EEG MICROSTATES ANALYSIS IN PATIENTS WITH EPILEPSY

Analysis of EEG microstates is a promising topographical method that is currently being studied for diagnosis of neuro-psychiatric diseases such as schizophrenia, dementia, etc. The aim of our study is to describe the possibility of using the microstate analysis of electroencephalographic recordings (EEG) for examination of the epileptic activity. The EEG recordings were measured on patients with epilepsy and on control subjects (with no epileptic pathology) in the system 10 - 20. The data are analysed in average montage and filtered with bandpass from 0.5 to 30.0 Hz. We calculate the global field power (GFP) curve to extract microstates from the EEG recordings. We take local maxima (peaks) of GFP curve to create amplitude topographic maps. The microstate 1 seems to have higher occurrence for the non-epileptic controls than the patients with epilepsy. The duration of the microstate 4 seems to be higher in the epileptic patients than the non-epileptic controls. We have found that there is a significant difference in the duration, occurrence and contribution of the amplitude topographic maps between the non-epileptic controls and the patients with epilepsy

Weather sensitivity in migraineurs

The scientific evidence for weather being a trigger factor for migraine attacks is inconclusive. We investigated the association between weather components and the onset and severity of attacks. Headache diaries of 20 migraineurs were analyzed retrospectively and correlated in 4-h intervals to atmospheric air pressure, temperature, and relative air humidity in Berlin (Germany) for a period of 12 consecutive months. Absolute values and relative changes within the preceding 24 h were analyzed. Migraine attacks started most frequently at 4 a.m. and reached the highest intensity between 4 and 8 a.m. A highly significant association between meteorological variables and the occurrence of migraine attacks was found in six patients. The onset of an attack as well as high headache intensity was associated with lower temperature and higher humidity. Our data indicate that a subgroup of migraineurs is highly sensitive to changes of certain weather components

Ground Water Chemistry Changes before Major Earthquakes and Possible Effects on Animals

Prior to major earthquakes many changes in the environment have been documented. Though often subtle and fleeting, these changes are noticeable at the land surface, in water, in the air, and in the ionosphere. Key to understanding these diverse pre-earthquake phenomena has been the discovery that, when tectonic stresses build up in the Earth’s crust, highly mobile electronic charge carriers are activated. These charge carriers are defect electrons on the oxygen anion sublattice of silicate minerals, known as positive holes, chemically equivalent to O− in a matrix of O2−. They are remarkable inasmuch as they can flow out of the stressed rock volume and spread into the surrounding unstressed rocks. Travelling fast and far the positive holes cause a range of follow-on reactions when they arrive at the Earth’s surface, where they cause air ionization, injecting massive amounts of primarily positive air ions into the lower atmosphere. When they arrive at the rock-water interface, they act as •O radicals, oxidizing water to hydrogen peroxide. Other reactions at the rock-water interface include the oxidation or partial oxidation of dissolved organic compounds, leading to changes of their fluorescence spectra. Some compounds thus formed may be irritants or toxins to certain species of animals. Common toads, Bufo bufo, were observed to exhibit a highly unusual behavior prior to a M6.3 earthquake that hit L’Aquila, Italy, on April 06, 2009: a few days before the seismic event the toads suddenly disappeared from their breeding site in a small lake about 75 km from the epicenter and did not return until after the aftershock series. In this paper we discuss potential changes in groundwater chemistry prior to seismic events and their possible effects on animals

Distribution, abundance and habitat selection of northern pygmy and barred owls along the eastern slopes of the Alberta Rocky mountains

Bibliography: p. 87-100.Surveys for northern pygmy (NPOW) and barred (BAOW) owls were conducted to determine distribution, abundance and habitat selection along Alberta's eastern slopes. The effect of environmental conditions on owl response rates was examined and density estimates were produced using an analytical method that models variation in species detectability (distance sampling). Both species were widely distributed and occurred at low densities throughout the study area (NPOW: D=0.048 birds/km2, CVb=55.8, BAOW: D=0.025 birds/km2, CVb=30. 7). Stepwise logistic and autologistic regression were used to develop predictive models for each species. Autologistic models accounted for observed spatial dependencies. All models considered biophysical variable selection at two spatial scales, minimum and maximum home range. Habitat selection models will enable managers to set and reach habitat goals by quantifying species habitat requirements and determining predicted habitat availability based on management actions

Guidance for reclamation planning to achieve multiple end land uses

In the Athabasca oil sands region, large open-pit mining operations require reclamation to restore the landscape. Oil sand mine operators responsible for reclamation use a revegetation guidance manual, Guidelines for Reclamation to Forest Vegetation in the Athabasca Oil Sands Region, 2nd Edition (the revegetation manual) (Alberta Environment 2010), which is a guidance document that is both a technical document and a planning tool. Operators use the revegetation manual in the development of revegetation plans for reclamation of terrestrial ecosystems, and are required to use the revegetation manual under their Environmental Protection and Enhancement Act (EPEA) approvals. Associated Environmental Consultants along with Integral Ecology Group worked with the Terrestrial Subgroup (TSG) of the Cumulative Environmental Management Association (CEMA) to revise the revegetation manual in preparation for its third update in 2017. Our input focussed on techniques to establish upland forest ecosystems to support multiple end land uses, specifically commercial forestry, wildlife habitat, aboriginal traditional use, and recreation. The approach to changes to the guidance document involved multi-stakeholder collaboration and in the end it provided guidance on working with indigenous communities in reclamation planning. Recommended changes to the manual include: 1) alternative decision-flow charts to guide reclamation planning, and 2) detailed checklists to provide guidance and a way of tracking reclamation inputs towards specific end land uses.Non UBCUnreviewedOthe

Artifacts in Simultaneous hdEEG/fMRI Imaging: A Nonlinear Dimensionality Reduction Approach

Simultaneous recordings of electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) are at the forefront of technologies of interest to physicians and scientists because they combine the benefits of both modalities—better time resolution (hdEEG) and space resolution (fMRI). However, EEG measurements in the scanner contain an electromagnetic field that is induced in leads as a result of gradient switching slight head movements and vibrations, and it is corrupted by changes in the measured potential because of the Hall phenomenon. The aim of this study is to design and test a methodology for inspecting hidden EEG structures with respect to artifacts. We propose a top-down strategy to obtain additional information that is not visible in a single recording. The time-domain independent component analysis algorithm was employed to obtain independent components and spatial weights. A nonlinear dimension reduction technique t-distributed stochastic neighbor embedding was used to create low-dimensional space, which was then partitioned using the density-based spatial clustering of applications with noise (DBSCAN). The relationships between the found data structure and the used criteria were investigated. As a result, we were able to extract information from the data structure regarding electrooculographic, electrocardiographic, electromyographic and gradient artifacts. This new methodology could facilitate the identification of artifacts and their residues from simultaneous EEG in fMRI

Real-Time Excitation of Slow Oscillations during Deep Sleep Using Acoustic Stimulation

Slow-wave synchronous acoustic stimulation is a promising research and therapeutic tool. It is essential to clearly understand the principles of the synchronization methods, to know their performances and limitations, and, most importantly, to have a clear picture of the effect of stimulation on slow-wave activity (SWA). This paper covers the mentioned and currently missing parts of knowledge that are essential for the appropriate development of the method itself and future applications. Artificially streamed real sleep EEG data were used to quantitatively compare the two currently used real-time methods: the phase-locking loop (PLL) and the fixed-step stimulus in our own implementation. The fixed-step stimulation method was concluded to be more reliable and practically applicable compared to the PLL method. The sleep experiment with chronic insomnia patients in our sleep laboratory was analyzed in order to precisely characterize the effect of sound stimulation during deep sleep. We found that there is a significant phase synchronization of delta waves, which were shown to be the most sensitive metric of the effect of acoustic stimulation compared to commonly used averaged signal and power analyses. This finding may change the understanding of the effect and function of the SWA stimulation described in the literature

Identification of a sequence motif upstream of the Drosophila Dopa decarboxylase gene that enhances heterologous gene expression

In this paper we have examined the role that element S, a DNA sequence motif found approximately 215 bp upstream of the Dopa decarboxylase (Ddc) gene, might play in regulating Ddc expression. Nearly identical versions of the element are present upstream of four other Drosophila genes. For two of these, the element appears to be an important component of the upstream regulatory region, since mutations in it reduce expression of the downstream gene. Because an element S polymorphism differentiates the Ddc+ allele of an inbred laboratory strain from the Ddc+4 allele present in a strain isolated from the wild, we decided to test the activity of both forms. Oligonucleotides containing Ddc+ or Ddc+4 versions of element S were synthesized and their ability to drive the expression of an heterologous (Adh) reporter gene at the second molt was examined. Transgenic larvae carrying the element S – Adh fusion constructs consistently exhibited Adh levels that were elevated 1.5-fold above those seen in control organisms..., Les auteurs ont étudié le rôle que peut jouer un élément S dans la régulation de l\u27expression du gène de la décarboxylase (Ddc) de Dopa; un élément S est un motif séquentiel d\u27ADN situé à environ 215 pb en amont du gène Ddc. Des versions presque identiques de cet élément sont présentes en amont de quatre autres gènes du Drosophila. Pour deux d\u27entre eux, l\u27élément semble être un composant important de la région régulatrice de l\u27amont, puisque les mutations dans cette région réduisent l\u27expression de l\u27aval du gène. Du fait que le polymorphisme de l\u27élément S différencie l\u27allèle Ddc+ d\u27une souche croisée en laboratoire de l\u27allèle Ddc+ d\u27une souche indigène isolée, il a été décidé de tester l\u27activité de ces deux formes. Des oligonucléotides contenant les versions Ddc+ ou Ddc+4 de l\u27élément S ont été synthétisés et leur aptitude à accroître l\u27expression d\u27un gène rapporteur hétérologue (Adh), lors du second stade de mue (« molt ») a été étudiée. Des larves transgéniques, porteuses de formation de fusions ..

Apnea Detection in Polysomnographic Recordings Using Machine Learning Techniques

Sleep disorders are diagnosed in sleep laboratories by polysomnography, a multi-parameter examination that monitors biological signals during sleep. The subsequent evaluation of the obtained records is very time-consuming. The goal of this study was to create an automatic system for evaluation of the airflow and SpO2 channels of polysomnography records, through the use of machine learning techniques and a large database, for apnea and desaturation detection (which is unusual in other studies). To that end, a convolutional neural network (CNN) was designed using hyperparameter optimization. It was then trained and tested for apnea and desaturation. The proposed CNN was compared with the commonly used k-nearest neighbors (k-NN) method. The classifiers were designed based on nasal airflow and blood oxygen saturation signals. The final neural network accuracy for apnea detection reached 84%, and that for desaturation detection was 74%, while the k-NN classifier reached accuracies of 83% and 64% for apnea detection and desaturation detection, respectively