Downloads de música, blogs e juventude: guerrilha cultural ou crime?

Trata este trabalho de uma primeira aproximação com o universo dos blogs que tem por finalidade distribuir acessos a arquivos de música pela Internet.Procura abordar as transformações que ocorreram na indústria musical e o seu público, nos processos de produção comunicacional e do envolvimento de jovens na criação de novas apropriações dos instrumentos midiáticos. É sua função, também, abrir a discussão sobre os meios de se produzir leituras analíticas neste ambiente ainda pouco perscrutado.This study is a first approach to the blogs universe that provide access to music files via internet. It aims to respond the changes in the music industry and in its public in the communication process production and youth participation in creating new uses of media resources. It is also function of this study to open a discussion about the possibilities to carry out analysis in this universe still unexamined.Cette étude est une première approximation à l’univers des blogs qui permettent l’accès aux fichiers de musique via internet. Il vise à répondre aux changements dans l’industrie de la musique et du public dans le processus de production de la communication et la participation des jeunes à la création de nouvelles utilisations des ressources des médias. Il est également la fonction de cette étude discuter les moyens de production des lectures analytiques dans cet environnement encore peu examinés

Effects of high-color-discrimination capability spectra on color-deficient vision

Light sources with three spectral bands in specific spectral positions are known to have high-color-discrimination capability. W. A. Thornton hypothesized that they may also enhance color discrimination for color-deficient observers. This hypothesis was tested here by comparing the Rösch–MacAdam color volume for color-deficient observers rendered by three of these singular spectra, two reported previously and one derived in this paper by maximization of the Rösch–MacAdam color solid. It was found that all illuminants tested enhance discriminability for deuteranomalous observers, but their impact on other congenital deficiencies was variable. The best illuminant was the one derived here, as it was clearly advantageous for the two red–green anomalies and for tritanopes and almost neutral for red–green dichromats. We conclude that three-band spectra with high-color-discrimination capability for normal observers do not necessarily produce comparable enhancements for color-deficient observers, but suitable spectral optimization clearly enhances the vision of the color deficient.This work was supported by the European Regional Development Fund through Program COMPETE (FCOMP-01-0124-FEDER-009858), by National Portuguese funds through Fundação para a Ciência e a Tecnologia (grant PTDC/EEAEEL/098572/2008), and by the European Union and Spanish Ministry of Economy and Competitiveness under grant DPI2011-30090-C02-02

Number of discernible colors for color-deficient observers estimated from the MacAdam limits

We estimated the number of colors perceived by color normal and color-deficient observers when looking at the theoretic limits of object-color stimuli. These limits, the optimal color stimuli, were computed for a color normal observer and CIE standard illuminant D65, and the resultant colors were expressed in the CIELAB and DIN99d color spaces. The corresponding color volumes for abnormal color vision were computed using models simulating for normal trichromatic observers the appearance for dichromats and anomalous trichomats. The number of colors perceived in each case was then computed from the color volumes enclosed by the optimal colors also known as MacAdam limits. It was estimated that dichromats perceive less than 1% of the colors perceived by normal trichromats and that anomalous trichromats perceive 50%–60% for anomalies in the medium-wavelength-sensitive and 60%–70% for anomalies in the long-wavelength-sensitive cones. Complementary estimates obtained similarly for the spectral locus of monochromatic stimuli suggest less impairment for color-deficient observers, a fact that is explained by the two-dimensional nature of the locus.This work was supported by the Spanish Ministry for Education and Science (DPI2005-08999-C02-02); the Spanish Ministry of Science and Innovation (DPI2008-06455-C02-02); the Centro de Física at Minho University, Braga, Portugal and the Portuguese Fundação para a Ciência e a Tecnologia (PTDC/EEA-EEL/098572/2008). Esther Perales was supported by the Spanish Ministry for Education and Science with the BES-2006-13518 grant, and João M. M. Linhares was supported by the Portuguese Fundação para a Ciência e a Tecnologia with the SFRH/BD/35874/ grant