Specific Restriction Research Articles

T790M mutation upconversion fluorescence biosensor via mild ATRP strategy and site-specific DNA cleavage of restriction endonuclease.

A unique combination of a specific nucleic acid restriction endonuclease (REase) and atom transfer radical polymerization (ATRP) signal amplification strategy was employed for the detection of T790M mutations prevalent in the adjuvant diagnosis of lung cancer. REase selectively recognizes and cleaves T790M mutation sites on double-stranded DNA formed by hybridization of a capture sequence and a target sequence. At the same time, the ATRP strategy resulted in the massive aggregation of upconverted nanoparticles (UCNPs), which significantly improved the sensitivity of the biosensor. In addition, the UCNPs have excellent optical properties and can eliminate the interference of autofluorescence in the samples, thus further improving the detection sensitivity. The proposed upconversion fluorescent biosensor is characterized by high specificity, high sensitivity, mild reaction conditions, fast response time, and a detection limit as low as 0.14 fM. Theperformance of the proposed biosensor is comparable to that of clinical PCR methods when applied to clinical samples. This work presents a new perspective for assisted diagnosis in the pre-intervention stage of tumor diagnostics in the early stage of precision oncology treatments.

Description of Paralocks language semantics in TLA+

One of the basic aspects of information flow control in applications is security policy language. Such language should allow to define security policies for evaluation environment elements in coherence with higher level access control rules. So the language is expected to be flexible because there may be different access control paradigms implemented on the system level: mandatory, role-based etc. An application may also have its own specific restrictions. Finally it is also desirable that the language support declassification (controlled release of information) during the computation. One of such languages is Paralocks. The research is devoted to the logical semantics of modified version of Paralocks realized in TLA+. Paralocks represents a language basis for the perspective information flow control platform PLIF which is being developed for the analysis of PL/SQL program blocks with author’s participation. It includes the proofs of the partial order and lattice defined on the set of security policy expressions.

Global research on RNA vaccines for COVID-19 from 2019 to 2023: a bibliometric analysis.

Since the global pandemic of COVID-19 has broken out, thousands of pieces of literature on COVID-19 RNA vaccines have been published in various journals. The overall measurement and analysis of RNA vaccines for COVID-19, with the help of sophisticated mathematical tools, could provide deep insights into global research performance and the collaborative architectural structure within the scientific community of COVID-19 mRNA vaccines. In this bibliometric analysis, we aim to determine the extent of the scientific output related to COVID-19 RNA vaccines between 2019 and 2023. We applied the Bibliometrix R package for comprehensive science mapping analysis of extensive bibliographic metadata retrieved from the Web of Science Core Collection database. On January 11th, 2024, the Web of Science database was searched for COVID-19 RNA vaccine-related publications using predetermined search keywords with specific restrictions. Bradford's law was applied to evaluate the core journals in this field. The data was analyzed with various bibliometric indicators using the Bibliometrix R package. The final analysis included 2962 publications published between 2020 and 2023 while there is no related publication in 2019. The most productive year was 2022. The most relevant leading authors in terms of publications were Ugur Sahin and Pei-Yong, Shi, who had the highest total citations in this field. The core journals were Vaccines, Frontiers in Immunology, and Viruses-Basel. The most frequently used author's keywords were COVID-19, SARS-CoV-2, and vaccine. Recent COVID-19 RNA vaccine-related topics included mental health, COVID-19 vaccines in humans, people, and the pandemic. Harvard University was the top-ranked institution. The leading country in terms of publications, citations, corresponding author country, and international collaboration was the United States. The United States had the most robust collaboration with China. The research hotspots include COVID-19 vaccines and the pandemic in people. We identified international collaboration and research expenditure strongly associated with COVID-19 vaccine research productivity. Researchers' collaboration among developed countries should be extended to low-income countries to expand COVID-19 vaccine-related research and understanding.

Analisis Semiotika Pola Komunikasi Keluarga pada Film “Noktah Merah Perkawinan”

The film 'Noktah Merah Perkawinan' tells the story of a married couple who have been married for several years and have two children. The communication patterns between the characters Gilang and Ambar depict events that reflect realities often observed in society, such as conflicts within a household. Therefore, the objective of this research is to analyze the semiotics of family communication patterns in the film 'Noktah Merah Perkawinan.' This research employs the semiotic analysis method of Ferdinand De Saussure, which comprises two elements: signifier and signified. Additionally, the research categorizes communication patterns based on De Vito's classification, including monopolistic family communication, balanced separate communication, unbalanced separate communication, and equality communication. According to this classification, the findings reveal that in monopolistic communication patterns, one party significantly dominates based on their influence within the family. In the case of balanced separate family communication, each family member plays their respective roles. Unbalanced separate communication occurs when communication within the family involves only one individual dominating due to their perceived expertise on a particular issue. In contrast, equality communication is characterized by open communication among family members without any specific restrictions. In conclusion, the research demonstrates that family communication patterns in this film vary widely, with each family member having their distinct role. Moreover, it suggests that all conflicts depicted in the film 'Noktah Merah Perkawinan' can be resolved through effective communication without any imposed limitations, as seen in the equality communication pattern. Keywords: Noktah Merah Perkawinan, Family Communication Patterns, Semiotic

Asymptotic behaviour for a parabolic p-Laplacian equation with an advection force

The rescaling method is presented to allow us establishing the interface functions and the nonnegative local solutions to the evolution of nonlinear degenerate parabolic p-Laplacian process with conservation laws that are posed in one-dimensional space. This equation has a self-similar solution which represents the main feature of this work. The Cauchy problem (CP) for this equation with specific restrictions in the range of parameters and the negative advection coefficient is considered. In this work, there are several regions to discuss the qualitative analysis for the local weak solutions and the asymptotic interfaces in the irregular domains. The dominating of the advection force over the p-Laplacian type diffusion will appear clearly in these regions. Moreover, the solutions of the CP for the degenerate parabolic p-Laplacian advection equations are asymptotically equal to the solutions of advection equations under some restrictions.

ATR1 A1166C (rs5186), FII G20210A (rs1799963), FV G1691A (rs6025), FXIII 97G > T (rs11466016) and MTHFR A1298C (rs1801131) polymorphisms and the risk of ST-elevation myocardial infarction in young Mexican individuals.

Previous studies had identified genetic variants associated with Myocardial Infarction, but results are inconclusive. We examined the association between FII G20210A (rs1799963), FV G1691A (rs6025), FXIII 97G > T (rs11466016), ATR1 A1166C (rs5186) and MTHFR A1298C (rs1801131) polymorphisms and ST elevation Myocardial Infarction in young Mexican individuals. We included a total of 350 patients with Myocardial Infarction <45 years old and 350 controls matched by age and gender. The polymorphisms were analyzed by PCR-RFLP using specific restriction enzymes. DNA fragments were separated by electrophoresis in 2% gel of agarose and visualized using SYBR green. The A1166C (p = 0.004) but not FXIII 97G > T (p = 0.19), G20210A (p = 0.32), G1691A (p = No significant) and A1298C (p = 0.21) polymorphisms were associated with increased risk for ST elevation Myocardial Infarction. Moreover, dyslipidemia, hypertension, smoking and family history of atherothrombotic disease were associated. We found that A1166C represented increased risk for ST elevation Myocardial Infarction. However, G20210A, G1691A, 97G > T, and A1298C were not associated. In addition, we had determined that Glu298Asp, PLA1/A2, TAFI Thr325Ile, ACE I/D, AGT M235T and PAI-1 4G/5G polymorphisms represented increased risk in the same group of patients. However, MTHFR C677T, AGT T174M, FV G1691A, TSP-1 N700S, MTHFR C677T and TAFI 174M polymorphisms were no associated. Our results suggest that in young patients with ST Myocardial Infarction, those polymorphisms could contribute to premature endothelial dysfunction, atherothrombosis, vasoconstriction, increased platelet aggregation, muscle cell migration and proliferation. Further studies are required to try to better assess gene-gene and gene-modifiable factors interaction.

Socio-legal conditioning of the differentiation of criminal responsibility for corruption offenses

The article states that it is advisable to consider the problem of social and legal validity of differentiation of criminal responsibility for corruption criminal offenses in two planes: external and internal.&#x0D; In order to establish very specific restrictions on the use of incentive criminal law measures against persons who have committed corruption criminal offenses, the legislator needed an appropriate tool: the definition of the concept of corruption criminal offense subsequently. This is due to the separation in the General part of the Criminal Code of Ukraine of a group of corruption criminal offenses and the legal consequences of their commission, which constitutes, conditionally speaking, an “external” differentiation of criminal liability. There are also legal reasons for the “external” differentiation of criminal responsibility for a corruption criminal offense, since the concept of “corruption offense” is defined in the Law of Ukraine on Prevention of Corruption (Part 1, Article 1), and corruption crimes are generally conventional and have a relatively autonomous existence determined by the provisions of international law, those documents ratified by Ukraine.&#x0D; The first step of the “internal” differentiation of criminal liability for corruption criminal offenses is determined by legal factors - the definition of the concept of “corruption” in the Law of Ukraine “On Prevention of Corruption”. The next step of “internal” differentiation is to take into account the types of special subjects of corruption criminal offenses and those spheres of social relations in which they participate and may abuse their powers or receive undue benefits. The reasons for such a differentiation seem to lie in the differences in the relations in which the above-mentioned special subjects are participants. The legislator, differentiating responsibility taking into account these spheres, firstly, determines the place of the article on the corruption criminal offense in the structure of the Special Part of the Criminal Code of Ukraine, and secondly, taking into account the importance of the relevant relations, constructs independent sanctions of criminal law norms.

Extending the pressure-time method to bend using 3D-CFD

According to the IEC 60041 standard, the pressure-time method (1D PTM) can be employed to determine the flow rate in hydraulic turbines. This method assumes a one-dimensional flow and applies to straight pipes with uniform cross-sections, with specific restrictions on the pipe length, fluid velocity, and distance between the measurement sections from any irregularities in the pipeline. However, challenges arise when applying this method in low-head hydropower plants due to the short lengths, irregularities like bends and developing flows in the intake. The present paper aims to improve the performance of the method in the presence of a bend. To this end, a test rig has been developed and measurements performed, including such geometry.The data are evaluated using the development of a newly proposed approach combining the 1D PTM based on an energy balance formulation and three-dimensional computational fluid dynamics (3D CFD) developed for axis-symmetrical accelerating flows. The updated methodology includes a correction of the experimental pressure measurements used in the 1D PTM to account for the effects of the Dean vortices present after the bend as well as the kinetic energy correction factors which deviate from known values in transient conditions.The results obtained under conditions involving the presence of bends either between or in close proximity to one show a significant improvement compared to the standard one-dimensional pressure-time method.

A GIS-Based Emotion Detection Framework for Multi-Risk Analysis in Urban Settlements

The application of sentiment analysis approaches to information flows extracted from the social networks connected to particular critical periods generated by pandemic, climatic and extreme environmental phenomena allow the decision maker to detect the emotional states of citizens and to determine which areas are most at risk and require specific resilient adaptation interventions. Of particular relevance today is the need to analyze the multiple risks generated by extreme phenomena in urban settlements in order for the decision maker to identify which areas are most at risk and prepare resilient intervention plans with respect to all the phenomena analyzed. In recent years, the COVID 19 pandemic emergency has forced citizens to undergo specific restrictions to protect their health; to these were added critical issues due to the occurrence of extreme climatic or environmental phenomena. In order to monitor pandemic and climate/environmental multi-risks in urban settlements, we propose a GIS-based framework in which an emotion detection method is applied to determine the prevailing emotional categories in urban study areas during pandemic periods and in the presence of extreme climatic phenomena. The framework was tested on a study area based in the six districts of the city of Bologna (Italy) in order to detect, based on the emotions expressed on social channels, which were the most critical city neighborhoods in pandemic periods and in the presence of extreme heat wave climatic events. The results show that the proposed model can represent a valid tool to support decision makers in identifying the most critical urban areas in the presence of pandemic and climate/environmental multi-risks.

Source-free domain adaptation with unrestricted source hypothesis

Domain adaptation aims to bridge the distribution discrepancy across different domains and improve the generalization ability of learning models on the target domain. The existing domain adaptation approaches align the distribution shift via adversarial training on the source and target data. In practice, however, the source data is usually unavailable due to the privacy factor. In this work, we mainly focus on the source-free domain adaptation setting, in which we are only accessible to the model trained on the source data and the unlabeled target data. To this end, we propose the Source-Free Adversarial Domain Adaptation (SFADA) approach to align the distribution of the target domain data in the absence of source domain data. In particular, we develop an effective metric to measure the domain discrepancy by introducing the proxy data of the source domain. To generate the proxy data, our approach retrieves target data which lie over the intersection of the supports of the source and target domains. We also derive the learning bound of the source-free domain adaptation theoretically and show that our proposed SFADA approach is capable of reducing the bound effectively. Additionally, instead of modifying the source model in previous source-free approaches, our SFADA does not require training the source model with specific restrictions (i.e., normalizing the classifier weight) for practice and privacy-related concerns. State-of-the-art results are achieved for different standard domain adaptation benchmarks. The code can be available from https://github.com/tiggers23/SFADA-main.

Extending SysML to Integrate Cost Analysis Into Model-Based Systems Engineering

Model-based systems design (MBSD), a current trend adopted by INCOSE, employs the systems modeling language (SysML), a standard introduced by OMG and INCOSE. Though there are numerous works on integrating performance exploitation in SysML, cost is not sufficiently explored as a driving design parameter. By integrating cost analysis in a popular modeling language like SysML, the proposed approach may be applied to any system designed using standardized languages and tools. In this work, we integrate cost analysis within SysML models at a generic level to explore design alternatives under specific cost and performance restrictions and perform tradeoff analysis. The proposed SysML extensions provide: 1) cost-related entities to encode cost aspects, such as capital and operating expenses, and 2) functions that enable the automatic computation of costs; these extensions are contained in a custom SysML cost profile. The feasibility and benefits of the approach are explored in two distinct real-world case studies with different purpose and characteristics. 1) Configuring a remote elderly monitoring system, taking into consideration patients' budgetary and operational concerns regarding the equipment installed in their homes. In this case, patients had the opportunity to evaluate and prioritize their concerns prior to using the system. 2) Exploring the improvement of the passengers' comfort as a level of service indicator in the Athens Metro railway system, taking into account operational cost constraints. In this case, the operator obtained forecasts of performance and cost of the metro system operation in order to choose between different operational policies.

Development of web based system for immigration daily returns

The Daily Border Returns System is a web-based system designed to automate the current manual documentation of border daily returns. The system facilitates efficient data management for day-to-day border activities, such as compiling daily travelers' reports, monthly reports, and situation reports. It utilizes a centralized database to store and manage relevant information about travelers, their immigration status, and any specific conditions or restrictions associated with their cases. The system enables immigration officers to easily access, update, and send information to headquarters, and it can print daily and monthly returns, aiding in decision-making and ensuring accurate and up-todate records. The system will be developed using Python, which is suitable due to its excellent support for working with data and generating reports. JavaScript will be used for web development, as it integrates well with HTML and CSS and has a vast ecosystem of libraries and frameworks, making it a good choice for the web-based interface of the Immigration Daily Border Returns System.

Aspects Regarding the Surface Temperature for Electric Motors used in Potentially Explosive Atmosphere

Most of the equipment operating in potentially explosive atmospheres in oil and gas industry is represented by electric motors, which in most situations act on various other elements (e.g. pumps, valves, fans etc.). Evaluation of explosion-proof protected electrical equipment in scope of certification is extremely important considering the risk of explosion that has to be minimized in order to ensure life safety and health of workers and to prevent damaging of property and the environment, as well as free movement of goods when they meet the essential safety requirements at European level. Even if electric motors for explosive atmospheres are designed and manufactured following some of the same principles as the ones used for other electric machinery, they have certain particularities related to their field of use. Thus, a series of specific restrictions and tests are required to be considered in their case. A very important component on which the explosion protection depends is the surface temperature of the equipment. This is the highest temperature reached in operation under the most unfavorable conditions (but within the tolerances set), by any part or surface of the electrical equipment (in the case of gaseous explosive atmospheres which may occur in technical installations operating in oil and gas industry, this temperature may appear on an internal component or on the outer surface of the case , depending on the type of protection used). To prevent an explosion it is very important that the tests performed on the equipment are done correctly and in the most unfavorable conditions. The purpose of this paper is to present the importance of performing tests to determine the surface temperature for electric motors designed to be used in explosive atmosphere generated by gases and vapors.

HIDDEN ENTREPRENEURSHIP IN THE NATIONAL ECONOMY: REASONS AND FEATURES

The purpose of the article is to substantiate and systematize the causes and features of hidden entrepreneurship in the national economy. It is noted that the generalization of the problem of the appearance and reasons for the development of hidden entrepreneurship creates conditions for determining the methods of reducing its level in Ukraine at the current stage. Identification of the main reasons, as well as awareness of the negative consequences of the further development of hidden entrepreneurship for the national economy should become the foundation for the transformation of the institutional environment in the country. Attention is focused on the fact that in scientific works there is a position that the emergence of the "underground economy" is due to endogenous reasons of self-awareness of entrepreneurs, their attitude to existing restrictions and prohibitions, as well as their attitude to the justice of the existence of such restrictions. The reasons for the appearance of hidden entrepreneurship are divided into general and partial. It was determined that common causes exist as a result of prohibitions and restrictions that are established regarding the regulation of the main aspects of economic activity. In turn, partial or specific reasons lead to the emergence of hidden entrepreneurship at the level of individual operations, types of activities, in relation to a specific restriction or prohibition. It was determined that the next stage in the development of social business began at the end of the 20th century as a result of the creation of the first social enterprises. It is during this period that the concept of "social business" begins to be used, which takes on the characteristics of a socio-economic phenomenon and is the subject of independent research by scientists. Thus, analyzing the given historical milestones in the development of the phenomenon of social entrepreneurship, two approaches to solving social problems that have arisen in society are highlighted: financial and institutional. It is substantiated that a significant reason for the possible appearance of hidden entrepreneurship is the practical implementation of the relationship between politics and the shadow economy. In addition, an important reason for the appearance of hidden entrepreneurship is the intention and desire of business to "survive" in conditions of socio-economic instability. This is due to the fact that the excessive costs faced by entrepreneurship in the legal sphere put the entrepreneur himself on the edge of survival, which leads to the forced transfer of the business into the shadows. It is pointed out that the reasons for the appearance of hidden entrepreneurship are also related to circumstances of an objective nature. In this case, it is not so much about a deliberate violation of the established restrictions as about their absence or insufficient formation. It is primarily about the emergence of operations and activities related to the intensification of the use and spread of information and communication technologies, the development of creative industries, social networks, etc. It is justified that in order to explain the cause-and-effect relationships of hidden entrepreneurship, it is advisable to pay attention to the possibilities of using a behavioral approach. That is, the study of the essence of behavior regarding the implementation of hidden entrepreneurship is expedient to conduct also from the standpoint of a behavioral approach and a separate aspect – deviant behavior. Attention is focused on the fact that the basis of behavior oriented towards hidden entrepreneurship is the motive of preserving activity, saving costs, and striving to increase one's own wealth. Usually, this behavior is accompanied by the choice of a form of shadow operations, given the scale of the business and risk appetite. It was determined that the main essential characteristics of behavior oriented towards hidden entrepreneurship are: individuality, propensity to risk, the search for a compromise between the expectation of income and the avoidance of losses. It was concluded that hidden entrepreneurship from the point of view of cause-and-effect relationships is one of the forms of the embodiment of the behavior of the subject of economic relations, which reflects the complex interaction of his rational and emotional motives. The main consequences of hidden entrepreneurship can be: a decrease in competition, especially in the case of an established partnership of shadow business with politics; receiving benefits, privileges, exclusive rights in the state, including due to corruption and lobbying for draft laws; reducing the risks of economic activity; the possibility of legalization of illegally obtained income; illegal appropriation of rights to economic benefits; the formation of stocks of money of shadow origin, due to the need to pay shadow expenses.

Content and types of special restrictions for public officers of certain state bodies

Content and types of special restrictions for public officers of certain state bodies

In Citizenship We Trust? The Citizenship Question Need Not Impede Puerto Rican Decolonization

Puerto Rico is an uncomfortable reminder of the democratic deficits within the world’s oldest constitutional democracy. Puerto Ricans are U.S. citizens who live in a U.S. territory that is subject to the plenary authority of Congress, to which they cannot elect voting members. In 2022, under unified Democratic control for the first time in a decade, Congress considered the Puerto Rico Status Act, legislation that would finally decolonize Puerto Rico. The Status Act offered Puerto Rican voters three alternatives to the colonial status quo—statehood, independence, or sovereignty in free association—and committed Congress to implementing whichever alternative won majority support from Puerto Rican voters. The Status Act sought to define how any change in status would affect Puerto Ricans’ access to U.S. citizenship. The Status Act proposed that all Puerto Ricans would retain their U.S. citizenship if Puerto Rico became independent or entered free association but included special restrictions that would limit Puerto Ricans’ ability to pass on their U.S. citizenship to children born after a change in status. While this Note appreciates the Status Act’s efforts to decolonize Puerto Rico, it argues that the Status Act erred in proposing this specialized regime for citizenship claims. Instead, it contends that the existing derivative citizenship framework would better regulate citizenship for Puerto Rican U.S. citizens born after a change in status. Although the Status Act died in the Senate, it represents a new and influential formula for decolonizing Puerto Rico. Future proponents of status reform should draw on the existing derivative citizenship law because it offers clearer provisions that can better ensure a large number of Puerto Ricans may rely on U.S. citizenship—a benefit Puerto Ricans themselves clearly value—even after a change in status.

프랑스의 반부패규율 정책의 함의와 시사점

Corruption acts that negatively affect the our macroeconomy as well as distortion of resource allocation vary considerably in their type and scope of persons involved, so the regulation for them should also be secured at a multi-faceted and systematic level. Considering that several acts that cannot be seen as violations of the legal provision can also be classified as types of corruption, such as solicitation through indirect strings and distortion of decision-making using influence within and between organizations, the need for more diverse and flexible regulation against corruption can be admitted. It is also important to set corruption acts as punishable acts through elements of a crime and to specify the regulations for them. However, the situation, such as the diverse type of corruption, difficulty in setting the category of related persons who commits corrupt, and the emergence of continuous new types of corruption acts, make us to acknowledge the necessity and validity of proactive regulative measures rather than passive, that is, post-punishment. Accordingly, the Institute of Internal Auditors has recently thrown up the topic of internal audit, that is, 3 Line Model, and France is focusing on various regulative activities against corrupt centered on anti-corruption agencies such as Cour Des Comptes France, AFA etc. We are also focusing on corruption regulations through various laws, including the Public Servant's Ethics Act, Conflict of Interest Prevention Act for Public Officials and the Act on the Establishment and Operation of the Anti- Corruption and Anti-Corruption and Civil Rights Commission, and various organizations such as the Board of Audit and Inspection and the Anti-Corruption and Civil Rights Commission etc. These acts mainly deal with specific restrictions on behavior and there are many cases of overlapping regulations, and there is no primary institution functionally responsible for corruption regulations. On the other hand, there are various corruption regulation measures such as AFA in France and thus we can consider the policy of France in our policy on regulation against corruptions. And furthermore, considering the experience of France, we are able to take into account of the policy that the full-fledged implementation of internal audits in that there are difficulties in swift legal response.

Analysis of the Implementation of Good Corporate Governance (GCG) Principles to Improve Service Quality at Bumiputera Syariah Life Insurance Company

In the case of PT AJB Bumiputera 1912, special restrictions are needed because insurance is different from a business established as a PT. This is where the difference is clear: in a PT, this is not always the case, but in a joint venture, the policy will inevitably also seek company investors. This feature involves legal risks as it requires each investor to accept liability for the company incurring losses. As a result, AJB Bumiputera's policyholders are responsible for any business activities that contain the risk of loss and are entitled to a portion of the company's income. The implementation of good corporate governance (GCG) at AJB Bumiputera is the subject of this research. The research method used in this study is qualitative. The findings of this study show that although AJB Bumiputera has tried to implement GCG principles (such as accountability, openness, and fairness), AJB Bumiputera has not implemented it optimally, in other words, the implementation has not been effective.

THE IMPACT OF GOVERNMENT POLITICAL DECISIONS ON ACCESS TO RECREATIONAL FACILITIES DURING THE COVID-19 PANDEMIC AND THE LEISURE PREFERENCES OF YOUNG PEOPLE

Purpose. Determining the impact of government policy in the field of applicable restrictions on access to recreational facilities during the COVID-19 pandemic on leisure behaviours (on the example of physical activity and the use of social media) of young people attending secondary schools and higher education facilities in Kraków (Poland).Method. The main research method used in the research process was a diagnostic online targeted population survey using the questionnaire technique. The research was conducted between 29 January and 26 March 2021 on a sample of secondary school and university students in Kraków (with particular emphasis on students from the University of Physical Education in Kraków). The survey resulted in 1,714 correctly completed questionnaires. An auxiliary research method was using focus group interviews conducted via the Internet.Findings. Government policies regarding the restrictions introduced during the COVID-19 pandemic affected the leisure activities of young people. They were generally less physically active than prior to the pandemic. In addition, the restrictions affected the selected forms of physical activity in free time – young people preferred mainly walks and hiking. At the same time, most of the respondents indicated spending more time on social media than they did before the pandemic. They used it to maintain social contacts with family and friends, as well as for entertainment, educational and professional purposes.Research conclusions and limitations. The empirical research concerns only secondary school and university students from Kraków and covers only the first year of the COVID-19 pandemic in Poland.Practical implications. The results of the research can be used by decision-making institutions in the scope of introducing restrictions on the functioning of the State (e.g. the Ministry of Health), as they indicate consequences of specific restrictions. The article may also be helpful for institutions organising leisure time, such as the Society for the Promotion of Physical Culture, the Polish Scouting Association, sports and recreation centres or local cultural centres. It will enable them to adapt their offer to leisure behaviours preferred by young people during lockdowns.Originality. The study of leisure behaviours relates to the situation of the COVID-19 pandemic outbreak, making it novel and not previously studied or analysed.Type of paper. Article presenting the results of an empirical study.

Selection of optimal structure of an energy-supply system for objects in an agro-industrial complex based on renewable-energy sources

This study considers the issues in constructing optimal systems for autonomous energy supply to objects in an agro-industrial complex using renewable-energy sources (RESs). The regularities of distribution of the zones for optimal use of solar, wind, hydraulic, and integrated power plants are revealed by comparing their operational and economic indicators. To determine the zones of optimal use of various RESs types, a systematic approach is employed, which allows conducting a comprehensive analysis of the object, strictly systematizing of research, and performing synthesis, i.e., finding the optimal system under given conditions. The level of functional and structural perfection of the systems is considered by evaluating their internal characteristics through a functional and structural approach using structural, functional, and functional–structural descriptions of the systems where each system generates the corresponding model types. Synthesis of the optimal structure of a renewable energy supply system (RESs) is carried out based on the operating conditions and consumer power consumption according to an “efficiency–cost” criterion, an integral-quality indicator, a complex efficiency criterion, and private indicators of the quality and cost of the systems. An algorithm and a calculation program are developed that allows determining the optimal structure of autonomous RESs under specific cases and restrictions. The developed recommendations on the choice of an optimal system for autonomous power supply using RESs under Kazakhstan conditions provide practical importance because they can potentially minimize errors in the choice of RESs types during the design stage.