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The discovery of melanopsin as a third type of retinal photoreceptor, contributing to both perceptual vision and reflex light responses, represents a new opportunity to optimise the design of artificial light sources for practical applications and to generate experimental stimuli. In the case of emissive displays, multiprimary designs incorporating a cyan primary could be used to allow melanopic radiance to be controlled independent of colour and luminance. Here we explore the performance a five-primary (violet, cyan, green, yellow, red) display device and find an anomaly in colour appearance when the cyan primary is employed. The anomaly took the form of a reddish/pinkish tinge in the central visual field, consistent with descriptions of Maxwell’s spot. This effect was apparent in some full colour images and in uniform discs over a range of chromaticities. Its appearance in coloured discs correlated with differences in calculated colour coordinate between central and peripheral vision. A simulation indicated that inclusion of any primary with predominant output in the 470–500 nm range has the potential to produce such a discrepancy in central vs peripheral appearance. Applying an additional constraint in colour processing to reproduce naturally occurring differences in central vs peripheral colour coordinate eliminated appearance of the spot and produced acceptable colour images.

Recent progress in tuneable solid-state light sources opens new opportunities in a niche and high added value lighting applications. The standard colorimetric technique of composing an identical colour coordinate metameric light spectra are facing the challenges due to the colour discrepancy noticed by the observers. A side-by-side colour matching experiment was performed with two tuneable tetrachromatic RAGB lamps (638 nm red, 598 nm pc amber, 518 nm green, 451 nm blue LEDs) to compare the colour of the metameres in a 10-deg viewing angle. The metameric light matching was investigated using a 2-deg (CIE 1931) and 10-deg (CIE 1964) XYZ colour matching function. Both colour matching functions of standard colorimetric observers were shown to be inaccurate for aligning of metameric spectral power distributions without a noticeable difference in a perceived colour. On the other hand, a wide scatter of individual results revealed that the standard colour matching functions are inherently limited and in some cases, especially in professional lighting applications, the individually adjustable metameric lighting approach is to be considered.

An indoor positioning method based on metameric white light sources and subpixels on a color image sensor is proposed in this paper. Metameric white light sources are obtained by merging multiple-color light-emitting diode (LED) chips with different intensity ratios. The output intensity ratios of subpixels on color image sensor at the receiver are employed to identify the respective metameric white light sources. Proof of concept experiments demonstrates that the average error of 2-D indoor positioning is 1.50 cm and 3-D indoor positioning is 3.58 cm. The indoor positioning system with the proposed method is cost effective and convenient because image sensors in nowadays available mobile devices can be utilized.

This manuscript presents a preliminary investigation on the applicability of hyperspectral imaging technology for nondestructive and rapid analysis to reveal covered original handwritings. The hyperspectral imager Nuance-Macro was used to collect the reflected light signature of inks from the overlapping parts. The software Nuance1p46 was used to analyze the reflected light signature of inks which shows the covered original handwritings. Different types of black/blue ballpoint pen inks and black/blue gel pen inks were chosen for sample preparation. From the hyperspectral images examined, the covered original handwritings of application were revealed in 90.5%, 69.1%, 49.5%, and 78.6% of the cases. Further, the correlation between the revealing effect and spectral characteristics of the reflected light of inks at the overlapping parts was interpreted through theoretical analysis and experimental verification. The results indicated that when the spectral characteristics of the reflected light of inks at the overlapping parts were the same or very similar to that of the ink that was used to cover the original handwriting, the original handwriting could not be shown. On the contrary, when the spectral characteristics of the reflected light of inks at the overlapping parts were different to that of the ink that was used to cover the original handwriting, the original handwriting was revealed.

If surfaces from a scene are visually indistinguishable under one light, they may become distinguishable under another. The aim here was to test whether the frequency of such metamerism can be predicted by a statistical property of the colours of a scene, namely their conditional entropy. Simulations were based on 50 hyperspectral images of natural scenes under sunlight and north skylight. The correlation between the logarithm of the conditional frequency of metamerism and the conditional entropy of colours was strong, with r = 0.80–0.87. Additionally, the more likely that indistinguishable surfaces were distinguishable under a different daylight, the more reliable the prediction by conditional entropy. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down., {"references":["[1] Wyszecki, G. and Stiles, W. S. 1982. Color Science: Concepts and Methods, Quantitative Data and Formulae, 2nd ed. John Wiley & Sons, New York.\n[2] Foster, D. H., Amano, K., Nascimento, S. M. C., and Foster, M. J. 2006. Frequency of metamerism in natural scenes. J. Opt. Soc. Am. A - Opt. Image Sci. Vis., 23, 2359-2372. DOI = http://dx.doi.org/10.1364/JOSAA.23.002359\n[3] Cover, T. M. and Thomas, J. A. 2006. Elements of Information Theory, 2nd ed. John Wiley & Sons, Inc., Hoboken, New Jersey.\n[4] Feng, G. and Foster, D. H. 2012. Predicting frequency of metamerism in natural scenes by entropy of colors. J. Opt.\nSoc. Am. A - Opt. Image Sci. Vis., 29, A200-A208. DOI =\nhttp://dx.doi.org/10.1364/JOSAA.29.00A200\n[5] Marín-Franch, I. and Foster, D. H. 2012. Estimating information from image colors: an application to digital\ncameras and natural scenes. IEEE Trans. Pattern Anal. Mach. Intell., in press, DOI = http://doi.ieeecomputersociety.org/10.1109/TPAMI.2012.78 \n[6] CIE. 2004. Colorimetry, 3rd Edition. CIE Central Bureau, Vienna CIE Publication 15:2004.\n[7] CIE. 2004. A Colour Appearance Model for Colour Management Systems: CIECAM02. CIE Central Bureau, Vienna CIE Publication 159:2004.\n[8] Luo, M. R., Cui, G., and Li, C. 2006. Uniform colour spaces based on CIECAM02 colour appearance model. Color Res. Appl., 31, 320-330.\n[9] Melgosa, M., Huertas, R., and Berns, R. S. 2008. Performance of recent advanced color-difference formulas using the standardized residual sum of squares index. J. Opt. Soc. Am. A - Opt. Image Sci. Vis., 25, 1828-1834.\n[10] Kozachenko, L. F. and Leonenko, N. N. 1987. Sample estimate of the entropy of a random vector. Problems of Information Transmission (Tr. Problemy Peredachi\nInformatsii. Vol. 23, No.2, pp. 9-16, 1987), 23, 95-101. [11] Montgomery, D. B. and Morrison, D. G. 1973. A Note on\nAdjusting R2. J. Financ., 28, 1009-1013."]}

espanolA. Faulconer en su libro "Foundations of Anesthesiology" refiriendose a Pages afirma: "No se encuentran apenas datos sobre la vida de este importante cirujano espanol". Esta concluyente afirmacion unida a imperdonables omisiones de la figura de Pages por historiografos de la anestesia o de la cirugia, y a graves errores en datos sobre su vida u obra, nos movio a realizar una aproximacion, lo mas exacta posible, a la obra cientifica del Comandante Medico Fidel Pages Mirave. Escasas han sido las figuras espanolas que hayan aportado alguna interesante novedad al mundo de la anestesia. Pero ninguna tan injustamente tratada y olvidada como la de Pages, verdadero pionero de la anestesia epidural, que el denominaria Anestesia Metamerica en su articulo publicado en el mes de marzo de 1921 en la Revista Espanola de Cirugia, por el fundada. Anos despues, en 1931, Dogliotti, Profesor de Cirugia de Modena publico sus experiencias sobre la anestesia epidural, a la que llamo Anestesia Peridural Segmentaria, ignorando el trabajo de Pages publicado diez anos antes. El trabajo de Dogliotti fue rapidamente reconocido, asumiendo todos los meritos de la paternidad de la tecnica epidural, quedando Pages relegado a un olvido injusto que con este trabajo tratamos de reparar. En la necesidad de ubicar a Pages en el entorno en el que desarrollo su obra cientifica, tratamos de realizar una vision de las principales aportaciones quirurgicas y anestesicas de aquellos cirujanos que fueron coetaneos con nuestro personaje. Con especial abundamiento, profundizamos en los precedentes historicos de las tecnicas de anestesia intradural o caudal, asi como las descripciones posteriores a Pages sobre el abordaje lumbar de la via epidural. A su vez realizamos un analisis comparativo del trabajo de Pages sobre la anestesia metamerica, en relacion con la actual vigencia que puedan tener sus observaciones, descripciones, indicaciones y contraindicaciones. La idea central del trabajo versara sobre el reconocimiento de Pages como verdadero promotor del abordaje epidural con fines quirurgicos. Asi como valorar una obra que, aunque corta, bien pudiera incluirse entre los mejores cirujanos espanoles de principio de siglo. Nos centramos, para la recopilacion de datos, en sus expedientes academicos (Zaragoza y Madrid), en su hoja de servicios como Medico Militar y en las publicaciones sobre Historia de la Anestesia, Historia de la Cirugia y de la Sanidad Militar. Para mejor conocer al Personaje hemos localizado a su familia y revisamos los diarios oficiales del Ministerio de la Guerra las colecciones completas de la principal prensa de la epoca, especialmente las de Madrid y Melilla. EnglishA. Faulconer in his book "Foundations of Anesthesiology", referring to Pages says: "There are little data on the life of this important Spanish surgeon". This conclusive statement attached to unforgivable omissions to the figure of Pages by historians of anesthesia or surgery, and to serious errors in facts about his life or work, led us to make an approximation as accurate as possible, to the scientific work of the Medical commander Fidel Pages Mirave. Few figures have been the Spanish who have made some interesting news to the world of anesthesia. But none so wronged and forgotten like Pages, a true pioneer of epidural anesthesia, that he would call Metameric Anesthesia in his article published in the month of March, 1921, in the Spanish Journal of Surgery, founded by him. Years later, in 1931, Dogliotti, Professor of Surgery in Modena published his experiences on the epidural, which he called Segmental Epidural Anesthesia, ignoring the work published ten years earlier by Pages. Dogliotti's work was quickly recognized, assuming all the merits of the paternity of the epidural technique, being Pages relegated to an unfair oblivion that this work is trying to repair. Feeling the need to locate Pages on the environment in which he developed his scientific work, we try to realize a vision of the main surgical and anesthetic contributions of surgeons who were contemporaries with Pages. With special sake, we delve into the historical precedents of spinal or caudal anesthesia techniques, as well as Pages later descriptions on the lumbar approach of the epidural route. At the same time, we conducted a comparative analysis of the work of Pages on metameric anesthesia in relation to the current force that may have their comments, descriptions, indications and contraindications. The central idea of the work will focus on the recognition of Pages as a true promoter of the epidural approach with surgical aims. And to evaluate a work which, though short, may well be included among the best spanish surgeons in the beginning of the century. We focus for the collection of data on their records (Zaragoza and Madrid), on his records as a military doctor and on publications about the History of Anesthesia, history of Surgery and of the Military Health. To better know his character we have located his family and review the official journals of the Ministry of War, the complete collections of the main newspapers of the time, especially in Madrid and Melilla.

Traditionally, digital imaging systems rely on the use of dedicated photodetectors to capture specific wavelengths in the visible spectrum. These photodetectors, which are commonly made of silicon, are arranged as arrays to capture the red, green and blue wavelengths. The signal captured by the individual photodetectors must then be interpolated and integrated to obtain the closest color match and the finest possible resolution with reference to the actual object. The use of spatially separated detectors to sense primary colors reduces the resolution by a factor of three compared to black and white imaging. The FOVEON detector technology greatly improves the color and resolution of the image through its vertically arranged, triple well photodetector. This is achieved by exploiting the variation of absorption coefficient of silicon with wavelength in the visible spectrum. Hence, in a silicon detector, the shorter wavelength (e.g. blue) would be mainly absorbed at a shallow depth. A longer wavelength (e.g. red) would penetrate the material deeper than the shorter wavelengths and be primarily absorbed at a greater depth. By producing a layered silicon detector, all three primary colour wavelengths of red, green and blue can be captured simultaneously. This thesis aims to study the FOVEON camera's ability to image light from the near Infrared (NIR) to the Ultra-Violet (UV) range of the electromagnetic spectrum. The imaged obtained using a set of bandpass filters show that the camera has response both in the UV as well as NIR regions. http://archive.org/details/detectingnearuvn109451284 Major, Singapore Armed Forces Approved for public release; distribution is unlimited.

The amphioxus tail bud is similar to the amphibian tail bud in having an epithelial organization without a mesenchymal component. We characterize three amphioxus Wnt genes (AmphiWnt3, AmphiWnt5, and AmphiWnt6) and show that their early expression around the blastopore can subsequently be traced into the tail bud; in vertebrate embryos, there is a similar progression of expression domains for Wnt3, Wnt5, and Wnt6 genes from the blastopore lip (or its equivalent) to the tail bud. In amphioxus, AmphiWnt3, AmphiWnt5, and AmphiWnt6 are each expressed in a specific subregion of the tail bud, tentatively suggesting that a combinatorial code of developmental gene expression may help generate specific tissues during posterior elongation and somitogenesis. In spite of similarities within their tail buds, vertebrate and amphioxus embryos differ markedly in the relation between the tail bud and the nascent somites: vertebrates have a relatively extensive zone of unsegmented mesenchyme (i.e., presomitic mesoderm) intervening between the tail bud and the forming somites, whereas the amphioxus tail bud gives rise to new somites directly. It is likely that presomitic mesoderm is a vertebrate innovation made possible by developmental interconversions between epithelium and mesenchyme that first became prominent at the dawn of vertebrate evolution.

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Given a fixed set of viewing conditions, a colour appearance model provides a method for transforming tristimulus values to perceptual attributes correlates, and vice versa. Current colour appearance models, like CIECAM02 [1], have been developed assuming the CIE31 Standard Observer. However a general model must adequately describe the colorimetric behaviour of a large enough set of real observers. In this work we analyse the variability of the different parameters defined by CIECAM02 when different sets of colour-matching functions associated with real observers are considered. All our sets of colour-matching functions are for small-size fields (smaller than 4o). Our main goal is to evaluate the observer metamerism provided in CIECAM02 for a set of 13 real observers, when the reflectances of the 24 chips of the GretagMacbetch ColorChecker are illuminated under D65 and A illuminants. Research Project FIS2007-64266, Ministerio de Educación y Ciencia (Spain), with FEDER support.