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.

Spectral BRDF-based determination of proper measurement geometries to characterize color shift of special effect coatings

A reduced set of measurement geometries allows the spectral reflectance of special effect coatings to be predicted for any other geometry. A physical model based on flake-related parameters has been used to determine nonredundant measurement geometries for the complete description of the spectral bidirectional reflectance distribution function (BRDF). The analysis of experimental spectral BRDF was carried out by means of principal component analysis. From this analysis, a set of nine measurement geometries was proposed to characterize special effect coatings. It was shown that, for two different special effect coatings, these geometries provide a good prediction of their complete color shift.

Nondiffracting Bessel plasmons

We report on the existence of nondiffracting Bessel surface plasmon polaritons (SPPs), advancing at either superluminal or subluminal phase velocities. These wave fields feature deep subwavelength FWHM, but are supported by high-order homogeneous SPPs of a metal/dielectric (MD) superlattice. The beam axis can be relocated to any MD interface, by interfering multiple converging SPPs with controlled phase matching. Dissipative effects in metals lead to a diffraction-free regime that is limited by the energy attenuation length. However, the ultra-localization of the diffracted wave field might still be maintained by more than one order of magnitude.

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.

Color representation and interpretation of special effect coatings

A representation of the color gamut of special effect coatings is proposed and shown for six different samples, whose colors were calculated from spectral bidirectional reflectance distribution function (BRDF) measurements at different geometries. The most important characteristic of the proposed representation is that it allows a straightforward understanding of the color shift to be done both in terms of conventional irradiation and viewing angles and in terms of flake-based parameters. A different line was proposed to assess the color shift of special effect coatings on a*,b*-diagrams: the absorption line. Similar to interference and aspecular lines (constant aspecular and irradiation angles, respectively), an absorption line is the locus of calculated color coordinates from measurement geometries with a fixed bistatic angle. The advantages of using the absorption lines to characterize the contributions to the spectral BRDF of the scattering at the absorption pigments and the reflection at interference pigments for different geometries are shown.

Global color estimation of special-effect coatings from measurements by commercially available portable multiangle spectrophotometers

Colors of special-effect coatings have strong dependence on illumination/viewing geometry and an appealing appearance. An open question is to ask about the minimum number of measurement geometries required to completely characterize their observed color shift. A recently published principal components analysis (PCA)-based procedure to estimate the color of special-effect coatings at any geometry from measurements at a reduced set of geometries was tested in this work by using the measurement geometries of commercial portable multiangle spectrophotometers X-Rite MA98, Datacolor FX10, and BYK-mac as reduced sets. The performance of the proposed PCA procedure for the color-shift estimation for these commercial geometries has been examined for 15 special-effect coatings. Our results suggest that for rendering the color appearance of 3D objects covered with special-effect coatings, the color accuracy obtained with this procedure may be sufficient. This is the case especially if geometries of X-Rite MA98 or Datacolor FX10 are used.

Evolución de la Ley de Directrices y Bases de la Ley de Educación Nacional Law - nº 5.692/1971 la enfermería profesional en Brasil

A garantia da memória histórica do ensino em nível profissionalizante em enfermagem, na década de 1970, foi o objeto dessa investigação. Teve como objetivos descrever e analisar o contexto sócio-político e as circunstâncias históricas em que a Lei nº 5.692, de 12 de agosto de 1971, das Diretrizes e Bases da Educação Nacional, foi promulgada, bem como discutir as mudanças e desdobramentos dessa no ensino profissionalizante em enfermagem. Trata-se de estudo descritivo, qualitativo, exploratório e de natureza histórico-social, com base em análise documental. Optou-se pela Micro-história para dar sustentação teórica à discussão dos resultados dessa investigação, pois a análise dos documentos históricos, sob o prisma de que, embora não seja possível enxergar a sociedade inteira a partir de um fragmento social, é possível enxergar algo da realidade social que envolve o fragmento humano examinado. A delimitação das fontes históricas do estudo compreende o Acervo do Arquivo Histórico da Associação Brasileira de Enfermagem - Seção São Paulo; o Acervo documental sobre a ABEn/SP, existente no Centro Histórico Cultural da Enfermagem Ibero-Americana da Escola de Enfermagem da USP e a Série Documenta do Ministério da Educação e Cultura. A partir dessa LDB nº 5.692/71, o ensino de Enfermagem foi totalmente integrado ao sistema nacional de Educação e sua promulgação ocorreu durante a Ditadura Militar e a ideologia do “milagre econômico”. De acordo com essa ideologia, o sistema educacional brasileiro deveria adequar-se ao modelo econômico desenvolvimentista, com treinamento de pessoal de nível técnico, visando aumentar e baratear os recursos humanos para o trabalho. A ABEn, como entidade representativa dos interesses políticos e ideológicos dos profissionais da área, liderava os debates sobre as questões da formação dos recursos humanos na enfermagem, sendo que na década de 70 mais da metade do contingente de enfermagem era majoritariamente sem formação específica. Também por conta dessa realidade, houve iniciativas governamentais para tentar reverter essa situação. Apesar das questões do ensino da enfermagem não se encontrarem explicitadas no texto da LDB nº 5.692/71, os resultados deste trabalho revelaram que a legislação estudada teve desdobramentos nas decisões políticas no âmbito do ensino profissionalizante e, consequentemente, impactou sobre a formação dos profissionais de enfermagem.