Dynamics of large-scale neuronal networks of the human cortex functional connectivity : From Twenty First Annual Computational Neuroscience Meeting: CNS*2012 Decatur, GA, USA. 21-26 July 2012

Published by BioMed Central Vuksanović, Vesna ; Hövel, Philipp : Dynamics of large-scale neuronal networks of the human cortex functional connectivity : From Twenty First Annual Computational Neuroscience Meeting: CNS*2012 Decatur, GA, USA. 21-26 July 2012. - In: BMC Neuroscience. - ISSN 1471-2202 (online). - 13 (2012), suppl. 1, P117. - doi:10.1186/1471-2202-13-S1-P117

Genetic basis of anatomical asymmetry and aberrant dynamic functional networks in Alzheimer’s disease

Acknowledgements V.V. conceptualized the study, analysed genetic and fMRI data, drafted the manuscript and supervised the project. N.R. conducted analysis of functional MRI data. V.V and G.R. reviewed the manuscript. V.V. would like to thank Dr Juliane Mueller, Cambridge Clinical Neuroscience, for useful and very informative discussions about gene expressions in healthy and diseased brains. Funding This work is supported by funds from Roland Sutton Academic Trust (RG:#RG13688 and #DSR1058-100).Peer reviewe

Synchronization in Functional Networks of the Human Brain

AV and PH acknowledge support by Deutsche Forschungsgemeinschaft under Grant No. HO4695/3-1 and within the framework of Collaborative Research Center 910. We thank Yasser Iturria-Medina for sharing the DW-MRI data including fiber lengths used in the study. We also thank Jason Bassett for helpful discussions.Peer reviewedPostprin

MODIFICATION OF THE COBWEB MODEL INTO GENERALIZED LOGISTIC EQUATION FOR THE WHEAT PRICE ANALYSIS

In the paper we constructed the new wheat growth model, based on the generalized logistic equation. Starting from the theoretical framework of the cobweb model, we adapted generalized logistic equation to better fit the real data of wheat prices, according to the presented wheat growth model. The aim of the paper is to present how logistic and generalized logistic equations can be used for both prediction of wheat prices and for the wheat price stability analysis. Data analysis showed better performances of the generalized logistic map in comparation with the conventional logistic map as a main result of this paper. For estimated parameters of the model the bifurcation diagrams also have been presented to show stability of wheat price over time. The conclusion is that the proposed model can be useful in predicting future wheat prices in the short-run period, as well as for the analysis of stability in conditions of uncertainty, which is also a recommendation for the application of the model in the future research

Synchronization in functional networks of the human brain

Understanding the relationship between structural and functional organization represents one of the most important challenges in neuroscience. An increasing amount of studies show that this organization can be better understood by considering the brain as an interactive complex network. This approach has inspired a large number of computational models that combine experimental data with numerical simulations of brain interactions. In this paper, we present a summary of a data-driven computational model of synchronization between distant cortical areas that share a large number of overlapping neighboring (anatomical) connections. Such connections are derived from in vivo measures of brain connectivity using diffusion-weighted magnetic resonance imaging and are additionally informed by the presence of significant resting-state functionally correlated links between the areas involved. The dynamical processes of brain regions are simulated by a combination of coupled oscillator systems and a hemodynamic response model. The coupled oscillatory systems are represented by the Kuramoto phase oscillators, thus modeling phase synchrony between regional activities. The focus of this modeling approach is to characterize topological properties of functional brain correlation related to synchronization of the regional neural activity. The proposed model is able to reproduce remote synchronization between brain regions reaching reasonable agreement with the experimental functional connectivities. We show that the best agreement between model and experimental data is reached for dynamical states that exhibit a balance of synchrony and variations in synchrony providing the integration of activity between distant brain regions

Structural, optical and mechanical characterization of PMMA- MXene composites functionalized with MEMO silane

Processing and characterization of PMMA-MXene composites were investigated. γ-Methacryloxypropyltrimethoxy (MEMO) silane was used to modify the surface of MXenes and improve the compatibility between MXenes and the polymer. The FTIR analysis revealed the formation of a chemical bond between MXene and MEMO silane, while the XPS analysis confirmed the presence of silicon in the functionalized MXene. PMMA composites with non-functionalized and functionalized MXene were prepared using a solution casting method. Tensile tests showed that, compared to neat PMMA, Young’s modulus increased in both composites by 22.1 and 27.6%, respectively. As a result of coupling between the PMMA matrix and the surface-modified MXenes, the tensile strength also increased by about 37%. In addition, optical spectroscopy showed higher absorption for the composite with surface-modified MXenes and short-lived fluorescence with emission intensity sensitive to the crumpling of functionalized MXene nanosheets

Mechanical Properties of Biomass-derived Silica Nanoparticles Reinforced PMMA Composite Material

Rice husk was used to produce silica particles, which were then used to reinforce the polymer matrix. The synthesized SiO2 particles were characterized using X-ray diffraction, Fourier transforms infrared spectroscopy (FTIR) and scanning electron microscopy with EDS. In a PMMA matrix, prepared SiO2 particles in amounts of 1, 3, and 5 wt.% were used as reinforcing agents. The goal of this research was to see if SiO2 particles had any effect on the mechanical properties of polymer composite materials. The morphology of the composites was examined using a field emission scanning electron microscope (FE-SEM). Vickers microindentation hardness and impact testing were used to determine the mechanical properties of the obtained composites. The indentation creep’s behavior of a polymethylmetacrylate (PMMA) composite material with varying amounts of nanoparticles (SiO2) was investigated and analyzed