IMAGE CONVERSION OF ϭ- AND π-COMPONENTS OF RADIATION OF RELATIVISTIC ELECTRON AND METROLOGICAL CHARACTERISTICS OF THE PHOTON FLUX IN THE SYNCHROTRON RADIATION OUTLET

The paper deals with the efficiency of the capture of a photon flux of the synchrotron radiation (SR) σ- and π-components by the optical window in the SR quantum extraction channel of the NESTOR generator. It also anal-yses the dependence between the capture quality and different radiation wavelengths. Consideration has been giv-en to the beam size effect on the shape and dimensions of the angular distribution of the photon flux. A model has been constructed to describe the optical imaging in the registration plane. Expressions are given for estimating the efficiency of the capture of SR quanta into the optical window of the extraction channel. The factors that exert influence on the efficiency of capturing through the window are analyzed. Examples of numerical calculations are provided for formation of the final SR spectral density of the 225 MeV relativistic electrons at the output of the optical channel. The dimensions of the optical window have been determined, which ensure the reliable registration of the total flux of SR quanta for the chosen spectral range of SR quanta wavelengths.

MVPAlab: A Machine Learning decoding toolbox for multidimensional electroencephalography data

MVPAlab is a MATLAB-based and very flexible decoding toolbox for multidimensional electroencephalography and mag-netoencephalography data. The MVPAlab Toolbox implements several machine learning algorithms to compute multivari-ate pattern analyses, cross-classification, temporal generalization matrices and feature and frequency contribution anal-yses. It also provides access to an extensive set of preprocessing routines for, among others, data normalization, data smoothing, dimensionality reduction and supertrials generation. To draw statistical inferences at the group level, MVPAlab includes a non-parametric cluster-based permutation approach. This toolbox has been designed to include an easy-to-use and very intuitive graphic user interface and data representation software, which makes MVPAlab a very convenient tool for those users with few or no previous coding experience. However, MVPAlab is not for beginners only, as it implements several high and low-level routines allowing more experienced users to design their own projects in a highly flexible manner.

Virtual Reality Headsets – Comparison, Analysis and Use in Training and Learning

Virtual Reality (VR) technologies have developed rapidly in recent years. We have seen tremendous progress in the development of both VR software and hardware. VR is in creas ingly used as a tool for training and learning in various areas of life. This paper presents the currently available types of VR devices and compares their technical properties, technologies and price. It anal yses the capabilities of certain devices and offers possible ways of using VR headsets in education. The purpose of the study is to help choose the right VR headset in the processes of training and learning. These helmets are divided into three classes – low, medium and high – depending on their technical characteristics, the technologies they use, and their price. Cost can be an important factor in the need for mass training. The results determine the following devices as the best ones in each class: Samsung Gear VR (low class), Oculus Quest (middle class), VIVE Pro Eye and Varjo VR-2 Pro (high class). The latter is regarded as the most powerful VR headset. The paper also considers the latest technologies that have already been integrated in some VR headsets – eye tracking, hand tracking, tracking with Base Stations, object tracking and wireless connection. They may be absolutely necessary for the training and learning processes, or completely unnecessary which may reduce costs.

Emerging patterns of artistic organizations in Portugal: A three case studies analysis

In the wake of the 2008 global financial and economic crisis, new forms of work organization emerged in Europe. Following this trend, Portugal has undergone a reconfiguration of its artistic organizations. In the performing arts, some organiza-tions seem to have crystalized and others are reinventing their artistic mission. They follow a plurality of organizational patterns and resilient profiles framed by cyclical, structural and occupational changes. Artistic organizations have had to adopt new models of work and seek new opportunities to try out alternatives in order to deal, namely, with the constraints of the labour market. The article anal-yses some of the restructuring processes taking place in three Portuguese artistic organizations, focusing on their contexts, individual trajectories and collective missions for adapting to contemporary challenges of work in the arts. We conclude that organizations are a key domain for understanding the changes taking place.

DO SPLEEN MACROPHAGE AGGREGATES UNDERGO SEASON-DEPENDENT CHANGES? A STEREOMICROSCOPIC INVESTIGATION IN WILD OHRID TROUT (SALMO LETNICA KAR.)

In past decades macrophage aggregates (MACs) were being used in many monitoring studies as useful immu-nological biomarkers of environmental pollution and they are still encountered in the so-called “future biomarkers”, since quantitative studies in aquaculture and/or field of their normal fluctuations as a result of the influence of natural factors are extremely rare. Our investigation was designed to quantitatively evaluate the influence of the seasons on MAC's relative volume, number and diameter in the Ohrid trout (Salmo letnica Kar.) spleen. Data showed that all investigated parameters had significantly higher values in fish collected during spring and winter. Correlation anal-yses revealed that the increasing of the relative volume of MACs is a result of the increasing of the relative volume of melanin loaded MACs, as well as the increasing of their number and diameter. These results confirmed that the sea-son can affect MACs variations and should be taken into consideration, especially when spleen MACs are used as pollution biomarkers in monitoring studies.

Bioindicative values of microfungi in starch and possible deficiencies of the new Serbian regulation on food hygiene

The results of tests on the presence of yeasts and molds in cornstarch [AD ?IPOK? Zrenjanin, 2007-2008, made at the time when previous Regulations were valid] were analyzed in terms of bioindicative values of microfungi as indicators of quality and safety of raw material or final food products. Microbiological analysis was used to detect the presence of a number of microorganisms MMI-0001, and a questionnaire was designed at the Department of Public Health in Zrenjanin town (Republic of Serbia), where the anal?yses were done, regarding the microbiological tests on starch. In order to rationalize the analyses and make them more economical, several areas of product quality control (water, food, raw materials, space) were recommended either to be excluded or regarded as optional. Thus, analysis of presence of microfungi as indicators of product quality was categorized as optional. The results obtained from this research suggest a different conclusion because the bacteria in the samples indicated ?microbiologically?, namely bacteriologically, safe samples of food, while, on the contrary, the presence of some microfungi as distinct xerophilous or xerotolerant microorganisms, indicated that the food was mycologically non-safe. The obtained data are crucial for questioning the decision to exclude the earlier required (mycological) analysis of the samples (in the production of starch, or end products, etc.) and categorize such analyses in new Regulations as optional, depending on the manufacturer?s preference. Bioindicative values of microfungi as indicators of the quality of starch, clearly point to the shortsightedness of the new Regulations on food hygiene and safety, where tests on certain microorganisms (in this case, yeasts and molds) are not legally defined as mandatory, but the Law leaves manufacturers a possibility to choose (or not to choose) the testing and frequency of testing on the presence (absence) of microorganisms, which can be risky, both in the production and marketing of the finial products.