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Experience often does not produce veridical memory. Understanding false attribution of events constitutes an important problem in memory research. “Peak shift” is a well-characterized, controllable phenomenon in which human and animal subjects that receive reinforcement associated with one sensory stimulus later respond maximally to another stimulus in post-training stimulus generalization tests. Peak shift ordinarily develops in discrimination learning (reinforced CS+, unreinforced CS−) and has long been attributed to the interaction of an excitatory gradient centered on the CS+ and an inhibitory gradient centered on the CS−; the shift is away from the CS−. In contrast, we have obtained peak shifts during single tone frequency training, using stimulation of the cholinergic nucleus basalis (NB) to implant behavioral memory into the rat. As we also recorded cortical activity, we took the opportunity to investigate the possible existence of a neural frequency gradient that could account for behavioral peak shift. Behavioral frequency generalization gradients (FGGs, interruption of ongoing respiration) were determined twice before training while evoked potentials were recorded from the primary auditory cortex (A1), to obtain a baseline gradient of “habituatory” neural decrement. A post-training behavioral FGG obtained 24 h after three daily sessions of a single tone paired with NB stimulation (200 trials/day) revealed a peak shift. The peak of the FGG was at a frequency lower than the CS while the cortical inhibitory gradient was at a frequency higher than the CS frequency. Further analysis indicated that the frequency location and magnitude of the gradient could account for the behavioral peak shift. These results provide a neural basis for a systematic case of memory misattribution and may provide an animal model for the study of the neural bases of a type of “false memory”. | Neural mechanisms underlying the capacity of memory to be rich in sensory detail are largely unknown. A candidate mechanism is learning-induced plasticity that remodels the adult sensory cortex. Here, expansion in the primary auditory cortical (A1) tonotopic map of rats was induced by pairing a 3.66-kHz tone with activation of the nucleus basalis, mimicking the effects of natural associative learning. Remodeling of A1 produced de novo specific behavioral memory, but neither memory nor plasticity was consistently at the frequency of the paired tone, which typically decreased in A1 representation. Rather, there was a specific match between individual subjects' area of expansion and the tone that was strongest in each animal's memory, as determined by post-training frequency generalization gradients. These findings provide the first demonstration of a match between the artificial induction of specific neural representational plasticity and artificial induction of behavioral memory. As such, together with prior and present findings for detection, correlation and mimicry of plasticity with the acquisition of memory, they satisfy a key criterion for neural substrates of memory. This demonstrates that directly remodeling sensory cortical maps is sufficient for the specificity of memory formation. | Phase-shifted parallel (PSP) operation of IGBTs is proposed for unity PF boost converters, to increase both the converter power rating and operating frequency. This technique allows unity PF operation of medium power AC and DC motor drives, and switch mode power supplies from a single-phase, unregulated AC Supply, with minimum line current harmonic distortion. Since operating frequency is increased by integer multiples of IGBT switching frequency, the same core size for the boost inductor can be used to transfer larger amounts of power at the expense of additional power switching elements and a simple pulse separation circuit. Equal average current sharing is inherent in PSP operation strategy without any external circuits for equalisation. The design and implementation of a 28 kW, 40 kHz unity PF boost converter with two phase-shifted parallel IGBTs are presented. Advantages and disadvantages of PSP IGBT operation in increasing the power rating of boost converters are also given in comparison with other converter and power semiconductor parallel operation techniques. | eng_Latn | 10,600 |
Successful communication in everyday life crucially involves the processing of auditory and visual components of speech. Viewing our interlocutor and processing visual components of speech facilitates speech processing by triggering auditory processing. Auditory phoneme processing, analyzed by event-related brain potentials (ERP), has been shown to be associated with impairments in reading and spelling (i.e. developmental dyslexia), but visual aspects of phoneme processing have not been investigated in individuals with such deficits. The present study analyzed the passive visual Mismatch Response (vMMR) in school children with and without developmental dyslexia in response to video-recorded mouth movements pronouncing syllables silently. Our results reveal that both groups of children showed processing of visual speech stimuli, but with different scalp distribution. Children without developmental dyslexia showed a vMMR with typical posterior distribution. In contrast, children with developmental dyslexia showed a vMMR with anterior distribution, which was even more pronounced in children with severe phonological deficits and very low spelling abilities. As anterior scalp distributions are typically reported for auditory speech processing, the anterior vMMR of children with developmental dyslexia might suggest an attempt to anticipate potentially upcoming auditory speech information in order to support phonological processing, which has been shown to be deficient in children with developmental dyslexia. | Objective Precise temporal coding of speech plays a pivotal role in sound processing throughout the central auditory system, which, in turn, influences literacy acquisition. The current study tests whether an electrophysiological measure of this precision predicts literacy skills. Methods Complex auditory brainstem responses were analysed from 62 native German-speaking children aged 11–13 years. We employed the cross-phaseogram approach to compute the quality of the electrophysiological stimulus contrast [da] and [ba]. Phase shifts were expected to vary with literacy. Results Receiver operating curves demonstrated a feasible sensitivity and specificity of the electrophysiological measure. A multiple regression analysis resulted in a significant prediction of literacy by delta cross-phase as well as phonological awareness. A further commonality analysis separated a unique variance that was explained by the physiological measure, from a unique variance that was explained by the behavioral measure, and common effects of both. Conclusions Despite multicollinearities between literacy, phonological awareness, and subcortical differentiation of stop consonants, a combined assessment of behavior and physiology strongly increases the ability to predict literacy skills. Significance The strong link between the neurophysiological signature of sound encoding and literacy outcome suggests that the delta cross-phase could indicate the risk of dyslexia and thereby complement subjective psychometric measures for early diagnoses. | A unique case of dural arteriovenous malformation developing far from the site of a previously removed meningioma is reported. The AVM was successfully treated by emobilisation. The possible etiological factors are discussed. | eng_Latn | 10,601 |
Traditionally, the neural encoding of vestibular information is studied by applying either passive rotations or translations in isolation. However, natural vestibular stimuli are typically more complex. During everyday life, our self-motion is generally not restricted to one dimension, but rather comprises both rotational and translational motion that will simultaneously stimulate receptors in the semicircular canals and otoliths. In addition, natural self-motion is the result of self-generated and externally generated movements. However, to date, it remains unknown how information about rotational and translational components of self-motion is integrated by vestibular pathways during active and/or passive motion. Accordingly, here, we compared the responses of neurons at the first central stage of vestibular processing to rotation, translation, and combined motion. Recordings were made in alert macaques from neurons in the vestibular nuclei involved in postural control and self-motion perception. In response to passive stimulation, neurons did not combine canal and otolith afferent information linearly. Instead, inputs were subadditively integrated with a weighting that was frequency dependent. Although canal inputs were more heavily weighted at low frequencies, the weighting of otolith input increased with frequency. In response to active stimulation, neuronal modulation was significantly attenuated (∼70%) relative to passive stimulation for rotations and translations and even more profoundly attenuated for combined motion due to subadditive input integration. Together, these findings provide insights into neural computations underlying the integration of semicircular canal and otolith inputs required for accurate posture and motor control, as well as perceptual stability, during everyday life. | Despite an easy control and the direct effects on vestibular neurons, the clinical applications of galvanic vestibular stimulation (GVS) have been restricted because of its unclear activities as input. On the other hand, some critical conclusions have been made in the peripheral and the central processing of neural information by kinetic stimuli with different motion frequencies. Nevertheless, it is still elusive how the neural responses to simultaneous GVS and kinetic stimulus are modified during transmission and integration at the central vestibular area. To understand how the neural information was transmitted and integrated, we examined the neuronal responses to GVS, kinetic stimulus, and their combined stimulus in the vestibular nucleus. The neuronal response to each stimulus was recorded, and its responding features (amplitude and baseline) were extracted by applying the curve fitting based on a sinusoidal function. Twenty-five (96.2%) comparisons of the amplitudes showed that the amplitudes decreased during the combined stimulus (p < 0.001). However, the relations in the amplitudes (slope = 0.712) and the baselines (slope = 0.747) were linear. The neuronal effects by the different stimuli were separately estimated; the changes of the amplitudes were mainly caused by the kinetic stimulus and those of the baselines were largely influenced by GVS. Therefore, the slopes in the comparisons implied the neural sensitivity to the applied stimuli. Using the slopes, we found that the reduced amounts of the neural information were transmitted. Overall, the comparisons of the responding features demonstrated the linearity and the subadditivity in the neural transmission. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 10,602 |
The aim of this study was to investigate the functionality of cochlear active mechanisms in normal-hearing subjects affected by Williams syndrome (WS). Transient evoked otoacoustic emissions (TEOAEs) were recorded in a group of young WS subjects and a group of typically developing control subjects, all having normal-hearing thresholds and normal middle-ear functionality. We also analysed the narrow-band frequency components of TEOAEs, extracted from the broad-band TEOAE recordings by using a time–frequency analysis algorithm based on the Wavelet transform. We observed that TEOAEs and the frequency components extracted from TEOAEs measured in WS subjects had significantly lower energy compared to the controls. Also, the narrow-band frequency components of TEOAEs measured in WS subjects had slightly increased latency compared to the controls. Overall, results would suggest a subtle (i.e., sub-clinical) dysfunction of the cochlear active mechanisms in WS subjects with otherwise normal hearing. Also, results point out the relevance of using otoacoustic emissions in the audiological evaluation and monitoring of WS subjects to early identify possible subtle auditory dysfunctions, before the onset of mild or moderate hearing loss that could exacerbate language or cognitive impairments associated with WS. | The aims of this study were to characterize and quantify time-frequency changes in transient-evoked otoacoustic emissions (TEOAEs) recorded in children diagnosed with retinoblastoma who were receiving carboplatin chemotherapy. A signal processing technique, the wavelet transform (WT), was used to analyze TEOAE waveforms in narrow-band frequency components. Ten children (aged 3–72 months) diagnosed with unilateral or bilateral retinoblastoma were enrolled in the study. TEOAEs were acquired from the children with linear sequences of 70 dB peak equivalent SPL clicks. After WT analysis, TEOAE energy, latency and normalized energy in the narrow-band frequency components were compared before and during carboplatin chemotherapy treatment (average dose 1693 mg/m2). On a group basis, no significant differences (p > 0.05) in the TEOAE energy, latency or normalized energy before and after carboplatin treatment were observed. There were decreases in normalized energy on an individual basis in 10 out of 18 ears in the sample. Exposure to carboplatin chemotherapy did not cause significant changes in TEOAE energy, latency and normalized energy during treatment. However, long-term monitoring of hearing with measurements of TEOAEs is warranted, given the risks of delayed hearing loss in some children receiving carboplatin chemotherapy. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 10,603 |
Expressions are derived for the aperture time-harmonic electromagnetic fields in the feed gap of a solid infinite antenna along the z axis. This is done by matching the Fourier representation of th... | Expressions are presented for the input admittance and the current distribution along a linear antenna without restrictions on either the length or the thickness. These expressions which are based on Hurd's Wiener-Hopf type analysis, are used to find the characteristics of short as well as thick antennas. It is found that although using one term of the solution asymptotic series produces accurate results for thick antennas, more series terms have to be used when the antenna is thin. | The effect of spatial separation on the ability of listeners to report keywords from two simultaneous talkers was examined. The talkers were presented with equal intensity at a clearly audible level, and were designed to have little spectral overlap in order to reduce energetic interference. The two talkers were presented in a virtual auditory environment with various angular separations around references of -45o, 0o, or 45o azimuth. In Experiment 1, the virtual space was created using head-related transfer functions (HRTFs) which contained natural energy variations as a function of location. In Experiment 2, these energy variations were removed and the virtual space was created using only interaural time differences (ITDs). Overall, performance did not vary dramatically but depended on spatial separation, reference direction, and type of simulation. Around the 0o reference azimuth, performance in the HRTF condition tended to first increase and then decrease with increasing separation. This effect was greatly reduced in the ITD condition and thus appears to be related primarily to energy variations at the two ears. For sources around the ± 45o reference azimuths, there was an advantage to separating the two sources in both HRTF and ITD conditions, suggesting that perceived spatial separation is advantageous in a divided attention task, at least for lateral sources. | eng_Latn | 10,604 |
We study the contribution to the entanglement entropy of (2+1)-dimensional conformal field theories coming from a sharp corner in the entangling surface. This contribution is encoded in a function $a(\theta)$ of the corner opening angle, and was recently proposed as a measure of the degrees of freedom in the underlying CFT. We show that the ratio $a(\theta)/C_T$, where $C_T$ is the central charge in the stress tensor correlator, is an almost universal quantity for a broad class of theories including various higher-curvature holographic models, free scalars and fermions, and Wilson-Fisher fixed points of the $O(N)$ models with $N=1,2,3$. Strikingly, the agreement between these different theories becomes exact in the limit $\theta\rightarrow \pi$, where the entangling surface approaches a smooth curve. We thus conjecture that the corresponding ratio is universal for general CFTs in three dimensions. | We study the finite term of the holographic entanglement entropy of finite domains with smooth shapes and for four dimensional gravitational backgrounds. Analytic expressions depending on the unit vectors normal to the minimal area surface are obtained for both stationary and time dependent spacetimes. The special cases of AdS4, asymptotically AdS4 black holes, domain wall geometries and Vaidya-AdS backgrounds have been analysed explicitly. When the bulk spacetime is AdS4, the finite term is the Willmore energy of the minimal area surface viewed as a submanifold of the three dimensional flat Euclidean space. For the static spacetimes, some numerical checks involving spatial regions delimited by ellipses and non convex domains have been performed. In the case of AdS4, the infinite wedge has been also considered, recovering the known analytic formula for the coefficient of the logarithmic divergence. | The effect of spatial separation on the ability of listeners to report keywords from two simultaneous talkers was examined. The talkers were presented with equal intensity at a clearly audible level, and were designed to have little spectral overlap in order to reduce energetic interference. The two talkers were presented in a virtual auditory environment with various angular separations around references of -45o, 0o, or 45o azimuth. In Experiment 1, the virtual space was created using head-related transfer functions (HRTFs) which contained natural energy variations as a function of location. In Experiment 2, these energy variations were removed and the virtual space was created using only interaural time differences (ITDs). Overall, performance did not vary dramatically but depended on spatial separation, reference direction, and type of simulation. Around the 0o reference azimuth, performance in the HRTF condition tended to first increase and then decrease with increasing separation. This effect was greatly reduced in the ITD condition and thus appears to be related primarily to energy variations at the two ears. For sources around the ± 45o reference azimuths, there was an advantage to separating the two sources in both HRTF and ITD conditions, suggesting that perceived spatial separation is advantageous in a divided attention task, at least for lateral sources. | eng_Latn | 10,605 |
This study examined the effects of electrode placement on the early auditory evoked response in normally hearing subjects. The electrodes are termed noninverting, inverting, and common. Ten commonly used electrode combinations were evaluated. Both amplitudes and latencies of Waves I, III, and V were measured for each electrode combination. No mean differences in latencies were observed for Waves I, III, or V with any of the 10 electrode combinations. Similarly, no statistically significant Wave I or Wave III amplitude differences were found among the 10 electrode montages. However, larger Wave V amplitudes were found with placement of the noninverting electrode at the vertex (0.53 mu v) as compared to the upper forehead (0.39 mu v). Moreover, Wave V amplitudes were larger for inverting/common electrode placements at the seventh cervical vertebra/forehead, neck/forehead, and neck/neck (approximately 0.50 mu v) than for mastoid/mastoid and mastoid/forehead placements (approximately 0.40 mu v). Thus, three combinations of electrodes gave the largest Wave V amplitudes. These placements for the noninverting, inverting, and common electrodes, respectively, were (a) vertex-seventh-forehead, (b) vertex-neck-forehead, and (c) vertex-neck-neck. | The effects of rise time and center frequency on the auditory brainstem response (ABR) elicited by high-frequency tone bursts were examined in six normal-hearing adults. Tone bursts with rise times of 0.1, 0.25, 0.5, and 1.0 msec, duration of 2 msec, and center frequencies of 8, 10, and 12 kHz were used in this study. The absolute latencies of waves I, III, and V were obtained in all subjects, and interpeak intervals of I-III, III-V, and I-V were calculated. As would be expected, rise time significantly affected the absolute latencies of waves I, III, and V, i.e., faster rise times shortened the absolute latencies, but did not affect the interpeak latencies . The tone-burst frequency significantly affected the latency of wave I but not the later waves . No significant differences were found in reliability of the response at different rise times or frequencies, within or across sessions. An estimate of the effective bandwidth of the stimulus suggests that frequency specificity of the response is maintained with fast rise time tone-burst stimuli . | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 10,606 |
Emotions can be viewed as action dispositions, preparing an individual to act efficiently and successfully in situations of behavioral relevance. To initiate optimized behavior, it is essential to accurately process the perceptual elements indicative of emotional relevance. The present chapter discusses effects of affective content on neural and behavioral parameters of perception, across different information channels. Electrocortical data are presented from studies examining affective perception with pictures and words in different task contexts. As a main result, these data suggest that sensory facilitation has an important role in affective processing. Affective pictures appear to facilitate perception as a function of emotional arousal at multiple levels of visual analysis. If the discrimination between affectively arousing vs. nonarousing content relies on fine-grained differences, amplification of the cortical representation may occur as early as 60–90 ms after stimulus onset. Affectively arousing information as conveyed via visual verbal channels was not subject to such very early enhancement. However, electrocortical indices of lexical access and/or activation of semantic networks showed that affectively arousing content may enhance the formation of semantic representations during word encoding. It can be concluded that affective arousal is associated with activation of widespread networks, which act to optimize sensory processing. On the basis of prioritized sensory analysis for affectively relevant stimuli, subsequent steps such as working memory, motor preparation, and action may be adjusted to meet the adaptive requirements of the situation perceived. | Current knowledge on the architecture of exogenous attention (also called automatic, bottom-up, or stimulus-driven attention, among other terms) has been mainly obtained from studies employing neutral, anodyne stimuli. Since, from an evolutionary perspective, exogenous attention can be understood as an adaptive tool for rapidly detecting salient events, reorienting processing resources to them, and enhancing processing mechanisms, emotional events (which are, by definition, salient for the individual) would seem crucial to a comprehensive understanding of this process. This review, focusing on the visual modality, describes 55 experiments in which both emotional and neutral irrelevant distractors are presented at the same time as ongoing task targets. Qualitative and, when possible, meta-analytic descriptions of results are provided. The most conspicuous result is that, as confirmed by behavioral and/or neural indices, emotional distractors capture exogenous attention to a significantly greater extent than do neutral distractors. The modulatory effects of the nature of distractors capturing attention, of the ongoing task characteristics, and of individual differences, previously proposed as mediating factors, are also described. Additionally, studies reviewed here provide temporal and spatial information—partially absent in traditional cognitive models—on the neural basis of preattention/evaluation, reorienting, and sensory amplification, the main subprocesses involved in exogenous attention. A model integrating these different levels of information is proposed. The present review, which reveals that there are several key issues for which experimental data are surprisingly scarce, confirms the relevance of including emotional distractors in studies on exogenous attention. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 10,607 |
Persistence of excitation and neural adaptation are competing theories proposed to explain the mechanisms underlying psychophysical forward masking. Previous research has been directed towards finding models that accurately describe the phenomenon but cannot account for the underlying explanation. The current study was designed to determine which theory best accounts for results obtained from behavioral gap duration adjustment tasks. Thirteen adults adjusted the gap within asymmetrical noise markers to be subjectively equal to the gap within equal-intensity-noise markers. The duration of the perceived gap between the asymmetrical markers is expected to vary depending on which theory dominates perception. The persistence of excitation mechanism would lead to longer duration gaps when the second noise marker is lower in intensity than the preceding. Neural adaptation would result in matched gaps that are shorter in duration when the second noise marker was lower in level. The outcome of our data analysis is consistent with the persistence of excitation as a dominant mechanism in forward masking. | Masking has been used to study human perception of tactile stimuli, including those created on haptic touch screens. Earlier studies have investigated the effect of in-site masking on tactile perception of electrovibration. In this study, we investigated whether it is possible to change the detection threshold of electrovibration at fingertip of index finger via remote masking, i.e. by applying a (mechanical) vibrotactile stimulus on the proximal phalanx of the same finger. The masking stimuli were generated by a voice coil (Haptuator). For eight participants, we first measured the detection thresholds for electrovibration at the fingertip and for vibrotactile stimuli at the proximal phalanx. Then, the vibrations on the skin were measured at four different locations on the index finger of subjects to investigate how the mechanical masking stimulus propagated as the masking level was varied. Finally, electrovibration thresholds were measured in the presence of vibrotactile masking stimuli. Our results show that vibrotactile masking stimuli generated sub-threshold vibrations around fingertip and, hence, probably did not mechanically interfere with the electrovibration stimulus. However, there was a clear psychophysical masking effect due to central neural processes. Electrovibration absolute threshold increased approximately 0.19 dB for each dB increase in the masking level. | We report nearly complete preservation of “spin memory” between optical absorption and photoluminescence under excitation >0.2 eV above the band gap in nanometer GaSe slabs. | eng_Latn | 10,608 |
This paper presents a learning rule, CBA, to develop oriented receptive fields similar to those founded in cat striate cortex. The inherent complexity of the development of selectivity in visual cortex has led most authors to test their models by using a restricted input environment. Only recently, some learning rules (the PCA and the BCM rules) have been studied in a realistic visual environment. For these rules, which are based upon Hebbian learning, single neuron models have been proposed in order to get a better understanding of their properties and dynamics. These models suffered from unbounded growing of synaptic strength, which is remedied by a normalization process. However, normalization seems biologically implausible, given the non-local nature of this process. A detailed stability analysis of the proposed rule proves that the CBA attains a stable state without any need for normalization. Also, a comparison among the results achieved in different types of visual environments by the PCA, the BCM and the CBA rules is provided. The final results show that the CBA rule is appropriate for studying the biological process of receptive field formation and its application in image processing and artificial vision tasks. | The development of stimulus selectivity in the primary sensory cortex of higher vertebrates is considered in a general mathematical framework. A synaptic evolution scheme of a new kind is proposed in which incoming patterns rather than converging afferents compete. The change in the efficacy of a given synapse depends not only on instantaneous pre- and postsynaptic activities but also on a slowly varying time-averaged value of the postsynaptic activity. Assuming an appropriate nonlinear form for this dependence, development of selectivity is obtained under quite general conditions on the sensory environment. One does not require nonlinearity of the neuron's integrative power nor does one need to assume any particular form for intracortical circuitry. This is first illustrated in simple cases, e.g., when the environment consists of only two different stimuli presented alternately in a random manner. The following formal statement then holds: the state of the system converges with probability 1 to points of maximum selectivity in the state space. We next consider the problem of early development of orientation selectivity and binocular interaction in primary visual cortex. Giving the environment an appropriate form, we obtain orientation tuning curves and ocular dominance comparable to what is observed in normally reared adult cats or monkeys. Simulations with binocular input and various types of normal or altered environments show good agreement with the relevant experimental data. Experiments are suggested that could test our theory further. | Principal component analysis (PCA) was applied to assets and other household data, collected as part of the Bangladesh Demographic and Health Survey (BDHS) in 2004, to rank individuals according to a household socioeconomic index and to investigate whether this predicts access to the sanitation system or outcomes. PCA was used for determining wealth indices for 11,440 women in 10,500 households in Bangladesh. The index was based on the presence or absence of items from a list of 13 specific household assets and three housing characteristics. PCA revealed 35 components, of which the first component accounted for 18% of the total variance. Ownership of assets and housing features contributed almost equally to the variance in the first component. In this study, ownership of latrines was examined as an example of sanitation-intervention access, and rates of mortality of neonates, infant, and children aged less than five years (under-five mortality) as examples of health outcomes. The analysis demonstrated significant gradients in both access and outcome measures across the wealth quintiles. The findings call for more attention to approaches for reducing health inequalities. These could include reforms in the health sector to provide more equitable allocation of resources, improvement in the quality of health services offered to the poor, and redesigning interventions and their delivery to ensure that they are more pro-poor. | eng_Latn | 10,609 |
The implementation of the EC′s programme to liberalise the financial services sector as part of the movement towards a Single European Market will significantly reduce the costs of entry into non‐domestic markets for Community banks. Reducing entry costs will increase competition in banking markets, but it is unlikely that all segments of the banking market will experience the same patterns of change. The large‐scale corporate market already displays a high volume of cross‐border trade, while retail markets may be inaccessible for many non‐domestic banks, except by acquisition. The small‐ and medium‐sized corporate sector is widely regarded as an attractive niche market at the European level and it is suggested that there are particular gaps in this market in the UK. These gaps may make such a market susceptible to increased competition from non‐UK Community banks, although at the same time, improvements in the product offerings to this market by UK banks may provide the basis for a strategy to protect ex... | The availability of well structured financial resources is the key factor for successful implementation of an energy efficient project or a renewable energy project (herein after referred as sustainable energy (SE) projects 2 ). This paper is focused on description of prerequisites for successful cooperation between financial institutions (banks) and developers of sustainable energy projects, particularly on those characterized as SMEs 3 . The purpose of this paper is (i) to determine, whether there are any barriers against proper functioning of such cooperation and (ii) to propose methods or ways to overcome them. The paper also introduces strategies of IFC, the member of World Bank Group, which have been used for successful implementation of many projects around the globe, while overcoming above mentioned barriers. The paper consists of three main parts. First chapter describes theory of SME financing from perspective of the client, whilst second chapter outlines position of the commercial financial institutions to the same issue. Experience of IFC with SE financing is shown in the third chapter, where paper describes market reality using example of successfully implemented financing program and surveys. Paper is concluded by summary of the World Bank activities in the SE financing area. | Patterns of threshold distributions for single-cycle sinusoidal electrical stimulation and single pulse electrical stimulation were compared in primary auditory cortex of the adult cat. Furthermore, the effects of auditory deprivation on these distributions were evaluated and compared across three groups of adult cats. Threshold distributions for single and multiple unit responses from the middle cortical layers were obtained on the ectosylvian gyrus in an acutely implanted animal; 2 wk after deafening and implantation (short-term group); and neonatally deafened animals implanted following 2–5 yr of deafness (long-term group). For all three cases, we observed similar patterns of circumscribed regions of low response thresholds in the region of primary auditory cortex (AI). A dorsal and a ventral region of low response thresholds were found separated by a narrow, anterior-posterior strip of elevated thresholds. The ventral low-threshold regions in the short-term group were cochleotopically arranged. By contrast, the dorsal region in the short-term animals and both low-threshold regions in long-term deafened animals maintained only weak cochleotopicity. Analysis of the spatial extent of the low-threshold regions revealed that the activated area for sinusoidal stimulation was smaller and more circumscribed than for pulsatile stimulation for both dorsal and ventral AI. The width of the high-threshold ridge that separated the dorsal and ventral low-threshold regions was greater for sinusoidal stimulation. Sinusoidal and pulsatile threshold behavior differed significantly for electrode configurations with low and high minimum thresholds. Differences in threshold behavior and cortical response distributions between the sinusoidal and pulsatile stimulation suggest that stimulus shape plays a significant role in the activation of cortical activity. Differences in the activation pattern for short-term and long-term deafness reflect deafness-induced reorganizational changes based on factors such as differences in excitatory and inhibitory balance that are affected by the stimulation parameters. | eng_Latn | 10,610 |
A major new insight into cochlear mechanisms is the recognition of an active process, the cochlear amplifier, that contributes energy to the mechanical movement of the basilar membrane at low sound intensities. The extra energy makes possible the great sensitivity of hearing and also the very sharp tuning of individual neural units, ie, the tips of their tuning curves. The inner hair cells are the final receptor cells, but the outer hair cells are essential for the amplifier action. The amplifier is much more sensitive to anoxia, ototoxic drugs, noise, etc, than the inner hair cell system alone. Severe impairment of the amplifier causes a sensorineural hearing loss with recruitment. Only the tails of tuning curves remain. Thus the cochlea is a dual sensory system, a robust but insensitive broadly tuned passive component sided by a vulnerable, sensitive sharply tuned active component. | A model for cochlear mechanics is proposed to take account of its two systems, one passive and one active. The classical passive system stimulates the inner hair cells directly at levels above about 40 dB SL. At intensities below about 60 dB an active process, the 'cochlear amplifier' (CA), somehow provides additional energy that enhances the vibration of a narrow segment of the basilar membrane near the apical foot of the familiar, traveling wave envelope. The outer hair cells are essential for CA. The active system acts like a high-Q acoustic resonator, and it accounts for the great sensitivity and sharp tuning expressed by the 'tips' of neural tuning curves. The tips are selectively vulnerable to anoxia, noise exposure and other trauma. The CA model explains the detection of small differences in time as well as in frequency, the dual character of the electrocochleogram, recruitment of loudness in cochlear hearing impairment, the long latency of normal neural responses near threshold, acoustic emissions (both stimulated and spontaneous) and the locus of TTS in the frequency range above the exposure tone. Both the classical high-intensity system and the active low-level CA system are highly nonlinear and they combine to compress the great dynamic range of hearing into a much narrower range of mechanical movement of the cilia of the inner hair cells. The mechanism of CA is unknown, and the problem remains of how its action can be triggered by submolecular movements near threshold. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 10,611 |
An observer’s inference that multimodal signals originate from a common underlying source facilitates cross-modal binding. This ‘unity assumption’ causes asynchronous auditory and visual speech streams to seem simultaneous (Vatakis & Spence, Perception & Psychophysics, 69(5), 744–756, 2007). Subsequent tests of non-speech stimuli such as musical and impact events found no evidence for the unity assumption, suggesting the effect is speech-specific (Vatakis & Spence, Acta Psychologica, 127(1), 12–23, 2008). However, the role of amplitude envelope (the changes in energy of a sound over time) was not previously appreciated within this paradigm. Here, we explore whether previous findings suggesting speech-specificity of the unity assumption were confounded by similarities in the amplitude envelopes of the contrasted auditory stimuli. Experiment 1 used natural events with clearly differentiated envelopes: single notes played on either a cello (bowing motion) or marimba (striking motion). Participants performed an un-speeded temporal order judgments task; viewing audio-visually matched (e.g., marimba auditory with marimba video) and mismatched (e.g., cello auditory with marimba video) versions of stimuli at various stimulus onset asynchronies, and were required to indicate which modality was presented first. As predicted, participants were less sensitive to temporal order in matched conditions, demonstrating that the unity assumption can facilitate the perception of synchrony outside of speech stimuli. Results from Experiments 2 and 3 revealed that when spectral information was removed from the original auditory stimuli, amplitude envelope alone could not facilitate the influence of audiovisual unity. We propose that both amplitude envelope and spectral acoustic cues affect the percept of audiovisual unity, working in concert to help an observer determine when to integrate across modalities. | In two experiments, we measured audio-visual crossmodal attraction on the time dimension, using a sensorimotor synchronization task. Synchronization performance made it possible to split up the total crossmodal attraction (demonstrated in earlier studies through inter-modal temporal order judgments) into its modality-specific components, the auditory bias of the visual event's perceived time of occurrence and the visual bias of the auditory event's perceived time of occurrence. Participants were asked to produce tapping movements in synchrony with a sequence of isochronously repeated pacing signals. In Experiment 1, pacing signals were light flashes, each preceded or followed, at one of several stimulus onset asynchronies (SOAs), by an auditory distracter that the participant was instructed to ignore. The timing of the tap was, in spite of that instruction, strongly biased toward the distracter. In Experiment 2, the converse task was used. The pacing signals were auditory and the to be ignored distracters, light flashes. The timing of the taps was biased significantly here also toward the distracter, but to a much lesser extent. Taken together, these results clearly demonstrate that audition plays a bigger role than vision in temporal ventriloquism and is probably generally superior to vision for processing the temporal dimension of events. | ABSTRACTUNC-45A is an ubiquitously expressed protein highly conserved throughout evolution. Most of what we currently know about UNC-45A pertains to its role as a regulator of the actomyosin system... | eng_Latn | 10,612 |
This paper will discuss the interdependence between navigation and Precise Time and Time Interval (PTTI) systems. The modern role that navigation systems play in the field of timekeeping is shown through examples of how Omega, Loran-C, TRANSIT, and the Global Positioning System (GPS) are utilized by the PTTI community. | A proposal is made for improvement of J. A. Pierce's composite wave technique for the reduction of diurnal and solar flare effects on OMEGA navigation signals. Based on calculations of a fictitious free-space transmission time Tc and multi-frequency phase measurements, a general formalism is presented for the compensation of phase shifts due to changes in the earth-ionosphere waveguide parameters. In principle, phase measurements at (n + 1) discrete frequencies are necessary to compensate for variations in n parameters such as reference height, ionospheric conductivity gradient, etc. For n = 1 (compensation of height changes), explicit expressions for Tc are derived from various models of the earth-ionosphere waveguide using phase measurements recorded at the basic OMEGA frequencies of 10.2 and 13.6 kHz. For a flat earth with perfectly conducting boundaries, the results are very similar to those of Pierce. More realistic waveguide models (spherical earth with exponential ionosphere) result in a considerable reduction of diurnal shifts and anomalies due to solar disturbances. It is also shown that no further improvements result from the addition of a third signal because of unrealistic accuracy requirements for phase measurements. | Associative learning forms when there is temporal relationship between a stimulus and a reinforcer, yet the inter-trial-interval (ITI), which is usually much longer than the stimulus-reinforcer-interval, contributes to learning-rate and memory strength. The neural mechanisms that enable maintenance of time between trials remain unknown, and it is unclear if the amygdala can support time scales at the order of dozens of seconds. We show that the ITI indeed modulates rate and strength of aversive-learning, and that single-units in the primate amygdala and dorsal-anterior-cingulate-cortex signal confined periods within the ITI, strengthen this coding during acquisition of aversive-associations, and diminish during extinction. Additionally, pairs of amygdala-cingulate neurons synchronize during specific periods suggesting a shared circuit that maintains the long temporal gap. The results extend the known roles of this circuit and suggest a mechanism that maintains trial-structure and temporal-contingencies for learning. It further suggests a novel model for maladaptive behaviors. | eng_Latn | 10,613 |
The Edwards Aquifer, near San Antonio, Texas, is an important water source for both pumping and spring flow, which in turn provides water for recreation and habitat for several endangered species. A management authority is charged with aquifer management and is mandated to reduce pumping, facilitate water markets, protect agricultural rights, and protect the species habitat. This paper examines the economic dimensions of authority duties. A combined hydrologic-economic model is used in the investigation. The results indicate that proposed pumping limits are shown to have large consequences for agricultural usage and to decrease the welfare of current aquifer pumping users. However, the spring flow habitat is found to be protected, and the gains from that protection would have to exceed pumping user losses in order for the protection measures to increase regional economic welfare. Agricultural guarantees are shown to cause use value differences, indicating the opportunity for emergence of an active water market. Fixed quantity pumping limits are found to be an expensive way of insuring adequate spring flow. | [1] Most cities rely on firm water supply capacity to meet demand, but increasing scarcity and supply costs are encouraging greater use of temporary transfers (e.g., spot leases, options). This raises questions regarding how best to coordinate the use of these transfers in meeting cost and reliability objectives. This paper combines a hydrologic–water market simulation with an optimization approach to identify portfolios of permanent rights, options, and leases that minimize the expected costs of meeting a city's annual demand with a specified reliability. Spot market prices are linked to hydrologic conditions and described by monthly lease price distributions which are used to price options via a risk-neutral approach. Monthly choices regarding when and how much water to acquire through temporary transfers are made on the basis of anticipatory decision rules related to the ratio of expected supply to expected demand. The simulation is linked with an algorithm that uses an implicit filtering search method designed for solution surfaces that exhibit high-frequency, low-amplitude noise. This simulation-optimization approach is applied to a region that currently supports an active water market, with results suggesting that temporary transfers can reduce expected water supply costs substantially, while still maintaining high reliability. Also evaluated are trade-offs between expected costs and cost variability that occur with variation in a portfolio's distribution of rights, options, and leases. | In order to investigate the temporal mechanisms of the auditory system, psychophysical forward masking experiments were conducted in cochlear implant users who had preserved acoustic hearing in the ipsilateral ear. This unique electric-acoustic stimulation (EAS) population allowed the measurement of threshold recovery functions for acoustic or electric probes in the presence of electric or acoustic maskers, respectively. In the electric masking experiment, the forward masked threshold elevation of acoustic probes was measured as a function of the time interval after the offset of the electric masker, i.e. the masker-to-probe interval (MPI). In the acoustic masking experiment, the forward masked threshold elevation of electric probe stimuli was investigated under the influence of a preceding acoustic masker. Since electric pulse trains directly stimulate the auditory nerve, this novel experimental setup allowed the acoustic adaptation properties (attributed to the physiology of the hair cells) to be differentiated from the subsequent processing by more central mechanisms along the auditory pathway. For instance, forward electric masking patterns should result more from the auditory-nerve response to electrical stimulation, while forward acoustic masking patterns should primarily be the result of the recovery from adaptation at the hair-cell neuron interface. Electric masking showed prolonged threshold elevation of acoustic probes, which depended significantly on the masker-to-probe interval. Additionally, threshold elevation was significantly dependent on the similarity between acoustic stimulus frequency and electric place frequency, the electric-acoustic frequency difference (EAFD). Acoustic masking showed a reduced, but statistically significant effect of electric threshold elevation, which did not significantly depend on MPI. Lastly, acoustic masking showed longer decay times than electric masking and a reduced dependency on EAFD. In conclusion, the forward masking patterns observed for combined electric-acoustic stimulation provide further insights into the temporal mechanisms of the auditory system. For instance, the asymmetry in the amount of threshold elevation, the dependency on EAFD and the time constants for the recovery functions of acoustic and electric masking all indicate that there must be several processes with different latencies (e.g. neural adaptation, depression of spontaneous activity, efferent systems) that are involved in forward masking recovery functions. | eng_Latn | 10,614 |
Eyeball deformation in total darkness leads to an activation of on-center ganglion cells and an inhibition of off-center ganglion cells. After “deformation off” most on-center ganglion cell activity decreased slowly to the normal spontaneous dark level, while in off-center ganglion cells some returned according to an exponential function to normal dark activity, while others had a transient postinhibitory activation period. In general, the response type of latency class I and latency class II neurons was the same. Dark adaptation of 30–45 min duration only changed this neuronal response pattern slightly, if at all. A detailed statistical analysis is provided for the four classes of retinal ganglion cells recorded: latency class I on-center and off-center neurons and latency class II on-center and off-center neurons. The missing effects of dark adaptation on neuronal responses evoked by eyeball deformation are explained by three possible models. The more plausible one assumes that horizontal cells are depolarized by retinal stretch. Their interaction with cone on-bipolars or cone off-bipolars is fairly independent of photoreceptor adaptation or transmitter release at the cone pedicles and is still effective when all molecular receptor sites at cone/bipolar cell synapses are occupied during scotopic states of dark adaptation. In psychophysical experiments (two subjects), as in the neuronal responses, we also could not find any indication that the “pressure phosphenes” evoked by lateral eyeball indentation are altered during dark adaptation. | Focused ultrasound has been shown to be effective at stimulating neurons in vivo, ex vivo and in vitro preparations. Ultrasonic neuromodulation is the only non-invasive method of stimulation that could reach deep in the brain with high spatial-temporal resolution, and thus has potential for use in clinical applications and basic studies of the nervous system. Understanding the physical mechanism by which energy in a high acoustic frequency wave is delivered to stimulate neurons will be important to optimize this technology. Two primary candidates for a physical mechanism are radiation force, the delivery of momentum by the acoustic wave, and cavitation, oscillating gas bubbles. We imaged the isolated salamander retina during ultrasonic stimuli that drive ganglion cell activity and observed micron scale displacements consistent with radiation force. We recorded ganglion cell spiking activity with a planar multielectrode array and changed the acoustic carrier frequency across a broad range (0.5 - 43 MHz), finding that increased stimulation occurs at higher acoustic frequencies, a result that is consistent with radiation force but not cavitation. A quantitative radiation force model can explain retinal responses, and could potentially explain previous in vivo results in the mouse, suggesting a new hypothesis to be tested in vivo. Finally, we found that neural activity was strongly modulated by the distance between the transducer and the electrode array showing the influence of standing waves on the response. We conclude that radiation force is the physical mechanism underlying ultrasonic neurostimulation in the ex vivo retina, and that the control of standing waves is a new potential method to modulate these effects. | The reduction of proline by Clostridium sporogenes NCIB8053 is coupled to transmembrane proton translocation in an uncoupler-sensitive fashion (and might therefore conserve free energy). This finding serves to explain the increase in the growth yield of this organism when proline is added to a defined growth medium containing glucose as the catabolic substrate. | eng_Latn | 10,615 |
Bullock and Basar (1988) report that “when the extracellular ongoing, spontaneous potentials recorded from the surface or the depth of the cerebrum are compared in terms of gross wave form and power spectral density, there are no systematic differences among vertebrate classes (mammals, reptiles, birds, amphibians, bony and cartilaginous fishes) and that the differences in brain electrical activity between fish and mammals are smaller, if any, in spite of the major histological differences, than those in different states and loci within the same individual.” For instance, among various bony fishes and elasmobranchs there are no differences in the parameters of ongoing activity. On the other hand, cerebellar cortex, tegmentum, medulla, and cord show quite different forms of ongoing activity (Bullock and Basar 1988). | Comparatively analyses of electrophysiological correlates across species during evolution, alpha activity during brain maturation, and alpha activity in complex cognitive processes are presented to illustrate a new multidimensional “Cartesian System” brain function. The main features are: (1) The growth of the alpha activity during evolution, increase of alpha during cognitive processes, and decrease of the alpha entropy during evolution provide an indicator for evolution of brain cognitive performance. (2) Human children younger than 3 years are unable to produce higher cognitive processes and do not show alpha activity till the age of 3 years. The mature brain can perform higher cognitive processes and demonstrates regular alpha activity. (3) Alpha activity also is significantly associated with highly complex cognitive processes, such as the recognition of facial expressions. The neural activity reflected by these brain oscillations can be considered as constituent “building blocks” for a great number of functions. An overarching statement on the alpha function is presented by extended analyzes with multiple dimensions that constitute a “Cartesian Hyperspace” as the basis for oscillatory function. Theoretical implications are considered. | The security of computer systems often relies upon decisions and actions of end users. In this paper, we set out to investigate user-centered security by concentrating at the most fundamental component governing user behavior - the human brain. We introduce a novel neuroscience-based study methodology to inform the design of user-centered security systems. Specifically, we report on an fMRI study measuring users' security performance and the underlying neural activity with respect to two critical security tasks: (1) distinguishing between a legitimate and a phishing website, and (2) heeding security (malware) warnings. At a higher level, we identify neural markers that might be controlling users' performance in these tasks, and establish relationships between brain activity and behavioral performance as well as between users' personality traits and security behavior. Our results provide a largely positive perspective towards users' capability and performance vis-a-vis these crucial security tasks. First , we show that users exhibit significant brain activity in key regions associated with decision-making, attention, and problem-solving (phishing and malware warnings) as well as language comprehension and reading (malware warnings), which means that users are actively engaged in these security tasks. Second , we demonstrate that certain individual traits, such as impulsivity measured via an established questionnaire, can have a significant negative effect on brain activation in these tasks. Third , we discover a high degree of correlation in brain activity (in decision-making regions) across phishing detection and malware warnings tasks, which implies that users' behavior in one task may potentially be predicted by their behavior in the other task. Finally , we discuss the broader impacts and implications of our work on the field of user-centered security, including the domain of security education, targeted security training, and security screening. | eng_Latn | 10,616 |
This technical note introduces a conductance-based neural field model that combines biologically realistic synaptic dynamics—based on transmembrane currents—with neural field equations, describing the propagation of spikes over the cortical surface. This model allows for fairly realistic inter-and intra-laminar intrinsic connections that underlie spatiotemporal neuronal dynamics. We focus on the response functions of expected neuronal states (such as depolarization) that generate observed electrophysiological signals (like LFP recordings and EEG). These response functions characterize the model's transfer functions and implicit spectral responses to (uncorrelated) input. Our main finding is that both the evoked responses (impulse response functions) and induced responses (transfer functions) show qualitative differences depending upon whether one uses a neural mass or field model. Furthermore, there are differences between the equivalent convolution and conductance models. Overall, all models reproduce a characteristic increase in frequency, when inhibition was increased by increasing the rate constants of inhibitory populations. However, convolution and conductance-based models showed qualitatively different changes in power, with convolution models showing decreases with increasing inhibition, while conductance models show the opposite effect. These differences suggest that conductance based field models may be important in empirical studies of cortical gain control or pharmacological manipulations. | The theoretical changes in shape and velocity of an action potential were computed in regions of changing core conductor geometry. Step decrease and step increase of diameter, branch points, and gradual taper or flare of diameter were studied. Results showed increase of both velocity and peak height as the action potential approaches a point of step decrease. A step increase causes decrease of both velocity and peak height with approach; propagation may either fail, succeed with brief delay, or, with longer delay, succeed in both forward and reverse directions. With branching, both the shape and the dimensionless velocity, τθ/λ, remain unchanged when the d3/2 values are matched. Without such matching, the changes of shape and dimensionless velocity of an action potential correspond to those found for step decrease or step increase of diameter. For regions of flare or taper, it was found (for a specific previously defined class) that velocity changed in proportion with the changing length constant. A simple formula was found to predict how this proportionality constant depends upon the amount of flare or taper. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 10,617 |
Watching the lips of a speaker enhances speech perception. At the same time, the 100 ms response to speech sounds is suppressed in the observer9s auditory cortex. Here, we used whole-scalp 306-channel magnetoencephalography (MEG) to study whether lipreading modulates human auditory processing already at the level of the most elementary sound features, i.e., pure tones. We further envisioned the temporal dynamics of the suppression to tell whether the effect is driven by top-down influences. Nineteen subjects were presented with 50 ms tones spanning six octaves (125–8000 Hz) (1) during “lipreading,” i.e., when they watched video clips of silent articulations of Finnish vowels /a/, /i/, /o/, and /y/, and reacted to vowels presented twice in a row; (2) during a visual control task; (3) during a still-face passive control condition; and (4) in a separate experiment with a subset of nine subjects, during covert production of the same vowels. Auditory-cortex 100 ms responses (N100m) were equally suppressed in the lipreading and covert-speech-production tasks compared with the visual control and baseline tasks; the effects involved all frequencies and were most prominent in the left hemisphere. Responses to tones presented at different times with respect to the onset of the visual articulation showed significantly increased N100m suppression immediately after the articulatory gesture. These findings suggest that the lipreading-related suppression in the auditory cortex is caused by top-down influences, possibly by an efference copy from the speech-production system, generated during both own speech and lipreading. | A question that has emerged over recent years is whether audiovisual (AV) speech perception is a special case of multi-sensory perception. Electrophysiological (ERP) studies have found that auditory neural activity (N1 component of the ERP) induced by speech is suppressed and speeded up when a speech sound is accompanied by concordant lip movements. In Experiment 1, we show that this AV interaction is not speech-specific. Ecologically valid nonspeech AV events (actions performed by an actor such as handclapping) were associated with a similar speeding-up and suppression of auditory N1 amplitude as AV speech (syllables). Experiment 2 demonstrated that these AV interactions were not influenced by whether A and V were congruent or incongruent. In Experiment 3 we show that the AV interaction on N1 was absent when there was no anticipatory visual motion, indicating that the AV interaction only occurred when visual anticipatory motion preceded the sound. These results demonstrate that the visually induced speeding-up and suppression of auditory N1 amplitude reflect multisensory integrative mechanisms of AV events that crucially depend on whether vision predicts when the sound occurs. | Corruption, which is a persistent feature in human societies throughout time and space, affects not only the administration of the state but also every societal organ including the church. The ‘virus of corruption’ has penetrated into functioning systems of the various stakeholders both locally and globally. Various approaches have been used in trying to curb corruption at different levels from a secular perspective, but with little progress as the vice eminently still exists in the society. To the contrary and from a theological perspective, the long-lasting solutions in curbing corruption are realised through engaging the main root cause of the problem, which in this case is the heart of man. Theologically, ken ō sis as a theoretical framework and solution goes beyond the gist of secular approaches as it addresses issues of the hearts of men which in turn produces reformed systems. In this article, I look into ken ō sis of the Synod operational system in relation to imitating the incarnate work of Christ. The article assesses the Synod anti-corruption initiatives from a ken ō sis perspective and then identifies and proposes the effective steps to improve and strengthen the Synod’s kenotic actions in Public Square. The CCAP Livingstonia Synod assessment process is geared to show how far kenotic the church must go in emulating and confronting systems as a way of fulfilling the demands of incarnation and works of Christ. This highlights the critical areas that add value in the Synod’s public engagement in anti-corruption. Intradisciplinary and/or interdisciplinary implications: This is an interdisciplinary article that focuses on systematic, church history, public theology and social development. The article assesses the public role of the church in anti-corruption and provides a paradigm shift in the fight against corruption from secular to theological based approaches. | eng_Latn | 10,618 |
Dynamic vision requires both stability of the current perceptual representation and sensitivity to the accumulation of sensory evidence over time. Here we study the electrophysiological signatures of this intricate balance between temporal segregation and integration in vision. Within a forward masking paradigm with short and long stimulus onset asynchronies (SOA), we manipulated the temporal overlap of the visual persistence of two successive transients. Human observers enumerated the items presented in the second target display as a measure of the informational capacity read-out from this partly temporally integrated visual percept. We observed higher β-power immediately before mask display onset in incorrect trials, in which enumeration failed due to stronger integration of mask and target visual information. This effect was timescale specific, distinguishing between segregation and integration of visual transients that were distant in time (long SOA). Conversely, for short SOA trials, mask onset evoked a stronger visual response when mask and targets were correctly segregated in time. Examination of the target-related response profile revealed the importance of an evoked α-phase reset for the segregation of those rapid visual transients. Investigating this precise mapping of the temporal relationships of visual signals onto electrophysiological responses highlights how the stream of visual information is carved up into discrete temporal windows that mediate between segregated and integrated percepts. Fragmenting the stream of visual information provides a means to stabilize perceptual events within one instant in time. | Considerable interest has been raised by non-phase-locked episodes of synchronization in the gamma-band (30–60 Hz). One of their putative roles in the visual modality is feature-binding. We tested the stimulus specificity of high-frequency oscillations in humans using three types of visual stimuli: two coherent stimuli (a Kanizsa and a real triangle) and a noncoherent stimulus (“no-triangle stimulus”). The task of the subject was to count the occurrences of a curved illusory triangle. A time–frequency analysis of single-trial EEG data recorded from eight human subjects was performed to characterize phase-locked as well as non-phase-locked high-frequency activities. We found an early phase-locked 40 Hz component, maximal at electrodes Cz–C4, which does not vary with stimulation type. We describe a second 40 Hz component, appearing around 280 msec, that is not phase-locked to stimulus onset. This component is stronger in response to a coherent triangle, whether real or illusory: it could reflect, therefore, a mechanism of feature binding based on high-frequency synchronization. Because both the illusory and the real triangle are more target-like, it could also correspond to an oscillatory mechanism for testing the match between stimulus and target. At the same latencies, the low-frequency evoked response components phase-locked to stimulus onset behave differently, suggesting that low- and high-frequency activities have different functional roles. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 10,619 |
Persistent regular oscillations of the pupil of the eye can be induced using a slit-lamp. The period of these oscillations, pupil cycle time (PCT), is simple to measure with a hand-held stop-watch. Evidence from pharmacological testing suggests that PCT is a sensitive measure of dysfunction of the parasympathetic efferent limb of the pupillary light reflex arc. This is confirmed by the finding that PCT is prolonged in a high proportion of patients with evidence of autonomic neuropathy judged by abnormalities of their cardiovascular reflexes. The method provides a simple, non-invasive way of quantifying an autonomic reflex and it may be of value in investigating patients with diseases affecting the autonomic nervous system. | Fractals are self-similar structures or patterns that repeat at increasingly fine magnifications. Research has revealed fractal patterns in many natural and physiological processes. This article investigates pupillary size over time to determine if their oscillations demonstrate a fractal pattern. We predict that pupil size over time will fluctuate in a fractal manner and this may be due to either the fractal neuronal structure or fractal properties of the image viewed. We present evidence that low complexity fractal patterns underlie pupillary oscillations as subjects view spatial fractal patterns. We also present evidence implicating the autonomic nervous system's importance in these patterns. Using the variational method of the box-counting procedure we demonstrate that low complexity fractal patterns are found in changes within pupil size over time in millimeters (mm) and our data suggest that these pupillary oscillation patterns do not depend on the fractal properties of the image viewed. | A study of business cycles defined as sequences of expansions and contractions in the level of general economic activity does not require trend estimation and elimination, but a study of growth cycles defined as sequences of high and low growth phases does. Major cyclical slowdowns and booms deserve to be analyzed along with classical recessions and expansions, but the needed time series decomposition presents difficult problems, mainly because trends and cycles influence each other. We compare cyclical movements in levels, deviations from trend, and smoothed growth rates of the principal measures of aggregate economic activity - the quarterly real GDP and the monthly U.S. Coincident Index - using the phase average trend (PAT). Then we compare alternative trend estimates, deterministic and stochastic, linear and nonlinear, and the corresponding estimates of 'cyclical components,' that is, series of deviations from these trends. We discuss how these measures differ in terms of the patterns, timing, amplitudes, and smoothness of the resulting estimates of U.S. growth cycles in the post-World War II period. The results of PAT show great similarity to the results obtained with the H-P and band-pass filtering methods, but in matters of detail PAT is often superior. | eng_Latn | 10,620 |
It is argued that a loudness scale based on the discriminability criterion would be better than one based on those methods which assume that direct numerical responses adequately reflect the nature of the loudness experience. The evidence and argument presented show: First, there is just as good a logical basis for accepting the discriminability criterion as for accepting the direct response criterion. In both cases we have to assert face validity which is arbitrary and may be incorrect. Second, the scales based on the discriminability criterion show less interobserver variability, are influenced less by specific experimental conditions, and are less affected by stimulus context than scales based on the fractionation procedure—the major direct response method used. Third, and most important, most of the direct response procedures themselves give results which agree with scales based on a discriminability criterion. It is, in fact, only the ratio scaling or fractionation procedures which give results at va... | Several successful theories of psychophysical judgment imply that exponents of power functions in scaling tasks should covary with measures of intensity resolution such asd’ in the same tasks, whereas the prevailing metatheory of ideal psychophysical scaling asserts the independence of the two. In a direct test of this relationship, three prominent psychophysical scaling paradigms were studied: category judgment without an identification function, absolute magnitude estimation, and cross-modality matching with light intensity as the response continuum. Separate groups of subjects for each scaling paradigm made repeated judgments of the loudnesses of the pure tones that constituted each of two stimulus ensembles. The narrow- and wide-range ensembles shared six identical stimulus intensities in the middle of each set. Intensity resolution, as measured byd’-like distances, of these physically identical stimuli was significantly worse for the wide-range set for all three methods. Exponents of power functions fitted to geometric mean responses, and in magnitude estimation and cross-modality matching the geometric mean responses themselves, were also significantly smaller in the wide-range condition. The variation of power function exponents, and of psychophysical scale values, for stimulus intensities that were identical in the two stimulus sets with the intensities of other members of the ensembles is inconsistent with the metatheory on which modern psychophysical scaling practice is based, although it is consistent with other useful approaches to measurement of psychological magnitudes. | Distillation at an infinite reflux ratio in combination with an infinite number of trays has been investigated. | eng_Latn | 10,621 |
Oscillatory brain activity is believed to play a central role in neural coding. Accumulating evidence shows that features of these oscillations are highly dynamic: power, frequency and phase fluctuate alongside changes in behavior and task demands. The role and mechanism supporting this variability is however poorly understood. We here analyze a network of recurrently connected spiking neurons with time delay displaying stable synchronous dynamics. Using mean-field and stability analyses, we investigate the influence of dynamic inputs on the frequency of firing rate oscillations. We show that afferent noise, mimicking inputs to the neurons, causes smoothing of the system’s response function, displacing equilibria and altering the stability of oscillatory states. Our analysis further shows that these noise-induced changes cause a shift of the peak frequency of synchronous oscillations that scales with input intensity, leading the network towards critical states. We lastly discuss the extension of these principles to periodic stimulation, in which externally applied driving signals can trigger analogous phenomena. Our results reveal one possible mechanism involved in shaping oscillatory activity in the brain and associated control principles. | Summary Perception routinely integrates inputs from different senses. Stimulus temporal proximity critically determines whether or not these inputs are bound together. Despite the temporal window of integration being a widely accepted notion, its neurophysiological substrate remains unclear. Many types of common audio-visual interactions occur within a time window of ∼100 ms [1–5]. For example, in the sound-induced double-flash illusion, when two beeps are presented within ∼100 ms together with one flash, a second illusory flash is often perceived [2]. Due to their intrinsic rhythmic nature, brain oscillations are one candidate mechanism for gating the temporal window of integration. Interestingly, occipital alpha band oscillations cycle on average every ∼100 ms, with peak frequencies ranging between 8 and 14 Hz (i.e., 120–60 ms cycle). Moreover, presenting a brief tone can phase-reset such oscillations in visual cortex [6, 7]. Based on these observations, we hypothesized that the duration of each alpha cycle might provide the temporal unit to bind audio-visual events. Here, we first recorded EEG while participants performed the sound-induced double-flash illusion task [4] and found positive correlation between individual alpha frequency (IAF) peak and the size of the temporal window of the illusion. Participants then performed the same task while receiving occipital transcranial alternating current stimulation (tACS), to modulate oscillatory activity [8] either at their IAF or at off-peak alpha frequencies (IAF±2 Hz). Compared to IAF tACS, IAF−2 Hz and IAF+2 Hz tACS, respectively, enlarged and shrunk the temporal window of illusion, suggesting that alpha oscillations might represent the temporal unit of visual processing that cyclically gates perception and the neurophysiological substrate promoting audio-visual interactions. | The natural variability of regional climatic conditions poses certain difficulties in detecting global climate change at a local scale. The question about the ratio between the contribution of human forcing, induced by the increase in atmospheric carbon dioxide concentration, and the contribution of natural variability in atmospheric and oceanic circulation arises in each particular case. The purpose of the study reported in this article was to evaluate the contribution of the North Atlantic Oscillation to the decrease in the climate continentality of Moscow during the period of 1951–2000. The results show that a significant part of the decrease in continentality could be attributed to the increase in the North Atlantic Oscillation index observed during this period. | eng_Latn | 10,622 |
Using a reading task, the present study investigated saccade-related brain potentials (SRPs) accompanying the perception of the final words of proverbs, i.e. of sentences where the context allows a strong anticipation of the final word. The sentences were presented one at a time on a TV monitor. The proverbs appeared either in their original form or with their final word changed to be incongruous with the sentence context. SRPs to the two types of final words were recorded from 4 scalp areas. The onset of the saccade leading to the final word was used to trigger the averaging of SRPs. Incongruent and congruent brain responses were also compared by means of difference waveforms. The results showed that a difference between SRPs to congruous vs incongruous final words of proverbs already appeared simultaneously with the SRP component indicating the analysis of the visual pattern of the word. This finding supports an interactive model of word perception. | Exploration of the real world usually expresses itself through a perceptual behaviour that is complex and adaptive — an interplay between external visual and internal cognitive states. However, up to now, the measurement of electrophysiological correlates of cognitive processes has been limited to situations, in which the experimental setting confined visual exploration to the mere reception of a strict serial order of events. Here we show – exemplified by the well known old/new effect in the domain of visual word recognition – that an alternative approach that utilizes brain potentials corresponding to eye fixations during free exploration reveals effects as reliable as conventional event-related brain potentials. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 10,623 |
Cochlear root neurons (CRNs) are second-order neurons interspersed among the fibers of the cochlear nerve in certain rodents. They project, among other nuclei, mainly to the pontine reticular nucleus, and participate in the acoustic startle response (ASR), a short-latency motor reflex initiated by sudden intense sounds. The sound-evoked activity of CRNs has not previously been described. Here we describe extracellular responses of CRNs located in the infranuclear portion of the cochlear nerve root. CRNs exhibited secure responses to tone bursts, with first-spike latencies of approximately 2.2 ms. The characteristic frequencies of the recorded CRNs were about 30 kHz, and the best-characterized CRN had a threshold of 10 dB sound pressure level and sharpness of tuning similar to that of cochlear nerve fibers. The peristimulus time histograms were primary-like with notch. The observed response properties were consistent with the suggestion that CRNs provide the short-latency acoustic input to the reticular formation that leads to an ASR. | The acoustic startle reflex (ASR) is a survival mechanism of alarm, which rapidly alerts the organism to a sudden loud auditory stimulus. In rats, the primary ASR circuit encompasses three serially connected structures: cochlear root neurons (CRNs), neurons in the caudal pontine reticular nucleus (PnC), and motoneurons in the medulla and spinal cord. It is well-established that both CRNs and PnC neurons receive short-latency auditory inputs to mediate the ASR. Here, we investigated the anatomical origin and functional role of these inputs using a multidisciplinary approach that combines morphological, electrophysiological and behavioral techniques. Anterograde tracer injections into the cochlea suggest that CRNs somata and dendrites receive inputs depending, respectively, on their basal or apical cochlear origin. Confocal colocalization experiments demonstrated that these cochlear inputs are immunopositive for the vesicular glutamate transporter 1 (VGLUT1). Using extracellular recordings in vivo followed by subsequent tracer injections, we investigated the response of PnC neurons after contra-, ipsi-, and bilateral acoustic stimulation and identified the source of their auditory afferents. Our results showed that the binaural firing rate of PnC neurons was higher than the monaural, exhibiting higher spike discharges with contralateral than ipsilateral acoustic stimulations. Our histological analysis confirmed the CRNs as the principal source of short-latency acoustic inputs, and indicated that other areas of the cochlear nucleus complex are not likely to innervate PnC. Behaviorally, we observed a strong reduction of ASR amplitude in monaural earplugged rats that corresponds with the binaural summation process shown in our electrophysiological findings. Our study contributes to understand better the role of neuronal mechanisms in auditory alerting behaviors and provides strong evidence that the CRNs-PnC pathway mediates fast neurotransmission and binaural summation of the ASR. | The acoustic startle reflex (ASR) is a survival mechanism of alarm, which rapidly alerts the organism to a sudden loud auditory stimulus. In rats, the primary ASR circuit encompasses three serially connected structures: cochlear root neurons (CRNs), neurons in the caudal pontine reticular nucleus (PnC), and motoneurons in the medulla and spinal cord. It is well-established that both CRNs and PnC neurons receive short-latency auditory inputs to mediate the ASR. Here, we investigated the anatomical origin and functional role of these inputs using a multidisciplinary approach that combines morphological, electrophysiological and behavioral techniques. Anterograde tracer injections into the cochlea suggest that CRNs somata and dendrites receive inputs depending, respectively, on their basal or apical cochlear origin. Confocal colocalization experiments demonstrated that these cochlear inputs are immunopositive for the vesicular glutamate transporter 1 (VGLUT1). Using extracellular recordings in vivo followed by subsequent tracer injections, we investigated the response of PnC neurons after contra-, ipsi-, and bilateral acoustic stimulation and identified the source of their auditory afferents. Our results showed that the binaural firing rate of PnC neurons was higher than the monaural, exhibiting higher spike discharges with contralateral than ipsilateral acoustic stimulations. Our histological analysis confirmed the CRNs as the principal source of short-latency acoustic inputs, and indicated that other areas of the cochlear nucleus complex are not likely to innervate PnC. Behaviorally, we observed a strong reduction of ASR amplitude in monaural earplugged rats that corresponds with the binaural summation process shown in our electrophysiological findings. Our study contributes to understand better the role of neuronal mechanisms in auditory alerting behaviors and provides strong evidence that the CRNs-PnC pathway mediates fast neurotransmission and binaural summation of the ASR. | eng_Latn | 10,624 |
We argue that 4 fundamental gestalt phenomena in perception apply to the control of motor action. First, a motor gestalt, like a perceptual gestalt, is holistic in the sense that it is processed as a single unit. This notion is consistent with reaction time results indicating that all gestures for a brief unit of action must be programmed prior to initiation of any part of the movement. Additional reaction time results related to initiation of longer responses are consistent with processing in terms of a sequence of indivisible motor gestalts. Some actions (e.g., many involving coordination of the hands) can be carried out effectively only if represented as a unitary gestalt. Second, a perceptual gestalt is independent of specific sensory receptors, as evidenced by perceptual constancy. In a similar manner a motor gestalt can be represented independently of specific muscular effectors, thereby allowing motor constancy. Third, just as a perceptual pattern (e.g., a Necker cube) is exclusively structured into only 1 of its possible configurations at any moment in time, processing prior to action is limited to 1 motor gestalt. Fourth, grouping in apparent motion leads to stream segregation in visual and auditory perception; this segregation is present in motor action and is dependent on the temporal rate. We discuss congruence of gestalt phenomena across perception and motor action (a) in relation to a unitary perceptual-motor code, (b) with respect to differences in the role of awareness, and (c) in conjunction with separate neural pathways for conscious perception and motor control. | There is a whole body of research that provides evidence that the motor system plays a crucial role in control- ling as well as perceiving movements. So far a lot of evidence for the interaction of action and perception derives from studies in the visual domain. However, up to now not much is known about the role of acoustic information. The focus of this review is to provide an overview regarding the role of the motor system and auditory sense during action perception and motor control. Recent theories and studies that discuss the interaction of perception and action will be reviewed with an emphasis on the use of acoustic information. Empirical evidence derived from behavioral as well as neuroscience re- search using simple as well as whole-body movements will be provided. Additionally, we will provide perspectives re- garding future research questions to bring forward our understanding of the role of acoustic information in the control and perception of actions and its underlying mechanisms. | It is proved, by using topological properties, that when a group automorphism of a locally compact totally disconnected group is ergodic under the Haar measure, the group is compact. The result is an answer for Halmos's question that has remained open for the totally disconnected case. | eng_Latn | 10,625 |
Temporal sensitivity, defined as the reciprocal of the minimum exposure duration required for a grating to be detected, was measured for gratings with constant contrasts in a range of spatial frequencies. Temporal sensitivity functions were found to be given by curves with maximum sensitivity at 0.7 approximately 0.8 C/deg. Two criteria of detection were used: the detection of any change on the screen and the detection of patterns. The difference between temporal sensitivities under the two criteria was large at low spatial frequencies but was small at high spatial frequencies. | Much evidence indicates that humans and other species process large-scale visual information before fine spatial detail. Neurophysiological data obtained with paralyzed eyes suggest that this coarse-to-fine sequence results from spatiotemporal filtering by neurons in the early visual pathway. However, the eyes are normally never stationary: rapid gaze shifts (saccades) incessantly alternate with slow fixational movements. To investigate the consequences of this oculomotor cycle on the dynamics of perception, we combined spectral analysis of visual input signals, neural modeling, and gaze-contingent control of retinal stimulation in humans. We show that the saccade/fixation cycle reformats the flow impinging on the retina in a way that initiates coarse-to-fine processing at each fixation. This finding reveals that the visual system uses oculomotor-induced temporal modulations to sequentially encode different spatial components and suggests that, rather than initiating coarse-to-fine processing, spatiotemporal coupling in the early visual pathway builds on the information dynamics of the oculomotor cycle. | Three experiments show that the magnitude of the unconditioned GSR to tones of equal intensity is largest between 10,000 and 20,000 Hz and is a valid index of the frequency sensitivity of the mouse... | eng_Latn | 10,626 |
Seven experiments are described investigating the effect of high intensity white noise during the visual presentation of words on a number of short-term memory tasks. The findings were: ::: ::: 1In a free recall task recall of items decreased at the highest intensity used (85 dB) compared with a quiet and a 75 dB condition. ::: 2In free recall, recall by category decreased and recall in the original sequence increased in the 75 dB compared with the other two conditions. ::: 3Recall of the position of words in the list increased as noise intensity increased, but only when the learning of position was incidental, not when it was intentional. It is inferred that the effect is due to direction of attention or change in the learning strategy. ::: 4Recall of the original sequence (as shown by the ability to give in response to a word from a list the word which had followed it in the original list) was superior in the 75 dB compared with the other two conditions, but only when recall of the second word was required, not when it had to be recognized among all the items from the original list. It is argued that this can be explained if noise intensity affects the strength of traces and hence the interconnexions established between them, on which retrieval depends. ::: ::: ::: The results for position learning are compatible with the theories of Hockey & Hamilton (1970) or Domic (1973), but the results for sequence learning cannot be explained by either of these theories. A final experiment confirmed a prediction from the above theory that when recalling the original sequence, omissions (recalling no word) will decrease and transpositions (giving the wrong word) will increase as noise level increases. | Immediate memory for visually presented verbal material is disrupted by concurrent speech, even when the speech is unattended and in a foreign language. Unattended noise does not produce a reliable decrement. These results have been interpreted in terms of a phonological short-term store that excludes non-speechlike sounds. The characteristics of this exclusion process were explored by studying the effects of music on the serial recall of sequences of nine digits presented visually. Experiment 1 compared the effects of unattended vocal or instrumental music with quiet and showed that both types of music disrupted STM performance, with vocal music being more disruptive than instrumental music. Experiment 2 attempted to replicate this result using more highly trained subjects. Vocal music caused significantly more disruption than instrumental music, which was not significantly worse than the silent control condition. Experiment 3 compared instrumental music with unattended speech and with noise modulated in... | The phenomenon of job satisfaction generates high costs for organizations, as it impacts on the processes of selection, training, and motivation of their human resources, while affecting the produc... | eng_Latn | 10,627 |
Approaches to predictably control neural oscillations are needed to understand their causal role in brain function in healthy and diseased states and to advance the development of neuromodulation therapies. In this article, we present a neural control approach and optimization framework to actively suppress or amplify neural oscillations observed in local field potentials in real-time by using electrical stimulation. The rationale behind this control approach is that neural oscillatory activity evoked by electrical pulses can suppress or amplify spontaneous oscillations via destructive or constructive interference when stimulation pulses are continuously delivered at precise phases of these oscillations in a closed-loop scheme. We demonstrate that this technique, referred to as phase-locked brain stimulation, is capable of actively suppressing or amplifying 8-17 Hz oscillations in the subthalamic nucleus of two parkinsonian nonhuman primates, which exhibited a robust increase in oscillatory power in this frequency band following administration of the neurotoxin MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine). | Currently employed strategies for therapeutic brain stimulation take a static approach to determining stimulation parameters. However, it is well understood that brain states fluctuate over time, depending for instance upon differing behavioural or disease states. Here, we characterize the impact of changes in connectivity upon the emergence of rhythmic neural activity in the circuits formed by the cortex, basal-ganglia, and thalamus. Importantly, we show how the efficacy of interaction with these rhythms via phase-specific stimulation is highly dependent upon the current network state. We take a computational approach to do this, modelling the population activity of the cortico-basal ganglia-thalamic circuit and fitting model parameters to match the spectral features of empirical data obtained from a 6-OHDA lesioned rat model of Parkinson’s disease. Using this fitted model, we then dissect the role of the circuit’s multiple loops in the maintenance of subcortical beta rhythms and their synchronization. We show that a competition of cortical and striato-pallidal inputs to the subthalamic nucleus, a main input hub of the basal-ganglia, determines the frequency, amplitude, and timing of beta band (14-30 Hz) activity. In addition, we demonstrate how the efficacy of cortical inputs in modulating ongoing subthalamic beta activity is dependent upon their relative phase alignment- with their precise effects in turn determined by the connectivity state of the network. These results inform our understanding of: (a) how alterations in circuit connectivity can lead to the emergence of pathologically amplified rhythms; (b) how precisely timed phasic stimulation can be leveraged to modulate aberrant brain activity; and (c) how effective stimulation parameters depend on the “connectivity state” of the circuit; highlighting the importance of incorporating an estimation of brain state in the determination of optimum stimulation parameters. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 10,628 |
Summary We utilized the high temporal resolution, whole head coverage and novel analysis methodology of magnetoencephalography (MEG) to record the dynamics of cerebellar activation during focal motor seizures. We analyzed ictal MEG data from a four-year old using an event-related beamformer to localize and display ictal changes over the motor cortex and cerebellum. Contralateral activation of the cerebellum was seen 14 s after MEG ictal onset over the motor cortex. These findings represent the first indication of ictal activity within the cerebellum in humans, measured non-invasively with MEG. | The functional electrophysiology of the human cerebellum remains poorly characterized. Existing knowledge originates primarily from lesion studies and increasingly from hemodynamic measures such as functional magnetic resonance imaging, along with some evidence in recent years from transcranial magnetic stimulation. In this context, we revisit the few existing records of intracranial recordings from the human cerebellum, and uncover additional little-known reports { three from the Soviet Union, published in Russian between 1949-1951, and one from Belgium, published in French in 1964. These studies together demonstrate electrical rhythms of the human cerebellar cortex at frequencies as high as 250 Hz, including task-related modulations. A reanalysis of their electrode traces with state-of-the-art spectral analysis techniques conrm the reported frequency bands, and showed that these modulations were sustained for 100-200 ms. These remarkable observations from the early ages of intracranial mapping of the human brain are in line with recent electrophysiological studies of oscillations in the rodent cerebellum as well as magnetoencephalographic ndings in humans. Time-frequency analyses have provided valuable insight into the function of cerebral cortex, and may prove even more critical for the diering neurophysiology of the cerebellum. We contend that these insights will be invaluable to bridge the role of oscillatory networks in the cerebellum with those of cerebral cortex in mediating perception, action, and cognition and to investigate possible cerebellar involvement in neurological dysfunction. Highlights - The functional electrophysiology and spectral prole of the human cerebellum remains unclear - Recent animal LFP literature demonstrate the cerebellum produces high frequency oscillations - We review the exceptionally rare reports of intracranial EEG from the human cerebellum - Previously uncited studies in French and Russian demonstrate task-related oscillatory modulations up to 250 Hz - We discuss implications for noninvasive detection of cerebellar oscillations with MEG and EEG | MLL1 regulates circadian promoters by depositing H3K4 trimethyl marks, whose levels are also modulated by the NAD+-dependent deacetylase SIRT1. SIRT1 is now shown to promote circadian deacetylation of MLL1, thus affecting MLL1's methyltransferase activity. | eng_Latn | 10,629 |
Ss were presented two stimuli of equal duration separated in time. The parrs of stimuli were vibrotactile, auditory, or visual. The Ss adjusted the time between the two stimuli to be equal to the duration of the first stimulus. The results show that for stimulus durations ranging from 100 to 1,200 msec, Ss set the tune between the two stimuli too long and by a constant amount. For vibrotactfle stimuli, the constant was 596 msec; for auditory stimuli, 657 msec; and for visual stimuli, 436 msec. Changing the intensity of the vibrotactile stimuli did not change the size of the constant error. When Ss were presented two tones with a burst of white noise between the tones and adjusted the duration of the white noise to be equal to the duration of the first tone, the white noise was not adjusted too long by a constant amount. The results suggest that there is a constant error in the perception of unfilled relative to filled temporal intervals. | There is ample literature on the influence of nontemporal variables on temporal properties of events (Allan, 1979). In the present research, it was hypothesised the influence of the vertical segregation of an auditory event on the global duration of the sequences. Two experiments were carried out in which the method of adjustment was used. In the first experiment the stimuli were sequences of three elements. Results demonstrated that the stimulus onset asychrony-within (SOA-within) decreases when an “empty” interval is placed between two sounds. In the second experiment, a white noise was placed between or after two sounds. Data analysis showed a significant reduction of perceptual duration in sequences with vertical segregation of the white noise. These results suggest that temporal dimension of the sequences is related to the perceptual grouping of the auditory events. | ABSTRACTUNC-45A is an ubiquitously expressed protein highly conserved throughout evolution. Most of what we currently know about UNC-45A pertains to its role as a regulator of the actomyosin system... | eng_Latn | 10,630 |
Cortical neurons that initially extract motion signals have small receptive-fields, and narrow orientation- and bandpass-spatial-frequency tuning. Accurate extraction of the veridical motion of objects typically requires the global pooling of the output of multiple local-motion units across orientation and space. We examined whether the narrow spatial-frequency tuning present at the local-motion level is preserved at the global-motion-pooling stage. Stimuli consisted of numerous drifting Gabor or plaid elements that were either signal (carrier drift-speed consistent with a given global-motion vector) or noise (drift speed consistent with a random, noise vector). The carrier spatial-frequencies of the signal and noise elements were independently varied. Regardless of the frequency of the signal elements, broad low-pass masking functions were obtained for both Gabor (one-dimensional) and Plaid (two-dimensional) conditions when measuring the threshold signal ratio for identification of the global-motion direction. For the Gabor stimuli, this pattern of results was also independent of the relative orientations of the signal and noise elements. These results indicate that in the global-motion pooling of one-dimensional and two-dimensional signals, local-motion signals of all spatial frequencies are pooled into a single system that exhibits broadband, low-pass tuning. | The problem of processing visual motion is underconstrained---many possible real world motions are compatible with any given dynamic retinal image. Recent psychophysical and neurophysiological experiments have shown that the primate visual system's normally veridical interpretation of moving patterns is attained through utilization of image segmentation cues unrelated to motion per se. These findings challenge notions of modularity in which it is assumed that the processing of specific scene properties, such as motion, can be studied in isolation from other visual processes. We discuss the implications of these findings with regard to both experimental and computational approaches to the study of visual motion. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 10,631 |
An orientation experiment was carried out in a spatially immersive virtual environment. The task of subjects was to navigate with 6 degrees of freedom flying method through a predefined route guided by visual cues. Simultaneously they should keep the model oriented in upright position as well as possible. In the experiment we had three different implementations of auditory artificial horizon, and for the reference the subjects accomplish the task also without the auditory support. According to the results the auditory artificial horizon helps subjects to keep the model oriented during the task. | Spatial auditory displays have received a great deal of attention in the community investigating how to present information through sound. This short commentary discusses our 2001 ICAD paper (Shinn-Cunningham, Streeter, and Gyss), which explored whether it is possible to provide enhanced spatial auditory information in an auditory display. The discussion provides some historical context and discusses how work on representing information in spatial auditory displays has progressed over the last 5 years. | ABSTRACTUNC-45A is an ubiquitously expressed protein highly conserved throughout evolution. Most of what we currently know about UNC-45A pertains to its role as a regulator of the actomyosin system... | eng_Latn | 10,632 |
Electrical stimulation of spiral ganglion neurons in deafened cochlea, via a cochlear implant, provides a means of investigating the effects of the removal and subsequent restoration of afferent input on the functional organization of the primary auditory cortex (AI). We neonatally deafened seventeen cats before the onset of hearing, thereby abolishing virtually all afferent input from the auditory periphery. In seven animals, the auditory pathway was chronically reactivated with environmentally-derived electrical stimuli presented via a multi-channel intracochlear electrode array implanted at eight weeks of age. Electrical stimulation was provided by a clinical cochlear implant that was used continuously for periods of up to seven months. In ten long-term deafened cats and three age-matched normal hearing controls, an intracochlear electrode array was implanted immediately prior to cortical recording. We recorded from a total of 812 single unit and multi-unit clusters in AI of all cats as adults, using a combination of single tungsten and multi-channel silicon electrode arrays. The absence of afferent activity in the long-term deafened animals had little effect on the basic response properties of AI neurons but resulted in complete loss of the normal cochleotopic organization of AI. This effect was almost completely reversed by chronic reactivation of the auditory pathway via the cochlear implant. We hypothesize that maintenance or re-establishment of a cochleotopically organized AI by activation of a restricted sector of the cochlea – as demonstrated in the present study - contributes to the remarkable clinical performance observed among human patients implanted at a young age. | In multichannel cochlear implants (CIs), current is delivered to specific electrodes along the cochlea in the form of amplitude-modulated pulse trains, to convey temporal and spectral cues. Our previous studies have shown that focused multipolar (FMP) and tripolar (TP) stimulation produce more restricted neural activation and reduced channel interactions in the inferior colliculus (IC), compared to traditional monopolar (MP) stimulation, suggesting that focused stimulation could produce better transmission of spectral information. The present study explored the capability of IC neurons to detect modulated CI stimulation with FMP and TP stimulation, compared to MP stimulation. The study examined multiunit responses of IC neurons in acutely deafened guinea pigs by systematically varying the stimulation configuration, modulation depth and stimulation level. Stimuli were sinusoidal amplitude-modulated pulse trains (carrier rate of 120 pulses/sec). Modulation sensitivity was quantified by measuring modulation detection thresholds (MDTs), defined as the lowest modulation depth required to differentiate the response of a modulated stimulus from an unmodulated one. While MP stimulation showed significantly lower MDTs than FMP and TP stimulation (p-values<0.05) at stimulation ≤ 2 dB above threshold, all stimulation configurations were found to have similar modulation sensitivities at 4 dB above threshold. There was no difference found in modulation sensitivity between FMP and TP stimulation. The present study demonstrates that current focusing techniques such as FMP and TP can adequately convey amplitude modulation, and are comparable to MP stimulation especially at higher stimulation levels, although there may be some trade-off between spectral and temporal fidelity with current focusing stimulation. | MLL1 regulates circadian promoters by depositing H3K4 trimethyl marks, whose levels are also modulated by the NAD+-dependent deacetylase SIRT1. SIRT1 is now shown to promote circadian deacetylation of MLL1, thus affecting MLL1's methyltransferase activity. | eng_Latn | 10,633 |
Harmonic complex tones are a particularly important class of sounds found in both speech and music. Although these sounds contain multiple frequency components, they are usually perceived as a coherent whole, with a pitch corresponding to the fundamental frequency (F0). However, when two or more harmonic sounds occur concurrently, e.g., at a cocktail party or in a symphony, the auditory system must separate harmonics and assign them to their respective F0s so that a coherent and veridical representation of the different sounds sources is formed. Here we review both psychophysical and neurophysiological (single-unit and evoked-potential) findings, which provide some insight into how, and how well, the auditory system accomplishes this task. A survey of computational models designed to estimate multiple F0s and segregate concurrent sources is followed by a review of the empirical literature on the perception and neural coding of concurrent harmonic sounds, including vowels, as well as findings obtained using single complex tones with mistuned harmonics. | It is unclear whether the perceptual segregation of a mistuned harmonic from a periodic complex tone depends specifically on harmonic relations between the other components. A procedure used previously for harmonic complexes [W. M. Hartmann et al., J. Acoust. Soc. Am. 88, 1712-1724 (1990)] was adapted and extended to regular inharmonic complexes. On each trial, subjects heard a 12-component complex followed by a pure tone in a continuous loop. In experiment 1, a mistuning of +/- 4% was applied to one of the components 2-11. The complex was either harmonic, frequency shifted, or spectrally stretched. Subjects adjusted the pure tone to match the pitch of the mistuned component. Near matches were taken to indicate segregation, and were almost as frequent in the inharmonic conditions as in the harmonic case. Also, small but consistent mismatches, pitch shifts, were found in all conditions. These were similar in direction and size to earlier findings for harmonic complexes. Using a range of mistunings, experiment 2 showed that the segregation of components from regular inharmonic complexes could be sensitive to mistunings of 1.5% or less. These findings are consistent with the proposal that aspects of spectral regularity other than harmonic relations can also influence auditory grouping. | Every function of n inputs can be efficiently computed by a complete network of n processors in such a way that: If no faults occur, no set of size t n /2 of players gets any additional information (other than the function value), Even if Byzantine faults are allowed, no set of size t n /3 can either disrupt the computation or get additional information. Furthermore, the above bounds on t are tight! | eng_Latn | 10,634 |
A simple model is considered for an open system consisting of an aggregation of magnetic particles (like greigite) in the presence of a magnetic field (H), and interacting linearly with a bath of 3D harmonic oscillators. Using the Feynman-Vernon formalism, as given in Weiss (termed FVW), the time-evolved reduced density matrix (after eliminating the bath d.o.f.'s), is examined for environmental decoherence as defined in the FVW formalism. While decoherence is usually positive for most two-way couplings with the enviroment, it is found that a $three-way$ interaction involving the system plus bath plus H-field all together, can facilitate a $reversal$ of sign of this quantity! This may have implications for quantum coherence based phenomena on the origins of life. | Cairns-Smith (2008) has argued for a pre-Darwinian era, with a simpler basis for life's functioning via primitive "crystal genes" (information transfer, kinetic control on metabolic reactions). At the other extreme, guided by the structural similarity of clusters in early-evolved enzymes to iron-sulphide minerals like greigite, the hydrothermal mound scenario of Russell and coworkers (1994) presents how non-equilibrium forces rooted in geochemistry could be extrapolated to understand the metabolic functioning of living systems. The informational vs metabolic aspects of life in these respective scenarios can be linked together via a framboid-based theory of Sawlowicz (2000), as these assemblies typically form in colloidal environments. In this background, we consider the ramifications of a magnetic rock field on the mound scenario, asking if soft matter assemblies are compatible with a coherent order. | The construct validity of the Verbal Comprehension. Perceptual Organization, and Freedom from Distractibility factor scores was examined in a sample of school-aged referred children. Examination of correlations between factor scores and neuropsychological and achievement tests generally supported the construct validity of the factors. The Verbal Comprehension factor was associated with verbal, quantitative, and concept-formation abilities. The Perceptual Organization factor was related to nonverbal concept formation, tactual performance, and visual attention. The Freedom from Distractibility factor demonstrated a complex pattern of correlations and appeared to reflect a range of abilities including quantitative, language, attentional, and concept formation. | eng_Latn | 10,635 |
Electrical stimulation of the auditory nerve is being investigated as a way to provide information useful for speech communication in the profoundly deaf. Single-channel systems that tend to stimulate all fibers alike have had little success in achieving this goal. Multichannel systems that allow excitation of more complex temporal-spatial patterns of activity are now being introduced. Psychoacoustical experiments providing evidence that electrodes of a multichannel implant are able to separately excite distinct groups of neural elements are reviewed. New results using multiple electrodes and speech-like stimuli are presented. The synthetic stimuli were vowels (/a/, /i/, /u/) and consonant-vowel (CV) syllables (/ba/, /da/, /ga/, /ta/). Vowels and CV syllables were presented in an AXB discrimination task with different signal processing schemes and electrode configurations. A four-channel, frequency-selective system produced faultless discrimination scores for all stimuli and spontaneous recognition of the vowels while the scores for the single-channel system were generally much lower. Although understanding free running speech by the profoundly deaf does not seem imminent, the results presented indicate that the multichannel system tested shows more promise of approaching this goal than the single-channel scheme. | The intelligibility of a 16-item consonant set was assessed for 10 patients who use the Symbion four-channel cochlear implant. The patients were selected on the basis of «good» speech recognition scores. For each patient, consonant intelligibility was assessed when his/her processor was configured to pass from one to four channels of information. The results suggest, most generally, that two channels, one low frequency and one high frequency, provide most of the information about consonant identity | MLL1 regulates circadian promoters by depositing H3K4 trimethyl marks, whose levels are also modulated by the NAD+-dependent deacetylase SIRT1. SIRT1 is now shown to promote circadian deacetylation of MLL1, thus affecting MLL1's methyltransferase activity. | eng_Latn | 10,636 |
An external matrix field problem generalizing a discretized bosonic string field theory in (−2) dimensions is solved and analyzed in the double scaling limit. By an appropriate choice of the external field one can reach new multicritical regimes. A remarkable feature of a pth multicritical point is the absence of the conbributions to the main singularity for the genera which are not multiples of p. | Recently, D. Wang has devised a new contour integral based method to simplify certain matrix integrals. Capitalizing on that approach, we derive a new expression for the probability density function (p.d.f.) of the joint eigenvalues of a complex non-central Wishart matrix with a rank-1 mean. The resulting functional form in turn enables us to use powerful classical orthogonal polynomial techniques in solving three problems related to the non-central Wishart matrix. To be specific, for an $n\times n$ complex non-central Wishart matrix $\mathbf{W}$ with $m$ degrees of freedom ($m\geq n$) and a rank-1 mean, we derive a new expression for the cumulative distribution function (c.d.f.) of the minimum eigenvalue ($\lambda_{\min}$). The c.d.f. is expressed as the determinant of a square matrix, the size of which depends only on the difference $m-n$. This further facilitates the analysis of the microscopic limit for the minimum eigenvalue which takes the form of the determinant of a square matrix of size $m-n$ with the Bessel kernel. We also develop a moment generating function based approach to derive the p.d.f. of the random variable $\frac{\text{tr}(\mathbf{W})}{\lambda_{\min}}$, where $\text{tr}(\cdot)$ denotes the trace of a square matrix. This random quantity is of great importance in the so-called smoothed analysis of Demmel condition number. Finally, we find the average of the reciprocal of the characteristic polynomial $\det[z\mathbf{I}_n+\mathbf{W}],\; |\arg z|<\pi$, where $\mathbf{I}_n$ and $\det[\cdot]$ denote the identity matrix of size $n$ and the determinant, respectively. | The relation of the individual speech-in-noise performance differences in cochlear implant (CI) users to underlying physiological factors is currently poorly understood. This study approached this research question by a step-wise individualization of a computer model of speech intelligibility mimicking the details of CI signal processing and some details of the physiology present in CI users. Two factors, the electrical field spatial spread and internal noise (as a coarse model of the individual cognitive performance) were incorporated. Internal representations of speech-in-noise mixtures calculated by the model were classified using an automatic speech recognizer backend employing Hidden Markov Models with a Gaussian probability distribution. One-dimensional electric field spatial spread functions were inferred from electrical field imaging data of 14 CI users. Simplified assumptions of homogenously distributed auditory nerve fibers along the cochlear array and equal distance between electrode array and nerve tissue were assumed in the model. Internal noise, whose standard deviation was adjusted based on either anamnesis data, or text-reception-threshold data, or a combination thereof, was applied to the internal representations before classification. A systematic model evaluation showed that predicted speech-reception-thresholds (SRTs) in stationary noise improved (decreased) with decreasing internal noise standard deviation and with narrower electric field spatial spreads. The model version that was individualized to actual listeners using internal noise alone (containing average spatial spread) showed significant correlations to measured SRTs, reflecting the high correlation of the text-reception threshold data with SRTs. However, neither individualization to spatial spread functions alone, nor a combined individualization based on spatial spread functions and internal noise standard deviation did produce significant correlations with measured SRTs. | eng_Latn | 10,637 |
This article focuses on the use of combined electroencephalography and functional MR imaging (EEG-fMRI) as a tool to investigate the relationship between epileptiform discharges and hemodynamic changes. Essentially an functional MR imaging technique, EEG-fMRI can provide whole-brain maps of those changes, and hence has the potential to give a new form of localizing information on the generators of epileptiform discharges. The author briefly reviews the problem of localization in epilepsy and, in particular, the roles of EEG and functional MR imaging, and then discusses the motivations for combined EEG and functional MR imaging experiments, the possible ways in which the data can be acquired, and the associated technical requirements. This is followed by a presentation of the analysis methods used and a discussion of the applications of EEG-fMRI in epilepsy. An overview and discussion of the main findings and ideas for future research is also provided. | In a case where tracking control is carried out by a lens actuator in performing a tracking pull-in operation in which tracking control is started in the state where tracking control is out of operation, the tracking control circuit brings control into stable tracking control by moving the light spot onto a groove on the optical disc. After that, when tracking onto a land is needed, the tracking control circuit moves the light spot onto the land. This enables a pull-in action toward a stable tracking operation. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 10,638 |
Behavioral investigations of Belgian Waterslager canaries (BWCs) have demonstrated a congenital hearing impairment that primarily affects high frequencies. Research into the surface anatomy of the basilar papilla of these birds has pointed to the hair cells as the site of the lesion. Given that the basilar papilla and the vestibular organs both develop from the otocyst, we were interested in ascertaining whether the vestibular sensory epithelia also displayed abnormal hair cells. The inner ear of adult BWCs was examined by scanning electron microscopy. As expected, hair cells in the basilar papilla of BWCs were abnormal. As for the vestibular parenchyma, abnormal hair cells were detected in only one structure: the sacculus. Morphological abnormalities of the cochlea and sacculus are pathognomonic signs of Scheibe's dysplasia, the most common inner ear defect associated with congenital hearing loss. Our results suggest that BWCs are afflicted by this genetic disorder. | Belgian Waterslager canaries (BWC), bred for a distinct low-pitched song, have an inherited high-frequency hearing loss associated with hair cell abnormalities. Hair cells near the abneural edge of the papilla, which receive primarily efferent innervation in normal birds, are among the most severely affected. These cells are thought to support nonlinear active processing in the avian ear, though the mechanisms are poorly understood. Here we present psychophysical evidence that suggests degraded active processing in BWC compared to normal-hearing non-BWC. Critical ratios, psychophysical masking patterns and phase effects on masking by harmonic complexes were measured in BWC and non-BWC using operant conditioning procedures. Critical ratios were much larger in BWC than in non-BWC at high frequencies. Psychophysical tuning curves derived from the masking patterns for BWC were broadened at high frequencies. BWC also showed severely reduced phase effects on masking by harmonic complexes compared to non-BWC. As has been hypothesized previously for hearing-impaired humans, these results are consistent with a loss of active processing mechanisms in BWC. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 10,639 |
Heterogeneous Asymmetric Dynamic Conditional Correlation Model with Stock Return and Range | The paper considers the return and range model with dynamic conditional correlations (DCC). The paper suggests the new speci cations for the asymmetric effects on log-volatilities and dynamic correlations, combined with long-run dependences. The new DCC model can be estimated by the quasi-maximum likelihood method. The empirical analysis on Nikkei 225, Hang Seng and Straits Times indices shows the daily, weekly and monthly pattern of the asymmetric effects. For the period including the global nancial crisis, the new DCC model provides plausible one-step-ahead forecasts of the VaR thresholds, and yields positive economic values of switching from other DCC models. | Since about twenty years, the otoneurology functional exploration possesses auditory tool to analyze objectively the state of the nervous conduction of additive pathway. In this paper, we present a new classification approach based on the Hidden Markov Models (HMM) which used to design a Computer aided medical diagnostic (CAMD) tool that asserts auditory pathologies based on Brain-stem Evoked Response Auditory based biomedical test, which provides an effective measure of the integrity of the auditory pathway. Case study, experimental results and comparison with a conventional neural networks models have been reported and discussed. | eng_Latn | 10,640 |
Electric and Magnetic Field Strengths in the Open and in Shielded Rooms in the ULF- to LF-Zone | In this chapter the Centimeter-Second-Ampere-Volt system (cm-s-A-V), used conventionally in electrodynamics is employed. The Maxwell Equations are thus written: ::: ::: $${\rm Curl }\mathop {\rm H}\limits^ \to = {\rm \sigma E + \varepsilon }{{\partial \mathop {\rm E}\limits^ \to } \over {\partial {\rm t}}}$$ ::: ::: (1) ::: ::: ::: ::: $${\rm Curl }\mathop {\rm E}\limits^ \to = - {\rm \mu }{{\partial \mathop {\rm H}\limits^ \to } \over {\partial {\rm t}}} = - {{\partial \mathop{\rm B}\limits^ \to } \over {\partial {\rm t}}}$$ ::: ::: (2) ::: ::: The arrows over E and H are to express the vector-nature of field strength. | This review concerns physiological studies of the neural mechanisms of sound localization. We will describe the responses of neurons in the central auditory system to sounds presented dichotically or in the free field. The free‐field studies have sought to define the spatial receptive fields of these neurons and their topographical organization in the brain. Although the functional aspects of these cells are most effectively addressed by free‐field methods, the mechanism by which these cells accomplish this task is best studied using dichotic stimulation. Influenced by the duplex theory and human psychoacoustics, the major focus of neurophysiological studies using dichotic stimulation has been the investigation of the effects of varying interaural phase and intensity. The neuronal responses to these stimuli and their relationship to the frequency domain will be discussed with a particular emphasis on the concept of characteristic delay. In an attempt to define the underlying circuitry, we will compare the... | eng_Latn | 10,641 |
Neural Antecedents of Spontaneous Voluntary Movement: A New Perspective | Fifty years ago, Kornhuber and Deecke first reported their discovery of the Bereitschaftspotential [1], or cortical ‘readiness potential’ (RP) (see Glossary), a slow build-up of scalp electrical potential preceding the onset of subjectively spontaneous voluntary movements (SVMs). The RP was interpreted as ‘the electro-physiological sign of planning, preparation, and initiation of volitional acts’ [2], implicitly presumed to reflect the consequence of a decision process in the brain. Then, in the early 1980s, Benjamin Libet found that the onset of the RP precedes subjective estimates of the time of the conscious ‘urge’ to move by 300 ms or more [3] – a result that has since been confirmed at the single-neuron level [4]. | We find a general formula for the distribution of time averaged observables for weakly non-ergodic systems. Such type of ergodicity breaking is known to describe certain systems which exhibit anomalous fluctuations, e.g. blinking quantum dots and the sub-diffusive continuous time random walk model. When the fluctuations become normal we recover usual ergodic statistical mechanics. Examples of a particle undergoing fractional dynamics in a binding force field are worked out in detail. We briefly discuss possible physical applications in single particle experiments. | eng_Latn | 10,642 |
Intensity coding in the auditory nerve | The mechanisms by which intensity is coded in the discharges of single auditory nerve fibers have not been fully determined, although hypotheses involving changes in discharge rate fiber recruitment have been proposed. In this paper, we will review the characteristics of auditory nerve fiber responses that may code for loudness growth and intensity discrimination. Psychophysical dynamic ranges, which are in excess of 100 dB, cannot be accounted for by the 30–40 dB dynamic range displayed by the majority of individual auditory nerve fibers. Recently, however, a subpopulation of auditory nerve fibers has been identified within each characteristic frequency (CF) region. The characteristics of these fibers include low spontaneous activities, a wide range (greater than 70 dB) of thresholds, high sensitivities to changes in intensity (i.e., steep rate‐intensity functions), and dynamic ranges as high as 60–70 dB. These results indicate that the responses of fibers having similar CFs and spanning the normal range... | Individual nuclear spins in diamond can be optically detected through hyperfine couplings with the electron spin of a single nitrogen-vacancy (NV) center; such nuclear spins have outstandingly long coherence times. Among the hyperfine couplings in the NV center, the nearest neighbor 13C nuclear spins have the largest coupling strength. Nearest neighbor 13C nuclear spins have the potential to perform fastest gate operations, providing highest fidelity in quantum computing. Herein, we report on the control of coherences in the NV center where all three nearest neighbor carbons are of the 13C isotope. Coherence among the three and four qubits are generated and analyzed at room temperature. | eng_Latn | 10,643 |
Rediscovering auditory coherence in phonetic patterns | It has been suggested that phonetic percepts are achieved by invoking the use of a specialized speech mode in processing the acoustic signal [A. M. Liberman and I. G. Mattingly, Cognition 21, 1–36 (1985)]. In support of this contention are demonstrations of differences between speech and nonspeech perception of the same set of stimuli. For example, subjects provided with speech labels (/ra/ and /la/) for categorizing a three‐formant tone analog continuum that varied in only the F3 transition dimension demonstrated categorical perception, while those subjects provided with nonspeech labels did not [C. T. Best et al., Percept. Psychophys. 45, 237–250 (1989)]. However, an alternative explanation is that the nonspeech group's poor categorization performance may have resulted from a failure to provide adequate training. In the present study, providing more extensive training resulted in steep identification functions for both speech and nonspeech groups. In addition, peaked discrimination functions were found ... | What is the best characterization of mergers and acquisitions time-series? The traditional response is that mergers occur in "waves." I estimate a two-state, Markov switching-regime model which should capture wave structure if it is present in the data. Linear and nonlinear diagnostics tests suggest that the switching regime model fits the data well, and better than ARIMA models. Said differently, the underlying pattern in the M&A data can be characterized by dichotomous shifts between high and low levels of activity. In addition, objective inferences about the precise dates for these waves are available through a nonlinear filter. Copyright 1992 by John Wiley & Sons, Ltd. | eng_Latn | 10,644 |
A Normative Model of Attention: Modulation of Neural Response | When a sensory stimulus is encoded in a lossy fashion for ef- ficient transmission, there are necessarily tradeoffs between the represented fidelity of various aspects of the input pat- tern. In the model of attention presented here, a top-down signal informs the encoder of these tradeoffs. Given an en- semble of input patterns and tradeoff requirements, our sys- tem can learn to encode its inputs optimally. This general model is instantiated in a simple network: an autoencoder with a bottleneck, innervated by a top-down attentional sig- nal, trained using backpropagation. The only information the encoder receives concerning the semantics of the top-down attentional signal is from the optimization criterion, which penalizes the system more heavily for errors made near a simple attentional spotlight. The modulation of neural activ- ity learned by this model qualitatively matches that measured in animals during covert visual attention tasks. | I read with interest the paper by McNamara et al. ([1][1]), which supports the findings of our previous report of a logistic model that identifies factors associated with restoration of normal ventricular function in this patient population ([2][2]). As we noted in that paper, which indeed | eng_Latn | 10,645 |
Auditory brainstem response in FMR-1 knockout mice | Objective To identify Fmr1 knockout mice,the ABR threshold was examined and compared to wild type at different ages.Methods Experimented animals FVB strain mice,Fmr-1 knockout(FMR-/-) and their wild type(FMR+/+) counterparts were used.They were genotyped by PCR to confirm the lack of the FMR-1 gene.Experimented animals were divided into 5 groups according to their genotype and age: KO group(3weeks,4weeks,6weeks,8weeks,10weeks) and WT group(3weeks,4 weeks,6 weeks,8 weeks,10 weeks),each group has 30 FVB mouse.ABR was detected after anesthesia.Results ABR threshold of KO group(3 weeks,4 weeks) was increased remarkably compared with the control group(P0.01).There were no differernce between KO group and WT group in 6 weeks,8w and 10 weeks,respectively(P0.05).Conclusion ABR threshold has significantly difference between immature KO mice and immature WT mice.ABR threshold has no significantly difference between mature KO mice and mature WT mice. | This paper presents an autonomous symbolic indoor tracking system for ubiquitous computing applications. The proposed approach is based upon the assumption that topologically discriminable information can be assigned explicitly to different spaces of a given indoor environment. On that assumption, continuous time-of-flight (ToF) measurements of echo-bursts obtained from four orthogonally and coplanarly mounted ultrasonic transducer are used to learn a stochastic room model. While the individual acoustic representation of space is captured using Gaussian mixture densities, the stochastic variabilities in the moving direction of a person are modeled by hidden-Markov-models (HMMs). Experiments within a six room environment resulted in a room recognition rate of 92.21% and a room sequence recognition rate of 66.00% without any pre-fixed devices. | eng_Latn | 10,646 |
One example of an auditory illusion is a Shepard tone . | A Shepard tone is an auditory illusion . | `` Hapax legomena '' are quite common , as predicted by Zipf 's law , which states that the frequency of any word in a work ( corpus ) is inversely related to its rank in the frequency table . | eng_Latn | 10,647 |
PREDICTION OF PEAK VELOCITY OF BLASTING VIBRATION BASED ON NEURAL NETWORK | Because of the influence of charge parameters and rock properties,it is difficult to accurately predicate the vibration characteristics in the engineering blasting.Based on the 20 meters platform and nuclear island blasting excavation monitoring in the second phase of Linga′o nuclear power station,Guangdong Province,the artificial neural network is adopted to predict the peak velocity of blasting vibration.In the analysis,the charge hole diameter,distance,and depth,column distance between charge holes,line of least resistance,maximum charge of single hole,maximum charge weight per delay interval,clogging depth of hole,total charge,magnitude of relative altitude and explosive distance are considered to establish the back-propagation neural network model.The prediction results through artificial neural network are more accurate than those of Sadaovsk formula. | Abstract The effects of lesions in the ventro-medial nucleus of the hypothalamus, the septal region or the lateral hypothalamic area on flinch and jump shock thresholds and on whole brain norepinephrine concentrations was investigated. Lesion-induced changes in behavior were associated with alterations in both flinch and jump shock thresholds. Also, a decrease in norepinephrine concentrations occurred within the brains of hypothalamically-lesioned rats, the effect being greater in the rats with lesions of the ventro-medial nucleus. Implications and possible mechanisms of action are discussed. | yue_Hant | 10,648 |
Impaired sensorimotor gating of the acoustic startle response in the prodrome of schizophrenia | ackground: Schizophrenia patients exhibit impairment in prepulse inhibition (PPI) of the acoustic startle response (ASR), which is ommonly interpreted as a sensorimotor gating deficit. To date, it is unclear when these gating deficits arise. Results of animal studies and ome human data suggest that PPI deficits are in part genetically determined, such that gating deficits could be present before the onset of full-blown psychosis. To test this assumption, we investigated PPI of ASR in individuals with prodromal symptoms of schizophrenia and atients with first-episode schizophrenia. | The focus is on the establishment of a Z-source small-signal model to analyze the impact of the inductance and capacitance parameters that may have on system performance. The results showed that larger capacitance and inductance parameters were conducive to the stability of the system, but the zero point of the transfer function was closer to the origin point, leading to the deterioration in the dynamic performance. Based on the analysis of the conventional SVPWM, the SVPWM control mode was introduced for Z-source inverter, with a particular focus on the pass-through segmentation SVPWM control, plus the derived constraints relationship between the modulation factor M and the passthrough duty cycle d. | eng_Latn | 10,649 |
Effect of ceria doping on random-field-related polarization reversal in strontium barium niobate ceramics | Polarization reversal has been investigated in undoped and Ce3+-doped Sr0.5Ba0.5Nb2O6 in terms of a power-law random-field model. The random fields, excess polarization, and the volume contribution to the excess polarization were evaluated and found to be linearly dependent on the concentration of Ce doping. The origin of the random fields arising form Ce doping is discussed. | a reaction-time (RT) experiment was carried out in which five groups consisting of subjects with various degrees of left and right handedness, participated. The words left and right were presented binaurally, one at a time, either to the left or to the right side, implying four presentation modes. The two interfering presentation modes are regarded as Stroop tasks. Two reaction conditions .were applied in separate sessions; 1. reacting to the perceived location, and 2. reacting to the content of the word. ::: ::: With specific hypotheses concerning cerebral dominance for verbal functions in right-handed subjects, but with considerably less clear anticipations with respect to left-handers, we obtained an interaction between side of presentation, Stroop effect and handedness. ::: ::: The results are discussed in terms of the relation between the conceptualization of space and cerebral dominance. | eng_Latn | 10,650 |
Trace tritium removal in China reduced activation ferritic-martensitic steels through thermal desorption with/without hydrogen isotope exchange | Abstract Effective removal of deuterium and tritium accumulated in fusion reactor materials is crucial for practical and safe fusion energy. In this paper, investigations on tritium removal in China Low Activation Martensitic (CLAM) steel and China Low-activation Ferritic (CLF-1) steel through thermal desorption with/without hydrogen isotope exchange have been performed. The results indicate that the tritium radioactivity in CLF-1 steel is higher than that of CLAM steel. The tritium removal efficiency is both less than 50% at 473 K, while significantly improved after introduction of hydrogen, 82.24% for CLAM steel and 70.34% for CLF-1 steel respectively. With the increase of temperature, the tritium removal efficiency can be further improved, however, hydrogen isotope exchange can slightly enhance tritium release at 673 K. In consequence, tritium retained in both steels can be removed effectively at relatively moderate temperature ( | Purpose:To examine white matter abnormalities in band heterotopia (BHT) using diffusion tensor imaging (DTI).Patients and Methods:A 17-year-old female with BHT was scanned and white matter fiber tracts were mapped using three-dimensional DTI-based tractography.Results:Fragmented fibers were found in the patient’s prefrontal lobe and association cortex, most of which were not comparable to healthy controls. Furthermore, fibers in the corpus callosum were sparse, and the majority of the inner white matter fibers were stemmed from heterotopic gray matter.Conclusion:The results suggest that the inner heterotopic gray matter may play some role in brain function and that there is altered fiber organization in the frontal regions of BHT. | eng_Latn | 10,651 |
Infant reaching is truly predictive and based on an inertia-like principle at 6 months of age | IN ORDER TO ASSESS THE ABILITY OF 6-MONTH-OLD INFANTS TO MARE A PRINCIPLED PREDICTION ABOUT THE FUTURE MOTION OF AN OBJECT, 10 SUBJECTS WERE PRESENTED WITH A TOY MOVING ALONG 24 DIFFERENT PATHS OF OBJECT MOTION. EACH OF THESE PATHS MOVED A SMALL TOY ALONG A LINEAR TRAJECTORY AND BRIEFLY WITHIN REACH OF THE SUBJECT (SEE FIGURE). A VIDEO RECORD OF THE INFANTS WAS MADE FROM OVERHEAD AND SIDE POSITIONS, ALLOWING A RECONSTRUCTION OF THE THREE-DIMENSIONAL REACHING MOTIONS OF THEINFANTS. | Objective:To explore the value of brainstem auditory evoked potential(BAEP) for pre- dicting prognosis of comatose patents with intracranial venous sinus thrombosis(IVST).Methods:BA- EPs were detected in 24 comatose patients with ST,and peak latency(PL)of I,Ⅲ,V waves and inter- peak latency(IPL)of I-Ⅲ,Ⅲ-V waves on BAEP were analysed.The clinical manifestations were e- valuated by Glasgow Coma Scale(GCS)simultaneously.Results:PL ofⅢ,V waves were lengthened in 17 cases,Ⅲ,Vwaves disappeared in 7 of the patients.Both the presence and disappearance ofⅢ,V waves were related to the prognosis of comatose patients with IVST.Conclusions:BAEP shoud be valu- able for the prognosis of comatose patients with IVST. | eng_Latn | 10,652 |
Network analysis of nonlinear devices under multi-frequency excitation | This paper describes a measurement technique suitable for characterizing nonlinear microwave devices operating under multi-frequency excitation. A dual six-port network analyzer configured for simultaneous load-pull and source-pull measurement allows the characterization of nonlinear devices under multi-tone excitation, for use as mixers and broadband power amplifiers. The performance of a particular circuit can be optimize as a function of source and load impedances, at each input and output signal frequencies. Measurement results for the MESFET NE 76184, resistive mixer (2.9 to 7.1 GHz) show that a higher performance can be obtained by choosing independently the appropriate termination for input and output frequencies. The experimental results are also useful for the device modelling purposes. > | BACKGROUND ::: The aim of this study was to test the feasibility of using the tail of Macaca mulatta for neurophysiological testing of the peripheral nervous system. ::: ::: ::: METHODS ::: Motor and sensory nerve conduction studies (NCS) of the tail were obtained by surface stimulation and recording. The technique utilized was novel. Unlike other NCS obtained from other peripheral nerves, this technique did not require any special neurophysiological expertise. ::: ::: ::: RESULTS ::: The latency of the motor and sensory response was 2.5 +/- 0.71 and 1.1 +/- 0.27 ms respectively. The amplitude of the motor and sensory response was 8.1 +/- 5.1 mV and 14.6 +/- 9.4 microV respectively. Similar to human beings, there was a statistically significant relationship between age and motor amplitude, motor latency and sensory latency. ::: ::: ::: CONCLUSIONS ::: Based on our results, a relatively simple, reproducible neurophysiological monitoring technique of the peripheral nervous system is possible. | eng_Latn | 10,653 |
Retrograde Cochlear Neuronal Degeneration in Human Subjects | The purpose of this study was to identify the structural changes in the organ of Corti that correlate with retrograde cochlear neuronal degeneration. Thirty-eight temporal bones with excellent histological preparation from 23 subjects having hearing losses caused by cochlear disease were selected for study. Cytohistograms were prepared for inner and outer hair cells, inner and outer pillar cells, inner phalangeal cells, and cochlear neurons. The extent of neuronal degeneration was found to be directly related to the extent of injury to inner pillar cells and inner phalangeal cells, but not to loss of inner or outer hair cells. In most cochleas the loss of dendritic nerve fibers exceeded the loss of cell bodies. The findings support the concept that retrograde neuronal degeneration is initiated by injury to the dendritic nerve fibers, secondary to collapse and/or degeneration of the inner pillar cells and inner phalangeal cells. | Background: Cardiac resynchronization therapy (CRT) has significant nonresponse rates. We assessed whether machine learning (ML) could predict CRT response beyond current guidelines. Methods: We an... | eng_Latn | 10,654 |
Similar neuronal alterations induced by axonal injury and learning in Aplysia | Learning in the marine mollusk Aplysia has been associated with enhanced sensory function, expressed in mechanosensory neurons as (i) decreases in action potential threshold, accommodation, and afterhyperpolarization, and (ii) increases in action potential duration, afterdischarge, and synaptic transmission. These alterations also occur, with a delay, after sensory axons are injured under conditions in which synaptic transmission is severely reduced. The latency and specificity of injury-induced alterations indicate that induction signals are generated at the site of injury and conveyed centrally by axonal transport. Similarities in neuronal modifications support the hypothesis that some memory mechanisms evolved from mechanisms of injury-induced sensory compensation and repair. | Purpose To investigate the hypothesis that vowel production is more variable in adults with acquired apraxia of speech (AOS) relative to healthy individuals with unimpaired speech. Vowel formant fr... | eng_Latn | 10,655 |
Kinds of stimuli that you can run fast? | List three stimuli that will make you run fastwrite the sense organs that will receive and avt on the message? | Does your pulse race when scared? | eng_Latn | 10,656 |
What do neuron use to maintain its potential? | What particular kind of neuron fires when you observe someones behavior? | Why was Napeleon sent to Elba? | eng_Latn | 10,657 |
What is the typical speed that axons send their electrical signals? | The brains of all species are composed primarily of two broad classes of cells: neurons and glial cells. Glial cells (also known as glia or neuroglia) come in several types, and perform a number of critical functions, including structural support, metabolic support, insulation, and guidance of development. Neurons, however, are usually considered the most important cells in the brain. The property that makes neurons unique is their ability to send signals to specific target cells over long distances. They send these signals by means of an axon, which is a thin protoplasmic fiber that extends from the cell body and projects, usually with numerous branches, to other areas, sometimes nearby, sometimes in distant parts of the brain or body. The length of an axon can be extraordinary: for example, if a pyramidal cell, (an excitatory neuron) of the cerebral cortex were magnified so that its cell body became the size of a human body, its axon, equally magnified, would become a cable a few centimeters in diameter, extending more than a kilometer. These axons transmit signals in the form of electrochemical pulses called action potentials, which last less than a thousandth of a second and travel along the axon at speeds of 1–100 meters per second. Some neurons emit action potentials constantly, at rates of 10–100 per second, usually in irregular patterns; other neurons are quiet most of the time, but occasionally emit a burst of action potentials. | Dismayed to find that groundbreaking work had already been undertaken by Helmholtz who had conveyed vowel sounds by means of a similar tuning fork "contraption", he pored over the German scientist's book. Working from his own erroneous mistranslation of a French edition, Bell fortuitously then made a deduction that would be the underpinning of all his future work on transmitting sound, reporting: "Without knowing much about the subject, it seemed to me that if vowel sounds could be produced by electrical means, so could consonants, so could articulate speech." He also later remarked: "I thought that Helmholtz had done it ... and that my failure was due only to my ignorance of electricity. It was a valuable blunder ... If I had been able to read German in those days, I might never have commenced my experiments!"[N 7] | eng_Latn | 10,658 |
Axons send signals that are named what? | The brains of all species are composed primarily of two broad classes of cells: neurons and glial cells. Glial cells (also known as glia or neuroglia) come in several types, and perform a number of critical functions, including structural support, metabolic support, insulation, and guidance of development. Neurons, however, are usually considered the most important cells in the brain. The property that makes neurons unique is their ability to send signals to specific target cells over long distances. They send these signals by means of an axon, which is a thin protoplasmic fiber that extends from the cell body and projects, usually with numerous branches, to other areas, sometimes nearby, sometimes in distant parts of the brain or body. The length of an axon can be extraordinary: for example, if a pyramidal cell, (an excitatory neuron) of the cerebral cortex were magnified so that its cell body became the size of a human body, its axon, equally magnified, would become a cable a few centimeters in diameter, extending more than a kilometer. These axons transmit signals in the form of electrochemical pulses called action potentials, which last less than a thousandth of a second and travel along the axon at speeds of 1–100 meters per second. Some neurons emit action potentials constantly, at rates of 10–100 per second, usually in irregular patterns; other neurons are quiet most of the time, but occasionally emit a burst of action potentials. | The model also shows all the memory stores as being a single unit whereas research into this shows differently. For example, short-term memory can be broken up into different units such as visual information and acoustic information. In a study by Zlonoga and Gerber (1986), patient 'KF' demonstrated certain deviations from the Atkinson–Shiffrin model. Patient KF was brain damaged, displaying difficulties regarding short-term memory. Recognition of sounds such as spoken numbers, letters, words and easily identifiable noises (such as doorbells and cats meowing) were all impacted. Interestingly, visual short-term memory was unaffected, suggesting a dichotomy between visual and audial memory. | eng_Latn | 10,659 |
A simple model is also referred to as what? | In a simple model, often referred to as the transmission model or standard view of communication, information or content (e.g. a message in natural language) is sent in some form (as spoken language) from an emisor/ sender/ encoder to a destination/ receiver/ decoder. This common conception of communication simply views communication as a means of sending and receiving information. The strengths of this model are simplicity, generality, and quantifiability. Claude Shannon and Warren Weaver structured this model based on the following elements: | All vertebrate brains share a common underlying form, which appears most clearly during early stages of embryonic development. In its earliest form, the brain appears as three swellings at the front end of the neural tube; these swellings eventually become the forebrain, midbrain, and hindbrain (the prosencephalon, mesencephalon, and rhombencephalon, respectively). At the earliest stages of brain development, the three areas are roughly equal in size. In many classes of vertebrates, such as fish and amphibians, the three parts remain similar in size in the adult, but in mammals the forebrain becomes much larger than the other parts, and the midbrain becomes very small. | eng_Latn | 10,660 |
in the wave equation s(x;t) why is s a function of 2 variables while x & t arent independant? | I assume you are talking about any wave equation, not just a QM probability density function.\n\nIn any case, what do you mean that you have a "different x for every instant t"? That is not the case. I suspect you are thinking of travelling along with the crest or trough of a wave. As t changes, the location of the crest and trough changes, but that is not the only location on the wave.\n\nWhat the wave equation specifies is the magnitude of the wave at *any* location x, at any time t. So, if you are at a constant location x', the magnitude of the wave will vary periodically in time at that location. If you were a cork on the water, you would bob up and down at your location as the waves passed you. But similarly, if we were to somehow freeze time, and travel up and down our x axis, the magnitude of the wave would vary periodically in space as well. So now, rather than a cork bobbing on the water, imagine you're on a jet ski that is going across the water so fast, compared to the speed of the waves, that it's almost like the waves aren't moving. Yet you bob up and down as you cross the waves that lie in your path in space.\n\nHence, the wave varies both in x and t, independently. | The brain is part of the nervous system. The smallest component of the nervous system are axons, which have a head and a tail. Millions of these line up head to tail and form the nerve endings in your body. In the space between each head and tail (called a synapse) chemicals can flow. When something happens (you prick yourself), an axon signals chemicals to flow between the synapse, activate the next axon, and the next until the message reaches your brain and you react. Different drugs affect the ability for these chemicals to flow across the synapse (speeding up, slowing down, or not at all) or wipe out axons all together leaving gaps in the message chain. | eng_Latn | 10,661 |
Monosynaptic Circuit Tracing with Glycoprotein-Deleted Rabies Viruses. | A Cortical Circuit for Gain Control by Behavioral State | Collocation and Thai Word Segmentation | eng_Latn | 10,662 |
Monosynaptic Circuit Tracing with Glycoprotein-Deleted Rabies Viruses. | A Cortical Circuit for Gain Control by Behavioral State | A robust and high-throughput Cre reporting and characterization system for the whole mouse brain | eng_Latn | 10,663 |
what is the threshold for action potential | Asker's rating. Report Abuse. A threshold potential is the level at which an action potential will fire. For example, if a cell has a resting membrane potential of -90mEV, and the threshold potential is -60mEV, a stimulus must depolarize the membrane by 30mEV to cause the action potential to fire. | Formation of an action potential. The formation of an action potential can be divided into five steps. (1) A stimulus from a sensory cell or another neuron causes the target cell to depolarize toward the threshold potential. (2) If the threshold of excitation is reached, all Na+ channels open and the membrane depolarizes. | eng_Latn | 10,664 |
relative refractory period definition | In summary, the relative refractory period is a time in which the neuron can fire an action potential, but it needs a greater stimulus. During an action potential, voltage-gated sodium channels open to let in positive ions - sodium. These depolarize the cell. | The interval from the beginning of the QRS complex to the apex of the T wave is referred to as the absolute refractory period. The last half of the T wave is referred to as the relative refractory period (or vulnerable period). The T wave contains more information than the QT interval. | eng_Latn | 10,665 |
what is the primary function of wave summation? | Question: What is the primary function of wave summation? ... What is the primary function of wave summation? 1. prevent muscle fatigue 2. increase muscle tension 3. prevent muscle relaxation 4. produce smooth, continuous muscle contraction. Best answer. | Summation, also known as frequency summation is the method of signal transduction between neurons, which determines whether or not an action potential will be triggered by the combined effects of postsynaptic potentials. | eng_Latn | 10,666 |
what is the threshold | 3. any point of entering or beginning: the threshold of a new career. 4. Also called limen. the point at which a stimulus is of sufficient intensity to begin to produce an effect: the threshold of consciousness; a low threshold of pain. | View Full Document. ⢠Absolute threshold: Minimum amount of stimulation necessary for a person to detect a stimulus 50% of the time. Thresholds and the Dawn of Psychophysics Ernst Weber discovered that the smallest change in a stimulus that can be detected is a constant proportion of the stimulus level. ⢠Weberâs law: The principle describing the relationship between stimulus and resulting sensation that says the JND is a constant fraction of the comparison | eng_Latn | 10,667 |
what part of the ear transforms sound energy into electrical energy | There are three main parts to the ear, including the inner ear, middle ear and outer ear. In order for hearing to occur, there is a sequence of actions that must occur to transform waves of sound in the air into electrical impulses. These impulses are transmitted to the brain by the auditory (hearing) nerve. | The sound wave then travels through the auditory canal which funnels the sound to thâ¦e ear drum causing it to vibrate. The ear drum then amplifies the poo sound by vibration of bones. It is in the middle ear where sound energy is converted into mechanical energy. The cochlea in the inner ear converts the vibrations into electrical impulses before sending signals to the brain. The brain then interprets the impulses as sound. | eng_Latn | 10,668 |
Can You Hear Nature's Sounds? | Last week, South Florida's nature came alive for me as much through sound as through sight: the flapping of wings as a great blue heron soared up over a river; the plashing of water when an alligator slipped off the riverbank to swim away; the huffing of a manatee taking a breath at the water's surface before she slowly sank again to the river bottom to munch grass. I was lucky. My husband and I heard those animal sounds in two exceptionally quiet locations — down an isolated road in the Everglades for the heron and the alligator, and at a Miami waterway with no boat or people traffic for the manatee. It's becoming harder by the year for those of us who visit wilderness areas, much less seek tranquility in urban areas, to hear natural sounds. The constant thrum of noise in our daily environments causes us to tune out many sounds we hear, so that, in effect, we are undergoing a process of "learned deafness." That was the message delivered Monday by National Park Service scientist Kurt Fristrup to the American Association for the Advancement of Science (AAAS) meeting in San Jose, Calif. — and reported by The Guardian newspaper. According to The Guardian, Fristrup told AAAS attendees: "This learned deafness is a real issue. We are conditioning ourselves to ignore the information coming into our ears. "This gift that we are born with — to reach out and hear things hundreds of metres away, all these incredible sounds — is in danger of being lost through a generational amnesia. "There is a real danger, both of loss of auditory acuity, where we are exposed to noise for so long that we stop listening, but also a loss of listening habits, where we lose the ability to engage with the environment the way we were built to. As you raise background sound levels it has the same effect on your hearing that fog would have on your vision." If our children — and as a parent I've had this experience when our daughter was younger — don ear buds along with their backpacks when we take them into the wild, the problem becomes a kind of vicious cycle, with more and more anthropogenic sounds claiming our auditory attention. And, of course, it's not only we ourselves who are disturbed by anthropogenic noise. In an email response to me Tuesday, Fristrup (who has the coolest job title I've come across — senior scientist at the National Park Service Natural Sounds and Night Skies Division) noted how other animals are affected too: "We have recently participated in a series of noise playback experiments that have decisively demonstrated that noise alone alters habitat utilization and the behavior of those animals that do occupy noisy areas." Christopher Solomon made a parallel point about our effect on the environment in last Sunday's New York Times: "More and more studies over the last 15 years have found that when we visit the great outdoors, we have much more of an effect than we realize. Even seemingly low-impact activities like hiking, cross-country skiing and bird-watching often affect wildlife, from bighorn sheep to wolves, birds, amphibians and tiny invertebrates, and in subtle ways." It's not a pretty picture: humans swarming through natural areas, oblivious to the damage we cause and not even hearing what's around us as we go. Fristrup, though, stresses that we can all push back against learned deafness and train ourselves to hear natural sounds more acutely — a process that can only help with our taking care in, and of, the wilderness. He told me about a project his team is working on, together with colleagues Bob Manning of the University of Vermont and Peter Newman of Pennsylvania State University, that involves visitors to national parks: "In order to avoid the potential to cue our participants to complain about noise, we have them sit quietly, listen, and write down every sound they hear and rate its acceptability in a park setting and whether it is pleasing or not. To give some examples, flowing water sounds are universally rated as highly pleasing and acceptable, personal electronic sounds are rated as highly inappropriate and annoying, mosquito sounds are rated as acceptable and annoying. "Most noise sources do not fare well in these ratings, which affirms the negative evaluations we get from questionnaires that do ask specifically about noise. The pleasant surprise from attentive listening studies is the spontaneous comment we get from most participants, thanking us for helping them experience the park in a new and stimulating way." Fristrup's research has called up many auditory memories for me, beyond last week's visit to Florida. They include grazing bison's soft vocalizations in Yellowstone National Park, an angry ocean and angrier skies at the Jersey Shore, and octaves of birdsong in my own Virginia backyard. To listen. To be still. To let the sounds of nature refresh us and delight us. What pleasure this brings. Barbara J. King, an anthropology professor at the College of William and Mary, often writes a | Former Dream Syndicate frontman Steve Wynn, and his band the Miracle 3 have a new album, Tick, Tick, Tick. The record is the final installment of Wynn's Tuscon Trilogy, which were all recorded at the Wavelab Studio in Arizona. The Wavelab is famous for its use of old-style recording techniques, which in this case, dramatically showcases the band's cohesive and energetic performances. This segment originally aired on March 16, 2006. | eng_Latn | 10,669 |
Okay, why do people turn their radios down in the car when they are lost? | So they can hear themselves think of course!\n\nIt's the same as when I can't hear you until I've put my glasses on. We're just insane human beings!\n\nOh, yeah. My favorite was when my mom kept ducking to make sure her van could make it through a parking garage. | 1) for the feeling they get from the music... this extends beyond just 'listening to the beat', but doesnt exclude it. Music is an emotional pastime and evokes passion not just from words, but from the inflection (tone of the words) as well. These feelings dont require meaning or explanation... they just 'feel' right.\n\n2) to learn the language. I'm learning Chinese by listening to chinese music and comparing it to the written lyrics. | eng_Latn | 10,670 |
Evaluation of auditory cortex tonotopical organization in rats Through Principal Component Analysis | Ethological communication permits the exchange of context-specific information among mammals. In recent literature, many investigations have been performed on behavioral responses but little is known about neurophysiological pattern activation. In this study we investigated neuron patterns in response to ultrasound vocalizations, mapping the auditory cortex in order to find the specific activation area which best fits with perceived vocalization in rats. Receptive fields were directly reached through implanted electrodes in order to record the ultrasound information into the auditory system, bypassing sense organs. Techniques based on Principal Component Analysis and statistical analysis were used to investigate the tonotopic organization exploiting local field-potential classifications. The results, according to the sensitivity index, identified two tonotopic fields with a gradient from high-to-low best frequency using unsupervised classification algorithm. | We address the problem of effectiveness of the high resolution techniques applied to the conditional model. The rationale is based on a definition of the probability of resolution of maximum likelihood estimators which is computable in the asymptotic region of operation (in SNR and/or in large number of snapshots). The application case is the multiple tones estimation problem (Doppler frequencies estimation in radar). | eng_Latn | 10,671 |
The motor-evoked potential threshold evaluated by tractography and electrical stimulation | Object To validate the corticospinal tract (CST) illustrated by diffusion tensor imaging, the authors used tractography-integrated neuronavigation and direct fiber stimulation with monopolar electric currents. Methods Forty patients with brain lesions adjacent to the CST were studied. During the operation, the motor responses (motor evoked potential [MEP]) elicited at the hand by the cortical stimulation to the hand motor area were continuously monitored, maintaining the consistent stimulus intensity (mean 15.1 ± 2.21 mA). During lesion resection, direct fiber stimulation was applied to elicit MEP (referred to as fiber MEP) to identify the CST functionally. The threshold intensity for the fiber MEP was determined by searching for the best stimulus point and changing the stimulus intensity. The minimum distance between the resection border and illustrated CST was measured on postoperative isotropic images. Results Direct fiber stimulation demonstrated that tractography accurately reflected anatomical CST f... | Publisher Summary This chapter summarizes results from the theory of pseudopotentials that relate to choosing suitable mathematical forms forfitting. The procedures used are described. It is reported that it is important to distinguish between what is exact and what is approximate, and to discuss where various approximations might be reasonably appropriate and where not. The chapter reviews all the experimentally fitted pseudopotentials. Primarily they come from Fermi surface studies in the case of metals and analysis of optical properties for semiconductors, but phonon spectra, resistivities of liquid metals, and other data have also been important. It is suggested that by making use of all the theory, all the fitted results by interpolating, extrapolating, cajoling, and cudgeling, one should be able to produce a useful pseudopotential for many elements in many situations. | eng_Latn | 10,672 |
Neural Mechanisms of Selective Auditory Attention in Rats A Dissertation | Stony Brook University Libraries. ::: SBU Graduate School in Neuroscience. ::: Lawrence Martin (Dean of Graduate School), Anthony M. Zador – Dissertation Advisor ::: Professor, Cold Spring Harbor laboratory, Zachary F. Mainen – Chairperson of Defense ::: Associate Professor, Cold Spring Harbor Laboratory, Josh Dubnau1 ::: Assistant Professor, Cold Spring Harbor Laboratory, Jonathan B. Fritz ::: Assistant Professor, Institute for Systems Research ::: University of Maryland. | O. Introduction This lecture will unfortunately not be a systematic review of the subject of rigorous results in non-equilibrium statistical mechanics. A preliminary attempt to outline such a review led me quickly to the conclusion that the field is too diverse to be summarized in a single lecture. I have therefore decided instead to discuss a few related.works in depth. The works I have chosen are: 1. The paper of J. Fritz and R. L. Dobrushin[5] on two-dimensional dynamics. 2. The paper of W. Braun and K. Hepp[3] on classical mechanics in the Vlasov limit. 3. A recent preprint by H. van Beijeren, J. L. Lebowitz, H. Spohn, and myself[2] on autocorrelations and fluctuations in the dilute equilibrium hard-sphere gas. | eng_Latn | 10,673 |
Effect of Gaba on Non-Synaptic Potassium Channels in Crayfish Muscle | The application of excitatory transmitter substances to postsynaptic membranes in vertebrate and invertebrate muscle induces the synaptic membrane current to fluctuate around its mean value due to the random opening and closing of ionic channels located in the postsynaptic membrane. The statistical analysis of this current noise yields information about the properties of an individual synaptic channel in terms of its conductance γ and its mean lifetime τ (cf. Neher and Stevens 1977). | The model of the catfish retina (Siminoff, in press) has been extended to the turtle retina with incorporation of color-coding. The turtle retina contains 6 types of cones of which 4 are red-sensitive and the other 2 are green- and blue-sensitive, respectively. The cone-horizontal circuit incorporates negative feedback from the L-HC to all the cones having input to the L-HC. By use of systems analysis, Laplace transforms and the convolution theorem, impulse responses, that give information as to gain and phase, for the cone-types and L-HC were simulated. As with the catfish retina, negative feedback gain was proportional to the dc level of the L-HC and therefore, the mean illuminance level. It was shown that this mechanism can be an important factor in chromatic adaptation, since the gains of the various cone-types are preferentially altered dependent on mean illuminance level and wavelength of the background light. | eng_Latn | 10,674 |
HIV-1 infects and alters immune function of a monocyte subset expressing low CD14 surface phenotype. | ABSTRACT Monocytes represent a leukocyte subset that express high levels of CD14 on their surface (CD14-high). These cells play a critical role in the pathogenesis of HIV-1 infection. In the present study, we have identified a monocyte subset expressing an extremely low level of CD14 (CD14-low), and examined their susceptibility to HIV-1 infection. Phenotypic analysis by flow cytometry of these cells revealed a low level of CD4, but the absence of CD3, CD14, CD19, and CD83 surface markers. Both CD14-low and CD14-high cell populations expressed CD13 and CD33 markers on their surface, suggesting these cells to be of myeloid origin. Morphologically, CD14-low cells were indistinguishable from CD14-high cells. CD14-low cells were susceptible to infection with a monocytotropic strain of HIV-1 (HIVADA)- However, like CD14-high monocytes, CD14-low cells could not be productively infected with a T cell tropic strain of HIV-1 (H9/HTLVIIIB). Similar to CD14-high monocytes, CD14-low cells were capable of inducing ant... | Single cells isolated in the vestibular complex of the awake monkey were studied as a function of stimulus input. The stimulus utilized in this study was sinusoidal tilt in the anterior-posterior plane about a vertical axis. Once a single cell was isolated its response to tilt was determined. Changes in amplitude and period of the stimulus brought about corresponding changes in the unitary discharge pattern which could best be described as spike frequency modulation of stimulus input. Some cells displayed a greater rate of change than others. Techniques and procedures necessary to record from the awake monkey are described. | eng_Latn | 10,675 |
Oscillations: Synchrony shows mice the way | Synchronized, high-frequency gamma oscillations contribute to successful decision making in a working-memory task in mice and may, therefore, reflect content in working memory entering the animal's 'awareness'. | The observation data of the crustal movement observation network base stations ars selected,two groups total zenith delays are calculated in two case of taken into account and disregard of the ocean tide correction model,and comparative analysis is presented.In the same time,the characteristics of frequency and amplitude are analyzed,more about the impact of ocean tide on the total zenith delay observations of ground-based GNSS is studied,and useful conclusions are summed up. | eng_Latn | 10,676 |
Ultrasonic irradiation enhanced cell nucleation : An effective approach to microcellular foams of both high cell density and expansion ratio | In this work, ultrasonic irradiation (UI) was used as the external energy source to assist polystyrene foaming process by using supercritical CO2 as the physical blowing agent. It is shown that by introducing the UI at the very start of foaming, the resultant polymer foam exhibited significant and concurrent increase in cell density, i.e., three orders of magnitude, and expansion ratio, i.e., 1–3 times, compared to those without UI. Further experiments indicate that the enhanced cell nucleation induced by UI was the main reason for this unique phenomenon. This method also provided new insight into the mechanism of cell nucleation. | Ethological communication permits the exchange of context-specific information among mammals. In recent literature, many investigations have been performed on behavioral responses but little is known about neurophysiological pattern activation. In this study we investigated neuron patterns in response to ultrasound vocalizations, mapping the auditory cortex in order to find the specific activation area which best fits with perceived vocalization in rats. Receptive fields were directly reached through implanted electrodes in order to record the ultrasound information into the auditory system, bypassing sense organs. Techniques based on Principal Component Analysis and statistical analysis were used to investigate the tonotopic organization exploiting local field-potential classifications. The results, according to the sensitivity index, identified two tonotopic fields with a gradient from high-to-low best frequency using unsupervised classification algorithm. | eng_Latn | 10,677 |
Sequences of predictive saccades are correlated over a span of ∼2 s and produce a fractal time series | We previously demonstrated that there is an abrupt (rather than smooth) transition between reactive and predictive modes of eye-movement tracking of target lights (a phase transition). We also found evidence that the sequence of eye movements in the reactive mode was independent, whereas those in the predictive mode were correlated and possibly formed a random fractal sequence. Here we confirm the finding of fractal structure by quantifying the rate of decay of nonlinear forecasting when applied to these data. We also estimate the window over which consecutive trials are correlated and show that the duration of this window is fixed in time rather than number of trials. These results have implications for the neural mechanisms that drive predictive movements. | Measured and simulated power penalties were compared for 10Gbit/s NRZ loop experiments for cascaded AWG filters with 50GHz and 100GHz channel spacings. The results show that spectral flatness of cascaded filters can strongly influence the performance of high-speed systems with small channel spacing. | eng_Latn | 10,678 |
Ear asymmetry in an auditory Spatial Stroop Task as a Function of Handedness | a reaction-time (RT) experiment was carried out in which five groups consisting of subjects with various degrees of left and right handedness, participated. The words left and right were presented binaurally, one at a time, either to the left or to the right side, implying four presentation modes. The two interfering presentation modes are regarded as Stroop tasks. Two reaction conditions .were applied in separate sessions; 1. reacting to the perceived location, and 2. reacting to the content of the word. ::: ::: With specific hypotheses concerning cerebral dominance for verbal functions in right-handed subjects, but with considerably less clear anticipations with respect to left-handers, we obtained an interaction between side of presentation, Stroop effect and handedness. ::: ::: The results are discussed in terms of the relation between the conceptualization of space and cerebral dominance. | Purpose To investigate the hypothesis that vowel production is more variable in adults with acquired apraxia of speech (AOS) relative to healthy individuals with unimpaired speech. Vowel formant fr... | eng_Latn | 10,679 |
Expression of the green fluorescent protein gene in conifer tissues | The gene coding for the green fluorescent protein (GFP) from jellyfish was introduced into conifer tissues by microprojectile bombardment and its transient expression was detected. Two versions of the GFP gene, wild-type GFP and modified GFP with a cryptic intron removed, were directly compared for their expression in black spruce pollen. While the wild-type GFP gene resulted in a low level of expression, the modified GFP gene gave a dramatic increase in amount of expression (>100 times). The expression of GFP was detected in all the tissues tested : pollen, embryonal masses, suspension culture, and somatic embryos. Also, the GFP gene was introduced and expressed in three different conifer species (black spruce, white spruce, and white pine). The successful expression of the GFP gene in various tissues and different species suggests that it will be a useful reporter/marker gene for conifers. | We report on a newborn with peracute glycine encephalopathy. The child exhibited poor feeding, incipient respiratory failure and increasing muscular hypotonia from the first few days of life onwards and was admitted to hospital at six weeks due to regression of the symptoms. Following respiratory arrest the child had to be placed on controlled ventilation and died at the age of four months in spite of therapeutic measures. Previous papers on this rare disease have described elevated CSF glycine levels, EEG patterns, CT scan and acoustic and visual evoked potentials. We have supplemented these for the first time by somatosensory evoked potentials. The following is an account of the clinical course and the therapy given. | eng_Latn | 10,680 |
Estimating the Size of Homogeneous Population via Bayesian Method under a complex Dual-record System | For Dual-record system, in the context of human population, the popular ChandrasekarDeming model incorporates only the time variation eect on capture probabilities. However, in practice population may undergo behavioral change after being captured rst time. In this paper we focus on the Dual-record system model (equivalent to capturerecapture model with two sampling occasions) with both the time as well as behavioral response variation. The relevant model suers from identiability problem. Two approaches are proposed from which approximate Bayes estimates can be obtained using very simple Gibbs sampling strategies. We explore the features of our two proposed methods and their usages depending on the availability (or non-availability) of the information on the nature of behavioral response eect. Extensive simulation studies are carried out to evaluate their performances and compare with few available approaches. Finally, a real data application is provided to the model and the methods. | Since about twenty years, the otoneurology functional exploration possesses auditory tool to analyze objectively the state of the nervous conduction of additive pathway. In this paper, we present a new classification approach based on the Hidden Markov Models (HMM) which used to design a Computer aided medical diagnostic (CAMD) tool that asserts auditory pathologies based on Brain-stem Evoked Response Auditory based biomedical test, which provides an effective measure of the integrity of the auditory pathway. Case study, experimental results and comparison with a conventional neural networks models have been reported and discussed. | eng_Latn | 10,681 |
A Projector Augmented Wave (PAW) code for electronic structure calculations, Part I: atompaw for generating atom-centered functions | The computer program atompaw generates projector and basis functions which are needed for performing electronic structure calculations based on the Projector Augmented Wave (PAW) method. The program is applicable to materials throughout the periodic table. For each element, the user inputs the atomic number, the electronic configuration, a choice of basis functions, and an augmentation radius. The program produces an output file containing the projector and basis functions and the corresponding matrix elements in a form which can be read be the pwpaw PAW code. Additional data files are also produced which can be used to help evaluate the accuracy and efficiency of the generated functions. | Ethological communication permits the exchange of context-specific information among mammals. In recent literature, many investigations have been performed on behavioral responses but little is known about neurophysiological pattern activation. In this study we investigated neuron patterns in response to ultrasound vocalizations, mapping the auditory cortex in order to find the specific activation area which best fits with perceived vocalization in rats. Receptive fields were directly reached through implanted electrodes in order to record the ultrasound information into the auditory system, bypassing sense organs. Techniques based on Principal Component Analysis and statistical analysis were used to investigate the tonotopic organization exploiting local field-potential classifications. The results, according to the sensitivity index, identified two tonotopic fields with a gradient from high-to-low best frequency using unsupervised classification algorithm. | eng_Latn | 10,682 |
Hearing and saying The functional neuro-anatomy of auditory word processing | Summary The neural systems involved in hearing and repeating single words were investigated in a series of experiments using PET. Neuropsychological and psycholinguistic studies implicate the involvement of posterior and anterior left perisylvian regions (Wernicke's and Broca's areas). Although previous functional neuroimaging studies have consistently shown activation of Wernicke's area, there has been only variable implication of Broca's area. This study demonstrates that Broca's area is involved in both auditory word perception and repetition but activation is dependent on task (greater during repetition than hearing) and stimulus presentation (greater when hearing words at a slow rate). The peak of | This is a phenomenological study of the communication processes around quality in a symphony chorus, addressing the research question, How do the communication processes in which organizational mem... | eng_Latn | 10,683 |
Temporal estimation by a model big brown bat | The big brown bat, Eptesicus fuscus, uses echolocation to locate prey and displays extraordinary acuity in the perception of temporal cues in acoustic signals. Behaviorally the bat can detect changes at submicrosecond levels but individual neurons in the inferior colliculus (IC) and cortex operate with much less precision. Most of these cells are poor temporal markers with response variation on the order of a few milliseconds and some in tens of milliseconds. A temporal estimator was created incorporating the response properties of recorded neurons and behaviorally appropriate limitations on the number of echolocation emissions. The response of the neurons can be characterized as probability density functions in time and frequency. The characteristics of these neurons were used to create large simulated populations of IC and cortical neurons that show the full range of recorded variation. The connections between these two populations were simulated using a self‐organizing neural network. If more than one ... | This note presents an estimator of the hazard rate function based on right censored data. A collection of estimators are built from a regression-type contrast, in a general collection of linear models. Then, a penalised model selection procedure gives an estimator which satisfies an oracle inequality. In particular, we can prove that it is adaptive in the minimax sense on H\"{o}lder spaces. | eng_Latn | 10,684 |
BILATERAL DIFFERENCES IN THE HUMAN OCCIPITAL ELECTROENCEPHALOGRAM WITH UNILATERAL PHOTIC DRIVING. | Differential activity was induced in the electroencephalograms of the occipital lobes by limiting intermittent photic stimulation to the right or left halves of the two retinas. The results indicate that the driving of one hemisphere also affects the opposite hemisphere and that the amount and pattern of the effect is determined by the hemisphere being directly stimulated. | Whatispresented isanewapproach forimplementing Bosnianphonemerecognition. Whilemostofthe literature onphonemerecognition isbasedonhidden Markovmodels (HMM),orontherecognition byneural networks (NN)ofonetype,thepresent systemis implemented byhybrid cascaded LVQ/Elman NN.This modelwascreated, because wenoted that sometypes of NN achieve better recognition rateforsomephonemes, whiletheother typesofNN better recognize other phonemes. Presented system usesLVQNN asafront-end recognizer, anddepending ontheobtained output, makes there-recognition ofthesamephoneme byElmanNN. Thissystem achieved higher recognition accuracy then standalone NN models. IndexTerms-Bosnian phoneme recognition, Melfrequency cepstral coefficients, hybridcascaded LVQ/Elman neural network. | yue_Hant | 10,685 |
Memory disruption by unilateral low level, sub-seizure stimulation of the medial amygdaloid nucleus. | Abstract In four experiments 413 male albino rats were used to evaluate memory disruption during a retention test given 24 hr after passive avoidance learning. In Experiment 1, unilateral brain stimulation of 5 μA intensity significantly disrupted retention when applied to the amygdala but not to the dorsal hippocampus. This finding of retention disruption following amygdala stimulation was further corroborated in Experiment 2, and stimulation in the medial nucleus was indicated as the primary source for the obtained disruption. In Experiment 3, epileptogenic effects of 5 μA amygdala stimulation on hippocampal activity were contraindicated. In Experiment 4, use of a finer wire electrode to study the relative importance of individual nuclear groups confirmed that stimulation of the medial amygdaloid nucleus caused retention disruption. | The article describe operating principle of the single-particle microbeam device,we implanted the SAM and RAM of embryos with a 2.0 MeV of energy and 25 μm of diameter proton microbeam at the fluence of 6×106ions.The embryos' root patterning parameters was observed in detail,such as the development of primary root and the formation of lateral root.The results indicated that some contributions of vacuum treatment might be involved in the biological effects,ion-beam bombardment and the interactions might be existed between each other.The results showed that auxin signal transduction might be relevant. | eng_Latn | 10,686 |
Proceedings of the Seventh International Workshop on Advances in Electrocorticography | The Seventh International Workshop on Advances in Electrocorticography (ECoG) convened in Washington, DC, on November 13-14, 2014. Electrocorticography-based research continues to proliferate widely across basic science and clinical disciplines. The 2014 workshop highlighted advances in neurolinguistics, brain-computer interface, functional mapping, and seizure termination facilitated by advances in the recording and analysis of the ECoG signal. The following proceedings document summarizes the content of this successful multidisciplinary gathering. | Copyright: 2015 Materials Research Society. Due to copyright restrictions, the attached PDF file only contains the abstract of the full text item. For access to the full text item, please consult the publisher's website. The definitive version of the work is published in Journal of Materials Research, 30(1), 66-78 | eng_Latn | 10,687 |
Coherence analysis of EEG via multichannel AR modeling | The multichannel autoregressive model and the periodogram approach are used to determine coherence and phase measures between the electrical activity in two distinct brain structures of the rat namely, the subfields CA1 and dentate gyrus in the hippocampal formation, during the vigilance states of quiet waking (QW), slow-wave sleep (SWS), and rapid-eye-movement (REM) sleep. Using both periodogram and multichannel autoregressive modeling techniques, high coherence and consistent phase differences were found to exist within the theta range of frequencies (4-11 Hz) only during REM sleep. > | The Eckart‐Wigner theorem is generalized to include nonunitary groups. The proof is based on the connection between corepresentations of a nonunitary group and the representations of its unitary part. All possible cases of the corepresentations have been considered, and general expressions for matrix elements of operators with given symmetry have been obtained. It has been shown that the antiunitary symmetry leads, in general, to additional connections between different matrix elements. | eng_Latn | 10,688 |
The Brookhaven hypernuclear physics program | Abstract Recent experimental results as well as anticipated future work in the field of hypernuclear physics from Brookhaven National Laboratory and others, are presented in this paper. | Covers a broad range of contemporary topics in behavioral neuroscience. This book focuses on the mammalian suprachiasmatic nucleus system emphasizing inputs to the 'clock', their neurochemical phenotype, and outputs from the 'clock' to behavioral and other effector systems. | eng_Latn | 10,689 |
Functional imaging of unilateral tinnitus using fMRI | Conclusions. This article shows that the inferior colliculus plays a key role in unilateral subjective tinnitus. Objectives. The major aim of this study was to determine tinnitus-related neural activity in the central auditory system of unilateral tinnitus subjects and compare this to control subjects without tinnitus. Subjects and methods. Functional MRI (fMRI) was performed in 10 patients (5 males) with unilateral tinnitus (5 left-sided, 5 right-sided) and 12 healthy subjects (6 males); both groups had normal hearing or mild hearing loss. fMRI experiments were performed using a 3T Philips Intera Scanner. Auditory stimuli were presented left or right and consisted of dynamically rippled broadband noise with a sound pressure level of 40 or 70 dB SPL. The responses of the inferior colliculus and the auditory cortex to the stimuli were measured. Results. The response to sound in the inferior colliculus was elevated in tinnitus patients compared with controls without tinnitus. | The construction of a host of interesting patterns over one and two dimensions, as transformations of multifractal measures via fractal interpolating functions related to simple affine mappings, is reviewed. It is illustrated that, while space-filling fractal functions most commonly yield limiting Gaussian distribution measures (bells), there are also situations (depending on the affine mappings parameters) in which there is no limit. Specifically, the one-dimensional case may result in oscillations between two bells, whereas the two-dimensional case may give rise to unexpected circle map dynamics of an arbitrary number of two-dimensional circular bells. It is also shown that, despite the multitude of bells over two dimensions, whose means dance making regular polygons or stars inscribed on a circle, the iteration of affine maps yields exotic kaleidoscopes that decompose such an oscillatory pattern in a way that is similar to the many cases that converge to a single bell. | eng_Latn | 10,690 |
Efficient Partition of N-Dimensional Intervals in the Framework of One-Point-Based Algorithms | In this paper, the problem of the minimal description of the structure of a vector function f(x) over an N-dimensional interval is studied. Methods adaptively subdividing the original interval in smaller subintervals and evaluating f(x) at only one point within each subinterval are considered. Two partition strategies traditionally used for solving this problem are analyzed. A new partition strategy based on an efficient technique developed for diagonal algorithms is proposed and studied. | Dynamical properties of neural populations are studied using probabilistic cellular automata. Previous work demonstrated the emergence of critical behavior as the function of system noise and density of long-range axonal connections. Finite-size scaling theory identified critical properties, which were consistent with properties of a weak Ising universality class. The present work extends the studies to neural populations with excitatory and inhibitory interactions. It is shown that the populations can exhibit narrow-band oscillations when confined to a range of inhibition levels, with clear boundaries marking the parameter region of prominent oscillations. Phase diagrams have been constructed to characterize unimodal, bimodal, and quadromodal oscillatory states. The significance of these findings is discussed in the context of large-scale narrow-band oscillations in neural tissues, as observed in electroencephalographic and magnetoencephalographic measurements. | eng_Latn | 10,691 |
Changes of summating potentials in the guinea pig cochlea after impulse sound exposure | Compound action potentials (CAP) and action potential-summating potential complex (AP-SP) evoked by click and tone burst respectively were recorded from the round window in guinea pigs. Correlations between the positive and negative summating potentials (SP+ and SP-) were examined befroe and after impulse sound exposure. The results show that the SP- is related to CAP threshold shift. In comparison to normal condition, it appears with high incidence when auditory threshold shift reaches 30 dB or more. SP- increases in amplitude when SP+ decreases. The smaller the amplitude of SP+, the larger that of SP-. This suggests that in normal hearing condition SP- may be suppressed by SP+. Such suppression may be released if OHC are injured. The dominant SP- as a sign of recruitment may be due to the change in the nonlinear character of IHC following OHC damage. | In this article,an S potential energy function based on Bayesian theorem is presented which is used to test the loop decoys.The fine result shows that this S potential energy function is efficient and suited for loop structure prediction and the prediction ability is better than the RAPDF by the discrimination rate of the loop structure. | eng_Latn | 10,692 |
Optical recording of responses to frequency-modulated sounds in the auditory cortex. | Using an optical recording method with a voltage-sensitive dye, we recorded activities in the primary auditory cortex (AI) of anesthetized guinea pigs in response to frequency-modulated (FM) sounds and sounds with stepwise changes in frequency (SF). Responses to the FM sound showed a spatiotemporal pattern in which a localized active spot traversed the isofrequency bands in the AI, and they differed from the band-like responses to the SF sound. These results indicate that time-varying sounds are represented as spatiotemporal activation of tonotopic organization in the AI by spectral cues with interactions between frequency bands. | Contemporary treatments for Oropharyngeal cancer (OPSCC) are associated with a number of debilitating side-effects. Whilst these have a significant impact on the patient’s quality of life, they are often not measured in clinical trials. Additionally there is no standardisation of outcome selection and reporting, even amongst trials of comparable interventions. This reduces the volume of data available for meta-analyses leading to difficulties in both interpreting treatment effect and in making evidence based healthcare decisions. The development of a Core Outcome Set (COS) is proposed to address these problems. | eng_Latn | 10,693 |
[Effect of music on motor reaction time and interhemispheric relations]. | Influence of music on motor reaction time (RT) was studied. Warning and triggering stimuli were presented either in the left or in the right visual fields. RT was recorded when playing classical or variety music; control sessions were not accompanied by music. Music shortened RT, and its stimulating effect was the stronger the longer were the initial RTs without music. The influence of variety music was more effective than of the classic one. RT was shortened more when the triggering stimulus was presented in the left visual field. This phenomenon is considered to be an evidence of predominant influence of music on the right cerebral hemisphere due to greater activation from emotional structures. | Since about twenty years, the otoneurology functional exploration possesses auditory tool to analyze objectively the state of the nervous conduction of additive pathway. In this paper, we present a new classification approach based on the Hidden Markov Models (HMM) which used to design a Computer aided medical diagnostic (CAMD) tool that asserts auditory pathologies based on Brain-stem Evoked Response Auditory based biomedical test, which provides an effective measure of the integrity of the auditory pathway. Case study, experimental results and comparison with a conventional neural networks models have been reported and discussed. | eng_Latn | 10,694 |
On the nuclear optical-model potential | Abstract The nuclear optical-model potential is investigated from a non-phenomenological standpoint. Its range of application is extended to the region of negative energies for the calculation of bound state energies and reduced widths. From general arguments and shell-model considerations, a form of the generalized optical-model potential is proposed consisting of an energy-independent term, a sum of factorable terms containing real and complex poles in the energy plane and a weakly energy-dependent “direct” term. | Covers a broad range of contemporary topics in behavioral neuroscience. This book focuses on the mammalian suprachiasmatic nucleus system emphasizing inputs to the 'clock', their neurochemical phenotype, and outputs from the 'clock' to behavioral and other effector systems. | eng_Latn | 10,695 |
Variability of single visual evoked potentials evaluated by two new statistical tests | Abstract In this paper the trial-to-trial variability of brain responses (as opposed to the non-event-related background variability) in flash-evoked potential experiments is investigated by means of two new statistical tests, proposed by Mocks et al. (1984). In two groups of normal children, a considerable number of inhomogeneous responders could be detected, and evidence was found that two different modes of response variability are independently present in the data. The paper also gives a precise description of the computing algorithm and an empirical validation of the applicability to EP data of the two tests. | We consider the cross area of the PP_ and PSV_wave window as the best window for joint PP_ and PSV_wave acquisition in VTI media. Within the effective window, the PP_ and PSV_wave's raypathes and phase angles at all reflection points are calculated, and the reflection (or transmission) coefficients' ratios of PSV- to PP_wave solved from Zoeppritz equations are defined as the controlling factor G. Then we use G values as the main controlling parameters of joint PP_ and PSV_wave acquisition design in VTI media, determine the best receiving window of detectors by analyzing G values, and derive the method of optimizing the receiving window for acquisition of multi_component converted seismic data in VTI media. | eng_Latn | 10,696 |
Narrow-band oscillations in probabilistic cellular automata. | Dynamical properties of neural populations are studied using probabilistic cellular automata. Previous work demonstrated the emergence of critical behavior as the function of system noise and density of long-range axonal connections. Finite-size scaling theory identified critical properties, which were consistent with properties of a weak Ising universality class. The present work extends the studies to neural populations with excitatory and inhibitory interactions. It is shown that the populations can exhibit narrow-band oscillations when confined to a range of inhibition levels, with clear boundaries marking the parameter region of prominent oscillations. Phase diagrams have been constructed to characterize unimodal, bimodal, and quadromodal oscillatory states. The significance of these findings is discussed in the context of large-scale narrow-band oscillations in neural tissues, as observed in electroencephalographic and magnetoencephalographic measurements. | Problems associated with the modelling and calculation of quasi-steady-state postfault regimes are considered for abrupt power unbalances. A program permitting calculation of quasi-steady-state postfault regimes with allowance for frequency dynamics and the investigation of their stability is described. Results of calculations based on this program are compared with experiments using an electrodynamic model. It is shown that allowance must be made for frequency dynamics in the analysis of postfault regimes. 9 refs. | eng_Latn | 10,697 |
Music a scientific art: A call for review of Department of Music, University of Nigeria Nsukka’s curriculum and course outline | Every academic discipline ranging from the Social Sciences, Engineering, Physical Sciences, Arts, and Humanities is typically categorized as either a Science or Arts discipline. While Music is artistic and creative, there is harm in designating music as solely an Arts discipline. It is literally true that music is art, yet the viral damage of categorizing music as solely an Art discipline cannot be overemphasized. Just like a “wolf in sheep skin,” music is science dressed up like art. Music is an offspring of pure science (physics) expressed as art. Music is made up sound, frequency, pitch, resonance, vibration, echo, and Doppler effect; these topics are pure science with mathematical derived formulas and not just art. For example, the action of a typical upright piano obeys Newton’s third law. This paper condemns the outright definition and categorization of music as strictly an art and recommends the re-evaluation of music education at the university. The music curriculum should be rejuvenated and embed... | Ethological communication permits the exchange of context-specific information among mammals. In recent literature, many investigations have been performed on behavioral responses but little is known about neurophysiological pattern activation. In this study we investigated neuron patterns in response to ultrasound vocalizations, mapping the auditory cortex in order to find the specific activation area which best fits with perceived vocalization in rats. Receptive fields were directly reached through implanted electrodes in order to record the ultrasound information into the auditory system, bypassing sense organs. Techniques based on Principal Component Analysis and statistical analysis were used to investigate the tonotopic organization exploiting local field-potential classifications. The results, according to the sensitivity index, identified two tonotopic fields with a gradient from high-to-low best frequency using unsupervised classification algorithm. | eng_Latn | 10,698 |
Which type of brain waves is emittee when a person enters stage one sleep? | Which type of brain wave is emmitted when a person enters stage one sleep? | Which type of brain wave is emmitted when a person enters stage one sleep? | eng_Latn | 10,699 |
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