Cosmology in the Universe with distance dependent Lorentz-violating bakground

We consider a cosmological setup with the inflaton field in the presence of a redshift dependent Lorentz-violating time-like background to address the inflationary regime and other phases of the Universe. We also show that the regime of dark energy at large distances (low redshifts) is essentially dominated by the presence of the Lorentz-violating background.Comment: 8 pages, no figure, Latex, to appear in AHE

Recognizing Cultural Differences on Food

Cultural differences play a very important role in matching ICT in- teraction to the expectations of users from different national and cultural back- grounds. But to date, there has been few research as to the extent of such differ- ences, and how to produce software that takes into account these differences. Considering the third wave of HCI research on context, involving the intangible aspects of the interaction with users and ICT solutions, like culture, we are studying these issues using a unique resource: Common Sense knowledge bases in different languages. We have knowledge bases containing millions of sen- tences describing people and everyday activities, collected from volunteer Web contributors, in three different cultures: Brazil, Mexico and the USA. It is de- scribed the experiences with these knowledge bases. Though preliminary, we hope that our work will contribute to software that takes better account of such differences, and fosters inter-cultural collaboration

Person localization using sensor information fusion

Nowadays the incredible grow of mobile devices market led to the need for location-aware applications. However, sometimes person location is di cult to obtain, since most of these devices only have a GPS (Global Positioning System) chip to retrieve location. In order to sup- press this limitation and to provide location everywhere (even where a structured environment doesn't exist) a wearable inertial navigation sys- tem is proposed, which is a convenient way to track people in situations where other localization systems fail. The system combines pedestrian dead reckoning with GPS, using widely available, low-cost and low-power hardware components. The system innovation is the information fusion and the use of probabilistic methods to learn persons gait behavior to correct, in real-time, the drift errors given by the sensors.This work is part-funded by ERDF - European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT Fundao para a Cincia e a Tecnologia (Portuguese Foundation for Science and Technology) within project FCOMP-01-0124-FEDER- 028980 (PTDC/EEI-SII/1386/2012). Ricardo also acknowledge FCT for the support of his work through the PhD grant (SFRH/DB/70248/2010)

On the dual equivalence between self-dual and Maxwell-Chern-Simons models with Lorentz symmetry breaking

In this paper, we use gauge embedding procedure and master action approach to establish the equivalence between the self-dual and Maxwell-Chern-Simons models with Lorentz symmetry breaking. As a result, new kinds of Lorentz-breaking terms arise.Comment: 14 pages, minor corrections, version accepted to Physical Review

Caracterização físico-química de amostras de méis produzidas por Apis mellifera L. em fragmento de cerrado no município de Itirapina, São Paulo.

A fisionomia vegetal mais representativa do país, depois da floresta amazônica, é o cerrado, que ocupa atualmente dois milhões de km2 do território brasileiro. Este trabalho teve como objetivo determinar as características físicoquímicas de amostras de mel produzidas por Apis mellifera em um fragmento de cerrado, localizado em Itirapina, SP (22º14?S e 47º49?W). As amostras foram coletadas mensalmente, em cinco colméias, entre fevereiro e outubro de 2005 e as características avaliadas foram: açúcares redutores, redutores totais, sacarose, umidade, hidroximetilfurfural (HMF), cor, condutividade elétrica, pH, acidez, índice de formol, teor de cinzas, proteínas e viscosidade, além da análise polínica. Os resultados obtidos indicam que os limites estabelecidos pela legislação brasileira para parâmetros físico-químicos analisados são atendidos pela maioria das amostras de mel. Com relação à análise polínica, foi verificada a presença de Eucalyptus sp. como pólen dominante nos meses de fevereiro a julho e o de Citrus sp. no mês de outubro, em virtude da maior atratividade destes dois cultivos sobre as abelhas