Vilnius University Press Scholarly Journals
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A few generalizations of Kendall’s tau. Part II: Intrinsic meaning, properties, and computational aspects
No full textContinuing our investigation on generalizations of Kendall’s τ, started in Part I of the paper, here we elaborate on the intrinsic meaning and degree of such polynomial-type concordance measures, as well as present many examples of their computation. In particular, we interpret generalized Kendall’s τφ as the difference between the average capacities of concordance and discordance, and, for power-type distortion functions φ, we obtain polynomial-type concordance measures of various degree, which could stimulate further research of their characterization as achieved for degree-one polynomial-type concordance measures by Taylor, Edwards, and Mikusiński
Codimension-two bifurcation analysis of a discrete predator–prey system with fear effect and Allee effect
No full textIn this paper, we study the dynamic behavior of a discrete predator–prey model with fear effect and Allee effect by theoretical analysis and numerical simulation. Firstly, the existence and stability of the equilibrium points of the model are proved. Secondly, the existence of codimension-2 bifurcations (1 : 2, 1 : 3, and 1 : 4 strong resonances) in the case of two parameters is verified by bifurcation theory. In order to illustrate the complexity of the dynamic behavior of the model in the two-parameter space, we simulate the bifurcation diagrams, phase diagrams, maximum Lyapunov exponent diagrams, and isoperiodic diagram, and we verify the influence of model parameters on the population size
A discontinuous nonlinear singular elliptic problem with the fractional rho-Laplacian
No full textIn this paper, we use the topological degree method, based on the abstract Hammerstein equation, to investigate the existence of weak solutions for a certain class of elliptic Dirichlet boundary value problems. These problems involve the fractional ρ-Laplacian operator and involve discontinuous nonlinearities in the framework of fractional Sobolev spaces
The finite-time ruin probabilities of a dependent bidimensional risk model with subexponential claims and Brownian perturbations
No full textThe paper considers a dependent bidimensional risk model with stochastic return and Brownian perturbations in which the price processes of the investment portfolio of the two lines of business are two geometric Lévy processes, and the claim-number processes of the two lines of business follows two different stochastic processes, which can be dependent. When the two components of each pair of claims from the two lines of business are strongly asymptotically independent and have subexponential distributions, the asymptotics of the finite-time ruin probability are obtained. Numerical studies are carried out to check the accuracy of the asymptotics of the finite-time ruin probability for the claims having regularly varying tail distributions
Symmetry analysis, soliton solutions and conservation laws of the Q(L, m, n) equation
No full textIn the present paper, symmetry and soliton solutions of the Q(L, m, n) equation are investigated. The infinitesimal operator of this equation is obtained by virtue of Lie group analysis. Taking different values of the parameters for the coefficients, the corresponding vector fields are obtained. Subsequently, soliton solutions of this equation are obtained for different parameters relying on the solitary wave ansatz method. According to different parameters, new soliton solutions are obtained. Also, conservation laws are also derived. Reciprocal Bäcklund transformations of conservation laws presented from the known conservation laws
A mathematical model for degradation of forest area by industrialization causing migration of wildlife species
No full textThis study presents a nonlinear mathematical model incorporating four key variables: forest area, biomass density, industrialization level, and wildlife population. The model assumes that biomass is proportional to forest area and that wildlife density depends on biomass availability. Our analysis demonstrates that increasing industrialization leads to significant forest depletion, which in turn accelerates wildlife migration. The results highlight critical thresholds beyond which forest degradation becomes irreversible, emphasizing the urgent need for sustainable industrial policies and conservation strategies. Numerical simulations and sensitivity analysis validate the model outcomes and provide insights for ecological preservation
Finite-time synchronization and quasi-synchronization of fractional-order fuzzy BAM neural networks with time delays
No full textThis paper concentrates on the finite-time synchronization (FTS) and the quasi-synchronization (QS) problems for a kind of fractional-order fuzzy BAM neural networks with time delays (FOFBAMNNs). In order to reach the goals of synchronization, two novel controllers are designed. Then, based on finite-time stability theorem, Lyapunov function theory, and several inequality techniques, through the application of two different designed controllers, several criteria for both FTS and QS are established. Moreover, more precise error level and settling times are given. The effectiveness of the derived criteria is ultimately validated through two simulations
Efficient computation of blood velocity in the left atrial appendage: A practical perspective
No full textThe goal of the paper is to present the FSI (fluid-structure interaction) CFD (computational fluid dynamics) simulations of the blood flow in the LA (left atrium) for patient-specific geometry of the left atrium appendage (LAA). These simulations are important for the decision making in cardiology and cardiac surgery of the patients with atrial fibrillation. Nowadays according current atrial fibrillation treatment guidelines, initiation of oral anticoagulant therapy is recommended for patients with a CHA2DS2–VASc score greater or equal to 2 for males, and greater or equal to 3 for females, for lowering stroke risk. This therapy although has undesirable effects and provokes bleeding in a part of cases. That is why it is important to detect the stagnation zones of the blood flow in LAA. The presence of such zones justifies the necessity of the anticoagulant therapy.
The FSI CFD simulations in the heart is a challenging problem: the existing softwares are not too robust for real life Reynolds numbers and often do not converge to the solution of the Navier–Stokes equations for the blood coupled with the elasticity equations of the wall. That is why we first provide the CFD computations with the rigid wall when the codes are more stable. Using this solution as a source of parameters for the implicit numerical scheme solver, we then provide the FSI computations, which become much more robust
Mokslinė-praktinė konferencija. Slaugos mokslo naujovės: 2025. Konferencijos tezės
No full textThe scientific and practical conference "Nursing Science Innovations: 2025" brought together Lithuanian and foreign general nurses, advanced practice nurses, students of all levels of nursing study programmes, nursing researchers, and scientists to present the latest achievements in nursing science, share research results, and discuss current topics of nursing science and practice.
The abstracts of the conference presentations published in this journal supplement reflect three main thematic areas: nursing research, presenting research in English by Lithuanian and foreign researchers; clinical nursing research, focusing on the evaluation of practical interventions, improving the quality of patient care, and evidence-based practice; and nursing education, focusing on the use of innovative teaching methods and the development of nurses\u27 professional competencies.
We thank the conference organisers for their ideas, efforts, and work and the conference scientific committee for their peer review and evaluation of the abstracts.
We hope this publication will stimulate scientific discussion, contribute to the dissemination of nursing science, and inspire conference participants to further research relevant to academia and nursing practice.Mokslinė – praktinė konferencija „Slaugos mokslo naujovės: 2025“ subūrė Lietuvos ir užsienio įvairių specializacijų bendrosios praktikos slaugytojus, išplėstinės praktikos slaugytojus, visų pakopų slaugos studijų programų studentus, slaugos tyrėjus ir mokslininkus siekiant pristatyti naujausius slaugos mokslo pasiekimus, dalytis tyrimų rezultatais ir aptarti aktualias slaugos mokslo bei praktikos kryptis.
Šiame žurnalo priede publikuojamos mokslinės – praktinės konferencijos pranešimų santraukos atspindi tris pagrindines temines kryptis: slaugos moksliniai tyrimai, kuriuose pristatomi moksliniai tyrimai anglų kalba lietuvių ir užsienio tyrėjų; klinikiniai slaugos tyrimai, orientuoti į praktinių intervencijų vertinimą, pacientų priežiūros kokybės gerinimą ir įrodymais grįstą praktiką; bei slaugos edukacija, kurioje didesnis dėmesys skiriamas inovatyvių mokymo metodų taikymui, slaugytojų profesinės kompetencijos ugdymui.
Dėkojame konferencijos organizatoriams už idėjas, pastangas ir darbą bei konferencijos moksliniam komitetui už pranešimų santraukų recenzavimą ir vertinimą.
Tikimės, kad ši publikacija paskatins mokslinę diskusiją, prisidės prie slaugos mokslo sklaidos ir įkvėps konferencijos dalyvius tolesniems tyrimams, reikšmingus tiek akademinei bendruomenei, tiek slaugos praktikai
Sudden Unexpected Death and Alcohol Addiction: Case Report on Disulfiram Use
No full textBackground: Disulfiram is a type of medication widely prescribed in order to cease alcohol consumption. When used with alcohol, the ‘disulfiram-alcohol reaction’ occurs, causing nausea and vomiting. Disulfiram blocks alcohol dissolving enzymes thus increasing acetaldehyde concentration and inducing the above-mentioned symptoms. These undesirable symptoms are similar to the side effects that occur to oncological patients after the administration of chemotherapy.Materials and methods: Descriptive research method was used. The literature focusing on alcohol, medications and drug consumption was reviewed.Case report: The primary abstinence at the beginning of treatment with Disulfiram does not guarantee that alcohol usage will not get manifested again at the further stages of treatment. Alcohol addiction forces patients to search for a way to avoid the unwanted reactions. Sometimes, patients tend to be quite ingenious while trying to suppress the arising side effects. In many cases, it involves the usage of additional medication.Conclusions: When alcohol addiction overpowers, the patient tries to reduce the undesirable symptoms and may even die if alcohol is combined with disulfiram. Death may occur due to the cardio and neurotoxic effects of acetaldehyde