bluuebunny/crossref_metadata_2025 huggingface dataset:
A study of acute toxicity of newly synthesized compound on adult hydrobiont Danio rerio
Authors: Safonov A. A. , Karpenko Yu. V. , Knysh Ye. H.
Published: April 2021

From ancient times the people used different poisons as a treatment for diseases of different genesis. To date, almost nothing has changed. One of the main conditions for the development of a new drug is its low toxicity. Literature analysis has shown that 1,2,4-triazole-3-thione derivatives are low-toxic compounds and exhibit a wide range of pharmacological activities.

The aim of this work was the investigate acute toxicity LC50 in vivo of sodium 2-((4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-yl)thio)acetate on the Zebrafish (Danio rerio) aquatic model according to OECD instruction № 203.

Materials and methods. Determination of acute toxicity LC50 of the test compound was performed in vivo on a model of the aquatic organism Zebrafish (Danio rerio) according to the instruction OECD № 203 (Fish, Acute Toxicity Test) for testing chemical compounds (acute toxicity test on fish from 10.12.2009).

It was used fish 2 months of age, 11.8 ± 0.1 mm long, and weighing 2.6 ± 0.2 g in the experiment. The concentration of the test compound ranged from 5.0 mg/l to 100.0 mg/l. Test water-soluble compounds were dissolved in distilled water. Each mini-aquarium with a certain dose of the compound contained at least 7 individuals of Danio rerio. During the experiments, the fish were kept on a diet for a test 96 hours and their mortality was checked every 24, 48, 72 and 96 hours. Statistical analysis of the results was performed using the program Statistica 6.

Results. According to the obtained data, graphs of the dependence of the concentration on the fish mortality percentage were constructed. Then the corresponding values of LC50 sodium 2-((4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-yl)thio)acetate were calculated.

According to the acute toxicity of LC50 (96 hours) of sodium 2-((4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-yl)thio)acetate, which according to the classification of D. R. Passino and co-authors allowed it to be classified as a moderately toxic compound.

Conclusions. The acute toxicity LC50 in vivo of sodium 2-((4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-yl)thio)acetate on the Zebrafish (Danio rerio) aquatic model was investigated. The research was conducted in accordance with the national “General Ethical Principles of Animal Experimentation” approved by the First National Congress on Bioethics and the “Bioethical Expertise of Preclinical and Other Animal Research”.

The highest fish mortality occurs on the last day of observation (96 hours). The highest number of Zebrafish deaths is at a minimum concentration of the substance. The acute toxicity LC50 (96 hours) of the test substance was 4.5364 mg/l.
Experiences With Smoking Cessation Attempts and Prior Use of Cessation Aids in Smokers With HIV: Findings From a Focus Group Study Conducted in Durham, North Carolina
Authors: Pacek Lauren R. , Holloway Alicia D. , Cropsey Karen L. , Meade Christina S. , Sweitzer Maggie M. , Davis James M. , Joseph McClernon F.
Published: April 2021

Cigarette smoking remains disproportionately prevalent and is increasingly a cause of death and disability among people with HIV (PWH). Many PWH are interested in quitting, but interest in and uptake of first-line smoking cessation pharmacotherapies are varied in this population. To provide current data regarding experiences with and perceptions of smoking cessation and cessation aids among PWH living in Durham, North Carolina, the authors conducted five focus group interviews (total n = 24; 96% African American) using semistructured interviews. Interviews were recorded, transcribed, coded, and thematically analyzed. Major themes included ambivalence and/or lack of interest in cessation; presence of cessation barriers; perceived perceptions of ineffectiveness of cessation aids; perceived medication side effects; and conflation of the harms resulting from use of tobacco products and nicotine replacement therapy. Innovative and effective interventions must account for the aforementioned multiple barriers to cessation as well as prior experiences with and misperceptions regarding cessation aids.
KOAGÜLAZ-NEGATİF STAPHYLOCOCCUS (KNS) VE MACROCOCCUS CASEOLYTICUS SUŞLARININ BİYOFİLM OLUŞTURMA ÖZELLİKLERİNİN VE ADEZYON FAKTÖRLERİNİN ARAŞTIRILMASI
Authors: YERLİ Gaye Asuman , ÖZDEN TUNCER Banu
Published: April 2021

Bu çalışmada geleneksel fermente Türk sucuklarından izole edilmiş toplam 50 adet koagulaz-negatif Staphylococcus (KNS) ve 10 adet Macrococcus caseolyticus suşlarının biyofilm oluşturma özellikleri fenotipik olarak belirlenmiş ve aynı zamanda suşlarda biyofilm oluşumu ile ilişkili genler ve adezyon genlerinin varlığı multipleks polimeraz zincir reaksiyonu (mPZR) ile araştırılmıştır. Fenotipik olarak slaym (slime) üretimi Congo Red agar (CRA), biyofilm üretim düzeyi mikrotitre plaka yöntemi ile belirlenmiştir. CRA besiyerinde slaym üreticisi olduğu belirlenen 33 suşun tamamının mikrotitre plaka yöntemi ile biyofilm üreticisi olduğu tespit edilmiştir. KNS ve M. caseolyticus suşlarının 28’inin orta, 23’ünün zayıf ve 1’nin güçlü biyofilm üreticisi olduğu saptanmıştır. Sekiz suşta ise biyofilm üretiminin olmadığı tespit edilmiştir. mPZR denemeleri sonucu biyofilm üreticisi olduğu belirlenen KNS ve M. caseolyticus suşlarının %84.62’sinin araştırılan genlerden en az birini içerdiği bulunmuştur. Suşların %66.67’sinde eno geni, %15.67’sinde icaA geni varlığı belirlenmiştir. Diğer taraftan biyofilm üreticisi olduğu belirlenen 8 suşun ise çalışma kapsamında araştırılan biyofilm genlerinin hiçbirini içermediği tespit edilmiştir.
FARKLI KARBONHİDRAT FORMÜLASYONLARI İLE ÜRETİLMİŞ AYVA SUYU KONSANTRESİ KATKILI SERT ŞEKERLERİN KALİTE ÖZELLİKLERİNİN İNCELENMESİ
Authors: RAYMAN ERGÜN Ahsen , TEKGÜL Yeliz
Published: April 2021

Bu çalışmada farklı karbonhidrat formülasyonları kullanılarak ayva suyu konsantresi katkılı sert şeker üretimi amaçlanmıştır. Her bir karbonhidrat formülasyonu (%100 sakkaroz, %75 sakkaroz+%25 glikoz, %75 sakkaroz+%25 fruktoz) için geleneksel açık kazan üretim yöntemi kullanılarak sert şeker üretilmiştir. Ürünlerin renk, camsı geçiş sıcaklığı (Tg) ve higroskopisite değerleri, şeker kompozisyonları, duyusal özellikleri incelenmiştir. % 100 sakkaroz kullanılarak üretilen sert şekerlerin L*, a* ve b* değerleri en yüksek olarak bulunmuştur. Şeker formülasyonlarına glikoz ve fruktoz ilavesi ürünlerin Tg değerinde azalmaya neden olmuştur. %75 sakkaroz+ %25 fruktoz formülasyonu kullanılarak üretilen sert şekerlerin higroskopisite değeri en yüksek olarak bulunmuştur. Karbonhidrat formülasyonundaki farklılık ürünlerin şeker kompozisyonunu etkilemiştir. Formülasyonunda glikoz içeren sert şekerler genel beğeni kriteri açısından en yüksek puanlanmıştır
El antiguo Díolkos de Corinto. Análisis de las propuestas sobre su trazado y cálculo de trayectoria óptima
Authors: García Ruiz Pere
Published: April 2021

En nuestro artículo nos proponemos una reinterpretación del trazado del antiguo Díolkos de Corinto desde una perspectiva científica y rigurosa. Con las herramientas informáticas actuales y la cartografía de la región del Istmo anterior a la apertura del canal, hemos elaborado un conjunto de programas que nos permiten evaluar los posibles trayectos aportados por los estudiosos del tema y, además, elaborar una propuesta de trayectoria óptima.
En nuestro trabajo pensamos que el hecho de abordar el estudio de esta ruta desde el punto de vista de la física y la ingeniería puede aportar una visión complementaria y enriquecedora a los trabajos históricos y arqueológicos, basados exclusivamente en las fuentes históricas. Esperamos que nuestra contribución sea de utilidad a la hora de evaluar los requerimientos técnicos y las dificultades del traslado de embarcaciones entre los golfos del Istmo de Corinto, así como profundizar en el interés económico y estratégico de esta famosa vía.
El primer PSOE ante el sufragio universal (1879-1891): el movimiento obrero como agente democratizador en el sistema de la Restauración
Authors: Sánchez Castillo Adrián
Published: April 2021

Los inicios del movimiento obrero en la historia contemporánea que aborda el siglo XIX, tanto a escala internacional como en sus historias nacionales, suelen vincularse, en términos prácticos, a la pugna económica en la sociedad de clases configurada a raíz de la Revolución Industrial y, en términos teóricos, a la evolución ideológica de sus diferentes corrientes organizadas. Es ya en los estudios dedicados al siglo XX donde encontramos mayor incidencia del papel que jugó el movimiento obrero en la democratización de las sociedades contemporáneas. Teniendo en cuenta la influencia clave que el socialismo tendría en este proceso en España, el presente trabajo analiza los orígenes más remotos de su práctica política democratizadora en torno a la cuestión del sufragio universal en el contexto sistémico de la Restauración con el objetivo de comprender las bases de las que partió un sujeto que sumaría a miles de personas por primera vez a la sociedad política de la época.
Considering unemployment in Ecuador during the Great Depression
Authors: Naranjo Navas Cristian Paúl
Published: April 2021

The Great Depression struck Latin America through the commerce: the reduction in revenues from the external commerce spread to the rest of the economy, resulting in the continue decreasing of the monetary supply. The Ecuadorian monetary policy until 1932, based on the gold standard, faced the phenomenon of deflation, which caused real salaries to grow. Since 1932, the monetary supply increased due to the abandonment of the gold standard, which caused real wages to decreased. In the same period, from 1928 to 1935, the primary data of the central offices of eight institutions shows that public employment decreased abruptly from 1928 to 1930, from 109.4 to 83.1 points (1927=100). After 1930, there was a quick recovery until 1932, and, from this point in time, it remained relatively stable until 1935. This article constructs, for the first time in the Ecuadorian historiography, an employment index which serves to see employment as the adjustment variable of the Great Depression.
“Combatir al comunismo sin hacerle el juego”. Una aproximación a las memorias de militantes del Movimiento Nacionalista Tacuara
Authors: Albornoz Celina
Published: April 2021

El Movimiento Nacionalista Tacuara (MNT) fue una agrupación de la derecha nacionalista argentina que actuó entre finales de la década de 1950 y principios de la de 1970. Extremadamente católicos, anticomunistas y antisemitas, perseguían la creación de un “orden” bajo el lema “Dios, patria y hogar”. En este trabajo nos proponemos como objetivo reconstruir la memoria de exmilitantes del MNT acerca de su uso de la violencia, instrumentalizada principalmente contra personas e instituciones de izquierda y judías. Para ello, se utilizan entrevistas realizadas a ex militantes, empleando las herramientas de la historia oral. Se verá que existe un intento de desprenderse del  antisemitismo y una pretensión de transmutación del anticomunismo en una militancia que perseguía la concreción de una revolución nacional. Además, se observará que emergen códigos masculinos que caracterizan la violencia ejercida por la agrupación.
Geographic information system (GIS) based soil loss estimation using RUSLE model for soil and water conservation planning in anka_shashara watershed, southern Ethiopia
Authors: Bekele Meseret
Published: April 2021

Water induced soil erosion has been continued to threaten the land resources in sub humid northwestern highlands of Ethiopia. Human-induced land cover (LC) changes due to improper land management practices are contributing factors in deteriorating soil quality. Soil and water conservation measures have been implemented without site-specific scientifically quantified soil erosion data and priority bases in this regard; this study was conducted with a view to quantifying soil erosion in Anka-Shashara watershed. To do this, we have opted to use the RUSLE model based on geographic information systems. By collecting data on rainfall, soils, vegetation, slopes and conservation practices separately as a layer and determining the pixel values for each of these factors, a quantified assessment of erosion in the basin is obtained. The result reveals that the mean annual soil loss (15.22t/ha/yr) of the most parts of study area falls in tolerable levels and almost 66% (1594 ha), moderate level about 23% and 10% at high level of watershed. The soil loss of watershed is classified in to four main classes. None to Slight rates of soil erosion (0-10t/ha) is cover the almost 66% of watershed moderate about 23% and high about 10% of erosion rate as seen from the erosion rate distribution map. The upstream of catchment needs management and protection of those existing resources and the fundamental attention for SWC as recommended bases. Therefore, to reduce sedimentation problem and ensue sustainability of the watershed need to special attention for implementing recommended SWC intervention at the earlier.
Changes in Neurodevelopmental Outcomes From Age 2 to 10 Years for Children Born Extremely Preterm
Authors: Taylor Genevieve L. , Joseph Robert M. , Kuban Karl C.K. , Douglass Laurie M. , Laux Jeff , Andrews Bree , Fry Rebecca C. , Price Wayne A. , O’Shea Thomas M.
Published: April 2021

OBJECTIVES:

Evidence-based care of extremely preterm infants (<28 weeks’ gestation) depends heavily on research in which a primary outcome is infant neurodevelopmental impairment (NDI), yet it is unclear how well NDI in infancy predicts long-term NDI. In this study, we aim to assess the relationship between 2- and 10-year neurodevelopment using a well-known 2-year definition and a 10-year definition developed by an expert panel.

METHODS:

Using data from the Extremely Low Gestational Age Newborn Study cohort, we classified 2-year NDI using definitions developed by the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. We classified 10-year NDI using definitions developed by an expert panel, which added epilepsy and ASD at 10 years.

RESULTS:

Of 1506 infants, 80% survived. Data sufficient to classify severity of NDI at both 2 and 10 years were available for 67% of survivors (n = 802). Among children classified as having moderate to severe NDI at 2 years, 63% had none to mild NDI at 10 years; among children classified as having profound NDI at 2 years, 36% had none to mild NDI at 10 years. Cohen’s κ statistic indicated minimal to fair agreement between NDI at 2 and 10 years (0.34, P < .001).

CONCLUSIONS:

NDI in infancy, as defined in this study, only weakly predicts NDI in middle childhood. For the parents at risk for delivery of an extremely preterm infant, a hopeful message can be taken from our findings that one-third of surviving children classified as having profound NDI and nearly two-thirds of those classified as having moderate to severe NDI at 2 years had none to mild NDI at 10 years.
Efecto de diferentes tipos de entrenamiento físico en la altura de salto de gimnastas: meta-análisis
Authors: Ulloa-Sánchez Paul , Hernández Elizondo Jessenia
Published: April 2021

El principal objetivo del presente estudio fue determinar el efecto de diferentes tipos de entrenamiento físico en la altura de salto de gimnastas, bajo la metodología de meta-análisis. Se siguió los lineamientos PRISMA, las bases de datos electrónicas consultadas en la búsqueda fueron EBSCOhost (SPORTDiscus, MEDLINE, Academic Search Complete, E-Journals, OmniFile Full Text Select (H.W. Wilson), Web of Science, Scopus, SciencDirect, Research Gate y Pubmed para identificar los artículos relevantes que investigaron la aplicación de un entrenamiento físico y evaluaron la altura salto en gimnastas antes y después de la intervención. Después del proceso de selección de estudios y a partir de los criterios de inclusión, se codificaron 29 estudios individuales y se codificaron 157 tamaños de efecto (TE) individuales. La muestra total de sujetos fue 688 gimnastas. El grupo experimental mostró un TE global de bajo a moderado y significativo (TE = 0.33, p<0.001*). Se evidenció una diferencia significativa (p = p<0.001*) entre los tipos de entrenamiento; el análisis Post Hoc mostró que el TE global del entrenamiento de pliometría (TE = 0.85, p<0.001*) fue mayor al de estiramiento (TE = -0.07, p = 0.56) y “otros” (TE = 0.48, p<0.001*), pero no al de vibración (TE = 0.54, p<0.001*); además, el TE global de tipo de estiramiento fue significativamente menor a todos los tipos de entrenamiento. Se concluyó que el tipo de entrenamiento que mostró el mayor TE global fue pliometría, seguido por el entrenamiento en plataforma vibratoria. Parece que el estiramiento no se relaciona significativamente con la altura de salto de gimnastas.
Application of P4 rapid test and exogenous source of progesterone in prevention of early embryonic death in dairy cows
Authors: Bonev G.
Published: April 2021

Abstract. The objectives of this study were: 1) to determine the percent of cows with low P4 at Day 7-8 post-AI; 2) to treat the animal with low progesterone for 14 days with a P4-releasing intravaginal device (PRID DELTA); 3) to analyze the influence of P4 exogenous supplementation on pregnancy rate in treated and non-treated cows and 4) to create a protocol using “P4 Rapid” test allowing increased pregnancy rate under farm conditions. For this purpose, the current study has been conducted on 155 repeat breeding Holstein cows (<3 artificially inseminated – AI) with prolonged estrus cycle (<26 days). At day 7 and 8 post-AI, the milk progesterone levels were measured (P4 Rapid test). The cows with low P4 (n=104 or 67%) were divided into two groups each n=52. In Group I the progesterone devices were inserted for two weeks and control Group II without progesterone devices. At days 40 and 50 post artificial insemination (AI) all animals (n=104) were submitted to ultrasound pregnancy detection. Pregnancy was registered in 27 animals (51.9%) for Group 1, and in 16 cows (30.7%) for Group II. P4 Rapid is a quick, easy and practically applicable test to measure milk progesterone levels in dairy farms. The method is highly accurate and detects animals with low or high P4 at Day 7-8 after insemination. It also allows identification of conditions such as ovarian cysts, ovarian hypofunction and distinguishing of cycling and non-cycling cows. The combination of P4 measurement by P4 Rapid test and treatment with exogenous P4 to increase circulating concentrations in the first few days after conception can prevent embryo death and improve reproductive efficiency in dairy cattle.
Fuel consumption of a machine-tractor unit in direct sowing of wheat
Authors: Tihanov G. , Ivanov N.
Published: April 2021

Abstract. A study has been conducted on the fuel consumption in direct sowing of wheat with a Horsch Avatar 6.16 SD direct seeder aggregated to a John Deere 7250 R tractor. The experimental field (29.53 ha) was sown with winter soft wheat (Silverio variety) at a sowing rate of 195 kg/ha. The data from the sowing unit were collected using the JD Link telematics system, downloaded from the system and imported and compiled in a database. Fuel consumption was analyzed in accordance with the operation mode, the idle mode and the transportion mode of the machine-tractor unit. It was found that the average fuel consumption in work mode (when the seeder was sowing) was 23.08 l/h, while in transportion mode the seeding unit consumed 16.55 l/h and while the unit was idling it consumed 4.30 l/h. The results also show that the seeding unit has travelled 63 km and consumed 185 L of diesel fuel at an average diesel consumption of 23.08 l/h.
Length-weight relationship of European catfish (Silurus glanis L.) fry reared at different stocking densities under controlled conditions
Authors: Krasteva V. , Yankova M.
Published: April 2021

Abstract. The present paper investigates the body length and weight, and the size-weight variations of one-month-old European catfish reared at 4 variants of stocking density: Variant 1 – 5 spec/l; Variant 2 – 10 spec/l; Variant 3 – 15 spec/l and Variant 4 – 28 spec/l. The experiment is carried out at the Institute of Fisheries and Aquaculture, Plovdiv for a period of 16 days, using a production system consisting of tubs with continuous water flow (0.7 l/min). At the end of the experiment, the fish from each variant are sorted in three size-weight groups: A – large, B – medium and C – small. The number of fish in each group is established. From the group of the medium- and small-sized fish, 150 speciments are measured, while from the group of the large specimens, which are the smallest in number, all specimens are measured for the biometric parameters body weight (BW, g) and total body length (TL, cm). The results from the study show small variations in the length and weight of the fish reared at the lowest stocking density (Variant 1). As the density increase, the size-weight differences between the specimens from Group A also increased, while of those from Group B they decrease. The number of the medium-sized fish decrease (p≤0.001) while the number of large specimens (p≤0.01) and small fish increase (p≤0.001).
Isolation and characterization of Lactobacillus microflora from homemade white sheep’s milk cheeses during ripening
Authors: Stojanovski S. , Cilev G. , Trajanoska B.
Published: April 2021

Abstract. The Lactobacillus microflora of white cheese made from sheep’s milk was studied during the maturation period of 10 to 100 days in the basement at a temperature of 10-12°C. Eight samples from different stages of natural white cheese ripening were taken for testing. A total of 28 strains were isolated and identified as Lactobacillus spp. based on their growth, gram-stain activity, catalase and oxidase. Their affiliation to this genus was confirmed by PCR with genus specific primers, 16S ribosomal RNA. The results show that in the early stages of cheese ripening (5th-6th, 10-39 day) the most commonly found species are: Lactobacillus plantarum and Lactobacillus curvatus, while in later stages of the cheese ripening (7th-10th, 40-80 day), the following species are found: Lactobacillus plantarum and Lactobacillus paracasei subsp. Paracasei.
COMBINED CRITERION FOR THE CHOICE OF ROUTING BASED ON D2D TECHNOLOGY
Authors: Bulashenko А. V.
Published: April 2021

Context. 5G network is able to improve existing services and provide a new quality of services. 5G communication networks combine various radio technologies and technologies of fixed communication networks, therefore they are often called heterogeneous, which emphasizes their difference from other networks. One of the main features of such networks is over-density and ultra-low latency. It is the Internet of things that is the basic component of the concept of super dense networks. 3GPP suggests planning 5G networks based on the condition that 1 million devices is 1 km2. Also, ultra-low latency communications networks have a big impact on networking methods, especially for the tactile Internet concept. Such networks require decentralization through 1 ms delay requirements. This requires new approaches to building a new generation of networks, which is the reason for the development of new technologies. One such technology is D2D (device-to-device) technology. This technology allows you to reduce the load on the core of the network due to the use of a significant proportion of the traffic directly between devices and reduces the delay in providing services.

Objective. The goal of the work is to create an optimal combined criterion for choosing effective traffic routes in a wireless network based on D2D technology.

Method. Many modern works are devoted to the study of D2D technology, but they are not exhaustive in the study of routing in such networks. It is objective enough to study networks built on the basis of the interaction of devices with each other using D2D technology, since such interactions have proven to be effective technologies. This, in turn, involves the development of appropriate routing methods in networks using D2D technology, especially taking into account the property of over-density 5G networks. The paper proposes a criterion for selecting routes, taking into account interference within the channels forming the network nodes. This criterion combines the choice of routes according to the length criteria and the criterion of maximum throughput.

Results. A developed combined criterion for selecting traffic routing in a wireless network that uses D2D technology. The results of the study are shown in graphic data.

Conclusions. The experiments confirmed the efficiency and effectiveness of the developed method and allow us to recommend this method for practical use as a result of route selection, taking into account those network properties that are more likely to affect the quality of the route.
ONLINE FUZZY CLUSTERING OF INCOMPLETE DATA USING CREDIBILISTIC APPROACH AND SIMILARITY MEASURE OF SPECIAL TYPE
Authors: Bodyanskiy Ye. V. , Shafronenko A. Yu. , Klymova I. N.
Published: April 2021

Context. In most clustering (classification without a teacher) tasks associated with real data processing, the initial information is usually distorted by abnormal outliers (noise) and gaps. It is clear that “classical” methods of artificial intelligence (both batch and online) are ineffective in this situation.The goal of the paper is to propose the procedure of fuzzy clustering of incomplete data using credibilistic approach and similarity measure of special type.

Objective. The goal of the work is credibilistic fuzzy clustering of distorted data, using of credibility theory.

Method. The procedure of fuzzy clustering of incomplete data using credibilistic approach and similarity measure of special type based on the use of both robust goal functions of a special type and similarity measures, insensitive to outliers and designed to work both in batch and its recurrent online version designed to solve Data Stream Mining problems when data are fed to processing sequentially in real time.

Results. The introduced methods are simple in numerical implementation and are free from the drawbacks inherent in traditional methods of probabilistic and possibilistic fuzzy clustering data distorted by abnormal outliers (noise) and gaps.

Conclusions. The conducted experiments have confirmed the effectiveness of proposed methods of credibilistic fuzzy clustering of distorted data operability and allow recommending it for use in practice for solving the problems of automatic clusterization of distorted data. The proposed method is intended for use in hybrid systems of computational intelligence and, above all, in the problems of learning artificial neural networks, neuro-fuzzy systems, as well as in the problems of clustering and classification.
IMPLEMENTATION OF THE INDICATOR SYSTEM IN MODELING OF COMPLEX TECHNICAL SYSTEMS
Authors: Leoshchenko S. D. , Subbotin S. A. , Oliinyk A. O. , Narivs’kiy O. E.
Published: April 2021

Context. The problem of determining the optimal topology of a neuromodel, which is characterized by a high level of logical transparency in modeling complex technical systems, is considered. The object of research is the process of applying an indicator system to simplify and select the topology of neuromodels.

Objective of the work is to develop and use a system of indicators to determine the level of complexity of the modeling problem and gradually select the optimal logically transparent topology of the neuromodel.

Method. A method is proposed for selecting an optimal, logically transparent neural network topology for modeling complex technical systems using a system of corresponding indicators. At the beginning, the method determines the overall level of complexity of the modeling task and, using the obtained estimate, determines the method for further optimization of the neuromodel. Then, using Task data and input data characteristics, the method allows to obtain the most optimal structure of the neural model for further modeling of the system. The method reduces trainingvtime and increases the level of logical transparency of neuromodels, which significantly expands the practical use of such models, without using neuroevolution methods, which may not be justified by resource-intensive tasks.

Results. The developed method is implemented and investigated in solving the problem of modeling the dynamics of pitting processes of steel alloys. Using the developed method made it possible to reduce the training time of the model by 22%, depending on the computing resources used. The method also increased the level of logical transparency of the model by reducing the number of computing nodes by 50%, which also indicates faster and more efficient use of resources.

Conclusions. The conducted experiments confirmed the operability of the proposed mathematical support and allow us to recommend it for use in practice in the design of topologies of neuromodels for further solving modeling, diagnosis and evaluation problems. Prospects for further research may consist in the development of methods for structural optimization of previously synthesized models and the development of new methods for feature selection.
DEEP REINFORCEMENT LEARNING WITH SPARSE DISTRIBUTED MEMORY FOR “WATER WORLD” PROBLEM SOLVING
Authors: Novotarskyi M. A. , Stirenko S. G. , Gordienko Y. G. , Kuzmych V. A.
Published: April 2021

Context. Machine learning is one of the actively developing areas of data processing. Reinforcement learning is a class of machine learning methods where the problem involves mapping the sequence of environmental states to agent’s actions. Significant progress in this area has been achieved using DQN-algorithms, which became one of the first classes of stable algorithms for learning using deep neural networks. The main disadvantage of this approach is the rapid growth of RAM in real-world tasks. The approach proposed in this paper can partially solve this problem.

Objective. The aim is to develop a method of forming the structure and nature of access to the sparse distributed memory with increased information content to improve reinforcement learning without additional memory.

Method. A method of forming the structure and modification of sparse distributed memory for storing previous transitions of the actor in the form of prototypes is proposed. The method allows increasing the informativeness of the stored data and, as a result, to improve the process of creating a model of the studied process by intensifying the learning of the deep neural network. Increasing the informativeness of the stored data is the result of this sequence of actions. First, we compare the new transition and the last saved transition. To perform this comparison, this method introduces a rate estimate for the distance between transitions. If the distance between the new transition and the last saved transition is smaller than the specified threshold, the new transition is written in place of the previous one without increasing the amount of memory. Otherwise, we create a new prototype in memory while deleting the prototype that has been stored in memory the longest.

Results. The work of the proposed method was studied during the solution of the popular “Water World” test problem. The results showed a 1.5-times increase in the actor’s survival time in a hostile environment. This result was achieved by increasing the informativeness of the stored data without increasing the amount of RAM.

Conclusions. The proposed method of forming and modifying the structure of sparse distributed memory allowed to increase the informativeness of the stored data. As a result of this approach, improved reinforcement learning parameters on the example of the “Water World” problem by increasing the accuracy of the model of the physical process represented by a deep neural network.
СOMPUTER MODELING PARAMETERS OF TECHNOGENIC EMERGENCY SITUATIONS ON ENGINEERING INFRASTRUCTURE OF THE MEGAPOLIS
Authors: Novozhylova M. V. , Andronov V. A. , Melezhik R. S.
Published: April 2021

Context. The urgency of the research is to develop methods for analyzing and processing space-time information, namely the set of data distributed both in space and time and creating on this basis a computer probabilistic model of the process of predicting manmade emergencies on city engineering infrastructure. The spatio-temporal nature of data series causes additional requirements for the identification procedures of the mathematical model of a series, therefore, the number of approaches identifying its structure and construction of a series model has been proposed.

Objective is methodical and software implementation of a computer model of the space-time series being intended to predict the future values of locations and times of man-made emergencies on the engineering infrastructure of the metropolis and increase decision-making efficiency.

Method. A projection approach providing independent determination of random spatial parameters defining location of emergency units on engineering infrastructure as a sequence of two one-dimensional uniform distributions and describing time distribution of moments of accidents as non-stationary Poisson distribution has been developed. Proposed is an integrated approach which includes the construction of generator points, the power of which (characteristic of the accident complexity) based on the implementation of the comparative statics approach with so-called cumulative effect within a certain time. A relaxation approach based on the reduction of a two-dimensional simulation model of determining the city of possible emergency location to a set of independent onedimensional non-stationary (including stationary) distributions to generate the time of occurrence has been constructed. Formalization of the space-time field, procedures of information support of the process of forecasting the parameters of a possible emergency, typification of initial data for numerical experiments on the implementation of methods for forecasting the parameters of a possible emergency on the example of water supply and sewerage network of utility company Kharkivvodokal, city Kharkiv have been developed.

Results. A dual methodology to determine the simulation model parameters of the space-time series, which contains both projection and integral approaches, as well as a combined method − relaxation approach, have been proposed. Numerical experiments based on the constructed model were performed. The model being considered is the theoretical basis to construct the forecast using a large amount of historical data.

Conclusions. The method to predict the parameters of space-time series considering the nonstationarity property of the time component distribution has been further developed. Using the proposed computer simulation tools allows to increase the accuracy of the forecast of the location, time of occurrence and severity of a possible accident on the engineering infrastructure of the metropolis.
Indigenous ways of disaster preparedness in Zimbabwe: Lessons from living Heritage
Authors:   Chinhoyi University of Technology, Mapara Jacob
Published: April 2021

This paper argues that today’s communities have suffered considerably due to severe droughts, floods and storms occurring in what can best be described as coming out of season. These have led to loss of lives, livestock and property. It asserts that some of these disasters are avoidable if communities learn from the intangible cultural heritage that guided the pre-colonials and those of the pre independence period when most Blacks still respected and appreciated their beliefs and value systems. It notes that while it is important to rely on the Meteorological Services Department for weather forecasting, events over the past few years have shown this Department’s forecasts at times as unreliable. The paper therefore argues that Zimbabweans, especially those involved in crop and livestock production should also observe natural phenomena such as flora and fauna as was done by the people of old who got early warning signs from Mother Nature herself.
‘Kunemera Mufi’: Exploring Performance at Korekore Funerals
Authors:   Great Zimbabwe University, Yule Julia , Vhutuza Ephraim ,   Midlands State University, Zimbabwe, Gwirayi Christina ,   Great Zimbabwe University
Published: April 2021

The study reconnoitred elements of performance that are found at Korekore funerals. The purpose of the study was to revisit indigenous performance practices and elaborate elements of performance that are embodied within. Korekore funerals of Guruve district, Zimbabwe were used as a case study in this article. The paper argues that Korekore funerals demonstrate the use of theatre elements where space, actors, stagecraft and improvisation are key to a ‘Kunemera Mufi’ production. We argue that the ‘Kunemera Mufi’ at a typical Korekore funeral demonstrate the fact that theatre has always existed among the indigenous African people well before the first Whiteman came to Africa. Theatre was and remains part of the everyday activities among the Korekore, not only at funerals but also in other everyday chores such as hunting, work, child games, rites of passages, rituals and ceremonies. Thus, the paper argues against the Eurocentric definition of theatre or performance by elaborating the elements of performance at a Korekore funeral.
Umdala wethu legacy: The contested memories and the fatherhead role of Joshua Nkomo in Zimbabwe
Authors:   Leaders for Africa Network, Zimbabwe, Mahomva Richard
Published: April 2021

his paper revisits the under-currencies of the normative and empirical motivations of the official iconic ornamentation of Joshua Nkomo’s legacy during the Mugabe era. The urgency of this analysis is justified by how the ruling and Zimbabwe’s former Head of State, Robert Gabriel Mugabe, strategically exploited the memorialization of Joshua Nkomo for political expedience. This was orchestrated through the state’s Umdala wethu ‘cultural nationalism’ since 1999 as well as the infrastructural immortalisation of Umdala wethu in 2013. The state’s monopoly over Nkomo’s legacy competed with the anti-establishment and ethnicity inclined appropriation of Joshua Nkomo’s legacy in the Matebeleland regions. One refers to this alternative and public consented appropriation of Joshua Nkomo’s legacy as the traditional affirmative reposition of Father-Zimbabwe’s political fatherhood in Zimbabwe’s body politic. Further, the paper posits that the clashing entitlements to Nkomo’s legacy represents polarity of national memory in Zimbabwe.
Reflecting on death through song among the Shona people of Zimbabwe
Authors:   Midlands State University, Zimbabwe, Muranda Richard
Published: April 2021

Singing is undertaken by individuals and the community in dealing with real life experiences including death. Death is a reality which humans and animals are not immune to. It defines the end of life and brings pain to humanity. However, humans have mechanisms to deal with pain caused by death, and singing is one of them. The article examines how song is used to tackle the inevitable incidence of death. In this study, traditional and contemporary popular songs were purposively sampled to analyse and reflect on the nature of music used to cope with death. The study engaged 20 people, among them musicians and the elderly. Basing on Kubler-Ross’ (1969) five stage DABDA model of dealing with grief, the paper contends that Shona people celebrate life and death through song. Through singing, the Shona express ways of dealing with death. Some Shona beliefs in life after death inform the paper with ways of dealing with pain and how subsequently the Shona people come to accept the reality of death. The bereaved also exhibit some spirited embodiment, and reverence of the departed regardless of their earthly conduct. The study concludes that through song, the Shona people draw solace, hope, and peace of mind with regard to life after death. The frame of mind that accepts the imminence of death is embraced by many as they prepare for death through preparatory moves in taking funeral and general insurance policies. The engagement into singing tends to weaken the sting of death.
The Role of Culture in Managing Biodiversity: The Case of the Karanga Community in Zvishavane, Zimbabwe
Authors:   Bindura University of Science Education, Nyoni Chamunogwa , Dodo Obediah ,   Bindura University of Science Education
Published: April 2021

The concept of biodiversity is not new among traditional communities in Zimbabwe. Traditional communities have always ensured biodiversity from time immemorial. They have always co-existed with their environment and have always appreciated the importance of biodiversity in life. As a result, they have employed various measures to ensure this. Much of the measures that have been done are premised on the observations from culture. This paper sought to establish various cultural measures that have been relied upon by the traditional communities in Zimbabwe to promote the concept of biodiversity. The paper tackles the threat to cultural mechanisms in the management of biodiversity. The paper argues that ‘totemism’, taboos and superstitions have been relied upon as measures employed to safeguard biodiversity among the traditional Karanga ethnic group of Zvishavane. The paper further observes that culture has been a vehicle for promoting co-existence among the different species of the world.
Communicating Mathematics and Science in the Classroom: Exploring the Interactive Route
Authors:   University of Fort Hare, Nhlanhla Landa , Zhou Sindiso ,   BinduraUniversity of Science Education
Published: April 2021

Communicating mathematical problems and scientific concepts is considered as a complex and difficult endeavour. Teaching, whether of complex mathematical problems and scientific concepts or of 'straightforward and clear' ideas in the humanities, is a process of communication. This paper argues that communication skills are an integral part of the teaching of Science and Mathematics. Communicating Science and Mathematics in the classroom involves thorough explanations and, because the concepts dealt with are in themselves complex, this may involve going over the concepts repeatedly. This ability to put across the mathematical or scientific message is the ability by the teacher to communicate. Research has insisted that the ability to communicate and to pose questions are central attributes of an effective teacher. This paper argues that more than being able to communicate and ask questions, for effective teaching of Mathematics and Science the teacher needs to employ interactive teaching techniques to involve learners; this way the teacher actively involves learners in communication and therefore in both the teaching and learning process. The teacher and learner roles in the contemporary classroom need not be distinctively outlined as this creates an obstacle to understanding. This allows both the teacher and student to understand concepts from each other's perspective. Through interaction between teacher and student, the teacher is able to explain the mathematical problem to the student from the student's perspective. Through a semi-structured interview and observation the study involves a sample of 32 students from four secondary schools in the two provinces of Midlands and Bulawayo.
Communicating Through Music: An Analysis of Selected Songs from the Second Chimurenga
Authors:   Bindura University of Science Education, Pfukwa Charles
Published: April 2021

Every community has its own songs and performance styles that communicate, among other issues, its culture, ideology as well as its whims and fantasies. It can be used to communicate parts of all cultural activities and beliefs ranging from joy to the sombre tones of a funeral. Music becomes a social/ideological thread that holds a community together and facilitates all cultural activities in any community in the world. In this article, the writer discusses some effective ways in which music was effectively used to communicate and arouse positive feelings towards the Zimbabwean liberation struggle.
A stress-strain state analysis of the road transport works foundations on seasonally freezing soils
Authors: Permikin Anatoliy , Ovchinnikov Igor , Gricuk Anastasiya
Published: April 2021

This article discusses the road transport works foundations when they are located in the seasonally freezing soils zone. Some culvert aqueduct utilized structures were considered and analyzed as an example, in the scope of most common structures on the road network and that also has an insignificant weight. Some constructive solutions disadvantages of these pipes were pointed out. It is noted that the operational characteristics of nonfrost-susceptible soil decrease in the watercourse filtering process and settling small particles and reported the dependence of the relative soil frost boil on the fine aggregate percentage.
As an example of the frost boil forces influence, a typical culvert aqueduct design is considered. The calculation of axial and tangential heaving forces that affect the crown of tube is performed, assuming that the bedding soil is contaminated. Based on the calculation, rise calculated value dependence graphs of the unstressed base on the soil dampness and the heaving soil thickness, and the heaving pressure on the soil dampness are presented here.
Due to the insufficient value of the forces holding back against lifting, possible negative consequences of the frost boil impact forces are presented, this affects not only the culvert aqueduct operational characteristics but also the roadbed smoothness and traffic safety. Thus, the need for additional measures to prevent soil swelling under the pipe head is justified. Recommended measures to prevent excessive deformations during frost boil, as well as modern aspects of the development of such technologies, are considered. Conclusions are made about their applicability and feasibility in relation to small artificial structures of transport infrastructure.
Modified bituminous binders for road construction in the Republic of Sakha (Yakutia)
Authors: Lazareva Tatyana , Parfenov Aleksey
Published: April 2021

Take into the account climate and environmental conditions of this region are necessary during modern road construction technologies introduction in the Republic of Sakha (Yakutia). This region’s climate and environmental conditions in many ways are identified as extreme. First of all, it should be noted that Yakutia is the coldest region of the Russian Federation, its territory is completely located in the permafrost zone. At the constructional materials testing center of the Pacific National University, were executed experimental studies to develop technological regulations for the modified bituminous binder manufacturing intended for paving the Lena highway (Yakutsk – Never).
In this work, for the polymer-bitumen binder manufacturing, was used bitumen petroleum viscous for road building, grade BND 130/200. In the course of the research, the polymer-bitumen binders PBV 200 and PBV 300 with a brittle temperature not exceeding -35 °C and -40 °C with the thermoplastic elastomers SBS LG 502 (South Korea) and SBS R 30-00A (JSC «Voronezhsintezkauchuk») additives use the formula selecting problem were solved, as well as plasticizer – industrial oil I-40A. To optimize the composition of the binder and further improve its characteristics, it is proposed to use bitumen with increased content of maltene fractions and to include in its composition an adhesion additive of the amphoteric type DAD-1. The resulting polymer-bitumen binder is characterized by a wide performance range – an increased softening temperature and a low brittleness temperature, elasticity (ability to reversible deformations), high adhesion to various rocks. Achieving these goals will improve the asphalt concrete pavement quality and durability in difficult climatic conditions.