The information-theoretic meaning of Gagliardo--Nirenberg type inequalities

Gagliardo--Nirenberg inequalities are interpolation inequalities which were proved independently by Gagliardo and Nirenberg in the late fifties. In recent years, their connections with theoretic aspects of information theory and nonlinear diffusion equations allowed to obtain some of them in optimal form, by recovering both the sharp constants and the explicit form of the optimizers. In this note, at the light of these recent researches, we review the main connections between Shannon-type entropies, diffusion equations and a class of these inequalities

The Active plus protocol: systematic development of two theory- and evidence-based tailored physical activity interventions for the over-fifties

<p>Abstract</p> <p>Background</p> <p>Limited data are available on the development, implementation and evaluation processes of physical activity promotion programmes among older adults. More integrative insights into interventions describing the planned systematic development, implementation and evaluation are needed.</p> <p>Methods and design</p> <p>The purpose of this study is to give an integrative insight into the development of the Active <it>plus </it>programme applying the six-step Intervention Mapping protocol. The Active <it>plus </it>programme consisted of two theory- and evidence-based tailored physical activity promotion interventions, both comprising three tailored letters delivered over four months and aimed at raising awareness of insufficient physical activity, and stimulating physical activity initiation and maintenance among the over-fifties.</p> <p>The first intervention, the basic tailored intervention, provided tailored letters that intervened on the psychosocial determinants of physical activity. The second intervention, the intervention <it>plus</it>, provided the same tailored information but additionally provided tailored information about physical activity opportunities in the specific environment in which the older adults lived. This environment-based component also provided access to a forum and e-buddy system on a website. A plan for implementation and evaluation is also described.</p> <p>Discussion</p> <p>The planned development of the Active <it>plus </it>programme resulted in two theory- and evidence-based tailored physical activity interventions targeted at the over-fifties.</p> <p>Trial Registration</p> <p>Dutch Trial Register NTR 920</p

Three-nucleon interactions: dynamics

A discussion is presented of the dynamics underlying three-body nuclear forces, with emphasis on changes which occurred over several decades.Comment: Talk given at the FM50 symposium, Tokyo, October 200

Cameron Shelley, Multiple Analogies in Science and Philosophy

An analysis of Cameron Shelley's book on multiple analogies in science and philosophy

A State’s Gendered Response to Political Instability: Gendering Labor Policy in Semi-Authoritarian El Salvador (1944-1972)

Unlike much of the gender and welfare literature, this study examines why a regime that constrains pressure from below would adopt gendered social policies. The Salvadoran case (1944-1972) suggests that political instability rather than societal pressures may prompt semi-authoritarian regimes to adopt gendered labor reforms. We extend the motivations for adopting gendered labor reforms to include co-opting labor by examining gendered labor reforms in the context of El Salvador’s historically contingent labor strategy. This gendered analysis helps explain how a semi-authoritarian regime secured political stability and reveals the special appeal gendered labor reforms may have to semi-authoritarian regimes

Barriers and facilitators to public bicycle scheme use: A qualitative approach

The purpose of this study was to explore barriers and facilitators to using CityCycle, a public bicycle share scheme in Brisbane, Australia. Focus groups were conducted with participants belonging to one of three categories. Group one consisted of infrequent and noncyclists (no bicycle riding over the past month), group two were regular bicycle riders (ridden a bicycle at least once in the past month) and group three was composed of CityCycle members. A thematic analytic method was used to analyse the data. Three main themes were found: Accessibility/spontaneity, safety and weather/topography. The lengthy sign-up process was thought to stifle the spontaneity typically thought to attract people to public bike share. Mandatory helmet legislation was thought to reduce spontaneous use. Safety was a major concern for all groups and this included a perceived lack of suitable bicycle infrastructure, as well as regular riders describing a negative attitude of some car drivers. Interestingly, CityCycle riders unanimously perceived car driver attitudes to improve when on CityCycle bicycles relative to riding on personal bicycles. Conclusions: In order to increase the popularity of the CityCycle scheme, the results of this study suggest that a more accessible, spontaneous sign-up process is required, 24/7 opening hours, and greater incentives to sign up new members and casual users, as seeing people using CityCycle appears critical to further take up

Spectral graph theory : from practice to theory

Graph theory is the area of mathematics that studies networks, or graphs. It arose from the need to analyse many diverse network-like structures like road networks, molecules, the Internet, social networks and electrical networks. In spectral graph theory, which is a branch of graph theory, matrices are constructed from such graphs and analysed from the point of view of their so-called eigenvalues and eigenvectors. The first practical need for studying graph eigenvalues was in quantum chemistry in the thirties, forties and fifties, specifically to describe the Hückel molecular orbital theory for unsaturated conjugated hydrocarbons. This study led to the field which nowadays is called chemical graph theory. A few years later, during the late fifties and sixties, graph eigenvalues also proved to be important in physics, particularly in the solution of the membrane vibration problem via the discrete approximation of the membrane as a graph. This paper delves into the journey of how the practical needs of quantum chemistry and vibrating membranes compelled the creation of the more abstract spectral graph theory. Important, yet basic, mathematical results stemming from spectral graph theory shall be mentioned in this paper. Later, areas of study that make full use of these mathematical results, thus benefitting greatly from spectral graph theory, shall be described. These fields of study include the P versus NP problem in the field of computational complexity, Internet search, network centrality measures and control theory.peer-reviewe

Pentaquark Resonances from Collision Times

Having successfully explored the existing relations between the S-matrix and collision times in scattering reactions to study the conventional baryon and meson resonances, the method is now extended to the exotic sector. To be specific, the collision time in various partial waves of K+ N elastic scattering is evaluated using phase shifts extracted from the K+ N --> K+ N data as well as from model dependent T-matrix solutions. We find several pentaquark resonances including some low-lying ones around 1.5 to 1.6 GeV in the P_01, P_03 and D_03 partial waves of K+ N elastic scattering.Comment: Talk given at the International Workshop PENTAQUARK04, July 20-23 at Spring-8, Japa

Normalized entropy aggregation for inhomogeneous large-scale data

It was already in the fifties of the last century that the relationship between information theory, statistics, and maximum entropy was established, following the works of Kullback, Leibler, Lindley and Jaynes. However, the applications were restricted to very specific domains and it was not until recently that the convergence between information processing, data analysis and inference demanded the foundation of a new scientific area, commonly referred to as Info-Metrics. As huge amount of information and large-scale data have become available, the term "big data" has been used to refer to the many kinds of challenges presented in its analysis: many observations, many variables (or both), limited computational resources, different time regimes or multiple sources. In this work, we consider one particular aspect of big data analysis which is the presence of inhomogeneities, compromising the use of the classical framework in regression modelling. A new approach is proposed, based on the introduction of the concepts of info-metrics to the analysis of inhomogeneous large-scale data. The framework of information-theoretic estimation methods is presented, along with some information measures. In particular, the normalized entropy is tested in aggregation procedures and some simulation results are presented.publishe