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Vascular tone plays a vital role in regulating blood pressure and coronary circulation, and it determines the peripheral vascular resistance. Vascular tone is dually regulated by the perivascular nerves and the cells in the inside lining of blood vessels (endothelial cells). Only a few methods for measuring vascular tone are available. Because of this, determining vascular tone in different arteries of the human body and monitoring tone changes is a vital challenge. This work presents an approach for determining vascular tone in human extremities based on multi-channel bioimpedance measurements. Detailed steps for processing the bioimpedance signals and extracting the main parameters from them have been presented. A graphical interface has been designed and implemented to display the vascular tone type in all channels with the phase of breathing during each cardiac cycle. This study is a key step towards understanding the way vascular tone changes in the extremities and how the nervous system regulates these changes. Future studies based on records of healthy and diseased people will contribute to increasing the possibility of early diagnosis of cardiovascular diseases.

The main sources of this article are letters from ‘ordinary people’ to Soviet leaders. Counterbalancing current theories about trust and distrust, it analyses correspondence between people and state to explore for the first time the phenomenon of ‘forced trust’ as a central feature of Communist modernity. Forced trust represents a paradox that contributed to the collapse of the Soviet state: an illiberal system was promoting a liberal subject who was forced to trust in the state and the party but, at the same time, experienced his/her limited autonomy by generating personal meanings, interests and needs as a part of life under the dictatorship.

The absence of sunlight during the winter in the High Arctic results in a strong surface-based atmospheric temperature inversion, especially during clear skies and light surface wind conditions. The inversion suppresses turbulent heat transfer between the ground and the boundary layer. As a result, the difference between the surface air temperature, measured at a height of 2 m, and the ground skin temperature can exceed several degrees Celsius. Such inversions occur very frequently in polar regions, are of interest to understand the mechanisms responsible for surface–atmosphere heat, mass, and momentum exchanges, and are critical for satellite validation studies. In this paper we present the results of operations of two commercial remotely piloted aircraft systems, or drones, at the Polar Environment Atmospheric Research Laboratory, Eureka, Nunavut, Canada, at 80∘ N latitude. The drones are the Matrice 100 and Matrice 210 RTK quadcopters manufactured by DJI and were flown over Eureka during the February–March field campaigns in 2017 and 2020. They were equipped with a temperature measurement system built on a Raspberry Pi single-board computer, three platinum-wire temperature sensors, a Global Navigation Satellite System receiver, and a barometric altimeter. We demonstrate that the drones can be effectively used in the extremely challenging High Arctic conditions to measure vertical temperature profiles up to 75 m above the ground and sea ice surface at ambient temperatures down to −46 ∘C. Our results indicate that the inversion lapse rates within the 0–10 m altitude range above the ground can reach values of ∼ 10–30 ∘C(100m)-1 (∼ 100–300 ∘Ckm-1). The results are in good agreement with the coincident surface air temperatures measured at 2, 6, and 10 m levels at the National Oceanic and Atmospheric Administration flux tower at the Polar Environment Atmospheric Research Laboratory. Above 10 m more gradual inversion with order-of-magnitude smaller lapse rates is recorded by the drone. This inversion lapse rate agrees well with the results obtained from the radiosonde temperature measurements. Above the sea ice drone temperature profiles are found to have an isothermal layer above a surface-based layer of instability, which is attributed to the heat flux through the sea ice. With the drones we were able to evaluate the influence of local topography on the surface-based inversion structure above the ground and to measure extremely cold temperatures of air that can pool in topographic depressions. The unique technical challenges of conducting drone campaigns in the winter High Arctic are highlighted in the paper.

Background: Cardiovascular magnetic resonance (CMR) is the clinical gold standard for assessing cardiac anatomy and function. However, the manual segmentation of cardiac structures and myocardial infarction (MI) is time-consuming, prone to inter-observer variability, and often depends on contrast-enhanced imaging. Although deep learning (DL) has enabled substantial automation, challenges remain in generalizability, particularly for MI detection from non-contrast cine CMR. Objective: This study proposes a comprehensive DL-based framework for automatic segmentation of cardiac structures and myocardial infarction using contrast-free cine CMR. Methods: The framework integrates multiple convolutional neural network (CNN) architectures for cardiac structure segmentation with an attention-based deep learning model for MI localization. Post-processing refinement using stacked autoencoders and active contour modeling is applied to improve anatomical consistency. Segmentation performance is evaluated using overlap-based and boundary-based metrics, including the Dice Similarity Coefficient (DSC), Mean Contour Distance (MCD), and Hausdorff Distance (HD). Results: The best-performing model achieved Dice scores of 0.93 ± 0.05 for the left ventricular (LV) cavity, 0.89 ± 0.04 for the LV myocardium, and 0.91 ± 0.06 for the right ventricular (RV) cavity, with consistently low boundary errors across all structures. Myocardial infarction segmentation achieved a Dice score of 0.80 ± 0.02 with high recall, demonstrating reliable infarct localization without the use of contrast agents. Conclusions: By enabling accurate cardiac structure and myocardial infarction segmentation from contrast-free cine CMR, the proposed framework supports broader clinical applicability, particularly for patients with contraindications to gadolinium-based contrast agents and in emergency or resource-limited settings. This approach facilitates scalable, contrast-independent cardiac assessment.

The electrical impedance myography method is widely used in solving bionic control problems and consists of assessing the change in the electrical impedance magnitude during muscle contraction in real time. However, the choice of electrode systems sizes is not always properly considered when using the electrical impedance myography method in the existing approaches, which is important in terms of electrical impedance signal expressiveness and reproducibility. The article is devoted to the determination of acceptable sizes for the electrode systems for electrical impedance myography using the Pareto optimality assessment method and the electrical impedance signals formation model of the forearm area, taking into account the change in the electrophysical and geometric parameters of the skin and fat layer and muscle groups when performing actions with a hand. Numerical finite element simulation using anthropometric models of the forearm obtained by volunteers’ MRI 3D reconstructions was performed to determine a sufficient degree of the forearm anatomical features detailing in terms of the measured electrical impedance. For the mathematical description of electrical impedance relationships, a forearm two-layer model, represented by the skin-fat layer and muscles, was reasonably chosen, which adequately describes the change in electrical impedance when performing hand actions. Using this model, for the first time, an approach that can be used to determine the acceptable sizes of electrode systems for different parts of the body individually was proposed.

The incidence of cardiovascular diseases is continuously increasing around the world. Therefore, the study of new methods for diagnosing cardiovascular diseases is very important. Early diagnosis and evaluation of the effectiveness of treatments are among the most important tasks. In this work, we study changes in vascular compliance and vascular tone of the lower extremities in a patient diagnosed with an early stage of varicose veins. The study is based on recording the bioimpedance signals of the lower extremities and their parts using the Rheo-32 multichannel device. Registration in the monitoring system takes place in two stages: the first in a state of relaxation, and the second after applying a local massage on one of the legs for five minutes. The results indicate a change in the type of vascular tone of the lower extremities after the massage, while the type of vascular tone changes and shifts on average towards the normotonic type. The method proposed in this study makes it possible to quantitatively and qualitatively assess changes in the tone of the vessels of the extremities.

This article discusses the main fundamental options for circuit designs of solar heat supply systems (SHS) with integrated automation elements. The subject of these elements’ study in this work is the degree of their influence on the operating parameters of the mentioned systems, in order to find the most versatile and effective way to optimize and increase the solar plants productivity. At the same time, the main focus was the achievement of such a result, in which the successful implementation of the renewable energy and solar heat supply systems development trend, in particular, is possible. In order to achieve the final result of the study, the analysis for the technical and economic feasibility of the considered circuit designs of solar power plants and individual parametric values from the number of these systems’ operating characteristics has been carried out.

Only by striving to understand the alien behavior of a remote time and place can one hope to understand whence we have come and how much of the past still lives unrecognized within us. Edward Muir2 The State as a Family: Speaking Kinship, Being Soviet and Reinventing Tradition in the USSR The dominance of classic political history for many years led to the disregarding of «relatives’ letters» as a crucial source for understanding the formation of the Soviet state and society. These were letters to Soviet officials from ordinary people who perceived the state as family, and who imagined the state leaders as their close relatives. Broadening a dominant concept in recent Soviet studies (that of speaking Bolshevik), I explore «relatives’ letters» by analysing the fact that their authors were speaking kinship as evidence that reveals the premodern foundations of modern states and uncovers a social practice for generating power in everyday routines. Without being limited by the constraints of Weberian-modernisationist and Burkhardtian paradigms, I reflect on the ways in which seemingly opposed ideas about tradition and modernity, power and kinship, status and marginality, the licit and the illicit have infused representations of «Soviet citizenship», and analyse how letter writers justified their connections with the abstract concept of «the state». «Relatives’ letters» show that the state lived in and through its subjects: Imagining a state as a political family and leaders as close relatives not only provided a source of identity and contributed to social cohesion in the Soviet empire; it also explains the very nature of contemporary informal relationships. Consequently, speaking kinship became a universal political language of governance and the language of ordinary people's emotional attachment to the paternalistic state.

The introduction to the special issue defines trust/distrust from an interdisciplinary perspective, treating these emotions as analytical categories and outlining their potential for historical analysis. Inspired by the emotional and sensory turns, the guest editor examines the shift from Stalinist violence towards a politics of trust and empathy. This new politics saw these feelings as powerful emotional forces and moral resources that not only made it possible to renegotiate a social contract between the state, society and the individual, but also enabled the stabilisation of the Eastern bloc as a whole in the post-Stalin era. Differentiating between regimes and communities of trust/distrust, the author sheds light on the grammar of trust and distrust under state socialism, which impacted the shared sense of stability and inner hybridity of the socialist personality. By connecting trust and distrust with the key analytical categories of gender and generation, morality and power, consumption and materiality, and self and subjectivity, this special issue is a contribution to a history of trust and distrust that provides further reflection on the unceasing debate about what socialism was and what the lived experience of socialism continues to be in post-communist space.