Decoding working memory-related information from repeated psychophysiological EEG experiments using convolutional and contrastive neural networks

Objective. Extracting reliable information from electroencephalogram (EEG) is difficult because the low signal-to-noise ratio and significant intersubject variability seriously hinder statistical analyses. However, recent advances in explainable machine learning open a new strategy to address this problem. Approach. The current study evaluates this approach using results from the classification and decoding of electrical brain activity associated with information retention. We designed four neural network models differing in architecture, training strategies, and input representation to classify single experimental trials of a working memory task. Main results. Our best models achieved an accuracy (ACC) of 65.29 ± 0.76 and Matthews correlation coefficient of 0.288 ± 0.018, outperforming the reference model trained on the same data. The highest correlation between classification score and behavioral performance was 0.36 (p = 0.0007). Using analysis of input perturbation, we estimated the importance of EEG channels and frequency bands in the task at hand. The set of essential features identified for each network varies. We identified a subset of features common to all models that identified brain regions and frequency bands consistent with current neurophysiological knowledge of the processes critical to attention and working memory. Finally, we proposed sanity checks to examine further the robustness of each model's set of features. Significance. Our results indicate that explainable deep learning is a powerful tool for decoding information from EEG signals. It is crucial to train and analyze a range of models to identify stable and reliable features. Our results highlight the need for explainable modeling as the model with the highest ACC appeared to use residual artifactual activity

Polimorfizm w genie N-acetylotransferazy 2 u chorych na raka płuca. Doniesienie wstępne

Introduction: Individual’s risk of developing lung cancer depends not only on exposure to tobacco smoke, but also on the activity of enzymes involved in the activation or deactivation of carcinogens. Arylamine N-acetyltransferase (EC 2.3.1.5) is an enzyme involved in biotransformation of xenobiotics, mainly aromatic and heterocyclic amines and hydrazines. The different acetylation phenotypes within a population are derived from mutations in the NAT 2 gene. These mutations influence the activity (specifically resulting in high or low activity) of the NAT enzyme. Some authors have demonstrated lung cancer predisposing role of slow acetylator phenotype, whereas other reported increased lung cancer risk for fast acetylators or neutral effect of the NAT2 polymorphism. The aim of this preliminary report was to determine the NAT2 gene polymorphism in patients with lung cancer. Material and methods: 39 patients with inoperable lung cancer (29 — NSCLC and 10 — SCLC), median age 59 years (42– –72) entered the study. Acetylation genotype was determined in the genomic DNA using an allele-specific polymerase chain reaction. We investigated four genetic mutations, C481T, G590A, A803G i G857A, of the gene NAT2. Results: There were 10 different NAT2 genotypes among the 39 patients. Fourteen patients with a NAT2*2 4/4, *4/5, *4/6 and *4/7 were classified as fast acetylators; and 25 patients with a NAT2*5/5, *5/6, *5/7, *6/6, *6/7 or *7/7 genotype were classified as slow acetylators. Among the 10 patients with SCLC — 4 were fast acetylators, and among 29 patients with NSCLC dominated slow acetylation type found in 19 patients (genotypes NAT2 *5/5 and NAT2 *5/6). Conclusions: Among patients with small cell lung cancer, there was no predominance of genotype of acetylation, whereas among patients with non-small cell lung cancer predominated NAT2*5/5 and NAT2*5/6 genotypes (slow acetylators).Wstęp: Indywidualne ryzyko zachorowania na raka płuca zależy nie tylko od ekspozycji na dym tytoniowy, ale również od aktywności enzymów biorących udział w aktywacji lub deaktywacji substancji rakotwórczych. Arylamino N-acetylotransferazy (EC 2.3.1.5) są enzymami biorącymi udział w biotransformacji ksenobiotyków, amin aromatycznych i heterocyklicznych oraz hydrazyn. Zaobserwowane różnice w aktywności enzymu i szybkości metabolizowania substancji zależnych od N-acetylotransferazy 2 (NAT2) powiązano z polimorfizmem genu kodującego ten enzym. Niektórzy autorzy wskazują na wolny typ acetylacji, jako predysponujący do wystąpienia raka płuca, podczas gdy inni wykazują brak wpływu polimorfizmu NAT2 lub większe ryzyko raka płuca wśród szybkich acetylatorów. Celem pilotażowego badania była ocena polimorfizmu genu NAT2 umożliwiającego określenie typu acetylacji u chorych na raka płuca. Materiały i metody: Badaną grupę stanowiło 39 chorych na nieoperacyjnego raka płuca (29 — rak niedrobnokomórkowy, 10 — rak drobnokomórkowy), mediana wieku wynosiła 59 lat (42–72 lata). Do badania pobierano 5 ml krwi. Genotyp NAT2 został określony na podstawie identyfikacji czterech mutacji, C481T, G590A, A803G i G857A. Wyniki: W przebadanej grupie 39 chorych zidentyfikowano występowanie 10 różnych genotypów NAT2. Czternastu chorych z genotypami NAT2 *4/4, *4/5, *4/6 i *4/7 zostało sklasyfikowanych jako szybcy acetylatorzy a 25 z genotypami NAT2 *5/ 5, *5/6, *5/7, *6/6, *6/7 lub *7/7 jako wolni acetylatorzy. Wśród 10 chorych na DRP — 4 chorych to szybcy acetylatorzy, zaś wśród 29 chorych na NDRP dominował wolny typ acetylacji stwierdzony u 19 chorych (genotypy NAT2*5/5 i NAT2*5/6). Wnioski: Wśród chorych na drobnokomórkowego raka płuca nie stwierdzono dominacji określonego genotypu acetylacji, natomiast wśród chorych na niedrobnokomórkowego raka płuca przeważali pacjenci z genotypami NAT2*5/5 i NAT2*5/6 (wolni acetylatorzy)

Graphene on quartz modified with rhenium oxide as a semitransparent electrode for organic electronic

Our research shows that commercially available graphene on quartz modified with rhenium oxide meets the requirements for its use as a conductive and transparent anode in optoelectronic devices. The cluster growth of rhenium oxide enables an increase in the work function of graphene by 1.3 eV up to 5.2 eV, which guarantees an appropriate adjustment to the energy levels of the organic semiconductors used in OLED devices.Comment: 8 pages, 3 figure

2011 SOSORT guidelines: Orthopaedic and Rehabilitation treatment of idiopathic scoliosis during growth

<p>Abstract</p> <p>Background</p> <p>The International Scientific Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT), that produced its first Guidelines in 2005, felt the need to revise them and increase their scientific quality. The aim is to offer to all professionals and their patients an evidence-based updated review of the actual evidence on conservative treatment of idiopathic scoliosis (CTIS).</p> <p>Methods</p> <p>All types of professionals (specialty physicians, and allied health professionals) engaged in CTIS have been involved together with a methodologist and a patient representative. A review of all the relevant literature and of the existing Guidelines have been performed. Documents, recommendations, and practical approach flow charts have been developed according to a Delphi procedure. A methodological and practical review has been made, and a final Consensus Session was held during the 2011 Barcelona SOSORT Meeting.</p> <p>Results</p> <p>The contents of the document are: methodology; generalities on idiopathic scoliosis; approach to CTIS in different patients, with practical flow-charts; literature review and recommendations on assessment, bracing, physiotherapy, Physiotherapeutic Specific Exercises (PSE) and other CTIS. Sixty-five recommendations have been given, divided in the following topics: Bracing (20 recommendations), PSE to prevent scoliosis progression during growth (8), PSE during brace treatment and surgical therapy (5), Other conservative treatments (3), Respiratory function and exercises (3), Sports activities (6), Assessment (20). No recommendations reached a Strength of Evidence level I; 2 were level II; 7 level III; and 20 level IV; through the Consensus procedure 26 reached level V and 10 level VI. The Strength of Recommendations was Grade A for 13, B for 49 and C for 3; none had grade D.</p> <p>Conclusion</p> <p>These Guidelines have been a big effort of SOSORT to paint the actual situation of CTIS, starting from the evidence, and filling all the gray areas using a scientific method. According to results, it is possible to understand the lack of research in general on CTIS. SOSORT invites researchers to join, and clinicians to develop good research strategies to allow in the future to support or refute these recommendations according to new and stronger evidence.</p

Modular Approach for Modelling Warming up Process in Water Installations with Flow-Regulating Elements

The paper presents a new method for modelling the warming up process of a water system with elements regulating the flow in a stochastic manner. The paper presents the basic equations describing the work of typical elements which the water installation is composed of. In the proposed method, a new computational algorithm was used in the form of an iterative procedure enabling the use of boundary conditions that can be stochastically modified during the warming-up process. A typical situation, when such a modification is processed, is the regulation of the medium flow through two-way or three-way valves or applying additional heat source. Moreover, the presented method does not require the transformation of the differential equations, describing the operation of individual elements, into a linear form, which significantly facilitates analytical work and makes it more flexible. The example of analysis of the operation of water installation used for controlling temperature of the process gases in a chemical installation shows the functionality and flexibility of the method. The adopted calculation schematics enable changing the direction of the heat flow while the heat exchanger is in operation. Additionally, the sequence of calculation processed in modules describing operation of installation elements is elective (there is no situation that output parameters from one element are used as input parameters for other element in the same calculation step)

Purification of model biogas from toluene using deep eutectic solvents

Biogas from landfills and wastewater treatment facilities typically contain a wide range of volatile organic compounds (VOCs), that can cause severe operational problems when biogas is used as fuel. Among the contaminants commonly occur aromatic compounds, i.e. benzene, ethylbenzene, toluene and xylenes (BTEX). In order to remove BTEX from biogas, different processes can be used. A promising process for VOCs removal is their absorption in deep eutectic solvents (DES). In this work, three DES: ([ChCl] U TEG [choline chloride]:urea:tetraethylene glycol (1:2:2), [ChCl] U [choline chloride]:urea (1:2), [ChCl] DEG [choline chloride]:diethylene glycol (1:2)) and water were tested to toluene absorption in concentration of 2000 ppm v/v in nitrogen stream. The results demonstrated the high absorption capacity of toluene using DES based on glycols

Recent Progress on Hydrogen Storage and Production Using Chemical Hydrogen Carriers

Depleting fossil fuel resources and anthropogenic climate changes are the reasons for the intensive development of new, sustainable technologies based on renewable energy sources. One of the most promising strategies is the utilization of hydrogen as an energy vector. However, the limiting issue for large-scale commercialization of hydrogen technologies is a safe, efficient, and economical method of gas storage. In industrial practice, hydrogen compression and liquefaction are currently applied; however, due to the required high pressure (30–70 MPa) and low temperature (−253 °C), both these methods are intensively energy consuming. Chemical hydrogen storage is a promising alternative as it offers safe storage of hydrogen-rich compounds under ambient conditions. Although many compounds serving as hydrogen carriers are considered, some of them do not have realistic perspectives for large-scale commercialization. In this review, the three most technologically advanced hydrogen carriers—dimethyl ether, methanol, and dibenzyltoluene—are discussed and compared. Their potential for industrial application in relation to the energy storage, transport, and mobility sectors is analyzed, taking into account technological and environmental aspects

Impact of EEG Frequency Bands and Data Separation on the Performance of Person Verification Employing Neural Networks

The paper is devoted to the study of EEG-based people verification. Analyzed solutions employed shallow artificial neural networks using spectral EEG features as input representation. We investigated the impact of the features derived from different frequency bands and their combination on verification results. Moreover, we studied the influence of a number of hidden neurons in a neural network. The datasets used in the analysis consisted of signals recorded during resting state from 29 healthy adult participants performed on different days, 20 EEG sessions for each of the participants. We presented two different scenarios of training and testing processes. In the first scenario, we used different parts of each recording session to create the training and testing datasets, and in the second one, training and testing datasets originated from different recording sessions. Among single frequency bands, the best outcomes were obtained for the beta frequency band (mean accuracy of 91 and 89% for the first and second scenarios, respectively). Adding the spectral features from more frequency bands to the beta band features improved results (95.7 and 93.1%). The findings showed that there is not enough evidence that the results are different between networks using different numbers of hidden neurons. Additionally, we included results for the attack of 23 external impostors whose recordings were not used earlier in training or testing the neural network in both scenarios. Another significant finding of our study shows worse sensitivity results in the second scenario. This outcome indicates that most of the studies presenting verification or identification results based on the first scenario (dominating in the current literature) are overestimated when it comes to practical applications

Recent Progress on Hydrogen Storage and Production Using Chemical Hydrogen Carriers

Depleting fossil fuel resources and anthropogenic climate changes are the reasons for the intensive development of new, sustainable technologies based on renewable energy sources. One of the most promising strategies is the utilization of hydrogen as an energy vector. However, the limiting issue for large-scale commercialization of hydrogen technologies is a safe, efficient, and economical method of gas storage. In industrial practice, hydrogen compression and liquefaction are currently applied; however, due to the required high pressure (30&ndash;70 MPa) and low temperature (&minus;253 &deg;C), both these methods are intensively energy consuming. Chemical hydrogen storage is a promising alternative as it offers safe storage of hydrogen-rich compounds under ambient conditions. Although many compounds serving as hydrogen carriers are considered, some of them do not have realistic perspectives for large-scale commercialization. In this review, the three most technologically advanced hydrogen carriers&mdash;dimethyl ether, methanol, and dibenzyltoluene&mdash;are discussed and compared. Their potential for industrial application in relation to the energy storage, transport, and mobility sectors is analyzed, taking into account technological and environmental aspects