bluuebunny/crossref_metadata_2025 huggingface dataset:
Is there a “renal-pulmonary syndrome” in rheumatoid arthritis?
Authors: Gordeev A. V. , Galushko E. A. , Matyanova E. V. , Pozhidaev E. V. , Zotkin E. G. , Lila A.  M.
Published: April 2024

Objective: to compare the course of “rheumatoid disease” in multimorbid patients with and without interstitial lung disease (ILD).

Material and methods. Two groups were formed of 1034 patients with active rheumatoid arthritis (RA) who met the 2010 ACR/EULAR criteria: one group with ILD identified by high-resolution computed tomography of the lungs (n=82) and another – without ILD (n=900). In all patients, estimated glomerular filtration rate (eGFR) was determined using the Cockroft–Gault formula. The presence and stage of chronic kidney disease (CKD) was assessed depending on the eGFR level: stage I CKD was diagnosed in eGFR <89 ml/min, stage II (subclinical) – 60<eGFR <89 ml/min, stage IIIa (clinical) – 45<eGFR<59 ml/min and IIIb – 30<eGFR<45 ml/min.

Results and discussion. Arterial hypertension (p=0.004), cerebrovascular disease (p=0.0001), diabetes mellitus (p=0.04), obesity, psoriasis (p=0.009) and stage II–III CKD (p=0.04) were more frequently observed in the group with ILD.

Conclusion. The combination of CKD and ILD frequently found in patients with RA and the known similarity and close interrelationship of the pathogenesis of these diseases, suggest a type of “renal-pulmonary syndrome” associated with a specific variant of RA.
Libman–Sachs endocarditis: regression after immunosuppressive therapy in a patient with systemic lupus erythematosus
Authors: Pugach V. A. , Bulanov N. M. , Shevtsova T. P. , Kurginyan K. V. , Novikov P. I. , Moiseev S. V.
Published: April 2024

Libman–Sachs endocarditis (nonbacterial thrombotic endocarditis, NBTE) may be one of the cardiac manifestations of systemic lupus erythematosus (SLE). It is characterized by the presence of sterile platelet thrombi on previously normal heart valves. The diagnosis of NBTE is difficult as it is often asymptomatic until complications such as systemic emboli or valvular dysfunction occur. Patients with Libman–Sachs endocarditis and SLE are treated with immunosuppressive and anticoagulant therapy and, if it is ineffective, surgical treatment.

A clinical case of SLE and Libman–Sachs endocarditis is presented. The clinical manifestations, diagnostic methods and treatment of NBTE in SLE are discussed. The difficulties in differential diagnosis and selection of optimal treatment tactics faced by physicians are highlighted.
Systemic lupus erythematosus with juvenile onset: current status of the problem (literature review)
Authors: Kaleda M. I. , Nikishina I.  P.
Published: April 2024

Patients with juvenile-onset systemic lupus erythematosus (jSLE) account for up to 25% of all SLE patients. The main difference between jSLE and SLE in adults is the greater role of genetic factors in the pathogenesis, higher activity, earlier development of complications and the need for more aggressive immunosuppressive therapy, which allows us to consider the onset of the disease in childhood as a special phenotype of SLE. The relevance of the study of jSLE arises from the variability of clinical manifestations and the unpredictability of the course, the difficulty of early diagnosis, the rapid development of organ damage and the unfavorable life prognosis.

The article presents the most important modern data on the diagnosis, classification, features of the clinical picture and treatment approaches of jSLE from a practical point of view.
Heterodoxo e histórico: el Proceso de Ottawa y la Convención sobre la prohibición de las minas antipersonales. 25 años de una historia de éxito del multilateralismo
Authors: Valcárcel Silvela Amaya
Published: April 2024

La Convención de Ottawa sobre la prohibición de las minas antipersonales de 1997 entró en vigor hace 25 años, el 1 de marzo de 1999, y fue el resultado del Proceso de Ottawa, un proceso independiente de negociación fuera de los foros facilitados por las Naciones Unidas y cuyo objetivo era la ilegalización de las minas antipersonales. Fue también el resultado de una asociación cohesiva y estratégica inusual entre gobiernos, organizaciones internacionales, como el ICRC, las agencias de la ONU y la sociedad civil, representada por la Campaña Internacional para Prohibir las Minas Antipersonales (ICBL). Este artículo explica el Proceso de Ottawa, desde la perspectiva de los supervivientes, jesuitas y hermanas religiosas que se involucraron desde sus inicios en la ICBL. Recordando al papa Francisco en su reciente exhortación apostólica Laudate Deum, el artículo presenta este proceso como un ejemplo para reconfigurar el multilateralismo. También busca ser una nueva apelación a la prohibición de las minas antipersonales a nivel global y su desactivación en lugares como Myanmar, Ucrania o Irak, para que así las personas desplazadas puedan, algún día, volver a sus hogares de manera segura.
Creaciones Telúricas, como emanación de las Artes de la Madre Tierra en contextos formativos
Authors: Gari Muriel Gary
Published: April 2024

Este artículo presenta una síntesis de la reflexión generada sobre un espectro de acontecimientos creadores que he denominado Creaciones Telúricas, configurados en el marco de un proceso de tesis doctoral adelantada en interacciones sinérgicas desarrolladas con diferentes actantes vinculados a procesos formativos de comunidades académicas y activistas, con quienes se adelantó el proceso investigativo.  Partiendo del análisis acerca de los modos de hacer, asumidos desde la investigación creación (Gómez, 2021) y las ecologías de saberes (Santos, 2019), se destacan los principales hallazgos en torno a procedimientos emergentes en los ámbitos de las visualidades y las sonoridades; así como en el plano de las cosechas epistémico-espirituales no hegemónicas. Las conclusiones destacan la importancia del enfoque biocéntrico del proyecto; y señalan algunas posibles variantes a seguir en procesos de formación artística escolar.
Unveiling the Creation of AI-Generated Artworks: Broadening Worringerian Abstraction and Empathy Beyond Contemplation
Authors: Arriagada Leonardo
Published: April 2024

En su obra pionera, Abstracción y empatía, Wilhelm Worringer profundizó en las complejidades de algunas obras de arte abstracto y figurativo, afirmando que evocan distintos impulsos en el público, específicamente, los impulsos hacia la abstracción y la empatía. Este artículo afirma la presencia de evidencia empírica que apoya la extensión de los conceptos de Worringer más allá del ámbito de la apreciación del arte al dominio de la creación artística.
En consecuencia, se postula que la abstracción y la empatía sirven como principios fundamentales que guían la producción tanto del arte abstracto como del figurativo.
Esto tiene una importancia particular en el siglo XXI, donde la inteligencia artificial (IA) asume un papel creativo que estaba ausente en la formulación inicial de la teoría de Worringer. Por lo tanto, este artículo postula que la IA alberga inherentemente una predisposición para la generación de arte abstracto, debido a sus orígenes y funcionamiento no vivos e inorgánicos.
Comparative analysis of ventricular stiffness across species
Authors: Usui Yuu , Hanashima Akira , Hashimoto Ken , Kimoto Misaki , Ohira Momoko , Mohri Satoshi
Published: April 2024

Investigating ventricular diastolic properties is crucial for understanding the physiological cardiac functions in organisms and unraveling the pathological mechanisms of cardiovascular disorders. Ventricular stiffness, a fundamental parameter that defines ventricular diastolic functions in chordates, is typically analyzed using the end‐diastolic pressure–volume relationship (EDPVR). However, comparing ventricular stiffness accurately across chambers of varying maximum volume capacities has been a long‐standing challenge. As one of the solutions to this problem, we propose calculating a relative ventricular stiffness index by applying an exponential approximation formula to the EDPVR plot data of the relationship between ventricular pressure and values of normalized ventricular volume by the ventricular weight. This article reviews the potential, utility, and limitations of using normalized EDPVR analysis in recent studies. Herein, we measured and ranked ventricular stiffness in differently sized and shaped chambers using ex vivo ventricular pressure‐volume analysis data from four animals: Wistar rats, red‐eared slider turtles, masu salmon, and cherry salmon. Furthermore, we have discussed the mechanical effects of intracellular and extracellular viscoelastic components, Titin (Connectin) filaments, collagens, physiological sarcomere length, and other factors that govern ventricular stiffness. Our review provides insights into the comparison of ventricular stiffness in different‐sized ventricles between heterologous and homologous species, including non‐model organisms.
Discrimination of five commercial Guibourtia wood species using terahertz time domain spectroscopy combined with machine learning approaches
Authors: Yu Min , Wang Jinbo , Yang Meng , Wang Jiajun , Zhou Liang , Qian Liangcun , Gao Junlan
Published: April 2024

Terahertz waves hold significant potential for applications in wood identification, owing to their good penetration and distinctive fingerprints in wood. This study focuses on wood samples from five different Guibourtia species as the research objects. The terahertz time-domain spectroscopy (THz-TDS) is employed to acquire the spectroscopic signals of the wood samples and to extract their optical parameter data. The THz refractive indices are dimensionally reduced through principal component analysis (PCA), and three machine learning models, namely partial least squares-discriminant analysis (PLS-DA), random forest (RF), and support vector machine (SVM), are employed to classify the wood of five different Guibourtia species. Time delays of the wood samples from five different Guibourtia species are concentrated in the range of 60–62 ps and exhibit different amplitudes in the frequency domain. Refractive indices showed significant variations within the THz band. PCA for dimensionality reduction of terahertz time-domain spectral data significantly improves the recognition rate of machine learning models. Applying PCA to the refractive index data, the RF model achieves a highest recognition rate of 96.9 % and an overall classification accuracy of 98 %. Current results demonstrate that THz-TDS enables rapid, accurate, and non-destructive classification and identification of wood from the Guibourtia species.
Prenatal presentation of a hyperfunctioning thyroid nodule
Authors: Scrushy Marinda G. , Liu Christopher , Lopez Ximena , Diesen Diana
Published: April 2024

Objectives

Fetal and neonatal hyperthyroidism are most commonly seen in patients whose mothers have Graves’ disease. Rarely, it can be caused by non-autoimmune conditions. As these conditions are rare, the workup and treatment is not uniform and can lead to persistent symptoms and long-term negative health effects.

Case presentation

This report describes a patient with congenital hyperthyroidism from a toxic adenoma presenting with fetal tachycardia. The patient was initially managed medically after birth, but was eventually treated with thyroidectomy.

Conclusions

This case report highlights an additional, important, differential diagnosis for fetal hyperthyroidism when maternal Graves’ disease has been ruled out.
Coherent light-emitting metasurfaces based on bound states in the continuum
Authors: Farazi Soheil , Tadigadapa Srinivas
Published: April 2024

An emergent need exists for solid state tunable coherent light emitters in the mid-infrared range for spectroscopy, sensing, and communication applications where current light sources are dominated by spontaneous emitters. This paper demonstrates a distinct class of coherent thermal emitters operating in the mid-infrared wavelength regime. The structure of the light source consists of a dielectric metasurface fabricated on a phononic substrate. In this study, we present the first implementation of off-Γ Friedrich–Wintgen bound states in the continuum at mid-infrared wavelengths suitable for developing the next generation of coherent light emitters. Numerical analysis of the emissivity spectrum reveals the interference of resonances leading to avoided crossings and the formation of Friedrich–Wintgen bound states in the radiation spectrum. Additionally, significant localized field enhancements are observed within the metasurface at operating wavelengths. The emissivity spectra measured by reflectivity and emission experiments exhibit temporally coherent emission peaks in the vicinity of the bound state in the continuum, the first such demonstration in the mid-infrared region for wavelengths longer than 7 µm. These results represent a new approach for significant advancement in realizing mid-infrared coherent light emitters with promising implications for future technologies.
Viral-mediated inflammation by Poly I:C induces the chemokine CCL5 in NK cells and its receptors CCR1 and CCR5 in microglia in the neonatal rat cerebellum
Authors: Perez-Pouchoulen Miguel , Holley Amanda S. , Reinl Erin L. , VanRyzin Jonathan W. , Mehrabani Amir , Dionisos Christie , Mirza Muhammed , McCarthy Margaret M.
Published: April 2024

Objectives

To study the effect of viral inflammation induced by Polyinosinic:polycytidylic acid (PIC) on the cerebellum during a critical period of development in rats.

Methods

Neonatal rat pups were treated with PIC on postnatal days (PN) 8 and 10 after which we quantified RNA using Nanostring, qRT-PCR and RNAscope and analyzed immune cells through flow cytometry and immunohistochemistry on PN11. Using the same paradigm, we also analyzed play juvenile behavior, anxiety-like behavior, motor balance using the balance beam and the rotarod assays as well as fine motor behavior using the sunflower seed opening test.

Results

We determined that male and female pups treated with PIC reacted with a significant increase in CCL5, a chemotactic cytokine that attracts T-cells, eosinophils and basophils to the site of inflammation, at PN11. PIC treatment also increased the expression of two receptors for CCL5, CCR1 and CCR5 in the cerebellar vermis in both males and females at PN11. In-situ hybridization (RNAscope®) for specific transcripts revealed that microglia express both CCL5 receptors under inflammatory and non-inflammatory conditions in both males and females. PIC treatment also increased the total number of CCL5+ cells in the developing cerebellum which were determined to be both natural killer cells and T-cells. There were modest but significant impacts of PIC treatment on large and fine motor skills and juvenile play behavior.

Conclusions

Our findings suggest an important role for CCL5 and other immune cells in mediating inflammation in the developing cerebellum that potentially impact the maturation of cerebellar neurons during a critical period of development.
Asian People Reached by the Centers for Disease Control and Prevention HIV Testing Program in the United States: HIV Testing, Linkage to HIV Medical Care, and Interview for Partner Services 2014–2020
Authors: Xu Songli , Wang Guoshen , Williams Weston , Marano Lee Mariette , Wright Carolyn , Uhl Gary
Published: April 2024

The purpose of this analysis is to describe HIV tests and associated outcomes for Asian people reached by the Centers for Disease Control and Prevention (CDC) HIV testing program. We analyzed CDC-funded HIV tests among Asian individuals in the United States, Puerto Rico, and the U.S. Virgin Islands (2014-2020). Of the 415,560 tests, the positivity of new diagnoses was higher among males (0.49%, aPR = 7.64) than females (0.06%), and in the West (0.42%, aPR = 1.15) than in the South (0.25%). In non-health care settings, positivity was highest among men who have sex with men (MSM; 0.87%) and transgender people (0.46%). Linkage to HIV medical care among Asian people was 87.5%, and 70.7% were interviewed for partner services. Our findings suggest that improvements are crucial, particularly for Asian MSM, in linkage to care and interview for partner services.
Witnessing Meaningful Interpersonal Encounters Facilitates the Perception of Social Emotions
Authors: Westmoreland Kirsten E. , Gilchrist Iain D. , Quadflieg Susanne
Published: April 2024

Judging the emotional states of others based on visual information alone is a fundamental aspect of rapid impression formation. However, it remains unclear whether complex social emotions (such as feelings of pride or envy) can be inferred by merely observing others. Here we demonstrate consistent perception of such complex social emotions when a person is seen in the context of a meaningful interpersonal encounter. In Study 1, we show that the perception of social emotions is enhanced when emotionally expressive target individuals are seen with meaningful social companions rather than with social distractors or in isolation. In Study 2, we illustrate that the perception of social emotions increases systematically when formerly isolated individuals are subsequently seen with meaningful social companions rather than with social distractors or objects. We conclude that interpersonal encounters play an integral part in the perception of social emotions.
La fermeture des établissements scolaires en temps de pandémie : point de vue d’adolescents et d’adolescentes en région éloignée sur les changements perçus dans leur pratique d’activité physique
Authors: Guay Sandrine , Pouliot Eve , Maltais Danielle , Giroux Patrick , Simard Ann-Sophie , Maltais-Dufour Olivia , Lacelle Catherine
Published: April 2024

En raison de la pandémie, en mars 2020, les adolescents et les adolescentes se sont retrouvés confinés à leur domicile pour un temps indéterminé. Afin de mieux comprendre leur vécu dans ce contexte particulier, notamment en ce qui concerne leurs habitudes de vie, des entrevues de groupe (n=10) ont été réalisées auprès de 57 jeunes fréquentant trois écoles secondaires du Saguenay-Lac-Saint-Jean en 2021-2022. Les résultats soulignent la pertinence de mieux comprendre leur vécu et leurs besoins en temps de crise, de même que l’importance du rôle des milieux scolaires quant à la pratique d’activité physique chez les jeunes, et ce, en vue d’améliorer la qualité du soutien qui leur est offert.
Agroforestry in temperate-climate commercial agriculture: Feedback from agroforestry practitioners in the Mid-Atlantic United States
Authors: McRae Sebastian M.
Published: April 2024

Industrially managed annual monocultures are the primary agricultural system used to grow most crops in developed countries. These systems necessitate the destruction of natural ecological complexity for their management and contribute substantially to the environmental problems facing society in the 21st century, including climate change, biodiversity and habitat loss, water pollution, topsoil loss, and desertification. Agroforestry is a promising set of alternative practices that involve integrating trees into agricultural systems to optimize biophysical system interactions and achieve a range of environmental and economic benefits. Much of the agroforestry literature has focused on potential adopters rather than farmers who have implemented agroforestry, but researchers and farmers alike stand to gain from insights into farmer experiences. This study aims to address that gap through qualitative interviews with farmers in New York, Pennsylvania, and Maryland who utilize production-oriented agroforestry. Perceived benefits of agroforestry included: improved climate resilience; lifestyle and mental health benefits; improved water management; improved soil health; increased presence of wildlife; improved livestock wellbeing; improved business resilience; provision of food, fuel, or fiber; improved ecological connectivity; reduced need for purchased inputs; low labor requirements; improved yields; improved pasture or crop health; and high product quality. Perceived challenges included: early setbacks; negative interactions within agroforestry systems; high labor requirements; difficulty mechanizing; tree establishment work; delayed or uncertain yields; novel crop challenges; meat processing challenges; difficulty planning for the future; high startup costs; and high management complexity. Farmers identified the value of both farmer–farmer networking and government support in the form of flexible and context-specific grant funding, system examples, business planning, and technical assistance. Many of the challenges farmers face can be overcome with agroforestry system designs that optimize early cash flow, balance labor productivity and environmental outcomes, and allow for harmonious integration of animals and appropriate-scale machinery.
Features of the Formation of Fractal-Holographic Thinking of Students: Perceptual Challenges of the Digital
Authors:   Institute of Education Development of the Republic of Bashkortostan, Madjhuga Anatoly Gennadievich , Polikarpova Elena V. ,   Southern Federal University, Gadaborsheva Zarina I. ,   Chechen State Pedagogical University, Dzhegistaeva Larisa I. ,   Chechen State Pedagogical University, Dashkueva Petimat V. ,   Chechen State Pedagogical University
Published: April 2024

Introduction. The article examines the features of the formation of fractal-holographic thinking of students in the system of modern education, starting from kindergarten and ending with university, in the context of the methodology of transdisciplinary research, organically linked to the synergetic paradigm, the key point of which is the fractal approach. The purpose of the article is to consider the essence of fractal-holographic thinking of students and the features of its formation in the context of the perceptual challenges of the digital age. Methodology and methods of research. The methodological basis of the research is fractal and transdisciplinary approaches that allow us to consider the process of formation of fractal-holographic thinking of students, emphasizing the perceptual challenges of the digital era in the context of the interaction of trends in aestheticization and technologization. Building the scientific concept of “fractal-holographic thinking of students”, philosophical statements about man as a bio-psycho-socio-cultural-existential phenomenon are taken into account. The results of the study. For the first time, the authors explore the fractal-holographic thinking of man from the perspective of such fundamental concepts as the concept of “beauty of fractals”, expressing the laws of harmony of nature, the concept of T.V. Chernihovskaya “The universe is a work of Baroque art”, as well as the archetypes of the unconscious Jung. Special attention is paid to the mechanisms of formation of fractal-holographic thinking of students, which functions in the context of an aestheticized and technologized world. The content of the study describes fundamentally new approaches regarding the phenomenology of “perceptual challenge”, which make it possible to effectively form fractal-holographic thinking of students in the era of digitalization. For the first time, an attempt has been made to classify and describe the perceptual challenges underlying the formation of fractal-holographic thinking of students of the third millennium in the context of the interaction of aestheticization and technologization trends. Conclusion. When explaining the essence of fractal-holographic thinking, its relationship with holographic and synergetic thinking is shown, the role of fractal-holographic thinking in the hierarchy of human thinking types is determined, and the emphasis is on the importance of art, which among human activities has the highest degree of creativity.
A Retrospective of Specialized Psychological and Pedagogical Classes and Technology of their Practical Implementation in a Pedagogical University
Authors:   Voronezh State Pedagogical University, Fetisov Alexandr S. , Kudinova Yulia V. ,   Voronezh State Pedagogical University
Published: April 2024

The article provides a historical overview of the development of psychological and pedagogical classes, as well as the current state of the network of psychological and pedagogical classes in the Russian Federation. The importance of psychological and pedagogical classes in the system of pre-professional pedagogical training is shown. The purpose of the article is to analyze the retrospective of specialized psychological and pedagogical and to show the technology of their practical implementation in a pedagogical university. The main methods of this article are: content analysis of the concepts of “pre-professional pedagogical training” and “psychological and pedagogical class”, analysis of scientific and methodological literature, analysis of historical and pedagogical, normative and comparative sources, as well as the results of domestic and international studies of specialized pedagogical classes, their formation, specialization, features of manifestation in different regions and model specifics. The results of the study. It is revealed that the idea of creating specialized psychological and pedagogical classes is not new. The conducted historical and pedagogical analysis showed that pedagogical classes arose in the middle of the XIX century and are connected with the history of the formation of women’s education in Russia. Over more than a century of history, teaching classes have acquired new formats, been abolished several times and revived again. A new period in the history of specialized psychological and pedagogical classes began in 2021 with the adoption of the Concept of specialized psychological and pedagogical classes. The technology of practical implementation of the Concept of specialized psychological and pedagogical classes in a pedagogical university is shown on the example of one of the models. The experience of organizing psychological and pedagogical classes in the Voronezh region is analyzed. In conclusion, conclusions are drawn about the importance of psychological and pedagogical classes in the system of continuing pedagogical education, as well as the integration of pedagogically gifted schoolchildren into professional community at the stage of studying at school. Various model organizations in the educational practice of psychological and pedagogical classes contribute to increasing the status of a teacher, as evidenced by the practice of the Voronezh region on the example of the Voronezh State Pedagogical University.
Using Dual Learning Technologies to Prepare for a Demonstration Exam in Secondary Vocational Education
Authors:   Reshetnev Siberian State University of Science and Technology, Kolga Vadim V. , Shuvalova Marina A. ,   Aerospace College Reshetnev Siberian State University of Science and Technology
Published: April 2024

The article updates the problem of the need for highly qualified technicians and workers, without solving which it is impossible to further develop both the high-tech enterprises of the country in general and the regional economy in particular. This is confirmed by the analysis of the need for specialists. The article discusses the problem of preparing future technicians and highly qualified workers for a demonstration exam using dual training technologies in secondary vocational education. The purpose of the article is to identify and test a set of dual training technologies that contribute to effective preparation and successful passing of a demonstration exam, which provides simulation of real production conditions for technicians and highly qualified workers. The methodology for organizing training consists of implementing professional modules in in-demand specialties on the territory of a partner enterprise with a schedule of individual training at the college. Using the method of pedagogical experiment, the developed proposals were tested and their effectiveness was tested using the example of training students of the specialty 02/15/08 Mechanical Engineering Technology in the competencies “Milling work on CNC machines” and “Turning work on CNC machines.” Based on the results of the experimental work, the conclusion is made about the positive dynamics of completing the tasks of the demonstration exam in the experimental group, which meet the requirements of employers of partner enterprises in the real sector of the economy.
Model of Implementation of Consistency in Professional and Pedagogical Activities of math Teachers
Authors:   Novosibirsk State Pedagogical University, Shilo Nadezhda Grigoryevna , Taranova Marina Vladimirovna ,   Novosibirsk State Pedagogical University, Abakumova Ksenia V. ,   Novosibirsk State Pedagogical University
Published: April 2024

This article shows one of the possible theoretical models for the implementation of system city in the professional and pedagogical activities of a future mathematics teacher in the learning process. The constructed model is presented from the position of a systemic and methodological approach to the activities of the teacher as a carrier of activity and is focused on updating system city in the upcoming professional and pedagogical activities. In the proposed theoretical model, one of the most important components is a set of special means: systemic-structural, subject knowledge and procedural-didactic, which correspond to the general scientific (methodological), the actual subject and educational and didactic activities of the teacher. Our own pedagogical experience confirms that the use of this complex of special tools in a teacher’s activities gives rise to a special systematic style (way) of his practical and mental activity. The purpose of the article is to reveal the essence and content of the theoretical model for the implementation of system city in the professional and pedagogical activities of a future mathematics teacher. Methodology. The methodological foundations of this study are the starting points and ideas of theoretical-constructive and analytical-reflexive theory. The basic methods and means of a systemic strategy of mental and practical activity, a systemic-structural and constructive methodology for the implementation of scientific research activities, as well as the basic ideas of the theory of knowledge, thinking and reflection were used. Research results. Based on the systemic-methodological approach to defining the activities of a teacher, the content and structure of a conceptual-theoretical model for the implementation and actualization of system city in the professional and pedagogical activities of a mathematics teacher have been developed. To sum up, conclusions are drawn about the need to implement and update the presented theoretical model, functionally oriented towards the implementation of system city in the professional and pedagogical activities of a mathematics teacher. At the same time, further practical implementation of this model will improve the quality of the teacher’s work in the process of teaching mathematics, optimize the learning process, and also increase the efficiency of mathematics education.
Estudio diacrónico del dequeísmo en un corpus de cartas privadas
Authors: Vaamonde Gael
Published: April 2024

Pese al notable interés que ha suscitado el dequeísmo en los estudios gramaticales del español, lo cierto es que apenas contamos con trabajos que traten esta construcción desde una perspectiva diacrónica. Además, el dequeísmo parece ser un fenómeno escasamente documentado en la historia del español, a juzgar por los números que suelen arrojar los corpus históricos de referencia, lo que sin duda limita la base empírica para su investigación. En este trabajo presentamos nuevos datos y nuevos ejemplos sobre el dequeísmo en el español clásico y moderno extraídos de Post Scriptum, un corpus formado por cartas de particulares escritas entre el siglo XVI y el primer tercio del siglo XIX. Partiendo de la información que contiene este corpus y de las particularidades que ofrece, abordamos cuatro cuestiones acerca del dequeísmo en épocas pasadas: (i) su consideración como fenómeno marginal y propio de la lengua popular (ii) su relación con el progresivo empleo de la secuencia de que en oraciones completivas (iii) su conversión en una variante visible a lo largo de la Edad Moderna y (iv) su distribución en función de la procedencia geográfica de los hablantes. Finalmente, y en términos más generales, el presente artículo invita a reflexionar sobre la utilidad de los corpus de pequeño dominio para la investigación en lingüística histórica.
Physical and mechanical properties of mycelium-based fiberboards
Authors: Gezer Engin Derya , Uçar Ezel , Gümüşkaya Esat
Published: April 2024

Mycelium-based fiberboards were evaluated as potential environmentally friendly substitutes for conventional wood-based composites. The goal of this study was to produce and test fiberboards out of yellow pine and poplar fiber mixtures without using any extra adhesive. Pleurotus ostreatus and Ganoderma lucidum fungi were used. The physical and mechanical characteristics of the fiberboards were tested under the influence of two different types of fungi and two different incubation periods. The key findings indicated that the mycelium-based fiberboards had higher water absorption and thickness swelling percentages compared to control boards produced with adhesives. The fiberboards produced from fibers inoculated with Ganoderma lucidum and incubated for 30 days had higher mechanical properties compared to other test fiberboards. This indicated the possibility of utilizing them in specific applications. Although the mycelium-based fiberboards did not fully meet all the EN 622-5 (2009) standard requirements for dry-condition use, the results highlighted their potential in sustainable material development. This study provided useful insights into the utilization of mycelium for the development of mycelium-based fiberboards.
Determining the coefficients of a hydrodynamic model of cavitating pumps of liquid-propellant rocket engines from their theoretical transfer matrices
Authors:   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Dolgopolov S.I.
Published: April 2024

The characterization of cavitating pumps of liquid-propellant rocket engines (LPRE) is an important problem because of the need to provide the pogo stability of liquid-propellant launch vehicles and the stability of liquid-propellant propulsion systems for cavitation oscillations. The development of a reliable mathematical model of LPRE cavitating pumps allows this problem to be resolved. The goal of this work is to determine the cavitation number and operating parameter dependences of the coefficients of a lumped-parameter hydrodynamic model of LPRE cavitating pumps from their theoretical transfer matrices obtained by a distributed-parameter model. The following coefficients are found as a function of operating parameters: the cavitation elasticity, the cavitation resistance, the cavity-caused disturbance transfer delay time, and the cavitation resistance distribution coefficient. The last two coefficients are new in the hydrodynamic model of cavitating pumps, and they were introduced when verifying the model using experimental and theoretical pump transfer matrices. Analyzing the cavitation resistance distribution coefficient as a function of operating parameters shows that it markedly decreases with increasing cavitation number. This testifies to that the location of the lumped cavity compliance is shifted from the mid position towards the pump inlet. Therefore, the assumption that the lumped cavity compliance is located in the middle of the attached cavity regardless of the cavitation number is not justified. The fact that the distribution coefficient as a function of cavitation number intersects the abscissa axis near a cavitation number of 0.25 may indicate the boundary of existence of attached cavities and thus the applicability boundary of the theoretical model. The disturbance transfer delay time as a function of cavitation number sharply increases at cavitation numbers of about 0.05. At cavitation numbers of about 0.25, it is close to a constant.
Finite-element model of a vertical tank on a rigid foundation
Authors:   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Kucherenko O. Ye.
Published: April 2024

This study addresses the problem of finite element modeling of a 20,000 m3 vertical steel tank subjected to static loads. The structure includes a cylindrical wall of total height 17,880 mm and diameter 39,900 mm. The shell thicknesses of the cylindrical wall are determined according to strength and buckling design standards. The geometric model is axisymmetric. The analysis involves the calculation of the stress and strain fields of the cylindrical wall and the contact zone between the flat bottom and the rigid foundation under various combinations of external loads, namely, excessive and hydrostatic pressures. The ANSYS Mechanical software is used for finite element analysis. Three-dimensional SOLID186 and SHELL281 elements are used for axisymmetric modeling of the shell structure in a three-dimensional formulation. To simulate the contact zone, CONTA174 and TARGE170 finite elements are used to model the moving contact surface of the bottom and the fixed surface of the rigid foundation, respectively. The model is verified by comparing the radial displacements calculated numerically and analytically. The discrepancy does not exceed 4%, thus evidencing the adequacy of the finite element model. The contact zone is analyzed for non-standard service conditions, such an excessive internal pressure in the tank (2.5 and 3 kPa compared to 2 kPa under normal conditions). The unilaterally constrained "bottom–foundation" contact zone model allows the bottom to detach from the foundation, thus leading to contact opening. A full detachment occurs under a certain combination of the excessive and the hydrostatic pressure. For certain liquid levels in the tank, the gap decreases, which may be due to a reduced effect of the excessive pressure. This is accompanied by the development of internal detachment caused by the increasing moment from the hydrostatic pressure. The internal detachment increases the bending moment at the wall–bottom junction, which, under certain conditions, may cause plastic deformations followed by the development of an emergency state.
Particle size determination in grinding
Authors:   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Ternova K. V. , Priadko O. V. ,   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, Muzyka L. V. ,   Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine
Published: April 2024

Mathematical approaches to particle size determination in closed grinding cycles are considered. The features of average particle size calculation for different fractions with account for the grinding kinetics are shown. Particle size calculation algorithms for the entire fraction range are proposed. Particular attention is paid to output determination for fractions of arbitrarily small particles. A particle size determination method based on a lognormal distribution function is shown. In choosing the mathematical approach, the process requirements are taken into account. The basis of in-flow noncontact particle size control is the acoustic monitoring of the process and the established relationships between the particle size and the acoustic characteristics. The signal amplitude during material transportation in the energy carrier flow and jet grinding was found as a function of the particle size and grinding conditions. In order to determine the fractional composition of a mixture, the frequency characteristics of acoustic signals and their variation during the transportation of narrow fractions and mixtures were considered. The analysis of the amplitude-frequency characteristics of acoustic signals during the compressed-air transportation of narrow fractions in the jet mill channels confirmed the presence of signals with frequencies characteristic for each fraction. These frequencies were experimentally related to the particle size of a fraction in a mixture. These studies form a basis for a noncontact method of determining the particle size distribution of a material in an air flow, in particular in jet grinding. The results may be used for engineering and technological calculations in mineral dressing and the development of process equipment for the chemical industry, construction, mining, and metallurgy.
Rational Mode Parameters of Power Units Operating in Modern Energy Market Conditions
Authors:   Anatolii Pidhornyi Institute of Mechanical Engineering Problems of NAS of Ukraine, Tarelin Anatolii O.
Published: April 2024

The paper analyzes the operation of condensing and heating turbines in modern energy market conditions with an assessment of the impact of operating parameters of live and secondary steam on economic indicators. It has been shown that when operating at variable loads, the most effective in terms of high-pressure turbines is a rational reduction in the initial pressure ps (sliding pressure), which leads to an increase in thermal efficiency by 1-1.5%. The experimental results of a study of the vacuum effect in the condenser on fuel consumption are presented in the paper as well. Using a specific example of the K-320-26.5 turbine unit, the need for a rational choice of cooling water flow in winter season to ensure optimal vacuum is shown. The issue of choosing a rational steam reheat temperature tr is examined in more detail. It has been established that one of the main reasons for the decrease in the efficiency of turbine units when operating in variable modes is the irrational use of the reheat temperature and the heat of phase transition in the flow part of the low pressure cylinder. The physical explanation of these processes in the turbine as tr decreases is given in detail. It has been shown that, as a result of analyzing the operation of turbine units of various capacities, a rational choice of reheat temperature (reducing tr by 10-20 °C) increases thermal efficiency by 1-2 %, and turbine efficiency - by 0.4-1.0 %. It is recommended to consider the pressure of the hot steam of the high pressure cylinder (рs), the pressure in the condenser (рc=f(tcirc.water)), as well as the reheating temperature tr, which altogether leads to a reduction in heat consumption by 2.5-3.5 % as rational parameters of steam when operating in variable modes. In order to increase the economic efficiency of the operation of turbine units of TPPs and CPPs at reduced loads, it is recommended to revise the regulatory documentation on the current amendments for changes in the reheat temperature. It is stated that with strict adherence to the recommendations discussed above, fuel savings at TTPs and CHPs in Ukraine can amount to 250–300 thousand tons of coal per year.
Increase of the Efficiency of Heat Supply Units of the CHP Plants Due to the Choice of Rational Heat Release Modes
Authors:   Anatolii Pidhornyi Institute of Mechanical Engineering Problems of NAS of Ukraine, Shubenko Oleksandr L. , Alyokhina Svitlana V. ,   University of Applied Sciences Technikum Wien, Holoshchapov Volodymyr M. ,   Anatolii Pidhornyi Institute of Mechanical Engineering Problems of NAS of Ukraine, Babenko Olha A. ,   Anatolii Pidhornyi Institute of Mechanical Engineering Problems of NAS of Ukraine, Kotulska Olha V. ,   Anatolii Pidhornyi Institute of Mechanical Engineering Problems of NAS of Ukraine
Published: April 2024

The possibilities of increasing the efficiency of heat supply turbines of CHPPs due to the choice of rational modes of operation of network water heaters are analyzed. With the help of a software and computing complex developed at the Institute of Mechanical Engineering Problems of the National Academy of Sciences of Ukraine and adapted by the authors to the operating conditions of CHPP generating equipment with one or two network heaters, a set of calculation studies of various ways of connecting them depending on the outdoor air temperature is conducted in the paper. Areas of positive effect associated with increase in the electric power of the power plant have been established. The calculation study was carried out at typical power plant water consumption from 1000 t/h to 4500 t/h, in the range of changes in the outdoor air temperature from -11 ºС to 10 ºС (heating season) and more than 10 ºС (hot water supply). The load change of the power unit was carried out due to the consumption of fresh steam at a constant pressure and temperature at the turbine inlet. As shown by the results of the operation of the T-100/120-130 heat supply turbine in operating conditions with one or two heat supply steam selections, in the area of positive outdoor air temperatures above 2 ºС, it is advisable to use one lower selection (with the upper one turned off) for all network water consumption. At the same time, additional electric power in the area of outdoor air temperatures above 6ºС can be from 0.25 MW to 2.15 MW. However, when the outdoor air temperature is less than 2 ºС, work with one lower heating selection becomes irrational. From the point of view of choosing rational modes of operation of turbine plants, the most important are the results of determining the optimal distribution of heat load between network heaters. The gain in electrical power of the turbine can be up to 2.46 MW in the nominal mode of operation with two heaters, and up to 7.84 MW in comparison with the use of single-stage heating. The nature of the influence of the distribution of the heat load indicates that during deprivation from the instructional uniform distribution of the heat load between network heaters, it is possible to obtain additional electricity.
Factors Impact of the Stock Market Performance During the Covid-19 Crisis
Authors: Goh Thomas Sumarsan , Henry Henry , Erika Erika
Published: April 2024

Research originality: This research adds the exchange rate variable and the use of the Vector Autoregressive (VAR) model that can add to the financial literature.Research Objectives: This study examines how macroeconomics can impact a business during a crisis. The stock market has associated access with new COVID-19 cases and new deaths in Indonesia. During the pandemic, the exchange rate is critical, so this study observes the exchange rate of IDR against USD. This paper investigates the relationship between new cases, new deaths, and the exchange rate with the stock market index.Research Methods: The study retrieves the daily data from March 2, 2020, to June 30, 2022, from Our World in Data, Indonesia's stock exchange, and Indonesia's Statistic Central Bureau. We have used the ADF, Vector Autoregressive (VAR) Model, impulse response function, and the Toda Yamamoto causality test. Empirical Results: The findings reveal a significant negative impact of new COVID-19 cases, new deaths, and exchange rates on the stock market. Toda Yamamoto's causality analysis reveals substantial evidence of unidirectional daily growth of new COVID-19 deaths in the stock market and a bidirectional causality of new COVID-19 cases and new COVID-19 deaths.Implications: The policy implications of this study are to stabilize markets, impact overall financial stability, support entrepreneurship, and develop a competitive market environment that can encourage innovation. JEL Classification: C5, E31, F31How to Cite:Goh, T. S., Henry, H., & Erika, E. (2024). Factors Impact of the Stock Market Performance During the Covid-19 Crisis. Etikonomi, 23(1), 47 – 62. https://doi.org/10.15408/etk.v23i1.32005