Search results for "interaction [dark matter]"
showing 10 items of 363 documents
Phylostratic Shift of Whole-Genome Duplications in Normal Mammalian Tissues towards Unicellularity Is Driven by Developmental Bivalent Genes and Reve…
2020
Tumours were recently revealed to undergo a phylostratic and phenotypic shift to unicellularity. As well, aggressive tumours are characterized by an increased proportion of polyploid cells. In order to investigate a possible shared causation of these two features, we performed a comparative phylostratigraphic analysis of ploidy-related genes, obtained from transcriptomic data for polyploid and diploid human and mouse tissues using pairwise cross-species transcriptome comparison and principal component analysis. Our results indicate that polyploidy shifts the evolutionary age balance of the expressed genes from the late metazoan phylostrata towards the upregulation of unicellular and early m…
ChemInform Abstract: Weak Interactions Between Trivalent Pnictogen Centers: Computational Analysis of Bonding in Dimers X3E···EX3(E: Pnictogen, X: Ha…
2009
The nature of weak interactions in dimers X3E···EX3 (E = N−Bi, X = F−I) was investigated by wave function and density functional theory (DFT)-based methods. Out of the 20 systems studied, 10 are found to be bound at the CP-MP2 and LMP2 levels of theory. Detailed partition of the interaction energy into different components revealed that dispersion is the primary force holding the dimers together but there also exists an important ionic component whose contribution increases with increasing halogen size. As expected, standard density functionals fail to describe bonding in the studied systems. However, the performance of DFT methods can be easily improved via empirical dispersion correction …
Hydration of agarose double helix: A monte carlo simulation
2009
The structure of the water around agarose double helix is analyzed with ab initio quantum mechanical calculations and Monte Carlo simulations. The potential surface is sampled by computing the interaction energy between fragments of agarose and a water molecule placed at 221 different orientations and/or positions. These energy values are fitted to a simple analytical expression representing atom-atom pair potentials for a water molecule interacting with agarose. A preliminary understanding of the agarose-water interaction is obtained from isoenergy contour maps at planar cross sections, perpendicular to the long axis of the double helix, and for cylindrical surfaces enclosing the double he…
A study of coronene?coronene association using atom?atom pair potentials
1996
A study of the coronene—coronene association using different interaction potentials based on an atom-atom pair potential proposed by Fraga has been performed. The interaction potentials employed differ in the way the electrostatic and/or dispersion contributions are computed. The influence of both contributions on the geometries predicted for the coronene dimer is discussed in order to analyze the effectiveness of the different interaction potentials. The stationary points found in each interaction energy hypersurface are characterized by calculating the Hessian eigenvalues. Results are discussed in the light of those previously reported for the benzene dimer. Stacked-displaced structures a…
Modelling of the cation motions in complex system: case of Na-mordenites
2002
Abstract Semi-empirical inter-atomic potentials and Monte Carlo algorithms are proposed to predict the evolution of the interaction energy between sodium ions and a mordenite type aluminosilicate network as a function of Si/Al ratio. This result is favourably compared with the activation energy barriers for Na + `jumps' responsible for the polarization change, measured by thermally stimulated current (TSC) spectroscopy, for Na-mordenites characterized by Si/Al ratios ranged from 5.5 to 12. Finally, we propose a possible mechanism for the cation motions, which involves activation barriers within the same order of magnitude than those measured by TSC.
Description of the Retention and Peak Profile for Chromolith Columns in Isocratic and Gradient Elution Using Mobile Phase Composition and Flow Rate a…
2014
The effect of the modifier concentration and flow rate on the chromatographic performance of a second generation Chromolith® RP-18e column, under isocratic and gradient elution with acetonitrile-water mixtures, was examined using four sulphonamides as probe compounds. The acetonitrile concentration was varied between 5 and 55% (v/v), and the flow rate between 0.1 and 5.0 mL/min, keeping the other factors constant. The changes in both retention and peak profile were modelled, and used to build simple plots, where the logarithm of the retention factor was represented against the modifier concentration (in gradient elution, against the initial modifier concentration), and the half-widths or wi…
Reverse engineering a mouse embryonic stem cell-specific transcriptional network reveals a new modulator of neuronal differentiation
2012
Gene expression profiles can be used to infer previously unknown transcriptional regulatory interaction among thousands of genes, via systems biology 'reverse engineering' approaches. We 'reverse engineered' an embryonic stem (ES)-specific transcriptional network from 171 gene expression profiles, measured in ES cells, to identify master regulators of gene expression ('hubs'). We discovered that E130012A19Rik (E13), highly expressed in mouse ES cells as compared with differentiated cells, was a central 'hub' of the network. We demonstrated that E13 is a protein-coding gene implicated in regulating the commitment towards the different neuronal subtypes and glia cells. The overexpression and …
Transcriptome and metabolome analysis of citrus fruit to elucidate puffing disorder.
2014
a b s t r a c t A systems-level analysis reveals details of molecular mechanisms underlying puffing disorder in Citrus fruit. Flavedo, albedo and juice sac tissues of normal fruits and fruits displaying symptoms of puffing disorder were studied using metabolomics at three developmental stages. Microarrays were used to compare normal and puffed fruits for each of the three tissues. A protein-protein interaction network inferred from previous work on Arabidopsis identified hub proteins whose transcripts show significant changes in expression. Glycolysis, the backbone of primary metabolism, appeared to be severely affected by the disorder, based on both transcriptomic and metabolomic results. …
Sonic Interaction Design
2009
Sound is an integral part of every user experience but a neglected medium in design disciplines. Design of an artifact's sonic qualities is often limited to the shaping of functional, representational, and signaling roles of sound. The interdisciplinary field of sonic interaction design (SID) challenges these prevalent approaches by considering sound as an active medium that can enable novel sensory and social experiences through interactive technologies. This book offers an overview of the emerging SID research, discussing theories, methods, and practices, with a focus on the multisensory aspects of sonic experience. Sonic Interaction Design gathers contributions from scholars, artists, an…
Developing hand-worn input and haptic support for real-world target finding
2019
Locating places in cities is typically facilitated by handheld mobile devices, which draw the visual attention of the user on the screen of the device instead of the surroundings. In this research, we aim at strengthening the connection between people and their surroundings through enabling mid-air gestural interaction with real-world landmarks and delivering information through audio to retain users' visual attention on the scene. Recent research on gesture-based and haptic techniques for such purposes has mainly considered handheld devices that eventually direct users' attention back to the devices. We contribute a hand-worn, mid-air gestural interaction design with directional vibrotacti…