Papers by Andrzej Swierniak
in Chamonix, France, covered these three main areas: bioinformatics, biomedical technologies, and... more in Chamonix, France, covered these three main areas: bioinformatics, biomedical technologies, and biocomputing. Bioinformatics deals with the system-level study of complex interactions in biosystems providing a quantitative systemic approach to understand them and appropriate tool support and concepts to model them. Understanding and modeling biosystems requires simulation of biological behaviors and functions. Bioinformatics itself constitutes a vast area of research and specialization, as many classical domains such as databases, modeling, and regular expressions are used to represent, store, retrieve and process a huge volume of knowledge. There are challenging aspects concerning biocomputation technologies, bioinformatics mechanisms dealing with chemoinformatics, bioimaging, and neuroinformatics. Biotechnology is defined as the industrial use of living organisms or biological techniques developed through basic research. Bio-oriented technologies became very popular in various re...
Biocybernetics and Biomedical Engineering – Current Trends and Challenges, 2021
IFAC Proceedings Volumes, 1998
In this paper , the continuous time linear systems with abrupt changes of parameters modelled by ... more In this paper , the continuous time linear systems with abrupt changes of parameters modelled by discrete-state :'v1arkov processes are considered. Under the assumption of the existence of a suitable control law , the necessary and sufficient conditions for the stochastic stabilizability of the nominal model of this class of systems using JLQ controllers is given. Moreover assuming that the parameters of the real system may differ from their nominal values and the existance of external disturbances sufficient conditions of the robustness for the real systems are presented. Two different control structures are proposed: centralized and decentalized. The comparision of the results is discussed.
Lecture Notes in Computer Science, 2010
Fuzzy Sets and Systems, 1986
Abstract We present a possibility of fuzzy systems design basing on a special fixed point theorem... more Abstract We present a possibility of fuzzy systems design basing on a special fixed point theorem. We consider systems described by input-output models with fuzzy uncertainty. A control objective is to reach the desired output neighborhood.
It is well accepted that cells, in response to radiation, may release transmissible factors. Thes... more It is well accepted that cells, in response to radiation, may release transmissible factors. These transmissible factors, clastogenic factors, have been reported to induce genomic instability in cells that have not been directly exposed to radiation. We hypothesize that this observed bystander effect might be a consequence of cellular interactions via secretory proteins released by the irradiated cells to affect the non-irradiated cells and initiate a systemic stress response to deal with the exposure. TK6 cells, a human lymphoblastoid cell line with a stable karyotype (47 chromosomes) and a functional p53 protein, were chosen as the surrogate for determining the stress response activation. Non-irradiated TK6 cells were co-cultured with 1 Gy γ-irradiated and non-irradiated TK6 cells in trans-wells, where the cells were kept separate but the culture media was free to diffuse across the membrane. Microarray analysis 8 hours post co-culturing monitored the gene expression changes and the dicentric assay was used to evaluate cytogenetic aberrations. Our findings show that this research model is an effective method of demonstrating the bystander effect using the dicentric assay and γ-irradiated cells. From the cytogenetic results it is evident that a bystander effect can be seen; although chromosomal aberrations are more frequent in the irradiated samples compared to the bystander samples, the numbers seen in the bystander samples are significantly greater than those in the controls. From the microarray data, a number of possible protein biomarkers have been identified. These results, taken together, provide a foundation for our future work of identifying systemic protein biomarkers of radiation exposure.
International Journal of Applied Mathematics and Computer Science, 2003
This paper presents an analysis of some class of bilinear systems that can be applied to biomedic... more This paper presents an analysis of some class of bilinear systems that can be applied to biomedical modelling. It combines models that have been studied separately so far, taking into account both the phenomenon of gene amplification and multidrug chemotherapy in their different aspects. The mathematical description is given by an infinite dimensional state equation with a system matrix whose form allows decomposing the model into two interacting subsystems. While the first one, of a finite dimension, can have any form, the other is infinite dimensional and tridiagonal. A methodology of the analysis of such models, based on system decomposition, is presented. An optimal control problem is defined in the l 1 space. In order to derive necessary conditions for optimal control, the model description is transformed into an integro-differential form. Finally, biomedical implications of the obtained results are discussed.
Proceedings of the 16th International Joint Conference on Biomedical Engineering Systems and Technologies
Lecture Notes in Computer Science, 2022
Proceedings of the International Conference on Information Technology & Systems (ICITS 2018), 2018
Automatic cancer diagnosis can be performed based on different types of data sets. Some of them a... more Automatic cancer diagnosis can be performed based on different types of data sets. Some of them are microarray data, clinical trial data and cytopathological data. Usually class prediction is done by chosen classification method, for example a machine learning algorithm, and uses only one type of the available data. In this work an additional predictive value of a fusion of these three types of data is examined. To perform such research, authors upgrade and use their recently developed Spicy system. Different data fusion strategies have been tested on thyroid cancer data set. The workflow that has been created and the new module of a data fusion implemented in the Spicy system allows to qualify fusion of microarray data, clinical trials data and information about the Bethesda system class as a valuable method of prediction the thyroid nodule malignancy.
Journal of Medical Informatics and Technologies, 2001
Przegląd Elektrotechniczny, 2010
Advances in Intelligent Systems and Computing, 2019
Pre- or post-operational chemo-radiotherapy have become one of the standard adjuvant therapies in... more Pre- or post-operational chemo-radiotherapy have become one of the standard adjuvant therapies in recent years. Though both chemo- and radiotherapy protocols are standardized, the question about the order in which they should be applied, or concurrency, remains an open question. In this work we attempt to answer it with mathematical modeling and optimization of two-dimensional control that represents therapy in a control-theory based approach. In order to address this problem, two issues are discussed. First, two different ways of modeling tumor growth under therapy are compared. For each of them, the necessary conditions for optimal control representing the therapy are presented and discussed. Then, Kaplan-Meier survival curves are compared for standard therapy protocols used in clinics and different approaches to model tumor growth. Finally, a framework for analysis of treatment efficacy is presented, in which optimization and survival analysis are used sequentially.
Journal of Clinical Oncology, 2007
21150 Background: The aim of the study was to analyze the gene expression profile of pancreatic c... more 21150 Background: The aim of the study was to analyze the gene expression profile of pancreatic cancer by multivariate methods of class prediction. Methods: The snap-frozen or RNA-later preserved samples of 18 pancreatic adenocarcinomas, 9 chronic pancreatitis cases and 6 specimens collected from microscopically unchanged pancreas (N/CP) were analyzed by HG-U133 Plus 2.0 oligonucleotide microarrays (Affymetrix). The obtained dataset was pre-processed using GC-RMA method, gene selection was carried out both by class comparison methods (Welch test with Benjamini-Hochberg correction, False Discovery Rate FDR<5%) and by our own algorithms of class prediction, based on Support Vector Machines technique (Recurrent Feature Replacement and Bootstrap-Based Feature Ranking). Real- time quantitative PCR (Q-PCR) was carried out on Applied Biosystems 7900 HT machine, with Universal Probe Library (Roche) fluorescent probes and normalization by three reference genes index (geNorm, Vandesompele ...
Mathematica Applicanda, 2019
Journal of theoretical biology, Sep 20, 2016
Living cells, like whole living organisms during evolution, communicate with their neighbors, int... more Living cells, like whole living organisms during evolution, communicate with their neighbors, interact with the environment, divide, change their phenotypes, and eventually die. The development of specific ways of communication (through signaling molecules and receptors) allows some cellular subpopulations to survive better, to coordinate their physiological status, and during embryonal development to create tissues and organs or in some conditions to become tumors. Populations of cells cultured in vitro interact similarly, also competing for space and nutrients and stimulating each other to better survive or to die. The results of these intercellular interactions of different types seem to be good examples of biological evolutionary games, and have been the subjects of simulations by the methods of evolutionary game theory where individual cells are treated as players. Here we present examples of intercellular contacts in a population of living human cancer HeLa cells cultured in v...
Communications in Computer and Information Science, 2016
Testing biomedical hypotheses is performed based on advanced and usually many-step analysis of bi... more Testing biomedical hypotheses is performed based on advanced and usually many-step analysis of biomedical data. This requires sophisticated analytical methods and data structures that allow to store intermediate results, which are needed in the subsequent steps. However, biomedical data, especially reference data, often change in time and new analytical methods are created every year. This causes the necessity to repeat the iterative analyses with new methods and new reference data sets, which in turn causes frequent changes of the underlying data structures. Such instability of data structures can be mitigated by the use of the idea of data lake, instead of traditional database systems.
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Papers by Andrzej Swierniak