Attributes of lateral consonants

Amplitude change at consonantal release has been proposed as an invariant acoustic property distinguishing between the classes of stops and glides [Mack and Blumstein, J. Acoust. Soc. Am. 73, 1739-1750 (1983)]. Following procedures of Mack and Blumstein, we measured the amplitude change in the vicinity of the consonantal release for two speakers. The results for one speaker matched those of Mack and Blumstein, while those for the second speaker showed some differences. In a subsequent experiment, we tested the hypothesis that a difference in amplitude change serves as an invariant perceptual cue for distinguishing between continuants and noncontinuants, and more specifically, as a critical cue for identifying stops and glides [Shinn and Blumstein, J. Acoust. Soc. Am. 75, 1243-1252 (1984)]. Interchanging the amplitude envelopes of natural /bV/ and /wV/ syllables containing the same vowel had little effect on perception: 97% of all syllables were identified as originally produced. Thus, although amplitude change in the vicinity of consonantal release may distinguish acoustically between stops and glides with some consistency, the change is not fully invariant, and certainly does not seem to be a critical perceptual cue in natural speech.

Thalamo-cortical mechanisms underlying changes in amplitude and frequency of human alpha oscillations

Much of the work in alpha NFT has focused on evaluating changes in alpha amplitude. However, the generation mechanism of training-induced alpha activity has not yet been clarified. The present study aimed to identify sources of training-induced alpha activity through four temporal/spectral analytic techniques, i.e., the max peak average (MPA), positive average (PA), negative average (NA) and event-related spectral perturbation average (ERSPA) methods. Thirty-five healthy participants were recruited into an alpha group receiving feedback of 8–12-Hz amplitudes, and twenty-eight healthy participants were recruited into a control group receiving feedback of random 4-Hz amplitudes from the range of 7 to 20 Hz. Twelve sessions were performed within 4 weeks (3 sessions per week). The control group had no change in the amplitude spectrum. In contrast, twenty-nine participants in the alpha group showed significant alpha amplitude increases exclusively and were identified as “responders”. A whole-head EEG was recorded for the “responders” after NFT. The epochs of training-induced alpha activity from whole-head EEG were averaged by four different methods for equivalent current dipole source analysis. High agreement and Cohen’s kappa coefficients on dipole source localization between each method were observed, showing that the dipole clusters of training-induced alpha activity were consistently located in the precuneus, posterior cingulate cortex (PCC) and middle temporal gyrus. The residual variance (goodness of fit) for dipole estimation of the MPA was significantly smaller than that of the others. Our findings indicate that the precuneus, PCC and middle temporal gyrus play important roles in enhancing training-induced alpha activity. The four averaging methods (especially the MPA method) were suitable for investigating sources of brainwaves. Additionally, three dipoles can be used for dipole source analysis of training-induced alpha activity in future research, especially the training sites are around the central regions.

As one of the serial experiments on the osmotic constancy within the body, the effects of intraabdominal injection of the solutions which were prepared by combining different amounts and osmolarities on the contractile property of the lymph heart were investigated in the anaesthetized toad. The properties of the peritoneal surface, respectively sensitive to the change in the volume and osmolarity in the abdominal cavity, were examined with respect to the change in amplitude and in frequency of the mechanical properties of the lymph heart.1. The lymph heart activity is controlled essentially by the spinal cord, and hence the changes occurred were reflexive in nature, except for few cases of which change in lymph heart motility was supposed to be caused by a direct effect of the solution injected on the lymph heart muscle itself.2. Heterotonic solutions which were injected into the abdominal cavity caused the change in frequency of the rhythmical lymph heart activity. Hypertonic solutions affected more strongly than hypotonic solutions. The increase in the volume of the solutions injected resulted in the addition of the increase in amplitude. The amount exceeding about 3 ml was enough to generate the volumetric response. The change in frequency was equivalent to the osmoceptive response and the change in amplitude the volumoceptive response.Isotonic solutions, either electrolytic or nonelectrolytic, when the amount was excessive, caused only volumetric response.3. Volumoceptive response was occurred immediately after the procedure, while osmoceptive response was relatively delayed even under the condition capable of producing both responses. The change in osmotic pressure of the solutions injected resulted always in the change in frequency of the motility even if the solution was hypertonic or hypotonic. The functional distinction of the osmoceptive and volumoceptive properties on the peritoneal surface was evident.

When two brief vibrotactile stimulations are sequentially applied to observers’ lower back, there is systematic mislocalization of the stimulation: if the second stimulation is of higher intensity than the first one, observers tend to respond that the second stimulation was above the first one, and vice versa when weak intensity stimulation follows a strong one. This haptic mislocalization effect has been called the intensity order illusion . In the original demonstration of the illusion, frequency and amplitude of the stimulation were inextricably linked so that changes in amplitude also resulted in changes in frequency. It is therefore unknown whether the illusion is caused by changes in frequency, amplitude or both. To test this, we performed a multifactorial experiment, where we used L5 actuators that allow independent manipulation of frequency and amplitude. This approach enabled us to investigate the effects of stimulus amplitude, frequency and location, and to assess any potential interactions among these factors. We report four main findings: (1) we were able to replicate the intensity order illusion with the L5 tactors; (2) the illusion mainly occurred in the upwards direction, or in other words, when strong stimulation following a weaker one occurred above or in the same location as the first stimulation; (3) the illusion did not occur when similar stimulation patterns were applied in the horizontal direction; and (4) the illusion was solely due to changes in amplitude, whereas changes in frequency (100 Hz vs 200 Hz) had no effect.

The precise seismic substructural interpretation of the Turkwal oil field in the Central Potwar region of district Chakwal of Pakistan has been carried out. The research work was confined to the large fore‐thrust that serves as an anticlinal structural trap through ten 2D seismic lines. A precise seismic substructural model of the Eocene Chorgali Limestone with precise orientation of thrust and oblique slip faults shows the presence of a huge fracture, which made this deposit a good reservoir. The abrupt surface changes in dip azimuth for the Eocene Chorgali Limestone verifies the structural trends and also the presence of structural traps in the Turkwal field. The logs of three wells (Turkwal deep X‐2, Turkwal‐01 and Fimkassar‐01) were analyzed for petrophysical studies, well synthetic results and generation of an Amplitude Versus Offset (AVO) model for the area. The AVO model of Turkwal deep X‐2 shows abrupt changes in amplitude, which depicts the presence of hydrocarbon content. Well correlation technique was used to define the overall stratigraphic setting and the thickness of the reservoir formation in two wells, Turkwal‐01 and Turkwal deep X‐2. The Eocene Chorgali Limestone in Turkwal‐01 is an upward thrusted anticlinal structure and because of the close position of both wells to the faulted anticlinal structure, its lesser thickness differs compared to Turkwal deep X‐2. The overall results confirm that the Turkwal field is comparable to several similar thrust‐bound oil‐bearing structures in the Potwar basin.

Frequency-change in DPOAE evoked by 1 s/octave sweeping primaries in newborns and adults

On-demand stimulation improves the efficacy of vagus nerve stimulation (VNS) in refractory epilepsy. The vagus nerve is the main peripheral parasympathetic connection and seizures are known to exhibit autonomic symptoms. Therefore, we hypothesized that seizure detection is possible through vagus nerve electroneurogram (VENG) recording. We developed a metric able to measure abrupt changes in amplitude and frequency of spontaneous vagus nerve action potentials. A classifier was trained using a "leave-one-out" method on a set of 6 seizures and 3 control recordings to utilize the VENG spike feature-based metric for seizure detection. We were able to detect pentylenetetrazol (PTZ) induced acute seizures in 6/6 animals during different stages of the seizure with no false detection. The classifier detected the seizure during an early stage in 3/6 animals and at the onset of tonic clonic stage of the seizure in 3/6 animals. EMG and motion artefacts often accompany epileptic activity. We showed the "epileptic" neural signal to be independent from EMG and motion artefacts. We confirmed the existence of seizure related signals in the VENG recording and proved their applicability for seizure detection. This detection might be a promising tool to improve efficacy of VNS treatment by developing new responsive stimulation systems.

Developing chicks between the day of hatching and three weeks after hatching were subjected to hypothermia of 20°C followed by nitrogenous hypoxia until breathing ceased and the cerebral electroencephalogram was reduced to zero potential. Resuscitation was started 15 minutes later; 86% of the chicks resumed spontaneous breathing. Eighty percent of the resuscitated chicks showed electroencephalographic episodes usually lasting 1 to 3 minutes and consisting of conspicuously rhythmic blunt spike‐like waves of large amplitude and complex patterns with frequencies in the range of 1 to 7 waves per second until the episode was terminated at almost zero potential. Monopolar techique using the comb as the reference electrode indicated that the EEG episodes were either predominantly bilateral or unilateral, with both gradual and abrupt changes in amplitude, frequency, and site of origin. During episodes the chicks were either motionless or showed tremors of eyelids, limbs, trunk, with occasional staring and chirping. During progressive recovery, as episodes approached, large amplitude waves increased in amplitude and frequency, and changed from domes to blunt spikes. Similar slow waves apeared during episodes and continued during recovery eventually culminating in normal EEG patterns of sleep. Statistically the younger chicks showed briefer and fewer episodes, with the lowest maximum frequency. On the day following experimentation 86% of the resuscitated chicks were alive and showed normal EEG patterns and behavior: death was not limited to chicks having episodes.

In an effort to increase the efficiency and power density of electric vehicles and aircraft, the automobile and aerospace industries are adopting variable-speed generators as part of the powertrain. Herein, the engine directly drives a permanent magnet synchronous machine, which generates a variable-frequency/amplitude output ac-voltage. More specifically, this unique ac-voltage profile serves as the input for an ac-dc power converter that energizes the main dc-bus of the powertrain. In this paper, a smart active rectifier for hybrid/all-electric powertrains is presented. A direct model reference adaptive control (MRAC) scheme is utilized to address the rapid changes in amplitude and frequency while regulating the dc-bus voltage at unity power factor. Moreover, the MRAC requires minimal tuning due to its capability of adjusting its gains adaptively with the input voltage variations. As a result, the MRAC exhibits seamless dynamics. The performance of the MRAC is verified experimentally under accelerating and decelerating variable-frequency/amplitude input voltage ramps using a laboratory-scale 2-kW 270-V SiC-MOSFET-based power converter supplied by a programmable grid emulator. Lastly, a classic proportional-integral (PI) control scheme is implemented experimentally with the same converter as a benchmark to highlight the merits of the proposed converter.

Dose-dependent recruitment of pancreatic acinar cells during receptor-mediated calcium mobilization

Infrared dielectric function of photochromic thiazolothiazole-embedded polymer

The orexin neuropeptide family consists of orexin-A and orexin-B, which are coded from the same prepro-mRNA. Although peripherally administered orexin-A abolishes small intestinal interdigestive contractions in rats, it still remains unclear whether orexin-A of lateral hypothalamic area(LHA) effects on the gastric motility in rats. We selected Wistar rats as our subjects. A stainless-steel injection cannula was implanted unilaterally into the LHA. A force transducer was embedmented into the stomach to record circular muscle contractiontions in freely moving conscious rats. The gastric motility was monitored by administration of ghrelin into LHA. The changes of amplitude of constriction and frequency of gastric motility were monitored in conscious rats by a transducer. Subdiaphragmatic vagotomy was performed to elucidate the neural pathways of orexin-A. After microinjection of orexin-A into LHA 5-20 min later, Orexin-A dose-dependently increased the amplitude of contraction and accelerated frequency of gastric motility in the stomach. The effect of orexin-A on promoting the amplitude and frequency of gastric contraction disappeared after 0.5μg orexin-A +6.0μg SB-334867 mixture was microinjection into LHA. However, there was no significant changes of amplitude and frequency of gastric contraction while injection of orexin-A receptor antagonists SB-334867 alone. The stimulatory effect of orexin-A on gastric motility was abolished by subdiaphragmatic vagotomy. It is suggested that exogenous orexin-A of LHA may promote gastric motility, the effect may be accomplished through the LHA-vagus pathway.

The secretion of LH during the preovulatory surge has been shown to be pulsatile in several species. We confirmed this phenomenon in intact ewes in two experiments in which we studied the LH surge in detail. In the first experiment, the levels of LH were measured in discrete blood samples taken every 5 min around the onset of oestrus in 5 intact Merino ewes. For 2-5 h immediately prior to the onset of the surge, the median pulse interval was 17.5 min (range 10-55) and the median pulse amplitude was 0.70 ng/ml (range 0.28-1.33 ng/ml). During the ascending phase of the surge, the pulse interval did not change significantly (median 18.3 min) but the median pulse amplitude increased 20 fold to 18.0 ng/ml. During the descending phase, the median pulse interval was 22.5 min and the median amplitude decreased to 8.1 ng/ml (P less than 0.005). During the surge, intervals of 10 min and amplitudes over 30 ng/ml were common. In the second experiment with 2 oestrous Romanov x Préalpes-du-Sud ewes, blood was withdrawn continuously and samples were pooled over 4 min periods for 19-27 h. In the resulting profiles, individual pulses were better defined but the pulse frequencies (median interval 15.2 min during ascending phase) and amplitudes (median 35.0 ng/ml) varied in similar fashion to the Merinos. Using a simple mathematical description of pulsatile secretion, and assuming that LH is only released in pulses, we also found that the high concentrations normally achieved during the surge can only be explained by pulse frequencies and amplitudes well above those normally observed in other physiological situations, including the follicular phase or following ovariectomy. These findings strongly support the experimental data and the combined results of the two studies suggest that the initiation and execution of the LH surge is probably accomplished by changes in the amplitude of pulses. A high frequency is also essential and our data suggest that it may be established some time before the onset of the surge proper, but this requires confirmation. Respectively, the changes in amplitude and frequency reflect the pituitary and hypothalamic components of the positive feedback mechanism. The theoretical study suggested that a change in clearance rate could also contribute to the surge and this awaits further investigation.

Effects of calcium on the dynamic process of transmitter release which generates either skew- or bell-MEPPs