The revolution will be tweeted : how the internet can stimulate the public exercise of freedoms

This article discusses how new technologies of communication, especially the Internet and, more specifically, social network services, can interfere in social interactions and in political relations. The main objective is to problematize the concept of public liberty and verify how the new technologies can promote the reoccupation of public spaces and the recovery of public life, in opposition to the tendency to valorize the private sphere, observed in the second half of the twentieth century. The theoretical benchmark adopted for the investigation is Hannah Arendt's theory about the exercise of fundamental political capacities in order to establish a public space of freedom, as presented in “On Revolution”. The “Praia da Estação” (“Station Beach”) case is chosen to test the hypothesis. In 2010 in the Brazilian city of Belo Horizonte, different individuals articulated a movement through blogs, Twitter and facebook, in order to protest against the Mayor’s act that banned the assembling of cultural events in one of the main public places of the city, the “Praça da Estação” (Station Square). By applying Arendt's concepts to the selected case, it is possible to demonstrate that the Internet can assume an important role against governmental arbitrariness and abuse of power, as it can stimulate the public exercise of fundamental freedoms, such as freedom of assembly and manifestation

Sistema de instrumentação mecanizada Hyflex EDM

A Endodontia é uma área em constante evolução. Consideráveis desenvolvimentos nos materiais e técnicas têm sido essenciais para o melhoramento dos resultados nos tratamentos realizados. É exemplo disso mesmo a constituição dos instrumentos Endodônticos primordiais, construídos em cordas de piano, com evolução para aço de carbono, material este que sofria corrosão provocado pelo cloro presente no hipoclorito de sódio. O aço de carbono evoluiu para aço inoxidável e deste as limas endodônticas passaram a ser feitas em níquel-titânio, conferindo-lhes melhor flexibilidade e efeito de memória de forma. Mesmo com todas estas melhorias significativas, fraturas de instrumentos e erros durante a instrumentação continuam a acontecer e com eles veio a necessidade da pesquisa de possíveis melhorias da constituição das limas em NiTi. Como resultado surgiram ligas como o M-wire, fase-R e CM-wire, criadas a partir de tratamentos térmicos, que trouxeram às limas Endodônticas maior flexibilidade e resistência à fratura que os instrumentos feitos em NiTi convencional. A mais recente evolução das limas Ni-Ti, desenvolvida pela Coltene Whaldent (Allstätten, Suiça), são as limas Hyflex EDM, limas para canais radiculares de 5ª geração. O seu processo de fabrico por eletroerosão cria uma superfície única fazendo com que estas limas sejam mais duras e resistam mais à quebra, aliado à sua alta flexibilidade. É possível assim reduzir o número de limas para a limpeza e modelagem dos canais durante os tratamentos endodônticos sem comprometer a preservação da anatomia dos canais. As limas Hyflex EDM possuem, tal como as limas Hyflex CM, o efeito de controle de memória (CM), o que confere propriedades muito similares entre os dois sistemas.Considerable research has been taken into Endodontics in order to improve materials and techniques which have been crucial to achieve better results in the performed treatments. Example of that is the constitution of ancient Endodontic instruments, made of piano strings, which evolved to carbon steel, but as corrosion occurred due to chloride present in sodium hypochlorite, there was a new evolution from carbon steel to stainless steel and thus Endodontic files began to be made of titanium nickel offering them greater flexibility and shape memory effects. Even with all these significant improvements, Endodontic instruments fracture and mistakes during instrumentation still occur, so there was the need to research for possible constitution improvements in Ni-Ti files. As a result, alloys such as M-Wire, R- Phase and CM-Wire, created from thermal treatments, appeared and brought more flexibility and fracture resistance to Endodontic files than the instruments made in conventional Ni-Ti. Hyflex EDM files, the first Endodontic instruments manufactured with EDM, for root canal 5th generation are the most recent Ni-Ti files evolution developed by Coltene Whaledent (Allstätten, Switzerland). Its manufacturing process by electro erosion creates a single surface enabling these files to be tougher and more resistant to fracture, allied to its greater flexibility. Thus, it´s possible to reduce the number of files for cleaning and shaping of canals during endodontic treatments without compromising the preservation of their autonomy. Hyflex EDM files have, such as Hyflex CM files, memory control (CM) effect, which provides very similar properties between the two systems

Superpropagators for explicitly broken 3D-supersymmetric theories

A systematic algorithm to derive superpropagators in the case of either explicitly or spontaneously broken supersymmetric three-dimensional theories is presented. We discuss how the explicit breaking terms that are introduced at tree-level induce 1-loop radiative corrections to the effective action. We also point out that the renormalisation effects and the breaking-inducing-breaking mechanism become more immediate whenever we adopt the shifted superpropagators discussed in this letter.Comment: 6 pages, LaTex, references added. To appear in Phys.Lett.

Quantum state transfer in optomechanical arrays

Quantum state transfer between distant nodes is at the heart of quantum processing and quantum networking. Stimulated by this, we propose a scheme where one can achieve quantum state transfer with a high fidelity between sites in a cavity quantum optomechanical network. In our lattice, each individual site is composed of a localized mechanical mode which interacts with a laser-driven cavity mode via radiation pressure, while photons hop between neighboring sites. After diagonalization of the Hamiltonian of each cell, we show that the system can be reduced to an effective Hamiltonian of two decoupled bosonic chains, and therefore we can apply the well-known results in quantum state transfer together with an additional condition on the transfer times. In fact, we show that our transfer protocol works for any arbitrary joint quantum state of a mechanical and an optical mode. Finally, in order to analyze a more realistic scenario we take into account the effects of independent thermal reservoirs for each site. By solving the standard master equation within the Born-Markov approximation, we reassure both the effective model and the feasibility of our protocol

Semilinear fractional differential equations: global solutions, critical nonlinearities and comparison results

In this work we study several questions concerning to abstract fractional Cauchy problems of order α ∈ (0, 1). Concretely, we analyze the existence of local mild solutions for the problem, and its possible continuation to a maximal interval of existence. The case of critical nonlinearities and corresponding regular mild solutions is also studied. Finally, by establishing some general comparison results, we apply them to conclude the global well-posedness of a fractional partial differential equation coming from heat conduction theory.Conselho Nacional de Desenvolvimento Científico e TecnológicoCoordenação de aperfeiçoamento de pessoal de nivel superiorFundação de Amparo à Pesquisa do Estado de São PauloMinisterio de EducaciónMinisterio de Ciencia e InnovaciónJunta de Andalucí