Daugavpils University
  • Daugavpils, Latvia
Recent publications
The first observations of myrmecophilous ant cricket Myrmecophilus acervorum (Panzer, 1799) and the family Myrmecophilidae from Latvia are presented. The observations were made in two locations subject to flooding in springtime. Adult and juvenile female individuals were observed. The discussed records appear to be the northernmost known distribution limit of this species.
Background and Objectives: Adolescent smoking is influenced by sociodemographic and psychological factors, including emotional and conduct problems. Understanding how sample size impacts the interpretation of these associations is critical for improving study design and public health interventions. This study examines the relationships between smoking behaviours, sociodemographic factors, and emotional and conduct problems, focusing on how sample size affects statistical significance and effect size interpretation. Materials and Methods: Data from the Latvian Health Behaviour in School-aged Children study was analysed. Chi-square tests and logistic regression were conducted to evaluate associations between smoking behaviours, sociodemographic factors, and emotional and conduct problems. Analyses were performed on both a large general sample and ten smaller generated subsamples to compare the impact of sample size on statistical outcomes. Results: Age and conduct problems emerged as the most consistent predictors of adolescent smoking behaviours across large and small samples, while other predictors, such as family affluence and family structure, showed weaker and less consistent associations. A large sample produced significant results even for weak predictors. Conclusions: This study highlights the importance of integrating effect size interpretation with statistical significance, particularly in large datasets, to avoid overstating findings. By leveraging real-world data, it provides practical recommendations for improving study design and interpretation in behavioural, medical, and public health research, contributing to more effective interventions targeting adolescent smoking.
This paper opens new possibilities for application of chaos theory in the financial industry, namely analyzing solutions of systems of ordinary differential equations using the Lyapunov exponent and Kaplan-York dimensions. Using mathematical tools, including two-dimensional and three-dimensional attractor projections, a three-dimensional financial model constructed using ordinary differential equations is analyzed in detail, and conclusions are drawn about the chaotic behavior of the solutions of the system. This paper considers both a financial chaotic system proposed by Gao and Ma in 2009 and its modified analog. The 2D and 3D images of the attractor are provided.
This paper presents new records and noteworthy data on the following taxa in SE Europe and adjacent regions: lichenised fungus Solorina bispora var. subspongiosa, saprotrophic fungi Geastrum berkeleyi and Marasmius epiphylloides, liverworts Bazzania trilo
We consider a mathematical model of genetic regulatory networks (GRN). This model consists of a nonlinear system of ordinary differential equations. The vector of solutions X(t) is interpreted as the current state of a network for a given value of time t. The evolution of a network and future states depend heavily on the attractors of a system of ODE. We discuss this issue for low-dimensional networks and show how the results can be applied to the study of large-size networks. Examples and visualizations are provided. The remarkable feature of our research is that the interactions in a network are supposed to be variable. We focus on the interaction of variable activation-inhibition cycles.
Export product diversification (EPD) mitigates a country's vulnerability to global trade shocks, contributes to its high-quality economic progress, and increases its resilience. Natural resource endowment (NRE) is considered as one of the important determinants of EPD that is less explored by scholars. The contribution of NRE to EPD will remain a matter of debate in China. The paper aims to identify the drivers of the diversification of export products in China using the province level data from 2011 to 2019. It considers key determinants including foreign direct investment (FDI), human capital (HC), technological innovation (TI), and trade openness (TO). The results of the Fixed Effect-Driscoll-Kraay standard errors (FE-DKSE) indicate a positive and significant relationship between NRE and EPD. This suggests that a rise in NRE within a country promotes EPD. Furthermore, FDI, TO, TI, and HC have statistically significant positive links with EPD. Moreover, the findings of our research are consistent across all regions. The robustness analysis provides evidence that our findings are both significant and robust. The empirical findings indicate that the included variables are fundamental determinants of EPD, which provides policymakers with crucial policy implications. To encourage EPD, the government should implement policies that stimulate these determinants. ■
In this article, the focus is on exploring planar piecewise smooth quadratic systems, a significant class of dynamical systems that exhibit changes in behavior under different conditions but with smooth transitions between these states. The main objective is to introduce a second-order averaged method designed specifically to identify limit cycles, repeating trajectories in a system's phase space indicative of periodic behavior. This innovative method not only allows for the detection of these cycles but also quantifies their number, providing a deeper understanding of the system's long-term behavior. The paper highlights its applicability by demonstrating the maximum number of limit cycles that can exist in two distinct systems, offering valuable insights into the dynamics of such systems and contributing to the broader field of mathematical modeling and analysis.
This article examines the implementation and challenges of the 1778 Master Plan for Rēzekne, a town in modern-day Latvia, over the period from 1778 to 1836. Developed as part of the Russian Empire’s broader urban planning efforts under Catherine the Great, the plan aimed to impose Enlightenment ideals of order and rationality. However, its execution faced significant challenges due to the geographical and social distance between the imperial centre and its peripheral colony. The plan’s failure to account for Rēzekne’s actual topography – particularly its swampy eastern areas – along with resistance from the town’s predominantly Jewish population contributed to its partial and problematic implementation. Despite these obstacles, the 1778 Plan laid the groundwork for future urban development, which culminated in the 1836 Master Plan under Nicholas I. By analysing contemporary maps and visual sources, this article highlights how imperial ambitions clashed with local realities.
The publication highlights the versatile applications and synthesis strategies of 7H-benzo[de]anthracen-7-one (benzanthrone) derivatives explored in the past 27 years, obtained through direct synthesis such as palladium-catalyzed cyclizations or functionalization through nucleophilic aromatic substitution, Kabachnik-Fields, Sonogashira, Vilsmeier-Haack type and other reactions. These approaches have enabled the development of compounds with tailored luminescent properties. Among the diverse applications, significant focus is placed on the role of benzanthrone derivatives in biomedical imaging, liquid crystal systems and fluorescence-based sensing technologies, with emerging uses in optoelectronics and materials science. This comprehensive review underscores the pivotal role of benzanthrone derivatives in advancing fluorescent materials science while highlighting ongoing innovations and their impact on technological and scientific advancements. Publicaton: https://link.springer.com/epdf/10.1007/s11696-025-03977-x?sharing_token=kXxEmy9K5J_f7BkUpjRsyve4RwlQNchNByi7wbcMAY6igDgo4YtnKkWv50GN7SUaYZm8pOhnfAWlwSQY9xxwjuI8YGyKhGrjDfvmxDhCD98pRCQKdXmKUilp3lGwuudg_lbbWuFL_nwGOOd2ASXHfgOa2pDhjdoyETVnGQzQb1I%3D
Predator fear can leave long-lasting impacts on the neural circuitry and behaviours of prey organisms, leading to enduring effects on memory characteristic of post-traumatic stress disorder. Previous research showed better survival in Drosophila grown with predators and, thus, stress. A better long-term memory can likely help Drosophila avoid visiting places where predators have been spotted before. We investigated the link between predator-induced stress exposure and memory retention in two groups of Drosophila . In this study, one group of Drosophila was exposed to visual and olfactory signals of spiders during the first five days of their adult stage, prior to memory testing. We found that 1 h short-term memory did not differ between experimental flies and flies in the control group, which were raised without spiders. In contrast, flies exposed to predator presence exhibited better long-term memory than control flies 24 h later. The strain of Drosophila used was found to possess a diabetes-like biochemical phenotype in a previous study, indicating metabolic shifts between glucose and lipids, which influences memory formation and retention. We show that linking long-term memory, body and brain metabolism, and predation risk-induced stress is needed to better understand the post-traumatic stress-associated biochemical and behavioural adaptations of Drosophila .
Background: Apical surgery can address periapical pathologies when conventional endodontic treatments fail. Advanced platelet-rich fibrin (A-PRF) has emerged as a regenerative material with the potential to enhance healing in periapical surgery. In this study, we evaluated the effect of A-PRF on periapical lesion healing using cone beam computed tomography (CBCT). Methods: A randomized controlled trial at Rīga Stradiņš University Institute of Stomatology included 43 participants (15 males, 28 females; mean age: 44 years) with periradicular lesions. Participants were divided into experimental and control groups. Baseline and follow-up CBCT imaging assessed lesion volumes at 6 and 12 months post-surgery. Results: Mean lesion volumes significantly decreased from 431.4 mm³ at baseline to 102.8 mm³ at 6 months and 49.2 mm³ at 12 months (p < 0.001). A-PRF did not significantly reduce the lesion sizes compared to the controls (p = 0.043), but was associated with reduced inflammation and enhanced soft tissue healing. Key confounders included gender and baseline lesion volume, with males exhibiting smaller lesion sizes postoperatively. Conclusions: The results suggest that A-PRF may not offer a significant advantage in terms of reducing defect size or improving radiographic resolution.
We present a genome assembly from a specimen of Anaspis regimbarti (the false flower beetle; Arthropoda; Insecta; Coleoptera; Scraptiidae). The genome sequence has a total length of 457.61 megabases. Most of the assembly (99.89%) is scaffolded into 8 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 16.39 kilobases in length.
Background: Angioedema (AE) is a localized, non-pitting swelling affecting subcutaneous and/or submucosal tissues. Despite varying underlying mechanisms, AE significantly impacts patients’ quality of life (QoL), which is closely linked to disease activity and control. Objectives: This study aimed to translate and linguistically validate the angioedema activity score (AAS), angioedema control test (AECT), and angioedema quality of life (AE-QoL) questionnaires into Latvian, and to use these validated tools to assess disease activity, control, and quality of life within the study population. Methods: PROMs, including the AECT, AAS, and AE-QoL, underwent a standardized linguistic validation process. Patients with hereditary angioedema (HAE), mast cell-mediated angioedema (AE-MC), and angioedema of unknown origin (AE-UNK) were recruited from two separate studies conducted at Riga Stradiņš University. Results: We enrolled 41 participants (90.2% women) with a mean age of 46.3 years. AE-MC was the most common (63.4%), followed by HAE (19.5%) and AE-UNK (17.1%). The mean AAS score was 15.8, with no significant differences regarding AE type, gender, or age. The mean AECT score was 8.29, revealing significant gender differences (women: 7, men: 13.5). The AE-QoL total score was 45.5, with significant gender differences in most domains. Strong correlations were found between AE-QoL scores and both AAS and AECT, highlighting the impact of both disease activity and control on QoL. Conclusions: The Latvian adaptation of the AAS, AECT, and AE-QoL questionnaires effectively assesses AE activity, control, and disease-related QoL. Our study reveals poor disease control, underscoring the need for tailored interventions and regular PROM evaluations, with the Latvian version of the AE-QoL questionnaire identifying five distinct domains compared to four in the original version.
Background: It is important to accurately determine the legal age at which a person is considered and treated as an adult; in many countries, it is 18. With the increasing migration flow to European countries, accurate age estimation methods must be implemented. In this study, the third molar maturity (I3m) index and mandible condyle cortication stage were tested to distinguish adult from non-adult Latvian individuals using dental panoramic radiographs. Methods: This study included 716 selected dental panoramic radiographs of patients between the ages of 14 and 22. The lower-left third molar apical root parts were analyzed, and the I3m index was calculated. In addition, the condyle cortication stage was evaluated. Results: All logistic regression models achieved statistically significant results (p < 0.001). The accuracy was high for all groups (males: 0.90, females: 0.87, both genders: 0.89), and the sensitivity was lower than the specificity, particularly for females (sensitivity: 0.55). The I3m index appears to be a strong predictor across all models, while the mandibular condyle cortication stage plays a more nuanced role, depending on sex and the stage of condyle maturation. A higher I3m index value (greater than the cut-off of 0.095 in males) indicates a higher likelihood of being classified as a non-adult male for this model; however, in females, a cut-off point higher than 0.150 indicated a higher likelihood of being classified as a non-adult female. The new proposed cut-off values need to be tested on a new sample. Conclusions: The I3m index is a reliable age estimation tool, and a modified cut-off value could be determined for each gender in Latvian individuals. The condyle cortication stage is a weak tool for chronological age estimation in dental panoramic radiographs.
Introduction The Game Immersion Questionnaire (GIQ) serves as a tool for evaluating immersion within the realm of online gaming. Immersion is a crucial psychological state experienced by users interacting with digital environments, influencing their engagement, engrossment, and total involvement. While the original GIQ was structured around seven first-order factors and three second-order factors, its applicability beyond gaming contexts remains unexplored. This study extends the GIQ to capture the immersion experiences of a more expansive cohort of online users beyond gamers. Methods The extended GIQ was administered to a cohort of active internet users from Latvia (n = 227), aged 13 to 65 (M = 26.6, SD = 8.4), with 53.7% identifying as female, 33% as male, and 13.2% as nonbinary. Factor analysis was conducted to examine the structure of the extended questionnaire and validate its applicability to a broader range of online users. Results Factor analysis revealed three first-order factors – Engagement, Engrossment, and Total Immersion – that together form a global second-order factor named the Level of Immersion in the Digital Environment. These findings align with the original hierarchical structure of the GIQ while extending its relevance to a wider population of online users. Discussion The extended GIQ provides insights into the immersion experiences of a diverse range of online users across various digital environments. By adapting the GIQ for broader use, this study contributes to the understanding of immersion beyond gaming and supports its application in different online contexts.
The adoption of renewable energy sources offers significant economic and sustainability benefits. These sources—solar, wind, hydro, biomass, and geothermal—are crucial for transitioning to a sustainable, low-pollution energy model. Key benefits of renewable energy include job creation, reduced energy costs, decreased reliance on imported resources, minimized environmental impact, and long-term economic stability. Renewable energy also plays a vital role in achieving environmental and sustainability goals. By reducing dependence on imported energy resources, it enhances energy security. Countries investing in renewables lower their reliance on international supply chains and geopolitical risks, which is particularly relevant for European Union nations historically dependent on energy imports. Domestic renewable energy resources help stabilize prices and ensure a consistent long-term energy supply. This study aimed to assess the impact of renewable energy sources on the economy and sustainable development in the European Union. Data for all variables were collected from the Eurostat database. The unbalanced panel data sample consisted of 27 EU countries (N = 27), covering the period 2001–2022 (T = 22). The analysis and generalization of the scientific literature compared theoretical and practical statements, econometric models, and the least squares method. Here, the hypothesis that “the transition to renewable energy sources will have a smaller negative impact on economic growth when the country is more dependent on imported energy sources” was accepted, and this means that using renewable energy sources not only contributes to environmental goals and climate change mitigation but also provides various economic benefits, including job creation, lower energy prices, greater energy security, and long-term sustainability. It is essential in the transition to a cleaner and more sustainable economy.
The purpose of this study was to investigate the most important factors shaping the quality of life in a social care institution from the clients’ perspective. This study examines factors beyond direct care that affect the quality of life for clients in social care institutions, focusing on Riga Municipality’s Social Care Center “Gailezers”. Structured interviews with 95 clients assessed six domains: autonomy, relationships, activities, environment, food, and care quality. This study emphasizes the need to align services with clients’ views to enhance their well-being. Based on the results, this study aimed to develop practical proposals for adjusting the content and organization of social care services to better align with the clients’ understanding of the factors affecting their quality of life in the institution.
Introduction. The discussion surrounding the formulation of educational outcomes for higher education programs at contemporary universities is gaining renewed significance due to the increasing diversity of student populations and the demand for equitable and affordable education. Aim. This research aims to identify the specific aspects of personal potential as a component of the structure of educational outcomes for students, particularly in the context of the inclusive university transformation. Methodology and research methods. The structure of educational outcomes in the context of higher inclusive education was developed based on a comparative analysis of D. Leontiev’s personal potential model and a universal competence framework created within the methodology for assessing supra-professional competencies by A. G. Komissarov, E. A. Stepаshkina, O. B. Soboleva, and others. The empirical study employed methods for assessing supra-professional competencies as adapted by A. G. Komissarov and E. A. Stepаshkina. The sample comprised 505 students from the University of Tyumen. The data collected were subjected to cluster and correlation analyses using IBM SPSS Statistics. Results. The analysis and interpretation of the psychological profiles obtained from students enabled the identification of personal potential as a central educational outcome within the framework of the inclusive university transformation. Universal design for learning serves as a tool that facilitates the adaptation of educational strategies to align with the unique characteristics of each student’s personal potential. Scientific novelty. The authors outline the structure of educational outcomes within the framework of an inclusive transformation of the university. In this context, the primary function is fulfilled by personal competencies (self-skills), while personal potential serves as the connecting factor among the various levels of competencies, including hard skills, soft skills, and self-skills. Practical significance. The university administration and faculty, by considering the diverse profiles of students with varying levels of personal potential, can create the most favorable and effective educational environment based on the principles of universal design.
The society in Latvia, like many other societies, is driven by commercial practices and consumerism. Commercialization can be viewed as a part of a wider globalized consumer society aimed at increasing the profit of some players through marketing certain products. Religion is about a set of values that keep the society integrated but commercialization of religion leads to higher levels of self-proclaimed individualism and egoism. More often religions have been commercialized for the benefit of certain groups of people. This paper reveals some aspects of commercialization and simplification of religion and religious practices of members of the Latvian population who have no religious training and background as well as those generations of people who have grown without any religious upbringing at all. This can be explained by the historic circumstances of the atheistic ideology imposed on the whole generation that was raised without any substantial religious training and a new generation that was raised in the circumstances of globalization when religion was perceived mainly as one of the goods in the global marketplace to be consumed. Research questions: How is the commercialization of religion and religious practice viewed by the representatives of different generations as reinforced by media? For this purpose the author conducted semi-structured interviews with ten participants representing two different generations. The methodology of the paper involves individual interviews with representatives of two generations, namely, Generation X that grew up in the conditions of the ideology of atheism and Generation Z that has grown up in the circumstances of globalization and consumerism.
The article seeks to answer the question “Can ecopedagogy mitigate the impact of unsustainable education?” The aim of the article is a phenomenological and hermeneutical reflection on some issues relevant to ecopedagogy at the beginning of the Anthropocene era, when education policy, its governance, the transformation of the holistic approach into a more holistic one and the biological origins and deep cosmological roots of the human species have started to diminish. These and other wicked problems have been used in a reflexive participatory action research setting, which was initiated in 2000 for the development of a teacher program and a reflexive ecopedagogy course. The study adopts a holistic evolutionary-ecological perspective. Through this perspective, the indivisibility of the evolutionary-ecological phenomenon is highlighted, which opens, highlights and “fuses” the natural cosmic relation of human beings to the environment and society in the pursuit of humanity’s goals . The evolutionary-ecological framework of the phenomenon is considered in the context of the emergence and understanding of a transdisciplinary approach. Two types of transdisciplinary platforms developed within the evolutionary-ecological phenomenon are examined. Through the origins of these platforms, educators are offered the opportunity to discover the relation between the transdisciplinary approach and the evolutionary-ecological phenomenon in pedagogy and the emergence of ideas or emergent recursion in complex evolutionary-ecological processes at different levels, which is enacted through the teacher as living learning aimed at a noble humanity.
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283 members
Arvīds Barševskis
  • Institute of Life Sciences and Technology, Coleopterological Research center
Juris Soms
  • Dept. of Environmental Science and Chemistry
Vadims Krasko
  • Department of Economics
Irēna Mihailova
  • G.Liberts' Innovative Microscopy Centre
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Daugavpils, Latvia
Head of institution
Arvīds Barševskis