bluuebunny/crossref_metadata_2025 huggingface dataset:
Scaffolding in Supporting Senior High School Students’ Critical Thinking Skills in Sequences and Series Problems
Authors: Tazkia Savirra , Siswono Tatag Yuli Eko
Published: July 2023

Critical thinking skills are important for every individual, that they need to be developed in classroom learning, one of which is through learning sequences and series material. However, there are still many students who have difficulty solving problems on sequences and series material, so they need help using scaffolding. This study aims to describe students' thinking skills on sequences and series material, as well as scaffolding which helps students' critical thinking skills in solving sequence and series material questions. The subjects of this study were 2 students who failed to complete the two critical thinking skills tests given. The two students were then interviewed and given scaffolding. The interviews were conducted in a semi-structured manner, that the researcher prepared several questions which could indicate indicators of critical thinking skills, as well as scaffolding which could assist students in solving problems, but the researcher was free to improvise by asking for other information according to the conditions during the interview. The data obtained was then analyzed by reducing the data, presenting the data, and drawing conclusions. The results showed that scaffolding in the form of reviewing played a dominant role for supporting the failure of critical thinking skills on the indicators of interpretation, analysis, evaluation and explanation. Restructuring helps the failure of critical thinking skills on the indicators of interpretation. Explaining helps the failure of critical thinking skills on evaluation indicators. Developing conceptual thinking helps indicators of critical thinking skills analysis, inference, and self-regulation.
Student’s Numeracy on Solving Data and Uncertainty Problems in Term of Self-Efficacy
Authors: Nisa' Thoiffatul Khusnun , Ekawati Rooselyna , Kohar Ahmad Wachidul
Published: July 2023

Numeraticy is the ability to analyze, interpret information, and find a solution by involving one's mathematical knowledge. Numeracy is known to be influenced by self-efficacy. This study aims to describe students' numeracy in solving data and uncertainty problems in terms of high and low self-efficacy. This study is descriptive research with a qualitative approach was carried out by collecting data from research subjects purposively consisting of three students with high self-efficacy and three students with low self-efficacy. The instruments used included a self-efficacy questionnaire, three data and uncertainty questions, and an interview guide. The data is then analyzed using the numeracy’s sub-indicators. The results showed that in general the numeracy of the group of students with high self-efficacy in solving questions containing data problems and uncertainties was better than the group of students with low self-efficacy. Based on these significant differences, it is recommended for teachers to create a learning climate that can support increased student self-efficacy and numeracy. As well as from the results of the interviews which only focused on parts that were not clear from the student's answers, future researchers should conduct interviews on all of the student’s numeracy in order to obtain more complete research data.
Numerasi Siswa SMP dalam Memecahkan Soal Setara AKM Konten Geometri dan Pengukuran Ditinjau dari Kecerdasan Majemuk
Authors: Rosidah Novi Eka Nor , Ekawati Rooselyna
Published: July 2023

This study aims to describe the numeracy of junior high school students in solving AKM  geometry and measurement content questions in terms of multiple intelligences. The research method used is descriptive research method with a qualitative approach. The research subjects were three students selected by purposive sampling, each of whom had linguistic, logical-mathematical, and spatial intelligence. The research instruments are multiple intelligence identification tests, mathematical ability tests, AKM tests of geometry and measurement content, and interview guidelines. The results of the study show that subjects with linguistic intelligence through several processes  namely (1) identifying and representing information in mathematical form using language representations and symbol representations, but the choice of words used is inappropriate; (2) design and implement strategies to obtain solving results in line with AKM problems, geometry and measurement content; and (3) interpret the results of the solution by making conclusions according to the context of the problem in the AKM problem geometry and measurement content. Subjects with logical-mathematical intelligence through several processes, namely (1) identifying information and representing it in mathematical form i.e. using language representations and symbol representations; (2) design and implement strategies to obtain the results of solving geometry and measurement AKM problems using mathematical concepts; and (3) interpret the results of the solution obtained by making conclusions according to the context of the problem on the AKM geometry and measurement. Subjects with spatial intelligence through several processes,  namely (1) identifying information and representing it in mathematical form using representations of language, symbols, and images; (2) design and implement strategies to obtain solving results from geometry and measurement AKM problems using mathematical concepts; and (3) interpret the results of the solution obtained by making conclusions in accordance with the context of the problem in the in line with AKM problem, geometry content and measurement.
Penerapan Goal-Free Problems dalam Pembelajaran Matematika secara Kolaboratif untuk Melatih Kemampuan Siswa dalam Memecahkan Masalah
Authors: Setiawan Dimas Bagus , Susanah Susanah
Published: July 2023

This study aims to (1) describe the application of teachers in carrying out mathematics learning with collaborative learning using the Goal-Free Problems strategy. (2) describe student activities while participating in collaborative learning with a goal-free problems strategy. (3) describe students' ability to solve problems after implementing collaborative learning with a goal-free problems strategy. (4) describes students' extraneous cognitive load when applying collaborative learning models with goal-free problems strategies. This research is a descriptive study with a quantitative approach that was carried out in class VIII F of SMP Muhammadiyah 2 Taman. The research instruments used included teacher activity observation sheets, student activity observation sheets, student problem-solving ability test questions, and student response questionnaires. The results showed that the observation of the application of learning by the teacher obtained an average score of 3.81 with very good criteria; student activity obtained a total score of 89.88%, which is classified as active during learning; students' ability to solve problems is classified as good because they get a classical mastery percentage of 79.31%; and 8 out of 10 student response statements got good and very good responses.
Pengembangan Media Pembelajaran Interaktif pada Materi Sistem Persamaan Linear Dua Variabel
Authors: Putra Chandra Kusuma Hadi , Wintarti Atik , Prihartiwi Nina Rinda
Published: July 2023

This study aims to develop interactive learning media based on PowerPoint VBA on a system of two-variable linear equations and determine the results of the development of learning media in terms of validity, practicality, and effectiveness. This research uses the ADDIE development model. The instruments used included media validation sheets for media experts, media validation sheets for material experts, pretest-posttest sheets, student and teacher observation sheets, and user response questionnaire sheets. Based on the results of the research that has been done, an average validity value of 3.08 (media expert) and 3.29 (material expert) is obtained so that it can be categorized that PowerPoint VBA-based interactive learning media is valid. This learning media trial was conducted on a limited basis to 25 class VII students of SMP Negeri 1 Dlanggu to obtain data from practicality (student observation sheets, teacher observation sheets, and user response questionnaires) and media effectiveness (pretest and posttest). The results of the study after being tested and evaluated, that this learning media is said to be practical because based on the percentage of user response questionnaires obtained 75.75% or it can be used without revision and based on student and teacher observation sheets each obtained a very good category with a percentage of 93.68 % and 78.57%. Based on the pretest and posttest with an N-Gain value of 0.37, it can be said that this PowerPoint VBA-based interactive learning media is effective in the moderate category.
Análise Superficial da Cabeceira de Drenagem na Vila Maria no Município de Garanhuns – Pernambuco
Authors: Arruda Italo Rodrigo Paulino de , Santos Larissa Furtado Lins dos , Silva Viviane Trajano da , Assis Keila Suzana Glicério de , Silva Osvaldo Girão da
Published: July 2023

O presente artigo tem por objetivo realizar uma análise sistêmica da paisagem a partir do uso de geotecnologias, associadas ao trabalho de campo e às pesquisas bibliográficas, a fim de compreender a geodinâmica de uma área de cabeceira de drenagem localizada na Vila Maria, inserida no município de Garanhuns, no Estado de Pernambuco. Esta avaliação se baseia na identificação dos principais processos que implicam modificações do uso da terra por ações antrópicas e os resultados destas ações, associados à dinâmica geomorfológica. Destaca-se também nesta análise as relações de conectividades, expressas entre encosta e a região das cabeceiras, bem como a ligação longitudinal entre jusante e montante do curso do rio Mundaú. A metodologia empregada foi pautada na realização de extensa revisão bibliográfica, trabalho de campo e processamento de imagens através do Google Earth Pro, o que permitiu a obtenção de resultados preliminares satisfatórios, tornando possível a concretização dos objetivos do trabalho.Superficial Analysis of the Drainage Head at Vila das Lavadeiras in the Municipality of Garanhuns – Pernambuco A B S T R A C TThis article aims to perform a systemic analysis of the landscape from the use of geotechnologies, associated with fieldwork and bibliographic research, in order to understand the geodynamics of a drainage head area located in Vila Maria, inserted in the municipality Garanhuns, in the State of Pernambuco. This evaluation is based on the identification of the main processes that imply changes in land use by human actions and the results of these actions, associated with geomorphological dynamics. Also highlighted in this analysis are the connectivity relationships, expressed between the slope and the headwaters region, as well as the longitudinal connection between downstream and upstream of the course of the Mundaú River. The methodology employed was based on an extensive bibliographic review, fieldwork and image processing through Google Earth Pro, which allowed satisfactory preliminary results to be obtained, making it possible to achieve the objectives of the work.Keywords: River Geomorphology; Systemic analysis; Vila Maria; Pernambuco.
XXI. mendeko etnomusikologiaren inguruan: folklorismoaren auzia, arloaren ikasketak eta eztabaida
Authors: Saenz Abarzuza Igor
Published: July 2023

Etnomusikologiaren bilakaera antropologia eta musikologiari lotuta egon da eta horrela jarraitzen du gaur egun. Arloak, pixkanaka, ibilbide propio eta sendo batekin, bere bidea aurkitu du, ikerketa-eremuak handituz eta kide dituen aipatutako alorretan eraginez. Etnomusikologoaren profilak folkloristaren ezaugarri batzuk mantentzen ditu, baino biziki aldatu da: egun, arloa guztiz zientifikoa da. Bestetik, folklore eta folklorismo terminoen arteko ertzen inguruko problematika dago. Artikulu honetan, aipatutakoaren ildotik, arloaren auzia eta dituen eztabaidak aurkezten dira. Horrez gain, etnomusikologia ikasteko dagoen aukera sakabanatua azaltzen da, Euskal Herriko egoerari hanpadura berezi bat eskainiz.
PREPARATION OF A COMBINATION OF NANO- MEDICINAL PLANTS AS ANTIOXIDANTS AND MICROORGANISMS
Authors:   1 Assistant Professor PhD. Market Research and consumer protection center, University. of Baghdad, Baghdad, Iraq, cioffi16@yahoo.com, Al-Hamdani Hamdia, M. S. , Ahamed Sundus H. ,   2 Assistant Professor PhD. Biological Department, Al-Mustansiriya University, Baghdad, Iraq. sundusahmed@yahoo.com
Published: July 2023

The controversy is currently revolving around industrial additives, including antioxidants, their negative effects on consumer health and the emergence of various and various diseases, which led scientists and researchers to intensify most studies on natural antioxidants and their synthesis from medicinal plants mentioned in ancient medicine and in divine books as potential antioxidants of increasing importance. Therefore, this study was designed to synthesize silver nitrate particles from plant leaf extracts (Figs, Olives, and Moringa) and study their effect on bacterial inhibition of each of the undesirable Coliform bacteria (E-Coli,- gram) and the streptococcus bacteria of (Staphylococcus aureus + Gram) and antioxidants after analysis of phytochemicals and essential compounds of these plants. The results showed that it contained a high percentage of phenols and total flavonoids, followed by coumarin, then it contained good amounts of alkaloids, tannins, saponins, resins, terpenes and steroids. The study also showed a high and significant inhibition of the plant mixture nano extract on coliform bacteria, as well as streptococcus bacteria, in addition to its effectiveness as an antioxidant compared to the synthetic antioxidant Butylated Hydroxy Toluene (BHT) and the extract of the natural combination. The results of this study proved that the leaves of the plants blend (Fig, Olive and Moringa) are an excellent natural source of anti-bacterial and antioxidant effects that interfere with their effects on public health. Therefore, this botanical mixture, as mentioned in the Great Book of God (Figs, Olives, and Sennin phase) has great benefits and a promising future in several areas, including nutritional supplements and food additives for various food products instead of industrial oxidation additives and their known side effects, in addition to that this mixture has a promising future. Also in the manufacture of fast-curing Nano medicines in direct contact with pathogens. .
TRANSITION FROM TRADITIONAL TO RESEARCH UNIVERSITIES, INVESTING IN TRAINING AND DEVELOPING STUDENTS AND SUPPORTING THE NATIONAL ECONOMY
Authors:   Assistant Professor., Market Research and Consumer Protection Center, University of Baghdad, Baghdad, Iraq. alsaffar2005@mracpc.uobaghdad.edu.iq, ALsaffar Nibras Mohammed A.
Published: July 2023

The research was conducted at the University of Baghdad/ Jadiriyah Complex from February to August 2021 and data was collected from 6 consulting offices as well as 5 research centers. Baghdad University/Jadiriyah Complex is a combination of traditional university and research university through their available advisory offices and research centers whose primary duty is to research and study according to a pre-prepared annual plan, both of which provide services and advice to the public and private sectors. as well as laboratories and clinics serving students, researchers and citizens at nominal wages, Research and studies carried out by researchers for the purpose of obtaining scientific promotion, changing scientific titles, etc., as well as supervising graduate research, some of which are solutions to problems in the public and private sectors. Through research sources, there has been a clear lack of cooperation between State ministries, their departments and the private sector with advisory offices and scientific research centers within the University/ Jadiriyah Complex, although they are accredited by the Ministry of Higher Education and Scientific Research and related bodies. There was also a weakness in terms of information for the purpose of informing citizens of the services provided by the above offices and centers, as well as in terms of the remuneration of examinations and consultations, where there was a difference between them and the offices of the private sector, which were similar to the government advisory offices, as well as the specialization of a consulting office. (Advisory Office of the Centre for Urban and Regional Higher Education Planning) in urban planning, which is not similar in operation at the University of Baghdad but in Iraq, as well as one of the research centers The Market Research and Consumer Protection Center is the only center at the University and in Iraq specializing in market research and studies and consumer protection.
STUDY OF THE SYNERGISTIC EFFECT OF PROTEINS PRODUCED FROM Saccharomyces cerevisiae WITH LACTOFERRIN AGAINST MULTI RESISTANT DIARRHEAL BACTERIA
Authors:   Professor PhD., Department of Science, College of Basic Education, University of Al-Mustansiriah, Baghdad, Iraq. ragaad.edbs@uomustansiriyah.edu.iq, Aziz Raghad A.
Published: July 2023

The research included the isolation of 12 bacterial isolates from stool samples of children with acute watery and bloody diarrhea under the age of five years, as it was possible to obtain 6 isolates of Escherichia coli, 3 isolates of Salmonella typhimurium, and 3 isolates of Shigella flexneri. Vitek2 system, and the inhibitory activity of lactoferrin and killer toxin produced from S. cerevisiae against pathogenic bacteria was studied by the well diffusion method, as the results recorded that the killer toxin had the highest inhibitory activity towards pathological bacteria with varying results, and the lowest inhibitory concentration was determined The MIC of the lactoferrin and the killer toxin against the bacterial isolates under study using the turbidity method in the tubes. for antibiotics, as the results showed a The relationship was synergistic due to the activity of lactoferrin with killer toxin in inhibiting the action of pathogenic bacteria, whose inhibitory activity increases with increasing concentration used.
STUDY OF OXIDATIVE ENZYMES IN MANY GENOTYPES OF (Zea mays L.)
Authors:   1 University of Baghdad, College of Agricultural Engineering Sciences, field of crop science, Baghdad, Iraq. Sallyabdali@yahoo.com, Wahed Sally Ali Abdul , Al-Azawi Nagham Majeed ,   2 Assistant professor, University of Baghdad, College of Agricultural Engineering Sciences, field of crop science, Baghdad, Iraq.  naghamalazawi@yahoo.com
Published: July 2023

The aim of this study was to evaluate the activity of some oxidative enzymes in three genotypes of maize namely (Baghdad, 5018, Sara) under three sowing dates: (26July, 4August and 12August) and denote (D1, D2 and D3). A field experiment was conducted at field of College of Agricultural Engineering Sciences, University of Baghdad/Al- Jadriya for the fall season 2021- 2022, factorial experiment was conducted using randomized blocks (RCBD) with three replicates. Significant differences were found among genotypes for the number of grains in the row, and the number of kernels in the ear. The results showed that superiority of the genotype (Baghdad) in the characteristic of Tasseling and Silking flowering 50%, plant yield with averages of 58.89d, 62.89d and 164.6g, respectively. While the genotype (Sara) was superior to the weight of 100 kernels, with an average weight of 27.34g. Genotype (5018) gave the highest value for Catalase (CAT) and Peroxidase (POD) enzyme, which was 2.16 u/mg and 0.51 u/mg, respectively, while genotype (Sara) gave the highest value for Superoxide dismutases (SODs), which was 50.15u/mg The (D1) showed an increase in most of the traits averages, especially (50% tasseling which gave 65.00d),(50% Silking which gave 68.00d),(weight of 100 grains which reached 26.91g) and (POD enzyme 0.56 u/mg). The (D3) gave the highest value for plant yield which was 162.1g, CAT enzyme 2.54u/mg and SOD enzyme 57.34u/mg.
ASSOCIATION OF CYP17 GENE POLYMORPHISME IN PRODUCTIVE AND REPRODUCTIVE PERFORMANCE IN GOAT
Authors:   1Department of Animal Production, College of Agricultural Engineering Sciences, University of Baghdad, Iraq,‏ walaa.mohammed1201a@coagri.uobaghdad.edu.iq ‏, Abdullah Wala'a Mohammed , Abraheem Wafa'a Ismail ,   2Animal production Department, College of Agricultural Engineering Science, University of Baghdad, wafaa.i@coagri.uobaghdad.edu.iq, Abdullah Ali Najm ,   3 Animal Production Department, Office of Agricultural Researches, Ministry of Agricultural,  naali127@yahoo.com
Published: July 2023

This study was conducted in the Ruminants Research Station, Office of Agricultural Research/ Ministry of Agriculture- Iraq to detect CYP17 gene polymorphisms in Local and Shami goat, as well as to establish if SNPs could be associated with some productive and reproductive traits such as total milk yield (TMY) and its components, in addition to reproductive traits which included litter size and fertility. An important single nucleotide polymorphisms (SNPs) (G2276C) were found in the studying fragment (804 bp), which include Exon2, intron2, and partial of Exon3 by using DNA sequencing technique, two genotypes were produced wild GG and GC in both breeds. Results proposed a highly differences among distribution of genotypes percentage and allele frequencies in both breeds, Results stated a significant relationship between polymorphisms of this SNPs and milk fat percentage and litter size, where hetero genotype GC exceeded GG genotype in milk fat percentage and litter size in Local goat, whereas wild genotype GG distinguished in milk fat percentage in Shami goat.
EFFICACY OF PSEUDOMONAS FLUORESCENS AND IRON CHELATED FE-EDDHA AGAINST FUSARIUM OXYSPORUM F. SP. THE CAUSAL AGENT OF ROOT ROT AND WILT DISEASE ON PEPPER
Authors:   1Researcher, Environmental Research Center, University of Technology, Baghdad-Iraq. ali.nasser1204a@coagri.uobaghdad.edu.iq, AL-Aamel Ali Nasser Ali , AL-Maliky Bushra  Subair Abdulsada ,   2Assistant Professor, Department Plant Protection, College of Agricultural Engineering Sciences, University of Baghdad, Iraq.
Published: July 2023

An experiment was conducted to evaluate the biological control activity of Pseudomonas fluorescens PO2 and chelated iron Fe-EDDHA (Fe) at a concentration of 0.5% and the interaction between them for inhibiting Fusarium oxysporum Fo6 on pepper. In vitro, PO2 significantly inhibited the growth of Fo6 with an inhibition rate of 83.33% compared with control, and chelated iron caused a significant decrease for Fo6 with an inhibition rate 66.67% compared with control, while was not affecting the growth of PO2. The results of the pot experiment showed that the treatment (Fo6+PO2+Fe) showed a highest significant difference in reducing the disease incidence and disease severity which amounted to 6.67% compared with control (Pathogen only) (100, 85)% respectively. Also, the treatment (PO2+Fe without the pathogen) was increased the total fresh root and vegetative weight (46.17, 136.8) g respectively and was increase in the dry root and vegetative weight as reached (4.87, 10.07) g respectively compared with control (not inoculated plants) which amounted (12.1, 75.67, 1.83, 5.33) g respectively. In greenhouse experiment the results showed the excellence of the treatment (Fo6+PO2+Fe) in reducing the incidence of infection, which amounted to 10% and the severity of injury amounted to 5.83% compared with the control which recorder to (100, 74)% respectively, as well showed a significant increase in the iron percentage due to response of plant for adding chelated iron into roots with significant differences between treatments. Depending on the results, the use of P. fluorescens with chelated iron can be recommended to control pepper wilt disease caused by F. oxysporum.
INDUCING SYSTEMIC ACQUIRED RESISTANCE IN PEPPER PLANTS AGAINST RHIZOCTONIA SOLANI
Authors:   1 Agriculture Research Directorate, Department of  Plant Protection, Baghdad , Iraq. alaaraadmousa@gmail.com, Mousa Alaa Raad , Hassan Aalaa Khudair ,   2College of Agricultural Engineering Sciences, Department of  Plant Protection, Baghdad, Iraq. aalaammh@gmail.com
Published: July 2023

This study was initiated to assess the efficacy of some biological materials separately or mixed to control Rhizoctonia root rot disease caused by the fungus Rhizoctonia solani. In vitro efficacy assessment showed; glutathione could inhabit fungal growth up to 100% at concentration 3000 mg/L. Whereas, the bacterium Azospirillum brasilense scored 78.63% inhibitory at 10-5 concentration. The fungal bio-agent Trichoderma viride scored 1.33 highest antagonistic activity 5 days of inoculation on PDA medium. Under greenhouse conditions, (Tr + Az + G+ R. solani) and (Tr + G+ R. solani) combination treatments could decrease R.solani infectivity and disease severity up to 0.00% compared to 73.33 and 68.33% for control treatment, respectively. Similarly, these two treatments could induce systemic acquired resistance (SAR) when scored the highest polyphenol oxidase (PPO) activity 6 and 12d of pathogenic fungus inoculation compared to healthy control. They scored 82.14 and 67.07, 78.12 and 65.33 absorbance increase rate (AIR)/min/g fresh leaf weight, respectively, compared to 41.67, 40.08 for AIR/min/g fresh leaf weight, respectively, for healthy control. Amongst other treatments, (Az + R.solani) scored 11.553% highest protein content compared to 9.433% for healthy control.
Exploring the Relationship between Tertiary Education and Child Maltreatment: An ARDL Analysis
Authors: Shaari Mohd Shahidan , Mohd Nasir Noormahayu , Harun Nor Hidayah , Muhsain Siti Nur Fathini , Ridzuan Abdul Rahim
Published: July 2023

This study aims to investigate the correlation between child abuse and tertiary education as a potential determining factor, in addition to established variables such as unemployment, inflation, and economic growth. The data spanning from 1989 to 2020 is analyzed using the Autoregressive Distributed Lag (ARDL) technique. Our findings reveal that inflation can have both short-term and long-term effects on child abuse, while unemployment primarily has a long-term impact on child abuse. However, an interesting discovery emerges as tertiary education demonstrates a protective effect, effectively reducing child abuse in the long run. These findings emphasize the significance of formulating strategies to mitigate the child abuse rate. Policymakers should consider allocating increased resources to enhance tertiary education, recognizing its potential role in preventing child abuse. By focusing on education and addressing the other identified determinants, the government can develop a comprehensive approach to safeguarding children and promoting their well-being. The novelty of this study lies in highlighting the importance of tertiary education and its potential for reducing child abuse, providing valuable insights for policymakers, researchers, and advocates in their efforts to protect vulnerable children. Doi: 10.28991/HEF-2022-03-04-05 Full Text: PDF
Robust stabilizability and stabilization of three-time-scale linear time-invariant singularly perturbed systems with delay
Authors: Naligama Ch. A. , Tsekhan O. B.
Published: July 2023

The objective of this study is to obtain the stabilizability conditions and a stabilizing composite state feedback control for the exponential stabilization of three-time-scale singularly perturbed linear time-invariant systems with multiple commensurate delays in the slow state variables and with two small parameters of perturbation (TSPLTISD). The stabilizability conditions and the stabilizing feedback do not depend on the small parameters and are valid for all of their sufficiently small values. The approach used in this work is the nondegenerate decoupling transformation that splits the TSPLTISD into three regularly dependent on the small parameters subsystems, which are lower in dimensions than the TSPLTISD. Further, the decoupled subsystems are approximated by three subsystems that do not depend on the small parameters. It is proven that the stabilizability of the approximating subsystems guarantees the robust (with respect to small parameters) stabilizability of the original TSPLTISD. Finally, we obtain a representation of a parameter free composite feedback control for the TSPLTISD, stabilizing it for all sufficiently small values of the parameters. A numerical example is given.
The maximum weight ({K1,K2},k,l)-packing problem in a graph
Authors: Lepin V. V.
Published: July 2023

In this paper, we consider the maximum weight ({K1,K2},k,l)-packing problem in a graph. This problem generalizes a number of well-known problems, for example: maximum induced matching, k-separated matching, connected matching, independent set, dissociating set, k-packing. We show that in the class of cographs, a maximum weight ({K1,K2},k,l)- packing can be computed in O(n + m) time. Let Γ be a class of graphs and Γ* be a class of all simple (with respect to the modular decomposition) induced subgraphs from Γ. It is proven that if the maximum weight ({K1,K2},k,l)-packing problem can be solved in the class of graphs Г* in time O(np ), where p ≥ 2 is a constant, then this problem can be solved in the class of graphs Г in time O(np ).
Upper bounding the number of bent functions using 2-row bent rectangles
Authors: Agievich S. V.
Published: July 2023

Using the representation of bent functions (maximum nonlinear functions) by bent rectangles, that is, special matrices with restrictions on columns and rows, we obtain herein an upper bound on the number of bent functions that improves the previously known bounds in a practical range of dimensions. The core of our method is the following fact based on the recent observation by V. Potapov (arXiv:2107.14583): a 2-row bent rectangle is completely determined by one of its rows and the remaining values in slightly more than half of the columns.
Prediction of solar flares using neutrino detectors of the second generation
Authors: Boyarkin O. M. , Boyarkina I. O.
Published: July 2023

In this paper, we propose a physics-based method of prediction high-energy solar flares (SFs) with the help of neutrino detectors utilizing coherent elastic neutrino-nucleus scattering (CEνNS). The behavior of neutrino beams passing through coupled sunspots (CSs) being the sources of future SFs is investigated. We consider the evolution of left-handed electron neutrino νeL and muon neutrino νμL beams formed in the convective zone after the passage of the Micheev – Smirnov – Wolfenstein resonance. It is assumed that the neutrinos possess the charge radius, the magnetic and anapole moments while the CS magnetic field is vortex, nonhomogeneous and has twisting. Estimations of the weakening of the neutrino beams after traversing the resonant layers are given. It is shown that for SFs this weakening could be registered by neutrino detectors of the second generation only when neutrinos have the Dirac nature.
Reciprocity relations for interference coatings
Authors: Sotsky A. B. , Chudakov E. A.
Published: July 2023

By analyzing the wave equations, the coincidence of the energy reflection and transmission coefficients for the s- and p-polarization waves is herein substantiated when they are incident on the interference coating from opposite directions. The coating can be characterized by an arbitrary spatial profile of the refractive index, the limiting condition is the absence of optical losses in it. Reciprocity relations are obtained for the energy reflection and transmission coefficients of natural light for a structure in the form of a plane-parallel dielectric plate with interference coatings on its opposite sides. It is shown that when a structure with an absorbing plate is illuminated in opposite directions, the energy reflection coefficients can differ, while the energy transmission coefficients always coincide. Reciprocity relations are applied to the calculation of broadband antireflective interference coatings consisting of alternate layers Nb2O5 and SiO2 deposited on a polycarbonate plate. As a result, their correctness is confirmed and it is shown that the optimized antireflection two-sided interference coating provides approximately a five times lower averaged energy reflection coefficient compared to the optimized one-sided coating.
The statement and the mathematical model of the problem of planning the inspection and repair of cargo containers
Authors: Lukashevich M. N. , Kovalyov M. Y.
Published: July 2023

In this paper, using mathematical programming methods we investigate the problem of optimally planning the inspection and repair of cargo containers at several port facilities over time. Its relevance is conditioned by the necessity of optimization of the processes of planning logistics operations. We represent a formulation of this problem and its reduction to a mixed integer linear programming (MILP). Containers have several types and levels of quality, which determine the cost of their repair. The objective function includes total costs of storage, inspection, repair, transportation of containers and penalties for both container rejection and unsatisfied consumer demand. Using the proposed model, it is possible to achieve reasonable computing time for port operations and minimize underutilization or overutilization of port capacity, preventing financial losses and increasing efficiency. Also, this model can be easily converted to solve optimization problems in other areas of logistics.
On the approximation of the | sin |s x function by rational trigonometric operators of the Fejér type
Authors: Kazlouskaya N. Yu. , Rovba Ya. A.
Published: July 2023

Approximation by trigonometric Fourier series is a well-developed branch of the theory of approximation by polynomials. Methods of approximation by rational trigonometric Fourier series have not been researched so deeply yet. In particular, rational trigonometric operators of the Fejér type have not been used in the rational approximation with free poles. In this paper, we consider the approximation of the function | sin | , (0;2), ∈ s x s by rational trigonometric operators of the Fejér type. An integral representation of the remainder for the above-mentioned approximation is obtained. An estimate of approximations is found in the points of analyticity of the function | sin |s x under the condition that the corresponding system of rational functions is complete. It is shown that the order of uniform approximation in the case of approximation by rational Fejér functions with two geometrically different poles is higher than the order of approximation by trigonometric polynomials. As a result, an asymptotic estimation of the uniform approximation by trigonometric Fejér sums in the polynomial case is obtained.
Classical solution of the Cauchy problem for a quasi-linear wave equation with discontinuous initial conditions
Authors: Korzyuk V. I. , Rudzko J. V.
Published: July 2023

We consider the Cauchy problem for a one-dimensional weakly quasi-linear wave equation given in the upper half-plane. The initial conditions have a first-kind discontinuity at one point. We construct the solution using the method of characteristics in implicit analytical form as a solution of some integro-differential equations. The solvability of these equations, as well the smoothness of their solutions, is studied. For the problem in question, we prove the uniqueness of the solution and establish the conditions, under which its classical solution exists.
Motion stability of the system of two bodies and their mass center in an inhomogeneous medium
Authors: Ryabushko A. P. , Zhur T. A.
Published: July 2023

Within the framework of Newtonian celestial mechanics, a material system is considered. It consists of two spherically symmetrical bodies of comparable masses moving inside a gas dust ball with a spherically symmetrical density distribution of the medium in it. Problems are formulated and solved. They give an answer to the degree of influence of the gravitational field of an inhomogeneous medium on the motion stability of bodies and their mass center relative to the coordinates of the bodies, the coordinates of their mass center, as well as on the orbital stability according to Lyapunov. Additionally, the problems of the motion stability of bodies in the sense of Lagrange and Poisson are considered. It is proved that the gravitational field of a spherically symmetrically distributed medium transforms the considered motions, which are stable in vacuum, into unstable ones in the sense of Lagrange, Poisson, Lyapunov. Some numerical estimates related to instabilities are presented. They show that for popular pairs of stars and pairs of galaxies in an inhomogeneous medium, their additional displacements of the order of many millions of kilometers arise. When dark matter is taken into account, the displacements should not be an order of magnitude greater than the last estimate. The noted instabilities are a consequence of a secular displacement along the cycloid or deformed cycloid of the mass center of the system of two bodies and the absence of a barycentric coordinate system when taking into account the influence of the gravitational field of a spherically symmetrically distributed medium on the motion of bodies (the considered material system is not closed). It is proved that for this system, circular and elliptical orbits of bodies cannot exist. Instead of these orbits, we have “turns” shown in the figure given in the article. In planetary systems (such as the Solar System) immersed into an inhomogeneous medium, the displacements of the mass centers are negligible and therefore we can assume that circular and elliptical orbits can practically exist.
De novo design of potential SARS-CoV-2 main protease inhibitors using artificial intelligence and molecular modeling technologies
Authors: Andrianov A. M. , Furs K. V. , Shuldau M. A. , Tuzikov A. V.
Published: July 2023

De novo design of 95 775 potential ligands of SARS-CoV-2 main protease (Mpro), playing an important role in the process of virus replication, was carried out using a deep learning generative neural network that was developed previously based on artificial intelligence technologies. Molecular docking and molecular dynamics methods were used to evaluate the binding affinity of these molecules to the catalytic site of the enzyme. As a result, 7 leading compounds exhibiting Gibbs free energy low values comparable with the values obtained using an identical computational protocol for two potent non-covalent SARS-CoV-2 Mpro inhibitors used in calculations as a positive control were selected. The results obtained indicate the promise of applying identified compounds for development of new antiviral drugs able to inhibit the catalytic activity of SARSCoV-2 Mpro.
Anti-tuberculosis activity of Rivaroxabane in silico and in vitro
Authors: Lakhvich T. T. , Ryneiskaya V. M. , Golyak N. S. , Yurkshtovich N. K. , Nasennikava K. E. , Lakhvich F. A.
Published: July 2023

The activity of Rivaroxoban of oxazolidinone series against Mycobacterium terrae was investigated in silico and in vitro. In silico studies have shown a high binding affinity of Rivaroxaban to β-ketoacyl[ACP]synthase I that plays a key role in the biosynthesis of mycolic acids, being the components of the mycobacterial cell wall. In the molecular docking study, two main binding sites of Rivaroxaban with protein were predicted and evaluated: the minimum binding energies were found for the both sites with the values of –10.26 kcal/mol and –8.99 kcal/mol. A solution of Rivaroxaban (200 μg/ml) has been shown to inhibit the growth of a Mycobacterium terrae culture. The data obtained open up the prospect of developing new effective anti-tuberculosis drugs of oxazolidinone series.
KASP genotyping of loci associated with the “1000-grain weight” trait in common wheat (Tríticum aestívum L.)
Authors: Lemesh V. A. , Gryb S. I. , Lagunovskaya A. V. , Kipen V. N. , Buloichik A. A. , Bushtevich V. N. , Sakovich V. I.
Published: July 2023

Using the KASP technology, the allelic composition of TaTGW6-A1, TaGASR7-A1, TaCKX6-D1, and TaGs3-D1 loci associated with the 1000-grain weight trait was identified in 25 varieties and variety accessions of the common wheat of Belarusian and foreign breeding. Annotated DNA sequences were selected for modeling and synthesis of KASP primers. It was demonstrated that the examined genotypes had carried both favorable alleles associated with 1000-grain weight, and the alleles producing a negative effect on the trait under study. Six wheat accessions of Belarusian breeding were identified. They carried a complex of alleles positively correlating with the 1000-grain weight trait: variety Vestochka-17, accessions E-2318, E-2263, E-2298, E-1569, and E-2695.
Characteristic of the Mycobacterium tuberculosis genome of Beijing genotype of cluster 100-32 displaying pre-extended drug resistance
Authors: Slizen V. V. , Akhremchuk A. E. , Surkova L. K. , Gurevich G. L. , Titov L. P.
Published: July 2023

A whole genome sequencing was performed of strain M. tuberculosis 11502 (NCBI biosamples database, access code SAMN17832565) that was assigned to the Beijing genotype subtype B0/W148 of cluster 100-32, based on the MIRU- VNTR loci (n = 24) structure, a nd t hat exhibited pre-extended d rug resistance. M. tuberculosis 11502 was resistant to isoniazid, rifampicin, ethambutol, levofloxacin, and ethionamide, which correlated with the presence of mutations in the genes: resistance to isoniazid – the mutations in the fabG1 promoter (p.-8T>C), the katG promoter (p.S315T), to ethionamide – the mutations in ethA (deletion of T at position 4 335 027 (gatgc-gagc)); to fluoroquinolones – in the gyrA gene (p.D94G); to ethambutol – in the embB gene (p.M306I); to streptomycin – in the rpsL gene (p.K43R). M. tuberculosis 11502 genome (Gen- Bank NCBI access code – CP070338) contained 4 420 561 base pairs, 4 104 genes, 4 053 CDSs (coding proteins – 3 874) and differed from reference strain M. tuberculosis H37Rv by the presence of 2 055 mutations. A slight drift of mutations towards the G+C accumulation was revealed, which indicates the importance of maintaining a high G+C content in the Mycobacterium spp.genome Strain M. tuberculosis 11502 has a higher number of mutations in comparison to previously sequenced M. tuberculosis 4860 (GenBank Access Code, NCBI: CP053092) belonging to the LAM genotype (2055 vs. 1577 mutations), which may be a consequence of a longer circulation of M. tuberculosis 11502, or some biological features providing the promutagenic effect.
Primary nature, composition, and evolution of the early precambrian protocore in ancient platforms and endogenous processes of its transformation
Authors: Dominikovskaya D. A.
Published: July 2023

The issues of formation of the earth’s crust in the Early Precambrian are considered: the primary composition of a protomatter, the time of its occurrence and evolution, the participation of endogenous and cosmic forces in its transformation in two main periods of formation of the protocrust – pregeological (4.65–4.0 billion years) and geological (4.0–1.65 billion years) consisting of three stages. The rock associations, their mineral and chemical composition, and successive transformation at each stage, as well as the petrological results for rocks during the formation of the earth’s crust are described. The formation of a variety of rock formations from a single igneous protomatter, which manifested itself on the entire planet Earth, is substantiated. The indicator value of potassium-sodium ratios in rock associations is shown to determine the formation of their belonging, the magnitudes of growth of these ratios in the process of evolution are revealed, and their use is proposed to assess a relative age of rock formations.
Boron-enriched pyrolitic carbon: material for biomedical and engineering applications
Authors: Demidenko M. I. , Adamchuk D. V. , Rusanov A. P. , Sirotkin S. V. , Ivanko L. V. , Maksimenko S. A.
Published: July 2023

The article describes a technological set-up and the synthesis methodology of boron-enriched pyrolytic carbon (B-PyC). The chemical vapor deposition (CVD) approach lies in the basis of the methodology. The synthesis occurs on the inner surface of a cylindrical graphite assembly indirectly heated to the temperatures of 1450–1570 °C. Controlled low-density flows of nitrogen, boron trichloride and carbonaceous gases react in the assembly, producing a B-PyC film deposited on the graphite substrate. The set-up has been designed to provide fabrication of B-PyC plates possessing features required for heart valve endoprosthesis: chemical inertia and biocompatibility combined with high hardness, high elasticity, and long operating life. The morphology and chemical composition of the material have been studied by electron scanning microscopy and Raman spectroscopy. The material is used at the “Electronmash Plant” for fabrication of heart valve endoprosthesis leaflets.
Diagnostic genesis markers of soils in Belarus
Authors: Romanova T. A. , Ivakhnenko N. N. , Chervan A. N.
Published: July 2023

A set of data for eight soil varieties are considered using the spectrum of properties included into the program of fundamental research of genetic soil science. To expand our understanding of the essence of soil formation and soil nature, the sustainable land use principles, we studied the properties of autochonous moistening of soils developed on loess-like loams as a basis of diagnosis of their genesis and diversity. It is found that soils differ from soil-like bodies. Soil genesis is identified as a function of water conditions. The role of microbiota are established as a basis of rock conversion into soil. The models for chemical differentiation of profiles and bioenergy potential of soils are analyzed. The studies performed favor increasing the utilization efficiency of soils based on their genesis together with diagnosis of water conditions as a marker and informing soil maps providing the development of precision farming systems.
Influence of laser hardening modes on the properties of 40X13 steel
Authors: Mishchiruk O. M. , Verameichyk A. I. , Devoino O. G. , Neroda M. V. , Kholodar B. G.
Published: July 2023

We have studied the dependence of the characteristics, strength and plasticity, as well as the microhardness of specimens made of corrosion-resistant steel 40X13 on the modes of laser surface hardening by a fiber laser. Depending on the size of the scanning spot and the scanning speed, 3–5 tracks were applied on opposite planes of the sample with overall dimensions of 20 × 200 mm. Samples were tested for static fracture and the microhardness of the material of the samples was studied in terms of the depth of the changed structure. It was found that the fracture of the treated samples in all cases was of a brittle nature with a low level of destructive deformations at stresses below the tensile strength of the original material. The plotted tension diagrams indicate an insignificant effect of laser processing on the value of the elastic modulus of the material. Studies of the hardness of the material of the laser-hardened track and the microhardness of the material along the depth of the zone of the changed structure showed their increase up to 3–4 times compared with the initial characteristics. The results obtained can serve as a basis for studying the relationship between the modes of heating by a laser beam and the properties of the material of the hardened zone.