bluuebunny/crossref_metadata_2025 huggingface dataset:
Relaxations of the matroid axioms I: Independence, Exchange and Circuits
Authors: Samper Jose ́ Alejandro
Published: August 2021

Motivated by a question of Duval and Reiner about higher Laplacians of simplicial complexes, we describe various relaxations of the defining axioms of matroid theory to obtain larger classes of simplicial complexes that contain pure shifted simplicial complexes. The resulting classes retain some of the matroid properties and allow us to classify matroid properties according to the relevant axioms needed to prove them. We illustrate this by discussing Tutte polynomials. Furthermore, we extend a conjecture of Stanley on h-vectors and provide evidence to show that the extension is better suited than matroids to study the conjecture.
Refined dual stable Grothendieck polynomials and generalized Bender-Knuth involutions
Authors: Galashin Pavel , Grinberg Darij , Liu Gaku
Published: August 2021

The dual stable Grothendieck polynomials are a deformation of the Schur functions, originating in the study of the K-theory of the Grassmannian. We generalize these polynomials by introducing a countable family of additional parameters such that the generalization still defines symmetric functions. We outline two self-contained proofs of this fact, one of which constructs a family of involutions on the set of reverse plane partitions generalizing the Bender-Knuth involutions on semistandard tableaux, whereas the other classifies the structure of reverse plane partitions with entries 1 and 2.
Monodromy and K-theory of Schubert curves via generalized jeu de taquin
Authors: Gillespie Maria Monks , Levinson Jake
Published: August 2021

We establish a combinatorial connection between the real geometry and the K-theory of complex Schubert curves Spλ‚q, which are one-dimensional Schubert problems defined with respect to flags osculating the rational normal curve. In a previous paper, the second author showed that the real geometry of these curves is described by the orbits of a map ω on skew tableaux, defined as the commutator of jeu de taquin rectification and promotion. In particular, the real locus of the Schubert curve is naturally a covering space of RP1, with ω as the monodromy operator.We provide a fast, local algorithm for computing ω without rectifying the skew tableau, and show that certain steps in our algorithm are in bijective correspondence with Pechenik and Yong's genomic tableaux, which enumerate the K-theoretic Littlewood-Richardson coefficient associated to the Schubert curve. Using this bijection, we give purely combinatorial proofs of several numerical results involving the K-theory and real geometry of Spλ‚q.
GL(n, q)-analogues of factorization problems in the symmetric group
Authors: Lewis Joel Brewster , Morales Alejandro H.
Published: August 2021

We consider GLn (Fq)-analogues of certain factorization problems in the symmetric group Sn: ratherthan counting factorizations of the long cycle(1,2, . . . , n) given the number of cycles of each factor, we countfactorizations of a regular elliptic element given the fixed space dimension of each factor. We show that, as in Sn, the generating function counting these factorizations has attractive coefficients after an appropriate change of basis.Our work generalizes several recent results on factorizations in GLn (Fq) and also uses a character-based approach.We end with an asymptotic application and some questions.
Maximal green sequences for arbitrary triangulations of marked surfaces (Extended Abstract)
Authors: Mills Matthew R.
Published: August 2021

In general, the existence of a maximal green sequence is not mutation invariant. In this paper we show that it is in fact mutation invariant for cluster quivers associated to most marked surfaces. We develop a procedure to find maximal green sequences for cluster quivers associated to an arbitrary triangulation of closed higher genus marked surfaces with at least two punctures. As a corollary, it follows that any triangulation of a marked surface with at least one boundary component has a maximal green sequence.
Rational Dyck Paths in the Non Relatively Prime Case
Authors: Gorsky Eugene , Mazin Mikhail , Vazirani Monica
Published: August 2021

We study the relationship between rational slope Dyck paths and invariant subsets in Z, extending the work of the first two authors in the relatively prime case. We also find a bijection between (dn, dm)–Dyck paths and d-tuples of (n, m)-Dyck paths endowed with certain gluing data. These are first steps towards understanding the relationship between the rational slope Catalan combinatorics in non relatively prime case and the geometry of affine Springer fibers and representation theory.
Categorifying the tensor product of the Kirillov-Reshetikhin crystal B1,1 and a fundamental crystal
Authors: Kvinge Henry , Vazirani Monica
Published: August 2021

We use Khovanov-Lauda-Rouquier (KLR) algebras to categorify a crystal isomorphism between a funda-mental crystal and the tensor product of a Kirillov-Reshetikhin crystal and another fundamental crystal, all in affine type. The nodes of the Kirillov-Reshetikhin crystal correspond to a family of “trivial” modules. The nodes of the fun-damental crystal correspond to simple modules of the corresponding cyclotomic KLR algebra. The crystal operators correspond to socle of restriction and behave compatibly with the rule for tensor product of crystal graphs.
Asymptotics of lattice walks via analytic combinatorics in several variables
Authors: Melczer Stephen , Wilson Mark C.
Published: August 2021

We consider the enumeration of walks on the two-dimensional non-negative integer lattice with steps defined by a finite set S ⊆ {±1, 0}2 . Up to isomorphism there are 79 unique two-dimensional models to consider, and previous work in this area has used the kernel method, along with a rigorous computer algebra approach, to show that 23 of the 79 models admit D-finite generating functions. In 2009, Bostan and Kauers used Pade ́-Hermite approximants to guess differential equations which these 23 generating functions satisfy, in the process guessing asymptotics of their coefficient sequences. In this article we provide, for the first time, a complete rigorous verification of these guesses. Our technique is to use the kernel method to express 19 of the 23 generating functions as diagonals of tri-variate rational functions and apply the methods of analytic combinatorics in several variables (the remaining 4 models have algebraic generating functions and can thus be handled by univariate techniques). This approach also shows the link between combinatorial properties of the models and features of its asymptotics such as asymptotic and polynomial growth factors. In addition, we give expressions for the number of walks returning to the x-axis, the y-axis, and the origin, proving recently conjectured asymptotics of Bostan, Chyzak, van Hoeij, Kauers, and Pech.
New hook-content formulas for strict partitions
Authors: Han Guo-Niu , Xiong Huan
Published: August 2021

We introduce the difference operator for functions defined on strict partitions and prove a polynomiality property for a summation involving the bar length (hook length) and content statistics. As an application, several new hook-content formulas for strict partitions are derived.
Quasi-isomorphisms of cluster algebras and the combinatorics of webs (extended abstract)
Authors: Fraser Chris
Published: August 2021

We provide bijections between the cluster variables (and clusters) in two families of cluster algebras which have received considerable attention. These cluster algebras are the ones associated with certain Grassmannians of k-planes, and those associated with certain spaces of decorated SLk-local systems in the disk in the work of Fock and Goncharov. When k is 3, this bijection can be described explicitly using the combinatorics of Kuperberg's basis of non-elliptic webs. Using our bijection and symmetries of these cluster algebras, we provide evidence for conjectures of Fomin and Pylyavskyy concerning cluster variables in Grassmannians of 3-planes. We also prove their conjecture that there are infinitely many indecomposable nonarborizable webs in the Grassmannian of 3-planes in 9-dimensional space.
The facial weak order in finite Coxeter groups
Authors: Dermenjian Aram , Hohlweg Christophe , Pilaud Vincent
Published: August 2021

We investigate a poset structure that extends the weak order on a finite Coxeter group W to the set of all faces of the permutahedron of W. We call this order the facial weak order. We first provide two alternative characterizations of this poset: a first one, geometric, that generalizes the notion of inversion sets of roots, and a second one, combinatorial, that uses comparisons of the minimal and maximal length representatives of the cosets. These characterizations are then used to show that the facial weak order is in fact a lattice, generalizing a well-known result of A. Bjo ̈rner for the classical weak order. Finally, we show that any lattice congruence of the classical weak order induces a lattice congruence of the facial weak order, and we give a geometric interpretation of its classes.
The twist for positroids
Authors: Muller Greg , Speyer David E.
Published: August 2021

There are two reasonable ways to put a cluster structure on a positroid variety. In one, the initial seed is a set of Plu ̈cker coordinates. In the other, the initial seed consists of certain monomials in the edge weights of a plabic graph. We will describe an automorphism of the positroid variety, the twist, which takes one to the other. For the big positroid cell, this was already done by Marsh and Scott; we generalize their results to all positroid varieties. This also provides an inversion of the boundary measurement map which is more general than Talaska's, in that it works for all reduced plabic graphs rather than just Le-diagrams. This is the analogue for positroid varieties of the twist map of Berenstein, Fomin and Zelevinsky for double Bruhat cells. Our construction involved the combinatorics of dimer configurations on bipartite planar graphs.
The Mixing Time for a Random Walk on the Symmetric Group Generated by Random Involutions
Authors: Bernstein Megan
Published: August 2021

The involution walk is a random walk on the symmetric group generated by involutions with a number of 2-cycles sampled from the binomial distribution with parameter p. This is a parallelization of the lazy transposition walk onthesymmetricgroup.Theinvolutionwalkisshowninthispapertomixfor1 ≤p≤1fixed,nsufficientlylarge 2 in between log1/p(n) steps and log2/(1+p)(n) steps. The paper introduces a new technique for finding eigenvalues of random walks on the symmetric group generated by many conjugacy classes using the character polynomial for the characters of the representations of the symmetric group. This is especially efficient at calculating the large eigenvalues. The smaller eigenvalues are handled by developing monotonicity relations that also give after sufficient time the likelihood order, the order from most likely to least likely state. The walk was introduced to study a conjecture about a random walk on the unitary group from the information theory of back holes.
Schur polynomials and matrix positivity preservers
Authors: Belton Alexander , Guillot Dominique , Khare Apoorva , Putinar Mihai
Published: August 2021

A classical result by Schoenberg (1942) identifies all real-valued functions that preserve positive semidefi- niteness (psd) when applied entrywise to matrices of arbitrary dimension. Schoenberg's work has continued to attract significant interest, including renewed recent attention due to applications in high-dimensional statistics. However, despite a great deal of effort in the area, an effective characterization of entrywise functions preserving positivity in a fixed dimension remains elusive to date. As a first step, we characterize new classes of polynomials preserving pos- itivity in fixed dimension. The proof of our main result is representation theoretic, and employs Schur polynomials. An alternate, variational approach also leads to several interesting consequences including (a) a hitherto unexplored Schubert cell-type stratification of the cone of psd matrices, (b) new connections between generalized Rayleigh quo- tients of Hadamard powers and Schur polynomials, and (c) a description of the joint kernels of Hadamard powers.
A bijective proof of Macdonald's reduced word formula
Authors: Billey Sara , Holroyd Alexander , Young Benjamin
Published: August 2021

We describe a bijective proof of Macdonald's reduced word identity using pipe dreams and Little's bumping algorithm. The proof extends to a principal specialization of the identity due to Fomin and Stanley. Our bijective tools also allow us to address a problem posed by Fomin and Kirillov from 1997, using work of Wachs, Lenart and Serrano- Stump.
Non-ambiguous trees: new results and generalization
Authors: Aval Jean-Christophe , Boussicault Adrien , Delcroix-Oger Bérénice , Hivert Florent , Laborde-Zubieta Patxi
Published: August 2021

We present a new definition of non-ambiguous trees (NATs) as labelled binary trees. We thus get a differ- ential equation whose solution can be described combinatorially. This yield a new formula for the number of NATs. We also obtain q-versions of our formula. And we generalize NATs to higher dimension.
Detection number of bipartite graphs and cubic graphs
Authors: Havet Frederic , Paramaguru Nagarajan , Sampathkumar Rathinaswamy
Published: August 2021

For a connected graph G of order |V(G)| ≥3 and a k-labelling c : E(G) →{1,2,…,k} of the edges of G, the code of a vertex v of G is the ordered k-tuple (ℓ1,ℓ2,…,ℓk), where ℓi is the number of edges incident with v that are labelled i. The k-labelling c is detectable if every two adjacent vertices of G have distinct codes. The minimum positive integer k for which G has a detectable k-labelling is the detection number det(G) of G. In this paper, we show that it is NP-complete to decide if the detection number of a cubic graph is 2. We also show that the detection number of every bipartite graph of minimum degree at least 3 is at most 2. Finally, we give some sufficient condition for a cubic graph to have detection number 3.
The number of corner polyhedra graphs
Authors: Dervieux Clement , Poulalhon Dominique , Schaeffer Gilles
Published: August 2021

Corner polyhedra were introduced by Eppstein and Mumford (2014) as the set of simply connected 3D polyhedra such that all vertices have non negative integer coordinates, edges are parallel to the coordinate axes and all vertices but one can be seen from infinity in the direction (1, 1, 1). These authors gave a remarkable characterization of the set of corner polyhedra graphs, that is graphs that can be skeleton of a corner polyhedron: as planar maps, they are the duals of some particular bipartite triangulations, which we call hereafter corner triangulations.In this paper we count corner polyhedral graphs by determining the generating function of the corner triangulations with respect to the number of vertices: we obtain an explicit rational expression for it in terms of the Catalan gen- erating function. We first show that this result can be derived using Tutte's classical compositional approach. Then, in order to explain the occurrence of the Catalan series we give a direct algebraic decomposition of corner triangu- lations: in particular we exhibit a family of almond triangulations that admit a recursive decomposition structurally equivalent to the decomposition of binary trees. Finally we sketch a direct bijection between binary trees and almond triangulations. Our combinatorial analysis yields a simpler alternative to the algorithm of Eppstein and Mumford for endowing a corner polyhedral graph with the cycle cover structure needed to realize it as a polyhedral graph.
Persisting randomness in randomly growing discrete structures: graphs and search trees
Authors: Grübel Rudolf
Published: August 2021

The successive discrete structures generated by a sequential algorithm from
random input constitute a Markov chain that may exhibit long term dependence on
its first few input values. Using examples from random graph theory and search
algorithms we show how such persistence of randomness can be detected and
quantified with techniques from discrete potential theory. We also show that
this approach can be used to obtain strong limit theorems in cases where
previously only distributional convergence was known.
The Flip Diameter of Rectangulations and Convex Subdivisions
Authors: Ackerman Eyal , Allen Michelle M. , Barequet Gill , Löffler Maarten , Mermelstein Joshua , Souvaine Diane L. , Tóth Csaba D.
Published: August 2021

We study the configuration space of rectangulations and convex subdivisions
of $n$ points in the plane. It is shown that a sequence of $O(n\log n)$
elementary flip and rotate operations can transform any rectangulation to any
other rectangulation on the same set of $n$ points. This bound is the best
possible for some point sets, while $\Theta(n)$ operations are sufficient and
necessary for others. Some of our bounds generalize to convex subdivisions of
$n$ points in the plane.
Exponential multivalued forbidden configurations
Authors: Dillon Travis , Sali Attila
Published: August 2021

The forbidden number $\mathrm{forb}(m,F)$, which denotes the maximum number
of unique columns in an $m$-rowed $(0,1)$-matrix with no submatrix that is a
row and column permutation of $F$, has been widely studied in extremal set
theory. Recently, this function was extended to $r$-matrices, whose entries lie
in $\{0,1,\dots,r-1\}$. The combinatorics of the generalized forbidden number
is less well-studied. In this paper, we provide exact bounds for many
$(0,1)$-matrices $F$, including all $2$-rowed matrices when $r > 3$. We also
prove a stability result for the $2\times 2$ identity matrix. Along the way, we
expose some interesting qualitative differences between the cases $r=2$, $r =
3$, and $r > 3$.
Equivalence checking for weak bi-Kleene algebra
Authors: Kappé Tobias , Brunet Paul , Luttik Bas , Silva Alexandra , Zanasi Fabio
Published: August 2021

Pomset automata are an operational model of weak bi-Kleene algebra, which
describes programs that can fork an execution into parallel threads, upon
completion of which execution can join to resume as a single thread. We
characterize a fragment of pomset automata that admits a decision procedure for
language equivalence. Furthermore, we prove that this fragment corresponds
precisely to series-rational expressions, i.e., rational expressions with an
additional operator for bounded parallelism. As a consequence, we obtain a new
proof that equivalence of series-rational expressions is decidable.
DIGITAL PLATFORMS FOR THE OIL MARKET IN THE RUSSIAN FEDERATION AND ABROAD
Authors:   LLC Oil Resource Group, Tereshkin S.I. , Nefedov A.Yu. ,   LLC Oil Resource Group, Babkin V.A. ,   LLC ORG-Market
Published: August 2021

Digitalization of the economic system of the Russian Federation is a natural process dictated by modern requirements for the development of the international market of goods and services. The widespread adoption of digital technologies will reduce the costs of the production process, as well as spend less time on obtaining a unit of production or on providing a service. The purpose of this study is to identify the advantages and disadvantages of digital platforms for the oil market. The research is based on the analysis of digital platforms developed by vertically integrated oil companies and other legal entities. As a result of the conducted research, it was revealed that the existing digital platforms differ in their functional purpose: some allow to optimize and control all stages of the production process; others are platforms for the implementation of various software solutions for the oil industry; others are an ecosystem designed for the purchase and sale of various product categories. The results obtained allow us to conclude that the oil market is in a favorable position for the development of a modern digital platform that takes into account the advantages and disadvantages of analogues, as well as creating its own ecosystem
SHORT-TERM CALCULATION OF ECONOMIC EFFICIENCY OF RETAIL REVERSE LOGISTICS SYSTEMS
Authors:   Ural State University of Economics, Yekaterinburg, Beysenbaev R.M.
Published: August 2021

The current market environment of retail trade enterprises indicates the need for accounting and management of reverse logistics, regardless of the size of the retailer. In 2020, only in the United States, retailers' losses from product returns amounted to about 400 billion dollars. More liberal return policies and a growing online sales market lead to more returned products and an increase in the volume of losses from returns, and it seems possible to believe that these trends will continue in the coming years, which indicates the need for retailers to have a way to assess the economical effectiveness of their systematic interaction with return flows in order to make management decisions on an objective and reliable information basis.
ENTREPRENEURSHIP AND LABOUR IN RELATION OF NEW EDITION OF THE NATIONAL GOALS
Authors:   Samara State University of Economics, Zhabin A.P. , Volkodavova E.V. ,   Samara State University of Economics
Published: August 2021

The article considers the correlation between the national goals set by the Decree of the President of the Russian Federation No. 474 of 21.07.2020 and the key initiatives in the areas defined in the developed strategy of socio-economic development of the Russian Federation. The national goal, designated as "decent, effective labour and successful entrepreneurship", is particularly highlighted. The article reveals the multi-layered content of this goal, its connection with other components of the system of national goals and with the key initiatives of the developed strategy. It analyzes the problems of practical implementation of a set of measures implemented in the regions of the Russian Federation to support the development of entrepreneurship, puts forward and justifies proposals for improving federal and regional support practices.
DYNAMICS OF HEALTHCARE DEVELOPMENT IN THE UNITED STATES OF AMERICA
Authors:   Ryazan State Agrotechnological University Named after P.A. Kostychev, Minat V.N.
Published: August 2021

The novelty of the work is seen in the combination of theoretical and comparative historical analysis with the cyclical socio-economic development of American society, in relation to the subject of this study – the evolution of US healthcare. The identification and justification of trends in the evolution of American healthcare in terms of ensuring the effectiveness, safety, quality and availability of medical services is based on the traditional methodological basis of statistical and economic analysis of the average annual growth of the main indicators of the development of American healthcare during the formation of its modern institutional, managerial and organizational-functional structure in 1951–2020. The results reflect the general direction of the evolution of US healthcare as a haphazard complex mechanism that functions in direct resonance with the socio-economic cycle.
POSTINDUSTRIALIZATION AND DEINDUSTRIALIZATION IN THE GLOBAL ECONOMY IN THE CONTEXT OF RUSSIA'S ECONOMIC SECURITY
Authors:   Samara State University of Economics, Noskov V.A.
Published: August 2021

The purpose of the publication is to assess the world experience of post-industrial development and deindustrialization in the economies of both developed and developing countries. The importance of the crisis of the post-industrial paradigm for the development of the world economy, the application of this experience in the process of import substitution and the unfolding reindustrialization in Russia is noted. The analysis of the world experience of post-industrial development and deindustrialization of the economy, its macro-regional features is carried out in the context of maintaining and developing Russia's economic security. The author's understanding of the problems and prospects of the development of import substitution and reindustrialization processes in the world is proposed. Import substitution is considered as part of the strategy of economic development and ensuring the national security of the country. It is proposed to build recommendations for improving the policy of import substitution and reindustrialization carried out by Russia, taking into account the author's developments.
Un trágico itinerario guatemalteco: determinismo y tragedia de El Norte de Gregory Nava
Authors: Taiano Leonor
Published: August 2021

El propósito de este estudio es analizar uno de los conflictos que más han marcado la realidad de los agricultores mayas de Guatemala: la migración hacia Estados Unidos. Para llevarlo a cabo, el artículo examina la película El Norte de Gregory Nava, pues esta refleja de manera subjetiva el trágico itinerario de la mayor parte de los migrantes guatemaltecos, cuyo éxodo está marcado por historias de sacrificio y de lucha. Ellos se han convertido en personajes secundarios del mundo global contemporáneo. Metodológicamente, el artículo usa un acercamiento neohistoricista que permite profundizar la manera cómo los diálogos entre los personajes principales, los desplazamientos y el contexto geopolítico del guion consienten que la película se convierta en un instrumento de reflexión sobre la complicada situación de los migrantes guatemaltecos en Estados Unidos. El estudio porta a la conclusión de que la historia de los protagonistas, Enrique y Rosa, tiene una connotación trágica porque se realiza por medio de personas que los introducen en el tenebroso mundo de la ilegalidad y, por consiguiente, se convierten en individuos invisibles de la sociedad estadounidense.
Psychosocial impact of COVID-19 on the Brazilian elderly population
Authors: De Castro Larissa Pinheiro , De Souza Lúcia Aparecida , Da Fonseca Hortência Gueve , Modesto João Gabriel , Pernambuco Marília Lopes , Lima Clara Mariana Gonçalves , Pagnossa Jorge Pamplona
Published: August 2021

ABSTRACT

COVID-19 is a highly contagious disease caused by the new betacoronavirus of severe acute respiratory syndrome 2 (SARS-CoV-2). The high mortality of the disease occurs in a small portion of the infected population, especially in elderly individuals. The main measure adopted in Brazil to contain the virus is social isolation and this can have an impact on the mental health of the elderly population. This study aims to provide an educational intervention, understanding the repercussions that the COVID-19 pandemic has on the routine of the elderly. This is a study carried out through documentary analysis, based on bibliographic reviews, national and international, of specialists in the subject. It was found that mandatory social isolation causes uncertainties, insecurity, fear, and sometimes low self-esteem, which can lead to an emotional imbalance during this period of the pandemic of the new coronavirus, causing the elderly to become more fragile. Therefore, it is important to give special attention to this group based on specific health plans during this period together with the relatives of these elderly, which will enable better results in coping with COVID-19 in this group, besides preventing a spike in the incidence of mental health-related diseases.

 

RESUMEN

La COVID-19 es una enfermedad altamente contagiosa causada por el nuevo betacoronavirus del síndrome respiratorio agudo severo 2 (SARS-CoV-2). La elevada mortalidad de la enfermedad se produce en una pequeña parte de la población infectada, especialmente en individuos de edad avanzada. La principal medida adoptada en Brasil para contener el virus es el aislamiento social y esto puede tener un impacto en la salud mental de la población anciana. Este estudio tiene como objetivo proporcionar una intervención educativa, entendiendo las repercusiones que la pandemia de COVID-19 tiene en la rutina de los ancianos. Se trata de un estudio realizado a través de un análisis documental, basado en revisiones bibliográficas, nacionales e internacionales, de especialistas en el tema. Se constató que el aislamiento social obligatorio provoca incertidumbres, inseguridad, miedo y, a veces, baja autoestima, lo que puede llevar a un desequilibrio emocional durante este período de la pandemia del nuevo coronavirus, provocando la fragilidad de los ancianos. Por lo tanto, es importante dar una atención especial a este grupo en base a planes de salud específicos durante este período junto con los familiares de estos ancianos, lo que permitirá obtener mejores resultados en el afrontamiento de la COVID-19 en este grupo, además de evitar un repunte en la incidencia de enfermedades relacionadas con la salud mental.
A literature review of finite element models for the study of cervical spondylomyelopathy
Authors: de Albuquerque Bonelli Marília , Casimiro da Costa Ronaldo , Séllos Costa Fabiano
Published: August 2021

Cervical spondylomyelopathy (CSM), or wobbler syndrome, affects mainly the cervical region of the vertebral column of large- and giant-breed dogs, causing compression of the spinal cord and/or nerve roots. Dynamic components are considered to play a role in the condition, but its pathophysiology has not been fully explained. Finite element analysis consists in creating a computer model capable of simulating the biomechanics of the structures of interest. The present work aims to clarify aspects related with construction of finite element models and CSM through a review of literature on both topics, stressing the benefits of using finite element models to study the pathophysiology and treatment of CSM. Despite existing difficulties in generating a finite element model that represents the cervical spine of the dog, development of such a model and further biomechanical studies should contribute for a greater understanding of CSM.
NITROGEN-CONTAINING CHELATE COMPLEXES AND MONOMERS BASED ON THEM
Authors: Mavisakalyan Valentina M. , Yeritsyan Mejlum L.
Published: August 2021

By the interaction between N-methylolthiourea and Co2+, Mn2+ acetates are obtained compounds that were later used for the synthesis of vinyl bifunctional groups containing polymerizable chelate complexes. These compounds are recommended to be used as crosslinkers for obtaining, on the basis of water-based soluble monomers, spatially cross-linked water-swellable copolymers with applied purpose. There are dynamics of water absorption of copolymers from the time of their stay in water.
SPECIES OF AMAUROMYZA HENDEL IN ARTSAKH REPUBLIC
Authors: Grigoryan Nonna M. , Hovhannisyan Varuzhan S.
Published: August 2021

The article presents two species of the genus Amauromyza (Diptera, Agromyzidae): A. leonuri (Spencer, 1971) and A. flavifrons (Meigen, 1830), which are widespread in Artsakh Republic. Their biological, ecological and morphological features, prevalence and intensity of infestation, as well as the types of mines are described.
Activities and Financial Status of Bukhara Mangit Rulers in The Years Of Independence
Authors: Utaeva Feruza Kholmamatovna  , Jumaeva Nilufar Akhmatovna  , Turaeva Guli Bakhritdinovna
Published: August 2021

In this article, articles on the personality and socio-political activities of the rulers of Mangit inBukhara, the financial and economic situation, the source significance of the periodicals ofindependence have been scientifically studied and analyzed on a new methodological basis.
The Role of Reading in The Process of Foreign Language Teaching
Authors: Farrukh Ilyosov
Published: August 2021

Learning a foreign language contributes to the development of cognitive functions of the human psyche. In the process of mastering a foreign language practicing different memorization techniques, formed philological thinking, expand knowledge of reality. Especially reading helps to develop all these skills. At the initial stage of learning, reading comes to master the technique of reading aloud, and only to some extent, self-reading. As reading is one of the most important means of obtaining information and it has a significant place in the life of an educated person, this article deals with the role of reading in the process of teaching the foreign language
Issues of Economic and Social Development of Kumkurgan District
Authors: Abdunazarov Husan Menglievich  , Niyazov Khojakul Mirzaboboevich
Published: August 2021

This article examines the issues of socio-economic development of Kumkurgan district, the largest administrative district of Surkhandarya region. The issues of development of industry and transport networks are covered in detail.
Taxonomic Analysis of Hunting Milk Markers in Uzbekistan
Authors: Rustamovich Rayimov Avaz , Rakhimovich Rakhmonov Rashid , Kenjayevana Nurova Hikoyat , Qizi Rustamova MoxinurAvaz
Published: August 2021

Of the 19 species of mammals allowed to hunt in Uzbekistan, 13 species have been identified in Bukhara region. In particular, the taxonomic analysis of mammals hunted in the region revealed that 5 species of mammals were hunted on the basis of appropriate permits, 4 species of mammals were hunted illegally.  Of these, 3 species (Canis lupus, Felislibyca, Ondatrazibethicus) and 1 species (Gazellasubgutturoza) were identified as hunting in the Red Data Book of the Republic of Uzbekistan. [1].
Morphofuctional State of Thymus Gland among Children of Early Age with Thymomegalia
Authors: Uktamovich Khusanov Erkin , Oblakulovich Korzhavov Sherali , Abduganievich Ochilov Sardor , Sadullaevna Umarova Mulkizhahon , Akramzhonovich Berkinov Abbos
Published: August 2021

The morphometric characteristics in children of early age with thymomegalia were studied. In this case was found the increase of the area of lobule of thymus due to the predominance of the cerebral cortex and a significant increase in the ratio of thymocytes / epithelial reticular cells because of the increase of the absolute number of thymocytes. The differences in area and diameter of the Hassall’s corpuscles in the two compared groups were not revealed, however, was found a slight tendency to the decrease of these indicators in case of hyperplasia of thymus gland. These changes indicate the Morphofunctional inferiority of the thymus among children of early age with thymomegalia.
Lexico-Semantic Features of Phraseological Units Denoting Parts of The Human Body
Authors: Teshaboeva Gulnoza
Published: August 2021

The article examines the lexical and semantic nature of the phraseological unit associated with the names of parts of the human body. This work describes the meaning of phraseological units expressed in a literary text, and the expressive meanings of the text in external speech.
The use of Advanced and Interactive Teaching Methods in the Educational Process
Authors: Jumaboevna Tojiboeva Nargiza
Published: August 2021

This article examines the importance of modern pedagogical technologies in the acquisition and education of students' knowledge in the educational process. The article highlights such terms as teaching methods, methodology, pedagogical technology.
La Escuela Rural: ¿un destino deseado por los docentes?
Authors: Álvarez-Álvarez Carmen , Gómez-Cobo Paula
Published: August 2021

Estudios previos han puesto de manifiesto que el profesorado prefiere los destinos en escuelas urbanas. En Cantabria son numerosos los centros educativos existentes en el contexto rural y suelen ser los primeros destinos para los docentes durante los primeros años de interinidad. Hemos realizado un estudio para conocer si hay disposición por parte de los docentes para trabajar en estos centros. Para estudiarla, se ha empleado una metodología mixta basada en entrevistas en profundidad y cuestionarios a docentes activos y jubilados y alumnado del Grado en Educación Primaria. Los resultados ponen de relieve que la escuela rural es un destino muy deseado por el profesorado existiendo una visión positiva de esta tipología de escuelas y una adecuada predisposición a conocer o continuar impartiendo clase en ellas. Es posible concluir mencionando la importancia que tiene aún en la actualidad el mundo rural en esta comunidad, la escasa formación universitaria sobre escuela rural, la estabilidad en sus plantillas y la valoración de las posibilidades de su escuela por encima de las limitaciones, lo que lleva a verla como una opción viable a la hora de escoger destino.
Desarrollo de saberes experienciales y escritura de relatos en la formación docente
Authors: Pañagua Laura , Martín-Alonso Diego , Blanco Nieves
Published: August 2021

En este artículo abordamos el valor formativo de la escritura de relatos de aula para el desarrollo de saberes experienciales en docentes en formación. Hemos llevado a cabo este estudio durante tres años junto a seis estudiantes del grado de Educación Primaria en sus asignaturas de prácticas profesionales, centrándonos en la escritura de relatos a partir de sus vivencias en las escuelas. El propósito es conocer de qué manera la escritura de relatos de aula: i) favorece en los estudiantes el conocimiento de sus ideas pedagógicas; ii) promueve la reflexión sobre cuestiones pedagógicas relevantes; iii) posibilita el desarrollo de un pensamiento propio sobre la educación. Metodológicamente se trata de una investigación con modalidad de auto-estudio, realizando observaciones, entrevistas y el análisis de los relatos elaborados por los estudiantes. En los resultados identificamos tres momentos que posibilitan el desarrollo de saberes experienciales: a) narrar la vivencia de un suceso movilizador; b) reflexionar sobre lo vivido; y c) pensar pedagógicamente, tomando en consideración las situaciones narradas. Concluimos observando la potencialidad formativa de escribir relatos de aula, ya que estos ayudan a profundizar narrativamente la educación, permitiendo el desarrollo de un pensamiento reflexivo con capacidad para captar aspectos relevantes de la vida en las aulas.
DOES THE CHOICE OF LANGUAGE IN TESTS HAVE AN IMPACT ON GENDER EQUALITY IN PRIMARY EDUCATION? A CASE STUDY IN SENEGAL
Authors: Chazeaud Alexandre
Published: August 2021

Purpose: The present study analyses the possible impact on gender equality when using a language familiar to students in tests at primary schools in Sub-Saharan Africa where a European language is the unique medium of instruction and assessment.

Methodology: To this aim, students at grades 3 and 6 (83 girls and 66 boys) in primary schools in rural Senegal were given two different tests: Mathematics problem-solving tasks and multiple-choice questions of Social Sciences. They were divided at random into a control group if they received the tests in Seerer, the local language familiar to them, or French, the sole official language in the Senegalese education system. After data collection, results were codified for analysis considering two variables: Gender and grade. First, we calculated both the percentage of students who scored the set mark and those who obtained the highest scores. Second, we checked for statistically significant differences between groups by means of One-Way-ANOVA and Tukey tests.

Findings: Although Seerer as language of tests was found to benefit both genders, results suggest that its use may especially determine girls’ success at school: Girls in the experimental group obtained higher results than girls in the control group, especially the youngest, and many reached the highest scores.

Unique contribution to theory, practice and policy: Findings suggest that first, the use of a language familiar to students in tests seems to have positive effects on their academic results, and second, that it may play a role in bridging the gap between genders in some education models thanks to the evident benefits for girls, especially young ones. Such results might be taken into consideration by education authorities together with other existing examples to introduce local languages in the education system of Senegal and other Sub-Saharan countries where only a European language is employed, as it seems to contribute to reaching gender equality in education. We suggest that local languages could be used in tests from the lower levels of primary education in bilingual programs, thus favouring transfer of linguistic skills and content from the local to the European language, and increasing school success
INFLUENCE OF HUMAN RESOURCE MANAGEMENT PRACTICES ON THE PERFORMANCE OF HEALTH WORKERS IN KIAMBU COUNTY, KENYA
Authors: Mutwiri Jacob , Mwangi Eunice , Edwin Osiyel
Published: August 2021

Purpose: The general objective of the study was to establish the role of human resource management practices on the performance of health workers in Kiambu County, Kenya.

Methodology: The study adopted cross sectional research design, using both descriptive quantitative and qualitative techniques. The study targeted managers and workers of four hospitals which were purposefully chosen. The data was collected by administering questionnaires to the respondents and conducting KII to the managers. The data was analyzed using SPSS V27. The data was presented using tables and charts to summarize responses. For further analysis and comparison, the generated quantitative reports were subjected through tabulations, percentages, measure of central tendencies, correlation coefficient, chi square test, and inferential statistics.

Findings: The study reviewed that training opportunities and performance management practices improves staff motivation and performance (mean of 4.23, and 4.13). Planning (2.66) was biggest hindrances to utilizing training to improve performance. The managers were not well trained on using appraisals, ratings and feedback (2.06) for performance management. The institutions were not embracing performance culture (2.60), and using it for continuous improvement (1.82). Additionally, the study showed that hospitals did not carry out performance measurement regularly (2.81) and the systems for data collection were inadequate (2.43).

Unique contribution to theory, practice and policy: The study showed that human resource management practices improve health workers performance. Institutions should formulate and review policies to support human resource management practices that improve performance of the health workers
Traveling With the Greek Language through Time
Authors: Panagiotis Kaltsas Evangelos
Published: August 2021

Introduction. A language is the fundamental characteristic of a nation’s identity. It can unite the members of an ethic team and set them apart from the members of other ethnic teams. Aim. In this current review, the study presents the evolution of the Greek language from the ancient times, all the way up to today. Methodology. The study’s material consists of articles related to the topic, found in Greek and International και databases, the Google Scholar, and the Hellenic Academic Libraries (HEAL-Link). Results. The Greek language has been used since the third millennia B.C.. During the ancient times, it was the most widely used language in the Mediterranean Sea and South Europe. Until the fifth century B.C., the Greek language was a total of dialects. The Attica Dialect stood out from this dialectical mosaic. Then came the Hellenistic Common, which became the hegemonic language, the lingua franca of the "universe". The Hellenistic Common evolved to the Middle Ages Greek, and later the New Greek (fifth century A.D. - today). Besides, the creation of the New Greek state resulted to the gradual formation of the New Common, which will become the modern New Greek Common, under the effect of the scholar language. Conclusion. The Greek language keeps borrowing and assimilating words from other languages today, just like it did in the past, remaining unbroken for forty centuries.
EVALUATION OF PLANNING AND MANAGEMENT OF DISTANCE EDUCATION. ACRITICAL LITERATURE REVIEW
Authors: Kimani Cassan
Published: August 2021

Purpose: The rapid technological changes in education today have become paramount towards meeting our educational demands for the 21st century. The emerging trend in the use of Information Communication Technology has helped in bringing down the traditional barriers of access to higher education leading to access of quality education and training. This has provided learners with opportunities for lifelong learning and meaningful participation in the world of work and society as productive citizens through distance learning. The general objective of the study was to conduct an evaluation of planning and management of distance education.

Methodology: The paper used a desk study review methodology where relevant empirical literature was reviewed to identify main themes and to extract knowledge gaps.

Findings: From the study findings, it is concluded that little difference was found in the community found in the web-based course in comparison with their traditional courses. With the special characteristics associated with distance education, special measures should be taken to see that communities are established. Choosing exercises or activities that are collaborative will increase the potential for developing a community of learners. In addition, frequent use of online discussion or bulletin boards will also assist with this endeavor. Professional development on how to build a community for traditional and web-based courses is needed.

Recommendations: The study recommends that is a need for assessment of whether or not faculty are adequately prepared to teach at a distance, especially in light of the fact that faculty tend to teach in the same manner in which they were taught, is definitely warranted. A check list that would help identify the preparedness of the faculty member before they are responsible for distance student learning would help the students and program. Instructor training should be required before faculty are considered qualified to teach distance courses which necessitates the discovery of quality training programs. Support staff that is needed to assist faculty members when making the transition from a face-to-face to a virtual environment should be identified
ANALISIS HUBUNGAN MODAL KERJA DENGAN NET PROFIT MARGIN PT. BASILAM INDAH KABUPATEN BATUBARA
Authors: Sriwiyanti Eva
Published: August 2021

Abstract

This study aims to analyze the relationship between working capital and net profit margin. Descriptive quantitative method where quantitative data that has been processed, the results are described in sentences. The data analysis technique used is quantitative descriptive analysis with reference to the calculation results of working capital and net profit margin. The results of this study indicate that the value of the Current Ratio (CR) in 2017 is 2.4%. in 2018 the value of the Current Ratio (CR) increased to 3.8%. Then in 2019 the Current Ratio (CR) value again increased to 7.6%. The difference in the Current Ratio (CR) value from 2017 to 2018 is 1.4%. The difference in the Current Ratio (CR) value from 2018 to 2019 is 3.8%. This means that the value of the Current Ratio (CR) has increased every year.

The value of Net Profit Margin (NPM) in 2017 is 6%. In 2018 the Net Profit Margin (NPM) value increased to 7%. Then in 2019 the Net Profit Margin (NPM) value again increased to 8%. The difference in the value of the Net Profit Margin (NPM) from 2017 to 2018 is 1%. The difference in the value of the Net Profit Margin (NPM) from 2018 to 2019 is 1%. This means that the value of Net Profit Margin (NPM) has increased every year.

Keywords : Modal Kerja; Net Profit Margin,