bluuebunny/crossref_metadata_2025 huggingface dataset:
Interaction of the oncoprotein transcription factor MYC with its chromatin cofactor WDR5 is essential for tumor maintenance
Authors: Thomas Lance R. , Adams Clare M. , Wang Jing , Weissmiller April M. , Creighton Joy , Lorey Shelly L. , Liu Qi , Fesik Stephen W. , Eischen Christine M. , Tansey William P.
Published: November 2019

The oncoprotein transcription factor MYC is overexpressed in the majority of cancers. Key to its oncogenic activity is the ability of MYC to regulate gene expression patterns that drive and maintain the malignant state. MYC is also considered a validated anticancer target, but efforts to pharmacologically inhibit MYC have failed. The dependence of MYC on cofactors creates opportunities for therapeutic intervention, but for any cofactor this requires structural understanding of how the cofactor interacts with MYC, knowledge of the role it plays in MYC function, and demonstration that disrupting the cofactor interaction will cause existing cancers to regress. One cofactor for which structural information is available is WDR5, which interacts with MYC to facilitate its recruitment to chromatin. To explore whether disruption of the MYC–WDR5 interaction could potentially become a viable anticancer strategy, we developed a Burkitt's lymphoma system that allows replacement of wild-type MYC for mutants that are defective for WDR5 binding or all known nuclear MYC functions. Using this system, we show that WDR5 recruits MYC to chromatin to control the expression of genes linked to biomass accumulation. We further show that disrupting the MYC–WDR5 interaction within the context of an existing cancer promotes rapid and comprehensive tumor regression in vivo. These observations connect WDR5 to a core tumorigenic function of MYC and establish that, if a therapeutic window can be established, MYC–WDR5 inhibitors could be developed as anticancer agents.
MAIT Cells Are Major Contributors to the Cytokine Response in Group A Streptococcal Toxic Shock Syndrome
Authors: Emgård Johanna , Bergsten Helena , McCormick John K. , Barrantes Israel , Skrede Steinar , Sandberg Johan K. , Norrby-Teglund Anna
Published: November 2019

Streptococcal toxic shock syndrome (STSS) is a rapidly progressing, life-threatening, systemic reaction to invasive infection caused by group A streptococci (GAS). GAS superantigens are key mediators of STSS through their potent activation of T cells leading to a cytokine storm and consequently vascular leakage, shock, and multiorgan failure. Mucosal-associated invariant T (MAIT) cells recognize MR1-presented antigens derived from microbial riboflavin biosynthesis and mount protective innate-like immune responses against the microbes producing such metabolites. GAS lack de novo riboflavin synthesis, and the role of MAIT cells in STSS has therefore so far been overlooked. Here we have conducted a comprehensive analysis of human MAIT cell responses to GAS, aiming to understand the contribution of MAIT cells to the pathogenesis of STSS. We show that MAIT cells are strongly activated and represent the major T cell source of IFNγ and TNF in the early stages of response to GAS. MAIT cell activation is biphasic with a rapid TCR Vβ2-specific, TNF-dominated response to superantigens and a later IL-12- and IL-18-dependent, IFNγ-dominated response to both bacterial cells and secreted factors. Depletion of MAIT cells from PBMC resulted in decreased total production of IFNγ, IL-1β, IL-2, and TNFβ. Peripheral blood MAIT cells in patients with STSS expressed elevated levels of the activation markers CD69, CD25, CD38, and HLA-DR during the acute compared with the convalescent phase. Our data demonstrate that MAIT cells are major contributors to the early cytokine response to GAS, and are therefore likely to contribute to the pathological cytokine storm underlying STSS.
Optical waveguiding by atomic entanglement in multilevel atom arrays
Authors: Asenjo-Garcia Ana , Kimble H. J. , Chang Darrick E.
Published: November 2019

Significance

Atomic ensembles constitute a dominant platform for realizing quantum interfaces between light and matter. In dense and ordered arrays, destructive interference in photon emission leads to the emergence of subradiant states, which are protected from radiative decay and have long lifetimes. This phenomenon has attracted a lot of interest recently, with work showing that collective emission can be used to realize improved quantum memories and atomic mirrors. These ideas strongly rely on one assumption: that atoms have a unique ground state. Our work discusses the survival of subradiance for atoms with complex internal structure. In particular, we unveil a different mechanism for subradiance, which crucially depends on entanglement, a radical departure from the physics of classical-dipole lattices or 2-level atom arrays.
Linking energy loss in soft adhesion to surface roughness
Authors: Dalvi Siddhesh , Gujrati Abhijeet , Khanal Subarna R. , Pastewka Lars , Dhinojwala Ali , Jacobs Tevis D. B.
Published: November 2019

A mechanistic understanding of adhesion in soft materials is critical in the fields of transportation (tires, gaskets, and seals), biomaterials, microcontact printing, and soft robotics. Measurements have long demonstrated that the apparent work of adhesion coming into contact is consistently lower than the intrinsic work of adhesion for the materials, and that there is adhesion hysteresis during separation, commonly explained by viscoelastic dissipation. Still lacking is a quantitative experimentally validated link between adhesion and measured topography. Here, we used in situ measurements of contact size to investigate the adhesion behavior of soft elastic polydimethylsiloxane hemispheres (modulus ranging from 0.7 to 10 MPa) on 4 different polycrystalline diamond substrates with topography characterized across 8 orders of magnitude, including down to the angstrom scale. The results show that the reduction in apparent work of adhesion is equal to the energy required to achieve conformal contact. Further, the energy loss during contact and removal is equal to the product of the intrinsic work of adhesion and the true contact area. These findings provide a simple mechanism to quantitatively link the widely observed adhesion hysteresis to roughness rather than viscoelastic dissipation.
High-throughput assessment of hemoglobin polymer in single red blood cells from sickle cell patients under controlled oxygen tension
Authors: Di Caprio Giuseppe , Schonbrun Ethan , Gonçalves Bronner P. , Valdez Jose M. , Wood David K. , Higgins John M.
Published: November 2019

Significance

Sickle cell disease is the first “molecular disease” described more than 100 years ago. All morbidity and mortality are ultimately caused by polymerization of the variant sickle hemoglobin molecule in red blood cells (RBCs). However, despite decades of intense research, we are unable to measure the amount of hemoglobin polymer in individual RBCs with high throughput at arbitrary oxygen tension. We describe a high-throughput method to assess hemoglobin polymer at the single-cell level under controlled oxygen tension. The assay infers hemoglobin polymer fraction by measuring its effect on cellular oxygen affinity. This method provides biomarkers promising to improve management of sickle cell patients and to optimize the development and prioritization of candidate cures.
Oral ionic liquid for the treatment of diet-induced obesity
Authors: Nurunnabi Md , Ibsen Kelly N. , Tanner Eden E. L. , Mitragotri Samir
Published: November 2019

Significance

Obesity is considered a strong factor in many chronic diseases, including heart disease, diabetes, and cancer. Along with genetics, consumption of excessive fat and cholesterol-rich food are the primary causes of obesity. We have developed an ionic liquid that interacts with fat to form micrometer-sized particles. The ionic liquid prevents the fat from penetrating through the intestinal membrane. We have observed that a regular dose of 10 μL of CAGE (equivalent to a 500-mg human dose) resulted in 12% less body weight gain compared with the rats treated with CAGE. The results from the animal studies support oral CAGE as a promising approach for treating obesity.
Glutathionylation primes soluble glyceraldehyde-3-phosphate dehydrogenase for late collapse into insoluble aggregates
Authors: Zaffagnini Mirko , Marchand Christophe H. , Malferrari Marco , Murail Samuel , Bonacchi Sara , Genovese Damiano , Montalti Marco , Venturoli Giovanni , Falini Giuseppe , Baaden Marc , Lemaire Stéphane D. , Fermani Simona , Trost Paolo
Published: November 2019

Protein aggregation is a complex physiological process, primarily determined by stress-related factors revealing the hidden aggregation propensity of proteins that otherwise are fully soluble. Here we report a mechanism by which glycolytic glyceraldehyde-3-phosphate dehydrogenase of
Arabidopsis thaliana
(AtGAPC1) is primed to form insoluble aggregates by the glutathionylation of its catalytic cysteine (Cys149). Following a lag phase, glutathionylated AtGAPC1 initiates a self-aggregation process resulting in the formation of branched chains of globular particles made of partially misfolded and totally inactive proteins. GSH molecules within AtGAPC1 active sites are suggested to provide the initial destabilizing signal. The following removal of glutathione by the formation of an intramolecular disulfide bond between Cys149 and Cys153 reinforces the aggregation process. Physiological reductases, thioredoxins and glutaredoxins, could not dissolve AtGAPC1 aggregates but could efficiently contrast their growth. Besides acting as a protective mechanism against overoxidation, S-glutathionylation of AtGAPC1 triggers an unexpected aggregation pathway with completely different and still unexplored physiological implications.
Unexpected quenching effect on new particle formation from the atmospheric reaction of methanol with SO
3
Authors: Liu Ling , Zhong Jie , Vehkamäki Hanna , Kurtén Theo , Du Lin , Zhang Xiuhui , Francisco Joseph S. , Zeng Xiao Cheng
Published: November 2019

Significance

New particle formation (NPF) is an important global phenomenon, contributing nearly half of the cloud condensation nuclei in nature. Today, NPF is believed to be mainly promoted by low-volatile species formed in atmosphere. Herein, we show that in certain cases, the formation of low-volatile species could undermine NPF. Specifically, we identify previously unreported catalytic reactions between alcohols and SO
3
which yield low-volatile organic sulfates. Rather than being a promoter to NPF, the low-volatile organic sulfates can compete for consuming SO
3
, thereby disfavoring H
2
SO
4
formation. Such unexpected quenching effects on NPF are most likely to occur in dry and polluted regions with abundant alcohols, illustrating the importance in understanding the interplay between nucleation precursor formation and subsequent NPF.
IATE 2
Authors: Zorrilla-Agut Paula , Fontenelle Thierry
Published: November 2019

The redevelopment of the European Union’s interinstitutional terminology database IATE (InterActive Terminology
for Europe) has been an opportunity to rethink the technologies, architecture and data structure of the system in order to prepare
it for future challenges, including interoperability, modularity, scalability and data exchange, among other things. This article
describes which strategies are being put in place to allow IATE data – one of the largest multilingual terminology databases in
the world – to be consumed by third-party tools, particularly computer-assisted translation environments (CATEs). The
modernisation of the application, aligning it with the latest software and systems engineering standards and technologies for the
benefit of all users and for improved data management by EU linguists, is also described.
Using open data to create the Catalan IATE e-dictionary
Authors: Vàzquez Mercè , Oliver Antoni , Casademont Elisabeth
Published: November 2019

Linguistic resources available in the form of open data are an essential source of information for creating e-dictionaries, but access to these linguistic resources is still limited. This paper presents a method for maximising use of open access linguistic resources and integrating them into specialised e-dictionaries. The method combines automatic compilation of terminology data with the creation of specialised linguistic corpora to produce a Catalan version of the IATE (InterActive Terminology for Europe) database. The paper presents new methodological advances applied here to the production of terminological e-dictionaries, using open access linguistic resources. We observe that, as a result of this new methodology, the Catalan version of the IATE will be able to include specialised economics, law and health dictionaries. In conclusion, the new methodology presented here permits the creation of new models of specialised e-dictionaries, facilitates the compilation of terminology in any language and unifies the access format for terminology data.
EcoLexicon and by-products
Authors: León-Araúz Pilar , Reimerink Arianne , Faber Pamela
Published: November 2019

Reutilization and interoperability are major issues in the fields of knowledge representation and extraction, as
reflected in initiatives such as the Semantic Web and the Linked Open Data Cloud. This paper shows how terminological resources
can be integrated and reused within different types of application. EcoLexicon is a multilingual terminological knowledge base
(TKB) on environmental science that integrates conceptual, linguistic and visual information. It has led to the following
by-products: (i) the EcoLexicon English Corpus; (ii) EcoLexiCAT, a terminology-enhanced translation tool; and (iii) Manzanilla, an
image annotation tool. This paper explains EcoLexicon and its by-products, and shows how the latter exploit and enhance the data
in the TKB.
Molecular insights into the mechanism of substrate recognition of Streptomyces transglutaminases
Authors: Tokai Shota , Uraji Misugi , Hatanaka Tadashi
Published: November 2019

The microbial TGase from Streptomyces mobaraensis has used in various food industries. However, the detailed substrate specificities of TGases from the Streptomyces species toward the natural peptides remains to be unclear. In this study, we conducted the comparison of two different TGases from Streptomyces mobaranensis (SMTG) and Streptomyces cinnamoneus (SCTG). To clarify the region associated with the characteristics of enzymes, we constructed a chimeric enzyme of CM, of which is consisted of N-terminal half of SCTG and C-terminal half of SMTG. To reveal the differences in the substrate specificity between SCTG and SMTG toward natural peptides, we investigated the time dependence of TGase activity on the productivity of cross-linking peptide with tryptic casein and lysine by using LC-MS. We identified two peptides of “VLPVPQK” and “AVPYPQR” as substrates for both of the TGases.
Blood concentrations of small extracellular vesicles are determined by a balance between abundant secretion and rapid clearance
Authors: Matsumoto Akihiro , Takahashi Yuki , Chang Hsin‐Yi , Wu Yi‐Wen , Yamamoto Aki , Ishihama Yasushi , Takakura Yoshinobu
Published: November 2019

Small extracellular vesicles (sEVs) are important mediators of cell–cell communication with respect to diverse physiological processes. To further understand their physiological roles, understanding blood sEV homoeostasis in a quantitative manner is desired. In this study, we propose novel kinetic approaches to estimate the secretion and clearance of mouse plasma–derived sEVs (MP‐sEVs) based on the hypothesis that blood sEV concentrations are determined by a balance between the secretion and clearance of sEVs. Using our specific and sensitive sEV labelling technology, we succeeded in analysing MP‐sEV clearance from the blood after intravenous administration into mice. This revealed the rapid disappearance of MP‐sEVs with a half‐life of approximately 7 min. Moreover, the plasma sEV secretion rate, which is presently impossible to directly evaluate, was calculated as 18 μg/min in mice based on pharmacokinetic (PK) analysis. Next, macrophage‐depleted mice were prepared as a model of disrupted sEV homoeostasis with retarded sEV clearance. MP‐sEV concentrations were increased in macrophage‐depleted mice, which probably reflected a shift in the balance of secretion and clearance. Moreover, the increased MP‐sEV concentration in macrophage‐depleted mice was successfully simulated using calculated clearance rate constant, secretion rate constant and volume of distribution, suggesting the validity of our PK approaches. These results demonstrate that blood sEV concentration homoeostasis can be explained by the dynamics of rapid secretion/clearance.
Calibration simulation for stereoscopic optical systems using optical design software
Authors: Gorevoy A V , Machikhin A S , Batshev V I , Kolyuchkin V Y
Published: November 2019

To reconstruct three-dimensional (3D) structure of objects and measure their geometric parameters using stereoscopic imaging systems, it is necessary to implement a number of algorithms. For higher system efficiency, the choice of these algorithms and mathematical models should be taken into account at the stage of optical system design. We demonstrate the capabilities of optical design software to perform computer simulation of geometrical calibration for stereoscopic systems. The simulation allows comparison of mathematical models used for 3D reconstruction and estimation of 3D measurements errors caused by tolerances of optical elements, temperature variations and other factors. Using this technique, we analyze the design of prism-based stereoscopic system and show that the proposed ray tracing camera model considering pupil aberrations provides high measurement precision. The results of computer simulation are confirmed by experiments with the self-developed stereoscopic system.
Prospects for creating a laser nanolithography system for tasks of diffractive optics and nanophotonics
Authors: Korolkov V P , Shimansky RV , Khomutov V N , Seduhin A G , Nasyrov R K , Kiryanov V P , Kiryanov A V , Zavyalova M A
Published: November 2019

This paper considers the basic concepts of constructing an advanced direct laser writing nanolithographic system dedicated to a high-resolution synthesis of large-sized planar elements of diffractive optics and nanophotonics. The issues of the rational implementation of optical, mechanical and electronic units of the system are solved together with considering the functional structure for a precise computer control of the mentioned units. The proposed design of the opto-mechanical unit aims to reduce significantly the distortions of fabrication of the optical elements due to the use of a new symmetrical two-channel construction and a differential laser interferometer for the radial positioning of a focused laser beam. A complex of issues on constructing a long-working distance superresolving focusing system are also considered alongside. The complex modernization of the nanolithographic system software and hardware complex based on system-on-chip (SoC) using hybrid processors (FPGA+ARM) is considered, which will make the system more universal and portable to various IT platforms.
Tunable liquid crystal astigmatic plate
Authors: Kotova S P , Mayorova A M , Prokopova D V , Samagin S A
Published: November 2019

We proposed two schemes of compact tunable liquid crystal astigmatic plate. The device is a modal spatial light modulator with a specific electrodes configuration. Numerical simulations of operation of the device showed its capability to form astigmatic wave front describing by Z22and Z2-2Zernike polynomials and also by their superposition. Various modes of operation of LC device are considered. The capability of operation as a truncated axicon is shown.
Comparative simulation of spiral zone plates with a relief from silica glass and silver
Authors: Kozlova E S , Kotlyar V V
Published: November 2019

Comparative simulation of optical vortices generation by spiral zone plates with a relief from silver and silica glass using a frequency depended finite difference time domain method. The right circularly polarized Gaussian pulse was used as incident light. An analysis of the Umov-Poynting vector, amplitude and phase distributions in the focal plane shows was the presence of complex optical vortices with an inverse energy flow in its’ centre. Influence of the amplitude spiral zone plate relief height on energy backflow is studied. Comparison of simulation results for two types of spiral zone plate confirms the possibility of using the amplitude analogue instead of the phase zone plate since it is simpler to manufacture.
Investigation of the vortex laser beam shift relative to the optical element using high performance computer systems
Authors: Savelyev D A
Published: November 2019

The spatial distribution of the Gauss-Laguerre beams with circular polarization is investigated subject to the beam position relative to the element, the axicon numerical aperture and order of the vortex phase in the 3D model. Modeling of diffraction is numerically investigated by the finite difference time domain (FDTD) method using high-performance computing. It is shown that using the diffraction axicon, polarization transformations can be carried out in the near zone, which, in particular, is expressed that the number of dark bands corresponds to the m (vortex laser beam number).
Investigation of characteristics of waveguide channels system formed in PDLC with inhomogeneity of the amplitude-phase distribution of forming field
Authors: Dudnik D I , Kvasova I A , Gusachenko K O , Semkin A O , Sharangovich S N
Published: November 2019

This work presents the results of modeling the influence of amplitude, phase and amplitude-phase heterogeneities of the forming field on the spatial distribution of the refractive index profile and, accordingly, the mode composition of radiation capable of propagating in waveguides formed by the holographic method in the photopolymer-liquid crystalline compositions. The spatial distribution of the refractive index is found by solving the system of kinetic equations. The mode composition of the radiation is determined by solving the dispersion equation for TE-modes.
Conventional Raman and surface-enhanced Raman spectroscopy of ascitic fluid
Authors: Bratchenko L A , Bratchenko I A , Artemyev D N , Moryatov A A , Starikova J V , Tupikova E N , Platonov I A , Kozlov S V , Zakharov V P
Published: November 2019

The aim of this study is to analyze the spectral characteristics of ascitic fluid using Raman spectroscopy and surface-enhanced Raman spectroscopy (SERS). The utilization of SERS allows for detection the presence of ascitic fluid components that are not available for revealing when analyzed using conventional Raman spectroscopy. The potential to detect the spectral contribution of a number of pathogenic microorganisms utilizing the proposed SERS-based optical approach has been demonstrated.
Representation of shifted vortex beams of arbitrary order as a combination of nonshifted vortices
Authors: Ustinov A V
Published: November 2019

In this paper, we investigate the focusing of beams with a displaced vortex of arbitrary order. For these purposes, we use the following mathematical model: the beam is represented as a combination of beams having a nonshifted vortex. It is shown theoretically that an optical vortex of an arbitrary integer order m displaced within an axisymmetric beam is equivalent to the finite sum of nonshifted vortices of orders from 0 to m inclusive. If the order of the displaced vortex beam is non-integer, then the sum is replaced by an infinite series.

Numerical simulation was carried out under sharp focusing conditions in the Debye approximation. The obtained pictures of the focused displaced vortex beams, regardless of the order of the vortex and the magnitude of the displacement, have a qualitatively identical form - the shape of the Crescent. To obtain focal pictures of another type, the illuminating beam must contain an optical vortex of the opposite sign. The obtained results are relevant for multichannel communication systems based on the separation of laser beams carrying orbital angular momentum.
Refinements to the microwave waveguide material parameters measurements. Case study
Authors: Zeyde K M , Sharov V V , Malkin A I
Published: November 2019

This work presents the results of experimental measurements of permittivity and permeability of materials (dried pine, paraffin, acrylic resin, bitumen, polypropylene and texolite) that has a comparative values. The laboratory installation compile from waveguides 23x10 mm that provides the frequency range 8 – 12 GHz. The results processing lay not only in comparison with the existing data, but also in investigation of physical conditions that should be taken into account for waveguide experiment setup. The main aim is to establish the variation of electro physical parameters of the material measured in waveguides and in free space. Selection of reference material samples is the main part of this work.
Spectrometry of molecular interactions in clusters
Authors: Nepomnyashchaya E K
Published: November 2019

Molecular interactions in clusters have always been an important problem as to theoretical and experimental studies. In this paper, we describe a combination of spectrometric techniques for experimental analysis of molecular interactions and dynamics in clusters. We study different types of biological molecules (for instance, well-known albumin molecule) and metallic nanoparticles (for instance, Fe3O4) while their binding in solutions with help of laser correlation and absorption spectrometric techniques. Results of spectrometry of biomolecules interacting with metals show different degrees of association between different molecules and nanoparticles. This paper offers original data on spectrometry of such processes, which is useful both for medical and bioelectronics problems.
Analysis of diffraction efficiency of phase gratings in dependence of duty cycle and depth
Authors: Meshalkin A Yu , Podlipnov V V , Ustinov A V , Achimova E A
Published: November 2019

The analysis of dependence of diffraction efficiency on duty cycle and modulation depth of phase gratings with rectangular and Gaussian profile was performed by means of specially designed program. An Angular Spectrum method applied for monochromatic light propagation in far field through phase grating was used for calculation of diffraction efficiency of gratings. Diffraction efficiency maps of 0-5th diffraction orders were obtained for different grating profiles. It is shown that changing the duty cycle of grating makes it possible to tune smoothly the diffraction efficiency and to redirect the light intensity in required orders.
Experimental study of the photon structures holographic formation by Bessel-like light beams in photopolymer materials
Authors: Dolgirev V O , Dudnik D I , Semkin A O , Sharangovich S N
Published: November 2019

This paper presents experimental results of holographic formation of diffractive optical elements for the Gaussian light beams transformation into Bessel-like (one-dimensional and two-dimensional) in photopolymer materials using amplitude transparency (AT).
Synthesis of silicon nanowires using plasma chemical etching process for solar cell applications
Authors: Mokshin P V , Juneja S , Pavelyev V S
Published: November 2019

Recently, research on silicon nanowire solar cells has been developed rapidly and it is one of the very young research fields. The production of highly oriented long silicon nanowires is a challenging task. Here, in this article we report the optimization of successful synthesis of highly oriented long silicon nanowires on silicon substrates by plasma chemical etching process. The produced silicon structures were firstly examined using scanning electron microscopy (SEM). The SEM results clearly show the highly oriented nanowires on the silicon substrate. The flowing carrier gas, temperature, pressure and voltage are main parameters responsible for the formation of the silicon nanowires. The successful synthesis of silicon nanowires shows bright perspectives for further research on silicon nanostructure properties.
Study of electrical and optical properties of a new composite material based on carbon nanotubes and titanium oxide
Authors: Hussein S M R H , Gavad A M
Published: November 2019

In this regard, the aim of this work is to study the features of the atomic structure and to predict the electronic energy characteristics of the composite material based on carbon nanotube and ceramic particles – titanium oxide using computer simulation methods. To achieve this goal, the following tasks were solved: construction of a geometric model of the rutile nanoparticle; identification of the energy-stable configuration of the composite based on the carbon nanotube and rutile nanoparticles; determination of the electron-energy characteristics of the composite. The structure of the composite was selected so that the total energy of the composite in absolute value was less than that of the individual tube and rutile the enthalpy of the reaction of the tube and rutile becomes negative, which means that the formation of such a nanocomposite is energetically advantageous. one of the most important applications of such composite is to act as photocatalyst for some chemical reactions because of electrical characteristics and high optical absorption.
Investigation of the formation of hybrid polarized laser beams using a four-sector polarization converter
Authors: Podlipnov V V , Karpeev S V
Published: November 2019

The paper presents the manufacturing technology of a four-sector polarization converter for the formation of beams with different hybrid polarizations. A calcite crystal was used as a transducer, two opposite sectors of which were etched to a depth of 1970 nm. The work is demonstrated and experimental patterns of the total intensity distribution, x-components and y-components in the wavelength range of 500-800 nm for the light transmitted through the transducer and also in the focus distribution are shown. The theoretical and experimental dependence of the degree of conversion is described depending on the parameters of manufacturing the sectors of a four-sector converter. For this purpose, a tunable laser was used in the experiment. The operation of the transducer for the vortex field was simulated.
Autoregressive models of random fields on the circle
Authors: Krasheninnikov V R , Kuvayskova Yu E , Subbotin A U
Published: November 2019

At present, the vast majority of known image models are varieties of random fields defined on rectangular flat grids or grids of higher dimension. In some practical situations, images have a circular or radial-circular structure. For example, an image of a facies (a thin film of dried biological fluid), an eye, a biological cell, a flower, a slice of a tree trunk, etc. This circumstance requires the development of appropriate models of random fields describing images of this type. This paper proposes autoregressive models of homogeneous and inhomogeneous random fields defined on a circular spiral. The problem of correlation analysis of such models is considered. Examples of imitation of circular images are given. This paper proposes linear autoregressive models of homogeneous and inhomogeneous random fields defined on a circle. The samples of these fields are defined on a circular or spiral grid. The next field value is a linear combination of several previous values and a standard random variable. Expressions of the correlation function of these fields are given depending on the values of the autoregression parameters. A graphic representation of the correlation function on a circle and examples of simulated images are presented in the figures.
A comparative study of the optimal and interpolation methods for restoration a stationary continuous signal from discrete values
Authors: Maksimov A I , Sergeyev V V
Published: November 2019

In this paper, we consider the task of restoration of a continuous signal by its discrete values. We compare the optimal and interpolation restoration techniques for the continuous-discrete observation model. The expression for the root-mean-square error of the restoration of a stationary continuous signal from its discrete values is derived. For the optimal restoration case, the signal is reconstructed by the means of an optimal restoration filter. For the interpolation restoration, the signal is reconstructed with the use of linear interpolation. The results of a comparison of the root-mean-square errors of the optimal restoration and interpolation procedures with the same parameters of the input signal, additive noise, and dynamic distortion are presented.
Probabilistic finite modeling of stochastic estimation of image inter-frame geometric deformations
Authors: Tashlinskii A G , Safina G L , Kovalenko R O
Published: November 2019

The paper proposes an approach to probabilistic finite modeling of the process of stochastic estimation of the parameters of interframe geometric deformations of images. As the quantities characterizing the state of the stochastic procedure at each iteration of the estimation, the demolition probabilities of the formed parameter estimates (improvements, deterioration, or no change in the vector of estimates in the parameter space) are used. At the same time, the models of images and noises are given by probability distribution densities and autocorrelation functions. This made it possible to simplify the description of a complex set of factors influencing the formation of estimates. The use of adaptive limitation of the parameter space used for modeling reduces the computational cost several times while maintaining the adequacy of the model. In practice, probabilistic modeling can be used to find the accuracy and probability characteristics of stochastic algorithms for estimating interframe deformations of images for a given number of iterations.
Visual product recommendation using neural aggregation network and context gating
Authors: Demochkin K V , Savchenko A V
Published: November 2019

In this paper we focus on the problem of user interests’ classification in visual product recommender systems. We propose the two-stage procedure. At first, the visual features are learned by fine-tuning the convolutional neural network, e.g., MobileNet. At the second stage, we use such learnable pooling techniques as neural aggregation network and context gating in order to compute a weighted average of image features. As a result we can capture the relationships between the products images purchased by the same user. We provide an experimental study with the Amazon product dataset. It was shown that our approach achieves a F1-score of 0.90 for 15 recommendations, which is much higher when compared to 0.66 F1-measure classification of traditional averaging of the feature vector.
Subjective modeling of image shape
Authors: Chulichkov A I
Published: November 2019

The paper presents two approaches to subjective modelling incomplete and uncertain information about possible shape of images. The shape is understood as a set of images of the scene, recorded under all possible conditions (lighting, exposure, etc.). To simulate the likelihood, the measure of likelihood introduced by Yu.P. Pytyev is used. This measure is a function defined on a set of statements and ordering them according to plausibility. The obtained subjective models of shapes allow using the theory of optimal strategies for solving morphological problems.
Promotion of Russian scientific journals into the international databases through the example of the Computer Optics journal
Authors: Zhilavskaya I V
Published: November 2019

The article is devoted to the issues of promoting Russian scientific journals in the international research area, it describes the historical prerequisites for the recognition of the Russian scientific school by the world scientific community, and provides some characteristics of the national peculiarities of the Russian research culture. Particular attention is paid to the difficulties associated with the fact that some Russian researchers underestimate the necessity for the Russian scientific journals to enter the international databases, the need to increase the citation index of scientists and publish their works in English. The result of this situation is a certain scientific isolationism and Russia’s lagging behind the world trends. The relevance and effectiveness of international scientific integration is shown through the example of the Computer Optics journal. The fundamental points are emphasized that allowed this journal to gain high prestige among the scientists working in the field of computer optics and image processing all over the world. These points include, in particular, compliance with the international standards for reviewing the articles and with the rules of publication ethics, high level of scientific publications, compliance with the requirements for the format of articles and the openness policy. All the above, together with the strategic planning, efficient organization and regulation of the publishing process allowed the journal to achieve good performance in the international scientometric databases Scopus and Web of Science.
Application of spinning electrodynamic tether system in changing system orbital parameters
Authors: Lu H , Zabolotnov Y M , Li A
Published: November 2019

Spinning electrodynamic tether system is known to be promising in many applications, including space debris removal, transportation missions, changing orbital parameters of spacecrafts and so on. Feasibility of spinning electrodynamic tether system for changing system orbital parameters is analysed in this paper. The main advantage of spinning electrodynamic tether system is the stability of its movement under the action of perturbations. However, when the conductive tether spins in a magnetic field, the Lorentz force constantly changes its direction, which leads to the need to develop special control methods that ensure desired change in system orbital parameters. In this paper, control laws are proposed for changing the semi-major axis and the eccentricity of the orbit, which take the change of tether spatial position into account. To change the semi-major axis, the current is regulated by the cosine law. To change the eccentricity of the orbit, the onboard power system provides a given amount of current when the system is near the apogee and perigee of the orbit. The combination of executing both manoeuvres at the same time is also studied. The numerical results show that the proposed laws enable spinning electrodynamic tether system to change the parameters of the orbit to the desired values.
Status of creation of hardware-software complex of automatic control of the insulin delivery
Authors: Tutubalin P , Novikova S , Semenova A , Komissarova E , Arutyunova N , Sotnikov S , Alexandrov A
Published: November 2019

The article discusses issues related to the prospects for the implementation of the idea of creating a hardware-software complex for automated regulation of insulin delivery. Today, there are drugs that allow people to live relatively comfortable even with the m ost serious types of diabetes. The m ain difficulty of insulin therapy is the need for consistency (at any time, day or night) of carrying out the control and regulation the infusion of the drug into the patient’s body. Unfortunately, not all patients are able to perform it properly. The ideal solution could be a system that performs all these actions automatically without the participation of the patient. Therefore, the implementation of the idea of creating a hardware-software system for automatic regulation of insulin delivery using the program-adaptive control scheme is relevant. The article forms the general requirements for an approach capable of providing safe medical care for people with type 1 diabetes. There are requirements for the hardware-software complexes of automatic regulation of insulin delivery must correspond are formulated. Also the block diagram is presented.
Modelling of oscillations in slow/fast models of population dynamics
Authors: Shchepakina E
Published: November 2019

This paper deals with the modelling of oscillations in a class of population dynamics models with slow and fast variables. The approach discussed is based on the geometric method of invariant manifolds, and the techniques of canards and black swans.
Structures of absolutely invariant measuring systems and conditions for their physical realizability
Authors: Nesterov V N , Li A R
Published: November 2019

The synthesis method for creating invariant measuring transducers and systems is presented. The method is based on the principle of double channeling, which was proposed by academician Petrov B.N. The advantage of this method is that it allows compensating disturbing influences. The system is influenced by disturbing factors through two symmetrical channels. The efficiency of this method is illustrated by dual-channel Nesterov measuring bridge. Moreover, the entire class of dual-channel measuring transducers was designed based on this method. This class of dual-channel measuring transducers includes measuring bridges and voltage dividers. Dual-channel systems have significant advantages over their standard equivalents.
Nutational oscillations suppression in attitude dynamics of spacecraft by relative motion of its movable module
Authors: Doroshin A V , Eremenko A V
Published: November 2019

Attitude dynamics of a spacecraft with a movable module on retractable beams are considered. The movable module is attached to the main body of the spacecraft by retractable beams of variable length. The spacecraft main body contains a simple jet-engine with constant thrust. The retractable beams can tilt the movable module relatively the main part of the spacecraft, which shifts the position of the mass center. The control scheme of the nutation oscillations suppressing is constructed. This control scheme uses the impulses of the jet-engine on intervals of positive values of the equatorial component of the spacecraft angular velocity at the constant angular displacement of the movable unit. The main aim of this work is to develop the simplest control algorithm, which can be applied in cases of simple constructional forms of the small spacecraft with primitive equipment, including nano-satellites, that is economically profitable and can be used in more space missions.
Representation and simulating of extended Markov chains over a finite field with a predefined precision
Authors: Eminov B F , Zakharov V M , Shalagin S V
Published: November 2019

A method is proposed for representing and simulating the extended Markov chains of a defined type by minimal polynomials over finite field GF(q). Simulation problem is being solved as a problem of constructing the minimal polynomial over field GF(q) using the Berlekamp-Massey algorithm. The polynomial produces a sequence of the length of N. A stochastic matrix relevant to that sequence approximates the given stochastic matrix of an extended Markov chain with a predefined precision proportional to the 1/N value. The polynomial constructed defines unambiguously the structure of a q-ary linear shift register for simulating extended Markov chains. The method allows constructing the implementations of this class of Markov sequences on linear q-ary shift registers with a pre-defined “linear complexity” defined by the value of N.
The van der Pol oscillator under hysteretic control: regular and chaotic dynamics
Authors: Semenov M E , Reshetova O O , Sobolev V A , Solovyov A M , Meleshenko P A , Bogaychuk A N
Published: November 2019

In this work we provide the novel hysteretic approach to control the chaotic dynamics of the van der Pol oscillator under periodic excitation. Using the phenomenological Bouc-Wen model, as well as in the frame of the small parameter approach we investigate the influence of the hysteretic control to the dynamical characteristics of this system. Based on the analysis of numerical results in the form of bifurcation diagrams and Lyapunov exponents, the efficiency of the stabilizing role of the hysteretic control element is established. In addition, we investigate the synchronization of oscillations in the system of coupled van der Pol oscillators (with “simple” linear coupling, as well as under hysteretic control). The stabilizing role of the hysteretic control in this case is also demonstrated.
The simulation results of the operation of a small spacecraft motion control system with an electrothermal microdrive
Authors: Belousov A I , Sedelnikov A V , Gorozhakina A S
Published: November 2019

The work simulates the operation of the motion control system of a small spacecraft. The main Executive body of this system is the engine-flywheel. It is proposed to use an electrothermal micro-motor to reduce the kinetic moment of the flywheel motor. In emergency situations, it can be used as the main Executive body of the management system. A comparative analysis of the advantages and disadvantages of using magnetic actuators and electrothermal micro-motor to reduce the kinetic moment of the flywheel motor. Conclusions are drawn on the feasibility of their application for various small spacecrafts.
Method for modeling of Spacecraft onboard apparatus and building of consistent control logic with limited onboard resources
Authors: Tyugashev A A , Sygurov Yu M
Published: November 2019

The paper is devoted to the method for building consistent spacecraft onboard control logic in case of limited available resources. The consistent onboard control logic is extremely important for the success of a space mission. The special aspect of the complexity of control logic related to limited available onboard resources – electric energy, computer power, etc. The paper introduces the mathematical models for onboard resources, equipment and devices, and their working modes. Also, we present some prototypes of software tool allowing automated checking of control logic whether they violate the resource constraints as well as the design of new control logic from scratch
The effect of climber initial velocity on orbital space elevator dynamics
Authors: Aslanov V S , Ledkova T A
Published: November 2019

This research is devoted to the problem of delivering a small payload to the Earth from the orbit using an orbital space elevator, which consists of two space stations connected by a massless tether and a passive climber moving along the tether. The aim of the work is to study the possibility of transferring the climber from one end of the orbital elevator to the other end due to its initial velocity. The mathematical model of the mechanical system is constructed using the Lagrange equation of the second kind. An analytical expression, which depends on the parameters of the mechanical system and determines the required initial velocity, was found using a simplified mathematical model that does not take into account the bending of the tether. The validity of the expression was verified using the mathematical model. The analysis of the system motion was carried out, and recommendations on its mass-geometric parameters choice were given.