Search results for "DF"
showing 10 items of 1699 documents
The influence of solvent on conformational properties of peptides with Aib residue—a DFT study
2017
The conformational propensities of the Aib residue on the example of two model peptides Ac-Aib-NHMe (1) and Ac-Aib-NMe2 (2), were studied by B3LYP and M06-2X functionals, in the gas phase and in the polar solvents. To verify the reliability of selected functionals, we also performed MP2 calculations for the tested molecules in vacuum. Polarizable continuum models (PCM and SMD) were used to estimate the solvent effect. Ramachandran maps were calculated to find all energy minima. Noncovalent intramolecular interactions due to hydrogen-bonds and dipole attractions between carbonyl groups are responsible for the relative stabilities of the conformers. In order to verify the theoretical results,…
Towards Axiomatic Basis of Inductive Inference
2001
The language for the formulation of the interesting statements is, of course, most important. We use first order predicate logic. Our main achievement in this paper is an axiom system which we believe to be more powerful than any other natural general purpose discovery axiom system. We prove soundness of this axiom system in this paper. Additionally we prove that if we remove some of the requirements used in our axiom system, the system becomes not sound. We characterize the complexity of the quantifier prefix which guaranties provability of a true formula via our system. We prove also that if a true formula contains only monadic predicates, our axiom system is capable to prove this formula…
Crowdfunding Prospects in New Emerging Markets: The Cases of India and Bangladesh
2020
AbstractCrowdfunding is a viable approach to financing start-ups and supporting social causes in advanced economies. The World Bank estimates a vast potential for crowdfunding also in emerging markets. The South Asia region consists of predominantly collectivist societies where helping others through donations is an integral part of prevailing religious obligations and societal norms. Thus, these countries share certain cultural and religious traits that are highly consistent with the principles of crowdfunding. In the current chapter, we explore the history, ongoing activity, and future prospects of crowdfunding in new emerging markets, specifically, India and Bangladesh. We observe that I…
Determining the potential impacts of fire and different land uses on splash erosion in the margins of drylands
2021
Abstract This research aimed to estimate the splash erosion and its evolution during the first months in specific land uses after a forest fire. The study area was located in Congosto (North-West Spain), in the margins of Spanish drylands, after a wildfire occurred in May 2012, which burned 15.56 ha of scrubland and Pinus reforestation. Two different burned land uses were selected and compared to control areas: i) burned pine forest; and, scrublands. Rainfall intensity and the number, sizes and speed of raindrops were measured by an optical disdrometer and soil loss by funnels. Moreover, infiltration, soil moisture content, aggregate stability, water repellence, pH and organic matter were a…
STANDARD OPERATING PROCEDURES IN SPORTS SCIENCES AND HEALTH PROMOTION PROGRAMS IN DIFFERENT POPULATIONS
2021
In recent years, the population is becoming more sedentary and characterized by an increase in the mean age. One of the consequences is a population with a higher risk of chronic diseases, increasing the risk to incur in disability and death. Consequently, health promotion programs, cheaper than interventions, are acquiring an increasingly central role in the politics of Governments. Health promotion programs want to maintain and improve the physical, cognitive, psychical, and social sphere of people. Considering that psychic and social sphere are strictly dependent on the physical condition, the interest of this thesis was on motor tests ideal for health promotion programs. The motor evalu…
A Three-Dimensional Object Point Process for Detection of Cosmic Filaments
2007
Summary We propose to apply an object point process to delineate filaments of the large scale structure in red shift catalogues automatically. We illustrate the feasibility of the idea on an example of the recent 2dF Galaxy Redshift Survey, describe the procedure and characterize the results.
Assessing covariate imbalance in meta-analysis studies.
2010
The main goal of meta-analysis is to combine data across studies or data sets to obtain summary estimates. In this paper, the novelty is to propose a statistical tool to assess a possible covariate imbalance in baseline variables to investigate similarity of trials. We conducted the detection of the covariate imbalance, first, through some graphical comparison of the empirical cumulative distribution functions or ECDFs, which are built by putting together arms or trials according to some risk factor, and second, through some non-parametric tests such as the Kolmogorov–Smirnov and the Anderson–Darling tests. To overcome the huge presence of ties, we conducted the statistical tests on perturbe…
Lévy processes in bounded domains: path-wise reflection scenarios and signatures of confinement
2022
We discuss an impact of various (path-wise) reflection-from-the barrier scenarios upon confining properties of a paradigmatic family of symmetric $\alpha $-stable L\'{e}vy processes, whose permanent residence in a finite interval on a line is secured by a two-sided reflection. Depending on the specific reflection "mechanism", the inferred jump-type processes differ in their spectral and statistical characteristics, like e.g. relaxation properties, and functional shapes of invariant (equilibrium, or asymptotic near-equilibrium) probability density functions in the interval. The analysis is carried out in conjunction with attempts to give meaning to the notion of a reflecting L\'{e}vy process…
Anomalous diffusion and nonlinear relaxation phenomena in stochastic models of interdisciplinary physics
2020
The study of nonlinear dynamical systems in the presence of both Gaussian and non-Gaussian noise sources is the topic of this research work. In particular, after shortly present new theoretical results for statistical characteristics in the framework of Markovian theory, we analyse four different physical systems in the presence of Levy noise source. (a) The residence time problem of a particle subject to a non-Gaussian noise source in arbitrary potential profile was analyzed and the exact analytical results for the statistical characteristics of the residence time for anomalous diffusion in the form of Levy flights in fully unstable potential profile was obtained. Noise enhanced stability …
Magnetic properties of vanadium(IV)-based extended systems: [(VO)3(μ-PO4)2(2,2′-bpy)(μ-OH2)]*1/3H2O and (VO)2H4P2O9
2013
International audience; The magnetic properties of [(VO)3(μ-PO4)2(2,2′-bpy)(μ-OH2)]1/3H2O (1) and (VO)2H4P2O9 (2), a tubular and a layered vanadium(IV) phosphates containing triply oxido bridged VIV dimers, are analyzed considering the Bleaney-Bowers S = 1/2 dimer model. In compound 1 the presence of an additional VIV connected with the VIV dimers through μ1,2-PO43− bridges is described with a Curie-Weiss type correction. This model reproduces the magnetic properties of compound 1 with g = 1.956, Jdim = −102.1 cm−1, θ = −0.4 cm−1 and Nα = 278 × 10−6 emu mol−1. In compound 2, the presence of a small percentage of paramagnetic impurity has to be considered to account for the divergence of χm …