1,721,370 research outputs found
Jubilees and news
No full textsummary:Netuka, Ivan; Veselý, Jiří: Sedmdesátiny profesora Jana Maříka.
Volf, Ivo: 21. mezinárodní fyzikální olympiáda.
Volf, Petr: Tradice pražské konference o teorii informace pokračuje
Jubilees and news
No full textsummary:Netuka, Ivan; Veselý, Jiří: Sedmdesátiny profesora Jana Maříka.
Volf, Ivo: 21. mezinárodní fyzikální olympiáda.
Volf, Petr: Tradice pražské konference o teorii informace pokračuje
Foundations of statistical survival analysis with application to analysis of reliability
No full textThe contribution provides an overview of survival analysis methods with application to the statistical reliability analysis. It also contains some new results of the author in the field of regression models for the hazard rate. Methods are illustrated on examples
Smelly interactions: host-borne volatile organic compounds triggering behavioural responses in mosquitoes, sand flies, and ticks
No full textVolatile organic compounds (VOCs) are chemicals emitted as products of cell metabolism, which reflects the physiological and pathological conditions of any living organisms. These compounds play a key role as olfactory cues for arthropod vectors such as mosquitoes, sand flies, and ticks, which act in the transmission of pathogens to many animal species, including humans. Some VOCs may influence arthropod behaviour, e.g., host preference and oviposition site selection for gravid females. Furthermore, deadly vector-borne pathogens such as Plasmodium falciparum and Leishmania infantum are suggested to manipulate the VOCs profile of the host to make them more attractive to mosquitoes and sand fly vectors, respectively. Under the above circumstances, studies on these compounds have demonstrated their potential usefulness for investigating the behavioural response of mosquitoes, sand flies, and ticks toward their vertebrate hosts, as well as potential tools for diagnosis of vector-borne diseases (VBDs). Herein, we provide an account for scientific data available on VOCs to study the host seeking behaviour of arthropod vectors, and their usefulness as attractants, repellents, or tools for an early diagnosis of VBDs
Bio-ecology and management of phlebotomine sand flies: unraveling the complexity of vector control
No full textPhlebotomine sand flies (Diptera: Psychodidae) are small, blood-feeding insects found in a wide range of ecosystems, from tropical and subtropical regions to temperate climates. Among the pathogens transmitted by these tiny insects (i.e., viruses, bacteria, and protozoa), Leishmania spp. are the most significant disease agents affecting humans and domestic animals, mainly in low-income countries, where prevention and control are challenging. Despite substantial progress in understanding the biology of sand flies and the parasites they transmit, critical knowledge gaps remain regarding their biology and ecology. Research into sand fly behavior, feeding preferences, resting sites, and breeding sites across various ecological settings is relevant for designing targeted interventions. Additionally, advances in innovative control tools are being explored to reduce the use of pyrethroids. These may include natural repellents (e.g., volatile organic compounds produced by vertebrate hosts), genetically modified sand flies (through gene editing or symbiont modification), and biological agents such as entomopathogenic fungi. These alternative tools offer promising avenues for developing a sustainable and integrated control strategy for sand flies. In this review, we provide insights into the bioecology of sand flies and highlight novel approaches that may enhance the effectiveness of sand fly control efforts
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Random point processes and models of hazard functions, with application to statistical reliability analysis and quality control.
No full textThe main objective of the presented thesis is the presentation of contemporary statistical methodology for systematic modelling and analysis of processes of events and of risk of these events, with application to the models of hazard rates (intensities) of failures and other events influencing the system reliability. The thesis describes the ideas and techniques developed in the corresponding fields of mathematical statistics and theory of probability, namely of the event-history analysis, survival analysis, random point processes (e.g. counting processes). The main features of the approach are explained, relevant theoretical and methodological results are presented, with particular attention to the contribution of the author. The models and methods are illustrated with the help of examples from the area of reliability analysis and control, and also of other areas. Namely, two last chapters deal with the cases and models of survival of technical devices. A selection of author's relevant publications is attached.Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi
Random Processes in Reliability Analysis
No full textTitle: Random Processes in Reliability Analysis Author: Kamil Chovanec Department: Department of Probability and Mathematical Statistics Supervisor: Doc. Petr Volf, CSc. Supervisor's e-mail address: [email protected] Abstract: The thesis is aimed at the reliability analysis with special em- phasis at the Aalen additive model. The result of hypothesis testing in the reliability analysis is often a process that converges to a Gaussian martingale under the null hypothesis. We can estimate the variance of the martingale using a uniformly consistent estimator. The result of this estimation is a new hypothesis about the process resulting from the original hypothesis. There are several ways to test for this hypothesis. The thesis presents some of these tests and compares their power for various models and sample sizes using Monte Carlo simulations. In a special case we derive a point that maximizes the asymptotic power of two of the tests. Keywords: Martingale, Aalen's additive model, hazard function
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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