Search results for "Modeling"
showing 10 items of 4489 documents
IN THE SEARCH OF LEPTIN AGONISTS AS ANTI-OBESITY DRUGS: PROTEIN/PROTEIN DOCKING, MOLECULAR DYNAMICS, AND VIRTUAL SCREENING
2012
The body weight control is a mechanism thinly regulated by several hormonal, metabolic, and nervous pathways (1). Recessive homozygous mutations in the ob/ob and db/db mouse strain cause extreme obesity. The products of the ob and db genes are leptin and its receptor, respectively. The leptin receptor is crucial for energy homeostasis and regulation of food uptake. Leptin is a 16 kDa hormone that is mainly secreted by fat cells into the bloodstream. Under normal circumstances, circulating leptin levels are proportionate to the fat body mass. Sensing of elevated leptin levels by the hypothalamic neurocircutry activates a negative feedback loop resulting in reduced food intake and increased e…
On the limit velocity and buckling phenomena of axially moving orthotropic membranes and plates
2011
In this paper, we consider the static stability problems of axially moving orthotropic membranes and plates. The study is motivated by paper production processes, as paper has a fiber structure which can be described as orthotropic on the macroscopic level. The moving web is modeled as an axially moving orthotropic plate. The original dynamic plate problem is reduced to a two-dimensional spectral problem for static stability analysis, and solved using analytical techniques. As a result, the minimal eigenvalue and the corresponding buckling mode are found. It is observed that the buckling mode has a shape localized in the regions close to the free boundaries. The localization effect is demon…
Damage accumulation and life prediction in carbon fibre composite pressure vessels
2009
Composites and nanostructures
Biogenic Fenton process - A possible mechanism for the mineralization of organic carbon in fresh waters.
2020
To explore the mechanisms that mineralize poorly bioavailable natural organic carbon (OC), we measured the mineralization of OC in two lake waters over long-term experiments (up to 623 days) at different pH and iron (Fe) levels. Both the microbial and photochemical mineralization of OC was higher at pH acidified to 4 than at the ambient pH 5 or an elevated pH 6. During 244 days, microbes mineralized up to 60% of OC in the 10-mu m filtrates of lake water and more than 27% in the 1-mu m filtrates indicating that large-sized microbes/grazers enhance the mineralization of OC. A reactivity continuum model indicated that the acidification stimulated the microbial mineralization of OC especially i…
Differential VASP phosphorylation controls remodeling of the actin cytoskeleton
2009
Proteins of the Enabled/vasodilator-stimulated phosphoprotein (Ena/VASP) family link signal transduction pathways to actin cytoskeleton dynamics. VASP is substrate of cAMP-dependent, cGMP-dependent and AMP-activated protein kinases that primarily phosphorylate the sites S157, S239 and T278, respectively. Here, we systematically analyzed functions of VASP phosphorylation patterns for actin assembly and subcellular targeting in vivo and compared the phosphorylation effects of Ena/VASP family members. Methods used were the reconstitution of VASP-null cells with `locked' phosphomimetic VASP mutants, actin polymerization of VASP mutants in vitro and in living cells, site-specific kinase-mediated…
Analysis of the effects of magnetic field on the induced stress in drilled plates
2013
Abstract A drilled plate of ferromagnetic material suitably coupled by coils of enameled copper wire fed by a DC power supply to 30 V is considered in this paper. It is analyzed with finite element and later experiments are performed to validate the obtained results. After polishing the plate, two strain gauges for measuring the deformation along the x axis and along the z axis are installed. The values of strain are 5 μm/m in z direction and −2 μm/m in x direction. The experimental–numerical comparison shows that the laboratory results are lower than numerical, while signs and orders of magnitude are the same. It is concluded that the results of the FEM analysis can be considered acceptabl…
Adding ‘Sense’ to Conceptual Modeling : An Interdisciplinary Approach
2019
In this paper, our aim is to widen the prevailing foundations of conceptual modeling theories and practices, particularly in the context of information systems development. The approach shifts the focus from the link between a model and the modelled reality to the link between human cognition and the model. Our approach combines theoretical issues of different disciplines relevant to conceptual modeling. We shall make an explicit distinction between individual conceptions and interpersonal concepts and show how this distinction could be utilized to have conceptual models of a better consistency. We wish that this article could also serve as a starting point for a profound scientific discuss…
International Conference for Mathematical Modeling and Optimization in Mechanics : book of abstracts : University of Jyväskylä, March 6-7, 2014
2014
This book of abstracts presents materials of the International Conference for Mathematical Modeling and Optimization in Mechanics (MMOM 2014) 6-7 March 2014, Jyväskylä, Finland. This event is dedicated to Professor Nikolay Banichuk in occasion of his 70th anniversary. It is aimed to present the latest results of leading scientists in mathematical modeling, numerical analysis, and optimization theory and to discuss the state of the art and open problems in the field. The book is divided in five sections: 1. Mathematical Modelling of Complex Systems 2. Stability Analysis and Vibration 3. Optimization 4. Methods of Numerical Analysis 5. Shape Optimization
Bayesian semiparametric long memory models for discretized event data
2020
We introduce a new class of semiparametric latent variable models for long memory discretized event data. The proposed methodology is motivated by a study of bird vocalizations in the Amazon rain forest; the timings of vocalizations exhibit self-similarity and long range dependence. This rules out Poisson process based models where the rate function itself is not long range dependent. The proposed class of FRActional Probit (FRAP) models is based on thresholding, a latent process. This latent process is modeled by a smooth Gaussian process and a fractional Brownian motion by assuming an additive structure. We develop a Bayesian approach to inference using Markov chain Monte Carlo and show g…
Molecular dynamics simulations of heavy ion induced defects in SiC Schottky diodes
2018
Heavy ion irradiation increases the leakage current in reverse-biased SiC Schottky diodes. This letter demonstrates, via molecular dynamics simulations, that a combination of bias and ion-deposited energy is required to produce the degradation. Peer reviewed