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Search Results: 1 - 10 of 1945 matches for " Monika Liguz-Lecznar "
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Influence of Inflammation on Poststroke Plasticity
Monika Liguz-Lecznar,Malgorzata Kossut
Neural Plasticity , 2013, DOI: 10.1155/2013/258582
Influence of Inflammation on Poststroke Plasticity
Monika Liguz-Lecznar,Malgorzata Kossut
Neural Plasticity , 2013, DOI: 10.1155/2013/258582
Abstract: Age-related brain injuries including stroke are a leading cause of morbidity and mental disability worldwide. Most patients who survive stroke experience some degree of recovery. The restoration of lost functions can be explained by neuronal plasticity, understood as brain ability to reorganize and remodel itself in response to changed environmental requirements. However, stroke triggers a cascade of events which may prevent the normal development of the plastic changes. One of them may be inflammatory response initiated immediately after stroke, which has been found to contribute to neuronal injury. Some recent evidence though has suggested that inflammatory reaction can be also neuroprotective. This paper attempts to discuss the influence of poststroke inflammatory response on brain plasticity and stroke outcome. We also describe the recent anti-inflammatory strategies that have been effective for recovery in experimental stroke. 1. Introduction Ischemic stroke results from two main pathological processes: a loss of oxygen and an interruption of glucose supply to a particular brain region. The collapse of energy provision leads to the dysfunction of ionic pumps, loss of membrane potential, and uncontrolled release of neurotransmitters. The consequence of those processes is the increase of intracellular calcium concentrations that, among many deleterious effects, result in the generation of free radicals, leading to disintegration of cell membranes and subsequent neuronal death in the core of infarction [1]. Necrosis in the center of infarction can start a few minutes after stroke and is followed by peri-infarct depolarizations, excitotoxicity, edema, and oxidative stress [2]. The more delayed processes accompanying stroke are inflammation and apoptosis. They are initiated several hours after ischemic attack and can persist even for several weeks [3]. Although a great progress has been made in understanding the cellular and molecular mechanisms of ischemic tissue damage, the only approved therapy is still thrombolysis achieved by intravenous administration of recombinant tissue plasminogen activator (tPA). Unfortunately, short therapeutic window for this therapy strongly limits the fraction of patient that can benefit from the treatment. Moreover, stroke induces a complex cascade of inflammatory response which contributes to the postischemic damage. The complex nature of phenomena after ischemic event hampers a successful design of effective therapeutic strategies (Figure 1). Figure 1: Acute cerebral ischemia, neuroinflammation, and plasticity.
The Effect of Different Movement Exercises on Cognitive and Motor Abilities  [PDF]
Monika Thomas
Advances in Physical Education (APE) , 2012, DOI: 10.4236/ape.2012.24030
Abstract: The influence of physical activity on motor and cognitive performance has been approved in several studies. However, it is still unclear which functions are affected, and why. It also remains unknown what type of physical training is best suitable. The present study focuses on special movement aspects based on the Brain Gym? program. Four groups of subjects (n = 64) participated in two experiments with pre-post intervention design. In experiment 1 two groups of subjects were exposed to a sensorimotor adaptation study design by executing center out pointing movements under distorted visual feedback conditions with their dominant and non-dominant arm to test for intermanual transfer (IMT) as pre- and posttest. The intervention in both groups consisted of specified movement exercises with the right and left extremities: participants of Experimental group executed movements crossing the body midline and participants of Control group movements without crossing the body midline. Results showed a decreased retention of adaptation but larger IMT for Experimental group during posttest. We conclude that movements crossing the body midline impede retention but enhance IMT of sensorimotor adaptation. A potential relationship to an improvement of communication between the cerebral hemispheres evoked by the movement exercises crossing the body midline is rather speculative. In experiment 2 two groups were exposed to the d2-test measuring concentration and attention and a dice-test testing for visual-spatial abilities as pre- and posttest. The interventions were similar to experiment 1. Results yielded no differences between groups such that different effects of both interventions could not have been shown.
Two Blind Adaptive Equalizers Connected in Series for Equalization Performance Improvement  [PDF]
Monika Pinchas
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.41008

A variable step-size parameter is usually used to accelerate the convergence speed of a blind adaptive equalizer with N1 + N2 -1 coefficients where N1 and N2 are odd values. In this paper we show that improved equalization performance is achieved when using two blind adaptive equalizers connected in series where the first and second blind adaptive equalizer have N1 and N2 coefficients respectively compared with the case where a single blind adaptive equalizer is applied with N1 + N2 -1 coefficients. It should be pointed out that the same algorithm (cost function) is used for updating the filter taps for the different equalizers and that a fixed step-size parameter is used. Simulation results show that for the low signal to noise ratio (SNR) environment and for the case where the convergence speed is slow due to the channel characteristics, the new method has a faster convergence speed with a factor of approximately two while leaving the system with approximately the same or lower residual intersymbol interference (ISI).

Under What Condition Do We Get Improved Equalization Performance in the Residual ISI with Non-Biased Input Signals Compared with the Biased Version  [PDF]
Monika Pinchas
Journal of Signal and Information Processing (JSIP) , 2015, DOI: 10.4236/jsip.2015.62008
Abstract: Recently, closed-form approximated expressions were obtained for the residual Inter Symbol Interference (ISI) obtained by blind adaptive equalizers for the biased as well as for the non-biased input case in a noisy environment. But, up to now it is unclear under what condition improved equalization performance is obtained in the residual ISI point of view with the non-biased case compared with the biased version. In this paper, we present for the real and two independent quadrature carrier case a closed-form approximated expression for the difference in the residual ISI obtained by blind adaptive equalizers with biased input signals compared with the non-biased case. Based on this expression, we show under what condition improved equalization performance is obtained from the residual ISI point of view for the non-biased case compared with the biased version.
Convolutional Noise Analysis via Large Deviation Technique  [PDF]
Monika Pinchas
Journal of Signal and Information Processing (JSIP) , 2015, DOI: 10.4236/jsip.2015.64024
Abstract: Due to non-ideal coefficients of the adaptive equalizer used in the system, a convolutional noise arises at the output of the deconvolutional process in addition to the source input. A higher convolutional noise may make the recovering process of the source signal more difficult or in other cases even impossible. In this paper we deal with the fluctuations of the arithmetic average (sample mean) of the real part of consecutive convolutional noises which deviate from the mean of order higher than the typical fluctuations. Typical fluctuations are those fluctuations that fluctuate near the mean, while the other fluctuations that deviate from the mean of order higher than the typical ones are considered as rare events. Via the large deviation theory, we obtain a closed-form approximated expression for the amount of deviation from the mean of those fluctuations considered as rare events as a function of the system’s parameters (step-size parameter, equalizer’s tap length, SNR, input signal statistics, characteristics of the chosen equalizer and channel power), for a pre-given probability that these events may occur.
Convergence Curve for Non-Blind Adaptive Equalizers  [PDF]
Monika Pinchas
Journal of Signal and Information Processing (JSIP) , 2016, DOI: 10.4236/jsip.2016.71002
Abstract: In this paper a closed-form approximated expression is proposed for the Intersymbol Interference (ISI) as a function of time valid during the entire stages of the non-blind adaptive deconvolution process and is suitable for the noisy, real and two independent quadrature carrier input case. The obtained expression is applicable for type of channels where the resulting ISI as a function of time can be described with an exponential model having a single time constant. Based on this new expression for the ISI as a function of time, the convergence time (or number of iteration number required for convergence) of the non-blind adaptive equalizer can be calculated. Up to now, the equalizer’s performance (convergence time and ISI as a function of time) could be obtained only via simulation when the channel coefficients were known. The new proposed expression for the ISI as a function of time is based on the knowledge of the initial ISI and channel power (which is measurable) and eliminates the need to carry out any more the above mentioned simulation. Simulation results indicate a high correlation between the simulated and calculated ISI (based on our proposed expression for the ISI as a function of time) during the whole deconvolution process for the high as well as for the low signal to noise ratio (SNR) condition.
The Psychosocial Risks in Workplace as a Category in Research. Comparative Diagnosis  [PDF]
Monika Budnik
Open Journal of Social Sciences (JSS) , 2019, DOI: 10.4236/jss.2019.72004
Abstract: Article presents the issue of psychosocial risks from perspective diversity on culture context. This context is socially appointed through the meanings by using and conceptualization notions, legitimizing these concepts of notion in the law and through studying phenomena through tools to adequately measure the scale of occurrence of a given psychosocial threat. The main idea of this article focuses on the social constructing concepts and definitions reproduced in the society through: using the notion of psychosocial hazards, different methods and research techniques in the social sciences themselves to explore these phenomena, the different scale of the declared occurrence of social threats to the culturally diverse dimensions of national cultures. Presented areas of psychosocial risks from European perspective, contain differentiated standards which are used in theory and research. Moreover the short article presents the diverse needs of measurement methods adequate for the broad frameworks of psychosocial risks such as mobbing, harcèlement moral, stress and presenteeism.
Synthesis, characterization and biocidal properties of platinum metal complexes derived from 2,6-diacetylpyridine (bis thiosemicarbazone)  [PDF]
Monika Tyagi, Sulekh Chandra
Open Journal of Inorganic Chemistry (OJIC) , 2012, DOI: 10.4236/ojic.2012.23007
Abstract: The coordination compounds of PdII, PtII, RhIII and IrIII metal ions with a Schiff base ligand (L) i.e. 2,6- diacetylpyridine bis(thiosemicarbazone) have been synthesized and characterized by elemental analyses, molar conductance, magnetic susceptibility measurements, IR, NMR and electronic spectral studies. On the basis of molar conductance and elemental analyses the complexes were found to have composition [M(L)]Cl2 and [M’(L)Cl]Cl2, where M = Pd(II), Pt(II) and M’ = Rh(III), Ir(III). The spectral studies reveal that the complexes possess monomeric composition. Complexes of PdII and PtII were found to have four coordinated square planar geometry whereas the complexes of RhIII and IrIII posses six coordinated octahedral geometry. The ligand field parameters were calculated using various energy level diagrams. In vitro synthesized compounds and metal salts have been tested against some species of plant pathogenic fungi and bacteria in order to assess their antimicrobial properties.
Adsorptive Removal of Antimony (III) Using Modified Montmorillonite: A Study on Sorption Kinetics  [PDF]
Ansar Anjum, Monika Datta
Journal of Analytical Sciences, Methods and Instrumentation (JASMI) , 2012, DOI: 10.4236/jasmi.2012.23027
Abstract: The adsorptive removal of antimony (III) has been successfully obtained on montmorillonite (MMT) and modified MMT from synthetic solution. The adsorption behavior of the modified and unmodified MMT has been investigated as a function of initial concentration of metal ion in the solution, pH of the solution and contact time using a batch extraction process. The optimized process can be applied for the adsorption, detection and estimation of antimony from 0.006 μg/ml (6.0 ppb) to 100.00 μg/ml (100.0 ppm) in aqueous solution. It has been observed that almost 99% of antimony (III) can be successfully extracted from a solution containing 100 μg/ml of the metal ion at pH 6.0 at 25?C ± 2?C. The investigation of the kinetics of sorption of antimony (III) on MMT/modified MMTshows intraparticle diffusion to be the rate limiting step during the initial stages of adsorption followed by chemisorption.
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