Basic Research Research Articles

SERGEY A. TOKAREV’S CONCEPTUAL IDEAS ON THE SOCIAL ORGANIZATION OF THE YAKUTS IN THE 17th CENTURY AND THE MODERN HISTORIOGRAPHY

The article discusses the outstanding contribution of S. A. Tokarev (1899–1985) to the study of the Yakuts’ social organization in the 17th century employing a modern theoretical and methodological approach. Although the researcher generally worked within the strict framework of the formational approach commonly accepted in Soviet historiography, sometimes he managed to go beyond it in an effort to be objective. This was possible due to his deep knowledge of not only ethnographic materials, but also of Russian written sources of the 17th century. He studied huge arrays of cursive columns from the funds of the Siberian Prikaz and the Yakut Voivode’s Hut, stored in the central archives, and used them in a comparative analysis with other sources. The original concept of the social organization of the Yakuts in the 17th century that he developed in the 1930s and subsequently revised in his major works in the 1940–1950s, made an outstanding contribution to Russian historiography, supplemented it with new data and offered a holistic view of the historical and ethnographic realities of the Yakut late medieval society. However, S. A. Tokarev’s intention to remain on reliable historical ground, based on specific documentary sources of the 17th century, provoked substantial criticism. His research was cast in a continuous search for the closest scientific definitions to the categories of social organization of the Yakuts, which he identified. He used the entire toolkit of theoretical approaches and research methods and his experience, based on the best traditions of Russian historical and ethnographic science. Modern achievements of Yakut studies of historical knowledge confirm the scientific significance and relevance of the main conclusions and observations of S. A. Tokarev.

How knee muscles and ground reaction forces shape knee buckling and ankle push-off in neuromuscular simulations of human walking

Ankle push-off is important for efficient, human-like walking, and many prosthetic devices mimic push-off using motors or elastic elements. The knee is extended throughout the stance phase and begins to buckle just before push-off, with timing being crucial. However, the exact mechanisms behind this buckling are still unclear. We use a predictive neuromuscular simulation to investigate whether active muscles are required for knee buckling and to what extent ground reaction forces (GRFs) drive it. In a systematic parameter search, we tested how long the knee muscles vastus (VAS), gastrocnemius (GAS), and hamstrings could be deactivated while maintaining a stable gait with impulsive push-off. VAS deactivation up to 35% of the gait cycle resulted in a dynamic gait with increased ankle peak power. GAS deactivation up to 20% of the gait cycle was detrimental to gait efficiency and showed reduced ankle peak power. At the start of knee buckling, the GRF vector is positioned near the knee joint’s neutral axis, assisting in knee flexion. However, this mechanism is likely not enough to drive knee flexion independently. Our findings contribute to the biomechanical understanding of ankle push-off, with applications in prosthetic and bipedal robotic design, and fundamental research on human gait mechanics.

Semimetal–dielectric–metal metasurface for infrared camouflage with high-performance energy dissipation in non-atmospheric transparency window

Abstract The development of novel camouflage technologies is of great significance, exerting an impact on both fundamental science and diverse military and civilian applications. Effective camouflage aims to reduce the recognizability of an object, making it to effortlessly blend with the environment. For infrared camouflage, it necessitates precise control over surface emissivity and temperature to ensure that the target blends effectively with the surrounding infrared background. This study presents a semimetal–dielectric–metal metasurface emitter engineered for the application of infrared camouflage. The metasurface, with a total thickness of only 545 nm, consists of a Bi micro-disk array and a continuous ZnS and Ti film beneath it. Unlike conventional metal-based metasurface design, our approach leverages the unique optical properties of Bi, achieving an average emissivity of 0.91 in the 5–8 μm non-atmospheric transparency window. Experimental results indicate that the metasurface emitter achieves lower radiation and actual temperatures compared to those observed in comparative experiments, highlighting its superior energy dissipation and thermal stability. The metasurface offers advantages such as structural simplicity, cost-effectiveness, angular insensitivity, and deep-subwavelength features, rendering it suitable for a range of applications including military camouflage and anti-counterfeiting, with potential for broad deployment in infrared technologies.

CausalXtract, a flexible pipeline to extract causal effects from live-cell time-lapse imaging data.

Live-cell microscopy routinely provides massive amounts of time-lapse images of complex cellular systems under various physiological or therapeutic conditions. However, this wealth of data remains difficult to interpret in terms of causal effects. Here, we describe CausalXtract, a flexible computational pipeline that discovers causal and possibly time-lagged effects from morphodynamic features and cell-cell interactions in live-cell imaging data. CausalXtract methodology combines network-based and information-based frameworks, which is shown to discover causal effects overlooked by classical Granger and Schreiber causality approaches. We showcase the use of CausalXtract to uncover novel causal effects in a tumor-on-chip cellular ecosystem under therapeutically relevant conditions. In particular, we find that cancer-associated fibroblasts directly inhibit cancer cell apoptosis, independently from anticancer treatment. CausalXtract uncovers also multiple antagonistic effects at different time delays. Hence, CausalXtract provides a unique computational tool to interpret live-cell imaging data for a range of fundamental and translational research applications.

Flame–Flame Interactions and Jet–Jet Interactions in Gas Turbine Swirl Combustors

Annular combustors are widely used in newly developed aero-engines. Nevertheless, the development of annular combustors requires substantial air supplies and high-power heaters during testing, leading to high experimental costs. To reduce these costs during the design phase, researchers often simplify annular combustors into single-dome configurations using aerodynamic and thermodynamic similarity principles. A fundamental divergence exists between the boundary conditions of annular and simplified single-dome combustors, which is reviewed in this article. It highlights the limitations of single-dome model combustors in accurately representing the crucial features of annular combustors, particularly flame–flame interaction (FFI) and jet–jet interaction (JJI). FFI and JJI existing in annular combustors are observed to result in alternating flow patterns and the superposition of mass and energy transfer between adjacent domes, which can deteriorate flame stabilization and increase NOx emissions. This review emphasizes the characteristics of multi-dome combustors and notes a lack of research comparing single-dome and multi-dome combustors under engine-relevant conditions. Addressing this research gap in the future can better connect fundamental combustion research and engine development, providing more guidance for engine designers.

The interplay of sex and genotype in disease associations: a comprehensive network analysis in the UK Biobank

BackgroundDisease comorbidities and longer-term complications, arising from biologically related associations across phenotypes, can lead to increased risk of severe health outcomes. Given that many diseases exhibit sex-specific differences in their genetics, our objective was to determine whether genotype-by-sex (GxS) interactions similarly influence cross-phenotype associations. Through comparison of sex-stratified disease-disease networks (DDNs)—where nodes represent diseases and edges represent their relationships—we investigate sex differences in patterns of polygenicity and pleiotropy between diseases.ResultsUsing UK Biobank summary statistics, we built male- and female-specific DDNs for 103 diseases. This revealed that male and female diseasomes have similar topology and central diseases (e.g., hypertensive, chronic respiratory, and thyroid-based disorders), yet some phenotypes exhibit sex-specific influence in cross-phenotype associations. Multiple sclerosis and osteoarthritis are central only in the female DDN, while cardiometabolic diseases and skin cancer are more prominent in the male DDN. Edge comparison indicated similar shared genetics between the two graphs relative to a random model of disease association, though notable discrepancies in embedding distances and clustering patterns imply a more expansive genetic influence on multimorbidity risk for females than males. Analysis of pleiotropic contributions of two sexually-dimorphic single-nucleotide polymorphisms related to thyroid disorders further validated a distinct genetic architecture across sexes that influences associations, confirmed through examination of corresponding gene expression profiles from the GTEx Portal.ConclusionsOur analysis affirms the presence of GxS interactions in cross-phenotype associations, emphasizing the need to investigate the role of sex in disease onset and its importance in biomedical discovery and precision medicine research.

Transitioning to Green Discovery-Based Catalysis.

Pressure is mounting to minimize the carbon footprint of chemical industry while increasing its sustainability. An argument is made that working from Green Chemistry principles during discovery-based catalysis results in effective chemistry and circumvents a need to "rediscover" chemical reactivity under sustainable conditions. Examples of comparative success in selected examples of hydrophosphination catalysis in various degrees of development are provided to support two main ideas: 1) Starting from more sustainable practices in chemical discovery is inertia in methodology that should be overcome, and 2) Substantial challenges remain in catalysis for which sustainable solution would positively impact other areas of chemistry. Examples of successes, even in the face of the challenges noted, are presented herein indications that as a starting point, sustainability can meet short- and long-term needs. These ideas indicate critical but simple strategies for fundamental research to be impactful in the sustainability of the chemical industry broadly.

Symmetry-governed dynamics of magnetic skyrmions under field pulses

Topological magnetic solitons, such as skyrmions, exhibit intriguing particle-like properties that make them attractive for fundamental research and practical applications. While many magnetic systems can host skyrmions as statically stable configurations, chiral magnets stand out for their ability to accommodate a wide diversity of skyrmions with arbitrary topological charges and varied morphologies. Despite extensive investigation, a complete understanding of chiral magnetic skyrmions has remained elusive. We present a classification of all chiral skyrmions, demonstrating three classes based on their response to external magnetic field pulses: stationary, translating, and rotating. We highlight the role of magnetic texture symmetry in this classification. Skyrmions with varied dynamics offer avenues for exploring phenomena like skyrmion-skyrmion scattering that might be crucial for future applications.

Versatile High-Throughput Platform for Focused Ultrasound In Vitro Application

For the more efficient application of ultrasound in future therapies, fundamental research is needed on the mode of action of ultrasound on biological systems using therapeutic frequencies. To address this need, a new versatile high-throughput platform for focused ultrasound in vitro application was designed, developed, and characterized. The applicator was aligned with the dimensions of a 96-well plate and frequencies commonly used in the therapeutic ultrasound range (0.5–2.0 MHz). Two different platform configurations were developed: (a) a low-intensity version with 96 individual transducers allowing dry coupling of the well plate; and (b) a high-intensity version with water cooling, supporting parallel sonication of 32 out of 96 wells. The platforms were characterized by performing an analysis of the homogeneity of the sound pressure and intensity, the impact of filled volume per well, the cross-coupling effect between the wells, and the influence of the well plate. The low-intensity design delivers pressure levels up to 605 kPa inside the well with maximum ISPPA values between 0.78 and 12.38 W/cm2. In contrast, the high-intensity system achieves pressures up to 1460 kPa and a maximum ISPPA of 72 W/cm2 inside the wells. The successfully developed high-throughput platform supports parallelized sonication in standard, well-plate formats and is suitable for focused ultrasound applications in vitro.

ФОРМУВАННЯ МЕХАНІЗМІВ ПУБЛІЧНОГО ІНВЕСТУВАННЯ ПРОЄКТІВ РЕГІОНАЛЬНОГО РОЗВИТКУ: КОНЦЕПТУАЛЬНИЙ БАЗИС

Introduction. The development of mechanisms for public investment in regional development projects is an important task of modern economic policy in the context of globalization, decentralization, and the growing role of regions as centers of economic growth. The effectiveness of these mechanisms affects not only the progress of individual territories but also the sustainable development of the national economy as a whole. The necessary to study this topic is due, first, to the complexity of the process of forming public investment mechanisms: modern economic theory offers a wide range of approaches to solving this problem, but their adaptation to the realities of Ukraine requires additional research. Secondly, the insufficient use of the conceptual framework: the formation of new investment mechanisms should be based on scientifically sound concepts and take into account the best international practices. Third, the lack of an integrated approach: existing mechanisms are fragmented and do not always take into account the specifics of the regions, which reduces their effectiveness. Fourth, the low level of involvement of innovative financial instruments, such as public-private partnerships, development bonds, or grant funding. Fifth, the need to prepare policy recommendations: the results of the study will contribute to the development of effective tools to support regional development based on scientific analysis. Objective. The purpose of the article is to comprehensively study and build mechanisms for public investment in regional development projects. Methods. The methodological basis of the study is the theoretical provisions of economic and financial sciences, works of famous scientists. To solve the research tasks, the paper uses the dialectical method of scientific knowledge, methods of empirical and theoretical research, in particular, conceptual and logical analysis and a systematic approach. Results. Practical testing of the state policy, including at the regional and local levels, involves the use of both complex and purely functional mechanisms, tools, and means. The mechanism as the most systematic means of regulation is considered as a controlled set of elements (subjects, objects, purpose, goals, objectives, functions, principles, means, measures, tools for monitoring, control and adjustment, etc.) used to implement and solve public administration tasks in the relevant functional or other sphere of development of the state, its regions, territories. At the same time, the achievement of the general goal and policy objectives in such a complex area as public investment in regional development projects requires the use of a certain holistic system of mechanisms for such purposes, the basic of which are: institutional and legal, institutional and organizational, infrastructure, economic, social and psychological, monitoring and control. Conclusions. The formation and implementation of each of these mechanisms have their own clearly defined goals and objectives, which are generally subordinated to the general goal of the State policy in the analyzed area - the public investment institution's acting as a powerful factor in the development of communities, territories, and regions of the country.

Gender differences in entrepreneurial equity financing—a systematic literature review

Abstract A growing body of literature explores whether and why female and male entrepreneurs differ in their access to equity financing. This trend has led to an increasing fragmentation of the research field, as many studies analyze various mechanisms and focus on a certain form of equity financing. To advance research on gender differences in equity financing, it is necessary to identify patterns and inconsistent findings in the literature related to these mechanisms. Therefore, we perform a systematic literature review to provide an overview of the current state of knowledge on gender differences in the key forms of entrepreneurial equity financing (venture capital, angel investment, and equity crowdfunding). Based on 75 studies from 2001 to mid-2024, our review indicates that male entrepreneurs have an advantage in raising capital from venture capitalists and business angels, whereas female entrepreneurs are more successful in equity crowdfunding. These gender differences stem from a complex combination of mechanisms, which we categorize into four thematic dimensions that capture entrepreneurs’ characteristics, investors’ characteristics, the ventures’ characteristics and strategies, and contextual factors. We propose specific future research directions for each dimension, and discuss theoretical and methodological research opportunities that are applicable across dimensions to improve our understanding of gender differences in equity financing.

Unravelling the nonlinear generation of designer vortices with dielectric metasurfaces

Vortex beams are currently drawing a great deal of interest, from fundamental research to several promising applications. While their generation in bulky optical devices limits their use in integrated complex systems, metasurfaces have recently proven successful in creating optical vortices, especially in the linear regime. In the nonlinear domain, of strategic importance for the future of classical and quantum information, to date orbital angular momentum has only been created in qualitative ways, without discussing discrepancies between design and experimental results. Here, we demonstrate and analyze the generation of high-purity second harmonic (SH) optical vortices via dielectric meta-holograms. Through full-wave simulations and a proper fabrication protocol, we achieve efficient frequency doubling of an unstructured pump beam into SH vortices with topological charges from 1 to 10. Interferometric and modal-purity measurements confirm the generation of high-quality SH vortices with minimal deviations from the intended design thanks to a quasi-local control over the SH phase. Through systematic comparisons between experimental data and semi-analytical calculations, we also provide a clear insight into the occurrence of ghost vortices in the metasurface-generated harmonic beams, highlighting the importance of simple designs that can be readily transposed into fabricated devices with high fidelity. Our findings underscore the potential of nonlinear dielectric metasurfaces for versatile structured-light generation and manipulation, paving the way for future developments in integrated photonic systems.

Transition of Perovskite Solar Technologies to Being Flexible.

Perovskite technologies has taken giant steps on its advances in only a decade time, from fundamental science to device engineering. The possibility to exploit this technology on a thin flexible substrate gives an unbeatable power to weight ratio compares to similar photovoltaic systems, opening new possibilities and new integration concepts, going from building integrated and applied photovoltaics (BIPV, BAPV) to internet of things (IoT). In this perspective, the recent progress of perovskite solar technologies on flexible substrates are summarized, focusing on the challenges that researchers face upon using flexible substrates. A dig into material science is necessary to understand what kind of mechanisms are limiting its efficiency compare to rigid substrates, and which physical mechanism limits the upscaling on flexible substrate. Furthermore, an overview of stability test on flexible modules will be described, suggesting common standard procedure and guidelines to follow, showing additional issues that flexible modules face upon bending, and how to prevent device degradation providing an ad-hoc encapsulation. Finally, the recent advances of flexible devices in the perovskite market will be shown, giving an outline of how this technology is exploited on flexible substrates, and what are still missing that need stakeholders' attention.

Indian Millennials’ continued usage intentions toward online dating apps: the interplay between trust and perceived autonomy

Purpose This study aims to empirically examine the role of privacy, security, trust and autonomy in Millennials’ continued use of online dating applications. Emerging markets have been famous for their rapid modernization, growth and cultural shifts. Yet, consumer worries about online dating consumption need to be addressed in the literature through a better understanding of their behavioural intentions. This study examines the interplay of the underlying variables by testing a conceptual framework grounded on the theory of reasoned action (TRA), the self-determination theory (SDT) and the information systems continuance theory (ISCT) with regard to an emerging market. Design/methodology/approach A cross-sectional and quantitative research design is adopted. Using a well-designed structured questionnaire adapted from established scales, data was collected through a survey featuring 332 substantive responses from actively involved Millennial users of online dating apps in India. The data was analysed using confirmatory factor analysis (CFA) and structural equation modelling (SEM) through IBM SPSS AMOS (Analysis of Moment Structures) 24.0 to provide evidence of the reliability and validity of constructs alongside testing the hypothesis in the proposed model. Furthermore, Preacher and Hayes’ (2004) approach is used to explore mediation effects. Findings The results show that autonomy and trust positively affect the continued use of online dating apps. The study further reveals that autonomous behaviour motivates Millennials to use online dating apps, overriding their concerns for privacy and security. Furthermore, the results indicate that trust fully mediates the relationship between concern for privacy, perceived security and continued usage intention. Therefore, trust affects users’ intentions to continue using online dating apps as it bridges the effect of users’ concern for privacy and the perceived security in the online dating platform, making these dimensions relevant as a whole. Research limitations/implications This study provides critical insights into the theory and practice. The findings demonstrate that autonomy is more significant in motivating Millennials to use online dating apps than concerns about privacy and perceptions of security. In addition, trust plays a crucial role in mediating the relationship between these variables. Therefore, app developers, app marketers and app stores can use the findings to motivate Millennials to continue using their platforms by encouraging a sense of freedom and a better inner self, fostering engagement and conveying user trust. Originality/value Several studies have investigated the pre-adoption behaviour of users of online dating apps, and little attention has been paid to continuance usage. This study provides a unique theoretical research model and perspective for online dating apps that uncovers the role of concern for privacy, perceived security and trust that affect post-adoption behaviour by integrating the TRA, SDT and ISCT. This integration offers a more futuristic and refined perspective on human behaviour by considering both cognitive and motivational aspects. The study establishes that autonomy outweighs concern for privacy and perceived security.

Target Localization and Pursuit With Networked Robotic Vehicles: Theory, Simulation, and Experiments

ABSTRACTThis paper addresses the problem of range‐based simultaneous localization and pursuit (SLAP) with networked robotic vehicles from a theoretical and practical standpoint. The work presented builds upon and extends previous theoretical research by Hung, Rego, and Pascoal on the subject of range‐based SLAP using multiple trackers and a cooperative distributed estimation and control (DEC) strategy. The key novel contributions of the paper are twofold: Event‐triggered communication (ETC) mechanisms for the DEC strategy are proposed, with formal guarantees of stability of the multiple vehicle ensemble. In this approach, each tracking vehicle only communicates with its neighbors—both for target estimation and cooperative control purposes when deemed necessary—thus reducing the cost of communications. The paper presents experimental results from multiple field trials conducted with three autonomous marine vehicles. These trials assess the effectiveness of the proposed DEC/ETC strategy in a real‐world environment.Simulation results are also included and analyzed. For the sake of completeness, source codes and links to auxiliary materials are provided, enabling the readers to run simulations and even implement the DEC/ETC strategy using both Matlab and ROS/Gazebo platforms.Matlab codes: https://github.com/hungrepo/slap-etc.ROS packages: http://github.com/dsor-isr/slap.Aerial view of field trials: http://youtu.be/4LR4WSJHyz8.

Adaptation of clinical bacteriology techniques for remote polar research.

Antimicrobial resistance (AMR) represents one of the key global public health threats currently facing humanity. The recent UN High-Level Meeting on AMR highlighted the need for greater knowledge generation on its environmental aspects while also considering the potential adverse effects of climate change. The polar regions of the world offer a unique opportunity for AMR research in a near-pristine environment while also holding the potential for novel resistance mechanisms and/or antimicrobial peptide discovery within melting permafrost or glacial ice. Despite considerable technological advances in microbiology, operating in severe cold environments continues to present significant operational challenges. Our report here offers a basis for adaptations to enable both environmental and clinical antimicrobial resistance, microbiome, and discovery research for operating in the harshest of remote environments.

Long-lived entanglement of molecules in magic-wavelength optical tweezers.

Realizing quantum control and entanglement of particles is crucial for advancing both quantum technologies and fundamental science. Substantial developments in this domain have been achieved in a variety of systems1-5. In this context, ultracold polar molecules offer new and unique opportunities because of their more complex internal structure associated with vibration and rotation, coupled with the existence of long-range interactions6,7. However, the same properties make molecules highly sensitive to their environment8-10, affecting their coherence and utility in some applications. Here we show that by engineering an exceptionally controlled environment using rotationally magic11,12 optical tweezers, we can achieve long-lived entanglement between pairs of molecules using detectable hertz-scale interactions. We prepare two-molecule Bell states with fidelity , limited by detectable leakage errors. When correcting for these errors, the fidelity is . We show that the second-scale entanglement lifetimes are limited solely by these errors, providing opportunities for research in quantum-enhanced metrology7,13, ultracold chemistry14 and the use of rotational states in quantum simulation, quantum computation and as quantum memories. The extension of precise quantum control to complex molecular systems will enable their additional degrees of freedom to be exploited across many domains of quantum science15-17.

Modeling of flows under dams using the method of singular points

Today, the relevance of issues related to regular and safe water supply for human beings, society and the economy is beyond doubt. One of the main ways to store and man age water resources is the construction and operation of dams. The most important task of sustainable existence and development of reservoir projects is dam safety. To ensure this, theoretical research, creation of mathematical and computer models of the physical phe nomena and engineering structures under study are necessary. The paper proposes methods for constructing flows in the middle sections of a dam with a linear filtration law by ap propriately placing special flow points and applying conformal transformations. Filtration f lows with different outlines of impermeable floodplain, flows under a dam with filters in homogeneously isotropic and heterogeneously anisotropic soils are considered.

Preference learning based deep reinforcement learning for flexible job shop scheduling problem

The flexible job shop scheduling problem (FJSP) holds significant importance in both theoretical research and practical applications. Given the complexity and diversity of FJSP, improving the generalization and quality of scheduling methods has become a hot topic of interest in both industry and academia. To address this, this paper proposes a Preference-Based Mask-PPO (PBMP) algorithm, which leverages the strengths of preference learning and invalid action masking to optimize FJSP solutions. First, a reward predictor based on preference learning is designed to model reward prediction by comparing random fragments, eliminating the need for complex reward function design. Second, a novel intelligent switching mechanism is introduced, where proximal policy optimization (PPO) is employed to enhance exploration during sampling, and masked proximal policy optimization (Mask-PPO) refines the action space during training, significantly improving efficiency and solution quality. Furthermore, the Pearson correlation coefficient (PCC) is used to evaluate the performance of the preference model. Finally, comparative experiments on FJSP benchmark instances of varying sizes demonstrate that PBMP outperforms traditional scheduling strategies such as dispatching rules, OR-Tools, and other deep reinforcement learning (DRL) algorithms, achieving superior scheduling policies and faster convergence. Even with increasing instance sizes, preference learning proves to be an effective reward mechanism in reinforcement learning for FJSP. The ablation study further highlights the advantages of each key component in the PBMP algorithm across performance metrics.

The Impact of VR Technology on Music Education in the Context of "Internet Plus" Teaching

With the advancement of modern technology, virtual reality (VR) technology, as a product of high-tech innovation, has brought convenience to people's daily lives. This paper uses VR technology as a medium and takes domestic music education in China as its research basis to explore the characteristics, application value, and impact of VR technology in music teaching. Through theoretical research, the paper aims to promote the development of VR technology in music education in China, creating possibilities for more innovative classroom teaching approaches