Cantuhassan2000

Finally, we investigated the narrowing of a levodopa therapeutic index with the progression of the disease as a result of these nonlinearities. In conclusion, various consequences of nonlinear dynamics in Parkinson's disease treatment were studied by developing an integrative model. This model paves the way toward individualization of a dosing regimen. Using sensor based information, the parameters of the model could be fitted to individual data to propose optimal individual regimens.We present an efficient technique for control of synchrony in a globally coupled ensemble by pulsatile action. We assume that we can observe the collective oscillation and can stimulate all elements of the ensemble simultaneously. We pay special attention to the minimization of intervention into the system. The key idea is to stimulate only at the most sensitive phase. To find this phase, we implement an adaptive feedback control. Estimating the instantaneous phase of the collective mode on the fly, we achieve efficient suppression using a few pulses per oscillatory cycle. LNG-451 purchase We discuss the possible relevance of the results for neuroscience, namely, for the development of advanced algorithms for deep brain stimulation, a medical technique used to treat Parkinson's disease.Expressive moments in communicative hand gestures often align with emphatic stress in speech. It has recently been found that acoustic markers of emphatic stress arise naturally during steady-state phonation when upper-limb movements impart physical impulses on the body, most likely affecting acoustics via respiratory activity. In this confirmatory study, participants (N = 29) repeatedly uttered consonant-vowel (/pa/) mono-syllables while moving in particular phase relations with speech, or not moving the upper limbs. This study shows that respiration-related activity is affected by (especially high-impulse) gesturing when vocalizations occur near peaks in physical impulse. This study further shows that gesture-induced moments of bodily impulses increase the amplitude envelope of speech, while not similarly affecting the Fundamental Frequency (F0). Finally, tight relations between respiration-related activity and vocalization were observed, even in the absence of movement, but even more so when upper-limb movement is present. The current findings expand a developing line of research showing that speech is modulated by functional biomechanical linkages between hand gestures and the respiratory system. This identification of gesture-speech biomechanics promises to provide an alternative phylogenetic, ontogenetic, and mechanistic explanatory route of why communicative upper limb movements co-occur with speech in humans.Two-dimensional grid-free compressive beamforming with a planar microphone array is a potential approach to estimating direction-of-arrivals (DOAs) and quantifying the strengths of acoustic sources in front of the array. The existing methods involve a prior noise parameter, which is challenging to accurately estimate in many situations. To circumvent this prior parameter, an iterative Vandermonde decomposition and shrinkage-thresholding based two-dimensional grid-free compressive beamforming is proposed. Compared to the existing methods with accurately estimated noise, the proposed method achieves an equivalent DOA estimation accuracy and a higher source strength quantification accuracy.Active noise control (ANC) over an extended spatial region using multiple microphones and multiple loudspeakers has become an important problem. The maximum noise reduction (NR) potential over the control area is a critical evaluation variable as it indicates the fundamental limitation of a given ANC system. In this paper, a method to mathematically formulate the NR potential for any given multichannel ANC systems is developed. First, the residual error in the multichannel feedforward ANC system is formulated, and then the multiple-input-multiple-output problem is decomposed into the parallel-channel problem. The total energy of the residual error is further decomposed into three different terms representing (i) the signal coherence between the reference signals and error signals, (ii) the filter, and (iii) the system null space. The experimental results validate the proposed evaluation method and illustrate the effectiveness on the maximum NR performance evaluation for given systems. Using the proposed analyzing method, more insight into the contribution of each component to the NR potential can be achieved.In this work, the propagation of an ultrasonic nonlinear wave through a multiple scattering medium is experimentally studied. The interaction between multiple scattering and nonlinear phenomena is analyzed by the cross correlation of the scattered field. This approach corresponds to a virtual time reversal. The cross correlated field is focused in both time and space. In linear regime, it is known that the focal width decreases as the thickness of the multiple scattering medium is increased. In this work, it is shown that this behavior is followed by a nonlinear wave and its harmonics. Moreover, due to the spectral richness of the nonlinear wave, the focal width is reduced in the nonlinear regime. This fact allows for the conclusion that the harmonics propagate following a linear scattering equation, although a nonlinear regime is required to generate them. Beside the experimental work, an estimation on the order of magnitude of the parameters that quantify nonlinearity and scattering phenomena is performed. The estimation shows that the Lighthill-Westervelt equation is as an accurate theoretical model for describing the multiple scattering of a nonlinear wave in the experiments.Adults benefit more from visual speech in speech maskers than in noise maskers because visual speech helps perceptually isolate target talkers from competing talkers. To investigate whether children use visual speech to perceptually isolate target talkers, this study compared children's speech recognition thresholds in auditory and audiovisual condition across two maskers two-talker speech and noise. Children demonstrated similar audiovisual benefit in both maskers. Individual differences in speechreading accuracy predicted audiovisual benefit in each masker to a similar degree. Results suggest that although visual speech improves children's masked speech recognition thresholds, children may use visual speech in different ways than adults.