Search

Collective particle transport across periodic energy landscapes is ubiquitously present in many condensed matter systems spanning from vortices in high-temperature superconductors, frictional atomic sliding, driven skyrmions to biological and active matter. Here we report the emergence of fast solitons propagating against a rotating optical landscape. These experimentally observed solitons are stable cluster waves that originate from a coordinated particle exchange process which occurs when the number of trapped microparticles exceeds the number of potential wells. The size and speed of individual solitons rapidly increase with the particle diameter as predicted by theory and confirmed by numerical simulations. We show that when several solitons coexist, an effective repulsive interaction can stabilize their propagation along the periodic potential. Our experiments demonstrate a generic mechanism for cluster-mediated transport with potential applications to condensed matter systems on different length scales.

Among fishes, salmonids (family Salmonidae) have attracted a great deal of research attention focused on sexual dimorphism and associated selective forces. Most of this research has been directed toward anadromous and mostly semelparous salmon and trout (Oncorhynchus,Salmo), and comparatively little is known about intersexual variability in strictly iteroparous freshwater salmonids. We examined a comprehensive data set of 28 linear morphometric characters in 11 of 15 currently recognised species of grayling (Thymallinae,Thymallus), a genus consisting of iteroparous species only, to identify general patterns of intersexual morphological variability. Overall, we found that all grayling species show common sex-specific traits particularly relating to size dimensions of the dorsal, anal, pelvic and pectoral fins. Although the magnitude of sexual dimorphism differed among species, there was no significant phylogenetic signal associated with these differences across the genus. These results are discussed in terms of the assumed selection pressures driving sexual dimorphism in graylings and are compared to existing knowledge in Salmonidae as a whole where similarities and differences with both Salmoninae and Coregoninae exist. The present study provides the first detailed genus-wide comparison of sexually dimorphic phenotypic characters in graylings, and highlights the need for more large-scale comparative studies in multiple salmonid species to better understand general macroevolutionary trends among this important group of freshwater fishes.

We performed spectral measurements of two low-temperature discrete Josephson junction (JJ) arrays on a Fourier-transform spectrometer. The arrays contain up to 9000 niobium based junctions located in the area 5 × 5 mm and composed of different designs. The spectrum of each array demonstrates a narrow peak in the frequency range near 140 GHz with the line width 160–170 MHz corresponding to the resolution limit of the spectrometer. It implies the coherent subterahertz radiation from niobium JJ arrays that is necessary for most applications where the JJ array based on similar technology would be implemented. The radiation coherence follows from numerical simulation of Josephson antennas with the self-made algorithm combining the Finite-Difference Time Domain Method with the Resistively and Capacitively Shunted Junction (RCSJ) model. Exploring the spectrum of Beverage-like Josephson antenna simulated by this algorithm we revealed the pure monochromatic emission of all junctions.

We propose a simulation method for Brownian dynamics of hard rods in one dimension for arbitrary continuous external force fields. It is an event-driven procedure based on the fragmentation and mergers of clusters formed by particles in contact. It allows one to treat particle interactions in addition to the hard-sphere exclusion as long as the corresponding interaction forces are continuous functions of the particle coordinates. We furthermore develop a treatment of sticky hard spheres as described by Baxter's contact interaction potential., Comment: 12 pages, 7 figures

Introduction The aim of this multicenter prospective study was to analyze the outcomes of bone lengthening by external fixator associated with flexible intramedullary nailing (FIN) in acquired limb length discrepancy (LLD). Hypothesis Hydroxyapatite (HA)-coated FIN enables reduced External Fixation Index in limb lengthening for acquired leg length discrepancies in comparison to non-HA-coated FIN. Material and methods This study included 54 patients (mean age, 17.9 years) operated on for femoral or tibial lengthening by combined technique (External fixator with FIN) for acquired length discrepancy. Titanium non-HA-coated FIN (29 cases) or HA-coated FIN (25 cases) were used. The factors that might influence external fixation index, complication occurrence and outcome were analyzed: age, amount of lengthening, nail diameter, HA-coating vs. non-HA-coated nails. Results The mean External Fixation Indexes (EFI) of groups compared for non-HA-coated nails vs. HA-coated nails were not significantly different: 26.5 d/cm and 27.2 d/cm in femoral lengthening and 34.9 d/cm and 31.7 d/cm in tibial lengthening. Positive correlation between the “nail diameter/inner distance between cortices at osteotomy site” ratio and EFI in tibial lengthening was revealed (p = 0.034). The nail types and the “nail diameter/medullary canal diameter” ratio interact and have significant simultaneous effect on EFI in femoral lengthening (p = 0.021). Discussion The results of this study revealed no differences with regards to EFI using HA-coated or non-HA-coated titanium FIN in lengthening for acquired leg-length discrepancies. Combined technique allowed reduced EFI and avoided major complications. Both non-HA-nail and HA-coated nail lengthening provided good and excellent outcomes. Level of evidence III; (controlled trial without randomization) prospective comparative study.

Hybridization and introgression are very common among freshwater fishes due to the dynamic nature of hydrological landscapes. Cyclic patterns of allopatry and secondary contact provide numerous opportunities for interspecific gene flow, which can lead to discordant paths of evolution for mitochondrial and nuclear genomes. Here, we used double digest restriction-site associated DNA sequencing (ddRADseq) to obtain a genome-wide single nucleotide polymorphism (SNP) dataset comprehensive for allThymallus (Salmonidae)species to infer phylogenetic relationships and evaluate potential recent and historical gene flow among species. The newly obtained nuclear phylogeny was largely concordant with a previously published mitogenome-based topology but revealed a few cyto-nuclear discordances. These incongruencies primarily involved the placement of internal nodes rather than the resolution of species, except for one European species where anthropogenic stock transfers are thought to be responsible for the observed pattern. The analysis of four contact zones where multiple species are found revealed a few cases of mitochondrial capture and limited signals of nuclear introgression. Interestingly, the mechanisms restricting interspecific gene flow might be distinct; while in zones of secondary contact, small-scale physical habitat separation appeared as a limiting factor, biologically based reinforcement mechanisms are presumed to be operative in areas where species presumably evolved in sympatry. Signals of historical introgression were largely congruent with the routes of species dispersal previously inferred from mitogenome data. Overall, the ddRADseq dataset provided a robust phylogenetic reconstruction of the genus Thymallus including new insights into historical hybridization and introgression, opening up new questions concerning their evolutionary history.

BACKGROUND Hydroxyapatite (HA) coated flexible intramedullary nailing (FIN) stimulates osteogenic activity. The role of HA-coated intramedullary nails remains unclear in normal bone lengthening. The goal of this study was to quantify the influence of FIN on the External Fixation Index (EFI) in patients with congenital lower limb discrepancy. METHODS Patients with femoral deficiency and fibular hemimelia underwent lengthening by the combined technique of external fixation with titanium (Ti) FIN or HA coated FIN and returned for follow-up at least 12 months after frame removal. RESULTS Seventy patients (mean age of 12.6 y) were included: 19 monofocal femoral lengthenings, 35 tibial monofocal lengthenings, 16 tibial bifocal lengthenings. The mean EFI's for those treated with and without HA-coated nails were not significantly different. The Conover posthoc analysis did not reveal a significant influence of the type of FIN on EFI in any subgroup. However, 2-way analysis of variance revealed simultaneous effects of nail types and age on the EFI in tibial bifocal lengthening.Significant positive correlation between the ratio "nail diameter/medullary shaft diameter" and EFI in tibial bifocal non-HA-coated FIN lengthening, and a significant positive correlation between age and EFI for femoral non-HA-coated FIN lengthening, tibial monofocal and bifocal HA-coated FIN lengthening were revealed.There were 4 cases of fracture at lengthening site required unscheduled surgery. In the non-HA-coated group, there was a statistically significant negative correlation between nail diameter and fracture occurrence at the lengthening site after frame removal. A ratio of

At modern manufacturing enterprises, machines and mechanisms that emit pulsed noise are widely used. Pulse noise has a more harmful effect on workers than time-constant, time fluctuating and intermittent noises. Pulse noise reduction is possible through the application of design changes in the pulse noise source and the development of organizational, technological, construction and acoustic measures. The choice of specific events is made on the basis of their acoustic efficiency assessment. For this purpose, it is necessary to have a method for calculating pulse noise that takes into account its space-time characteristics and their possible changes with structural changes of the source, as well as with changes in the space-planning and acoustic parameters of premises. In the article, to assess the acoustic efficiency of pulse noise, it is proposed to use a combined calculation method developed by the authors, taking into account the real mirror-diffuse nature of sound reflection from the room fences. On its basis, it is analyzed the possibilities of using various methods and means to reduce the impact of noise on the workers in rooms with pulsed sound sources.

Solitons are commonly known as waves that propagate without dispersion. Here we show that they can occur for driven overdamped Brownian dynamics of hard spheres in periodic potentials at high densities. The solitons manifest themselves as periodic sequences of different assemblies of particles moving in the limit of zero noise, where transport of single particles is not possible. They give rise to particle currents at even low temperature that appear in band-like structures around certain hard-sphere diameters. At high temperatures, the band-like structures are washed out by the noise, but the particle transport is still dominated by the solitons. All these predicted features should occur in a broad class of periodic systems and are amenable to experimental tests., 6 pages, 4 figures plus supplemental material with 7 pages and 1 figure; 5 ancillary movie files

The article is devoted to a research of an effectiveness of high-level synthesis approach, based on Xilinx's high-level synthesis tool - Vivado, for a hardware implementation of sorting algorithms, which are one of the key algorithm for Big Data analysis, Data Mining, Data Storage and Management. Performance and hardware costs are the measures of the effectiveness in the provided research. The research methods are simulation and comparative analysis. Effectiveness of software implementation of the selected sorting algorithms based on a universal processor is compared with effectiveness of hardware implementation of the same sorting algorithms, obtained by high-level synthesis procedure with help of Xilinxs synthesis tool. The article discusses approaches to optimize the description of the sorting algorithms and assignments in boundaries of high-level synthesis procedure to achieve optimal effectiveness of the final hardware solutions. The article shows that the main effectiveness gain is provided by: the internal features of the sorting algorithm, selected for hardware implementation; the ability to parallelize the processing of the source arrays, which is achieved both by the settings of the Vivado synthesis tool and description style used for source code. Article summarizes research results and provide a direction for the future research works.

Structural and technological aspects of obtaining composite materials based on polytetrafluoroethylene are considered. It is shown that due to the manifestation of the inertness of the components in the processes of interfacial interaction with an increase in the degree of filling, within the framework of the traditional technological paradigm, a structural paradox is realized. This paradox consists in a proportional decrease in the tensile strength parameter of fluorocomposites with an increase in their degree of filling. Based on the concept of energy and technological compliance of components, technological principles for eliminating the negative impact of the structural paradox by controlling the structure of fluorine composites at various levels of organization: molecular, supramolecular, phase and interfacial are proposed. Efficient methods have been developed for manufacturing products from highly filled fluorine composites containing 25–35% (wt.) carbon fiber and having parameters of stress-strain characteristics that are 1.5–2.0 times higher than the parameters of the analogues "Flubon", "Fluvis".

The choice and acoustic efficiency of construction and acoustic means of noise control is determined on the basis of calculations of changes in the spatio-temporal characteristics of the pulses of sound energy emitted by the sound source. The paper proposes a combined computational model for estimating the energy characteristics of pulse noise and their spatiotemporal changes. The model describes the formation and distribution of the reflected sound energy of pulses in the mirror-scattered reflection of sound from the fences. The principles of construction of the computational model and the computer program implementing it are stated. Evaluation of the computational model is performed by comparative analysis of experimental and computational data obtained by the action of a pulsed noise source in complex geometrically shaped rooms. It is found that the calculated graphs of the decay of the reflected pulse energy in time coincide with the experimentally determined declines.

In crowded systems, particle currents can be mediated by propagating collective excitations which are generated as rare events, are localized and have a finite lifetime. The theoretical description of such excitations is hampered by the problem of identifying complex many-particle transition states, calculation of their free energies, and the evaluation of propagation mechanisms and velocities. Here we show that these problems can be tackled for a highly jammed system of hard spheres in a periodic potential. We derive generation rates of collective excitations, their anomalously high velocities, explain the occurrence of an apparent jamming transition and its strong dependence on the system size. The particle currents follow a scaling behavior, where for small systems the current is proportional to the generation rate and for large systems given by the geometric mean of the generation rate and velocity. Our theoretical approach is widely applicable to dense nonequilibrium systems in confined geometries. It provides new perspectives for studying dynamics of collective excitations in experiments., 23 pages, 9 figures

Restrictions of current architectures of Heterogeneous High-Performance Computing (HPC) systems lead to Reconfigurable Heterogeneous HPC (RH HPC) which are able to adapt to a particular solved task on the hardware level. Highly disruptive technologies like Artificial Intelligence (AI), Internet of Things (IoT), and Machine Learning (ML) are expected to lead not only fundamental shift in classical multi-cores and multi-treads-based approaches to high-performance computing, but also open new direction in designing systems with dynamically reconfigurable runtime environment. The state-of-the-art integrated circuits allow realizing the general architecture of RH HPC at different levels of the distributed HPC: from the level of the supercomputer, to the level of user computers and the remote, built-in units intended for data acquisition, management, and control. The article describes proposed architecture for new generation of Reconfigurable Heterogeneous Distributed HPC (RHD HPC) system, including architectures of each sub-parts and highlights already developed components for such RHD HPC.

Carbon forms (graphite, pyrolytic graphite, highly oriented pyrolytic graphite (HOPG), glassy carbon, carbon foam, graphene, buckypaper, etc) are a wide class of materials largely used in technology and energy storage. The huge request of carbon compounds with reliable and tunable physical and chemical properties is tackled by contriving new production protocols and/or compound functionalizations. To achieve these goals, new samples must be tested in a trial-and-error strategy with techniques that provide information in terms of both specimen quality and properties. In this work, we prove that electrochemical scanning probe techniques allow testing the performances of carbon compounds when are used as an electrode inside an electrochemical cell. Comparing the results with a reference sample (namely, HOPG) gives an insight on defects in the specimen structure, performances, and possible applications of the new samples. In this study, we concentrate on traditional carbon forms already employed in many fields versus new recently-developed specimens, in view of possible applications to the field of energy storage.

The article is devoted to MES systems in the era of industry 4.0 development. Theoretical foundations are given, principles are formulated, methods are defined and methods of application of MES systems are justified. It is shown that the use of modern MES systems is an integral part of Industry 4.0 and contributes to the integration of industrial equipment and information systems in a single information space. Manufacturing management is one of the key areas where production management systems or MES systems are used in the era of the digital economy. The main objectives of the article are to describe the current state of MES systems, to represent their relationship with other information systems of the enterprise and to identify the key problems associated with MES. The prospects of these systems in the rapidly growing business in Industry 4.0 were also considered.

In typical computer system design flows, hardware microarchitecture is commonly considered a dynamically developing domain, where abstract mechanisms remain mostly in conceptual form and exhibit poor source code reuse in designs. However, many important basic mechanisms appear to be pervasive and persistent. This paper summarizes original efforts to propose generic implementations of microarchitectural mechanisms for in-order and out-of-order microarchitectures and various demo designs based on these implementations. The basic EDA components proposed for this design approach are “Kernel IP (KIP) cores”—open-source collection of programmable hardware generators inferred from microarchitectural templates. KIP cores feasibility for their role is demonstrated from the viewpoints of abstract representation of microarchitectural mechanisms, support of functional differentiation of designs, and generic optimizations. Experimental designing according to this approach has shown useful separation of concerns in hardware design activities, lower design effort, and increased formalization and code reuse.

The research addresses implementation of custom internal mechanisms of computational process management abstractly from application functionality in hardware design. Explicit allocation of “microarchitectural middleware” design level is proposed. The key design components used at this level are custom programmable and synthesizable execution kernels — “micro-language” IP (MLIP) cores. The supporting framework is being developed by the authors. Experimental designing based on MLIP approach has demonstrated significant (up to 63%) code reusability for hardware cores that do not have any common structural submodules but do share custom internal scheduling and synchronization mechanisms that are cross-cutting relative to the hardware cores structure.

The study describes preliminary experience of the use of external fixators for limb lengthening and deformity correction in combination with flexible intramedullary nailing in management of polyostotic fibrous dysplasia. Patients and methods The retrospective study included 8 patients (mean age 11.6 ± 3.38 years; range 7–17 years) with polyostotic fibrous dysplasia operated on using external circular frame and flexible intramedullary nailing. Mean follow-up was 2.6 years. Surgical technique consisted of percutaneous osteotomy of a segment and application of circular external frame. The intramedullary nailing was done using two bent nails. Hydroxyapatite-coated nails were applied in three patients; five patients had titanium nails. Amount of lengthening (cm and %), amount of deformity correction, duration of external fixator use, index of external fixation, “nail/medullary canal at narrowest site” ratio, “nail-medullary canal at osteotomy site” ratio were analyzed. Results and complications were assessed according to Lascombes's classification. Results The mean amount of lengthening was 4.5 cm (or 13.7 ± 6.0% per segment). This gave a mean external fixation index of 32.5 ± 13.97 days/cm. The mean ratio of IM nail diameter/medullary canal diameter at the narrowest site was 0.22 ± 0.07 (range, 0.125–0.3 mm). No migration of IM nails into medullary canal were noticed. But in one case there was external migration of Ti-nail. In a year after frame removal, the results of treatment were classified as grade I in 7 cases and IIb in one case.At the latest follow-up control, mechanical axis deviation was found within normal limits in six patients. Two patients had excessive MAD of 11 and 28 mm. In the first case a partial varus deformity recurrence occurred at middle shaft site where a large dysplastic zone was presented. In the second case, a specific shepherd's crook deformity developed and caused excessive MAD. Mean lower limb length discrepancy varied from 1 to 15 mm. Conclusion There are advantages of using elastic intramedullary nailing and external fixation in the treatment of limb length discrepancy and deformity of long bones in patients with PFD. This strategy ensures reduced external fixation time and high accuracy of alignment. Intramedullary nails left in situ, especially nails with HA-coating, seem to prevent deformity recurrence and stimulate remodeling in dysplastic fibrous zones.

Artificial intelligence has become a frequent subject of discussion at different international forums in recent years. Classified by the European Union as one of the “most strategic technologies in the 21st century”, in 2018 the EU Commission mandated a 52-member strong High-Level Expert Group on AI to discuss the ethical, legal, economic and social impact of this promising technology. Providing a holistic view on the main ethical and legal questions surrounding AI-powered systems, this chapter intends to explore the latest EU initiatives on AI governance with a view to identifying the main challenges ahead for the EU to become a “leader in cutting-edge AI that can be trusted throughout the world”.