bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical and chemical structure of the Serpens filament: Fast formation and gravity-driven accretion
Authors: Gong Y. , Belloche A. , Du F. J. , Menten K. M. , Henkel C. , Li G. X. , Wyrowski F. , Mao R. Q.
Published: December 2020

Context.The Serpens filament, a prominent elongated structure in a relatively nearby molecular cloud, is believed to be at an early evolutionary stage, so studying its physical and chemical properties can shed light on filament formation and early evolution.

Aims.The main goal is to address the physical and chemical properties as well as the dynamical state of the Serpens filament at a spatial resolution of ~0.07 pc and a spectral resolution of ≲0.1 km s−1.

Methods.We performed13CO (1–0), C18O (1–0), C17O (1–0),13CO (2–1), C18O (2–1), and C17O (2–1) imaging observations toward the Serpens filament with the Institut de Radioastronomie Millimétrique 30-m and Atacama Pathfinder EXperiment telescopes.

Results.Widespread narrow13CO (2–1) self-absorption is observed in this filament, causing the13CO morphology to be different from the filamentary structure traced by C18O and C17O. Our excitation analysis suggests that the opacities of C18O transitions become higher than unity in most regions, and this analysis confirms the presence of widespread CO depletion. Further we show that the local velocity gradients have a tendency to be perpendicular to the filament’s long axis in the outskirts and parallel to the large-scale magnetic field direction. The magnitudes of the local velocity gradients decrease toward the filament’s crest. The observed velocity structure can be a result of gravity-driven accretion flows. The isochronic evolutionary track of the C18O freeze-out process indicates the filament is young with an age of ≲2 Myr.

Conclusions.We propose that the Serpens filament is a newly-formed slightly-supercritical structure which appears to be actively accreting material from its ambient gas.
Stellar chromospheric activity of 1674 FGK stars from the AMBRE-HARPS sample
Authors: Gomes da Silva J. , Santos N. C. , Adibekyan V. , Sousa S. G. , Campante T. L. , Figueira P. , Bossini D. , Delgado-Mena E. , Monteiro M. J. P. F. G. , de Laverny P. , Recio-Blanco A. , Lovis C.
Published: December 2020

Aims.The main objective of this project is to characterise chromospheric activity of FGK stars from the HARPS archive. We start, in this first paper, by presenting a catalogue of homogeneously determined chromospheric emission (CE), stellar atmospheric parameters, and ages for 1674 FGK main sequence (MS), subgiant, and giant stars. The analysis of CE level and variability is also performed.

Methods.We measured CE in the Ca IIH&K lines using more than 180 000 high-resolution spectra from the HARPS spectrograph, as compiled in the AMBRE project, obtained between 2003 and 2019. We converted the fluxes to bolometric and photospheric corrected chromospheric emission ratio,RHK′. Stellar atmospheric parametersTeff, logg, and [Fe/H] were retrieved from the literature or determined using a homogeneous method.M⋆,R⋆, and ages were determined from isochrone fitting.

Results.We show that our sample has a distribution of CE for MS stars that is consistent with an unbiased sample of solar-neighbour MS stars. We analysed the CE distribution for the different luminosity classes and spectral types and confirmed the existence of the very inactive (VI) star and very active star populations at logRHK′ <  −5.1 and >  − 4.2 dex, respectively. We found indications that the VI population is composed mainly of subgiant and giant stars and that logRHK′ = −5.1 dex marks a transition in stellar evolution. Overall, CE variability decreases with decreasing CE level but its distribution is complex. There appears to be at least three regimes of variability for inactive, active, and very active stars, with the inactive and active regimes separated by a diagonal, extended Vaughan-Preston (VP) gap. We show that stars with low activity levels do not necessarily have low variability. In the case of K dwarfs, which show high CE variability, inactive and active stars have similar levels of activity variability. This means that activity levels alone are not enough to infer the activity variability of a star. We also explain the shape of the VP gap observed in the distribution of CE using the CE variability-level diagram. In the CE variability-level diagram, the Sun is located in the high-variability region of the inactive MS stars zone. A method to extract the probability density function of the CE variability for a given logRHK′level is discussed, and a python code to retrieve it is provided.
Modal synthesis of precision control systems
Authors: Vasiljev E M , Serdechnaya E. A. , Tavolzhanskij A V
Published: December 2020

The problem of synthesis of precision modal control systems is considered. It is noted that a common approach to solving this problem is to consistently meet the requirements for the nature of the transient process and for the indicators of its accuracy. This approach to synthesis is faced with the need to make design decisions under incomplete conditions. In practice, this circumstance leads to obtaining synthesis results with undesirable deviations from technical requirements. When designing precision control systems, such deviations are unacceptable. To eliminate the difficulties that arise, a transition to interval methods for formulating and solving modal synthesis problems is proposed. The theoretical possibility of the interval approach is based on the excessive variety of possible placement of eigenvalues in the spectrum of the characteristic matrix of the system. An example of an interval synthesis of a system with a modal controller and additional output feedback is considered. The restrictions on the spectrum of the specified matrix are formed, which determine the fulfillment of the requirements for the monotonicity of the transient process, the regulation time and the accuracy of the response to harmonic influences. It is noted that the variety of solutions obtained creates the preconditions for a multi-alternative approach to modal synthesis of systems.
Increasing the reliability of information management systems for complex objects
Authors: Levchenkov A
Published: December 2020

This article describes one of the possible approaches to the implementation of a set of mechanisms and tools for assessing and monitoring software safety based on static and dynamic analysis of programs, which provides an effective check of the operating and developed software. To solve this problem, it is proposed to use mathematical models of program circuits, modern software development technologies and methods of software analysis.
Thermal and hydraulic calculation in a model of industrial branched pipeline transporting a single-phase liquid flow
Authors: Mayakova S. A. , Privalov L. Y.
Published: December 2020

This paper proposes a system of differential equations that describes changes of pressure and temperature of a stationary liquid flow through straight, turning, and branched pipeline sections. We developed a program, using the proposed system of equations, that carries through hydraulic and thermohydraulic calculations, allows to choose diameter of various pipeline systems. The key feature of the program is the ability to solve monophasic problems such as: friction losses; local resistance losses; heat dissipation into the environment; flow distribution.
Problem statement for practical modeling of temperature fields of gyroscopes in space navigation systems
Authors: Pankratov V M , Golikov A V , Barulina M. A. , Pankratova E V , Efremov M V
Published: December 2020

The paper describes a method of studying temperature fields in fiber-optic gyroscopes that are part of complex navigation systems, using the example fiber-optic gyroscope as part of the angular velocity measurement system BIUS-M-1, developed by “Antares” (Saratov). The work relevance is due to the fact that currently existing methods for studying external and internal thermal effects on precision devices, and the resulting three-dimensional non-stationary temperature fields may be too complicated for practical application, or require significant computation and time resource. Also, not all contemporary models take into account such parameters, as low pressure and vacuum, the importance of which for devices operating in space orbital conditions cannot be underestimated. Therefore, modeling of the thermal process in various devices should be carried out at the design stage. At the same time, such modeling should not be labor-intensive, do not require large financial investment and computing resources. In this paper, the authors formulate a research problem, develop a thermal model, and present the main relations that are the components of the mathematical model of nonstationary three-dimensional inhomogeneous temperature fields in the fiber-optic gyroscope. The resulting model can be implemented quite simply in computational algorithms and software.
Analysis of the theoretical current-voltage characteristic of non-stationary transport in the cross-section of the desalination channel
Authors: Shkorkina I , Chubyr N , Gudza V , Urtenov M
Published: December 2020

In practice, the current-voltage characteristic (CVC) is the most important characteristic of transport in electromembrane systems, since it is using CVC that the concept of limiting current is introduced, various modes of operation of electromembrane systems are analyzed, and their efficiency is evaluated. At present, experimental CVC methods of Fourier analysis, wavelet analysis, and dynamical systems are well studied. At the same time, the study of theoretical CVC is not sufficiently developed. Previously, we derived a formula for calculating the CVC of a non-stationary 1:1 transfer of an electrolyte in the cross-section of the desalination channel, which includes an anion-exchange (AEM) and cation-exchange (CEM) membranes, and establishing the fundamental laws of changes in CVC over time. The simulation is based on the NernstPlanck-Poisson equations. In this paper, we analyze this formula and identify the fundamental laws of the CVC of non-stationary 1:1 transfer of the electrolyte in the cross-section of the desalination channel. It is shown that in the prelimiting mode, the migration current and the diffusion current give approximately the same contribution to the total current, and in the overlimiting mode, the main contribution is given by the migration current, the value of the displacement current does not depend on time and is proportional to the sweep speed. It is found that the average conduction current is many times greater than the displacement current, starting from a few seconds. The results obtained allow to construct and analyze the CVC for the cross-section of the desalination channel.
Strapdown inertial navigation systems readings correction based on navigational data of other sensors and systems with intelligent selection of the priority adjuster
Authors: Trefilov P.M. , Mamchenko M.V. , Korol’kov A.V.
Published: December 2020

Strapdown inertial navigation systems (SINS) are one of the main components of the navigation systems of the drones and aircraft (including autonomous ones), but their readings need to be instanly corrected due to the constant accumulation of errors. This paper comprises the review of existing approaches to using one or more sensors or systems to correct the navigation data of SINS algorithms (herein after – correctors) using integrated information processing. A common disadvantage of the analysed approaches is the lack of flexibility concerning the types and the number of SINS correctors used, as well as the growth of computational burden due to the use of the measurement vectors of all the correctors in the process of forming the state vector of the system. This article proposes the use of the original adaptive scheme based on the selection of the least noisy data, taking into account environmental conditions, for the integrated processing of the SINS and the correctos’ navigation parameters. The essence of the approach is that the state vector is estimated on the basis of the most reliable corrector. This allows reducing the correlation of errors in the correctors’ measurement of navigational parameters, since only the measurement vectors (or vector) with best navigational data signal/noise ratio (received from the corresponding correctors) are used in forming the state vector. Furthermore, the proposed navigational data fusion scheme has a modular structure and greater flexibility in comparison with the loosely coupled systems, and also implies the use of an arbitrary number of correction sensors and systems regardless of the physical nature of their measurements.
GIS technologies used in zoning agricultural land for optimizing regional land use
Authors: Tsoraeva Eleonora , Mezhyan Sirunik , Kataeva Marina , Hugaeva Ludmila , Rogova Tatyana
Published: December 2020

The paper discusses the main definitions and advantages of using GIS technologies in land management. The results of the implementation of the use of GIS technologies in agriculture are given, which will greatly facilitate the work of specialists. Work with various maps, digitization and explication of lands using the MapInfo geoinformation product is clearly presented. High-quality introduction of new technologies is necessary in Russia.
Machine learning as a tool for choice of enterprise development strategy
Authors: Krichevsky M , Serova E
Published: December 2020

One of the main objectives of strategic management is the development and selection of strategies to achieve the desired results. The main goal of this paper is the analysis of the main domains or areas of machine learning application to support the process of strategic planning and decision making. The scientific methodology of the research studies is methods and procedures of modeling and intelligent analysis. This is theoretical and empirical paper in equal measure. This paper deals with the issues of machine learning implementation and how intellectual models and systems can be used to support the process of strategic planning. At the preprocessing stage on the basis of a modeled base of examples of strategy options, the use of clustering methods for forming groups of similar parameters that influence the choice of strategies and groups of similar enterprise objects, each of which has a certain type of strategy, is demonstrated. On the next step the selection of ranked characteristics that affect the choice of strategy is made. At the stage of solving the problem of choosing strategies, module Classifier Learner from MatLab 2018b is used.
Prediction of the course of primary open-angle glaucoma in combination with diabetic retinopathy using a mathematical model
Authors: Vorobyeva I V
Published: December 2020

It is possible to accurately diagnose diseases in the early stages using optical coherence tomography. A mathematical model has been developed for two diseases: glaucoma and diabetic retinopathy. The model takes into account digital data of ophthalmological equipment obtained from the optic nerve disk and macular area. Criteria that take into account the thickness of the macular zone and the parameters of the optic nerve disc were developed (integral volume and area of the neuroretinal rim, the area of the optic disc excavation). The proposed mathematical model gives the opportunity to predict the development of combined pathology in relation of the integral area of the neuroretinal rim to the integral volume, as well as to a criterion that takes into account the thickness of the macula and the area of excavation of the optic nerve head. The model makes it possible to give a clear risk of developing diseases (low, high) and a significant prognosis of the course of diseases (good prognosis for vision, bad prognosis for vision). The capability of the mathematical model to predict the development of the disease in a patient with type 2 diabetes is demonstrated.
The integration of information systems in a medical facility to improve the efficiency of decision-making
Authors: Bolsunovskaya Marina , Leksashov Alexander , Gintciak Aleksey , Shirokova Anastasiia
Published: December 2020

This paper describes a project for integrating a medical and diagnostic information system in a medical facility. At the moment, making effective and timely decisions in diagnosis and treatment is most important. Integration of systems has significantly improved the efficiency of decision-making by updating data. The unified information space allowed to increase the objectivity of diagnostics and increase the reliability of the information system. A critical factor in making a decision is the stage at which the disease is detected, as well as a description of what types of medical care are important for analysis. In addition, the need to synchronize on the basis of the detailed information for operational planning and routing of patients. Integration of solutions will increase the speed of passing examinations and the speed of making a final diagnosis. Thanks to the implemented solution, it became possible to increase the speed and improve the quality of services provided. The ability to synchronize activity planning based on effective diagnostics is essential.
Development of rice pre-breeding resources with blast resistance
Authors: Mukhina Zh M , Savenko E G , Korotenko T L , Suprun I I , Bragina O. A. , Chukhir I N , Zheng Wenjing , Zuobin Ma , Changhua Wang
Published: December 2020

Within the framework of this study, the first Russian-Chinese joint program for development of rice varieties with long-term blast resistance was launched on the basis of rice germplasm exchange and the subsequent comprehensive study of the obtained breeding samples, hybridization of Russian and Chinese varieties with specified traits. The genetic diversity of the Chinese rice samples obtained by exchange was studied by biological and morphological traits of plants, taxonomic belonging to a botanical variety, elements of the yield structure, and resistance to lodging. 31 hybrid combinations (F1) from the crossing of Russian and Chinese varieties were used to obtain the BC1 generation. The technologies of cultivation of isolated rice anthers in vitro have been optimized in relation to Chinese genotypes in order to accelerate the genetic stabilization of breeding material obtained from crossing. Phenotyping of Russian and Chinese breeding samples was carried out on the basis of resistance to the local population of the blast pathogen (Magnaporthe grisea (T.T. Hebert) M.E. Barr)), on natural and artificial infectious backgrounds. DNA identification of genes for blast resistance was carried out for the same breeding samples. Based on the experimental data obtained, promising samples were selected - prototypes of new rice varieties.
The degree of restoration of the soil properties developed under the fallows in the early stages of succession
Authors: Filimonova D. A. , Solovev S V , Bezborodova A N , Miller G F
Published: December 2020

At present, the return of fallow lands to agricultural circulation is an important and one of the topical issues of the whole world. Research related to the restoration of soil properties of fallows is of particular value. Therefore, it is necessary to know what processes occur in the vegetation and soil cover of fallows at the different stages of their development, taking into account local natural features. The paper presents the results of a survey of young (up to four years) and middle-aged (up to ten years) fallows of the forest-steppe zone of Western Siberia within the Novosibirsk region. It is established that in the first decade of succession in fallow areas there are two stages of overgrowth, and when analyzing the structure of plant matter, it is shown that the ratio of their fractional composition reflects the general tendency to restore the ecosystem that preceded plowing. Restoration of soil properties under young and middle-aged fallows is much slower. Data of humus content analysis allow us to conclude that its content is somewhat higher in the upper parts of the profile in middle-aged fallows compared to young fallows. The research on soil-physical characteristics and vegetation cover allowed us to note the trends of restoration of the initial state of soils.
Study of high fat feed for sturgeon fish
Authors: Osepchuk D V , Yurina N. A. , Kuzminova E V , Gneush A N , Yurin D. A. , Maxim E. A.
Published: December 2020

The objective of the study is to analyze the growth and development of sturgeon fish when feeding trout food with a higher fat content and to conduct ultrasound diagnostics of the fish liver. The research was carried out on the basis of the fish farm of Albashi LLC, Leningradsky district, Krasnodar Territory. The experiment used juvenile Russian-Siberian sturgeon. The basal diet is sturgeon forage with a granule size of 3 mm, produced by Aller Trident EX, trout forage from Aller Silver is also used for comparability of observation series. The experiment lasted 90 days. Aller Trident EX feed ingredients: vitamins, premixes and minerals, yeast, corn gluten, sunflower protein, wheat, wheat gluten, rapeseed oil, fish oil, fish meal, soy protein, soy. Although the increased content of fat for sturgeon fish in the compound feed contributes to an increase in their weight, but this occurs due to metabolic disorders and fat accumulation, which is also evidenced by an increase in juvenile waste in the experimental groups by 2.04.0% and the onset of pathological processes in the liver. Such fish can be used for commercial purposes and sale when the weight reaches 1000 g.
History and prospects of the application of X-ray in seed production and seed studies
Authors: Musaev F B , Potrakhov N N , Beletskiy S L
Published: December 2020

A retrospective analysis of the history of the application of the method of radiography in the course of studies of the structure of seeds for the purposes of seed production and seed studies was carried out. It is shown that the beginning of X-ray studies of seeds is directly related to the development in the late 70s of the last century in the Special Design Bureau for X-ray Instruments, Leningrad Association of Electronic Instrumentation “Svetlana” of a specialized X-ray apparatus based on the X-ray emitter REIS with a voltage of 25 kV. The methodological part of the research was provided by the leading specialized enterprises of our country, now they are FSBSI API, FSBI Research Institute for Storage Problems of the Federal Reserve FSBSI FSVC. In the early 2000s, ETU “LETI”, represented by a small enterprise of the Technopark LETI, CJSC “ELTECH-Med”, actively joined the research. LETI is associated with the transition to digital receivers of X-ray images, which made it possible to fundamentally increase the efficiency of research by employees of CJSC “ELTECH-Med” together with specialists from Agrophysical Research Institute, FSBI Research Institute for Storage Problems of the Federal Reserve, FSBSI FSVC developed a number of technical means for obtaining digital 2 and 3 dimensional X-ray images of seeds.
Management of small agricultural cooperation and corporatization
Authors: Tolmachev Alexey , Smirnov Vitaliy , Grishin Evgeniy , Syromyatnikov Denis
Published: December 2020

The possibility of applying the principles of corporate governance in the practice of small agricultural businesses is considered. The authors believe that cooperative associations of small market participants can transform into corporate associations at a certain stage of development. The scientific novelty is represented by an improved economic mechanism of two-level cooperation of small agricultural enterprises with the financial participation of municipalities, regional and Federal authorities and the formation of their own cooperative Bank. The mechanism recommended by the authors is aimed at motivating small business participants to cooperate by the possibility of subsequent corporatization. The implementation of the cooperation development plan will require temporary exemption of its participants from the tax burden, while the state should practice joint construction of processing, logistics and other necessary facilities in the agricultural sector, with the subsequent transfer of its shares to consumer cooperatives of small businesses.
Transformation of corporate governance models in investment funds
Authors: Metzger Aleksandr
Published: December 2020

The article is devoted to the phenomenon of corporate governance in investment funds, as one of the key elements ensuring the effective functioning of this institution of financial intermediation. A narrow and formal understanding of the term “corporate governance” in mutual funds is reduced to the relationship between owners and leaders of the management companies. This problem is devoid of practical sense in the context of highly concentrated ownership in these companies. The author proposes an expanded interpretation of corporate governance based on considering an investment fund as an “investment corporation”, in which the participants are various categories of investors, fund management, as well as a number of other participants and stakeholders, depending on the nature of the investment process. Considering corporate governance as a system of control and management in Russian investment funds, the author comes to a number of conclusions. The current model considers the protection of the interests of fund investors from the opportunism of managers as a priority and meets the specifics of a certain market segment. The same model, but under different conditions, becomes redundant or even destructive. The analysis of the specifics of the activities of the investment funds for qualified investors makes it possible to formulate adequate changes in the corporate governance model. These include: 1) the transition to a model of coordinating the interests of the investors (controlling and minority), as well as other participants in the investment process, 2) reducing external regulation and moving to internal mechanisms for assessing and making decisions, taking into account the qualifications of the participants themselves, 3) limiting or compensation for the excessive influence of the controlling investor with a concentrated structure of investors.
Modeling the stakeholder value and stakeholder risks
Authors: Zlygostev Alexander , Makarova Elena
Published: December 2020

The aim of the paper is to expand understanding of stakeholder value and consider possibilities of its assessing for minimizing stakeholder risks. The study makes contributions to achieving a balance between interests of stakeholders and implementation of sustainable business development principles. The paper introduces a practical toolkit for modeling stakeholder value and stakeholder risks. New methods, developed by the authors to model and analyze stakeholder value and risks, determine the novelty of the study. The paper provides the results of new methodology validation performed with the use of mathematical and econometric methods applied to open source data. Models of contributions and benefits of stakeholders are examined, levels of the “gap” between contributions and benefits by groups of stakeholders are outlined, the map of “stakeholder risks” is presented. The analysis of the results allows to make conclusions and provide recommendations on establishing balanced relationships with stakeholders and minimizing stakeholder risks in order to harmonize interests for sustainable business development.
Fiscal and investment indicators for evaluating professional sports facilities
Authors: Gordienko Mikhail , Ekimova Ksenia , Glubokova Nadezhda , Shuvalova Elena
Published: December 2020

The article is devoted to the formation of a methodology for assessing the investment and fiscal attractiveness of professional sports facilities, for which there are many similar techniques, but no single universal one. The authors made an attempt to form such a methodology, based on the ecosystem approach, within which the attractiveness of a particular object is assessed in aggregate and taking into account the interrelationships of the object and the macroeconomic environment (state, territorial and sectoral regulation), as well as the microeconomic environment (the financial position of the organization and the characteristics of the object itself). The article gives examples of indicators, their variants of values and estimated values and presents a general algorithm for applying the technique and basic formulas for calculations.
Development of ‘smart’manufacturing in Russia: Empirical region-specific study of system technologies
Authors: Starikov Evgeniy , Evseeva Marina , Tkachenko Irina
Published: December 2020

The purpose of the paper is to consider the concept of Industry 4.0 through the prism of ‘Factories of the Future’ program as a system of integrated technological solutions for creating ‘smart’ industries.The paper analyzes the TechNet road map proposed by the National Technological Initiative, a program aiming at enhancing the global competitiveness of Russian industry by 2035. Aregion-specific empirical study focuses on system technologies that contribute to the development of ‘smart’ manufacturing in four industrial regions of Russia: Sverdlovskaya, Chelyabinskaya, Kurganskaya and Tumenskaya Oblasts. The conclusion is made about the upward trendin thedevelopment of ‘smart’ industries in Sverdlovskaya and Chelyabinskaya Oblasts.
Interaction of technology entrepreneurship and higher education as a factor in the innovative development of the region
Authors: Mantaeva Elza , Goldenova Victoria , Batyreva Dayana , Batyrev Dolgan
Published: December 2020

The purpose of the study is to substantiate the strengthening of the role of scientific and educational institutions as centers for the formation of technological, managerial and innovative competencies in the formation of an innovation ecosystem, as an environment for the functioning of technological entrepreneurship. In the course of the work, it was revealed that the motivation of the entrepreneurial sector in funding scientific research of educational and scientific institutions should come to the fore. It has been substantiated that it is precisely the close interaction of business, educational and government structures that is the key to increasing investment and innovation activity in the region. The theoretical significance of the article is to substantiate the need to strengthen the role of educational institutions as centers for the formation of technological, managerial and innovative competencies in the formation of an innovation ecosystem, as an environment for the functioning of technological entrepreneurship.
Load-velocity Profiles Change after Training Programs with Different Set Configurations
Authors: Iglesias-Soler Eliseo , Rial-Vázquez Jessica , Boullosa Daniel , Mayo Xian , Fariñas Juan , Rúa-Alonso María , Santos Luis
Published: December 2020

This study explored the changes in load-velocity relationship of bench press and parallel squat exercises following two programs differing in the set configuration. A randomized controlled trial was carried out in a sample of 39 physically active individuals. Participants were assigned to rest redistribution set configuration, traditional set configuration, or control groups. Over 5 weeks, the experimental groups completed 10 sessions with the 10 repetitions maximum load of both exercises. Rest redistribution sets consisted in 16 sets of 2 repetitions with 60 s of rest between sets, and 5 min between exercises, whereas traditional sets entailed 4 sets of 8 repetitions with 5 min of rest between sets and exercises. The load-velocity relationships of both exercises were obtained before and after the training period. For bench press, an increase of the velocity axis intercept, and a decrease of the slope at post-test were observed in both rest redistribution (p<0.001, G=1.264; p<0.001; G=0.997) and traditional set (p=0.01, G=0.654; p=0.001; G=0.593) groups. For squat, the slope decreased (p<0.001; G=0.588) and the velocity axis intercept increased (p<0.001; G=0.727) only in the rest redistribution group. These results show that rest redistribution sets were particularly efficient for inducing changes in the load-velocity relationship.
Role of Dkk2 in the Muscle/bone Interaction of Androgen-Deficient Mice
Authors: Iemura Shunki , Kawao Naoyuki , Akagi Masao , Kaji Hiroshi
Published: December 2020

Androgen deficiency is known to cause both osteoporosis and sarcopenia. Myokines, humoral factors secreted from the skeletal muscles, have recently been getting attention as the key factors related to the interactions between muscle and bone. Dickkopf (Dkk) 2 is known as an inhibitor of canonical Wnt/β-catenin signaling, and Wnt/β-catenin signaling is crucial for the maintenance of muscle and bone. The present study was therefore performed to investigate the roles of Dkk2 in the alterations of muscle and bone of androgen-deficient mice with orchidectomy (ORX). ORX significantly enhanced Dkk2 mRNA levels, but not other Dkks and secreted frizzled related proteins, in the soleus muscles of mice. Moreover, ORX enhanced serum Dkk2 levels, but not Dkk2 mRNA levels in the tibial bone tissues, the white adipose tissues and liver of mice. In simple regression analyses, serum Dkk2 levels were negatively related to trabecular bone mineral density at the tibias in mice employed in the experiments. In vitro experiments, testosterone suppressed Dkk2 mRNA levels in mouse muscle C2C12 cells. In conclusion, we showed that androgen deficiency enhances Dkk2 expression and secretion in the muscles of mice. Dkk2 might be involved in androgen deficiency-induced muscle wasting and osteopenia as a myokine linking muscle to bone.
Optical diagnosis of colorectal polyp images using a newly developed computer-aided diagnosis system (CADx) compared with intuitive optical diagnosis
Authors: van der Zander Quirine E. W. , Schreuder Ramon M. , Fonollà Roger , Scheeve Thom , van der Sommen Fons , Winkens Bjorn , Aepli Patrick , Hayee Bu'Hussain , Pischel Andreas B. , Stefanovic Milan , Subramaniam Sharmila , Bhandari Pradeep , de With Peter H. N. , Masclee Ad A. M. , Schoon Erik J.
Published: December 2020

Background Optical diagnosis of colorectal polyps remains challenging. Image-enhancement techniques such as narrow-band imaging and blue-light imaging (BLI) can improve optical diagnosis. We developed and prospectively validated a computer-aided diagnosis system (CADx) using high-definition white-light (HDWL) and BLI images, and compared the system with the optical diagnosis of expert and novice endoscopists.

Methods CADx characterized colorectal polyps by exploiting artificial neural networks. Six experts and 13 novices optically diagnosed 60 colorectal polyps based on intuition. After 4 weeks, the same set of images was permuted and optically diagnosed using the BLI Adenoma Serrated International Classification (BASIC).

Results CADx had a diagnostic accuracy of 88.3 % using HDWL images and 86.7 % using BLI images. The overall diagnostic accuracy combining HDWL and BLI (multimodal imaging) was 95.0 %, which was significantly higher than that of experts (81.7 %, P = 0.03) and novices (66.7 %, P < 0.001). Sensitivity was also higher for CADx (95.6 % vs. 61.1 % and 55.4 %), whereas specificity was higher for experts compared with CADx and novices (95.6 % vs. 93.3 % and 93.2 %). For endoscopists, diagnostic accuracy did not increase when using BASIC, either for experts (intuition 79.5 % vs. BASIC 81.7 %, P = 0.14) or for novices (intuition 66.7 % vs. BASIC 66.5 %, P = 0.95).

Conclusion CADx had a significantly higher diagnostic accuracy than experts and novices for the optical diagnosis of colorectal polyps. Multimodal imaging, incorporating both HDWL and BLI, improved the diagnostic accuracy of CADx. BASIC did not increase the diagnostic accuracy of endoscopists compared with intuitive optical diagnosis.
Right Sinus of Valsalva Aneurysm Mimicking Right Coronary Artery Ischemia
Authors: Bivona Antonio , Caruso Vincenzo , Shah Samir
Published: December 2020

An aneurysm of a single sinus of Valsalva is rare. It is usually asymptomatic and rarely discovered, unless it compresses the adjacent cardiac structures, or it presents in association with other pathology. We herein describe a case of a male, with known ischemic heart disease, collapsing after sudden back pain. A computed tomography scan demonstrated an aneurysm of the right sinus of Valsalva. The surgical repair aimed to exclude the aneurysm, preserving and reconstructing the aortic root.
New-Onset Atrial Fibrillation and Adverse In-Hospital Outcome in Patients with Acute Pulmonary Embolism
Authors: Jing Yan-Yan , Tang Ri-Bo , Xu Zhi-Yuan , Dong Jian-Zeng , Du Xin , Wu Jia-Hui , Yu Rong-Hui , Long De-Yong , Ning Man , Sang Cai-Hua , Jiang Chen-Xi , Bai Rong , Liu Nian , Wen Song-Nan , Li Song-Nan , Chen Xuan , Huang Shu-Tao , Cui Yi-Kai , Ma Chang-Sheng
Published: December 2020

Atrial fibrillation (AF) can be secondary to acute pulmonary embolism (PE). This study aimed to investigate the prognostic impact of new-onset AF on patients with acute PE. In this study, 4,288 consecutive patients who were diagnosed with acute PE were retrospectively screened. In total, 77 patients with acute PE and new-onset AF were analyzed. Another 154 acute PE patients without AF were selected as the age- and sex-matched control group. Adverse in-hospital outcome comprised one of the following conditions: all-cause death, endotracheal intubation, cardiopulmonary resuscitation, and intravenous catecholamine therapy. The patients with new-onset AF had higher prevalence of congestive heart failure, higher simplified PE severity index (sPESI), higher creatinine, and larger left atrium diameter. The incidences of adverse in-hospital outcomes were 10.4 and 2.6% in patients with new-onset AF and no AF, respectively (p = 0.02). Patients with sPESI ≥ 1 had higher incidence of adverse in-hospital outcomes than those with sPESI = 0 (9.4 vs. 0.9%, p < 0.01). The area under the receiver operating characteristic curve of sPESI and sPESI + AF (adding 1 point for new-onset AF) scores in assessing the adverse in-hospital outcome were 0.80 (95% confidence interval [CI]: 0.68–0.93) and 0.84 (95% CI: 0.72–0.96), respectively. In multivariable analysis, sPESI ≥ 1 (odds ratio, 8.88; 95% CI: 1.10–72.07; p = 0.04) was an independent predictor of adverse in-hospital outcome. However, new-onset AF was not an independent predictor. In the population studied, sPESI is an independent predictor of adverse in-hospital outcomes, whereas new-onset AF following acute PE is not, but it may add predictive value to sPESI.
Right Atrial Thrombosis and Pulmonary Embolism: A Narrative Review
Authors: Anfinogenova Nina D. , Vasiltseva Oksana Y. , Vrublevsky Alexander V. , Vorozhtsova Irina N. , Popov Sergey V. , Smorgon Andrey V. , Mochula Olga V. , Ussov Wladimir Y.
Published: December 2020

Prompt diagnosis of pulmonary embolism (PE) remains challenging, which often results in a delayed or inappropriate treatment of this life-threatening condition. Mobile thrombus in the right cardiac chambers is a neglected cause of PE. It poses an immediate risk to life and is associated with an unfavorable outcome and high mortality. Thrombus residing in the right atrial appendage (RAA) is an underestimated cause of PE, especially in patients with atrial fibrillation. This article reviews achievements and challenges of detection and management of the right atrial thrombus with emphasis on RAA thrombus. The capabilities of transthoracic and transesophageal echocardiography and advantages of three-dimensional and two-dimensional echocardiography are reviewed. Strengths of cardiac magnetic resonance imaging (CMR), computed tomography, and cardiac ventriculography are summarized. We suggest that a targeted search for RAA thrombus is necessary in high-risk patients with PE and atrial fibrillation using transesophageal echocardiography and/or CMR when available independently on the duration of the disease. High-risk patients may also benefit from transthoracic echocardiography with right parasternal approach. The examination of high-risk patients should involve compression ultrasonography of lower extremity veins along with the above-mentioned technologies. Algorithms for RAA thrombus risk assessment and protocols aimed at identification of patients with RAA thrombosis, who will potentially benefit from treatment, are warranted. The development of treatment protocols specific for the diverse populations of patients with right cardiac thrombosis is important.
The Role of the Transorbital Superior Eyelid Approach in the Management of Selected Spheno-orbital Meningiomas: In-Depth Analysis of Indications, Technique, and Outcomes from the Study of a Cohort of 35 Patients
Authors: Locatelli Davide , Restelli Francesco , Alfiero Tommaso , Campione Alberto , Pozzi Fabio , Balbi Sergio , Arosio Alberto , Castelnuovo Paolo
Published: December 2020

Objective Primary goal in spheno-orbital meningioma (SOM) surgery still remains complete resection. Nevertheless, given their highly infiltrative nature, a growing body of literature suggests to shift toward function-sparing surgeries. We here present our experience in the management of SOMs through the endoscopic superior eyelid approach (SEA).

Methods Surgical database from our multidisciplinary work group was retrospectively reviewed to identify patients treated for SOMs in the last 10 years by our senior authors, analyzing and correlating clinical, radiological, and outcome variables among the different approaches used.

Results There were 35 patients (mean age of 57.3 ± 12.86 years), with a mean follow-up of 31.5 months (range: 6–84 months). The most common preoperative complaint was proptosis (62.9%) followed by diplopia and visual deficit. Greater and lesser sphenoid wings were the areas mainly involved by the pathology (91.4% and 88.6%, respectively), whereas orbital invasion was evidenced in one-third of cases. Patients were operated on through craniotomic (48.6%), endoscopic superior eyelid (37.1%), and combined cranioendoscopic (14.3%) approaches. Simpson grades 0 to II were accomplished in 46.2% of SEA and 76.5% of craniotomies. All patients with a preoperative visual deficit improved in the postoperative period, independently from the approach used. On patients who underwent endoscopic SEA, there was improved their short-/long-term postoperative Karnofsky Performance Status.

Conclusions Endoscopic SEA is a safe and effective alternative to transcranial approaches in very selected cases of SOMs, where the planned primary objective was to obtain a maximally safe resection, aimed at symptom relief, rather than a gross total resection at any cost.
Correlation of Vitamin D Deficiency with Predictors of Mortality in Critically Ill Children at a Tertiary Care Centre in North India—A Prospective, Observational Study
Authors: Bansal Shilpa , Kaur Amarpreet , Rai Seema , Kaur Gurmeet , Goyal Gitanjali , Singh Jasbir , Sandhu Jaskirat Kaur
Published: December 2020

This study was conducted to assess the relationship of vitamin D deficiency (VDD) with various demographic characteristics, laboratory parameters, and predictors of mortality. This prospective observational study was performed at pediatric intensive care unit (PICU) of a tertiary care hospital situated in north India. A total of 125 children admitted in PICU with age from 2 months to 14 years were analyzed. The subjects were classified as Vitamin D deficient (≤20 ng/mL) and nondeficient (>20 ng/mL). The relationship between VDD and predictors of mortality were analyzed using correlation and multivariate analysis. Respiratory system (40%) was most commonly involved. VDD was seen in 72% of the patients. There was statistically significant correlation of VDD with age (p = 0.019), season (p = 0.018), height (p = 0.005), and weight (p = 0.003). On multivariate analysis factors associated with VDD were age (odds ratio [OR] = 1.01, 95% confidence interval [CI] 1.00–1.03, p = 0.006), season (OR = 3.98, 95% CI 1.09–14.50, p = 0.036). VDD was also correlated to bacteriuria (p = 0.033), cardiovascular sequential sepsis-related organ failure assessment score (CV-SOFA score) (p = 0.001), and mechanical ventilation (p = 0.043). On multivariate analysis, factors associated with VDD were bacteriuria (OR = 4.88, 95% CI 1.04–22.89, p = 0.04), mechanical ventilation requirement (OR = 2.95, 95% CI 1.12–7.85, p = 0.029), and CV-SOFA score (OR = 2.33, 95% CI 1.14–4.76, p = 0.021). Median (interquartile range) duration of PICU stay in VDD patients was (3–7) days while in nondeficient patients it was (2–6) days (p = 0.107). VDD was a significant risk factor for the need of mechanical ventilation, bacteriuria, and mortality among patients in our cohort.
Spectral continuity for aperiodic quantum systems: Applications of a folklore theorem
Authors: Beckus Siegfried , Bellissard Jean , De Nittis Giuseppe
Published: December 2020

This work provides a necessary and sufficient condition for a symbolic dynamical system to admit a sequence of periodic approximations in the Hausdorff topology. The key result proved and applied here uses graphs that are called De Bruijn graphs, Rauzy graphs, or Anderson–Putnam complex, depending on the community. Combining this with a previous result, the present work justifies rigorously the accuracy and reliability of algorithmic methods used to compute numerically the spectra of a large class of self-adjoint operators. The so-called Hamiltonians describe the effective dynamic of a quantum particle in aperiodic media. No restrictions on the structure of these operators other than general regularity assumptions are imposed. In particular, nearest-neighbor correlation is not necessary. Examples for the Fibonacci and the Golay–Rudin–Shapiro sequences are explicitly provided illustrating this discussion. While the first sequence has been thoroughly studied by physicists and mathematicians alike, a shroud of mystery still surrounds the latter when it comes to spectral properties. In light of this, the present paper gives a new result here that might help uncovering a solution.
Understanding modes of negative differential resistance in amorphous and polycrystalline vanadium oxides
Authors: Nandi Sanjoy Kumar , Das Sujan Kumar , Estherby Caleb , Gentle Angus , Elliman Robert G.
Published: December 2020

Metal–oxide–metal devices based on amorphous VOx are shown to exhibit one of two distinct negative differential resistance (NDR) characteristics depending on the maximum current employed for electroforming. For low compliance currents they exhibit a smooth S-type characteristic and have a temperature-dependent device resistance characterized by an activation energy of 0.25 eV, consistent with conduction in polycrystalline VO2, while for high compliance currents they exhibit an abrupt snap-back characteristic and a resistance characterized by an activation energy of 0.025 eV, consistent with conduction in oxygen deficient VOx. In both cases, the temperature dependence of the switching voltage implies that the conductivity change is due to the insulator–metal transition in VO2. From this analysis, it is concluded that electroforming at low currents creates a conductive filament comprised largely of polycrystalline VO2, while electroforming at high currents creates a composite structure comprised of VO2 and a conductive halo of oxygen deficient VOx. The effect of electroforming on the NDR mode is then explained with reference to a lumped element model of filamentary conduction that includes the effect of a parallel resistance created by the halo. These results provide new insight into the NDR response of vanadium-oxide-based devices and a basis for designing devices with specific characteristics.