Using neural network for simulations to improve the quality of disease diagnosis: Technical aspects

Mathematical models are important for the processes of cognition and decision-making. They provide a concise representation of significant relationships in the description of objects and situations. Adding new relationships leads to narrowing the scope of applicability of the model. The formula is an example of a compressed description of a potentially infinite set of objects and situations. Knowledge processing is based on the use of mathematical methods. In this case, it is the most thorough, at least from the point of view of strict logic and consistent formalization. To process knowledge, we must present it in some form that is convenient for analysis. Thus, when analyzing data and knowledge, we do not use them directly, but their representations. Mathematical models of objects and phenomena are an effective way of representation. This is now the most powerful method of cognition of processes, objects and phenomena. Modeling is a special way of scientific research. A mathematical model of an object is a mathematical structure interpreted within a given domain. © 2020, World Academy of Research in Science and Engineering. All rights reserved

The use of virtual machines in education institutions

The possibility of virtual machines are wide enough. They address many issues related to application compatibility and operating system, as well as the safe use of a personal computer, which in turn is important for educational institutions due to the rapid pace of development of information technologiesВозможности виртуальных машин достаточно широки. Они решают многие вопросы, связанные с совместимостью приложений и операционной системы, а так же с безопасным использованием персонального компьютера, что, в свою очередь, важно для образовательных учреждений в силу быстрых темпов развития информационных технологи

Didactic principles on the basis of use of virtual machines

This article describes the generally recognized didactic principles, considered the idea of the use of virtual machines in the educational process, as well as didactic principles underlying the use of virtual machinesВ данной статье рассмотрены общепризнанные дидактические принципы, рассмотрена идея о применении виртуальных машин в образовательном процессе, а также дидактические принципы, положенные в основу использования виртуальных маши

Bulk Oxygen Diffusion and Surface Exchange Limitations in La2−xSrxNi1-yFeyO4+δ

The oxygen permeation flux through dense La1.2Sr0.8Ni0.9Fe0.1O4

Bone remodeling markers after experimental augmentation of trabecular bone defects with resorbable and non-resorbable osteoplastic materials in rabbits

To study the effect of bone defect augmentation on the dynamics of bone remodeling markers. Material and methods The effect of resorbable xenoplastic material (RXM), synthetic beta-tricalcium phosphate (b-TCP), porous titanium implant (PTI) and nanostructured carbon implant (NCI) on the markers of bone remodeling (osteocalcin, OC; bone alkaline phosphatase, BALP; C-terminal telopeptide of type I collagen, CTX-1) and inflammation marker (C-reactive protein, CRP) was investigated using bone defect model in rabbits. 24 animals were divided into 4 groups (n = 6 in each group) according to the type of osteoplastic material. Control group (n = 6) was without augmentation. An impression fracture of the proximal tibia was modeled. Blood samples were taken on days 1, 3, 7, 14, 45, 90, 180 after surgery. Results CTX-1was not detected in the control, b-TCP, PTI, and RXM groups after 90 days, but in the NCI group CTX-1 remained elevated until the end of the study. OC in the control, b-TCP, PTI groups reached a maximum at 14-45 days. No significant increase in OC was found in the NCI group. The BALP in the control group peaked at 90 days. In the b-TCP and PTI groups the concentration of BALP increased more rapidly. The dynamics of CRP in the RXM, b-TCP and PTI groups was similar to the dynamics in the control group, in the NCI group an increased level of CRP remained until the end of the study. Conclusion When a bone defect was augmented with both resorbable b-TCP and nonresorbable PTI, high osteogenesis activity and low osteoresorption activity were detected. The use of xenoplastic material did not reveal any advantages in comparison with surgery performed without augmentation. An increase in osteoresorption and a low level of osteogenesis were found by using NCI. © Yildiz K., Yildiz V., 2020

Synthesis, Crystal Structure, and Properties of NdNi0.5Mn0.5O3−

The crystal structure and properties of NdNi0.5Mn0.5O3

Crystal structure, oxygen non-stoichiometry and conductivity of Nd1-xAxMn0.5Fe0.5O3-δ (A=Ca, Sr, Ba)

This work was financially supported by RFBR (project No. 16-53-45010 IND_а)

Sentinel headache as a warning symptom of ischemic stroke

Background: There are no previous controlled studies of sentinel headache in ischemic stroke. The purpose of the present study was to evaluate the presence of such headache, its characteristics and possible risk factors as compared to a simultaneous control group. Methods: Eligible patients (n = 550) had first-ever acute ischemic stroke with presence of new infarction on magnetic resonance imaging with diffusion-weighted imaging (n = 469) or on computed tomography (n = 81). As a control group we studied in parallel patients (n = 192) who were admitted to the emergency room without acute neurological deficits or serious neurological or somatic disorders. Consecutive patients with stroke and a simultaneous control group were extensively interviewed soon after admission using validated neurologist conducted semi-structured interview forms. Based on our previous study of sentinel headache in transient ischemic attacks we defined sentinel headache as a new type of headache or a previous kind of headache with altered characteristics (severe intensity, increased frequency, absence of effect of drugs) within seven days before stroke. Results: Among 550 patients with stroke 94 patients (17.1%) had headache during seven days before stroke and 12 (6.2%) controls (p < 0.001; OR 3.9; 95% CI 1.7-5.8). Totally 81 patients (14.7%) had sentinel headache within the last week before stroke and one control. Attacks of arrythmia during seven days before stroke were significantly associated with sentinel headache (p = 0.04, OR 2.3; 95% CI 1.1-4.8). Conclusions: A new type of headache and a previous kind of headache with altered characteristics during one week before stroke are significantly more prevalent than in controls. These headaches represent sentinel headaches. Sudden onset of such headaches should alarm about stroke. © 2020 The Author(s)

Geographic and chronographic variations of coloration in population of Polistes gallicus (Linnaeus, 1767) (Hymenoptera, Vespidae)

The article presents the results of studying geographic and chronographic colour variability of paper wasp Polistes gallicus (Linnaeus, 1767) in Kherson Area of Ukraine in 2004-2005. Colour and pattern variations on clypeus (6), mesonotum (3), the first tergite of abdomen (4) and the second tergite of abdomen (3) were investigated for 1839 wasps (queens and future foundresses). Colour and pattern variations on clypeus and mesonotum of 255 queens collected in May-June 2005 in three places of the Kherson Area (The Black Sea Reserve, Kherson and Khorly) didn’t differ, but colour variations on the first tergite of abdomen were significantly different in those three sites under study. Variability being of a clinal character, this allowed making a conclusion that the wasps of these three sites belonged to one and the same population. A comparison of colour variation frequencies for the Black Sea reserve subpopulation throughout 2004-2005 revealed similarity in clypeus and the first tergite of abdomen and significant differences for queens’ and future foundresses’ mesonotum. A change in colour variation of the population was expressed more significantly in 2004 and had cyclic character. The subpopulation as a whole maintained its stability in those characteristics. A possibility of such variability as a result of some selection factors is discussed