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Dynamic 2- and 3-connectivity on planar graphs
1992
We study the problem of maintaining the 2-edge-, 2-vertex-, and 3-edge-connected components of a dynamic planar graph subject to edge deletions. The 2-edge-connected components can be maintained in a total of O(n log n) time under any sequence of at most O(n) deletions. This gives O(log n) amortized time per deletion. The 2-vertex- and 3-edge-connected components can be maintained in a total of O(n log2n) time. This gives O(log2n) amortized time per deletion. The space required by all our data structures is O(n).
<title>Stereovision studies by disbalanced images</title>
2003
Studies are focused on design and appraisal of an objective test of the quality of stereovision depending on optical stimuli blurring and detecting of the stereovision threshold at various stimuli blur degree. The method is based on the principles of grayscale and color random dot stereotests. Experiments may be divided with respect to the principle of demonstration: 1) the blur is modeled by defocusing an optical lens - the strength of the optical system is varied at a constant quality of the stimulus, or 2) the blur is simulated on the computer screen - here the quality of the stimulus varies. To obtain an independent description and to measure blurring the experimentally demonstrated ima…
The use of Stokes-Mueller polarimetry for assessment of amyloid-β progression in a mouse model of Alzheimer’s disease
2020
Abstract Alzheimer’s disease, being a major societal burden, demands improvement of current techniques for its treatment and diagnostics. Currently only autopsy histology is able to provide the definite diagnosis for Alzheimer’s disease. However, the procedure is rather time consuming and costly. In the current study, we utilized Stokes and Mueller polarimetry techniques to screen for amyloid-β (Aβ) deposits in formalin-fixed, paraffin-embedded mouse brain tissue at different stages of Alzheimer’s disease. The study has shown that the presence of Aβ plaques influences the properties of scattered polarized light. The Poincaré sphere was used as a graphical tool for the visualization of the a…
Decoding vibrational states of Concanavalin A amyloid fibrils.
2015
International audience; Amyloid and amyloid-like fibrils are a general class of protein aggregates and represent a central topic in life sciences for their involvement in several neurodegenerative disorders and their unique mechanical and supramolecular morphological properties. Both their biological role and their physical properties, including their high mechanical stability and thermodynamic inertia, are related to the structural arrangement of proteins in the aggregates at molecular level. Significant variations may exist in the supramolecular organization of the commonly termed cross-β structure that constitutes the amyloid core. In this context, a fine knowledge of the structural deta…
K-means Clustering to Study How Student Reasoning Lines Can Be Modified by a Learning Activity Based on Feynman’s Unifying Approach
2017
Background:Research in Science Education has shown that often students need to learn how to identify differences and similarities between descriptive and explicative models. The development and use of explicative skills in the field of thermal science has always been a difficult objective to reach. A way to develop analogical reasoning is to use in Science Education unifying conceptual frameworks.Material and methods:A questionnaire containing six open-ended questions on thermally activated phenomena was administered to the students before instruction. A second one, similar but focused on different physical content was administered after instruction. Responses were analysed using k-means Cl…
La Grammaire de Condillac face au paradoxe de l'origine naturelle du langage
2012
The recent discovery of mirror neurons has rivived the gestural-imitative theory of the origin of language advocated by Condillac in the XVIIIth century. Condillac develops this theory in two stages: in the Essai (1746) he proposes a gestural theory based on the arbitrariness of the sign, while in the Grammaire (1775) he refuses arbitrariness and accepts the theory of analogy and natural imitation proposed by Charles de Brosses (1765). This choice depends on the fact that in Rousseau (1755) and Beauzee (1765) arbitrariness, as a "paradox of the original contract", now plays the role of key argument in favor of the divine origin of language. So, the theory of analogy and natural imitation is…
Error estimation and reduction with cross correlations
2010
Besides the well-known effect of autocorrelations in time series of Monte Carlo simulation data resulting from the underlying Markov process, using the same data pool for computing various estimates entails additional cross correlations. This effect, if not properly taken into account, leads to systematically wrong error estimates for combined quantities. Using a straightforward recipe of data analysis employing the jackknife or similar resampling techniques, such problems can be avoided. In addition, a covariance analysis allows for the formulation of optimal estimators with often significantly reduced variance as compared to more conventional averages.
Zero Viscosity Limit for Analytic Solutions of the Primitive Equations
2016
The aim of this paper is to prove that the solutions of the primitive equations converge, in the zero viscosity limit, to the solutions of the hydrostatic Euler equations. We construct the solution of the primitive equations through a matched asymptotic expansion involving the solution of the hydrostatic Euler equation and boundary layer correctors as the first order term, and an error that we show to be \({O(\sqrt{\nu})}\). The main assumption is spatial analyticity of the initial datum.
Procedure for automated background correction in flow systems with infrared spectroscopic detection and changing liquid-phase composition
2009
This paper describes a partial least squares (PLS) based automatic procedure to correct for changes in the spectral contribution of the solvent or solvent mixtures from solute spectra recorded in these solvents. The procedure was developed for successful on-line Fourier transform infrared (FT-IR) detection in gradient high-performance liquid chromatography (HPLC) separations. It requires a reference FT-IR data set containing all possible combinations of the expected variation in solvent composition. Furthermore, a spectral region ( A) in these spectra is required where the solvents show absorption but the analytes do not. This is the case for the system ACN:H2O, an often-applied solvent mi…
Observation of interaction forces by investigation of the influence of eluent additives on the retention behavior of aqueous nanoparticle dispersions…
2020
The investigation and subsequent understanding of the interactions of nanomaterials with components of their surrounding media is important to be able to evaluate both potential use cases as well as potential risks for human health and for the environment. To investigate such interactions, asymmetrical flow field-flow fractionation (AF4) is an interesting analytical tool. This statement grounds on the fact that interactions of the analyte with the membrane and with components of the eluent are crucial for the retention behavior of the analyte within the field-flow fractionation (FFF) channel. Therefore, the investigation of the retention behavior provides an insight in the nature of the int…