PL
 |
EN
Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 17

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  neurons
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Argeting neurons overcoming extra and intracellular barriers with biomaterial-based vectors to promote neuroprotection and neuroregeneration
100%
Pêgo A. P.
Engineering of Biomaterials
|
2018
|
tom Vol. 21, no. 148
7
2
Content available Neuroplasticity and Microglia Functions Applied in Dense Wireless Networks
100%
Kułacz Ł. , Kliks A.
Journal of Telecommunications and Information Technology
|
2019
|
tom nr 1
39--46
EN
This paper presents developments in the area of brain-inspired wireless communications relied upon in dense wireless networks. Classic approaches to network design are complemented, firstly, by the neuroplasticity feature enabling to add the learning ability to the network. Secondly, the microglia ability enabling to repair a network with damaged neurons is considered. When combined, these two functionalities guarantee a certain level of fault-tolerance and self-repair of the network. This work is inspired primarily by observations of extremely energy efficient functions of the brain, and of the role that microglia cells play in the active immune defense system. The concept is verified by computer simulations, where messages are transferred through a dense wireless network based on the assumption of minimized energy consumption. Simulation encompasses three different network topologies which show the impact that the location of microglia nodes and their quantity exerts on network performance. Based on the results achieved, some algorithm improvements and potential future work directions have been identified.
3
Content available Dense Wireless Network Inspired by the Nervous System
100%
Kułacz Ł. , Kliks A.
International Journal of Electronics and Telecommunications
|
2020
|
tom Vol. 66, No. 1
93--98
EN
This work presents concepts of the use of algorithms inspired by the functions and properties of the nervous system in dense wireless networks. In particular, selected features of the brain consisting of a large number of nerve connections were analyzed, which is why they are a good model for a dense network. In addition, the action of a selected cells from the nervous system (such as neuron, microglia or astrocyte) as well as phenomena observed in it (e.g. neuroplasticity) are presented.
4
Content available remote The Stochastic Loss of Spikes in Spiking Neural P Systems : Design and Implementation of Reliable Arithmetic Circuits
88%
Xu Z. , Cavaliere M. , An P. , Vrudhula S. , Cao Y.
Fundamenta Informaticae
|
2014
|
tom Vol. 134, nr 1/2
183--200
EN
Spiking neural P systems (in short, SN P systems) have been introduced as computing devices inspired by the structure and functioning of neural cells. The presence of unreliable components in SN P systems can be considered in many different aspects. In this paper we focus on two types of unreliability: the stochastic delays of the spiking rules and the stochastic loss of spikes. We propose the implementation of elementary SN P systems with DRAM-based CMOS circuits that are able to cope with these two forms of unreliability in an efficient way. The constructed bio-inspired circuits can be used to encode basic arithmetic modules.
5
Content available remote A model of axonal transport drug delivery
88%
Kuznetsov A.
Open Physics
|
2012
|
tom 10
|
nr 2
320-328
EN
In this paper a model of targeted drug delivery by means of active (motor-driven) axonal transport is developed. The model is motivated by recent experimental research by Filler et al. (A.G. Filler, G.T. Whiteside, M. Bacon, M. Frederickson, F.A. Howe, M.D. Rabinowitz, A.J. Sokoloff, T.W. Deacon, C. Abell, R. Munglani, J.R. Griffiths, B.A. Bell, A.M.L. Lever, Tri-partite complex for axonal transport drug delivery achieves pharmacological effect, Bmc Neuroscience 11 (2010) 8) that reported synthesis and pharmacological efficiency tests of a tri-partite complex designed for axonal transport drug delivery. The developed model accounts for two populations of pharmaceutical agent complexes (PACs): PACs that are transported retrogradely by dynein motors and PACs that are accumulated in the axon at the Nodes of Ranvier. The transitions between these two populations of PACs are described by first-order reactions. An analytical solution of the coupled system of transient equations describing conservations of these two populations of PACs is obtained by using Laplace transform. Numerical results for various combinations of parameter values are presented and their physical significance is discussed.
6
Content available remote Effect of kinesin velocity distribution on slow axonal transport
88%
Kuznetsov A.
Open Physics
|
2012
|
tom 10
|
nr 4
779-788
EN
The goal of this paper is to investigate the effect that a distribution of kinesin motor velocities could have on cytoskeletal element (CE) concentration waves in slow axonal transport. Previous models of slow axonal transport based on the stop-and-go hypothesis (P. Jung, A. Brown, Modeling the slowing of neurofilament transport along the mouse sciatic nerve, Physical Biology 6 (2009) 046002) assumed that in the anterograde running state all CEs move with one and the same velocity as they are propelled by kinesin motors. This paper extends the aforementioned theoretical approach by allowing for a distribution of kinesin motor velocities; the distribution is described by a probability density function (PDF). For a two kinetic state model (that accounts for the pausing and running populations of CEs) an analytical solution describing the propagation of the CE concentration wave is derived. Published experimental data are used to obtain an analytical expression for the PDF characterizing the kinesin velocity distribution; this analytical expression is then utilized as an input for computations. It is demonstrated that accounting for the kinesin velocity distribution increases the rate of spreading of the CE concentration waves, which is a significant improvement in the two kinetic state model.
7
Content available remote Analytical solution of equations describing slow axonal transport based on the stop-and-go hypothesis
75%
Kuznetsov A.
Open Physics
|
2011
|
tom 9
|
nr 3
662-673
EN
This paper presents an analytical solution for slow axonal transport in an axon. The governing equations for slow axonal transport are based on the stop-and-go hypothesis which assumes that organelles alternate between short periods of rapid movement on microtubules (MTs), short on-track pauses, and prolonged off-track pauses, when they temporarily disengage from MTs. The model includes six kinetic states for organelles: two for off-track organelles (anterograde and retrograde), two for running organelles, and two for pausing organelles. An analytical solution is obtained for a steady-state situation. To obtain the analytical solution, the governing equations are uncoupled by using a perturbation method. The solution is validated by comparing it with a high-accuracy numerical solution. Results are presented for neurofilaments (NFs), which are characterized by small diffusivity, and for tubulin oligomers, which are characterized by large diffusivity. The difference in transport modes between these two types of organelles in a short axon is discussed. A comparison between zero-order and first-order approximations makes it possible to obtain a physical insight into the effects of organelle reversals (when organelles change the type of a molecular motor they are attached to, an anterograde versus retrograde motor).
8
Content available remote Effect of cytoskeletal element degradation on merging of concentration waves in slow axonal transport
75%
Kuznetsov A. , Avramenko A. , Blinov D.
Open Physics
|
2011
|
tom 9
|
nr 4
898-908
EN
The aim of this paper is to investigate, by means of a numerical simulation, the effect of the half-life of cytoskeletal elements (CEs) on superposition of several waves representing concentrations of running, pausing, and off-track anterograde and retrograde CE populations. The waves can be induced by simultaneous microinjections of radiolabeled CEs in different locations in the vicinity of a neuron body; alternatively, the waves can be induced by microinjecting CEs at the same location several times, with a time interval between the injections. Since the waves spread out as they propagate downstream, unless their amplitude decreases too fast, they eventually superimpose. As a result of superposition and merging of several waves, for the case with a large half-life of CEs, a single wave is formed. For the case with a small half-life the waves vanish before they have enough time to merge.
9
Content available Application of NucleoCounter for the comprehensive assessment of murine cultured neurons during infection with Equine Herpesvirus type 1 (EHV-1)
75%
Chodkowski M. , Serafińska I. , Brzezicka J. , Bańbura M. W. , Cymerys J.
|
2017
|
nr 4
10
Content available Czy potrzebny jest nowy model neuropoezy?
63%
Rieske P.
Aktualności Neurologiczne
|
2006
|
tom 6
|
nr 3
164-168
EN
Models of neuropoiesis make it possible to determine at what stage of differentiation are neuronal cells. These models reflect our current knowledge about neuropoiesis, but they have also practical significance. In vitro determination whether neuronal stem cells differentiate to neuronal, astrocytic or oligodendrocytic progenitors is of utmost importance for cellular transplantologists. It seems that the use of progenitor cells and not fully differentiated cells or stem cells provides transplantologists with the greatest chance for therapeutic success: stem cells may choose a differentiation pathway other than planned by transplantologist, while mature cell, e.g. neurons, are quite sensitive to environmental changes. Determination of the progenitor type currently requires screening of expression of markers recognized as specific for particular cell type. Studies conducted for several years indicate that in the case of many markers this strategy is not appropriate. For example, the GFAP protein considered until recently a specific marker of astrocytes is also expressed in some neuronal stem cells. This discovery has led to a considerable chaos in the way cells are being defined. Furthermore, results of studies of the team where the author of this publication belongs indicate that stem cells may show coexpression of glial and neuronal markers. For the neuropoiesis model constructed upon this kind of data, a name “model of suppression of discordant phenotypes'’ has been proposed.
PL
Modele neuropoezy pozwalają określać, na jakim etapie różnicowania znajdują się komórki neuralne. Modele te oddają stan naszej wiedzy o neuropoezie, niemniej mają również znaczenie praktyczne. Stwierdzenie w warunkach in vitro, czy neuralne komórki macierzyste różnicują się do progenitorów neuronalnych, astrocytarnych czy oligodendrocytarnych, jest bardzo ważne dla transplantologów komórkowych. Wydaje się bowiem, że stosowanie właśnie progenitorów, a nie komórek w pełni zróżnicowanych czy komórek macierzystych, daje transplantologom największe szanse na sukces terapeutyczny – komórki macierzyste mogą wybrać szlak różnicowania inny niż planowany przez transplantologa, natomiast komórki dojrzałe, takie jak np. neurony, nie są odporne na zmiany środowiska. Ustalenie, z jakim progenitorem mamy do czynienia, wymaga obecnie określenia ekspresji markerów uznawanych za specyficzne dla danych komórek. Badania prowadzone od kilku lat pokazują jednak, iż w przypadku wielu markerów taka strategia nie jest właściwa. Dla przykładu, białko GFAP uznawane do niedawna za marker astrocytów ulega ekspresji także w niektórych nerwowych komórkach macierzystych. Odkrycie to prowadzi do poważnego zamętu w sposobie definiowania komórek. Ponadto wyniki badań zespołu, do którego należy autor niniejszej publikacji, wskazują, że komórki macierzyste mogą wykazywać koekspresję markerów komórek glejowych i neuronalnych. Dla modelu neuropoezy skonstruowanego w oparciu o tego typu wyniki zaproponowano nazwę: „model supresji niespójnych fenotypów”.
11
Content available Enteric neuronal development in canine small intestine – an immunohistochemical study
63%
Serzysko T. , Skwarek A. , Chudziak E. , Malina M. , Kaleczyc J. , Sienkiewicz W. , Serzysko T. , Skwarek A. , Chudziak E. , Malina M. , Kaleczyc J. , Sienkiewicz W.
|
|
tom 24
|
nr 2
12
Content available The expression of androgen receptor in neurons of the anterior pelvic ganglion and celiac-superior mesenteric ganglion in the male pig
63%
Kaleczyc J. , Kasica-Jarosz N. , Pidsudko Z. , Przyborowska A. , Sienkiewicz W. , Kaleczyc J. , Kasica-Jarosz N. , Pidsudko Z. , Przyborowska A. , Sienkiewicz W.
|
13
Recurrent neural networks for non-linear system identification
63%
Krejsa J. , Dolezal R.
Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska
|
1999
|
tom z. 11
37-40
EN
The contribution shows Elman neural network used for non-linear system identification. A simple example of non-linear dynamic system is used to test the performance of networks with different number of hidden units. Results shows that higher number of hidden neurons surprisingly degrades the performance of the network both in training and generalisation abilities.
PL
W pracy przedstawiono zastosowanie neuronowej sieci Elmana do identyfikacji układu nieliniowego. Na przykładzie prostego nieliniowego układu dynamicznego zbadano osiągi sieci z różną liczbą ukrytych neuronów. Wyniki wskazują, że większe liczb)' ukrytych neuronów zmniejszają zdolności treningowe i uogólniające sieci.
14
Content available remote What Can a Mathematician do in Neuroscience?
63%
Karbowski J.
Mathematica Applicanda
|
2012
|
tom Vol. 40, No. 1
27-37
EN
Mammalian brain is one of the most complex objects in the known universe, as it governs every aspect of animal’s and human behavior. It is fair to say that we have a very limited knowledge of how the brain operates and functions. Computational Neuroscience is a scientific discipline that attempts to understand and describe the brain in terms of mathematical modeling. This user-friendly review tries to introduce this relatively new field to mathematicians and physicists by showing examples of recent trends. It also discusses briefly future prospects for constructing an integrated theory of brain function.
PL
Mózg ssaków jest jednym z najbardziej złożonych obiektów we wszechświecie. Jest odpowiedzialny za sterowanie wszystkimi aspektami zachowań zwierzęcia i człowieka. Obecnie usprawiedliwione wydaje się stwierdzenie, ze nasza wiedza na temat pracy mózgu i jego funkcjach jest dość ograniczona. Neurobiologia obliczeniowa jest dyscyplina naukowa, która próbuje zrozumieć i opisać mózg w kategoriach modelowania matematycznego. W tej pracy zawarto przyjazny dla czytelnika przegląd zagadnień, który ma na celu wprowadzenie w ten stosunkowo nowy dla matematyków i fizyków obszar badawczy, pokazując przykłady najnowszych trendów w tej dziedzinie. Artykuł omawia także krótko przyszłe perspektywy dla budowy zintegrowanej teorii funkcji mózgu. Neurobiologia Obliczeniowa ma wiele osiągnięć w modelowaniu procesów neurofizjologicznych. W szczególności, realistyczne modelowanie dynamiki pojedynczych neuronów osiągnęło wysoki poziom wierności z danymi eksperymentalnymi. Wielkim wyzwaniem pozostaje natomiast kluczowe zagadnienie, jak przejść od opisu dynamiki pojedynczych neuronów do realistycznego opisu dynamiki całej sieci neuronów. Generalnie, poznanie i zrozumienie funkcjonowania mózgu w oparciu o modele matematyczne może mieć kolosalne znaczenie praktyczne dla społeczeństwa. Po pierwsze, w medycynie w radzeniu sobie z neurologicznymi schorzeniami takimi jak autyzm, schizofrenia, czy Alzheimer, które są coraz powszechniejsze. Mechanizmy biofizyczne tych chorób nie są znane, i być może dobra teoria funkcjonalna mogłaby w tym pomóc. Po drugie, w technologii tzw. inteligentnych urządzeń. Obecnie nawet najszybsze superkomputery nie są w stanie poradzić sobie z wydawało by się prostym zadaniem takim jak efektywne rozpoznawanie twarzy czy obiektów, z czym dość wolny ludzki mózg nie ma żadnych problemów. Bez wątpienia, inteligentne urządzenia skonstruowane na bazie mózgu miałyby bardzo wiele zastosowań, w różnych sferach działalności człowieka. Wydaje się, że zintegrowana teoria pracy mózgu mogłaby wiele wnieść w tym kierunku
15
Gęsta sieć bezprzewodowa inspirowana układem nerwowym
63%
Kułacz Ł. , Kliks A.
Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
|
2019
|
tom nr 6
487--492, CD
PL
W tej pracy przedstawiono koncepcje zastosowania algorytmów inspirowanych funkcjami i własnościami układu nerwowego w gęstych sieciach bezprzewodowych. W szczególności analizie poddano wybrane cechy mózgu składającego się z ogromnej liczby połączeń nerwowych, dlatego będących dobrym wzorem dla gęstej sieci. Ponadto przedstawiono działanie wybranych komórek z układu nerwowego (takich jak neuron, mikroglej czy astrocyt) a także zjawiska w nim obserwowane (np. neuroplastyczność).
EN
This work presents concepts of the use of algorithms inspired by the functions and properties of the nervous system in dense wireless networks. In particular, selected features of the brain consisting of a large number of nerve connections were analyzed, which is why they are a good model for a dense network. In addition, the action of selected cells from the nervous system (such as neuron, microglia or astrocyte) as well as phenomena observed in it (eg. neuroplasticity) are presented.
16
Content available remote Identification of proteins associated with amyloidosis by polarity index method
63%
Polanco C. , Samaniego J. , Uversky V. , Castañón-González J. , Buhse T. , Leopold-Sordo M. , Madero-Arteaga A. , Morales-Reyes A. , Tavera-Sierra L. , González-Bernal J. , Arias-Estrada M.
Acta Biochimica Polonica
|
2015
|
tom 62
|
nr 1
41-55
EN
There is a natural protein form, insoluble and resistant to proteolysis, adopted by many proteins independently of their amino acid sequences via specific misfolding-aggregation process. This dynamic process occurs in parallel with or as an alternative to physiologic folding, generating toxic protein aggregates that are deposited and accumulated in various organs and tissues. These proteinaceous deposits typically represent bundles of β-sheet-enriched fibrillar species known as the amyloid fibrils that are responsible for serious pathological conditions, including but not limited to neurodegenerative diseases, grouped under the term amyloidoses. The proteins that might adopt this fibrillar conformation are some globular proteins and natively unfolded (or intrinsically disordered) proteins. Our work shows that intrinsically disordered and intrinsically ordered proteins can be reliably identified, discriminated, and differentiated by analyzing their polarity profiles generated using a computational tool known as the polarity index method (Polanco & Samaniego, 2009; Polanco et al., 2012; 2013; 2013a; 2014; 2014a; 2014b; 2014c; 2014d). We also show that proteins expressed in neurons can be differentiated from proteins in these two groups based on their polarity profiles, and also that this computational tool can be used to identify proteins associated with amyloidoses. The efficiency of the proposed method is high (i.e. 70%) as evidenced by the analysis of peptides and proteins in the APD2 database (2012), AVPpred database (2013), and CPPsite database (2013), the set of selective antibacterial peptides from del Rio et al. (2001), the sets of natively unfolded and natively folded proteins from Oldfield et al. (2005), the set of human revised proteins expressed in neurons, and non-human revised proteins expressed in neurons, from the Uniprot database (2014), and also the set of amyloidogenic proteins from the AmyPDB database (2014).
17
Content available Dense Wireless Network Inspired by the Nervous System
63%
Kułacz Ł. , Kliks A. , Kułacz Ł. , Kliks A.
|
|
nr 1
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.