Realization of tangent perturbations in discrete and continuous time conservative systems

We prove that any perturbation of the symplectic part of the derivative of a Poisson diffeomorphism can be realized as the derivative of a $C^1$-close Poisson diffeomorphism. We also show that a similar property holds for the Poincar\'e map of a Hamiltonian on a Poisson manifold. These results are the conservative counterparts of the Franks lemma, a perturbation tool used in several contexts most notably in the theory of smooth dynamical systems.Comment: 18 pag

External dependency, value added generation and structural change: an inter-industry approach

The external dependency of many industries and the corresponding low value added generated in production, combined with a relatively weak export potential, create high external deficits and growing debt to GDP ratios in several open economies. In this paper we propose an empirical method to assess the evolution of these vulnerabilities, based on a new treatment of interindustry production multipliers. The (gross)output growth potential given by the column sums of the Leontief inverse matrix (backward linkage indicators) results from three terms: interindustry consumptions, value added and imported inputs. After a convenient arrangement of these terms, the evolution of backward linkage indicators can be used to detect structural changes, particularly quantifying a (net) growth effect (more value-added generation) and an external dependency effect (more imported inputs), and to classify the productive sectors accordingly. An application to the Portuguese Economy is made, using input-output tables for the years 1980, 1995 and 2005. This method can also be useful as a simple, but suggestive, device to compare the evolution of two or more economies, along their development processes in time.

External dependency, value added generation and structural change: an interindustry approach

The external dependency of many industries and the corresponding low value added generated in production create high external deficits and growing debt to GDP ratios in several open economies. In this paper we propose an empirical method to assess the evolution of these vulnerabilities, based on a new treatment of interindustry production multipliers. The (gross) output growth potential given by the column sums of the Leontief inverse matrix (backward linkage indicators) results from three terms: interindustry consumptions, value added and imported inputs. After a convenient arrangement of these terms, the evolution of backward linkage indicators can be used to detect structural changes, particularly quantifying a (net) growth effect (more value-added generation) and an external dependency effect (more imported inputs), and to classify the productive sectors accordingly. An application to the Portuguese Economy is made, using input-output tables for the years 1980, 1995 and 2005. This method can also be useful as a simple, but suggestive, device to compare the evolution of two or more economies, along their development processes in time.input-output linkages; external dependency; structural change; Portugal

National industry cluster templates and the structure of industry output dynamics: a stochastic geometry approach

Cluster analysis has been widely used in an Input-Output framework, with the main objective of uncover the structure of production, in order to better identify which sectors are strongly connected with each other and choose the key sectors of a national or regional economy. There are many empirical studies determining potential clusters from interindustry flows directly, or from their corresponding technical (demand) or market (supply) coefficients, most of them applying multivariate statistical techniques. In this paper, after identifying clusters this way, and since it may be expected that strongly (interindustry) connected sectors share a similar growth and development path, the structure of sectoral dynamics is uncovered, by means of a stochastic geometry technique based on the correlations of industry outputs in a given period of time. An application is made, using Portuguese input-output data, and the results do not clearly support this expectation.Clusters, Input-output analysis, Industry output dynamics

Brjuno condition and renormalization for Poincaré flows

In this paper we give a new proof of the local analytic linearization of flows on t² with a Brjuno rotation number, using renormalization techniques.info:eu-repo/semantics/publishedVersio

Hamiltonian elliptic dynamics on symplectic 4-manifolds

We consider C2 Hamiltonian functions on compact 4-dimensional symplectic manifolds to study elliptic dynamics of the Hamiltonian flow, namely the so-called Newhouse dichotomy. We show that for any open set U intersecting a far from Anosov regular energy surface, there is a nearby Hamiltonian having an elliptic closed orbit through U. Moreover, this implies that for far from Anosov regular energy surfaces of a C2-generic Hamiltonian the elliptic closed orbits are generic.Comment: 9 page

O público vai ao Teatro: uma etnografia dos públicos em ação

A partir de um desafio lançado pelo Teatro Municipal de Lisboa, as companhias de teatro independente do Porto foram convidadas a organizar a programação daquela instituição durante um mês. Uma jovem companhia portuense respondeu ironicamente com a apresentação do projeto “O Público Vai ao Teatro”. Tal projeto consistia em promover uma performance que parodiava uma excursão folclórica dos públicos provincianos do Porto à capital, antecedida de vários workshops de familiarização com os códigos da linguagem teatral. A pesquisa sociológica consistiu em, através da investigação-ação de cariz etnográfico, analisar e mediar modos de relacionamento com a cultura e com as instituições teatrais por parte das pessoas recrutadas. Este artigo faz uma primeira avaliação do projeto, não incluindo ainda a sessão final, a partir de um diagnóstico das representações dessa população sobre os seus modos de relação com o teatro.Challenged by Teatro Municipal de Lisboa, independent theatre companies from Oporto were invited to organize that institution’s programming throughout a month. “The public goes to the theatre” was the ironic response of a young company from Oporto to the challenge. This project aimed to promote a performance, a folk parody excursion that would lead the provincial public of Oporto to the capital, a journey preceded by several workshops to help them familiarize with theatrical language codes. Via research-action-oriented ethnographic methods, the sociological research intended to analyze and mediate the recruited individual’s relationship with culture and theater institutions. This article draws a preliminary assessment of the project, not including the final session, a diagnosis based on the population’s representations and theater relation approach.À partir d’un défi lancé par le Théâtre Municipal de Lisbonne, les compagnies de théâtre indépendant de Porto ont été invitées à préparer la programmation de cette salle pendant un mois. Une jeune compagnie de Porto a répondu sur le ton de l’ironie en présentant le projet “ Le Public va au Théâtre ”: une performance qui parodiait une excursion folklorique des publics provinciaux de Porto à la capitale, précédée de plusieurs ateliers de familiarisation aux codes du langage théâtral. La recherche sociologique, menée au travers de l’enquête-action de nature ethnographique, a consisté à identifier et à analyser les rapports des personnes recrutées avec la culture et avec les compagnies théâtrales. Cet article propose une première évaluation du projet, sans inclure la séance finale, à partir d’un diagnostic des représentations de cette population sur son rapport au théâtre.A partir de un desafío lanzado por el Teatro Municipal de Lisboa, las compañías de teatro independiente de Porto fueron invitadas a organizar la programación de aquella institución durante un mes. Una joven compañía de Porto respondió irónicamente con la presentación del proyecto “El público va al teatro”. Tal proyecto consistía en promover un performance que parodiaba una excursión folclórica de los públicos provincianos de Porto a la capital, antecedida de varios workshops de familiarización con los códigos del lenguaje teatral. La investigación sociológica ha consistido en una de investigación-acción de tipo etnográfico, analizar y mediar modos de relacionamiento con la cultura y con las instituciones teatrales por parte de las personas reclutadas. Este artículo hace una primera evaluación del proyecto, sin incluir la sesión final), a partir de un diagnóstico de las representaciones de esa población sobre sus modos de relación con el teatro

The Paris agreement and electricity markets outside the EU

Climate change has been at the center of economic and social discussion for some years. The passage of time has intensified this debate and reflection. A well-known relevant event in this domain was the signature of the Paris Agreement in 2014, and its subsequent enforcement by European Union (EU) member countries. This study examines if the climate change measures adopted by the Agreement had an impact on the electricity sector outside the EU28, seeking to assess whether there is international diversity in these markets or if they work uniformly at global level. The goal of this work is to study the behavior of spot electricity prices before and after the Agreement was signed by EU members, analyze its effect in terms of spot prices, and determine the conditions that lead to stability and non-stability. We examine the behavior of spot electricity prices in two different electricity markets: the US and Brazil. The study applies both qualitative methodologies, namely fsQCA, and quantitative methodology, in order to identify changes in the pattern of electricity price behavior with the advent of the Agreement. Arguably, regulatory theory still incorporates the effects of the emergence of global dynamics in the regulation process. However, what this article suggests is that changes in regulatory frameworks with global impact, even if exogenous to a specific market, can profoundly alter the dynamics of that market.info:eu-repo/semantics/publishedVersio

MR and ablation for cancer and prostatic artery embolization for benign prostatic hyperplasia

© 2019 The Authors. Published by the British Institute of Radiology.Multiparametric MRI (mpMRI) has proven to be an essential tool for diagnosis, post-treatment follow-up, aggressiveness assessment, and active surveillance of prostate cancer. Currently, this imaging technique is part of the daily practice in many oncological centres. This manuscript aims to review the use of mpMRI in the set of prostatic diseases, either malignant or benign: mpMRI to detect and stage prostate cancer is discussed, as well as its use for active surveillance. Image-guided ablation techniques for prostate cancer are also reviewed. The need to establish minimum acceptable technical parameters for prostate mpMRI, standardize reports, uniform terminology for describing imaging findings, and develop assessment categories that differentiate levels of suspicion for clinically significant prostate cancer led to the development of the Prostate Imaging Reporting and Data System that is reviewed. Special focus will also be given on the most up-to-date evidence of prostatic artery embolization (PAE) for symptomatic benign prostatic hyperplasia (BPH). Management of patients with BPH, technical aspects of PAE, expected outcomes and level of evidence are reviewed with the most recent literature. PAE is a challenging technique that requires dedicated anatomical knowledge and comprehensive embolization skills. PAE has been shown to be an effective minimally-invasive treatment option for symptomatic BPH patients, that can be viewed between medical therapy and surgery. PAE may be a good option for symptomatic BPH patients that do not want to be operated and can obviate the need for prostatic surgery in up to 80% of treated patients.publishersversionpublishe