Biomechanical analysis of parameters influencing pressure-volume relationship in the human eye

Purpose: To study the effects of different mechanical properties of the sclera and the cornea, such as their anisotropy, non-uniformity, and deflections in their spherical shapes on pressure-volume relationship. Methods: Correlations between the intraocular pressure (IOP) and the intraocular volume (IOV) were found for spherical and ellipsoidal orthotropic layers by means of 3D-theory of elasticity. Subsequently, the corneoscleral shell of the eye was modeled as a conjugated shell consisting of two segments. The sclera and the cornea are generally assumed to be the parts of the orthotropic elliptic shells with different geometrical and mechanical properties. Relationship between IOP and IOV was obtained for three mechanical models with following problem statements: 1) sclera and cornea are assumed to be soft shells; 2) sclera and cornea are supposedto be orthotropic shells with small modules of elasticity in the thickness direction; for this model calculations were made due to applied shell theory by Chernykh; 3) sclera and cornea are modeled as 3D elastic solids with FEM/ANSYS (ANSYS, Inc.,Canonsburg, PA). The calculations were performed for different sets of parameters for all three mechanical models and were compared to clinical data. Results: Transversal isotropic shells of revolution of different shapes (modelling the sclera) with equal initial volumes showed linear pressure-volume relationship, while proportionality factor (K) is minimal for a spherical shell (emmetropic eye).If the ratio of the axial length (AL) and the equatorial diameter of the shell (D) increases (the case of a shell modelling a myopic eye), then factor K increases up to 5-10%. If the ratio AL/D decreases (for a shell modelling a hyperopic eye), then factorK starkly increases up to 100%. The same effect was observed for the 2-segments model. Conclusions: Both the orthotropic properties of the sclera (the ratio of two tangential modules of elasticity) and the non-uniformity of the sclera have a significant effect on the character of the pressure-volume relationship and, thus, on the rigidity of the human eye. Geometric and elastic properties of the cornea also affect the relationship, although to the less extent

Economic mechanism of regulating land relations in the agricultural sector of Russia

The present study substantiates the economic basis for regulating land relations in the agricultural sector, outline the main stages of the formation and development of land relations in Russia. It also carries out a comparative analysis of land relations in Russia and foreign countries, presents theoretical aspects of economic regulation of land relations in the agricultural sector and considers domestic and foreign experience of the regulation of land relations. The activities of human society in connection with land are carried out on the basis of social relations, the key element of which is land relations. Transformations and regulation of land relations occur in the process of agrarian transformations. Historically, it has been proven that the implementation of agrarian reforms that change the socioeconomic situation, the working conditions of people, the production and marketing of products, does not bring about solid results without a proper transformation of land relations. The unique role of land relations in the system of agrarian reforms suggests that agrarian restructuring must begin with land reform.peer-reviewe

Economic and mathematical modeling of regional industrial processes

The paper presents a method for the parallel optimization of the structure of sown areas for calculating economic and mathematical models for the traditional and organic-oriented land use systems characterized by the introduction of an additional set of environmental criteria constraints. Based on the proposed methodology, an economic-mathematical model has been calculated and the effectiveness of the functioning of the Altai Foothills zonal agroecocluster has been proved. Considering the full involvement in the agricultural production turnover of land suitable to produce organic products, the level of profitability was 39.7% against 17.3% in case of optimizing the structure of the sown areas in the traditional system of agricultural production.peer-reviewe

Ensuring the national security of agriculture in the digital era through the formation of human capital

Purpose: Over the past few years in many literary sources and the media an issue of the digital economy is rapidly gaining popularity due to the qualitative technological changes in society. In current circumstances the qualitative component of labor resources called “human capital” is a priority value. Design/Methodology/Approach: The following research methods have been used in the work: monographic, abstract-logical, sociological, economic-mathematical and calculation-constructive ones. Findings: The solution of the problem of ensuring food security of the population of the region depends on the methods and strategies of applying technologies in domestic and global agriculture, as well as on the correct and effective use of scientific-technical implementations in the industry. Practical implications: Identification of segments in tourism is mainly made based on their geographical, demographical, socio-economic, psychographic, behavior characteristics or their combinations. On the other hand, the authors stress on the fact that there is no universal segmentation approach and therefore, potential tourists can be classified based on other characteristics. Originality/Value: The use of digital technologies in the agricultural industry will increase the efficiency of production activities.peer-reviewe

Финансовые взаимосвязи сценарных индикаторов бюджетного прогнозирования с показателями федерального бюджета России

The realism of the scenario indicators used in the formation of the federal budget of the Russian Federation in the context of the special significance of the budgetary mechanism for the adaptation of the national economy to global challenges becomes of particular importance while maintaining internal and external sanctions risks. The purpose of this study is to assess the validity of the forecast values of scenario macroeconomic indicators that determine the key characteristics of the Russian federal budget in the current budget cycle, and to develop proposals for clarifying the composition and concretizing approaches to their forecasting for the medium term in conditions of increased uncertainty. The study is based on an abstract-logical method, including a critical analysis of the predictive values of macro-indicators adopted as the basis for the parameters of the federal budget of the Russian Federation in 2023 and the planned period of 2024 and 2025 (using the level of consumer prices and the exchange rate of the ruble as an example), establishing causal relationships between the reliability of projected budget parameters at the federal level and the state of the Russian economy, identifying possible directions for the development of approaches to forecasting initial indicators for the preparation of the federal budget. In particular, the article suggests that in the forecasting of basic scenario parameters to detail the accounting for the dynamics of world prices, the real effective exchange rate of the ruble, to optimize the selection of exchange rate factors, and to take into account the variability of exchange rate volatility. The author’s developments presented in the article contribute to the efficiency of the execution of the federal budget in terms of the use of its resources, and therefore can be used in the activities of state authorities in the development of budget policy. Реалистичность сценарных показателей, используемых при формировании федерального бюджета Российской Федерации в контексте особой значимости бюджетного механизма для адаптации национальной экономики к глобальным вызовам, приобретает особое значение при сохранении внутренних и внешних санкционных рисков. Цель настоящего исследования —  оценка обоснованности прогнозных значений сценарных макроэкономических показателей, определяющих ключевые характеристики федерального бюджета России в текущем бюджетном цикле, и разработка предложений по уточнению состава и конкретизации подходов к их прогнозированию на среднесрочный период в условиях повышенной неопределенности. В основу исследования положен абстрактно-логический метод, включающий критический анализ прогнозных значений макроиндикаторов, принятых в качестве базы параметров федерального бюджета Российской Федерации в 2023 г. и плановом периоде 2024 и 2025 гг. (на примере уровня потребительских цен и валютного курса рубля), установление причинно-следственных связей между достоверностью проектируемых бюджетных параметров на федеральном уровне и состоянием российской экономики, выявление возможных направлений развития подходов прогнозирования исходных индикаторов для составления федерального бюджета. В частности, в статье предлагается при прогнозировании базовых сценарных параметров детализировать учет динамики мировых цен, реального эффективного курса рубля, оптимизировать отбор курсообразующих факторов, учитывать вариативность курсовой волатильности. Представленные в статье авторские разработки способствуют эффективности исполнения федерального бюджета и могут быть использованы в деятельности государственных органов власти при разработке бюджетной политики

Directions to improve economic efficiency of regional production

The paper provides theoretical grounding and the directions for improving the economic efficiency of the regional feedstuff production. The study develops a conceptual model of distributing management functions of feedstuff production between the regional authorities of state sectoral and economic management and the district level. The authors suggest the methodology for calculating potential capacity of intraregional feedstuff market, considering the demands of all categories of agricultural manufacturers. The study examines possibilities for implementing the strategy of diversified growth and development of the intraregional feedstuff market, including the terms of interaction between the large and micro-business inside the industry and cooperation of micro-business feedstuff manufacturers with agricultural production. The authors have developed the methodology for assessing the efficiency of feedstuff production, based on the aggregate estimation of the management organization, conditions for the development of feedstuff production and changes in the feedstuff production and livestock breeding industry.peer-reviewe

Economic potential and development prospects of small businesses in rural areas

The article examines the role of small business in the development of rural areas by the example of bakery production. Moreover, it demonstrates the need for the interaction of small bakery businesses with large enterprises of the industry and grain processors. The article reveals the development trends of small bakery production in rural areas. The conditions for the participation of small bakery businesses in rural areas in the development of the production of functional and specialized bread are substantiated. The article proposes the directions and mechanisms of support for small bakery production at the level of rural territories. The development of modern methods of redistribution of bakery production in proportion to the living population, measures of state support for small bakery production and expansion of the range of bread products that contribute to improving the health of the population of Russia, is the theme of this study. The object of the research is the development of small bakery production as a condition for improving the quality of life of the population in rural areas. The subject of the research is production and management relations that ensure the development of small bakery production and its impact on the quality of life of the population in rural areas.peer-reviewe

Ontogeny of the Human Pancreas

Pancreatic disorders are the most common pathologies in humans worldwide. Detailed information on pancreatic cytoarchitecture, vascularisation, innervation, morphogenesis, and cell differentiation is required for the development of new approaches to the treatment of these diseases. Currently, the majority of studies on pancreas development are performed on experimental animals (mainly rodents). Studies on human pancreatic prenatal development are restricted in number by ethical constraints and some technical difficulties. However, interspecies differences in pancreatic structure and development are considerable. Therefore, data obtained in experiments on animals and cell cultures must be supplemented with information obtained directly from human pancreatic autopsies. In this chapter, we summarise our previous results and the literature data on human pancreatic ontogeny. Special attention has been paid to the endocrine pancreas, which undergoes morphogenetic restructuring during human development. Several forms of structural organisation of the endocrine pancreas (single endocrine cells, small clusters of endocrine cells, mantle, bipolar, and mosaic islets) gradually appear during development. It is important that this restructuring is accompanied by changes in the ratio of pancreatic endocrine cells. The mechanisms of these changes are still unclear. The difficulties in identifying progenitor cells and tracking cell differentiation are the main problems associated with this issue

Comparative Analysis of Clinical, Hormonal and Morphological Studies in Patients with Neuroendocrine ACTH-Producing Tumours

This paper highlights the problem of neuroendocrine tumours (NETs) with clinical symptoms of hypercorticism caused by hypersecretion of adrenocorticotropic hormone (ACTH) by tumour cells. In most cases (85%), the tumours were localized in the pituitary gland (Cushing's disease); 15% of the patients had an extrapituitary tumour that manifest as an ectopic ACTH secretion (EAS). Comparative analysis of clinical, hormonal, histological, and immunohistochemical characteristics of pituitary and extrapituitary ACTH-secreting NET was performed. It included 46 patients with CD and 38 ones exhibiting ectopic ACTH secretion (EAS). Results of the study suggest differences between CD and EAS in terms of the severity of clinical manifestations and duration of the disease. Hormonal studies showed that EAS unlike CD was associated with high plasma ACTH and cortisol levels, late-evening salivary cortisol and daily urinary free cortisol, the absence of a 60% or greater reduction of cortisol in the HDDST test, and the presence of a low (less than 2) ACTH gradient in response to desmopressin administration with catheterization of cavernous sinuses. The study of morphofunctional characteristics of the removed NET demonstrated the ability of both pituitary and extrapituitary NETs to express ACTH as well as GH, PRL, LH, and FSH. The angiogenic markers (CD31 and VEGF) were detected with equal frequency regardless of the NET localization. The histological structure of all corticotropinomas suggested their benign origin, but extrapituitary NETs were represented by different morphological types with varying malignancy, invasiveness, and metastatic properties. A higher cell proliferation potential (Ki-67) was documented for NET in patients presenting with an ectopic ACTH secretion compared to those having corticotropinomas