Silesian University

Sosnowiec, Poland

Silesian University

Sosnowiec, Poland
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Siminski R.,Silesian University
Advances in Intelligent Systems and Computing | Year: 2017

This article presents the theoretical background for implementation of KBExplorer software package and the summary of the empirical study focused on the evaluation of this software on large, real-word knowledge bases. KBExplorer package is the own, originally designed software which provides most of the expert system shell’s common functions. The fundamental part of such software is the KBExpertLib library. This library allows to build domain expert systems using Java programming language. The first part of experiments was focused on the effectiveness of rules partition algorithm and estimation of the memory occupancy for additional data necessary for storing information about rules groups. The effectiveness evaluation of the forward and backward inference algorithms was the main goal of the second part of the experiments. © Springer International Publishing AG 2017.


Datta K.,University of Warwick | Thomas P.A.,University of Warwick | Roleder K.,Silesian University
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

Temperature-dependent structural phase transitions and dielectric properties for a series of x Na0.5 Bi0.5 TiO3 - (1-x) BaTiO3 (NBT-BT) samples where x ranges from 0.05 to 0.30 have been investigated. Non-ambient x-ray diffraction together with dielectric data as a function of temperature have demonstrated an enhancement in the ferroelectric to paraelectric phase transition temperature with the increase in NBT content, including inhibition of two well-known low-temperature polymorphic phase transitions of BaTiO3. Anomalous dielectric response has been observed for samples with x≥0.20 suggesting a crossover from a first-order to a second-order phase transition. The critical point lies between x=0.15 and x=0.20. Deviation from the classical Curie-Weiss law has been seen for samples having x≥0.10. A modified Curie-Weiss law was employed to model the dielectric response in the paraelectric phase and the maximum value of the critical exponent γ was found to be 1.45 for x=0.30. It is suggested that the dielectric properties are heavily influenced by the induced strain upon doping rather than chemical inhomogeneities and structural disorder, which are common occurrences in doped ferroelectrics. © 2010 The American Physical Society.


Zawisza B.,Silesian University
Journal of Analytical Atomic Spectrometry | Year: 2010

The extremely low fluorescent yield and long-wavelength characteristic radiation are the major limitations for direct XRF determination of the elements of low atomic numbers. In the case of lithium, the determination of this element by X-ray fluorescence spectrometry (XRF) is not possible. Thus, an indirect method for the determination of lithium by X-ray fluorescence spectrometry was proposed. The method is based on the determination of lithium through iron in the potassium lithium periodatoferrate(III) complex. The complex was collected on the membrane filter and the Fe Kα line was measured by XRF. The optimum conditions for LiKFeIO6 complex formation and XRF measurement were studied. A good ratio of lithium to iron (1 to 8) and a sensitive Fe Kα line give the possibility to determine a low lithium amount. The proposed method allows the determination of 20 g of lithium collected on a filter. The validity of the proposed method was verified with certified lithium ores. The agreement between XRF analysis and certified values is satisfactory and indicates the usefulness of the carried out method. © The Royal Society of Chemistry 2010.


The process of ciliogenesis that accompanies the differentiation of the thyroid gland in grass snake Natrix natrix L. embryos was studied ultrastructurally. Based on this study, it can be concluded that the ciliogenesis occurred in two waves and that new centrioles duplicated via centriolar pathways. The first wave of ciliogenesis started in the post-mitotic thyrocytes before their polarisation. It ended approximately halfway through the developmental period. The second wave of ciliogenesis took place after the polarization of thyrocytes and before the resting phase of the embryonic thyroid. This wave of ciliogenesis stopped shortly before hatching when fully differentiated thyrocytes restarted their activity. During the first half of thyroid differentiation, the cilia were formed "intracellularly" but during the second half, they differentiated "extracellularly" In the differentiating thyrocytes one cilium per cell was found; however, it could not be excluded that more than one cilium per cell may be formed. These cilia lacked central fibres and therefore they had a 9. +. 0 formula that suggested that they were immotile. © 2012 Elsevier Ltd.


Wojnarowska Z.,Silesian University | Roland C.M.,U.S. Navy | Swiety-Pospiech A.,Silesian University | Grzybowska K.,Silesian University | Paluch M.,Silesian University
Physical Review Letters | Year: 2012

Using broadband dielectric spectroscopy, we investigated the effect of hydrostatic pressure on the conductivity relaxation time τ σ of the supercooled protic ionic liquid, procainamide hydrochloride, a common pharmaceutical. The pressure dependence of τ σ exhibited anomalous behavior in the vicinity of the glass transition T g, manifested by abrupt changes in activation volume. This peculiar behavior, paralleling the change in temperature dependence of τ σ near T g, is a manifestation of the decoupling between electrical conductivity and structural relaxation. Although the latter effectively ceases in the glassy state, free ions retain their mobility but with a reduced sensitivity to thermodynamic changes. This is the first observation of decoupling of ion migration from structural relaxation in a glassy conductor by isothermal densification. © 2012 American Physical Society.


The differentiation of the thyroid primordium of reptilian species is poorly understood. The present study reports on structural and ultrastructural studies of the developing thyroid gland in embryos of the grass snake Natrix natrix L. At the time of oviposition, the thyroid primordium occupied its final position in the embryos. Throughout developmental stages I-IV, the undifferentiated thyroid primordium contained cellular cords, and the plasma membranes of adjacent cells formed junctional complexes. Subsequently, the first follicular lumens started to form. The follicular lumens were of intracellular origin, as in other vertebrate species, but the mechanism of their formation is as yet unclear. At developmental stages V-VI, the thyroid anlage was composed of small follicles with lumens and cellular cords. Cells of the thyroid primordium divided, and follicles were filled with a granular substance. At developmental stage VI, the cells surrounding the follicular lumen were polarized, the apical cytoplasm contained dark granules and the Golgi complex and the rough endoplasmic reticulum (RER) developed gradually. Resorption of the colloid began at developmental stage VIII. At the end of this stage, the embryonic thyroid gland was surrounded by a definitive capsule. During developmental stages IX-X, the follicular cells contained granules and vesicles of different sizes and electron densities and a well-developed Golgi apparatus and RER. At developmental stage XI, most follicles were outlined by squamous epithelial cells and presented wide lumens filled with a light colloid. The Golgi complex and RER showed changes in their morphology indicating a decrease in the activity of the thyroid gland. At developmental stage XII, the activity of the embryonic thyroid gradually increased, and at the time of hatching, it exhibited the features of a fully active gland. © 2011 Elsevier GmbH.


Racki G.,Silesian University
Acta Palaeontologica Polonica | Year: 2012

For the past three decades, the Alvarez impact theory of mass extinction, causally related to catastrophic meteorite impacts, has been recurrently applied to multiple extinction boundaries. However, these multidisciplinary research efforts across the globe have been largely unsuccessful to date, with one outstanding exception: the Cretaceous-Paleogene boundary. The unicausal impact scenario as a leading explanation, when applied to the complex fossil record, has resulted in force-fitting of data and interpretations ("great expectations syndrome". The misunderstandings can be grouped at three successive levels of the testing process, and involve the unreflective application of the impact paradigm: (i) factual misidentification, i.e., an erroneous or indefinite recognition of the extraterrestrial record in sedimentological, physical and geochemical contexts, (ii) correlative misinterpretation of the adequately documented impact signals due to their incorrect dating, and (iii) causal overestimation when the proved impact characteristics are doubtful as a sufficient trigger of a contemporaneous global cosmic catastrophe. Examples of uncritical belief in the simple cause-effect scenario for the Frasnian-Famennian, Permian-Triassic, and Triassic-Jurassic (and the Eifelian-Givetian and Paleocene-Eocene as well) global events include mostly item-1 pitfalls (factual misidentification), with Ir enrichments and shocked minerals frequently misidentified. Therefore, these mass extinctions are still at the first test level, and only the F-F extinction is potentially seen in the context of item-2, the interpretative step, because of the possible causative link with the Siljan Ring crater (53 km in diameter). The erratically recognized cratering signature is often marked by large timing and size uncertainties, and item-3, the advanced causal inference, is in fact limited to clustered impacts that clearly predate major mass extinctions. The multi-impact lag-time pattern is particularly clear in the Late Triassic, when the largest (100 km diameter) Manicouagan crater was possibly concurrent with the end-Carnian extinction (or with the late Norian tetrapod turnover on an alternative time scale). The relatively small crater sizes and cratonic (crystalline rock basement) setting of these two craters further suggest the strongly insufficient extraterrestrial trigger of worldwide environmental traumas. However, to discuss the kill potential of impact events in a more robust fashion, their location and timing, vulnerability factors, especially target geology and palaeogeography in the context of associated climate-active volatile fluxes, should to be rigorously assessed. The current lack of conclusive impact evidence synchronous with most mass extinctions may still be somewhat misleading due to the predicted large set of undiscovered craters, particularly in light of the obscured record of oceanic impact events. Copyright © 2012.


Urbisz A.Z.,Silesian University | Swiatek P.,Silesian University
Zoology | Year: 2013

The aim of the present study is to describe the organization of the ovary and mode of oogenesis at the ultrastructural level in two representatives of Lumbriculida - Lumbriculus variegatus and Stylodrilus heringianus. In both species studied, the ovaries are small and conically shaped structures that are attached to the intersegmental septum via a thin ligament. The ovaries are composed of germline cysts formed by germ cells interconnected by stable cytoplasmic bridges. As a rule, the cyst center is occupied by a poorly developed anuclear cytoplasmic mass, termed a cytophore, whereas the germ cells are located at the periphery of the cyst. Germline cysts are enveloped by somatic cells. The ovaries of the species studied are polarized, i.e., along the long axis of the ovary there is an evident gradient of germ cell development. The data obtained suggest ovary meroism, i.e., two categories of germ cells were found: oocytes, which continue meiosis, gather nutrients, grow and protrude into the body cavity, and nurse cells, which do not grow and are supposed to supply oocytes with cell organelles and macromolecules via the cytophore. The ovary structure and mode of oogenesis in the species studied were compared with those of other clitellate annelids. As a rule, in all clitellates studied to date, the ovaries are composed of germline cysts equipped with a cytophore and associated with somatic cells; however, the ovary morphology differs between taxa regarding several quantitative and qualitative features. The ovary organization and mode of oogenesis in L. variegatus and S. heringianus strongly resemble those found in Tubificinae and Branchiobdellida studied to date. Our results also support a sister-group relationship between Lumbriculida and a clade comprising ectoparasitic clitellates (i.e., Branchiobdellida, Acanthobdellida and Hirudinida) with Branchiobdellida as a plesiomorphic sister group to Acanthobdellida and Hirudinida. © 2013 Elsevier GmbH.


Racki G.,Silesian University
Acta Palaeontologica Polonica | Year: 2014

Some paradigms in the impact-volcanic controversy that we regard as having first been established in the 1980s in fact can be traced much farther back in time, as exemplified by the heuristic neocatastrophic concepts proposed by Dmitri Sobolev and other progressive Russian scholars (Aleksey P. Pavlov, Mikhail A. Usov) of the early 20th century. They were truly conceptual forerunners of the global catastrophe model in Earth history which is now widely accepted as the volcanic/ greenhouse scenario, even if preceding thought-provoking concepts of some leading European scholars (e.g., Svante Arrhenius, Jacques J. Ėbelmen) were unknown to them. From time to time, scientific society is astonished by the discovery that supposedly modern concepts originated many decades ago. For example, mass extinction themes are still the subject of intense debate in mainstream science, but some paradigms have a beginning that can be traced far back in time. © 2014 G. Racki.


Kaminski K.,Silesian University
Journal of physics. Condensed matter : an Institute of Physics journal | Year: 2010

Broadband dielectric measurements performed on D-glucose, L-sorbose, D-fructose and D-galactose revealed that, except for the structural relaxation process, one can detect in the liquid phase of these carbohydrates a much slower relaxation mode. Recently we have demonstrated that in D-glucose this relaxation mode might be related to the long range correlation of density fluctuations (LRCDF), also called Fischer clusters (FC). Based on the dielectric data obtained for the four monosaccharides we were able to make a more general conclusion about the characteristic dielectric features of the slow mode in the whole family of carbohydrates. We found out that the timescale separation between structural and considered relaxation reaches up to six decades at the glass transition temperature and the dielectric strength decreases significantly with lowering temperature. Another very interesting feature of the slow process is that it can be described by an almost exponential response function. We have found out that the fragility of the slow process lies within the range m = 44-50. Finally, we have also shown that there is a close link between structural and slow relaxation.

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