetitive behavior was affected by reproductive experience. These data support a beneficial transgenerational effect of EE on repetitive behavior development and suggest a novel benefit of reproductive experience. Copyright © 2016 Elsevier B.V. All rights reserved.

Word and nonword repetition in patients with Schizophrenia

Directory of Open Access Journals (Sweden)

Alireza Farnam

2015-08-01

Full Text Available Introduction: The assessment of the verbal repetition is important in the study of acquired language disorders and neuropsychology. It is helpful in differential diagnosis of aphasia subtypes, auditory breakdowns, and working memory (WM performance. Though different linguistic disorders have been identified in patients with schizophrenia, very little is known about their verbal repetition ability. Methods: The present study was conducted in the inpatient ward of Razi Psychiatric Hospital, Tabriz University of Medical Sciences, Iran, during the year 2013. Participants were: 30 patients diagnosed with schizophrenia during the maintenance phase of treatment and 30 healthy people as control group. They were asked to repeat 15 words and 15 nonwords immediately. The stimuli were 1, 2, and 3 syllabic in Turkish language. Any incorrect repetition scored 1 and correct repetitions scored 0. Lexicalization errors were compared between groups too. Results: Both groups repeated words better than nonwords. Patients showed lower ability to repeat nonwords than controls, especially in 3 syllabics. There was no significant difference in the repetition of words between groups though it was better in controls. Patients with schizophrenia made more errors in both words and nonwords and lexicalization errors were twice more. Conclusion: Lower ability to repeat nonwords (than words in patients with schizophrenia may show the involvement of phonological loop of WM. More lexicalization errors may take place because of dis-inhibition.

High frequency repetitive sensory stimulation improves temporal discrimination in healthy subjects.

Science.gov (United States)

Erro, Roberto; Rocchi, Lorenzo; Antelmi, Elena; Palladino, Raffaele; Tinazzi, Michele; Rothwell, John; Bhatia, Kailash P

2016-01-01

High frequency electrical stimulation of an area of skin on a finger improves two-point spatial discrimination in the stimulated area, likely depending on plastic changes in the somatosensory cortex. However, it is unknown whether improvement also applies to temporal discrimination. Twelve young and ten elderly volunteers underwent the stimulation protocol onto the palmar skin of the right index finger. Somatosensory temporal discrimination threshold (STDT) was evaluated before and immediately after stimulation as well as 2.5h and 24h later. There was a significant reduction in somatosensory temporal threshold only on the stimulated finger. The effect was reversible, with STDT returning to the baseline values within 24h, and was smaller in the elderly than in the young participants. High frequency stimulation of the skin focally improves temporal discrimination in the area of stimulation. Given previous suggestions that the perceptual effects rely on plastic changes in the somatosensory cortex, our results are consistent with the idea that the timing of sensory stimuli is, at least partially, encoded in the primary somatosensory cortex. Such a protocol could potentially be used as a therapeutic intervention to ameliorate physiological decline in the elderly or in other disorders of sensorimotor integration. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Application of a repetitive process setting to design of monotonically convergent iterative learning control

Science.gov (United States)

Boski, Marcin; Paszke, Wojciech

2015-11-01

This paper deals with the problem of designing an iterative learning control algorithm for discrete linear systems using repetitive process stability theory. The resulting design produces a stabilizing output feedback controller in the time domain and a feedforward controller that guarantees monotonic convergence in the trial-to-trial domain. The results are also extended to limited frequency range design specification. New design procedure is introduced in terms of linear matrix inequality (LMI) representations, which guarantee the prescribed performances of ILC scheme. A simulation example is given to illustrate the theoretical developments.

An increased rectal maximum tolerable volume and long anal canal are associated with poor short-term response to biofeedback therapy for patients with anismus with decreased bowel frequency and normal colonic transit time.

Science.gov (United States)

Rhee, P L; Choi, M S; Kim, Y H; Son, H J; Kim, J J; Koh, K C; Paik, S W; Rhee, J C; Choi, K W

2000-10-01

Biofeedback is an effective therapy for a majority of patients with anismus. However, a significant proportion of patients still failed to respond to biofeedback, and little has been known about the factors that predict response to biofeedback. We evaluated the factors associated with poor response to biofeedback. Biofeedback therapy was offered to 45 patients with anismus with decreased bowel frequency (less than three times per week) and normal colonic transit time. Any differences in demographics, symptoms, and parameters of anorectal physiologic tests were sought between responders (in whom bowel frequency increased up to three times or more per week after biofeedback) and nonresponders (in whom bowel frequency remained less than three times per week). Thirty-one patients (68.9 percent) responded to biofeedback and 14 patients (31.1 percent) did not. Anal canal length was longer in nonresponders than in responders (4.53 +/- 0.5 vs. 4.08 +/- 0.56 cm; P = 0.02), and rectal maximum tolerable volume was larger in nonresponders than in responders. (361 +/- 87 vs. 302 +/- 69 ml; P = 0.02). Anal canal length and rectal maximum tolerable volume showed significant differences between responders and nonresponders on multivariate analysis (P = 0.027 and P = 0.034, respectively). This study showed that a long anal canal and increased rectal maximum tolerable volume are associated with poor short-term response to biofeedback for patients with anismus with decreased bowel frequency and normal colonic transit time.

The development of interactive multimedia based on auditory, intellectually, repetition in repetition algorithm learning to increase learning outcome

Science.gov (United States)

Munir; Sutarno, H.; Aisyah, N. S.

2018-05-01

This research aims to find out how the development of interactive multimedia based on auditory, intellectually, and repetition can improve student learning outcomes. This interactive multimedia is developed through 5 stages. Analysis stages include the study of literature, questionnaire, interviews and observations. The design phase is done by the database design, flowchart, storyboards and repetition algorithm material while the development phase is done by the creation of web-based framework. Presentation material is adapted to the model of learning such as auditory, intellectually, repetition. Auditory points are obtained by recording the narrative material that presented by a variety of intellectual points. Multimedia as a product is validated by material and media experts. Implementation phase conducted on grade XI-TKJ2 SMKN 1 Garut. Based on index’s gain, an increasing of student learning outcomes in this study is 0.46 which is fair due to interest of student in using interactive multimedia. While the multimedia assessment earned 84.36% which is categorized as very well.

Does combined strength training and local vibration improve isometric maximum force? A pilot study.

Science.gov (United States)

Goebel, Ruben; Haddad, Monoem; Kleinöder, Heinz; Yue, Zengyuan; Heinen, Thomas; Mester, Joachim

2017-01-01

The aim of the study was to determine whether a combination of strength training (ST) and local vibration (LV) improved the isometric maximum force of arm flexor muscles. ST was applied to the left arm of the subjects; LV was applied to the right arm of the same subjects. The main aim was to examine the effect of LV during a dumbbell biceps curl (Scott Curl) on isometric maximum force of the opposite muscle among the same subjects. It is hypothesized, that the intervention with LV produces a greater gain in isometric force of the arm flexors than ST. Twenty-seven collegiate students participated in the study. The training load was 70% of the individual 1 RM. Four sets with 12 repetitions were performed three times per week during four weeks. The right arm of all subjects represented the vibration trained body side (VS) and the left arm served as the traditional trained body side (TTS). A significant increase of isometric maximum force in both body sides (Arms) occurred. VS, however, significantly increased isometric maximum force about 43% in contrast to 22% of the TTS. The combined intervention of ST and LC improves isometric maximum force of arm flexor muscles. III.

High-dose phenobarbital with intermittent short-acting barbiturates for acute encephalitis with refractory, repetitive partial seizures.

Science.gov (United States)

Uchida, Takashi; Takayanagi, Masaru; Kitamura, Taro; Nishio, Toshiyuki; Numata, Yurika; Endo, Wakaba; Haginoya, Kazuhiro; Ohura, Toshihiro

2016-08-01

Acute encephalitis with refractory, repetitive partial seizures (AERRPS) is characterized by repetitive seizures during the acute and chronic phases and has a poor neurological outcome. Burst-suppression coma via continuous i.v. infusion of a short-acting barbiturate is used to terminate refractory seizures, but the severe side-effects of short-acting barbiturates are problematic. We report on a 9-year-old boy with AERRPS who was effectively treated with very-high-dose phenobarbital (VHDPB) combined with intermittent short-acting barbiturates. VHDPB side-effects were mild, especially compared with those associated with continuous i.v. infusion of short-acting barbiturates (dosage, 40-75 mg/kg/day; maximum blood level, 290 μg/mL). Using VHDPB as the main treatment, short-acting barbiturates were used intermittently and in small amounts. This is the first report to show that VHDPB, combined with intermittent short-acting barbiturates, can effectively treat AERRPS. After treatment, convulsions were suppressed and daily life continued, but intellectual impairment and high-level dysfunction remained. © 2016 Japan Pediatric Society.

Fusion neutron generation by high-repetitive target injection

International Nuclear Information System (INIS)

Kitagawa, Yoneyoshi

2015-01-01

Pellet injection and repetitive laser illumination are key technologies for realizing inertial fusion energy. The Graduate School for the Creation of New Photonics Industries, Hamamatsu Photonics K. K. and Toyota Motor Corporation demonstrate the pellet injection, counter laser beams' engagement and neutron generation. Deuterated polystyrene (CD) bead pellets, after free-falling for a distance of 18 cm at 1 Hz, are successfully engaged by two counter laser beams from a diode-pumped, ultra-intense laser HAMA. The laser energy, pulse duration, wavelength and the intensity are 0.63 J per beam, 104 fs, 811 nm and 4.7 x 10 18 W/cm 2 , respectively. The irradiated pellets produce D (D, n) 3 He-reacted neutrons with a maximum yield of 9.5 x 10 4 /4π sr/shot. A straight channel with 10 μm-diameter is found through the beads. The pellet size is 1 mm. The results indicate potentially useful technologies for the next step in realizing inertial fusion energy. The results are reviewed as well as some oversea activities. (author)

Fluorescence fluctuation of Rhodamine 6G dye for high repetition rate laser excitation

International Nuclear Information System (INIS)

Singh, Nageshwar; Patel, Hemant K.; Dixit, S.K.; Vora, H.S.

2013-01-01

In this paper, fluorescence from Rhodamine 6G dye for stationary and flowing liquid medium, excited by copper vapor laser, operating at 6 kHz pulse repetition frequency, was investigated. Large fluctuations in spectral width (about 5 nm) and spectral intensity in the fluorescence from stationary dye solution were observed, while fluctuations in the spectral width diminish in a flowing dye medium. However, this increases spectral intensity and slightly red shifts the fluorescence peak emission wavelength. Theoretical analysis was carried out to explain the observed results by incorporating the temperature induced refractive index, beam deflection and spectral variation in stationary dye solution. Numerical analysis of thermal load and contour of temperature in the optical pumped region inside the dye cell in stationary, 0.2 and 1.5 m/s flow velocity was also investigated to support our analysis. - Highlights: ► High repetition rate excitation generates inhomogeneity in the gain medium. ► Fluorescence of Rhodamine 6G in stationary and flowing medium was carried out. ► Fluorescence fluctuations lessen in flowing medium in contrast to stationary medium. ► Our theoretical and numerical analysis enlightens the experimented outcome trend.

Speed Estimation in Geared Wind Turbines Using the Maximum Correlation Coefficient

DEFF Research Database (Denmark)

Skrimpas, Georgios Alexandros; Marhadi, Kun S.; Jensen, Bogi Bech

2015-01-01

to overcome the above mentioned issues. The high speed stage shaft angular velocity is calculated based on the maximum correlation coefficient between the 1 st gear mesh frequency of the last gearbox stage and a pure sinus tone of known frequency and phase. The proposed algorithm utilizes vibration signals...

Physics of the Brain. Prevention of the Epileptic Seizures by the Multi-photon Pulsed-operated Fiber Lasers in the Ultraviolet Range of Frequencies.

Science.gov (United States)

Stefan, V. Alexander; IAPS Team

The novel study of the epileptogenesis mechanisms is proposed. It is based on the pulsed-operated (amplitude modulation) multi-photon (frequency modulation) fiber-laser interaction with the brain epilepsy-topion (the epilepsy onset area), so as to prevent the excessive electrical discharge (epileptic seizure) in the brain. The repetition frequency, Ω, matches the low frequency (epileptic) phonon waves in the brain. The laser repetition frequency (5-100 pulses per second) enables the resonance-scanning of the wide range of the phonon (possible epileptic-to-be) activity in the brain. The tunable fiber laser frequencies, Δω (multi photon operation), are in the ultraviolet frequency range, thus enabling monitoring of the electrical charge imbalance (within the 10s of milliseconds), and the DNA-corruption in the epilepsy-topion, as the possible cause of the disease. Supported by Nikola Tesla Labs., Stefan University.

Frequency-agile dual-comb spectroscopy

Science.gov (United States)

Millot, Guy; Pitois, Stéphane; Yan, Ming; Hovhannisyan, Tatevik; Bendahmane, Abdelkrim; Hänsch, Theodor W.; Picqué, Nathalie

2016-01-01

Spectroscopic gas sensing and its applications to, for example, trace detection or chemical kinetics, require ever more demanding measurement times, acquisition rates, sensitivities, precisions and broad tuning ranges. Here, we propose a new approach to near-infrared molecular spectroscopy, utilizing advanced concepts of optical telecommunications and supercontinuum photonics. We generate, without mode-locked lasers, two frequency combs of slightly different repetition frequencies and moderate, but rapidly tunable, spectral span. The output of a frequency-agile continuous-wave laser is split and sent into two electro-optic intensity modulators. Flat-top low-noise frequency combs are produced by wave-breaking in a nonlinear optical fibre of normal dispersion. With a dual-comb spectrometer, we record Doppler-limited spectra spanning 60 GHz within 13 μs and an 80 kHz refresh rate, at a tuning speed of 10 nm s-1. The sensitivity for weak absorption is enhanced by a long gas-filled hollow-core fibre. New opportunities for real-time diagnostics may be opened up, even outside the laboratory.

Circumvention of noise contributions in fiber laser based frequency combs.

Science.gov (United States)

Benkler, Erik; Telle, Harald; Zach, Armin; Tauser, Florian

2005-07-25

We investigate the performance of an Er:fiber laser based femtosecond frequency comb for precision metrological applications. Instead of an active stabilization of the comb, the fluctuations of the carrier-envelope offset phase, the repetition phase, and the phase of the beat from a comb line with an optical reference are synchronously detected. We show that these fluctuations can be effectively eliminated by exploiting their known correlation. In our experimental scheme, we utilize two identically constructed frequency combs for the measurement of the fluctuations, rejecting the influence of a shared optical reference. From measuring a white frequency noise level, we demonstrate that a fractional frequency instability better than 1.4 x 10(-14) for 1 s averaging time can be achieved in frequency metrology applications using the Er:fiber based frequency comb.

Generation of µW level plateau harmonics at high repetition rate.

Science.gov (United States)

Hädrich, S; Krebs, M; Rothhardt, J; Carstens, H; Demmler, S; Limpert, J; Tünnermann, A

2011-09-26

The process of high harmonic generation allows for coherent transfer of infrared laser light to the extreme ultraviolet spectral range opening a variety of applications. The low conversion efficiency of this process calls for optimization or higher repetition rate intense ultrashort pulse lasers. Here we present state-of-the-art fiber laser systems for the generation of high harmonics up to 1 MHz repetition rate. We perform measurements of the average power with a calibrated spectrometer and achieved µW harmonics between 45 nm and 61 nm (H23-H17) at a repetition rate of 50 kHz. Additionally, we show the potential for few-cycle pulses at high average power and repetition rate that may enable water-window harmonics at unprecedented repetition rate. © 2011 Optical Society of America

Autism and exergaming: effects on repetitive behaviors and cognition

Directory of Open Access Journals (Sweden)

Anderson-Hanley C

2011-09-01

Full Text Available Cay Anderson-Hanley, Kimberly Tureck, Robyn L Schneiderman Department of Psychology, Union College, Schenectady, NY, USA Abstract: Autism is a neurodevelopmental disorder that leads to impairment in social skills and delay in language development, and results in repetitive behaviors and restricted interests that impede academic and social involvement. Physical exercise has been shown to decrease repetitive behaviors in autistic children and improve cognitive function across the life-span. Exergaming combines physical and mental exercise simultaneously by linking physical activity movements to video game control and may yield better compliance with exercise. In this investigation, two pilot studies explored the potential behavioral and cognitive benefits of exergaming. In Pilot I, twelve children with autism spectrum disorders completed a control task and an acute bout of Dance Dance Revolution (DDR; in Pilot II, ten additional youths completed an acute bout of cyber cycling. Repetitive behaviors and executive function were measured before and after each activity. Repetitive behaviors significantly decreased, while performance on Digits Backwards improved following the exergaming conditions compared with the control condition. Additional research is needed to replicate these findings, and to explore the application of exergaming for the management of behavioral disturbance and to increase cognitive control in children on the autism spectrum. Keywords: autism, repetitive behaviors, exergaming, exercise, executive function

Carrier-envelope offset frequency stabilization of an ultrafast semiconductor laser

Science.gov (United States)

Jornod, Nayara; Gürel, Kutan; Wittwer, Valentin J.; Brochard, Pierre; Hakobyan, Sargis; Schilt, Stéphane; Waldburger, Dominik; Keller, Ursula; Südmeyer, Thomas

2018-02-01

We present the self-referenced stabilization of the carrier-envelope offset (CEO) frequency of a semiconductor disk laser. The laser is a SESAM-modelocked VECSEL emitting at a wavelength of 1034 nm with a repetition frequency of 1.8 GHz. The 270-fs pulses are amplified to 3 W and compressed to 120 fs for the generation of a coherent octavespanning supercontinuum spectrum. A quasi-common-path f-to-2f interferometer enables the detection of the CEO beat with a signal-to-noise ratio of 30 dB sufficient for its frequency stabilization. The CEO frequency is phase-locked to an external reference with a feedback signal applied to the pump current.

A longitudinal investigation of perfectionism and repetitive negative thinking in perinatal depression.

Science.gov (United States)

Egan, Sarah J; Kane, Robert T; Winton, Karen; Eliot, Catherine; McEvoy, Peter M

2017-10-01

Repetitive negative thinking and perfectionism have both been proposed as processes that are related to depressive symptoms. The purpose of this study was to investigate concurrent and prospective relationships between antenatal and postnatal depression, perfectionism, and repetitive negative thinking. A longitudinal design was used and 71 women were followed from their third trimester of pregnancy to six weeks post birth. A structural equation model was tested with antenatal perfectionism predicting antenatal repetitive negative thinking, perfectionism predicting postnatal depression, and antenatal repetitive negative thinking predicting antenatal and postnatal depression. The final model provided an adequate fit to the data but the pathway from antenatal repetitive negative thinking to postnatal depression was not significant. The findings provide support for the role of perfectionism and repetitive negative thinking in the onset and maintenance of perinatal symptoms of depression. It is suggested that future research investigates the efficacy of targeting repetitive negative thinking and perfectionism in pregnancy to examine if this can reduce perinatal depression. Copyright © 2017. Published by Elsevier Ltd.

Concreteness of Positive, Negative, and Neutral Repetitive Thinking About the Future

Science.gov (United States)

Behar, Evelyn; McGowan, Sarah Kate; McLaughlin, Katie A.; Borkovec, T.D.; Goldwin, Michelle; Bjorkquist, Olivia

2014-01-01

Consistent with assertions that the adaptiveness of repetitive thinking is influenced by both its valence and style, Stöber (e.g., Stöber & Borkovec, 2002) has argued that worry is characterized by a reduced concreteness of thought content and that the resulting abstractness contributes to its inhibition of some aspects of anxious responding. However, extant research does not provide a direct test of Stöber’s reduced concreteness theory of worry. We sought to test Stöber’s theory and to examine the adaptiveness of repetitive worrisome thinking by randomly assigning 108 participants to engage in five consecutive periods of repetitive thinking about positively, negatively, or neutrally valenced potential future events. Results based on coding of thought data indicated that (a) repetitive thinking became increasingly less concrete as periods progressed; (b) contrary to Stöber’s theory, both negative and positive repetitive future thinking were more concrete than neutral repetitive future thinking (and did not differ from each other); and (c) abstractness of thought during negative repetitive future thinking was associated with reduced reports of imagery-based activity. Results based on self-reported affect indicated that negatively valenced repetitive future thinking was uniquely associated with initial decreases in anxious affect, followed by increased anxious affect that coincided with increased imagery-based activity. This suggests that worry is associated with a sequential mitigation of anxious meaning followed by a strengthening of anxious meaning over time. Theoretical and clinical implications of these findings are discussed. PMID:22440067

Effects of repetition and temperature on Contingent Electrical Stimulation

DEFF Research Database (Denmark)

Castrillon, Eduardo E.; Zhou, Xinwen; Svensson, Peter

) activity associated with bruxism. Repetition of the electrical stimulus and skin surface temperature (ST) may affect the perception of CES and possibly also the inhibitory EMG effects.Objectives: To determine the effects of stimulus repetition and skin ST on the perception of CES.  Methods: Healthy...

Repetitive transcranial magnetic stimulation in psychiatry

Directory of Open Access Journals (Sweden)

Biswa Ranjan Mishra

2011-01-01

Full Text Available Repetitive transcranial magnetic stimulation (rTMS is a non-invasive and relatively painless tool that has been used to study various cognitive functions as well as to understand the brain-behavior relationship in normal individuals as well as in those with various neuropsychiatric disorders. It has also been used as a therapeutic tool in various neuropsychiatric disorders because of its ability to specifically modulate distinct brain areas. Studies have shown that repeated stimulation at low frequency produces long-lasting inhibition, which is called as long-term depression, whereas repeated high-frequency stimulation can produce excitation through long-term potentiation. This paper reviews the current status of rTMS as an investigative and therapeutic modality in various neuropsychiatric disorders. It has been used to study the cortical and subcortical functions, neural plasticity and brain mapping in normal individuals and in various neuropsychiatric disorders. rTMS has been most promising in the treatment of depression, with an overall milder adverse effect profile compared with electroconvulsive therapy. In other neuropsychiatric disorders such as schizophrenia, mania, epilepsy and substance abuse, it has been found to be useful, although further studies are required to establish therapeutic efficacy. It appears to be ineffective in the treatment of obsessive compulsive disorder. There is a paucity of studies of efficacy and safety of rTMS in pediatric and geriatric population. Although it appears safe, further research is required to optimize its efficacy and reduce the side-effects. Magnetic seizure therapy, which involves producing seizures akin to electroconvulsive therapy, appears to be of comparable efficacy in the treatment of depression with less cognitive adverse effects.

Estimating the maximum potential revenue for grid connected electricity storage :

Energy Technology Data Exchange (ETDEWEB)

Byrne, Raymond Harry; Silva Monroy, Cesar Augusto.

2012-12-01

The valuation of an electricity storage device is based on the expected future cash flow generated by the device. Two potential sources of income for an electricity storage system are energy arbitrage and participation in the frequency regulation market. Energy arbitrage refers to purchasing (stor- ing) energy when electricity prices are low, and selling (discharging) energy when electricity prices are high. Frequency regulation is an ancillary service geared towards maintaining system frequency, and is typically procured by the independent system operator in some type of market. This paper outlines the calculations required to estimate the maximum potential revenue from participating in these two activities. First, a mathematical model is presented for the state of charge as a function of the storage device parameters and the quantities of electricity purchased/sold as well as the quantities o ered into the regulation market. Using this mathematical model, we present a linear programming optimization approach to calculating the maximum potential revenue from an elec- tricity storage device. The calculation of the maximum potential revenue is critical in developing an upper bound on the value of storage, as a benchmark for evaluating potential trading strate- gies, and a tool for capital nance risk assessment. Then, we use historical California Independent System Operator (CAISO) data from 2010-2011 to evaluate the maximum potential revenue from the Tehachapi wind energy storage project, an American Recovery and Reinvestment Act of 2009 (ARRA) energy storage demonstration project. We investigate the maximum potential revenue from two di erent scenarios: arbitrage only and arbitrage combined with the regulation market. Our analysis shows that participation in the regulation market produces four times the revenue compared to arbitrage in the CAISO market using 2010 and 2011 data. Then we evaluate several trading strategies to illustrate how they compare to the

Post-exercise cortical depression following repetitive passive finger movement.

Science.gov (United States)

Otsuka, Ryohei; Sasaki, Ryoki; Tsuiki, Shota; Kojima, Sho; Onishi, Hideaki

2017-08-24

This study aimed to clarify the influence of range of repetitive passive finger movement on corticospinal excitability. Thirteen healthy subjects participated in this study. Passive index finger adduction-abduction movements were performed from 15° abduction to 15° adduction, 15° abduction to 0°, 0° to 15° adduction, and 15° adduction to 30° adduction, each at 15°/s for 10min on separate days. Motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation and M- and F-waves were measured before and after each repetitive passive index finger movement protocol to evaluate changes in corticospinal excitability. MEP amplitude significantly decreased after all passive movements, while F-wave amplitude, F-wave persistence, and M-wave amplitude remained stable. These results suggest that cortical excitability decreases after repetitive passive movement. However, the range of repetitive passive movement does not markedly influence the magnitude of cortical depression. Copyright © 2017 Elsevier B.V. All rights reserved.

Pulse repetition rate multiplication by Talbot effect in a coaxial fiber

Science.gov (United States)

Dhingra, Nikhil; Saxena, Geetika Jain; Anand, Jyoti; Sharma, Enakshi K.

2018-03-01

We use a coaxial fiber, which is a cylindrical coupled waveguide structure consisting of two concentric cores, the inner rod and an outer ring core as a first order dispersive media to achieve temporal Talbot effect for pulse repetition rate multiplication (PRRM) in high bit rate optical fiber communication. It is observed that for an input Gaussian pulse train with pulse width, 2τ0=1ps at a repetition rate of 40 Gbps (repetition period, T=25ps), an output repetition rate of 640 Gbps can be achieved without significant distortion at a length of 40.92 m.

Evaluating the role of prefrontal and parietal cortices in memory-guided response with repetitive transcranial magnetic stimulation

OpenAIRE

Hamidi, Massihullah; Tononi, Giulio; Postle, Bradley R.

2008-01-01

The dorsolateral prefrontal cortex (dlPFC) plays an important role in working memory, including the control of memory-guided response. In this study, with 24 subjects, we used high frequency repetitive transcranial magnetic stimulation (rTMS) to evaluate the role of the dlPFC in memory-guided response to two different types of spatial working memory tasks: one requiring a recognition decision about a probe stimulus (operationalized with a yes/no button press), another requiring direct recall ...

Long distance measurement with a femtosecond laser based frequency comb

Science.gov (United States)

Bhattacharya, N.; Cui, M.; Zeitouny, M. G.; Urbach, H. P.; van den Berg, S. A.

2017-11-01

Recent advances in the field of ultra-short pulse lasers have led to the development of reliable sources of carrier envelope phase stabilized femtosecond pulses. The pulse train generated by such a source has a frequency spectrum that consists of discrete, regularly spaced lines known as a frequency comb. In this case both the frequency repetition and the carrier-envelope-offset frequency are referenced to a frequency standard, like an atomic clock. As a result the accuracy of the frequency standard is transferred to the optical domain, with the frequency comb as transfer oscillator. These unique properties allow the frequency comb to be applied as a versatile tool, not only for time and frequency metrology, but also in fundamental physics, high-precision spectroscopy, and laser noise characterization. The pulse-to-pulse phase relationship of the light emitted by the frequency comb has opened up new directions for long range highly accurate distance measurement.

Properties of water surface discharge at different pulse repetition rates

International Nuclear Information System (INIS)

Ruma,; Yoshihara, K.; Hosseini, S. H. R.; Sakugawa, T.; Akiyama, H.; Akiyama, M.; Lukeš, P.

2014-01-01

The properties of water surface discharge plasma for variety of pulse repetition rates are investigated. A magnetic pulse compression (MPC) pulsed power modulator able to deliver pulse repetition rates up to 1000 Hz, with 0.5 J per pulse energy output at 25 kV, was used as the pulsed power source. Positive pulse with a point-to-plane electrode configuration was used for the experiments. The concentration and production yield of hydrogen peroxide (H 2 O 2 ) were quantitatively measured and orange II organic dye was treated, to evaluate the chemical properties of the discharge reactor. Experimental results show that the physical and chemical properties of water surface discharge are not influenced by pulse repetition rate, very different from those observed for under water discharge. The production yield of H 2 O 2 and degradation rate per pulse of the dye did not significantly vary at different pulse repetition rates under a constant discharge mode on water surface. In addition, the solution temperature, pH, and conductivity for both water surface and underwater discharge reactors were measured to compare their plasma properties for different pulse repetition rates. The results confirm that surface discharge can be employed at high pulse repetition rates as a reliable and advantageous method for industrial and environmental decontamination applications.

Evidence-Based Behavioral Interventions for Repetitive Behaviors in Autism

Science.gov (United States)

Boyd, Brian A.; McDonough, Stephen G.; Bodfish, James W.

2012-01-01

Restricted and repetitive behaviors (RRBs) are a core symptom of autism spectrum disorders (ASD). There has been an increased research emphasis on repetitive behaviors; however, this research primarily has focused on phenomenology and mechanisms. Thus, the knowledge base on interventions is lagging behind other areas of research. The literature…

Repetitive sequences: the hidden diversity of heterochromatin in prochilodontid fish

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Maria L. Terencio

2015-08-01

Full Text Available The structure and organization of repetitive elements in fish genomes are still relatively poorly understood, although most of these elements are believed to be located in heterochromatic regions. Repetitive elements are considered essential in evolutionary processes as hotspots for mutations and chromosomal rearrangements, among other functions – thus providing new genomic alternatives and regulatory sites for gene expression. The present study sought to characterize repetitive DNA sequences in the genomes of Semaprochilodus insignis (Jardine & Schomburgk, 1841 and Semaprochilodus taeniurus (Valenciennes, 1817 and identify regions of conserved syntenic blocks in this genome fraction of three species of Prochilodontidae (S. insignis, S. taeniurus, and Prochilodus lineatus (Valenciennes, 1836 by cross-FISH using Cot-1 DNA (renaturation kinetics probes. We found that the repetitive fractions of the genomes of S. insignis and S. taeniurus have significant amounts of conserved syntenic blocks in hybridization sites, but with low degrees of similarity between them and the genome of P. lineatus, especially in relation to B chromosomes. The cloning and sequencing of the repetitive genomic elements of S. insignis and S. taeniurus using Cot-1 DNA identified 48 fragments that displayed high similarity with repetitive sequences deposited in public DNA databases and classified as microsatellites, transposons, and retrotransposons. The repetitive fractions of the S. insignis and S. taeniurus genomes exhibited high degrees of conserved syntenic blocks in terms of both the structures and locations of hybridization sites, but a low degree of similarity with the syntenic blocks of the P. lineatus genome. Future comparative analyses of other prochilodontidae species will be needed to advance our understanding of the organization and evolution of the genomes in this group of fish.

Relationship Between Postural Control and Restricted, Repetitive Behaviors in Autism Spectrum Disorders

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Krestin eRadonovich

2013-05-01

Full Text Available Restricted, repetitive behaviors (RRBs are one of the core diagnostic criteria of autism spectrum disorders (ASD, and include simple repetitive motor behaviors and more complex cognitive behaviors, such as compulsions and restricted interests. In addition to the core symptoms, impaired movement is often observed in ASD. Research suggests that the postural system in individuals with ASD is immature and may never reach adult levels. RRBs have been related to postural sway in individuals with mental retardation.Our goals were to determine whether subjects with ASD had greater postural sway and whether RBS-R scores were related to the magnitude of postural sway. We compared the center of pressure (COP sway area during quiet stance with scores on the Repetitive Behavior Scale-Revised (RBS-R in children with ASD and typically developing controls (TD ages 3-16. All subjects had Nonverbal IQ>70. Subjects performed four quiet stance trials at a self–selected stance width for 15 seconds. Subjects with ASD had greater postural sway area compared to controls. Not surprisingly, subjects with ASD exhibited greater frequencies and intensities of RRBs overall and on all 6 subscales. Further, there was a positive correlation between postural sway area and presence of RRBs. Interestingly, results of the postural sway area for the ASD group suggests that roughly half of the ASD subjects scored comparable to TD controls, whereas the other half scored >2 SD worse. Motor impaired children did not have significantly worse IQ scores, but were younger and had more RRBs.Results support previous findings of relationships between RRBs and postural control. It appears that motor control impairments may characterize a subset of individuals with ASD. Better delineation of motor control abilities in individuals with ASD will be important to help explain variations of abilities in ASD, inform treatment, and guide examination of underlying neural involvement in this diverse

Hemispheric Asymmetries in Repetition Enhancement and Suppression Effects in the Newborn Brain.

Science.gov (United States)

Bouchon, Camillia; Nazzi, Thierry; Gervain, Judit

2015-01-01

The repeated presentation of stimuli typically attenuates neural responses (repetition suppression) or, less commonly, increases them (repetition enhancement) when stimuli are highly complex, degraded or presented under noisy conditions. In adult functional neuroimaging research, these repetition effects are considered as neural correlates of habituation. The development and respective functional significance of these effects in infancy remain largely unknown. This study investigates repetition effects in newborns using functional near-infrared spectroscopy, and specifically the role of stimulus complexity in evoking a repetition enhancement vs. a repetition suppression response, following up on Gervain et al. (2008). In that study, abstract rule-learning was found at birth in cortical areas specific to speech processing, as evidenced by a left-lateralized repetition enhancement of the hemodynamic response to highly variable speech sequences conforming to a repetition-based ABB artificial grammar, but not to a random ABC grammar. Here, the same paradigm was used to investigate how simpler stimuli (12 different sequences per condition as opposed to 140), and simpler presentation conditions (blocked rather than interleaved) would influence repetition effects at birth. Results revealed that the two grammars elicited different dynamics in the two hemispheres. In left fronto-temporal areas, we reproduce the early perceptual discrimination of the two grammars, with ABB giving rise to a greater response at the beginning of the experiment than ABC. In addition, the ABC grammar evoked a repetition enhancement effect over time, whereas a stable response was found for the ABB grammar. Right fronto-temporal areas showed neither initial discrimination, nor change over time to either pattern. Taken together with Gervain et al. (2008), this is the first evidence that manipulating methodological factors influences the presence or absence of neural repetition enhancement effects in

Hemispheric Asymmetries in Repetition Enhancement and Suppression Effects in the Newborn Brain.

Directory of Open Access Journals (Sweden)

Camillia Bouchon

Full Text Available The repeated presentation of stimuli typically attenuates neural responses (repetition suppression or, less commonly, increases them (repetition enhancement when stimuli are highly complex, degraded or presented under noisy conditions. In adult functional neuroimaging research, these repetition effects are considered as neural correlates of habituation. The development and respective functional significance of these effects in infancy remain largely unknown.This study investigates repetition effects in newborns using functional near-infrared spectroscopy, and specifically the role of stimulus complexity in evoking a repetition enhancement vs. a repetition suppression response, following up on Gervain et al. (2008. In that study, abstract rule-learning was found at birth in cortical areas specific to speech processing, as evidenced by a left-lateralized repetition enhancement of the hemodynamic response to highly variable speech sequences conforming to a repetition-based ABB artificial grammar, but not to a random ABC grammar.Here, the same paradigm was used to investigate how simpler stimuli (12 different sequences per condition as opposed to 140, and simpler presentation conditions (blocked rather than interleaved would influence repetition effects at birth.Results revealed that the two grammars elicited different dynamics in the two hemispheres. In left fronto-temporal areas, we reproduce the early perceptual discrimination of the two grammars, with ABB giving rise to a greater response at the beginning of the experiment than ABC. In addition, the ABC grammar evoked a repetition enhancement effect over time, whereas a stable response was found for the ABB grammar. Right fronto-temporal areas showed neither initial discrimination, nor change over time to either pattern.Taken together with Gervain et al. (2008, this is the first evidence that manipulating methodological factors influences the presence or absence of neural repetition enhancement

Influence of modulation frequency in rubidium cell frequency standards

Science.gov (United States)

Audoin, C.; Viennet, J.; Cyr, N.; Vanier, J.

1983-01-01

The error signal which is used to control the frequency of the quartz crystal oscillator of a passive rubidium cell frequency standard is considered. The value of the slope of this signal, for an interrogation frequency close to the atomic transition frequency is calculated and measured for various phase (or frequency) modulation waveforms, and for several values of the modulation frequency. A theoretical analysis is made using a model which applies to a system in which the optical pumping rate, the relaxation rates and the RF field are homogeneous. Results are given for sine-wave phase modulation, square-wave frequency modulation and square-wave phase modulation. The influence of the modulation frequency on the slope of the error signal is specified. It is shown that the modulation frequency can be chosen as large as twice the non-saturated full-width at half-maximum without a drastic loss of the sensitivity to an offset of the interrogation frequency from center line, provided that the power saturation factor and the amplitude of modulation are properly adjusted.

A clinical repetitive transcranial magnetic stimulation service in Australia: 6 years on.

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Galletly, Cherrie A; Clarke, Patrick; Carnell, Benjamin L; Gill, Shane

2015-11-01

There is considerable research evidence for the effectiveness of repetitive transcranial magnetic stimulation in the treatment of depression. However, there is little information about its acceptability and outcomes in clinical settings. This naturalistic study reports on a clinical repetitive transcranial magnetic stimulation service that has been running in Adelaide, South Australia (SA), for 6 years. During this time, 214 complete acute courses were provided to patients with treatment-resistant Major Depressive Disorder. Patients received either sequential bilateral or right unilateral repetitive transcranial magnetic stimulation treatment involving either 18 or 20 sessions given over 6 or 4 weeks respectively. Data included patient demographic details, duration of depression, and medication at the beginning of their repetitive transcranial magnetic stimulation course. The Hamilton Depression Rating Scale was used to assess response to repetitive transcranial magnetic stimulation. Of those undergoing a first-time acute treatment course of repetitive transcranial magnetic stimulation (N = 167), 28% achieved remission, while a further 12% met the criteria for a response to treatment. Most patients (N = 123, 77%) had previously been treated with five or more antidepressant medications, and 77 (47%) had previously received electroconvulsive therapy. Referral rates remained high over the 6 years, indicating acceptance of the treatment by referring psychiatrists. There were no significant adverse events, and the treatment was generally well tolerated. In all, 41 patients (25%) had a second course of repetitive transcranial magnetic stimulation and 6 (4%) patients had a third course; 21 patients subsequently received maintenance repetitive transcranial magnetic stimulation. This naturalistic study showed that repetitive transcranial magnetic stimulation was well accepted by both psychiatrists and patients, and has good efficacy and safety. Furthermore

A repetitive elements perspective in Polycomb epigenetics.

Directory of Open Access Journals (Sweden)

Valentina eCasa

2012-10-01

Full Text Available Repetitive elements comprise over two-thirds of the human genome. For a long time, these elements have received little attention since they were considered non functional. On the contrary, recent evidence indicates that they play central roles in genome integrity, gene expression and disease. Indeed, repeats display meiotic instability associated with disease and are located within common fragile sites, which are hotspots of chromosome rearrangements in tumors. Moreover, a variety of diseases have been associated with aberrant transcription of repetitive elements. Overall this indicates that appropriate regulation of repetitive elements’ activity is fundamental.Polycomb group (PcG proteins are epigenetic regulators that are essential for the normal development of multicellular organisms. Mammalian PcG proteins are involved in fundamental processes, such as cellular memory, cell proliferation, genomic imprinting, X-inactivation, and cancer development. PcG proteins can convey their activity through long-distance interactions also on different chromosomes. This indicates that the 3D organization of PcG proteins contributes significantly to their function. However, it is still unclear how these complex mechanisms are orchestrated and which role PcG proteins play in the multi-level organization of gene regulation. Intriguingly, the greatest proportion of Polycomb-mediated chromatin modifications is located in genomic repeats and it has been suggested that they could provide a binding platform for Polycomb proteins.Here, these lines of evidence are woven together to discuss how repetitive elements could contribute to chromatin organization in the 3D nuclear space.

The roles of stimulus repetition and hemispheric activation in visual half-field asymmetries.

Science.gov (United States)

Sullivan, K F; McKeever, W F

1985-10-01

Hardyck, Tzeng, and Wang (1978, Brain and Language, 5, 56-71) hypothesized that ample repetition of a small number of stimuli is required in order to obtain VHF differences in tachistoscopic tasks. Four experiments, with varied levels of repetition, were conducted to test this hypothesis. Three experiments utilized the general task of object-picture naming and one utilized a word-naming task. Naming latencies constituted the dependent measure. The results demonstrate that for the object-naming paradigm repetition is required for RVF superiority to emerge. Repetition was found to be unnecessary for RVF superiority in the word-naming paradigm, with repetition actually reducing RVF superiority. Experiment I suggested the possibility that RVF superiority developed for the second half of the trials as a function of practice or hemispheric activation, regardless of repetition level. Subsequent experiments, better designed to assess this possibility, clearly refuted it. It was concluded that the effect of repetition depends on the processing requirements of the task. We propose that, for tasks which can be processed efficiently by one hemisphere, the effect of repetition will be to reduce VHF asymmetries; but tasks requiring substantial processing by both hemispheres will show shifts to RVF superiority as a function of repetition.

Generalized Frequency-Domain Correlator for Software GPS Receiver: Preliminary Test Results and Analysis (PREPRINT)

National Research Council Canada - National Science Library

Yang, Chun; Miller, Mikel; Nguyen, Thao; Akos, Dennis

2006-01-01

.... The use of a GFDC can offer several advantages. First, as a generalization of the FFT-implemented correlation with a block repetitive processing capability, it enables fast acquisition through simultaneous code delay and Doppler frequency search...

A case of cerebral reversible vasoconstriction syndrome triggered by repetition transcranial magnetic stimulation.

Science.gov (United States)

Sato, Mamiko; Yamate, Koji; Hayashi, Hiromi; Miura, Toyoaki; Kobayashi, Yasutaka

2017-08-31

A 75-year-old man was admitted for combined low-frequency repetitive transcranial magnetic stimulation (rTMS) and intensive occupational therapy. Five days after the initiation of rTMS, he developed hypotension and temporary exacerbation of the right hemiplegia with thunderclap headache. MRA showed segmental stenosis of the left middle cerebral artery, which findings were improved at 9 days after the onset of the headache. He was diagnosed as having the reversible cerebral vasoconstriction syndrome (RCVS). The rTMS was recognized as safe rehabilitation treatment. However, it is necessary to recognize that RCVS can become one of the precipitants. This is the first report of RCVS triggered by rTMS.

Ultrafast electron diffraction with megahertz MeV electron pulses from a superconducting radio-frequency photoinjector

Energy Technology Data Exchange (ETDEWEB)

Feng, L. W.; Lin, L.; Huang, S. L.; Quan, S. W.; Hao, J. K.; Zhu, F.; Wang, F.; Liu, K. X., E-mail: kxliu@pku.edu.cn [Institute of Heavy Ion Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Jiang, T.; Zhu, P. F.; Fu, F.; Wang, R.; Zhao, L.; Xiang, D., E-mail: dxiang@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China)

2015-11-30

We report ultrafast relativistic electron diffraction operating at the megahertz repetition rate where the electron beam is produced in a superconducting radio-frequency (rf) photoinjector. We show that the beam quality is sufficiently high to provide clear diffraction patterns from gold and aluminium samples. With the number of electrons, several orders of magnitude higher than that from a normal conducting photocathode rf gun, such high repetition rate ultrafast MeV electron diffraction may open up many new opportunities in ultrafast science.

A 7.8 kV nanosecond pulse generator with a 500 Hz repetition rate

Science.gov (United States)

Lin, M.; Liao, H.; Liu, M.; Zhu, G.; Yang, Z.; Shi, P.; Lu, Q.; Sun, X.

2018-04-01

Pseudospark switches are widely used in pulsed power applications. In this paper, we present the design and performance of a 500 Hz repetition rate high-voltage pulse generator to drive TDI-series pseudospark switches. A high-voltage pulse is produced by discharging an 8 μF capacitor through a primary windings of a setup isolation transformer using a single metal-oxide-semiconductor field-effect transistor (MOSFET) as a control switch. In addition, a self-break spark gap is used to steepen the pulse front. The pulse generator can deliver a high-voltage pulse with a peak trigger voltage of 7.8 kV, a peak trigger current of 63 A, a full width at half maximum (FWHM) of ~30 ns, and a rise time of 5 ns to the trigger pin of the pseudospark switch. During burst mode operation, the generator achieved up to a 500 Hz repetition rate. Meanwhile, we also provide an AC heater power circuit for heating a H2 reservoir. This pulse generator can be used in circuits with TDI-series pseudospark switches with either a grounded cathode or with a cathode electrically floating operation. The details of the circuits and their implementation are described in the paper.

Influence of spatial and temporal spot distribution on the ocular surface quality and maximum ablation depth after photoablation with a 1050 Hz excimer laser system.

Science.gov (United States)

Mrochen, Michael; Schelling, Urs; Wuellner, Christian; Donitzky, Christof

2009-02-01

To investigate the effect of temporal and spatial distributions of laser spots (scan sequences) on the corneal surface quality after ablation and the maximum ablation of a given refractive correction after photoablation with a high-repetition-rate scanning-spot laser. IROC AG, Zurich, Switzerland, and WaveLight AG, Erlangen, Germany. Bovine corneas and poly(methyl methacrylate) (PMMA) plates were photoablated using a 1050 Hz excimer laser prototype for corneal laser surgery. Four temporal and spatial spot distributions (scan sequences) with different temporal overlapping factors were created for 3 myopic, 3 hyperopic, and 3 phototherapeutic keratectomy ablation profiles. Surface quality and maximum ablation depth were measured using a surface profiling system. The surface quality factor increased (rough surfaces) as the amount of temporal overlapping in the scan sequence and the amount of correction increased. The rise in surface quality factor was less for bovine corneas than for PMMA. The scan sequence might cause systematic substructures at the surface of the ablated material depending on the overlapping factor. The maximum ablation varied within the scan sequence. The temporal and spatial distribution of the laser spots (scan sequence) during a corneal laser procedure affected the surface quality and maximum ablation depth of the ablation profile. Corneal laser surgery could theoretically benefit from smaller spot sizes and higher repetition rates. The temporal and spatial spot distributions are relevant to achieving these aims.

Modeling repetitive motions using structured light.

Science.gov (United States)

Xu, Yi; Aliaga, Daniel G

2010-01-01

Obtaining models of dynamic 3D objects is an important part of content generation for computer graphics. Numerous methods have been extended from static scenarios to model dynamic scenes. If the states or poses of the dynamic object repeat often during a sequence (but not necessarily periodically), we call such a repetitive motion. There are many objects, such as toys, machines, and humans, undergoing repetitive motions. Our key observation is that when a motion-state repeats, we can sample the scene under the same motion state again but using a different set of parameters; thus, providing more information of each motion state. This enables robustly acquiring dense 3D information difficult for objects with repetitive motions using only simple hardware. After the motion sequence, we group temporally disjoint observations of the same motion state together and produce a smooth space-time reconstruction of the scene. Effectively, the dynamic scene modeling problem is converted to a series of static scene reconstructions, which are easier to tackle. The varying sampling parameters can be, for example, structured-light patterns, illumination directions, and viewpoints resulting in different modeling techniques. Based on this observation, we present an image-based motion-state framework and demonstrate our paradigm using either a synchronized or an unsynchronized structured-light acquisition method.

Body-focused repetitive behavior disorders in ICD-11

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Jon E. Grant

2014-01-01

Full Text Available This article addresses the question of how body-focused repetitive behavior disorders (e.g., trichotillomania and skin-picking disorder should be characterized in ICD-11. The article reviews the historical nosology of the two disorders and the current approaches in DSM-5 and ICD-10. Although data are limited and mixed regarding the optimal relationship between body-focused repetitive behavior disorders and nosological categories, these conditions should be included within the obsessive-compulsive and related disorders category, as this is how most clinicians see these behaviors, and as this may optimize clinical utility. The descriptions of these disorders should largely mirror those in DSM-5, given the evidence from recent field surveys. The recommendations regarding ICD-11 and body-focused repetitive behavior disorders should promote the global identification and treatment of these conditions in primary care settings.

Repetition suppression and multi-voxel pattern similarity differentially track implicit and explicit visual memory.

Science.gov (United States)

Ward, Emily J; Chun, Marvin M; Kuhl, Brice A

2013-09-11

Repeated exposure to a visual stimulus is associated with corresponding reductions in neural activity, particularly within visual cortical areas. It has been argued that this phenomenon of repetition suppression is related to increases in processing fluency or implicit memory. However, repetition of a visual stimulus can also be considered in terms of the similarity of the pattern of neural activity elicited at each exposure--a measure that has recently been linked to explicit memory. Despite the popularity of each of these measures, direct comparisons between the two have been limited, and the extent to which they differentially (or similarly) relate to behavioral measures of memory has not been clearly established. In the present study, we compared repetition suppression and pattern similarity as predictors of both implicit and explicit memory. Using functional magnetic resonance imaging, we scanned 20 participants while they viewed and categorized repeated presentations of scenes. Repetition priming (facilitated categorization across repetitions) was used as a measure of implicit memory, and subsequent scene recognition was used as a measure of explicit memory. We found that repetition priming was predicted by repetition suppression in prefrontal, parietal, and occipitotemporal regions; however, repetition priming was not predicted by pattern similarity. In contrast, subsequent explicit memory was predicted by pattern similarity (across repetitions) in some of the same occipitotemporal regions that exhibited a relationship between priming and repetition suppression; however, explicit memory was not related to repetition suppression. This striking double dissociation indicates that repetition suppression and pattern similarity differentially track implicit and explicit learning.

Repetition Blindness: Out of Sight or Out of Mind?

Science.gov (United States)

Morris, Alison L.; Harris, Catherine L.

2004-01-01

Does repetition blindness represent a failure of perception or of memory? In Experiment 1, participants viewed rapid serial visual presentation (RSVP) sentences. When critical words (C1 and C2) were orthographically similar, C2 was frequently omitted from serial report; however, repetition priming for C2 on a postsentence lexical decision task was…

Progress in developing repetitive pulse systems utilizing inductive energy storage

Energy Technology Data Exchange (ETDEWEB)

Honig, E.M.

1983-01-01

High-power, fast-recovery vacuum switches were used in a new repetitive counterpulse and transfer circuit to deliver a 5-kHz pulse train with a peak power of 75 MW (at 8.6 kA) to a 1-..cap omega.. load, resulting in the first demonstration of fully controlled, high-power, high-repetition-rate operation of an inductive energy-storage and transfer system with nondestructive switches. New circuits, analytical and experimental results, and feasibility of 100-kV repetitive pulse generation are discussed. A new switching concept for railgun loads is presented.

Experimental study of the performance of a very small repetitive plasma focus device in different working conditions

Energy Technology Data Exchange (ETDEWEB)

Goudarzi, S., E-mail: sgoudarzi@aeoi.org.ir; Babaee, H.; Esmaeli, A.; Nasiri, A. [Atomic Energy Organization of Iran, Plasma and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute (Iran, Islamic Republic of)

2017-01-15

SORENA-1 is a very small repetitive Mather-type plasma focus device (20 J) that can operate at frequencies up to 1 Hz. This device has been designed and constructed in the Plasma and Nuclear Fusion Research School of the Nuclear Science and Technology Research Institute of Iran. In this article, the structure of SORENA-1 is described and results of experiments with Ar, Ne, and D{sub 2} working gases at several discharge voltages and initial pressures are presented and analyzed.

The one repetition maximum test and the sit-to-stand test in the assessment of a specific pulmonary rehabilitation program on peripheral muscle strength in COPD patients.

Science.gov (United States)

Zanini, Andrea; Aiello, Marina; Cherubino, Francesca; Zampogna, Elisabetta; Azzola, Andrea; Chetta, Alfredo; Spanevello, Antonio

2015-01-01

Individuals with COPD may present reduced peripheral muscle strength, leading to impaired mobility. Comprehensive pulmonary rehabilitation (PR) should include strength training, in particular to lower limbs. Furthermore, simple tools for the assessment of peripheral muscle performance are required. To assess the peripheral muscle performance of COPD patients by the sit-to-stand test (STST), as compared to the one-repetition maximum (1-RM), considered as the gold standard for assessing muscle strength in non-laboratory situations, and to evaluate the responsiveness of STST to a PR program. Sixty moderate-to-severe COPD inpatients were randomly included into either the specific strength training group or into the usual PR program group. Patients were assessed on a 30-second STST and 1-minute STST, 1-RM, and 6-minute walking test (6MWT), before and after PR. Bland-Altman plots were used to evaluate the agreement between 1-RM and STST. The two groups were not different at baseline. In all patients, 1-RM was significantly related to the 30-second STST (r=0.48, Ptest. In the specific strength training group significant improvements were observed in the 30-second STST (P<0.001), 1-minute STST (P=0.005), 1-RM (P<0.001), and in the 6MWT (P=0.001). In the usual PR program group, significant improvement was observed in the 30-second STST (P=0.042) and in the 6MWT (P=0.001). Our study shows that in stable moderate-to-severe inpatients with COPD, STST is a valid and reliable tool to assess peripheral muscle performance of lower limbs, and is sensitive to a specific PR program.

Repetitive tactile stimulation changes resting-state functional connectivity – implications for treatment of sensorimotor decline

Directory of Open Access Journals (Sweden)

Frank eFreyer

2012-05-01

Full Text Available Neurological disorders and physiological aging can lead to a decline of perceptual abilities. In contrast to the conventional therapeutic approach that comprises intensive training and practicing, passive repetitive sensory stimulation (RSS has recently gained increasing attention as an alternative to countervail the sensory decline by improving perceptual abilities without the need of active participation. A particularly effective type of high-frequency RSS, utilizing Hebbian learning principles, improves perceptual acuity as well as sensorimotor functions and has been successfully applied to treat chronic stroke patients and elderly subjects. High-frequency RSS has been shown to induce plastic changes of somatosensory cortex such as representational map reorganization, but its impact on the brain’s ongoing network activity and resting-state functional connectivity has not been investigated so far. Here, we applied high-frequency RSS in healthy human subjects and analyzed resting state Electroencephalography (EEG functional connectivity patterns before and after RSS by means of imaginary coherency (ImCoh, a frequency-specific connectivity measure which is known to reduce overestimation biases due to volume conduction and common reference. Thirty minutes of passive high-frequency RSS lead to significant ImCoh-changes of the resting state mu-rhythm in the individual upper alpha frequency band within distributed sensory and motor cortical areas. These stimulation induced distributed functional connectivity changes likely underlie the previously observed improvement in sensorimotor integration.

Table for monthly average daily extraterrestrial irradiation on horizontal surface and the maximum possible sunshine duration

International Nuclear Information System (INIS)

Jain, P.C.

1984-01-01

The monthly average daily values of the extraterrestrial irradiation on a horizontal surface (H 0 ) and the maximum possible sunshine duration are two important parameters that are frequently needed in various solar energy applications. These are generally calculated by scientists each time they are needed and by using the approximate short-cut methods. Computations for these values have been made once and for all for latitude values of 60 deg. N to 60 deg. S at intervals of 1 deg. and are presented in a convenient tabular form. Values of the maximum possible sunshine duration as recorded on a Campbell Stoke's sunshine recorder are also computed and presented. These tables should avoid the need for repetition and approximate calculations and serve as a useful ready reference for solar energy scientists and engineers. (author)

Repetitive laser fusion experiment and operation using a target injection system

International Nuclear Information System (INIS)

Nishimura, Yasuhiko; Komeda, Osamu; Mori, Yoshitaka

2017-01-01

Since 2008, a collaborative research project on laser fusion development based on a high-speed ignition method using repetitive laser has been carried out with several collaborative research institutes. This paper reports the current state of operation of high repetition laser fusion experiments, such as target introduction and control based on a target injection system that allows free falling under 1 Hz, using a high repetition laser driver that has been under research and development, as well as the measurement of targets that freely fall. The HAMA laser driver that enabled high repetition fusion experiments is a titanium sapphire laser using a diode-pumped solid-state laser KURE-I of green light output as a driver pump light source. In order to carry out high repetition laser fusion experiments, the target injection device allows free falling of deuterated polystyrene solid sphere targets of 1 mm in diameter under 1 Hz. The authors integrated the developed laser and injection system, and succeeded first in the world in making the nuclear fusion reaction continuously by hitting the target to be injected with laser, which is essential technology for future laser nuclear fusion reactor. In order to realize repetition laser fusion experiments, stable laser, target synchronization control, and target position measurement technologies are indispensable. (A.O.)

Preliminary design of a 150 kJ repetitive plasma focus for the production of 18-F

Science.gov (United States)

Sumini, Marco; Mostacci, Domiziano; Rocchi, Federico; Frignani, Michele; Tartari, Agostino; Angeli, Ergisto; Galaverni, Dario; Coli, Ugo; Ascione, Bernardino; Cucchi, Giorgio

2006-06-01

Experiments in the past five years have demonstrated production of short-lived radioisotopes with a Plasma Focus device, using the so-termed Endogenous Mode. So far radioisotope activities of only a few microcuries have been obtained from single discharges in small scale Plasma Focus machines (capacitor bank energies of approximately 7 kJ). It is expected that higher activities could be obtained with larger bank energies, operating at high pulse repetition rates, e.g. 1 Hz. However, many scientific and technological issues must be addressed for a high-energy Plasma Focus device to run at one pulse per second. Aim of this paper is to present preliminary results pertaining to the plasma, electrical, fluid-dynamical, thermal, material and mechanical design of a 150 kJ Plasma Focus, capable of a repetition rate of 1 Hz, that will be operated at 30 kV with a 350 μF capacitor bank and a maximum total current of 1.5 MA. This device will be used to breed 18-F for the synthesis of drugs used in positron-emission medical examinations, such as FDG for PET.

Preliminary design of a 150 kJ repetitive plasma focus for the production of 18-F

International Nuclear Information System (INIS)

Sumini, Marco; Mostacci, Domiziano; Rocchi, Federico; Frignani, Michele; Tartari, Agostino; Angeli, Ergisto; Galaverni, Dario; Coli, Ugo; Ascione, Bernardino; Cucchi, Giorgio

2006-01-01

Experiments in the past five years have demonstrated production of short-lived radioisotopes with a Plasma Focus device, using the so-termed Endogenous Mode. So far radioisotope activities of only a few microcuries have been obtained from single discharges in small scale Plasma Focus machines (capacitor bank energies of approximately 7 kJ). It is expected that higher activities could be obtained with larger bank energies, operating at high pulse repetition rates, e.g. 1 Hz. However, many scientific and technological issues must be addressed for a high-energy Plasma Focus device to run at one pulse per second. Aim of this paper is to present preliminary results pertaining to the plasma, electrical, fluid-dynamical, thermal, material and mechanical design of a 150 kJ Plasma Focus, capable of a repetition rate of 1 Hz, that will be operated at 30 kV with a 350 μF capacitor bank and a maximum total current of 1.5 MA. This device will be used to breed 18-F for the synthesis of drugs used in positron-emission medical examinations, such as FDG for PET

Repetition and brain potentials when recognizing natural scenes: task and emotion differences

Science.gov (United States)

Bradley, Margaret M.; Codispoti, Maurizio; Karlsson, Marie; Lang, Peter J.

2013-01-01

Repetition has long been known to facilitate memory performance, but its effects on event-related potentials (ERPs), measured as an index of recognition memory, are less well characterized. In Experiment 1, effects of both massed and distributed repetition on old–new ERPs were assessed during an immediate recognition test that followed incidental encoding of natural scenes that also varied in emotionality. Distributed repetition at encoding enhanced both memory performance and the amplitude of an old–new ERP difference over centro-parietal sensors. To assess whether these repetition effects reflect encoding or retrieval differences, the recognition task was replaced with passive viewing of old and new pictures in Experiment 2. In the absence of an explicit recognition task, ERPs were completely unaffected by repetition at encoding, and only emotional pictures prompted a modestly enhanced old–new difference. Taken together, the data suggest that repetition facilitates retrieval processes and that, in the absence of an explicit recognition task, differences in old–new ERPs are only apparent for affective cues. PMID:22842817

The "sticking period" in a maximum bench press.

Science.gov (United States)

van den Tillaar, Roland; Ettema, Gertjan

2010-03-01

The purpose of this study was to examine muscle activity and three-dimensional kinematics in the ascending phase of a successful one-repetition maximum attempt in bench press for 12 recreational weight-training athletes, with special attention to the sticking period. The sticking period was defined as the first period of deceleration of the upward movement (i.e. from the highest barbell velocity until the first local lowest barbell velocity). All participants showed a sticking period during the upward movement that started about 0.2 s after the initial upward movement, and lasted about 0.9 s. Electromyography revealed that the muscle activity of the prime movers changed significantly from the pre-sticking to the sticking and post-sticking periods. A possible mechanism for the existence of the sticking period is the diminishing potentiation of the contractile elements during the upward movement together with the limited activity of the pectoral and deltoid muscles during this period.

Maximum power gains of radio-frequency-driven two-energy-component tokamak reactors

International Nuclear Information System (INIS)

Jassby, D.L.

1974-11-01

Two-energy-component fusion reactors in which the suprathermal component (D) is produced by harmonic cyclotron ''runaway'' of resonant ions are considered. In one ideal case, the fast hydromagnetic wave at ω = 2ω/sub cD/ produces an energy distribution f(W) approximately constant (up to W/sub max/) that includes all deuterons, which then thermalize and react with the cold tritons. In another ideal case, f(W) approximately constant is maintained by the fast wave at ω = ω/sub cD/. If one neglects (1) direct rf input to the bulk-plasma electrons and tritons, and (2) the fact that many deuterons are not resonantly accelerated, then the maximum ideal power gain is about 0.85 Q/sub m/ in the first case and 1.05 Q/sub m/ in the second case, where Q/sub m/ is the maximum fusion gain in the beam-injection scheme (e.g., Q/sub m/ = 1.9 at T/sub e/ = 10 keV). Because of nonideal effects, the cyclotron runaway phenomenon may find its most practical use in the heating of 50:50 D--T plasmas to ignition. (auth)

Effect of repetitive transcranial magnetic stimulation on rectal function and emotion in humans

International Nuclear Information System (INIS)

Aizawa, Yuuichi; Morishita, Joe; Kano, Michiko; Mori, Takayuki; Izumi, Shin-ichi; Kanazawa, Motoyori; Fukudo, Shin; Tsutsui, Kenichiro; Iijima, Toshio

2011-01-01

A previous brain imaging study demonstrated activation of the right dorsolateral prefrontal cortex (DLPFC) during visceral nociception, and this activation was associated with anxiety. We hypothesized that functional modulation of the right DLPFC by repetitive transcranial magnetic stimulation (rTMS) can reveal the actual role of right DLPFC in brain-gut interactions in humans. Subjects were 11 healthy males aged 23.5±1.4 (mean±spin echo (SE)) years. Viscerosensory evoked potential (VEP) with sham (0 mA) or actual (30 mA) electrical stimulation (ES) of the rectum was taken after sham, low frequency rTMS at 0.1 Hz, and high frequency rTMS at 10 Hz to the right DLPFC. Rectal tone was measured with a rectal barostat. Visceral perception and emotion were analyzed using an ordinate scale, rectal barostat, and VEP. Low frequency rTMS significantly reduced anxiety evoked by ES at 30 mA (p<0.05). High frequency rTMS-30 mA ES significantly produced more phasic volume events than sham rTMS-30 mA ES (p<0.05). We successfully modulated the gastrointestinal function of healthy individuals through rTMS to the right DLPFC. Thus, rTMS to the DLPFC appears to modulate the affective, but not direct, component of visceral perception and motility of the rectum. (author)

Effect of kinetically altering a repetition via the use of chain resistance on velocity during the bench press.

Science.gov (United States)

Baker, Daniel G; Newton, Robert U

2009-10-01

It is theorized that the force and velocity profile of a repetition performed during a standard barbell exercise may be altered by substituting suspended chains for some portion of the total resistance. The purpose of this study was to document the alterations in lifting velocity that occur when the bench press exercise is performed as standard (BP) or with the substitution of resistance via chains draped over the barbell (BP+CH). Thirteen professional rugby league players participated in this study as part of their usual training program. Each subject performed 2 sets of 3 repetitions under the following conditions: The BP+CH condition, where the barbell resistance of 60% 1RM (repetition maximum) was supplemented by 17.5-kg in chains draped over the barbell (total resistance was about 75% 1RM), and the BP condition, where the total resistance was the same but was constituted in the form of standard barbell weights. The BP+CH condition resulted in increases in mean and peak concentric lifting velocities of around 10% in both sets as compared to both BP sets. Eccentric peak velocities were more varied in response, but generally the addition of chain resistance could be said to allow for increased velocities. The result may be partially explained by the eccentric unloading that occurs as the chain links furl upon the floor in the latter stages of the eccentric range. This eccentric unloading precipitates a more rapid stretch-shorten cycle (SSC) transition and possibly a within-repetition postactivation potentiation (PAP) that allows the subject to utilize faster lifting velocities in the initial concentric portion, which flow through to the remainder of the concentric phase. Therefore the use of chains appears warranted when athletes need to lift heavy resistances explosively.

Repetition or Reconfiguration

DEFF Research Database (Denmark)

Andersen, Kristina Vaarst

, the cognitive quality of knowledge held by individual professionals is the key microfoundation for project level performance. This paper empirically tests effects of project participants with and without knowledge diversity for project level performance for projects aiming for varying degrees of repetition...... and reconfiguration. The results indicate that project performance benefits form contributions from individuals holding diverse knowledge only when projects aim for high differentiation levels. This positive association is not just moderated, it may even be reversed in the case of professionals participating in low...

On Maximum Entropy and Inference

Directory of Open Access Journals (Sweden)

Luigi Gresele

2017-11-01

Full Text Available Maximum entropy is a powerful concept that entails a sharp separation between relevant and irrelevant variables. It is typically invoked in inference, once an assumption is made on what the relevant variables are, in order to estimate a model from data, that affords predictions on all other (dependent variables. Conversely, maximum entropy can be invoked to retrieve the relevant variables (sufficient statistics directly from the data, once a model is identified by Bayesian model selection. We explore this approach in the case of spin models with interactions of arbitrary order, and we discuss how relevant interactions can be inferred. In this perspective, the dimensionality of the inference problem is not set by the number of parameters in the model, but by the frequency distribution of the data. We illustrate the method showing its ability to recover the correct model in a few prototype cases and discuss its application on a real dataset.

Visual attention to advertising : The impact of motivation and repetition

NARCIS (Netherlands)

Pieters, RGM; Rosbergen, E; Hartog, M; Corfman, KP; Lynch, JG

1996-01-01

Using eye-tracking data, we examine the impact of motivation and repetition on visual attention to advertisements differing in argument quality. Our analyses indicate that repetition leads to an overall decrease in the amount of attention. However, while at first high motivation subjects attend to

Extending Injury- and Disease-Resistant CNS Phenotypes by Repetitive Epigenetic Conditioning

Directory of Open Access Journals (Sweden)

Jeffrey M. Gidday

2015-03-01

Full Text Available Significant reductions in the extent of acute injury in the CNS can be achieved by exposure to different preconditioning stimuli, but the duration of the induced protective phenotype is typically short-lasting, and thus is deemed as limiting its clinical applicability. Extending the period over which such adaptive epigenetic changes persist – in effect, expanding conditioning’s therapeutic window – would significantly broaden the potential applications of such a treatment approach in patients. The frequency of the conditioning stimulus may hold the key. While transient (1-3 days protection against CNS ischemic injury is well established preclinically following a single preconditioning stimulus, repetitively presenting preconditioning stimuli extends the duration of ischemic tolerance by many weeks. Moreover, repetitive intermittent postconditioning enhances postischemic recovery metrics and improves long-term survival. Intermittent conditioning is also efficacious for preventing or delaying injury in preclinical models of chronic neurodegenerative disease, and for promoting long-lasting functional improvements in a number of other pathologies as well. Although the detailed mechanisms underlying these protracted kinds of neuroplasticity remain largely unstudied, accumulating empirical evidence supports the contention that all of these adaptive phenotypes are epigenetically mediated. Going forward, additional preclinical demonstrations of the ability to induce sustained beneficial phenotypes that reduce the burden of acute and chronic neurodegeneration, and experimental interrogations of the regulatory constructs responsible for these epigenetic responses, will accelerate the identification of not only efficacious, but practical, adaptive epigenetics-based treatments for individuals with neurological disease.

Pull-production in repetitive remanufacturing

Energy Technology Data Exchange (ETDEWEB)

McCaskey, D.W. Jr.

1992-09-01

In the past, production activity control practices in most repetitive remanufacturing facilities resembled those used in intermittent production operations. These operations were characterized by large amounts of work-in-process (WIP), frequent work stoppages due to part shortages, excessive overtime, low product velocity, informal scheduling between dependent operations, low employee and management moral, and a lot of wasted time, material, labor, and space. Improvement in production activity control (PAC) methods for repetitive remanufactures has been hampered by uncertainty in: supply of incoming assets, configuration of assets, process times to refurbish assets, and yields in reclamation processes. collectively these uncertainties make shop floor operations seem uncontrollable. However, one United States Army depot has taken on the challenge. Through management supported, cross-functional teams, the Tooele Army Depot has designed and implemented pull-production systems for two of its major products, with several others to follow. This article presents a generalized version of Tooele`s pull-production system and highlights design characteristics which are specific to remanufacturing applications.

Pull-production in repetitive remanufacturing

Energy Technology Data Exchange (ETDEWEB)

McCaskey, D.W. Jr.

1992-09-01

In the past, production activity control practices in most repetitive remanufacturing facilities resembled those used in intermittent production operations. These operations were characterized by large amounts of work-in-process (WIP), frequent work stoppages due to part shortages, excessive overtime, low product velocity, informal scheduling between dependent operations, low employee and management moral, and a lot of wasted time, material, labor, and space. Improvement in production activity control (PAC) methods for repetitive remanufactures has been hampered by uncertainty in: supply of incoming assets, configuration of assets, process times to refurbish assets, and yields in reclamation processes. collectively these uncertainties make shop floor operations seem uncontrollable. However, one United States Army depot has taken on the challenge. Through management supported, cross-functional teams, the Tooele Army Depot has designed and implemented pull-production systems for two of its major products, with several others to follow. This article presents a generalized version of Tooele's pull-production system and highlights design characteristics which are specific to remanufacturing applications.

Active power filter for harmonic compensation using a digital dual-mode-structure repetitive control approach

DEFF Research Database (Denmark)

Zou, Zhixiang; Wang, Zheng; Cheng, Ming

2012-01-01

This paper presents an digital dual-mode-structure repetitive control approach for the single-phase shunt active power filter (APF), which aims to enhance the tracking ability and eliminate arbitrary order harmonic. The proposed repetitive control scheme blends the characteristics of both odd......-harmonic repetitive control and even-harmonic repetitive control. Moreover, the convergence rate is faster than conventional repetitive controller. Additionally, the parameters have been designed and optimized for the dual-mode structure repetitive control to improve the performance of APF system. Experimental...

Improved discrimination of visual stimuli following repetitive transcranial magnetic stimulation.

Directory of Open Access Journals (Sweden)

Michael L Waterston

Full Text Available BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS at certain frequencies increases thresholds for motor-evoked potentials and phosphenes following stimulation of cortex. Consequently rTMS is often assumed to introduce a "virtual lesion" in stimulated brain regions, with correspondingly diminished behavioral performance. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated the effects of rTMS to visual cortex on subjects' ability to perform visual psychophysical tasks. Contrary to expectations of a visual deficit, we find that rTMS often improves the discrimination of visual features. For coarse orientation tasks, discrimination of a static stimulus improved consistently following theta-burst stimulation of the occipital lobe. Using a reaction-time task, we found that these improvements occurred throughout the visual field and lasted beyond one hour post-rTMS. Low-frequency (1 Hz stimulation yielded similar improvements. In contrast, we did not find consistent effects of rTMS on performance in a fine orientation discrimination task. CONCLUSIONS/SIGNIFICANCE: Overall our results suggest that rTMS generally improves or has no effect on visual acuity, with the nature of the effect depending on the type of stimulation and the task. We interpret our results in the context of an ideal-observer model of visual perception.

GHz band frequency hopping PLL-based frequency synthesizers

Institute of Scientific and Technical Information of China (English)

XU Yong; WANG Zhi-gong; GUAN Yu; XU Zhi-jun; QIAO Lu-feng

2005-01-01

In this paper we describe a full-integrated circuit containing all building blocks of a completed PLL-based synthesizer except for low pass filter(LPF).The frequency synthesizer is designed for a frequency hopping (FH) transceiver operating up to 1.5 GHz as a local oscillator. The architecture of Voltage Controlled Oscillator (VCO) is optimized to get better performance, and a phase noise of -111.85-dBc/Hz @ 1 MHz and a tuning range of 250 MHz are gained at a centre frequency of 1.35 GHz.A novel Dual-Modulus Prescaler(DMP) is designed to achieve a very low jitter and a lower power.The settling time of PLL is 80 μs while the reference frequency is 400 KHz.This monolithic frequency synthesizer is to integrate all main building blocks of PLL except for the low pass filter,with a maximum VCO output frequency of 1.5 GHz,and is fabricated with a 0.18 μm mixed signal CMOS process. Low power dissipation, low phase noise, large tuning range and fast settling time are gained in this design.

Changes in spine loading patterns throughout the workday as a function of experience, lift frequency, and personality.

Science.gov (United States)

Chany, Anne-Marie; Parakkat, Julia; Yang, Gang; Burr, Deborah L; Marras, William S

2006-01-01

Psychosocial stressors have been associated with low back pain reporting. However, response to psychosocial risk factors may be dependent on the individual's personality type that, in turn, can affect muscle recruitment and spine loading. This study explores how personality might be associated with spine loading during repetitive lifting performed throughout an entire work shift. Assess spine loading as a function of an individual's personality type during repetitive, long-term exposure to a materials handling tasks. Laboratory experiment where experienced and inexperienced participants performed repetitive, asymmetric lifts at various load and lift frequency levels throughout a series of 8-hour exposure periods. Spine loads were monitored throughout the work period. Twelve novice and 12 experienced materials handlers who were asymptomatic for back pain. Spine compression, anterior-posterior (A/P) shear, and lateral shear at the L5-S1 level. Participants were categorized into personality types based upon the Myers-Briggs personality type indicator. An electromyography-assisted biomechanical model was used to assess spine compression, A/P shear, and lateral shear throughout the exposure period. The results indicate that intuitors had higher shear spinal loading regardless of moment exposure, lift frequency, and time through the work period, compared with the sensor personality type. In addition, higher spine compressive and shear forces occurred in the perceiver personality compared with the judgers' personality trait, regardless of moment and, often, lift frequency. Novice lifters typically experienced greater spine loading. The results suggest that when there exists a personality-job environment mismatch, spinal loading increases via an increase in antagonistic co-contraction. The trends suggest that inherent personality characteristics may play a role in one's motor control strategies when performing a repetitive lifting task.

Effects of low-frequency repetitive transcranial magnetic stimulation on upper extremity motor recovery and functional outcomes in chronic stroke patients: A randomized controlled trial.

Science.gov (United States)

Aşkın, Ayhan; Tosun, Aliye; Demirdal, Ümit Seçil

2017-06-01

Repetitive transcranial magnetic stimulation (rTMS) was suggested as a preconditioning method that would increase brain plasticity and that it would be optimal to combine rTMS with intensive rehabilitation. To assess the efficacy of inhibitory rTMS on upper extremity motor recovery and functional outcomes in chronic ischemic stroke patients. In this randomized controlled trial, experimental group received low-frequency (LF) rTMS to the primary motor cortex of the unaffected side + physical therapy (PT), and control group received PT. No statistically significant difference was found in baseline demographical and clinical characteristics of the subjects including stroke severity or severity of paralysis prior to intervention. There were statistically significant improvements in all clinical outcome measures except for the Brunnstrom Recovery Stages. Fugl-Meyer Assessment, Box and Block test, motor and total scores of Functional Independence Measurement (FIM), and Functional Ambulation Scale (FAS) scores were significantly increased in both groups, however, these changes were significantly greater in the rTMS group except for FAS score. FIM cognitive scores and standardized mini-mental test scores were significantly increased and distal and hand Modified Ashworth Scale scores were significantly decreased only in the rTMS group (p functional, and cognitive deficits in chronic stroke. Further studies with a larger number of patients with longer follow-up periods are needed to establish its effectiveness in stroke rehabilitation.

Negative effects of item repetition on source memory

OpenAIRE

Kim, Kyungmi; Yi, Do-Joon; Raye, Carol L.; Johnson, Marcia K.

2012-01-01

In the present study, we explored how item repetition affects source memory for new item–feature associations (picture–location or picture–color). We presented line drawings varying numbers of times in Phase 1. In Phase 2, each drawing was presented once with a critical new feature. In Phase 3, we tested memory for the new source feature of each item from Phase 2. Experiments 1 and 2 demonstrated and replicated the negative effects of item repetition on incidental source memory. Prior item re...

Functional dissociations in top-down control dependent neural repetition priming.

NARCIS (Netherlands)

Klaver, P.; Schnaidt, M.; Fell, J.; Ruhlmann, J.; Elger, C.E.; Fernandez, G.S.E.

2007-01-01

Little is known about the neural mechanisms underlying top-down control of repetition priming. Here, we use functional brain imaging to investigate these mechanisms. Study and repetition tasks used a natural/man-made forced choice task. In the study phase subjects were required to respond to either

Practical system for the generation of pulsed quantum frequency combs.

Science.gov (United States)

Roztocki, Piotr; Kues, Michael; Reimer, Christian; Wetzel, Benjamin; Sciara, Stefania; Zhang, Yanbing; Cino, Alfonso; Little, Brent E; Chu, Sai T; Moss, David J; Morandotti, Roberto

2017-08-07

The on-chip generation of large and complex optical quantum states will enable low-cost and accessible advances for quantum technologies, such as secure communications and quantum computation. Integrated frequency combs are on-chip light sources with a broad spectrum of evenly-spaced frequency modes, commonly generated by four-wave mixing in optically-excited nonlinear micro-cavities, whose recent use for quantum state generation has provided a solution for scalable and multi-mode quantum light sources. Pulsed quantum frequency combs are of particular interest, since they allow the generation of single-frequency-mode photons, required for scaling state complexity towards, e.g., multi-photon states, and for quantum information applications. However, generation schemes for such pulsed combs have, to date, relied on micro-cavity excitation via lasers external to the sources, being neither versatile nor power-efficient, and impractical for scalable realizations of quantum technologies. Here, we introduce an actively-modulated, nested-cavity configuration that exploits the resonance pass-band characteristic of the micro-cavity to enable a mode-locked and energy-efficient excitation. We demonstrate that the scheme allows the generation of high-purity photons at large coincidence-to-accidental ratios (CAR). Furthermore, by increasing the repetition rate of the excitation field via harmonic mode-locking (i.e. driving the cavity modulation at harmonics of the fundamental repetition rate), we managed to increase the pair production rates (i.e. source efficiency), while maintaining a high CAR and photon purity. Our approach represents a significant step towards the realization of fully on-chip, stable, and versatile sources of pulsed quantum frequency combs, crucial for the development of accessible quantum technologies.

Intraglomerular inhibition maintains mitral cell response contrast across input frequencies.

Science.gov (United States)

Shao, Zuoyi; Puche, Adam C; Shipley, Michael T

2013-11-01

Odor signals are transmitted to the olfactory bulb by olfactory nerve (ON) synapses onto mitral/tufted cells (MTCs) and external tufted cells (ETCs); ETCs provide additional feed-forward excitation to MTCs. Both are strongly regulated by intraglomerular inhibition that can last up to 1 s and, when blocked, dramatically increases ON-evoked MC spiking. Intraglomerular inhibition thus limits the magnitude and duration of MC spike responses to sensory input. In vivo, sensory input is repetitive, dictated by sniffing rates from 1 to 8 Hz, potentially summing intraglomerular inhibition. To investigate this, we recorded MTC responses to 1- to 8-Hz ON stimulation in slices. Inhibitory postsynaptic current area (charge) following each ON stimulation was unchanged from 1 to 5 Hz and modestly paired-pulse attenuated at 8 Hz, suggesting there is no summation and only limited decrement at the highest input frequencies. Next, we investigated frequency independence of intraglomerular inhibition on MC spiking. MCs respond to single ON shocks with an initial spike burst followed by reduced spiking decaying to baseline. Upon repetitive ON stimulation peak spiking is identical across input frequencies but the ratio of peak-to-minimum rate before the stimulus (max-min) diminishes from 30:1 at 1 Hz to 15:1 at 8 Hz. When intraglomerular inhibition is selectively blocked, peak spike rate is unchanged but trough spiking increases markedly decreasing max-min firing ratios from 30:1 at 1 Hz to 2:1 at 8 Hz. Together, these results suggest intraglomerular inhibition is relatively frequency independent and can "sharpen" MC responses to input across the range of frequencies. This suggests that glomerular circuits can maintain "contrast" in MC encoding during sniff-sampled inputs.

Autism and exergaming: effects on repetitive behaviors and cognition.

Science.gov (United States)

Anderson-Hanley, Cay; Tureck, Kimberly; Schneiderman, Robyn L

2011-01-01

Autism is a neurodevelopmental disorder that leads to impairment in social skills and delay in language development, and results in repetitive behaviors and restricted interests that impede academic and social involvement. Physical exercise has been shown to decrease repetitive behaviors in autistic children and improve cognitive function across the life-span. Exergaming combines physical and mental exercise simultaneously by linking physical activity movements to video game control and may yield better compliance with exercise. In this investigation, two pilot studies explored the potential behavioral and cognitive benefits of exergaming. In Pilot I, twelve children with autism spectrum disorders completed a control task and an acute bout of Dance Dance Revolution (DDR); in Pilot II, ten additional youths completed an acute bout of cyber cycling. Repetitive behaviors and executive function were measured before and after each activity. Repetitive behaviors significantly decreased, while performance on Digits Backwards improved following the exergaming conditions compared with the control condition. Additional research is needed to replicate these findings, and to explore the application of exergaming for the management of behavioral disturbance and to increase cognitive control in children on the autism spectrum.

Understanding the relationship between repetition priming and mere exposure.

Science.gov (United States)

Butler, Laurie T; Berry, Dianne C

2004-11-01

Over the last two decades interest in implicit memory, most notably repetition priming, has grown considerably. During the same period, research has also focused on the mere exposure effect. Although the two areas have developed relatively independently, a number of studies has described the mere exposure effect as an example of implicit memory. Tacit in their comparisons is the assumption that the effect is more specifically a demonstration of repetition priming. Having noted that this assumption has attracted relatively little attention, this paper reviews current evidence and shows that it is by no means conclusive. Although some evidence is suggestive of a common underlying mechanism, even a modified repetition priming (perceptual fluency/attribution) framework cannot accommodate all of the differences between the two phenomena. Notwithstanding this, it seems likely that a version of this theoretical framework still offers the best hope of a comprehensive explanation for the mere exposure effect and its relationship to repetition priming. As such, the paper finishes by offering some initial guidance as to ways in which the perceptual fluency/attribution framework might be extended, as well as outlining important areas for future research.

High-throughput machining using high average power ultrashort pulse lasers and ultrafast polygon scanner

Science.gov (United States)

Schille, Joerg; Schneider, Lutz; Streek, André; Kloetzer, Sascha; Loeschner, Udo

2016-03-01

In this paper, high-throughput ultrashort pulse laser machining is investigated on various industrial grade metals (Aluminium, Copper, Stainless steel) and Al2O3 ceramic at unprecedented processing speeds. This is achieved by using a high pulse repetition frequency picosecond laser with maximum average output power of 270 W in conjunction with a unique, in-house developed two-axis polygon scanner. Initially, different concepts of polygon scanners are engineered and tested to find out the optimal architecture for ultrafast and precision laser beam scanning. Remarkable 1,000 m/s scan speed is achieved on the substrate, and thanks to the resulting low pulse overlap, thermal accumulation and plasma absorption effects are avoided at up to 20 MHz pulse repetition frequencies. In order to identify optimum processing conditions for efficient high-average power laser machining, the depths of cavities produced under varied parameter settings are analyzed and, from the results obtained, the characteristic removal values are specified. The maximum removal rate is achieved as high as 27.8 mm3/min for Aluminium, 21.4 mm3/min for Copper, 15.3 mm3/min for Stainless steel and 129.1 mm3/min for Al2O3 when full available laser power is irradiated at optimum pulse repetition frequency.

Resonant circuit which provides dual frequency excitation for rapid cycling of an electromagnet

Science.gov (United States)

Praeg, Walter F.

1984-01-01

Disclosed is a ring magnet control circuit that permits synchrotron repetition rates much higher than the frequency of the cosinusoidal guide field of the ring magnet during particle acceleration. the control circuit generates cosinusoidal excitation currents of different frequencies in the half waves. During radio frequency acceleration of the particles in the synchrotron, the control circuit operates with a lower frequency cosine wave and thereafter the electromagnets are reset with a higher frequency half cosine wave. Flat-bottom and flat-top wave shaping circuits maintain the magnetic guide field in a relatively time-invariant mode during times when the particles are being injected into the ring magnets and when the particles are being ejected from the ring magnets.

The effects of poliomyelitis on motor unit behavior during repetitive muscle actions: a case report.

Science.gov (United States)

Trevino, Michael A; Herda, Trent J; Cooper, Michael A

2014-09-06

Acute paralytic poliomyelitis is caused by the poliovirus and usually results in muscle atrophy and weakness occurring in the lower limbs. Indwelling electromyography has been used frequently to investigate the denervation and innervation characteristics of the affected muscle. Recently developed technology allows the decomposition of the raw surface electromyography signals into the firing instances of single motor units. There is limited information regarding this electromyographic decomposition in clinical populations. In addition, regardless of electromyographic methods, no study has examined muscle activation parameters during repetitive muscle actions in polio patients. Therefore, the purpose of this study was to examine the motor unit firing rates and electromyographic amplitude and center frequency of the vastus lateralis during 20 repetitive isometric muscle actions at 50% maximal voluntary contraction in healthy subjects and one patient that acquired acute paralytic poliomyelitis. One participant that acquired acute type III spinal poliomyelitis (Caucasian male, age = 29 yrs) at 3 months of age and three healthy participants (Caucasian females, age = 19.7 ± 2.1 yrs) participated in this study. The polio participant reported neuromuscular deficiencies as a result of disease in the hips, knees, buttocks, thighs, and lower legs. None of the healthy participants reported any current or ongoing neuromuscular diseases or musculoskeletal injuries. An acute bout of poliomyelitis altered motor unit behavior, such as, healthy participants displayed greater firing rates than the polio patient. The reduction in motor unit firing rates was likely a fatigue protecting mechanism since denervation via poliomyelitis results in a reduction of motorneurons. In addition, the concurrent changes in motor unit firing rates, electromyography amplitude and frequency for the polio participant would suggest that the entire motorneuron pool was utilized in each contraction unlike

A New High Frequency Injection Method Based on Duty Cycle Shifting without Maximum Voltage Magnitude Loss

DEFF Research Database (Denmark)

Wang, Dong; Lu, Kaiyuan; Rasmussen, Peter Omand

2015-01-01

The conventional high frequency signal injection method is to superimpose a high frequency voltage signal to the commanded stator voltage before space vector modulation. Therefore, the magnitude of the voltage used for machine torque production is limited. In this paper, a new high frequency...... amplitude. This may be utilized to develop new position estimation algorithm without involving the inductance in the medium to high speed range. As an application example, a developed inductance independent position estimation algorithm using the proposed high frequency injection method is applied to drive...... injection method, in which high frequency signal is generated by shifting the duty cycle between two neighboring switching periods, is proposed. This method allows injecting a high frequency signal at half of the switching frequency without the necessity to sacrifice the machine fundamental voltage...

Narrow band interference cancelation in OFDM: Astructured maximum likelihood approach

KAUST Repository

Sohail, Muhammad Sadiq; Al-Naffouri, Tareq Y.; Al-Ghadhban, Samir N.

2012-01-01

This paper presents a maximum likelihood (ML) approach to mitigate the effect of narrow band interference (NBI) in a zero padded orthogonal frequency division multiplexing (ZP-OFDM) system. The NBI is assumed to be time variant and asynchronous

BOLD repetition decreases in object-responsive ventral visual areas depend on spatial attention.

Science.gov (United States)

Eger, E; Henson, R N A; Driver, J; Dolan, R J

2004-08-01

Functional imaging studies of priming-related repetition phenomena have become widely used to study neural object representation. Although blood oxygenation level-dependent (BOLD) repetition decreases can sometimes be observed without awareness of repetition, any role for spatial attention in BOLD repetition effects remains largely unknown. We used fMRI in 13 healthy subjects to test whether BOLD repetition decreases for repeated objects in ventral visual cortices depend on allocation of spatial attention to the prime. Subjects performed a size-judgment task on a probe object that had been attended or ignored in a preceding prime display of 2 lateralized objects. Reaction times showed faster responses when the probe was the same object as the attended prime, independent of the view tested (identical vs. mirror image). No behavioral effect was evident from unattended primes. BOLD repetition decreases for attended primes were found in lateral occipital and fusiform regions bilaterally, which generalized across identical and mirror-image repeats. No repetition decreases were observed for ignored primes. Our results suggest a critical role for attention in achieving visual representations of objects that lead to both BOLD signal decreases and behavioral priming on repeated presentation.

Frequency-doubled green picosecond laser based on K3B6O10Br nonlinear optical crystal

Science.gov (United States)

Meng, Luping; Zhang, Ling; Hou, Zhanyu; Wang, Lirong; Xu, Hui; Shi, Meng; Wang, Lingwu; Yang, Yingying; Qi, Yaoyao; He, Chaojian; Yu, Haijuan; Lin, Xuechun; Su, Fufang; Xia, Mingjun; Li, Rukang

2018-05-01

We report a frequency-doubled green picosecond (ps) laser based on K3B6O10Br (KBB) nonlinear optical crystal with cutting angle of θ = 34.7° and φ = 30°. Through intracavity frequency doubling using a type I phase-matched KBB crystal with dimensions of 4 mm × 4 mm × 13.2 mm, the average output power of 185.00 mW green ps laser was obtained with a repetition rate of 80 MHz and pulse width of 25.0 ps. In addition, we present external frequency doubling using KBB crystal. The average output power of 3.00 W green ps laser was generated with a repetition rate of 10 kHz and pulse width of 38.1 ps, which corresponds to a pulse energy of 0.30 mJ and a peak power 7.89 MW, respectively. The experimental results show that KBB crystal is a promising nonlinear optical material.

Maximum Available Accuracy of FM-CW Radars

Directory of Open Access Journals (Sweden)

V. Ricny

2009-12-01

Full Text Available This article deals with the principles and above all with the maximum available measuring accuracy analyse of FM-CW (Frequency Modulated Continuous Wave radars, which are usually employed for distance and velocity measurements of moving objects in road traffic, as well as air traffic and in other applications. These radars often form an important part of the active safety equipment of high-end cars – the so-called anticollision systems. They usually work in the frequency bands of mm waves (24, 35, 77 GHz. Function principles and analyses of factors, that dominantly influence the distance measurement accuracy of these equipments especially in the modulation and demodulation part, are shown in the paper.

Risk factors for hand-wrist disorders in repetitive work

DEFF Research Database (Denmark)

Thomsen, J. F.; Mikkelsen, S.; Andersen, JH

2007-01-01

OBJECTIVES: To identify the risk of hand-wrist disorders related to repetitive movements, use of hand force and wrist position in repetitive monotonous work. METHODS: Using questionnaires and physical examinations, the prevalence and incidence of hand-wrist pain and possible extensor tendonitis...... (wrist pain and palpation tenderness) were determined in 3123 employees in 19 industrial settings. With the use of questionnaires and video recordings of homogenous work tasks number of wrist movements, hand force requirements and wrist position were analysed as risk factors for hand-wrist disorders......, controlling for potential personal and psychosocial confounders. All participants were re-examined three times during a follow-up period of three years. RESULTS: Force but not repetition and position was related to hand-wrist pain and possible tendonitis in the baseline analyses showing an exposure...

Tunable and broadband microwave frequency combs based on a semiconductor laser with incoherent optical feedback

International Nuclear Information System (INIS)

Zhao Mao-Rong; Wu Zheng-Mao; Deng Tao; Zhou Zhen-Li; Xia Guang-Qiong

2015-01-01

Based on a semiconductor laser (SL) with incoherent optical feedback, a novel all-optical scheme for generating tunable and broadband microwave frequency combs (MFCs) is proposed and investigated numerically. The results show that, under suitable operation parameters, the SL with incoherent optical feedback can be driven to operate at a regular pulsing state, and the generated MFCs have bandwidths broader than 40 GHz within a 10 dB amplitude variation. For a fixed bias current, the line spacing (or repetition frequency) of the MFCs can be easily tuned by varying the feedback delay time and the feedback strength, and the tuning range of the line spacing increases with the increase in the bias current. The linewidth of the MFCs is sensitive to the variation of the feedback delay time and the feedback strength, and a linewidth of tens of KHz can be achieved through finely adjusting the feedback delay time and the feedback strength. In addition, mappings of amplitude variation, repetition frequency, and linewidth of MFCs in the parameter space of the feedback delay time and the feedback strength are presented. (paper)

Prenatal lipopolysaccharide induces hypothalamic dopaminergic hypoactivity and autistic-like behaviors: Repetitive self-grooming and stereotypies.

Science.gov (United States)

Kirsten, Thiago B; Bernardi, Maria M

2017-07-28

Previous investigations by our group have shown that prenatal exposure to lipopolysaccharide (LPS), which mimics infection by gram-negative bacteria, induces social, cognitive, and communication deficits. For a complete screening of autistic-like behaviors, the objective of this study was to evaluate if our rat model also induces restricted and repetitive stereotyped behaviors. Thus, we studied the self-grooming microstructure. We also studied the neurochemistry of hypothalamus and frontal cortex, which are brain areas related to autism to better understand central mechanisms involved in our model. Prenatal LPS exposure on gestational day 9.5 increased the head washing episodes (frequency and time), as well as the total self-grooming. However, body grooming, paw/leg licking, tail/genital grooming, and circling behavior/tail chasing did not vary significantly among the groups. Moreover, prenatal LPS induced dopaminergic hypoactivity (HVA metabolite and turnover) in the hypothalamus. Therefore, our rat model induced restricted and repetitive stereotyped behaviors and the other main symptoms of autism experimentally studied in rodent models and also found in patients. The hypothalamic dopaminergic impairments seem to be associated with the autistic-like behaviors. Copyright © 2017 Elsevier B.V. All rights reserved.

Shal/K(v4 channels are required for maintaining excitability during repetitive firing and normal locomotion in Drosophila.

Directory of Open Access Journals (Sweden)

Yong Ping

2011-01-01

Full Text Available Rhythmic behaviors, such as walking and breathing, involve the coordinated activity of central pattern generators in the CNS, sensory feedback from the PNS, to motoneuron output to muscles. Unraveling the intrinsic electrical properties of these cellular components is essential to understanding this coordinated activity. Here, we examine the significance of the transient A-type K(+ current (I(A, encoded by the highly conserved Shal/K(v4 gene, in neuronal firing patterns and repetitive behaviors. While I(A is present in nearly all neurons across species, elimination of I(A has been complicated in mammals because of multiple genes underlying I(A, and/or electrical remodeling that occurs in response to affecting one gene.In Drosophila, the single Shal/K(v4 gene encodes the predominant I(A current in many neuronal cell bodies. Using a transgenically expressed dominant-negative subunit (DNK(v4, we show that I(A is completely eliminated from cell bodies, with no effect on other currents. Most notably, DNK(v4 neurons display multiple defects during prolonged stimuli. DNK(v4 neurons display shortened latency to firing, a lower threshold for repetitive firing, and a progressive decrement in AP amplitude to an adapted state. We record from identified motoneurons and show that Shal/K(v4 channels are similarly required for maintaining excitability during repetitive firing. We then examine larval crawling, and adult climbing and grooming, all behaviors that rely on repetitive firing. We show that all are defective in the absence of Shal/K(v4 function. Further, knock-out of Shal/K(v4 function specifically in motoneurons significantly affects the locomotion behaviors tested.Based on our results, Shal/K(v4 channels regulate the initiation of firing, enable neurons to continuously fire throughout a prolonged stimulus, and also influence firing frequency. This study shows that Shal/K(v4 channels play a key role in repetitively firing neurons during prolonged

Accurate computations of monthly average daily extraterrestrial irradiation and the maximum possible sunshine duration

International Nuclear Information System (INIS)

Jain, P.C.

1985-12-01

The monthly average daily values of the extraterrestrial irradiation on a horizontal plane and the maximum possible sunshine duration are two important parameters that are frequently needed in various solar energy applications. These are generally calculated by solar scientists and engineers each time they are needed and often by using the approximate short-cut methods. Using the accurate analytical expressions developed by Spencer for the declination and the eccentricity correction factor, computations for these parameters have been made for all the latitude values from 90 deg. N to 90 deg. S at intervals of 1 deg. and are presented in a convenient tabular form. Monthly average daily values of the maximum possible sunshine duration as recorded on a Campbell Stoke's sunshine recorder are also computed and presented. These tables would avoid the need for repetitive and approximate calculations and serve as a useful ready reference for providing accurate values to the solar energy scientists and engineers

Two-photon direct frequency comb spectroscopy of alkali atoms

Science.gov (United States)

Palm, Christopher; Pradhananga, Trinity; Nguyen, Khoa; Montcrieffe, Caitlin; Kimball, Derek

2012-11-01

We have studied transition frequencies and excited state hyperfine structure in rubidium using 2-photon transitions excited directly with the frequency-doubled output of a erbium fiber optical frequency comb. The frequency comb output is directed in two counterpropagating directions through a vapor cell containing the rubidium vapor. A pair of optical filters is used to select teeth of the comb in order to identify the transition wavelengths. A photomultiplier tube (PMT) measures fluorescence from a decay channel wavelength selected with another optical filter. Using different combinations of filters enables a wide range of transitions to be investigated. By scanning the repetition rate, a Doppler-free spectrum can be obtained enabling kHz-resolution spectral measurements. An interesting dependence of the 2-photon spectrum on the energy of the intermediate state of the 2-photon transition is discussed. Our investigations are laying the groundwork for a long-term research program to use direct frequency comb spectroscopy to understand the complex spectra of rare-earth atoms.

Characterization and distribution of repetitive elements in association with genes in the human genome.

Science.gov (United States)

Liang, Kai-Chiang; Tseng, Joseph T; Tsai, Shaw-Jenq; Sun, H Sunny

2015-08-01

Repetitive elements constitute more than 50% of the human genome. Recent studies implied that the complexity of living organisms is not just a direct outcome of a number of coding sequences; the repetitive elements, which do not encode proteins, may also play a significant role. Though scattered studies showed that repetitive elements in the regulatory regions of a gene control gene expression, no systematic survey has been done to report the characterization and distribution of various types of these repetitive elements in the human genome. Sequences from 5' and 3' untranslated regions and upstream and downstream of a gene were downloaded from the Ensembl database. The repetitive elements in the neighboring of each gene were identified and classified using cross-matching implemented in the RepeatMasker. The annotation and distribution of distinct classes of repetitive elements associated with individual gene were collected to characterize genes in association with different types of repetitive elements using systems biology program. We identified a total of 1,068,400 repetitive elements which belong to 37-class families and 1235 subclasses that are associated with 33,761 genes and 57,365 transcripts. In addition, we found that the tandem repeats preferentially locate proximal to the transcription start site (TSS) of genes and the major function of these genes are involved in developmental processes. On the other hand, interspersed repetitive elements showed a tendency to be accumulated at distal region from the TSS and the function of interspersed repeat-containing genes took part in the catabolic/metabolic processes. Results from the distribution analysis were collected and used to construct a gene-based repetitive element database (GBRED; http://www.binfo.ncku.edu.tw/GBRED/index.html). A user-friendly web interface was designed to provide the information of repetitive elements associated with any particular gene(s). This is the first study focusing on the gene

Repetitive Bibliographical Information in Relational Databases.

Science.gov (United States)

Brooks, Terrence A.

1988-01-01

Proposes a solution to the problem of loading repetitive bibliographic information in a microcomputer-based relational database management system. The alternative design described is based on a representational redundancy design and normalization theory. (12 references) (Author/CLB)

Frequency Stepped Pulse Train Modulated Wind Sensing Lidar

DEFF Research Database (Denmark)

Olesen, Anders Sig; Pedersen, Anders Tegtmeier; Rottwitt, Karsten

2011-01-01

of frequency shifts corresponding to a specific distance. The spatial resolution depends on the repetition rate of the pulses in the pulse train. Directional wind measurements are shown and compared to a CW lidar measurement. The carrier to noise ratio of the FSPT lidar compared to a CW lidar is discussed......In this paper a wind sensing lidar utilizing a Frequency Stepped Pulse Train (FSPT) is demonstrated. One of the advantages in the FSTP lidar is that it enables direct measurement of wind speed as a function of distance from the lidar. Theoretically the FSPT lidar continuously produces measurements...... as is the case with a CW lidar, but at the same time with a spatial resolution, and without the range ambiguity originating from e.g. clouds. The FSPT lidar utilizes a frequency sweeping source for generation of the FSPT. The source generates a pulse train where each pulse has an optical carrier frequency...

The Effect of Rest Interval Length on Repetition Consistency and Perceived Exertion During Near Maximal Loaded Bench Press Sets.

Science.gov (United States)

Scudese, Estevão; Willardson, Jeffrey M; Simão, Roberto; Senna, Gilmar; de Salles, Belmiro F; Miranda, Humberto

2015-11-01

The purpose of this study was to compare different rest intervals between sets on repetition consistency and ratings of perceived exertion (RPE) during consecutive bench press sets with an absolute 3RM (3 repetition maximum) load. Sixteen trained men (23.75 ± 4.21 years; 74.63 ± 5.36 kg; 175 ± 4.64 cm; bench press relative strength: 1.44 ± 0.19 kg/kg of body mass) attended 4 randomly ordered sessions during which 5 consecutive sets of the bench press were performed with an absolute 3RM load and 1, 2, 3, or 5 minutes of rest interval between sets. The results indicated that significantly greater bench press repetitions were completed with 2, 3, and 5 minutes vs. 1-minute rest between sets (p ≤ 0.05); no significant differences were noted between the 2, 3, and 5 minutes rest conditions. For the 1-minute rest condition, performance reductions (relative to the first set) were observed commencing with the second set; whereas for the other conditions (2, 3, and 5 minutes rest), performance reductions were not evident until the third and fourth sets. The RPE values before each of the successive sets were significantly greater, commencing with the second set for the 1-minute vs. the 3 and 5 minutes rest conditions. Significant increases were also evident in RPE immediately after each set between the 1 and 5 minutes rest conditions from the second through fifth sets. These findings indicate that when utilizing an absolute 3RM load for the bench press, practitioners may prescribe a time-efficient minimum of 2 minutes rest between sets without significant impairments in repetition performance. However, lower perceived exertion levels may necessitate prescription of a minimum of 3 minutes rest between sets.

Transcutaneous Auricular Vagus Nerve Stimulation with Concurrent Upper Limb Repetitive Task Practice for Poststroke Motor Recovery: A Pilot Study.

Science.gov (United States)

Redgrave, Jessica N; Moore, Lucy; Oyekunle, Tosin; Ebrahim, Maryam; Falidas, Konstantinos; Snowdon, Nicola; Ali, Ali; Majid, Arshad

2018-03-23

Invasive vagus nerve stimulation (VNS) has the potential to enhance the effects of physiotherapy for upper limb motor recovery after stroke. Noninvasive, transcutaneous auricular branch VNS (taVNS) may have similar benefits, but this has not been evaluated in stroke recovery. We sought to determine the feasibility of taVNS delivered alongside upper limb repetitive task-specific practice after stroke and its effects on a range of outcome measures evaluating limb function. Thirteen participants at more than 3 months postischemic stroke with residual upper limb dysfunction were recruited from the community of Sheffield, United Kingdom (October-December 2016). Participants underwent 18 × 1-hour sessions over 6 weeks in which they made 30-50 repetitions of 8-10 arm movements concurrently with taVNS (NEMOS; Cerbomed, Erlangen, Germany, 25 Hz, .1-millisecond pulse width) at maximum tolerated intensity (mA). An electrocardiogram and rehabilitation outcome scores were obtained at each visit. Qualitative interviews determined the acceptability of taVNS to participants. Median time after stroke was 1.16 years, and baseline median/interquartile range upper limb Fugl-Meyer (UFM) score was 63 (54.5-99.5). Participants attended 92% of the planned treatment sessions. Three participants reported side effects, mainly fatigue, but all performed mean of more than 300 arm repetitions per session with no serious adverse events. There was a significant change in the UFM score with a mean increase per participant of 17.1 points (standard deviation 7.8). taVNS is feasible and well-tolerated alongside upper limb repetitive movements in poststroke rehabilitation. The motor improvements observed justify a phase 2 trial in patients with residual arm weakness. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

The repetition effect in building and construction works

DEFF Research Database (Denmark)

Gottlieb, Stefan Christoffer; Haugbølle, Kim

are then applied on the Public Transport Authorities' main account structure of units and costs, and a method for assessing the possibilities of achieving effects of repetition for each account is described. Finally, the report summarises the core conditions necessary to take into consideration in relation......This report summarises the results from the work undertaken for the Public Transport Authority on the effect of learning and repetition in building and construction works. The results are applied by the Public Transport Authority in a new budgeting model, while the agency investigates...

Efficient diode-end-pumped actively Q-switched Nd:YAG/SrWO4/KTP yellow laser.

Science.gov (United States)

Cong, Zhenhua; Zhang, Xingyu; Wang, Qingpu; Liu, Zhaojun; Li, Shutao; Chen, Xiaohan; Zhang, Xiaolei; Fan, Shuzhen; Zhang, Huaijin; Tao, Xutang

2009-09-01

An efficient intracavity frequency-doubled Raman laser was obtained by using an SrWO(4) Raman medium, an Nd:YAG ceramic gain medium, and a KTP frequency-doubling medium. Three laser cavities, including a two-mirror cavity, a three-mirror coupled cavity, and a folded cavity, were investigated. With the coupled cavity, a 2.93 W, 590 nm laser was obtained at an incident pump power of 16.2 W and a pulse repetition frequency of 20 kHz; the corresponding conversion efficiency was 18.1%. The highest conversion efficiency of 19.2% was obtained at an incident pump power of 14.1 W and a pulse repetition frequency of 15 kHz. The obtained maximum output power and conversion efficiency were much higher than the results previously obtained with intracavity frequency-doubled solid-state Raman lasers.

Contribution of fronto-striatal regions to emotional valence and repetition under cognitive conflict.

Science.gov (United States)

Chun, Ji-Won; Park, Hae-Jeong; Kim, Dai Jin; Kim, Eosu; Kim, Jae-Jin

2017-07-01

Conflict processing mediated by fronto-striatal regions may be influenced by emotional properties of stimuli. This study aimed to examine the effects of emotion repetition on cognitive control in a conflict-provoking situation. Twenty-one healthy subjects were scanned using functional magnetic resonance imaging while performing a sequential cognitive conflict task composed of emotional stimuli. The regional effects were analyzed according to the repetition or non-repetition of cognitive congruency and emotional valence between the preceding and current trials. Post-incongruence interference in error rate and reaction time was significantly smaller than post-congruence interference, particularly under repeated positive and non-repeated positive, respectively, and post-incongruence interference, compared to post-congruence interference, increased activity in the ACC, DLPFC, and striatum. ACC and DLPFC activities were significantly correlated with error rate or reaction time in some conditions, and fronto-striatal connections were related to the conflict processing heightened by negative emotion. These findings suggest that the repetition of emotional stimuli adaptively regulates cognitive control and the fronto-striatal circuit may engage in the conflict adaptation process induced by emotion repetition. Both repetition enhancement and repetition suppression of prefrontal activity may underlie the relationship between emotion and conflict adaptation. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of repetitive transcranial magnetic stimulation in drug resistant depressed patients

International Nuclear Information System (INIS)

Chung, Yong An; Yoo, Ie Ryung; Kang, Bong Joo; Chae, Jeong Ho; Lee, Hye Won; Moon, Hyun Jin; Kim, Sung Hoon; Sohn, Hyung Sun; Chung, Soo Kyo

2007-01-01

Repetitive transcranial magnetic stimulation (rTMS) has recently been clinically applied in the treatment of drug resistant depressed patients. There are mixed findings about the efficacy of rTMS on depression. Furthermore, the influence of rTMS on the physiology of the brain is not clear. We prospectively evaluated changes of regional cerebral blood flow (rCBF) between pre- and post-rTMS treatment in patients with drug resistant depression. Twelve patients with drug-resistant depression (7 male, 5 female; age range; 19∼ 52 years; mean age: 29.3 ± 9.3 years) were given rTMS on right prefrontal lobe with low frequency (1 Hz) and on left prefrontal lobe with high frequency (20 Hz), with 20-minute-duration each day for 3 weeks. Tc-99m ECD brain perfusion SPECT was obtained before and after rTMS treatment. The changes of cerebral perfusion were analyzed using statistical parametric mapping (SPM; t=3.14, uncorrected ρ < 0.01, voxel = 100). Following areas showed significant increase in rCBF after 3 weeks rTMS treatment: the cingulate gyrus, fusiform gyrus of right temporal lobe, precuneus, and left lateral globus pallidus. Significant decrement was noted in the precental and middle frontal gyrus of right frontal lobe, and fusiform gyrus of left occipital lobe. Low-frequency rTMS on the right prefrontal cortex and high-frequency rTMS on the left prefrontal cortex for 3 weeks as an add-on regimen have increased and decreased rCBF in the specific brain regions in drug-resistant depressed patients. Further analyses correlating clinical characteristics and treatment paradigm with functional imaging data may be helpful in clarifying the pathophysiology of drug-resistant patients

Effect of repetitive transcranial magnetic stimulation in drug resistant depressed patients

Energy Technology Data Exchange (ETDEWEB)

Chung, Yong An; Yoo, Ie Ryung; Kang, Bong Joo; Chae, Jeong Ho; Lee, Hye Won; Moon, Hyun Jin; Kim, Sung Hoon; Sohn, Hyung Sun; Chung, Soo Kyo [The Catholic University of Korea, Seoul (Korea, Republic of)

2007-02-15

Repetitive transcranial magnetic stimulation (rTMS) has recently been clinically applied in the treatment of drug resistant depressed patients. There are mixed findings about the efficacy of rTMS on depression. Furthermore, the influence of rTMS on the physiology of the brain is not clear. We prospectively evaluated changes of regional cerebral blood flow (rCBF) between pre- and post-rTMS treatment in patients with drug resistant depression. Twelve patients with drug-resistant depression (7 male, 5 female; age range; 19{approx} 52 years; mean age: 29.3 {+-} 9.3 years) were given rTMS on right prefrontal lobe with low frequency (1 Hz) and on left prefrontal lobe with high frequency (20 Hz), with 20-minute-duration each day for 3 weeks. Tc-99m ECD brain perfusion SPECT was obtained before and after rTMS treatment. The changes of cerebral perfusion were analyzed using statistical parametric mapping (SPM; t=3.14, uncorrected {rho} < 0.01, voxel = 100). Following areas showed significant increase in rCBF after 3 weeks rTMS treatment: the cingulate gyrus, fusiform gyrus of right temporal lobe, precuneus, and left lateral globus pallidus. Significant decrement was noted in the precental and middle frontal gyrus of right frontal lobe, and fusiform gyrus of left occipital lobe. Low-frequency rTMS on the right prefrontal cortex and high-frequency rTMS on the left prefrontal cortex for 3 weeks as an add-on regimen have increased and decreased rCBF in the specific brain regions in drug-resistant depressed patients. Further analyses correlating clinical characteristics and treatment paradigm with functional imaging data may be helpful in clarifying the pathophysiology of drug-resistant patients.

Tunable radio-frequency photonic filter based on an actively mode-locked fiber laser.

Science.gov (United States)

Ortigosa-Blanch, A; Mora, J; Capmany, J; Ortega, B; Pastor, D

2006-03-15

We propose the use of an actively mode-locked fiber laser as a multitap optical source for a microwave photonic filter. The fiber laser provides multiple optical taps with an optical frequency separation equal to the external driving radio-frequency signal of the laser that governs its repetition rate. All the optical taps show equal polarization and an overall Gaussian apodization, which reduces the sidelobes. We demonstrate continuous tunability of the filter by changing the external driving radio-frequency signal of the laser, which shows good fine tunability in the operating range of the laser from 5 to 10 GHz.

Pulsed electron beam generation with fast repetitive double pulse system

Energy Technology Data Exchange (ETDEWEB)

Sharma, Surender Kumar; Deb, Pankaj; Shyam, Anurag, E-mail: surender80@gmail.com [Energetics and Electromagnetics Division, Bhabha Atomic Research Centre, Visakhapatnam (India); Sharma, Archana [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Mumbai (India)

2014-07-01

Longer duration high voltage pulse (∼ 100 kV, 260 ns) is generated and reported using helical pulse forming line in compact geometry. The transmission line characteristics of the helical pulse forming line are also used to develop fast repetition double pulse system with very short inter pulse interval. It overcomes the limitations caused due to circuit parameters, power supplies and load characteristics for fast repetitive high voltage pulse generation. The high voltage double pulse of 100 kV, 100 ns with an inter pulse repetition interval of 30 ns is applied across the vacuum field emission diode for pulsed electron beam generation. The electron beam is generated from cathode material by application of negative high voltage (> 100 kV) across the diode by explosive electron emission process. The vacuum field emission diode is made of 40 mm diameter graphite cathode and SS mesh anode. The anode cathode gap was 6 mm and the drift tube diameter was 10 cm. The initial experimental results of pulsed electron beam generation with fast repetitive double pulse system are reported and discussed. (author)

Spared behavioral repetition effects in Alzheimer's disease linked to an altered neural mechanism at posterior cortex.

Science.gov (United States)

Broster, Lucas S; Li, Juan; Wagner, Benjamin; Smith, Charles D; Jicha, Gregory A; Schmitt, Frederick A; Munro, Nancy; Haney, Ryan H; Jiang, Yang

2018-02-20

Individuals with dementia of the Alzheimer type (AD) classically show disproportionate impairment in measures of working memory, but repetition learning effects are relatively preserved. As AD affects brain regions implicated in both working memory and repetition effects, the neural basis of this discrepancy is poorly understood. We hypothesized that the posterior repetition effect could account for this discrepancy due to the milder effects of AD at visual cortex. Participants with early AD, amnestic mild cognitive impairment (MCI), and healthy controls performed a working memory task with superimposed repetition effects while electroencephalography was collected to identify possible neural mechanisms of preserved repetition effects. Participants with AD showed preserved behavioral repetition effects and a change in the posterior repetition effect. Visual cortex may play a role in maintained repetition effects in persons with early AD.

Repetitive trauma and nerve compression.

Science.gov (United States)

Carragee, E J; Hentz, V R

1988-01-01

Repetitive movement of the upper extremity, whether recreational or occupational, may result in various neuropathies, the prototype of which is the median nerve neuropathic in the carpal canal. The pathophysiology of this process is incompletely understood but likely involves both mechanical and ischemic features. Experimentally increased pressures within the carpal canal produced reproducible progressive neuropathy. Changes in vibratory (threshold-type) sensibility appears to be more sensitive than two-point (innervation density-type) sensibility. The specific occupational etiologies of carpal neuropathy are obscured by methodologic and sociological difficulties, but clearly some occupations have high incidences of CTS. History and physical examination are usually sufficient for the diagnosis, but diagnostic assistance when required is available through electrophysiological testing, CT scanning, and possibly MRI. Each of these tests has limitations in both sensitivity and specificity. Treatment by usual conservative means should be combined with rest from possible provocative activities. Surgical release of the carpal canal is helpful in patients failing conservative therapy. Occupational modifications are important in both treatment and prevention of median neuropathy due to repetitive trauma.

Optical frequency comb generation based on the dual-mode square microlaser and a nonlinear fiber loop

Science.gov (United States)

Weng, Hai-Zhong; Han, Jun-Yuan; Li, Qing; Yang, Yue-De; Xiao, Jin-Long; Qin, Guan-Shi; Huang, Yong-Zhen

2018-05-01

A novel approach using a dual-mode square microlaser as the pump source is demonstrated to produce wideband optical frequency comb (OFC). The enhanced nonlinear frequency conversion processes are accomplished in a nonlinear fiber loop, which can reduce the stimulated Brillouin scattering threshold and then generate a dual-mode Brillouin laser with improved optical signal-to-noise ratio. An OFC with 130 nm bandwidth and 76 GHz repetition rate is successfully generated under the four-wave mixing, and the number of the comb lines is enhanced by 26 times compared with the system without fiber loop. In addition, the repetition rate of the comb can be adjusted by changing the injection current of the microlaser. The pulse width of the comb spectrum is also compressed from 3 to 1 ps with an extra amplification-nonlinear process.

Investigation of Gas Heating by Nanosecond Repetitively Pulsed Glow Discharges Used for Actuation of a Laminar Methane-Air Flame

KAUST Repository

Lacoste, Deanna

2017-05-24

This paper reports on the quantification of the heating induced by nanosecond repetitively pulsed (NRP) glow discharges on a lean premixed methane-air flame. The flame, obtained at room temperature and atmospheric pressure, has an M-shape morphology. The equivalence ratio is 0.95 and the thermal power released by the flame is 113 W. The NRP glow discharges are produced by high voltage pulses of 10 ns duration, 7 kV amplitude, applied at a repetition frequency of 10 kHz. The average power of the plasma, determined from current and voltage measurements, is 1 W, i.e. about 0.9 % of the thermal power of the flame. Broadband vibrational coherent anti-Stokes Raman spectroscopy of nitrogen is used to determine the temperature of the flame with and without plasma enhancement. The temperature evolution in the flame area shows that the thermal impact of NRP glow discharges is in the uncertainty range of the technique, i.e., +/- 40 K.

Repetitive Elements in Mycoplasma hyopneumoniae Transcriptional Regulation.

Directory of Open Access Journals (Sweden)

Amanda Malvessi Cattani

Full Text Available Transcriptional regulation, a multiple-step process, is still poorly understood in the important pig pathogen Mycoplasma hyopneumoniae. Basic motifs like promoters and terminators have already been described, but no other cis-regulatory elements have been found. DNA repeat sequences have been shown to be an interesting potential source of cis-regulatory elements. In this work, a genome-wide search for tandem and palindromic repetitive elements was performed in the intergenic regions of all coding sequences from M. hyopneumoniae strain 7448. Computational analysis demonstrated the presence of 144 tandem repeats and 1,171 palindromic elements. The DNA repeat sequences were distributed within the 5' upstream regions of 86% of transcriptional units of M. hyopneumoniae strain 7448. Comparative analysis between distinct repetitive sequences found in related mycoplasma genomes demonstrated different percentages of conservation among pathogenic and nonpathogenic strains. qPCR assays revealed differential expression among genes showing variable numbers of repetitive elements. In addition, repeats found in 206 genes already described to be differentially regulated under different culture conditions of M. hyopneumoniae strain 232 showed almost 80% conservation in relation to M. hyopneumoniae strain 7448 repeats. Altogether, these findings suggest a potential regulatory role of tandem and palindromic DNA repeats in the M. hyopneumoniae transcriptional profile.

Repetitive Elements in Mycoplasma hyopneumoniae Transcriptional Regulation.

Science.gov (United States)

Cattani, Amanda Malvessi; Siqueira, Franciele Maboni; Guedes, Rafael Lucas Muniz; Schrank, Irene Silveira

2016-01-01

Transcriptional regulation, a multiple-step process, is still poorly understood in the important pig pathogen Mycoplasma hyopneumoniae. Basic motifs like promoters and terminators have already been described, but no other cis-regulatory elements have been found. DNA repeat sequences have been shown to be an interesting potential source of cis-regulatory elements. In this work, a genome-wide search for tandem and palindromic repetitive elements was performed in the intergenic regions of all coding sequences from M. hyopneumoniae strain 7448. Computational analysis demonstrated the presence of 144 tandem repeats and 1,171 palindromic elements. The DNA repeat sequences were distributed within the 5' upstream regions of 86% of transcriptional units of M. hyopneumoniae strain 7448. Comparative analysis between distinct repetitive sequences found in related mycoplasma genomes demonstrated different percentages of conservation among pathogenic and nonpathogenic strains. qPCR assays revealed differential expression among genes showing variable numbers of repetitive elements. In addition, repeats found in 206 genes already described to be differentially regulated under different culture conditions of M. hyopneumoniae strain 232 showed almost 80% conservation in relation to M. hyopneumoniae strain 7448 repeats. Altogether, these findings suggest a potential regulatory role of tandem and palindromic DNA repeats in the M. hyopneumoniae transcriptional profile.

Narrow band interference cancelation in OFDM: Astructured maximum likelihood approach

KAUST Repository

Sohail, Muhammad Sadiq

2012-06-01

This paper presents a maximum likelihood (ML) approach to mitigate the effect of narrow band interference (NBI) in a zero padded orthogonal frequency division multiplexing (ZP-OFDM) system. The NBI is assumed to be time variant and asynchronous with the frequency grid of the ZP-OFDM system. The proposed structure based technique uses the fact that the NBI signal is sparse as compared to the ZP-OFDM signal in the frequency domain. The structure is also useful in reducing the computational complexity of the proposed method. The paper also presents a data aided approach for improved NBI estimation. The suitability of the proposed method is demonstrated through simulations. © 2012 IEEE.

Repetitive elements in parasitic protozoa

Directory of Open Access Journals (Sweden)

Clayton Christine

2010-05-01

Full Text Available Abstract A recent paper published in BMC Genomics suggests that retrotransposition may be active in the human gut parasite Entamoeba histolytica. This adds to our knowledge of the various types of repetitive elements in parasitic protists and the potential influence of such elements on pathogenicity. See research article http://www.biomedcentral.com/1471-2164/11/321

Mid-Infrared Frequency-Agile Dual-Comb Spectroscopy

Science.gov (United States)

Luo, Pei-Ling; Yan, Ming; Iwakuni, Kana; Millot, Guy; Hänsch, Theodor W.; Picqué, Nathalie

2016-06-01

We demonstrate a new approach to mid-infrared dual-comb spectroscopy. It opens up new opportunities for accurate real-time spectroscopic diagnostics and it significantly simplifies the technique of dual-comb spectroscopy. Two mid-infrared frequency combs of slightly different repetition frequencies and moderate, but rapidly tunable, spectral span are generated in the 2800-3200 cm-1 region. The generators rely on electro-optic modulators, nonlinear fibers for spectral broadening and difference frequency generation and do not involve mode-locked lasers. Flat-top frequency combs span up to 10 cm-1 with a comb line spacing of 100 MHz (3×10-3 cm-1). The performance of the spectrometer without any phase-lock electronics or correction scheme is illustrated with spectra showing resolved comb lines and Doppler-limited spectra of methane. High precision on the spectroscopic parameter (line positions and intensities) determination is demonstrated for spectra measured on a millisecond time scale and it is validated with comparison with literature data. G. Millot, S. Pitois, M. Yan, T. Hovannysyan, A. Bendahmane, T.W. Hänsch, N. Picqué, Frequency-agile dual-comb spectroscopy, Nature Photonics 10, 27-30 (2016).

Experimental Determination of Operating and Maximum Power Transfer Efficiencies at Resonant Frequency in a Wireless Power Transfer System using PP Network Topology with Top Coupling

Science.gov (United States)

Ramachandran, Hema; Pillai, K. P. P.; Bindu, G. R.

2017-08-01

A two-port network model for a wireless power transfer system taking into account the distributed capacitances using PP network topology with top coupling is developed in this work. The operating and maximum power transfer efficiencies are determined analytically in terms of S-parameters. The system performance predicted by the model is verified with an experiment consisting of a high power home light load of 230 V, 100 W and is tested for two forced resonant frequencies namely, 600 kHz and 1.2 MHz. The experimental results are in close agreement with the proposed model.

Oxotremorine treatment reduces repetitive behaviors in BTBR T+ tf/J mice

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Dionisio A. Amodeo

2014-08-01

Full Text Available Repetitive behaviors with restricted interests is one of the core criteria for the diagnosis of autism spectrum disorder (ASD. Current pharmacotherapies that target the dopaminergic or serotonergic systems have limited effectiveness in treating repetitive behaviors. Previous research has demonstrated that administration of muscarinic cholinergic receptor (mAChR antagonists can exacerbate motor stereotypies while mAChR agonists reduce stereotypies. The present study determined whether the mAChR agonist, oxotremorine affected repetitive behaviors in the BTBR T+ tf/J (BTBR mouse model of autism. To test the effects of oxotremorine on repetitive behaviors, marble burying and grooming behavior were measured in BTBR mice and compared to that in C57BL/6J (B6 mice. The effects of oxotremorine on locomotor activity was also measured. Thirty minutes before each test, mice received an intraperitoneal injection of saline, 0.001 mg or 0.01 mg of oxotremorine methiodide. Saline- treated BTBR mice exhibited increased marble burying and self-grooming behavior compared to that of saline-treated B6 mice. Oxotremorine significantly reduced marble burying and self-grooming behavior in BTBR mice, but had no significant effect in B6 mice. In addition, oxotremorine did not affect locomotor activity in BTBR mice, but significantly reduced locomotor activity in B6 mice at the 0.01 mg dose. These findings demonstrate that activation of mAChRs reduces repetitive behavior in the BTBR mouse and suggest that treatment with a mAChR agonist may be effective in reducing repetitive behaviors in ASD.

Optimality based repetitive controller design for track-following servo system of optical disk drives.

Science.gov (United States)

Chen, Wentao; Zhang, Weidong

2009-10-01

In an optical disk drive servo system, to attenuate the external periodic disturbances induced by inevitable disk eccentricity, repetitive control has been used successfully. The performance of a repetitive controller greatly depends on the bandwidth of the low-pass filter included in the repetitive controller. However, owing to the plant uncertainty and system stability, it is difficult to maximize the bandwidth of the low-pass filter. In this paper, we propose an optimality based repetitive controller design method for the track-following servo system with norm-bounded uncertainties. By embedding a lead compensator in the repetitive controller, both the system gain at periodic signal's harmonics and the bandwidth of the low-pass filter are greatly increased. The optimal values of the repetitive controller's parameters are obtained by solving two optimization problems. Simulation and experimental results are provided to illustrate the effectiveness of the proposed method.

Combined effect of repetitive work and cold on muscle function and fatigue.

Science.gov (United States)

Oksa, Juha; Ducharme, Michel B; Rintamäki, Hannu

2002-01-01

This study compared the effect of repetitive work in thermoneutral and cold conditions on forearm muscle electromyogram (EMG) and fatigue. We hypothesize that cold and repetitive work together cause higher EMG activity and fatigue than repetitive work only, thus creating a higher risk for overuse injuries. Eight men performed six 20-min work bouts at 25 degrees C (W-25) and at 5 degrees C while exposed to systemic (C-5) and local cooling (LC-5). The work was wrist flexion-extension exercise at 10% maximal voluntary contraction. The EMG activity of the forearm flexors and extensors was higher during C-5 (31 and 30%, respectively) and LC-5 (25 and 28%, respectively) than during W-25 (P forearm flexors at the end of W-25 was 15%. The corresponding values at the end of C-5 and LC-5 were 37% (P < 0.05 in relation to W-25) and 20%, respectively. Thus repetitive work in the cold causes higher EMG activity and fatigue than repetitive work in thermoneutral conditions.

Electrophysiological Repetition Effects in Persons with Mild Cognitive Impairment depend upon Working Memory Demand.

Science.gov (United States)

Broster, Lucas S; Jenkins, Shonna L; Holmes, Sarah D; Edwards, Matthew G; Jicha, Gregory A; Jiang, Yang

2018-05-07

Forms of implicit memory, including repetition effects, are preserved relative to explicit memory in clinical Alzheimer's disease. Consequently, cognitive interventions for persons with Alzheimer's disease have been developed that leverage this fact. However, despite the clinical robustness of behavioral repetition effects, altered neural mechanisms of repetition effects are studied as biomarkers of both clinical Alzheimer's disease and pre-morbid Alzheimer's changes in the brain. We hypothesized that the clinical preservation of behavioral repetition effects results in part from concurrent operation of discrete memory systems. We developed two experiments that included probes of emotional repetition effects differing in that one included an embedded working memory task. We found that neural repetition effects manifested in patients with amnestic mild cognitive impairment, the earliest form of clinical Alzheimer's disease, during emotional working memory tasks, but they did not manifest during the task that lacked the embedded working memory manipulation. Specifically, the working memory task evoked neural repetition effects in the P600 time-window, but the same neural mechanism was only minimally implicated in the task without a working memory component. We also found that group differences in behavioral repetition effects were smaller in the experiment with a working memory task. We suggest that cross-domain cognitive challenge can expose "defunct" neural capabilities of individuals with amnestic mild cognitive impairment. Copyright © 2018. Published by Elsevier Ltd.

Physiological responses to four hours of low-level repetitive work

DEFF Research Database (Denmark)

Garde, A Helene; Hansen, Åse Marie; Jensen, Bente R

2003-01-01

OBJECTIVES: The study investigated physiological responses to 4 hours of standardized low-level repetitive work. It was hypothesized that accumulative effects not observed after 1 hour could be found after 4 hours of repetitive work. METHODS: Ten healthy women performed intermittent (5 seconds + 5...... muscle activity during a mental reference task with low exerted force indicated attention-related muscle activity. Finally, it was indicated that repetitive work including high demands for attention is performed at the expense of the precision of the exerted force....... seconds) handgrip contractions at 10% of the maximal voluntary contraction combined with mental demands for concentration and attention. Muscle activity in the working forearm muscles, cardiovascular responses, and concentrations of biomarkers in biological fluids were recorded along with exerted force...

Diagrams of ion stability in radio-frequency mass spectrometry

International Nuclear Information System (INIS)

Sudakov, M.Yu.

1994-01-01

For solving radio-frequency mass spectrometry problems and dynamic ion containment are studied and systematized different ways for constructing the ion stability diagrams. A new universal set of parameters is proposed for diagram construction-angular variables, which are the phase raid of ion oscillational motion during positive and negative values of the supplying voltage. An effective analytical method is proposed for optimization of the parameters of the pulsed supplying voltage, in particular its repetition rate

The correlation between the length of repetitive domain and mechanical properties of the recombinant flagelliform spidroin

Directory of Open Access Journals (Sweden)

Xue Li

2017-03-01

Full Text Available Spider silk is an attractive biopolymer with numerous potential applications due to its remarkable characteristics. Among the six categories of spider silks, flagelliform (Flag spider silk possesses longer and more repetitive core domains than others, therefore performing the highest extensibility. To investigate the correlation between the recombinant spidroin size and the synthetic fiber properties, four recombinant proteins with different sizes [N-Scn-C (n=1-4] were constructed and expressed using IMPACT system. Subsequently, different recombinant spidroins were spun into fibers through wet-spinning via a custom-made continuous post-drawing device. Mechanical tests of the synthetic fibers with four parameters (maximum stress, maximum extension, Young's modulus and toughness demonstrated that the extensibility of the fibers showed a positive correlation with spidroin size, consequently resulting in the extensibility of N-Sc4-C fiber ranked the highest (58.76% among four fibers. Raman data revealed the relationship between secondary structure content and mechanical properties. The data here provide a deeper insight into the relationship between the function and structure of Flag silk for future design of artificial fibers.

Relationship between maximum dynamic force of inferior members and body balance in strength training apprentices

Directory of Open Access Journals (Sweden)

Ariane Martins

2010-08-01

Full Text Available The relationship between force and balance show controversy results and has directimplications in exercise prescription practice. The objective was to investigate the relationshipbetween maximum dynamic force (MDF of inferior limbs and the static and dynamic balances.Participated in the study 60 individuals, with 18 to 24 years old, strength training apprentices.The MDF was available by mean the One Maximum Repetition (1MR in “leg press” and “kneeextension” and motor testes to available of static and dynamic balances. The correlation testsand multiple linear regression were applied. The force and balance variables showed correlationin females (p=0.038. The corporal mass and static balance showed correlation for the males(p=0.045. The explication capacity at MDF and practices time were small: 13% for staticbalance in males, 18% and 17%, respectively, for static and dynamic balance in females. Inconclusion: the MDF of inferior limbs showed low predictive capacity for performance in staticand dynamic balances, especially for males.

Thermal neutron measurement using the instrumented test bundle and assessment of maximum linear power in HANARO

Energy Technology Data Exchange (ETDEWEB)

Lee, C. S.; Seo, C. K.; Lee, B. C.; Kim, H. N.; Kang, B. W. [KAERI, Taejon (Korea, Republic of)

2000-10-01

The HANARO fuel, U{sub 3}Si-Al, has been developed by AECL and tested in NRU reactor. Due to the lack of the data performed under the high power, the repetitive conduct of the irradiation test was required under the power greater than 108kW/m, which is the estimated maximum linear power in the design stage. Accordingly, the instrumented test bundle with SPND(Self Powered Neutron Detector) was fabricated and its irradiation test was performed in IR2 of HANARO. The measured thermal neutron flux with SPND is compared with calculation results by HANAFMS(HANARO Fuel Management System). The difference in the measured and calculated thermal flux values are below {+-}11% and the accuracy of the linear power predicted by HANAFMS is consequently accompanied. Therefore, it is believed that the maximum linear power above 120kW/m is achieved during the irradiation test of the test bundle.

Multi-Channel Maximum Likelihood Pitch Estimation

DEFF Research Database (Denmark)

Christensen, Mads Græsbøll

2012-01-01

In this paper, a method for multi-channel pitch estimation is proposed. The method is a maximum likelihood estimator and is based on a parametric model where the signals in the various channels share the same fundamental frequency but can have different amplitudes, phases, and noise characteristics....... This essentially means that the model allows for different conditions in the various channels, like different signal-to-noise ratios, microphone characteristics and reverberation. Moreover, the method does not assume that a certain array structure is used but rather relies on a more general model and is hence...

Repetitive transcranial magnetic stimulator with controllable pulse parameters

Science.gov (United States)

Peterchev, Angel V.; Murphy, David L.; Lisanby, Sarah H.

2011-06-01

The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topology incorporating two energy storage capacitors and two insulated-gate bipolar transistor (IGBT) modules to generate near-rectangular electric field pulses with adjustable number, polarity, duration, and amplitude of the pulse phases. This controllable pulse parameter TMS (cTMS) device can induce electric field pulses with phase widths of 10-310 µs and positive/negative phase amplitude ratio of 1-56. Compared to conventional monophasic and biphasic TMS, cTMS reduces energy dissipation up to 82% and 57% and decreases coil heating up to 33% and 41%, respectively. We demonstrate repetitive TMS trains of 3000 pulses at frequencies up to 50 Hz with electric field pulse amplitude and width variability less than the measurement resolution (1.7% and 1%, respectively). Offering flexible pulse parameter adjustment and reduced power consumption and coil heating, cTMS enhances existing TMS paradigms, enables novel research applications and could lead to clinical applications with potentially enhanced potency.

Left prefrontal repetitive transcranial magnetic stimulation in schizophrenia.

Science.gov (United States)

Holi, Matti M; Eronen, Markku; Toivonen, Kari; Toivonen, Päivi; Marttunen, Mauri; Naukkarinen, Hannu

2004-01-01

In a double-blind, controlled study, we examined the therapeutic effects of high-frequency left prefrontal repetitive transcranial magnetic stimulation (rTMS) on schizophrenia symptoms. A total of 22 chronic hospitalized schizophrenia patients were randomly assigned to 2 weeks (10 sessions) of real or sham rTMS. rTMS was given with the following parameters: 20 trains of 5-second 10-Hz stimulation at 100 percent motor threshold, 30 seconds apart. Effects on positive and negative symptoms, self-reported symptoms, rough neuropsychological functioning, and hormones were assessed. Although there was a significant improvement in both groups in most of the symptom measures, no real differences were found between the groups. A decrease of more than 20 percent in the total PANSS score was found in 7 control subjects but only 1 subject from the real rTMS group. There was no change in hormone levels or neuropsychological functioning, measured by the MMSE, in either group. Left prefrontal rTMS (with the used parameters) seems to produce a significant nonspecific effect of the treatment procedure but no therapeutic effect in the most chronic and severely ill schizophrenia patients.

Maximum coherent superposition state achievement using a non-resonant pulse train in non-degenerate three-level atoms

International Nuclear Information System (INIS)

Deng, Li; Niu, Yueping; Jin, Luling; Gong, Shangqing

2010-01-01

The coherent superposition state of the lower two levels in non-degenerate three-level Λ atoms is investigated using the accumulative effects of non-resonant pulse trains when the repetition period is smaller than the decay time of the upper level. First, using a rectangular pulse train, the accumulative effects are re-examined in the non-resonant two-level atoms and the modified constructive accumulation equation is analytically given. The equation shows that the relative phase and the repetition period are important in the accumulative effect. Next, under the modified equation in the non-degenerate three-level Λ atoms, we show that besides the constructive accumulation effect, the use of the partial constructive accumulation effect can also achieve the steady state of the maximum coherent superposition state of the lower two levels and the latter condition is relatively easier to manipulate. The analysis is verified by numerical calculations. The influence of the external levels in such a case is also considered and we find that it can be avoided effectively. The above analysis is also applicable to pulse trains with arbitrary envelopes.

Coherent lidar modulated with frequency stepped pulse trains for unambiguous high duty cycle range and velocity sensing in the atmosphere

DEFF Research Database (Denmark)

Lindelöw, Per Jonas Petter; Mohr, Johan Jacob

2007-01-01

Range unambiguous high duty cycle coherent lidars can be constructed based on frequency stepped pulse train modulation, even continuously emitting systems could be envisioned. Such systems are suitable for velocity sensing of dispersed targets, like the atmosphere, at fast acquisition rates....... The lightwave synthesized frequency sweeper is a suitable generator yielding fast pulse repetition rates and stable equidistant frequency steps. Theoretical range resolution profiles of modulated lidars are presented....

Exploration of verbal repetition in people with dementia using an online symptom-tracking tool.

Science.gov (United States)

Reeve, Emily; Molin, Pierre; Hui, Amaris; Rockwood, Kenneth

2017-06-01

Online tools can be used by people with dementia and their caregivers to self-identify and track troubling symptoms, such as verbal repetition. We aimed to explore verbal repetition behaviors in people with dementia. Participants were recruited via an online resource for people with dementia and their caregivers. Respondents were instructed to complete information about symptoms that are most important to them for tracking over time. In this cross-sectional study, we analyzed data pertaining to individuals with dementia who had at least three symptoms selected for tracking. Of the 3,573 participants who began a user profile, 1,707 fulfilled criteria for analysis. Verbal repetition was identified as a treatment target in 807 respondents (47.3%). Verbal repetition was more frequent in individuals with mild dementia compared to those with moderate and severe dementia (57.2% vs. 36.0% and 39.9%, p < 0.01) and in those with Alzheimer's disease versus other dementias (65.2% vs. 29.7%, p < 0.001). Repetitive questioning was the most frequent type of verbal repetition (90.5% of individuals with verbal repetition). Verbal repetition was most strongly associated with difficulties operating gadgets/appliances (OR 3.65, 95%CI: 2.82-4.72), lack of interest and/or initiative (3.52: 2.84-4.36), misplacing or losing objects (3.25: 2.64-4.01), and lack of attention and/or concentration (2.62: 2.12-3.26). Verbal repetition is a common symptom in people at all stages of dementia but is most commonly targeted for monitoring and treatment effects in its mild stage. Much research is required to further elucidate the underlying mechanisms and the effect of different treatment strategies.

Quantifying repetitive speech in autism spectrum disorders and language impairment.

Science.gov (United States)

van Santen, Jan P H; Sproat, Richard W; Hill, Alison Presmanes

2013-10-01

We report on an automatic technique for quantifying two types of repetitive speech: repetitions of what the child says him/herself (self-repeats) and of what is uttered by an interlocutor (echolalia). We apply this technique to a sample of 111 children between the ages of four and eight: 42 typically developing children (TD), 19 children with specific language impairment (SLI), 25 children with autism spectrum disorders (ASD) plus language impairment (ALI), and 25 children with ASD with normal, non-impaired language (ALN). The results indicate robust differences in echolalia between the TD and ASD groups as a whole (ALN + ALI), and between TD and ALN children. There were no significant differences between ALI and SLI children for echolalia or self-repetitions. The results confirm previous findings that children with ASD repeat the language of others more than other populations of children. On the other hand, self-repetition does not appear to be significantly more frequent in ASD, nor does it matter whether the child's echolalia occurred within one (immediate) or two turns (near-immediate) of the adult's original utterance. Furthermore, non-significant differences between ALN and SLI, between TD and SLI, and between ALI and TD are suggestive that echolalia may not be specific to ALN or to ASD in general. One important innovation of this work is an objective fully automatic technique for assessing the amount of repetition in a transcript of a child's utterances. © 2013 International Society for Autism Research, Wiley Periodicals, Inc.

Repetitive Behavior in Rubinstein-Taybi Syndrome: Parallels with Autism Spectrum Phenomenology

Science.gov (United States)

Waite, Jane; Moss, Joanna; Beck, Sarah R.; Richards, Caroline; Nelson, Lisa; Arron, Kate; Burbidge, Cheryl; Berg, Katy; Oliver, Chris

2015-01-01

Syndrome specific repetitive behavior profiles have been described previously. A detailed profile is absent for Rubinstein-Taybi syndrome (RTS). The Repetitive Behaviour Questionnaire and Social Communication Questionnaire were completed for children and adults with RTS (N = 87), Fragile-X (N = 196) and Down (N = 132) syndromes, and individuals…

How vision is shaped by language comprehension--top-down feedback based on low-spatial frequencies.

Science.gov (United States)

Hirschfeld, Gerrit; Zwitserlood, Pienie

2011-03-04

Effects of language comprehension on visual processing have been extensively studied within the embodied-language framework. However, it is unknown whether these effects are caused by passive repetition suppression in visual processing areas, or depend on active feedback, based on partial input, from prefrontal regions. Based on a model of top-down feedback during visual recognition, we predicted diminished effects when low-spatial frequencies were removed from targets. We compared low-pass and high-pass filtered pictures in a sentence-picture-verification task. Target pictures matched or mismatched the implied shape of an object mentioned in a preceding sentence, or were unrelated to the sentences. As predicted, there was a large match advantage when the targets contained low-spatial frequencies, but no effect of linguistic context when these frequencies were filtered out. The proposed top-down feedback model is superior to repetition suppression in explaining the current results, as well as earlier results about the lateralization of this effect, and peculiar color match effects. We discuss these findings in the context of recent general proposals of prediction and top-down feedback. Copyright © 2010 Elsevier B.V. All rights reserved.

Repetitive, small-bore two-stage light gas gun

International Nuclear Information System (INIS)

Combs, S.K.; Foust, C.R.; Fehling, D.T.; Gouge, M.J.; Milora, S.L.

1991-01-01

A repetitive two-stage light gas gun for high-speed pellet injection has been developed at Oak Ridge National Laboratory. In general, applications of the two-stage light gas gun have been limited to only single shots, with a finite time (at least minutes) needed for recovery and preparation for the next shot. The new device overcomes problems associated with repetitive operation, including rapidly evacuating the propellant gases, reloading the gun breech with a new projectile, returning the piston to its initial position, and refilling the first- and second-stage gas volumes to the appropriate pressure levels. In addition, some components are subjected to and must survive severe operating conditions, which include rapid cycling to high pressures and temperatures (up to thousands of bars and thousands of kelvins) and significant mechanical shocks. Small plastic projectiles (4-mm nominal size) and helium gas have been used in the prototype device, which was equipped with a 1-m-long pump tube and a 1-m-long gun barrel, to demonstrate repetitive operation (up to 1 Hz) at relatively high pellet velocities (up to 3000 m/s). The equipment is described, and experimental results are presented. 124 refs., 6 figs., 5 tabs

A pulsed single-frequency Nd:GGG/BaWO4 Raman laser

Science.gov (United States)

Liu, Zhaojun; Men, Shaojie; Cong, Zhenhua; Qin, Zengguang; Zhang, Xingyu; Zhang, Huaijin

2018-04-01

A single-frequency pulsed laser at 1178.3 nm was demonstrated in a crystalline Raman laser. A crystal combination of Nd:GGG and BaWO4 was selected to realize Raman conversion from a 1062.5 nm fundamental wave to a 1178.3 nm Stokes wave. An entangled cavity was specially designed to form an intracavity Raman configuration. Single-longitudinal-mode operation was realized by introducing two Fabry-Perot etalons into the Raman laser cavity. This laser operated at a pulse repetition rate of 50 Hz with 2 ms long envelopes containing micro pulses at a 30 kHz repetition rate. The highest output power was 41 mW with the micro pulse duration of 15 ns. The linewidth was measured to be less than 130 MHz.

Effects of slow repetitive transcranial magnetic stimulation in patients with corticobasal syndrome.

Science.gov (United States)

Civardi, Carlo; Pisano, Fabrizio; Delconte, Carmen; Collini, Alessandra; Monaco, Francesco

2015-06-01

Corticobasal syndrome is characterized by asymmetric cortical sensorimotor dysfunction and parkinsonism; an altered cortical excitability has been reported. We explored with transcranial magnetic stimulation the motor cortical excitability in corticobasal syndrome, and the effects of slow repetitive transcranial magnetic stimulation. With transcranial magnetic stimulation, we studied two corticobasal syndrome patients. We determined bilaterally from the first dorsal interosseous muscle: relaxed threshold, and contralateral and ipsilateral silent period. We also evaluated the contralateral silent period after active/sham slow repetitive transcranial magnetic stimulation on the most affected side. At T0 the silent period was bilaterally short. On the most affected side, active slow repetitive transcranial magnetic stimulation induced a short lasting prolongation of the contralateral silent period. In corticobasal syndrome, transcranial magnetic stimulation showed a reduction cortical inhibitory phenomenon potentially reversed transiently by slow repetitive transcranial magnetic stimulation.

Dissociating mere exposure and repetition priming as a function of word type.

Science.gov (United States)

Butler, Laurie T; Berry, Dianne C; Helman, Shaun

2004-07-01

The mere exposure effect is defined as enhanced attitude toward a stimulus that has been repeatedly exposed. Repetition priming is defined as facilitated processing of a previously exposed stimulus. We conducted a direct comparison between the two phenomena to test the assumption that the mere exposure effect represents an example of repetition priming. In two experiments, having studied a set of words or nonwords, participants were given a repetition priming task (perceptual identification) or one of two mere exposure (affective liking or preference judgment) tasks. Repetition priming was obtained for both words and nonwords, but only nonwords produced a mere exposure effect. This demonstrates a key boundary for observing the mere exposure effect, one not readily accommodated by a perceptual representation systems (Tulving & Schacter, 1990) account, which assumes that both phenomena should show some sensitivity to nonwords and words.

Sustainment of spherical tokamak by means of repetitive injection of compact torus plasma

International Nuclear Information System (INIS)

Shimamura, Shin; Matsura, Ken; Takahashi, Tsutomu; Nogi, Yasuyuki

2000-01-01

Sustainment of spherical tokamak (S.T.) has been studied. A compact torus (C.T.) plasma was injected into confinement region by magnetized coaxial gun. For start-up and sustainment of large main spherical tokamak, single pulsed injection of small C.T. is not sufficient in many cases. C.T.plasma injection of high repetition rate is required. For this purpose magnetized coaxial gun was driven with high repetition rate current. The first injected C.T. plasma could start-up S.T. without other help. The repetitive C.T. injection grew and sustained the S.T. plasma. A CCD camera with fast gated image intensifier took a cross sectional view of S.T. during the repetitive C.T. injection. (author)

PCR amplification of repetitive sequences as a possible approach in relative species quantification

DEFF Research Database (Denmark)

Ballin, Nicolai Zederkopff; Vogensen, Finn Kvist; Karlsson, Anders H

2012-01-01

Abstract Both relative and absolute quantifications are possible in species quantification when single copy genomic DNA is used. However, amplification of single copy genomic DNA does not allow a limit of detection as low as one obtained from amplification of repetitive sequences. Amplification...... of repetitive sequences is therefore frequently used in absolute quantification but problems occur in relative quantification as the number of repetitive sequences is unknown. A promising approach was developed where data from amplification of repetitive sequences were used in relative quantification of species...... to relatively quantify the amount of chicken DNA in a binary mixture of chicken DNA and pig DNA. However, the designed PCR primers lack the specificity required for regulatory species control....

Design and implementation of fast charging circuit for repetitive compact torus injector

International Nuclear Information System (INIS)

Onchi, T.; McColl, D.; Dreval, M.; Wolfe, S.; Xiao, C.; Hirose, A.

2014-01-01

A novel circuit for compact torus (CT) injector operated at high repetition rates has been developed. The core technology adopted in the present work is to charge a large storage capacitor bank and quickly charge the CT capacitor bank through a stack of insulated-gate bipolar transistors (IGBTs). A system consisting of IGBTs and slow banks for the repetitive operation has been developed and installed for each discharge circuit of the University of Saskatchewan Compact Torus Injector (USCTI). A repetition rate up to 1.7 Hz and a burst of 8 CTs have been achieved

Automatic frequency control system for driving a linear accelerator

International Nuclear Information System (INIS)

Helgesson, A.L.

1976-01-01

An automatic frequency control system is described for maintaining the drive frequency applied to a linear accelerator to produce maximum particle output from the accelerator. The particle output amplitude is measured and the frequency of the radio frequency source powering the linear accelerator is adjusted to maximize particle output amplitude

Universal data compression and repetition times

NARCIS (Netherlands)

Willems, Frans M J

1989-01-01

A new universal data compression algorithm is described. This algorithm encodes L source symbols at a time. For the class of binary stationary sources, its rate does not exceed [formula omitted] [formula omitted] bits per source symbol. In our analysis, a property of repetition times turns out to be

High-repetition-rate hydrogen chamber: Preliminary studies; Chambre a hydrogene a haut taux de repetition: Etudes preliminaires

Energy Technology Data Exchange (ETDEWEB)

NONE

1967-01-01

This report is a conclusion to the tests realised with an experimental bubbles chamber in view to study the possibilities to increase the repetition rate. The more important parameters (the evolution of the bubbles, the expansion system) are considered in a theoretical way. Then the hardware is described. To end, experimental results are compared with the first evaluations. The calculations and the experimentation are against an oscillation system for the expansion. A system with a locking is to he considered. (authors) [French] Ce rapport est une conclusion aux essais realises avec une chambre a bulles experimentale en vue d'etudier les possibilites d'accroitre les taux de repetition. Les parametres les plus importants (evolution des bulles, mecanique de la detente) sont etudies par voie theorique. Puis l'appareillage est decrit. Enfin, les resultats experimentaux sont compares aux evaluations donnees au debut. Ces calculs et cette experimentation ne sont pas en faveur d'un systeme oscillant pour la detente et il faut envisager un systeme avec verrouillage. (auteurs)

Effects of die profile on grain refinement in Al–Mg alloy processed by repetitive corrugation and straightening

Energy Technology Data Exchange (ETDEWEB)

Thangapandian, N., E-mail: erpandian@gmail.com [Department of Mechanical Engineering, College of Engineering Guindy, Anna University, Chennai 600025 (India); Balasivanandha Prabu, S. [Department of Mechanical Engineering, College of Engineering Guindy, Anna University, Chennai 600025 (India); Padmanabhan, K.A. [Centre for Nanotechnology, University of Hyderabad, Hyderabad 500046 (India)

2016-01-01

It is shown that a proper selection of corrugation die profile and die parameters is essential for achieving homogeneous grain refinement in materials subjected to repetitive corrugation and straightening (RCS). An Al–Mg (AA 5083) alloy was subjected to the RCS process using three different corrugation die profiles (V-groove, Flat groove, and Semi-circular groove), followed by straightening to determine the allowable maximum number of passes prior to surface cracking/fracture. Mechanical properties, i.e., hardness and tensile strength of the RCS samples were measured and compared as functions of corrugation die profiles and number of passes and the changes in microstructure. Grain refinement was studied using Electron Back Scattered Diffraction (EBSD) analysis and Transmission Electron Microscopy (TEM).

Low power fast settling multi-standard current reusing CMOS fractional-N frequency synthesizer

Institute of Scientific and Technical Information of China (English)

Lou Wenfeng; Feng Peng; Wang Haiyong; Wu Nanjian

2012-01-01

A low power fast settling multi-standard CMOS fractional-N frequency synthesizer is proposed.The current reusing and frequency presetting techniques are adopted to realize the low power fast settling multi-standard fractional-N frequency synthesizer.An auxiliary non-volatile memory (NVM) is embedded to avoid the repetitive calibration process and to save power in practical application.This PLL is implemented in a 0.18μm technology.The frequency range is 0.3 to 2.54 GHz and the settling time is less than 5μs over the entire frequency range.The LC-VCO with the stacked divide-by-2 has a good figure of merit of-193.5 dBc/Hz.The measured phase noise of frequency synthesizer is about -115 dBc/Hz at 1 MHz offset when the carrier frequency is 2.4 GHz and the reference spurs are less than -52 dBc.The whole frequency synthesizer consumes only 4.35 mA @ 1.8 V.

Iodine laser of high efficiency and fast repetition rate

Energy Technology Data Exchange (ETDEWEB)

Hohla, K; Witte, K J

1976-07-01

The scaling laws of an iodine laser of high efficiency and fast repetition rate are reported. The laser is pumped with a new kind of low pressure Hg-UV-lamps which convert 32% of the electrical input in UV-light in the absorption band of the iodine laser and which can be fired up to 100 Hz. Details of a 10 kJ/1 nsec system as dimensions, energy density, repetition rate, flow velocity, gas composition and gas pressure and the overall efficiency are given which is expected to be about 2%.

High Frequency Oscillatory Ventilation

Directory of Open Access Journals (Sweden)

AC Bryan

1996-01-01

Full Text Available High frequency oscillatory (HFO ventilation using low tidal volume and peak airway pressures is extremely efficient at eliminating carbon dioxide and raising pH in the newborn infant with acute respiratory failure. Improvement in oxygenation requires a strategy of sustained or repetitive inflations to 25 to 30 cm H2O in order to place the lung on the deflation limb of the pressure-volume curve. This strategy has also been shown to decrease the amount of secondary lung injury in animal models. Experience of the use of HFO ventilation as a rescue therapy as well as several published controlled trials have shown improved outcomes and a decrease in the use of extracorporeal membrane oxygenation when it has been used in newborns.

Heavy-duty high-repetition-rate generators

NARCIS (Netherlands)

Heesch, van E.J.M.; Yan, K.; Pemen, A.J.M.

2002-01-01

We present our results on high-power repetitive pulse sources for continuous operation. Two 1-10-kW systems using advanced spark gap technology and a transmission line transformer have been tested for several hundred hours at a 60-MW pulse level. High reliability and above 90% overall efficiency are

A Comparative Frequency Analysis of Maximum Daily Rainfall for a SE Asian Region under Current and Future Climate Conditions

Directory of Open Access Journals (Sweden)

Velautham Daksiya

2017-01-01

Full Text Available The impact of changing climate on the frequency of daily rainfall extremes in Jakarta, Indonesia, is analysed and quantified. The study used three different models to assess the changes in rainfall characteristics. The first method involves the use of the weather generator LARS-WG to quantify changes between historical and future daily rainfall maxima. The second approach consists of statistically downscaling general circulation model (GCM output based on historical empirical relationships between GCM output and station rainfall. Lastly, the study employed recent statistically downscaled global gridded rainfall projections to characterize climate change impact rainfall structure. Both annual and seasonal rainfall extremes are studied. The results show significant changes in annual maximum daily rainfall, with an average increase as high as 20% in the 100-year return period daily rainfall. The uncertainty arising from the use of different GCMs was found to be much larger than the uncertainty from the emission scenarios. Furthermore, the annual and wet seasonal analyses exhibit similar behaviors with increased future rainfall, but the dry season is not consistent across the models. The GCM uncertainty is larger in the dry season compared to annual and wet season.

Clinical and electrophysiological impact of repetitive low-frequency transcranial magnetic stimulation on the sensory–motor network in patients with restless legs syndrome

Science.gov (United States)

Cantone, Mariagiovanna; Aricò, Debora; Lanuzza, Bartolo; Cosentino, Filomena Irene Ilaria; Paci, Domenico; Papotto, Maurizio; Pennisi, Manuela; Bella, Rita; Pennisi, Giovanni; Paulus, Walter; Ferri, Raffaele

2018-01-01

Background: Based on the hyperexcitability and disinhibition observed in patients with restless legs syndrome (RLS) following transcranial magnetic stimulation (TMS), we conducted a study with low-frequency repetitive TMS (rTMS) over the primary motor (M1) and somatosensory cortical areas (S1) in patients with RLS. Methods: A total of 13 right-handed patients and 10 age-matched controls were studied using clinical scales and TMS. Measurements included resting motor threshold (rMT), motor-evoked potentials (MEPs), cortical silent period (CSP), and central motor conduction time (CMCT). A single evening session of rTMS (1 Hz, 20 trains, 50 stimuli each) was administered over the left M1, left S1, and sham stimulation over M1 in a random order. Clinical and TMS measures were repeated after each stimulation modality. Results: Baseline CSP was shorter in patients than in controls and remained shorter in patients for both motor and somatosensory stimulation. The patients reported a subjective improvement of both initiating and maintaining sleep the night after the rTMS over S1. Patients exhibited a decrease in rMT after rTMS of S1 only, although the effect was smaller than in controls. MEP latency and CMCT changed only in controls after stimulation. Sham stimulation was without effect on the observed variables. Conclusions: rTMS on S1-M1 connectivity alleviated the sensory–motor complaints of RLS patients. The TMS indexes of excitation and inhibition indicate an intracortical and corticospinal imbalance, mainly involving gamma-aminobutyric acid (GABA)ergic and glutamatergic circuitries, as well as an impairment of the short-term mechanisms of cortical plasticity. The rTMS-induced activation of the dorsal striatum with the consequent increase of dopamine release may have contributed to the clinical and neurophysiological outcome. PMID:29511386

Clinical and electrophysiological impact of repetitive low-frequency transcranial magnetic stimulation on the sensory-motor network in patients with restless legs syndrome.

Science.gov (United States)

Lanza, Giuseppe; Cantone, Mariagiovanna; Aricò, Debora; Lanuzza, Bartolo; Cosentino, Filomena Irene Ilaria; Paci, Domenico; Papotto, Maurizio; Pennisi, Manuela; Bella, Rita; Pennisi, Giovanni; Paulus, Walter; Ferri, Raffaele

2018-01-01

Based on the hyperexcitability and disinhibition observed in patients with restless legs syndrome (RLS) following transcranial magnetic stimulation (TMS), we conducted a study with low-frequency repetitive TMS (rTMS) over the primary motor (M1) and somatosensory cortical areas (S1) in patients with RLS. A total of 13 right-handed patients and 10 age-matched controls were studied using clinical scales and TMS. Measurements included resting motor threshold (rMT), motor-evoked potentials (MEPs), cortical silent period (CSP), and central motor conduction time (CMCT). A single evening session of rTMS (1 Hz, 20 trains, 50 stimuli each) was administered over the left M1, left S1, and sham stimulation over M1 in a random order. Clinical and TMS measures were repeated after each stimulation modality. Baseline CSP was shorter in patients than in controls and remained shorter in patients for both motor and somatosensory stimulation. The patients reported a subjective improvement of both initiating and maintaining sleep the night after the rTMS over S1. Patients exhibited a decrease in rMT after rTMS of S1 only, although the effect was smaller than in controls. MEP latency and CMCT changed only in controls after stimulation. Sham stimulation was without effect on the observed variables. rTMS on S1-M1 connectivity alleviated the sensory-motor complaints of RLS patients. The TMS indexes of excitation and inhibition indicate an intracortical and corticospinal imbalance, mainly involving gamma-aminobutyric acid (GABA)ergic and glutamatergic circuitries, as well as an impairment of the short-term mechanisms of cortical plasticity. The rTMS-induced activation of the dorsal striatum with the consequent increase of dopamine release may have contributed to the clinical and neurophysiological outcome.

Nanosecond repetitively pulsed discharges in air at atmospheric pressure-the spark regime

International Nuclear Information System (INIS)

Pai, David Z; Lacoste, Deanna A; Laux, Christophe O

2010-01-01

Nanosecond repetitively pulsed (NRP) spark discharges have been studied in atmospheric pressure air preheated to 1000 K. Measurements of spark initiation and stability, plasma dynamics, gas temperature and current-voltage characteristics of the spark regime are presented. Using 10 ns pulses applied repetitively at 30 kHz, we find that 2-400 pulses are required to initiate the spark, depending on the applied voltage. Furthermore, about 30-50 pulses are required for the spark discharge to reach steady state, following initiation. Based on space- and time-resolved optical emission spectroscopy, the spark discharge in steady state is found to ignite homogeneously in the discharge gap, without evidence of an initial streamer. Using measured emission from the N 2 (C-B) 0-0 band, it is found that the gas temperature rises by several thousand Kelvin in the span of about 30 ns following the application of the high-voltage pulse. Current-voltage measurements show that up to 20-40 A of conduction current is generated, which corresponds to an electron number density of up to 10 15 cm -3 towards the end of the high-voltage pulse. The discharge dynamics, gas temperature and electron number density are consistent with a streamer-less spark that develops homogeneously through avalanche ionization in volume. This occurs because the pre-ionization electron number density of about 10 11 cm -3 produced by the high frequency train of pulses is above the critical density for streamer-less discharge development, which is shown to be about 10 8 cm -3 .

Nanosecond repetitively pulsed discharges in air at atmospheric pressure—the spark regime

Science.gov (United States)

Pai, David Z.; Lacoste, Deanna A.; Laux, Christophe O.

2010-12-01

Nanosecond repetitively pulsed (NRP) spark discharges have been studied in atmospheric pressure air preheated to 1000 K. Measurements of spark initiation and stability, plasma dynamics, gas temperature and current-voltage characteristics of the spark regime are presented. Using 10 ns pulses applied repetitively at 30 kHz, we find that 2-400 pulses are required to initiate the spark, depending on the applied voltage. Furthermore, about 30-50 pulses are required for the spark discharge to reach steady state, following initiation. Based on space- and time-resolved optical emission spectroscopy, the spark discharge in steady state is found to ignite homogeneously in the discharge gap, without evidence of an initial streamer. Using measured emission from the N2 (C-B) 0-0 band, it is found that the gas temperature rises by several thousand Kelvin in the span of about 30 ns following the application of the high-voltage pulse. Current-voltage measurements show that up to 20-40 A of conduction current is generated, which corresponds to an electron number density of up to 1015 cm-3 towards the end of the high-voltage pulse. The discharge dynamics, gas temperature and electron number density are consistent with a streamer-less spark that develops homogeneously through avalanche ionization in volume. This occurs because the pre-ionization electron number density of about 1011 cm-3 produced by the high frequency train of pulses is above the critical density for streamer-less discharge development, which is shown to be about 108 cm-3.

Nanosecond repetitively pulsed discharges in air at atmospheric pressure-the spark regime

Energy Technology Data Exchange (ETDEWEB)

Pai, David Z; Lacoste, Deanna A; Laux, Christophe O [Laboratoire EM2C, CNRS UPR288, Ecole Centrale Paris, 92295 Chatenay-Malabry (France)

2010-12-15

Nanosecond repetitively pulsed (NRP) spark discharges have been studied in atmospheric pressure air preheated to 1000 K. Measurements of spark initiation and stability, plasma dynamics, gas temperature and current-voltage characteristics of the spark regime are presented. Using 10 ns pulses applied repetitively at 30 kHz, we find that 2-400 pulses are required to initiate the spark, depending on the applied voltage. Furthermore, about 30-50 pulses are required for the spark discharge to reach steady state, following initiation. Based on space- and time-resolved optical emission spectroscopy, the spark discharge in steady state is found to ignite homogeneously in the discharge gap, without evidence of an initial streamer. Using measured emission from the N{sub 2} (C-B) 0-0 band, it is found that the gas temperature rises by several thousand Kelvin in the span of about 30 ns following the application of the high-voltage pulse. Current-voltage measurements show that up to 20-40 A of conduction current is generated, which corresponds to an electron number density of up to 10{sup 15} cm{sup -3} towards the end of the high-voltage pulse. The discharge dynamics, gas temperature and electron number density are consistent with a streamer-less spark that develops homogeneously through avalanche ionization in volume. This occurs because the pre-ionization electron number density of about 10{sup 11} cm{sup -3} produced by the high frequency train of pulses is above the critical density for streamer-less discharge development, which is shown to be about 10{sup 8} cm{sup -3}.

Maximum Likelihood Approach for RFID Tag Set Cardinality Estimation with Detection Errors

DEFF Research Database (Denmark)

Nguyen, Chuyen T.; Hayashi, Kazunori; Kaneko, Megumi

2013-01-01

Abstract Estimation schemes of Radio Frequency IDentification (RFID) tag set cardinality are studied in this paper using Maximum Likelihood (ML) approach. We consider the estimation problem under the model of multiple independent reader sessions with detection errors due to unreliable radio...... is evaluated under dierent system parameters and compared with that of the conventional method via computer simulations assuming flat Rayleigh fading environments and framed-slotted ALOHA based protocol. Keywords RFID tag cardinality estimation maximum likelihood detection error...

High repetition rate intense ion beam source

International Nuclear Information System (INIS)

Hammer, D.A.; Glidden, S.C.; Noonan, B.

1992-01-01

This final report describes a ≤ 150kV, 40kA, 100ns high repetition rate pulsed power system and intense ion beam source which is now in operation at Cornell University. Operation of the Magnetically-controlled Anode Plasma (MAP) ion diode at > 100Hz (burst mode for up to 10 pulse bursts) provides an initial look at repetition rate limitations of both the ion diode and beam diagnostics. The pulsed power systems are capable of ≥ 1kHz operation (up to 10 pulse bursts), but ion diode operation was limited to ∼100Hz because of diagnostic limitations. By varying MAP diode operating parameters, ion beams can be extracted at a few 10s of keV or at up to 150keV, the corresponding accelerating gap impedance ranging from about 1Ω to about 10Ω. The ability to make hundreds of test pulses per day at an average repetition rate of about 2 pulses per minute permits statistical analysis of diode operation as a function of various parameters. Most diode components have now survived more than 10 4 pulses, and the design and construction of the various pulsed power components of the MAP diode which have enabled us to reach this point are discussed. A high speed data acquisition system and companion analysis software capable of acquiring pulse data at 1ms intervals (in bursts of up to 10 pulses) and processing it in ≤ min is described

MIMICRY, DIFFERENCE AND REPETITION

Directory of Open Access Journals (Sweden)

Marcelo Mendes de Souza

2008-07-01

Full Text Available This article addresses Homi K. Bhabha’s concept of mimicry in a broader context, other than that of cultural studies and post-colonial studies, bringing together other concepts, such as that of Gilles Deleuze in Difference and repetition, among other texts, and other names, such as Silviano Santiago, Jorge Luís Borges, Franz Kafka and Giorgio Agamben. As a partial conclusion, the article intends to oppose Bhabha’s freudian-marxist view to Five propositions on Psychoanalysis (1973, Gilles Deleuze’s text about Psychoanalysis published right after his book The Anti-Oedipus.

Neurobehavioural Correlates of Abnormal Repetitive Behaviour

Directory of Open Access Journals (Sweden)

R. A. Ford

1991-01-01

Full Text Available Conditions in which echolalia and echopraxia occur are reviewed, followed by an attempt to elicit possible mechanisms of these phenomena. A brief description of stereotypical and perseverative behaviour and obsessional phenomena is given. It is suggested that abnormal repetitive behaviour may occur partly as a result of central dopaminergic dysfunction.

Laterality of repetitive finger movement performance and clinical features of Parkinson's disease.

Science.gov (United States)

Stegemöller, Elizabeth; Zaman, Andrew; MacKinnon, Colum D; Tillman, Mark D; Hass, Chris J; Okun, Michael S

2016-10-01

Impairments in acoustically cued repetitive finger movement often emerge at rates near to and above 2Hz in persons with Parkinson's Disease (PD) in which some patients move faster (hastening) and others move slower (bradykinetic). The clinical features impacting this differential performance of repetitive finger movement remain unknown. The purpose of this study was to compare repetitive finger movement performance between the more and less affected side, and the difference in clinical ratings among performance groups. Forty-one participants diagnosed with idiopathic PD completed an acoustically cued repetitive finger movement task while "on" medication. Eighteen participants moved faster, 10 moved slower, and 13 were able to maintain the appropriate rate at rates above 2Hz. Clinical measures of laterality, disease severity, and the UPDRS were obtained. There were no significant differences between the more and less affected sides regardless of performance group. Comparison of disease severity, tremor, and rigidity among performance groups revealed no significant differences. Comparison of posture and postural instability scores revealed that the participants that demonstrated hastening had worse posture and postural instability scores. Consideration of movement rate during the clinical evaluation of repetitive finger movement may provide additional insight into varying disease features in persons with PD. Copyright © 2016 Elsevier B.V. All rights reserved.

Psychophysical Estimates of Frequency Discrimination: More than Just Limitations of Auditory Processing

Directory of Open Access Journals (Sweden)

Beate Sabisch

2013-07-01

Full Text Available Efficient auditory processing is hypothesized to support language and literacy development. However, behavioral tasks used to assess this hypothesis need to be robust to non-auditory specific individual differences. This study compared frequency discrimination abilities in a heterogeneous sample of adults using two different psychoacoustic task designs, referred to here as: 2I_6A_X and 3I_2AFC designs. The role of individual differences in nonverbal IQ (NVIQ, socioeconomic status (SES and musical experience in predicting frequency discrimination thresholds on each task were assessed using multiple regression analyses. The 2I_6A_X task was more cognitively demanding and hence more susceptible to differences specifically in SES and musical training. Performance on this task did not, however, relate to nonword repetition ability (a measure of language learning capacity. The 3I_2AFC task, by contrast, was only susceptible to musical training. Moreover, thresholds measured using it predicted some variance in nonword repetition performance. This design thus seems suitable for use in studies addressing questions regarding the role of auditory processing in supporting language and literacy development.

Repetitive element transcripts are elevated in the brain of C9orf72 ALS/FTLD patients.

Science.gov (United States)

Prudencio, Mercedes; Gonzales, Patrick K; Cook, Casey N; Gendron, Tania F; Daughrity, Lillian M; Song, Yuping; Ebbert, Mark T W; van Blitterswijk, Marka; Zhang, Yong-Jie; Jansen-West, Karen; Baker, Matthew C; DeTure, Michael; Rademakers, Rosa; Boylan, Kevin B; Dickson, Dennis W; Petrucelli, Leonard; Link, Christopher D

2017-09-01

Significant transcriptome alterations are detected in the brain of patients with amyotrophic lateral sclerosis (ALS), including carriers of the C9orf72 repeat expansion and C9orf72-negative sporadic cases. Recently, the expression of repetitive element transcripts has been associated with toxicity and, while increased repetitive element expression has been observed in several neurodegenerative diseases, little is known about their contribution to ALS. To assess whether aberrant expression of repetitive element sequences are observed in ALS, we analysed RNA sequencing data from C9orf72-positive and sporadic ALS cases, as well as healthy controls. Transcripts from multiple classes and subclasses of repetitive elements (LINEs, endogenous retroviruses, DNA transposons, simple repeats, etc.) were significantly increased in the frontal cortex of C9orf72 ALS patients. A large collection of patient samples, representing both C9orf72 positive and negative ALS, ALS/FTLD, and FTLD cases, was used to validate the levels of several repetitive element transcripts. These analyses confirmed that repetitive element expression was significantly increased in C9orf72-positive compared to C9orf72-negative or control cases. While previous studies suggest an important link between TDP-43 and repetitive element biology, our data indicate that TDP-43 pathology alone is insufficient to account for the observed changes in repetitive elements in ALS/FTLD. Instead, we found that repetitive element expression positively correlated with RNA polymerase II activity in postmortem brain, and pharmacologic modulation of RNA polymerase II activity altered repetitive element expression in vitro. We conclude that increased RNA polymerase II activity in ALS/FTLD may lead to increased repetitive element transcript expression, a novel pathological feature of ALS/FTLD. © The Author 2017. Published by Oxford University Press.

Nonword Repetition and Vocabulary Knowledge as Predictors of Children's Phonological and Semantic Word Learning.

Science.gov (United States)

Adlof, Suzanne M; Patten, Hannah

2017-03-01

This study examined the unique and shared variance that nonword repetition and vocabulary knowledge contribute to children's ability to learn new words. Multiple measures of word learning were used to assess recall and recognition of phonological and semantic information. Fifty children, with a mean age of 8 years (range 5-12 years), completed experimental assessments of word learning and norm-referenced assessments of receptive and expressive vocabulary knowledge and nonword repetition skills. Hierarchical multiple regression analyses examined the variance in word learning that was explained by vocabulary knowledge and nonword repetition after controlling for chronological age. Together with chronological age, nonword repetition and vocabulary knowledge explained up to 44% of the variance in children's word learning. Nonword repetition was the stronger predictor of phonological recall, phonological recognition, and semantic recognition, whereas vocabulary knowledge was the stronger predictor of verbal semantic recall. These findings extend the results of past studies indicating that both nonword repetition skill and existing vocabulary knowledge are important for new word learning, but the relative influence of each predictor depends on the way word learning is measured. Suggestions for further research involving typically developing children and children with language or reading impairments are discussed.

High-speed repetitive pellet injector prototype for magnetic confinement fusion devices

International Nuclear Information System (INIS)

Frattolillo, A.; Gasparotto, M.; Migliori, S.; Angelone, G.; Baldarelli, M.; Scaramuzzi, F.; Ronci, G.; Reggiori, A.; Riva, G.; Carlevaro, R.; Daminelli, G.B.

1992-01-01

The design of a test facility aimed at demonstrating the feasibility of high-speed repetitive acceleration of solid D 2 pellets for fusion applications, developed in a collaboration between Oak Ridge National Laboratory and ENEA Frascati, is presented. The results of tests performed at the CNPM/CNR on the piston wear in a repetitively operating two-stage gun are also reported

Influence of thermal reduced depolarization on a repetition-frequency laser amplifier and compensation

Institute of Scientific and Technical Information of China (English)

Xin-ying Jiang; Xiong-wei Yan; Zhen-guo Wang; Jian-gang Zheng; Ming-zhong Li; Jing-qin Su

2015-01-01

Thermal stress can induce birefringence in a laser medium, which can cause depolarization of the laser. The depolarization effect will be very severe in a high-average-power laser. Because the depolarization will make the frequency doubling efficiency decline, it should be compensated. In this paper, the thermal characteristics of two kinds of materials are analyzed in respect of temperature, thermal deformation and thermal stress. The depolarization result from thermal stress was simulated. Depolarization on non-uniform pumping was also simulated, and the compensation method is discussed.

Adaptation behavior of skilled infant bouncers to different spring frequencies

Directory of Open Access Journals (Sweden)

Olinda Habib Perez

2015-05-01

Full Text Available Infants explore their environments through repetitive movements that are constrained or facilitated by the environmental context. In this study, we evaluated how skilled bouncers adapted to bouncing in systems with four different spring conditions (natural frequencies of 0.9, 1.15, 1.27 and 1.56 Hz. Trunk kinematics and vertical ground reaction forces (VGRFs were recorded from three pre-walking infants (mean age 10.6 ±0.9 months. Bounce frequency, trunk displacement, peak VGRF, percent of time on the ground and time to peak force as a function of time on the ground were analyzed. In addition, infant bounce frequencies were compared to measured oscillations of an inert mass equivalent to each infant’s mass. All infants bounced above the natural frequency of the spring system in all conditions suggesting that they did not behave solely like mass-spring systems. Infants produced asymmetrical VGRF loading patterns suggesting that a timing component, such as bounce frequency, was regulated. Skilled infants consistently increased their bounce frequency as their vertical trunk displacement decreased; however, the mode for regulating bounce frequency differed from infant to infant.

Widespread Chromatin Accessibility at Repetitive Elements Links Stem Cells with Human Cancer

Directory of Open Access Journals (Sweden)

Nicholas C. Gomez

2016-11-01

Full Text Available Chromatin regulation is critical for differentiation and disease. However, features linking the chromatin environment of stem cells with disease remain largely unknown. We explored chromatin accessibility in embryonic and multipotent stem cells and unexpectedly identified widespread chromatin accessibility at repetitive elements. Integrating genomic and biochemical approaches, we demonstrate that these sites of increased accessibility are associated with well-positioned nucleosomes marked by distinct histone modifications. Differentiation is accompanied by chromatin remodeling at repetitive elements associated with altered expression of genes in relevant developmental pathways. Remarkably, we found that the chromatin environment of Ewing sarcoma, a mesenchymally derived tumor, is shared with primary mesenchymal stem cells (MSCs. Accessibility at repetitive elements in MSCs offers a permissive environment that is exploited by the critical oncogene responsible for this cancer. Our data demonstrate that stem cells harbor a unique chromatin landscape characterized by accessibility at repetitive elements, a feature associated with differentiation and oncogenesis.

Tactile Ranschburg effects: facilitation and inhibitory repetition effects analogous to verbal memory.

Science.gov (United States)

Roe, Daisy; Miles, Christopher; Johnson, Andrew J

2017-07-01

The present paper examines the effect of within-sequence item repetitions in tactile order memory. Employing an immediate serial recall procedure, participants reconstructed a six-item sequence tapped upon their fingers by moving those fingers in the order of original stimulation. In Experiment 1a, within-sequence repetition of an item separated by two-intervening items resulted in a significant reduction in recall accuracy for that repeated item (i.e., the Ranschburg effect). In Experiment 1b, within-sequence repetition of an adjacent item resulted in significant recall facilitation for that repeated item. These effects mirror those reported for verbal stimuli (e.g., Henson, 1998a . Item repetition in short-term memory: Ranschburg repeated. Journal of Experimental Psychology: Learning, Memory, and Cognition, 24(5), 1162-1181. doi:doi.org/10.1037/0278-7393.24.5.1162). These data are the first to demonstrate the Ranschburg effect with non-verbal stimuli and suggest further cross-modal similarities in order memory.

ReRep: Computational detection of repetitive sequences in genome survey sequences (GSS

Directory of Open Access Journals (Sweden)

Alves-Ferreira Marcelo

2008-09-01

Full Text Available Abstract Background Genome survey sequences (GSS offer a preliminary global view of a genome since, unlike ESTs, they cover coding as well as non-coding DNA and include repetitive regions of the genome. A more precise estimation of the nature, quantity and variability of repetitive sequences very early in a genome sequencing project is of considerable importance, as such data strongly influence the estimation of genome coverage, library quality and progress in scaffold construction. Also, the elimination of repetitive sequences from the initial assembly process is important to avoid errors and unnecessary complexity. Repetitive sequences are also of interest in a variety of other studies, for instance as molecular markers. Results We designed and implemented a straightforward pipeline called ReRep, which combines bioinformatics tools for identifying repetitive structures in a GSS dataset. In a case study, we first applied the pipeline to a set of 970 GSSs, sequenced in our laboratory from the human pathogen Leishmania braziliensis, the causative agent of leishmaniosis, an important public health problem in Brazil. We also verified the applicability of ReRep to new sequencing technologies using a set of 454-reads of an Escheria coli. The behaviour of several parameters in the algorithm is evaluated and suggestions are made for tuning of the analysis. Conclusion The ReRep approach for identification of repetitive elements in GSS datasets proved to be straightforward and efficient. Several potential repetitive sequences were found in a L. braziliensis GSS dataset generated in our laboratory, and further validated by the analysis of a more complete genomic dataset from the EMBL and Sanger Centre databases. ReRep also identified most of the E. coli K12 repeats prior to assembly in an example dataset obtained by automated sequencing using 454 technology. The parameters controlling the algorithm behaved consistently and may be tuned to the properties

High power all-solid-state fourth harmonic generation of 266 nm at the pulse repetition rate of 100 kHz

International Nuclear Information System (INIS)

Liu, Q; Yan, X P; Fu, X; Gong, M; Wang, D S

2009-01-01

14.8 W UV laser at 266 nm was reported with the extra cavity frequency quartered configuration. The fundamental frequency IR source is a high-power high-beam-quality acoustic-optic Q-switched Nd:YVO 4 master-oscillator-power-amplifier laser. The type-I phase-matched LBO and type-I phase-matched BBO crystals were used as the extra-cavity frequency doubled and quartered crystal respectively. 14.8 W UV laser of 266 nm was obtained at the pulse repetition rate of 100 kHz with the conversion efficiency of 18.3% from green to UV, and the pulse duration of the UV laser was 10 ns corresponding to the pulse peak power of 14.8 kW. At 150 kHz, 11.5 W power output was obtained. The highest peak power of 21 kW was also achieved at 80 kHz with the average output power of 14.5 W

Human sensory-evoked responses differ coincident with either "fusion-memory" or "flash-memory", as shown by stimulus repetition-rate effects

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Baird Bill

2006-02-01

Full Text Available Abstract Background: A new method has been used to obtain human sensory evoked-responses whose time-domain waveforms have been undetectable by previous methods. These newly discovered evoked-responses have durations that exceed the time between the stimuli in a continuous stream, thus causing an overlap which, up to now, has prevented their detection. We have named them "A-waves", and added a prefix to show the sensory system from which the responses were obtained (visA-waves, audA-waves, somA-waves. Results: When A-waves were studied as a function of stimulus repetition-rate, it was found that there were systematic differences in waveshape at repetition-rates above and below the psychophysical region in which the sensation of individual stimuli fuse into a continuity. The fusion phenomena is sometimes measured by a "Critical Fusion Frequency", but for this research we can only identify a frequency-region [which we call the STZ (Sensation-Transition Zone]. Thus, the A-waves above the STZ differed from those below the STZ, as did the sensations. Study of the psychophysical differences in auditory and visual stimuli, as shown in this paper, suggest that different stimulus features are detected, and remembered, at stimulation rates above and below STZ. Conclusion: The results motivate us to speculate that: 1 Stimulus repetition-rates above the STZ generate waveforms which underlie "fusion-memory" whereas rates below the STZ show neuronal processing in which "flash-memory" occurs. 2 These two memories differ in both duration and mechanism, though they may occur in the same cell groups. 3 The differences in neuronal processing may be related to "figure" and "ground" differentiation. We conclude that A-waves provide a novel measure of neural processes that can be detected on the human scalp, and speculate that they may extend clinical applications of evoked response recordings. If A-waves also occur in animals, it is likely that A-waves will provide

Human sensory-evoked responses differ coincident with either "fusion-memory" or "flash-memory", as shown by stimulus repetition-rate effects

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Jewett, Don L; Hart, Toryalai; Larson-Prior, Linda J; Baird, Bill; Olson, Marram; Trumpis, Michael; Makayed, Katherine; Bavafa, Payam

2006-01-01

Background: A new method has been used to obtain human sensory evoked-responses whose time-domain waveforms have been undetectable by previous methods. These newly discovered evoked-responses have durations that exceed the time between the stimuli in a continuous stream, thus causing an overlap which, up to now, has prevented their detection. We have named them "A-waves", and added a prefix to show the sensory system from which the responses were obtained (visA-waves, audA-waves, somA-waves). Results: When A-waves were studied as a function of stimulus repetition-rate, it was found that there were systematic differences in waveshape at repetition-rates above and below the psychophysical region in which the sensation of individual stimuli fuse into a continuity. The fusion phenomena is sometimes measured by a "Critical Fusion Frequency", but for this research we can only identify a frequency-region [which we call the STZ (Sensation-Transition Zone)]. Thus, the A-waves above the STZ differed from those below the STZ, as did the sensations. Study of the psychophysical differences in auditory and visual stimuli, as shown in this paper, suggest that different stimulus features are detected, and remembered, at stimulation rates above and below STZ. Conclusion: The results motivate us to speculate that: 1) Stimulus repetition-rates above the STZ generate waveforms which underlie "fusion-memory" whereas rates below the STZ show neuronal processing in which "flash-memory" occurs. 2) These two memories differ in both duration and mechanism, though they may occur in the same cell groups. 3) The differences in neuronal processing may be related to "figure" and "ground" differentiation. We conclude that A-waves provide a novel measure of neural processes that can be detected on the human scalp, and speculate that they may extend clinical applications of evoked response recordings. If A-waves also occur in animals, it is likely that A-waves will provide new methods for

Don't Throw out the Baby with the Bathwater: Verbal Repetition, Mnemonics, and Active Learning

Science.gov (United States)

Saber, Jane Lee; Johnson, Richard D.

2008-01-01

The effectiveness of using verbal repetition and first-letter acronyms to teach a common marketing framework was examined in two experiments. In Experiment 1, 345 undergraduate students were exposed to the framework using one of four conditions: control, verbal repetition, acronym, and verbal repetition plus acronym in a traditional learning…

Frequency Up-Converted Low Frequency Vibration Energy Harvester Using Trampoline Effect

International Nuclear Information System (INIS)

Ju, S; Chae, S H; Choi, Y; Jun, S; Park, S M; Lee, S; Ji, C-H; Lee, H W

2013-01-01

This paper presents a non-resonant vibration energy harvester based on magnetoelectric transduction mechanism and mechanical frequency up-conversion using trampoline effect. The harvester utilizes a freely movable spherical permanent magnet which bounces off the aluminum springs integrated at both ends of the cavity, achieving frequency up-conversion from low frequency input vibration. Moreover, bonding method of magnetoelectric laminate composite has been optimized to provide higher strain to piezoelectric material and thus obtain a higher output voltage. A proof-of-concept energy harvesting device has been fabricated and tested. Maximum open-circuit voltage of 11.2V has been obtained and output power of 0.57μW has been achieved for a 50kΩ load, when the fabricated energy harvester was hand-shaken

Frequency Up-Converted Low Frequency Vibration Energy Harvester Using Trampoline Effect

Science.gov (United States)