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In this paper, we transform a modified Leslie–Gower predator–prey system into the corresponding fast–slow version by assuming that prey reproduces much faster than predator, and then perform a complete analysis about its dynamics. More specifically, we find the necessary and sufficient conditions of the exact number (zero, one or two) of positive equilibria of the slow–fast system and its (or their) location, and then we further fully determine its (or their) dynamics under explicit conditions. Besides, by converting the slow–fast system into its slow–fast normal form, we are able to characterize its rich dynamics completely, including relaxation oscillation, singular Hopf bifurcation, canard explosion, homoclinic orbits, heteroclinic orbits and global attraction of equilibrium. Moreover, the sufficient conditions to guarantee these various rich dynamics are explicitly given, including the explicit conditions to determine whether singular Hopf bifurcation is supercritical or subcritical, which generally cannot be explicitly derived in the existing literatures. Additionally, the cyclicity of diverse canard cycles is found under explicit conditions. Of particular interest is that we show the existence and uniqueness of one canard cycle without head whose cyclicity is at most two under explicit parameters conditions. Our results complement and enrich the previous work (relaxation oscillation, and global attraction of a boundary equilibrium) about this fast–slow system. We also employ numerical simulations to illustrate our theoretical analysis. [ABSTRACT FROM AUTHOR]

The aim of this work is to give conditions on the parameters of a family of analytic planar vector fields with a fixed Newton diagram and a monodromic singularity in order to guarantee that the coefficient (generalized first Lyapunov constant) of the linear part of the Poincaré map has an explicit formula that depends only on the Newton diagram. As far as we know, all the monodromic classes appearing in the literature satisfy that formula. [ABSTRACT FROM AUTHOR]

Per- and poly-fluoroalkylated substances (PFAS) are a large group of chemicals that persist both in the environment and in the body. Legacy PFAS, e.g., perfluorooctanoic acid and perfluorooctane sulfonic acid, are implicated as endocrine disruptors and reproductive and developmental toxicants in epidemiological and animal model studies. This review describes female reproductive outcomes of reported studies and includes where associative relationships between PFAS exposures and female reproductive outcomes have been observed as well as where those are absent. In animal models, studies in which PFAS are documented to cause toxicity and where effects are lacking are described. Discrepancies exist in both human and animal studies and are likely attributable to human geographical contamination, developmental status, duration of exposure, and PFAS chemical identity. Similarly, in animal investigations, the model used, exposure paradigm, and developmental status of the female are important and vary widely in documented studies. Taken together, support for PFAS as reproductive and developmental toxicants exists, although the disparity in study conditions and human exposures contribute to the variation in effects noted. [ABSTRACT FROM AUTHOR]

The article aims to show one of the crucial features of religious lyrics: cyclicity and network as a poetic feature. A crucial subgenre in this regard is represented by the works called “gandz” and the Gandzaran anthologies they compose, viewed in the context of historical, ecclesiastical liturgical ritual and practice, and medieval religious life. Networking in this article refers to the means, images, and narratives transferred between different genres and subgenres used for the same purpose, which create the paradigmatic image of the liturgical texts of the Christian Middle Ages. The article analyzes the dynamics operating in the network system of different texts and how the characteristic units of different texts become the most significant component of the poetics of the “Gandz” subgenre. The article analyzes the functionality of the “gandz” subgenre in the literary and social sense, its performance, the historical context of its origin and development, its paradigmatic significance in Armenian medieval literature, and its being a network unit in the theological context. One of the crucial aspects of the article is the study of the interaction between gandz and sermon based on their similar social function.

The article is dedicated to the study of certain aspects of the constitution development cyclicity and the factors that influence such cyclicity. The author emphasizes that the state, society and the constitution are in constant interconnection with each other, and therefore formation of cyclicity of constitution development is inseparable from other legal phenomena. It was found that cyclicity is characterized by stability (invariability of the stages (phases) forming cyclicity of constitution development) and survivability (dynamics that forms the constitution’s ability to adapt to new challenges and tasks arising in society). The author draws attention to both actual and legal constitutions. It was established that: a) actual and legal constitutions are indeed independent juridical phenomena, however, they interact with each other and that is manifested in the aspect that de facto relations which influence emergence of an actual constitution contribute to changes of a legal constitution; b) the factors under which de facto relations are formed in the state serve as prerequisites for beginning, development or termination of the stages of adoption, reform and invalidation of the constitution. The author specifies that, since the constitution functions within the political organization of society, all factors relating to cyclicity of its development in relation to the state can be divided into internal factors arising in the state (social, cultural, economic, political, etc.) and foreign policy factors (adoption of international acts, unilateral acts of other states, etc.) which influence determination of a political course and orientation of the state and contribute to dynamism of the constitution’s life cycle. The author gives an example of an internal (political) factor influencing cyclicity of the constitution development-a choice of a new vector of Ukraine’s policy towards membership in the European Union and the North Atlantic Treaty Organization that resulted in introduction of amendments to the Constitution of Ukraine in 2019. The other example given is associated with a foreign policy factor-constitutional changes in Germany in 2022 aimed at increasing the budget expenditures of the state for its army’s defense capability because of the full-scale invasion of Ukraine. [ABSTRACT FROM AUTHOR]

Introduction: Pubertal attainment is critical to reproductive longevity in heifers. Previously, four heifer pubertal classifications were identified according to attainment of blood plasma progesterone concentrations > 1 ng/ml: 1) Early; 2) Typical; 3) Start-Stop; and 4) Non-Cycling. Early and Typical heifers initiated and maintained cyclicity, Start-Stop started and then stopped cyclicity and Non-Cycling never initiated cyclicity. Start-Stop heifers segregated into Start-Stop-Discontinuous (SSD) or Start-Stop-Start (SSS), with SSD having similar phenotypes to Non-Cycling and SSS to Typical heifers. We hypothesized that these pubertal classifications are heritable, and loci associated with pubertal classifications could be identified by genome wide association studies (GWAS). Methods: Heifers (n = 532; 2017 - 2022) genotyped on the Illumina Bovine SNP50 v2 or GGP Bovine 100K SNP panels were used for variant component estimation and GWAS. Heritability was estimated using a univariate Bayesian animal model. Results: When considering pubertal classifications: Early, Typical, SSS, SSD, and Non-Cycling, pubertal class was moderately heritable (0.38 ± 0.08). However, when heifers who initiated and maintained cyclicity were compared to those that did not cycle (Early+Typical vs. SSD+Non-Cycling) heritability was greater (0.59 ± 0.19). A GWAS did not identify single nucleotide polymorphisms (SNPs) significantly associated with pubertal classifications, indicating puberty is a polygenic trait. A candidate gene approach was used, which fitted SNPs within or nearby a set of 71 candidate genes previously associated with puberty, PCOS, cyclicity, regulation of hormone secretion, signal transduction, and methylation. Eight genes/regions were associated with pubertal classifications, and twentytwo genes/regions were associated with whether puberty was attained during the trial. Additionally, whole genome sequencing (WGS) data on 33 heifers were aligned to the reference genome (ARS-UCD1.2) to identify variants in FSHR, a gene critical to pubertal attainment. Fisher's exact test determined if FSHR SNPs segregated by pubertal classification. Two FSHR SNPs that were not on the bovine SNP panel were selected for additional genotyping and analysis, and one was associated with pubertal classifications and whether they cycled during the trial. Discussion: In summary, these pubertal classifications are moderately to highly heritable and polygenic. Consequently, genomic tools to inform selection/management of replacement heifers would be useful if informed by SNPs associated with cyclicity and early pubertal attainment. [ABSTRACT FROM AUTHOR]

We study canard cycles and their cyclicity of a fast–slow Leslie–Gower predator–prey system with Allee effect. More specifically, we find necessary and sufficient conditions of the exact number (zero, one or two) of positive equilibria of the slow–fast system and its location (or their locations), and then we further completely determine its (or their) dynamics under explicit conditions. Besides, by geometric singular perturbation theory and the slow–fast normal form, we find explicit sufficient conditions to characterize singular Hopf bifurcation and canard explosion of the system. Additionally, the cyclicity of canard cycles is completely solved, and of particular interest is that we show the existence and uniqueness of a canard cycle, whose cyclicity is at most two, under corresponding precise explicit conditions. [ABSTRACT FROM AUTHOR]

Purpose: This paper examines the impact of global crises, including the Global Financial Crisis (GFC), the COVID-19 pandemic, and the subsequent inflation crisis, on the fluctuations of the Real Effective Exchange Rate (REER). The cyclicality of REER has been examined as influenced by economic shocks, highlighting how pandemic-induced economic disruptions have reshaped REER dynamics differently from the more financially triggered fluctuations of the Global Financial Crisis. Design/methodology/approach: The methodology employs a comparative spectral analysis approach, utilizing time-series data to track REER movements across various countries. Findings: The findings indicate that the GFC and the COVID-19 pandemic led to shortening periods of cyclicality. Moreover, there has been a noticeable improvement in the synchronization of REER movements post-GFC, suggesting that economies may converge in their responses to global economic shocks. This convergence implies a potential stabilization of exchange rate movements in the face of future crises, underlining the importance of coordinated monetary policies. Research limitations/implications: To model the REER index, one can use also classical analytical methods such as VAR models, where macroeconomic factors can serve as variables. In spectral analysis itself, other filters like the Hodrick-Prescott filter or applying a spectral window can be used. Practical implications: The conducted study implies an improvement in synchronization among financial systems, with this knowledge, more appropriate and rational monetary decisions can be made, and private entities can better employ hedging strategies against currency exchange rate fluctuations. The study also aids in identifying inflationary pressures and the impact of the global financial system on the inflation index in individual countries. Originality/value: The methods used in the article represent an innovative approach to modeling the REER index, providing new insights into the cyclicality of the index and the shortening periods of its occurrence. The article is addressed both to researchers in this field and to individuals involved with the monetary system and those working in the financial industry. [ABSTRACT FROM AUTHOR]

The precise nature of Ā-dependencies that terminate in a pronoun has been a long-standing subject of cross-linguistic research. Traditionally, it has been assumed that there are two derivational strategies to form resumptive Ā-dependencies: movement and base generation. Island configurations have played a crucial role in determining which derivational strategy is employed in a given language, as islands effects are expected to arise from dependencies created by movement but not by base generation. The body of cross-linguistic research on resumption has shown that the situation is more complicated once other diagnostics are taken into account, as languages can have mixed resumption profiles. In this paper, we discuss resumption in Ā-dependencies in Akan, a Kwa language spoken in Ghana, and illustrate that, despite their general insensitivity to islands, resumptive dependencies also show many classic hallmarks of movement. We situate these findings in the broader context of a general understanding of resumption cross-linguistically and discuss how the conflicting diagnostics might be reconciled with a movement-based analysis. [ABSTRACT FROM AUTHOR]

Historically, the Republic of Turkey is one of the few states in the Middle East, in a civilizational sense, located between East and West. As time has passed since a number of unsuccessful attempts to integrate into Western institutions and with the beginning of geopolitical changes in the international arena, Turkey has made a “pivot to the East”. Considering the increasing role of the Non-West within the framework of the formation of a polycentric system of international relations, the study of Turkey as one of the key centers of forces of our time, as well as the identification of its characteristics, eastern and western features, is of particular relevance. The purpose of the study is to examine the civilizational characteristics of modern Turkey. By applying civilizational approach, Turkey’s position of a “middle state” was revealed, which has both Western and Eastern features, but is increasingly gravitating towards the non-Western world. At the same time, amid the ideology of “neo-Ottomanism” implemented by the current leadership and the increasing role of the ideological and value factor, Western features are gradually fading away, remaining only in the form of official secularism and stable ties with Western institutions. While the Turkish orientality, along with unofficial islamization, have a clearer image. Turkey develops in progressive-regressive cycles, where the Western cycle is replaced by the Eastern and vice versa. However, the West is systematically ceasing to be a symbol of progress. The authors conclude that the non-Western path of development is the most promising for modern Turkey, however, with the condition that eastern development will not be moderated by Islamist circles and supporters of political Islam.

The author of the article notes the influence of the research of Russian folklorists and cultural historians on the interpretation of the 20th century art and captures the humanitarian trend towards searching for primarily archetypal situations and images in contemporary art, Soviet film comedy included. The article highlights the importance of the concepts by V. Propp and M. Bakhtin for the current perception of works of art and urges us not to limit ourselves to this, but to place new accents — to look for differences between the ancient and modern worldviews, between the impersonal solutions to dramatic situations and characters types, on the one hand, and the author’s aesthetics and individual interpretations of the world and man, on the other hand. Based on the material of the comedy films by L. Gaidai and E. Ryazanov, the fairy tale film An Ordinary Miracle by M. Zakharov, the author shows how far the artistic messages of these directors are from the archaic concepts of laughter and comedy, from the ideas of carnival freedom and harmony, which, however, does not deny the use of satire drama structures, palliata, and paired archetypical characters. This refers to the cultural layering of the images of Shurik, Nina, Saakhov, and the comical trio of the Coward, the Fool and the Pro. In addition, the article analyses the role of the water element in the comedy The Irony of Fate... and gives a detailed interpretation of the non-normative behaviours of Zhenya Lukashin and Ippolit possessing only external signs of carnivality. Conclusions are drawn about the dramatic heuristicity of laughter in the comedy films by Gaidai and Ryazanov, which had adaptive psychological functions and also contributed to the internal self-reflection of the Soviet audience.

Yao and Huzak [2022] proved that the cyclicity of canard cycles in a singularly perturbed Leslie–Gower predator–prey model with prey harvesting is at most two in a region of parameters. In this paper, we further show that there exists only one canard cycle with cyclicity at most two under explicit parameters conditions. [ABSTRACT FROM AUTHOR]

We present a Monte Carlo model of Einstein–Podolsky–Rosen experiments that may be implemented on two independent computers and resembles the measurements of the Clauser–Aspect–Zeilinger-type which are performed in two distant stations S A and S B . Our computer model is local deterministic because we show that a theorist in station S B is able to conceive the products of the measurement outcomes of both stations, conditional to any possible equipment configuration in station S A . We show that the Monte Carlo model violates Bell-type inequalities and approaches the results of quantum theory for certain relationships between the number of measurements performed and the number of possible different physical properties of the entangled photon pairs. These relationships are clearly linked to Vorob'ev cyclicities, which always enforce Bell-type inequalities. The realization of this cyclicity depends, however, on combinatorial symmetry considerations that, in turn, depend on the mathematical properties of Einstein's elements of physical reality. Because these mathematical properties have never been investigated and, therefore, may be free to be chosen in the models for all published experiments, Einstein's physics does not contradict the experimental findings, instantaneous influences at a distance are put into question and the paradox of Einstein–Podolsky–Rosen and Bell is, thus, resolved. [ABSTRACT FROM AUTHOR]

Morphophonological derivations are often simultaneously isomorphic to both surface morphotactics, cyclic phonology, and to abstract morphosemantic structure. On the surface, passive verbs in Armenian violate this isomorphism. Verbs consist of a bound stem plus suffixes. Passive stems are pre-consonantal and seem morphologically derived from roots, but their phonological structure is only predictable from the pre-vocalic stem of active verbs. I capture this predictability by combining cyclicity with affix truncation (Aronoff 1976). The interaction between cyclicity and affix deletion causes the opaque overapplication of phonological rules in passives, because such rules applied cyclically early in the active verb. This approach is a cyclic alternative to using Output-Output constraints. However, our cyclic analysis likewise predicts *ABA effects in the morphosemantics of passives, among other non-phonological dependencies. Thus, our analysis creates a cyclic dependency between two bound stems that is visible across grammatical modules. [ABSTRACT FROM AUTHOR]

The study of a core of borehole 8 drilled in the town of Maloyaroslavets to a depth of 94 m has made it possible to obtain the biostratigraphic characteristics of the Tarusian and Protvian regional substages of the Serpukhovian Stage and lower part of the Vereian Regional Substage of the Moscovian Stage based on foraminifers and conodonts. The Tarusian Regional Substage is attributed to the Neoarchaediscus postrugosus Zone. The Eostaffellina paraprotvae Zone has been established in the Protvian Regional Substage, and a deep-water conodont assemblage of the Gnathodus bollandensis Zone has been found in its upper part (6.8–12.0 m above the base). The generalization of all data on conodonts of the Protvian Regional Substage of the Moscow Syneclise has shown that it contains at least four transgressive–regressive cyclites. The type locality of the species Eostaffellina protvaeensis has been specified in the Tetyuevo section in the Rzhev Volga region. A rich assemblage of conodonts from the Vereian Alyutovo Formation of the Moscovian Stage belongs to the Declinognathodus donetzianus Zone. [ABSTRACT FROM AUTHOR]

Microfacies studies were carried out on the Middle Miocene Marmarica Formation exposed at the Gabal Western Bahi El-Din and Gabal El-Najdeen, the Siwa Oasis, northwestern Desert (Egypt). It was distinguished into the lower, middle, and upper members. Eleven microfacies types were recognized, which include skeletal lime-mudstone, dolomitic lime-mudstone, intraclastic wackestone, bryozoan wackestone, foraminiferal wackestone, foraminiferal bryozoan packstone, glauconitic molluscan packstone, molluscan intraclastic packstone, pelletal peloidal skeletal packstone, dolostones, and claystone microfacies. This formation includes several types of emergence- meter-scale cycles (shallowing-upward). Field observations and petrographic analyses revealed that these cycles consist of pure carbonates and mixed siliciclastic carbonates. These cycles consist of four types of gradual cycles and six types of non-gradual cycles. The gradual emergence cycles indicate a balance between the rate of subsidence, sea level oscillations, and sedimentation rate. The non-gradual cycles indicate an irregular balance between sedimentation rate and subsidence rate. The non-gradual cycles denote high-frequency sea level variation and/or short-term sea level oscillations, which are associated with high carbonate formation. The depositional environments of the Marmarica Formation are restricted to lagoonal at the base, followed upward to open marine conditions. Both environments most probably characterize the platform setting. [ABSTRACT FROM AUTHOR]

Copyright of Contratexto is the property of Contratexto and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Replacive overwriting by morphological tone has been used as major evidence for cyclic construction approaches to phonology (Hyman 2013 , Inkelas 2018 , Rolle 2018). In this article, I show that this argument is unwarranted: tonal overwriting can be derived by simple concatenation of tonal morphemes, general phonological constraints, and minimal access to morphological information—in Autosegmental Colored Containment Theory. In detailed analyses, I demonstrate that neither morpheme-specific phonology nor cyclicity is necessary to capture tonal overwriting, whereas cyclic analyses actually make wrong predictions on possible overwriting patterns. [ABSTRACT FROM AUTHOR]

Introduction: Pubertal attainment is critical to reproductive longevity in heifers. Previously, four heifer pubertal classifications were identified according to attainment of blood plasma progesterone concentrations > 1 ng/ml: 1) Early; 2) Typical; 3) Start-Stop; and 4) Non-Cycling. Early and Typical heifers initiated and maintained cyclicity, Start-Stop started and then stopped cyclicity and Non-Cycling never initiated cyclicity. Start-Stop heifers segregated into Start-Stop-Discontinuous (SSD) or Start-Stop-Start (SSS), with SSD having similar phenotypes to Non-Cycling and SSS to Typical heifers. We hypothesized that these pubertal classifications are heritable, and loci associated with pubertal classifications could be identified by genome wide association studies (GWAS).Methods: Heifers (n = 532; 2017 – 2022) genotyped on the Illumina Bovine SNP50 v2 or GGP Bovine 100K SNP panels were used for variant component estimation and GWAS. Heritability was estimated using a univariate Bayesian animal model.Results: When considering pubertal classifications: Early, Typical, SSS, SSD, and Non-Cycling, pubertal class was moderately heritable (0.38 ± 0.08). However, when heifers who initiated and maintained cyclicity were compared to those that did not cycle (Early+Typical vs. SSD+Non-Cycling) heritability was greater (0.59 ± 0.19). A GWAS did not identify single nucleotide polymorphisms (SNPs) significantly associated with pubertal classifications, indicating puberty is a polygenic trait. A candidate gene approach was used, which fitted SNPs within or nearby a set of 71 candidate genes previously associated with puberty, PCOS, cyclicity, regulation of hormone secretion, signal transduction, and methylation. Eight genes/regions were associated with pubertal classifications, and twenty-two genes/regions were associated with whether puberty was attained during the trial. Additionally, whole genome sequencing (WGS) data on 33 heifers were aligned to the reference genome (ARS-UCD1.2) to identify variants in FSHR, a gene critical to pubertal attainment. Fisher’s exact test determined if FSHR SNPs segregated by pubertal classification. Two FSHR SNPs that were not on the bovine SNP panel were selected for additional genotyping and analysis, and one was associated with pubertal classifications and whether they cycled during the trial.Discussion: In summary, these pubertal classifications are moderately to highly heritable and polygenic. Consequently, genomic tools to inform selection/management of replacement heifers would be useful if informed by SNPs associated with cyclicity and early pubertal attainment.

Oxytocin has been used to treat neurodevelopmental conditions in adolescent patients but possible effects on reproductive development have not been well investigated. The effects of daily intra-nasal oxytocin treatment (12-18 months of age) on puberty and fertility were studied in colony-housed, male and female titi monkeys (Plecturocebus cupreus). Body weight, urinary conjugated pregnanes and estrogens (defining cyclicity) in females, and androgens and sperm in urine of in males, were measured from 1 to 3 years of age to detect puberty. Serum testosterone was also measured in males at 13, 23 and 33 months of age and hemi-castration at 3 years of age enabled assessment of testicular morphometry and oxytocin receptor expression. An oxytocin treatment*time interaction suggested a minor, transient suppression in weight gain after treatment ended. Note that females weighed 10% less across all ages. Oxytocin-treated females exhibited early, spurious ovulations but neither regular cyclicity (≈30 months) nor pregnancies were affected by treatment. Oxytocin did not affect the pubertal increase in urinary androgen or the first appearance of sperm, which occurred as early as 15 months of age. Treatment did delay the puberty-associated rise in serum testosterone in males. All males were pubertal by 22 months and all females by 32 months of age. Although no major male or female fertility outcome was observed, oxytocin demonstrated some physiological effects through a delay of testosterone secretion in males, induction of precocious ovulation in females, and a suppression of general weight gain for the months following treatment.

The main goal of the investigation was to reveal the lateral and vertical regularities of element distribution in the elementary landscape-geochemical system (ELGS) type: summit-slope-closing depression. We used an isotope 137Cs as a tracer of migration of chemical elements in soil and vegetation cover. The study was performed in a test site characterizing undisturbed forest landscapes in the Russian zone of the Chernobyl accident. Investigated ELGS was 16-m long with a relative height difference of 1.5 m. Field measurements of 137Cs activity was performed with a 1-meter step by the modified portable gamma-spectrometer Violinist-III (USA). Cs-137 content in moss and soil cores sampled with the same lateral step was determined in the laboratory using Canberra (USA, HPGe detector). The upper soil layer 8-cm thick contained from 70 to 96% of 137Cs, and 89–99% of the total inventory was fixed in the top 20-cm layer. Cs-137 activity in both the soil and moss cover demonstrated a cyclic type of variability, which was described and modeled using Fourier analysis. Correlation between the actual and modeled activity values (r0.01 = 0.868) showed that three main harmonics are sufficient for representative modeling of the observed cycles. We infer that the revealed patterns are characteristic for most of the chemical elements and may be useful for practical purposes. [ABSTRACT FROM AUTHOR]

Copyright of Acta Sedimentologica Sinica is the property of Acta Sedimentologica Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Gases desorbed by the vacuum method from the tree rings of discs of deciduous trees are measured. The content of residual gases vacuum-desorbed from tree rings is analyzed with an optoacoustic gas analyzer with a tunable CO2 laser. The chronologies of residual CO2 and (CO2 + H2O) of some deciduous trees growing near the city of Tomsk (Western Siberia) have been derived. All the chronologies are cyclic with pronounced 2–4-year cycles. A correlation was found between the content of gases and summer temperatures and precipitation. We believe that the annual distribution of residual gases in the discs reflects the pattern of annual release of the gases from the stems of the deciduous trees into the atmosphere. [ABSTRACT FROM AUTHOR]

The thermal load in the piston head is becoming heavy with the application of supercharging technology. This makes the piston cooling become more challenging to ensure the reliability of the piston. In this study, an oil-injection cooling process in a medium-speed V-type diesel engine is numerically investigated. The simulations are performed for the direct coupling of the piston head structure and the two-phase flow in the cooling gallery. The effect of the flow pattern on heat transfer characteristics during the whole process is discussed. The results reveal a series of the flow characteristics including thrown flow, interrupted flow, wall impingement, oil oscillating and sedimentation during the reciprocating movement of the piston and the flow characteristics become more obvious with the increase of the engine speed, but the cooling oil is more widely distributed in the oil gallery due to more intense oscillation. After multi-cycle calculations, the flow characteristics of the cooling oil and the heat transfer characteristics of the piston both have a certain periodicity. [ABSTRACT FROM AUTHOR]

Per- and poly-fluoroalkylated substances (PFAS) are a large group of chemicals that persist both in the environment and in the body. Legacy PFAS, e.g., perfluorooctanoic acid and perfluorooctane sulfonic acid, are implicated as endocrine disruptors and reproductive and developmental toxicants in epidemiological and animal model studies. This review describes female reproductive outcomes of reported studies and includes where associative relationships between PFAS exposures and female reproductive outcomes have been observed as well as where those are absent. In animal models, studies in which PFAS are documented to cause toxicity and where effects are lacking are described. Discrepancies exist in both human and animal studies and are likely attributable to human geographical contamination, developmental status, duration of exposure, and PFAS chemical identity. Similarly, in animal investigations, the model used, exposure paradigm, and developmental status of the female are important and vary widely in documented studies. Taken together, support for PFAS as reproductive and developmental toxicants exists, although the disparity in study conditions and human exposures contribute to the variation in effects noted.

The article is aimed at studying the peculiarities of maintaining financial stability of the banking sector under the influence of destructive factors of the VUCA environment. The analysis of publications allowed us to identify the essence of the concept of the VUCA environment and systematize its main components. It is substantiated that the VUCA environment causes a cumulative process as a source and material carrier of economic development, responsible for its undulating nature. As a result of the study, it was proved that the VUCA environment is characterized by chaotic changes that are not associated with economic cycles. At this, the latter are able to accelerate as a result of the impact of digital technologies and the VUCA environment on GDP. It is revealed that the use of digital technologies ensures the timeliness of information, helps to identify new problems in terms of risk and control, improves understanding of what may go wrong, sharpens foresight regarding the appropriate response strategy. The article systematizes the views of the main economic schools on the factors of financial instability. It is proposed to consider the factors of instability of the banking sector and systemic risks through the prism of VUCA in order to assess the capabilities of banks to withstand systemic risks. The essence banking risks is determined and the structure of these risks is systematized in the form of a matrix on the basis of taking into account the features of quantitative or qualitative assessment and sources of their production. The systemic risks in the composition of external financial risks as the most dangerous for the functioning of the banking sector have been allocated. Prospects for further research in this direction are to identify the peculiarities of ensuring financial stability of the banking sector under the influence of digital transformations on this process.

In this paper, we study the cyclicity problem with respect to the forward shift operator Sb acting on the de Branges–Rovnyak space ℋ (b) associated to a function b in the closed unit ball of H∞ and satisfying log(1− |b| ∈ L1(𝕋). We present a characterisation of cyclic vectors for Sb when b is a rational function which is not a finite Blaschke product. This characterisation can be derived from the description, given in [22], of invariant subspaces of Sb in this case, but we provide here an elementary proof. We also study the situation where b has the form b = (1+ I)/2, where I is a non-constant inner function such that the associated model space KI = ℋ (I) has an orthonormal basis of reproducing kernels.

We consider analytic families of planar vector fields depending analytically on the parameters in Λ\Lambda that guarantee the existence of a (may be degenerate and with characteristic directions) monodromic singularity. We characterize the structure of the asymptotic Dulac series of the Poincaré map associated to the singularity when the family possesses a Puiseux inverse integrating factor in terms of its multiplicity and index. This characterization is only valid in a restricted monodromic parameter space Λ\Λ∗\Lambda \backslash {\Lambda }^{\ast } associated to the nonexistence of local curves with zero angular speed. As a byproduct, we are able to study the center-focus problem (under the assumption of the existence of some Cauchy principal values) in very degenerated cases where no other tools are available. We illustrate the theory with several nontrivial examples.

The semi‐enclosed marginal Japan Sea is sensitive to global changes and responds to orbital‐scale variability. Sediment core samples from Integrated Ocean Drilling Program Site U1423 were processed for detrital grain size and semi‐quantitative mineral analysis to assess the sediment characterization and depositional environment in the Japan Sea over the last 1200 ka. The mean grain data suggest the dominance of the silt size fraction over sand and clay in the whole period, while sand content increases dramatically between 600 and 150 ka. The end‐member energy modelling of grain size data suggests that sediment deposition took place under two energy conditions over the last 1200 ka. The low‐energy conditions observed during the middle Pleistocene transition (MPT) is mainly related to the wind deposition with the sediment characteristics being moderately to poorly sorted and coarse to nearly symmetrical skewed during global cooling and enhanced East Asian Winter Monsoon (EAWM) winds in the northern Japan Sea. Post MPT, periodic fluctuations between higher and lower energy conditions are observed, and the depositional environment is controlled by the EAWM wind, and precipitation intensity, glacio‐eustatic sea‐level changes and sea‐ice volumes. During the period, detrital sediments are poorly sorted and nearly symmetrically skewed, marked by the dominance of quartz, plagioclase and k‐feldspar. The spectral analysis grain size‐related data shows the presence of 228, 41 and 23 kyr orbital paced cycles, which are also observed in the Chinese Loess Plateau's normalized quartz mean grain size. This study is the first report of 228 kyr cycles from the Pleistocene Japan Sea sediments indicate that sediment deposition in the Japan Sea is associated with ~200 kyr eccentricity cycle as in the Chinese Loess Plateau. [ABSTRACT FROM AUTHOR]

We present a Monte Carlo model of Einstein–Podolsky–Rosen experiments that may be implemented on two independent computers and resembles the measurements of the Clauser–Aspect–Zeilinger-type which are performed in two distant stations SA and SB. Our computer model is local deterministic because we show that a theorist in station SB is able to conceive the products of the measurement outcomes of both stations, conditional to any possible equipment configuration in station SA. We show that the Monte Carlo model violates Bell-type inequalities and approaches the results of quantum theory for certain relationships between the number of measurements performed and the number of possible different physical properties of the entangled photon pairs. These relationships are clearly linked to Vorob’ev cyclicities, which always enforce Bell-type inequalities. The realization of this cyclicity depends, however, on combinatorial symmetry considerations that, in turn, depend on the mathematical properties of Einstein’s elements of physical reality. Because these mathematical properties have never been investigated and, therefore, may be free to be chosen in the models for all published experiments, Einstein’s physics does not contradict the experimental findings, instantaneous influences at a distance are put into question and the paradox of Einstein–Podolsky–Rosen and Bell is, thus, resolved.

Microfacies studies were carried out on the Middle Miocene Marmarica Formation exposed at the Gabal Western Bahi El-Din and Gabal El-Najdeen, the Siwa Oasis, northwestern Desert (Egypt). It was distinguished into the lower, middle, and upper members. Eleven microfacies types were recognized, which include skeletal lime-mudstone, dolomitic lime-mudstone, intraclastic wackestone, bryozoan wackestone, foraminiferal wackestone, foraminiferal bryozoan packstone, glauconitic molluscan packstone, molluscan intraclastic packstone, pelletal peloidal skeletal packstone, dolostones, and claystone microfacies. This formation includes several types of emergence- meter-scale cycles (shallowing-upward). Field observations and petrographic analyses revealed that these cycles consist of pure carbonates and mixed siliciclastic carbonates. These cycles consist of four types of gradual cycles and six types of non-gradual cycles. The gradual emergence cycles indicate a balance between the rate of subsidence, sea level oscillations, and sedimentation rate. The non-gradual cycles indicate an irregular balance between sedimentation rate and subsidence rate. The non-gradual cycles denote high-frequency sea level variation and/or short-term sea level oscillations, which are associated with high carbonate formation. The depositional environments of the Marmarica Formation are restricted to lagoonal at the base, followed upward to open marine conditions. Both environments most probably characterize the platform setting.

Recent work has argued for derivational expansion of the search space of ɸ-probes as a result of the cyclic interaction of Merge and Agree (cyclic Agree). Empirical evidence for such effects has come from the interaction of Agree with external Merge, but these accounts make the additional predictions that such interactions should also arise from the interaction of Agree with movement. In this paper, we argue based on evidence from Hindi-Urdu that movement may feed cyclic Agree in the same way as external Merge, bearing out this key prediction. The central empirical generalizations that we argue for are that (i) A-scrambling of an object over a subject may feed agreement in certain configurations, (ii) there is nonetheless a preference for agreement with the structurally lower subject, and (iii) A ‾ -scrambling of the object never feeds agreement. We develop a cyclic-Agree analysis that provides a principled explanation of these generalizations. Crucial to this explanation are that (i) search space is dynamic and interacts with movement, (ii) there is a preference for agreement with elements c-commanded by the head that hosts the probe (first-cycle Agree), and (iii) ɸ-probes project as part of the label, but not past the immediate projection line of the head. [ABSTRACT FROM AUTHOR]

Tectonic, paleoenvironmental, and paleoclimatic unstable conditions preceding the onset of the Messinian Salinity Crisis (MSC) highly affected marine life. Changes in calcareous plankton association are overall registered in the Mediterranean. They consist of a general transition from abundant and well-diversified planktonic associations to strictly oligotypic assemblages that precede their total disappearance at the onset of evaporitic precipitation. In this work, an accurate quantitative analysis of calcareous plankton, both foraminifers and nannofossils, has been carried out in the Torrente Vaccarizzo Section of Sicily (southern Italy). The aim is to independently define a chronostratigraphic pattern of bioevents preceding the MSC in the absence of magnetostratigraphic or radiometric constraints. The fluctuating abundance of the genus Orbulina fits well with the 100 ky Eccentricity maxima, and it is successfully applied to build an astronomically calibrated age-model for the section. On this basis, all the biohorizons have been recalibrated and discussed with regard to the previous literature. Abundant influxes of selected species demonstrated to be of local significance since they are highly affected by paleoenvironmental and paleoclimatic conditions. A chronological sequence of foraminifer and nannofossil events marks the onset of the MSC with a derived age of 5.957 My, which agrees well with previous findings from other Mediterranean sections. This methodology and the new biostratigraphic events may be useful for future studies on pre-evaporitic successions of the Mediterranean. [ABSTRACT FROM AUTHOR]

Traditional approaches to verbal periphrasis (compound tenses) treat auxiliary verbs as lexical items that enter syntactic derivation like any other lexical item, via Selection/Merge. An alternative view is that auxiliary verbs are inserted into a previously built structure (e.g., Bach 1967 , Arregi 2000 , Embick 2000 , Cowper 2010 , Bjorkman 2011 , Arregi and Klecha 2015). Arguments for the insertion approach include auxiliaries' last-resort distribution and the fact that, in many languages, auxiliaries are not systematically associated with a given inflectional category (Bjorkman's (2011) "overflow" distribution). Here, I argue against the insertion approach. I demonstrate that the overflow pattern and last-resort distribution follow from Cyclic Selection (Pietraszko 2017)—a Merge counterpart of Cyclic Agree (Béjar and Rezac 2009). I also show that the insertion approach makes wrong predictions about compound tenses in Swahili, a language with overflow periphrasis. Under my approach, an auxiliary verb is a verbal head externally merged as a specifier of a functional head, such as T. It then undergoes m-merger with that head, instantiating an External-Merge version of Matushansky's (2006) conception of head movement. [ABSTRACT FROM AUTHOR]

The development of modern information and analytical technologies opens up new opportunities for economic analysis and forecasting of market situations. Many technologies of modern financial analysis are based on the efficient market hypothesis, according to which price changes in the securities market in logarithmic coordinates represent a random (Gauss) process. However, studies of the last 30 years show that this is not the case and the usual statistical model is not suitable for analyzing most economic indicators. The effective roar hypothesis is replaced by the fractal theory and the fractal market hypothesis based on the concept of self-similarity in different time scales. The article is devoted to the mathematical and statistical analysis of the dynamics of economic indicators based on the theory of fractals. The results of the fractal analysis of the time series of the dynamics of the EUR/RUB exchange rate for the period 2013-2022 by the method of the normalized Hearst swing are presented. The result of the study was the identification of the fractal properties of the specified time series, the proof of its nonlinearity and the presence of the effect of long-term memory in the dynamics. The results obtained prove the necessity of using specialized fractal methods for further research and forecasting the dynamics of time series with a self-similar statistical structure. Purpose of the work is to analyze economic processes based on the tools of fractal mathematics. The method or methodology of work: in the course of the research, general methodological principles of scientific cognition were used: comparative, analytical, abstract-logical analyses, economic-mathematical, economic-statistical models and modeling using modern software. The calculations were carried out using the application programs Microsoft Excel, Statistica, R, Matrixer. Results: we have identified fractal properties of the financial time series, justified the need to use new methods of forecasting economic indicators. Scope of the results: it is advisable to apply the obtained results to economists, traders and business analysts studying the dynamics of economic and financial indicators.

In this paper we study planar polynomial Kolmogorov's differential systems \[ X_\mu\quad\begin{cases}{\dot{x}=f(x,y;\mu),}\\{\dot{y}=g(x,y;\mu),} \end{cases} \] with the parameter $\mu$ varying in an open subset $\Lambda\subset\mathbb{R}^N$. Compactifying $X_\mu$ to the Poincaré disc, the boundary of the first quadrant is an invariant triangle $\Gamma$, that we assume to be a hyperbolic polycycle with exactly three saddle points at its vertices for all $\mu\in\Lambda.$ We are interested in the cyclicity of $\Gamma$ inside the family $\{X_\mu\}_{\mu\in\Lambda},$ i.e., the number of limit cycles that bifurcate from $\Gamma$ as we perturb $\mu.$ In our main result we define three functions that play the same role for the cyclicity of the polycycle as the first three Lyapunov quantities for the cyclicity of a focus. As an application we study two cubic Kolmogorov families, with $N=3$ and $N=5$, and in both cases we are able to determine the cyclicity of the polycycle for all $\mu\in\Lambda,$ including those parameters for which the return map along $\Gamma$ is the identity.

The objectives of current study were to assess the prevalence and risk factors associated with postpartum anestrus in lactating dairy cows in Sylhet region, Bangladesh. A total of 420 postpartum cows of different breed and age were selected randomly from different dairy farms in studied area. Structured questionnaire was used to collect data from farm owner on prevalence and risk factors for postpartum anestrus. Observed heat within 60 days after parturition was considered as normal cyclic cows and others were considered as postpartum anestrus. The prevalence of postpartum anestrus was 36.20%. The study shows that older cows take relatively more time for ovarian resumption. Cow’s having first parity shows cyclicity within 60 days of parturition, and postpartum anestrus increases significantly with the advancement of parity. Postpartum anestrus was significantly higher (P< 0.001) in cows with poor (≤1.0) and excessive (>3) body condition scores (BCS), respectively, compared to those with moderate/optimal BCS (2– 3). The postpartum cyclicity in cows within 60 days with a history of normal placental expulsion was significantly higher than in the cows with RFM. Ovarian cyclicity was highest (75.92%) among the cows that were maintained in adequate hygienic conditions and lowest (43.51%) in a poor environment. The highest percentage (88.10%) of cows showed postpartum cyclicity with a history of short lactation length (0-150 days) and resumption of postpartum estrus cycle increases significantly with lactation length. Resumption of postpartum estrus cycles in cows takes more time with a history of minimal (<15 liters) daily milk production than the cow with medium (>15-25 liters) daily milk production. Cows get an adequate feed supply (both concentrate and green grass), which shows a positive effect on postpartum cyclicity. Pre and postpartum complications have a significant (p<0.001) effect on the postpartum cyclicity of cows. Endometritis (81.25%) followed by pyometra (75.76%) were recorded as major reproductive obstacles in ovarian resumption, whereas uterine prolapse (70.59%) followed by abortion (61.54%), milk fever (58.33%), stillbirth (58.33%) and dystocia (57.63%) were the major recorded complications in post-partum phase. The study also revealed that the non-restricted suckling period has a significant (p<0.001) negative effect on ovarian resumption. The risk factors including parity, BCS, placental expulsion, hygienic condition, lactation length, daily milk production and management system were significantly (P<0.01) influenced the postpartum cyclicity. Maintaining optimal BCS of cows, proper hygienic and good management practice, and farmer's training on management of cattle reproduction would improve the number of cows for breeding by 60 days postpartum. [ABSTRACT FROM AUTHOR]

Over the last decade, several lists of professions that will disappear soon have been published. In this aspect, the rapid development and spread of innovation, and digitalization of management processes threaten the existence of the accounting profession in its current traditional form. The article aims to outline the patterns of further evolution of the accounting profession in terms of scientific and technological progress based on the analysis of the history of the emergence and formation of accounting as a professional activity. The role of the accountant in the socio-economic structure of the world's major civilizations was analyzed from the emergence of the profession to the present time. The key features of accounting formation in the context of formational and civilizational approaches to understanding the historical process were considered. The scientific idea about the development of the accountant profession was deepened by highlighting the civilizational approach. In contrast to the formational approach, this approach involves cyclical development of the profession, variability of its manifestation and development in different parts of the world, and dependence on factors (economic, social, political, cultural, religious). The study results show that the development of the accounting profession follows a civilizational approach. Therefore, the potential replacement of some of its functions by technological solutions is not a threat to the profession's existence but rather a new stage of its development. A retrospective analysis of the accounting profession through the prism of a civilizational approach allows us to outline new accounting patterns and use them as a basis for its transformation to achieve compliance with the profession's future needs and challenges.

Abstract—The idea of the vital state of a tree as a combination of long-, medium-, and short-term components (according to the duration of restoration of the skeletal axes of the crown, branching axes, and leafy shoots) is substantiated using the example of the English oak in two contrasting ecotopes. It is shown that the same-name components of the growth of the trunk's early wood can serve as indicators of the vital state. The components of the growth of late wood characterize the potential of the life condition. The long-term component of the radial growth is described by the sum of the trend and a sinusoid; the medium-term component is described by the sum of two sinusoids. The trend is driven by competition in the stand; its decrease, due to the mass drying of the oak, improved the long-term component of the vital condition and the radial growth of surviving trees. The cyclicity of radial growth in the forest steppe is explained by the influence of droughts and phyllophages. The period of fluctuations of the long-term component of growth is equal to 31–35 years for early wood in the upland oak forest and 40–44 years in the floodplain and 28–30 years for late wood in the upland and 51–58 years in the floodplain. The periods of the main and additional sinusoids of the mean time component are similar in both oak forests: 12–13 and 7–9 years for early wood and 14–16 and 9–11 years for late wood, respectively. The risk of deterioration in the vital condition of the oak increases in the years of superimposition of minima of the cycles of the long- and medium-term components of the growth of the trunk's early wood. The risk of oak drying out increases with a decrease in latewood growth to 0.5 mm, which was observed in the floodplain oak forest during the period of mass oak drying and in the upland oak forest in the early 2000s, and it is expected in the late 2020s for oak trees of medium and worse development. [ABSTRACT FROM AUTHOR]

Microbiota regulate endometrial health in cattle. It is important to know what a 'good' microbiome is, in order to understand pathogeneses of uterine disease. Given that microbial influx into the genital tract of cows at calving is unavoidable, exploring the involvement of genital tract bacteria in promoting endometrial health is warranted. The dysbiosis of endometrial microbiota is associated with benign and malign uterine diseases. The present review discusses current knowledge about the altered endometrial microbiome and the implications of this modulation on endometrial inflammation, ovarian activity, fecundation, pregnancy, and postpartum complications. Intravaginal administration of symbiotic microbes in cattle is a realistic alternative to antibiotic and hormone therapy to treat uterine disease. Genital microbial diversity can be modeled by nutrition, as the energy balance would improve the growth of specific microbial populations. It may be that probiotics that alter the endometrial microbiome could provide viable alternatives to existing therapies for uterine disease in cattle. [ABSTRACT FROM AUTHOR]

An integrated approach combining petrography, photogrammetry, geochronology, SEM, and geochemical data was utilized to analyze lithofacies, stacking patterns, and lateral facies variations, and to interpret environmental dynamics during the deposition of carbonates from 'La Barre du Cengle' in the Early Paleogene. Located in the SE of France, the elliptical Cengle Plateau stretches 7 km from east to west and is 2 km wide, featuring cliffs ranging in thickness from 20 to 35 m. These cliffs showcase grayish, beige, and pinkish limestones dominated by palustrine facies, forming part of the 'Calcaire de Saint Marc' Formation of the Arc Basin. Sedimentary deposits within this interval were repeatedly subjected to subaerial exposure due to fluctuations in lake levels driven by climate, resulting in the organization of elementary sequences at decimetric to metric scales, which stack up into small-scale sequences at the decametric order. Deposition occurred under mainly subarid climatic conditions, with paleogeographic variations in the basin corresponding to changes in lake base levels over time and space. At least four frequencies of base level variation are present: very high and seasonal frequency, responsible for the formation of palustrine facies; high frequency, which generates the elementary sequences; medium frequency, which leads to the formation of the small-scale sequences; and low frequency which corresponds to the deposition of the entire set of limestones that form the Cengle cliff. The transition between lacustrine, palustrine, and pedogenic environments consistently occurs from west to east over time. In the more distal regions, the proportion of lacustrine facies tends to increase, and the thicknesses of the preserved sedimentary record tend to be greater. Conversely, palustrine and pedogenic facies predominate in the more proximal areas, typically resulting in decreased thickness. • Lithofacies anatomy reveals environmental dynamics in limestone deposition. • Vertical stacking pattern and lateral variation in lacustrine–palustrine sequences • Cyclical deposition patterns linked to climate-driven lake level fluctuations • Development of an exposure index as an indicator for subaerial exposure duration • Proposal of a model predicting facies & thickness in palustrine-dominated sequences [ABSTRACT FROM AUTHOR]

The article attempts to quantify the main parameters that characterize the economic crisis in Ukraine. Historical and systemic approaches are used as a basis of research methodology. In the course of the research the following methods were used: analysis to determine the comparative dynamics of macroeconomic indicators; Fourier analysis to determine the cyclical nature of the dynamics of macroeconomic indicators, the calculation of the duration and length of cycles; f-statistics to confirm the validity of the performed theoretical approximation of the lines of dynamics; analysis of variance to assess the variability of macroeconomic indicators; synthesis to build a time map of the aggravation of the crisis period of Ukraine’s economy. A comparative analysis of the dynamics of key macroeconomic indicators for the period 2010- 2020 in a quarterly manner. The cyclical nature of such dynamics is determined and formalized, with confirmation of reliability by means of f-statistics at the level of not less than 0.95. Two cycles of dynamics of macroeconomic indicators lasting 4 and 48 quarters were revealed. The beginning (IV quarter of 2010 / I quarter of 2011) and the end (IV quarter of 2023 / I quarter of 2024) of the modern period of economic crisis in Ukraine are determined. The variability of macroeconomic indicators according to their empirical values and deviations from the theoretical approximation of time lines is estimated and it is confirmed that the basis of variability of the analyzed indicators is their random fluctuations around the theoretical approximation of time lines. It was found that the greatest variability is inherent in price indices (consumer and industrial producers). The article further develops the methodological and practical principles of preventing the development of crisis processes in Ukraine by confirming their cyclicality and determining the duration of cycles, which allows to justify the application of countercyclical measures taking into account the specifics of quantitative patterns of crisis processes. The obtained results will contribute to the improvement of state regulation of economic development of Ukraine, taking into account its cyclical nature and duration of the current socioeconomic crisis.

According to the literature, there are several isolated range segments of Microtus socialis across the Palearctic, within which the distribution of the species has mosaic pattern. The westernmost range segment is located in the south of Ukraine covering steppe areas of the Crimea and southern Ukraine and stretching from the lower reaches of the Dnipro to Melitopol in the east and to Dnipro in the north. The social vole is represented in this centre of distribution by the subspecies Microtus socialis nikolajevi. The Yahorlyk Kut Peninsula in Kherson Oblast represents the westernmost edge of the subspecies’ range, where local conditions have practically remained in their natural state and the social vole (Microtus socialis) has a substantial population density. The Yahorlyk Kut Peninsula separates Yahorlyk Bay of the Black Sea from Tendra Bay. The western part of the peninsula (5540 ha) constitutes the ‘Yahorlyk Kut’ protected area of the Black Sea Biosphere Reserve, where steppe habitats have been partially preserved in their natural state in contrast to the area of the former bombing range, which was attached to the reserve in 1998, where the steppe has slightly transformed. This is the only area of typical halophytic wormwood–grass steppe that has avoided continuous ploughing and irrigation. The population density of M. socialis depends on the microrelief, hydrological conditions, and natural spring flooding. The disturbance of vegetation and soil cover due to fires and grazing disrupt the natural population dynamics of social voles. Recovery takes 2 to 3 years. After the cessation of the impact of hydrological, pyrogenic, or pascual factors, population density of the social vole in different habitats becomes balanced. Over 30 years, the population density of Microtus socialis ranged from 200 to 7000 ind./ha (on average 1800 ind./ha). The amplitude of fluctuations in the value of relative abundance in the periods between peaks is about 15 units. The cyclicity in population dynamics of the social vole in the Yahorlyk Kut Peninsula is 6–8 years. The dynamics of the number of social voles is determined by abiotic and biotic factors, which are also cyclical. Disturbances in the cyclicity of population dynamics can occur due to ‘force majeure’ situations of both natural and anthropogenic nature.

The economy of Ukraine’s regions is based on a linear model of production and consumption. This does not allow saving resource potential. The socio-economic paradigm of the use of resources in the state, developed for their preservation and mutual renewal, is the circular economy. Currently, a lot of attention is focused around the circular economy, as a new socio-economic doctrine of increasing the efficiency of resource use. The purpose of the article is to study the tools for the implementation of the circular economy, to determine the requirements for the transformation of the current economic system to adapt the cyclical reuse of raw materials. The method of theoretical knowledge, generalization, analysis, synthesis, modeling was used in the research process. The article reveals the essence of the concept of “circular economy” and offers its own definition of this concept as a way of economic development, where the value of products, materials and resources is preserved as long as possible, and waste is significantly reduced or even eliminated. The implementation of the circular economy model, which is based on the R-principles of its implementation, is considered. Therefore, the regional circular economy puts forward a more rational approach in the context of resource management. However, it also requires mass systemic transformations in the regions. Important for the implementation of the circular economy is the creation of urgent management conditions, as well as economic factors. It is substantiated that the main areas of development of the circular economy of the region are construction, mobility and transportation, food, products and services. The advantages of implementing the circular economy of the region are outlined. The scientific value of the work lies in the improvement of the concept of circular economy by the method of its implementation in the economic structure of a specific industry