Impact of the COVID-19 pandemic on college students' mental health and lifestyle factors.

This study examines how mental health and health behaviors evolved among college students nationwide before and during the onset of the COVID-19 pandemic. Data collected from college students across various campuses in Fall 2019 ( = 33,372) and Fall 2020 ( = 34,168) as part of the Healthy Minds Study. : The online survey was delivered Qualtrics.

A universal automated tool for reliable detection of seizures in rodent models of acquired and genetic epilepsy.

Objective: Prolonged electroencephalographic (EEG) monitoring in chronic epilepsy rodent models has become an important tool in preclinical drug development of new therapies, in particular those for antiepileptogenesis, disease modification, and treating drug-resistant epilepsy. We have developed an easy-to-use, reliable, computational tool for automated detection of electrographic seizures from prolonged EEG recordings in rodent models of epilepsy.

Methods: We applied a novel method based on advanced time-frequency analysis that detects EEG episodes with excessive activity in certain frequency bands.

Quantum theory of mass potentials.

Probabilistic formalism of quantum mechanics is used to quantitatively link the global scale mass potential with the underlying electrical activity of excitable cells. Previous approaches implemented methods of classical physics to reconstruct the mass potential in terms of explicit physical models of participating cells and the volume conductor. However, the multiplicity of cellular processes with extremely intricate mixtures of deterministic and random factors prevents the creation of consistent biophysical parameter sets.

Cortical arousal in children and adolescents with functional neurological symptoms during the auditory oddball task.

Objective: Stress, pain, injury, and psychological trauma all induce arousal-mediated changes in brain network organization. The associated, high level of arousal may disrupt motor-sensory processing and result in aberrant patterns of motor function, including functional neurological symptoms. We used the auditory oddball paradigm to assess cortical arousal in children and adolescents with functional neurological symptom disorder.

Increasing sensitivity in the measurement of heart rate variability: the method of non-stationary RR time-frequency analysis.

A novel method of the time-frequency analysis of non-stationary heart rate variability (HRV) is developed which introduces the fragmentary spectrum as a measure that brings together the frequency content, timing and duration of HRV segments. The fragmentary spectrum is calculated by the similar basis function algorithm. This numerical tool of the time to frequency and frequency to time Fourier transformations accepts both uniform and non-uniform sampling intervals, and is applicable to signal segments of arbitrary length.

Is borderline personality a particularly right hemispheric disorder? A study of P3a using single trial analysis.

Objective: To test the hypothesis that borderline personality disorder is a manifestation of a particularly right hemispheric disturbance, involving deficient higher order inhibition, and to consider the therapeutic implications of the findings.

Methods: A cohort of 17 medication free borderline patients were compared with 17 age and sex matched controls by means of a study of p3a, which reflects the activity of one of the two main generators of the P300 (P3) of the event-related-potential. P3b reflects the output of the other generator.

Somatization and stimulus entrapment.

A "vicious circle" hypothesis is put forward for the common kind of somatization which forms the basis of the DSM's "somatization disorder." Two compounding mechanisms are seen to be operative: (1) a failure of higher order inhibitory systems involved in the "medial pain system"; (2) amplification of stimulus intensity produced by the effect of attention. Attentional failure is produced not only by social factors but also by failure of sensory intensity modulation consequent upon (1).

Dynamic spectral analysis findings in first episode and chronic schizophrenia.

The quantified analysis of the electroencephalogram (qEEG) has enabled the extraction of additional psychophysiological information from the raw EEG, but in turn has introduced a number of distortions. This study compared Dynamic Spectral Analysis (DSA), a novel and mathematically stringent technique for the evaluation of qEEG activity with conventional power spectral analysis in subjects with both first episode and chronic schizophrenia and matched controls. Advantages of the technique in the automated processing of data, rejection of artefact, avoidance of artefact introduced by the mathematical trans-formation of the data and the identification of irregular low frequency artefactual activity "pi" are discussed in detail.

Distinct pattern of P3a event-related potential in borderline personality disorder.

P3a and P3b event-related brain potentials to auditory stimuli were recorded for 17 unmedicated patients with borderline personality disorder, 17 matched healthy controls and 100 healthy control participants spanning five decades. Using high-resolution fragmentary decomposition for single-trial event-related potential analysis, distinctive disturbances in P3a in borderline personality disorder patients were found: abnormally enhanced amplitude, failure to habituate and a loss of temporal locking with P3b. Normative age dependencies from 100 controls suggest that natural age-related decline in P3a amplitude is reduced in borderline personality disorder patients and is likely to indicate failure of frontal maturation.

Sex differences in adult ADHD: a double dissociation in brain activity and autonomic arousal.

It is now estimated that up to one-half of attention deficit hyperactivity disorder (ADHD) children continue to manifest symptoms in adulthood. A striking discrepancy between juvenile and adult populations is the increasing proportion of females with an ADHD diagnosis. To shed light on the psychophysiological mechanisms underlying adult ADHD, electroencephalography (EEG) and electrodermal index of arousal (skin conductance level or SCL) measures were employed under conditions of eyes-closed resting activity.

High-resolution fragmentary decomposition--a model-based method of non-stationary electrophysiological signal analysis.

Fragmentary decomposition (FD) is a recently developed method of non-stationary electrophysiological signal analysis addressed to mass potentials, such as electromyogram (EMG), event-related potential (ERP), evoked potential, electroencephalogram (EEG), electroretinogram, etc. Being supported by the generally accepted physiological notion that a peak is a functionally meaningful component of a mass potential, FD provides a way to avoid averaging and, instead, quantifies the component composition of complex electrophysiological signals directly from single-trials. The major computational procedures of FD include adaptive segmentation, the frequency domain component identification, and creation of the signal model as a linear aggregation of multiple components, with the generic mass potential (GMP) being the universal component template.

Single-event-related potential analysis by means of fragmentary decomposition.

A recently developed fragmentary decomposition method is employed to analyse single-trial event-related potentials (ERPs), thereby extending the traditional method of averaging. Using a conventional auditory oddball paradigm with 40 target stimuli, single-trial ERPs in 40 normal subjects were analysed for midline scalp (Fz, Cz and Pz) recording sites. The normalization effect, reported in our previous study of eye blink EMGs and proposed to be a characteristic property of a wide class of non-stationary physiological processes, was found to apply to these single-trial ERPs.

Numerical fourier transform spectroscopy of EMG half-waves: fragmentary-decomposition-based approach to nonstationary signal analysis.

A nonstationary signal analysis technique is introduced, which regards an oscillatory physiological signal as a sum of its fragments, presented in the form of a fragmentary decomposition (FD). The virtue of FD is that it is free of the necessity to choose a priori the basis functions intended for signal analysis or synthesis. FD uses an unchanged signal fragment between adjacent zero-crossings, as a natural basis function called the half-wave function (HWF).

[A conservative compression surgical orthodontic method for treating upper prognathism in adults].

A clinical example of effective treatment of an adult patient with combined deformations of the jaws (upper prognathism of the third degree and open occlusion of the second degree) is reported. Fragmented osteotomy of the maxilla at the level of symmetrical removal of second molars is performed. Due to Engle's arches soldered with Vasil'ev's splint and compression, a maxillary fragment was shifted 10 mm backward and downward at the expense of compressing the inter-root septae; the first molars were preserved.

Dynamic spectral analysis of event-related potentials.

This paper presents a new method for the identification of individual event related potential (ERP) components in both frequency and time domains. Using the similar basis function (SBF) algorithm the method provides a time to frequency transform, representing a frequency domain equivalent of the component waveform. Notable features of the SBF algorithm are that it allows for unevenly spaced sampled functions in both the time and frequency domains, and estimates of spectral densities are obtained by numerical computation of finite Fourier integrals.

Novel approach to a quantitative treatment of the quantal transmitter release at the frog neuromuscular junction.

To explain the discrepancy between estimates of parameters of quantal transmitter release received by different techniques the paper postulates a novel concept for quanta mobilization, which assumes that a quantum emitted by a vesicle transiently acquires a transition state in which it is immediately available for release. The working particle model is formulated in terms of probabilities of inter-state quanta transitions. The parameters of the model are determined by fitting solutions to the experimental curves representing short-term changes of synaptic efficacy at the frog neuromuscular junction as well as taking into account the morphologically estimated number of releasable vesicles.

Stochastic particle formulation of the vesicle hypothesis. Relevance to short-term phenomena.

Based on the vesicle hypothesis, the modes of elementary quantum-vesicle interactions have been formulated in terms of probabilities of induced and spontaneous interstate quanta transitions and generalized within the framework of the previously developed theory of the double barrier synapse. Among the three allowed states for a quantum, the transition state is a novel formulation for the fraction of immediately available quanta governed by both vesicle and presynaptic membranes. The parameters of the model were determined by fitting solutions to the experimental curves representing effects of single pulse and short train activation on transmitter release at the frog neuromuscular junction.

Direct evidence for the synaptic resonance phenomenon.

Via the parameter optimization method, well documented in the literature, data on the facilitated release of acetylcholine from the preganglionic nerve terminals during short trains of impulses have been quantitatively generalized within the framework of the previously developed theory of the double barrier synapse. This allowed unique transformation of the set of discrete measurements of facilitated transmitter release into continuous dependencies of facilitation on time and frequency and, subsequently, into the resonant curves having very readily interpreted computational meaning. Thus direct evidence is produced that an overall effect of facilitory action of presynaptic stimulation does indeed reflect resonant properties of the terminal in a form of the previously predicted synaptic resonance phenomenon.

Transient analysis of a chemical synaptic transmission.

The statistical dynamics of an impulse induced quanta turnover is studied by means of a nonstationary stochastic model--double barrier synapse--resulting from a previously developed mathematical theory of chemical synaptic transmission. An essential aspect of nonstationarities of the model is that the interpool quanta transfers follow binomial distribution at impulse arrival time, while in the absence of stimulation they obey Yule-Furry statistics. Under a variety of conditions, corresponding to those in actual experiments, the transient behaviour of the model is simulated and analysed in detail.

Pattern dependent form of synaptic modification and its quantal origins.

Presynaptic mechanisms of post-activation changes of synaptic efficacy have been quantitatively reconstructed via computer simulations with the previously suggested double-barrier quantal model of a chemical synapse. Successful in predicting the global changes in synaptic efficacy during and after short trains of presynaptic impulses, computer reconstructions have revealed in the post-activation period the stimulus dependent form of synapse modification from short-term to longer-term plasticity. An analysis of the quantal origins of the phenomenon suggests semantic or S-pattern as the trigger of the phenomenon.

Double barrier quantal model of neurotransmitter release.

As an extension of the particle concept in the quantitative descriptive of an entire neurotransmitter population, which participates in quanta release from the terminal, an improved system of quantal postulates is suggested. An essential aspect of the corresponding double barrier quantal model is its nonstationarity, resulting from combined application of binomial and Yule-Furry statistics. Results of the computer simulations show that the model combines enough ingredients to reproduce, with fair accuracy, the main characteristic features of short-term changes of synaptic efficacy under the different conditions of presynaptic stimulation.

[Possibility of predicting and preventing psychotic disorders during ketamine anesthesia].

The results of ketamine anesthesia are analyzed in 327 patients after stomach resection and cholecystectomy. Preoperative determination of nervous system type, using MMPI test, has revealed maximum incidence of psychotic disorders after ketamine anesthesia in anosognosia syndrome and paranoia. Administration of a neurometabolic stimulator nootropil (pyracetam) prior to extubation in 143 patients decreased the incidence of psychotic disorders from 23.