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Sample records for interaural time difference

  1. Localization by interaural time difference (ITD): Effects of interaural frequency mismatch

    International Nuclear Information System (INIS)

    Bonham, B.H.; Lewis, E.R.

    1999-01-01

    A commonly accepted physiological model for lateralization of low-frequency sounds by interaural time delay (ITD) stipulates that binaural comparison neurons receive input from frequency-matched channels from each ear. Here, the effects of hypothetical interaural frequency mismatches on this model are reported. For this study, the cat close-quote s auditory system peripheral to the binaural comparison neurons was represented by a neurophysiologically derived model, and binaural comparison neurons were represented by cross-correlators. The results of the study indicate that, for binaural comparison neurons receiving input from one cochlear channel from each ear, interaural CF mismatches may serve to either augment or diminish the effective difference in ipsilateral and contralateral axonal time delays from the periphery to the binaural comparison neuron. The magnitude of this increase or decrease in the effective time delay difference can be up to 400 μs for CF mismatches of 0.2 octaves or less for binaural neurons with CFs between 250 Hz and 2.5 kHz. For binaural comparison neurons with nominal CFs near 500 Hz, the 25-μs effective time delay difference caused by a 0.012-octave CF mismatch is equal to the ITD previously shown to be behaviorally sufficient for the cat to lateralize a low-frequency sound source. copyright 1999 Acoustical Society of America.

  2. Anatomical limits on interaural time differences: An ecological perspective

    Directory of Open Access Journals (Sweden)

    WILLIAM MORRIS HARTMANN

    2014-02-01

    Full Text Available Human listeners, and other animals too, use interaural time differences (ITDto localize sounds. If the sounds are pure tones, a simple frequency factorrelates the ITD to the interaural phase difference (IPD, for which there areknown iso-IPD boundaries, 90$^circ$, 180$^circ$~ldots defining regions ofspatial perception. In this article, iso-IPD boundaries for humans aretranslated into azimuths using a spherical head model, and the calculationsare checked by free-field measurements. The translated boundaries providequantitative tests of an ecological interpretation for the dramatic onset ofITD insensitivity at high frequencies. According to this interpretation, theinsensitivity serves as a defense against misinformation and can be attributedto limits on binaural processing in the brainstem. Calculations show that theecological explanation passes the tests only if the binaural brainstemproperties evolved or developed consistent with heads that are 50% smallerthan current adult heads. Measurements on more realistic head shapes relaxthat requirement only slightly. The problem posed by the discrepancy betweenthe current head size and a smaller, ideal head size was apparently solved bythe evolution or development of central processes that discount large IPDs infavor of interaural level differences. The latter become more important withincreasing head size.

  3. The effect of interaural-time-difference fluctuations on apparent source width

    DEFF Research Database (Denmark)

    Käsbach, Johannes; May, Tobias; Oskarsdottir, Gudrun

    2014-01-01

    For the perception of spaciousness, the temporal fluctuations of the interaural time differences (ITDs) and interaural level differences (ILDs) provide important binaural cues. One major characteristic of spatial perception is apparent source width (ASW), which describes the perceived width of a ...

  4. Effects of Interaural Level and Time Differences on the Externalization of Sound

    DEFF Research Database (Denmark)

    Dau, Torsten; Catic, Jasmina; Santurette, Sébastien

    Distant sound sources in our environment are perceived as externalized and are thus properly localized in both direction and distance. This is due to the acoustic filtering by the head, torso, and external ears, which provides frequency dependent shaping of binaural cues, such as interaural level...... differences (ILDs) and interaural time differences (ITDs). Further, the binaural cues provided by reverberation in an enclosed space may also contribute to externalization. While these spatial cues are available in their natural form when listening to real-world sound sources, hearing-aid signal processing...... is consistent with the physical analysis that showed that a decreased distance to the sound source also reduced the fluctuations in ILDs....

  5. A circuit for detection of interaural time differences in the nucleus laminaris of turtles.

    Science.gov (United States)

    Willis, Katie L; Carr, Catherine E

    2017-11-15

    The physiological hearing range of turtles is approximately 50-1000 Hz, as determined by cochlear microphonics ( Wever and Vernon, 1956a). These low frequencies can constrain sound localization, particularly in red-eared slider turtles, which are freshwater turtles with small heads and isolated middle ears. To determine if these turtles were sensitive to interaural time differences (ITDs), we investigated the connections and physiology of their auditory brainstem nuclei. Tract tracing experiments showed that cranial nerve VIII bifurcated to terminate in the first-order nucleus magnocellularis (NM) and nucleus angularis (NA), and the NM projected bilaterally to the nucleus laminaris (NL). As the NL received inputs from each side, we developed an isolated head preparation to examine responses to binaural auditory stimulation. Magnocellularis and laminaris units responded to frequencies from 100 to 600 Hz, and phase-locked reliably to the auditory stimulus. Responses from the NL were binaural, and sensitive to ITD. Measures of characteristic delay revealed best ITDs around ±200 μs, and NL neurons typically had characteristic phases close to 0, consistent with binaural excitation. Thus, turtles encode ITDs within their physiological range, and their auditory brainstem nuclei have similar connections and cell types to other reptiles. © 2017. Published by The Company of Biologists Ltd.

  6. Modeling Sluggishness in Binaural Unmasking of Speech for Maskers With Time-Varying Interaural Phase Differences.

    Science.gov (United States)

    Hauth, Christopher F; Brand, Thomas

    2018-01-01

    In studies investigating binaural processing in human listeners, relatively long and task-dependent time constants of a binaural window ranging from 10 ms to 250 ms have been observed. Such time constants are often thought to reflect "binaural sluggishness." In this study, the effect of binaural sluggishness on binaural unmasking of speech in stationary speech-shaped noise is investigated in 10 listeners with normal hearing. In order to design a masking signal with temporally varying binaural cues, the interaural phase difference of the noise was modulated sinusoidally with frequencies ranging from 0.25 Hz to 64 Hz. The lowest, that is the best, speech reception thresholds (SRTs) were observed for the lowest modulation frequency. SRTs increased with increasing modulation frequency up to 4 Hz. For higher modulation frequencies, SRTs remained constant in the range of 1 dB to 1.5 dB below the SRT determined in the diotic situation. The outcome of the experiment was simulated using a short-term binaural speech intelligibility model, which combines an equalization-cancellation (EC) model with the speech intelligibility index. This model segments the incoming signal into 23.2-ms time frames in order to predict release from masking in modulated noises. In order to predict the results from this study, the model required a further time constant applied to the EC mechanism representing binaural sluggishness. The best agreement with perceptual data was achieved using a temporal window of 200 ms in the EC mechanism.

  7. Reliability of Interaural Time Difference-Based Localization Training in Elderly Individuals with Speech-in-Noise Perception Disorder.

    Science.gov (United States)

    Delphi, Maryam; Lotfi, M-Yones; Moossavi, Abdollah; Bakhshi, Enayatollah; Banimostafa, Maryam

    2017-09-01

    Previous studies have shown that interaural-time-difference (ITD) training can improve localization ability. Surprisingly little is, however, known about localization training vis-à-vis speech perception in noise based on interaural time difference in the envelope (ITD ENV). We sought to investigate the reliability of an ITD ENV-based training program in speech-in-noise perception among elderly individuals with normal hearing and speech-in-noise disorder. The present interventional study was performed during 2016. Sixteen elderly men between 55 and 65 years of age with the clinical diagnosis of normal hearing up to 2000 Hz and speech-in-noise perception disorder participated in this study. The training localization program was based on changes in ITD ENV. In order to evaluate the reliability of the training program, we performed speech-in-noise tests before the training program, immediately afterward, and then at 2 months' follow-up. The reliability of the training program was analyzed using the Friedman test and the SPSS software. Significant statistical differences were shown in the mean scores of speech-in-noise perception between the 3 time points (P=0.001). The results also indicated no difference in the mean scores of speech-in-noise perception between the 2 time points of immediately after the training program and 2 months' follow-up (P=0.212). The present study showed the reliability of an ITD ENV-based localization training in elderly individuals with speech-in-noise perception disorder.

  8. Binaural processing of modulated interaural level differences

    DEFF Research Database (Denmark)

    Thompson, Eric Robert; Dau, Torsten

    2008-01-01

    Two experiments are presented that measure the acuity of binaural processing of modulated interaural level differences ILDs using psychoacoustic methods. In both experiments, dynamic ILDs were created by imposing an interaurally antiphasic sinusoidal amplitude modulation AM signal on high...... frequency, broadly tuned, bandpass-shaped patterns were obtained. Simulations with an existing binaural model show that a low-pass filter to limit the binaural temporal resolution is not sufficient to predict the results of the experiments....

  9. Reliability of Interaural Time Difference-Based Localization Training in Elderly Individuals with Speech-in-Noise Perception Disorder

    Directory of Open Access Journals (Sweden)

    Maryam Delphi

    2017-09-01

    Full Text Available Background: Previous studies have shown that interaural-time-difference (ITD training can improve localization ability. Surprisingly little is, however, known about localization training vis-à-vis speech perception in noise based on interaural time difference in the envelope (ITD ENV. We sought to investigate the reliability of an ITD ENV-based training program in speech-in-noise perception among elderly individuals with normal hearing and speech-in-noise disorder. Methods: The present interventional study was performed during 2016. Sixteen elderly men between 55 and 65 years of age with the clinical diagnosis of normal hearing up to 2000 Hz and speech-in-noise perception disorder participated in this study. The training localization program was based on changes in ITD ENV. In order to evaluate the reliability of the training program, we performed speech-in-noise tests before the training program, immediately afterward, and then at 2 months’ follow-up. The reliability of the training program was analyzed using the Friedman test and the SPSS software. Results: Significant statistical differences were shown in the mean scores of speech-in-noise perception between the 3 time points (P=0.001. The results also indicated no difference in the mean scores of speech-in-noise perception between the 2 time points of immediately after the training program and 2 months’ follow-up (P=0.212. Conclusion: The present study showed the reliability of an ITD ENV-based localization training in elderly individuals with speech-in-noise perception disorder.

  10. Interaural time sensitivity of high-frequency neurons in the inferior colliculus.

    Science.gov (United States)

    Yin, T C; Kuwada, S; Sujaku, Y

    1984-11-01

    Recent psychoacoustic experiments have shown that interaural time differences provide adequate cues for lateralizing high-frequency sounds, provided the stimuli are complex and not pure tones. We present here physiological evidence in support of these findings. Neurons of high best frequency in the cat inferior colliculus respond to interaural phase differences of amplitude modulated waveforms, and this response depends upon preservation of phase information of the modulating signal. Interaural phase differences were introduced in two ways: by interaural delays of the entire waveform and by binaural beats in which there was an interaural frequency difference in the modulating waveform. Results obtained with these two methods are similar. Our results show that high-frequency cells can respond to interaural time differences of amplitude modulated signals and that they do so by a sensitivity to interaural phase differences of the modulating waveform.

  11. Extraction of Inter-Aural Time Differences Using a Spiking Neuron Network Model of the Medial Superior Olive

    Directory of Open Access Journals (Sweden)

    Jörg Encke

    2018-03-01

    Full Text Available The mammalian auditory system is able to extract temporal and spectral features from sound signals at the two ears. One important cue for localization of low-frequency sound sources in the horizontal plane are inter-aural time differences (ITDs which are first analyzed in the medial superior olive (MSO in the brainstem. Neural recordings of ITD tuning curves at various stages along the auditory pathway suggest that ITDs in the mammalian brainstem are not represented in form of a Jeffress-type place code. An alternative is the hemispheric opponent-channel code, according to which ITDs are encoded as the difference in the responses of the MSO nuclei in the two hemispheres. In this study, we present a physiologically-plausible, spiking neuron network model of the mammalian MSO circuit and apply two different methods of extracting ITDs from arbitrary sound signals. The network model is driven by a functional model of the auditory periphery and physiological models of the cochlear nucleus and the MSO. Using a linear opponent-channel decoder, we show that the network is able to detect changes in ITD with a precision down to 10 μs and that the sensitivity of the decoder depends on the slope of the ITD-rate functions. A second approach uses an artificial neuronal network to predict ITDs directly from the spiking output of the MSO and ANF model. Using this predictor, we show that the MSO-network is able to reliably encode static and time-dependent ITDs over a large frequency range, also for complex signals like speech.

  12. On the influence of interaural differences on temporal perception of masked noise bursts.

    NARCIS (Netherlands)

    Schimmel, O.V.; Kohlrausch, A.G.

    2006-01-01

    In this research, the influence of interaural differences on temporal positioning of the perceived onset of a dichotic broadband noise target in a diotic broadband noise masker was explored. Interaural time or level differences, a combination of these differences, and filtering with head-related

  13. Effects of interaural level differences on the externalization of sound

    DEFF Research Database (Denmark)

    Catic, Jasmina; Santurette, Sébastien; Dau, Torsten

    2012-01-01

    Distant sound sources in our environment are perceived as externalized and are thus properly localized in both direction and distance. This is due to the acoustic filtering by the head, torso, and external ears, which provides frequency-dependent shaping of binaural cues such as interaural level...... differences (ILDs) and interaural time differences (ITDs). In rooms, the sound reaching the two ears is further modified by reverberant energy, which leads to increased fluctuations in short-term ILDs and ITDs. In the present study, the effect of ILD fluctuations on the externalization of sound......, for sounds that contain frequencies above about 1 kHz the ILD fluctuations were found to be an essential cue for externalization....

  14. Aging effects on the binaural interaction component of the auditory brainstem response in the Mongolian gerbil: Effects of interaural time and level differences.

    Science.gov (United States)

    Laumen, Geneviève; Tollin, Daniel J; Beutelmann, Rainer; Klump, Georg M

    2016-07-01

    The effect of interaural time difference (ITD) and interaural level difference (ILD) on wave 4 of the binaural and summed monaural auditory brainstem responses (ABRs) as well as on the DN1 component of the binaural interaction component (BIC) of the ABR in young and old Mongolian gerbils (Meriones unguiculatus) was investigated. Measurements were made at a fixed sound pressure level (SPL) and a fixed level above visually detected ABR threshold to compensate for individual hearing threshold differences. In both stimulation modes (fixed SPL and fixed level above visually detected ABR threshold) an effect of ITD on the latency and the amplitude of wave 4 as well as of the BIC was observed. With increasing absolute ITD values BIC latencies were increased and amplitudes were decreased. ILD had a much smaller effect on these measures. Old animals showed a reduced amplitude of the DN1 component. This difference was due to a smaller wave 4 in the summed monaural ABRs of old animals compared to young animals whereas wave 4 in the binaural-evoked ABR showed no age-related difference. In old animals the small amplitude of the DN1 component was correlated with small binaural-evoked wave 1 and wave 3 amplitudes. This suggests that the reduced peripheral input affects central binaural processing which is reflected in the BIC. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Lateralization of noise bursts in interaurally correlated or uncorrelated background noise using interaural level differences.

    Science.gov (United States)

    Reed, Darrin K; van de Par, Steven

    2015-10-01

    The interaural level difference (ILD) of a lateralized target source may be effectively reduced when the target is presented together with background noise containing zero ILD. It is not certain whether listeners perceive a position congruent with the reduced ILD or the actual target ILD in a lateralization task. Two sets of behavioral experiments revealed that many listeners perceived a position at or even larger than that corresponding to the presented target ILD when a temporal onset/offset asynchrony between the broadband target and the broadband background noise was present. When no temporal asynchrony was present, however, the perceived lateral position indicated a dependency on the coherence of the background noise for several listeners. With interaurally correlated background noise, listeners reported a reduced ILD resulting from the combined target and background noise stimulus. In contrast, several of the listeners made a reasonable estimate of the position corresponding to the target ILD for interaurally uncorrelated, broadband, background noise. No obvious difference in performance was seen between low- or high-frequency stimuli. Extension of a weighting template to the output of a standard equalization-cancellation model was shown to remove a lateral bias on the predicted target ILD resulting from the presence of background noise. Provided that an appropriate weighting template is applied based on knowledge of the background noise coherence, good prediction of the behavioral data is possible.

  16. Functional dissociation of transient and sustained fMRI BOLD components in human auditory cortex revealed with a streaming paradigm based on interaural time differences.

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    Schadwinkel, Stefan; Gutschalk, Alexander

    2010-12-01

    A number of physiological studies suggest that feature-selective adaptation is relevant to the pre-processing for auditory streaming, the perceptual separation of overlapping sound sources. Most of these studies are focused on spectral differences between streams, which are considered most important for streaming. However, spatial cues also support streaming, alone or in combination with spectral cues, but physiological studies of spatial cues for streaming remain scarce. Here, we investigate whether the tuning of selective adaptation for interaural time differences (ITD) coincides with the range where streaming perception is observed. FMRI activation that has been shown to adapt depending on the repetition rate was studied with a streaming paradigm where two tones were differently lateralized by ITD. Listeners were presented with five different ΔITD conditions (62.5, 125, 187.5, 343.75, or 687.5 μs) out of an active baseline with no ΔITD during fMRI. The results showed reduced adaptation for conditions with ΔITD ≥ 125 μs, reflected by enhanced sustained BOLD activity. The percentage of streaming perception for these stimuli increased from approximately 20% for ΔITD = 62.5 μs to > 60% for ΔITD = 125 μs. No further sustained BOLD enhancement was observed when the ΔITD was increased beyond ΔITD = 125 μs, whereas the streaming probability continued to increase up to 90% for ΔITD = 687.5 μs. Conversely, the transient BOLD response, at the transition from baseline to ΔITD blocks, increased most prominently as ΔITD was increased from 187.5 to 343.75 μs. These results demonstrate a clear dissociation of transient and sustained components of the BOLD activity in auditory cortex. © 2010 The Authors. European Journal of Neuroscience © 2010 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  17. Spectral composition of concurrent noise affects neuronal sensitivity to interaural time differences of tones in the dorsal nucleus of the lateral lemniscus.

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    Siveke, Ida; Leibold, Christian; Grothe, Benedikt

    2007-11-01

    We are regularly exposed to several concurrent sounds, producing a mixture of binaural cues. The neuronal mechanisms underlying the localization of concurrent sounds are not well understood. The major binaural cues for localizing low-frequency sounds in the horizontal plane are interaural time differences (ITDs). Auditory brain stem neurons encode ITDs by firing maximally in response to "favorable" ITDs and weakly or not at all in response to "unfavorable" ITDs. We recorded from ITD-sensitive neurons in the dorsal nucleus of the lateral lemniscus (DNLL) while presenting pure tones at different ITDs embedded in noise. We found that increasing levels of concurrent white noise suppressed the maximal response rate to tones with favorable ITDs and slightly enhanced the response rate to tones with unfavorable ITDs. Nevertheless, most of the neurons maintained ITD sensitivity to tones even for noise intensities equal to that of the tone. Using concurrent noise with a spectral composition in which the neuron's excitatory frequencies are omitted reduced the maximal response similar to that obtained with concurrent white noise. This finding indicates that the decrease of the maximal rate is mediated by suppressive cross-frequency interactions, which we also observed during monaural stimulation with additional white noise. In contrast, the enhancement of the firing rate to tones at unfavorable ITD might be due to early binaural interactions (e.g., at the level of the superior olive). A simple simulation corroborates this interpretation. Taken together, these findings suggest that the spectral composition of a concurrent sound strongly influences the spatial processing of ITD-sensitive DNLL neurons.

  18. Trading of dynamic interaural time and level difference cues and its effect on the auditory motion-onset response measured with electroencephalography.

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    Altmann, Christian F; Ueda, Ryuhei; Bucher, Benoit; Furukawa, Shigeto; Ono, Kentaro; Kashino, Makio; Mima, Tatsuya; Fukuyama, Hidenao

    2017-10-01

    Interaural time (ITD) and level differences (ILD) constitute the two main cues for sound localization in the horizontal plane. Despite extensive research in animal models and humans, the mechanism of how these two cues are integrated into a unified percept is still far from clear. In this study, our aim was to test with human electroencephalography (EEG) whether integration of dynamic ITD and ILD cues is reflected in the so-called motion-onset response (MOR), an evoked potential elicited by moving sound sources. To this end, ITD and ILD trajectories were determined individually by cue trading psychophysics. We then measured EEG while subjects were presented with either static click-trains or click-trains that contained a dynamic portion at the end. The dynamic part was created by combining ITD with ILD either congruently to elicit the percept of a right/leftward moving sound, or incongruently to elicit the percept of a static sound. In two experiments that differed in the method to derive individual dynamic cue trading stimuli, we observed an MOR with at least a change-N1 (cN1) component for both the congruent and incongruent conditions at about 160-190 ms after motion-onset. A significant change-P2 (cP2) component for both the congruent and incongruent ITD/ILD combination was found only in the second experiment peaking at about 250 ms after motion onset. In sum, this study shows that a sound which - by a combination of counter-balanced ITD and ILD cues - induces a static percept can still elicit a motion-onset response, indicative of independent ITD and ILD processing at the level of the MOR - a component that has been proposed to be, at least partly, generated in non-primary auditory cortex. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Discrimination and streaming of speech sounds based on differences in interaural and spectral cues.

    Science.gov (United States)

    David, Marion; Lavandier, Mathieu; Grimault, Nicolas; Oxenham, Andrew J

    2017-09-01

    Differences in spatial cues, including interaural time differences (ITDs), interaural level differences (ILDs) and spectral cues, can lead to stream segregation of alternating noise bursts. It is unknown how effective such cues are for streaming sounds with realistic spectro-temporal variations. In particular, it is not known whether the high-frequency spectral cues associated with elevation remain sufficiently robust under such conditions. To answer these questions, sequences of consonant-vowel tokens were generated and filtered by non-individualized head-related transfer functions to simulate the cues associated with different positions in the horizontal and median planes. A discrimination task showed that listeners could discriminate changes in interaural cues both when the stimulus remained constant and when it varied between presentations. However, discrimination of changes in spectral cues was much poorer in the presence of stimulus variability. A streaming task, based on the detection of repeated syllables in the presence of interfering syllables, revealed that listeners can use both interaural and spectral cues to segregate alternating syllable sequences, despite the large spectro-temporal differences between stimuli. However, only the full complement of spatial cues (ILDs, ITDs, and spectral cues) resulted in obligatory streaming in a task that encouraged listeners to integrate the tokens into a single stream.

  20. Lateralized speech perception with small interaural time differences in normal-hearing and hearing-impaired listeners

    DEFF Research Database (Denmark)

    Locsei, Gusztav; Santurette, Sébastien; Dau, Torsten

    2017-01-01

    and two-talker babble in terms of SRTs, HI listeners could utilize ITDs to a similar degree as NH listeners to facilitate the binaural unmasking of speech. A slight difference was observed between the group means when target and maskers were separated from each other by large ITDs, but not when separated...... SRMs are elicited by small ITDs. Speech reception thresholds (SRTs) and SRM due to ITDs were measured over headphones for 10 young NH and 10 older HI listeners, who had normal or close-to-normal hearing below 1.5 kHz. Diotic target sentences were presented in diotic or dichotic speech-shaped noise...... or two-talker babble maskers. In the dichotic conditions, maskers were lateralized by delaying the masker waveforms in the left headphone channel. Multiple magnitudes of masker ITDs were tested in both noise conditions. Although deficits were observed in speech perception abilities in speechshaped noise...

  1. Interaural difference values of vestibular evoked myogenic.

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    Marziyeh Moallemi

    2015-01-01

    Full Text Available Migraine is a neurologic disease, which often is associated with a unilateral headache. Vestibular abnormalities are common in migraine. Vestibular evoked myogenic potentials (VEMPs assess otolith function in particular functional integrity of the saccule and the inferior vestibular nerve. We used VEMP to evaluate if the migraine headache can affect VEMP asymmetry parameters. A total of 25 patients with migraine (22 females and 3 males who were diagnosed according to the criteria of IHS-1988 were enrolled in this cross-sectional study. Control group consisted of 26 healthy participants (18 female and 8 male, without neurotological symptoms and history of migraine. The short tone burst (95 dB nHL, 500 Hz was presented to ears. VEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid (SCM muscle. Although current results showed that the amplitude ratio is greater in migraine patients than normal group, there was no statistical difference between two groups in mean asymmetry parameters of VEMP. Asymmetry measurements in vestibular evoked myogenic potentials probably are not indicators of unilateral deficient in saccular pathways of migraine patients.

  2. Neuronal specializations for the processing of interaural difference cues in the chick

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    Harunori eOhmori

    2014-05-01

    Full Text Available Sound information is encoded as a series of spikes of the auditory nerve fibers (ANFs, and then transmitted to the brainstem auditory nuclei. Features such as timing and level are extracted from ANFs activity and further processed as the interaural time difference (ITD and the interaural level difference (ILD, respectively. These two interaural difference cues are used for sound source localization by behaving animals. Both cues depend on the head size of animals and are extremely small, requiring specialized neural properties in order to process these cues with precision. Moreover, the sound level and timing cues are not processed independently from one another. Neurons in the nucleus angularis (NA are specialized for coding sound level information in birds and the ILD is processed in the posterior part of the dorsal lateral lemniscus nucleus (LLDp. Processing of ILD is affected by the phase difference of binaural sound. Temporal features of sound are encoded in the pathway starting in nucleus magnocellularis (NM, and ITD is processed in the nucleus laminaris (NL. In this pathway a variety of specializations are found in synapse morphology, neuronal excitability, distribution of ion channels and receptors along the tonotopic axis, which reduces spike timing fluctuation in the ANFs-NM synapse, and imparts precise and stable ITD processing to the NL. Moreover, the contrast of ITD processing in NL is enhanced over a wide range of sound level through the activity of GABAergic inhibitory systems from both the superior olivary nucleus (SON and local inhibitory neurons that follow monosynaptic to NM activity.

  3. Interaural level differences do not suffice for restoring spatial release from masking in simulated cochlear implant listening.

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    Ihlefeld, Antje; Litovsky, Ruth Y

    2012-01-01

    Spatial release from masking refers to a benefit for speech understanding. It occurs when a target talker and a masker talker are spatially separated. In those cases, speech intelligibility for target speech is typically higher than when both talkers are at the same location. In cochlear implant listeners, spatial release from masking is much reduced or absent compared with normal hearing listeners. Perhaps this reduced spatial release occurs because cochlear implant listeners cannot effectively attend to spatial cues. Three experiments examined factors that may interfere with deploying spatial attention to a target talker masked by another talker. To simulate cochlear implant listening, stimuli were vocoded with two unique features. First, we used 50-Hz low-pass filtered speech envelopes and noise carriers, strongly reducing the possibility of temporal pitch cues; second, co-modulation was imposed on target and masker utterances to enhance perceptual fusion between the two sources. Stimuli were presented over headphones. Experiments 1 and 2 presented high-fidelity spatial cues with unprocessed and vocoded speech. Experiment 3 maintained faithful long-term average interaural level differences but presented scrambled interaural time differences with vocoded speech. Results show a robust spatial release from masking in Experiments 1 and 2, and a greatly reduced spatial release in Experiment 3. Faithful long-term average interaural level differences were insufficient for producing spatial release from masking. This suggests that appropriate interaural time differences are necessary for restoring spatial release from masking, at least for a situation where there are few viable alternative segregation cues.

  4. The effect of interaural-level-difference fluctuations on the externalization of sound

    DEFF Research Database (Denmark)

    Catic, Jasmina; Santurette, Sébastien; Buchholz, Jörg M.

    2013-01-01

    Real-world sound sources are usually perceived as externalized and thus properly localized in both direction and distance. This is largely due to (1) the acoustic filtering by the head, torso, and pinna, resulting in modifications of the signal spectrum and thereby a frequency-dependent shaping...... of interaural cues and (2) interaural cues provided by the reverberation inside an enclosed space. This study first investigated the effect of room reverberation on the spectro-temporal behavior of interaural level differences (ILDs) by analyzing dummy-head recordings of speech played at different distances...... in a standard listening room. Next, the effect of ILD fluctuations on the degree of externalization was investigated in a psychoacoustic experiment performed in the same listening room. Individual binaural impulse responses were used to simulate a distant sound source delivered via headphones. The ILDs were...

  5. On the precision of neural computation with interaural level differences in the lateral superior olive

    Czech Academy of Sciences Publication Activity Database

    Bureš, Zbyněk; Maršálek, P.

    2013-01-01

    Roč. 1536, Nov 6 (2013), s. 16-26 ISSN 0006-8993 R&D Projects: GA ČR(CZ) GAP303/12/1347 Grant - others:GA MZd(CZ) NT11532 Institutional support: RVO:68378041 Keywords : binaural hearing * interaural level difference * just -noticeable difference Subject RIV: FH - Neurology Impact factor: 2.828, year: 2013

  6. Interaural level differences do not suffice for restoring spatial release from masking in simulated cochlear implant listening.

    Directory of Open Access Journals (Sweden)

    Antje Ihlefeld

    Full Text Available Spatial release from masking refers to a benefit for speech understanding. It occurs when a target talker and a masker talker are spatially separated. In those cases, speech intelligibility for target speech is typically higher than when both talkers are at the same location. In cochlear implant listeners, spatial release from masking is much reduced or absent compared with normal hearing listeners. Perhaps this reduced spatial release occurs because cochlear implant listeners cannot effectively attend to spatial cues. Three experiments examined factors that may interfere with deploying spatial attention to a target talker masked by another talker. To simulate cochlear implant listening, stimuli were vocoded with two unique features. First, we used 50-Hz low-pass filtered speech envelopes and noise carriers, strongly reducing the possibility of temporal pitch cues; second, co-modulation was imposed on target and masker utterances to enhance perceptual fusion between the two sources. Stimuli were presented over headphones. Experiments 1 and 2 presented high-fidelity spatial cues with unprocessed and vocoded speech. Experiment 3 maintained faithful long-term average interaural level differences but presented scrambled interaural time differences with vocoded speech. Results show a robust spatial release from masking in Experiments 1 and 2, and a greatly reduced spatial release in Experiment 3. Faithful long-term average interaural level differences were insufficient for producing spatial release from masking. This suggests that appropriate interaural time differences are necessary for restoring spatial release from masking, at least for a situation where there are few viable alternative segregation cues.

  7. Detection of dynamically varying interaural time differences

    DEFF Research Database (Denmark)

    Kohlrausch, Armin; Le Goff, Nicolas; Breebaart, Jeroen

    2010-01-01

    of fringes surrounding the probe is equal to the addition of the effects of the individual fringes. In this contribution, we present behavioral data for the same experimental condition, called dynamically varying ITD detection, but for a wider range of probe and fringe durations. Probe durations varied...

  8. Reproduction of nearby sources by imposing true interaural differences on a sound field control approach

    DEFF Research Database (Denmark)

    Badajoz, Javier; Chang, Ji-ho; Agerkvist, Finn T.

    2015-01-01

    In anechoic conditions, the Interaural Level Difference (ILD) is the most significant auditory cue to judge the distance to a sound source located within 1 m of the listener's head. This is due to the unique characteristics of a point source in its near field, which result in exceptionally high...... as Pressure Matching (PM), and a binaural control technique. While PM aims at reproducing the incident sound field, the objective of the binaural control technique is to ensure a correct reproduction of interaural differences. The combination of these two approaches gives rise to the following features: (i......, distance dependent ILDs. When reproducing the sound field of sources located near the head with line or circular arrays of loudspeakers, the reproduced ILDs are generally lower than expected, due to physical limitations. This study presents an approach that combines a sound field reproduction method, known...

  9. Interaural Level Difference Dependent Gain Control and Synaptic Scaling Underlying Binaural Computation

    Science.gov (United States)

    Xiong, Xiaorui R.; Liang, Feixue; Li, Haifu; Mesik, Lukas; Zhang, Ke K.; Polley, Daniel B.; Tao, Huizhong W.; Xiao, Zhongju; Zhang, Li I.

    2013-01-01

    Binaural integration in the central nucleus of inferior colliculus (ICC) plays a critical role in sound localization. However, its arithmetic nature and underlying synaptic mechanisms remain unclear. Here, we showed in mouse ICC neurons that the contralateral dominance is created by a “push-pull”-like mechanism, with contralaterally dominant excitation and more bilaterally balanced inhibition. Importantly, binaural spiking response is generated apparently from an ipsilaterally-mediated scaling of contralateral response, leaving frequency tuning unchanged. This scaling effect is attributed to a divisive attenuation of contralaterally-evoked synaptic excitation onto ICC neurons with their inhibition largely unaffected. Thus, a gain control mediates the linear transformation from monaural to binaural spike responses. The gain value is modulated by interaural level difference (ILD) primarily through scaling excitation to different levels. The ILD-dependent synaptic scaling and gain adjustment allow ICC neurons to dynamically encode interaural sound localization cues while maintaining an invariant representation of other independent sound attributes. PMID:23972599

  10. Noninvasive fMRI investigation of interaural level difference processing in the rat auditory subcortex.

    Directory of Open Access Journals (Sweden)

    Condon Lau

    Full Text Available OBJECTIVE: Interaural level difference (ILD is the difference in sound pressure level (SPL between the two ears and is one of the key physical cues used by the auditory system in sound localization. Our current understanding of ILD encoding has come primarily from invasive studies of individual structures, which have implicated subcortical structures such as the cochlear nucleus (CN, superior olivary complex (SOC, lateral lemniscus (LL, and inferior colliculus (IC. Noninvasive brain imaging enables studying ILD processing in multiple structures simultaneously. METHODS: In this study, blood oxygenation level-dependent (BOLD functional magnetic resonance imaging (fMRI is used for the first time to measure changes in the hemodynamic responses in the adult Sprague-Dawley rat subcortex during binaural stimulation with different ILDs. RESULTS AND SIGNIFICANCE: Consistent responses are observed in the CN, SOC, LL, and IC in both hemispheres. Voxel-by-voxel analysis of the change of the response amplitude with ILD indicates statistically significant ILD dependence in dorsal LL, IC, and a region containing parts of the SOC and LL. For all three regions, the larger amplitude response is located in the hemisphere contralateral from the higher SPL stimulus. These findings are supported by region of interest analysis. fMRI shows that ILD dependence occurs in both hemispheres and multiple subcortical levels of the auditory system. This study is the first step towards future studies examining subcortical binaural processing and sound localization in animal models of hearing.

  11. Transformation of binaural response properties in the ascending auditory pathway: influence of time-varying interaural phase disparity.

    Science.gov (United States)

    Spitzer, M W; Semple, M N

    1998-12-01

    Transformation of binaural response properties in the ascending auditory pathway: influence of time-varying interaural phase disparity. J. Neurophysiol. 80: 3062-3076, 1998. Previous studies demonstrated that tuning of inferior colliculus (IC) neurons to interaural phase disparity (IPD) is often profoundly influenced by temporal variation of IPD, which simulates the binaural cue produced by a moving sound source. To determine whether sensitivity to simulated motion arises in IC or at an earlier stage of binaural processing we compared responses in IC with those of two major IPD-sensitive neuronal classes in the superior olivary complex (SOC), neurons whose discharges were phase locked (PL) to tonal stimuli and those that were nonphase locked (NPL). Time-varying IPD stimuli consisted of binaural beats, generated by presenting tones of slightly different frequencies to the two ears, and interaural phase modulation (IPM), generated by presenting a pure tone to one ear and a phase modulated tone to the other. IC neurons and NPL-SOC neurons were more sharply tuned to time-varying than to static IPD, whereas PL-SOC neurons were essentially uninfluenced by the mode of stimulus presentation. Preferred IPD was generally similar in responses to static and time-varying IPD for all unit populations. A few IC neurons were highly influenced by the direction and rate of simulated motion, but the major effect for most IC neurons and all SOC neurons was a linear shift of preferred IPD at high rates-attributable to response latency. Most IC and NPL-SOC neurons were strongly influenced by IPM stimuli simulating motion through restricted ranges of azimuth; simulated motion through partially overlapping azimuthal ranges elicited discharge profiles that were highly discontiguous, indicating that the response associated with a particular IPD is dependent on preceding portions of the stimulus. In contrast, PL-SOC responses tracked instantaneous IPD throughout the trajectory of simulated

  12. JNDS of interaural time delay (ITD) of selected frequency bands in speech and music signals

    Science.gov (United States)

    Aliphas, Avner; Colburn, H. Steven; Ghitza, Oded

    2002-05-01

    JNDS of interaural time delay (ITD) of selected frequency bands in the presence of other frequency bands have been reported for noiseband stimuli [Zurek (1985); Trahiotis and Bernstein (1990)]. Similar measurements will be reported for speech and music signals. When stimuli are synthesized with bandpass/band-stop operations, performance with complex stimuli are similar to noisebands (JNDS in tens or hundreds of microseconds); however, the resulting waveforms, when viewed through a model of the auditory periphery, show distortions (irregularities in phase and level) at the boundaries of the target band of frequencies. An alternate synthesis method based upon group-delay filtering operations does not show these distortions and is being used for the current measurements. Preliminary measurements indicate that when music stimuli are created using the new techniques, JNDS of ITDs are increased significantly compared to previous studies, with values on the order of milliseconds.

  13. Representation of dynamic interaural phase difference in auditory cortex of awake rhesus macaques.

    Science.gov (United States)

    Scott, Brian H; Malone, Brian J; Semple, Malcolm N

    2009-04-01

    Neurons in auditory cortex of awake primates are selective for the spatial location of a sound source, yet the neural representation of the binaural cues that underlie this tuning remains undefined. We examined this representation in 283 single neurons across the low-frequency auditory core in alert macaques, trained to discriminate binaural cues for sound azimuth. In response to binaural beat stimuli, which mimic acoustic motion by modulating the relative phase of a tone at the two ears, these neurons robustly modulate their discharge rate in response to this directional cue. In accordance with prior studies, the preferred interaural phase difference (IPD) of these neurons typically corresponds to azimuthal locations contralateral to the recorded hemisphere. Whereas binaural beats evoke only transient discharges in anesthetized cortex, neurons in awake cortex respond throughout the IPD cycle. In this regard, responses are consistent with observations at earlier stations of the auditory pathway. Discharge rate is a band-pass function of the frequency of IPD modulation in most neurons (73%), but both discharge rate and temporal synchrony are independent of the direction of phase modulation. When subjected to a receiver operator characteristic analysis, the responses of individual neurons are insufficient to account for the perceptual acuity of these macaques in an IPD discrimination task, suggesting the need for neural pooling at the cortical level.

  14. Effect of background noise on neuronal coding of interaural level difference cues in rat inferior colliculus.

    Science.gov (United States)

    Mokri, Yasamin; Worland, Kate; Ford, Mark; Rajan, Ramesh

    2015-07-01

    Humans can accurately localize sounds even in unfavourable signal-to-noise conditions. To investigate the neural mechanisms underlying this, we studied the effect of background wide-band noise on neural sensitivity to variations in interaural level difference (ILD), the predominant cue for sound localization in azimuth for high-frequency sounds, at the characteristic frequency of cells in rat inferior colliculus (IC). Binaural noise at high levels generally resulted in suppression of responses (55.8%), but at lower levels resulted in enhancement (34.8%) as well as suppression (30.3%). When recording conditions permitted, we then examined if any binaural noise effects were related to selective noise effects at each of the two ears, which we interpreted in light of well-known differences in input type (excitation and inhibition) from each ear shaping particular forms of ILD sensitivity in the IC. At high signal-to-noise ratios (SNR), in most ILD functions (41%), the effect of background noise appeared to be due to effects on inputs from both ears, while for a large percentage (35.8%) appeared to be accounted for by effects on excitatory input. However, as SNR decreased, change in excitation became the dominant contributor to the change due to binaural background noise (63.6%). These novel findings shed light on the IC neural mechanisms for sound localization in the presence of continuous background noise. They also suggest that some effects of background noise on encoding of sound location reported to be emergent in upstream auditory areas can also be observed at the level of the midbrain. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  15. Monaural and binaural contributions to interaural-level-difference sensitivity in human auditory cortex.

    Science.gov (United States)

    Stecker, G Christopher; McLaughlin, Susan A; Higgins, Nathan C

    2015-10-15

    Whole-brain functional magnetic resonance imaging was used to measure blood-oxygenation-level-dependent (BOLD) responses in human auditory cortex (AC) to sounds with intensity varying independently in the left and right ears. Echoplanar images were acquired at 3 Tesla with sparse image acquisition once per 12-second block of sound stimulation. Combinations of binaural intensity and stimulus presentation rate were varied between blocks, and selected to allow measurement of response-intensity functions in three configurations: monaural 55-85 dB SPL, binaural 55-85 dB SPL with intensity equal in both ears, and binaural with average binaural level of 70 dB SPL and interaural level differences (ILD) ranging ±30 dB (i.e., favoring the left or right ear). Comparison of response functions equated for contralateral intensity revealed that BOLD-response magnitudes (1) generally increased with contralateral intensity, consistent with positive drive of the BOLD response by the contralateral ear, (2) were larger for contralateral monaural stimulation than for binaural stimulation, consistent with negative effects (e.g., inhibition) of ipsilateral input, which were strongest in the left hemisphere, and (3) also increased with ipsilateral intensity when contralateral input was weak, consistent with additional, positive, effects of ipsilateral stimulation. Hemispheric asymmetries in the spatial extent and overall magnitude of BOLD responses were generally consistent with previous studies demonstrating greater bilaterality of responses in the right hemisphere and stricter contralaterality in the left hemisphere. Finally, comparison of responses to fast (40/s) and slow (5/s) stimulus presentation rates revealed significant rate-dependent adaptation of the BOLD response that varied across ILD values. Copyright © 2015. Published by Elsevier Inc.

  16. Room Volume Estimation Based on Ambiguity of Short-Term Interaural Phase Differences Using Humanoid Robot Head

    Directory of Open Access Journals (Sweden)

    Ryuichi Shimoyama

    2016-07-01

    Full Text Available Humans can recognize approximate room size using only binaural audition. However, sound reverberation is not negligible in most environments. The reverberation causes temporal fluctuations in the short-term interaural phase differences (IPDs of sound pressure. This study proposes a novel method for a binaural humanoid robot head to estimate room volume. The method is based on the statistical properties of the short-term IPDs of sound pressure. The humanoid robot turns its head toward a sound source, recognizes the sound source, and then estimates the ego-centric distance by its stereovision. By interpolating the relations between room volume, average standard deviation, and ego-centric distance experimentally obtained for various rooms in a prepared database, the room volume was estimated by the binaural audition of the robot from the average standard deviation of the short-term IPDs at the estimated distance.

  17. Electrophysiological and psychophysical asymmetries in sensitivity to interaural correlation gaps and implications for binaural integration time.

    Science.gov (United States)

    Lüddemann, Helge; Kollmeier, Birger; Riedel, Helmut

    2016-02-01

    Brief deviations of interaural correlation (IAC) can provide valuable cues for detection, segregation and localization of acoustic signals. This study investigated the processing of such "binaural gaps" in continuously running noise (100-2000 Hz), in comparison to silent "monaural gaps", by measuring late auditory evoked potentials (LAEPs) and perceptual thresholds with novel, iteratively optimized stimuli. Mean perceptual binaural gap duration thresholds exhibited a major asymmetry: they were substantially shorter for uncorrelated gaps in correlated and anticorrelated reference noise (1.75 ms and 4.1 ms) than for correlated and anticorrelated gaps in uncorrelated reference noise (26.5 ms and 39.0 ms). The thresholds also showed a minor asymmetry: they were shorter in the positive than in the negative IAC range. The mean behavioral threshold for monaural gaps was 5.5 ms. For all five gap types, the amplitude of LAEP components N1 and P2 increased linearly with the logarithm of gap duration. While perceptual and electrophysiological thresholds matched for monaural gaps, LAEP thresholds were about twice as long as perceptual thresholds for uncorrelated gaps, but half as long for correlated and anticorrelated gaps. Nevertheless, LAEP thresholds showed the same asymmetries as perceptual thresholds. For gap durations below 30 ms, LAEPs were dominated by the processing of the leading edge of a gap. For longer gap durations, in contrast, both the leading and the lagging edge of a gap contributed to the evoked response. Formulae for the equivalent rectangular duration (ERD) of the binaural system's temporal window were derived for three common window shapes. The psychophysical ERD was 68 ms for diotic and about 40 ms for anti- and uncorrelated noise. After a nonlinear Z-transform of the stimulus IAC prior to temporal integration, ERDs were about 10 ms for reference correlations of ±1 and 80 ms for uncorrelated reference. Hence, a physiologically motivated

  18. Binaural interaction in low-frequency neurons in inferior colliculus of the cat. II. Effects of changing rate and direction of interaural phase.

    Science.gov (United States)

    Yin, T C; Kuwada, S

    1983-10-01

    We used the binaural beat stimulus to study the interaural phase sensitivity of inferior colliculus (IC) neurons in the cat. The binaural beat, produced by delivering tones of slightly different frequencies to the two ears, generates continuous and graded changes in interaural phase. Over 90% of the cells that exhibit a sensitivity to changes in the interaural delay also show a sensitivity to interaural phase disparities with the binaural beat. Cells respond with a burst of impulses with each complete cycle of the beat frequency. The period histogram obtained by binning the poststimulus time histogram on the beat frequency gives a measure of the interaural phase sensitivity of the cell. In general, there is good correspondence in the shapes of the period histograms generated from binaural beats and the interaural phase curves derived from interaural delays and in the mean interaural phase angle calculated from them. The magnitude of the beat frequency determines the rate of change of interaural phase and the sign determines the direction of phase change. While most cells respond in a phase-locked manner up to beat frequencies of 10 Hz, there are some cells tht will phase lock up to 80 Hz. Beat frequency and mean interaural phase angle are linearly related for most cells. Most cells respond equally in the two directions of phase change and with different rates of change, at least up to 10 Hz. However, some IC cells exhibit marked sensitivity to the speed of phase change, either responding more vigorously at low beat frequencies or at high beat frequencies. In addition, other cells demonstrate a clear directional sensitivity. The cells that show sensitivity to the direction and speed of phase changes would be expected to demonstrate a sensitivity to moving sound sources in the free field. Changes in the mean interaural phase of the binaural beat period histograms are used to determine the effects of changes in average and interaural intensity on the phase sensitivity

  19. Adaptation and inhibition underlie responses to time-varying interaural phase cues in a model of inferior colliculus neurons.

    Science.gov (United States)

    Borisyuk, Alla; Semple, Malcolm N; Rinzel, John

    2002-10-01

    A mathematical model was developed for exploring the sensitivity of low-frequency inferior colliculus (IC) neurons to interaural phase disparity (IPD). The formulation involves a firing-rate-type model that does not include spikes per se. The model IC neuron receives IPD-tuned excitatory and inhibitory inputs (viewed as the output of a collection of cells in the medial superior olive). The model cell possesses cellular properties of firing rate adaptation and postinhibitory rebound (PIR). The descriptions of these mechanisms are biophysically reasonable, but only semi-quantitative. We seek to explain within a minimal model the experimentally observed mismatch between responses to IPD stimuli delivered dynamically and those delivered statically (McAlpine et al. 2000; Spitzer and Semple 1993). The model reproduces many features of the responses to static IPD presentations, binaural beat, and partial range sweep stimuli. These features include differences in responses to a stimulus presented in static or dynamic context: sharper tuning and phase shifts in response to binaural beats, and hysteresis and "rise-from-nowhere" in response to partial range sweeps. Our results suggest that dynamic response features are due to the structure of inputs and the presence of firing rate adaptation and PIR mechanism in IC cells, but do not depend on a specific biophysical mechanism. We demonstrate how the model's various components contribute to shaping the observed phenomena. For example, adaptation, PIR, and transmission delay shape phase advances and delays in responses to binaural beats, adaptation and PIR shape hysteresis in different ranges of IPD, and tuned inhibition underlies asymmetry in dynamic tuning properties. We also suggest experiments to test our modeling predictions: in vitro simulation of the binaural beat (phase advance at low beat frequencies, its dependence on firing rate), in vivo partial range sweep experiments (dependence of the hysteresis curve on

  20. Effects of diotic fringes on interaural disparity detection (L)

    DEFF Research Database (Denmark)

    Le Goff, Nicolas; Kohlrausch, Armin; Dau, Torsten

    2012-01-01

    Detection thresholds were measured for interaural time differences (ITDs) and interaural level differences (ILDs) that were carried by probe segments embedded in otherwise diotic broadband noise (fringe). The duration of the probe was varied between 5 and 200 ms, and the duration of the fringe...... was between 5 and 100 ms. Consistent with results of Akeroyd and Bernstein [(2001). J. Acoust. Soc. Am. 110, 2516-2526], it was found that a 5-ms fringe placed before a 5-ms probe (forward fringe) led to a larger threshold elevation than a 5-ms fringe placed after the probe (backward fringe). As suggested...... by Akeroyd and Bernstein, this effect was accounted for by a model providing an onset emphasis of a factor of 2. In contrast, for longer probe and fringe durations, which have not been tested before, a backward fringe had a stronger effect than a forward fringe. This surprising effect was accounted...

  1. Suitability of the Binaural Interaction Component for Interaural Electrode Pairing of Bilateral Cochlear Implants.

    Science.gov (United States)

    Hu, Hongmei; Kollmeier, Birger; Dietz, Mathias

    2016-01-01

    Although bilateral cochlear implants (BiCIs) have succeeded in improving the spatial hearing performance of bilateral CI users, the overall performance is still not comparable with normal hearing listeners. Limited success can be partially caused by an interaural mismatch of the place-of-stimulation in each cochlea. Pairing matched interaural CI electrodes and stimulating them with the same frequency band is expected to facilitate binaural functions such as binaural fusion, localization, or spatial release from masking. It has been shown in animal experiments that the magnitude of the binaural interaction component (BIC) derived from the wave-eV decreases for increasing interaural place of stimulation mismatch. This motivated the investigation of the suitability of an electroencephalography-based objective electrode-frequency fitting procedure based on the BIC for BiCI users. A 61 channel monaural and binaural electrically evoked auditory brainstem response (eABR) recording was performed in 7 MED-EL BiCI subjects so far. These BiCI subjects were directly stimulated at 60% dynamic range with 19.9 pulses per second via a research platform provided by the University of Innsbruck (RIB II). The BIC was derived for several interaural electrode pairs by subtracting the response from binaural stimulation from their summed monaural responses. The BIC based pairing results are compared with two psychoacoustic pairing methods: interaural pulse time difference sensitivity and interaural pitch matching. The results for all three methods analyzed as a function of probe electrode allow for determining a matched pair in more than half of the subjects, with a typical accuracy of ± 1 electrode. This includes evidence for statistically significant tuning of the BIC as a function of probe electrode in human subjects. However, results across the three conditions were sometimes not consistent. These discrepancies will be discussed in the light of pitch plasticity versus less plastic

  2. A Comparison of Two Objective Measures of Binaural Processing: The Interaural Phase Modulation Following Response and the Binaural Interaction Component.

    Science.gov (United States)

    Haywood, Nicholas R; Undurraga, Jaime A; Marquardt, Torsten; McAlpine, David

    2015-12-30

    There has been continued interest in clinical objective measures of binaural processing. One commonly proposed measure is the binaural interaction component (BIC), which is obtained typically by recording auditory brainstem responses (ABRs)-the BIC reflects the difference between the binaural ABR and the sum of the monaural ABRs (i.e., binaural - (left + right)). We have recently developed an alternative, direct measure of sensitivity to interaural time differences, namely, a following response to modulations in interaural phase difference (the interaural phase modulation following response; IPM-FR). To obtain this measure, an ongoing diotically amplitude-modulated signal is presented, and the interaural phase difference of the carrier is switched periodically at minima in the modulation cycle. Such periodic modulations to interaural phase difference can evoke a steady state following response. BIC and IPM-FR measurements were compared from 10 normal-hearing subjects using a 16-channel electroencephalographic system. Both ABRs and IPM-FRs were observed most clearly from similar electrode locations-differential recordings taken from electrodes near the ear (e.g., mastoid) in reference to a vertex electrode (Cz). Although all subjects displayed clear ABRs, the BIC was not reliably observed. In contrast, the IPM-FR typically elicited a robust and significant response. In addition, the IPM-FR measure required a considerably shorter recording session. As the IPM-FR magnitude varied with interaural phase difference modulation depth, it could potentially serve as a correlate of perceptual salience. Overall, the IPM-FR appears a more suitable clinical measure than the BIC. © The Author(s) 2015.

  3. Auditory cortical neurons are sensitive to static and continuously changing interaural phase cues.

    Science.gov (United States)

    Reale, R A; Brugge, J F

    1990-10-01

    1. The interaural-phase-difference (IPD) sensitivity of single neurons in the primary auditory (AI) cortex of the anesthetized cat was studied at stimulus frequencies ranging from 120 to 2,500 Hz. Best frequencies of the 43 AI cells sensitive to IPD ranged from 190 to 2,400 Hz. 2. A static IPD was produced when a pair of low-frequency tone bursts, differing from one another only in starting phase, were presented dichotically. The resulting IPD-sensitivity curves, which plot the number of discharges evoked by the binaural signal as a function of IPD, were deeply modulated circular functions. IPD functions were analyzed for their mean vector length (r) and mean interaural phase (phi). Phase sensitivity was relatively independent of best frequency (BF) but highly dependent on stimulus frequency. Regardless of BF or stimulus frequency within the excitatory response area the majority of cells fired maximally when the ipsilateral tone lagged the contralateral signal and fired least when this interaural-phase relationship was reversed. 3. Sensitivity to continuously changing IPD was studied by delivering to the two ears 3-s tones that differed slightly in frequency, resulting in a binaural beat. Approximately 26% of the cells that showed a sensitivity to static changes in IPD also showed a sensitivity to dynamically changing IPD created by this binaural tonal combination. The discharges were highly periodic and tightly synchronized to a particular phase of the binaural beat cycle. High synchrony can be attributed to the fact that cortical neurons typically respond to an excitatory stimulus with but a single spike that is often precisely timed to stimulus onset. A period histogram, binned on the binaural beat frequency (fb), produced an equivalent IPD-sensitivity function for dynamically changing interaural phase. For neurons sensitive to both static and continuously changing interaural phase there was good correspondence between their static (phi s) and dynamic (phi d

  4. The Effect of Microphone Placement on Interaural Level Differences and Sound Localization Across the Horizontal Plane in Bilateral Cochlear Implant Users.

    Science.gov (United States)

    Jones, Heath G; Kan, Alan; Litovsky, Ruth Y

    2016-01-01

    This study examined the effect of microphone placement on the interaural level differences (ILDs) available to bilateral cochlear implant (BiCI) users, and the subsequent effects on horizontal-plane sound localization. Virtual acoustic stimuli for sound localization testing were created individually for eight BiCI users by making acoustic transfer function measurements for microphones placed in the ear (ITE), behind the ear (BTE), and on the shoulders (SHD). The ILDs across source locations were calculated for each placement to analyze their effect on sound localization performance. Sound localization was tested using a repeated-measures, within-participant design for the three microphone placements. The ITE microphone placement provided significantly larger ILDs compared to BTE and SHD placements, which correlated with overall localization errors. However, differences in localization errors across the microphone conditions were small. The BTE microphones worn by many BiCI users in everyday life do not capture the full range of acoustic ILDs available, and also reduce the change in cue magnitudes for sound sources across the horizontal plane. Acute testing with an ITE placement reduced sound localization errors along the horizontal plane compared to the other placements in some patients. Larger improvements may be observed if patients had more experience with the new ILD cues provided by an ITE placement.

  5. Different Times?

    NARCIS (Netherlands)

    A. van den Broek; W.P. Knulst; K. Breedveld

    1999-01-01

    Original title: Naar andere tijden? The report Different times? Time use and time structuring in the Netherlands, 1975-1995 (Naar andere tijden? Tijdsbesteding en tijdsordening in Nederland, 1975-1995) paints a picture of the way in which the Dutch spend the 168 hours that are available each

  6. Across-frequency combination of interaural time difference in bilateral cochlear implant listeners

    Directory of Open Access Journals (Sweden)

    Antje eIhlefeld

    2014-03-01

    Full Text Available The current study examined how cochlear implant (CI listeners combine temporally interleaved envelope-ITD information across two sites of stimulation. When two cochlear sites jointly transmit ITD information, one possibility is that CI listeners can extract the most reliable ITD cues available. As a result, ITD sensitivity would be sustained or enhanced compared to single-site stimulation. Alternatively, mutual interference across multiple sites of ITD stimulation could worsen dual-site performance compared to listening to the better of two electrode pairs. Two experiments used direct stimulation to examine how CI users can integrate ITDs across two pairs of electrodes. Experiment 1 tested ITD discrimination for two stimulation sites using 100-Hz sinusoidally modulated 1000-pps-carrier pulse trains. Experiment 2 used the same stimuli ramped with 100 ms windows, as a control condition with minimized onset cues. For all stimuli, performance improved monotonically with increasing modulation depth. Results show that when CI listeners are stimulated with electrode pairs at two cochlear sites, sensitivity to ITDs was similar to that seen when only the electrode pair with better sensitivity was activated. None of the listeners showed a decrement in performance from the worse electrode pair. This could be achieved either by listening to the better electrode pair or by truly integrating the information across cochlear sites.

  7. Lateralization of noise-burst trains based on onset and ongoing interaural delays.

    Science.gov (United States)

    Freyman, Richard L; Balakrishnan, Uma; Zurek, Patrick M

    2010-07-01

    The lateralization of 250-ms trains of brief noise bursts was measured using an acoustic pointing technique. Stimuli were designed to assess the contribution of the interaural time delay (ITD) of the onset binaural burst relative to that of the ITDs in the ongoing part of the train. Lateralization was measured by listeners' adjustments of the ITD of a pointer stimulus, a 50-ms burst of noise, to match the lateral position of the target train. Results confirmed previous reports of lateralization dominance by the onset burst under conditions in which the train is composed of frozen tokens and the ongoing part contains multiple ambiguous interaural delays. In contrast, lateralization of ongoing trains in which fresh noise tokens were used for each set of two alternating (left-leading/right-leading) binaural pairs followed the ITD of the first pair in each set, regardless of the ITD of the onset burst of the entire stimulus and even when the onset burst was removed by gradual gating. This clear lateralization of a long-duration stimulus with ambiguous interaural delay cues suggests precedence mechanisms that involve not only the interaural cues at the beginning of a sound, but also the pattern of cues within an ongoing sound.

  8. Binaural dereverberation based on interaural coherence histograms

    DEFF Research Database (Denmark)

    Westermann, Adam; Buchholz, Jorg M.; Dau, Torsten

    2013-01-01

    A binaural dereverberation algorithm is presented that utilizes the properties of the interaural coherence (IC) inspired by the concepts introduced in Allen et al. [J. Acoust. Soc. Am. 62, 912-915 (1977)]. The algorithm introduces a non-linear sigmoidal coherence-to-gain mapping that is controlled...... of the proposed algorithm was objectively and subjectively evaluated in terms of its impacts on the amount of reverberation and overall quality. A binaural spectral subtraction method based on Lebart et al. [Acta Acust. Acust. 87, 359-366 (2001)] and a binaural version of the original method of Allen et al. were...

  9. This time it's different

    International Nuclear Information System (INIS)

    Leder, Frederic; Shapiro, Judith N.

    2008-01-01

    There is virtual agreement among geologists that world production of conventional oil will peak at some point in the future. Oil, after all, is a finite resource, while demand will only grow over time. Geologists disagree, however, exactly when the peak will occur. Using data from the International Energy Agency, the US Department of Energy, the Association for the Study of Peak Oil and Gas, and petroleum industry sources, we argue that conventional oil production will reach a worldwide maximum within the next 5-10 years, earlier than generally estimated, thus leaving a very short time frame within which to plan for conversion to alternative sources of energy. Unless planning is initiated immediately, the United States and other Western democracies will see their positions in the global economy undercut as military conflicts over limited energy resources increase, and wealth and power are shifted to authoritarian regimes in Russia, Venezuela, Africa and the Middle East

  10. Growth with Time Zone Differences

    OpenAIRE

    Toru Kikuchi; Sugata Marjit

    2010-01-01

    We propose a two-country growth model of intermediate business-services trade that captures the role of time zone differences. It is shown that a time-saving improvement in intermediate business-services trade involving production in different time zones can have a permanent impact on productivity.

  11. Interaural attenuation for Sennheiser HDA 200 circumaural earphones.

    Science.gov (United States)

    Brännström, K Jonas; Lantz, Johannes

    2010-06-01

    Interaural attenuation (IA) was evaluated for pure tones (frequency range 125 to 16000 Hz) using Sennheiser HDA 200 circumaural earphones and Telephonics TDH-39P earphones in nine unilaterally deaf subjects. Audiometry was conducted in 1-dB steps using the manual ascending technique in accordance with ISO 8253-1. For all subjects and for all tested frequencies, the lowest IA value for HDA 200 was 42 dB. The present IA values for TDH-39P earphones closely resemble previously reported data. The findings show that the HDA 200 earphones provide more IA than the TDH-39P, especially at lower frequencies (HDA 200 earphones when the level at the test ear is more than 40 dB above the threshold of the non-test ear.

  12. Accounting for binaural detection as a function of masker interaural correlation: effects of center frequency and bandwidth.

    Science.gov (United States)

    Bernstein, Leslie R; Trahiotis, Constantine

    2014-12-01

    Binaural detection was measured as a function of the center frequency, bandwidth, and interaural correlation of masking noise. Thresholds were obtained for 500-Hz or 125-Hz Sπ tonal signals and for the latter stimuli (noise or signal-plus-noise) transposed to 4 kHz. A primary goal was assessment of the generality of van der Heijden and Trahiotis' [J. Acoust. Soc. Am. 101, 1019-1022 (1997)] hypothesis that thresholds could be accounted for by the "additive" masking effects of the underlying No and Nπ components of a masker having an interaural correlation of ρ. Results indicated that (1) the overall patterning of the data depended neither upon center frequency nor whether information was conveyed via the waveform or by its envelope; (2) thresholds for transposed stimuli improved relative to their low-frequency counterparts as bandwidth of the masker was increased; (3) the additivity approach accounted well for the data across stimulus conditions but consistently overestimated MLDs, especially for narrowband maskers; (4) a quantitative approach explicitly taking into account the distributions of time-varying ITD-based lateral positions produced by masker-alone and signal-plus-masker waveforms proved more successful, albeit while employing a larger set of assumptions, parameters, and computational complexity.

  13. Modernity: Are Modern Times Different?

    Directory of Open Access Journals (Sweden)

    Lynn Hunt

    2014-12-01

    Full Text Available “Modernity” has recently been the subject of considerable discussion among historians. This article reviews some of the debates and argues that modernity is a problematic concept because it implies a complete rupture with “traditional” ways of life. Studies of key terms are undertaken with the aid of Google Ngrams. These show that “modernity,” “modern times,” and “traditional” —in English and other languages— have a history of their own. A brief analysis of the shift from a self oriented toward equilibrium to a self oriented toward stimulation demonstrates that modernity is not necessary to historical analysis.

  14. Low frequency eardrum directionality in the barn owl induced by sound transmission through the interaural canal

    DEFF Research Database (Denmark)

    Kettler, Lutz; Christensen-Dalsgaard, Jakob; Larsen, Ole Næsbye

    2016-01-01

    . Significant sound transmission across the interaural canal occurred at low frequencies. The sound transmission induces considerable eardrum directionality in a narrow band from 1.5 to 3.5 kHz. This is below the frequency range used by the barn owl for locating prey, but may conceivably be used for locating...

  15. Interaural Place-Mismatch Estimation With Two-Formant Vowels in Unilateral Cochlear- Implant Users

    DEFF Research Database (Denmark)

    Guérit, François; Santurette, Sébastien; Chalupper, Josef

    stimulation, with listeners showing either basal or apical shifts, or generally-poor vowel discrimination. Conclusion The two-formant-vowel method is a fast and clinic-friendly candidate to derive interaural place mismatches from a simple vowel-recognition task. However, it remains unclear whether...

  16. Effect of different planting time on different varieties of strawberries

    Science.gov (United States)

    Zhong, Yue; Luo, Ya; Ge, Cong; Mo, Qin; Lin, Yajie; Luo, Shu; Tang, Haoru

    2018-04-01

    The experiment chose two strawberry varieties which planted in two periods of September 10 and September 20, in order to identify the optimum planting time of strawberries by exploring the effects of different planting time on strawberry quality and flowering initially. The results showed that different planting time will affect the growth and quality of strawberry, and the quality of September 10 planting strawberries is better than September 20 planting strawberries while there do exist some differences between strawberry varieties. In summary, the preliminary determination is that in Hanyuan area, the Hong Yan and Zhang Ji's optimum planting time is 10 September.

  17. Interaural multiple frequency tympanometry measures: clinical utility for unilateral conductive hearing loss.

    Science.gov (United States)

    Norrix, Linda W; Burgan, Briana; Ramirez, Nicholas; Velenovsky, David S

    2013-03-01

    Tympanometry is a routine clinical measurement of the acoustic immittance of the ear as a function of ear canal air pressure. The 226 Hz tympanogram can provide clinical evidence for conditions such as a tympanic membrane perforation, Eustachian tube dysfunction, middle ear fluid, and ossicular discontinuity. Multiple frequency tympanometry using a range of probe tone frequencies from low to high has been shown to be more sensitive than a single probe tone tympanogram in distinguishing between mass- and stiffness-related middle ear pathologies (Colletti, 1975; Funasaka et al, 1984; Van Camp et al, 1986). In this study we obtained normative measures of middle ear resonance by using multiple probe tone frequency tympanometry. Ninety percent ranges for middle ear resonance and for interaural differences were calculated. In a mixed design, normative data were collected from both ears of male and female adults. Twelve male and 12 female adults with normal hearing and normal middle ear function participated in the study. Multiple frequency tympanograms were recorded with a commercially available immittance instrument (GSI Tympstar) to obtain estimates of middle ear resonant frequency (RF) using ΔB, positive tail, and negative tail methods. Data were analyzed using three-way mixed analyses of variance with gender as a between-subject variable and ear and method as within-subject variables. T-tests were performed, using the Bonferroni adjustment, to determine significant differences between means. Using the positive and negative tail methods, a wide range of approximately 500 Hz was found for middle ear resonance in adults with normal hearing and normal middle ear function. The difference in RF between an individual's ears is small with 90% ranges of approximately ±200 Hz, indicating that the right ear RF should be either 200 Hz higher or lower in frequency compared to the left ear. This was true for both negative and positive tail methods. Ninety percent ranges were

  18. Demographic Group Differences in Adolescents' Time Attitudes

    Science.gov (United States)

    Andretta, James R.; Worrell, Frank C.; Mello, Zena R.; Dixson, Dante D.; Baik, Sharon H.

    2013-01-01

    In the present study, we examined demographic differences in time attitudes in a sample of 293 adolescents. Time attitudes were measured using the Adolescent Time Attitude Scale (Mello & Worrell, 2007; Worrell, Mello, & Buhl, 2011), which assesses positive and negative attitudes toward the past, the present, and the future. Generally, African…

  19. Time perception and time perspective differences between adolescents and adults.

    Science.gov (United States)

    Siu, Nicolson Y F; Lam, Heidi H Y; Le, Jacqueline J Y; Przepiorka, Aneta M

    2014-09-01

    The present experiment aimed to investigate the differences in time perception and time perspective between subjects representing two developmental stages, namely adolescence and middle adulthood. Twenty Chinese adolescents aged 15-25 and twenty Chinese adults aged 35-55 participated in the study. A time discrimination task and a time reproduction task were implemented to measure the accuracy of their time perception. The Zimbardo Time Perspective Inventory (Short-Form) was adopted to assess their time orientation. It was found that adolescents performed better than adults in both the time discrimination task and the time reproduction task. Adolescents were able to differentiate different time intervals with greater accuracy and reproduce the target duration more precisely. For the time reproduction task, it was also found that adults tended to overestimate the duration of the target stimuli while adolescents were more likely to underestimate it. As regards time perspective, adults were more future-oriented than adolescents, whereas adolescents were more present-oriented than adults. No significant relationship was found between time perspective and time perception. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Envelope enhancement increases cortical sensitivity to interaural envelope delays with acoustic and electric hearing.

    Directory of Open Access Journals (Sweden)

    Douglas E H Hartley

    Full Text Available Evidence from human psychophysical and animal electrophysiological studies suggests that sensitivity to interaural time delay (ITD in the modulating envelope of a high-frequency carrier can be enhanced using half-wave rectified stimuli. Recent evidence has shown potential benefits of equivalent electrical stimuli to deaf individuals with bilateral cochlear implants (CIs. In the current study we assessed the effects of envelope shape on ITD sensitivity in the primary auditory cortex of normal-hearing ferrets, and profoundly-deaf animals with bilateral CIs. In normal-hearing animals, cortical sensitivity to ITDs (±1 ms in 0.1-ms steps was assessed in response to dichotically-presented i sinusoidal amplitude-modulated (SAM and ii half-wave rectified (HWR tones (100-ms duration; 70 dB SPL presented at the best-frequency of the unit over a range of modulation frequencies. In separate experiments, adult ferrets were deafened with neomycin administration and bilaterally-implanted with intra-cochlear electrode arrays. Electrically-evoked auditory brainstem responses (EABRs were recorded in response to bipolar electrical stimulation of the apical pair of electrodes with singe biphasic current pulses (40 µs per phase over a range of current levels to measure hearing thresholds. Subsequently, we recorded cortical sensitivity to ITDs (±800 µs in 80-µs steps within the envelope of SAM and HWR biphasic-pulse trains (40 µs per phase; 6000 pulses per second, 100-ms duration over a range of modulation frequencies. In normal-hearing animals, nearly a third of cortical neurons were sensitive to envelope-ITDs in response to SAM tones. In deaf animals with bilateral CI, the proportion of ITD-sensitive cortical neurons was approximately a fifth in response to SAM pulse trains. In normal-hearing and deaf animals with bilateral CI the proportion of ITD sensitive units and neural sensitivity to ITDs increased in response to HWR, compared with SAM stimuli

  1. Same Hours, Different Time Distribution: Any Difference in EFL?

    Science.gov (United States)

    Serrano, Raquel; Munoz, Carmen

    2007-01-01

    The effects of the distribution of instructional time on the acquisition of a second or foreign language are still not well known. This paper will analyze the performance of adult students enrolled in three different types of EFL programs in which the distribution of time varies. The first one, called "extensive", distributes a total of 110 h in 7…

  2. Time-dependent problems and difference methods

    CERN Document Server

    Gustafsson, Bertil; Oliger, Joseph

    2013-01-01

    Praise for the First Edition "". . . fills a considerable gap in the numerical analysis literature by providing a self-contained treatment . . . this is an important work written in a clear style . . . warmly recommended to any graduate student or researcher in the field of the numerical solution of partial differential equations."" -SIAM Review Time-Dependent Problems and Difference Methods, Second Edition continues to provide guidance for the analysis of difference methods for computing approximate solutions to partial differential equations for time-de

  3. Sound localization in common vampire bats: Acuity and use of the binaural time cue by a small mammal

    Science.gov (United States)

    Heffner, Rickye S.; Koay, Gimseong; Heffner, Henry E.

    2015-01-01

    Passive sound-localization acuity and the ability to use binaural time and intensity cues were determined for the common vampire bat (Desmodus rotundus). The bats were tested using a conditioned suppression/avoidance procedure in which they drank defibrinated blood from a spout in the presence of sounds from their right, but stopped drinking (i.e., broke contact with the spout) whenever a sound came from their left, thereby avoiding a mild shock. The mean minimum audible angle for three bats for a 100-ms noise burst was 13.1°—within the range of thresholds for other bats and near the mean for mammals. Common vampire bats readily localized pure tones of 20 kHz and higher, indicating they could use interaural intensity-differences. They could also localize pure tones of 5 kHz and lower, thereby demonstrating the use of interaural time-differences, despite their very small maximum interaural distance of 60 μs. A comparison of the use of locus cues among mammals suggests several implications for the evolution of sound localization and its underlying anatomical and physiological mechanisms. PMID:25618037

  4. Enhancing interaural-delay-based extents of laterality at high frequencies by using ``transposed stimuli''

    Science.gov (United States)

    Bernstein, Leslie R.; Trahiotis, Constantine

    2003-06-01

    An acoustic pointing task was used to determine whether interaural temporal disparities (ITDs) conveyed by high-frequency ``transposed'' stimuli would produce larger extents of laterality than ITDs conveyed by bands of high-frequency Gaussian noise. The envelopes of transposed stimuli are designed to provide high-frequency channels with information similar to that conveyed by the waveforms of low-frequency stimuli. Lateralization was measured for low-frequency Gaussian noises, the same noises transposed to 4 kHz, and high-frequency Gaussian bands of noise centered at 4 kHz. Extents of laterality obtained with the transposed stimuli were greater than those obtained with bands of Gaussian noise centered at 4 kHz and, in some cases, were equivalent to those obtained with low-frequency stimuli. In a second experiment, the general effects on lateral position produced by imposed combinations of bandwidth, ITD, and interaural phase disparities (IPDs) on low-frequency stimuli remained when those stimuli were transposed to 4 kHz. Overall, the data were fairly well accounted for by a model that computes the cross-correlation subsequent to known stages of peripheral auditory processing augmented by low-pass filtering of the envelopes within the high-frequency channels of each ear.

  5. Young people's leisure time: Gender differences

    Directory of Open Access Journals (Sweden)

    Marina Videnović

    2010-06-01

    Full Text Available Over the last three decades, topics relating to young peoples leisure time have become increasingly more present in academic literature. Among the numerous studies that delve into this subject, results point towards a relationship between the way teenagers spend their leisure time and their gender. In this study we wanted to answer the question if gender differences were evident in the way secondary school students in Serbia spent their leisure time. This problem was not looked into in more detail among secondary school students in Serbia. We conducted a survey on a sample of 922 secondary school teenagers from the 1st to 4th grade(ages 15–19 from nine Serbian towns. Research in this field commonly uses the rating scale. In this paper we have constructed an instrument that represents a methodological innovation in approaching a particular set of problems. It was a questionnaire. The task was to name all the activities they participated in, and the time frame in which the activities took place, over the course of one weekday and the Saturday of the previous week. The activities which best differentiate these two groups of surveyed teenagers are: sports, studying, computer use, spending time at friends’ homes and grooming. We did not discover differences in participating in creative activities while foreign studies show that such activities are more typical for girls.

  6. Exploratory analysis on the binaural characteristics of the rowing sound

    DEFF Research Database (Denmark)

    Hoffmann, Pablo F.; Hammershøi, Dorte; Ruffaldi, Emanuele

    2011-01-01

    Differences between the signals captured at the entrances to the left and right ears are generally quantified by interaural time differences (ITDs), interaural level differences (ILDs) and interaural crosscorrelation (IC). Here, we attempt to gain knowledge on the changes of these interaural param...

  7. The normalized interaural correlation : accounting for NoSp thresholds obtained with Gaussian and 'low-noise' masking noise

    NARCIS (Netherlands)

    Bernstein, L.R.; Par, van de S.L.J.D.E.; Trahiotis, C.T.

    1999-01-01

    Recently, [J. Acoust. Soc. Am. 103, 2578–2589 (1998)] and [J. Acoust. Soc. Am. 103, 2573–2577 (1998)] independently reported that greater masking of interaurally phase-reversed (Sp) tones was produced by diotic low-noise noise than by diotic Gaussian noise. Based on quantitative analyses, Eddins and

  8. Automation: is it really different this time?

    Science.gov (United States)

    Wajcman, Judy

    2017-03-01

    This review examines several recent books that deal with the impact of automation and robotics on the future of jobs. Most books in this genre predict that the current phase of digital technology will create massive job loss in an unprecedented way, that is, that this wave of automation is different from previous waves. Uniquely digital technology is said to automate professional occupations for the first time. This review critically examines these claims, puncturing some of the hyperbole about automation, robotics and Artificial Intelligence. The review argues for a more nuanced analysis of the politics of technology and provides some critical distance on Silicon Valley's futurist discourse. Only by insisting that futures are always social can public bodies, rather than autonomous markets and endogenous technologies, become central to disentangling, debating and delivering those futures. © London School of Economics and Political Science 2017.

  9. Regional differences in waiting time to pregnancy

    DEFF Research Database (Denmark)

    Juul, Svend; Karmaus, W; Olsen, Jørn

    1999-01-01

    of the pregnancies were planned (64%) and approximately 14% were the result of contraceptive failures. The study shows that smoking, body mass index, age and parity did not explain the differences in fecundity found between the centres. Regional differences in fecundity exist and the causes may be genetic or due...

  10. Same but Different: Space, Time and Narrative

    Science.gov (United States)

    Bansel, Peter

    2013-01-01

    In this paper, I give an account of the ways in which narratives and identities change over space and time. I give an account of a mobile and changing human subject, one who does not simply express or represent her- or himself through narrative, but is constructed and reconstructed through narrative. I draw on Paul Ricoeur's concepts of "narrative…

  11. Adiposity and different types of screen time.

    Science.gov (United States)

    Falbe, Jennifer; Rosner, Bernard; Willett, Walter C; Sonneville, Kendrin R; Hu, Frank B; Field, Alison E

    2013-12-01

    Few prospective studies have examined separate forms of screen time in relation to adiposity. Our objective was to assess independent relations of television, electronic games (video/computer), and digital versatile disc (DVD)/videos and total screen time with change in adolescent BMI. Using data from the 2004, 2006, and 2008 waves of the ongoing Growing up Today Study II, we assessed baseline and 2-year change in reported screen time in relation to concurrent change in BMI among 4287 girls and 3505 boys aged 9 to 16 years in 2004. Gender-specific models adjusted for previous BMI, age, race/ethnicity, growth/development, months between questionnaires, and physical activity. Among girls and boys, each hour per day increase in reported television viewing was associated with a 0.09 increase in BMI (Ps food advertising, was most consistently associated with BMI gains. Among girls, electronic games and DVDs/videos were also related to increased BMI, possibly due to influences of product placements and advergames on diet and/or distracted eating. Adolescents, especially overweight adolescents, may benefit from reduced time with multiple types of media.

  12. This time it's different

    Energy Technology Data Exchange (ETDEWEB)

    Leder, Frederic [2742 Sturges Highway, Westport, CT 06880 (United States)], E-mail: fredleder@optonline.net; Shapiro, Judith N. [796 Sport Hill Road, Easton, CT 06612 (United States)

    2008-08-15

    There is virtual agreement among geologists that world production of conventional oil will peak at some point in the future. Oil, after all, is a finite resource, while demand will only grow over time. Geologists disagree, however, exactly when the peak will occur. Using data from the International Energy Agency, the US Department of Energy, the Association for the Study of Peak Oil and Gas, and petroleum industry sources, we argue that conventional oil production will reach a worldwide maximum within the next 5-10 years, earlier than generally estimated, thus leaving a very short time frame within which to plan for conversion to alternative sources of energy. Unless planning is initiated immediately, the United States and other Western democracies will see their positions in the global economy undercut as military conflicts over limited energy resources increase, and wealth and power are shifted to authoritarian regimes in Russia, Venezuela, Africa and the Middle East.

  13. Liquidity crises on different time scales

    Science.gov (United States)

    Corradi, Francesco; Zaccaria, Andrea; Pietronero, Luciano

    2015-12-01

    We present an empirical analysis of the microstructure of financial markets and, in particular, of the static and dynamic properties of liquidity. We find that on relatively large time scales (15 min) large price fluctuations are connected to the failure of the subtle mechanism of compensation between the flows of market and limit orders: in other words, the missed revelation of the latent order book breaks the dynamical equilibrium between the flows, triggering the large price jumps. On smaller time scales (30 s), instead, the static depletion of the limit order book is an indicator of an intrinsic fragility of the system, which is related to a strongly nonlinear enhancement of the response. In order to quantify this phenomenon we introduce a measure of the liquidity imbalance present in the book and we show that it is correlated to both the sign and the magnitude of the next price movement. These findings provide a quantitative definition of the effective liquidity, which proves to be strongly dependent on the considered time scales.

  14. Time-Varying Distortions of Binaural Information by Bilateral Hearing Aids

    Science.gov (United States)

    Rodriguez, Francisco A.; Portnuff, Cory D. F.; Goupell, Matthew J.; Tollin, Daniel J.

    2016-01-01

    In patients with bilateral hearing loss, the use of two hearing aids (HAs) offers the potential to restore the benefits of binaural hearing, including sound source localization and segregation. However, existing evidence suggests that bilateral HA users’ access to binaural information, namely interaural time and level differences (ITDs and ILDs), can be compromised by device processing. Our objective was to characterize the nature and magnitude of binaural distortions caused by modern digital behind-the-ear HAs using a variety of stimuli and HA program settings. Of particular interest was a common frequency-lowering algorithm known as nonlinear frequency compression, which has not previously been assessed for its effects on binaural information. A binaural beamforming algorithm was also assessed. Wide dynamic range compression was enabled in all programs. HAs were placed on a binaural manikin, and stimuli were presented from an arc of loudspeakers inside an anechoic chamber. Stimuli were broadband noise bursts, 10-Hz sinusoidally amplitude-modulated noise bursts, or consonant–vowel–consonant speech tokens. Binaural information was analyzed in terms of ITDs, ILDs, and interaural coherence, both for whole stimuli and in a time-varying sense (i.e., within a running temporal window) across four different frequency bands (1, 2, 4, and 6 kHz). Key findings were: (a) Nonlinear frequency compression caused distortions of high-frequency envelope ITDs and significantly reduced interaural coherence. (b) For modulated stimuli, all programs caused time-varying distortion of ILDs. (c) HAs altered the relationship between ITDs and ILDs, introducing large ITD–ILD conflicts in some cases. Potential perceptual consequences of measured distortions are discussed. PMID:27698258

  15. Part-time and full-time medical specialists, are there differences in allocation of time?

    Directory of Open Access Journals (Sweden)

    Groenewegen Peter P

    2006-03-01

    Full Text Available Abstract Background An increasing number of medical specialists prefer to work part-time. This development can be found worldwide. Problems to be faced in the realization of part-time work in medicine include the division of night and weekend shifts, as well as communication between physicians and continuity of care. People tend to think that physicians working part-time are less devoted to their work, implying that full-time physicians complete a greater number of tasks. The central question in this article is whether part-time medical specialists allocate their time differently to their tasks than full-time medical specialists. Methods A questionnaire was sent by mail to all internists (N = 817, surgeons (N = 693 and radiologists (N = 621 working in general hospitals in the Netherlands. Questions were asked about the actual situation, such as hours worked and night and weekend shifts. The response was 53% (n = 411 for internists, 52% (n = 359 for surgeons, and 36% (n = 213 for radiologists. Due to non-response on specific questions there were 367 internists, 316 surgeons, and 71 radiologists included in the analyses. Multilevel analyses were used to analyze the data. Results Part-time medical specialists do not spend proportionally more time on direct patient care. With respect to night and weekend shifts, part-time medical specialists account for proportionally more or an equal share of these shifts. The number of hours worked per FTE is higher for part-time than for full-time medical specialists, although this difference is only significant for surgeons. Conclusion In general, part-time medical specialists do their share of the job. However, we focussed on input only. Besides input, output like the numbers of services provided deserves attention as well. The trend in medicine towards more part-time work has an important consequence: more medical specialists are needed to get the work done. Therefore, a greater number of medical specialists

  16. A Simple Model of Service Trade with Time Zone Differences

    OpenAIRE

    Kikuchi, Toru; Iwasa, Kazumichi

    2008-01-01

    This note proposes a two-country monopolistic competition model of service trade that captures the role of time zone differences as a determinant of trade patterns. It is shown that the utilization of time zone differences induces drastic change in trade patterns: Due to taking advantage of time zone differences, service firms learve larger countries for smaller countries.

  17. Finite difference time domain analysis of a chiro plasma

    International Nuclear Information System (INIS)

    Torres-Silva, H.; Obligado, A.; Reggiani, N.; Sakanaka, P.H.

    1995-01-01

    The finite difference time-domain (FDTD) method is one of the most widely used computational methods in electromagnetics. Using FDTD, Maxwell's equations are solved directly in the time domain via finite differences and time stepping. The basic approach is relatively easy to understand and is an alternative to the more usual frequency-domain approaches. (author). 5 refs

  18. Part-time and full-time medical specialists, are there differences in allocation of time?

    NARCIS (Netherlands)

    Jong, J.D. de; Heiligers, P.; Groenewegen, P.P.; Hingstman, L.

    2006-01-01

    BACKGROUND: An increasing number of medical specialists prefer to work part-time. This development can be found worldwide. Problems to be faced in the realization of part-time work in medicine include the division of night and weekend shifts, as well as communication between physicians and

  19. Part-time and full-time medical specialists, are there differences in allocation of time?

    NARCIS (Netherlands)

    Jong, Judith D. de; Heiligers, Phil; Groenewegen, Peter P.; Hingstman, Lammert

    2006-01-01

    Background: An increasing number of medical specialists prefer to work part-time. This development can be found worldwide. Problems to be faced in the realization of part-time work in medicine include the division of night and weekend shifts, as well as communication between physicians and

  20. Exploratory analysis on the binaural characteristics of the rowing sound

    Directory of Open Access Journals (Sweden)

    Fillipeschi Alessandro

    2011-12-01

    Full Text Available Differences between the signals captured at the entrances to the left and right ears are generally quantified by interaural time differences (ITDs, interaural level differences (ILDs and interaural crosscorrelation (IC. Here, we attempt to gain knowledge on the changes of these interaural parameters during rowing and to evaluate their potential as source of information to determine rowing expertise exclusively from acoustic signals.

  1. An Empirical Investigation of Individual Differences in Time to Learn

    Science.gov (United States)

    Anderson, Lorin W.

    1976-01-01

    Results show that student differences in time-on-task to learn to criterion are alterable and can be minimized over a sequence of learning units given appropriate adaptive learning strategies. (Author/DEP)

  2. Residence time determination for adsorbent beds of different configurations

    Energy Technology Data Exchange (ETDEWEB)

    Otermat, J.E.; Wikoff, W.O.; Kovach, J.L.

    1995-02-01

    The residence time calculations of ASME AG-1 Code, Section FC, currently specify a screen surface area method, that is technically incorrect. Test data has been obtained on Type II adsorber trays of different configurations to establish residence time in the adsorber trays. These data indicate that the air volume/carbon volume ratio or the average screen area are more appropriate for the calculation of the residence time calculation than the currently used, smallest screen area basis.

  3. Modelling financial markets with agents competing on different time scales and with different amount of information

    Science.gov (United States)

    Wohlmuth, Johannes; Andersen, Jørgen Vitting

    2006-05-01

    We use agent-based models to study the competition among investors who use trading strategies with different amount of information and with different time scales. We find that mixing agents that trade on the same time scale but with different amount of information has a stabilizing impact on the large and extreme fluctuations of the market. Traders with the most information are found to be more likely to arbitrage traders who use less information in the decision making. On the other hand, introducing investors who act on two different time scales has a destabilizing effect on the large and extreme price movements, increasing the volatility of the market. Closeness in time scale used in the decision making is found to facilitate the creation of local trends. The larger the overlap in commonly shared information the more the traders in a mixed system with different time scales are found to profit from the presence of traders acting at another time scale than themselves.

  4. Real-time craving differences between black and white smokers.

    Science.gov (United States)

    Carter, Brian L; Paris, Megan M; Lam, Cho Y; Robinson, Jason D; Traylor, Amy C; Waters, Andrew J; Wetter, David W; Cinciripini, Paul M

    2010-01-01

    Black and White smokers may experience aspects of nicotine dependence, including craving, differently. This study used a naturalistic technique, ecological momentary assessment (EMA), to explore differences in craving, mood, expectancy, and smoking enjoyment between Black and White smokers. Participants carried personal digital assistants (PDAs) programmed to obtain multiple daily assessments. Black smokers reported higher craving after smoking and at random assessment times and higher cigarette enjoyment. No differences were found in mood or expectancy. Racial differences in psychological factors related to smoking are explored in the contexts of genetic, sociological, and psychophysiological distinctions. Implications for practice and research are discussed. (Am J Addict 2010;00:1-5).

  5. Oxalate content of different drinkable dilutions of tea infusions after different brewing times.

    Science.gov (United States)

    Lotfi Yagin, Neda; Mahdavi, Reza; Nikniaz, Zeinab

    2012-01-01

    The aims of this study were to determine the effect of different brewing times and diluting on oxalate content of loose-packed black teas consumed in Tabriz, Iran. The oxalate content of black teas after brewing for 5, 10, 15, 30, 60 minutes was measured in triplicate by enzymatic assay. In order to attain the most acceptable dilution of tea infusions, tea samples which were brewed for 15, 30 and 60 minutes were diluted two (120 ml), three (80 ml) and four (60 ml) times respectively. There was a stepwise increase in oxalate concentrations associated with increased brewing times (Pbrewing times, respectively. There were significant differences between the mean oxalate content of different dilutions after brewing for 15, 30 and 60 minutes (Pbrewing times and different dilution was below the recommended levels. Therefore, it seems that consumption of black tea several times per day would not pose significant health risk in kidney stone patients and susceptible individuals.

  6. Finite-difference time-domain analysis of time-resolved terahertz spectroscopy experiments

    DEFF Research Database (Denmark)

    Larsen, Casper; Cooke, David G.; Jepsen, Peter Uhd

    2011-01-01

    In this paper we report on the numerical analysis of a time-resolved terahertz (THz) spectroscopy experiment using a modified finite-difference time-domain method. Using this method, we show that ultrafast carrier dynamics can be extracted with a time resolution smaller than the duration of the T...

  7. Time in Early Childhood: Creative Possibilities with Different Conceptions of Time

    Science.gov (United States)

    Farquhar, Sandy

    2016-01-01

    Time is an important driver of pedagogy which is often overlooked in the busy atmosphere of an early childhood centre. Engaging philosophically with three different concepts of time, and drawing examples from literature and art to focus attention on how time is constituted in early childhood centres, this article argues that we inhabit the…

  8. Retrieving autobiographical memories: How different retrieval strategies associated with different cues explain reaction time differences.

    Science.gov (United States)

    Uzer, Tugba

    2016-02-01

    Previous research has shown that memories cued by concrete concepts, such as objects, are retrieved faster than those cued by more abstract concepts, such as emotions. This effect has been explained by the fact that more memories are directly retrieved from object versus emotion cues. In the present study, we tested whether RT differences between memories cued by emotion versus object terms occur not only because object cues elicit direct retrieval of more memories (Uzer, Lee, & Brown, 2012), but also because of differences in memory generation in response to emotions versus objects. One hundred university students retrieved memories in response to basic-level (e.g. orange), superordinate-level (e.g. plant), and emotion (e.g. surprised) cues. Retrieval speed was measured and participants reported whether memories were directly retrieved or generated on each trial. Results showed that memories were retrieved faster in response to basic-level versus superordinate-level and emotion cues because a) basic-level cues elicited more directly retrieved memories, and b) generating memories was more difficult when cues were abstract versus concrete. These results suggest that generative retrieval is a cue generation process in which additional cues that provide contextual information including the target event are produced. Memories are retrieved more slowly in response to emotion cues in part because emotion labels are less effective cues of appropriate contextual information. This particular finding is inconsistent with the idea that emotion is a primary organizational unit for autobiographical memories. In contrast, the difficulty of emotional memory generation implies that emotions represent low-level event information in the organization of autobiographical memory. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Cognitive componets of speech at different time scales

    DEFF Research Database (Denmark)

    Feng, Ling; Hansen, Lars Kai

    2007-01-01

    Cognitive component analysis (COCA) is defined as unsupervised grouping of data leading to a group structure well aligned with that resulting from human cognitive activity. We focus here on speech at different time scales looking for possible hidden ‘cognitive structure’. Statistical regularities...

  10. Influence of different storage times and temperatures on blood gas ...

    African Journals Online (AJOL)

    The present study was designed to investigate the effects of storage temperature and time on blood gas and acid-base balance of ovine venous blood. Ten clinically healthy sheep were used in this study. A total number of 30 blood samples, were divided into three different groups, and were stored in a refrigerator adjusted ...

  11. Intercept Centering and Time Coding in Latent Difference Score Models

    Science.gov (United States)

    Grimm, Kevin J.

    2012-01-01

    Latent difference score (LDS) models combine benefits derived from autoregressive and latent growth curve models allowing for time-dependent influences and systematic change. The specification and descriptions of LDS models include an initial level of ability or trait plus an accumulation of changes. A limitation of this specification is that the…

  12. Finite difference time domain modelling of particle accelerators

    International Nuclear Information System (INIS)

    Jurgens, T.G.; Harfoush, F.A.

    1989-03-01

    Finite Difference Time Domain (FDTD) modelling has been successfully applied to a wide variety of electromagnetic scattering and interaction problems for many years. Here the method is extended to incorporate the modelling of wake fields in particle accelerators. Algorithmic comparisons are made to existing wake field codes, such as MAFIA T3. 9 refs., 7 figs

  13. Effect of different hydropriming times on the quantitative and ...

    African Journals Online (AJOL)

    ajl yemi

    2011-10-26

    Oct 26, 2011 ... characteristics and percentage of protein of chickpea (Cicer arietinum L.) were examined in a randomized complete block design with three replicates in 2010. Seeds of chickpea were exposed at six different hydropriming times (2 h, 4 h, 6 h, 8 h, 10 h and control). The results of this experiment showed.

  14. Timing resolution performance comparison of different SiPM devices

    Energy Technology Data Exchange (ETDEWEB)

    Dolinsky, Sergei, E-mail: dolinsky@ge.com; Fu, Geng; Ivan, Adrian

    2015-11-21

    Silicon photomultiplier (SiPM) devices with improved parameters were recently introduced by several vendors. In addition to published manufacturer performance specifications, different research groups have reported on measurements of the available SiPMs in different operating conditions and using different test setups. In this work we performed a consistent set of test procedures for SiPM devices from various vendors, with focus on Time-of-Flight (TOF) PET detectors applications. SiPMs from Hamamatsu (HPK), SensL, Ketek, and Excelitas were tested. The same experimental setup and procedures were used for comparison of timing resolution for small (3×3 mm{sup 2}) and large (6×6 mm{sup 2} or 4×6 mm{sup 2}) devices coupled to short (3×3×10 mm{sup 3}) and long (4×4×25 mm{sup 3}) LYSO crystals. The potential opportunities for TOF PET detectors are also evaluated.

  15. Fractal markets: Liquidity and investors on different time horizons

    Science.gov (United States)

    Li, Da-Ye; Nishimura, Yusaku; Men, Ming

    2014-08-01

    In this paper, we propose a new agent-based model to study the source of liquidity and the “emergent” phenomenon in financial market with fractal structure. The model rests on fractal market hypothesis and agents with different time horizons of investments. What is interesting is that though the agent-based model reveals that the interaction between these heterogeneous agents affects the stability and liquidity of the financial market the real world market lacks detailed data to bring it to light since it is difficult to identify and distinguish the investors with different time horizons in the empirical approach. results show that in a relatively short period of time fractal market provides liquidity from investors with different horizons and the market gains stability when the market structure changes from uniformity to diversification. In the real world the fractal structure with the finite of horizons can only stabilize the market within limits. With the finite maximum horizons, the greater diversity of the investors and the fractal structure will not necessarily bring more stability to the market which might come with greater fluctuation in large time scale.

  16. Gender differences in leisure-time versus non-leisure-time physical activity among Saudi adolescents.

    Science.gov (United States)

    Al-Sobayel, Hana; Al-Hazzaa, Hazzaa M; Abahussain, Nanda A; Qahwaji, Dina M; Musaiger, Abdulrahman O

    2015-01-01

    The aim of the study was to examine the gender differences and predictors of leisure versus non-leisure time physical activities among Saudi adolescents aged 14-19 years. The multistage stratified cluster random sampling technique was used. A sample of 1,388 males and 1,500 females enrolled in secondary schools in three major cities in Saudi Arabia was included. Anthropometric measurements were performed and Body Mass Index was calculated. Physical activity, sedentary behaviours and dietary habits were measured using a self-reported validated questionnaire. The total time spent in leisure and non-leisure physical activity per week was 90 and 77 minutes, respectively. The males spent more time per week in leisure-time physical activities than females. Females in private schools spent more time during the week in leisure-time physical activities, compared to females in Stateschools. There was a significant difference between genders by obesity status interaction in leisure-time physical activity. Gender, and other factors, predicted total duration spent in leisure-time and non-leisure-time physical activity. The study showed that female adolescents are much less active than males, especially in leisure-time physical activities. Programmes to promote physical activity among adolescents are urgently needed, with consideration of gender differences.

  17. Gender differences in leisure-time versus non-leisure-time physical activity among Saudi adolescents

    Directory of Open Access Journals (Sweden)

    Hana Al-Sobayel

    2015-05-01

    The study showed that female adolescents are much less active than males, especially in leisure-time physical activities. Programmes to promote physical activity among adolescents are urgently needed, with consideration of gender differences.

  18. Start time delays in operating room: Different perspectives

    Directory of Open Access Journals (Sweden)

    Babita Gupta

    2011-01-01

    Full Text Available Background: Healthcare expenditure is a serious concern, with escalating costs failing to meet the expectations of quality care. The treatment capacities are limited in a hospital setting and the operating rooms (ORs. Their optimal utilization is vital in efficient hospital management. Starting late means considerable wait time for staff, patients and waste of resources. We planned an audit to assess different perspectives of the residents in surgical specialities and anesthesia and OR staff nurses so as to know the causative factors of operative delay. This can help develop a practical model to decrease start time delays in operating room (ORs. Aims: An audit to assess different perspectives of the Operating room (OR staff with respect to the varied causative factors of operative delay in the OR. To aid in the development of a practical model to decrease start time delays in ORs and facilitate on-time starts at Jai Prakash Narayan Apex Trauma centre (JPNATC, All India Institute of Medical Sciences (AIIMS, New Delhi. Methods: We prepared a questionnaire seeking the five main reasons of delay as per their perspective. Results: The available data was analysed. Analysis of the data demonstrated the common causative factors in start time operative delays as: a lack of proper planning, deficiencies in team work, communication gap and limited availability of trained supporting staff. Conclusions: The preparation of the equipment and required material for the OR cases must be done well in advance. Utilization of newer technology enables timely booking and scheduling of cases. Improved inter-departmental coordination and compliance with preanesthetic instructions needs to be ensured. It is essential that the anesthesiologists perform their work promptly, well in time . and supervise the proceedings as the OR manager. This audit is a step forward in defining the need of effective OR planning for continuous quality improvement.

  19. Dynamic backcalculation with different load-time histories

    DEFF Research Database (Denmark)

    Madsen, Stine Skov; Levenberg, Eyal

    2017-01-01

    This paper focused attention to the falling weight deflectometer (FWD) load-time history. For a commonly used device, it studied the pulse generation mechanism and the influence of different load histories on backcalculation results. In this connection, a semi-analytic impact theory was first...... for an experimental dataset that resulted from operating an FWD with different loading configurations. It was found that backcalculated parameters are sensitive to the FWD pulse features. Consequently, it is recommended that, whenever advanced pavement characterisation is sought, experimental attention should...

  20. Time Perspective and Age: A Review of Age Associated Differences.

    Science.gov (United States)

    Laureiro-Martinez, Daniella; Trujillo, Carlos A; Unda, Juliana

    2017-01-01

    We investigate the relationship between age and the five dimensions of time perspective measured by the Zimbardo Time Perspective Inventory (ZTPI) (past negative, past positive, present hedonistic, present fatalistic, and future). Time perspective is related to well-being, decision-making, level of development, and many other psychological issues. Hence, the existence of a systematic relationship between time perspective and age should be considered in all studies for which time is a relevant variable. However, no specific research about this has been conducted. We collected 407 papers that referenced the ZTPI between 2001 and 2015. From those, 72 studies met our inclusion criteria. They included 29,815 participants from 19 countries whose age spans most phases of adulthood (from 13.5 to 75.5 years, mean 28.7). We analyzed these studies adapting meta-analytical techniques. We found that present hedonistic and past negative dimensions are negatively related to aging with partial eta squared effect sizes of roughly 0.15. Our results have implications for the design of studies related to time as our findings highlight the importance of taking into account the differences associated with age.

  1. Do the correlates of screen time and sedentary time differ in preschool children?

    Directory of Open Access Journals (Sweden)

    Katherine L Downing

    2017-03-01

    Full Text Available Abstract Background Preschool children can spend up to 12 h a day in sedentary time and few meet current recommendations for screen time. Little is known about ecological correlates that could be targeted to decrease specific versus total sedentary behaviour. This study examined whether the correlates of screen time and sedentary time differ in preschool boys and girls. Methods Parents participating in the HAPPY Study in 2008/09 in Melbourne, Australia reported their child’s usual screen time and potential individual, social and physical environment correlates. Children wore ActiGraph GT1M accelerometers for eight days to objectively assess sedentary time (<100 counts.min−1. Multivariable linear regression analyses were performed, stratified by sex and controlling for child age, preschool/childcare attendance and clustering by centre of recruitment. Correlates significantly associated with screen time or sedentary time in individual models (p < 0.05 were included in final combined models. Results Children were sedentary for 301.1 (SD 34.1 minutes/day and spent 108.5 (SD 69.6 minutes/day in screen time. There were no sex differences in screen or sedentary time. In the final models, sleep duration was inversely associated with girls’ sedentary time and boys’ screen time. The only other consistent correlates for boys and girls were parental self-efficacy to limit screen time and screen time rules, which were inversely associated with screen time for both sexes. Parents reporting that they get bored watching their child play was inversely associated and maternal television viewing was positively associated with boys’ screen time. Paternal age was positively associated with boys’ sedentary time. Maternal ethnicity was inversely associated and paternal education, child preferences for sedentary behaviour, and parental concerns about child’s physical activity and sedentary behaviour were positively associated with girls’ screen time

  2. Individual differences in long-range time representation.

    Science.gov (United States)

    Agostino, Camila S; Caetano, Marcelo S; Balci, Fuat; Claessens, Peter M E; Zana, Yossi

    2017-04-01

    On the basis of experimental data, long-range time representation has been proposed to follow a highly compressed power function, which has been hypothesized to explain the time inconsistency found in financial discount rate preferences. The aim of this study was to evaluate how well linear and power function models explain empirical data from individual participants tested in different procedural settings. The line paradigm was used in five different procedural variations with 35 adult participants. Data aggregated over the participants showed that fitted linear functions explained more than 98% of the variance in all procedures. A linear regression fit also outperformed a power model fit for the aggregated data. An individual-participant-based analysis showed better fits of a linear model to the data of 14 participants; better fits of a power function with an exponent β > 1 to the data of 12 participants; and better fits of a power function with β discount rates in intertemporal choice to the compressed nature of subjective time must entail the characterization of subjective time on an individual-participant basis.

  3. Implicit time-dependent finite different algorithm for quench simulation

    International Nuclear Information System (INIS)

    Koizumi, Norikiyo; Takahashi, Yoshikazu; Tsuji, Hiroshi

    1994-12-01

    A magnet in a fusion machine has many difficulties in its application because of requirement of a large operating current, high operating field and high breakdown voltage. A cable-in-conduit (CIC) conductor is the best candidate to overcome these difficulties. However, there remained uncertainty in a quench event in the cable-in-conduit conductor because of a difficulty to analyze a fluid dynamics equation. Several scientists, then, developed the numerical code for the quench simulation. However, most of them were based on an explicit time-dependent finite difference scheme. In this scheme, a discrete time increment is strictly restricted by CFL (Courant-Friedrichs-Lewy) condition. Therefore, long CPU time was consumed for the quench simulation. Authors, then, developed a new quench simulation code, POCHI1, which is based on an implicit time dependent scheme. In POCHI1, the fluid dynamics equation is linearlized according to a procedure applied by Beam and Warming and then, a tridiagonal system can be offered. Therefore, no iteration is necessary to solve the fluid dynamics equation. This leads great reduction of the CPU time. Also, POCHI1 can cope with non-linear boundary condition. In this study, comparison with experimental results was carried out. The normal zone propagation behavior was investigated in two samples of CIC conductors which had different hydraulic diameters. The measured and simulated normal zone propagation length showed relatively good agreement. However, the behavior of the normal voltage shows a little disagreement. These results indicate necessity to improve the treatment of the heat transfer coefficient in the turbulent flow region and the electric resistivity of the copper stabilizer in high temperature and high field region. (author)

  4. Milk oligosaccharides over time of lactation from different dog breeds.

    Directory of Open Access Journals (Sweden)

    Shirin Macias Rostami

    Full Text Available The partnership of humans and dogs goes back to over 10'000 years, yet relatively little is known about a dog's first extra-uterine nutrition particularly when it comes to milk oligosaccharides. We set out to identify and quantify milk oligosaccharides over the course of lactation from different dog breeds (Labrador retriever, Schnauzer and 3 Alaskan husky crossbreeds. To this end, 2 different chromatographic methods with fluorescence and mass spectrometry detection were developed and one was validated for quantification. Besides lactose and lactose-sulphate, we identified 2 different trisaccharides composed of 3 hexose units, 3'sialyllactose (3'SL, 6'sialyllactose (6'SL, 2'fucosyllactose (2'FL, and a tetrasaccharide composed of 2 hexoses, an N-acetylhexosamine and a deoxyhexose. 3'SL was present at the highest levels in milk of all dog breeds starting at around 7.5 g/L and dropping to about 1.5 g/L in the first 10 days of lactation. 6'SL was about 10 times less abundant and 2'FL and the tetrasaccharide had rather varying levels in the milk of the different breeds with the tetrasaccharide only detectable in the Alaskan husky crossbreeds. The longitudinal and quantitative data of milk oligosaccharides from different dog breeds are an important basis to further our understanding on their specific biological roles and also on the specific nutritional requirements of lactating puppies.

  5. Milk oligosaccharides over time of lactation from different dog breeds.

    Science.gov (United States)

    Macias Rostami, Shirin; Bénet, Thierry; Spears, Julie; Reynolds, Arleigh; Satyaraj, Ebenezer; Sprenger, Norbert; Austin, Sean

    2014-01-01

    The partnership of humans and dogs goes back to over 10'000 years, yet relatively little is known about a dog's first extra-uterine nutrition particularly when it comes to milk oligosaccharides. We set out to identify and quantify milk oligosaccharides over the course of lactation from different dog breeds (Labrador retriever, Schnauzer and 3 Alaskan husky crossbreeds). To this end, 2 different chromatographic methods with fluorescence and mass spectrometry detection were developed and one was validated for quantification. Besides lactose and lactose-sulphate, we identified 2 different trisaccharides composed of 3 hexose units, 3'sialyllactose (3'SL), 6'sialyllactose (6'SL), 2'fucosyllactose (2'FL), and a tetrasaccharide composed of 2 hexoses, an N-acetylhexosamine and a deoxyhexose. 3'SL was present at the highest levels in milk of all dog breeds starting at around 7.5 g/L and dropping to about 1.5 g/L in the first 10 days of lactation. 6'SL was about 10 times less abundant and 2'FL and the tetrasaccharide had rather varying levels in the milk of the different breeds with the tetrasaccharide only detectable in the Alaskan husky crossbreeds. The longitudinal and quantitative data of milk oligosaccharides from different dog breeds are an important basis to further our understanding on their specific biological roles and also on the specific nutritional requirements of lactating puppies.

  6. Coincidence-anticipation timing requirements are different in racket sports.

    Science.gov (United States)

    Akpinar, Selçuk; Devrilmez, Erhan; Kirazci, Sadettin

    2012-10-01

    The aim of this study was to compare the coincidence-anticipation timing accuracy of athletes of different racket sports with various stimulus velocity requirements. Ninety players (15 girls, 15 boys for each sport) from tennis (M age = 12.4 yr., SD = 1.4), badminton (M age = 12.5 yr., SD = 1.4), and table tennis (M age = 12.4 yr., SD = 1.2) participated in this study. Three different stimulus velocities, low, moderate, and high, were used to simulate the velocity requirements of these racket sports. Tennis players had higher accuracy when they performed under the low stimulus velocity compared to badminton and table tennis players. Badminton players performed better under the moderate speed comparing to tennis and table tennis players. Table tennis players had better performance than tennis and badminton players under the high stimulus velocity. Therefore, visual and motor systems of players from different racket sports may adapt to a stimulus velocity in coincidence-anticipation timing, which is specific to each type of racket sports.

  7. Variation of explosive force at different times of day

    Directory of Open Access Journals (Sweden)

    R Pereira

    2011-03-01

    Full Text Available AIM: The purpose of this study was to compare the explosive force and electromyographic (EMG activity at three different times of the day. METHODS: Thirty healthy subjects took part in the study, and carried out two maximum isometric voluntary knee extensions to measure explosive force, through contractile impulse (CI and rate of force development (RFD, and myoelectric signals from quadriceps muscles in the following periods: 07:30-09:30, 13:30-15:30 and 19:30-21:30 (called morning, afternoon and night respectively, on three non-consecutive days. RESULTS: The body temperature was lower in the morning than in the afternoon and night periods. The explosive force, evaluated through contractile impulse (CI and rate of force development (RFD, was greater at night than in the morning, without differences in the myoelectric signal. CONCLUSION: The ability to produce explosive force varies throughout different times of the day without variation in muscular recruitment, indicating that peripheral and not neural mechanisms could be responsible for this variation.

  8. Considerations on assessment of different time depending models adequacy

    International Nuclear Information System (INIS)

    Constantinescu, C.

    2015-01-01

    The operating period of nuclear power plants can be prolonged if it can be shown that their safety has remained on a high level, and for this, it is necessary to estimate how the aged systems, structures and components (SSCs) influence the NPP reliability and safety. To emphasize the ageing aspects the case study presented in this paper will assess different time depending models for rate of occurrence of failures with the goal to obtain the best fitting model. A sensitivity analysis for the impact of burn-in failures was performed to improve the result of the goodness of fit test. Based on the analysis results, a conclusion about the existence or the absence of an ageing trend could be developed. A sensitivity analysis regarding of the reliability parameters was performed, and the results were used to observe the impact over the time-dependent rate of occurrence of failures. (authors)

  9. [Collaborative application of BEPS at different time steps.

    Science.gov (United States)

    Lu, Wei; Fan, Wen Yi; Tian, Tian

    2016-09-01

    BEPSHourly is committed to simulate the ecological and physiological process of vegetation at hourly time steps, and is often applied to analyze the diurnal change of gross primary productivity (GPP), net primary productivity (NPP) at site scale because of its more complex model structure and time-consuming solving process. However, daily photosynthetic rate calculation in BEPSDaily model is simpler and less time-consuming, not involving many iterative processes. It is suitable for simulating the regional primary productivity and analyzing the spatial distribution of regional carbon sources and sinks. According to the characteristics and applicability of BEPSDaily and BEPSHourly models, this paper proposed a method of collaborative application of BEPS at daily and hourly time steps. Firstly, BEPSHourly was used to optimize the main photosynthetic parameters: the maximum rate of carboxylation (V c max ) and the maximum rate of photosynthetic electron transport (J max ) at site scale, and then the two optimized parameters were introduced into BEPSDaily model to estimate regional NPP at regional scale. The results showed that optimization of the main photosynthesis parameters based on the flux data could improve the simulate ability of the model. The primary productivity of different forest types in descending order was deciduous broad-leaved forest, mixed forest, coniferous forest in 2011. The collaborative application of carbon cycle models at different steps proposed in this study could effectively optimize the main photosynthesis parameters V c max and J max , simulate the monthly averaged diurnal GPP, NPP, calculate the regional NPP, and analyze the spatial distribution of regional carbon sources and sinks.

  10. Finite difference time domain modeling of spiral antennas

    Science.gov (United States)

    Penney, Christopher W.; Beggs, John H.; Luebbers, Raymond J.

    1992-01-01

    The objectives outlined in the original proposal for this project were to create a well-documented computer analysis model based on the finite-difference, time-domain (FDTD) method that would be capable of computing antenna impedance, far-zone radiation patterns, and radar cross-section (RCS). The ability to model a variety of penetrable materials in addition to conductors is also desired. The spiral antennas under study by this project meet these requirements since they are constructed of slots cut into conducting surfaces which are backed by dielectric materials.

  11. Diurnal Differences in OLR Climatologies and Anomaly Time Series

    Science.gov (United States)

    Susskind, Joel; Lee, Jae N.; Iredell, Lena; Loeb, Norm

    2015-01-01

    AIRS (Atmospheric Infrared Sounder) Version-6 OLR (Outgoing Long-Wave Radiation) matches CERES (Clouds and the Earth's Radiant Energy System) Edition-2.8 OLR very closely on a 1x1 latitude x longitude scale, both with regard to absolute values, and also with regard to anomalies of OLR. There is a bias of 3.5 watts per meter squared, which is nearly constant both in time and space. Contiguous areas contain large positive or negative OLR difference between AIRS and CERES are where the day-night difference of OLR is large. For AIRS, the larger the diurnal cycle, the more likely that sampling twice a day is inadequate. Lower values of OLRclr (Clear Sky OLR) and LWCRF (Longwave Cloud Radiative Forcing) in AIRS compared to CERES is at least in part a result of AIRS sampling over cold and cloudy cases.

  12. Copper patinas formed in different atmospheres and exposure times

    International Nuclear Information System (INIS)

    Lobo, V.M.M.; Almeida, M.E.; Balmayor, M.; Tomas, H.M.L.R.

    1998-01-01

    Atmospheric corrosion products in copper samples, known as patinas, formed in industrial-marine, severe-marine and rural atmospheres exposed for 1,2,3, and 4 years, have been studied. The nature and structure of the products formed, characterized by X-ray diffraction (XRD) and infrared spectrometry (FTIR) depend on the time of exposure and the type of atmosphere. Copper patinas have been extensively mentioned in the literature, but the structural nature of their compounds, which vary according to the time of exposure and types of atmospheres, is still not adequately described in the literature. In order to give a contribution to this area, copper panels were exposed for 1,2,3, and 4 years in different types of atmospheres representing situations commonly observed, and subsequently the patinas were studied by XRD and FTIR 150 mm x 1 mm copper panels from commercial copper were exposed to three different atmospheric conditions in Portugal: industrial-marine (Leixoes, near Oporto, highly industrialized city close to the Ocean, subject to SO 2 from refineries); rural (Pego, small village in rural environment). The panels, attached to the appropriate stands, in accordance with ISO 8565 (1), were exposed for periods of 1,2,3 and 4 years, adequately collected for laboratory analysis by infrared spectrometry (FTIR). (Author)

  13. Overcoming the Educational Time Warp: Anticipating a Different Future

    Directory of Open Access Journals (Sweden)

    Garry Jacobs

    2015-10-01

    Full Text Available Education abridges the time required for individual and social progress by preserving and propagating the essence of human experience. It delivers to youth the accumulated knowledge of countless past generations in an organized and abridged form, so that future generations can start off with all the capacities acquired by their predecessors. However, today education confronts a serious dilemma. We are living in an educational time warp. There is a growing gap between contemporary human experience and what is taught in our educational system and that gap is widening rapidly with each passing year. Today humanity confronts challenges of unprecedented scope, magnitude and intensity. The incremental development of educational content and pedagogy in recent decades has not kept with the ever-accelerating pace of technological and social evolution. Education is also subject to a generational time warp resulting from the fact that many of today’s teachers were educated decades ago during very different times and based on different values and perspectives. The challenge of preparing youth for the future is exasperated by the fact that the future for which we are educating youth does not yet exist and to a large extent is unknown or unknowable. The resulting gap between the content of education and societal needs inhibits our capacity to anticipate and effectively respond to social problems. All these factors argue for a major reorientation of educational content and pedagogy from transmission of acquired knowledge based on past experience to development of the knowledge, skills and capacities of personality needed in a future we cannot clearly envision. We may not be able to anticipate the precise nature of the future, but we can provide an education based on the understanding that it will be very different from the present. In terms of content, the emphasis needs to shift from facts regarding the actual state of affairs in the past, present and

  14. The cultural differences in time and time management: A socio-demographic approach

    Directory of Open Access Journals (Sweden)

    F. Venter

    2006-12-01

    Full Text Available Purpose/Objectives: The aim of this article is to investigate perceived cultural differences in the perceptions of time and time management, and the implications regarding productivity amongst socio-demographic groups in Gauteng. This study indicates that socio-demographic variables such as home language, gender, education, age and income are related to various factors of time perception. Design/Methodology/Approach: The questionnaire consisted of 35 questions to be rated on a five-point Likert scale. Six dimensions of time were measured, namely, the sense of purpose, effective organisation, structured routine, present orientation, persistence and a global time perception. A multi-cultural non-probability convenience sample (n=804 was drawn from residents in the Gauteng region. Respondents were selected from upper- middle- and lowerincome groups residing in various suburban areas and townships in the region. Students of the North-West University carried out the fieldwork. Findings/Implications: The research study found that the dimensions sense of purpose and persistence of time obtained the highest mean factor scores: 4.05 and 3.95 respectively on the 1 (negative to 5 (positive scale, with 87, 4% and 83.8% of the respondents obtaining high scores (above 3.40 respectively. This implies that most respondents felt that they spent their time usefully and meaningfully, while at the same time, would not give up until the task was completed. The dimension present orientation of time produced the lowest mean factor score of 3.09, with 29.4% of respondents obtaining scores below 2.60, indicating a lack of focusing on completing a task at a designated point in time. The study also found that organisations have to increase productivity and reduce costs. The consequences of this for many employees included increased workloads, longer working hours and greater time pressure. Originality/Value: The findings of this study are original and innovative. The

  15. Acoustic, finite-difference, time-domain technique development

    International Nuclear Information System (INIS)

    Kunz, K.

    1994-01-01

    A close analog exists between the behavior of sound waves in an ideal gas and the radiated waves of electromagnetics. This analog has been exploited to obtain an acoustic, finite-difference, time-domain (AFDTD) technique capable of treating small signal vibrations in elastic media, such as air, water, and metal, with the important feature of bending motion included in the behavior of the metal. This bending motion is particularly important when the metal is formed into sheets or plates. Bending motion does not have an analog in electromagnetics, but can be readily appended to the acoustic treatment since it appears as a single additional term in the force equation for plate motion, which is otherwise analogous to the electromagnetic wave equation. The AFDTD technique has been implemented in a code architecture that duplicates the electromagnetic, finite-difference, time-domain technique code. The main difference in the implementation is the form of the first-order coupled differential equations obtained from the wave equation. The gradient of pressure and divergence of velocity appear in these equations in the place of curls of the electric and magnetic fields. Other small changes exist as well, but the codes are essentially interchangeable. The pre- and post-processing for model construction and response-data evaluation of the electromagnetic code, in the form of the TSAR code at Lawrence Livermore National Laboratory, can be used for the acoustic version. A variety of applications is possible, pending validation of the bending phenomenon. The applications include acoustic-radiation-pattern predictions for a submerged object; mine detection analysis; structural noise analysis for cars; acoustic barrier analysis; and symphonic hall/auditorium predictions and speaker enclosure modeling

  16. Is networking different with doctors working part-time? Differences in social networks of part-time and full-time doctors.

    NARCIS (Netherlands)

    Heiligers, P.J.M.; Groenewegen, P.P.; Jong, J.D. de; Hingstman, L.; Völker, B.; Spreeuwenberg, P.

    2008-01-01

    BACKGROUND: Part-time working is a growing phenomenon in medicine, which is expected to influence informal networks at work differently compared to full-time working. The opportunity to meet and build up social capital at work has offered a basis for theoretical arguments. METHODS: Twenty-eight

  17. Foliage nitrogen turnover: differences among nitrogen absorbed at different times by Quercus serrata saplings

    Science.gov (United States)

    Ueda, Miki U.; Mizumachi, Eri; Tokuchi, Naoko

    2011-01-01

    Background and Aims Nitrogen turnover within plants has been intensively studied to better understand nitrogen use strategies. However, differences among the nitrogen absorbed at different times are not completely understood and the fate of nitrogen absorbed during winter is largely uncharacterized. In the present study, nitrogen absorbed at different times of the year (growing season, winter and previous growing season) was traced, and the within-leaf nitrogen turnover of a temperate deciduous oak Quercus serrata was investigated. Methods The contributions of nitrogen absorbed at the three different times to leaf construction, translocation during the growing season, and the leaf-level resorption efficiency during leaf senescence were compared using 15N. Key Results Winter- and previous growing season-absorbed nitrogen significantly contributed to leaf construction, although the contribution was smaller than that of growing season-absorbed nitrogen. On the other hand, the leaf-level resorption efficiency of winter- and previous growing season-absorbed nitrogen was higher than that of growing season-absorbed nitrogen, suggesting that older nitrogen is better retained in leaves than recently absorbed nitrogen. Conclusions The results demonstrate that nitrogen turnover in leaves varies with nitrogen absorption times. These findings are important for understanding plant nitrogen use strategies and nitrogen cycles in forest ecosystems. PMID:21515608

  18. Time, science and consensus: the different times involving scientific research, political decision and public opinion

    Directory of Open Access Journals (Sweden)

    José Aparecido de

    2010-01-01

    Full Text Available This essay analyses the asymmetrical relationship between the time of scientific research and the time of the different segments interested in their results, focusing mainly on necessity to establish technical consensus about the fields of science that require rigorous investigations and texts. In the last years, civil society sectors - mainly scientific journalism, legislative power, and public opinion - has shown growing interest in participating of the decision making process that regulates science routes. In this study, we analyzed the decision making process of the Biosafety Law, as it allows research with embryonic stem cells in Brazil. The results allow us to conclude that this asymmetrical relationship between the different times (of science, scientific disclosure, public opinion, and public power contribute to the maturing of the dialog on scientific policies, as well as to the establishment of a consensus concerning science routes, which aims at the democratization of scientific work.

  19. Interaural delay sensitivity and the classification of low best-frequency binaural responses in the inferior colliculus of the guinea pig.

    Science.gov (United States)

    McAlpine, D; Jiang, D; Palmer, A R

    1996-08-01

    Monaural and binaural response properties of single units in the inferior colliculus (IC) of the guinea pig were investigated. Neurones were classified according to the effect of monaural stimulation of either ear alone and the effect of binaural stimulation. The majority (309/334) of IC units were excited (E) by stimulation of the contralateral ear, of which 41% (127/309) were also excited by monaural ipsilateral stimulation (EE), and the remainder (182/309) were unresponsive to monaural ipsilateral stimulation (EO). For units with best frequencies (BF) up to 3 kHz, similar proportions of EE and EO units were observed. Above 3 kHz, however, significantly more EO than EE units were observed. Units were also classified as either facilitated (F), suppressed (S), or unaffected (O) by binaural stimulation. More EO than EE units were suppressed or unaffected by binaural stimulation, and more EE than EO units were facilitated. There were more EO/S units above 1.5 kHz than below. Binaural beats were used to examine the interaural delay sensitivity of low-BF (BF binaural facilitation, whilst those with larger BPs generally showed binaural suppression. The classification of units based upon binaural stimulation with BF tones was consistent with their interaural-delay sensitivity. Characteristic delays (CD) were examined for 96 low-BF units. A clear relationship between BF and CD was observed. CDs of units with very low BFs (binaural processing in the guinea pig at low frequencies is similar to that reported in all other species studied. However, the dependence of CD on BF would suggest that the delay line system that sets up the interaural-delay sensitivity in the lower brainstem varies across frequency as well as within each frequency band.

  20. Computational electrodynamics the finite-difference time-domain method

    CERN Document Server

    Taflove, Allen

    2005-01-01

    This extensively revised and expanded third edition of the Artech House bestseller, Computational Electrodynamics: The Finite-Difference Time-Domain Method, offers engineers the most up-to-date and definitive resource on this critical method for solving Maxwell's equations. The method helps practitioners design antennas, wireless communications devices, high-speed digital and microwave circuits, and integrated optical devices with unsurpassed efficiency. There has been considerable advancement in FDTD computational technology over the past few years, and the third edition brings professionals the very latest details with entirely new chapters on important techniques, major updates on key topics, and new discussions on emerging areas such as nanophotonics. What's more, to supplement the third edition, the authors have created a Web site with solutions to problems, downloadable graphics and videos, and updates, making this new edition the ideal textbook on the subject as well.

  1. Ignition in net for different energy confinement time scalings

    International Nuclear Information System (INIS)

    Johner, J.; Prevot, F.

    1988-06-01

    A zero-dimensional profile dependent model is used to assess the feasibility of ignition in the extended version of NET. Five recent scalings for the energy confinement time (Goldston, Kaye All, Kaye Big, Shimomura-Odajima, Rebut-Lallia) are compared in the frame of two different scenarii, i.e., H-mode with a flat density profile or L-mode with a peaked density profile. For the flat density H-mode case, ignition is accessible with none of the scalings except Rebut-Lallia's. For the peaked density L-mode case, ignition is accessible with none of the scalings except Rebut-Lallia's. For the two Kaye's scalings, ignition is forbidden in H-mode even with the peaked density profile. For the Rebut-Lallia scaling, ignition is allowed in L-mode even with the flat density profile

  2. Investigating Gender Differences under Time Pressure in Financial Risk Taking.

    Science.gov (United States)

    Xie, Zhixin; Page, Lionel; Hardy, Ben

    2017-01-01

    There is a significant gender imbalance on financial trading floors. This motivated us to investigate gender differences in financial risk taking under pressure. We used a well-established approach from behavior economics to analyze a series of risky monetary choices by male and female participants with and without time pressure. We also used second to fourth digit ratio (2D:4D) and face width-to-height ratio (fWHR) as correlates of pre-natal exposure to testosterone. We constructed a structural model and estimated the participants' risk attitudes and probability perceptions via maximum likelihood estimation under both expected utility (EU) and rank-dependent utility (RDU) models. In line with existing research, we found that male participants are less risk averse and that the gender gap in risk attitudes increases under moderate time pressure. We found that female participants with lower 2D:4D ratios and higher fWHR are less risk averse in RDU estimates. Males with lower 2D:4D ratios were less risk averse in EU estimations, but more risk averse using RDU estimates. We also observe that men whose ratios indicate a greater prenatal exposure to testosterone exhibit a greater optimism and overestimation of small probabilities of success.

  3. Reflections on the different sides of idleness in contemporary times

    Directory of Open Access Journals (Sweden)

    Patrícia Zaczuk Bassinello

    2015-04-01

    Full Text Available Over the last century, idleness experienced a modernization and democratization process especially with the crisis of a society focused on work – the post-Industrial Revolution - and the emergence of new ideas that put the free time, the leisure and recreation in the role of structural elements of the new social context and like tools for the new ways of life. In this work, we we seek to focus on the significant aspects of reality and function of leisure in our time, clarifying their relationship with the processes of personal, social and economic innovation by establishing a balance of our acts in thinking the leisure and work and leisure and life from different angles of approach. In order to analyze this phenomenon, we were based on scientific sources which are representative in the context, and then we elaborated a general overview of the subject from the contributions of the bakhtinian perspectives. We observed that the increase in leisure options in the last decades of the twentieth century, along with the growth of the studies of the idleness phenomenon and its possibilities, allowed an evolution of its concepts, from activities or practices associated to the consumption and to digital entertainment, to its understanding as an experience whose key of the discussion is the subject living these experiences. We believe that this reflection about idleness may open possibilities of a better comprehension of its insertion in the social and human sciences field and, especially, in its contribution to a new attitude of the relational production, centered on the subject, which stimulates a society that creates and innovates goods and services and who deepens the studies of leisure from the dynamic experiential horizon to the right to the otherness and to its time – the own one and the others’ – such as "the right to unfunctionality", from listening to the other word.

  4. The effect of different cochlear implant microphones on acoustic hearing individuals’ binaural benefits for speech perception in noise

    Science.gov (United States)

    Aronoff, Justin M.; Freed, Daniel J.; Fisher, Laurel M.; Pal, Ivan; Soli, Sigfrid D.

    2011-01-01

    Objectives Cochlear implant microphones differ in placement, frequency response, and other characteristics such as whether they are directional. Although normal hearing individuals are often used as controls in studies examining cochlear implant users’ binaural benefits, the considerable differences across cochlear implant microphones make such comparisons potentially misleading. The goal of this study was to examine binaural benefits for speech perception in noise for normal hearing individuals using stimuli processed by head-related transfer functions (HRTFs) based on the different cochlear implant microphones. Design HRTFs were created for different cochlear implant microphones and used to test participants on the Hearing in Noise Test. Experiment 1 tested cochlear implant users and normal hearing individuals with HRTF-processed stimuli and with sound field testing to determine whether the HRTFs adequately simulated sound field testing. Experiment 2 determined the measurement error and performance-intensity function for the Hearing in Noise Test with normal hearing individuals listening to stimuli processed with the various HRTFs. Experiment 3 compared normal hearing listeners’ performance across HRTFs to determine how the HRTFs affected performance. Experiment 4 evaluated binaural benefits for normal hearing listeners using the various HRTFs, including ones that were modified to investigate the contributions of interaural time and level cues. Results The results indicated that the HRTFs adequately simulated sound field testing for the Hearing in Noise Test. They also demonstrated that the test-retest reliability and performance-intensity function were consistent across HRTFs, and that the measurement error for the test was 1.3 dB, with a change in signal-to-noise ratio of 1 dB reflecting a 10% change in intelligibility. There were significant differences in performance when using the various HRTFs, with particularly good thresholds for the HRTF based on the

  5. Contribution of Binaural Masking Release to Improved Speech Intelligibility for different Masker types.

    Science.gov (United States)

    Sutojo, Sarinah; van de Par, Steven; Schoenmaker, Esther

    2018-06-01

    In situations with competing talkers or in the presence of masking noise, speech intelligibility can be improved by spatially separating the target speaker from the interferers. This advantage is generally referred to as spatial release from masking (SRM) and different mechanisms have been suggested to explain it. One proposed mechanism to benefit from spatial cues is the binaural masking release, which is purely stimulus driven. According to this mechanism, the spatial benefit results from differences in the binaural cues of target and masker, which need to appear simultaneously in time and frequency to improve the signal detection. In an alternative proposed mechanism, the differences in the interaural cues improve the segregation of auditory streams, a process, which involves top-down processing rather than being purely stimulus driven. Other than the cues that produce binaural masking release, the interaural cue differences between target and interferer required to improve stream segregation do not have to appear simultaneously in time and frequency. This study is concerned with the contribution of binaural masking release to SRM for three masker types that differ with respect to the amount of energetic masking they exert. Speech intelligibility was measured, employing a stimulus manipulation that inhibits binaural masking release, and analyzed with a metric to account for the number of better-ear glimpses. Results indicate that the contribution of the stimulus-driven binaural masking release plays a minor role while binaural stream segregation and the availability of glimpses in the better ear had a stronger influence on improving the speech intelligibility. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  6. Different contexts, different effects? Work time and mental health in the United States and Germany.

    Science.gov (United States)

    Kleiner, Sibyl; Schunck, Reinhard; Schömann, Klaus

    2015-03-01

    This paper takes a comparative approach to the topic of work time and health, asking whether weekly work hours matter for mental health. We hypothesize that these relationships differ within the United States and Germany, given the more regulated work time environments within Germany and the greater incentives to work long hours in the United States. We further hypothesize that German women will experience greatest penalties to long hours. We use data from the German Socioeconomic Panel and the National Longitudinal Survey of Youth to examine hours effects on mental health score at midlife. The results support our initial hypothesis. In Germany, longer work time is associated with worse mental health, while in the United States, as seen in previous research, the associations are more complex. Our results do not show greater mental health penalties for German women and suggest instead a selection effect into work hours operating by gender. © American Sociological Association 2015.

  7. Is networking different with doctors working part-time? Differences in social networks of part-time and full-time doctors.

    Science.gov (United States)

    Heiligers, Phil J M; de Jong, Judith D; Groenewegen, Peter P; Hingstman, Lammert; Völker, Beate; Spreeuwenberg, Peter

    2008-10-04

    Part-time working is a growing phenomenon in medicine, which is expected to influence informal networks at work differently compared to full-time working. The opportunity to meet and build up social capital at work has offered a basis for theoretical arguments. Twenty-eight teams of medical specialists in the Netherlands, including 226 individuals participated in this study. Interviews with team representatives and individual questionnaires were used. Data were gathered on three types of networks: relationships of consulting, communication and trust. For analyses, network and multilevel applications were used. Differences between individual doctors and between teams were both analysed, taking the dependency structure of the data into account, because networks of individual doctors are not independent. Teams were divided into teams with and without doctors working part-time. Contrary to expectations we found no impact of part-time working on the size of personal networks, neither at the individual nor at the team level. The same was found regarding efficient reachability. Whereas we expected part-time doctors to choose their relations as efficiently as possible, we even found the opposite in intended relationships of trust, implying that efficiency in reaching each other was higher for full-time doctors. But we found as expected that in mixed teams with part-time doctors the frequency of regular communication was less compared to full-time teams. Furthermore, as expected the strength of the intended relationships of trust of part-time and full-time doctors was equally high. From these findings we can conclude that part-time doctors are not aiming at efficiency by limiting the size of networks or by efficient reachability, because they want to contact their colleagues directly in order to prevent from communication errors. On the other hand, together with the growth of teams, we found this strategy, focussed on reaching all colleagues, was diminishing. And our data

  8. Urban travel time reliability at different traffic conditions

    NARCIS (Netherlands)

    Zheng, Fangfang; Li, Jie; van Zuylen, H.J.; Liu, Xiaobo; Yang, Hongtai

    2017-01-01

    The decision making of travelers for route choice and departure time choice depends on the expected travel time and its reliability. A common understanding of reliability is that it is related to several statistical properties of the travel time distribution, especially to the standard deviation

  9. Assessment of Differing Definitions of Accelerometer Nonwear Time

    Science.gov (United States)

    Evenson, Kelly R.; Terry, James W., Jr.

    2009-01-01

    Measuring physical activity with objective tools, such as accelerometers, is becoming more common. Accelerometers measure acceleration multiple times within a given frequency and summarize this as a count over a pre-specified time period or epoch. The resultant count represents acceleration over the epoch length. Accelerometers eliminate biases…

  10. Finite Difference Time Domain (FDTD) Simulations Using Graphics Processors

    National Research Council Canada - National Science Library

    Adams, Samuel; Payne, Jason; Boppana, Rajendra

    2007-01-01

    .... This paper shows how GPUs can be used to greatly speedup FDTD simulations. The main objective is to leverage GPU processing power for FDTD update calculations and complete computationally expensive simulations in reasonable time...

  11. Gender Differences in Time Poverty in Rural Mozambique

    OpenAIRE

    Diksha Arora

    2014-01-01

    This study examines the nature and extent of time poverty experienced by men and women in subsistence households in Mozambique. Gender roles, shaped by patriarchal norms, place heavy work obligations on women. Time-use data from a primary household survey in Mozambique is used for this analysis. The main findings suggest that women’s labor allocation to economic activities is comparable to that of men. Household chores and care work are women’s responsibility, which they perform with minimal ...

  12. Gender differences in leisure-time physical activity

    OpenAIRE

    Azevedo, Mario Renato; Ara?jo, Cora Luiza Pavin; Reichert, Felipe Fossati; Siqueira, Fernando Vinholes; da Silva, Marcelo Cozzensa; Hallal, Pedro Curi

    2007-01-01

    Summary. Objectives: To explore the association between gender and leisure-time physical activity in a population-based sample of adults living in Brazil. To study a variety of variables possibly associated with physical activity levels. Methods: A multistage sampling of households was undertaken in Pelotas, a medium-sized Southern Brazilian city. Leisure-time physical activity was measured using the long version of the International Physical Activity Questionnaire. Data on potential predicto...

  13. Individual Differences in Impulsive Choice and Timing in Rats

    Science.gov (United States)

    Galtress, Tiffany; Garcia, Ana; Kirkpatrick, Kimberly

    2012-01-01

    Individual differences in impulsive choice behavior have been linked to a variety of behavioral problems including substance abuse, smoking, gambling, and poor financial decision-making. Given the potential importance of individual differences in impulsive choice as a predictor of behavioral problems, the present study sought to measure the extent…

  14. Timing of gene expression from different genetic systems in shaping ...

    Indian Academy of Sciences (India)

    2011-12-16

    Dec 16, 2011 ... different genetic systems, nutrition quality traits were mainly controlled by the accumulative or net ... pable of providing valuable information on the expression of ...... protein, carbohydrates, and dietary fiber components.

  15. Individual difference predictors of change in career adaptability over time

    NARCIS (Netherlands)

    Zacher, Hannes

    Career adaptability is a psychosocial construct that reflects individuals' resources for managing career tasks and challenges. This study investigated the effects of demographic characteristics and three sets of individual difference variables (Big Five personality traits, core self-evaluations, and

  16. Do Leisure-time Expenditures Differ by Housing Type?

    Czech Academy of Sciences Publication Activity Database

    Sunega, Petr

    2011-01-01

    Roč. 9, č. 7-8 (2011), s. 11-13 ISSN 1214-1720 R&D Projects: GA ČR GA403/09/1915 Institutional research plan: CEZ:AV0Z70280505 Keywords : leisure time * inequalities * housing Subject RIV: AO - Sociology, Demography http://www.socioweb.cz/

  17. Differences in auditory timing between human and nonhuman primates

    NARCIS (Netherlands)

    Honing, H.; Merchant, H.

    2014-01-01

    The gradual audiomotor evolution hypothesis is proposed as an alternative interpretation to the auditory timing mechanisms discussed in Ackermann et al.'s article. This hypothesis accommodates the fact that the performance of nonhuman primates is comparable to humans in single-interval tasks (such

  18. Modality Differences in Timing and Temporal Memory throughout the Lifespan

    Science.gov (United States)

    Lustig, Cindy; Meck, Warren H.

    2011-01-01

    The perception of time is heavily influenced by attention and memory, both of which change over the lifespan. In the current study, children (8 yrs), young adults (18-25 yrs), and older adults (60-75 yrs) were tested on a duration bisection procedure using 3 and 6-s auditory and visual signals as anchor durations. During test, participants were…

  19. It is time to consider cultural differences in debriefing

    DEFF Research Database (Denmark)

    Chung, Hyun Soo; Dieckmann, Peter; Issenberg, Saul Barry

    2013-01-01

    Debriefing plays a critical role in facilitated reflection of simulation after the experiential component of simulation-based learning. The concept of framing and reflective learning in a debriefing session has emanated primarily from Western cultures. However, non-Western cultures have significant...... debriefing sessions. Our goal was to raise awareness of cultural differences and stimulate work to make progress in this regard....

  20. Playing time between senior rugby players of different ethnic groups ...

    African Journals Online (AJOL)

    Following the formation of a single body to govern rugby in South. Africa in 1992, the ... Players from across the country were identified and invited to various ... different levels of rugby cannot be evaluated because the players representing ..... programmes for youth and young adults is the disparity in body size and fitness of ...

  1. Attention: Reaction Time and Accuracy Reveal Different Mechanisms

    Science.gov (United States)

    Prinzmetal, William; McCool, Christin; Park, Samuel

    2005-01-01

    The authors propose that there are 2 different mechanisms whereby spatial cues capture attention. The voluntary mechanism is the strategic allocation of perceptual resources to the location most likely to contain the target. The involuntary mechanism is a reflexive orienting response that occurs even when the spatial cue does not indicate the…

  2. Same-different reaction times to odors: some unexpected findings

    NARCIS (Netherlands)

    Moeller, P.; Koester, E.P.; Dijkman, N.; Wijk, de R.A.; Mojet, J.

    2012-01-01

    Two experiments were carried out using olfactometers that delivered two stimuli with an interval of, respectively, 0.2 s (experiment 1) and 4.0 s (experiment 2) in a same–different paradigm. In experiment 1 (four men, age 38.5¿±¿15.2 and six women, age 25.8¿±¿1.2), four odors and in experiment 2

  3. Sex differences in the time course of emotion.

    Science.gov (United States)

    Gard, Marja Germans; Kring, Ann M

    2007-05-01

    Conventional wisdom holds that women are more "emotional" than men. However, research evidence suggests that sex differences in emotion are considerably more complex. The authors tested hypotheses about sex differences in the engagement of the approach and avoidance motivational systems thought to underpin emotional responses. The authors measured reported emotional experience and startle response magnitude both during the presentation and after the offset of emotional stimuli that engage these motivational systems to assess whether men and women differ in their patterns of immediate response to emotional stimuli and in their patterns of recovery from these responses. Our findings indicated that women were more experientially reactive to negative, but not positive, emotional pictures compared to men, and that women scored higher than men on measure of aversive motivational system sensitivity. Although both men and women exhibited potentiation of the startle response during the presentation of negative pictures relative to neutral pictures, only women continued to show this relative potentiation during the recovery period, indicating that women were continuing to engage the aversive motivational system after the offset of negative emotional pictures.

  4. Individual Differences in Recovery Time From Attentional Capture

    Science.gov (United States)

    Fukuda, Keisuke; Vogel, Edward K.

    2015-01-01

    Working memory capacity reflects a core ability of the individual that affects performance on many cognitive tasks. Recent work has suggested that an important covariate of memory capacity is attentional control, and specifically that low-capacity individuals are more susceptible to attentional capture by distractors than high-capacity individuals are, with the latter being able to resist capture. Here, we tested an alternative account according to which all individuals are equally susceptible to attentional capture, but high-capacity individuals recover more quickly than low-capacity individuals. Using psychophysical and electrophysiological methods, we measured recovery time from attentional capture. In two experiments, we found that high- and low-capacity individuals showed equivalent attentional capture effects in the initial moments following capture, but that low-capacity individuals took much longer to recover than high-capacity individuals did. These results suggest that the poor attentional control associated with low capacity is due to slow disengagement from distractors. PMID:21310945

  5. The third oil price surge. What's different this time?

    International Nuclear Information System (INIS)

    Kesicki, Fabian

    2010-01-01

    The period from 2003 to 2008 was marked by an oil price increase comparable to the two oil price crises in the 1970s. This paper looks in detail at the situation of the oil price crises 30 years ago and compares them along various aspects on the demand and supply side with the recent price increase to identify similarities and differences. While both oil price crises in 1973 and 1979/1980 were ultimately caused by supply actions of members of the Organisation of Petroleum Exporting Countries (OPEC), all three oil price crises were preceded by high demand growth. Other aspects that favoured a high oil price in all three cases were low investments in new oil fields, as a consequence low spare capacity, and a weak US dollar. In addition, the recent oil price surge has been characterised by a high global refinery utilisation and refineries that did not adapt fast enough to the rising demand for lighter oil products. Moreover, broader geopolitical uncertainties, combined with risks associated with the oil trade helped push the oil price into a triple-digit zone. Speculation played only a limited and temporary role in accelerating price movements during the recent price increase. (author)

  6. Nuclear Winter Revisited: can it Make a Difference This Time?

    Science.gov (United States)

    Schneider, S.

    2006-12-01

    news. Therefore, the re- examination in this AGU session of the entire subject of environmental and social after-effects of any nuclear weapons use is, unfortunately, once again timely. Hopefully it will convince anyone not already convinced based on conventional damages from nuclear weapons use of the urgent need to abate proliferation and monitor and control access to and potential capabilities of those who might contemplate using such weapons for some Strangelove-like strategic or ideological objective. The extent to which a scientific re-examination of the broader horrendous implications of any scale of use of nuclear weapons will deter those contemplating their use is questionable. However, it seems likely such research would increase the resolve of the large number of countries and institutions already pressing to prevent nuclear weapons use.

  7. Individual Differences and Possible Effects from Outdoor Education: Long Time and Short Time Benefits

    Science.gov (United States)

    Fiskum, Tove Anita; Jacobsen, Karl

    2012-01-01

    This study explores differences in the children's outcomes from outdoor education. The results revealed different outcomes within different subgroups: The children with an easy or a withdrawal temperament are good functioning both indoor and outdoor. Their outcomes from outdoor education are an increased vitality, which might be seen as a short…

  8. Time and Space: The difference between following time headway and distance headway instructions

    NARCIS (Netherlands)

    Risto, Malte; Martens, Marieke Hendrikje

    2013-01-01

    In order to guarantee safety, drivers are advised to keep large enough headways. However, headway advice is often provided in terms of time headway, without knowing whether this is the right way of presenting the advice. According to a psychophysics theory, attaining a time headway would indeed

  9. Time and space: The difference between following time headway and distance headway instructions

    NARCIS (Netherlands)

    Risto, M.; Martens, M.H.

    2013-01-01

    In order to guarantee safety, drivers are advised to keep large enough headways. However, headway advice is often provided in terms of time headway, without knowing whether this is the right way of presenting the advice. According to a psychophysics theory, attaining a time headway would indeed

  10. Numerical simulation of electromagnetic waves in Schwarzschild space-time by finite difference time domain method and Green function method

    Science.gov (United States)

    Jia, Shouqing; La, Dongsheng; Ma, Xuelian

    2018-04-01

    The finite difference time domain (FDTD) algorithm and Green function algorithm are implemented into the numerical simulation of electromagnetic waves in Schwarzschild space-time. FDTD method in curved space-time is developed by filling the flat space-time with an equivalent medium. Green function in curved space-time is obtained by solving transport equations. Simulation results validate both the FDTD code and Green function code. The methods developed in this paper offer a tool to solve electromagnetic scattering problems.

  11. Market size structure and small business lending : Are crisis times different from normal times?

    NARCIS (Netherlands)

    Berger, Allen N.; Cerqueiro, G.M.; Penas, Maria

    2015-01-01

    Conventional wisdom holds that small banks have comparative advantages vis-à-vis large banks in serving small firms, while recent literature suggests this may not be the case. Using a panel of recent US start-ups, we investigate how small bank presence affects these firms in normal times (2004–06)

  12. Me Time, or We Time? Age Differences in Motivation for Exercise.

    Science.gov (United States)

    Steltenpohl, Crystal N; Shuster, Michael; Peist, Eric; Pham, Amber; Mikels, Joseph A

    2018-04-23

    Increasing exercise continues to be an important health issue for both older and younger adults. Researchers have suggested several methods for increasing exercise motivation. Socioemotional selectivity theory (SST) posits that people's motivation shift from future-oriented instrumental goals to present-oriented emotionally meaningful goals as we age, which provides insight into how people's motivations for exercise may differ for older versus younger adults. The aim of our study was to examine how exercise motivation differs for older versus younger adults. Older (greater than 59 years old) and younger (aged 18-26 years) adults participated in focus groups. They discussed exercise motivation (or lack thereof), motivators and barriers to exercise, and preferences about when, where, and with whom they exercise. Focus group transcripts were analyzed using direct content analysis and iterative categorization. Consistent with SST, younger adults generally preferred to exercise alone to achieve instrumental fitness goals, whereas older adults preferred to exercise with others. Additionally, older adults tend to consider peripheral others (e.g., strangers, acquaintances), as a positive rather than a negative influence. SST provides a framework for exploring age-related shifts in exercise motivation. Additionally, the positivity effect was reflected in how older adults evaluated the influence of peripheral others. Motivational messages could be tailored to increase health behavior changes by focusing on instrumental exercise goals for younger adults and exercise focused on meaningful relationships for older adults.

  13. Decision of special monitoring time to minimize the difference of the committed effective dose evaluated from the different AMAD

    International Nuclear Information System (INIS)

    Lee, J. I.; Lee, T. Y.; Jang, S. Y.; Lee, J. K.

    2003-01-01

    The Committed Effective Doses (CEDs) per measured unit of activity in the bioassay compartments at any time (t) after an acute intake by the inhalation of a radionuclide with a different particle size (AMAD) were calculated and compared. As a result, the relative difference between the CEDs evaluated from the different AMAD is affected by the radionuclide, bioassay compartment, and the time (t) after intake. Therefore a special monitoring time to exclude or reduce the effect of AMAD was decided and presented in the evaluation for the CEDs following an acute intake by the inhalation of a radionuclide. If special monitoring is performed during this presented special time after intake, the relative difference of the evaluated CEDs resulted from AMAD can be excluded or reduced

  14. Sensitivity to binaural timing in bilateral cochlear implant users.

    Science.gov (United States)

    van Hoesel, Richard J M

    2007-04-01

    Various measures of binaural timing sensitivity were made in three bilateral cochlear implant users, who had demonstrated moderate-to-good interaural time delay (ITD) sensitivity at 100 pulses-per-second (pps). Overall, ITD thresholds increased at higher pulse rates, lower levels, and shorter durations, although intersubject differences were evident. Monaural rate-discrimination thresholds, using the same stimulation parameters, showed more substantial elevation than ITDs with increased rate. ITD sensitivity with 6000 pps stimuli, amplitude-modulated at 100 Hz, was similar to that with unmodulated pulse trains at 100 pps, but at 200 and 300 Hz performance was poorer than with unmodulated signals. Measures of sensitivity to binaural beats with unmodulated pulse-trains showed that all three subjects could use time-varying ITD cues at 100 pps, but not 300 pps, even though static ITD sensitivity was relatively unaffected over that range. The difference between static and dynamic ITD thresholds is discussed in terms of relative contributions from initial and later arriving cues, which was further examined in an experiment using two-pulse stimuli as a function of interpulse separation. In agreement with the binaural-beat data, findings from that experiment showed poor discrimination of ITDs on the second pulse when the interval between pulses was reduced to a few milliseconds.

  15. Directional spectrum of ocean waves from array measurements using phase/time/path difference methods

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, A.A.; Sarma, Y.V.B.; Menon, H.B.

    Wave direction has for the first time been consistently, accurately and unambiguously evaluated from array measurements using the phase/time/path difference (PTPD) methods of Esteva in case of polygonal arrays and Borgman in case of linear arrays...

  16. Time Difference Amplifier with Robust Gain Using Closed-Loop Control

    Science.gov (United States)

    Nakura, Toru; Mandai, Shingo; Ikeda, Makoto; Asada, Kunihiro

    This paper presents a Time Difference Amplifier (TDA) that amplifies the input time difference into the output time difference. Cross coupled chains of variable delay cells with the same number of stages are applicable for TDA, and the gain is adjusted via the closed-loop control. The TDA was fabricated using 65nm CMOS and the measurement results show that the time difference gain is 4.78 at a nominal power supply while the designed gain is 4.0. The gain is stable enough to be less than 1.4% gain shift under ±10% power supply voltage fluctuation.

  17. Difference in differences for stayers with a time-varying qualification: health expenditure elasticity of the elderly.

    Science.gov (United States)

    Lee, Myoung-Jae; Kim, Young-Sook

    2014-09-01

    In difference in differences, a treatment is applied only to a qualified group at some time point. The qualification may be time-constant as in gender, or time-varying as in residential location. When the qualification is time-varying, there appear four groups: the newly qualified (in-movers), the already qualified (in-stayers), the newly disqualified (out-movers), and the already disqualified (out-stayers). A change in qualification may affect the response variable of interest even when the treatment effect is zero, which is an 'untreated moving effect'. Also, when the treatment effect is not zero, it may be different across the four groups. The conventional difference in differences fails to remove untreated moving effects and ignores the possible treatment effect heterogeneity across the groups. This paper shows how to account for untreated moving effects and proposes 'the effect on in-stayers' as the main effect of interest. Our proposal can be implemented with least squares estimator for panel models or with nonparametric methods. An empirical analysis is provided using Korean data for the effects of the basic elder pension on health-care expenditure. Copyright © 2014 John Wiley & Sons, Ltd.

  18. Different target-discrimination times can be followed by the same saccade-initiation timing in different stimulus conditions during visual searches

    Science.gov (United States)

    Tanaka, Tomohiro; Nishida, Satoshi

    2015-01-01

    The neuronal processes that underlie visual searches can be divided into two stages: target discrimination and saccade preparation/generation. This predicts that the length of time of the prediscrimination stage varies according to the search difficulty across different stimulus conditions, whereas the length of the latter postdiscrimination stage is stimulus invariant. However, recent studies have suggested that the length of the postdiscrimination interval changes with different stimulus conditions. To address whether and how the visual stimulus affects determination of the postdiscrimination interval, we recorded single-neuron activity in the lateral intraparietal area (LIP) when monkeys (Macaca fuscata) performed a color-singleton search involving four stimulus conditions that differed regarding luminance (Bright vs. Dim) and target-distractor color similarity (Easy vs. Difficult). We specifically focused on comparing activities between the Bright-Difficult and Dim-Easy conditions, in which the visual stimuli were considerably different, but the mean reaction times were indistinguishable. This allowed us to examine the neuronal activity when the difference in the degree of search speed between different stimulus conditions was minimal. We found that not only prediscrimination but also postdiscrimination intervals varied across stimulus conditions: the postdiscrimination interval was longer in the Dim-Easy condition than in the Bright-Difficult condition. Further analysis revealed that the postdiscrimination interval might vary with stimulus luminance. A computer simulation using an accumulation-to-threshold model suggested that the luminance-related difference in visual response strength at discrimination time could be the cause of different postdiscrimination intervals. PMID:25995344

  19. Difference between ejection times measured at two different peripheral locations as a novel marker of vascular stiffness.

    Directory of Open Access Journals (Sweden)

    Yurie Obata

    Full Text Available Pulse wave velocity (PWV has been recommended as an arterial damage assessment tool and a surrogate of arterial stiffness. However, the current technology does not allow to measure PWV both continuously and in real-time. We reported previously that peripherally measured ejection time (ET overestimates ET measured centrally. This difference in ET is associated with the inherent vascular properties of the vessel. In the current study we examined ETs derived from plethysmography simultaneously at different peripheral locations and examined the influence of the underlying arterial properties on ET prolongation by changing the subject's position. We calculated the ET difference between two peripheral locations (ΔET and its corresponding PWV for the same heartbeat. The ΔET increased with a corresponding decrease in PWV. The difference between ΔET in the supine and standing (which we call ET index was higher in young subjects with low mean arterial pressure and low PWV. These results suggest that the difference in ET between two peripheral locations in the supine vs standing positions represents the underlying vascular properties. We propose ΔET in the supine position as a potential novel real-time continuous and non-invasive parameter of vascular properties, and the ET index as a potential non-invasive parameter of vascular reactivity.

  20. A study on the frequency of participation and time spent on sport in different organisational settings

    NARCIS (Netherlands)

    Borgers, J.; Breedveld, K.; Tienen-Raaphorst, A.; Thibaut, E.; Vandermeerschen, H.; Vos, S.B.; Scheerder, J.

    2016-01-01

    Research question: As a result of the expansion of opportunities for leisure-time sport participation (LTSP), the question arises if differing organisational settings relate to differences in participation behaviour. This paper compares participation frequency and time spent on sport between

  1. Optimal control of switching time in switched stochastic systems with multi-switching times and different costs

    Science.gov (United States)

    Liu, Xiaomei; Li, Shengtao; Zhang, Kanjian

    2017-08-01

    In this paper, we solve an optimal control problem for a class of time-invariant switched stochastic systems with multi-switching times, where the objective is to minimise a cost functional with different costs defined on the states. In particular, we focus on problems in which a pre-specified sequence of active subsystems is given and the switching times are the only control variables. Based on the calculus of variation, we derive the gradient of the cost functional with respect to the switching times on an especially simple form, which can be directly used in gradient descent algorithms to locate the optimal switching instants. Finally, a numerical example is given, highlighting the validity of the proposed methodology.

  2. Time-Domain Nuclear Magnetic Resonance Investigation of Water Dynamics in Different Ginger Cultivars.

    Science.gov (United States)

    Huang, Chongyang; Zhou, Qi; Gao, Shan; Bao, Qingjia; Chen, Fang; Liu, Chaoyang

    2016-01-20

    Different ginger cultivars may contain different nutritional and medicinal values. In this study, a time-domain nuclear magnetic resonance method was employed to study water dynamics in different ginger cultivars. Significant differences in transverse relaxation time T2 values assigned to the distribution of water in different parts of the plant were observed between Henan ginger and four other ginger cultivars. Ion concentration and metabolic analysis showed similar differences in Mn ion concentrations and organic solutes among the different ginger cultivars, respectively. On the basis of Pearson's correlation analysis, many organic solutes and 6-gingerol, the main active substance of ginger, exhibited significant correlations with water distribution as determined by NMR T2 relaxation, suggesting that the organic solute differences may impact water distribution. Our work demonstrates that low-field NMR relaxometry provides useful information about water dynamics in different ginger cultivars as affected by the presence of different organic solutes.

  3. Synchronization of Different Fractional Order Time-Delay Chaotic Systems Using Active Control

    Directory of Open Access Journals (Sweden)

    Jianeng Tang

    2014-01-01

    Full Text Available Chaos synchronization of different fractional order time-delay chaotic systems is considered. Based on the Laplace transform theory, the conditions for achieving synchronization of different fractional order time-delay chaotic systems are analyzed by use of active control technique. Then numerical simulations are provided to verify the effectiveness and feasibility of the developed method. At last, effects of the fraction order and the time delay on synchronization are further researched.

  4. A different outlook on time: visual and auditory month names elicit different mental vantage points for a time-space synaesthete.

    Science.gov (United States)

    Jarick, Michelle; Dixon, Mike J; Stewart, Mark T; Maxwell, Emily C; Smilek, Daniel

    2009-01-01

    Synaesthesia is a fascinating condition whereby individuals report extraordinary experiences when presented with ordinary stimuli. Here we examined an individual (L) who experiences time units (i.e., months of the year and hours of the day) as occupying specific spatial locations (January is 30 degrees to the left of midline). This form of time-space synaesthesia has been recently investigated by Smilek et al. (2007) who demonstrated that synaesthetic time-space associations are highly consistent, occur regardless of intention, and can direct spatial attention. We extended this work by showing that for the synaesthete L, her time-space vantage point changes depending on whether the time units are seen or heard. For example, when L sees the word JANUARY, she reports experiencing January on her left side, however when she hears the word "January" she experiences the month on her right side. L's subjective reports were validated using a spatial cueing paradigm. The names of months were centrally presented followed by targets on the left or right. L was faster at detecting targets in validly cued locations relative to invalidly cued locations both for visually presented cues (January orients attention to the left) and for aurally presented cues (January orients attention to the right). We replicated this difference in visual and aural cueing effects using hour of the day. Our findings support previous research showing that time-space synaesthesia can bias visual spatial attention, and further suggest that for this synaesthete, time-space associations differ depending on whether they are visually or aurally induced.

  5. Comparing the effects of rise time and inspiratory cycling criteria on 6 different mechanical ventilators.

    Science.gov (United States)

    Gonzales, Joshua F; Russian, Christopher J; Gregg Marshall, S; Collins, Kevin P

    2013-03-01

    Inspiratory rise time and cycling criteria are important settings in pressure support ventilation. The purpose of this study was to investigate the impact of minimum and maximum rise time and inspiratory cycling criteria settings on 6 new generation ventilators. Our hypothesis was there would be a difference in the exhaled tidal volume, inspiratory time, and peak flow among 6 different ventilators, based, on change in rise time and cycling criteria. The research utilized a breathing simulator and 4 different ventilator models. All mechanical ventilators were set to a spontaneous mode of ventilation with settings of pressure support 8 cm H2O and PEEP of 5 cm H2O. A minimum and maximum setting for rise time and cycling criteria were examined. Exhaled tidal volume, inspiratory time, and peak flow measurements were recorded for each simulation. Significant (P ventilator. Significant differences in exhaled tidal volume, inspiratory time, and peak flow were observed by adjusting rise time and cycling criteria. This research demonstrates that during pressure support ventilation strategy, adjustments in rise time and/or cycling criteria can produce changes in inspiratory parameters. Obviously, this finding has important implications for practitioners who utilize a similar pressure support strategy when conducting a ventilator wean. Additionally, this study outlines major differences among ventilator manufacturers when considering inspiratory rise time and cycling criteria.

  6. Different Ultimate Factors Define Timing of Breeding in Two Related Species.

    Directory of Open Access Journals (Sweden)

    Veli-Matti Pakanen

    Full Text Available Correct reproductive timing is crucial for fitness. Breeding phenology even in similar species can differ due to different selective pressures on the timing of reproduction. These selection pressures define species' responses to warming springs. The temporal match-mismatch hypothesis suggests that timing of breeding in animals is selected to match with food availability (synchrony. Alternatively, time-dependent breeding success (the date hypothesis can result from other seasonally deteriorating ecological conditions such as intra- or interspecific competition or predation. We studied the effects of two ultimate factors on the timing of breeding, synchrony and other time-dependent factors (time-dependence, in sympatric populations of two related forest-dwelling passerine species, the great tit (Parus major and the willow tit (Poecile montanus by modelling recruitment with long-term capture-recapture data. We hypothesized that these two factors have different relevance for fitness in these species. We found that local recruitment in both species showed quadratic relationships with both time-dependence and synchrony. However, the importance of these factors was markedly different between the studied species. Caterpillar food played a predominant role in predicting the timing of breeding of the great tit. In contrast, for the willow tit time-dependence modelled as timing in relation to conspecifics was more important for local recruitment than synchrony. High caterpillar biomass experienced during the pre- and post-fledging periods increased local recruitment of both species. These contrasting results confirm that these species experience different selective pressures upon the timing of breeding, and hence responses to climate change may differ. Detailed information about life-history strategies is required to understand the effects of climate change, even in closely related taxa. The temporal match-mismatch hypothesis should be extended to consider

  7. Fractional Differential Equations in Terms of Comparison Results and Lyapunov Stability with Initial Time Difference

    Directory of Open Access Journals (Sweden)

    Coşkun Yakar

    2010-01-01

    Full Text Available The qualitative behavior of a perturbed fractional-order differential equation with Caputo's derivative that differs in initial position and initial time with respect to the unperturbed fractional-order differential equation with Caputo's derivative has been investigated. We compare the classical notion of stability to the notion of initial time difference stability for fractional-order differential equations in Caputo's sense. We present a comparison result which again gives the null solution a central role in the comparison fractional-order differential equation when establishing initial time difference stability of the perturbed fractional-order differential equation with respect to the unperturbed fractional-order differential equation.

  8. Changes in occupational class differences in leisure-time physical activity: a follow-up study

    Directory of Open Access Journals (Sweden)

    Lahelma Eero

    2011-03-01

    Full Text Available Abstract Background Physical activity is known to have health benefits across population groups. However, less is known about changes over time in socioeconomic differences in leisure-time physical activity and the reasons for the changes. We hypothesised that class differences in leisure-time physical activity would widen over time due to declining physical activity among the lower occupational classes. We examined whether occupational class differences in leisure-time physical activity change over time in a cohort of Finnish middle-aged women and men. We also examined whether a set of selected covariates could account for the observed changes. Methods The data were derived from the Helsinki Health Study cohort mail surveys; the respondents were 40-60-year-old employees of the City of Helsinki at baseline in 2000-2002 (n = 8960, response rate 67%. Follow-up questionnaires were sent to the baseline respondents in 2007 (n = 7332, response rate 83%. The outcome measure was leisure-time physical activity, including commuting, converted to metabolic equivalent tasks (MET. Socioeconomic position was measured by occupational class (professionals, semi-professionals, routine non-manual employees and manual workers. The covariates included baseline age, marital status, limiting long-lasting illness, common mental disorders, job strain, physical and mental health functioning, smoking, body mass index, and employment status at follow-up. Firstly the analyses focused on changes over time in age adjusted prevalence of leisure-time physical activity. Secondly, logistic regression analysis was used to adjust for covariates of changes in occupational class differences in leisure-time physical activity. Results At baseline there were no occupational class differences in leisure-time physical activity. Over the follow-up leisure-time physical activity increased among those in the higher classes and decreased among manual workers, suggesting the emergence of

  9. Changes in occupational class differences in leisure-time physical activity: a follow-up study.

    Science.gov (United States)

    Seiluri, Tina; Lahti, Jouni; Rahkonen, Ossi; Lahelma, Eero; Lallukka, Tea

    2011-03-01

    Physical activity is known to have health benefits across population groups. However, less is known about changes over time in socioeconomic differences in leisure-time physical activity and the reasons for the changes. We hypothesised that class differences in leisure-time physical activity would widen over time due to declining physical activity among the lower occupational classes. We examined whether occupational class differences in leisure-time physical activity change over time in a cohort of Finnish middle-aged women and men. We also examined whether a set of selected covariates could account for the observed changes. The data were derived from the Helsinki Health Study cohort mail surveys; the respondents were 40-60-year-old employees of the City of Helsinki at baseline in 2000-2002 (n = 8960, response rate 67%). Follow-up questionnaires were sent to the baseline respondents in 2007 (n = 7332, response rate 83%). The outcome measure was leisure-time physical activity, including commuting, converted to metabolic equivalent tasks (MET). Socioeconomic position was measured by occupational class (professionals, semi-professionals, routine non-manual employees and manual workers). The covariates included baseline age, marital status, limiting long-lasting illness, common mental disorders, job strain, physical and mental health functioning, smoking, body mass index, and employment status at follow-up. Firstly the analyses focused on changes over time in age adjusted prevalence of leisure-time physical activity. Secondly, logistic regression analysis was used to adjust for covariates of changes in occupational class differences in leisure-time physical activity. At baseline there were no occupational class differences in leisure-time physical activity. Over the follow-up leisure-time physical activity increased among those in the higher classes and decreased among manual workers, suggesting the emergence of occupational class differences at follow-up. Women in

  10. Effects of Different Planting Times of Different Rice Cultivars on Control of the Striped Stem Borer (Chilo suppressalis (Lepidoptera: Pyralidae

    Directory of Open Access Journals (Sweden)

    T. Oskou

    2016-06-01

    measured on 10 sample hills on each plot after the end of growth germination and before harvesting respectively. Rice yields were measured on 80 sample hills (5 m2 on each plot. Sample hills were chosen diagonally. Effect of planting times and rice cultivars on striped stem borer infestation were determined by analyzing of variance using by two-way Analysis Of Variance (ANOVA and the mean difference were tested using Tukey test. Parameters were analyzed using the SAS software. Results and Discussion: Analyses of variance showed that there was significant difference between stem borer infestation at three planting time, cultivars and their interaction. Stem borer infestation in the third planting time was significantly higher than the other two planting times. The most degree of dead hearts (11.9% and white heads (31.23% infestation were belonged to Tarom cultivar in the first planting time and Fajr cultivar in third planting time, respectively. The least degree of dead hearts (0.6% and white heads (4.56% infestation was observed on Neda in the first planting time. Also, grain yield of all rice cultivars grown at the first and second planting was higher than that of the third planting time. As earlier discussed, rice crop of the first planting time was heavily infested with stem borer during early vegetative stage. Although affected rice plants had been replaced and recovery of replanted tillers was good, they grew slower. Yield potential of all six cultivars was significantly different. Yield of a cultivar depends upon its yield potential. However, biotic and abiotic threats could reduce its yield potential. The present study showed that stem borers are potential threat when their population is higher as shown in the third planting time. The least mean rice yield (3.875 t/h occurred in the third planting time compared to those found at the first and second planting time, i.e. 5.356t/h and 5.321 t/h respectively. Conclusion: It is concluded that adjustment of planting time

  11. Using ILD or ITD Cues for Sound Source Localization and Speech Understanding in a Complex Listening Environment by Listeners with Bilateral and with Hearing-Preservation Cochlear Implants

    Science.gov (United States)

    Loiselle, Louise H.; Dorman, Michael F.; Yost, William A.; Cook, Sarah J.; Gifford, Rene H.

    2016-01-01

    Purpose: To assess the role of interaural time differences and interaural level differences in (a) sound-source localization, and (b) speech understanding in a cocktail party listening environment for listeners with bilateral cochlear implants (CIs) and for listeners with hearing-preservation CIs. Methods: Eleven bilateral listeners with MED-EL…

  12. Study on mixis potential of rotifer resting eggs ( Brachionus plicatilis) with different collection times and different preservation periods

    Science.gov (United States)

    Zhou, Li; Zheng, Yan; Xiang, Jian-Hai

    2001-09-01

    The present study investigated the possible changes in the mixis potential of rotifer resting eggs produced by a single stock of Brachionus plicatilis and collected and preserved annually from 1985 1998. Several clones derived from each batch of resting eggs were cultured under the same conditions for 21 days. The percentage of clones appearing resting eggs and the average yield of resting eggs produced from each clone were recorded and statistically analyzed to find the differences between the mixis potential of those resting egg batches. Results showed that different batches of resting eggs had different mictic levels among their descendent clones; but no regular relationship was found between the mixis potential of resting eggs and their collection times/preservation periods. Several internal and external factors that might affect the mixis potential of resting eggs were discussed.

  13. Uncertainty Expressions in Accounting Standards: is there any effect of time in the differences of perception?

    Directory of Open Access Journals (Sweden)

    Rodrigo Fernandes Malaquias

    2017-04-01

    Full Text Available This paper examines whether differences in the perception of uncertainty expressions persist over time. The empirical analysis of this question involved two approaches: quantitative (with tests to compare means, medians, regression analysis with ordinary least squares and quantile regression, and qualitative, with interviews. Principal findings are that the differences in the perceptions of participants with respect to uncertainty expressions were not statistically significant, which differs from the findings reported in previous studies. This may be indicative of a tendency toward elimination of potential differences in the interpretation of accounting standards over time.

  14. The master symmetry and time dependent symmetries of the differential–difference KP equation

    International Nuclear Information System (INIS)

    Khanizadeh, Farbod

    2014-01-01

    We first obtain the master symmetry of the differential–difference KP equation. Then we show how this master symmetry, through sl(2,C)-representation of the equation, can construct generators of time dependent symmetries. (paper)

  15. Individual differences in motor timing and its relation to cognitive and fine motor skills.

    Directory of Open Access Journals (Sweden)

    Håvard Lorås

    Full Text Available The present study investigated the relationship between individual differences in timing movements at the level of milliseconds and performance on selected cognitive and fine motor skills. For this purpose, young adult participants (N = 100 performed a repetitive movement task paced by an auditory metronome at different rates. Psychometric measures included the digit-span and symbol search subtasks from the Wechsler battery as well as the Raven SPM. Fine motor skills were assessed with the Purdue Pegboard test. Motor timing performance was significantly related (mean r = .3 to cognitive measures, and explained both unique and shared variance with information-processing speed of Raven's scores. No significant relations were found between motor timing measures and fine motor skills. These results show that individual differences in cognitive and motor timing performance is to some extent dependent upon shared processing not associated with individual differences in manual dexterity.

  16. Nitrogen fixation in seedlings of Mimosa tenuiflora cultivated with different times of regeneration of caatinga

    International Nuclear Information System (INIS)

    Silva, Arthur Jorge da; Andrade, Monaliza Mirella de Morais; Santana, Augusto Cesar de Arruda; Freitas, Ana Dolores Santiago de

    2013-01-01

    The aim of this study was to estimate the efficiency of the populations of bacteria that form nodules on legumes (BNL) in areas at different times of regeneration of native 'caatinga' using a leguminous tree of the study area

  17. TIME ZONE DIFFERENCE, COMPARATIVE ADVANTAGE AND TRADE: A REVIEW OF LITERATURE

    Directory of Open Access Journals (Sweden)

    Alaka Shree Prasad

    2017-09-01

    Full Text Available With the growing development in communication technology and increased fragmentation of production process, services that were once considered non-tradable can now be traded across different nations. In this respect, trading countries located in different time zones of the world with non-overlapping working hours are able to develop a comparative advantage together for the supply of these services. Disintegrating the production of a service across different time zones can allow the production to be completed efficiently and make the product available in the market meeting consumer demand in a timely fashion. In this paper, we have reviewed some of important research that has been conducted in the area of time zone differences and trade. This type of trade further affects the factor market and production patterns of the involved countries and has also been significant for their growth and welfare.

  18. Nonlinear Variation of Parameters Formula for Impulsive Differential Equations with Initial Time Difference and Application

    Directory of Open Access Journals (Sweden)

    Peiguang Wang

    2014-01-01

    Full Text Available This paper establishes variation of parameters formula for impulsive differential equations with initial time difference. As an application, one of the results is used to investigate stability properties of solutions.

  19. Towards Real-Time Detection of Gait Events on Different Terrains Using Time-Frequency Analysis and Peak Heuristics Algorithm.

    Science.gov (United States)

    Zhou, Hui; Ji, Ning; Samuel, Oluwarotimi Williams; Cao, Yafei; Zhao, Zheyi; Chen, Shixiong; Li, Guanglin

    2016-10-01

    Real-time detection of gait events can be applied as a reliable input to control drop foot correction devices and lower-limb prostheses. Among the different sensors used to acquire the signals associated with walking for gait event detection, the accelerometer is considered as a preferable sensor due to its convenience of use, small size, low cost, reliability, and low power consumption. Based on the acceleration signals, different algorithms have been proposed to detect toe off (TO) and heel strike (HS) gait events in previous studies. While these algorithms could achieve a relatively reasonable performance in gait event detection, they suffer from limitations such as poor real-time performance and are less reliable in the cases of up stair and down stair terrains. In this study, a new algorithm is proposed to detect the gait events on three walking terrains in real-time based on the analysis of acceleration jerk signals with a time-frequency method to obtain gait parameters, and then the determination of the peaks of jerk signals using peak heuristics. The performance of the newly proposed algorithm was evaluated with eight healthy subjects when they were walking on level ground, up stairs, and down stairs. Our experimental results showed that the mean F1 scores of the proposed algorithm were above 0.98 for HS event detection and 0.95 for TO event detection on the three terrains. This indicates that the current algorithm would be robust and accurate for gait event detection on different terrains. Findings from the current study suggest that the proposed method may be a preferable option in some applications such as drop foot correction devices and leg prostheses.

  20. Quantum mechanics and stochastic mechanics for compatible observables at different times

    International Nuclear Information System (INIS)

    Correggi, M.; Morchio, G.

    2002-01-01

    Bohm mechanics and Nelson stochastic mechanics are confronted with quantum mechanics in the presence of noninteracting subsystems. In both cases, it is shown that correlations at different times of compatible position observables on stationary states agree with quantum mechanics only in the case of product wave functions. By appropriate Bell-like inequalities it is shown that no classical theory, in particular no stochastic process, can reproduce the quantum mechanical correlations of position variables of noninteracting systems at different times

  1. A Dynamical System Approach Explaining the Process of Development by Introducing Different Time-scales.

    Science.gov (United States)

    Hashemi Kamangar, Somayeh Sadat; Moradimanesh, Zahra; Mokhtari, Setareh; Bakouie, Fatemeh

    2018-06-11

    A developmental process can be described as changes through time within a complex dynamic system. The self-organized changes and emergent behaviour during development can be described and modeled as a dynamical system. We propose a dynamical system approach to answer the main question in human cognitive development i.e. the changes during development happens continuously or in discontinuous stages. Within this approach there is a concept; the size of time scales, which can be used to address the aforementioned question. We introduce a framework, by considering the concept of time-scale, in which "fast" and "slow" is defined by the size of time-scales. According to our suggested model, the overall pattern of development can be seen as one continuous function, with different time-scales in different time intervals.

  2. Effects of Scheduling Perceptions on Attitudes and Mobility in Different Part-Time Employee Types

    Science.gov (United States)

    Wittmer, Jenell L. S.; Martin, James E.

    2011-01-01

    Recent research supports the existence of a typology of part-time employees with demographic and behavioral differences. This research suggests that part-timers should not be viewed as one homogenous group and that certain part-time employee groups have fixed external role attachments, while others have more flexible attachments. Applying the…

  3. Is networking different with part-time working colleagues? A study of medical teams.

    NARCIS (Netherlands)

    Heiligers, P.; Jong, J. de; Groenewegen, P.; Hingstman, L.

    2007-01-01

    Changes in work arrangements like the introduction of part-time work can affect both formal and informal organization. This study will focus on informal networks amongst teams of medical specialists, some but not all of which include part-time workers. Are there notable differences in the structure

  4. Time Perception in Severe Traumatic Brain Injury Patients: A Study Comparing Different Methodologies

    Science.gov (United States)

    Mioni, G.; Mattalia, G.; Stablum, F.

    2013-01-01

    In this study, we investigated time perception in patients with traumatic brain injury (TBI). Fifteen TBI patients and 15 matched healthy controls participated in the study. Participants were tested with durations above and below 1s on three different temporal tasks that involved time reproduction, production, and discrimination tasks. Data…

  5. A Comparative Study of Personal Time Perspective Differences between Korean and American College Students

    Science.gov (United States)

    Kim, Oi-Sook; Geistfeld, Loren V.

    2007-01-01

    This article compares the personal time perspectives of Korean and American college students. The results indicate American students have a personal time perspective that is different from their Korean counterparts. Implications for working with Koreans and Americans as foreign students are considered. (Contains 5 tables.)

  6. Individual Differences in Components of Reaction Time Distributions and Their Relations to Working Memory and Intelligence

    Science.gov (United States)

    Schmiedek, Florian; Oberauer, Klaus; Wilhelm, Oliver; Suss, Heinz-Martin; Wittmann, Werner W.

    2007-01-01

    The authors bring together approaches from cognitive and individual differences psychology to model characteristics of reaction time distributions beyond measures of central tendency. Ex-Gaussian distributions and a diffusion model approach are used to describe individuals' reaction time data. The authors identified common latent factors for each…

  7. Effect of the different timing of AMF inoculation on plant growth and flower quality of chrysanthemum

    NARCIS (Netherlands)

    Sohn, B.K.; Kim, K.Y.; Chung, S.J.; Kim, W.S.; Park, S.M.; Kang, J.G.; Rim, Y.S.; Cho, J.S.; Kim, T.H.; Lee, J.H.

    2003-01-01

    Plant growth and flower quality of an ornamental plant (Chrysanthemum morifolium Ramat) var. Baekgwang in response to the different timing of arbuscular mycorrhizal fungi (AMF) inoculation were examined. To evaluate the effects of AMF inoculation timing on growth of chrysanthemum cuttings, AMF was

  8. Finite-Time Synchronization of Chaotic Systems with Different Dimension and Secure Communication

    Directory of Open Access Journals (Sweden)

    Shouquan Pang

    2016-01-01

    Full Text Available Finite-time synchronization of chaotic systems with different dimension and secure communication is investigated. It is rigorously proven that global finite-time synchronization can be achieved between three-dimension Lorenz chaotic system and four-dimension Lorenz hyperchaotic system which have certain parameters or uncertain parameters. The electronic circuits of finite-time synchronization using Multisim 12 are designed to verify our conclusion. And the application to the secure communications is also analyzed and discussed.

  9. Comparison of Sprint Reaction and Visual Reaction Times of Athletes in Different Branches

    Science.gov (United States)

    Akyüz, Murat; Uzaldi, Basar Basri; Akyüz, Öznur; Dogru, Yeliz

    2017-01-01

    The aims of this study are to analyse sprint reaction and visual reaction times of female athletes of different branches competing in Professional leagues and to show the differences between them. 42 voluntary female athletes from various branches of Professional leagues of Istanbul (volleyball, basketball, handball) were included in the…

  10. The Influence of Different Performance Level of Fencers on Simple and Choice Reaction Time

    Directory of Open Access Journals (Sweden)

    Štefan Balkó

    2016-09-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n4p391   In many sport disciplines reaction time plays a key role in the sport performance. It is good to point out for example ball games or fighting sports (fencing, karate etc.. The research is focused on detection of the differences in the simple and choice reaction time during visual stimulation among elite, sub-elite fencers and beginners. For the measurement a Fitrosword device and the SWORD software were used. An additional stimulus was added during measuring which should increase the overall number of stimuli, but shouldn’t force fencer to any reaction whatsoever. The results from presented study can be compared with Hicks law. The next focus of the study was to identify the difference in reaction time during two different movement tasks with different complexity movement requirements. The research was built up on a hypothesis that the results will differ among different performance groups of fencers. The difference however was overt among beginners and elite fencers (p = 0.0088, d = 0.5 in reaction time during different movement tasks (direct hit vs. lunge. The results of this research could be useful to trainers for training process organisation and increase the effectivity of muscle coordination during several movements in fencing.

  11. Detecting method for crude oil price fluctuation mechanism under different periodic time series

    International Nuclear Information System (INIS)

    Gao, Xiangyun; Fang, Wei; An, Feng; Wang, Yue

    2017-01-01

    Highlights: • We proposed the concept of autoregressive modes to indicate the fluctuation patterns. • We constructed transmission networks for studying the fluctuation mechanism. • There are different fluctuation mechanism under different periodic time series. • Only a few types of autoregressive modes control the fluctuations in crude oil price. • There are cluster effects during the fluctuation mechanism of autoregressive modes. - Abstract: Current existing literatures can characterize the long-term fluctuation of crude oil price time series, however, it is difficult to detect the fluctuation mechanism specifically under short term. Because each fluctuation pattern for one short period contained in a long-term crude oil price time series have dynamic characteristics of diversity; in other words, there exhibit various fluctuation patterns in different short periods and transmit to each other, which reflects the reputedly complicate and chaotic oil market. Thus, we proposed an incorporated method to detect the fluctuation mechanism, which is the evolution of the different fluctuation patterns over time from the complex network perspective. We divided crude oil price time series into segments using sliding time windows, and defined autoregressive modes based on regression models to indicate the fluctuation patterns of each segment. Hence, the transmissions between different types of autoregressive modes over time form a transmission network that contains rich dynamic information. We then capture transmission characteristics of autoregressive modes under different periodic time series through the structure features of the transmission networks. The results indicate that there are various autoregressive modes with significantly different statistical characteristics under different periodic time series. However, only a few types of autoregressive modes and transmission patterns play a major role in the fluctuation mechanism of the crude oil price, and these

  12. Dependence of the time-constant of a fuel rod on different design and operational parameters

    International Nuclear Information System (INIS)

    Elenkov, D.; Lassmann, K.; Schubert, A.; Laar, J. van de

    2001-01-01

    The temperature response during a reactor shutdown has been measured for many years in the OECD-Halden Project. It has been shown that the complicated shutdown processes can be characterized by a time constant τ which depends on different fuel design and operational parameters, such as fuel geometry, gap size, fill gas pressure and composition, burnup and linear heat rate. In the paper the concept of a time constant is analyzed and the dependence of the time constant on various parameters is investigated analytically. Measured time constants for different designs and conditions are compared with those derived from calculations of the TRANSURANUS code. Employing standard models results in a systematic underprediction of the time constant, i.e. the heat transfer during shutdown is overestimated. (author)

  13. Blood serum metabolites and meat quality in crossbred pigs experiencing different lairage time

    Directory of Open Access Journals (Sweden)

    Ivan Juric

    2010-01-01

    Full Text Available Pigs of two crosses: A (Duroc x Swedish Landrace x Pietrain (n=24 and B (Swedish Landrace x Large White x Pietrain (n=26 were used to investigate the effects of different lairage time (2 and 24 hours on levels of stress and meat quality traits. No direct effect of lairage time on cortisol, lactate, electrolytes and meat quality parameters was observed. However, after long lairage time, pigs showed lower level of glucose and higher CK, AST and ALT activity. Crossbred B pigs exposed to short lairage time, showed higher blood lactate, sodium, and potassium level, higher drip loss and lower pHi, whereas there were no significant differences between the crossbreeds in the long lairage group. The results indicate that long lairage time decreases blood glucose level and produces signs of muscle damage. In the short lairage period, the crossbreed B showed a higher response to pre-slaughter handling affecting the meat quality.

  14. Between-mode-differences in the value of travel time: Self-selection or strategic behaviour?

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Hjorth, Katrine; Lyk-Jensen, Stéphanie Vincent

    2010-01-01

    Using stated preference survey data, we measure the value of travel time for several transport modes. We find, like many before us, that the value of travel time varies across modes in the opposite direction of what would be the consequence of differences in comfort. We examine three candidate...... causes for the observed differences: Comfort effects, self-selection and strategic behaviour of respondents. Using experiments with both the current and an alternative mode we find that the differences in the value of travel time are consistent with self-selection and comfort effects. Moreover......, respondents having bus as the current or the alternative mode seem not to value comfort differently across modes. Strategic behaviour seems to play no role....

  15. Influence of dimension box differences and time differences during operations of red box for motorcycles at signalized intersection

    Science.gov (United States)

    Mulyadi, Agah Muhammad

    2017-11-01

    Performance of signalized intersection has declined due to a large number of motorcycles. The number of motorcycles reached 98.2 million units and the composition of motorcycles has reached around 81.7% of the total composition of vehicles in Indonesia (AISI, 2017). To solve that problem, the red box for motorcycles are provided at the signalized intersection. Red box for the motorcycle at signalized intersections was developed from the concept of Advance Stop Line (ASL) for bicycles. The Red Box was developed to split the queue between motorcycles and other vehicles when waiting at red light. This paper aims to evaluate the influence of the red box dimension and red time operation differences. The survey was conducted as many as 30 cycles of traffic signals per day. The data were analyzed using software IBM SPSS Statistics 20 by using Analysis of Variance (ANOVA) to obtain p-value (significant). The analysis shows that there are insignificant influences between the occupancy rates to the dimension of Red Box. Furthermore, that there is a significant difference that shows the dependency of only motorcycles in the Red Box Area towards red time operation.

  16. Contributed Review: Source-localization algorithms and applications using time of arrival and time difference of arrival measurements

    Science.gov (United States)

    Li, Xinya; Deng, Zhiqun Daniel; Rauchenstein, Lynn T.; Carlson, Thomas J.

    2016-04-01

    Locating the position of fixed or mobile sources (i.e., transmitters) based on measurements obtained from sensors (i.e., receivers) is an important research area that is attracting much interest. In this paper, we review several representative localization algorithms that use time of arrivals (TOAs) and time difference of arrivals (TDOAs) to achieve high signal source position estimation accuracy when a transmitter is in the line-of-sight of a receiver. Circular (TOA) and hyperbolic (TDOA) position estimation approaches both use nonlinear equations that relate the known locations of receivers and unknown locations of transmitters. Estimation of the location of transmitters using the standard nonlinear equations may not be very accurate because of receiver location errors, receiver measurement errors, and computational efficiency challenges that result in high computational burdens. Least squares and maximum likelihood based algorithms have become the most popular computational approaches to transmitter location estimation. In this paper, we summarize the computational characteristics and position estimation accuracies of various positioning algorithms. By improving methods for estimating the time-of-arrival of transmissions at receivers and transmitter location estimation algorithms, transmitter location estimation may be applied across a range of applications and technologies such as radar, sonar, the Global Positioning System, wireless sensor networks, underwater animal tracking, mobile communications, and multimedia.

  17. Countermovement jump height: gender and sport-specific differences in the force-time variables.

    Science.gov (United States)

    Laffaye, Guillaume; Wagner, Phillip P; Tombleson, Tom I L

    2014-04-01

    The goal of this study was to assess (a) the eccentric rate of force development, the concentric force, and selected time variables on vertical performance during countermovement jump, (b) the existence of gender differences in these variables, and (c) the sport-specific differences. The sample was composed of 189 males and 84 females, all elite athletes involved in college and professional sports (primarily football, basketball, baseball, and volleyball). The subjects performed a series of 6 countermovement jumps on a force plate (500 Hz). Average eccentric rate of force development (ECC-RFD), total time (TIME), eccentric time (ECC-T), Ratio between eccentric and total time (ECC-T:T) and average force (CON-F) were extracted from force-time curves and the vertical jumping performance, measured by impulse momentum. Results show that CON-F (r = 0.57; p differ between both sexes (p differ, showing a similar temporal structure. The best way to jump high is to increase CON-F and ECC-RFD thus minimizing the ECC-T. Principal component analysis (PCA) accounted for 76.8% of the JH variance and revealed that JH is predicted by a temporal and a force component. Furthermore, the PCA comparison made among athletes revealed sport-specific signatures: volleyball players revealed a temporal-prevailing profile, a weak-force with large ECC-T:T for basketball players and explosive and powerful profiles for football and baseball players.

  18. Efficacy of cold light bleaching using different bleaching times and their effects on human enamel.

    Science.gov (United States)

    Wang, Wei; Zhu, Yuhe; Li, Jiajia; Liao, Susan; Ai, Hongjun

    2013-01-01

    This study investigated the efficacy of cold light bleaching using different bleaching times and the effects thereof on tooth enamel. Before and after bleaching, stained tooth specimens were subjected to visual and instrumental colorimetric assessments using Vita Shade Guide and spectrophotometric shade matching. Enamel surface alterations were examined using scanning electron microscopy (SEM) to analyze surface morphology, surface microhardness (SMH) measurement to determine changes in mechanical properties, and X-ray diffraction (XRD) to characterize post-bleaching enamel composition. Cold light bleaching successfully improved tooth color, with optimal efficacy when bleaching time was beyond 10 min. Significant differences in surface morphology were observed among the different bleaching times, but no significant differences were observed for enamel composition and surface microhardness among the different bleaching times. Results of this study revealed an association between the bleaching time of cold light bleaching and its whitening efficacy. Together with the results on enamel surface changes, this study provided positive evidence to support cold light bleaching as an in-office bleaching treatment.

  19. Indication criteria for cataract extraction and gender differences in waiting time.

    Science.gov (United States)

    Smirthwaite, Goldina; Lundström, Mats; Albrecht, Susanne; Swahnberg, Katarina

    2014-08-01

    The purpose of this study was to investigate national indication criteria tool for cataract extraction (NIKE), a clinical tool for establishing levels of indications for cataract surgery, in relation to gender differences in waiting times for cataract extraction (CE). Data were collected by The Swedish National Cataract Register (NCR). Eye clinics report to NCR voluntarily and on regular basis (98% coverage). Comparisons regarding gender difference in waiting times were performed between NIKE-categorized and non-NIKE-categorized patients, as well as between different indication groups within the NIKE-system. All calculations were performed in spss version 20. Multivariate analyses were carried out using logistic regression, and single variable analyses were carried out by Student's t-test or chi square as appropriate. Gender, age, visual acuity and NIKE-categorization were associated with waiting time. Female patients had a longer waiting time to CE than male, both within and outside the NIKE-system. Gender difference in waiting time was somewhat larger among patients who had not been categorized by NIKE. In the non-NIKE-categorized group, women waited 0.20 months longer than men. In the group which was NIKE-categorized, women waited 0.18 months longer than men. It is reasonable to assume that prioritizing patients by means of NIKE helps to reduce the gender differences in waiting time. Gender differences in waiting time have decreased as NIKE was introduced and there may be a variety of explanations for this. However, with the chosen study design, we could not distinguish between effects related to NIKE and those due to other factors which occurred during the study period. © 2013 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  20. A Discrete-Time Geo/G/1 Retrial Queue with Two Different Types of Vacations

    Directory of Open Access Journals (Sweden)

    Feng Zhang

    2015-01-01

    Full Text Available We analyze a discrete-time Geo/G/1 retrial queue with two different types of vacations and general retrial times. Two different types of vacation policies are investigated in this model, one of which is nonexhaustive urgent vacation during serving and the other is normal exhaustive vacation. For this model, we give the steady-state analysis for the considered queueing system. Firstly, we obtain the generating functions of the number of customers in our model. Then, we obtain the closed-form expressions of some performance measures and also give a stochastic decomposition result for the system size. Moreover, the relationship between this discrete-time model and the corresponding continuous-time model is also investigated. Finally, some numerical results are provided to illustrate the effect of nonexhaustive urgent vacation on some performance characteristics of the system.

  1. A fast time-difference inverse solver for 3D EIT with application to lung imaging.

    Science.gov (United States)

    Javaherian, Ashkan; Soleimani, Manuchehr; Moeller, Knut

    2016-08-01

    A class of sparse optimization techniques that require solely matrix-vector products, rather than an explicit access to the forward matrix and its transpose, has been paid much attention in the recent decade for dealing with large-scale inverse problems. This study tailors application of the so-called Gradient Projection for Sparse Reconstruction (GPSR) to large-scale time-difference three-dimensional electrical impedance tomography (3D EIT). 3D EIT typically suffers from the need for a large number of voxels to cover the whole domain, so its application to real-time imaging, for example monitoring of lung function, remains scarce since the large number of degrees of freedom of the problem extremely increases storage space and reconstruction time. This study shows the great potential of the GPSR for large-size time-difference 3D EIT. Further studies are needed to improve its accuracy for imaging small-size anomalies.

  2. Difference in peak weight transfer and timing based on golf handicap.

    Science.gov (United States)

    Queen, Robin M; Butler, Robert J; Dai, Boyi; Barnes, C Lowry

    2013-09-01

    Weight shift during the golf swing has been a topic of discussion among golf professionals; however, it is still unclear how weight shift varies in golfers of different performance levels. The main purpose of this study was to examine the following: (a) the changes in the peak ground reaction forces (GRF) and the timing of these events between high (HHCP) and low handicap (LHCP) golfers and (b) the differences between the leading and trailing legs. Twenty-eight male golfers were recruited and divided based on having an LHCP 9. Three-dimensional GRF peaks and the timing of the peaks were recorded bilaterally during a golf swing. The golf swing was divided into different phases: (a) address to the top of the backswing, (b) top of the backswing to ball contact, and (c) ball contact to the end of follow through. Repeated measures analyses of variance (α = 0.05) were completed for each study variable: the magnitude and the timing of peak vertical GRF, peak lateral GRF, and peak medial GRF (α = 0.05). The LHCP group had a greater transfer of vertical force from the trailing foot to the leading foot in phase 2 than the HHCP group. The LHCP group also demonstrated earlier timing of peak vertical force throughout the golf swing than the HHCP group. The LHCP and HHCP groups demonstrated different magnitudes of peak lateral force. The LHCP group had an earlier timing of peak lateral GRF in phase 2 and earlier timing of peak medial GRF in phases 1 and 2 than the HHCP group. In general, LHCP golfers demonstrated greater and earlier force generation than HHCP golfers. It may be relevant to consider both the magnitude of the forces and the timing of these events during golf-specific training to improve performance. These data reveal weight shifting differences that can be addressed by teaching professionals to help their students better understand weight transfer during the golf swing to optimize performance.

  3. ARRIVAL TIME DIFFERENCES BETWEEN GRAVITATIONAL WAVES AND ELECTROMAGNETIC SIGNALS DUE TO GRAVITATIONAL LENSING

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryuichi [Faculty of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori 036-8561 (Japan)

    2017-01-20

    In this study we demonstrate that general relativity predicts arrival time differences between gravitational wave (GW) and electromagnetic (EM) signals caused by the wave effects in gravitational lensing. The GW signals can arrive earlier than the EM signals in some cases if the GW/EM signals have passed through a lens, even if both signals were emitted simultaneously by a source. GW wavelengths are much larger than EM wavelengths; therefore, the propagation of the GWs does not follow the laws of geometrical optics, including the Shapiro time delay, if the lens mass is less than approximately 10{sup 5} M {sub ⊙}( f /Hz){sup −1}, where f is the GW frequency. The arrival time difference can reach ∼0.1 s ( f /Hz){sup −1} if the signals have passed by a lens of mass ∼8000 M {sub ⊙}( f /Hz){sup −1} with the impact parameter smaller than the Einstein radius; therefore, it is more prominent for lower GW frequencies. For example, when a distant supermassive black hole binary (SMBHB) in a galactic center is lensed by an intervening galaxy, the time lag becomes of the order of 10 days. Future pulsar timing arrays including the Square Kilometre Array and X-ray detectors may detect several time lags by measuring the orbital phase differences between the GW/EM signals in the SMBHBs. Gravitational lensing imprints a characteristic modulation on a chirp waveform; therefore, we can deduce whether a measured arrival time lag arises from intrinsic source properties or gravitational lensing. Determination of arrival time differences would be extremely useful in multimessenger observations and tests of general relativity.

  4. The Impact of Time Difference between Satellite Overpass and Ground Observation on Cloud Cover Performance Statistics

    Directory of Open Access Journals (Sweden)

    Jędrzej S. Bojanowski

    2014-12-01

    Full Text Available Cloud property data sets derived from passive sensors onboard the polar orbiting satellites (such as the NOAA’s Advanced Very High Resolution Radiometer have global coverage and now span a climatological time period. Synoptic surface observations (SYNOP are often used to characterize the accuracy of satellite-based cloud cover. Infrequent overpasses of polar orbiting satellites combined with the 3- or 6-h SYNOP frequency lead to collocation time differences of up to 3 h. The associated collocation error degrades the cloud cover performance statistics such as the Hanssen-Kuiper’s discriminant (HK by up to 45%. Limiting the time difference to 10 min, on the other hand, introduces a sampling error due to a lower number of corresponding satellite and SYNOP observations. This error depends on both the length of the validated time series and the SYNOP frequency. The trade-off between collocation and sampling error call for an optimum collocation time difference. It however depends on cloud cover characteristics and SYNOP frequency, and cannot be generalized. Instead, a method is presented to reconstruct the unbiased (true HK from HK affected by the collocation differences, which significantly (t-test p < 0.01 improves the validation results.

  5. Introduction to the Finite-Difference Time-Domain (FDTD) Method for Electromagnetics

    CERN Document Server

    Gedney, Stephen

    2011-01-01

    Introduction to the Finite-Difference Time-Domain (FDTD) Method for Electromagnetics provides a comprehensive tutorial of the most widely used method for solving Maxwell's equations -- the Finite Difference Time-Domain Method. This book is an essential guide for students, researchers, and professional engineers who want to gain a fundamental knowledge of the FDTD method. It can accompany an undergraduate or entry-level graduate course or be used for self-study. The book provides all the background required to either research or apply the FDTD method for the solution of Maxwell's equations to p

  6. The relative value of safety and performance indicators and qualitative arguments in different time frames

    International Nuclear Information System (INIS)

    Alonso, J.; Rohlig, K.J.; Batandjieva, B.; Griffault, L.; Regent, A.; Schneider, J.; Storck, R.; Umeki, H.

    2002-01-01

    Indicators complementary to dose or risk are of great importance for the provision of multiple lines of reasoning at different time frames and therefore for the building of confidence within a safety case and that regulations should acknowledge this fact. They are also of great value with regard to the understanding of the safety case by and the communication to different audiences. The relative value of such indicators changes with time. For longer timescales qualitative information becomes more important. The meaning of calculated dose or risk is different for different timescales (ranging from expected performance to illustration) but dose or risk remains a valuable and central information for any time considered in a Safety Assessment. Certain indicators (concentrations and fluxes) can provide information by avoiding certain uncertainties which increase remarkably with time (biosphere, dilution) but apart from that no generic opinion or recommendation can be derived since the value of specific indicators and the required degree of aggregation (over different nuclides or even of consequence and probability) strongly depends on the many parameter. (authors)

  7. Transient analysis of printed lines using finite-difference time-domain method

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Shahid [Thomas Jefferson National Accelerator Facility, 12050 Jefferson Avenue, Suite 704, Newport News, VA, 23606, USA

    2012-03-29

    Comprehensive studies of ultra-wideband pulses and electromagnetic coupling on printed coupled lines have been performed using full-wave 3D finite-difference time-domain analysis. Effects of unequal phase velocities of coupled modes, coupling between line traces, and the frequency dispersion on the waveform fidelity and crosstalk have been investigated in detail. To discriminate the contributions of different mechanisms into pulse evolution, single and coupled microstrip lines without (ϵr = 1) and with (ϵr > 1) dielectric substrates have been examined. To consistently compare the performance of the coupled lines with substrates of different permittivities and transients of different characteristic times, a generic metric similar to the electrical wavelength has been introduced. The features of pulse propagation on coupled lines with layered and pedestal substrates and on the irregular traces have been explored. Finally, physical interpretations of the simulation results are discussed in the paper.

  8. Solving the Schroedinger equation using the finite difference time domain method

    International Nuclear Information System (INIS)

    Sudiarta, I Wayan; Geldart, D J Wallace

    2007-01-01

    In this paper, we solve the Schroedinger equation using the finite difference time domain (FDTD) method to determine energies and eigenfunctions. In order to apply the FDTD method, the Schroedinger equation is first transformed into a diffusion equation by the imaginary time transformation. The resulting time-domain diffusion equation is then solved numerically by the FDTD method. The theory and an algorithm are provided for the procedure. Numerical results are given for illustrative examples in one, two and three dimensions. It is shown that the FDTD method accurately determines eigenfunctions and energies of these systems

  9. Chaotic characteristic of electromagnetic radiation time series of coal or rock under different scales

    Energy Technology Data Exchange (ETDEWEB)

    Zhen-Tang Liu; En-Lai Zhao; En-Yuan Wang; Jing Wang [China University of Mining and Technology, Xuzhou (China). School of Safety Engineering

    2009-02-15

    Based on chaos theory, the chaotic characteristics of electromagnetic radiation time series of coal or rock under different loads was studied. The results show that the correlation of electromagnetic radiation time series of small-scale coal or rock and coal mine converges to a stable saturation value, which shows that these electromagnetic radiation time series have chaos characteristics. When there is danger of coal seam burst, the value of the saturation correlation dimension D{sub 2} of the electromagnetic radiation time series is bigger and it changes greatly; when there is no danger, its value is smaller and changes smoothly. The change of saturation correlation of electromagnetic radiation time series can be used to forecast coal or rock dynamic disasters. 11 refs., 4 figs.

  10. Quality and Quantity of Sorghum Hydroponic Fodder from Different Varieties and Harvest Time

    Science.gov (United States)

    Chrisdiana, R.

    2018-02-01

    This experiment was designed to compare different varieties and harvest time of sorghum hydroponic fodder based on nutrient content and biomass production. Experimental design for fodder productivity was completely randomized design with 2 x 3 factorial, i.e., sorghum varieties (KD 4 and Super-1) and time of harvesting the sorghum hydroponic fodder (8,12 and 16 d). Total biomass and DM production, were affected significantly (p<0.05) on harvest time. Total biomass and nutrient content were increased in longer harvest time. The nutrient content were increased with decreasing total value of DM. Super-1 varieties produce larger biomass and nutrient content higher than KD4 (p<0.05). Based on sorghum hidroponic fodder quality and quantity, sorghum hidroponic fodder with Super-1 varieties harvested at 12 d had a good quality of fodder and it can be alternative of technology providing quality forage and land saving with a short time planting period and continous production.

  11. Yield and crop cycle time of peaches cultivated in subtropical climates and subjected to different pruning times

    Directory of Open Access Journals (Sweden)

    Rafael Augusto Ferraz

    2015-12-01

    Full Text Available The cultivation of peaches in regions of subtropical and tropical climate is currently achieved through a set of practices such as using less demanding cultivars in cold conditions, applying plant growth regulators to break dormancy, and performing specific pruning, like production and renewal pruning. Research on the climate adaptation of cultivars is of great importance in establishing a crop in a given region. Therefore, the objective of this study was to evaluate the agronomic performance of three cultivars subjected to different production pruning times in Botucatu/SP, where 2-year old peach trees were evaluated, grown at a spacing of 6.0 x 4.0 meters. The experimental design was a split plot design with four blocks, using the cultivars Douradão, BRS Kampai and BRS Rubimel, and the subplots corresponded to pruning times in May, June, July and August. Ten plants were used per plot, with the four central plants considered useful and the remaining considered as margins. Pruning in June and July showed the best results in terms of percentage of fruit set and production. The cultivar BRS Rubimel showed the best percentage of fruit set when pruned in June (44.96%, and best fruit production when pruned in July (18.7 kg plant-1. Pruning in May anticipated the harvest of cultivar BRS Rubimel by 13 days whereas pruning carried out in July and August provided late harvests for cultivars Douradão and BRS Kampai.

  12. Contributed Review: Source-localization algorithms and applications using time of arrival and time difference of arrival measurements

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xinya [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA; Deng, Zhiqun Daniel [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA; Rauchenstein, Lynn T. [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA; Carlson, Thomas J. [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, USA

    2016-04-01

    Locating the position of fixed or mobile sources (i.e., transmitters) based on received measurements from sensors is an important research area that is attracting much research interest. In this paper, we present localization algorithms using time of arrivals (TOA) and time difference of arrivals (TDOA) to achieve high accuracy under line-of-sight conditions. The circular (TOA) and hyperbolic (TDOA) location systems both use nonlinear equations that relate the locations of the sensors and tracked objects. These nonlinear equations can develop accuracy challenges because of the existence of measurement errors and efficiency challenges that lead to high computational burdens. Least squares-based and maximum likelihood-based algorithms have become the most popular categories of location estimators. We also summarize the advantages and disadvantages of various positioning algorithms. By improving measurement techniques and localization algorithms, localization applications can be extended into the signal-processing-related domains of radar, sonar, the Global Positioning System, wireless sensor networks, underwater animal tracking, mobile communications, and multimedia.

  13. Sensory Attribute Identification Time Cannot Explain the Common Temporal Limit of Binding Different Attributes and Modalities

    Directory of Open Access Journals (Sweden)

    Waka Fujisaki

    2011-10-01

    Full Text Available An informative performance measure of the brain's integration across different sensory attributes/modalities is the critical temporal rate of feature alternation (between, eg, red and green beyond which observers could not identify the feature value specified by a timing signal from another attribute (eg, a pitch change. Interestingly, this limit, which we called the critical crowding frequency (CCF, is fairly low and nearly constant (∼2.5 Hz regardless of the combination of attributes and modalities (Fujisaki & Nishida, 2010, IMRF. One may consider that the CCF reflects the processing time required for the brain to identify the specified feature value on the fly. According to this idea, the similarity in CCF could be ascribed to the similarity in identification time for the attributes we used (luminance, color, orientation, pitch, vibration. To test this idea, we estimated the identification time of each attribute from [Go/ No-Go choice reaction time – simple reaction time]. In disagreement with the prediction, we found significant differences among attributes (eg, ∼160 ms for orientation, ∼70 ms for pitch. The results are more consistent with our proposal (Fujisaki & Nishida, Proc Roy Soc B that the CCF reflects the common rate limit of specifying what happens when (timing-content binding by a central, presumably postdictive, mechanism.

  14. Influence of different anoxic time exposures on active biomass, protozoa and filamentous bacteria in activated sludge.

    Science.gov (United States)

    Rodriguez-Perez, S; Fermoso, F G; Arnaiz, C

    Medium-sized wastewater treatment plants are considered too small to implement anaerobic digestion technologies and too large for extensive treatments. A promising option as a sewage sludge reduction method is the inclusion of anoxic time exposures. In the present study, three different anoxic time exposures of 12, 6 and 4 hours have been studied to reduce sewage sludge production. The best anoxic time exposure was observed under anoxic/oxic cycles of 6 hours, which reduced 29.63% of the biomass production compared with the oxic control conditions. The sludge under different anoxic time exposures, even with a lower active biomass concentration than the oxic control conditions, showed a much higher metabolic activity than the oxic control conditions. Microbiological results suggested that both protozoa density and abundance of filamentous bacteria decrease under anoxic time exposures compared to oxic control conditions. The anoxic time exposures 6/6 showed the highest reduction in both protozoa density, 37.5%, and abundance of filamentous bacteria, 41.1%, in comparison to the oxic control conditions. The groups of crawling ciliates, carnivorous ciliates and filamentous bacteria were highly influenced by the anoxic time exposures. Protozoa density and abundance of filamentous bacteria have been shown as promising bioindicators of biomass production reduction.

  15. Audibility of spectral differences in head-related transfer functions

    DEFF Research Database (Denmark)

    Hoffmann, Pablo F.F.; Møller, Henrik

    2006-01-01

    The spatial resolution at which head-related transfer functions (HRTFs) are available is an important aspect in the implementation of three-dimensional sound. Specifically, synthesis of moving sound requires that HRTFs are sufficiently close so the simulated sound is perceived as moving smoothly....... How close they must be, depends directly on how much the characteristics of neighboring HRTFs differ, and, most important, when these differences become audible. Differences between HRTFs exist in the interaural delay (ITD) and in the spectral characteristics, i.e. the magnitude spectrum of the HRTFs...

  16. Sex differences in accuracy and precision when judging time to arrival: data from two Internet studies.

    Science.gov (United States)

    Sanders, Geoff; Sinclair, Kamila

    2011-12-01

    We report two Internet studies that investigated sex differences in the accuracy and precision of judging time to arrival. We used accuracy to mean the ability to match the actual time to arrival and precision to mean the consistency with which each participant made their judgments. Our task was presented as a computer game in which a toy UFO moved obliquely towards the participant through a virtual three-dimensional space on route to a docking station. The UFO disappeared before docking and participants pressed their space bar at the precise moment they thought the UFO would have docked. Study 1 showed it was possible to conduct quantitative studies of spatiotemporal judgments in virtual reality via the Internet and confirmed reports that men are more accurate because women underestimate, but found no difference in precision measured as intra-participant variation. Study 2 repeated Study 1 with five additional presentations of one condition to provide a better measure of precision. Again, men were more accurate than women but there were no sex differences in precision. However, within the coincidence-anticipation timing (CAT) literature, of those studies that report sex differences, a majority found that males are both more accurate and more precise than females. Noting that many CAT studies report no sex differences, we discuss appropriate interpretations of such null findings. While acknowledging that CAT performance may be influenced by experience we suggest that the sex difference may have originated among our ancestors with the evolutionary selection of men for hunting and women for gathering.

  17. Comparative evaluation of nickel discharge from brackets in artificial saliva at different time intervals.

    Science.gov (United States)

    Jithesh, C; Venkataramana, V; Penumatsa, Narendravarma; Reddy, S N; Poornima, K Y; Rajasigamani, K

    2015-08-01

    To determine and compare the potential difference of nickel release from three different orthodontic brackets, in different artificial pH, in different time intervals. Twenty-seven samples of three different orthodontic brackets were selected and grouped as 1, 2, and 3. Each group was divided into three subgroups depending on the type of orthodontic brackets, salivary pH and the time interval. The Nickel release from each subgroup were analyzed by using inductively coupled plasma-Atomic Emission Spectrophotometer (Perkin Elmer, Optima 2100 DV, USA) model. Quantitative analysis of nickel was performed three times, and the mean value was used as result. ANOVA (F-test) was used to test the significant difference among the groups at 0.05 level of significance (P brackets have the highest at all 4.2 pH except in 120 h. The study result shows that the nickel release from the recycled stainless steel brackets is highest. Metal slot ceramic bracket release significantly less nickel. So, recycled stainless steel brackets should not be used for nickel allergic patients. Metal slot ceramic brackets are advisable.

  18. Reduction of teat skin mastitis pathogen loads: differences between strains, dips, and contact times.

    Science.gov (United States)

    Enger, B D; Fox, L K; Gay, J M; Johnson, K A

    2015-02-01

    The purpose of these experiments was to (1) assess differences in mastitis pathogen strain sensitivities to teat disinfectants (teat dips), and (2) determine the optimum time for premilking teat dips to remain in contact with teat skin to reduce pathogen loads on teat skin. Two experiments were conducted using the excised teat model. In experiment 1, the differences in mastitis pathogen strain sensitivities to 4 commercially available dips (dip A: 1% H2O2; dip B: 1% chlorine dioxide; dip C: 1% iodophor; and dip D: 0.5% iodophor) were evaluated. Four strains of 11 common mastitis pathogens (Staphylococcus aureus, Streptococcus agalactiae, Mycoplasma bovis, Streptococcus dysgalactiae, Streptococcus uberis, Escherichia coli, Staphylococcus chromogenes, Staphylococcus epidermidis, Staphylococcus hyicus, Staphylococcus xylosus, and Staphylococcus haemolyticus) were tested. In experiment 2, the percentage log reduction of mastitis pathogens (Escherichia coli, Streptococcus uberis, Streptococcus dysgalactiae, Klebsiella species, Staphylococcus chromogenes, Staphylococcus haemolyticus, Staphylococcus xylosus, and Staphylococcus epidermidis) on teat skin with 3 commercially available teat dips: dip A; dip D; and dip E: 0.25% iodophor, using dip contact times of 15, 30, and 45 s, was evaluated. Experiment 1 results indicated significant differences in strain sensitivities to dips within pathogen species: Staphylococcus aureus, Staphylococcus chromogenes, and Streptococcus uberis. Species differences were also found where Mycoplasma bovis (97.9% log reduction) was the most sensitive to tested teat dips and Staphylococcus haemolyticus (71.4% log reduction) the most resistant. Experiment 2 results indicated that contact times of 30 and 45 s were equally effective in reducing recovered bacteria for dips D and E and were also significantly more effective than a 15-s contact time. No differences were seen in recovered bacteria between tested contact times after treatment with dip

  19. Stability with respect to initial time difference for generalized delay differential equations

    Directory of Open Access Journals (Sweden)

    Ravi Agarwal

    2015-02-01

    Full Text Available Stability with initial data difference for nonlinear delay differential equations is introduced. This type of stability generalizes the known concept of stability in the literature. It gives us the opportunity to compare the behavior of two nonzero solutions when both initial values and initial intervals are different. Several sufficient conditions for stability and for asymptotic stability with initial time difference are obtained. Lyapunov functions as well as comparison results for scalar ordinary differential equations are employed. Several examples are given to illustrate the theory.

  20. Perfectly Matched Layer for the Wave Equation Finite Difference Time Domain Method

    Science.gov (United States)

    Miyazaki, Yutaka; Tsuchiya, Takao

    2012-07-01

    The perfectly matched layer (PML) is introduced into the wave equation finite difference time domain (WE-FDTD) method. The WE-FDTD method is a finite difference method in which the wave equation is directly discretized on the basis of the central differences. The required memory of the WE-FDTD method is less than that of the standard FDTD method because no particle velocity is stored in the memory. In this study, the WE-FDTD method is first combined with the standard FDTD method. Then, Berenger's PML is combined with the WE-FDTD method. Some numerical demonstrations are given for the two- and three-dimensional sound fields.

  1. Compositional and Mechanical Properties of Peanuts Roasted to Equivalent Colors using Different Time/Temperature Combinations

    Science.gov (United States)

    Peanuts in North America and Europe are primarily consumed after dry roasting. Standard industry practice is to roast peanuts to a specific surface color (Hunter L-value) for a given application; however, equivalent surface colors can be attained using different roast temperature/time combinations,...

  2. The finite-difference time-domain method for electromagnetics with Matlab simulations

    CERN Document Server

    Elsherbeni, Atef Z

    2016-01-01

    This book introduces the powerful Finite-Difference Time-Domain method to students and interested researchers and readers. An effective introduction is accomplished using a step-by-step process that builds competence and confidence in developing complete working codes for the design and analysis of various antennas and microwave devices.

  3. A normalized difference vegetation index (NDVI) time-series of idle agriculture lands: A preliminary study

    NARCIS (Netherlands)

    Vaiphasa, C.; Piamduaytham, S.; Vaiphasa, T.; Skidmore, A.K.

    2011-01-01

    In this paper, the NDVI time-series collected from the study area between year 2003 and 2005 of all land cover types are plotted and compared. The study area is the agricultural zones in Banphai District, Khonkean, Thailand. The LANDSAT satellite images of different dates were first transformed into

  4. Age differences in the understanding of wealth and power: the mediating role of future time perspective.

    Science.gov (United States)

    Li, Tianyuan; Tsang, Vivian Hiu-Ling

    2016-12-01

    Individuals' understanding of wealth and power largely determines their use of resources. Moreover, the age range of wealth and power holders is increasing in modern societies. Thus, the current study examines how people of different ages understand wealth and power. As varying future time perspective is related to changes in prioritised life goals, it was tested as a potential mediator of the age differences. A total of 133 participants aged 18-78 years were asked 8 open-ended questions regarding their understanding of the possible use and desired use of wealth and power, after which they reported their future time perspective. Compared with possible use, the participants mentioned relatively more prosocial elements when they talked about their desired use of the resources, especially power. The older adults expressed more prosocial understanding in regard to the desired use of wealth and the possible use of power compared to their younger counterparts. The age differences were fully mediated by future time perspective. The results suggest that age is a critical factor that influences individuals' conceptualisation of wealth and power. Life-span developmental stage and future time perspective are important factors to consider for explaining individual differences in the exercise of wealth and power and for promoting their prosocial usage.

  5. Sex differences in the timing of identification among children and adults with autism spectrum disorders

    NARCIS (Netherlands)

    Begeer, S.; Mandell, S.; Wijnker-Holmes, B.; Venderbosch, S.; Rem, D.; Stekelenburg, F.; Koot, H.M.

    2013-01-01

    To examine differences by sex in the timing of identification of individuals with autism spectrum disorders (ASD), survey data were collected in the Netherlands from 2,275 males and females with autistic disorder, Asperger's syndrome and PDD-NOS. Among participants <18 years of age, females with

  6. Poor School Bonding and Delinquency over Time: Bidirectional Effects and Sex Differences

    Science.gov (United States)

    Liljeberg, Jenny Freidenfelt; Eklund, Jenny M.; Fritz, Marie Vafors; Klinteberg, Britt af

    2011-01-01

    The association between poor school bonding and delinquency has only been partly addressed in earlier research. Using a longitudinal design, the objective of our study was to investigate possible bidirectional effects and sex differences between adolescents' experienced school bonding and self-rated delinquency over time. A total of 788…

  7. Effect of different defoliants and application times on the yield and ...

    African Journals Online (AJOL)

    This study was conducted to determine the effect of different defoliants (Dropp ultra® (DU): thidiazuron+diuron and Roundup (RU): glyphosate) and application times [60, 75 and 90 days after flowering (DAF)] on cotton. The research was carried out at the Harran University, Faculty of Agriculture Research and Application ...

  8. Effects of harvesting time on some yield and quality traits of different ...

    African Journals Online (AJOL)

    The effect of harvesting time was investigated on yield and quality traits for spring season production in different maturing potato (Solanum tuberosum L.) cultivars under agro-climatic conditions of southern of Turkey in 2006 and 2007. The experimental layout was a randomized split plot with three replications, including six ...

  9. Television Time among Brazilian Adolescents: Correlated Factors are Different between Boys and Girls

    Directory of Open Access Journals (Sweden)

    Diego Augusto Santos Silva

    2014-01-01

    Full Text Available Objective. The aim of this study was to identify the prevalence of excess television time and verify correlated factors in adolescent males and females. Methods. This cross-sectional study included 2,105 adolescents aged from 13 to 18 years from the city of Aracaju, Northeastern Brazil. Television time was self-reported, corresponding to the time spent watching television in a typical week. Several correlates were examined including age, skin color, socioeconomic status, parent education, physical activity level, consumption of fruits and vegetables, smoking status, alcohol use, and sports team participation. Results. The prevalence excess television time (≥2 hours/day in girls and boys was 70.9% and 66.2%, respectively. Girls with low socioeconomic status or inadequate consumption of fruits and vegetables were more likely to have excess television time. Among boys, those >16 years of age or with black skin color were more likely to have excess television time. Conclusions. Excess television time was observed in more than two-thirds of adolescents, being more evident in girls. Correlated factors differed according to sex. Efforts to reduce television time among Brazilian adolescents, and replace with more active pursuits, may yield desirable public health benefits.

  10. Television time among Brazilian adolescents: correlated factors are different between boys and girls.

    Science.gov (United States)

    Silva, Diego Augusto Santos; Tremblay, Mark Stephen; Gonçalves, Eliane Cristina de Andrade; Silva, Roberto Jerônimo dos Santos

    2014-01-01

    The aim of this study was to identify the prevalence of excess television time and verify correlated factors in adolescent males and females. This cross-sectional study included 2,105 adolescents aged from 13 to 18 years from the city of Aracaju, Northeastern Brazil. Television time was self-reported, corresponding to the time spent watching television in a typical week. Several correlates were examined including age, skin color, socioeconomic status, parent education, physical activity level, consumption of fruits and vegetables, smoking status, alcohol use, and sports team participation. The prevalence excess television time (≥ 2 hours/day) in girls and boys was 70.9% and 66.2%, respectively. Girls with low socioeconomic status or inadequate consumption of fruits and vegetables were more likely to have excess television time. Among boys, those >16 years of age or with black skin color were more likely to have excess television time. Excess television time was observed in more than two-thirds of adolescents, being more evident in girls. Correlated factors differed according to sex. Efforts to reduce television time among Brazilian adolescents, and replace with more active pursuits, may yield desirable public health benefits.

  11. MODELING TIME DISPERSION DUE TO OPTICAL PATH LENGTH DIFFERENCES IN SCINTILLATION DETECTORS*

    Science.gov (United States)

    Moses, W.W.; Choong, W.-S.; Derenzo, S.E.

    2015-01-01

    We characterize the nature of the time dispersion in scintillation detectors caused by path length differences of the scintillation photons as they travel from their generation point to the photodetector. Using Monte Carlo simulation, we find that the initial portion of the distribution (which is the only portion that affects the timing resolution) can usually be modeled by an exponential decay. The peak amplitude and decay time depend both on the geometry of the crystal, the position within the crystal that the scintillation light originates from, and the surface finish. In a rectangular parallelpiped LSO crystal with 3 mm × 3 mm cross section and polished surfaces, the decay time ranges from 10 ps (for interactions 1 mm from the photodetector) up to 80 ps (for interactions 50 mm from the photodetector). Over that same range of distances, the peak amplitude ranges from 100% (defined as the peak amplitude for interactions 1 mm from the photodetector) down to 4% for interactions 50 mm from the photodetector. Higher values for the decay time are obtained for rough surfaces, but the exact value depends on the simulation details. Estimates for the decay time and peak amplitude can be made for different cross section sizes via simple scaling arguments. PMID:25729464

  12. Modelling a variable valve timing spark ignition engine using different neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Beham, M. [BMW AG, Munich (Germany); Yu, D.L. [John Moores University, Liverpool (United Kingdom). Control Systems Research Group

    2004-10-01

    In this paper different neural networks (NN) are compared for modelling a variable valve timing spark-ignition (VVT SI) engine. The overall system is divided for each output into five neural multi-input single output (MISO) subsystems. Three kinds of NN, multilayer Perceptron (MLP), pseudo-linear radial basis function (PLRBF), and local linear model tree (LOLIMOT) networks, are used to model each subsystem. Real data were collected when the engine was under different operating conditions and these data are used in training and validation of the developed neural models. The obtained models are finally tested in a real-time online model configuration on the test bench. The neural models run independently of the engine in parallel mode. The model outputs are compared with process output and compared among different models. These models performed well and can be used in the model-based engine control and optimization, and for hardware in the loop systems. (author)

  13. Electron and VLF travel time differences for wave-particle interactions at L=4: Pt. 2

    International Nuclear Information System (INIS)

    Rash, J.P.S.; Scourfield, M.W.J.; Dougherty, M.K.

    1984-01-01

    The cyclotron resonance or gyroresonance interaction has been widely invoked as a generation mechanism for discrete VLF emissions and plasmaspheric hiss. This interaction involves electrons and VLF waves travelling in opposite directions along a geomagnetic field line. We examine, for an interaction region in the equatorial plane at L=4, the energy of the resonant electrons as a function of VLF wave frequency and ambient equatorial electron density. Then for two different spatial configurations of the interaction and two standard plasma distribution models we examine the difference in travel times to a ground-based observer in the Southern hemisphere for the electrons and waves taking part in the interaction. This difference in travel times is shown as a function of VLF wave frequency and equatorial electron density. The results, and their significance for observations of auroral electrons and VLF at Sanae, Antarctica, are discussed and compared with similar results for the Cerenkov interaction discussed in an earlier paper

  14. Composition of essential oil of lemon thyme (Thymus × citriodorus) at different hydrodistillation times.

    Science.gov (United States)

    Jurevičiūtė, Rūta; Ložienė, Kristina; Bruno, Maurizio; Maggio, Antonella; Rosselli, Sergio

    2018-02-02

    Distillation time can both to optimise the production and to engineer the composition of essential oil in essential oil bearing plants. Purpose of this study was to evaluate the effect of duration of hydrodistillation on composition of essential oil of Thymus × citriodorus, the natural source of commercially important geraniol and citral, a component with valuable biological properties. Essential oils were isolated by hydrodistillation at different distillation times and analysed by GC/MS analytical methods. Increase in percentage of essential oil during all hydrodistillation time gradient was uneven. Elongation of hydrodistillation time decreased percentages of monoterpenes but increased percentages of sesquiterpenes in essential oil. Results showed that the hydrodistillation of essential oil from lemon thyme longer than 60 min is useless.

  15. Finite difference time domain solution of electromagnetic scattering on the hypercube

    International Nuclear Information System (INIS)

    Calalo, R.H.; Lyons, J.R.; Imbriale, W.A.

    1988-01-01

    Electromagnetic fields interacting with a dielectric or conducting structure produce scattered electromagnetic fields. To model the fields produced by complicated, volumetric structures, the finite difference time domain (FDTD) method employs an iterative solution to Maxwell's time dependent curl equations. Implementations of the FDTD method intensively use memory and perform numerous calculations per time step iteration. The authors have implemented an FDTD code on the California Institute of Technology/Jet Propulsion Laboratory Mark III Hypercube. This code allows to solve problems requiring as many as 2,048,000 unit cells on a 32 node Hypercube. For smaller problems, the code produces solutions in a fraction of the time to solve the same problems on sequential computers

  16. Comparison of Taxi Time Prediction Performance Using Different Taxi Speed Decision Trees

    Science.gov (United States)

    Lee, Hanbong

    2017-01-01

    In the STBO modeler and tactical surface scheduler for ATD-2 project, taxi speed decision trees are used to calculate the unimpeded taxi times of flights taxiing on the airport surface. The initial taxi speed values in these decision trees did not show good prediction accuracy of taxi times. Using the more recent, reliable surveillance data, new taxi speed values in ramp area and movement area were computed. Before integrating these values into the STBO system, we performed test runs using live data from Charlotte airport, with different taxi speed settings: 1) initial taxi speed values and 2) new ones. Taxi time prediction performance was evaluated by comparing various metrics. The results show that the new taxi speed decision trees can calculate the unimpeded taxi-out times more accurately.

  17. Differences in leisure-time activities according to level of physical activity in adolescents.

    Science.gov (United States)

    Mota, Jorge; Santos, Maria Paula; Ribeiro, Jose Carlos

    2008-03-01

    The main goals of this study were: (1) to examine the relationship between physical activity (PA) involvement and other leisure activities in a sample of Portuguese youth and (2) to analyze gender differences in PA and leisure-time activity structure. The sample comprised 1123 adolescents that were classified according to PA levels as active (n = 589) and nonactive (n = 534). A questionnaire assessing leisure-time activities was used. Girls were significantly more engaged in social leisure, dutiful, and individual artistic activities during leisure time, whereas boys were more involved in sports and computer and TV viewing activities. Significant associations between PA and social leisure were found in girls (r = .18, P leisure (girls: r = .56, P importance of organized and nonorganized sports/PA during leisure time for overall levels of PA in adolescents.

  18. Time delay induced different synchronization patterns in repulsively coupled chaotic oscillators

    Science.gov (United States)

    Yao, Chenggui; Yi, Ming; Shuai, Jianwei

    2013-09-01

    Time delayed coupling plays a crucial role in determining the system's dynamics. We here report that the time delay induces transition from the asynchronous state to the complete synchronization (CS) state in the repulsively coupled chaotic oscillators. In particular, by changing the coupling strength or time delay, various types of synchronous patterns, including CS, antiphase CS, antiphase synchronization (ANS), and phase synchronization, can be generated. In the transition regions between different synchronous patterns, bistable synchronous oscillators can be observed. Furthermore, we show that the time-delay-induced phase flip bifurcation is of key importance for the emergence of CS. All these findings may light on our understanding of neuronal synchronization and information processing in the brain.

  19. The Timing of the Circadian Clock and Sleep Differ between Napping and Non-Napping Toddlers.

    Science.gov (United States)

    Akacem, Lameese D; Simpkin, Charles T; Carskadon, Mary A; Wright, Kenneth P; Jenni, Oskar G; Achermann, Peter; LeBourgeois, Monique K

    2015-01-01

    The timing of the internal circadian clock shows large inter-individual variability across the lifespan. Although the sleep-wakefulness pattern of most toddlers includes an afternoon nap, the association between napping and circadian phase in early childhood remains unexplored. This study examined differences in circadian phase and sleep between napping and non-napping toddlers. Data were collected on 20 toddlers (34.2±2.0 months; 12 females; 15 nappers). Children followed their habitual napping and non-napping sleep schedules (monitored with actigraphy) for 5 days before an in-home salivary dim light melatonin onset (DLMO) assessment. On average, napping children fell asleep during their nap opportunities on 3.6±1.2 of the 5 days before the DLMO assessment. For these napping children, melatonin onset time was 38 min later (p = 0.044; d = 0.93), actigraphically-estimated bedtime was 43 min later (p = 0.014; d = 1.24), sleep onset time was 59 min later (p = 0.006; d = 1.46), and sleep onset latency was 16 min longer (p = 0.030; d = 1.03) than those not napping. Midsleep and wake time did not differ by napping status. No difference was observed in the bedtime, sleep onset, or midsleep phase relationships with DLMO; however, the wake time phase difference was 47 min smaller for napping toddlers (p = 0.029; d = 1.23). On average, nappers had 69 min shorter nighttime sleep durations (p = 0.006; d = 1.47) and spent 49 min less time in bed (p = 0.019; d = 1.16) than non-nappers. Number of days napping was correlated with melatonin onset time (r = 0.49; p = 0.014). Our findings indicate that napping influences individual variability in melatonin onset time in early childhood. The delayed bedtimes of napping toddlers likely permits light exposure later in the evening, thereby delaying the timing of the clock and sleep. Whether the early developmental trajectory of circadian phase involves an advance associated with the decline in napping is a question necessitating

  20. The Timing of the Circadian Clock and Sleep Differ between Napping and Non-Napping Toddlers.

    Directory of Open Access Journals (Sweden)

    Lameese D Akacem

    Full Text Available The timing of the internal circadian clock shows large inter-individual variability across the lifespan. Although the sleep-wakefulness pattern of most toddlers includes an afternoon nap, the association between napping and circadian phase in early childhood remains unexplored. This study examined differences in circadian phase and sleep between napping and non-napping toddlers. Data were collected on 20 toddlers (34.2±2.0 months; 12 females; 15 nappers. Children followed their habitual napping and non-napping sleep schedules (monitored with actigraphy for 5 days before an in-home salivary dim light melatonin onset (DLMO assessment. On average, napping children fell asleep during their nap opportunities on 3.6±1.2 of the 5 days before the DLMO assessment. For these napping children, melatonin onset time was 38 min later (p = 0.044; d = 0.93, actigraphically-estimated bedtime was 43 min later (p = 0.014; d = 1.24, sleep onset time was 59 min later (p = 0.006; d = 1.46, and sleep onset latency was 16 min longer (p = 0.030; d = 1.03 than those not napping. Midsleep and wake time did not differ by napping status. No difference was observed in the bedtime, sleep onset, or midsleep phase relationships with DLMO; however, the wake time phase difference was 47 min smaller for napping toddlers (p = 0.029; d = 1.23. On average, nappers had 69 min shorter nighttime sleep durations (p = 0.006; d = 1.47 and spent 49 min less time in bed (p = 0.019; d = 1.16 than non-nappers. Number of days napping was correlated with melatonin onset time (r = 0.49; p = 0.014. Our findings indicate that napping influences individual variability in melatonin onset time in early childhood. The delayed bedtimes of napping toddlers likely permits light exposure later in the evening, thereby delaying the timing of the clock and sleep. Whether the early developmental trajectory of circadian phase involves an advance associated with the decline in napping is a question

  1. Effects of stunning with different carbon dioxide concentrations and exposure times on suckling lamb meat quality.

    Science.gov (United States)

    Bórnez, R; Linares, M B; Vergara, H

    2009-03-01

    Forty-nine Manchega breed male suckling lambs were used to determine the effect of different stunning methods (using two different CO2 concentrations and exposure times) on lamb meat quality. The lambs were allocated to five stunning treatments including four CO2 treatments [80% CO2 for 90s (G1); 90% CO2 for 90s (G2); 90% CO2 for 60s (G3); 80% CO2 for 60s (G4)] and an electrically stunned control group (G5). The gas-stunning treatments did not cause neither haematomas nor blood splash in the carcasses. Meat quality was evaluated by testing pH, colour (L(∗), a(∗), b(∗), chroma, hue values), water holding capacity (WHC), cooking loss (CL), shear force (SF), drip loss (DL) and total aerobic bacteria. Statistical differences in pH at 24h post-mortem, colour, WHC and CL were not found among groups. After 7 days post-mortem, there were statistical differences among groups in pH (highest in G4 and G5) and in DL (highest in G1). There were differences in SF due to stunning method evident after 72h and 7 days ageing. The statistical differences (Plambs since a highest stability with ageing time on meat quality was found using 90% CO2.

  2. Seismic wavefield modeling based on time-domain symplectic and Fourier finite-difference method

    Science.gov (United States)

    Fang, Gang; Ba, Jing; Liu, Xin-xin; Zhu, Kun; Liu, Guo-Chang

    2017-06-01

    Seismic wavefield modeling is important for improving seismic data processing and interpretation. Calculations of wavefield propagation are sometimes not stable when forward modeling of seismic wave uses large time steps for long times. Based on the Hamiltonian expression of the acoustic wave equation, we propose a structure-preserving method for seismic wavefield modeling by applying the symplectic finite-difference method on time grids and the Fourier finite-difference method on space grids to solve the acoustic wave equation. The proposed method is called the symplectic Fourier finite-difference (symplectic FFD) method, and offers high computational accuracy and improves the computational stability. Using acoustic approximation, we extend the method to anisotropic media. We discuss the calculations in the symplectic FFD method for seismic wavefield modeling of isotropic and anisotropic media, and use the BP salt model and BP TTI model to test the proposed method. The numerical examples suggest that the proposed method can be used in seismic modeling of strongly variable velocities, offering high computational accuracy and low numerical dispersion. The symplectic FFD method overcomes the residual qSV wave of seismic modeling in anisotropic media and maintains the stability of the wavefield propagation for large time steps.

  3. Snacking now or later? Individual differences in following intentions or habits explained by time perspective.

    Science.gov (United States)

    Onwezen, M C; Van 't Riet, J; Dagevos, H; Sijtsema, S J; Snoek, H M

    2016-12-01

    Even when individuals are aware of long-term health effects of their diet, and form healthy intentions, they often engage in relatively unhealthy snacking habits. Some individuals fall back on unhealthy habits more easily than others. We aim to explore whether time perspective can explain why some individuals are more prone to rely on habits and others on intentions. Study 1 (N = 1503) provides a first exploration of the role of time perspective by exploring individual differences in perception of long-term and short-term consequences. In accordance with our hypotheses, Study 1 shows that habits are associated with short-term consequences and intentions with long-term consequences. Study 2 (N = 1497) shows that the effects of habits on snacking behaviour are strengthened by a present time perspective, whereas the effects of intentions on snacking behaviour are strengthened by a future time perspective. These findings imply that there is a fundamental difference in the guiding function of intentions and habits which might explain individual differences in following intentions versus habits. Individuals with a long-term perspective are more inclined to follow intentions and individuals with a short-term perspective are more inclined to follow habits. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Numerical simulation of homogenization time measurement by probes with different volume size

    International Nuclear Information System (INIS)

    Thyn, J.; Novy, M.; Zitny, R.; Mostek, M.; Jahoda, M.

    2004-01-01

    Results of continuous homogenization time measurement of liquid in a stirred tank depend on the scale of scrutiny. Experimental techniques use a probe, which is situated inside as a conductivity method, or outside of the tank as in the case of gamma-radiotracer methods. Expected value of homogenization time evaluated for a given degree of homogenization is higher when using the conductivity method because the conductivity probe measures relatively small volume in contrast to application of radiotracer, when the volume is much greater. Measurement through the wall of tank is a great advantage of radiotracer application but a comparison of the results with another method supposes a determination of measured volume, which is not easy. Simulation of measurement by CFD code can help to solve the problem. Methodology for CFD simulation of radiotracer experiments was suggested. Commercial software was used for simulation of liquid homogenization in mixed vessel with Rushton turbine. Numerical simulation of liquid homogenization time by CFD for different values of detected volume was confronted with measurement of homogenization time with conductivity probe and with different radioisotopes 198 Au, 82 Br and 24 Na. Detected size of the tank volume was affected by different energy of radioisotope used. (author)

  5. Microbubble responses to a similar mechanical index with different real-time perfusion imaging techniques.

    Science.gov (United States)

    Porter, Thomas R; Oberdorfer, Joseph; Rafter, Patrick; Lof, John; Xie, Feng

    2003-08-01

    The purpose of this study was to determine differences in contrast enhancement and microbubble destruction rates with current commercially available low-mechanical index (MI) real-time perfusion imaging modalities. A tissue-mimicking phantom was developed that had vessels at 3 cm (near field) and 9 cm (far field) from a real-time transducer. Perfluorocarbon-exposed sonicated dextrose albumin microbubbles (PESDA) were injected proximal to a mixing chamber, and then passed through these vessels while the region was insonified with either pulses of alternating polarity with pulse inversion Doppler (PID) or pulses of alternating amplitude by power modulation (PM) at MIs of 0.1, 0.2 and 0.3. Effluent microbubble concentration, contrast intensity and the slope of digital contrast intensity vs. time were measured. Our results demonstrated that microbubble destruction already occurs with PID at an MI of 0.1. Contrast intensity seen with PID was less than with PM. Therefore, differences in contrast enhancement and microbubble destruction rates occur at a similar MI setting when using different real-time pulse sequence schemes.

  6. Residence times and alluvial architecture of a sediment superslug in response to different flow regimes

    Science.gov (United States)

    Moody, John A.

    2017-01-01

    A superslug was deposited in a basin in the Colorado Front Range Mountains as a consequence of an extreme flood following a wildfire disturbance in 1996. The subsequent evolution of this superslug was measured by repeat topographic surveys (31 surveys from 1996 through 2014) of 18 cross sections approximately uniformly spaced over 1500 m immediately above the basin outlet. These surveys allowed the identification within the superslug of chronostratigraphic units deposited and eroded by different geomorphic processes in response to different flow regimes.Over the time period of the study, the superslug went through aggradation, incision, and stabilization phases that were controlled by a shift in geomorphic processes from generally short-duration, episodic, large-magnitude floods that deposited new chronostratigraphic units to long-duration processes that eroded units. These phases were not contemporaneous at each channel cross section, which resulted in a complex response that preserved different chronostratigraphic units at each channel cross section having, in general, two dominant types of alluvial architecture—laminar and fragmented. Age and transit-time distributions for these two alluvial architectures evolved with time since the extreme flood. Because of the complex shape of the distributions they were best modeled by two-parameter Weibull functions. The Weibull scale parameter approximated the median age of the distributions, and the Weibull shape parameter generally had a linear relation that increased with time since the extreme flood. Additional results indicated that deposition of new chronostratigraphic units can be represented by a power-law frequency distribution, and that the erosion of units decreases with depth of burial to a limiting depth. These relations can be used to model other situations with different flow regimes where vertical aggradation and incision are dominant processes, to predict the residence time of possible contaminated

  7. Residence times and alluvial architecture of a sediment superslug in response to different flow regimes

    Science.gov (United States)

    Moody, John A.

    2017-10-01

    A superslug was deposited in a basin in the Colorado Front Range Mountains as a consequence of an extreme flood following a wildfire disturbance in 1996. The subsequent evolution of this superslug was measured by repeat topographic surveys (31 surveys from 1996 through 2014) of 18 cross sections approximately uniformly spaced over 1500 m immediately above the basin outlet. These surveys allowed the identification within the superslug of chronostratigraphic units deposited and eroded by different geomorphic processes in response to different flow regimes. Over the time period of the study, the superslug went through aggradation, incision, and stabilization phases that were controlled by a shift in geomorphic processes from generally short-duration, episodic, large-magnitude floods that deposited new chronostratigraphic units to long-duration processes that eroded units. These phases were not contemporaneous at each channel cross section, which resulted in a complex response that preserved different chronostratigraphic units at each channel cross section having, in general, two dominant types of alluvial architecture-laminar and fragmented. Age and transit-time distributions for these two alluvial architectures evolved with time since the extreme flood. Because of the complex shape of the distributions they were best modeled by two-parameter Weibull functions. The Weibull scale parameter approximated the median age of the distributions, and the Weibull shape parameter generally had a linear relation that increased with time since the extreme flood. Additional results indicated that deposition of new chronostratigraphic units can be represented by a power-law frequency distribution, and that the erosion of units decreases with depth of burial to a limiting depth. These relations can be used to model other situations with different flow regimes where vertical aggradation and incision are dominant processes, to predict the residence time of possible contaminated

  8. Striatal lesions produce distinctive impairments in reaction time performance in two different operant chambers.

    Science.gov (United States)

    Brasted, P J; Döbrössy, M D; Robbins, T W; Dunnett, S B

    1998-08-01

    The dorsal striatum plays a crucial role in mediating voluntary movement. Excitotoxic striatal lesions in rats have previously been shown to impair the initiation but not the execution of movement in a choice reaction time task in an automated lateralised nose-poke apparatus (the "nine-hole box"). Conversely, when a conceptually similar reaction time task has been applied in a conventional operant chamber (or "Skinner box"), striatal lesions have been seen to impair the execution rather than the initiation of the lateralised movement. The present study was undertaken to compare directly these two results by training the same group of rats to perform a choice reaction time task in the two chambers and then comparing the effects of a unilateral excitotoxic striatal lesion in both chambers in parallel. Particular attention was paid to adopting similar parameters and contingencies in the control of the task in the two test chambers. After striatal lesions, the rats showed predominantly contralateral impairments in both tasks. However, they showed a deficit in reaction time in the nine-hole box but an apparent deficit in response execution in the Skinner box. This finding confirms the previous studies and indicates that differences in outcome are not simply attributable to procedural differences in the lesions, training conditions or tasks parameters. Rather, the pattern of reaction time deficit after striatal lesions depends critically on the apparatus used and the precise response requirements for each task.

  9. Nitrogen fertilization in irrigated common bean at different times, with and without dose division

    Directory of Open Access Journals (Sweden)

    Danilo Pereira Ramos

    2014-03-01

    Full Text Available This article aims to evaluate the effect of nitrogen fertilization at different times on the agronomic characteristics of common bean cultivars, within the intercrop period. An experiment was installed in the town of Gurupi, Tocantins, Brazil, with randomized blocks, under a 3 x 5 factorial scheme, consisting of 3 cultivars and 5 nitrogen application times, with 4 repetitions. We evaluated the cultivars IAC Alvorada, IPR Juriti, and BRS Requinte. Regarding nitrogen fertilization, we evaluated 5 times, the first corresponding to control (E1 = N zero and the others applying 100 kg.ha-1 of nitrogen, using urea as their source, as follows: E2 = 100% of N applied at sowing; E3 = 100% of N applied 25 days after emergence (DAE; E4 = 50% of N applied 20 DAE and 50% 30 DAE; E5 = 33% of N applied 15 DAE, 33% 25 DAE, and 33% 35 DAE. There was genetic variability among cultivars with regard to response, as well as differences between nitrogen fertilization times. The cultivars IAC Alvorada and IPR Juriti obtained higher grain yields. The nitrogen application time divided into 15, 25 and 35 DAE enabled a higher grain yield for the cultivars IAC Alvorada and IPR Juriti.

  10. Chinese and Australians showed difference in mental time travel in emotion and content but not specificity

    Directory of Open Access Journals (Sweden)

    Xing-jie eChen

    2015-06-01

    Full Text Available Mental time travel refers to the ability to recall episodic past and imagine future events. The present study aimed to investigate cultural differences in mental time travel between Chinese and Australian university students. A total of 231 students (108 Chinese & 123 Australians participated in the study. Their mental time travel abilities were measured by the Sentence Completion for Events from the Past Test (SCEPT and the Sentence Completion for Events in the Future Test (SCEFT. Results showed that there were no cultural differences in the number of specific events generated for the past or future. Significant differences between the Chinese and Australian participants were found mainly in the emotional valence and content of the events generated. Both Chinese and Australian participants generated more specific positive events compared to negative events when thinking about the future and Chinese participants were more positive about their past than Australian participants when recalled specific events. For content, Chinese participants recalled more events about their interpersonal relationships, while Australian participants imagined more about personal future achievements. These findings shed some lights on cultural differences in episodic past and future thinking.

  11. A real time chemotaxis assay unveils unique migratory profiles amongst different primary murine macrophages.

    Directory of Open Access Journals (Sweden)

    Asif J Iqbal

    Full Text Available Chemotaxis assays are an invaluable tool for studying the biological activity of inflammatory mediators such as CC chemokines, which have been implicated in a wide range of chronic inflammatory diseases. Conventional chemotaxis systems such as the modified Boyden chamber are limited in terms of the data captured given that the assays are analysed at a single time-point. We report the optimisation and validation of a label-free, real-time cell migration assay based on electrical cell impedance to measure chemotaxis of different primary murine macrophage populations in response to a range of CC chemokines and other chemoattractant signalling molecules. We clearly demonstrate key differences in the migratory behavior of different murine macrophage populations and show that this dynamic system measures true macrophage chemotaxis rather than chemokinesis or fugetaxis. We highlight an absolute requirement for Gαi signaling and actin cytoskeletal rearrangement as demonstrated by Pertussis toxin and cytochalasin D inhibition. We also studied the chemotaxis of CD14(+ human monocytes and demonstrate distinct chemotactic profiles amongst different monocyte donors to CCL2. This real-time chemotaxis assay will allow a detailed analysis of factors that regulate macrophage responses to chemoattractant cytokines and inflammatory mediators.

  12. A Real Time Chemotaxis Assay Unveils Unique Migratory Profiles amongst Different Primary Murine Macrophages

    Science.gov (United States)

    Iqbal, Asif J.; Regan-Komito, Daniel; Christou, Ivy; White, Gemma E.; McNeill, Eileen; Kenyon, Amy; Taylor, Lewis; Kapellos, Theodore S.; Fisher, Edward A.; Channon, Keith M.; Greaves, David R.

    2013-01-01

    Chemotaxis assays are an invaluable tool for studying the biological activity of inflammatory mediators such as CC chemokines, which have been implicated in a wide range of chronic inflammatory diseases. Conventional chemotaxis systems such as the modified Boyden chamber are limited in terms of the data captured given that the assays are analysed at a single time-point. We report the optimisation and validation of a label-free, real-time cell migration assay based on electrical cell impedance to measure chemotaxis of different primary murine macrophage populations in response to a range of CC chemokines and other chemoattractant signalling molecules. We clearly demonstrate key differences in the migratory behavior of different murine macrophage populations and show that this dynamic system measures true macrophage chemotaxis rather than chemokinesis or fugetaxis. We highlight an absolute requirement for Gαi signaling and actin cytoskeletal rearrangement as demonstrated by Pertussis toxin and cytochalasin D inhibition. We also studied the chemotaxis of CD14+ human monocytes and demonstrate distinct chemotactic profiles amongst different monocyte donors to CCL2. This real-time chemotaxis assay will allow a detailed analysis of factors that regulate macrophage responses to chemoattractant cytokines and inflammatory mediators. PMID:23516549

  13. Differences in ground contact time explain the less efficient running economy in north african runners.

    Science.gov (United States)

    Santos-Concejero, J; Granados, C; Irazusta, J; Bidaurrazaga-Letona, I; Zabala-Lili, J; Tam, N; Gil, S M

    2013-09-01

    The purpose of this study was to investigate the relationship between biomechanical variables and running economy in North African and European runners. Eight North African and 13 European male runners of the same athletic level ran 4-minute stages on a treadmill at varying set velocities. During the test, biomechanical variables such as ground contact time, swing time, stride length, stride frequency, stride angle and the different sub-phases of ground contact were recorded using an optical measurement system. Additionally, oxygen uptake was measured to calculate running economy. The European runners were more economical than the North African runners at 19.5 km · h(-1), presented lower ground contact time at 18 km · h(-1) and 19.5 km · h(-1) and experienced later propulsion sub-phase at 10.5 km · h(-1),12 km · h(-1), 15 km · h(-1), 16.5 km · h(-1) and 19.5 km · h(-1) than the European runners (P Running economy at 19.5 km · h(-1) was negatively correlated with swing time (r = -0.53) and stride angle (r = -0.52), whereas it was positively correlated with ground contact time (r = 0.53). Within the constraints of extrapolating these findings, the less efficient running economy in North African runners may imply that their outstanding performance at international athletic events appears not to be linked to running efficiency. Further, the differences in metabolic demand seem to be associated with differing biomechanical characteristics during ground contact, including longer contact times.

  14. Evaluation of different time schedules in training with the Da Vinci simulator.

    Science.gov (United States)

    Güldner, C; Orth, A; Dworschak, P; Diogo, I; Mandapathil, M; Teymoortash, A; Walliczek-Dworschak, U

    2017-10-01

    This prospective study analyzed the effect of different time schedules in training on the main performance outcomes: overall score, time to complete, and economy of motion. The study was performed on the da Vinci Skills Simulator from December 2014 to April 2016. Forty robotic novices were randomized into two groups of 20 participants, which trained in the same three exercises but with different intervals between their training sessions. Each group performed training in Peg Board 1 in their first week, Match Board 2 in their second week, and Ring and Rail 2 in their third week. On their last day, Needle Targeting and Energy Dissection 2, for which no previous training had been received, were performed. Regarding the different training intervals, group 1 trained each exercise six times in a row once a week. Group 2 performed their training once a day for 5 days. Technical performance parameters were recorded by the Mimics simulator software for further analysis. In addition, the participants were asked to fill out a questionnaire concerning the robotics training. Group 2 performed significantly better compared to group 1 in the main metrics in the more advanced exercises. For the easier exercises, the training frequency did not lead to significant differences in performance outcome. A significant skills gain was seen between the first and last training sessions for all exercises in both groups. Performance in the final exercise NT was significantly better in group 2 than group 1. Regarding ED 2, no difference was found between the two groups. As the training of group 2 led to significantly better outcomes, we suggest that, especially for advanced exercises, it seems to be more favorable to perform training every day for a short period than to train once a week six times in a row.

  15. Analysis of oscillational instabilities in acoustic levitation using the finite-difference time-domain method

    DEFF Research Database (Denmark)

    Santillan, Arturo Orozco

    2011-01-01

    The aim of the work described in this paper has been to investigate the use of the finite-difference time-domain method to describe the interactions between a moving object and a sound field. The main objective was to simulate oscillational instabilities that appear in single-axis acoustic...... levitation devices and to describe their evolution in time to further understand the physical mechanism involved. The study shows that the method gives accurate results for steady state conditions, and that it is a promising tool for simulations with a moving object....

  16. Performance evaluation of the short-time objective intelligibility measure with different band importance functions

    DEFF Research Database (Denmark)

    Heidemann Andersen, Asger; de Haan, Jan Mark; Tan, Zheng-Hua

    performance measures: root-mean-squared-error, Pearson correlation, and Kendall rank correlation. The results show substantially improved performance when fitting and evaluating on the same dataset. However, this advantage does not necessarily subsist when fitting and evaluating on different datasets. When...... with a filter bank, 2) envelopes are extracted from each band, 3) the temporal correlation between clean and degraded envelopes is computed in short time segments, and 4) the correlation is averaged across time and frequency bands to obtain the final output. An unusual choice in the design of the STOI measure...

  17. Finite difference time domain modeling of light matter interaction in light-propelled microtools

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Palima, Darwin; Aabo, Thomas

    2013-01-01

    save time as it helps optimize the structures prior to fabrication and experiments. In addition to field distributions, optical forces can also be obtained using the Maxwell stress tensor formulation. By calculating the forces on bent waveguides subjected to tailored static light distributions, we...... may trigger highly localized non linear processes in the surface of a cell. Since these functionalities are strongly dependent on design, it is important to use models that can handle complexities and take in little simplifying assumptions about the system. Hence, we use the finite difference time...

  18. Time-dependent Perpendicular Transport of Energetic Particles for Different Turbulence Configurations and Parallel Transport Models

    Energy Technology Data Exchange (ETDEWEB)

    Lasuik, J.; Shalchi, A., E-mail: andreasm4@yahoo.com [Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada)

    2017-09-20

    Recently, a new theory for the transport of energetic particles across a mean magnetic field was presented. Compared to other nonlinear theories the new approach has the advantage that it provides a full time-dependent description of the transport. Furthermore, a diffusion approximation is no longer part of that theory. The purpose of this paper is to combine this new approach with a time-dependent model for parallel transport and different turbulence configurations in order to explore the parameter regimes for which we get ballistic transport, compound subdiffusion, and normal Markovian diffusion.

  19. Measurement of the Retention Time of Different Ophthalmic Formulations with Ultrahigh-Resolution Optical Coherence Tomography.

    Science.gov (United States)

    Gagliano, Caterina; Papa, Vincenzo; Amato, Roberta; Malaguarnera, Giulia; Avitabile, Teresio

    2018-04-01

    Purpose/aim of the study: The purpose of this study was to measure the pre-corneal retention time of two marketed formulations (eye drops and eye gel) of a steroid-antibiotic fixed combination (FC) containing 0.1% dexamethasone and 0.3% netilmicin. Pre-corneal retention time was evaluated in 16 healthy subjects using an ultrahigh-resolution anterior segment spectral domain optical coherence tomography (OCT). All subjects randomly received both formulations of the FC (Netildex, SIFI, Italy). Central tear film thickness (CTFT) was measured before instillation (time 0) and then after 1, 10, 20, 30, 40 50, 60 and 120 min. The pre-corneal retention time was calculated by plotting CTFT as a function of time. Differences between time points and groups were analyzed by Student's t-test. CTFT increased significantly after the instillation of the eye gel formulation (p < 0.001). CTFT reached its maximum value 1 min after instillation and returned to baseline after 60 min. No effect on CTFT was observed after the instillation of eye drops. The difference between the two formulations was statistically significant at time 1 min (p < 0.0001), 10 min (p < 0.001) and 20 min (p < 0.01). The FC formulated as eye gel was retained on the ocular surface longer than the corresponding eye drop solution. Consequently, the use of the eye gel might extend the interval between instillations and decrease the frequency of administration.

  20. High luminescent L-cysteine capped CdTe quantum dots prepared at different reaction times

    Science.gov (United States)

    Kiprotich, Sharon; Onani, Martin O.; Dejene, Francis B.

    2018-04-01

    This paper reports a facile synthesis route of high luminescent L-cysteine capped CdTe quantum dots (QDs). The effect of reaction time on the growth mechanism, optical and physical properties of the CdTe QDs was investigated in order to find the suitability of them towards optical and medical applications. The representative high-resolution transmission microscopy (HRTEM) analysis showed that the as-obtained CdTe QDs appeared as spherical particles with excellent monodispersity. The images exhibited clear lattice fringes which are indicative of good crystallinity. The X-ray diffraction (XRD) pattern displayed polycrystalline nature of the QDs which correspond well to zinc blende phase of bulk CdTe. The crystallite sizes calculated from the Scherrer equation were less than 10 nm for different reaction times which were in close agreement with the values estimated from HRTEM. An increase in reaction time improved crystallinity of the sample as explained by highest peak intensity of the XRD supported by the photoluminescence emission spectra which showed high intensity at a longer growth time. It was observed that for prolonged growth time the emission bands were red shifted from about 517-557 nm for 5-180 min of reaction time due to increase in particle sizes. Ultraviolet and visible analysis displayed well-resolved absorption bands which were red shifted upon an increase in reaction time. There was an inverse relation between the band gap and reaction time. Optical band gap decreases from 3.98 to 2.59 eV with the increase in reaction time from 15 to 180 min.

  1. Cost minimization analysis of different growth hormone pen devices based on time-and-motion simulations

    Directory of Open Access Journals (Sweden)

    Kim Jaewhan

    2010-04-01

    Full Text Available Abstract Background Numerous pen devices are available to administer recombinant Human Growth Hormone (rhGH, and both patients and health plans have varying issues to consider when selecting a particular product and device for daily use. Therefore, the present study utilized multi-dimensional product analysis to assess potential time involvement, required weekly administration steps, and utilization costs relative to daily rhGH administration. Methods Study objectives were to conduct 1 Time-and-Motion (TM simulations in a randomized block design that allowed time and steps comparisons related to rhGH preparation, administration and storage, and 2 a Cost Minimization Analysis (CMA relative to opportunity and supply costs. Nurses naïve to rhGH administration and devices were recruited to evaluate four rhGH pen devices (2 in liquid form, 2 requiring reconstitution via TM simulations. Five videotaped and timed trials for each product were evaluated based on: 1 Learning (initial use instructions, 2 Preparation (arrange device for use, 3 Administration (actual simulation manikin injection, and 4 Storage (maintain product viability between doses, in addition to assessment of steps required for weekly use. The CMA applied micro-costing techniques related to opportunity costs for caregivers (categorized as wages, non-drug medical supplies, and drug product costs. Results Norditropin® NordiFlex and Norditropin® NordiPen (NNF and NNP, Novo Nordisk, Inc., Bagsværd, Denmark took less weekly Total Time (p ® Pen (GTP, Pfizer, Inc, New York, New York or HumatroPen® (HTP, Eli Lilly and Company, Indianapolis, Indiana. Time savings were directly related to differences in new package Preparation times (NNF (1.35 minutes, NNP (2.48 minutes GTP (4.11 minutes, HTP (8.64 minutes, p Conclusions Time-and-motion simulation data used to support a micro-cost analysis demonstrated that the pen device with the greater time demand has highest net costs.

  2. Generalized Projective Synchronization between Two Different Neural Networks with Mixed Time Delays

    Directory of Open Access Journals (Sweden)

    Xuefei Wu

    2012-01-01

    Full Text Available The generalized projective synchronization (GPS between two different neural networks with nonlinear coupling and mixed time delays is considered. Several kinds of nonlinear feedback controllers are designed to achieve GPS between two different such neural networks. Some results for GPS of these neural networks are proved theoretically by using the Lyapunov stability theory and the LaSalle invariance principle. Moreover, by comparison, we determine an optimal nonlinear controller from several ones and provide an adaptive update law for it. Computer simulations are provided to show the effectiveness and feasibility of the proposed methods.

  3. Individual Differences and Time-Sharing Ability: A Critical Review and Analysis.

    Science.gov (United States)

    1982-03-01

    the mythical innkeeper for which it is named. The paradigm involves the following steps: I) The user chooses a factor solution of interest as a "target...A) L L(T) L(C) LL L(A) A ACT ) A(C) Individual Differences and Time-Sharing Abilities Page 41 TABLE 21: LATENT ROOT PARALLEL A’ALYSIS -- DIFFERENCE...753 10 C(A) .350 11 L .711 12 L(T) .399 13 L(C) .650 14 LL .740 15 L(A) .521 16 A .504 17 ACT ) .489 18 A(C) .559 19 A(L) .545 7. FIGURE 1. LATENT

  4. Separating timing, movement conditions and individual differences in the analysis of human movement

    DEFF Research Database (Denmark)

    Raket, Lars Lau; Grimme, Britta; Schöner, Gregor

    2016-01-01

    mixed-effects models as viable alternatives to conventional analysis frameworks. The model is then combined with a novel factor-analysis model that estimates the low-dimensional subspace within which movements vary when the task demands vary. Our framework enables us to visualize different dimensions......A central task in the analysis of human movement behavior is to determine systematic patterns and differences across experimental conditions, participants and repetitions. This is possible because human movement is highly regular, being constrained by invariance principles. Movement timing...

  5. The impact of different prioritisation policies on waiting times: case studies of Norway and Scotland.

    Science.gov (United States)

    Januleviciute, Jurgita; Askildsen, Jan Erik; Kaarboe, Oddvar; Holmås, Tor Helge; Sutton, Matt

    2013-11-01

    We investigate the distributional consequences of two different waiting times initiatives, one in Norway, and one in Scotland. The primary focus of Scotland's recent waiting time reforms, introduced in 2003, and modified in 2005 and 2007, has been on reducing maximum waiting times through the imposition of high profile national targets accompanied by increases in resources. In Norway, the focus of the reform introduced in September 2004, has been on assigning patients referred to hospital a maximum waiting time based on disease severity, the expected benefit and the cost-effectiveness of the treatment. We use large, national administrative datasets from before and after each of these reforms and assign priority groups based on the maximum waiting times stipulated in medical guidelines. The analysis shows that the lowest priority patients benefited most from both reforms. This was at the cost of longer waiting times for patients that should have been given higher priority in Norway, while Scotland's high priority patients remained unaffected. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Time Prospects and Migratory Attitudes of Magadan Students at Different Stages of Education

    Directory of Open Access Journals (Sweden)

    Снежана Анатольевна Кузнецова

    2018-12-01

    Full Text Available The relevance of the study is due to the insufficient knowledge of the influence of conditions the migration-mobile region on the formation of time perspectives for young people. The purpose was to study the correlation of time perspectives and migration attitudes of Magadan students at different stages of education. Methods: a questionnaire for studying the time perspectives of ZPTI F. Zimbardo in the adaptation of A. Syrtsova and the “Scale of Migratory Personality Attitudes”, based on the author’s concept of migration attitudes. Conclusions: the study showed that as learning in the university decreases the role of assessing the past in the territorial self-determination of Magadan students and the role of satisfaction/dissatisfaction with the present increases. The younger students, satisfied with the past, are more committed to the place of residence, and the students of the senior courses are satisfied with the present. The dual role of meaningful people in forming the time perspectives of the undergraduates is revealed: expectations from relatives and support for the student’s migratory attitudes open up a future time perspectives for him, and vice versa, the absence of such leads to frustration, a sense of hopelessness described in the terminology of ZPTI as a “fatalistic present”. The lack of a link between their own migration attitudes and the time perspectives of the future means that some of the purposeful students connect their perspectives with the actual place of residence, some with a possible move.

  7. Real-time reflectance-difference spectroscopy of GaAs molecular beam epitaxy homoepitaxial growth

    Energy Technology Data Exchange (ETDEWEB)

    Lastras-Martínez, A., E-mail: alm@cactus.iico.uaslp.mx, E-mail: alastras@gmail.com; Ortega-Gallegos, J.; Guevara-Macías, L. E.; Nuñez-Olvera, O.; Balderas-Navarro, R. E.; Lastras-Martínez, L. F. [Instituto de Investigación en Comunicación Optica, Universidad Autónoma de San Luis Potosí, Alvaro Obregón 64, San Luis Potosí, SLP 78000 (Mexico); Lastras-Montaño, L. A. [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Lastras-Montaño, M. A. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, California 93106 (United States)

    2014-03-01

    We report on real time-resolved Reflectance-difference (RD) spectroscopy of GaAs(001) grown by molecular beam epitaxy, with a time-resolution of 500 ms per spectrum within the 2.3–4.0 eV photon energy range. Through the analysis of transient RD spectra we demonstrated that RD line shapes are comprised of two components with different physical origins and determined their evolution during growth. Such components were ascribed to the subsurface strain induced by surface reconstruction and to surface stoichiometry. Results reported in this paper render RD spectroscopy as a powerful tool for the study of fundamental processes during the epitaxial growth of zincblende semiconductors.

  8. Reaction time inconsistency in a spatial stroop task: age-related differences through childhood and adulthood.

    Science.gov (United States)

    Williams, Benjamin R; Strauss, Esther H; Hultsch, David F; Hunter, Michael A

    2007-07-01

    Age-related differences in inconsistency of reaction time (RT) across the life span were examined on a task with differing levels of demand on executive control. A total of 546 participants, aged 5 to 76 years, completed a spatial Stroop task that permitted observations under three conditions (congruent, incongruent, and neutral) according to the correspondence between the required response (based on stimulus direction) and stimulus location. An interference effect was observed across all ages. Analyses of neutral condition data replicated previous research demonstrating RT inconsistency follows a U-shaped developmental curve across the life span. The relationship between age and inconsistency, however, depended on condition: inconsistency in the congruent condition was higher than inconsistency in both the neutral and incongruent conditions across middle-aged groups. Reaction time inconsistency may reflect processing efficiency that is maximal in young adulthood and may also be sensitive to fluctuations in performance that reflect momentarily highly efficient responding.

  9. Real-time reflectance-difference spectroscopy of GaAs molecular beam epitaxy homoepitaxial growth

    Directory of Open Access Journals (Sweden)

    A. Lastras-Martínez

    2014-03-01

    Full Text Available We report on real time-resolved Reflectance-difference (RD spectroscopy of GaAs(001 grown by molecular beam epitaxy, with a time-resolution of 500 ms per spectrum within the 2.3–4.0 eV photon energy range. Through the analysis of transient RD spectra we demonstrated that RD line shapes are comprised of two components with different physical origins and determined their evolution during growth. Such components were ascribed to the subsurface strain induced by surface reconstruction and to surface stoichiometry. Results reported in this paper render RD spectroscopy as a powerful tool for the study of fundamental processes during the epitaxial growth of zincblende semiconductors.

  10. Decay Time Measurement for Different Energy Depositions of Plastic Scintillator Fabricated by High Temperature Polymerization Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Cheol Ho; Son, Jaebum; Lee, Sangmin; Kim, Tae Hoon; Kim, Yong-Kyun [Hanyang University, Seoul (Korea, Republic of)

    2016-10-15

    Plastic scintillators are based on organic fluorite. They have many advantages such as fast rise and decay time, high optical transmission, ease of manufacturing, low cost, and large available size. For these reasons they are widely used for particle identification. Also, protection of people against a variety of threats (such as nuclear, radiological, and explosive) represents a true challenge along with the continuing development of science and technology. The plastic scintillator is widely used in various devise, which serves for nuclear, photonics, quantum, and high-energy physics. The plastic scintillator is probably the most widely used organic detector, and polystyrene is one of the most widely used materials in the making of the plastic scintillator detector. Thus, a styrene monomer as a solvent was used to fabricate the plastic scintillator by using high temperature polymerization reaction, and then the emission wavelength and the decay times for different energy depositions were measured by using the fabricated plastic scintillator. A plastic scintillator was fabricated to measure decay time for different energy depositions using the high temperature polymerization. Emission wavelength was measured of 426.05 nm to confirm a scintillator property using the spectrophotometer. Four gamma-ray sources (Cs-137, Co-60, Na-22, and Ba-133) were used to evaluate effect for decay time of different energy depositions. The average decay time of the fabricated plastic scintillator was measured to approximately 4.72 ns slightly higher more than commercial plastic scintillator. In future, light output and linearity will be measured to evaluate other property compared with the commercial scintillator.

  11. Decay Time Measurement for Different Energy Depositions of Plastic Scintillator Fabricated by High Temperature Polymerization Reaction

    International Nuclear Information System (INIS)

    Lee, Cheol Ho; Son, Jaebum; Lee, Sangmin; Kim, Tae Hoon; Kim, Yong-Kyun

    2016-01-01

    Plastic scintillators are based on organic fluorite. They have many advantages such as fast rise and decay time, high optical transmission, ease of manufacturing, low cost, and large available size. For these reasons they are widely used for particle identification. Also, protection of people against a variety of threats (such as nuclear, radiological, and explosive) represents a true challenge along with the continuing development of science and technology. The plastic scintillator is widely used in various devise, which serves for nuclear, photonics, quantum, and high-energy physics. The plastic scintillator is probably the most widely used organic detector, and polystyrene is one of the most widely used materials in the making of the plastic scintillator detector. Thus, a styrene monomer as a solvent was used to fabricate the plastic scintillator by using high temperature polymerization reaction, and then the emission wavelength and the decay times for different energy depositions were measured by using the fabricated plastic scintillator. A plastic scintillator was fabricated to measure decay time for different energy depositions using the high temperature polymerization. Emission wavelength was measured of 426.05 nm to confirm a scintillator property using the spectrophotometer. Four gamma-ray sources (Cs-137, Co-60, Na-22, and Ba-133) were used to evaluate effect for decay time of different energy depositions. The average decay time of the fabricated plastic scintillator was measured to approximately 4.72 ns slightly higher more than commercial plastic scintillator. In future, light output and linearity will be measured to evaluate other property compared with the commercial scintillator

  12. Measuring DHEA-S in saliva: time of day differences and positive correlations between two different types of collection methods

    Directory of Open Access Journals (Sweden)

    Klein Laura C

    2010-07-01

    Full Text Available Abstract Background The anabolic steroid, dehydroepiandosterone sulfate (DHEA-S, is secreted from the adrenal cortex. It plays a significant role in the body as a precursor to sex steroids as well as a lesser known role in the hypothalamic pituitary adrenal axis (HPA response to stress. DHEA-S can be measured reliably in saliva, making saliva collection a valuable tool for health research because it minimizes the need for invasive sampling procedures (e.g., blood draws. Typical saliva collection methods include the use of plain cotton swab collection devices (e.g., Salivette® or passive drool. There has been some speculation that the plain saliva cotton collection device may interfere with determination of DHEA-S by enzyme immunoassay (EIA bringing this saliva collection method into question. Because of the increasing popularity of salivary biomarker research, we sought to determine whether the cotton swab interferes with DHEA-S determination through EIA techniques. Findings Fifty-six healthy young adult men and women aged 18-30 years came to the lab in the morning (0800 hrs; 14 men, 14 women or late afternoon (1600 hrs; 14 men, 14 women and provided saliva samples via cotton Salivette and passive drool. Passive drool collection was taken first to minimize particle cross contamination from the cotton swab. Samples were assayed for DHEA-S in duplicate using a commercially available kit (DSL, Inc., Webster, TX. DHEA-S levels collected via Salivette and passive drool were positively correlated (r = + 0.83, p Conclusions Results suggest that DHEA-S can be measured accurately using passive drool or cotton Salivette collection methods. Results also suggest that DHEA-S levels change across the day and that future studies need to take this time of day difference into account when measuring DHEA-S.

  13. Impact of different cloud deployments on real-time video applications for mobile video cloud users

    Science.gov (United States)

    Khan, Kashif A.; Wang, Qi; Luo, Chunbo; Wang, Xinheng; Grecos, Christos

    2015-02-01

    The latest trend to access mobile cloud services through wireless network connectivity has amplified globally among both entrepreneurs and home end users. Although existing public cloud service vendors such as Google, Microsoft Azure etc. are providing on-demand cloud services with affordable cost for mobile users, there are still a number of challenges to achieve high-quality mobile cloud based video applications, especially due to the bandwidth-constrained and errorprone mobile network connectivity, which is the communication bottleneck for end-to-end video delivery. In addition, existing accessible clouds networking architectures are different in term of their implementation, services, resources, storage, pricing, support and so on, and these differences have varied impact on the performance of cloud-based real-time video applications. Nevertheless, these challenges and impacts have not been thoroughly investigated in the literature. In our previous work, we have implemented a mobile cloud network model that integrates localized and decentralized cloudlets (mini-clouds) and wireless mesh networks. In this paper, we deploy a real-time framework consisting of various existing Internet cloud networking architectures (Google Cloud, Microsoft Azure and Eucalyptus Cloud) and a cloudlet based on Ubuntu Enterprise Cloud over wireless mesh networking technology for mobile cloud end users. It is noted that the increasing trend to access real-time video streaming over HTTP/HTTPS is gaining popularity among both research and industrial communities to leverage the existing web services and HTTP infrastructure in the Internet. To study the performance under different deployments using different public and private cloud service providers, we employ real-time video streaming over the HTTP/HTTPS standard, and conduct experimental evaluation and in-depth comparative analysis of the impact of different deployments on the quality of service for mobile video cloud users. Empirical

  14. Adaptive Synchronization between Two Different Complex Networks with Time-Varying Delay Coupling

    International Nuclear Information System (INIS)

    Jian-Rui, Chen; Li-Cheng, Jiao; Jian-She, Wu; Xiao-Hua, Wang

    2009-01-01

    A new general network model for two complex networks with time-varying delay coupling is presented. Then we investigate its synchronization phenomena. The two complex networks of the model differ in dynamic nodes, the number of nodes and the coupling connections. By using adaptive controllers, a synchronization criterion is derived. Numerical examples are given to demonstrate the effectiveness of the obtained synchronization criterion. This study may widen the application range of synchronization, such as in chaotic secure communication. (general)

  15. Clinical characteristics and psychosocial impact of different reflux time in gastroesophageal reflux disease patients.

    Science.gov (United States)

    Chen, Jiann-Hwa; Wen, Shu-Hui; Hsu, Ching-Sheng; Yi, Chih-Hsun; Liu, Tso-Tsai; Chen, Chien-Lin; Wang, Chia-Chi

    2017-02-01

    Gastroesophageal reflux disease (GERD) is an emerging disease, and can impair quality of life and sleep. This study aimed to investigate whether GERD patients with different timings of reflux symptoms have different clinical characteristics. This study prospectively enrolled individuals who underwent upper gastrointestinal endoscopy during a health checkup. Each participant completed all questionnaires including Reflux Disease Questionnaire, Nighttime GERD questionnaire, Pittsburg Sleep Quality Index, Taiwanese Depression Questionnaire, and State-Trait Anxiety Inventory. Combined reflux was defined as the timing of reflux symptoms occurring at both daytime and nighttime. A total of 2604 participants were enrolled. Of them, 651 symptomatic GERD patients, according to the Reflux Disease Questionnaire score, were recruited for final analysis. Of them, 224 (34.4%) had erosive esophagitis on endoscopy. According to the timing of reflux symptoms, 184 (28.3%) were assigned to the daytime reflux group, 71 (10.9%) to the nighttime reflux group, and 396 (60.8%) to the combined reflux group. In post hoc analysis, the combined reflux group had a significantly higher Reflux Disease Questionnaire score than the daytime reflux group (p reflux groups had higher body mass index and longer duration (> 12 years) of education than the daytime reflux group (p reflux of have more troublesome symptoms than those with daytime reflux. GERD patients with different timings of reflux symptoms have different clinical characteristics in terms of body mass index and duration of education, but not in terms of esophageal inflammation, quality of sleep, and psychosocial status. Copyright © 2016. Published by Elsevier B.V.

  16. System of delay difference equations with continuous time with lag function between two known functions

    Directory of Open Access Journals (Sweden)

    Hajnalka Péics

    2016-08-01

    Full Text Available The asymptotic behavior of solutions of the system of difference equations with continuous time and lag function between two known real functions is studied. The cases when the lag function is between two linear delay functions, between two power delay functions and between two constant delay functions are observed and illustrated by examples. The asymptotic estimates of solutions of the considered system are obtained.

  17. The timing of the circadian clock and sleep differ between napping and non-napping toddlers

    OpenAIRE

    Akacem, Lameese D; Simpkin, Charles T; Carskadon, Mary A; Wright, Kenneth P; Jenni, Oskar G; Achermann, Peter; LeBourgeois, Monique K

    2015-01-01

    The timing of the internal circadian clock shows large inter-individual variability across the lifespan. Although the sleep-wakefulness pattern of most toddlers includes an afternoon nap, the association between napping and circadian phase in early childhood remains unexplored. This study examined differences in circadian phase and sleep between napping and non-napping toddlers. Data were collected on 20 toddlers (34.2±2.0 months; 12 females; 15 nappers). Children followed their habitual napp...

  18. The inner state differences of preterm birth rates in Brazil: a time series study

    OpenAIRE

    de Oliveira, Rosana Rosseto; Melo, Emiliana Cristina; Fujimori, Elizabeth; Mathias, Thais Aidar de Freitas

    2016-01-01

    Abstract Background Preterm birth is a serious public health problem, as it is linked to high rates of neonatal and child morbidity and mortality. The prevalence of premature births has increased worldwide, with regional differences. The objective of this study was to analyze the trend of preterm births in the state of Paraná, Brazil, according to Macro-regional and Regional Health Offices (RHOs). Methods This is an ecological time series study using preterm births records from the national l...

  19. Finite difference time domain (FDTD) modeling of implanted deep brain stimulation electrodes and brain tissue.

    Science.gov (United States)

    Gabran, S R I; Saad, J H; Salama, M M A; Mansour, R R

    2009-01-01

    This paper demonstrates the electromagnetic modeling and simulation of an implanted Medtronic deep brain stimulation (DBS) electrode using finite difference time domain (FDTD). The model is developed using Empire XCcel and represents the electrode surrounded with brain tissue assuming homogenous and isotropic medium. The model is created to study the parameters influencing the electric field distribution within the tissue in order to provide reference and benchmarking data for DBS and intra-cortical electrode development.

  20. Irradiation at different times of the day. Morphology and kinetics of the small intestine

    Energy Technology Data Exchange (ETDEWEB)

    Becciolini, A; Cremonini, D; Balzi, M; Fabbrica, D; Cinotti, S [Florence Univ. (Italy). Ist. di Radiologia

    1982-01-01

    Rats were irradiated at different times of the day with sublethal doses on the abdomen only, and qualitative and quantitative morphologic modifications were determined. The experiments seemed to demonstrate that in the groups irradiated at night and at the end of the light period early injury is not severe whereas in the group irradiated at the end of the dark period repair of the injury seems to be more effective.

  1. Tracking difference in gene expression in a time-course experiment using gene set enrichment analysis.

    Directory of Open Access Journals (Sweden)

    Pui Shan Wong

    Full Text Available Fistulifera sp. strain JPCC DA0580 is a newly sequenced pennate diatom that is capable of simultaneously growing and accumulating lipids. This is a unique trait, not found in other related microalgae so far. It is able to accumulate between 40 to 60% of its cell weight in lipids, making it a strong candidate for the production of biofuel. To investigate this characteristic, we used RNA-Seq data gathered at four different times while Fistulifera sp. strain JPCC DA0580 was grown in oil accumulating and non-oil accumulating conditions. We then adapted gene set enrichment analysis (GSEA to investigate the relationship between the difference in gene expression of 7,822 genes and metabolic functions in our data. We utilized information in the KEGG pathway database to create the gene sets and changed GSEA to use re-sampling so that data from the different time points could be included in the analysis. Our GSEA method identified photosynthesis, lipid synthesis and amino acid synthesis related pathways as processes that play a significant role in oil production and growth in Fistulifera sp. strain JPCC DA0580. In addition to GSEA, we visualized the results by creating a network of compounds and reactions, and plotted the expression data on top of the network. This made existing graph algorithms available to us which we then used to calculate a path that metabolizes glucose into triacylglycerol (TAG in the smallest number of steps. By visualizing the data this way, we observed a separate up-regulation of genes at different times instead of a concerted response. We also identified two metabolic paths that used less reactions than the one shown in KEGG and showed that the reactions were up-regulated during the experiment. The combination of analysis and visualization methods successfully analyzed time-course data, identified important metabolic pathways and provided new hypotheses for further research.

  2. Associations among Different Internet Access Time, Gender and Cyberbullying Behaviors in Taiwan?s Adolescents

    OpenAIRE

    Chao, Cheng-Min; Yu, Tai-Kuei

    2017-01-01

    With the increasing convenience of social networking sites and their interconnectedness with human interaction, verbal and image bullying have turned digital, making cyberbullying a new form of bullying attracting the attention of researchers, social workers, and schools. This study focuses on the status quo of attitude toward cyberbullying and cyberbullying behavior, explores associations of attitude toward behavior on cyberbullying behavior in gender and different internet access times. In ...

  3. Study on the bonding state for carbon-boron nitrogen with different ball milling time

    International Nuclear Information System (INIS)

    Xiong, Y.H.; Xiong, C.S.; Wei, S.Q.; Yang, H.W.; Mai, Y.T.; Xu, W.; Yang, S.; Dai, G.H.; Song, S.J.; Xiong, J.; Ren, Z.M.; Zhang, J.; Pi, H.L.; Xia, Z.C.; Yuan, S.L.

    2006-01-01

    The varied bonding state and microstructure characterization were discussed for carbon-boron nitrogen (CBN) with abundant phase structure and nanostructure, which were synthesized directly by mechanical alloying technique at room temperature. According to the results of SEM and X-ray photoelectron spectroscopy (XPS) of CBN with different ball milling time, it is substantiated that the bonding state and microstructure for CBN were closely related to the ball milling time. With the increase of the ball milling time, some new chemical bonding states of CBN were observed, which implies that some new bonding state and microstructures have been formed. The results of XPS are accordance with that of X-ray diffraction of CBN

  4. Finite-difference time-domain simulation of thermal noise in open cavities

    International Nuclear Information System (INIS)

    Andreasen, Jonathan; Cao Hui; Taflove, Allen; Kumar, Prem; Cao Changqi

    2008-01-01

    A numerical model based on the finite-difference time-domain (FDTD) method is developed to simulate thermal noise in open cavities owing to output coupling. The absorbing boundary of the FDTD grid is treated as a blackbody, whose thermal radiation penetrates the cavity in the grid. The calculated amount of thermal noise in a one-dimensional dielectric cavity recovers the standard result of the quantum Langevin equation in the Markovian regime. Our FDTD simulation also demonstrates that in the non-Markovian regime the buildup of the intracavity noise field depends on the ratio of the cavity photon lifetime to the coherence time of thermal radiation. The advantage of our numerical method is that the thermal noise is introduced in the time domain without prior knowledge of cavity modes

  5. Test of high time resolution MRPC with different readout modes for the BESIII upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S. [Department of Modern Physics, University of Science and Technology of China(USTC), Hefei 230026 (China); State Key Laboratory of Particle Detection and Electronics(USTC-IHEP) (China); Sun, Y.J., E-mail: sunday@ustc.edu.cn [Department of Modern Physics, University of Science and Technology of China(USTC), Hefei 230026 (China); State Key Laboratory of Particle Detection and Electronics(USTC-IHEP) (China); Li, C., E-mail: licheng@ustc.edu.cn [Department of Modern Physics, University of Science and Technology of China(USTC), Hefei 230026 (China); State Key Laboratory of Particle Detection and Electronics(USTC-IHEP) (China); Heng, Y.K.; Qian, S. [Institute of High Energy Physics, Chinese Academy of Sciences(IHEP), Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics(USTC-IHEP) (China); Chen, H.F.; Chen, T.X. [Department of Modern Physics, University of Science and Technology of China(USTC), Hefei 230026 (China); State Key Laboratory of Particle Detection and Electronics(USTC-IHEP) (China); Dai, H.L. [Institute of High Energy Physics, Chinese Academy of Sciences(IHEP), Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics(USTC-IHEP) (China); Fan, H.H.; Liu, S.B. [Department of Modern Physics, University of Science and Technology of China(USTC), Hefei 230026 (China); State Key Laboratory of Particle Detection and Electronics(USTC-IHEP) (China); Liu, S.D.; Jiang, X.S. [Institute of High Energy Physics, Chinese Academy of Sciences(IHEP), Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics(USTC-IHEP) (China); Shao, M.; Tang, Z.B.; Zhang, H.; Zhao, Z.G. [Department of Modern Physics, University of Science and Technology of China(USTC), Hefei 230026 (China); State Key Laboratory of Particle Detection and Electronics(USTC-IHEP) (China)

    2014-11-01

    In order to further enhance the particle identification capability of the Beijing Spectrometer (BESIII), it is proposed to upgrade the current end-cap time-of-flight (eTOF) detector with multi-gap resistive plate chamber (MRPC). The prototypes, together with the front end electronics (FEE) and time digitizer (TDIG) module have been tested at the E3 line of Beijing Electron Positron Collider (BEPCII) to study the difference between the single and double-end readout MRPC designs. The time resolutions (sigma) of the single-end readout MRPC are 47/53 ps obtained by 600 MeV/c proton/pion beam, while that of the double-end readout MRPC is 40 ps (proton beam). The efficiencies of three MRPC modules tested by both proton and pion beam are better than 98%. For the double-end readout MRPC, no incident position dependence is observed.

  6. Differences in the occurrence and characteristics of injuries between full-time and part-time dancers.

    Science.gov (United States)

    Vassallo, Amy Jo; Pappas, Evangelos; Stamatakis, Emmanuel; Hiller, Claire E

    2018-01-01

    Professional dancers are at significant risk of injury due to the physical demands of their career. Despite their high numbers, the experience of injury in freelance or part-time dancers is not well understood. Therefore, the aim of this study was to examine the occurrence and characteristics of injury in part-time compared with full-time Australian professional dancers. Data were collected using a cross-sectional survey distributed to employees of small and large dance companies and freelance dancers in Australia. Statistical comparisons between full-time and part-time dancer demographics, dance training, injury prevalence and characteristics were made using χ 2 , two-tailed Fisher's exact tests, independent t-tests and Mann-Whitney U tests. A total of 89 full-time and 57 part-time dancers were included for analysis. A higher proportion of full-time dancers (79.8%) than part-time dancers (63.2%) experienced an injury that impacted on their ability to dance in the past 12 months (p=0.035). Injuries characteristics were similar between groups with fatigue being the most cited contributing factor. Part-time dancers took longer to seek treatment while a higher proportion of full-time dancers were unable to dance in any capacity following their injury. More full-time dancers sustained an injury in the past 12 months, and were unable to dance in any capacity following their injury. However injuries still commonly occurred in part-time dancers without necessarily a large volume of dance activity. Part-time dancers often access general community clinicians for treatment, who may need additional education to practically advise on appropriate return to dance.

  7. Effects of moonlight on the capturability of frugivorous phyllostomid bats (Chiroptera: Phyllostomidae at different time scales

    Directory of Open Access Journals (Sweden)

    Marco A. R. Mello

    2013-08-01

    Full Text Available Some bat species seem to be lunar phobic, i.e., they avoid flying in bright areas or during bright periods of the night; however, the evidence is still controversial. We think that part of this controversy comes from pooling data on bat captures and moonlight intensity according to broad categories, such as moon phases, which conceal the high variability among nights. Therefore, we used detailed, long-term field data on three phyllostomid bat species, in order to test the hypothesis of lunar phobia at two different time scales: 1 among nights, by pooling data of different nights according to moon phases and testing for differences in the distribution of captures; and 2 within a night, by analyzing the relationship between capturability and moonlight intensity (measured as illuminance in one-hour intervals for 29 individual nights. Although most captures of the studied bat species occurred in the first half of the night, their activity pattern varied largely among nights, and was not always unimodal as commonly assumed. At the larger time scale, all studied bat species showed evidence of lunar phobia, as they were more frequently captured on dark moon phases. Nevertheless, at the smaller time scale, only Carollia perspicillata (Linnaeus, 1758 was less frequently captured on brighter periods of the night. We propose that the unimodal activity pattern assumed for frugivorous phyllostomid bats may be an artifact of data organization, and that activity and lunar phobia are much more variable than previously assumed.

  8. Apoptosis of bone marrow leukemia cells in mice after low dose radiation at different time

    International Nuclear Information System (INIS)

    Li Guangyu; Yu Mingming; Li Xianjun; Liu Zhixiang

    2007-01-01

    Objective: To investigate the apoptosis of bone marrow leukemia cell in mice after low dose radiation (LDR) at different time and the experimental basis for LDR auxiliary therapy on leukemia. Methods: WEHI-3 cells were injected into BALB/c mice through tail veins to make an experimental mice model of myelornonocytic leukemia. 60 leukemia mice models were divided half-and half. 30 mice models in experimental group were irradiated with LDR of 75mGy at the same time while the others 30 in the control group were not. 6 mice models with LDR and 6 mice models without LDR would be killed at the time the 1st day, the 2nd day, the 3rd day, the 5th day- and the l0th day after LDR in order to extract bone marrow samples. The apoptosis percentage of leukemia cells in bone marrow was examined. Results: The apoptosis percentage of leukemia cells in experimental group was increasing after LDR and went to top on the 2nd day and the 3rd day. The apoptosis percentage of leukemia cells was remarkably different between experimental and control group, all P<0.05. Conclusion: LDR could significantly increase the apoptosis percentage of bone marrow leukemia cells in mice. Its mechanism is remarkably different in kill and wound of big dose radiation to tumour cells. It is probably related to of the increase immune exciting response as to promote some cytokine secretion, in leukemia mice. (authors)

  9. The effects of pervanadate given at different times on the proliferation of irradiated NFS-60 cells

    International Nuclear Information System (INIS)

    Wang Yuan; Yuan Xiaoling; Zhao Zhenhu; Shan Yajun; Chen Jiapei; Cong Yuwen

    2004-01-01

    To comprehend the feasibility of the inhibitor of tyrosine phosphatase pervanadate using for therapy of radiation injury and inquire into the effects of tyrosine phosphatases on the radiation injury of hematopoietic cells, the effects of different times of administration on NFS-60 cells irradiated with different doses were observed. It was found that pervanadate could specifically enhance the proliferation of irradiated cells, such effects became obvious with the dose of irradiation increased and displayed time effects. For 3 Gy irradiated NFS-60 cells, good results were achieved when pervanadate was administrated 24h after irradiation, there were no difference between before and 30 mins after irradiation, but for 5 Gy irradiated cells, the best time administration is 24 and 48h after irradiation. Effects of pervanadate administrated before irradiation was better than that administrated 30 min after irradiation. These results suggest that protein tyrosine phosphatase might involve in the course of radiation injury of hematopoietic cells. It is hoped that enhancing receptor signal transduction by PTP inhibitors will become a new way of therapy of acute radiation disease

  10. Ecological stoichiometry of C, N and P on different time enclosed in desertification steppe soil

    Science.gov (United States)

    Yang, W. Z.; Jiao, Y.; Jia, Y. Q.

    2017-08-01

    It is the research object for the ecological stoichiometry of C, N and P on the different time of desertification grasslands enclosed and grazing grassland in Taibusi country of the Inner Mongolia, China. Through the measurement and analysis on ecological stoichiometric ratio of C, N and P in soil, the time of desertification grassland enclosed is determined. There are 13 soil of desertification grassland with different en-closure time, and 1 soil of grazing grassland. They are analyzed for the soil organic carbon, total nitro-gen, total phosphorus content and their density. The C/N of soil were increased with the extension of the time of desertification grassland enclosed. To 22 years enclosed, the C/N of grassland desertification soil enclosed is greater than the soil of grazing grassland that is 17. After the desertification grassland is en-closed, the C/N of soil is 13, and it is accumulated to maximum for C and N, and The grazing period is the best.

  11. Comparison of hydroxy naphthoquinone from North Qinglongyi with different storage times

    Science.gov (United States)

    Xin, G. S.; Ji, Y. B.; Wei, C.

    2017-12-01

    Objective: To determine the appropriate solvent for the extraction of hydroxy naphthoquinone, and to establish a method for the determination of the content of hydroxy naphthoquinone in the North Qinglongyi, and compare the changes of the content of hydroxy naphthoquinone in North Qinglongyi with different storage times. Methods: According to the nature of hydroxy naphthoquinone in alkaline solution will be discolored, so this experiment for Juglone as the standard reagent, 5% KOH solution as a developer, and the absorbance was measured by UV-spectrophotometry at the wavelength of 515 nm. The content of hydroxy naphthoquinone in North Qinglongyi was determined by colorimetric method, and the contents of hydroxy naphthoquinone in North Qinglongyi of different storage times were compared. Results: The optimum extraction solvent was ethyl acetate. The recoveries were 97.73%±1.11% and the RSD was 1.14% (n = 6). The contents of hydroxy naphthoquinone in the North Qinglunyi were 0.0141%, 0.0104% and 0.0073%, respectively, for one year, two years and three years. The content of hydroxy naphthoquinone decreased with the storage time prolonged. Conclusion This experimental method was stability, high recovery rate, simple and reliable. According to the results of this experiment, we can see that the storage time of North Qinglunyi should not be too long. Should try to choose this year’s North Qinglunyi for experimental research.

  12. Impact localization on composite structures using time difference and MUSIC approach

    Science.gov (United States)

    Zhong, Yongteng; Xiang, Jiawei

    2017-05-01

    1-D uniform linear array (ULA) has the shortcoming of the half-plane mirror effect, which does not allow discriminating between a target placed above the array and a target placed below the array. This paper presents time difference (TD) and multiple signal classification (MUSIC) based omni-directional impact localization on a large stiffened composite structure using improved linear array, which is able to perform omni-directional 360° localization. This array contains 2M+3 PZT sensors, where 2M+1 PZT sensors are arranged as a uniform linear array, and the other two PZT sensors are placed above and below the array. Firstly, the arrival times of impact signals observed by the other two sensors are determined using the wavelet transform. Compared with each other, the direction range of impact source can be decided in general, 0°to 180° or 180°to 360°. And then, two dimensional multiple signal classification (2D-MUSIC) based spatial spectrum formula using the uniform linear array is applied for impact localization by the general direction range. When the arrival times of impact signals observed by upper PZT is equal to that of lower PZT, the direction can be located in x axis (0°or 180°). And time difference based MUSIC method is present to locate impact position. To verify the proposed approach, the proposed approach is applied to a composite structure. The localization results are in good agreement with the actual impact occurring positions.

  13. Time, number and length: similarities and differences in discrimination in adults and children.

    Science.gov (United States)

    Droit-Volet, Sylvie; Clément, Angélique; Fayol, Michel

    2008-01-01

    The aim of this study was to focus on similarities in the discrimination of three different quantities--time, number, and line length--using a bisection task involving children aged 5 and 8 years and adults, when number and length were presented nonsequentially (Experiment 1) and sequentially (Experiment 2). In the nonsequential condition, for all age groups, although to a greater extent in the younger children, the psychophysical functions were flatter, and the Weber ratio higher for time than for number and length. Number and length yielded similar psychophysical functions. Thus, sensitivity to time was lower than that to the other quantities, whether continuous or not. However, when number and length were presented sequentially (Experiment 2), the differences in discrimination performance between time, number, and length disappeared. Furthermore, the Weber ratio values as well as the bisection points for all quantities presented sequentially appeared to be close to that found for duration in the nonsequential condition. The results are discussed within the framework of recent theories suggesting a common mechanism for all analogical quantities.

  14. Socioeconomic differences in waiting times for elective surgery: a population-based retrospective study

    Directory of Open Access Journals (Sweden)

    Petrelli Alessio

    2012-08-01

    Full Text Available Abstract Background Widespread literature on inequity in healthcare access and utilization has been published, but research on socioeconomic differences in waiting times is sparse and the evidence is fragmentary and controversial. The objective of the present study is the analysis of the relationship between individual socioeconomic level and waiting times for in-hospital elective surgery. Methods We retrospectively studied the waiting times experienced by patients registered on hospital waiting lists for 6 important surgical procedures by using the Hospital Discharge Database (HDD of the Piedmont Region (4,000,000 inhabitants in the North West of Italy from 2006 to 2008. The surgical procedures analyzed were: coronary artery by-pass (CABG, angioplasty, coronarography, endarterectomy, hip replacement and cholecystectomy. Cox regression models were estimated to study the relationship between waiting times and educational level taking into account the confounding effect of the following factors: sex, age, comorbidity, registration period, and Local Health Authorities (LHA as a proxy of supply. Results Median waiting times for low educational level were higher than for high educational level for all the selected procedures. Differences were particularly high for endarterectomy and hip replacement. For all considered procedures, except CABG, an inverse gradient between waiting times and educational level was observed: the conditional probabilities of undergoing surgery were lower among individuals with a low to middle level education than for individuals with a higher level of education after adjustment for sex, age, comorbidities, registration period, and LHAs. For most procedures the effect decreases over the follow up period. Conclusions The results of the study show evidence of inequalities in access to elective surgery in Italy. Implementation of policies aimed to promote national information initiatives that guarantee wider access to those

  15. Synthesizing the Nanocrytalline Cobalt-Iron Coating Through The Electrodeposition Process With Different Time Deposition

    Science.gov (United States)

    Rozlin Nik Masdek, Nik; Sorfian Hafiz Mansor, Mohd; Salleh, Zuraidah; Hyie, Koay Mei

    2018-03-01

    In the engineering world, electrodeposition or electroplating has become the most popular method of surface coating in improving corrosion behavior and mechanical properties of material. Therefore in this study, CoFe nanoparticle protective coating has been synthesized on the mild steel washer using electrodeposition method. The electrodeposition was conducted in the acidic environment with the pH value range from 1 to 2 with the controlled temperature of 50°C. The influence of deposition time (30, 60, 90 minutes) towards characteristic and properties such as particle size, surface morphology, corrosion behavior, and microhardness were studied in this investigation. Several results can be obtained by doing this experiment and testing. First, the surface morphology of Cobalt Iron (CoFe) on the electrodeposited mild steel washer are obtained. In addition, the microhardness of the mild steel washer due to the different deposition time are determined. Next, the observation on the difference in the grain size of CoFe that has been electrodeposited on the mild steel plate is made. Last but not least, the corrosion behavior was investigated. CoFe nanoparticles deposited for 30 minutes produced the smallest particle size and the highest microhardness of 86.17 and 236.84 HV respectively. The CoFe nanoparticles also exhibit the slowest corrosion rate at 30 minutes as compared to others. The crystalline size also increases when the time deposition is increased. The sample with 30 minute depositon time indicate the smallest crystalline size which is 15nm. The decrement of deposition time plays an important role in synthesizing CoFe nanoparticles with good corrosion resistance and microhardness. CoFe nanoparticles obtained at 30 minutes shows high corrosion resistance compared to others. In a nutshell, it was observed that the decrement of deposition time improved mechanical and corrosion properties of CoFe nanoparticles.

  16. Changes in setting time of alginate impression material with different water temperature

    Directory of Open Access Journals (Sweden)

    Decky J. Indrani

    2013-03-01

    Full Text Available Background: Previous studies showed that setting process of alginates can be influenced by temperature. Purpose: To determine the changes in setting time due to differences in water temperature and to determine the correlation between water temperature and the setting time. Methods: Seven groups of dough alginate were prepared by mixing alginate powder and water, each using a temperature between 13° C–28° C with a interval of 2.5° C. A sample mold (Θ = 30 mm, t = 16 mm was placed on a flat plate and filled with doug alginate. Immediately the flat end of a polished acrylic rod was placed in contact with the surface of dough alginate. Setting time of alginat was measured from the starting of the mix to the time when the alginate does not adhere to the end of the rod. Setting time alginate data were analyzed using one way ANOVA, LSD and Pearson. Results: Setting time of alginate with water temperature between 13° C–28° C were 87 to 119.4 seconds and were significantly different (p < 0.01. The setting time between group were also significantly different (p<0.01. There was an inverse correlation between water temperature and the setting time (r = -0.968. Conclusion: Water temperature between 13° C–28°C with a difference of 2.5° C produced significant differences in alginate setting time; the lower the water temperature being used the longer the setting time was produced.Latar belakang: Penelitian-penelitian sebelumnya menunjukkan bahwa proses pengerasan alginat dapat dipengaruhi oleh suhu. Tujuan: Mengetahui perubahan waktu pengerasan alginat akibat perbedaan suhu air serta mengetahui hubungan antara suhu air dan waktu pengerasan. Metode: Tujuh kelompok adonan alginat yang dipersiapkan dengan mencampur bubuk alginat dan air, masingmasing menggunakan suhu antara 13°C–28° C dengan interval 2,5° C. Pengukuran waktu pengerasan alginat dilakukan sesuai dengan spesifikasi ADA no.18. Sebuah cetakan sampel terbuat dari pralon berbentuk

  17. Acute effect of different time periods of passive static stretching on the hamstring flexibility.

    Science.gov (United States)

    Cini, Anelize; de Vasconcelos, Gabriela Souza; Lima, Claudia Silveira

    2017-01-01

    Several factors are associated with the presence of chronic low back pain; one of them is the flexibility of the hamstring muscles that influences the posture of the pelvic spine. Investigate the influence of two different time periods of passive static stretching on the flexibility of the hamstring. Forty-six physiotherapy students were divided into two groups performing stretching exercises: 30 s and 60 s duration. The collections consisted of: (1) pre-test: evaluation of the flexibility of the hip and knee, using a manual goniometer by means of the following tests: Straight Leg Raise Test (SLR), Passive Hip Flexion Test (PHFT) and Modified Knee Extension Test (MKET), (2) intervention: stretching with different runtimes, (3) post-test: reappraisal of flexibility, conducted immediately after the intervention. Significant difference was observed intra groups, group that did stretching exercises lasting 30 seconds (G30) (SLR p = 0.000. PHFT p = 0.003 and MKET p = 0.000) and group that did stretching exercises lasting 60 seconds (G60) (SLR p = 0.000. PHFT p = 0.001 and MKET p = 0.002). Comparing the groups, no significant difference was found (SLR p = 0.307; PHFT p = 0.904; MKET p = 0.132). Thus it can be inferred that 30 seconds are sufficient for increased flexibility of young women. Therefore the time-treatment sessions can be optimized. Only the acute effect of stretching was observed; further investigation of the long-term effect is required.

  18. A lower dimensional feature vector for identification of partial discharges of different origin using time measurements

    International Nuclear Information System (INIS)

    Evagorou, Demetres; Kyprianou, Andreas; Georghiou, George E; Lewin, Paul L; Stavrou, Andreas

    2012-01-01

    Partial discharge (PD) classification into sources of different origin is essential in evaluating the severity of the damage caused by its activity on the insulation of power cables and their accessories. More specifically, some types of PD can be classified as having a detrimental effect on the integrity of the insulation while others can be deemed relatively harmless, rendering the correct classification of different PD types of vital importance to electrical utilities. In this work, a feature vector was proposed based on higher order statistics on selected nodes of the wavelet packet transform (WPT) coefficients of time domain measurements, which can compactly represent the characteristics of different PD sources. To assess its performance, experimental data acquired under laboratory conditions for four different PD sources encountered in power systems were used. The two learning machine methods, namely the support vector machine and the probabilistic neural network, employed as the classification algorithms, achieved overall classification rates of around 98%. In comparison, the utilization of the scaled, raw WPT coefficients as a feature vector resulted in classification accuracy of around 99%, but with a significantly higher number of dimensions (1304 to 16), validating the PD identification ability of the proposed feature. Dimensionality reduction becomes a key factor in online, real-time data collection and processing of PD measurements, reducing the classification effort and the data-storage requirements. Therefore, the proposed method can constitute a potential tool for such online measurements, after addressing issues related to on-site measurements such as the rejection of interference. (paper)

  19. Modeling of GIC Impacts in Different Time Scales, and Validation with Measurement Data

    Science.gov (United States)

    Shetye, K.; Birchfield, A.; Overbye, T. J.; Gannon, J. L.

    2016-12-01

    Geomagnetically induced currents (GICs) have mostly been associated with geomagnetic disturbances (GMDs) originating from natural events such as solar coronal mass ejections. There is another, man-made, phenomenon that can induce GICs in the bulk power grid. Detonation of nuclear devices at high altitudes can give rise to electromagnetic pulses (EMPs) that induce electric fields at the earth's surface. EMPs cause three types of waves on different time scales, the slowest of which, E3, can induce GICs similar to the way GMDs do. The key difference between GMDs and EMPs is the rise time of the associated electric field. E3 electric fields are in the msec. to sec. range, whereas GMD electric fields are slower (sec. to min.). Similarly, the power grid and its components also operate and respond to disturbances in various time frames, right from electromagnetic transients (eg. lightning propagation) in the micro second range to steady state power flow ( hours). Hence, different power system component models need to be used to analyze the impacts of GICs caused by GMDs, and EMPs. For instance, for the slower GMD based GICs, a steady-state (static) analysis of the system is sufficient. That is, one does not need to model the dynamic components of a power system, such as the rotating machine of a generator, or generator controls such as exciters, etc. The latter become important in the case of an E3 EMP wave, which falls in the power system transient stability time frame of msec. to sec. This talk will first give an overview of the different time scales and models associated with power system operations, and where GMD and EMPs fit in. This is helpful to develop appropriate system models and test systems for analyzing impacts of GICs from various sources, and developing mitigation measures. Example test systems developed for GMD and EMP analysis, and their key modeling and analysis differences will be presented. After the modeling is discussed, results of validating

  20. Differences in crenate broomrape parasitism dynamics on three legume crops using a thermal time model

    Directory of Open Access Journals (Sweden)

    Alejandro Pérez-De-Luque

    2016-12-01

    Full Text Available Root parasitic weeds are a major limiting production factor in a number of crops, and control is difficult. Genetic resistance and chemical control lead the fight, but without unequivocal success. Models that help to describe and even predict the evolution of parasitism underground are a valuable tool for herbicide applications, and even could help in breeding programs. Legumes are heavily affected by Orobanche crenata (crenate broomrape in the Mediterranean basin. This work presents a descriptive model based on thermal time and correlating growing day-degrees (GDD with the different developmental stages of the parasite. The model was developed in three different legume crops (faba bean, grass pea and lentil attacked by crenate broomrape. The developmental stages of the parasite strongly correlated with the GDD and differences were found depending on the host crop.

  1. Manufacturing Enhancement through Reduction of Cycle Time using Different Lean Techniques

    Science.gov (United States)

    Suganthini Rekha, R.; Periyasamy, P.; Nallusamy, S.

    2017-08-01

    In recent manufacturing system the most important parameters in production line are work in process, TAKT time and line balancing. In this article lean tools and techniques were implemented to reduce the cycle time. The aim is to enhance the productivity of the water pump pipe by identifying the bottleneck stations and non value added activities. From the initial time study the bottleneck processes were identified and then necessary expanding processes were also identified for the bottleneck process. Subsequently the improvement actions have been established and implemented using different lean tools like value stream mapping, 5S and line balancing. The current state value stream mapping was developed to describe the existing status and to identify various problem areas. 5S was used to implement the steps to reduce the process cycle time and unnecessary movements of man and material. The improvement activities were implemented with required suggested and the future state value stream mapping was developed. From the results it was concluded that the total cycle time was reduced about 290.41 seconds and the customer demand has been increased about 760 units.

  2. Difference-based clustering of short time-course microarray data with replicates

    Directory of Open Access Journals (Sweden)

    Kim Jihoon

    2007-07-01

    Full Text Available Abstract Background There are some limitations associated with conventional clustering methods for short time-course gene expression data. The current algorithms require prior domain knowledge and do not incorporate information from replicates. Moreover, the results are not always easy to interpret biologically. Results We propose a novel algorithm for identifying a subset of genes sharing a significant temporal expression pattern when replicates are used. Our algorithm requires no prior knowledge, instead relying on an observed statistic which is based on the first and second order differences between adjacent time-points. Here, a pattern is predefined as the sequence of symbols indicating direction and the rate of change between time-points, and each gene is assigned to a cluster whose members share a similar pattern. We evaluated the performance of our algorithm to those of K-means, Self-Organizing Map and the Short Time-series Expression Miner methods. Conclusions Assessments using simulated and real data show that our method outperformed aforementioned algorithms. Our approach is an appropriate solution for clustering short time-course microarray data with replicates.

  3. Statistical analysis of two-degree of freedom systems to time history inputs with different durations

    International Nuclear Information System (INIS)

    Lin, C.W.; Li, D.L.

    1987-01-01

    A statistical study is conducted to determine the effect of input time history duration on the response of systems supported by the structure. The model used in the study is a one-degree-of-freedom system mass supported by another one degree of freedom structure mass. The input used is generated from a Monte-Carlo simulation procedure with a prescribed power spectrum density such that the input response spectrum matched the Reg. Guide 1.60 response spectrum. The models were analyzed for different combinations of mass ratios and frequency ratios (ratios of the system versus the supporting structure). Time history inputs used vary from 5 to 20 seconds. Only the 20 second time history matched the Reg. Guide 1.60 response spectrum. Time history inputs shorter than 20 seconds were simply truncated at the tail end. The results of the study indicate that it is necessary to increase the response magnitude by about 20% if a 5-second time history is to be used. For a 10-second input, an increase of 10% will suffice. Whereas for a 15-second input, no adjustment is necessary. (orig./HP)

  4. Performance evaluation of an interactive teleradiology system for real-time teleconsultation in different network environments

    International Nuclear Information System (INIS)

    Lian Ping; Gong Jun; Zhuang Jun; Sun Jianyong; Yang Yuanyuan; Zhang Jianguo; Meng Lili

    2004-01-01

    Objective: Measure the performance of self-developed Interoperable teleradiology system at various communication conditions. Methods: Through three different network media ( satellite network, Asymmetrical Digital Subscriber Loop (ADSL), and Shanghai health system's private broadband WAN), Digital images in radiology were transmitted and experiments on teleradiology consultation were applied. Results such as transmission time were recorded, effects of real-time consultation were evaluated subjectively, and experimental data were analyzed. Results: In satellite network, time spent on the transmission of images is long and effects of consultation is normal; in broadband network, time spent is short and no delay is observed in interoperation. Conclusion: teleconsultation can be hold on image sets composed of small matrix size images and compressed large matrix size images in satellite narrowband network, optimum transmission bandwidth is 192 kbps; original large matrix size images such as CR can be transmitted through broadband network and be used in teleconsultation. Real-time interoperation of the system doesn't require very high bandwidth. It can be implemented at various communication conditions

  5. Comparison of success rate and onset time of two different anesthesia techniques

    Science.gov (United States)

    Haghighat, Abbas; Hasheminia, Dariush; Samandari, Mohammad-Hasan; Safarian, Vajihe; Davoudi, Amin

    2015-01-01

    Background Using local anesthetic is common to control the pain through blocking the nerve reversibly in dental procedures. Gow-Gates (GG) technique has a high success rate but less common. This study aimed to compare the onset time and success rate in GG and standard technique of inferior alveolar nerve block (IANB). Material and Methods This descriptive, single blind study was consisted of 136 patients (59 males and 77 females) who were randomly received GG or IANB for extraction of mandibular molar teeth. Comparisons between the successes of two anesthetic injection techniques were analyzed with Chi-square test. Incidence of pulpal anesthesia and soft tissue anesthesia were analyzed with Kaplan-Meier method. Mean onset times of pulpal anesthesia, soft tissue and lip numbness were analyzed with Log-Rank test. Comparisons were considered significant at P≤0.05 by using SPSS software ver.15. Results The incidence of pulpal anesthesia in the IANB group (canine 49.3%, premolar 60.3%) were not significantly different from the GG group (canine 41.3%, premolar 74.6%) (P=0.200 and P=0.723). The success rate in the IANB group (80.82%) was not significantly different from the GG group (92.02%) (P=0.123). Furthermore, onset time of lip and buccal soft tissue numbness in GG group (3.25, 4.96 minutes) was quite similar to IANB group (3.22, 4.89 minutes) (all Pvalues >0.05). Conclusions Although this study demonstrated higher clinical success rate for GG than IANB technique, no significant differences in success rates and onset time were observed between two techniques. Key words: Anesthesia, Inferior alveolar nerve, nerve block, success rate. PMID:25858085

  6. Dimensional Stability of Two Polyvinyl Siloxane Impression Materials in Different Time Intervals

    Directory of Open Access Journals (Sweden)

    Aalaei Sh

    2015-12-01

    Full Text Available Statement of the Problem: Dental prosthesis is usually made indirectly; there- fore dimensional stability of the impression material is very important. Every few years, new impression materials with different manufacturers’ claims regarding their better properties are introduced to the dental markets which require more research to evaluate their true dimensional changes. Objectives: The aim of this study was to evaluate dimensional stability of additional silicone impression material (Panasil® and Affinis® in different time intervals. Materials and Methods: In this experimental study, using two additional silicones (Panasil® and Affinis®, we made sixty impressions of standard die in similar conditions of 23 °C and 59% relative humidity by a special tray. The die included three horizontal and two vertical lines that were parallel. The vertical line crossed the horizontal ones at a point that served as reference for measurement. All impressions were poured with high strength dental stone. The dimensions were measured by stereo-microscope by two examiners in three interval storage times (1, 24 and 168 hours.The data were statistically analyzed using t-test and ANOVA. Results: All of the stone casts were larger than the standard die. Dimensional changes of Panasil and Affinis were 0.07%, 0.24%, 0.27% and 0.02%, 0.07%, 0.16% after 1, 24 and 168 hours, respectively. Dimensional change for two impression materials wasn’t significant in the interval time, expect for Panasil after one week (p = 0.004. Conclusions: According to the limitations of this study, Affinis impressions were dimensionally more stable than Panasil ones, but it was not significant. Dimensional change of Panasil impression showed a statistically significant difference after one week. Dimensional changes of both impression materials were based on ADA standard limitation in all time intervals (< 0.5%; therefore, dimensional stability of this impression was accepted at least

  7. Evaluation of cytotoxicity and degree of conversion of orthodontic adhesives over different time periods

    Directory of Open Access Journals (Sweden)

    Matheus Melo Pithon

    2010-06-01

    Full Text Available As new orthodontic resin adhesives continue to be marketed, rapid and sensitive tests for examining their toxic effects at the ' cell and tissue level ' are needed because patient safety has been identifi ed as a legal concept. The objective of the present study was to evaluate the cytotoxicity and degree of monomer conversion of orthodontic adhesives over different time periods. Seven adhesives: Transbond® XT, Transbond® Color Change, Quick Cure, EagleBond, Orthobond®, Fill Mágic® and Biofix® were evaluated for their cytotoxicity in L929 fibroblastic cells and for their degree of monomer conversion over different time periods. Three control groups were also analysed: Positive control (C+, consisting of Tween 80 cell detergent; Negative control (C-, consisting of PBS; and cell control (CC, consisting of cells exposed to any material. The dye-uptake technique that involves the absorption of a neutral red dye in viable cells was used for the cytotoxicity evaluation and the degree of conversion was evaluated using spectroscopy with infrared. The results showed the cytotoxicity of the adhesives at 24, 48, 72 and 168 hours. At these times, the viability values presented for these materials were statistically different from the groups CC and C- (p 0.05. In the monomer conversions there was a percentage increase of monomer conversion from 24 to 72 hours. A direct correlation could be observed between cytotoxicity and monomer conversions. From this work it can be concluded that all adhesives evaluated are cytotoxic at the times of 24, 48 and 72 hours. Monomers continued conversion even after photopolymerization had stopped.

  8. Concentration of Umami Compounds in Pork Meat and Cooking Juice with Different Cooking Times and Temperatures.

    Science.gov (United States)

    Rotola-Pukkila, Minna K; Pihlajaviita, Seija T; Kaimainen, Mika T; Hopia, Anu I

    2015-12-01

    This study examined the concentrations of umami compounds in pork loins cooked at 3 different temperatures and 3 different lengths of cooking times. The pork loins were cooked with the sous vide technique. The free amino acids (FAAs), glutamic acid and aspartic acid; the 5'-nucleotides, inosine-5'-monophosphate (IMP) and adenosine-5'-monophosphate (AMP); and corresponding nucleoside inosine of the cooked meat and its released juice were determined by high-performance liquid chromatography. Under the experimental conditions used, the cooking temperature played a more important role than the cooking time in the concentration of the analyzed compounds. The amino acid concentrations in the meat did not remain constant under these experimental conditions. The most notable effect observed was that of the cooking temperature and the higher amino acid concentrations in the released juice of meat cooked at 80 °C compared with 60 and 70 °C. This is most likely due to the heat induced hydrolysis of proteins and peptides releasing water soluble FAAs from the meat into the cooking juice. In this experiment, the cooking time and temperature had no influence on the IMP concentrations observed. However, the AMP concentrations increased with the increasing temperature and time. This suggests that the choice of time and temperature in sous vide cooking affects the nucleotide concentration of pork meat. The Sous vide technique proved to be a good technique to preserve the cooking juice and the results presented here show that cooking juice is rich in umami compounds, which can be used to provide a savory or brothy taste. © 2015 Institute of Food Technologists®

  9. Diabetes patients show different time-course of myocardial perfusion improvement after coronary artery bypass grafting

    International Nuclear Information System (INIS)

    Lee, J. J.; Seok, J. W.; Eo, J. S.

    2005-01-01

    Diabetes mellitus is an independent risk factor of cardiovascular disease. Diabetes is known to cause microangiopathy. The microangiopathy is hardly detectable on the coronary angiography. Myocardial perfusion imaging shows the resultant perfusion status which reflects the microangiopathy. For patients who underwent revascularization, the microangiopathy could affect the myocardial perfusion improvement. Diabetes patients probably experience the different myocardial perfusion improvement as compared to the non-diabetes patients although they have similar angiographic findings. The aim of this study is to find out whether there is a time-course difference of perfusion improvement between the diabetes and non diabetes patients who showed patent angiographic findings after coronary artery grafting surgery (CABG). A total of 129 patients who underwent coronary artery bypass grafting surgery were enrolled in this study. Myocardial SPECTs performed at previous, short-term (3 month), and mid-term (1 year) to CABG. One-year follow up angiography was done 411±121 days after surgery. Graft patency was determined according to the FitzGibbon et al. Segments were assigned to vascular territories using a 20 segment model. The segments of excellent patency were included in this study. Time course differences of concerned segments were analyzed using RMANOVA. The number of segments enrolled was 764 of diabetes and 1083 of non-diabetes. At short-term follow up, reversibility score was 2.8±8.1% in diabetes and 0.3±7.5% in non-diabetes. At long-term follow up, reversibility score was 1.8±8.0% in diabetes and 0.1±7.3% in non-diabetes. The time-course of reversibility score was significantly different between the diabetes and non diabetes (p<0.001) Diabetic segments showed high residual reversibility score than non-diabetic segments after CABG although the angiographic finding was patent in both groups. This result is maybe attributable to microangiopathy induced by diabetes

  10. Pulsatility index variations using two different transit-time flowmeters in coronary artery bypass surgery.

    Science.gov (United States)

    Nordgaard, Håvard B; Vitale, Nicola; Astudillo, Rafael; Renzulli, Attilio; Romundstad, Pål; Haaverstad, Rune

    2010-05-01

    Transit-time flow measurement is widely accepted as an intra-operative assessment in coronary artery bypass grafting (CABG). However, the two most commonly applied flowmeters, manufactured by MediStim ASA and Transonic Inc., have different default filter settings of 20 and 10 Hz, respectively. This may cause different flow measurements, which will influence the reported results. The aim was to compare pulsatility index (PI) values recorded by the MediStim and Transonic flowmeters in two different clinical settings: (1) analysis of the flow patterns recorded simultaneously by both flowmeters in the same CABGs; and (2) evaluation of flow patterns under different levels of filter settings in the same grafts. Graft flow and PI were measured using the two different flowmeters simultaneously in 19 bypass grafts. Finally, eight grafts were assessed under different digital filter settings at 5, 10, 20, 30, 50 and 100 Hz. The Transonic flowmeter provided substantially lower PI as compared with the MediStim flowmeter. By increasing the filter setting in the flowmeter, PI increased considerably. The Transonic flowmeter displayed a lower PI than the MediStim, due to a lower filter setting. In the Transonic,flow signals are filtered at a lower level, rendering a 'smoother' pattern of flow curves. Because different filter settings determine different PIs, caution must be taken when flow values and flowmeters are compared. The type of flowmeter should be indicated whenever graft flow measurements and derived indexes are provided [corrected]. Copyright 2009 European Association for Cardio-Thoracic Surgery. All rights reserved.

  11. The spin project: safety and performance indicators in different time frames

    International Nuclear Information System (INIS)

    Storck, R.; Becker, D.A.

    2002-01-01

    Safety and performance indicators have been under discussion for many years in several countries and international organisations. If those indicators refer to the long term safety of the total disposal system, they are often called safety indicators. If they refer to the performance of subsystems or the total system from a more technical point of view, they are sometimes called performance indicators. The need for indicators other than dose rates derives e.g. from the long time frames involved in safety assessments of waste disposal systems and the increasing uncertainty in dose rate calculations over time due to uncertainty in evolution of the surface environment and of behaviour of man. Before introducing additional indicators into a safety case of a potential repository site, the applicability and usefulness of different indicators have to be investigated and evaluated. The systematic analysis and testing of safety and performance indicators for use in different time horizons after closure of the disposal facility is the task of the SPIN project. This is done by re-calculating four recent studies concerning repository projects in granite formations. (authors)

  12. Determining the Time of Flight and Speed of Sound on Different types of Edible Oil

    Science.gov (United States)

    Azman, N. A.; Hamid, S. B. Abd

    2017-11-01

    Edible oil is most often plant-based oils that have been extracted from various seeds. There are cases where the fully virgin edible oil was found to be a fraud. The adulterated edible oil indicates the intentional, fraudulent addition of extraneous, improper or cheaper ingredients puts into the oil or the dilution or removal of some valuable ingredient of the oil in order to increase profits. Hence, decrease the reliability of the Malaysian food product quality. This research was done by using the method of time of flight obtained using the Texas Instrument board, TDC1000-TDC7200 EVM connected to an ultrasonic transducer with 1 MHz frequency. The authors measured the time of flight and temperatures controlled from 20°C to 40°C of five vegetable oils (olive oil, sunflower oil, corn oil, coconut oil, and mustard oil). The value is observed and compared with other research from the literature review. From the study, time of flight values decreases exponentially while speed of sound value increases. This relationship will be useful in spectrum unfolding method to investigate the adulteration in different type of edible oil.This research outcome is to investigate the quality value of the different type of edible oil while eliminates the issues where the quality of Malaysian food product is not reliable.

  13. Gender, Parenthood and Wage Differences: The Importance of Time-Consuming Job Characteristics.

    Science.gov (United States)

    Magnusson, Charlotta; Nermo, Magnus

    2017-01-01

    Using data from the Swedish Level of Living Survey (2000, 2010), we investigate how the gender wage gap varies with occupational prestige and family status and also examine the extent to which this gap is explained by time-consuming working conditions. In addition, we investigate whether there is an association between parenthood, job characteristics and wage (as differentiated by gender). The analyses indicate that there are gender differences regarding prestige-based pay-offs among parents that are partly explained by fathers' greater access to employment characterized by time-consuming conditions. Separate analyses for men and women demonstrate the presence of a marriage wage premium for both genders, although only men have a parenthood wage premium. This fatherhood premium is however only present in high-prestigious occupations. Compared with childless men, fathers are also more advantaged in terms of access to jobs with time-consuming working conditions, but the wage gap between fathers and childless men is not explained by differences in access to such working conditions.

  14. Soft sensor modelling by time difference, recursive partial least squares and adaptive model updating

    International Nuclear Information System (INIS)

    Fu, Y; Xu, O; Yang, W; Zhou, L; Wang, J

    2017-01-01

    To investigate time-variant and nonlinear characteristics in industrial processes, a soft sensor modelling method based on time difference, moving-window recursive partial least square (PLS) and adaptive model updating is proposed. In this method, time difference values of input and output variables are used as training samples to construct the model, which can reduce the effects of the nonlinear characteristic on modelling accuracy and retain the advantages of recursive PLS algorithm. To solve the high updating frequency of the model, a confidence value is introduced, which can be updated adaptively according to the results of the model performance assessment. Once the confidence value is updated, the model can be updated. The proposed method has been used to predict the 4-carboxy-benz-aldehyde (CBA) content in the purified terephthalic acid (PTA) oxidation reaction process. The results show that the proposed soft sensor modelling method can reduce computation effectively, improve prediction accuracy by making use of process information and reflect the process characteristics accurately. (paper)

  15. IQ variations across time, race, and nationality: an artifact of differences in literacy skills.

    Science.gov (United States)

    Marks, David F

    2010-06-01

    A body of data on IQ collected over 50 years has revealed that average population IQ varies across time, race, and nationality. An explanation for these differences may be that intelligence test performance requires literacy skills not present in all people to the same extent. In eight analyses, population mean full scale IQ and literacy scores yielded correlations ranging from .79 to .99. In cohort studies, significantly larger improvements in IQ occurred in the lower half of the IQ distribution, affecting the distribution variance and skewness in the predicted manner. In addition, three Verbal subscales on the WAIS show the largest Flynn effect sizes and all four Verbal subscales are among those showing the highest racial IQ differences. This pattern of findings supports the hypothesis that both secular and racial differences in intelligence test scores have an environmental explanation: secular and racial differences in IQ are an artifact of variation in literacy skills. These findings suggest that racial IQ distributions will converge if opportunities are equalized for different population groups to achieve the same high level of literacy skills. Social justice requires more effective implementation of policies and programs designed to eliminate inequities in IQ and literacy.

  16. Measurement of the ecological flow of the Acaponeta river, Nayarit, comparing different time intervals

    Directory of Open Access Journals (Sweden)

    Guadalupe de la Lanza Espino

    2012-07-01

    Full Text Available The diverse management of river water in Mexico has been unequal due to the different anthropological activities, and it is associated with inter-annual changes in the climate and runoff patterns, leading to a loss of the ecosystem integrity. However, nowadays there are different methods to assess the water volume that is necessary to conserve the environment, among which are hydrological methods, such as those applied here, that are based on information on water volumes recorded over decades, which are not always available in the country. For this reason, this study compares runoff records for different time ranges: minimum of 10 years, medium of 20 years, and more than 50 years, to quantify the environmental flow. These time intervals provided similar results, which mean that not only for the Acaponeta river, but possibly for others lotic systems as well, a 10-year interval may be used satisfactorily. In this river, the runoff water that must be kept for environmental purposes is: for 10 years 70.1%, for 20 years 78.1% and for >50 years 68.8%, with an average of 72.3% of the total water volume or of the average annual runoff.

  17. The time-lapse AVO difference inversion for changes in reservoir parameters

    Science.gov (United States)

    Longxiao, Zhi; Hanming, Gu; Yan, Li

    2016-12-01

    The result of conventional time-lapse seismic processing is the difference between the amplitude and the post-stack seismic data. Although stack processing can improve the signal-to-noise ratio (SNR) of seismic data, it also causes a considerable loss of important information about the amplitude changes and only gives the qualitative interpretation. To predict the changes in reservoir fluid more precisely and accurately, we also need the quantitative information of the reservoir. To achieve this aim, we develop the method of time-lapse AVO (amplitude versus offset) difference inversion. For the inversion of reservoir changes in elastic parameters, we apply the Gardner equation as the constraint and convert the three-parameter inversion of elastic parameter changes into a two-parameter inversion to make the inversion more stable. For the inversion of variations in the reservoir parameters, we infer the relation between the difference of the reflection coefficient and variations in the reservoir parameters, and then invert reservoir parameter changes directly. The results of the theoretical modeling computation and practical application show that our method can estimate the relative variations in reservoir density, P-wave and S-wave velocity, calculate reservoir changes in water saturation and effective pressure accurately, and then provide reference for the rational exploitation of the reservoir.

  18. Real-Time Polymerase Chain Reaction Quantification of Phytophthora capsici in Different Pepper Genotypes.

    Science.gov (United States)

    Silvar, C; Díaz, J; Merino, F

    2005-12-01

    ABSTRACT Reliable and sensitive quantification of Phytophthora capsici in pepper plants is of crucial importance in managing the multiple syndromes caused by this pathogen. A real-time polymerase chain reaction (PCR) assay was developed for the determination of P. capsici in pepper tissues. DNA levels of a highly virulent and a less virulent isolate were measured in different pepper genotypes with varying degrees of resistance. Using SYBR Green and specific primers for P. capsici, the minimal amount of pathogen DNA quantified was 10 pg. Pathogen DNA was recorded as early as 8 h postinoculation. Thereafter, the increase was rapid in susceptible cultivars and slower in resistant ones. The amount of pathogen DNA quantified in each pepper genotype correlated with susceptibility to Phytophthora root rot. Likewise, there was a relationship between the virulence of the pathogen and the degree of colonization. Differences also were found in oomycete amount among pepper tissues, with maximal pathogen biomass occurring in stems. The real-time PCR technique developed in this study was sensitive and robust enough to assess both pathogen development and resistance to Phytophthora root rot in different pepper genotypes.

  19. Individual Differences in Diurnal Preference and Time-of-Exercise Interact to Predict Exercise Frequency.

    Science.gov (United States)

    Hisler, Garrett C; Phillips, Alison L; Krizan, Zlatan

    2017-06-01

    Diurnal preference (and chronotype more generally) has been implicated in exercise behavior, but this relation has not been examined using objective exercise measurements nor have potential psychosocial mediators been examined. Furthermore, time-of-day often moderates diurnal preference's influence on outcomes, and it is unknown whether time-of-exercise may influence the relation between chronotype and exercise frequency. The current study examined whether individual differences in diurnal preference ("morningness-eveningness") predict unique variance in exercise frequency and if commonly studied psychosocial variables mediate this relation (i.e., behavioral intentions, internal exercise control, external exercise control, and conscientiousness). Moreover, the study sought to test whether individuals' typical time-of-exercise moderated the impact of diurnal preference on exercise frequency. One hundred twelve healthy adults (mean age = 25.4; SD = 11.6 years) completed baseline demographics and then wore Fitbit Zips® for 4 weeks to objectively measure exercise frequency and typical time-of-exercise. At the end of the study, participants also self-reported recent exercise. Diurnal preference predicted both self-reported exercise and Fitbit-recorded exercise frequency. When evaluating mediators, only conscientiousness emerged as a partial mediator of the relation between diurnal preference and self-reported exercise. In addition, time-of-exercise moderated diurnal preference's relation to both self-reported exercise and Fitbit-recorded exercise frequency such that diurnal preference predicted higher exercise frequency when exercise occurred at a time that was congruent with one's diurnal preference. Based on these findings, diurnal preference is valuable, above and beyond other psychological constructs, in predicting exercise frequency and represents an important variable to incorporate into interventions seeking to increase exercise.

  20. Comparison of SAR calculation algorithms for the finite-difference time-domain method

    International Nuclear Information System (INIS)

    Laakso, Ilkka; Uusitupa, Tero; Ilvonen, Sami

    2010-01-01

    Finite-difference time-domain (FDTD) simulations of specific-absorption rate (SAR) have several uncertainty factors. For example, significantly varying SAR values may result from the use of different algorithms for determining the SAR from the FDTD electric field. The objective of this paper is to rigorously study the divergence of SAR values due to different SAR calculation algorithms and to examine if some SAR calculation algorithm should be preferred over others. For this purpose, numerical FDTD results are compared to analytical solutions in a one-dimensional layered model and a three-dimensional spherical object. Additionally, the implications of SAR calculation algorithms for dosimetry of anatomically realistic whole-body models are studied. The results show that the trapezium algorithm-based on the trapezium integration rule-is always conservative compared to the analytic solution, making it a good choice for worst-case exposure assessment. In contrast, the mid-ordinate algorithm-named after the mid-ordinate integration rule-usually underestimates the analytic SAR. The linear algorithm-which is approximately a weighted average of the two-seems to be the most accurate choice overall, typically giving the best fit with the shape of the analytic SAR distribution. For anatomically realistic models, the whole-body SAR difference between different algorithms is relatively independent of the used body model, incident direction and polarization of the plane wave. The main factors affecting the difference are cell size and frequency. The choice of the SAR calculation algorithm is an important simulation parameter in high-frequency FDTD SAR calculations, and it should be explained to allow intercomparison of the results between different studies. (note)

  1. Volatile compound profile of sous-vide cooked lamb loins at different temperature-time combinations.

    Science.gov (United States)

    Roldán, Mar; Ruiz, Jorge; Del Pulgar, José Sánchez; Pérez-Palacios, Trinidad; Antequera, Teresa

    2015-02-01

    Lamb loins were subjected to sous-vide cooking at different combinations of temperature (60 and 80°C) and time (6 and 24h) to assess the effect on the volatile compound profile. Major chemical families in cooked samples were aliphatic hydrocarbons and aldehydes. The volatile compound profile in sous-vide cooked lamb loin was affected by the cooking temperature and time. Volatile compounds arising from lipid oxidation presented a high abundance in samples cooked at low or moderate cooking conditions (60°C for 6 and 24h, 80°C for 6h), while a more intense time and temperature combination (80°C for 24h) resulted on a higher concentration of volatile compounds arising from Strecker degradations of amino acids, as 2-methylpropanal and 3-methylbutanal. Therefore, sous-vide cooking at moderately high temperatures for long times would result in the formation of a stronger meaty flavor and roast notes in lamb meat. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Accuracy, reproducibility, and time efficiency of dental measurements using different technologies.

    Science.gov (United States)

    Grünheid, Thorsten; Patel, Nishant; De Felippe, Nanci L; Wey, Andrew; Gaillard, Philippe R; Larson, Brent E

    2014-02-01

    Historically, orthodontists have taken dental measurements on plaster models. Technological advances now allow orthodontists to take these measurements on digital models. In this study, we aimed to assess the accuracy, reproducibility, and time efficiency of dental measurements taken on 3 types of digital models. emodels (GeoDigm, Falcon Heights, Minn), SureSmile models (OraMetrix, Richardson, Tex), and AnatoModels (Anatomage, San Jose, Calif) were made for 30 patients. Mesiodistal tooth-width measurements taken on these digital models were timed and compared with those on the corresponding plaster models, which were used as the gold standard. Accuracy and reproducibility were assessed using the Bland-Altman method. Differences in time efficiency were tested for statistical significance with 1-way analysis of variance. Measurements on SureSmile models were the most accurate, followed by those on emodels and AnatoModels. Measurements taken on SureSmile models were also the most reproducible. Measurements taken on SureSmile models and emodels were significantly faster than those taken on AnatoModels and plaster models. Tooth-width measurements on digital models can be as accurate as, and might be more reproducible and significantly faster than, those taken on plaster models. Of the models studied, the SureSmile models provided the best combination of accuracy, reproducibility, and time efficiency of measurement. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  3. Prediction of in-service time period of three differently stabilized single base propellants

    Energy Technology Data Exchange (ETDEWEB)

    Bohn, Manfred A. [Fraunhofer-Institut fuer Chemische Technologie (ICT), Pfinztal-Berghausen (Germany)

    2009-06-15

    Three nitrocellulose-based propellants for use in micro gas generators equipped with different stabilizing systems have been investigated to assess the stabilization capability with regard to in-service time, whereby strong time-temperature profiles have been applied. The three stabilizing systems have been (i) 0.74 mass-% diphenylamine (DPA) and 0.48 mass-% Akardite II (Ak II); (ii) 1.25 mass-% Ak II; (iii) 2.04 mass-% Ak II. Several profiles were considered. Two simulate the heating at sun exposure in hot areas, others consider environmental temperatures in hot-humid and hot-dry areas. They were evaluated according to the load and finally one was chosen for the assessment. The contents of stabilizers were determined by high performance liquid chromatography after Soxhlet type extraction. To describe stabilizer consumption, the most suitable kinetic model was taken. Therewith a prediction was made using the chosen time-temperature profile named 'Phoenix', designed for temperatures at the steering wheel. The objective was to reach with this profile 15 years until the consumption of primary stabilizer content. This is conservative, because with the stabilizing action of the consecutive products of the stabilizers longer times are possible. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  4. Assessment of the methods for determining net radiation at different time-scales of meteorological variables

    Directory of Open Access Journals (Sweden)

    Ni An

    2017-04-01

    Full Text Available When modeling the soil/atmosphere interaction, it is of paramount importance to determine the net radiation flux. There are two common calculation methods for this purpose. Method 1 relies on use of air temperature, while Method 2 relies on use of both air and soil temperatures. Nowadays, there has been no consensus on the application of these two methods. In this study, the half-hourly data of solar radiation recorded at an experimental embankment are used to calculate the net radiation and long-wave radiation at different time-scales (half-hourly, hourly, and daily using the two methods. The results show that, compared with Method 2 which has been widely adopted in agronomical, geotechnical and geo-environmental applications, Method 1 is more feasible for its simplicity and accuracy at shorter time-scale. Moreover, in case of longer time-scale, daily for instance, less variations of net radiation and long-wave radiation are obtained, suggesting that no detailed soil temperature variations can be obtained. In other words, shorter time-scales are preferred in determining net radiation flux.

  5. Decay-time measurements on 'pure' CsI scintillators prepared by different methods

    International Nuclear Information System (INIS)

    Keszthelyi-Landori, S.; Foeldvari, I.; Voszka, R.; Fodor, Z.; Seres, Z.

    1990-05-01

    The discovery of the fast decay time of the pure CsI and the various results of the measured samples led to the investigation of decay time of CsI crystals prepared by different methods. Carefully grown or prepared pure CsI behaves as fast scintillators with well or totally suppressed slow decay component. The estimated fast/slow or fast/total ratio is related to the preparation method and to the remaining built-in contamination of the samples. The fast decay of pure CsI consists of two components with decay times of ≅1 and ≅10 ns - with an intensity ratio of 0.3 and 0.65 for gamma and for alpha radiation, respectively. This new ≅1 ns component and the ≅0.8 fast/total ratio may achieve an important role in many applications where fast timing properties are needed, substituting BaF 2 . (author) 18 refs.; 8 figs.; 3 tabs

  6. Five different tests of reaction time evaluated in HIV seropositive men.

    Science.gov (United States)

    Dunlop, O; Bjørklund, R A; Abdelnoor, M; Myrvang, B

    1992-09-01

    In an attempt to develop a short neuropsychological test battery five different tests of reaction time were assessed according to their ability to discriminate between HIV seropositive men and healthy controls. In all tests a patient group with clinical symptoms was slower than the control group. In the complex reaction time test, which has a large cognitive aspect, even a clinically "asymptomatic" group was slower than the control group. The movement test, a new test with a large motor component, identified most slow responders, defining approximately half of the patients with clinical symptoms and one third of the "asymptomatic" patients as such. A test battery consisting of three tests is suggested for serial assessment and screening.

  7. Correlation between Chinese and international energy prices based on a HP filter and time difference analysis

    International Nuclear Information System (INIS)

    He, Yongxiu; Wang, Bing; Wang, Jianhui; Xiong, Wei; Xia, Tian

    2013-01-01

    To establish a reasonable system and mechanism for Chinese energy prices, we use the Granger causality test, Hodrick–Prescott (HP) filter and time difference analysis to research the pricing relationship between Chinese and international energy prices. We find that Chinese and international crude oil prices changed synchronously while Chinese refined oil prices follow the changes of international oil prices with the time difference being about 1 month to 2 months. Further, Australian coal prices Granger causes Chinese coal prices, and there is a high correlation between them. The U.S. electricity price is influenced by the WTI crude oil price, the U.S. gasoline price and the HenryHub gas price. Due to the unreasonable price-setting mechanism and regulation from the central government, China′s terminal market prices for both electricity and natural gas do not reflect the real supply–demand situation. This paper provides quantitative results on the correlation between Chinese and international energy prices to better predict the impact of international energy price fluctuations on China′s domestic energy supply and guide the design of more efficient energy pricing policies. Moreover, it provides references for developing countries to improve their energy market systems and trading, and to coordinate domestic and international energy markets. -- Highlights: •The Hodrick-Prescott filter and time difference analysis are used to research the correlation among energy prices. •Our study finds that the U.S. and British refined oil prices Granger cause the Chinese refined oil price. •Both Chinese and the Australian coal prices play an important role in the international coal market. •The Chinese terminal electric power and terminal natural gas prices are not highly correlated. •The results are useful for guiding the design of more efficient energy pricing policies in China

  8. The time aspect of bioenergy. Climate impacts of bioenergy due to differences in carbon uptake rates

    Energy Technology Data Exchange (ETDEWEB)

    Zetterberg, Lars [IVL Swedish Environmental Research Institute, Stockholm (Sweden); Chen, Deliang [Dept. of Earth Sciences, Univ. of Gothenburg, Gothenburg (Sweden)

    2011-07-01

    This paper investigates the climate impacts from bioenergy due to how they influence carbon stocks over time and more specifically how fast combustion related carbon emissions are compensated by uptake of atmospheric carbon. A set of fuel types representing different uptake rates are investigated, namely willow, branches and tops, stumps and coal. Net emissions are defined as emissions from utilizing the fuel minus emissions from a reference case of no utilisation. In the case of forest residues, the compensating 'uptake' is avoided emissions from the reference case of leaving the residues to decompose on the ground. Climate impacts are estimated using the measures radiative forcing and global average surface temperature, which have been calculated by an energy balance climate model. We conclude that there is a climate impact from using bioenergy due to how fast the emission pulse is compensated by uptake of atmospheric carbon (or avoided emissions). Biofuels with slower uptake rates have a stronger climate impact than fuels with a faster uptake rate, assuming all other parameters equal. The time perspective over which the analysis is done is crucial for the climate impact of biofuels. If only biogenic fluxes are considered, our results show that over a 100 year perspective branches and tops are better for climate mitigation than stumps which in turn are better than coal. Over a 20 year time perspective this conclusion holds, but the differences between these fuels are relatively smaller. Establishing willow on earlier crop land may reduce atmospheric carbon, provided new land is available. However, these results are inconclusive since we haven't considered the effects, if needed, of producing the traditional agricultural crops elsewhere. The analysis is not a life cycle assessment of different fuels and does therefore not consider the use of fossil fuels for logging, transportation and refining, other greenhouse gases than carbon or energy

  9. Trait differences between naturalized and invasive plant species independent of residence time and phylogeny.

    Science.gov (United States)

    Gallagher, R V; Randall, R P; Leishman, M R

    2015-04-01

    The ability to predict which alien plants will transition from naturalized to invasive prior to their introduction to novel regions is a key goal for conservation and has the potential to increase the efficacy of weed risk assessment (WRA). However, multiple factors contribute to plant invasion success (e.g., functional traits, range characteristics, residence time, phylogeny), and they all must be taken into account simultaneously in order to identify meaningful correlates of invasion success. We compiled 146 pairs of phylogenetically paired (congeneric) naturalized and invasive plant species in Australia with similar minimum residence times (i.e., time since introduction in years). These pairs were used to test for differences in 5 functional traits (flowering duration, leaf size, maximum height, specific leaf area [SLA], seed mass) and 3 characteristics of species' native ranges (biome occupancy, mean annual temperature, and rainfall breadth) between naturalized and invasive species. Invasive species, on average, had larger SLA, longer flowering periods, and were taller than their congeneric naturalized relatives. Invaders also exhibited greater tolerance for different environmental conditions in the native range, where they occupied more biomes and a wider breadth of rainfall and temperature conditions than naturalized congeners. However, neither seed mass nor leaf size differed between pairs of naturalized and invasive species. A key finding was the role of SLA in distinguishing between naturalized and invasive pairs. Species with high SLA values were typically associated with faster growth rates, more rapid turnover of leaf material, and shorter lifespans than those species with low SLA. This suite of characteristics may contribute to the ability of a species to transition from naturalized to invasive across a wide range of environmental contexts and disturbance regimes. Our findings will help in the refinement of WRA protocols, and we advocate the inclusion

  10. How does landscape structure influence catchment transit time across different geomorphic provinces?

    Science.gov (United States)

    Tetzlaff, D.; Seibert, J.; McGuire, K.J.; Laudon, H.; Burns, Douglas A.; Dunn, S.M.; Soulsby, C.

    2009-01-01

    Despite an increasing number of empirical investigations of catchment transit times (TTs), virtually all are based on individual catchments and there are few attempts to synthesize understanding across different geographical regions. Uniquely, this paper examines data from 55 catchments in five geomorphic provinces in northern temperate regions (Scotland, United States of America and Sweden). The objective is to understand how the role of catchment topography as a control on the TTs differs in contrasting geographical settings. Catchment inverse transit time proxies (ITTPs) were inferred by a simple metric of isotopic tracer damping, using the ratio of standard deviation of ??18O in streamwater to the standard deviation of ??18O in precipitation. Quantitative landscape analysis was undertaken to characterize the catchments according to hydrologically relevant topographic indices that could be readily determined from a digital terrain model (DTM). The nature of topographic controls on transit times varied markedly in different geomorphic regions. In steeper montane regions, there are stronger gravitational influences on hydraulic gradients and TTs tend to be lower in the steepest catchments. In provinces where terrain is more subdued, direct topographic control weakened; in particular, where flatter areas with less permeable soils give rise to overland flow and lower TTs. The steeper slopes within this flatter terrain appear to have a greater coverage of freely draining soils, which increase sub-surface flow, therefore increasing TTs. Quantitative landscape analysis proved a useful tool for intercatchment comparison. However, the critical influence of sub-surface permeability and connectivity may limit the transferability of predictive tools of hydrological function based on topographic parameters alone. Copyright ?? 2009 John Wiley & Sons, Ltd.

  11. Just-in-Time or Plenty-of-Time Teaching? Different Electronic Feedback Devices and Their Effect on Student Engagement

    Science.gov (United States)

    Sun, Jerry Chih-Yuan; Martinez, Brandon; Seli, Helena

    2014-01-01

    This study examines how incorporating different electronic feedback devices (i.e., clickers versus web-based polling) may affect specific types of student engagement (i.e., behavioral, emotional, and cognitive engagement), whether students' self-efficacy for learning and performance may differ between courses that have integrated clickers and…

  12. Effect of gamma irradiation on storage time of tomatoes in three different stages of ripending

    International Nuclear Information System (INIS)

    Ozbek, N.; Ozbilgin, S.; Aysan, P.; Celen, H.

    1985-01-01

    Effect of g-irradiation on storage time of tomatoes was studied and tomatoes of Diego variety in three different stages of ripening were used for the experiment. Green-mature tomatoes were treated with 100 and 200 krad, pink (half-mature) tomatoes were treated with 50, 100, 200, 300, 400 and 500 krad doses of gamma rays respectively. After irradiation the tomatoes were stored in a room where the temperature was kept at 22 C with a humidity of 65%. During storage period color changes, softening, spoilage and molding of the fruits were controlled daily, weight loss measurements and all necessary chemical analysis were made periodically. (author)

  13. Different but Equal: Total Work, Gender and Social Norms in EU and US Time Use

    OpenAIRE

    Daniel S Hamermesh; Michael C Burda; Philippe Weil

    2008-01-01

    Using time-diary data from 27 countries, we demonstrate a negative relationship between real GDP per capita and the female-male difference in total work time—the sum of work for pay and work at home. We also show that in rich non-Catholic countries on four continents men and women do the same amount of total work on average. Our survey results demonstrate that labor economists, macroeconomists, sociologists and the general public consistently believe that women perform more tot...

  14. Scattering analysis of periodic structures using finite-difference time-domain

    CERN Document Server

    ElMahgoub, Khaled; Elsherbeni, Atef Z

    2012-01-01

    Periodic structures are of great importance in electromagnetics due to their wide range of applications such as frequency selective surfaces (FSS), electromagnetic band gap (EBG) structures, periodic absorbers, meta-materials, and many others. The aim of this book is to develop efficient computational algorithms to analyze the scattering properties of various electromagnetic periodic structures using the finite-difference time-domain periodic boundary condition (FDTD/PBC) method. A new FDTD/PBC-based algorithm is introduced to analyze general skewed grid periodic structures while another algor

  15. Cost, Time, and Risk Assessment of Different Wave Energy Converter Technology Development Trajectories: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Jochem W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Laird, Daniel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Costello, Ronan [Wave Venture; Roberts, Jesse [Sandia National Laboratories; Bull, Diana [Sandia National Laboratories; Babarit, Aurelien [Ecole Centrale de Nantes; Nielsen, Kim [Ramboll; Ferreira, Claudio Bittencourt [DNV-GL; Kennedy, Ben [Wave Venture

    2017-09-14

    This paper presents a comparative assessment of three fundamentally different wave energy converter technology development trajectories. The three technology development trajectories are expressed and visualised as a function of technology readiness levels and technology performance levels. The assessment shows that development trajectories that initially prioritize technology readiness over technology performance are likely to require twice the development time, consume a threefold of the development cost, and are prone to a risk of technical or commercial failure of one order of magnitude higher than those development trajectories that initially prioritize technology performance over technology readiness.

  16. Comparison of different Kalman filter approaches in deriving time varying connectivity from EEG data.

    Science.gov (United States)

    Ghumare, Eshwar; Schrooten, Maarten; Vandenberghe, Rik; Dupont, Patrick

    2015-08-01

    Kalman filter approaches are widely applied to derive time varying effective connectivity from electroencephalographic (EEG) data. For multi-trial data, a classical Kalman filter (CKF) designed for the estimation of single trial data, can be implemented by trial-averaging the data or by averaging single trial estimates. A general linear Kalman filter (GLKF) provides an extension for multi-trial data. In this work, we studied the performance of the different Kalman filtering approaches for different values of signal-to-noise ratio (SNR), number of trials and number of EEG channels. We used a simulated model from which we calculated scalp recordings. From these recordings, we estimated cortical sources. Multivariate autoregressive model parameters and partial directed coherence was calculated for these estimated sources and compared with the ground-truth. The results showed an overall superior performance of GLKF except for low levels of SNR and number of trials.

  17. Modifications of small intestine lysosomal enzymes after irradiation at different times of the day

    Energy Technology Data Exchange (ETDEWEB)

    Becciolini, A; Giache, V; Lanini, A; Cremonini, D; Drighi, E [Florence Univ. (Italy). Ist. di Radiologia

    1982-01-01

    The modification of lysosomal enzyme activities in animals irradiated with the same sublethal dose at 4 different times of the day is reported. The results confirmed the absence of circadian fluctuations in all the lysosomal enzymes and in protein content. A difference in behaviour between acid ..beta..-galactosidase and ..beta..-glucuronidase on the one hand and between acid phosphatase and cathepsin D on the other was evident in irradiated animals. The results showed that acid ..beta..-galactosidase and ..beta..-glucuronidase increase from the early intervals after irradiation and reach the highest activity between 36 and 48 h. At these intervals autolysis phenomena, heavy cellular alterations and numerous phlogosis cells are present in the epithelium. Only ..beta..-glucuronidase and acid ..beta..-galactosidase indicate the level of radiation injury.

  18. Evaluation of the minimal replication time of Cauliflower mosaic virus in different hosts

    International Nuclear Information System (INIS)

    Khelifa, Mounia; Masse, Delphine; Blanc, Stephane; Drucker, Martin

    2010-01-01

    Though the duration of a single round of replication is an important biological parameter, it has been determined for only few viruses. Here, this parameter was determined for Cauliflower mosaic virus (CaMV) in transfected protoplasts from different hosts: the highly susceptible Arabidopsis and turnip, and Nicotiana benthamiana, where CaMV accumulates only slowly. Four methods of differing sensitivity were employed: labelling of (1) progeny DNA and (2) capsid protein, (3) immunocapture PCR,, and (4) progeny-specific PCR. The first progeny virus was detected about 21 h after transfection. This value was confirmed by all methods, indicating that our estimate was not biased by the sensitivity of the detection method, and approximated the actual time required for one round of CaMV replication. Unexpectedly, the replication kinetics were similar in the three hosts; suggesting that slow accumulation of CaMV in Nicotiana plants is determined by non-optimal interactions in other steps of the infection cycle.

  19. Educational differences in leisure-time physical inactivity: a descriptive and explanatory study.

    Science.gov (United States)

    Droomers, M; Schrijvers, C T; van de Mheen, H; Mackenbach, J P

    1998-12-01

    In this study we aim to explain educational differences in leisure-time physical inactivity in terms of psychosocial and material factors. Cross-sectional data were obtained from the baseline of the Dutch GLOBE study in 1991, including 2598 men and women, aged 15-74 years. Physical inactivity during leisure time was defined as not participating in any activity, such as sports, gardening, walking or cycling. Psychosocial factors included in the study were coping resources, personality, and stressors. Material factors were financial situation, employment status, and living conditions. Logistic regression models were used to calculate educational differences in physical inactivity. Physical inactivity was more prevalent in lower educational groups. Psychosocial factors related to physical inactivity were locus of control, parochialism, neuroticism, emotional social support, active problem focussing, optimistic and palliative coping styles. Material factors associated with physical inactivity were income, employment status and financial problems. All correlates of physical inactivity were unequally distributed over educational groups, except optimistic and palliative coping. Personality and coping style were the main contributors to the observed educational differences in physical inactivity. That is to say, parochialism, locus of control, neuroticism and active problem focussing explained about half of elevated odds ratios of physical inactivity in the lower educational groups. The material factors, equivalent income and employment status explained about 40% of the elevated odds ratios. Psychosocial and material correlates together reduced the odds ratios of lower educational groups by on average 75%. These results have practical consequences for the design of more effective interventions to promote physical activity. In particular, personality and coping style of risk groups, such as lower educational groups, should be taken into consideration at the future

  20. REAL-TIME STABILITY AND PROFILE COMPARISON MEASUREMENTS BETWEEN TWO DIFFERENT LTPS

    International Nuclear Information System (INIS)

    2005-01-01

    The Long Trace Profiler (LTP) is a precise angle measurement instrument, with a sensitivity and accuracy that can be in the sub-micron radian range. LTP characteristics depend on the particular LTP system schematic design, and the quality of components and assembly. The conditions of temperature, alignment, and mirror support during the measurement process vary between different laboratories, which influences significantly the test repeatability and accuracy. In this paper we introduce a direct comparison method to test the same object at the same point in the same environment at the same time by using two LTPs, which significantly increases the reliability of the comparison. A compact, portable LTP (PTLTP), which can be carried to different laboratories around the world, is used for comparison testing. Stability Comparison experiments between the LTP II at the National Synchrotron Radiation Research Center (NSRRC), and the PTLTP of Brookhaven National Laboratory (BNL) reveal significant differences in performance between the instruments. The experiment is set up so that each optical head simultaneously records both its own sample probe beam and also the probe beam from the other optical head. The two probe beams are reflected from same point on the mirror. Tests show that the stability of the PTLTP with a monolithic beam splitter is 10 times better than the stability of the LTP II which has a separated beam splitter unit. A scheme for comparing scanning measurements of a mirror is introduced. Experimental results show a significant difference between the two LTPs due mainly to distortions in the optical components inside the optical head. A new scheme is proposed for further mirror comparison scanning tests

  1. Incidence of Delirium Among Patients Having Cancer Injected With Different Opioids for the First Time.

    Science.gov (United States)

    Tanaka, Rei; Ishikawa, Hiroshi; Sato, Tetsu; Shino, Michihiro; Matsumoto, Teruaki; Mori, Keita; Omae, Katsuhiro; Osaka, Iwao

    2017-07-01

    Despite the risk of drug-induced delirium, it is difficult to avoid the use of opioids in palliative care. However, no previous study has carefully investigated how the development of delirium varies among patients injected with different opioids for the first time. To reveal the difference in the incidence of delirium between different opioids. The incidence of delirium was compared among 114 patients who had started morphine, oxycodone, or fentanyl injection at Shizuoka Cancer Center between June 2012 and September 2014. The incidence of delirium was 28.9% in the morphine group (n = 38), 19.5% in the oxycodone group (n = 41), and 8.6% in the fentanyl group (n = 35). There was a significant difference between the morphine and fentanyl groups (Fisher's exact test, P = 0.04) but not between the morphine and oxycodone groups (P = 0.43) nor between the oxycodone and fentanyl groups (P = 0.21). The incidence of delirium after the commencement of fentanyl injection was significantly lower, suggesting that fentanyl is a useful opioid injection drug from the perspective of delirium risk.

  2. Cross-cultural differences in mental representations of time: evidence from an implicit nonlinguistic task.

    Science.gov (United States)

    Fuhrman, Orly; Boroditsky, Lera

    2010-11-01

    Across cultures people construct spatial representations of time. However, the particular spatial layouts created to represent time may differ across cultures. This paper examines whether people automatically access and use culturally specific spatial representations when reasoning about time. In Experiment 1, we asked Hebrew and English speakers to arrange pictures depicting temporal sequences of natural events, and to point to the hypothesized location of events relative to a reference point. In both tasks, English speakers (who read left to right) arranged temporal sequences to progress from left to right, whereas Hebrew speakers (who read right to left) arranged them from right to left, replicating previous work. In Experiments 2 and 3, we asked the participants to make rapid temporal order judgments about pairs of pictures presented one after the other (i.e., to decide whether the second picture showed a conceptually earlier or later time-point of an event than the first picture). Participants made responses using two adjacent keyboard keys. English speakers were faster to make "earlier" judgments when the "earlier" response needed to be made with the left response key than with the right response key. Hebrew speakers showed exactly the reverse pattern. Asking participants to use a space-time mapping inconsistent with the one suggested by writing direction in their language created interference, suggesting that participants were automatically creating writing-direction consistent spatial representations in the course of their normal temporal reasoning. It appears that people automatically access culturally specific spatial representations when making temporal judgments even in nonlinguistic tasks. Copyright © 2010 Cognitive Science Society, Inc.

  3. Different time concepts in the classroom. From monologue to dialogue: space

    Directory of Open Access Journals (Sweden)

    Leonor Sáez Méndez

    2012-12-01

    Full Text Available This paper explores, taking as its starting point cognitive variables, the essential function which affective variables have in the teaching of foreign languages. The conceptual transposition a reorientation required to acquire a second language involves distinguishing different philosophical concepts about space and time. From the 1970s and on, the linguistic requirements of teaching a language have taken a Kantian turn. Together with the principles of pragmatics and interculturality, it is important to work with concepts such as perception, disposition, motivation, intuition, level of empathy, and fear. Bearing in mind that these are complex factors which have a great impact on the process of immersion in a foreign language, it is worth asking if they are just temporal. The actual learning process, involving self-study, requires additional support to focus the learner’s resources and encourage them to immerse themselves in and identify with the culture associated with the language they are learning. These areas are in the critical period, especially in the post-Kantian critical, empirical thresholds that shape our thinking and guide the choice of exercises. Our study aims 1 to refl ect on the diff erent conceptions of time (as inner meaning, cognitive time underlying foreign language teaching; 2 to explore whether is it possible to develop a methodology based just on time, therefore leaving, space to one side or, in contrast, whether it is space which rules over time in the process of foreign language acquisition.

  4. Effect of irradiation times on the polymerization depth of contemporary fissure sealants with different opacities

    Directory of Open Access Journals (Sweden)

    Boniek Castillo Dutra Borges

    2011-04-01

    Full Text Available The aim of this study was to evaluate the depth of curing of 10 contemporary blue light-activated dental flowable materials at several opacities, influenced by different irradiation times using FT-IR spectroscopy. Fifty-five specimens (n = 5 with a 5-mm diameter and 1-mm thickness of translucent (Opallis Flow T, yellowed (Master Flow A2; Opallis Flow A2; Natural Flow A2; Fluroshield Yellowed, and opaque materials (Master Flow OA2; Natural Flow O; Opallis Flow OA3.5; Opallis Flow OP; Fluroshield White were obtained at six curing times (10s, 20s, 30s, 40s, 50s, and 60s using a high-intensity LED (Coltolux, Coltène/Whaledent. The degree of conversion (DC (% was obtained using the Nexus 470 FTIR Spectrometer (Nicolet Instruments, USA. The FTIR-ATR spectra for uncured and cured samples were analyzed using a ZnSe crystal. The top and bottom surfaces of the cured specimens were analyzed to obtain the depth of curing. Two-way ANOVA was used to analyze the data. The highest curing depth was obtained by Natural Flow OA2, while the lowest was shown by Master Flow OA2. The shortest curing time generated similar depths of cure in comparison with the most extensive for Opallis Flow A2 and Fluroshield Yellowed. Therefore, depth of curing, influenced by the irradiation time, was dependent on the materials. Using the Natural Flow OA2 opaque sealant and the 10-s curing time for Opallis Flow A2 and Fluroshield Yellowed may represent alternative approaches to sealing tooth fissures.

  5. Contrast timing in computed tomography: Effect of different contrast media concentrations on bolus geometry

    International Nuclear Information System (INIS)

    Mahnken, Andreas H.; Jost, Gregor; Seidensticker, Peter; Kuhl, Christiane; Pietsch, Hubertus

    2012-01-01

    Objective: To assess the effect of low-osmolar, monomeric contrast media with different iodine concentrations on bolus shape in aortic CT angiography. Materials and methods: Repeated sequential computed tomography scanning of the descending aorta of eight beagle dogs (5 male, 12.7 ± 3.1 kg) was performed without table movement with a standardized CT scan protocol. Iopromide 300 (300 mg I/mL), iopromide 370 (370 mg I/mL) and iomeprol 400 (400 mg I/mL) were administered via a foreleg vein with an identical iodine delivery rate of 1.2 g I/s and a total iodine dose of 300 mg I/kg body weight. Time-enhancement curves were computed and analyzed. Results: Iopromide 300 showed the highest peak enhancement (445.2 ± 89.1 HU), steepest up-slope (104.2 ± 17.5 HU/s) and smallest full width at half maximum (FWHM; 5.8 ± 1.0 s). Peak enhancement, duration of FWHM, enhancement at FWHM and up-slope differed significantly between iopromide 300 and iomeprol 400 (p 0.05). Conclusions: Low viscous iopromide 300 results in a better defined bolus with a significantly higher peak enhancement, steeper up-slope and smaller FWHM when compared to iomeprol 400. These characteristics potentially affect contrast timing.

  6. How Similar Are Forest Disturbance Maps Derived from Different Landsat Time Series Algorithms?

    Directory of Open Access Journals (Sweden)

    Warren B. Cohen

    2017-03-01

    Full Text Available Disturbance is a critical ecological process in forested systems, and disturbance maps are important for understanding forest dynamics. Landsat data are a key remote sensing dataset for monitoring forest disturbance and there recently has been major growth in the development of disturbance mapping algorithms. Many of these algorithms take advantage of the high temporal data volume to mine subtle signals in Landsat time series, but as those signals become subtler, they are more likely to be mixed with noise in Landsat data. This study examines the similarity among seven different algorithms in their ability to map the full range of magnitudes of forest disturbance over six different Landsat scenes distributed across the conterminous US. The maps agreed very well in terms of the amount of undisturbed forest over time; however, for the ~30% of forest mapped as disturbed in a given year by at least one algorithm, there was little agreement about which pixels were affected. Algorithms that targeted higher-magnitude disturbances exhibited higher omission errors but lower commission errors than those targeting a broader range of disturbance magnitudes. These results suggest that a user of any given forest disturbance map should understand the map’s strengths and weaknesses (in terms of omission and commission error rates, with respect to the disturbance targets of interest.

  7. Paths towards Family‐friendly Working Time Arrangements: Comparing Workplaces in Different Countries and Industries

    Science.gov (United States)

    2016-01-01

    Abstract Although studies have examined the distribution and conditions of employer‐provided work–family arrangements, we still lack a systematic investigation of how these vary for different countries and industries. Based on the European Working Conditions Survey 2010, this study examines the conditions under which firms provide family‐friendly working time arrangements and what the differences are across four countries (Austria, Denmark, Italy and the UK) and four industries. The impact of employee representatives, employee involvement, manager support and female managers varies across countries and industries because of the institutional environment (prevailing family model, industrial relations) and workforce composition (gender). The impact of employee representatives depends on their co‐determination rights, and the direction of their effect on the prevailing family model (e.g. negative in conservative countries such as Austria) and the gender composition of the workforce (negative in male‐dominated production, but positive in services). Employee involvement in the work organization is significantly positive in Austria and Denmark (both with co‐operative industrial relations), while manager support has the strongest effect in the UK (liberal regime). At the industry level, female supervisors are positively associated with family‐friendly working time arrangements only in the male‐dominated production industry. These findings suggest that the effects of agency variables and their direction vary depending on the institutional context. PMID:29242672

  8. Paths towards Family-friendly Working Time Arrangements: Comparing Workplaces in Different Countries and Industries.

    Science.gov (United States)

    Wiß, Tobias

    2017-12-01

    Although studies have examined the distribution and conditions of employer-provided work-family arrangements, we still lack a systematic investigation of how these vary for different countries and industries. Based on the European Working Conditions Survey 2010, this study examines the conditions under which firms provide family-friendly working time arrangements and what the differences are across four countries (Austria, Denmark, Italy and the UK) and four industries. The impact of employee representatives, employee involvement, manager support and female managers varies across countries and industries because of the institutional environment (prevailing family model, industrial relations) and workforce composition (gender). The impact of employee representatives depends on their co-determination rights, and the direction of their effect on the prevailing family model (e.g. negative in conservative countries such as Austria) and the gender composition of the workforce (negative in male-dominated production, but positive in services). Employee involvement in the work organization is significantly positive in Austria and Denmark (both with co-operative industrial relations), while manager support has the strongest effect in the UK (liberal regime). At the industry level, female supervisors are positively associated with family-friendly working time arrangements only in the male-dominated production industry. These findings suggest that the effects of agency variables and their direction vary depending on the institutional context.

  9. Time-intensity profile of pitanga nectar (Eugenia uniflora L.) with different sweeteners: Sweetness and bitterness.

    Science.gov (United States)

    Freitas, Mírian Luisa Faria; de Lima Dutra, Mariana Borges; Bolini, Helena Maria André

    2016-01-01

    Pitanga has been used by the Brazilian food industry mainly for juice production. This fruit shows good economic potential due to its high concentration of vitamins and minerals. The aim of the present work was to characterize the time-intensity profile of pitanga nectar sweetened with different sweeteners to verify differences on the perception of sweet and bitter tastes. The sweeteners used to replace sucrose were sucralose, aspartame, stevia 40% rebaudioside A, stevia 95% rebaudioside A, neotame, and 2:1 cyclamate/saccharin blend. Fifteen assessors were selected according to their discriminating capability and trained to participate in the time-intensity analysis for sweetness and bitterness. The samples prepared with sucralose and 2:1 cyclamate/saccharin blend presented a similar sweetness profile to the sample prepared with sucrose, and the samples prepared with sucralose and aspartame presented a similar bitterness profile to the sample prepared with sucrose. Thus, sucralose would be the most suitable sweetener to replace sucrose in pitanga nectar. © The Author(s) 2015.

  10. Influence of Short-time Oxidation on Corrosion Properties of Directionally Solidified Superalloys with Different Orientations

    Directory of Open Access Journals (Sweden)

    MA Luo-ning

    2016-07-01

    Full Text Available In order to investigate the corrosion performance on intersecting and longitudinal surfaces of unoxidized and oxidized directionally solidified superalloys, Ni-base directionally solidified superalloy DZ125 and Co-base directionally solidified superalloy DZ40M were selected. Oxidation behavior on both alloys with different orientations was investigated at 1050℃ at different times, simulating the oxidation process of vanes or blades in service; subsequent electrochemical performance in 3.5%NaCl aqueous solution was studied on two orientations of unoxidized and oxidized alloys, simulating the corrosion process of superalloy during downtime. The results show that grain boundaries and sub-boundaries of directionally solidified superalloys are susceptible to corrosion and thus longitudinal surface with lower area fraction of grain boundaries has higher corrosion resistance. Compared to intersecting surface of alloys, the structure of grain boundaries of longitudinal surface is less conducive to diffusion and thus the oxidation rate on longitudinal surface is lower. Formation of oxide layers on alloys after short-time oxidation provides protective effect and enhances the corrosion resistance.

  11. Modelling of the acid base properties of two thermophilic bacteria at different growth times

    Science.gov (United States)

    Heinrich, Hannah T. M.; Bremer, Phil J.; McQuillan, A. James; Daughney, Christopher J.

    2008-09-01

    Acid-base titrations and electrophoretic mobility measurements were conducted on the thermophilic bacteria Anoxybacillus flavithermus and Geobacillus stearothermophilus at two different growth times corresponding to exponential and stationary/death phase. The data showed significant differences between the two investigated growth times for both bacterial species. In stationary/death phase samples, cells were disrupted and their buffering capacity was lower than that of exponential phase cells. For G. stearothermophilus the electrophoretic mobility profiles changed dramatically. Chemical equilibrium models were developed to simultaneously describe the data from the titrations and the electrophoretic mobility measurements. A simple approach was developed to determine confidence intervals for the overall variance between the model and the experimental data, in order to identify statistically significant changes in model fit and thereby select the simplest model that was able to adequately describe each data set. Exponential phase cells of the investigated thermophiles had a higher total site concentration than the average found for mesophilic bacteria (based on a previously published generalised model for the acid-base behaviour of mesophiles), whereas the opposite was true for cells in stationary/death phase. The results of this study indicate that growth phase is an important parameter that can affect ion binding by bacteria, that growth phase should be considered when developing or employing chemical models for bacteria-bearing systems.

  12. Arena3D: visualizing time-driven phenotypic differences in biological systems

    Directory of Open Access Journals (Sweden)

    Secrier Maria

    2012-03-01

    Full Text Available Abstract Background Elucidating the genotype-phenotype connection is one of the big challenges of modern molecular biology. To fully understand this connection, it is necessary to consider the underlying networks and the time factor. In this context of data deluge and heterogeneous information, visualization plays an essential role in interpreting complex and dynamic topologies. Thus, software that is able to bring the network, phenotypic and temporal information together is needed. Arena3D has been previously introduced as a tool that facilitates link discovery between processes. It uses a layered display to separate different levels of information while emphasizing the connections between them. We present novel developments of the tool for the visualization and analysis of dynamic genotype-phenotype landscapes. Results Version 2.0 introduces novel features that allow handling time course data in a phenotypic context. Gene expression levels or other measures can be loaded and visualized at different time points and phenotypic comparison is facilitated through clustering and correlation display or highlighting of impacting changes through time. Similarity scoring allows the identification of global patterns in dynamic heterogeneous data. In this paper we demonstrate the utility of the tool on two distinct biological problems of different scales. First, we analyze a medium scale dataset that looks at perturbation effects of the pluripotency regulator Nanog in murine embryonic stem cells. Dynamic cluster analysis suggests alternative indirect links between Nanog and other proteins in the core stem cell network. Moreover, recurrent correlations from the epigenetic to the translational level are identified. Second, we investigate a large scale dataset consisting of genome-wide knockdown screens for human genes essential in the mitotic process. Here, a potential new role for the gene lsm14a in cytokinesis is suggested. We also show how phenotypic

  13. [The effect of breast massage at different time in the early period after cesarean section].

    Science.gov (United States)

    Chu, J Y; Zhang, L; Zhang, Y J; Yang, M J; Li, X W; Sun, L L

    2017-11-06

    Objective: To evaluate the effect of breast massage at different time in the early period on maternal lactation after cesarean section. Methods: 80 women delivered by cesarean section were randomly selected from maternity ward of a hospital in Shandong province during Jan. 2013 to Jan. 2015; which were divided into four groups, with 20 patients in each. Three groups received 3 times of breast massage every 24 hoursbeginning from 2, 12 and 24 h after cesarean section, respectively. The control group didn't receive any breast massage. The starting time and status of lactation were observed and recorded after cesarean section. 5 ml venous blood sample was drawn from each patient respectively at 2 h before cesarean, 6, 12, 24, 48 and 72 h after cesarean to test the level of serum prolactin. The lactation status of each group was compared. Results: The P (50) ( P (25)- P (75)) of starting time of lactation of the three massage groups and control group were 3 (2-6) h, 4 (2-8) h, 4 (3-12) h and 4 (2-12) h, respectively, whose differences showed no statistical significance ( H =3.32, P= 0.345).The number of delivered women with adequate lactation 24 hours after cesarean was 10 in the group who received massage beginning from 2 h after cesarean; while the number was only 2 in the control group. The number of delivered women with adequate lactation 48 hours after cesarean was 18 in the group who received massage beginning from 2 h after cesarean; while the number was 8 in the control group. The differences showed statistical significances ( P values were 0.021 and 0.008, respectively). The serum prolactin level in the group of delivered women who received massage from 2 h after cesarean was separately (195.9±78.5), (176.0±96.5), (216.4±110.0), (190.0±56.8) and (184.8±69.6) μg/L at 2, 12, 24, 48 and 72 h after cesarean, which were significantly higher than those in the control group (which were (128.8±40.6), (127.3±66.8), (162.2±58.8), (145.1±64.7) and (141.7±49

  14. Using individual differences to test the role of temporal and place cues in coding frequency modulation.

    Science.gov (United States)

    Whiteford, Kelly L; Oxenham, Andrew J

    2015-11-01

    The question of how frequency is coded in the peripheral auditory system remains unresolved. Previous research has suggested that slow rates of frequency modulation (FM) of a low carrier frequency may be coded via phase-locked temporal information in the auditory nerve, whereas FM at higher rates and/or high carrier frequencies may be coded via a rate-place (tonotopic) code. This hypothesis was tested in a cohort of 100 young normal-hearing listeners by comparing individual sensitivity to slow-rate (1-Hz) and fast-rate (20-Hz) FM at a carrier frequency of 500 Hz with independent measures of phase-locking (using dynamic interaural time difference, ITD, discrimination), level coding (using amplitude modulation, AM, detection), and frequency selectivity (using forward-masking patterns). All FM and AM thresholds were highly correlated with each other. However, no evidence was obtained for stronger correlations between measures thought to reflect phase-locking (e.g., slow-rate FM and ITD sensitivity), or between measures thought to reflect tonotopic coding (fast-rate FM and forward-masking patterns). The results suggest that either psychoacoustic performance in young normal-hearing listeners is not limited by peripheral coding, or that similar peripheral mechanisms limit both high- and low-rate FM coding.

  15. Development of a real-time PCR to detect Demodex canis DNA in different tissue samples.

    Science.gov (United States)

    Ravera, Ivan; Altet, Laura; Francino, Olga; Bardagí, Mar; Sánchez, Armand; Ferrer, Lluís

    2011-02-01

    The present study reports the development of a real-time polymerase chain reaction (PCR) to detect Demodex canis DNA on different tissue samples. The technique amplifies a 166 bp of D. canis chitin synthase gene (AB 080667) and it has been successfully tested on hairs extracted with their roots and on formalin-fixed paraffin embedded skin biopsies. The real-time PCR amplified on the hairs of all 14 dogs with a firm diagnosis of demodicosis and consistently failed to amplify on negative controls. Eleven of 12 skin biopsies with a morphologic diagnosis of canine demodicosis were also positive. Sampling hairs on two skin points (lateral face and interdigital skin), D. canis DNA was detected on nine of 51 healthy dogs (17.6%) a much higher percentage than previously reported with microscopic studies. Furthermore, it is foreseen that if the number of samples were increased, the percentage of positive dogs would probably also grow. Moreover, in four of the six dogs with demodicosis, the samples taken from non-lesioned skin were positive. This finding, if confirmed in further studies, suggests that demodicosis is a generalized phenomenon in canine skin, due to proliferation of local mite populations, even though macroscopic lesions only appear in certain areas. The real-time PCR technique to detect D. canis DNA described in this work is a useful tool to advance our understanding of canine demodicosis.

  16. Time-temperature dependent variations in beta-carotene contents in carrot using different spectrophotometric techniques

    Science.gov (United States)

    Ullah, Rahat; Khan, Saranjam; Shah, Attaullah; Ali, Hina; Bilal, Muhammad

    2018-05-01

    The current study presents time dependent variations in the concentration of beta-carotene in carrot under different storage-temperature conditions using UV–VIS and Raman spectrophotometric techniques. The UV–VIS absorption spectra of beta-carotene extracted from carrot shows three distinct absorption peaks at 442, 467, and 500 nm with maximum absorption at 467 nm. These absorption peaks are very much reproducible and are assigned to β-carotene. Similarly, Raman spectra of carrot samples also confirmed the three main Raman peaks of beta-carotene at shift positions 1003, 1150, and 1515 cm‑1. An overall decrease in beta-carotene content has been observed for time-temperature conditions. These results depict a decrease of about 40% in the content of beta-carotene when carrot samples were stored in a refrigerator (4 °C) for the first 20 d, whereas a decrease of about 25% was observed when carrot samples were stored in a freezer (‑16 °C) for the same period. The objective of this study is to investigate the possible use of Raman spectroscopy and UV–VIS spectroscopy for quick and detailed analysis of changes (degradation) in beta-carotene content associated with time and temperature in storage (frozen foods) in order to promote quality foods for consumers. Future study with a greater focus on the concentration/content of beta-carotene in other fruits/vegetables is also desirable.

  17. Prescribed journeys through life: Cultural differences in mental time travel between Middle Easterners and Scandinavians.

    Science.gov (United States)

    Ottsen, Christina Lundsgaard; Berntsen, Dorthe

    2015-12-01

    Mental time travel is the ability to remember past events and imagine future events. Here, 124 Middle Easterners and 128 Scandinavians generated important past and future events. These different societies present a unique opportunity to examine effects of culture. Findings indicate stronger influence of normative schemas and greater use of mental time travel to teach, inform and direct behaviour in the Middle East compared with Scandinavia. The Middle Easterners generated more events that corresponded to their cultural life script and that contained religious words, whereas the Scandinavians reported events with a more positive mood impact. Effects of gender were mainly found in the Middle East. Main effects of time orientation largely replicated recent findings showing that simulation of future and past events are not necessarily parallel processes. In accordance with the notion that future simulations rely on schema-based construction, important future events showed a higher overlap with life script events than past events in both cultures. In general, cross-cultural discrepancies were larger in future compared with past events. Notably, the high focus in the Middle East on sharing future events to give cultural guidance is consistent with the increased adherence to normative scripts found in this culture. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Personal Best Time, Percent Body Fat, and Training Are Differently Associated with Race Time for Male and Female Ironman Triathletes

    Science.gov (United States)

    Knechtle, Beat; Wirth, Andrea; Baumann, Barbara; Knechtle, Patrizia; Rosemann, Thomas

    2010-01-01

    We studied male and female nonprofessional Ironman triathletes to determine whether percent body fat, training, and/or previous race experience were associated with race performance. We used simple linear regression analysis, with total race time as the dependent variable, to investigate the relationship among athletes' percent body fat, average…

  19. Color Stability of Enamel following Different Acid Etching and Color Exposure Times

    Directory of Open Access Journals (Sweden)

    Arezoo Jahanbin

    2014-06-01

    Full Text Available Background and aims. The aim of this study was to evaluate the effect of different etching times on enamel color stability after immediate versus delayed exposure to colored artificial saliva (CAS. Materials and methods. Human first premolars were divided into five groups of twenty. A colorimeter was used according to the CIE system on the mid-buccal and mid-lingual surfaces to evaluate initial tooth color. Samples in group A remained unetched. In groups B to E, buccal and lingual surfaces were initially etched with phosphoric acid for 15 and 60 seconds, respectively. Then, the samples in groups A and C were immersed in colored artificial saliva (cola+saliva. In group B, the teeth were immersed in simple artificial saliva (AS. Samples in groups D and E were immersed in AS for 24 and 72 hours, respectively before being immersed in colored AS. The teeth were immersed for one month in each solution before color measurement. During the test period, the teeth were retrieved from the staining solution and stored in AS for five minutes. This was repeated 60 times. Color changes of buccal and lingual surfaces were calculated. Kruskal-Wallis and Wilcoxon tests were used for statistical analysis (α ≤ 0.05. Results. There were no significant differences between the groups in term of ΔE of buccal (P = 0.148 and lingual surfaces (P = 0.73. Conclusion. Extended time of etching did not result in significant enamel color change. Immediate and delayed exposure of etched enamel to staining solutions did not result in clinically detectable tooth color changes.

  20. Use of the finite-difference time-domain method in electromagnetic dosimetry

    International Nuclear Information System (INIS)

    Sullivan, D.M.

    1987-01-01

    Although there are acceptable methods for calculating whole body electromagnetic absorption, no completely acceptable method for calculating the local specific absorption rate (SAR) at points within the body has been developed. Frequency domain methods, such as the method of moments (MoM) have achieved some success; however, the MoM requires computer storage on the order of (3N) 2 , and computation time on the order of (3N) 3 where N is the number of cells. The finite-difference time-domain (FDTD) method has been employed extensively in calculating the scattering from metallic objects, and recently is seeing some use in calculating the interaction of EM fields with complex, lossy dielectric bodies. Since the FDTD method has storage and time requirements proportional to N, it presents an attractive alternative to calculating SAR distribution in large bodies. This dissertation describes the FDTD method and evaluates it by comparing its results with analytic solutions in 2 and 3 dimensions. The results obtained demonstrate that the FDTD method is capable of calculating internal SAR distribution with acceptable accuracy. The construction of a data base to provide detailed, inhomogeneous man models for use with the FDTD method is described. Using this construction method, a model of 40,000 1.31 cm. cells is developed for use at 350 MHz, and another model consisting of 5000 2.62 cm. cells is developed for use at 100 MHz. To add more realism to the problem, a ground plane is added to the FDTD software. The needed changes to the software are described, along with a test which confirms its accuracy. Using the CRAY II supercomputer, SAR distributions in human models are calculated using incident frequencies of 100 MHz and 350 MHz for three different cases: (1) A homogeneous man model in free space, (2) an inhomogeneous man model in free space, and (3) an inhomogeneous man model standing on a ground plane

  1. Correlation Coefficients Between Different Methods of Expressing Bacterial Quantification Using Real Time PCR

    Directory of Open Access Journals (Sweden)

    Bahman Navidshad

    2012-02-01

    Full Text Available The applications of conventional culture-dependent assays to quantify bacteria populations are limited by their dependence on the inconsistent success of the different culture-steps involved. In addition, some bacteria can be pathogenic or a source of endotoxins and pose a health risk to the researchers. Bacterial quantification based on the real-time PCR method can overcome the above-mentioned problems. However, the quantification of bacteria using this approach is commonly expressed as absolute quantities even though the composition of samples (like those of digesta can vary widely; thus, the final results may be affected if the samples are not properly homogenized, especially when multiple samples are to be pooled together before DNA extraction. The objective of this study was to determine the correlation coefficients between four different methods of expressing the output data of real-time PCR-based bacterial quantification. The four methods were: (i the common absolute method expressed as the cell number of specific bacteria per gram of digesta; (ii the Livak and Schmittgen, ΔΔCt method; (iii the Pfaffl equation; and (iv a simple relative method based on the ratio of cell number of specific bacteria to the total bacterial cells. Because of the effect on total bacteria population in the results obtained using ΔCt-based methods (ΔΔCt and Pfaffl, these methods lack the acceptable consistency to be used as valid and reliable methods in real-time PCR-based bacterial quantification studies. On the other hand, because of the variable compositions of digesta samples, a simple ratio of cell number of specific bacteria to the corresponding total bacterial cells of the same sample can be a more accurate method to quantify the population.

  2. Evaluation of different enrichment methods for pathogenic Yersinia species detection by real time PCR

    Science.gov (United States)

    2014-01-01

    Background Yersiniosis is a zoonotic disease reported worldwide. Culture and PCR based protocols are the most common used methods for detection of pathogenic Yersinia species in animal samples. PCR sensitivity could be increased by an initial enrichment step. This step is particularly useful in surveillance programs, where PCR is applied to samples from asymptomatic animals. The aim of this study was to evaluate the improvement in pathogenic Yersinia species detection using a suitable enrichment method prior to the real time PCR (rtPCR). Nine different enrichment protocols were evaluated including six different broth mediums (CASO, ITC, PSB, PBS, PBSMSB and PBSSSB). Results The analysis of variance showed significant differences in Yersinia detection by rtPCR according to the enrichment protocol used. These differences were higher for Y. pseudotuberculosis than for Y. enterocolitica. In general, samples incubated at lower temperatures yielded the highest detection rates. The best results were obtained with PBSMSB and PBS2. Application of PBSMSB protocol to free-ranging wild board samples improved the detection of Y. enterocolitica by 21.2% when compared with direct rtPCR. Y. pseudotuberculosis detection was improved by 10.6% when results obtained by direct rtPCR and by PBSMSB enrichment before rtPCR were analyzed in combination. Conclusions The data obtained in the present study indicate a difference in Yersinia detection by rtPCR related to the enrichment protocol used, being PBSMSB enrichment during 15 days at 4°C and PBS during 7 days at 4°C the most efficient. The use of direct rtPCR in combination with PBSMSB enrichment prior to rtPCR resulted in an improvement in the detection rates of pathogenic Yersinia in wild boar and could be useful for application in other animal samples. PMID:25168886

  3. Survival time of bacteria on different plastics by application of ultraviolet rays and desinfectants

    International Nuclear Information System (INIS)

    Glueck, S.

    1975-01-01

    The survival times of four sorts of germs were studied (Staph. albus, Staph. aureus, E.coli and Clebsiella) on 28 different plastic surfaces under different ambient conditions, (darkness, daylight, UV-radiation) and after preceding disinfection of the surfaces. For these studies, a formaldehydecontaining, phenolic, and a surface-active preparation were used. No essential differences in the survival times of the 4 types of germs tested were found. Besides the chemical basic structure additional substances were found to play a substantial role for the autobactericides. The dark values which could help to obtain findings about auto-bactericides did not show significant correspondence within the groups of the plastics. Only for a few materials a safe auto-bactericide could be found (alkyd lake, phenol resin). In the case of some other substances (some preparations made of PVC, polystyrene, polyacetal) an effect on the germs could be seen which was, at least totally seen, unfavourable, if all test conditions (darkness, daylight, UV-radiation) are viewed as a total. As comparative values on glass had shown a lower lethal rate of the germs, a certain auto-bactericide is likely to exist in all plastics tested. A considerable antibacterial effect of daylight was found, even with low daylight quotients and clased windows. UV-rays also diminished the number of germs on the plastic surfaces considerably, even with only indirect irradiation. Delayed effects of desinfecting agents partially depend on the surface material. Thus the phenolic agent showed strong delayed effects on the acryl glas, polyethylene, phenol resin, polycarbonate, but less on PVC. Phormaldehyde showed a good long-term effect only on phenol resin. (orig.) [de

  4. Different types of employee well-being across time and their relationships with job crafting.

    Science.gov (United States)

    Hakanen, Jari J; Peeters, Maria C W; Schaufeli, Wilmar B

    2018-04-01

    We used and integrated the circumplex model of affect (Russell, 1980) and the conservation of resources theory (Hobfoll, 1998) to hypothesize how various types of employee well-being, which can be differentiated on theoretical grounds (i.e., work engagement, job satisfaction, burnout, and workaholism), may differently predict various job crafting behaviors (i.e., increasing structural and social resources and challenging demands, and decreasing hindering demands) and each other over time. At Time 1, we measured employee well-being, and 4 years later at Time 2, job crafting and well-being, using a large sample of Finnish dentists (N = 1,877). The results of structural equation modeling showed that (a) work engagement positively predicted both types of increasing resources and challenging demands and negatively predicted decreasing hindering demands; (b) workaholism positively predicted increasing structural resources and challenging demands; (c) burnout positively predicted decreasing hindering demands and negatively predicted increasing structural resources, whereas (d) job satisfaction did not relate to job crafting over time; and (e) work engagement positively influenced job satisfaction and negatively influenced burnout, whereas (f) workaholism predicted burnout after controlling for baseline levels. Thus, work engagement was a stronger predictor of future job crafting and other types of employee well-being than job satisfaction. Although workaholism was positively associated with job crafting, it also predicted burnout. We conclude that the relationship between job crafting and employee well-being may be more complex than assumed, because the way in which employees will craft their jobs in the future seems to depend on how they currently feel. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  5. Morphology, topography, and hardness of diffusion bonded sialon to AISI 420 at different bonding time

    Science.gov (United States)

    Ibrahim, Nor Nurulhuda Md.; Hussain, Patthi; Awang, Mokhtar

    2015-07-01

    Sialon and AISI 420 martensitic stainless steel were diffusion bonded in order to study the effect of bonding time on reaction layer's growth. Joining of these materials was conducted at 1200°C under a uniaxial pressure of 17 MPa in a vacuum ranging from 5.0 to 8.0×10-6 Torr with bonding time varied for 0.5, 2, and 3 h. Thicker reaction layer was formed in longer bonded sample since the elements from sialon could diffuse further into the steel. Sialon retained its microstructure but it was affected at the initial contact with the steel to form the new interface layer. Diffusion layer grew toward the steel and it was segregated with the parent steel as a result of the difference in properties between these regions. The segregation formed a stream-like structure and its depth decreased when the bonding time was increased. The microstructure of the steel transformed into large grain size with precipitates. Prolonging the bonding time produced more precipitates in the steel and reduced the steel thickness as well. Interdiffusions of elements occurred between the joined materials and the concentrations were decreasing toward the steel and vice versa. Silicon easily diffused into the steel because it possessed lower ionization potential compared to nitrogen. Formation of silicide and other compounds such as carbides were detected in the interface layer and steel grain boundary, respectively. These compounds were harmful due to silicide brittleness and precipitation of carbides in the grain boundary might cause intergranular corrosion cracking. Sialon retained its hardness but it dropped very low at the interface layer. The absence of crack at the joint in all samples could be contributed from the ductility characteristic of the reaction layer which compensated the residual stress that was formed upon the cooling process.

  6. Effectiveness of different approaches to disseminating traveler information on travel time reliability. [supporting datasets

    Science.gov (United States)

    2013-11-30

    Travel time reliability information includes static data about traffic speeds or trip times that capture historic variations from day to day, and it can help individuals understand the level of variation in traffic. Unlike real-time travel time infor...

  7. Outcome and process differences between professional and nonprofessional therapists in time-limited group psychotherapy.

    Science.gov (United States)

    Burlingame, G M; Barlow, S H

    1996-10-01

    The outcome of clients who saw one of four "expert" professional group therapists selected by peer nomination or four "natural helper" nonprofessional nominated by students is contrasted in a 15-session psychotherapy group. Process measures tapping specific group and "common factors" were drawn from sessions 3, 8, and 14; outcome was assessed at pre, mid, posttreatment, and a 6-month follow-up. Results were examined by leader condition (professional vs. nonprofessional therapists) and time (group development). Virtually no reliable differences were found on measures of outcome primarily because of a floor effect on several measures. Therapist differences on the process measures tapping the "common factors" of therapeutic alliance, client expectancy, and perception of therapists were either nonsignificant or disappeared by the end of treatment. A complex picture of differences on one therapeutic factor (insight), common factor measures and subtle variation in the outcome data suggests a distinct pattern of change, however. Methodological limitations are also addressed including problems inherent in large-scale clinical-trial studies, ethical concerns raised by using nonprofessional leaders, and problems with generalizability, given the absence of significant psychopathology in group members.

  8. Light energy attenuation through orthodontic ceramic brackets at different irradiation times.

    Science.gov (United States)

    Santini, Ario; Tiu, Szu Hui; McGuinness, Niall J P; Aldossary, Mohammed Saeed

    2016-09-01

    To evaluate the total light energy (TLE) transmission through three types of ceramic brackets with, bracket alone and with the addition of orthodontic adhesive, at different exposure durations, and to compare the microhardness of the cured adhesive. Three different makes of ceramic brackets, Pure Sapphire(M), Clarity™ ADVANCED(P) and Dual Ceramic(P) were used. Eighteen specimens of each make were prepared and allocated to three groups (n = 6). MARC(®)-resin calibrator was used to determine the light curing unit (LCU) tip irradiance (mW/cm(2)) and TLE (J/cm(2)) transmitted through the ceramic brackets, and through ceramic bracket plus Transbond™ XT Light Cure Adhesive, for 5, 10 and 20 s. Vickers-hardness values at the bottom of the cured adhesive were determined. Statistical analysis used one-way analysis of variance (ANOVA); P = 0.05. TLE transmission rose significantly among all samples with increasing exposure durations. TLE reaching the adhesive- enamel interface was less than 10 J/cm(2), and through monocrystalline and polycrystalline ceramic brackets was significantly different (P brackets. Clinicians are advised to measure the tip irradiance of their LCUs and increase curing time beyond 5 s. Orthodontic clinicians should understand the type of light curing device and the orthodontic adhesive used in their practice.

  9. Monthly Rainfall Erosivity: Conversion Factors for Different Time Resolutions and Regional Assessments

    Directory of Open Access Journals (Sweden)

    Panos Panagos

    2016-03-01

    Full Text Available As a follow up and an advancement of the recently published Rainfall Erosivity Database at European Scale (REDES and the respective mean annual R-factor map, the monthly aspect of rainfall erosivity has been added to REDES. Rainfall erosivity is crucial to be considered at a monthly resolution, for the optimization of land management (seasonal variation of vegetation cover and agricultural support practices as well as natural hazard protection (landslides and flood prediction. We expanded REDES by 140 rainfall stations, thus covering areas where monthly R-factor values were missing (Slovakia, Poland or former data density was not satisfactory (Austria, France, and Spain. The different time resolutions (from 5 to 60 min of high temporal data require a conversion of monthly R-factor based on a pool of stations with available data at all time resolutions. Because the conversion factors show smaller monthly variability in winter (January: 1.54 than in summer (August: 2.13, applying conversion factors on a monthly basis is suggested. The estimated monthly conversion factors allow transferring the R-factor to the desired time resolution at a European scale. The June to September period contributes to 53% of the annual rainfall erosivity in Europe, with different spatial and temporal patterns depending on the region. The study also investigated the heterogeneous seasonal patterns in different regions of Europe: on average, the Northern and Central European countries exhibit the largest R-factor values in summer, while the Southern European countries do so from October to January. In almost all countries (excluding Ireland, United Kingdom and North France, the seasonal variability of rainfall erosivity is high. Very few areas (mainly located in Spain and France show the largest from February to April. The average monthly erosivity density is very large in August (1.67 and July (1.63, while very small in January and February (0.37. This study addresses

  10. Effects of experimental occlusal interferences in individuals reporting different levels of wake-time parafunctions.

    Science.gov (United States)

    Michelotti, Ambra; Cioffi, Iacopo; Landino, Donatella; Galeone, Carlotta; Farella, Mauro

    2012-01-01

    To test the hypothesis that the effects of an experimental occlusal interference differ between individuals reporting a high or low frequency of wake-time oral parafunctions. Study participants reporting very high (HFP group; n = 10) or very low (LFP group; n = 10) levels of oral parafunctions were selected by means of a questionnaire administered to 200 medical students. The selected participants wore an experimental occlusal interference in a single-blind longitudinal study, which comprised different occlusal conditions: interference free (IFC) and active occlusal interference (AIC). Assessments included clinical examination, measurements of nonfunctional tooth contacts, state and trait anxiety, and visual analog scale scores for occlusal discomfort, masticatory muscle pain, and headache. Data were analyzed by repeated measures twoway analysis of variance on ranked data, followed by calculation of within- and between-group differences using Friedman tests and Mann-Whitney tests, respectively. During AIC, the frequency of nonfunctional tooth contacts significantly decreased in both groups (median [interquartile range, IQR]: in HFP from 55.3% [60.0%] to 31.1% [33.5%], P = .03; in LFP from 31.8% [32.4%] to 14.0% [22.8%], P interference caused more occlusal discomfort in the HFP group than in the LFP group (P = .02) and was associated with a significant increase of masticatory muscle pain (P = .05) and headache (P = .04) only in the HFP group. The application of an experimental occlusal interference has a different effect in individuals reporting a high or low frequency of oral parafunctions.

  11. T(2) relaxation time of hyaline cartilage in presence of different gadolinium-based contrast agents.

    Science.gov (United States)

    Wiener, Edzard; Settles, Marcus; Diederichs, Gerd

    2010-01-01

    The transverse relaxation time, T(2), of native cartilage is used to quantify cartilage degradation. T(2) is frequently measured after contrast administration, assuming that the impact of gadolinium-based contrast agents on cartilage T(2) is negligible. To verify this assumption the depth-dependent variation of T(2) in the presence of gadopentetate dimeglumine, gadobenate dimeglumine and gadoteridol was investigated. Furthermore, the r(2)/r(1) relaxivity ratios were quantified in different cartilage layers to demonstrate differences between T(2) and T(1) relaxation effects. Transverse high-spatial-resolution T(1)- and T(2)-maps were simultaneously acquired on a 1.5 T MR scanner before and after contrast administration in nine bovine patellae using a turbo-mixed sequence. The r(2)/r(1) ratios were calculated for each contrast agent in cartilage. Profiles of T(1), T(2) and r(2)/r(1) across cartilage thickness were generated in the absence and presence of contrast agent. The mean values in different cartilage layers were compared for global variance using the Kruskal-Wallis test and pairwise using the Mann-Whitney U-test. T(2) of unenhanced cartilage was 98 +/- 5 ms at 1 mm and 65 +/- 4 ms at 3 mm depth. Eleven hours after contrast administration significant differences (p cartilage thickness were close to 1.0 (range 0.9-1.3). At 1.5 T, T(2) decreased significantly in the presence of contrast agents, more pronounced in superficial than in deep cartilage. The change in T(2) relaxation rate was similar to the change in T(1). Cartilage T(2) measurements after contrast administration will lead to systematic errors in the quantification of cartilage degradation. 2010 John Wiley & Sons, Ltd.

  12. Physical Activity, Study Sitting Time, Leisure Sitting Time, and Sleep Time Are Differently Associated With Obesity in Korean Adolescents: A Population-Based Study.

    Science.gov (United States)

    Kong, Il Gyu; Lee, Hyo-Jeong; Kim, So Young; Sim, Songyong; Choi, Hyo Geun

    2015-11-01

    Low physical activity, long leisure sitting time, and short sleep time are risk factors for obesity, but the association with study sitting time is unknown. The objective of this study was to evaluate the association between these factors and obesity.We analyzed the association between physical activity, study sitting time, leisure sitting time, and sleep time and subject weight (underweight, healthy weight, overweight, and obese), using data from a large population-based survey, the 2013 Korea Youth Risk Behavior Web-based Survey. Data from 53,769 participants were analyzed using multinomial logistic regression analyses with complex sampling. Age, sex, region of residence, economic level, smoking, stress level, physical activity, sitting time for study, sitting time for leisure, and sleep time were adjusted as the confounders.Low physical activity (adjusted odds ratios [AORs] = 1.03, 1.12) and long leisure sitting time (AORs = 1.15, 1.32) were positively associated with overweight and obese. Low physical activity (AOR = 1.33) and long leisure sitting time (AOR = 1.12) were also associated with underweight. Study sitting time was negatively associated with underweight (AOR = 0.86) but was unrelated to overweight (AOR = 0.97, 95% confidence interval [CI] = 0.91-1.03) and obese (AOR = 0.94, 95% CI = 0.84-1.04). Sleep time (physical activity, decreasing leisure sitting time, and obtaining sufficient sleep would be beneficial in maintaining a healthy weight. However, study sitting time was not associated with overweight or obese.

  13. Copper, nickel and lead in lichen and tree bark transplants over different periods of time

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Mafalda S. [CIIMAR, Rua dos Bragas, 289, 4050-123 Porto (Portugal)], E-mail: abaptista@fc.up.pt; Vasconcelos, M. Teresa S.D. [CIIMAR, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Chemistry Department, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 687, 4169-071 Porto (Portugal)], E-mail: mtvascon@fc.up.pt; Cabral, Joao Paulo [CIIMAR, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Botany Department, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 1191, 4150-181 Porto (Portugal)], E-mail: jpcabral@fc.up.pt; Freitas, M. Carmo [ITN - Technological and Nuclear Institute, Reactor E.N. 10, 2686-953 Sacavem (Portugal)], E-mail: cfreitas@itn.mcies.pt; Pacheco, Adriano M.G. [CVRM-IST - Technical University of Lisbon, Avenida Rovisco Pais, 1, 1049-001 Lisbon (Portugal)], E-mail: apacheco@ist.utl.pt

    2008-01-15

    This work aimed at comparing the dynamics of atmospheric metal accumulation by the lichen Flavoparmelia caperata and bark of Platanus hybrida over different periods of time. Transplants were exposed in three Portuguese coastal cities. Samples were retrieved (1) every 2 months (discontinuous exposure), or (2) after 2-, 4-, 6-, 8- and 10-month periods (continuous exposure), and analysed for Cu, Ni and Pb. Airborne accumulation of metals was essentially independent of climatic factors. For both biomonitors [Pb] > [Ni] > [Cu] but Pb was the only element for which a consistent pattern of accumulation was observed, with the bark outperforming the lichen. The longest exposure periods hardly ever corresponded to the highest accumulation. This might have been partly because the biomonitors bound and released metals throughout the exposure, each with its own dynamics of accumulation, but both according to the environmental metal availability. - Lichen and tree bark have distinct dynamics of airborne metal accumulation.

  14. Copper, nickel and lead in lichen and tree bark transplants over different periods of time

    International Nuclear Information System (INIS)

    Baptista, Mafalda S.; Vasconcelos, M. Teresa S.D.; Cabral, Joao Paulo; Freitas, M. Carmo; Pacheco, Adriano M.G.

    2008-01-01

    This work aimed at comparing the dynamics of atmospheric metal accumulation by the lichen Flavoparmelia caperata and bark of Platanus hybrida over different periods of time. Transplants were exposed in three Portuguese coastal cities. Samples were retrieved (1) every 2 months (discontinuous exposure), or (2) after 2-, 4-, 6-, 8- and 10-month periods (continuous exposure), and analysed for Cu, Ni and Pb. Airborne accumulation of metals was essentially independent of climatic factors. For both biomonitors [Pb] > [Ni] > [Cu] but Pb was the only element for which a consistent pattern of accumulation was observed, with the bark outperforming the lichen. The longest exposure periods hardly ever corresponded to the highest accumulation. This might have been partly because the biomonitors bound and released metals throughout the exposure, each with its own dynamics of accumulation, but both according to the environmental metal availability. - Lichen and tree bark have distinct dynamics of airborne metal accumulation

  15. How Partner Characteristics Can Affect Performance of Alliances with Different Time Frames?

    Directory of Open Access Journals (Sweden)

    Seyed Hossein JALALI

    2017-11-01

    Full Text Available Firms increasingly adopt cooperative strategies and form strategic alliances with foreign partners to be prosperous in entering to international market. Most of scholars have typically focused on generic, conceptual models for alliances partner selection, addressing only limited dimensions of the partner characteristics. This paper presents a new empirical framework that considering the effect of partner characteristics on export performance of alliances, in the case of short/mediumterm alliances and long-term ones. The study explores the effective partner characteristics for each type of alliances based on a sample of 540 alliances which rooted in East European region and also, have at least one Iranian partner. The findings stress the differences between varied partner characteristics in short/medium-term and long-term alliances. More specifically, results introduce a framework that addresses certain and specific partner characteristics to improve the export performance of alliances, due to the time frame of strategic alliances.

  16. Analysis of microbial diversity in Shenqu with different fermentation times by PCR-DGGE

    Directory of Open Access Journals (Sweden)

    Tengfei Liu

    Full Text Available Abstract Shenqu is a fermented product that is widely used in traditional Chinese medicine (TCM to treat indigestion; however, the microbial strains in the fermentation process are still unknown. The aim of this study was to investigate microbial diversity in Shenqu using different fermentation time periods. DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis profiles indicated that a strain of Pediococcus acidilactici (band 9 is the predominant bacteria during fermentation and that the predominant fungi were uncultured Rhizopus, Aspergillus oryzae, and Rhizopus oryzae. In addition, pathogenic bacteria, such as Enterobacter cloacae, Klebsiella oxytoca, Erwinia billingiae, and Pantoea vagan were detected in Shenqu. DGGE analysis showed that bacterial and fungal diversity declined over the course of fermentation. This determination of the predominant bacterial and fungal strains responsible for fermentation may contribute to further Shenqu research, such as optimization of the fermentation process.

  17. Application of the symplectic finite-difference time-domain scheme to electromagnetic simulation

    International Nuclear Information System (INIS)

    Sha, Wei; Huang, Zhixiang; Wu, Xianliang; Chen, Mingsheng

    2007-01-01

    An explicit fourth-order finite-difference time-domain (FDTD) scheme using the symplectic integrator is applied to electromagnetic simulation. A feasible numerical implementation of the symplectic FDTD (SFDTD) scheme is specified. In particular, new strategies for the air-dielectric interface treatment and the near-to-far-field (NFF) transformation are presented. By using the SFDTD scheme, both the radiation and the scattering of three-dimensional objects are computed. Furthermore, the energy-conserving characteristic hold for the SFDTD scheme is verified under long-term simulation. Numerical results suggest that the SFDTD scheme is more efficient than the traditional FDTD method and other high-order methods, and can save computational resources

  18. Dispersive finite-difference time-domain (FDTD) analysis of the elliptic cylindrical cloak

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. Y.; Ahn, D. [University of Seoul, Seoul (Korea, Republic of)

    2012-05-15

    A dispersive full-wave finite-difference time-domain (FDTD) model is used to calculate the performance of elliptic cylindrical cloaking devices. The permittivity and the permeability tensors for the cloaking structure are derived by using an effective medium approach in general relativity. The elliptic cylindrical invisibility devices are found to show imperfect cloaking, and the cloaking performance is found to depend on the polarization of the incident waves, the direction of the propagation of those waves, the semi-focal distances and the loss tangents of the meta-material. When the semifocal distance of the elliptic cylinder decreases, the performance of the cloaking becomes very good, with neither noticeable scatterings nor field penetrations. For a larger semi-focal distance, only the TM wave with a specific propagation direction shows good cloaking performance. Realistic cloaking materials with loss still show a cloak that is working, but attenuated back-scattering waves exist.

  19. Microstructural Evolution of Advanced Radiation-Resistant ODS Steel with Different Lengths of Mechanical Alloying Time

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sanghoon; Kim, Ga Eon; Kang, Suk Hoon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling well occurred to 120dpa at high temperatures and this leads the decrease of the mechanical properties and dimensional stability. Compared to this, ferritic/ martensitic steel is a good solution because of excellent thermal conductivity and good swelling resistance. Unfortunately, the available temperature range of ferritic/martensitic steel is limited up to 650 .deg. C. ODS steel is the most promising structural material because of excellent creep and irradiation resistance by uniformly distributed nano-oxide particles with a high density which is extremely stable at the high temperature in ferritic/martensitic matrix. In this study, powder properties and microstructures of the ODS steel with different length of mechanical alloying time was investigated. The ODS steel milled 5h showed homogeneous grain structure with the highest hardness.

  20. Simulation of acoustic streaming by means of the finite-difference time-domain method

    DEFF Research Database (Denmark)

    Santillan, Arturo Orozco

    2012-01-01

    Numerical simulations of acoustic streaming generated by a standing wave in a narrow twodimensional cavity are presented. In this case, acoustic streaming arises from the viscous boundary layers set up at the surfaces of the walls. It is known that streaming vortices inside the boundary layer have...... directions of rotation that are opposite to those of the outer streaming vortices (Rayleigh streaming). The general objective of the work described in this paper has been to study the extent to which it is possible to simulate both the outer streaming vortices and the inner boundary layer vortices using...... the finite-difference time-domain method. To simplify the problem, thermal effects are not considered. The motivation of the described investigation has been the possibility of using the numerical method to study acoustic streaming, particularly under non-steady conditions. Results are discussed for channels...

  1. Microstructural Evolution of Advanced Radiation-Resistant ODS Steel with Different Lengths of Mechanical Alloying Time

    International Nuclear Information System (INIS)

    Noh, Sanghoon; Kim, Ga Eon; Kang, Suk Hoon; Kim, Tae Kyu

    2015-01-01

    Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling well occurred to 120dpa at high temperatures and this leads the decrease of the mechanical properties and dimensional stability. Compared to this, ferritic/ martensitic steel is a good solution because of excellent thermal conductivity and good swelling resistance. Unfortunately, the available temperature range of ferritic/martensitic steel is limited up to 650 .deg. C. ODS steel is the most promising structural material because of excellent creep and irradiation resistance by uniformly distributed nano-oxide particles with a high density which is extremely stable at the high temperature in ferritic/martensitic matrix. In this study, powder properties and microstructures of the ODS steel with different length of mechanical alloying time was investigated. The ODS steel milled 5h showed homogeneous grain structure with the highest hardness

  2. Localized diffusive motion on two different time scales in solid alkane nanoparticles

    International Nuclear Information System (INIS)

    Wang, S.-K.; Mamontov, Eugene; Bai, M.; Hansen, F.Y.; Taub, H.; Copley, J.R.D.; Garcia Sakai, V.; Gasparovic, Goran; Jenkins, Timothy; Tyagi, M.; Herwig, Kenneth W.; Neumann, D.A.; Montfrooij, W.; Volkmann, U.G.

    2010-01-01

    High-energy-resolution quasielastic neutron scattering on three complementary spectrometers has been used to investigate molecular diffusive motion in solid nano- to bulk-sized particles of the alkane n-C32H66. The crystalline-to-plastic and plastic-to-fluid phase transition temperatures are observed to decrease as the particle size decreases. In all samples, localized molecular diffusive motion in the plastic phase occurs on two different time scales: a 'fast' motion corresponding to uniaxial rotation about the long molecular axis; and a 'slow' motion attributed to conformational changes of the molecule. Contrary to the conventional interpretation in bulk alkanes, the fast uniaxial rotation begins in the low-temperature crystalline phase.

  3. Augmented Lagrange Programming Neural Network for Localization Using Time-Difference-of-Arrival Measurements.

    Science.gov (United States)

    Han, Zifa; Leung, Chi Sing; So, Hing Cheung; Constantinides, Anthony George

    2017-08-15

    A commonly used measurement model for locating a mobile source is time-difference-of-arrival (TDOA). As each TDOA measurement defines a hyperbola, it is not straightforward to compute the mobile source position due to the nonlinear relationship in the measurements. This brief exploits the Lagrange programming neural network (LPNN), which provides a general framework to solve nonlinear constrained optimization problems, for the TDOA-based localization. The local stability of the proposed LPNN solution is also analyzed. Simulation results are included to evaluate the localization accuracy of the LPNN scheme by comparing with the state-of-the-art methods and the optimality benchmark of Cramér-Rao lower bound.

  4. Analyses of fatalities from natural catastrophes in different income groups over time

    Science.gov (United States)

    Grimm, Tobias

    2017-04-01

    Identifying not only economic and insured losses but also numbers of fatalities from natural catastrophes provides new information on resilience and prevention measures in the countries affected. In this talk, we examine how fatalities from Munich Re's NatCatSERVICE database, caused by natural disasters have developed. In addition to the standard approach based on fatalities by country, we introduced a new measure, "fatalities per million inhabitants", and factored in population development over time. The World Bank definition was used to determine the wealth classification of individual countries. This methodology enables us to compare countries with different population sizes and thus produce an index for humanitarian impact. The analyses are key information on ascertaining whether prevention measures or early-warning systems have in fact reduced the number of fatalities in recent decades (1980-2016).

  5. Phosphoproteomics analysis of postmortem porcine muscle with pH decline rate and time difference

    DEFF Research Database (Denmark)

    Huang, Honggang; Larsen, Martin R; Karlsson, Anders H

    2012-01-01

    The aim of this study was to characterize the protein phosphorylation in postmortem (PM) muscle and reveal the change during meat quality development. The gel-based phosphoproteomic analysis of PM porcine muscle was performed in three pig groups with different pH decline rates from PM 1h to 24 h....... The sarcoplasmic and myofibrillar fractions were analyzed using gel electrophoresis in combination with a phosphoprotein specific staining. Globally, the group with fast pH decline rate had the highest phosphorylation level at PM 1 h, but lowest at PM 24 h, whereas the group with slow pH decline rate showed...... the reverse case. The phosphorylation level of 12 bands in sarcoplasmic fraction and 3 bands in myofibrillar fraction were significantly affected by the synergy effects of pH and time (p

  6. Time course of auditory streaming: Do CI users differ from normal-hearing listeners?

    Directory of Open Access Journals (Sweden)

    Martin eBöckmann-Barthel

    2014-07-01

    Full Text Available In a complex acoustical environment with multiple sound sources the auditory system uses streaming as a tool to organize the incoming sounds in one or more streams depending on the stimulus parameters. Streaming is commonly studied by alternating sequences of signals. These are often tones with different frequencies. The present study investigates stream segregation in cochlear implant (CI users, where hearing is restored by electrical stimulation of the auditory nerve. CI users listened to 30-s long sequences of alternating A and B harmonic complexes at four different fundamental frequency separations, ranging from 2 to 14 semitones. They had to indicate as promptly as possible after sequence onset, if they perceived one stream or two streams and, in addition, any changes of the percept throughout the rest of the sequence. The conventional view is that the initial percept is always that of a single stream which may after some time change to a percept of two streams. This general build-up hypothesis has recently been challenged on the basis of a new analysis of data of normal-hearing listeners which showed a build-up response only for an intermediate frequency separation. Using the same experimental paradigm and analysis, the present study found that the results of CI users agree with those of the normal-hearing listeners: (i the probability of the first decision to be a one-stream percept decreased and that of a two-stream percept increased as Δf increased, and (ii a build-up was only found for 6 semitones. Only the time elapsed before the listeners made their first decision of the percept was prolonged as compared to normal-hearing listeners. The similarity in the data of the CI user and the normal-hearing listeners indicates that the quality of stream formation is similar in these groups of listeners.

  7. Study of bioleaching under different hydraulic retention time for enhancing the dewaterability of digestate.

    Science.gov (United States)

    Li, Linshuai; Gao, Jingqing; Zhu, Songfeng; Li, Yonghong; Zhang, Ruiqin

    2015-12-01

    Dewatering of kitchen waste digestate is a key problem to solve so as to increase the application of kitchen waste after anaerobic digestion. In this study, the effects of bioleaching under different hydraulic retention time (HRT = 2, 2.5, and 3 days) on dewaterability of kitchen waste digestate were evaluated. A 12-stage plug flow bioreactor with 180 L working volume was used for digestate bioleaching. The bioleached digestate under different HRTs were collected and dewatered by plate-and-frame filter press. The results showed that the moisture contents of digestate cakes were 67.87 % at 2 days of HRT, 58.06 % at 2.5 days of HRT, and 54.45 % at 3 days of HRT, respectively, indicating the longer the HRT, the lower the moisture content of filter cake. Balanced between the cost and practical need, 2.5 days can be used as the HRT in engineering application. Under the condition of HRT of 2.5 days, the pH, specific resistance to filtration (SRF), capillary suction time (CST), and sedimentation rate of digestate changed from the initial values of 8.08, 210.6 s, 23.4 × 10(12) m kg(-1) and 10 % to 3.21, 32.7 s, 2.44 × 10(12) m kg(-1) and 76.8 %, respectively. Based on the observations above, the authors conclude that bioleaching technology is an effective method to enhance digestate dewaterability and reduce the cost of subsequent reutilization.

  8. Efficacy of Microwave Disinfection on Moist and Dry Dental Stone Casts with Different Irradiation Times

    Directory of Open Access Journals (Sweden)

    Mahmood Robati Anaraki

    2015-07-01

    Full Text Available Objectives: Dental practice contains the use of instruments and multiuse items that should be sterilized or disinfected properly. The aim of the current study was to investigate the effect of microwave irradiation on dental stone cast disinfection in moist and dry condition. Materials and Methods: In this in vitro study, 76 stone casts were prepared by a sterile method. The casts were contaminated by Pseudomonas aeruginosa (ATCC 9027, Staphylococcus aureus (ATCC 6538, Enterococcus faecalis (ATCC 29212 as well as Candida albicans (ATCC 10231. Half the samples were dried for two hours and the other half was studied while still moist. The samples were irradiated by a household microwave at 600 W for 3, 5 and 7 minutes. The microorganisms on the samples were extracted by immersion in tryptic soy broth and .001 ml of that was cultured in nutrient agar media, incubated overnight and counted and recorded as colony forming unit per milliliter (CFU/mL. Results: The findings showed that microorganisms reduced to 4.87 logarithm of CFU/mL value on dental cast within seven minutes in comparison with positive control. Although microbial count reduction was observed as a result of exposure time increase, comparison between moist and dried samples showed no significant difference. Conclusions: Seven-minute microwave irradiation at 600 W can effectively reduce the microbial load of dental stone casts. Wetting the casts does not seem to alter the efficacy of irradiation.   Keywords: Microwave Disinfection; Dental Stone Casts; Irradiation Times

  9. An individual differences approach to the suggestibility of memory over time.

    Science.gov (United States)

    Frost, Peter; Nussbaum, Gregory; Loconto, Taylor; Syke, Richard; Warren, Casey; Muise, Christina

    2013-04-01

    We examined how certain personality traits might relate to the formation of suggestive memory over time. We hypothesised that compliance and trust relate to initial acceptance of misinformation as memory, whereas fantasy proneness might relate to integration of misinformation into memory after later intervals (relative to the time of exposure to misinformation). Participants watched an excerpt from a movie--the simulated eyewitness event. They next answered a recall test that included embedded misinformation about the movie. Participants then answered a yes/no recognition test. A week later, participants answered a second yes/no recognition test about the movie (each yes/no recognition test included different questions). Before both recognition tests, participants were warned about the misinformation shown during recall and were asked to base their answer on the movie excerpt only. After completing the second recognition test, participants answered questions from the Neuroticism Extroversion Openness Personality Inventory-3 (McCrae, Costa, & Martin, 2005) and Creative Experiences Questionnaire (Merckelbach, Horselenberg, & Muris, 2001). While compliance correlated with misinformation effects immediately after exposure to misinformation, fantasy-prone personality accounted for more of the variability in false recognition rates than compliance after a 1-week interval.

  10. Chemical Properties and Characteristics of Cow Milk Yogurt with Different Additional Fruit and Storage Time

    Directory of Open Access Journals (Sweden)

    Putri Dian Wulansari

    2016-05-01

    Full Text Available This research was aimed to evaluate the composition (total solids, water content, fat and protein, qualitative properties (color, aroma, and texture and quantitative properties (free fatty acid and lactic acid of cow milk yogurt with different fruits addition and storage time. Experimental method applied Completely Randomized Design with five treatments namely control, dragon fruit, mango, apple and banana (20% v/v, each with 5 replicates. Qualitative characteristic assessment was conducted on 0, 5, 10 and 15 days of storage. Result showed that fruit addition significantly affected the composition and characteristics, while storage time significantly affected quantitative characteristics of yogurt. Apple and banana increased 13% total solids of plain yogurt, while the highest fat content (4,516% was observed in control yogurt which had the lowest protein content (2,564. The highest free fatty acid  was in control yogurt ripen for 15 days (22,885% while the lowest free fatty acid was in mango yogurt ripen for 10 days (13,915%. Fruit addition in yogurt ripen for 15 days at 5C resulted in a safe consumed product.

  11. A parallel algorithm for the two-dimensional time fractional diffusion equation with implicit difference method.

    Science.gov (United States)

    Gong, Chunye; Bao, Weimin; Tang, Guojian; Jiang, Yuewen; Liu, Jie

    2014-01-01

    It is very time consuming to solve fractional differential equations. The computational complexity of two-dimensional fractional differential equation (2D-TFDE) with iterative implicit finite difference method is O(M(x)M(y)N(2)). In this paper, we present a parallel algorithm for 2D-TFDE and give an in-depth discussion about this algorithm. A task distribution model and data layout with virtual boundary are designed for this parallel algorithm. The experimental results show that the parallel algorithm compares well with the exact solution. The parallel algorithm on single Intel Xeon X5540 CPU runs 3.16-4.17 times faster than the serial algorithm on single CPU core. The parallel efficiency of 81 processes is up to 88.24% compared with 9 processes on a distributed memory cluster system. We do think that the parallel computing technology will become a very basic method for the computational intensive fractional applications in the near future.

  12. Gene expression pattern at different time points following ALA-PDT

    International Nuclear Information System (INIS)

    Verwanger, T.; Sanovic, R.; Ruhdorfer, S.; Aberger, F.; Frischauf, A.; Krammer, B.

    2003-01-01

    Full text: The photo sensitizer protoporphyrin IX, endogenously accumulated from the precursor aminolevulinic acid (ALA), is a successful agent in photodynamic tumor therapy. In spite of encouraging clinical results, the basic mechanisms leading to cell death are not fully understood. We therefore set out to analyze the alteration of the gene expression pattern in the squamous cell carcinoma cell line A-431 at different time points after photodynamic treatment with endogenous protoporphyrin IX by cDNA-array technique. Cells were incubated for 16 hours with 100 μg/ml ALA and irradiated with a fluence of 3.5 J/cm 2 resulting in 50 % survival until 8 hours post treatment. RNA was isolated at 1.5, 3, 5 and 8 hours post treatment as well as of 3 controls (untreated, light only and dark), radioactively labelled by reverse transcription with 33P-dCTP and hybridized onto macroarray PCR filters containing PCR products of 2135 genes, which were selected for relevance in tumors, stress response and signal transduction. Verification of observed expression changes was carried out by real time PCR. We found a strong induction of expression of immediate early genes like c-fos as well as decreased expression of genes involved in proliferation like myc and the proliferating cell nuclear antigen (PCNA). (author)

  13. Differences between time domain and Fourier domain optical coherence tomography in imaging tissues.

    Science.gov (United States)

    Gao, W; Wu, X

    2017-11-01

    It has been numerously demonstrated that both time domain and Fourier domain optical coherence tomography (OCT) can generate high-resolution depth-resolved images of living tissues and cells. In this work, we compare the common points and differences between two methods when the continuous and random properties of live tissue are taken into account. It is found that when relationships that exist between the scattered light and tissue structures are taken into account, spectral interference measurements in Fourier domain OCT (FDOCT) is more advantageous than interference fringe envelope measurements in time domain OCT (TDOCT) in the cases where continuous property of tissue is taken into account. It is also demonstrated that when random property of tissue is taken into account FDOCT measures the Fourier transform of the spatial correlation function of the refractive index and speckle phenomena will limit the effective limiting imaging resolution in both TDOCT and FDOCT. Finally, the effective limiting resolution of both TDOCT and FDOCT are given which can be used to estimate the effective limiting resolution in various practical applications. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  14. Timing incorporation of different green manure crops to minimize the risk of nitrogen leaching

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    H. KÄNKÄNEN

    2008-12-01

    Full Text Available Seven field trials at four research sites were carried out to study the effect of incorporation time of different plant materials on soil mineral N content during two successive seasons. Annual hairy vetch (Vicia villosa Roth, red clover (Trifolium pratense L., westerwold ryegrass (Lolium multiflorum Lam. var. westerwoldicum and straw residues of N-fertilized spring barley (Hordeum vulgare were incorporated into the soil by ploughing in early September, late October and the following May, and by reduced tillage in May. Delaying incorporation of the green manure crop in autumn lessened the risk of N leaching. The higher the crop N and soil NO3-N content, the greater the risk of leaching. Incorporation in the following spring, which lessened the risk of N leaching as compared with early autumn ploughing, often had an adverse effect on the growth of the succeeding crop. After spring barley, the NO3-N content of the soil tended to be high, but the timing of incorporation did not have a marked effect on soil N. With exceptionally high soil mineral N content, N leaching was best inhibited by growing westerwold ryegrass in the first experimental year. ;

  15. Effects of Ischemic Preconditioning of Different Intraoperative Ischemic Times of Vascularized Bone Graft Rabbit Models

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    Ahmad Sukari Halim

    2013-11-01

    Full Text Available BackgroundIschemic preconditioning has been shown to improve the outcomes of hypoxic tolerance of the heart, brain, lung, liver, jejunum, skin, and muscle tissues. However, to date, no report of ischemic preconditioning on vascularized bone grafts has been published.MethodsSixteen rabbits were divided into four groups with ischemic times of 2, 6, 14, and 18 hours. Half of the rabbits in each group underwent ischemic preconditioning. The osteomyocutaneous flaps consisted of the tibia bone, from which the overlying muscle and skin were raised. The technique of ischemic preconditioning involved applying a vascular clamp to the pedicle for 3 cycles of 10 minutes each. The rabbits then underwent serial plain radiography and computed tomography imaging on the first, second, fourth, and sixth postoperative weeks. Following this, all of the rabbits were sacrificed and histological examinations were performed.ResultsThe results showed that for clinical analysis of the skin flaps and bone grafts, the preconditioned groups showed better survivability. In the plain radiographs, except for two non-preconditioned rabbits with intraoperative ischemic times of 6 hours, all began to show early callus formation at the fourth week. The computed tomography findings showed more callus formation in the preconditioned groups for all of the ischemic times except for the 18-hour group. The histological findings correlated with the radiological findings. There was no statistical significance in the difference between the two groups.ConclusionsIn conclusion, ischemic preconditioning improved the survivability of skin flaps and increased callus formation during the healing process of vascularized bone grafts.

  16. Associations among Different Internet Access Time, Gender and Cyberbullying Behaviors in Taiwan’s Adolescents

    Science.gov (United States)

    Chao, Cheng-Min; Yu, Tai-Kuei

    2017-01-01

    With the increasing convenience of social networking sites and their interconnectedness with human interaction, verbal and image bullying have turned digital, making cyberbullying a new form of bullying attracting the attention of researchers, social workers, and schools. This study focuses on the status quo of attitude toward cyberbullying and cyberbullying behavior, explores associations of attitude toward behavior on cyberbullying behavior in gender and different internet access times. In a cross-sectional survey, adolescents were surveyed through self-report questionnaires, 13,864 respondents were received among 150 high schools in Taiwan. Statistical analyses were performed using structural equation modeling (SEM). The study revealed that attitude toward cyberbullying has a direct effect on cyberbullying behavior; among the greatest direct impact were when students use the Internet during the time frame 10:00–14:00. Parents and schoolteachers pay special attention to students using the Internet during this time frame 10:00–14:00 and give guidance, express care, and help those being bullied to communicate and use the Internet in a correct manner. Among genders, male student attitude toward behavior has a greater effect than those of female students. Both male and female students know what cyberbullying is and have witnessed, heard of, or personally encountered cyberbullying behavior. We recommend students talk to parents or teachers or other people who care to reduce the negative effects of cyberbullying. We hopeful that the conceptualization model presented in this study serves as an activator for researches on attitude toward cyberbullying and cyberbullying behavior, and serves a guide and a call to attract more researches in this area. PMID:28713309

  17. Associations among Different Internet Access Time, Gender and Cyberbullying Behaviors in Taiwan’s Adolescents

    Directory of Open Access Journals (Sweden)

    Cheng-Min Chao

    2017-06-01

    Full Text Available With the increasing convenience of social networking sites and their interconnectedness with human interaction, verbal and image bullying have turned digital, making cyberbullying a new form of bullying attracting the attention of researchers, social workers, and schools. This study focuses on the status quo of attitude toward cyberbullying and cyberbullying behavior, explores associations of attitude toward behavior on cyberbullying behavior in gender and different internet access times. In a cross-sectional survey, adolescents were surveyed through self-report questionnaires, 13,864 respondents were received among 150 high schools in Taiwan. Statistical analyses were performed using structural equation modeling (SEM. The study revealed that attitude toward cyberbullying has a direct effect on cyberbullying behavior; among the greatest direct impact were when students use the Internet during the time frame 10:00–14:00. Parents and schoolteachers pay special attention to students using the Internet during this time frame 10:00–14:00 and give guidance, express care, and help those being bullied to communicate and use the Internet in a correct manner. Among genders, male student attitude toward behavior has a greater effect than those of female students. Both male and female students know what cyberbullying is and have witnessed, heard of, or personally encountered cyberbullying behavior. We recommend students talk to parents or teachers or other people who care to reduce the negative effects of cyberbullying. We hopeful that the conceptualization model presented in this study serves as an activator for researches on attitude toward cyberbullying and cyberbullying behavior, and serves a guide and a call to attract more researches in this area.

  18. The sigmoid volvulus: surgical timing and mortality for different clinical types

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    Spizzirri Alessandro

    2010-01-01

    Full Text Available Abstract Background In western countries intestinal obstruction caused by sigmoid volvulus is rare and its mortality remains significant in patients with late diagnosis. The aim of this work is to assess what is the correct surgical timing and how the prognosis changes for the different clinical types. Methods We realized a retrospective clinical study including all the patients treated for sigmoid volvulus in the Department of General Surgery, St Maria Hospital, Terni, from January 1996 till January 2009. We selected 23 patients and divided them in 2 groups on the basis of the clinical onset: patients with clear clinical signs of obstruction and patients with subocclusive symptoms. We focused on 30-day postoperative mortality in relation to the surgical timing and procedure performed for each group. Results In the obstruction group mortality rate was 44% and it concerned only the patients who had clinical signs and symptoms of peritonitis and that were treated with a sigmoid resection (57%. Conversely none of the patients treated with intestinal derotation and colopexy died. In the subocclusive group mortality was 35% and it increased up to 50% in those patients with a late diagnosis who underwent a sigmoid resection. Conclusions The mortality of patients affected by sigmoid volvulus is related to the disease stage, prompt surgical timing, functional status of the patient and his collaboration with the clinicians in the pre-operative decision making process. Mortality is higher in both obstructed patients with generalized peritonitis and patients affected by subocclusion with late diagnosis and surgical treatment; in both scenarios a Hartmann's procedure is the proper operation to be considered.

  19. Clinical correlation to differences in ranibizumab and aflibercept vascular endothelial growth factor suppression times.

    Science.gov (United States)

    Fauser, Sascha; Muether, Philipp S

    2016-11-01

    To determine clinical correlations to intraocular vascular endothelial growth factor A (VEGF-A) suppression times (VSTs) on the treatment of neovascular age-related macular degeneration (nAMD) with ranibizumab (Lucentis) or aflibercept (Eylea). Seven of 89 treatment-naïve nAMD eyes showed persistent choroidal neovascular membrane (CNV) activity throughout a spectral domain optical coherence tomography (SD-OCT)-driven pro re nata (PRN) regimen of intravitreal ranibizumab injections over 28±4 months. The treatment was switched to PRN aflibercept injections and patients were followed for another 15±2 months. A total of 160 aqueous humour specimens were collected before the intravitreal injections, and their VEGF-A concentrations were assayed by Luminex multiplex bead analysis (Luminex, Austin, Texas, USA). Intraocular VEGF-A concentrations were correlated to CNV activity shown by SD-OCT. The mean duration of suppression of VEGF-A concentrations in aqueous humour below the lower limit of quantification of our assay was 34±5 (26-69) days for ranibizumab and 67±14 (49-89) days for aflibercept (p<0.001). The percentual reduction of central retinal volume (CRV) 6 weeks after injection was higher for aflibercept compared with ranibizumab (p=0.009). The time point of clinical re-activity occurred about 50% earlier than the respective VST for each ranibizumab and aflibercept. The VST under aflibercept treatment exceeded that under ranibizumab treatment by a factor of 2. This difference correlated with differential clinical CRV reduction 6 weeks after the respective injection. For both medications, clinical activity was found at a time point as early as 50% of the individual VST. NCT01213667, post-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. Effects of different timing of stress on corticosterone, BDNF and memory in male rats.

    Science.gov (United States)

    Radahmadi, Maryam; Alaei, Hojjatallah; Sharifi, Mohammad Reza; Hosseini, Nasrin

    2015-02-01

    Learning and memory seem to be affected by chronic stress. Previous reports have considered chronic stress as a precipitating factor of different neuropsychological disorders, while others reported neurobiological adaptations following stress. The present study investigated the effects of chronic stress before, after, and during learning on the changes of learning and memory, on serum and hippocampal levels of corticosterone (CORT), brain-derived neurotrophic factor (BDNF) and body weight in rats. Male Wistar rats were randomly divided into four groups (n=10) including Control (Co), Stress-Learning-Rest (St-L-Re), Rest-Learning-Stress (Re-L-St), and Stress-Learning-Stress (St-L-St) groups. The chronic restraint stress was applied 6 h/day for 21 days. Moreover, the passive avoidance test was used to assess memory deficit, 1, 7, and 21 days after training. At the end of experiments, CORT and BDNF levels were measured. The findings did not support adaptation in chronic stress conditions. The acquisition time as well as the short and mid-term memories was significantly impaired in the St-L-Re group. Short, mid, and long-term memories were significantly impaired in the Re-L-St and St-L-St groups compared with the Co group, as a result of the enhancement of CORT and reduction of BDNF levels. In the St-L-St group, changes in memory functions were less pronounced than in the Re-L-St group. Also, body weight declined following the chronic stress, while recovery period enhanced the body weight gain in stressed rats. It can be concluded that a potential time-dependent involvement of stress and recovery period on the level of BDNF. Longer duration time of chronic stress might promote adaptive effects on memory and CORT level. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Estimation of Interchannel Time Difference in Frequency Subbands Based on Nonuniform Discrete Fourier Transform

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    Qiu Bo

    2008-01-01

    Full Text Available Binaural cue coding (BCC is an efficient technique for spatial audio rendering by using the side information such as interchannel level difference (ICLD, interchannel time difference (ICTD, and interchannel correlation (ICC. Of the side information, the ICTD plays an important role to the auditory spatial image. However, inaccurate estimation of the ICTD may lead to the audio quality degradation. In this paper, we develop a novel ICTD estimation algorithm based on the nonuniform discrete Fourier transform (NDFT and integrate it with the BCC approach to improve the decoded auditory image. Furthermore, a new subjective assessment method is proposed for the evaluation of auditory image widths of decoded signals. The test results demonstrate that the NDFT-based scheme can achieve much wider and more externalized auditory image than the existing BCC scheme based on the discrete Fourier transform (DFT. It is found that the present technique, regardless of the image width, does not deteriorate the sound quality at the decoder compared to the traditional scheme without ICTD estimation.

  2. Differences by age and sex in the sedentary time of adults in Scotland.

    Science.gov (United States)

    Strain, Tessa; Kelly, Paul; Mutrie, Nanette; Fitzsimons, Claire

    2018-04-01

    Previous nationally-representative research in Scotland found a j-shaped relationship between age and leisure sedentary time (ST): a decrease from young to middle-age, before rising steeply in older-age. This study investigated the effects of age and sex on weekday (including work) ST for all adults and stratified by work-status, and on weekend day ST. Differences in the relative contributions of component behaviours were also investigated. Responses from 14,367 adult (≥16 years) 2012-14 Scottish Health Survey participants were analysed using linear regressions. We found no j-shaped relationship between age and weekday ST. Instead, only 16-24 year olds reported lower levels than those over 75 years (6.6 (95% CI: 6.3-6.9) compared to 7.4 (95% CI: 7.2-7.6) hours/day; p work, and for weekend day ST for all groups. For those in work, work ST accounted for 45% of weekday ST. Television/screen ST made up over half of leisure ST on weekdays and weekend days, regardless of sex, age, or work-status. These results challenge our understanding of how ST varies by age. Interventions to reduce ST should consider differences in the relative contributions of ST behaviours by age and work-status.

  3. Simulation for light extraction in light emitting diode using finite domain time difference method

    International Nuclear Information System (INIS)

    Hong, Jun Hee; Park, Si Hyun

    2008-01-01

    InGaN based LEDs are indispensable to traffic light, full color displays, back lights in liquid crystals, and general lighting. The demand for high efficiency LEDs is on the increase. Recently we have reported the improvement of the light extraction efficiency of InGaN based LED. In this paper we show suitable a three dimensional (3 D)FDTD simulation method for LED simulation and we apply our FDTD simulation to our PNS LED structures, comparing the simulation results with the experimental results. For real FDTD simulation, we first must consider the spatial and temporal grid size. In order to obtain an accurate result, the spatial grid size must be so small that the feature of the field can be resolved. We computed the field power at each time at the surface 0.3mm away from the surface between GaN and air and integrate over surface. The calculations were conducted for the PNS LEDs employing the different height of SiO_2 columns, that is, h=160nm, h=350nm, h=550nm, h=750nm, and h=950nm. Simulation results according to different height is shown in Fig. 1(a,b). All simulation curves follow rough trend that it increases with column height and reaches the maximum at about 600nm height and then decreases with height. And this is a consistent with the trend from our experiments. Our FDTD simulation gives a possibility for design of LED structures of high extraction efficiency

  4. Changes in gravitational force affect gene expression in developing organ systems at different developmental times

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    Moorman Stephen J

    2005-05-01

    Full Text Available Abstract Background Little is known about the affect of microgravity on gene expression, particularly in vivo during embryonic development. Using transgenic zebrafish that express the gfp gene under the influence of a β-actin promoter, we examined the affect of simulated-microgravity on GFP expression in the heart, notochord, eye, somites, and rohon beard neurons. We exposed transgenic zebrafish to simulated-microgravity for different durations at a variety of developmental times in an attempt to determine periods of susceptibility for the different developing organ systems. Results The developing heart had a period of maximum susceptibility between 32 and 56 hours after fertilization when there was an approximately 30% increase in gene expression. The notochord, eye, somites, and rohon beard neurons all showed periods of susceptibility occurring between 24 and 72 hours after fertilization. In addition, the notochord showed a second period of susceptibility between 8 and 32 hours after fertilization. Interestingly, all organs appeared to be recovering by 80 hours after fertilization despite continued exposure to simulated-microgravity. Conclusion These results support the idea that exposure to microgravity can cause changes in gene expression in a variety of developing organ systems in live embryos and that there are periods of maximum susceptibility to the effects.

  5. Age-Related Differences of Maximum Phonation Time in Patients after Cardiac Surgery

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    Kazuhiro P. Izawa

    2017-12-01

    Full Text Available Background and aims: Maximum phonation time (MPT, which is related to respiratory function, is widely used to evaluate maximum vocal capabilities, because its use is non-invasive, quick, and inexpensive. We aimed to examine differences in MPT by age, following recovery phase II cardiac rehabilitation (CR. Methods: This longitudinal observational study assessed 50 consecutive cardiac patients who were divided into the middle-aged group (<65 years, n = 29 and older-aged group (≥65 years, n = 21. MPTs were measured at 1 and 3 months after cardiac surgery, and were compared. Results: The duration of MPT increased more significantly from month 1 to month 3 in the middle-aged group (19.2 ± 7.8 to 27.1 ± 11.6 s, p < 0.001 than in the older-aged group (12.6 ± 3.5 to 17.9 ± 6.0 s, p < 0.001. However, no statistically significant difference occurred in the % change of MPT from 1 month to 3 months after cardiac surgery between the middle-aged group and older-aged group, respectively (41.1% vs. 42.1%. In addition, there were no significant interactions of MPT in the two groups for 1 versus 3 months (F = 1.65, p = 0.20. Conclusion: Following phase II, CR improved MPT for all cardiac surgery patients.

  6. Age-Related Differences of Maximum Phonation Time in Patients after Cardiac Surgery.

    Science.gov (United States)

    Izawa, Kazuhiro P; Kasahara, Yusuke; Hiraki, Koji; Hirano, Yasuyuki; Watanabe, Satoshi

    2017-12-21

    Background and aims: Maximum phonation time (MPT), which is related to respiratory function, is widely used to evaluate maximum vocal capabilities, because its use is non-invasive, quick, and inexpensive. We aimed to examine differences in MPT by age, following recovery phase II cardiac rehabilitation (CR). Methods: This longitudinal observational study assessed 50 consecutive cardiac patients who were divided into the middle-aged group (<65 years, n = 29) and older-aged group (≥65 years, n = 21). MPTs were measured at 1 and 3 months after cardiac surgery, and were compared. Results: The duration of MPT increased more significantly from month 1 to month 3 in the middle-aged group (19.2 ± 7.8 to 27.1 ± 11.6 s, p < 0.001) than in the older-aged group (12.6 ± 3.5 to 17.9 ± 6.0 s, p < 0.001). However, no statistically significant difference occurred in the % change of MPT from 1 month to 3 months after cardiac surgery between the middle-aged group and older-aged group, respectively (41.1% vs. 42.1%). In addition, there were no significant interactions of MPT in the two groups for 1 versus 3 months (F = 1.65, p = 0.20). Conclusion: Following phase II, CR improved MPT for all cardiac surgery patients.

  7. EMG analysis tuned for determining the timing and level of activation in different motor units.

    Science.gov (United States)

    Lee, Sabrina S M; Miara, Maria de Boef; Arnold, Allison S; Biewener, Andrew A; Wakeling, James M

    2011-08-01

    Recruitment patterns and activation dynamics of different motor units greatly influence the temporal pattern and magnitude of muscle force development, yet these features are not often considered in muscle models. The purpose of this study was to characterize the recruitment and activation dynamics of slow and fast motor units from electromyographic (EMG) recordings and twitch force profiles recorded directly from animal muscles. EMG and force data from the gastrocnemius muscles of seven goats were recorded during in vivo tendon-tap reflex and in situ nerve stimulation experiments. These experiments elicited EMG signals with significant differences in frequency content (p<0.001). The frequency content was characterized using wavelet and principal components analysis, and optimized wavelets with centre frequencies, 149.94 Hz and 323.13 Hz, were obtained. The optimized wavelets were used to calculate the EMG intensities and, with the reconstructed twitch force profiles, to derive transfer functions for slow and fast motor units that estimate the activation state of the muscle from the EMG signal. The resulting activation-deactivation time constants gave r values of 0.98-0.99 between the activation state and the force profiles. This work establishes a framework for developing improved muscle models that consider the intrinsic properties of slow and fast fibres within a mixed muscle, and that can more accurately predict muscle force output from EMG. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Changes in the bilateral pulse transit time difference with a moving arm.

    Science.gov (United States)

    Jiang, Xinge; Wei, Shoushui; Zheng, Dingchang; Huang, Peng; Liu, Chengyu

    2018-04-20

    Changes of pulse transit time (PTT) induced by arm position were studied for unilateral arm. However, consistency of the PTT changes was not validated for both arm sides. We aimed to quantify the PTT changes between horizontal and non-horizontal positions from right arm and left arm in order to explore the consistency of both arms. Twenty-four normal subjects aged between 21 and 50 (14 male and 10 female) years were enrolled. Left and right radial artery pulses were synchronously recorded from 24 healthy subjects with one arm (left or right) at five angles (90∘, 45∘, 0∘, -45∘ and -90∘) and the other arm at the horizontal level (0∘) for reference. The overall mean PTT changes at the five angles (from 90∘ to -90∘) in the left arm (right as reference) were 16.1, 12.3, -0.5, -2.5 and -2.6 ms, respectively, and in the right arm (left as reference) were 18.0, 12.6, 1.6, -1.6 and -2.0 ms, respectively. Obvious differences were not found in the PTT changes between the two arms (left arm moving or right arm moving) under each of the five different positions (all P> 0.05).

  9. Differences in compliance with Surviving Sepsis Campaign recommendations according to hospital entrance time: day versus night.

    Science.gov (United States)

    Almeida, Mónica; Ribeiro, Orquídea; Aragão, Irene; Costa-Pereira, Altamiro; Cardoso, Teresa

    2013-04-23

    Higher compliance with Surviving Sepsis Campaign (SSC) recommendations has been associated with lower mortality. The authors evaluate differences in compliance with SSC 6-hour bundle according to hospital entrance time (day versus night) and its impact on hospital mortality. Prospective cohort study of all patients with community-acquired severe sepsis admitted to the intensive care unit of a large university tertiary care hospital, over 3.5 years with a follow-up until hospital discharge. Time to compliance with each recommendation of the SSC 6-hour bundle was calculated according to hospital entrance period: day (08:30 to 20:30) versus night (20:30 to 08:30). For the same periods, clinical staff composition and the number of patients attending the emergency department (ED) was also recorded. In this period 300 consecutive patients were included. Compliance rate was (night vs. day): serum lactate measurement 57% vs. 49% (P = 0.171), blood cultures drawn 59% vs. 37% (P 8 mmHg 45% vs. 29% (P = 0.021), and central venous oxygen saturation (SvcO₂) >70%, 7% vs. 2% (P = 0.082); fluids were administered in all patients with hypotension in both periods and vasopressors were administered in patients with hypotension not responsive to fluids in 100% vs. 99%. Time to get specific actions done was also different (night vs. day): serum lactate measurement (4.5 vs. 7 h, P = 0.018), blood cultures drawn (4 vs. 8 h, P night with a higher proportion of less differentiated doctors. The number of patients attending the Emergency Department was lower overnight. Hospital mortality rate was 34% in patients entering in the night period vs. 40% in those entering during the day (P = 0.281). Compliance with SSC recommendations was higher at night. A possible explanation might be the increased nurse to patient ratio in that period. Adjustment of the clinical team composition to the patients' demand is needed to increase compliance and improve prognosis.

  10. Trends over time in tree and seedling phylogenetic diversity indicate regional differences in forest biodiversity change.

    Science.gov (United States)

    Potter, Kevin M; Woodall, Christopher W

    2012-03-01

    Changing climate conditions may impact the short-term ability of forest tree species to regenerate in many locations. In the longer term, tree species may be unable to persist in some locations while they become established in new places. Over both time frames, forest tree biodiversity may change in unexpected ways. Using repeated inventory measurements five years apart from more than 7000 forested plots in the eastern United States, we tested three hypotheses: phylogenetic diversity is substantially different from species richness as a measure of biodiversity; forest communities have undergone recent changes in phylogenetic diversity that differ by size class, region, and seed dispersal strategy; and these patterns are consistent with expected early effects of climate change. Specifically, the magnitude of diversity change across broad regions should be greater among seedlings than in trees, should be associated with latitude and elevation, and should be greater among species with high dispersal capacity. Our analyses demonstrated that phylogenetic diversity and species richness are decoupled at small and medium scales and are imperfectly associated at large scales. This suggests that it is appropriate to apply indicators of biodiversity change based on phylogenetic diversity, which account for evolutionary relationships among species and may better represent community functional diversity. Our results also detected broadscale patterns of forest biodiversity change that are consistent with expected early effects of climate change. First, the statistically significant increase over time in seedling diversity in the South suggests that conditions there have become more favorable for the reproduction and dispersal of a wider variety of species, whereas the significant decrease in northern seedling diversity indicates that northern conditions have become less favorable. Second, we found weak correlations between seedling diversity change and latitude in both zones

  11. Assessment of Soybean Flowering and Seed Maturation Time in Different Latitude Regions of Kazakhstan.

    Science.gov (United States)

    Abugalieva, Saule; Didorenko, Svetlana; Anuarbek, Shynar; Volkova, Lubov; Gerasimova, Yelena; Sidorik, Ivan; Turuspekov, Yerlan

    2016-01-01

    Soybean is still a minor crop in Kazakhstan despite an increase in planting area from 4,500 to 11,400 km2 between 2006 and 2014. However, the Government's recently accepted crop diversification policy projects the expansion of soybean cultivation area to more than 40,000 km2 by 2020. The policy is targeting significant expansion of soybean production in South-eastern, Eastern, and Northern regions of Kazakhstan. Successful realization of this policy requires a comprehensive characterization of plant growth parameters to identify optimal genotypes with appropriate adaptive phenotypic traits. In this study 120 soybean accessions from different parts of the World, including 18 accessions from Kazakhstan, were field tested in South-eastern, Eastern, and Northern regions of the country. These studies revealed positive correlation of yield with flowering time in Northern Kazakhstan, with seed maturity time in Eastern Kazakhstan, and with both these growth stages in South-eastern Kazakhstan. It was determined that in South-eastern, Eastern and Northern regions of Kazakhstan the majority of productive genotypes were in maturity groups MGI, MG0, and MG00, respectively. The accessions were genotyped for four major maturity genes (E1, E2, E3, and E4) in order to assess the relationship between E loci and agronomic traits. The allele composition of the majority of accessions was e1-as/e2/E3/E4 (specific frequencies 57.5%, 91.6%, 65.0%, and 63.3%, respectively). Accessions with dominant alleles in either E3 or E4 genes showed higher yield in all three regions, although the specific genotype associated with greatest productivity was different for each site. Genotype-environment interaction studies based on yield performances suggest that South-east and East regions formed one mega-environment, which was well separated from North Kazakhstan where significantly earlier time to maturation is required. The results provide important insights into the relationship between genetic and

  12. Correlates of sedentary time in different age groups: results from a large cross sectional Dutch survey.

    Science.gov (United States)

    Bernaards, Claire M; Hildebrandt, Vincent H; Hendriksen, Ingrid J M

    2016-10-26

    Evidence shows that prolonged sitting is associated with an increased risk of mortality, independent of physical activity (PA). The aim of the study was to identify correlates of sedentary time (ST) in different age groups and day types (i.e. school-/work day versus non-school-/non-work day). The study sample consisted of 1895 Dutch children (4-11 years), 1131 adolescents (12-17 years), 8003 adults (18-64 years) and 1569 elderly (65 years and older) who enrolled in the Dutch continuous national survey 'Injuries and Physical Activity in the Netherlands' between 2006 and 2011. Respondents estimated the number of sitting hours during a regular school-/workday and a regular non-school/non-work day. Multiple linear regression analyses on cross-sectional data were used to identify correlates of ST. Significant positive associations with ST were observed for: higher age (4-to-17-year-olds and elderly), male gender (adults), overweight (children), higher education (adults ≥ 30 years), urban environment (adults), chronic disease (adults ≥ 30 years), sedentary work (adults), not meeting the moderate to vigorous PA (MVPA) guideline (children and adults ≥ 30 years) and not meeting the vigorous PA (VPA) guideline (4-to-17-year-olds). Correlates of ST that significantly differed between day types were working hours and meeting the VPA guideline. More working hours were associated with more ST on school-/work days. In children and adolescents, meeting the VPA guideline was associated with less ST on non-school/non-working days only. This study provides new insights in the correlates of ST in different age groups and thus possibilities for interventions in these groups. Correlates of ST appear to differ between age groups and to a lesser degree between day types. This implies that interventions to reduce ST should be age specific. Longitudinal studies are needed to draw conclusions on causality of the relationship between identified correlates and ST.

  13. Correlates of sedentary time in different age groups: results from a large cross sectional Dutch survey

    Directory of Open Access Journals (Sweden)

    Claire M. Bernaards

    2016-10-01

    Full Text Available Abstract Background Evidence shows that prolonged sitting is associated with an increased risk of mortality, independent of physical activity (PA. The aim of the study was to identify correlates of sedentary time (ST in different age groups and day types (i.e. school-/work day versus non-school-/non-work day. Methods The study sample consisted of 1895 Dutch children (4–11 years, 1131 adolescents (12–17 years, 8003 adults (18–64 years and 1569 elderly (65 years and older who enrolled in the Dutch continuous national survey ‘Injuries and Physical Activity in the Netherlands’ between 2006 and 2011. Respondents estimated the number of sitting hours during a regular school-/workday and a regular non-school/non-work day. Multiple linear regression analyses on cross-sectional data were used to identify correlates of ST. Results Significant positive associations with ST were observed for: higher age (4-to-17-year-olds and elderly, male gender (adults, overweight (children, higher education (adults ≥ 30 years, urban environment (adults, chronic disease (adults ≥ 30 years, sedentary work (adults, not meeting the moderate to vigorous PA (MVPA guideline (children and adults ≥ 30 years and not meeting the vigorous PA (VPA guideline (4-to-17-year-olds. Correlates of ST that significantly differed between day types were working hours and meeting the VPA guideline. More working hours were associated with more ST on school-/work days. In children and adolescents, meeting the VPA guideline was associated with less ST on non-school/non-working days only. Conclusions This study provides new insights in the correlates of ST in different age groups and thus possibilities for interventions in these groups. Correlates of ST appear to differ between age groups and to a lesser degree between day types. This implies that interventions to reduce ST should be age specific. Longitudinal studies are needed to draw conclusions on causality of

  14. Methods for assessment of climate variability and climate changes in different time-space scales

    International Nuclear Information System (INIS)

    Lobanov, V.; Lobanova, H.

    2004-01-01

    climate changes indexes of such classification have been developed which included: statistical significance or non-significance of climate changes, direction of climate change tendency in conditions of its statistical significance, assessment of its contribution and a form of the tendency if it enough complex over the time. In detected homogeneous regions the spatial generalization is fulfilled which includes different approach in dependence on regularities of spatial features. They are: an averaging, development of spatial distribution functions or spatial simulation. New spatial linear model has been developed and suggested which includes two coefficients connected with a gradient and a level of space field and one parameter which characterizes the internal inhomogeneity of the field. The last step of the suggested methodology is a using of the detected point and field climate changes for determination of design hydrological value. Traditional design characteristics (as one random event in each year) as well as new ones (POT, rare extremes, characteristics of cycles of climate variability), which can be rare or often than one value per year have been chosen. Approach and methods for using of detected climate changes in hydrological computations have been developed. Application of developed methods has been shown on some examples of different hydrometeorological characteristics (floods, low flow, annual runoff, monthly and annual temperature and precipitation) in some regions with different climatic conditions.(Author)

  15. Internalizing versus Externalizing Control: Different Ways to Perform a Time-Based Prospective Memory Task

    Science.gov (United States)

    Huang, Tracy; Loft, Shayne; Humphreys, Michael S.

    2014-01-01

    "Time-based prospective memory" (PM) refers to performing intended actions at a future time. Participants with time-based PM tasks can be slower to perform ongoing tasks (costs) than participants without PM tasks because internal control is required to maintain the PM intention or to make prospective-timing estimates. However, external…

  16. Characterization of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time.

    Science.gov (United States)

    Nath, Caroline Daiane; Neres, Marcela Abbado; Scheidt, Kácia Carine; Bersot, Luciano Dos Santos; Sunahara, Samantha Mariana Monteiro; Sarto, Jaqueline Rocha Wobeto; Stangarlin, José Renato; Gomes, Simone Damasceno; Sereno, Mallu Jagnow; Perin, Ana Paula

    2018-03-02

    The objective was to characterize the fermentative and microbiological profile of Tifton 85 bermudagrass haylage with different layers of polyethylene film and storage time. The experimental design consisted of a randomized block design with four and six wrapping layers (100 and 150 microns in total. respectively) allocated in the main plots, through repeated measures analysis (30, 60, and 90 days of storage) with four replicates. The storage time and number of wrapping layers did not show changes in the population of Clostridium and lactic acid bacteria. A decrease was observed in the enterobacteria population with an increase in the storage period in the two wrapping layers studied. Upon opening of the haylage at 30 days, the population of Bacillus was lower in haylages made with six layers of wrapping (3.63 log colony forming units (CFU) g-1). No growth of Listeria sp. or Salmonella sp. was observed during the experimental period. The fungal genera with greater occurrence were Penicillium sp. and Fusarium sp. The following mycotoxins were not detected: ochratoxin A, fumonisins, and zearalenone. Relative to the organic butyric, propionic, and acetic acids, the haylages presented a low concentration of lactic acid; this may have prevented a drop in the pH, which was high when the silos were opened (5.4). The levels of ammoniacal nitrogen and soluble carbohydrates presented no variation among the number of wrapping layers, with an overall average of 35.55 and 38.04 g kg-1. Tifton 85 bermudagrass haylage wrapped with four and six layers presented adequate fermentation and microbiological characteristics in the evaluated periods.

  17. Techno-economic analysis and climate change impacts of sugarcane biorefineries considering different time horizons.

    Science.gov (United States)

    Junqueira, Tassia L; Chagas, Mateus F; Gouveia, Vera L R; Rezende, Mylene C A F; Watanabe, Marcos D B; Jesus, Charles D F; Cavalett, Otavio; Milanez, Artur Y; Bonomi, Antonio

    2017-01-01

    Ethanol production from lignocellulosic feedstocks (also known as 2nd generation or 2G ethanol process) presents a great potential for reducing both ethanol production costs and climate change impacts since agricultural residues and dedicated energy crops are used as feedstock. This study aimed at the quantification of the economic and environmental impacts considering the current and future scenarios of sugarcane biorefineries taking into account not only the improvements of the industrial process but also of biomass production systems. Technology assumptions and scenarios setup were supported by main companies and stakeholders, involved in the lignocellulosic ethanol production chain from Brazil and abroad. For instance, scenarios considered higher efficiencies and lower residence times for pretreatment, enzymatic hydrolysis, and fermentation (including pentoses fermentation); higher sugarcane yields; and introduction of energy cane (a high fiber variety of cane). Ethanol production costs were estimated for different time horizons. In the short term, 2G ethanol presents higher costs compared to 1st generation (1G) ethanol. However, in the long term, 2G ethanol is more competitive, presenting remarkable lower production cost than 1G ethanol, even considering some uncertainties regarding technology and market aspects. In addition, environmental assessment showed that both 1G (in the medium and long term) and 2G ethanol can reduce climate change impacts by more than 80% when compared to gasoline. This work showed the great potential of 2G ethanol production in terms of economic and environmental aspects. These results can support new research programs and public policies designed to stimulate both production and consumption of 2G ethanol in Brazil, accelerating the path along the learning curve. Some examples of mechanisms include: incentives to the establishment of local equipment and enzyme suppliers; and specific funding programs for the development and use of

  18. Comparative evaluation of image quality in computed radiology systems using imaging plates with different usage time

    International Nuclear Information System (INIS)

    Lazzaro, M.V.; Luz, R.M. da; Capaverde, A.S.; Silva, A.M. Marques da

    2015-01-01

    Computed Radiology (CR) systems use imaging plates (IPs) for latent image acquisition. Taking into account the quality control (QC) of these systems, imaging plates usage time is undetermined. Different recommendations and publications on the subject suggest tests to evaluate these systems. The objective of this study is to compare the image quality of IPs of a CR system, in a mammography service, considering the usage time and consistency of assessments. 8 IPs were used divided into two groups: the first group included 4 IPs with 3 years of use (Group A); the second group consisted of 4 new IPs with no previous exposure (Group B). The tests used to assess the IP's quality were: Uniformity, Differential Signal to Noise Ratio (SDNR), Ghost Effect and Figure of Merit (FOM). Statistical results show that the proposed tests are shown efficient in assessing the conditions of image quality obtained in CR systems in mammography and can be used as determining factors for the replacement of IP's. Moreover, comparing the two sets of IP, results led to the replacement of all the set of IP’s with 3 years of use. This work demonstrates the importance of an efficient quality control, not only with regard to the quality of IP's used, but in the acquisition system as a whole. From this work, these tests will be conducted on an annual basis, already targeting as future work, monitoring the wear of IP's Group B and the creation of a baseline for analysis and future replacements. (author)

  19. Application of radon time series data for seismo - geochemical studies along different fault zones of Taiwan

    International Nuclear Information System (INIS)

    Walia, Vivek; Arvind Kumar; Lin, Shih-Jung; Liao, Yu-Tzu; Wen, Kuo-Liang; Yang, Tsanyao Frank; Fu, Ching-Chou; Chen, Cheng-Hong

    2015-01-01

    The Island of Taiwan is a product of the collision between Philippine Sea plate and Eurasian plate which makes it a region of high seismicity. In the southern part of the island the Eurasian plate is subducting under the Philippine Sea plate while in the northern area of the island the Philippine Sea plate bounded by the Ryukyu trench is subducting beneath the Eurasian plate. Behind the Ryukyu trench, the spreading Okinawa trough has developed. The northern part of Taiwan Island is located at the western extrapolation of the Okinawa trough. Over the last few years, we focused on the temporal variations of soil-gas composition at established geochemical observatories along the Hsincheng fault in the Hsinchu area, Hsinhua fault in the Tainan areas, and at Jaosi in the Ilan areas of Taiwan. As per the present practice, the data from various stations are examined synoptically to evaluate earthquake precursory signals against the backdrop of rainfall and other environmental factors. For the earthquake prediction the efficiency of an operation system depends not only upon its logical correctness, but also upon the response time. The database has been developed by the established network of continuous soil-gas monitoring stations along different faults covering NW, SW and eastern Taiwan. The data processing includes a low-pass filter to reduce the noise level. It filters out the high frequency noise and daily variation caused by different parameters like measurement uncertainty, background noise, environmental parameters and earth tides. The rolling average and normalization were used to quantify the probability distribution of variation in the data. In recent years manually operating real-time database had been developed and efforts were made to improve data processing system for earthquake precursory studies by changing the operating system from manual to automatic. We tried to replace the business package software 'Visual Signal' to an open source programming

  20. Effects of direct injection timing and blending ratio on RCCI combustion with different low reactivity fuels

    International Nuclear Information System (INIS)

    Benajes, Jesús; Molina, Santiago; García, Antonio; Monsalve-Serrano, Javier

    2015-01-01

    Highlights: • E85 requires notable lower premixed energy ratios to achieve a stable combustion. • E10-95 leads to shorter and advanced combustion with higher maximum RoHR peaks. • E20-95, E10-98 and E10-95 reach EURO VI NOx and soot levels for all the engine loads. • E10-95 allows a significant reduction in HC and CO emissions. - Abstract: This work investigates the effects of the direct injection timing and blending ratio on RCCI performance and engine-out emissions at different engine loads using four low reactivity fuels: E10-95, E10-98, E20-95 and E85 (port fuel injected) and keeping constant the same high reactivity fuel: diesel B7 (direct injected). The experiments were conducted using a heavy-duty single-cylinder research diesel engine adapted for dual-fuel operation. All the tests were carried out at 1200 rpm. To assess the blending ratio effect, the total energy delivered to the cylinder coming from the low reactivity fuel was kept constant for the different fuel blends investigated by adjusting the low reactivity fuel mass as required in each case. In addition, a detailed analysis of the air/fuel mixing process has been developed by means of a 1-D in-house developed spray model. Results suggest that notable higher diesel amount is required to achieve a stable combustion using E85. This fact leads to higher NOx levels and unacceptable ringing intensity. By contrast, EURO VI NOx and soot levels are fulfilled with E20-95, E10-98 and E10-95. Finally, the higher reactivity of E10-95 results in a significant reduction in CO and HC emissions, mainly at low load

  1. Sex Differences in Time to Return-to-Play Progression After Sport-Related Concussion.

    Science.gov (United States)

    Stone, Sarah; Lee, Bobby; Garrison, J Craig; Blueitt, Damond; Creed, Kalyssa

    2016-10-03

    Recently, female sports participation has increased, and there is a tendency for women to experience more symptoms and variable presentation after sport-related concussion (SRC). The purpose of this study was to determine whether sex differences exist in time to begin a return-to-play (RTP) progression after an initial SRC. After initial SRC, female athletes (11-20 years old) would take longer to begin an RTP progression compared with age-matched male athletes. Retrospective cohort study. Level 3. A total of 579 participants (365 males [mean age, 15.0 ± 1.7 years], 214 females [mean age, 15.2 ± 1.5 years]), including middle school, high school, and collegiate athletes who participated in various sports and experienced an initial SRC were included and underwent retrospective chart review. The following information was collected: sex, age at injury, sport, history of prior concussion, date of injury, and date of initiation of RTP progression. Participants with a history of more than 1 concussion or injury sustained from non-sport-related activity were excluded. Despite American football having the greatest percentage (49.2%) of sport participation, female athletes took significantly longer to start an RTP progression after an initial SRC (29.1 ± 26.3 days) compared with age-matched male athletes (22.7 ± 18.3 days; P = 0.002). On average, female athletes took approximately 6 days longer to begin an RTP progression compared with age-matched male athletes. This suggests that sex differences exist between athletes, ages 11 to 20 years, with regard to initiation of an RTP progression after SRC. Female athletes may take longer to recover after an SRC, and therefore, may take longer to return to sport. Sex should be considered as part of the clinical decision-making process when determining plan of care for this population. © 2016 The Author(s).

  2. Double adjoint method for determining the contribution of composition to reactivity at different times

    International Nuclear Information System (INIS)

    Christie, S.A.; Lathouwers, D.; Kloosterman, J.L.

    2013-01-01

    Highlights: ► The double adjoint method is described. ► System reloading is determined so the multiplication factor behaviour is repeated. ► Both fast and thermal systems behave as desired. ► Allowance must be made for indirect effects in thermal systems. ► An alternative definition of breeding ratio is derived. -- Abstract: The double adjoint method uses the adjoint reactivity and transmutation problems to describe how the system composition is related to the system reactivity at different points in time. Values of the contribution to the reactivity are determined using the adjoint reactivity problem, and these are then used as the source function for the adjoint transmutation problem. The method is applied to the problem of determining the contribution of the beginning of cycle composition to the end of cycle reactivity. It is tested in both fast and thermal systems by comparing the behaviour of the multiplication factor at the end of cycle in calculations with perturbed initial compositions to that predicted by the double adjoint method. The results from the fast system are good, while those from the thermal system are less favourable. This is believed to be due to the method neglecting the coupling between the composition and the flux, which plays a more significant role in thermal systems than fast ones. The importance of correcting for the effects of the fuel compound is also established. The values found are used in calculations to determine the appropriate fuel reloading of the systems tested, with the aim of duplicating the behaviour of the multiplication factor of the original system. Again the fast system gives good results, while the thermal system is less accurate. The double adjoint method is also used for a definition of breeding ratio, and some of the features of this definition are illustrated by examining the effects of different feed materials and reprocessing schemes. The method is shown to be a useful tool for the comparison of the

  3. Comparison of different real time VOC measurement techniques in a ponderosa pine forest

    Directory of Open Access Journals (Sweden)

    L. Kaser

    2013-03-01

    Full Text Available Volatile organic compound (VOC mixing ratios measured by five independent instruments are compared at a forested site dominated by ponderosa pine (Pinus Ponderosa during the BEACHON-ROCS field study in summer 2010. The instruments included a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS, a Proton Transfer Reaction Quadrupole Mass Spectrometer (PTR-MS, a Fast Online Gas-Chromatograph coupled to a Mass Spectrometer (GC/MS; TOGA, a Thermal Dissociation Chemical Ionization Mass Spectrometer (PAN-CIMS and a Fiber Laser-Induced Fluorescence Instrument (FILIF. The species discussed in this comparison include the most important biogenic VOCs and a selected suite of oxygenated VOCs that are thought to dominate the VOC reactivity at this particular site as well as typical anthropogenic VOCs that showed low mixing ratios at this site. Good agreement was observed for methanol, the sum of the oxygenated hemiterpene 2-methyl-3-buten-2-ol (MBO and the hemiterpene isoprene, acetaldehyde, the sum of acetone and propanal, benzene and the sum of methyl ethyl ketone (MEK and butanal. Measurements of the above VOCs conducted by different instruments agree within 20%. The ability to differentiate the presence of toluene and cymene by PTR-TOF-MS is tested based on a comparison with GC-MS measurements, suggesting a study-average relative contribution of 74% for toluene and 26% for cymene. Similarly, 2-hydroxy-2-methylpropanal (HMPR is found to interfere with the sum of methyl vinyl ketone and methacrolein (MVK + MAC using PTR-(TOF-MS at this site. A study-average relative contribution of 85% for MVK + MAC and 15% for HMPR was determined. The sum of monoterpenes measured by PTR-MS and PTR-TOF-MS was generally 20–25% higher than the sum of speciated monoterpenes measured by TOGA, which included α-pinene, β-pinene, camphene, carene, myrcene, limonene, cineole as well as other terpenes. However, this difference is consistent throughout the study

  4. Plasmonic Resonances for Spectroscopy Applications using 3D Finite-Difference Time-Domain Models

    Science.gov (United States)

    Ravi, Aruna

    Tuning plasmonic extinction resonances of sub-wavelength scale structures is essential to achieve maximum sensitivity and accuracy. These resonances can be controlled with careful design of nanoparticle geometries and incident wave attributes. In the first part of this dissertation, plasmonically enhanced effects on hexagonal-arrays of metal nanoparticles, metal-hole arrays (micro-mesh), and linear-arrays of metal nanorings are analyzed using three-dimensional Finite-Difference Time-Domain (3D-FDTD) simulations. The effect of particle size, lattice spacing, and lack of monodispersity of a self-assembled, hexagonal array layer of silver (Ag) nanoparticles on the extinction resonance is investigated to help determine optimal design specifications for efficient organic solar power harvesting. The enhancement of transmission resonances using plasmonic thin metal films with arrays of holes which enable recording of scatter-free infrared (IR) transmission spectra of individual particles is also explored. This method is quantitative, non-destructive and helps in better understanding the interaction of light with sub-wavelength particles. Next, plasmonically enhanced effects on linear arrays of gold (Au) rings are studied. Simulations employing 3D-FDTD can be used to determine the set of geometrical parameters to attain localized surface plasmon resonance (LSPR). The shifts in resonances due to changes in the effective dielectric of the structure are investigated, which is useful in sensing applications. Computational models enrich experimental studies. In the second part of this dissertation, the effect of particle size, shape and orientation on the IR spectra is investigated using 3D-FDTD and Mie-Bruggeman models. This computational analysis is extended to include clusters of particles of mixed composition. The prediction of extinction and absorption spectra of single particles of mixed composition helps in interpreting their physical properties and predict chemical

  5. Effect of using fluoxetine at different time windows on neurological functional prognosis after ischemic stroke.

    Science.gov (United States)

    Guo, Yi; He, Yitao; Tang, Bingshan; Ma, Kefu; Cai, Zhili; Zeng, Siling; Zhang, Ying; Jiang, Xin

    2016-01-01

    To evaluate the effect of using fluoxetine at different time intervals after ischemic stroke on neurological functional prognosis in China. The patients enrolled were randomly allocated to three groups. Group A received fluoxetine 20 mg/day immediately; group B received fluoxetine 20 mg/day 7 days after enrollment; and group C did not receive fluoxetine. The therapeutic duration of fluoxetine was 90 days and the follow-up period was 180 days. The mean NIHSS score at day 90 was significantly lower in group A than group C (P = 0.005), while at day 180, the mean score in group A was significantly lower than groups B and C (P = 0.035, P = 0.000), respectively. The mean BI score at day 90 was significantly higher in group A than group C (P = 0.001), while at day 180, the mean score in group A was significantly higher than groups B and C (P = 0.036, P = 0.000), respectively. Regression analysis indicated that lower NIHSS score and higher BI score at day 180 were attributed to the early administration of fluoxetine. In patients with ischemic stroke, early administration of fluoxetine may improve the neurological functional prognosis.

  6. Time-response of cultured deep-sea benthic foraminifera to different algal diets

    Science.gov (United States)

    Heinz, P.; Hemleben, Ch; Kitazato, H.

    2002-03-01

    The vertical distribution of benthic foraminifera in the surface sediment is influenced by environmental factors, mainly by food and oxygen supply. An experiment of three different time series was performed to investigate the response of deep-sea benthic foraminifera to simulated phytodetritus pulses under stable oxygen concentrations. Each series was fed constantly with one distinct algal species in equivalent amounts. The temporal reactions of the benthic foraminifera with regard to the vertical distribution in the sediment, the total number, and the species composition were observed and compared within the three series. Additionally, oxygen contents and bacterial cell numbers were measured to ensure that these factors were invariable and did not influence foraminiferal communities. The addition of algae leads to higher population densities 21 days after food was added. Higher numbers of individuals were probably caused by higher organic levels, which in turn induced reproduction. A stronger response is found after feeding with Amphiprora sp. and Pyramimonas sp., compared to Dunaliella tertiolecta. At a constant high oxygen supply, no migration to upper layers was observed after food addition, and more individuals were found in deeper layers. The laboratory results thus agree with the predictions of the TROX-model. An epifaunal microhabitat preference was shown for Adercotryma glomerata. Hippocrepina sp. was spread over the entire sediment depth with a shallow infaunal maximum. Melonis barleeanum preferred a deeper infaunal habitat. Bacterial cell concentrations were stable during the laboratory experiments and showed no significant response to higher organic fluxes.

  7. Different time trend and management of esophagogastric junction adenocarcinoma in three Asian countries.

    Science.gov (United States)

    Hatta, Waku; Tong, Daniel; Lee, Yeong Yeh; Ichihara, Shin; Uedo, Noriya; Gotoda, Takuji

    2017-04-01

    Esophagogastric junction (EGJ) adenocarcinoma has been on the increase in Western countries. However, in Asian countries, data on the incidence of EGJ adenocarcinoma are evidently lacking. In the present review, we focus on the current clinical situation of EGJ adenocarcinoma in three Asian countries: Japan, Hong Kong, and Malaysia. The incidence of EGJ adenocarcinoma has been reported to be gradually increasing in Malaysia and Japan, whereas it has stabilized in Hong Kong. However, the number of cases in these countries is comparatively low compared with Western countries. A reason for the reported difference in the incidence and time trend of EGJ adenocarcinoma among the three countries may be explained by two distinct etiologies: one arising from chronic gastritis similar to distal gastric cancer, and the other related to gastroesophageal reflux disease similar to esophageal adenocarcinoma including Barrett's adenocarcinoma. This review also shows that there are several concerns in clinical practice for EGJ adenocarcinoma. In Hong Kong and Malaysia, many EGJ adenocarcinomas have been detected at a stage not amenable to endoscopic resection. In Japan, histological curability criteria for endoscopic resection cases have not been established. We suggest that an international collaborative study using the same definition of EGJ adenocarcinoma may be helpful not only for clarifying the characteristics of these cancers but also for improving the clinical outcome of these patients. © 2017 The Authors. Digestive Endoscopy © 2017 Japan Gastroenterological Endoscopy Society.

  8. Time difference of arrival estimation of microseismic signals based on alpha-stable distribution

    Science.gov (United States)

    Jia, Rui-Sheng; Gong, Yue; Peng, Yan-Jun; Sun, Hong-Mei; Zhang, Xing-Li; Lu, Xin-Ming

    2018-05-01

    Microseismic signals are generally considered to follow the Gauss distribution. A comparison of the dynamic characteristics of sample variance and the symmetry of microseismic signals with the signals which follow α-stable distribution reveals that the microseismic signals have obvious pulse characteristics and that the probability density curve of the microseismic signal is approximately symmetric. Thus, the hypothesis that microseismic signals follow the symmetric α-stable distribution is proposed. On the premise of this hypothesis, the characteristic exponent α of the microseismic signals is obtained by utilizing the fractional low-order statistics, and then a new method of time difference of arrival (TDOA) estimation of microseismic signals based on fractional low-order covariance (FLOC) is proposed. Upon applying this method to the TDOA estimation of Ricker wavelet simulation signals and real microseismic signals, experimental results show that the FLOC method, which is based on the assumption of the symmetric α-stable distribution, leads to enhanced spatial resolution of the TDOA estimation relative to the generalized cross correlation (GCC) method, which is based on the assumption of the Gaussian distribution.

  9. Individual variation in habituation: behaviour over time toward different stimuli in threespine sticklebacks (Gasterosteus aculeatus)

    Science.gov (United States)

    Bell, Alison M.; Peeke, Harman V.S.

    2014-01-01

    Habituation, or the relatively permanent waning of a response as a result of repeated stimulation, is a form of behavioural plasticity that allows animals to filter out irrelevant stimuli and to focus selectively on important stimuli. Individuals that fail to habituate might be at a disadvantage if they continue to respond to irrelevant stimuli; therefore, habituation can have adaptive significance. In this study we compared rates of behaviour over time toward three different ecologically-relevant stimuli (food, a male intruder and a gravid female) in threespine sticklebacks (Gasterosteus aculeatus). We detected evidence for habituation to the stimuli, and males in this study were especially aggressive toward both male and female conspecifics. Although there were some clear temporal patterns that could be detected by looking at average behaviour, not all individuals behaved in the same ‘average’ way. We detected substantial inter-individual variation in behaviour toward all three stimuli, inter-individual variation in rates of habituation to both male and female conspecifics, but no evidence for correlations between behaviours across stimuli (behavioural syndromes). These results suggest that individual animals vary in rates of habituation, and prompt hypotheses about the causes and consequences of variation in rates of habituation. PMID:25678715

  10. Finite difference solution of the time dependent neutron group diffusion equations

    International Nuclear Information System (INIS)

    Hendricks, J.S.; Henry, A.F.

    1975-08-01

    In this thesis two unrelated topics of reactor physics are examined: the prompt jump approximation and alternating direction checkerboard methods. In the prompt jump approximation it is assumed that the prompt and delayed neutrons in a nuclear reactor may be described mathematically as being instantaneously in equilibrium with each other. This approximation is applied to the spatially dependent neutron diffusion theory reactor kinetics model. Alternating direction checkerboard methods are a family of finite difference alternating direction methods which may be used to solve the multigroup, multidimension, time-dependent neutron diffusion equations. The reactor mesh grid is not swept line by line or point by point as in implicit or explicit alternating direction methods; instead, the reactor mesh grid may be thought of as a checkerboard in which all the ''red squares'' and '' black squares'' are treated successively. Two members of this family of methods, the ADC and NSADC methods, are at least as good as other alternating direction methods. It has been found that the accuracy of implicit and explicit alternating direction methods can be greatly improved by the application of an exponential transformation. This transformation is incompatible with checkerboard methods. Therefore, a new formulation of the exponential transformation has been developed which is compatible with checkerboard methods and at least as good as the former transformation for other alternating direction methods

  11. Germanium nanoparticles grown at different deposition times for memory device applications

    International Nuclear Information System (INIS)

    Mederos, M.; Mestanza, S.N.M.; Lang, R.; Doi, I.; Diniz, J.A.

    2016-01-01

    In the present work, circular Metal-Oxide-Semiconductor capacitors with 200 μm of diameter and germanium (Ge) nanoparticles (NPs) embedded in the gate oxide are studied for memory applications. Optimal process parameters are investigated for Ge NPs growing by low pressure chemical vapor deposition at different deposition times. Photoluminescence measurements showed room-temperature size-dependent green-red region bands attributed to quantum confinement effects present in the NPs. High-frequency capacitance versus voltage measurements demonstrated the memory effects on the MOS structures due to the presence of Ge NPs in the gate oxide acting as discrete floating gates. Current versus voltage measurements confirmed the Fowler-Nordheim tunneling as the programming mechanism of the devices. - Highlights: • Ge nanoparticles with high density and uniforms sizes were obtained by LPCVD. • Room-temperature size-dependent bands of photoluminescence were observed. • MOS capacitors with Ge nanoparticles embedded in the oxide were fabricated. • Ge nanoparticles are the main responsible for the memory properties in the devices. • Fowler-Nordheim tunneling is the conduction mechanism observed on the devices.

  12. Devulcanization of ground tire rubber: Physical and chemical changes after different microwave exposure times

    Directory of Open Access Journals (Sweden)

    P. S. Garcia

    2015-11-01

    Full Text Available Microwave devulcanization is known to be a promising and an efficient rubber recycling method which makes possible for the rubber to regain its fluidity, and makes it capable of being remolded and revulcanized. The focus of this work is to understand the physical and chemical changes that occur in the ground tire rubber after different microwave exposure periods. For this purpose chemical, thermal, rheological and morphological analyses were performed on the tire rubber, which contains natural rubber (NR and styrene-butadiene rubber (SBR as polymeric material. The results showed that the microwave treatment promoted the breaking of sulfur cross-links and consequently increased the rubber fluidity. However, long periods of exposure led to degradation and modification of some properties. At nanoscale, the deformation of the devulcanized NR domain under stress was observed, and the morphology obtained appears to be a droplet dispersion morphology. The most exposed samples presented only one glass transition temperature, and from this it was concluded that the treatment may have played an important role in the compatibilization of the elastomeric blend. Based on the results, it is required to control the microwave exposure time and polymeric degradation in order to achieve a regenerated rubber with satisfactory properties.

  13. Avoidance test with Enchytraeus albidus (Enchytraeidae): Effects of different exposure time and soil properties

    International Nuclear Information System (INIS)

    Amorim, Monica J.B.; Novais, Sara; Roembke, Joerg; Soares, Amadeu M.V.M.

    2008-01-01

    Enchytraeids are ecologically relevant soil species and are commonly used in standardized toxicity tests. Their rapid reaction to a chemical exposure can be used as a toxicological measurement endpoint that assesses the avoidance behavior. The objectives of this investigation were to determine the effects of soil properties on the avoidance behavior of Enchytraeus albidus and to optimize the duration of avoidance test. The avoidance tests included (1) exposures in OECD artificial soil with standard or modified properties (pH, clay or peat content), and (2) exposures to copper chloride, cadmium chloride, and to the organic pesticides dimethoate and phenmedipham for different time periods. Results showed that alteration of OECD soil constituents significantly affected the avoidance behavior of enchytraeids, and that the 48-h exposure was the optimal duration of the test. Consideration of soil properties is important for selecting appropriate experimental design and interpreting the results of the enchytraeid avoidance test. - Optimal duration of the avoidance tests with potworm Enchytraeus albidus is 48 h; soil properties can affect performance of the test species

  14. Germanium nanoparticles grown at different deposition times for memory device applications

    Energy Technology Data Exchange (ETDEWEB)

    Mederos, M., E-mail: melissa.mederos@gmail.com [Center for Semiconductor Components and Nanotechnology (CCSNano), University of Campinas (Unicamp), Rua João Pandia Calógeras 90, Campinas, CEP: 13083-870, São Paulo (Brazil); Mestanza, S.N.M. [Federal University of ABC (UFABC), Rua Santa Adélia 166, Bangu, Santo André, CEP: 09210-170, São Paulo (Brazil); Lang, R. [Institute of Science and Technology, Federal University of São Paulo (UNIFESP), Rua Talim, 330, São José dos Campos, CEP: 12231-280, São Paulo (Brazil); Doi, I.; Diniz, J.A. [Center for Semiconductor Components and Nanotechnology (CCSNano), University of Campinas (Unicamp), Rua João Pandia Calógeras 90, Campinas, CEP: 13083-870, São Paulo (Brazil); School of Electrical and Computer Engineering, University of Campinas (Unicamp), Av. Albert Einstein 400, Campinas, CEP: 13083-852, São Paulo (Brazil)

    2016-07-29

    In the present work, circular Metal-Oxide-Semiconductor capacitors with 200 μm of diameter and germanium (Ge) nanoparticles (NPs) embedded in the gate oxide are studied for memory applications. Optimal process parameters are investigated for Ge NPs growing by low pressure chemical vapor deposition at different deposition times. Photoluminescence measurements showed room-temperature size-dependent green-red region bands attributed to quantum confinement effects present in the NPs. High-frequency capacitance versus voltage measurements demonstrated the memory effects on the MOS structures due to the presence of Ge NPs in the gate oxide acting as discrete floating gates. Current versus voltage measurements confirmed the Fowler-Nordheim tunneling as the programming mechanism of the devices. - Highlights: • Ge nanoparticles with high density and uniforms sizes were obtained by LPCVD. • Room-temperature size-dependent bands of photoluminescence were observed. • MOS capacitors with Ge nanoparticles embedded in the oxide were fabricated. • Ge nanoparticles are the main responsible for the memory properties in the devices. • Fowler-Nordheim tunneling is the conduction mechanism observed on the devices.

  15. Gender Differences Time Trends for Metabolic Syndrome and Its Components among Tehranian Children and Adolescents

    Directory of Open Access Journals (Sweden)

    Maryam Barzin

    2012-01-01

    Full Text Available Aims. To investigate the trend of metabolic syndrome and its components in Tehran children and adolescents during a median followup of 6.6 years. Methods. Data from 1999–2001 (phase I, 2002–2005 (phase II, and 2006–2008 (phase III of the Tehran, Lipid and Glucose Study were analyzed (=5439; age 6–18 years for the trend of metabolic syndrome (MetS and its components. General estimation equation (GEE models were used to analyze this correlated data. Results. The crude prevalence of MetS for boys at baseline was 13.2%, which increased to 16.4% in the third phase. In girls, the prevalence of Mets decreased from 11.8% at baseline to 6% during followup. The odd ratios (OR of obesity over the whole study period were raised in both sexes. The OR of abdominal obesity increased significantly in boys, but no change was observed in girls. No significant OR was observed in boys, while OR for MetS was shown to have a decreasing trend in girls during the followup. In the three time points, the ORs of MetS decreased significantly in girls but no significant difference was observed in boys. Conclusion. Inspite of increasing trend for obesity in both sexes, the trend of MetS decreased in girls and was relatively stable in boys, in Tehranian children, and adolescents.

  16. Abdominal MR imaging using a HASTE sequence : image comparison on the different echo times

    International Nuclear Information System (INIS)

    Park, Kwang Bo; Lee, Moon Gyu; Lim, Tae Hwan; Jeong, Yoong Ki; Ha, Hyun Kwon; Kim, Pyo Nyun; Auh, Yong Ho

    1999-01-01

    To determine the optimal parameters of abdominal HASTE imaging by means of a comparison of intermediate and long TE (echo time). We evaluated 30 consecutive patients who had undergone liver MR during a three-month period. Twelve patients were diagnosed as normal, four as having liver cirrhosis, and 14 were found to be suffering form hepatic hemangioma. On the basis of measured signal intensity of the liver, spleen, pancreas and gallbladder, and of fat, muscle, hemangioma, and background, we calculated the ratios of signal to noise (S/N), signal difference to noise (SD/N), and signal intensity (SI). Image quality was compared using these three ratios, and using two HASTE sequences with TEs of 90 msec and 134 msec, images were qualitatively evaluated. S/N ratio of the liver was higher when TE was 90 msec(p<.05), though S/N, SD/N and SI rations of the spleen, gallbladder, and pancreas-and of hemangiom-were higher when TE was 134 msec (p<.05). However, in muscle, all these three ratios were higher at a TE of 90 msec. SD/N ratio and SI of fat were higher at a TE of 134 msec. Overall image quality was better at a TE of 134 msec than at one of 90msec. A HASTE sequence with a TE of 134msec showed greater tissue contrast and stronger T2-weighted images than one with a TE of 90msec

  17. Heat Generation on Implant Surface During Abutment Preparation at Different Elapsed Time Intervals.

    Science.gov (United States)

    Al-Keraidis, Abdullah; Aleisa, Khalil; Al-Dwairi, Ziad Nawaf; Al-Tahawi, Hamdi; Hsu, Ming-Lun; Lynch, Edward; Özcan, Mutlu

    2017-10-01

    The purpose of this study was to evaluate heat generation at the implant surface caused by abutment preparation using a diamond bur in a high-speed dental turbine in vitro at 2 different water-coolant temperatures. Thirty-two titanium-alloy abutments were connected to a titanium-alloy implant embedded in an acrylic resin placed within a water bath at a controlled temperature of 37°C. The specimens were equally distributed into 2 groups (16 each). Group 1: the temperature was maintained at 20 ± 1°C; and group 2: the temperature was maintained at 32 ± 1°C. Each abutment was prepared in the axial plane for 1 minute and in the occlusal plane for 1 minute. The temperature of the heat generated from abutment preparation was recorded and measured at 3 distinct time intervals. Water-coolant temperature (20°C vs 32°C) had a statistically significant effect on the implant's temperature change during preparation of the abutment (P water-coolant temperature of 20 ± 1°C during preparation of the implant abutment decreased the temperature recorded at the implant surface to 34.46°C, whereas the coolant temperature of 32 ± 1°C increased the implant surface temperature to 40.94°C.

  18. Comparison of time-dependent changes in the surface hardness of different composite resins

    Science.gov (United States)

    Ozcan, Suat; Yikilgan, Ihsan; Uctasli, Mine Betul; Bala, Oya; Kurklu, Zeliha Gonca Bek

    2013-01-01

    Objective: The aim of this study was to evaluate the change in surface hardness of silorane-based composite resin (Filtek Silorane) in time and compare the results with the surface hardness of two methacrylate-based resins (Filtek Supreme and Majesty Posterior). Materials and Methods: From each composite material, 18 wheel-shaped samples (5-mm diameter and 2-mm depth) were prepared. Top and bottom surface hardness of these samples was measured using a Vicker's hardness tester. The samples were then stored at 37°C and 100% humidity. After 24 h and 7, 30 and 90 days, the top and bottom surface hardness of the samples was measured. In each measurement, the rate between the hardness of the top and bottom surfaces were recorded as the hardness rate. Statistical analysis was performed by one-way analysis of variance, multiple comparisons by Tukey's test and binary comparisons by t-test with a significance level of P = 0.05. Results: The highest hardness values were obtained from each two surfaces of Majesty Posterior and the lowest from Filtek Silorane. Both the top and bottom surface hardness of the methacrylate based composite resins was high and there was a statistically significant difference between the top and bottom hardness values of only the silorane-based composite, Filtek Silorane (P composite resin Filtek Silorane showed adequate hardness ratio, the use of incremental technic during application is more important than methacrylate based composites. PMID:24966724

  19. Structure of xanthan gum and cell ultrastructure at different times of alkali stress.

    Science.gov (United States)

    Luvielmo, Márcia de Mello; Borges, Caroline Dellinghausen; Toyama, Daniela de Oliveira; Vendruscolo, Claire Tondo; Scamparini, Adilma Regina Pippa

    2016-01-01

    The effect of alkali stress on the yield, viscosity, gum structure, and cell ultrastructure of xanthan gum was evaluated at the end of fermentation process of xanthan production by Xanthomonas campestris pv. manihotis 280-95. Although greater xanthan production was observed after a 24h-alkali stress process, a lower viscosity was observed when compared to the alkali stress-free gum, regardless of the alkali stress time. However, this outcome is not conclusive as further studies on gum purification are required to remove excess sodium, verify the efficiency loss and the consequent increase in the polymer viscosity. Alkali stress altered the structure of xanthan gum from a polygon-like shape to a star-like form. At the end of the fermentation, early structural changes in the bacterium were observed. After alkali stress, marked structural differences were observed in the cells. A more vacuolated cytoplasm and discontinuities in the membrane cells evidenced the cell lysis. Xanthan was observed in the form of concentric circles instead of agglomerates as observed prior to the alkali stress. Copyright © 2015 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  20. Speleothem Mg-isotope time-series data from different climate belts

    Science.gov (United States)

    Riechelmann, S.; Buhl, D.; Richter, D. K.; Schröder-Ritzrau, A.; Riechelmann, D. F. C.; Niedermayr, A.; Vonhof, H. B.; Wassenburg, J.; Immenhauser, A.

    2012-04-01

    Speleothem Mg-isotope time-series data from different climate belts Sylvia Riechelmann (1), Dieter Buhl(1), Detlev K. Richter (1), Andrea Schröder-Ritzrau (2), Dana F.C. Riechelmann (3), Andrea Niedermayr (1), Hubert B. Vonhof (4) , Jasper Wassenburg (1), Adrian Immenhauser (1) (1) Ruhr-University Bochum, Institute for Geology, Mineralogy and Geophysics, Universitätsstraße 150, D-44801 Bochum, Germany (2) Heidelberg Academy of Sciences, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany (3) Johannes Gutenberg-University Mainz, Institute of Geography, Johann-Joachim-Becher-Weg 21, D-55128 Mainz, Germany (4) Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands The Magnesium isotope proxy in Earth surface research is still underexplored. Recently, field and laboratory experiments have shed light on the complex suite of processes affecting Mg isotope fractionation in continental weathering systems. Magnesium-isotope fractionation in speleothems depends on a series of factors including biogenic activity and composition of soils, mineralogy of hostrock, changes in silicate versus carbonate weathering ratios, water residence time in the soil and hostrock and disequilibrium factors such as the precipitation rate of calcite in speleothems. Furthermore, the silicate (here mainly Mg-bearing clays) versus carbonate weathering ratio depends on air temperature and rainfall amount, also influencing the soil biogenic activity. It must be emphasized that carbonate weathering is generally dominant, but under increasingly warm and more arid climate conditions, silicate weathering rates increase and release 26Mg-enriched isotopes to the soil water. Furthermore, as shown in laboratory experiments, increasing calcite precipitation rates lead to elevated delta26Mg ratios and vice versa. Here, data from six stalagmite time-series Mg-isotope records (Thermo Fisher Scientific Neptune MC-ICP-MS) are shown. Stalagmites

  1. Effectiveness of different approaches to disseminating traveler information on travel time reliability.

    Science.gov (United States)

    2014-01-01

    The second Strategic Highway Research Program (SHRP 2) Reliability program aims to improve trip time reliability by reducing the frequency and effects of events that cause travel times to fluctuate unpredictably. Congestion caused by unreliable, or n...

  2. A Benchmark for Comparing Different Approaches for Specifying and Verifying Real-Time Systems

    Science.gov (United States)

    1993-01-01

    To be considered correct or useful, real - time systems must deliver results within specified time intervals, either without exception or with high...probability. Recently, a large number of formal methods have been invented for specifying and verifying real - time systems . It has been suggested that...these formal methods need to be tested out on actual real - time systems . Such testing will allow the scalability of the methods to be assessed and also

  3. Academic Performance Differences among Ethnic Groups: Do the Daily Use and Management of Time Offer Explanations?

    Science.gov (United States)

    Meeuwisse, Marieke; Born, Marise Ph.; Severiens, Sabine E.

    2013-01-01

    This explorative study describes time use and time management behaviour of ethnic minority and ethnic majority students as possible explanations for the poorer study results of ethnic minority students compared to those of majority students. We used a diary approach in a small sample to examine students' daily time use in both a lecture week…

  4. Estimation of traffic recovery time for different flow regimes on freeways.

    Science.gov (United States)

    2008-06-01

    This study attempts to estimate post-incident traffic recovery time along a freeway using Monte Carlo simulation techniques. It has been found that there is a linear relationship between post-incident traffic recovery time, and incident time and traf...

  5. Gender-related difference, geographical variation and time trend in dietary cadmium intake in Japan

    International Nuclear Information System (INIS)

    Watanabe, T.; Shimbo, S.; Nakatsuka, H.; Koizumi, A.; Higashikawa, K.; Matsuda-Inoguchi, N.; Ikeda, M.

    2004-01-01

    -related differences, and time-dependent decrease in dietary Cd intake in Japan were detected through analyses of food duplicate-based databases. The leading role of rice as dietary Cd source was also observed

  6. Strong gender differences in reproductive success variance, and the times to the most recent common ancestors.

    Science.gov (United States)

    Favre, Maroussia; Sornette, Didier

    2012-10-07

    The Time to the Most Recent Common Ancestor (TMRCA) based on human mitochondrial DNA (mtDNA) is estimated to be twice that based on the non-recombining part of the Y chromosome (NRY). These TMRCAs have special demographic implications because mtDNA is transmitted only from mother to child, while NRY is passed along from father to son. Therefore, the former locus reflects female history, and the latter, male history. To investigate what caused the two-to-one female-male TMRCA ratio r(F/M)=T(F)/T(M) in humans, we develop a forward-looking agent-based model (ABM) with overlapping generations. Our ABM simulates agents with individual life cycles, including life events such as reaching maturity or menopause. We implemented two main mating systems: polygynandry and polygyny with different degrees in between. In each mating system, the male population can be either homogeneous or heterogeneous. In the latter case, some males are 'alphas' and others are 'betas', which reflects the extent to which they are favored by female mates. A heterogeneous male population implies a competition among males with the purpose of signaling as alpha males. The introduction of a heterogeneous male population is found to reduce by a factor 2 the probability of finding equal female and male TMRCAs and shifts the distribution of r(F/M) to higher values. In order to account for the empirical observation of the factor 2, a high level of heterogeneity in the male population is needed: less than half the males can be alphas and betas can have at most half the fitness of alphas for the TMRCA ratio to depart significantly from 1. In addition, we find that, in the modes that maximize the probability of having 1.5times as many female as male ancestors. We also tested the effect of sex-biased migration and sex-specific death rates and found that these are unlikely to explain alone the sex-biased TMRCA ratio observed in humans. Our results support the view

  7. Why Dutch women work part-time: A Oaxaca-decomposition of differences in European female part-time work rates

    NARCIS (Netherlands)

    Deschacht, N.; Tijdens, K.

    2014-01-01

    We analyze differences in female part-time work rates across countries using European Social Survey data for 2012 to study composition and selectivity effects by means of Oaxaca-decompositions. A novel treatment of the selection term distinguishes the effect of country differences in employment

  8. Full Wave Analysis of Passive Microwave Monolithic Integrated Circuit Devices Using a Generalized Finite Difference Time Domain (GFDTD) Algorithm

    Science.gov (United States)

    Lansing, Faiza S.; Rascoe, Daniel L.

    1993-01-01

    This paper presents a modified Finite-Difference Time-Domain (FDTD) technique using a generalized conformed orthogonal grid. The use of the Conformed Orthogonal Grid, Finite Difference Time Domain (GFDTD) enables the designer to match all the circuit dimensions, hence eliminating a major source o error in the analysis.

  9. Representations of cycling in metropolitan newspapers - changes over time and differences between Sydney and Melbourne, Australia

    Directory of Open Access Journals (Sweden)

    Emilsen Adrian

    2010-06-01

    Full Text Available Abstract Background Cycling is important for health, transport, environmental and economic reasons. Newspaper reporting of cycling reflects and can influence public and policy maker attitudes towards resource allocation for cycling and cycling infrastructure, yet such coverage has not been systematically examined. Methods The Factiva electronic news archive was searched for articles referring to cycling published in four major metropolitan newspapers - two in Sydney and two in Melbourne, Australia, in the years from 1998 until 2008. After excluding articles not about cycling, there were 61 articles published in 1998, 45 in 1999, 51 in 2003, 82 in 2007 and 87 in 2008. Each article was coded for positive or negative orientation, and for framing of cyclists and cycling. Inter-rater reliability was calculated on a sample of 30 articles. Results Over the past decade there has been an increase in the reporting of cycling in the major newspapers in Sydney and Melbourne (from 106 in 1998/99 to 169 stories in 2007/08, with a significant increase in reporting of cycling in Melbourne, from 49 to 103 stories (p = 0.04. Recent reporting of cycling was generally positive (47% of articles, compared with 30% of articles which were negative and focused on benefits such as health and the environment. Three quarters of negative stories involved injury or death of a cyclist. The Sydney based The Daily Telegraph reported the most negative stories (n = 60. We found positive framing of 'cycling' was more widespread than negative, whereas framing of 'cyclists' was more negative than positive. Conclusions Quantity of reporting of cycling varies over time and by newspaper, and even between newspapers in different cities owned by the same media company. News coverage appears to reflect developments in the different cities, with increases in positive reporting of cycling in Melbourne following increases in cycling in that city. Negative cycling newspaper stories may deter

  10. Finite-difference time-domain simulation of electromagnetic bandgap and bi-anisotropic metamaterials

    Science.gov (United States)

    Bray, Matthew G.

    The term "Metamaterial" has been introduced into the electromagnetic lexicon in recent years to describe new artificial materials with electromagnetic properties that are not found in naturally occurring materials. Metamaterials exhibit electromagnetic properties that are not observed in its constituent materials, and/or not observed in nature. This thesis will analyze two different classes of metamaterials through the use of the finite-difference time-domain (FDTD) technique. The first class of metamaterials are artificial magnetic conductors (AMC) which approximate the behavior of a perfect magnetic conductor (PMC) over a finite frequency range. The AMC metamaterials are created through the use of an electromagnetic bandgap (EBG) structure. A periodic FDTD code is used to simulate a full-wave model of the metallodielectric EBG structures. The AMCs developed with the aid of the FDTD tool are then used to create low-profile antenna systems consisting of a dipole antenna in close proximity to an AMC surface. Through the use of this FDTD tool, several original contributions were made to the electromagnetic community. These include the first dual-band independently tunable EBG AMC ground plane and the first linearly polarized single-band and dual-band tunable antenna/EBG systems. The second class of materials analyzed are bi-anisotropic metamaterials. Bi-anisotropic media are the largest class of linear media which is able to describe the macroscopic material properties of artificial dielectrics, artificial magnetics, artificial chiral materials, left-handed materials, and other composite materials. The dispersive properties of these materials can be approximated by the oscillator model. This model assumes a Lorentzian frequency profile for the permittivity and permeability and a Condon model for chirality. A new FDTD formulation is introduced which can simulate this type of bi-anisotropic media. This FDTD method incorporates the dispersive material properties through

  11. The inner state differences of preterm birth rates in Brazil: a time series study.

    Science.gov (United States)

    de Oliveira, Rosana Rosseto; Melo, Emiliana Cristina; Fujimori, Elizabeth; Mathias, Thais Aidar de Freitas

    2016-05-17

    Preterm birth is a serious public health problem, as it is linked to high rates of neonatal and child morbidity and mortality. The prevalence of premature births has increased worldwide, with regional differences. The objective of this study was to analyze the trend of preterm births in the state of Paraná, Brazil, according to Macro-regional and Regional Health Offices (RHOs). This is an ecological time series study using preterm births records from the national live birth registry system of Brazil's National Health Service - Live Birth Information System (Sinasc), for residents of the state of Paraná, Brazil, between 2000 and 2013. The preterm birth rates was calculated on a yearly basis and grouped into three-year periods (2000-2002, 2003-2005, 2006-2008, 2009-2011) and one two-year period (2012-2013), according to gestational age and mother's Regional Health Office of residence. The polynomial regression model was used for trend analysis. The predominance of preterm birth rate increased from 6.8 % in 2000 to 10.5 % in 2013, with an average increase of 0.20 % per year (r(2) = 0.89), and a greater share of moderate preterm births (32 to rate of prematurity and average annual growth during that period (7.55 % and 0.35 %, respectively). The trend analysis of preterm birth rates according to RHO showed a growing trend for almost all RHOs - except for the 7(th) RHO where a declining trend was observed (-0.95 a year); and in the 20(th), 21(st) and 22(nd) RHOs which remained unchanged. In the last three-year of the study period (2011-2013), no RHO showed preterm birth rates below 7.3 % or prevalence of moderate preterm birth below 9.4 %. The results show an increase in preterm births with differences among Macro-regional and RHOs, which indicate the need to improve actions during the prenatal period according to the specificities of each region.

  12. The inner state differences of preterm birth rates in Brazil: a time series study

    Directory of Open Access Journals (Sweden)

    Rosana Rosseto de Oliveira

    2016-05-01

    Full Text Available Abstract Background Preterm birth is a serious public health problem, as it is linked to high rates of neonatal and child morbidity and mortality. The prevalence of premature births has increased worldwide, with regional differences. The objective of this study was to analyze the trend of preterm births in the state of Paraná, Brazil, according to Macro-regional and Regional Health Offices (RHOs. Methods This is an ecological time series study using preterm births records from the national live birth registry system of Brazil’s National Health Service - Live Birth Information System (Sinasc, for residents of the state of Paraná, Brazil, between 2000 and 2013. The preterm birth rates was calculated on a yearly basis and grouped into three-year periods (2000–2002, 2003–2005, 2006–2008, 2009–2011 and one two-year period (2012–2013, according to gestational age and mother’s Regional Health Office of residence. The polynomial regression model was used for trend analysis. Results The predominance of preterm birth rate increased from 6.8 % in 2000 to 10.5 % in 2013, with an average increase of 0.20 % per year (r2 = 0.89, and a greater share of moderate preterm births (32 to <37 weeks, which increased from 5.8 % to 9 %. The same pattern was observed for all Macro-regional Health Offices, with highlight to the Northern Macro-Regional Office, which showed the highest average rate of prematurity and average annual growth during that period (7.55 % and 0.35 %, respectively. The trend analysis of preterm birth rates according to RHO showed a growing trend for almost all RHOs – except for the 7th RHO where a declining trend was observed (−0.95 a year; and in the 20th, 21st and 22nd RHOs which remained unchanged. In the last three-year of the study period (2011–2013, no RHO showed preterm birth rates below 7.3 % or prevalence of moderate preterm birth below 9.4 %. Conclusions The results show an increase in preterm births

  13. Timing of phosphate application affects arsenic phytoextraction by Pteris vittata L. of different ages

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jorge A.G.; Gonzaga, Maria I.S. [Department of Soil Chemistry, Universidade Federal da Bahia, Cruz das Almas, 44380000 (Brazil); Ma, Lena Q. [Soil and Water Science Department, University of Florida, Gainesville, FL 32611-0290 (United States)], E-mail: lqma@ufl.edu; Srivastava, M. [Soil and Water Science Department, University of Florida, Gainesville, FL 32611-0290 (United States)

    2008-07-15

    The effects of timing in phosphate application on plant growth and arsenic removal by arsenic hyperaccumulator Pteris vittata L. of different ages were evaluated. The hydroponic experiment consisted of three plant ages (A{sub 45d}, A{sub 90d} and A{sub 180d}) and three P feeding regimens (P{sub 200+0}, P{sub 134+66} and P{sub 66+134}) growing for 45 d in 0.2-strength Hoagland-Arnon solution containing 145 {mu}g L{sup -1} As. While all plants received 200 {mu}M P, P was added in two phases: during acclimation and after arsenic exposure. High initial P-supply (P{sub 200+0}) favored frond biomass production and plant P uptake, while split-P application (P{sub 134+66} and P{sub 66+134}) favored plant root production. Single P addition favored arsenic accumulation in the roots while split-P addition increased frond arsenic accumulation. Young ferns (A{sub 45d}) in treatment P{sub 134+66} were the most efficient in arsenic removal, reducing arsenic concentration to below 10 {mu}g L{sup -1} in 35 d. The results indicated that the use of young ferns, coupled with feeding of low initial P or split-P application, increased the efficiency of arsenic removal by P. vittata. - Young ferns coupled with split-P application were effective in arsenic removal by Pteris vittata.

  14. Assessment of the real-time PCR and different digital PCR platforms for DNA quantification.

    Science.gov (United States)

    Pavšič, Jernej; Žel, Jana; Milavec, Mojca

    2016-01-01

    Digital PCR (dPCR) is beginning to supersede real-time PCR (qPCR) for quantification of nucleic acids in many different applications. Several analytical properties of the two most commonly used dPCR platforms, namely the QX100 system (Bio-Rad) and the 12.765 array of the Biomark system (Fluidigm), have already been evaluated and compared with those of qPCR. However, to the best of our knowledge, direct comparison between the three of these platforms using the same DNA material has not been done, and the 37 K array on the Biomark system has also not been evaluated in terms of linearity, analytical sensitivity and limit of quantification. Here, a first assessment of qPCR, the QX100 system and both arrays of the Biomark system was performed with plasmid and genomic DNA from human cytomegalovirus. With use of PCR components that alter the efficiency of qPCR, each dPCR platform demonstrated consistent copy-number estimations, which indicates the high resilience of dPCR. Two approaches, one considering the total reaction volume and the other considering the effective reaction size, were used to assess linearity, analytical sensitivity and variability. When the total reaction volume was considered, the best performance was observed with qPCR, followed by the QX100 system and the Biomark system. In contrast, when the effective reaction size was considered, all three platforms showed almost equal limits of detection and variability. Although dPCR might not always be more appropriate than qPCR for quantification of low copy numbers, dPCR is a suitable method for robust and reproducible quantification of viral DNA, and a promising technology for the higher-order reference measurement method.

  15. Real time RT-PCR assay for detection of different serotypes of FMDV in Egypt

    Directory of Open Access Journals (Sweden)

    Laila El-Shehawy

    Full Text Available Aim: The present study indicated that rRT-PCR could be provided for the detection of FMDV in infected, contact and carrier cattle and also provide a rapid sensitive tool aiming to aid in rapid disease detection and control. Foot and Mouth disease virus serotypes O and A still existing in Egypt. In January 2012, sever outbreaks struck the animal population in most Egyptian 1 governorates. The causative virus was identified as FMDV SAT2. Material and Methods: Five samples of tongue epithelium (ET and five oesophageal-pharyngeal (OP fluid samples were collected from FMD suspected cattle in infected farm at El-Fayoum and 20 OP samples from in-contact cattle at the same farm in addition to 30 OP samples from apparently healthy cattle at three different localities in El-Fayoum governorate (12 from Fayoum; 9 from Sinoras and 9 from Edsa in order to detect carrier cattle. All of these samples were collected during November and December 2011 and January 2012. Results: All the ET and OP samples were inoculated on BHK cell culture and baby mice. The obtained results were identified using complement fixation test in addition to real-time reverse transcriptase polymerase chain reaction (rRT-PCR. In the infected farm at El-Fayoum FMDV type SAT2 was detected in cattle which are considered as the first introduction of this type while FMDV type O and SAT2 were detected in the in-contact cattle in the same farm. The sensitivity of rRT-PCR was cleared in the in-contact cattle as 13 out of 20 OP samples were positive to FMDV by rRT-PCR while 11 out of 20 OP samples were positive to FMDV by CFT. The OP samples collected from apparently healthy cattle from Fayoum, Sinoras and Edsa localities in Fayoum governorate demonstrate the circulation of the FMDV type A, O and the recent SAT2 in carrier cattle which threaten cattle population in Fayoum governorate. Also the sensitivity of real time RT-PCR over the CFT in detection of FMDV carrier cattle was clearly noticed in

  16. Trait differences between naturalized and invasive plant species independent of residence time and phylogeny

    Science.gov (United States)

    Gallagher, R V; Randall, R P; Leishman, M R

    2015-01-01

    The ability to predict which alien plants will transition from naturalized to invasive prior to their introduction to novel regions is a key goal for conservation and has the potential to increase the efficacy of weed risk assessment (WRA). However, multiple factors contribute to plant invasion success (e.g., functional traits, range characteristics, residence time, phylogeny), and they all must be taken into account simultaneously in order to identify meaningful correlates of invasion success. We compiled 146 pairs of phylogenetically paired (congeneric) naturalized and invasive plant species in Australia with similar minimum residence times (i.e., time since introduction in years). These pairs were used to test for differences in 5 functional traits (flowering duration, leaf size, maximum height, specific leaf area [SLA], seed mass) and 3 characteristics of species’ native ranges (biome occupancy, mean annual temperature, and rainfall breadth) between naturalized and invasive species. Invasive species, on average, had larger SLA, longer flowering periods, and were taller than their congeneric naturalized relatives. Invaders also exhibited greater tolerance for different environmental conditions in the native range, where they occupied more biomes and a wider breadth of rainfall and temperature conditions than naturalized congeners. However, neither seed mass nor leaf size differed between pairs of naturalized and invasive species. A key finding was the role of SLA in distinguishing between naturalized and invasive pairs. Species with high SLA values were typically associated with faster growth rates, more rapid turnover of leaf material, and shorter lifespans than those species with low SLA. This suite of characteristics may contribute to the ability of a species to transition from naturalized to invasive across a wide range of environmental contexts and disturbance regimes. Our findings will help in the refinement of WRA protocols, and we advocate the

  17. Fathers' Involvement with Their Preschool-Age Children: How Fathers Spend Time with Their Children in Different Family Structures

    Science.gov (United States)

    Halme, Nina; Astedt-Kurki, Paivi; Tarkka, Marja-Terttu

    2009-01-01

    The purpose of this study was to describe how fathers (n = 263) spent time with their preschool-age children and to compare it in different family structures. Data were gathered by structured questionnaires. The instrument included five categories of variables for the time spent: the quantity of time, physical activities, fathers' attitude towards…

  18. Stress and disease resilience differences related to emergence time for first feeding in farmed rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Gesto, Manuel; Madsen, Lone; Andersen, Nikolaj Reducha

    2018-01-01

    Salmonid individuals show a relatively high variability in the time required to abandon the gravel nest where they hatch, the so-called "emergence time". Different behavioral and physiological traits have been shown to be associated to that emergence time in wild salmonids. In general, early- and...

  19. Comparison of different Methods for Univariate Time Series Imputation in R

    OpenAIRE

    Moritz, Steffen; Sardá, Alexis; Bartz-Beielstein, Thomas; Zaefferer, Martin; Stork, Jörg

    2015-01-01

    Missing values in datasets are a well-known problem and there are quite a lot of R packages offering imputation functions. But while imputation in general is well covered within R, it is hard to find functions for imputation of univariate time series. The problem is, most standard imputation techniques can not be applied directly. Most algorithms rely on inter-attribute correlations, while univariate time series imputation needs to employ time dependencies. This paper provides an overview of ...

  20. Immediate effects of different treatments for the wrist joints of subdominant hands, using electromechanical reaction time.

    Science.gov (United States)

    Hu, Chunying; Huang, Qiuchen; Yu, Lili; Zhou, Yue; Gu, Rui; Cui, Yao; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

    2016-08-01

    [Purpose] The aim of this study was to examine the immediate effects of muscle strength training and neuromuscular joint facilitation distal resistance training on wrist joints by using electromechanical reaction time. [Subjects and Methods] The subjects were 12 healthy young people (24.2 ± 3.1 years, 169.7 ± 6.5 cm, 65.3 ± 12.6 kg). Two kinds of isotonic contraction techniques were applied on the wrist joint: the wrist joint extension muscle strength training and the wrist joint extension pattern of neuromuscular joint facilitation. The electromechanical reaction time, premotor time, and motor time of the left upper limb were measured before and after each intervention session of muscle strength training and neuromuscular joint facilitation. [Results] The neuromuscular joint facilitation group showed significant shortening of the electromechanical reaction time and motor time after the intervention. [Conclusion] These results suggest that the electromechanical reaction time and motor time of the wrist joint can be improved by neuromuscular joint facilitation together with proximal resistance training, which can be used as a new form of exercise for improving the functions of subdominant hand wrist joints.

  1. Sex differences in cerebral venous thrombosis: A systematic analysis of a shift over time

    NARCIS (Netherlands)

    Zuurbier, Susanna M.; Middeldorp, Saskia; Stam, Jan; Coutinho, Jonathan M.

    2016-01-01

    In contemporary studies, cerebral venous thrombosis is three times more common in adult women than in men. To study the change in sex ratio over time in cerebral venous thrombosis. We systematically reviewed the literature. Any type of study with at least 40 patients with cerebral venous thrombosis

  2. Physical, chemical and sensory characteristics of red guava (Psidium guajava) velva at different fruit ripening time

    Science.gov (United States)

    Ishartani, D.; Rahman, F. L. F.; Hartanto, R.; Utami, R.; Khasanah, L. U.

    2018-01-01

    This study purposed to determine the effect of red guava fruit ripening time on the physical (overrun and melting rate), chemical (vitamin C, pH, total dissolved solid) and sensory (color, taste, aroma, texture, and overall compare to control (without ripening) velva) characteristic of red guava velva. Red guava fruits were harvested at 90 days after flowering, ripened and then processed into velva. This research used Completely Randomized Design with fruit ripening time (without ripening, 4 days, and 6 days) as single factor. The research was conducted in triplicate. Chemical and physical characteristic data was analysed using One Way Analysis of Varian whether sensory characteristic data was analyzed using Independent Sample T-test. The result showed that fruit ripening time significantly affected the physical, chemical and sensory characteristic of the velva. Vitamin C, pH, and total solid of the velva were increased as the ripening time prolonged. In other hand, increasing of fruit ripening time decreased the overrun and melting rate of the velva. Red guava velva made from 6 days ripening had better sensory characteristics compared to velva made from red guava fruit without ripening or 4 day ripening. This research conclude that 6 days ripening time gives better chemical, physical and sensory characteristics of the velva compare to 4 days ripening time. Red guava fruits ripened for 6 days were recommended as raw material in velva making.

  3. Timing of examinations affects school performance differently in early and late chronotypes

    NARCIS (Netherlands)

    van der Vinne, Vincent; Zerbini, Giulia; Siersema, Anne; Pieper, Amy; Merrow, Martha; Hut, Roelof A.; Roenneberg, Till; Kantermann, Thomas

    Circadian clocks of adolescents typically run lateincluding sleep timesyet adolescents generally are expected at school early in the morning. Due to this mismatch between internal (circadian) and external (social) times, adolescents suffer from chronic sleep deficiency, which, in turn, affects

  4. On a Stable and Consistent Finite Difference Scheme for a Time ...

    African Journals Online (AJOL)

    NJABS

    established time independent Schrodinger Wave Equation (SWE). To develop the stability criterion .... the rate at which signals in the numerical scheme travel will be faster than their real world counterparts and this unrealistic expectation leads ...

  5. Clonal differences in generation times of GPK epithelial cells in monolayer culture.

    Science.gov (United States)

    Riley, P A; Hola, M

    1980-01-01

    Pedigrees of cells in eight clones of guinea pig keratocyte (GPK) cells in monolayer culture were analyzed from a time-lapse film. The generation times and the position in the field of observation were recorded up to the sixth generation when the cultures were still subconfluent. Statistical analysis of the results indicates that the position in the culture has less significance than the clonal origin of the cell in determining the interval between successive mitoses.

  6. Seasonal Differences in Determinants of Time Location Patterns in an Urban Population: A Large Population-Based Study in Korea.

    Science.gov (United States)

    Lee, Sewon; Lee, Kiyoung

    2017-06-22

    Time location patterns are a significant factor for exposure assessment models of air pollutants. Factors associated with time location patterns in urban populations are typically due to high air pollution levels in urban areas. The objective of this study was to determine the seasonal differences in time location patterns in two urban cities. A Time Use Survey of Korean Statistics (KOSTAT) was conducted in the summer, fall, and winter of 2014. Time location data from Seoul and Busan were collected, together with demographic information obtained by diaries and questionnaires. Determinants of the time spent at each location were analyzed by multiple linear regression and the stepwise method. Seoul and Busan participants had similar time location profiles over the three seasons. The time spent at own home, other locations, workplace/school and during walk were similar over the three seasons in both the Seoul and Busan participants. The most significant time location pattern factors were employment status, age, gender, monthly income, and spouse. Season affected the time spent at the workplace/school and other locations in the Seoul participants, but not in the Busan participants. The seasons affected each time location pattern of the urban population slightly differently, but overall there were few differences.

  7. Seasonal Differences in Determinants of Time Location Patterns in an Urban Population: A Large Population-Based Study in Korea

    Directory of Open Access Journals (Sweden)

    Sewon Lee

    2017-06-01

    Full Text Available Time location patterns are a significant factor for exposure assessment models of air pollutants. Factors associated with time location patterns in urban populations are typically due to high air pollution levels in urban areas. The objective of this study was to determine the seasonal differences in time location patterns in two urban cities. A Time Use Survey of Korean Statistics (KOSTAT was conducted in the summer, fall, and winter of 2014. Time location data from Seoul and Busan were collected, together with demographic information obtained by diaries and questionnaires. Determinants of the time spent at each location were analyzed by multiple linear regression and the stepwise method. Seoul and Busan participants had similar time location profiles over the three seasons. The time spent at own home, other locations, workplace/school and during walk were similar over the three seasons in both the Seoul and Busan participants. The most significant time location pattern factors were employment status, age, gender, monthly income, and spouse. Season affected the time spent at the workplace/school and other locations in the Seoul participants, but not in the Busan participants. The seasons affected each time location pattern of the urban population slightly differently, but overall there were few differences.

  8. Age Differences in Negative Emotional Responses to Daily Stressors Depend on Time since Event

    Science.gov (United States)

    Scott, Stacey B.; Ram, Nilam; Smyth, Joshua M.; Almeida, David M.; Sliwinski, Martin J.

    2017-01-01

    Research on age differences in the experience of negative emotional states have produced inconsistent results, particularly when emotion is examined in the context of daily stress. Strength and vulnerability integration (SAVI; Charles, 2010) theory postulates that age differences in emotional states are contingent upon whether a stressor occurred,…

  9. Comparative analysis of time efficiency and spatial resolution between different EIT reconstruction algorithms

    International Nuclear Information System (INIS)

    Kacarska, Marija; Loskovska, Suzana

    2002-01-01

    In this paper comparative analysis between different EIT algorithms is presented. Analysis is made for spatial and temporal resolution of obtained images by several different algorithms. Discussions consider spatial resolution dependent on data acquisition method, too. Obtained results show that conventional applied-current EIT is more powerful compared to induced-current EIT. (Author)

  10. Real-time PCR assays for hepatitis B virus DNA quantification may require two different targets.

    Science.gov (United States)

    Liu, Chao; Chang, Le; Jia, Tingting; Guo, Fei; Zhang, Lu; Ji, Huimin; Zhao, Junpeng; Wang, Lunan

    2017-05-12

    Quantification Hepatitis B virus (HBV) DNA plays a critical role in the management of chronic HBV infections. However, HBV is a DNA virus with high levels of genetic variation, and drug-resistant mutations have emerged with the use of antiviral drugs. If a mutation caused a sequence mismatched in the primer or probe of a commercial DNA quantification kit, this would lead to an underestimation of the viral load of the sample. The aim of this study was to determine whether commercial kits, which use only one pair of primers and a single probe, accurately quantify the HBV DNA levels and to develop an improved duplex real-time PCR assay. We developed a new duplex real-time PCR assay that used two pairs of primers and two probes based on the conserved S and C regions of the HBV genome. We performed HBV DNA quantitative detection of HBV samples and compared the results of our duplex real-time PCR assays with the COBAS TaqMan HBV Test version 2 and Daan real-time PCR assays. The target region of the discordant sample was amplified, sequenced, and validated using plasmid. The results of the duplex real-time PCR were in good accordance with the commercial COBAS TaqMan HBV Test version 2 and Daan real-time PCR assays. We showed that two samples from Chinese HBV infections underestimated viral loads when quantified by the Roche kit because of a mismatch between the viral sequence and the reverse primer of the Roche kit. The HBV DNA levels of six samples were undervalued by duplex real-time PCR assays of the C region because of mutations in the primer of C region. We developed a new duplex real-time PCR assay, and the results of this assay were similar to the results of commercial kits. The HBV DNA level could be undervalued when using the COBAS TaqMan HBV Test version 2 for Chinese HBV infections owing to a mismatch with the primer/probe. A duplex real-time PCR assay based on the S and C regions could solve this problem to some extent.

  11. Photoacoustic study of curing time by UV laser radiation of a photoresin with different thickness

    Energy Technology Data Exchange (ETDEWEB)

    Pincel, P. Vieyra [UPIITA IPN, Avenida Instituto Politécnico Nacional, No. 2580, Col. Barrio la Laguna Ticomán, Delegación Gustavo A. Madero, C.P. 07340 México, D.F. (Mexico); Jiménez-Pérez, J.L., E-mail: jimenezp@fis.cinvestav.mx [UPIITA IPN, Avenida Instituto Politécnico Nacional, No. 2580, Col. Barrio la Laguna Ticomán, Delegación Gustavo A. Madero, C.P. 07340 México, D.F. (Mexico); Cruz-Orea, A. [Departamento de Física, CINVESTAV-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 México, D.F. (Mexico); Correa-Pacheco, Z.N. [Instituto Politécnico Nacional-Centro de Desarrollo de Productos Bióticos (CEPROBI). Carr. Yautepec–Jojutla, km 6. San Isidro, C.P. 62730 Yautepec, Morelos (Mexico); Rosas, J. Hernández [UPIITA IPN, Avenida Instituto Politécnico Nacional, No. 2580, Col. Barrio la Laguna Ticomán, Delegación Gustavo A. Madero, C.P. 07340 México, D.F. (Mexico)

    2015-04-20

    Highlights: • The curing of a resin in the presence of a UV laser radiation was studied. • Open photoacoustic cell technique was used to characterize the curing of the resin. • The curing of the resin as a function of time was studied. • A parabolic behavior of the resin thickness, as a function of time was observed. • UV–vis and FTIR spectroscopy were employed to characterize the resin. - Abstract: This paper deals with the study of the cure of a resin in the presence of a UV laser radiation used as the excitation source, operated at λ = 405 nm, with an output power of 20 mW. The open photoacoustic cell (OPC) technique was used to study the curing of the resins as a function of time. The curing characteristic time values were τ = 10.43, 20.99, 30.18, 45.84, 67.59 and 89.55 s for the resin thicknesses of 1000, 2000, 3000, 4000, 5000 and 6000 μm, respectively. A parabolic behavior of the resin thickness, as a function of the curing characteristic time, was obtained. UV–vis spectroscopy and infrared Fourier transform spectroscopy (FTIR) techniques were employed to characterize the resin in order to study the optical absorption and the chemical bonds, respectively. Our work has applications in the manufacture of 3D printing parts for applications, among others, in medicine.

  12. Accounting for baseline differences and measurement error in the analysis of change over time.

    Science.gov (United States)

    Braun, Julia; Held, Leonhard; Ledergerber, Bruno

    2014-01-15

    If change over time is compared in several groups, it is important to take into account baseline values so that the comparison is carried out under the same preconditions. As the observed baseline measurements are distorted by measurement error, it may not be sufficient to include them as covariate. By fitting a longitudinal mixed-effects model to all data including the baseline observations and subsequently calculating the expected change conditional on the underlying baseline value, a solution to this problem has been provided recently so that groups with the same baseline characteristics can be compared. In this article, we present an extended approach where a broader set of models can be used. Specifically, it is possible to include any desired set of interactions between the time variable and the other covariates, and also, time-dependent covariates can be included. Additionally, we extend the method to adjust for baseline measurement error of other time-varying covariates. We apply the methodology to data from the Swiss HIV Cohort Study to address the question if a joint infection with HIV-1 and hepatitis C virus leads to a slower increase of CD4 lymphocyte counts over time after the start of antiretroviral therapy. Copyright © 2013 John Wiley & Sons, Ltd.

  13. Photoacoustic study of curing time by UV laser radiation of a photoresin with different thickness

    International Nuclear Information System (INIS)

    Pincel, P. Vieyra; Jiménez-Pérez, J.L.; Cruz-Orea, A.; Correa-Pacheco, Z.N.; Rosas, J. Hernández

    2015-01-01

    Highlights: • The curing of a resin in the presence of a UV laser radiation was studied. • Open photoacoustic cell technique was used to characterize the curing of the resin. • The curing of the resin as a function of time was studied. • A parabolic behavior of the resin thickness, as a function of time was observed. • UV–vis and FTIR spectroscopy were employed to characterize the resin. - Abstract: This paper deals with the study of the cure of a resin in the presence of a UV laser radiation used as the excitation source, operated at λ = 405 nm, with an output power of 20 mW. The open photoacoustic cell (OPC) technique was used to study the curing of the resins as a function of time. The curing characteristic time values were τ = 10.43, 20.99, 30.18, 45.84, 67.59 and 89.55 s for the resin thicknesses of 1000, 2000, 3000, 4000, 5000 and 6000 μm, respectively. A parabolic behavior of the resin thickness, as a function of the curing characteristic time, was obtained. UV–vis spectroscopy and infrared Fourier transform spectroscopy (FTIR) techniques were employed to characterize the resin in order to study the optical absorption and the chemical bonds, respectively. Our work has applications in the manufacture of 3D printing parts for applications, among others, in medicine

  14. Modulation cues influence binaural masking-level difference in masking-pattern experiments.

    Science.gov (United States)

    Nitschmann, Marc; Verhey, Jesko L

    2012-03-01

    Binaural masking patterns show a steep decrease in the binaural masking-level difference (BMLD) when masker and signal have no frequency component in common. Experimental threshold data are presented together with model simulations for a diotic masker centered at 250 or 500 Hz and a bandwidth of 10 or 100 Hz masking a sinusoid interaurally in phase (S(0)) or in antiphase (S(π)). Simulations with a binaural model, including a modulation filterbank for the monaural analysis, indicate that a large portion of the decrease in the BMLD in remote-masking conditions may be due to an additional modulation cue available for monaural detection. © 2012 Acoustical Society of America

  15. Separating different scales of motion in time series of meteorological variables

    International Nuclear Information System (INIS)

    Eskridge, R.E.; Rao, S.T.; Porter, P.S.

    1997-01-01

    In this study, four methods are evaluated for detecting and tracking changes in time series of climate variables. The PEST algorithm and the monthly anomaly technique are shown to have shortcomings, while the wavelet transform and Kolmogorov-Zurbenko (KZ) filter methods are shown to be capable of separating time scales with minimal errors. The behavior of the filters are examined by transfer functions. The KZ filter, anomaly technique, and PEST were also applied to temperature data to estimate long-term trends. The KZ filter provides estimates with about 10 times higher confidence than the other methods. Advantages of the KZ filter over the wavelet transform method are that it may be applied to datasets containing missing observations and is very easy to use. 10 refs., 8 figs., 1 tab

  16. On Long-Time Instabilities in Staggered Finite Difference Simulations of the Seismic Acoustic Wave Equations on Discontinuous Grids

    KAUST Repository

    Gao, Longfei; Ketcheson, David I.; Keyes, David E.

    2017-01-01

    We consider the long-time instability issue associated with finite difference simulation of seismic acoustic wave equations on discontinuous grids. This issue is exhibited by a prototype algebraic problem abstracted from practical application

  17. Application of Cyclostationary Signal Selectivity to the Carry-On Multi-Platform GPS Assisted Time Difference of Arrival System

    National Research Council Canada - National Science Library

    Streight, David

    1997-01-01

    .... The Applied Research Lab at the University of Texas at Austin (ARL:UT) has developed a prototype TDOA system, the Carry-on Multi-platform GPS Assisted Time Difference of Arrival System for the Naval Information Warfare Activity...

  18. Gender Differences in Cognition in China and Reasons for Change over Time: Evidence from CHARLS

    OpenAIRE

    Lei, Xiaoyan; Smith, James P.; Sun, Xiaoting; Zhao, Yaohui

    2013-01-01

    In this paper, we model gender differences in cognitive ability in China using a new sample of middle-aged and older Chinese respondents. Modeled after the American Health and Retirement Survey (HRS), CHARLS respondents are 45 years and older and are nationally representative of the Chinese population in this age span. Our measures of cognition in CHARLS relies on two measures that proxy for different dimensions of adult cognition - episodic memory and intact mental status. We relate these co...

  19. Time use of parents in the United States: What difference did the Great Recession make?

    OpenAIRE

    Kongar, Ebru; Berik, Günseli

    2014-01-01

    Feminist and institutionalist literature has challenged the "Mancession" narrative of the 2007-09 recession and produced nuanced and gender-aware analyses of the labor market and well-being outcomes of the recession. Using American Time Use Survey (ATUS) data for 2003-12, this paper examines the recession's impact on gendered patterns of time use over the course of the 2003-12 business cycle. We find that the gender disparity in paid and unpaid work hours followed a U-shaped pattern, narrowin...

  20. Different Perceptions of Time Passage Among Older People: A Comparative Study in Terms of Age and Gender

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Nazari

    2016-04-01

    Conclusion: Research findings indicate that age affects time perception so that perceived time in the elderly people is shorter than the real physical time. Our findings also showed that if sources pay less attention to the passage of time or the memory capacity declines, the time estimation will be less. Based on cognitive changes in old age, the cognitive abilities of older people were found to decrease with increasing age. As the accurate processing of time intervals relates to memory capacity and attention, the changes in any cognitive process could affect the differences in the perception of time. Probably due to these factors, the reproduction of time in the older people shortens.

  1. Effect of different air-drying time on the microleakage of single-step self-etch adhesives

    OpenAIRE

    Moosavi, Horieh; Forghani, Maryam; Managhebi, Esmatsadat

    2013-01-01

    Objectives This study evaluated the effect of three different air-drying times on microleakage of three self-etch adhesive systems. Materials and Methods Class I cavities were prepared for 108 extracted sound human premolars. The teeth were divided into three main groups based on three different adhesives: Opti Bond All in One (OBAO), Clearfil S3 Bond (CSB), Bond Force (BF). Each main group divided into three subgroups regarding the air-drying time: without application of air stream...

  2. Explaining educational differences in leisure-time physical activity in Europe: the contribution of work-related factors

    DEFF Research Database (Denmark)

    Mäkinen, T E; Sippola, R; Borodulin, K

    2011-01-01

    Although educational differences in leisure-time physical activity (LTPA) exist across Europe, the independent effect of educational level on leisure-time physical activity has rarely been explored. This study examines the relative contribution of occupational class, employment status...... and employment status had only a modest effect on educational differences in LTPA in most of the examined countries, suggesting that education remains an important predictor of LTPA....

  3. Some considerations for different time-domain signal processing of pulse compression radar

    Directory of Open Access Journals (Sweden)

    Maria Graciela Molina

    2010-06-01

    Full Text Available Radar technology has for a long time used various systems that allow detection under high-resolution conditions, while emitting at the same time low peak power. Among these systems, transmitted pulse encoding by means of biphasic codes has been used for the advanced ionospheric sounder that was developed by the AIS-INGV ionosonde. In the receiving process, suitable decoding of the signal must be accomplished. This can be achieved in both the time and the frequency domains. Focusing on the time domain, different approaches are possible. In this study, two of these approaches have been compared, using data acquired by the AIS-INGV and processed by means of software tools (mainly Mathcad©. The analysis reveals the differences under both noiseless and noisy conditions, although this does not allow the conclusive establishment as to which method is better, as each of them has benefits and drawbacks.