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1
Content available remote Biocomputers information management in the human biological system
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EN
Human life is not just a matter of biology, it is also the structure of bioelectronics, which has an impact on health, illness and human behavior. In this new paradigm of bioelectronics a man in the field of Quantum Processes begins to appear and is understood as a device processing bioelectronics, storing and managing information. Quantum man is the same man as the physiological and anatomical one, but is received on the quantum way. His biological system consists of a biological material that is both electronic properties of piezoelectric material, and semiconductor pyroelectric. In this paradigm, bioelectronics nerve cell and the brain are treated as a quantum computer. The rapid development of molecular electronics and biotechnology will lead to the fact that our lives will have to adapt to the requirements of biological computers and many electronic devices, which will make people recording information in the brain and the school program. It will resemble a tape or a CD. In this new system of teaching the amount of information in the brain is expected to double X, the power of the body but not every psychic will be easy to Adopt this style of teaching, Which will often lead to many disorders of the human personality.
2
Content available remote Self-organized Patterning by Diffusible Factors : Roles of a Community Effect
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EN
For decades, scientists have sought to elucidate self-organized patterning during development of higher organisms. It has been shown that cell interaction plays a key role in this process. One example is the community effect, an interaction among undifferentiated cells. The community effect allows cell population to forge a common identity, that is, coordinated and sustained tissue-specific gene expression. The community effect was originally observed in muscle differentiation in Xenopus embryos, and is now thought to be a widespread phenomenon. From a modelling point of view, the community effect is the existence of a threshold size of cell populations, above which the probability of tissue-specific gene expression for a sustained period increases significantly. Below this threshold size, the cell population fails to maintain tissue-specific gene expression after the initial induction. In this work, we examine the dynamics of a community effect in space and investigate its roles in two other processes of self-organized patterning by diffusible factors: Turing’s reaction-diffusion system and embryonic induction by morphogens. Our major results are the following. First, we show that, starting from a one-dimensional space model with the simplest possible feedback loop, a community effect spreads in an unlimited manner in space. Second, this unrestricted expansion of a community effect can be avoided by additional negative feedback. In Turing’s reaction-diffusion system with a built-in community effect, if induction is localized, sustained activation also remains localized. Third, when a simple cross-repression gene circuitry is combined with a community effect loop, the system self-organizes. A gene expression pattern with a well-demarcated boundary appears in response to a transient morphogen gradient. Surprisingly, even when the morphogen distribution eventually becomes uniform, the system can maintain the pattern. The regulatory network thus confers memory of morphogen dynamics.
EN
Models of complex biological systems can be built using different types of Petri nets. Qualitative nets, for example, can be successfully used to obtain a model of such a system and on its basis a structure-based analysis can be performed. Time is an important factor influencing a whole biological system behaviour and in many cases it should be considered during building a model of such a system. In this paper various types of time Petri nets have been described and methods for studying corresponding models have been discussed. In particular, an algorithm using time parameters to enhance t-invariants based analysis is proposed. This algorithm allows for calculation of the minimal and maximal numbers of tokens (respectively, for an optimistic and pessimistic case) in particular places necessary to assure that all transitions from a given t-invariant support will be able to fire. Additionally, to address the problem of the proper assignment of time values to transitions, the known methods for calculation and evaluation of such time parameters based on the net structure have also been discussed.
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Content available remote On Minimality and Equivalence of Petri Nets
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EN
The context of this work is the reconstruction of Petri net models for biological systems from experimental data. Such methods aim at generating all network alternatives fitting the given data. To keep the solution set small while guaranteeing its completeness, the idea is to generate only Petri nets being “minimal” in the sense that all other networks fitting the data contain the reconstructed ones. In this paper, we consider Petri nets with extensions in two directions: priority relations among the transitions of a network in order to allow modeling deterministic systems, and control-arcs in order to represent catalytic or inhibitory dependencies. We define a containment relation for Petri nets taking both concepts, priority relations and control-arcs, into account. We discuss the consequences for this kind of Petri nets differing in their sets of control-arcs and priority relations, and the impact of our results towards the reconstruction of such Petri nets.
6
Content available remote Phytoplankton assemblage of a solar saltern in Port Fouad, Egypt
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EN
The present study is the first investigation of the phytoplankton community in one of Egypt's saltworks. The phytoplankton composition and distribution in five ponds of increasing salinity were investigated in the solar saltern of Port Fouad. The phytoplankton community consisted of 42 species belonging to cyanobacteria (16), diatoms (12), dinoflagellates (11), Euglenophyceae (2) and Chlorophyceae (1). The number of species decreased significantly and rapidly with increasing salinity, varying between 33 species in the first pond (P1) and one species in the crystallizer pond (P5). Conversely, the total phytoplankton density, except that recorded in P1, increased significantly with rising salinity, fluctuating between 8.7 and 56 × 10^5 individuals l-1 in P2 and P5 respectively. In spite of the local variations in climate and nutrient availability, the phytoplankton composition, density and spatial variations along the salinity gradient were, in many respects, very similar to what has been observed in other solar saltworks. The pond with the lowest salinity (P1 - < 52 g l-1) was characterized by a significant diversity and blooming of diatoms and dinoflagellates. Intermediate salinity ponds (P2 and P3) with salinity ? 112-180 g l-1 exhibited a decline in both species richness and density, but the stenohaline blue green algae ( Synechocystis salina) did flourish. The highly saline concentrating ponds and crystallizers (P4 and P5) with salinity ~ 223-340 g l-1 were characterized by few species, the disappearance of blue green algae and the thriving of the halotolerant green alga Dunaliella salina.
EN
Nonlinear oscillatory processes are discussed under the influence of external signals to improve the understanding of signal interaction with and within biological systems. The biological endogeneous rhythms are modelled by self-sustained oscillations (limit cycles). Main emphasis is on the combined influence of very slow and very fast stimuli compared to the relevant internal frequencies and on additional effects caused by external and internal noise sources. The models represent arrays of coupled passive and active nonlinear oscillators, an external harmonic signal stimulates the input oscillator (initial stage of signal chain). Signal transfer through the pathway is studied under the influence of noise. Different noise contributions are considered, including spatially-coherent and spatially-incoherent sources. Results reveal a stochastic resonance kind of behaviour at different stages of the signal transfer, the harmonic signal is transduced through the whole system of coupled oscillators. The combined action of different noise exhibits constructive as well as destructive influences on signal amplification. In addition, the influence of noise on the synchronous behaviour of coupled active systems is investigated. Noise-induced synchronization as well as desynchronization of the output signal to the external drive result. Besides signal amplification the systems exhibit the property to decode the frequency encoded information.
PL
W niniejszej pracy zbadano zjawisko chaosu i oscylacji okresowych w wybranych układach biologicznych. Przeanalizowano dwa modele matematyczne uwzględniające interakcje drapieżnik-ofiara : model oddziaływania między populacjami drapieżników ogólnego i specyficznego a dwiema populacjami ofiar oraz model oddziaływania między populacjami dwóch drapieżników specyficznych a dwiema populacjami ofiar. Przeanalizowano wpływ parametrów na zachowanie układu. W tym celu dla każdego modelu przeprowadzono serie symulacji numerycznych. W każdej kolejnej symulacji zmieniano tylko jeden parametr. Następnie dla każdej symulacji określono trajektorie zależności gęstości populacji od czasu. Jednocześnie wyznaczono zależności wskaźników całkowych od analizowanych parametrów. Następnie określono, czy maksymalna wartość wskaźników całkowych znajduje się w obszarze oscylacji.
EN
In this paper of the phenomenon of the chaos and periodical oscillations in chosen biological arrangements was investigated. Two mathematic models describing predator-prey interaction was studied : model of interaction between the specialist and generalist predators and its prey and model of interactions between two specialist predatprs and its prey. The influence of parameters on behaviour of arrangement was analyzed. For this purpose series of numerical simulations was carried out. In each simulation only one parameterwas changed. For each simulation trajectory population density on time was specified. Simultaneously the dependence of the integral index of analyzed parameters was determined. Then was specified whether maximum of values of integral indexes is in the area oscillations.
PL
Masa jest jedną z podstawowych i jednocześnie stosunkowo prostych do opisania i zmierzenia wielkości charakteryzujących indywidua chemiczne, pozwala na uzyskanie bardzo specyficznych informacji. Z tego właśnie powodu w nowoczesnej analizie chemicznej szeroko wykorzystuje się pomiar masy cząsteczek i atomów.
EN
Changes in the Ca2+ concentration are thought to affect many processes, including signal transduction in a vast number of biological systems. However, only in few cases the molecular mechanisms by which Ca2+ mediates its action are as well understood as in phototransduction. In dark-adapted photoreceptor cells, the equilibrium level of cGMP is maintained by two opposing activities, such as phosphodiesterase (PDE) and guanylate cyclase (GC). Upon absorption of photons, rhodopsin-G-protein- mediated activation of PDE leads to a transient decrease in [cGMP] and subsequently to lowering of [Ca2+]. In turn, lower [Ca2+] increases net production of cGMP by stimulation of GC until dark conditions are re-established. This activation of GC is mediated by Ca2+-free forms of Ca2+-binding proteins termed GC-activating proteins (GCAPs). The last decade brought the molecular identification of GCs and GCAPs in the visual system. Recent efforts have been directed toward understanding the properties of GC at the physiological and structural levels. Here, we summarize the recent progress and present a list of topics of ongoing research.
EN
The effect of counterion size on the electrical properties of an electrolyte solution in contact with charged planar, cylindrical and spherical surfaces is considered. Electrostatic interaction is considered by means of the mean electrostatic field, while the finite size of particles constituting the electrolyte solution is considered via the excluded volume effect within the lattice statistics. Different sizes of counterion are described by different values of the lattice constant. It is shown that the excluded volume effect considerably decreases the calculated number density of counterions near the charged surface. This effect is more pronounced in cylindrical geometry than in spherical geometry, and less pronounced than in planar geometry.
PL
Techniki spektrometrii mas pozwalają identyfikować strukturę i skład pierwiastkowy związków chemicznych w badanej próbce. Zastosowana procedura analityczna umożliwiła identyfikację i oznaczenie niskocząsteczkowych związków zawierających selen w próbkach tkanek pobranych od zwierząt po suplementacji związkami selenu.
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