Bas du spectre et delta-hyperbolicité en géométrie de Hilbert plane

International audienceOn montre l'équivalence entre l'hyperbolicité au sens de Gromov de la géométrie de Hilbert d'un domaine convexe du plan et la non nullité du bas du spectre de ce domain

Understanding the use of web technologies for aplications in open display networks

Open display networks represent a new paradigm for large scale networks of public displays that are open to applications and content from third party sources. Web technologies may be particularly interesting as a technological framework for third party application development in open display networks because of their portability and widespread use. However, there are also significant challenges involved that result from the specificities of this particular usage domain. In this work, we identify and characterize some of those specificities and analyze their implications for the use of web technologies. This contribution builds on our own experience with the development of multiple web-based applications for public displays and will inform the design of new models for this type of applications.Fundação para a Ciência e a Tecnologia (FCT

Area of ideal triangles and Gromov hyperbolicity in Hilbert Geometry

International audienceWe prove, in the context of Hilbert geometry, the equivalence between the existence of an upper bound on the area of ideal triangles and the Gromov-hyperbolicity

Web-based applications for open display networks : developers’ perspective

Open Display Networks represent a new paradigm for large scale networks of public displays that are open to applications and content from third parties. Web technologies may be particularly interesting as a technological framework for third-party application development in Open Display Networks because of their portability and widespread use. However, there are also significant challenges involved that result from the specificities of this particular usage domain and the lack of specific development insights for this context. In this work, we address the concept of public display application (display app) from a development perspective. The overall goal of this paper is to identify and characterize some of the key specificities of display applications and the appropriate Web solutions that can serve in the development of this type of application. The contribution of this paper builds on our extensive experience with the application development for a real world public display infrastructure and also on a short-term experiment with third party developers. Overall, the results show that Web technologies are valuable building blocks for public displays applications and their adoption is not only a subject for adaptation procedures but also for redesigning their use according to the characteristics and user experience offered by public displays. This research will inform the design of new Web-based models of display applications and shed light on the challenges that may impede third party development and the evolution of an application ecosystem in this area.Fundação para a Ciência e a Tecnologia (FCT

Situatedness for global display web apps

Most display systems are making use of static definition for the places in which they are situated. The content shown on these displays is predefined as is the case of television broadcasting. In this paper we present an approach that allows local display managers, e.g., display owners, to instantiate global display web applications on each display basis. We describe an innovative model for content presentation that takes into consideration both the display environmental data, e.g., sensors and user interactions, and app specific configuration. This approach enables the content being shown to be highly personalized, thus reflecting the dynamic and situated behavior of global display web apps.Fundação para a Ciência e a Tecnologia (FCT

Sémaphorines et cancers : état des lieux

Les sémaphorines jouent un rôle central dans le guidage axonal, la régénération axonale chez l'adulte et le développement de certains tissus. De plus, la découverte de leur implication dans l'angiogenèse et la réponse immunitaire indique une fonction beaucoup plus large de ces protéines. En 1996, trois études concomitantes ont permis de cloner les gènes codant pour deux de ces protéines, SEMA3B et SEMA3F, dans la région 3p21.3 qui subit de fréquentes pertes d'hétérozygotie dans les cancers du sein et du poumon. L'hypothèse avait alors été émise selon laquelle ces gènes pouvaient être des suppresseurs de tumeurs. Les études ultérieures ont confirmé ce rôle. à l'inverse, d'autres sémaphorines stimuleraient la croissance tumorale. Cet article fait le point sur les dernières connaissances acquises concernant le rôle des sémaphorines dans les cancers. Il souligne en particulier les propriétés anti-migratoires et anti-angiogéniques de ces molécules, qui pourraient jouer un rôle déterminant dans l'inhibition de la formation de métastases.Semaphorins, first described as axon guidance molecules, play an essential role in neural development, angiogenesis and immunological response. In 1996, two semaphorin genes, SEMA3B and SEMA3F, were isolated from chromosomal region 3p21.3 believed to contain a tumor suppressor gene based on frequent loss of heterozygosity in lung and breast cancer. Since these first studies, several semaphorins have been involved in tumor progression. Some semaphorins have been proposed to have pro-tumoral properties, whereas others have been shown to have tumor suppressive activity. This review summarizes the most recent data implicating semaphorins in cancers

A Física no Ensino Fundamental: onde estamos?

Trabalho de Conclusão de Curso (Graduação)O ensino básico brasileiro, principalmente no que diz respeito ao ensino da física sempre trouxe dificuldades para os professores no âmbito de metodologias e currículos a serem abordados, em especial no ensino fundamental, que geralmente não é objeto de trabalho dos professores de física, pois esses nem sempre foram alocados para ministrar as aulas de ciências. Matéria obrigatória e garantida por lei, as ciências naturais objetivam aproximar o indivíduo do entendimento dos fenômenos naturais como um processo de produção de conhecimento. Para entender melhor o papel da física no ensino de ciências no ensino fundamental se fez necessário percorrer a história dos documentos e programas educacionais do Brasil, desde da última constituição em vigor, buscando evidenciar onde está inserido os conteúdos da física. É averiguado no texto que a física, assim como a biologia e a química; áreas do conhecimento de ciências naturais; é posta de forma integradora e interdisciplinar, buscando a melhor compreensão de processos e fenômenos do dia a dia, mostrando que a física como conhecimento individualizado é mais presente apenas no último ano do ensino fundamental; o que não significa a ausência dos conceitos iniciais, bem como experimentações básicas para um futuro entendimento amplo da ciência