419 research outputs found
A doubly nonlinear Cahn-Hilliard system with nonlinear viscosity
In this paper we discuss a family of viscous Cahn-Hilliard equations with a
non-smooth viscosity term. This system may be viewed as an approximation of a
"forward-backward" parabolic equation. The resulting problem is highly
nonlinear, coupling in the same equation two nonlinearities with the diffusion
term. In particular, we prove existence of solutions for the related initial
and boundary value problem. Under suitable assumptions, we also state
uniqueness and continuous dependence on data.Comment: Key words and phrases: diffusion of species; Cahn-Hilliard equations;
viscosity; non-smooth regularization; nonlinearities; initial-boundary value
problem; existence of solutions; continuous dependenc
Entropy theorems in classical mechanics, general relativity, and the gravitational two-body problem
In classical Hamiltonian theories, entropy may be understood either as a
statistical property of canonical systems, or as a mechanical property, that
is, as a monotonic function of the phase space along trajectories. In classical
mechanics, there are theorems which have been proposed for proving the
non-existence of entropy in the latter sense. We explicate, clarify and extend
the proofs of these theorems to some standard matter (scalar and
electromagnetic) field theories in curved spacetime, and then we show why these
proofs fail in general relativity; due to properties of the gravitational
Hamiltonian and phase space measures, the second law of thermodynamics holds.
As a concrete application, we focus on the consequences of these results for
the gravitational two-body problem, and in particular, we prove the
non-compactness of the phase space of perturbed Schwarzschild-Droste
spacetimes. We thus identify the lack of recurring orbits in phase space as a
distinct sign of dissipation and hence entropy production.Comment: 39 pages, 3 figures; v2: version to appear in Phys. Rev. D,
references adde
The concept of limit between disability and adolescence: analysis of a For Special team
openAttraverso l'analisi di una squadra for Special di ragazzini con disabilitĂ accompagnati sul campo di calcio da adolescenti, si indaga il concetto di limite e di come esso si possa oltrepassare con un mutuo aiuto
Expression of Autophagic and Inflammatory Markers in Normal Mucosa of Individuals with Colorectal Adenomas: A Cross Sectional Study among Italian Outpatients Undergoing Colonoscopy
: Colorectal cancer (CRC) ranks among the three most common cancers in terms of both cancer incidence and cancer-related deaths in Western industrialized countries. Lifetime risk of colorectal cancer may reach 6% of the population living in developed countries. In the current era of personalized medicine, CRC is no longer considered as a single entity. In more recent years many studies have described the distinct differences in epidemiology, pathogenesis, genetic and epigenetic alterations, molecular pathways and outcome depending on the anatomical site. The aim of our study is to assess in a multidimensional model the association between metabolic status and inflammatory and autophagic changes in the normal colorectal mucosa classified as right-sided, left-sided and rectum, and the presence of adenomas. One hundred and sixteen patients undergoing colonoscopy were recruited and underwent a complete serum lipid profile, immunofluorescence analysis of colonic biopsies for MAPLC3 and myeloperoxidase expression, matched with clinical and anthropometric characteristics. Presence of adenomas correlated with cholesterol (total and LDL) levels, IL-6 levels, and MAPLC3 tissue expression, especially in the right colon. In conclusion, serum IL-6 amount and autophagic markers could be good predictors of the presence of colorectal adenomas
Positive temporal comparison facilitates a hope-induced system justification amongst women
We examined whether women’s support for gender-based pay inequality (i.e., system justification) might be explained by hope. In particular, we considered whether such hope is likely prompted by positive temporal comparisons: It is entirely possible (even if previously untested) that the more women believe that their outcomes are getting better relative to what it had been at some point in the past, the greater their optimism about a better gender-based outcome could be, prompting women to support the systems that permitted such advancements. These central propositions were derived from the social identity model of systems attitude (SIMSA) and were corroborated in a correlational study involving 611 female healthcare professionals (Study 1). Study 2 (213 Italian- and 79 Spanish-women) offered a conceptual replication and extension of the evidence from Study 1: It showed that inducing positive temporal contrasts caused women’s hope for a better gender-based outcome in the future to increase, consequently allowing them to support the prevailing gender-syste
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