Role of coupling delay in oscillatory activity in autonomous networks of excitable neurons with dissipation

We study numerically the effects of time delay in networks of delay-coupled excitable FitzHugh Nagumo systems with dissipation. The generation of periodic self-sustained oscillations and its threshold are analyzed depending on the dissipation of a single neuron, the delay time, and random initial conditions. The peculiarities of spatiotemporal dynamics of time-delayed bidirectional ring-structured FitzHugh-Nagumo neuronal systems are investigated in cases of local and nonlocal coupling topology between the nodes, and a first-order nonequilibrium phase transition to synchrony is established. It is shown that the emergence of oscillatory activity in delay-coupled FitzHugh-Nagumo neurons is observed for smaller values of the coupling strength as the dissipation parameter decreases. This can provide the possibility of controlling the spatiotemporal behavior of the considered neuronal networks. The observed effects are quantified by plotting distributions of the maximal Lyapunov exponent and the global order parameter in terms of delay and coupling strength.Comment: 14 pages, 17 figure

Evaluation of synthetic wheat lines (Triticum durum/Aegilops tausсhii) for vegetative period and resistance to diseases

The growth of the total wheat production and increase of yield stability from year to year are some of the priorities of agriculture in Russia. The yield of commercial varieties significantly diversifies due to huge losses of their potential under the influence of negative biotic and abiotic factors. Increase of resistance to stress factors in the emerging varieties can be achieved by utilizing the diversity of the genetic resources of related wild species and genera in crosses. The results of a phenotypic evaluation of the synthetic hexaploid wheat lines of CIMMYT breeding created by crossing durum wheat varieties from Institute of Breeding and Genetics (Odessa, Ukraine) and variety Pandur from Romania (T. durum Desf., AB genome) with Aegilops (Ae. tausshii Coss., D genome), and also 15 synthetic wheat lines of Kyoto University breeding (Japan) created by crossing durum wheat variety Langdon with different ecological forms Aegilops are presented. Research was performed on the experimental field of Omsk SAU under conditions of southern forest-steppe of West Siberia in 2016. Between synthetics, there was revealed a genotypic difference in the vegetative period duration and resistance to diseases. Lines of hybrid combination Aisberg/Ae.sq.(511) were characterized as the most early-maturity genotypes among the lines studied. The hybrid combinations Ae.sq.(369) with variety Aisberg, Ae.sq.(310) and Ukr-Od 1530, Ae.sq.(223) and Pandur are characterized by complex resistance to fungal diseases. Most of the lines demonstrated high and moderate resistance to rust fungus, severity ranging from 5 to 70 % and severity of powdery mildew being 10–90 %. Lines derived from variety Ukr-Od 1530.94 and accessions Ae. tauschii (392); (629); (1027); (1031) and lines Langdon/Ku-2074; Langdon/Ku-2075; Langdon/Ku-2100; Langdon/Ku-2079 are characterized by complex resistance to powdery mildew, leaf and stem rust. The synthetic lines with a complex of economically valuable traits present interest as an initial material for breeding programs

Stem rust in Western Siberia – race composition and effective resistance genes

Stem rust in recent years has acquired an epiphytotic character, causing significant economic damage  for wheat production in some parts of Western Siberia. On the basis of a race composition study of the stem rust  populations collected in 2016–2017 in Omsk region and Altai Krai, 13 pathotypes in Omsk population and 10 in  Altai population were identified. The race differentiation of stem rust using a tester set of 20 North American  Sr genes differentiator lines was carried out. The genes of stem rust pathotypes of the Omsk population are avirulent only to the resistance gene Sr31, Altai isolates are avirulent not only to Sr31, but also to Sr24, and Sr30. A low  frequency of virulence (10–25 %) of the Omsk population pathotypes was found for Sr11, Sr24,Sr30, and for Altai  population – Sr7b,Sr9b,Sr11,SrTmp, which are ineffective in Omsk region. Field evaluations of resistance to stem  rust were made in 2016–2018 in Omsk region in the varieties and spring wheat lines from three different sources.  The first set included 58 lines and spring bread wheat varieties with identified Sr genes – the so-called trap nursery  (ISRTN – International Stem Rust Trap Nursery). The second set included spring wheat lines from the Arsenal collection, that were previously selected according to a complex of economically valuable traits, with genes for resistance  to stem rust, including genes introgressed into the common wheat genome from wild cereal species. The third  set included spring bread wheat varieties created in the Omsk State Agrarian University within the framework of  a shuttle breeding program, with a synthetic wheat with the Ae. tauschiigenome in their pedigrees. It was established that the resistance genes Sr31, Sr40,Sr2 complexare effective against stem rust in the conditions of Western  Siberia. The following sources with effective Srgenes were selected: (Benno)/6*LMPG-6 DK42, Seri 82, Cham 10,  Bacanora (Sr31), RL 6087 Dyck (Sr40), Amigo (Sr24,1RS-Am), Siouxland (Sr24,Sr31), Roughrider (Sr6, Sr36), Sisson  (Sr6,Sr31,Sr36), and Fleming (Sr6,Sr24,Sr36,1RS-Am), Pavon 76 (Sr2 complex) from the ISRTN nursery; No. 1 BC 1F2 (96 × 113) × 145 × 113 (Sr2,Sr36,Sr44), No. 14а F 3(96 × 113) × 145 (Sr36,Sr44), No. 19 BC 2F3(96 × 113) × 113 (Sr2, Sr36, Sr44), and No. 20 F 3 (96 × 113) × 145  (Sr2,Sr36,Sr40, Sr44) from the Arsenal collection; and the Omsk State Agrarian  University varieties Element 22 (Sr31,Sr35), Lutescens 27-12, Lutescens 87-12 (Sr23,Sr36), Lutescens 70-13, and  Lutescens 87-13 (Sr23,Sr31,Sr36). These sources are recommended for inclusion in the breeding process for developing stem rust resistant varieties in the region

A novel quaternion linear matrix equation solver through zeroing neural networks with applications to acoustic source tracking

Due to its significance in science and engineering, time-varying linear matrix equation (LME) problems have received a lot of attention from scholars. It is for this reason that the issue of finding the minimum-norm least-squares solution of the time-varying quaternion LME (ML-TQ-LME) is addressed in this study. This is accomplished using the zeroing neural network (ZNN) technique, which has achieved considerable success in tackling time-varying issues. In light of that, two new ZNN models are introduced to solve the ML-TQ-LME problem for time-varying quaternion matrices of arbitrary dimension. Two simulation experiments and two practical acoustic source tracking applications show that the models function superbly

Prospects for Application of Ultrafiltration Technology for the Scaled Preparation of Plague Microbe and Cholera Vibrio Major Antigens

Demonstrated is the possibility of application of ultrafiltration technologies in the process of cholera toxin and plague agent capsular antigen precipitation under production conditions. Application of ultrafiltration techniques permits of the reduction of losses at the stages of isolation and purification of antigen preparations; and concentration of raw material or semi-finished product provides for the reduction of labor inputs. Thus it leads to the increase in productivity and economical efficiency

Developing an Individual Neurosurgical Strategy in Patients With a Two-Level Cervical Degenerative Disc Disease

Background: Little is written about substantiated clinical and biometric indications for dynamic stabilization, rigid fixation, and their combinations in patients with two-level degenerative disease of the cervical intervertebral discs (IVD).Objective: To study the risk factors for poor outcomes of two-segment interventions (total disk arthroplasty, TDA; anterior cervical discectomy and fusion, ACDF; and their combination) in patients with two-level degenerative diseases of the cervical IVD; to develop a custom clinical and instrumental assessment strategy for future interventions.Materials and methods: We retrospectively analyzed the outcomes in 118 patients with a two-level degenerative disease of the cervical IVD, who underwent TDA (n = 37), ACDF (n = 41), and their combination (n = 40) from 2005 to 2015. After this analysis, we built a mixed effects logistic regression model to identify and assess the impact of various risk factors on poor clinical outcomes in each intervention.Results: TDA correlated with favorable outcomes in patients with cervical lordosis over 12 °; I–III grade IVD changes according to Pfirrmann scale; I–II grade facet joints (FJ) changes according to Pathria criteria; no FJ tropism; segmental movements amplitude > 8 °; interbody space height ≤ 6 mm, and with no central spinal stenosis/spine interventions. Favorable ACDF outcomes may be achieved in patients with cervical lordosis ≥ 7 °; more than III grade IVD changes according to Pfirrmann scale; more than II grade changes in FJ according to Pathria criteria; segmental movements amplitude ≤ 8 °; interbody space height < 6 mm. FJ tropism, central spinal stenosis, and history of spine interventions do not affect ACDF outcomes.Conclusions: An individual approach to TDA, ACDF, and their combination as well as comprehensive preoperative clinical and instrumental assessment in patients with a two-level degenerative IVD disease contribute to the effective resolution of existing neurological symptoms, which reduced the pain severity in the cervical region and upper limbs, improve the patients’ functional status and quality of life in the late postoperative period, and reduce the number of postoperative complications and reinterventions

Wheat landraces as sources of high grain quality and nutritional properties

Background. Improving the grain quality of modern spring bread wheat cultivars is a highly relevant task of breeding. To solve this problem, old and local wheat varieties (landraces) are of considerable interest. A rich collection of them is available among the plant genetic resources preserved at VIR. With this in view, the aim of this research was to identify sources of high protein, gluten, macro- and micronutrient content out of the landraces from the VIR collection for improvement of wheat grain quality through breeding.Materials and methods. Field and laboratory research were conducted in the experimental field of Omsk State Agrarian University under the conditions of the southern forest-steppe of Western Siberia in 2020–2021. Sowing was carried out on fallow on conventional sowing dates. Mineral composition in the grain of the studied landraces was analyzed at the Kurchatov Genomic Center, Novosibirsk, using atomic absorption spectrometry techniques.Results. The research results showed that landraces from different regions of Russia, Kazakhstan, Tajikistan, and Kyrgyzstan were characterized by high levels of protein (18.4–18.8%) and gluten (35.9–36.0%) in grain. Landraces from Kazakhstan had low Zn content (on average 38.3 mg/kg), while those from Kyrgyzstan, on the contrary, had high content of Zn (41.9 mg/kg) and Fe (55.1 mg/kg), and landraces from Tajikistan had high K content (3820 mg/kg). A positive relationship between the concentrations of Mg, Mn, Fe, and Zn was found in the grain of wheat landraces.Conclusion. Wheat landraces are of interest as genetic resources for the development of high-protein cultivars with improved nutritional value of grain for the milling and breadmaking industries