The Auditory P50 Gating in Mild Cognitive Impairment: A Case-Control Study

Objective: Auditory P50 gating changed might be a neurophysiological biomarker of the diagnosis of Mild Cognitive Impairment (MCI). We aimed to determine the impact of MCI in auditory P50 gating. Methods: All recruited participants completed structured questionnaires and finished auditory P50 gating measure. Results: A total of 20 MCI patients and 17 controls had been recruited. MCI patients had a significant higher reduction of P50 gating at Fz site, when compared to controls (1.21 ± .68 vs .66 ± .37, P = .00). Zero point five was the best cut off point to distinguish MCI and control of auditory P50 gating S2/S1 at Fz site. The P50 average amplitude at Pz site in MCI patients was significantly higher than controls (2.62 ± 1.20 vs 1.70 ± .74, P = .01). Conclusion: MCI patients might have impaired the ability of inhibiting the repeated stimulus.

Impact of forest fire smoke on the state of the central nervous system of rats

Introduction. The adverse negative effect of forest fire smoke on human health represents a unique interdisciplinary challenge to the scientific community. The influence of forest fire smoke on locomotor activity, cognitive indices, and brain bioelectrical activity parameters in exposed rats is presented. Materials and methods. Experimental studies were carried out on outbred white male rats. The animals of the experimental group were exposed to smoke inhalation forest fire for one day. Immediately after the end of the exposure, the animals were examined, including testing in an open field and Morris water maze, as well as an electroencephalographic examination. Results. At twenty-four-hour exposure to wildfire smoke in the model, conditions showed increasing motor and research activity of male rats against the backdrop of growing anxiety. Disorders of indicators of spatial memory and navigation learning were not revealed. On the encephalogram of the exposed animals, in comparison with the control group, the δ-rhythm range predominated, more pronounced in the leads of the right hemisphere. A decrease in the power spectrum and the average amplitude β1-rhythm, as well as a tendency to decrease the average amplitude of θ-rhythm, were revealed. The indices of the primary EEG rhythms did not have statistically significant differences when compared with the control group. Conclusion. The results showed that forest fire smoke leads to changes in the bioelectric activity of brain structures and dysregulation of individual behaviour in animals, all of which may indicate the formation of increased levels of stressing beyond physiological adaptation.

Sea-Land Clutter Classification Based on Graph Spectrum Features

In this paper, an approach for radar clutter, especially sea and land clutter classification, is considered under the following conditions: the average amplitude levels of the clutter are close to each other, and the distributions of the clutter are unknown. The proposed approach divides the dataset into two parts. The first data sequence from sea and land is used to train the model to compute the parameters of the classifier, and the second data sequence from sea and land under the same conditions is used to test the performance of the algorithm. In order to find the essential structure of the data, a new data representation method based on the graph spectrum is utilized. The method reveals the nondominant correlation implied in the data, and it is quite different from the traditional method. Furthermore, this representation is combined with the support vector machine (SVM) artificial intelligence algorithm to solve the problem of sea and land clutter classification. We compare the proposed graph feature set with nine exciting valid features that have been used to classify sea clutter from the radar in other works, especially when the average amplitude levels of the two types of clutter are very close. The experimental results prove that the proposed extraction can represent the characteristics of the raw data efficiently in this application.

Application of methods of multidimensional statistical analysis for the classification of signal fragments during cutting processing

The preliminary processing of the signal coming from the vibration sensor is performed. Spectral analysis methods allow identifying the distinctive zones corresponding to three parameters: the average amplitude of vibrations, the average value of the spectrum, and the complex parameter of the vibration density obtained using interpolation methods. Hence, the vector contains the listed parameters as components produce a vector space, and the equations of separating surfaces in three-dimensional space and classification errors are calculated.

Intraoperative Serosal Extracellular Mapping of the Human Distal Colon: A Feasibility Study

Background:Cyclic motor patterns (CMP) are the predominant motor pattern in the distal colon, and are important in both health and disease. Their origin, mechanism and relation to bioelectrical slow-waves remain incompletely understood. During abdominal surgery, an increase in the CMP occurs in the distal colon. This study aimed to evaluate the feasibility of detecting propagating slow waves and spike waves in the distal human colon through intraoperative, high-resolution (HR), serosal electrical mapping. Methods:HR electrical recordings were obtained from the distal colon using validated flexible PCB arrays (6 x 16 electrodes; 4 mm inter-electrode spacing; 2.4 cm2, 0.3 mm diameter) for up to 15 minutes. Passive unipolar signals were obtained and analysed.Results:Eleven patients (33-71 years; six females) undergoing colorectal surgery under general anaesthesia (4 with epidurals) were recruited. After artifact removal and comprehensive manual and automated analytics, events consistent with regular propagating activity between 2-6 cpm were not identified in any patient. Intermittent clusters of spike-like activities lasting 10-180 s with frequencies of each cluster ranging between 24-42 cpm, and an average amplitude of 0.54 ± 0.37 mV were recorded.Conclusions:Intra-operative colonic serosal mapping in humans is feasible, but unlike in the stomach and small bowel, revealed no regular propagating electrical activity, although sporadic, synchronous spike-wave events were identifiable. Alternative techniques are required to characterise the mechanisms underlying the hyperactive CMP observed in the intra- and post-operative period.

Comparative Study on Transmission Performance of Manganese Phosphate Coated Gears

As an important part of transmission systems, coatings can improve the physical properties of gear surface. It is meaningful to research the effect of coating on the transmission performance of gears. In this paper, eight-degree-of-freedom dynamic response model of helical cylindrical gear is established considering friction, and the influence of friction factors on dynamic response is explored. The tribological properties and lubrication characteristics of the coating are investigated and compared with uncoated. The transmission performances of manganese phosphate conversion coated gears are studied experimentally. The results show that the coefficients of friction of Mn–P[C] coatings are reduced by 19%, the average amplitude and root mean square of vibration acceleration are obviously decreased, and the transmission efficiency is improved. The manganese phosphate conversion coating is beneficial to the transmission performance of gears.

Auditory cortex plasticity in musicians

Background The objective of this study was to verify wether it was possible to observe greater plasticity of the auditory cortex and greater benefits in terms of auditory processing, better discrimination, attention and identification of rare stimuli, in musicians, verified through the performance of Long Latency Auditory Evoked Potential, P300, with and without competitive noise, in musicians compared to non-musician. Methods 20 individuals were divided into two groups: 8 in the musicians, and 12 in the control group. The P300 values were compared between the two groups and then between the results of the P300 with and without competitive noise, in both groups. Results When comparing the results without competitive noise, it appears that the average amplitude was higher in the group of musicians compared to the control group, in both ears. Latency was lower in the control group, only in the right ear. With competitive noise, in both groups, the average amplitude is lower, compared to the results of the P300 without competitive noise, both in the right ear and in the left ear, and this effect is more considerable in the group of musicians. Regarding latency, theaverage of the P300 with competitive noise, in both ears, with a greater increase in latency values, in the group of musicians. Conclusion Musicians show a greater cortical inhibition effect compared to non-musicians, demonstrating that the musician’s central auditory system shows greater activation, which can result in better performance in functions such as attention and discrimination, due to training by musical practice.

Predictability of sinusoidally moving stimuli does not improve the accuracy of the accommodative response

Previous research work suggests that predictable target motion such as sinusoidal movement can be anticipated by the visual system, thereby improving the accommodative response. The validity of predictable motion for studying human dynamic accommodation is sometimes put into question. The aim of this work was to assess the effect of anticipation along with learning (and motivation, etc.) and fatigue (and boredom, loss of attention, etc.) on dynamic accommodation experiments from a practical perspective. Specifically, changes in amplitude and temporal phase lag were estimated within and between trials as 9 adult observers were instructed to focus on a stimulus that oscillated sinusoidally towards and away from the eye at specific temporal frequencies. On average, amplitude decreased whereas phase increased within trials. No evidence of anticipation or learning was observed either within or between trials. Fatigue consistently dominated anticipation and learning within the course of each trial. Even if the eye is equipped by a prediction operator as it is often assumed, fatigue confounds the results from dynamic accommodation experiments more than anticipation or learning.

Excellent Ductility in the Extruded AZ61 Magnesium Alloy Tube Induced by Electropulsing Treatment during Tension

In this work, we reported the high ductility of an extruded AZ61 magnesium alloy tube achieved by electropulsing current-assisted tension. The elongation of the alloy reached up to about 45%, which is largely superior to the majority of AZ61 wrought Mg alloys. We found that the hardening capacity of the alloy seemed to slightly increase as the electropulsing frequency increased. Furthermore, electropulsing can arouse the serrated flow phenomenon. Here we proposed an equation describing the correlation between the average amplitude and frequency: Aa = C − 6 × 10−3f, where Aa is the average amplitude, f is the frequency, and C is the constant. In addition, introducing electropulsing current pronouncedly reduced the tendency of twinning, but the twinning fraction seemed to fail depending on the electropulsing frequency. Based on microstructure analysis, we concluded that the outstanding ductility of the studied alloy was mainly due to the combined role of the thermal effects from Joule heating, the athermal effects from electron wind, and the magnetic effects from the electropulsing current. The serrated flow phenomenon occurred along stress–strain curves after electropulsing treatment, and the underlying reasons also were uncovered.

Intensity of Electromagnetic Wave into Layers with Fluctuations of Dielectric Permittivity

The study is made of the intensity of a plane electromagnetic wave propagating into the layer with random discrete irregularities of the dielectric permittivity. The mean intensity of scattered field as a function of the parameters of random irregularities of rectangular and triangular forms is analyzed. It is shown that the deviation of the average intensity from the unperturbed value increases both the average amplitude and its standard of fluctuations. It is found that the amplitude of the intensity oscillations for a layer with irregularities of the rectangular shape is significantly greater than for fluctuations with the triangular profile.