Does imbalance in chest X-ray datasets produce biased deep learning approaches for COVID-19 screening?

Background: The health crisis resulting from the global COVID-19 pandemic highlighted more than ever the need for rapid, reliable and safe methods of diagnosis and monitoring of respiratory diseases. To study pulmonary involvement in detail, one of the most common resources is the use different lung imaging modalities (like chest radiography) to explore the possible affected areas. Methods: In this work, we performed a comprehensive analysis of sex and age factors in chest X-ray images. The study of these recurrent patient characteristics in pathologies of this type is crucial, since there is a clear scarcity of data that may lead to biases when trying to develop systems that are as representative as possible, as well as to gain knowledge of the disease itself. To identify possible biases, we analyzed 3 different computational approaches for automatic COVID-19 screening: Normal vs COVID-19, Pneumonia vs COVID-19 and Non-COVID-19 vs COVID-19. The presented study was validated using two public chest X-ray datasets, allowing a reliable analysis to support the clinical decision-making process in the context of this dramatic global pandemic. Results: The obtained results for the sex-related imbalance analysis indicate that this factor slightly affects the system performance in the Normal VS COVID-19 and Pneumonia VS COVID-19 approaches, although the identified differences are not relevant enough to worsen considerably the system’s response. Regarding the age-related imbalance analysis, this factor was observed to be again influencing the system in a more consistent way than the sex factor, as it was present in all the approaches. Once again, this worsening is not a major problem for our data and system, as it is not of great magnitude. Conclusions: Multiple studies have been conducted in other fields in order to determine if certain patient characteristics such as sex or age influenced these deep learning systems. However, to the best of our knowledge, this study has not been done for COVID-19 despite the urgency and lack of COVID-19 chest x-ray images. The presented results evidenced that the proposed methodology and tested approaches allow a robust and reliable analysis to support the clinical decision-making process in this pandemic scenario.

Diversidade e abundância dos peixes comercializados no nordeste paraense, Amazônia costeira: o caso da feira livre de Bragança-PA

Bragança is an important municipality in Brazil regarding fishery production. In spite of its important for regional economy, data related to local fisheries such as the production and consumption profiles of commercial species are scarce. Therefore, the goal of this study was to provide an inventory of commercialized fishes in the street market of Bragança along with commercialization parameters. The data collection comprised information based on a questionnaire directed to fishmongers in two sites of the street market (“mercado” or indoor market and “feirinha” or outdoor market) for a 17-month period. The analyzed data included the abundance, seasonality and price of the commercialized species. A total of 103 commercial names were reported, representing about 98 species from 40 families and 15 orders. The indoor and outdoor market differed in relation to consumer’s profile and to the structure, volume, variety, quality and prices of commercial species. The volume and the diversity of commercial species in the indoor market were inferior to those observed in the outdoor market. The most abundant species in the outdoor market were influenced by dry and rainy seasons. This work represents the most reliable analysis in the street market of Bragança, being relevant to the management of regional fisheries. Keywords: Bragança, M. ancylodon, fishing dynamics, fish.

PROBLEMS OF METHODS FOR DETERMINING THE FINANCIAL CONDITION OF AN ENTERPRISE ON THE EXAMPLE OF JSC «VOSTOCHNAYA VERF»

The effective use of financial resources that ensure the work of any organization largely determines the results of economic activities. It follows from this that the key point in the functioning of the company is taking care of finances. In modern market conditions, organizations have acquired the independence of running and managing the economy, bear full economic responsibility for their decisions, and also manage the results of labor and resources. In this case, the financial success and well-being of the organization depends entirely on the effectiveness of the analysis of the financial condition. For a reliable analysis of bankruptcy, it is necessary to choose an assessment methodology that is suitable for the activities of the organization. This is the main problem of analysis: a large number of different ways create difficulties for diagnosing enterprise problems. When using standard approaches, the number of exceptions in the interpretation of the analysis results increases, and this causes an increase in the set of methods for analyzing the financial condition of an enterprise. With all this, a large number of different coefficients does not always improve the quality of the analysis, but often complicates its interpretation.

Preparation and analysis of pyrolysis oils

A critical review of the methods for producing pyrolysis waste oils was carried out, the possibilities and limitations of each approach were discussed. Liquid pyrolysis products (pyrolysis oils) are promising source of valuable chemical compounds, and can be also used as a fuel. A reliable analysis of pyrolysis oils is necessary to study their component composition, basic characteristics and to select the most suitable methods for the extraction of the necessary compounds. It is known that the results of GC-MS analysis of liquid pyrolysis products are usually ambiguous: there are problems of peaks overlapping and incorrect interpretation of the data, due to the complexity of the matrix and the multicomponent composition of the object. The paper presents data on the chemical composition of pyrolysis oils obtained by elemental analysis, IR spectroscopy, NMR spectrometry, GC-MS, GC-GC/MS. Based on the presented results, pyrolysis oil usually contains aromatic compounds, water-soluble substances and hydrocarbons. It was found out that there are conflicting data on the chemical composition of the pyrolysis oils of waste tires in the scientific literature. It is proposed to carry out sequential extraction sample preparation of pyrolysis mixtures to increase the reliability and accuracy of the componential and quantitative composition of the GC-MS method. Obviously, a reliable analysis of complex pyrolysis mixtures without preliminary targeted sample preparation seems unlikely.

Covert Jewish Sources of Christian Kabbalah: the Case of Guillaume Postel and ʿIyyun Traditions

The article focuses on Guillaume Postel’s Latin Zohar Commentary (1553), with the aim of uncovering a hitherto unknown influence of the medieval ʿIyyun Corpus on Postel’s Kabbalistic thought. Following a prefatory methodological exposition it is demonstrated that in addition to the more common Kabbalistic doctrines, such as those of the Zohar and other central theosophical-Kabbalistic treatises, Postel was also influenced by a different trend of Kabbalah, namely, the anonymous thirteenth-century mystical corpus originating in Languedoc, designated in scholarship as the ʿIyyun Writings. A reliable analysis of Kabbalistic Christian writings requires acquaintance with the writers’ sources, especially given the extent and divergence of medieval Kabbalistic literature. Therefore, we cannot make do with locating overt citations or references to known Kabbalistic treatises found in these writings, but also aim at uncovering covert Kabbalistic traditions which influenced them, as in the case of Postel and the ʿIyyun Corpus.