Impact of Adversarial Examples on the Efficiency of Interpretation and Use of Information from High-Tech Medical Images

In this paper we discuss the possibility of adversarial examples appearance in high-tech medical images (Computer tomography and Magnetic resonance imaging), due to the noise inherent in the technology of their formation, and therefore we suggest ways to counteract this effect. As the idea of the paper we put two questions: 1.Can individual instances of real high-tech medical images work as AE when being analyzed with the use of neural networks? 2. Is it possible to defend oneself against such "natural" adversarial attacks with the simplest possible means? In our research, we tried the following defence methods: adversarial training, Gaussian data augmentation and bounded RELU (see section 3 for a detailed description). We conducted the experiment with the use of the neural network - a variant of convolutional network structure combining U-Net with the region proposal networks. As the source data two datasets were chosen - the Lung Image Database Consortium image collection containing 1018 lung cancer screening thoracic CT scans and Brain MRI DataSet containing clinical imaging data of glioma patients (a total of 274 cases). The experiments showed that the degree of manifestation of AE varies depending on the type of training model. When training a model not using techniques of defences on adversarial examples, the number of incorrectly recognized images is quite large (200 per 10,000 for CT and 285 per 10,000 for MRI). By proper selecting of the activation function of CNN, it can be reduced to 60 and 68, respectively. With augmentation of training dataset by Gaussian noised images, this number drops to 21 and 26. An even greater reduction in the number of incorrectly recognized images is achieved using the Adversarial Training method - 12 and 15. Thus, it is shown that the adversarial effect is possible after the application of adversarial training techniques, but the degree of noise in such an image will be much higher than before using these techniques, and it will be easy enough for the doctor to recognize them visually and exclude them from further consideration

Cladoceran remains from the bottom sediments of Lake Lebedinoe (Yamalo-Nenets Autonomous Okrug, Arctic Russia)

Cladocerans are widely used as an indicator group in paleoecological studies: their exoskeleton remains accumulate in bottom sediments and can be helpful in inferring the history of a water body. In this work, an attempt is made to reconstruct the past climatic and ecological conditions of Lake Lebedinoe (17-Ya-02) located in the Yamalo-Nenets Autonomous Okrug. Paleolimnological analysis of the sediment core with a length of 36 cm collected from the studied lake is performed. A total of 28 Cladcoera registered in the cladoceran assemblage of the lake, with Bosmina (Eubosmina) longispina dominant throughout the core

Subfossil Cladocera from a sediment core of small thermokarst Lake in Pechora Delta, Nenets Autonomous Region, northern Russia

Subfossil Cladocera remains were examined from small thermorkarst Lake 17-PE-03 (68.183967 N, 53.808247 E, Pechora Delta, Nenets Autonomous Region, Russia) from one core (48 cm-long). Results of the analysis are presented in date base. For the first time, the species Phreatalona protzi (Hartwig, 1900) (Crustacea: Cladocera) has been found in the Nenets Autonomous Region, Russia

Cladoceran analysis of sediment core 17-Ya-01 from a anonymous lake in the Yamalo-Nenets Autonomous Okrug, Arctic Russia

Cladocerans are very promising for studying climate change risks owing to their inherently predictive nature. For paleoecological study, one sediment core (17-Ya-01) was sampled from lake in Yamalo-Nenets Autonomous Okrug (Russia). Cladoceran analysis of the sediment core with a length of 51 cm collected from the studied lake is performed. A total of 30 taxa were registered in the subfossil cladoceran community of the lake. Most of the identified taxa belong to the Chydoridae family. Bosmina (Eubosmina) longispina was the dominant species. Of special interest is the finding of Ophryoxus gracilis and Rhynchotalona latens - rare species

Correlation of Educational Material Ontology with the Individual Knowledge Structure of Students

In this paper we experimentally study the influence of the storage structure of the educational material, in particular ontologies, on the effectiveness of its use for students that have various levels of skills. The foreign language is used as a subject domain. The results of the research show that ontological structures are effective for storing the teaching material, but they must be transformable, in order not to cause the conflict with the already̵̵existing̵̵individual̵̵knowledge̵̵structure̵̵of̵̵the̵̵students

Palynologycal record of a long sediment core from Lake Shira (Minusinsk Depression, South Siberia, Russia)

In 2022, a 530 cm long sediment core (Shira core 3, 54°31̍18,2̎ N, 90°10̍43,7̎ E) was recovered from 24 m depth in the central part of Lake Shira. Lake Shira is located in Minusinsk Depression of the mountains of Southern Siberia (Khakassia, Russia). It is a meromictic lake with an area of 35.9 km2 and an average depth about 11 m (the maximum depth of 24 m). The lake's salinity varies considerably and can reach up to 27 g/l. The surrounding vegetation consist of steppe associations (Artemisia and Poaceae species predominate), birches and small forest patches

Diatoms from the bottom sediments of Lake Shira (Khakassia, Russia)

Diatoms are good indicators of a variety of lake water conditions including salinity, pH, light availability, temperature and nutrient levels, but diatoms as palaeoindicators are poorly studied in the Lake Shira. Our research on the species composition and ecological parameters of diatoms provide additional data for the regional databases and contributes to improving the accuracy of paleoecological reconstructions. In this study the diatom results of analysis a 528 cm long continuous sediments core from the Lake Shira (Khakassia, Russia) are presented. The core was collected in August 2020 from central part of the lake from a depth of 24 m. 39 samples were investigated by us for diatom analysis. Diatoms were found only in 13 samples. Diatom analysis of samples revealed 30 taxa, belonging to 19 genera. The analysis of the ecological structure of the diatom flora of the sediment core sample from the lake under study shows that it is dominated by the cosmopolitan representatives of benthic and planktonic-benthic, indifferent to salinity and halophiles organisms giving preference to the alkaline environmental conditions. The prevalence of Handmannia comta (Ehrenberg) Kociolek & Khursevich diatom in sediments have been established

Lateglacial and Holocene environmental history of the central Kola region, northwestern Russia revealed by a sediment succession from Lake Imandra

Bolshaya Imandra, the northern sub-basin of Lake Imandra, was investigated by a hydro-acoustic survey followed by sediment coring down to the acoustic basement. The sediment record was analysed by a combined physical, biogeochemical, sedimentological, granulometrical and micropalaeontological approach to reconstruct the regional climatic and environmental history. Chronological control was obtained by 14C dating, 137Cs, and Hg markers as well as pollen stratigraphy and revealed that the sediment succession offers the first continuous record spanning the Lateglacial and Holocene. Following the deglaciation prior to c. 13 200 cal. a BP, the lake's sub-basin initially was occupied by a glacifluvial river system, before a proglacial lake with glaciolacustrine sedimentation established. Rather mild climate, a sparse vegetation cover and successive retreat of the Scandinavian Ice Sheet (SIS) from the lake catchment characterized the Bølling/Allerød interstadial, lasting until 12 710 cal. a BP. During the subsequent Younger Dryas chronozone, until 11 550 cal. a BP, climate cooling led to a decrease in vegetation cover and a re-advance of the SIS. The SIS disappeared from the catchment at the Holocene transition, but small glaciers persisted in the mountains at the eastern lake shore. During the Early Holocene, until 8400 cal. a BP, sedimentation changed from glaciolacustrine to lacustrine and rising temperatures caused the spread of thermophilous vegetation. The Middle Holocene, until 3700 cal. a BP, comprises the regional Holocene Thermal Maximum (8000–4600 cal. a BP) with relatively stable temperatures, denser vegetation cover and absence of mountain glaciers. Reoccurrence of mountain glaciers during the Late Holocene, until 30 cal. a BP, presumably results from a slight cooling and increased humidity. Since c. 30 cal. a BP Lake Imandra has been strongly influenced by human impact, originating in industrial and mining activities. Our results are in overall agreement with vegetation and climate reconstructions in the Kola region