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Polypeptide N-acetylgalactosamine transferase 3 (ppGalNAc-T3) is an enzyme involved in the initiation of O-GalNAc glycan biosynthesis. Acting as a writer of frequent post-translational modification (PTM) on human proteins, ppGalNAc-T3 has key functions in the homeostasis of human cells and tissues. We review the relevant roles of this molecule in the biosynthesis of O-GalNAc glycans, as well as in biological functions related to human physiological and pathological conditions. With main emphasis in ppGalNAc-T3, we draw attention to the different ways involved in the modulation of ppGalNAc-Ts enzymatic activity. In addition, we take notice on recent reports of ppGalNAc-T3 having different subcellular localizations, highlight critical intrinsic and extrinsic functions in cellular physiology that are exerted by ppGalNAc-T3-synthesized PTMs, and provide an update on several human pathologies associated with dysfunctional ppGalNAc-T3. Finally, we propose biotechnological tools as new therapeutic options for the treatment of pathologies related to altered ppGalNAc-T3. KEY MESSAGES: ppGalNAc-T3 is a key enzyme in the human O-GalNAc glycans biosynthesis. enzyme activity is regulated by PTMs, lectin domain and protein-protein interactions. ppGalNAc-T3 is located in human Golgi apparatus and cell nucleus. ppGalNAc-T3 has a central role in cell physiology as well as in several pathologies. Biotechnological tools for pathological management are proposed.

Artículo con 3 tablas y 18 figuras, The general V(λ) mismatch index, f 1 ′ , of a photometer quantifies the deviation between its determined relative spectral responsivity, s rel λ , and its nominal responsivity, the spectral luminous efficiency function for photopic vision, V(λ). LED-based light sources now dominate in general lighting, displacing incandescent and fluorescent lamps. Furthermore, the calibration of photometers will very likely see the replacement of the reference CIE standard illuminant A with CIE reference spectrum L41. The article evaluates the consequences. Should we also change the definition of the general V(λ) mismatch index? Based on performance criteria, the individual indices are evaluated using various datasets with the help of statistical analyses. As a result, the authors can conclude that the current definition works very well even under changed calibration and application conditions and does not need to be changed. Other evaluated indices for a new index definition perform only slightly better in some cases, but do not generate generally better properties., This project 19NRM02 RevStdLED has received funding from the EMPIR program co-financed by the participating states and from the European Union's Horizon 2020 research and innovation program. Ville Mantela acknowledges partial support by the Academy of Finland Flagship Programme, Photonics Research and Innovation (PREIN), decision number: 320167. Furthermore, we thank Kevin G Smet for successfully implementing all the photometric and colorimetric functions in the LuxPy Python package, which we used to implement the calculations presented here. Special thanks from the authors go also to the Reviewer and Peter Zwick for their valuable advice in the preparation of the article.

Funding Information: This work has been done in the frame of the projects 16NRM08 BiRD and 18SIB03 BxDiff, that have received funding from the EMPIR programme co‐financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme. The work has also been supported by the Academy of Finland Flagship Programme, Photonics Research and Innovation (PREIN), decision number: 320167. Publisher Copyright: © 2022 The Authors. Color Research and Application published by Wiley Periodicals LLC. Modern studies of bidirectional reflectance distribution function (BRDF) and its applications using data and machine-driven science require formatting of BRDF data according to Findable, accessible, interoperable and reusable (FAIR) data principles. As a solution a FAIR universal BRDF file-format based on Java Script Object Notation (JSON) is proposed. JSON principles as well as file structure are explained and examples are given. Automatic validation of universal BRDF file format is realized with the help of JSON schema. Furthermore, the source code and accompanying documentation are presented in dedicated supporting material files. It is expected that after its wide adoption, the proposed BRDF file format will enhance collaboration between different research groups and benefit machine-driven science. The uptake is facilitated by introducing a BiRDview—a modern open-source web-based application for BRDF visualization.

13 pags., 7 figs., 1 tab., We built an improved 3D rendering framework to accurately visualize the complete appearance of effect coatings, including metallic effects, sparkle and iridescence. Spectral reflectance measurements and sparkle indexes from a commercially available multi-angle spectrophotometer (BYKmac-i) were used together with physics-based approaches, such as flake-based reflectance models, to implement efficiently the appearance reproduction from a small number of bidirectional measurement geometries. With this rendering framework, we rendered a series of effect coating samples on an iPad display, simulating how these samples would be viewed inside a Byko-spectra effect light booth. We validated the appearance fidelity through psychophysical methods. We asked observers to evaluate the most important visual attributes that directly affect the appearance of effect coatings, i.e., the color, the angular dependence of color (color flop) and the visual texture (sparkle and graininess). Observers were asked to directly compare the rendered samples with the real samples inside the Byko-spectra effect light booth. In this study, we first validated the accuracy of rendering the color flop of effect coatings by conducting two separate visual tests, using flat and curved samples respectively. The results show an improved accuracy when curved samples were used (acceptability of 93% vs 80%). Secondly, we validated the digital reproduction of both color and texture by using a set of 30 metallic samples, and by including texture in the rendering using a sparkle model. We optimized the model parameters based on sparkle measurement data from the BYK-mac I instrument and using a matrix-adjustment model for optimization. The results from the visual tests show that the visual acceptability of the rendering is high at 90%., Ministerio de Economía y Competitividad (FPIBES-2016-077325, RTI2018-096000-B-I00).

14 pags., 8 figs., 2 tabs., The bidirectional scattering-surface reflectance distribution function (BSSRDF) is the function that describes the variation of the radiance of the elementary areas of a surface with respect to the directionally incident radiant flux on that surface. Measurements of the BSSRDF are important for characterizing the translucency of objects and for obtaining those optical parameters affecting volume scattering. However, to date, no traceable measurements of this function are available, since, likely due to its technical complexity, no standard measurement procedure has been established. We have developed a primary facility for measuring the BSSRDF based on a gonio-spectrophotometer with spatial resolution in the collection, spectral resolution in the irradiation, and angular resolution both for irradiation and collection directions. The BSSRDF of twelve homogeneous and translucent samples (with controlled values for the mean diameter of the scattering particles and their concentration) have been measured with relative uncertainties below 3% inside the irradiated area. Some results are shown and commented. This primary facility will allow the BSSRDF scale to be transferred to other instruments., Comunidad de Madrid (S2018/NMT-4326-SINFOTON2-C); European Association of National Metrology Institutes (18SIB03); Ministerio de Economía, Industria y Competitividad, Gobierno de España (MCIU/AEI/FEDER,UE) PGC2018-096470-B-I00

9 pags., 11 figs., 1 tab., We validate a physically based and spectral rendering framework with improved color reproduction. With a recently developed model, we take into account both the colorimetric specifications of the rendering display as well as the spectral and angular characteristics of lighting and also the spectral reflectance of the objects. Therefore, it should provide much better color reproduction than those based on the common standard red, green, blue (sRGB) color space. In addition, it allows real-time rendering on modest hardware and displays. We evaluated the color reproduction of the new rendering framework by psychophysical tests using spectrophotometric measurements of 30 chromatic paint samples. They were rendered on an iPad display, as viewed inside the Byko-spectra effect light booth. We asked 16 observers to evaluate the color match by directly comparing the rendered samples with the physical samples, using two different psychophysical assessment methods. The color reproduction was found to be strongly improved with respect to results obtained with default sRGB color encoding space. The average color reproduction match was found to be equivalent to 1E = 1.6, which is a small but noticeable color difference. In 80% of the visual assessments, the color reproduction was described as being at least as good as between “differencevisible but still acceptable” and “difference visible, doubtful match.”, Ministerio de Economía y Competitividad (FPI BES-2016-077325, RTI2018-096000-B-I00).

12 pags., 4 figs., Large effect pigments, widely used in various fields of industrial applications, produce characteristic visual textures known as sparkle and graininess, which need to be quantified by objective or subjective methods. The development of preliminary measurement scales for sparkle and graininess, whose recommendation is now under discussion in the International Commission on Illumination (CIE), is described in this article. These scales are absolute, linear and traceable to standards of optical radiation metrology. The main purpose of this article is to justify the convenience of adopting these preliminary measurements scales, showing clear evidence that they correlate well with subjective evaluations. Before standardization, these scales need to be validated with more experimental data, including different specimens and experimental systems from other research groups., Ministerio de Ciencia, Innovación y Universidades (RTI2018-096000-B-I00); EURAMET and the European Union (16NRM08).

In this document the density of electrically-charged positive and negative particles in a two component plasma (TCP) will be studied. Particularly, we focus on a two dimensional system confined in a large rectangular box for $��=2$ in the presence of two electric impurities. A method for solution, which will be called, {\it dimensional reduction}, will be applied in order to study the redistribution of electrically charged particles along the line joining both impurities. Numerical results, by means of a finite elements method approach, show, due to the electric field generated by the impurities, an increase in the density of charges of opposite sign in the neighborhood of each impurity. On the other hand, the presence of charges of the same sign diminishes in the same region due to the existing electric repulsion; some of the repelled particles accumulate in the border of the box. Numerical expansions around the borders of the impurities and the box show an almost linear power law relation of the net density for the particular cases that have been analyzed. It is also studied how the maximum and minimum values of the net density depend on the electric charges of the impurities, under some particular conditions., 16 pages, 8 figures

Preprint abstract of a paperpublished in Optics Express, see https://doi.org/10.1364/OE.410225for the full publication.

The existence of a non-vanishing resistance in an RLC circuit connected to a DC battery is known to generate an exponentially–decaying behavior in the electrical charge stored in a capacitor and the electric current flowing across the circuit. Nonetheless, a connection to an AC power supply—particularly, a sinusoidal signal—is known to generate oscillatory terms that are not suppressed for large times. A careful analysis of the charge and the current induced by arbitrary time-varying signals in an RLC circuit is performed. It is shown that such exponential suppression disappears for the particular signals that have been analyzed. Moreover, results show that there exists a phenomenon of charge accumulation that takes place in the capacitor and resistance that slightly changes the behavior of the charge an current from one cycle to the next.

10 pags., 9 figs., 3 tabs., 1 app., The dependence of color differences on the illumination and viewing directions for two widely used gray scales for color change (SDCE and AATCC) was evaluated through measuring the spectral bidirectional reflectance distribution function (BRDF) by a gonio-spectrophotometer of metrological quality. Large incidence and viewing angles must be specially avoided using these gray scales because, in these conditions, color differences vary considerably from those established in ISO 105-A02 and ASTMD2616-12. While the visual appearance of the SDCE and AATCC gray scales for color change is similar, our results indicate that their goniochromatic properties are different. Finally, some recommendations regarding observation distance and illumination angle are given to correctly use these gray scales for visual experiments., European Metrology Research Programme (EMRP IND52); Ministerio de Economía y Competitividad (FIS2013-40661-P, FIS2016-80983-P); Comunidad de Madrid (S2013/MIT-2790).

11 pags., 11 figs., 3 tabs., app. -- OCIS codes: (290.1483) BSDF, BRDF, and BTDF; (120.1840) Densitometers, reflectometers; (120.5700) Reflection., The field of spectral radiance factor (SRF) measurements has seen growing interest in recent years. Scale conformity has so far only been established between the national metrology institutes (NMIs) of Germany and the USA. This study aims at a bigger, multilateral scale comparison. For this purpose, a total of six NMIs participated in a scale comparison of goniospectrophotometers based on neutral and colored diffusely reflecting ceramics samples. In addition, two universities, providing a home-built gonioreflectometer and two widely used commercially available color measurement instruments, respectively, were involved. The wavelength range of the scale comparison covers the visible wavelength range from 380 nm to 780 nm. Results indicate systematic issues and that the uncertainty evaluation of the NMIs requires further work; although for the greatest part of the covered spectral range the agreement is good., This work has been realized within the European Metrology Research Program (EMRP) project JRPIND52. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. We thank the European Commission and EURAMET e.V. for financial support.

7 págs., 7 figs., 1 tab., The technical committee TC 2-90 (“LED Reference spectrum for photometer calibration”) has been recently created by CIE to investigate, select and publish an LED Reference spectrum to complement the CIE Standard Illuminant A in photometric calibrations. This task additionally requires defining a spectral mismatch index to account for the match of spectral power distributions (SPDs) of real sources to the selected reference spectrum. The objective of this work is to propose such a spectral mismatch index, and to evaluate its performance using real and representative LED spectral power distributions and relative spectral responsivities of photometers., The work leading to this study is partly funded by the European Metrology Programme for Innovation and Research (EMPIR) Project 15SIB07 PhotoLED ‘Future Photometry Based on Solid State Lighting Products’. The EMPIR initiative is cofunded by the European Union’s Horizon 2020 research and innovation programme and the EMPIR Participating States.

8 págs.; 7 figs., The spectral bidirectional reflectance distribution function (BRDF) is the key quantity to specify the spectral reflectance of materials for any condition of irradiation and detection, and its characterization is quite important for surfaces with a high dependence on these conditions, such as iridescent coatings. In order to evaluate the calibration and measurement capabilities (CMC) of National Metrology Institutes with the ability to measure the spectral BRDF, a case study interlaboratory comparison is in progress. Spectral BRDF has both spectral and geometric dependence, and this multidimensionality must be treated in the comparison to provide useful information to the participants about their CMCs. A data analysis method for the comparison is presented in this work, which was tested by simulations for different scenarios. The proposed method assesses whether the experimental data from each participant are consistent with those from the others. Finally, one-dimensional and multidimensional degrees of equivalence are defined, which should allow systematic deviations of spectral and geometric nature to be identified., This report was compiled within the EMRP IND52 Project xD-Reflect ‘Multidimensional reflectometry for industry’. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. Part of the authors (Instituto de Óptica ‘Daza de Valdés’, Agencia Estatal CSIC) are also grateful to Comunidad de Madrid for funding the project SINFOTON-CM: S2013/MIT-2790.

13 pags., 2 figs., 1 tab., The bidirectional reflectance distribution function (BRDF) and the bidirectional scattering - surface reflectance distribution function (BSSRDF), which relate radiance at the surface to irradiance and radiant flux, respectively, are regarded as the most fundamental scattering quantities used to determine the reflectance of objects. However, for materials where the optical radiation is transmitted under the surface, this radiance depends not only on irradiance and radiant flux, but also on the size of the irradiated area of the surface. This article provides insight into such dependence under the special condition in which the radiance is evaluated within the irradiated area and, consequently, is produced by both the insurface reflection and the subsurface scattering, in contrast to the situation in which the radiance is evaluated at non-irradiated areas and only subsurface scattering contributes. By explicitly considering both contributions, two other scattering quantities are defined: one that accounts exclusively for the insurface reflection and the other that accounts for subsurface scattering. In this regard, these quantities might be considered more fundamental than the BRDF and the BSSRDF, although they are coincident with these two functions apart from the above-mentioned special condition and for materials with negligible subsurface scattering. In this work, the relevance of the proposed scattering quantities is supported by experimental data, practical considerations are given for measuring them, and their relation to the bidirectional transmittance distribution function (BTDF) is discussed., This investigation was carried out within the scope of EMPIR project 18SIB03, “New quantities for the measurement of appearance” (BxDiff). EMPIR is jointly funded by the EMPIR participating countries within EURAMET and the European Union. Some of the authors (CSIC) are would like to acknowledge project PGC2018-096470-B-I00 BISCAT (MCIU/AEI/FEDER,UE). We are grateful to Covestro Deutschland AG for providing with translucent samples.

© 2020 by the authors., The Bidirectional Reflectance Distribution Function (BRDF) of iridescent (or goniochromatic) surfaces may vary notably with both spectral and angular variables, and, therefore, finite spectral bandwidth and collection solid angles inherent to any measuring instrument introduce a deviation from the correct value. Experimental data of highly goniochromatic samples are used to analyse their impact on measurement uncertainty. The results indicate that it is advisable to standardize spectral and angular bandwidths because the systematic error is not negligible for typical measuring systems. The 95th percentile of the error distribution of the measurement of the BRDF due to these finite bandwidths, and also the 95th percentile of the calculated resulting color differences, are used as criteria to establish recommended values of spectral and angular bandwidths. The impact of the bandwidth is more critical in the measurement of the BRDF of diffraction-based than of interference-based coatings., This research was funded by EMPIR 16NRM08 Project “Bidirectional reflectance definitions” (BiRD), and by Comunidad de Madrid, grant number S2018/NMT-4326-SINFOTON2-C. The EMPIR is jointly funded by the EMPIR participating countries within EURAMET and the European Union.

18 pags., 15 figs., 1 tab., Large-effect pigments, due to their strongly specular reflectance, produce a special visual texture known as sparkle. The use of these pigments in many industries (automotive, cosmetic, paper, architecture...) makes the control of this visual texture necessary. Sparkle measurands have been defined in this article, so that traceability of sparkle measurements can be provided by national metrology institutes or designated institutes. Some of them (Physikalisch-Technische Bundesanstalt, Eidgenössisches Institut für Metrologie, Cesky Metrologicky Institut and Consejo Superior de Investigaciones Científicas) have tested their existing measurement capabilities for the defined sparkle measurands, and their results are presented and thoroughly compared. Two possible sources of systematic error have been identified: inadequate illumination and collection solid angles, and an inadequate size of the virtual aperture used to assess the luminous flux reflected by the effect pigments. Finally, it has been shown that the measures correlate excellently with the sparkle visual data. The results shown in this research support the sparkle measurands defined here as adequate quantities for defining the standard measurement scale of sparkle claimed by industry., This article was written within the EMPIR 16NRM08 Project ‘Bidirectional reflectance definition’ (BiRD). The EMPIR is jointly funded by the participating countries within EURAMET and the European Union. Some of the authors (Instituto de Optica ‘Daza de Valdes’) are also grateful to Comunidad de Madrid for funding the project S2018/NMT4326-SINFOTON2-C.

7 pags., 5 figs. -- CIE x046:2019, Proceedings of the 29th CIE SESSION Washington D.C., USA, June 14 – 22, 2019, Research project ¿Future photometry based on solid-state lighting products¿ (EMPIR 15SIB07 PhotoLED) has investigated the fundamental requirements for photometry based on white lightemitting diode (LED) sources. The project has developed new LED illuminants, LED standard lamps for luminous intensity and luminous flux, as well as new photometric measurement methods, addressing many technical challenges of the CIE research strategy. In this paper, we present the outcome of the 3-year scientific research project, whose work has been carried out by NMIs, universities, test laboratories and industrial partners working in the field of photometry and solid-state lighting., The work leading to this study is partly funded by the European Metrology Programme for Innovation and Research (EMPIR) Project 15SIB07 PhotoLED “Future Photometry Based on Solid State Lighting Products”. The EMPIR initiative is co-funded by the European Union’s Horizon 2020 research and innovation programme and the EMPIR Participating States. The project would like to thank CIE and the official collaborators NIM, NRC and IPQ for their support

10 pags., 8 figs., 3 tabs.-- Open Access funded by Creative Commons Atribution Licence 3.0, The assumption that the reflectance of white diffuse reflectance standards is identical to that of the perfect reflecting diffuser (PRD) allows these standards to be used to characterize reflectance or radiance factors of any surface at any irradiation/collection geometry simply by comparison. However, this assumption is only true within certain limits, and, for some applications, requirements may be out of those limits. PTB and IO-CSIC have studied the variation of the reflectance with respect to the bidirectional geometry for the four most typical white diffuse materials (barium sulfate, opal glass, ceramic and Spectralon), at in- A nd out-of plane geometries and at spectral range from 380 nm to 1700 nm. We have defined descriptors in order to more clearly quantify the spectral reflectance variation with the bidirectional geometries. The values obtained for these descriptors have been separately presented for the visible and near-infrared spectral ranges. In both spectral ranges, deviations of white diffuse reflectance standards with respect to the PRD were found, regarding both Lambertian behaviour and spectral constancy. The observed deviation from the BRDF is in general very large for high incidence and collection angles (reaching in many cases 20%). Therefore, it is not possible to assume Lambertianity in standards at those geometries when calibrating measuring systems., This article was written within the EMRP IND52 Project xDReflect ‘Multidimensional reflectometry for industry’. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. Part of the authors (Instituto de Óptica ‘Daza de Valdés’, CSIC) are also grateful to Comunidad de Madrid for funding the project SINFOTON-CM: S2013/MIT-2790.

10 pags., 5 figs. -- Open Access funded by Creative Commons Atribution Licence 4.0, The bidirectional reflectance distribution function (BRDF) is a well-defined quantity that allows the bidirectional reflectance of surfaces to be described. However, the light propagation in a specific direction cannot be perfectly realized in practice, because the physical apertures are not infinitesimal but finite. Consequently, a BRDF measurement cannot be considered fully bidirectional, although the measure coincides with the BRDF within a certain confidence level. To properly understand the impact of the finite apertures on the BRDF measures, the deviation between the real BRDF and the BRDF to be obtained using real experimental conditions with finite apertures was theoretically studied for surfaces with realistic BRDFs. The biconical reflectance factor was used to estimate these ‘‘measured BRDFs’’ in different geometrical conditions, and a family of negative exponential functions was defined to assess the impact on surfaces with different angular scattering distributions. An expression for estimating the relative error from finite apertures is given, which considers the angular variation of the BRDF and the different solid angles involved in the measurement., The funding for this was obtained from EURAMET and the European Union (16NRM08 Project BiRD), and Comunidad de Madrid (S2013/ MIT-2790). The author is also grateful to Comunidad de Madrid for funding the project SINFOTON-CM: S2013/MIT-2790.

11 pags., 5 figs., The General V(λ) Mismatch Index, f, was defined for a general description of the photometric performance of photometers. This index is widely-used in photometry, and it is very relevant for selecting photometers for low-uncertainty photometric measurements. It quantifies the spectral mismatch between the relative spectral responsivity of a photometer and the luminous e ciency function for photopic vision, V(λ). The linear correlation between the real general photometric measurement error and f of 77 photometers was studied for four sets of light sources: R, G and B LEDs (narrowband spectral power distributions, SPDs), blackbodies at di erent colour temperatures (broadband SPDs), phosphor-based LEDs at di erent correlated color temperatures (SPDs with narrow- and broad-band features), and a mixture of blackbodies and phosphor-based LED sources. This article shows that it can be defined an alternative index which is notably better correlated with the real general photometric measurement error of the photometers under light sources with broadband features in their SPDs, adequate for general lighting. This index is based on filtering the high spectral frequencies variations between the relative spectral responsivity of the photometer and V(λ). The use of this new index for the assessment of the general photometric performance of photometers would improve the selection of high quality photometers and, consequently, would contribute to the general improvement of photometric measurements., EURAMET and the European Union (15SIB07); Comunidad de Madrid (S2013/MIT-2790).

General lighting is undergoing a revolutionary change towards LED-based technologies. To provide firm scientific basis for the related colorimetric and photometric measurements, this paper presents the development of new white-LED-based illuminants for colorimetry, and their evaluation to recommend a new reference spectrum for calibration of photometers. Spectra of 1516 LED products were measured and used to calculate eight representative spectral power distributions for LED sources of different correlated colour temperature categories. The suitability of the calculated representative spectra for photometer calibration was studied by comparing average spectral mismatch errors with CIE Standard Illuminant A, which has been used for decades as the reference spectrum for incandescent standard lamps in calibration of photometers. It was found that in general, when compared with Standard Illuminant A, all the potential LED calibration spectra reduced spectral mismatch errors when measuring LED products. Out of thepotential LED calibration spectra tested, the white LED spectrum with correlated colour temperature of 4103 K was found to be the most suitable candidate to complement Standard Illuminant A in luminous responsivity calibrations of photometers. When compared with Standard Illuminant A, employing the 4103 K reference spectrum reduced the spectral mismatch errors, on average, by approximately a factor of two in measurements of LED products and lighting. Furthermore, the new LED reference spectrum was found to reduce the spectral mismatch errors in measurements of daylight, and many types of fluorescent and discharge lamps, indicating that the proposed reference spectrum is a viable alternative to Standard Illuminant A for calibration of photometers.

12 pags., 7 figs., Effect pigments in coatings produce eye-catching colour and texture effects and are widely used in automotive, cosmetics, coatings, inks, flooring, textile or decoration. One of these texture effects is graininess, which is the perceived texture exhibited when the effect coating is observed under diffuse illumination. To date there is not a standard procedure to measure graininess from reflectance measurements. The objective of this work is to propose a methodology for traceable graininess measurements, similarly as it was proposed for colour in 1931. In this article, the relevant reflectance-based quantities are clearly defined, and a formal relation with data from visual experiments is given. This methodology would allow a measurement scale of graininess and a difference formula to be agreed once conclusive visual data become available., The EMPIR is jointly funded by the EMPIR participating countries within EURAMET and the European Union. Part of the authors (Instituto de Óptica “Daza de Valdés” (IO, CSIC), Agencia Estatal CSIC) are also grateful to Comunidad de Madrid for funding the project SINFOTON-CM: S2013/MIT-2790. Part of the authors (Color & Vision Group, University of Alicante) are also grateful to Spanish Ministry of Economy and Competitiveness for funding the project ADIREVGAO: DPI2015-65814-R.

11 pags., 4 figs. -- This article belongs to the Special Issue Optical Biochemical Sensor Systems and Applications, Ultra-weak photon emission (UPE) is the spontaneous emission from living systems mainly attributed to oxidation reactions, in which reactive oxygen species (ROS) may play a major role. Given the capability of the next-generation electron-multiplying CCD (EMCCD) sensors and the easy use of liquid crystal tunable filters (LCTF), the aim of this work was to explore the potential of a simple UPE spectrometer to measure the UPE from a human hand. Thus, an easy setup was configured based on a dark box for inserting the subject’s hand prior to LCTF as a monochromator and an EMCCD sensor working in the full vertical binning mode (FVB) as a spectra detector. Under controlled conditions, both dark signals and left hand UPE were acquired by registering the UPE intensity at different selected wavelengths (400, 450, 500, 550, 600, 650, and 700 nm) during a period of 10 min each. Then, spurious signals were filtered out by ignoring the pixels whose values were clearly outside of the Gaussian distribution, and the dark signal was subtracted from the subject hand signal. The stepped spectrum with a peak of approximately 880 photons at 500 nm had a shape that agreed somewhat with previous reports, and agrees with previous UPE research that reported UPE from 420 to 570 nm, or 260 to 800 nm, with a range from 1 to 1000 photons s cm. Obtaining the spectral distribution instead of the total intensity of the UPE represents a step forward in this field, as it may provide extra information about a subject’s personal states and relationship with ROS. A new generation of CCD sensors with lower dark signals, and spectrographs with a more uniform spectral transmittance, will open up new possibilities for configuring measuring systems in portable formats.

8 pags., 7 figs., 1 tab., Determining reflectance factor and its variability across reference sites for Earth observation satellites is a problem involving large amounts of data and measurement time. Principal component analysis (PCA) may be used to simplify this problem by reducing the size of the data and by highlighting spectral features that could be related to physical phenomena. This work presents the results obtained in applying PCA to two reference sites for calibration and validation of Earth observation satellites located at La Crau (France) and Gobabeb (Namibia), respectively., To the European Metrology Research Program (EMRP), supporter of this work within the joint research project ENV53 “European metrology for Earth observation and climate” (MetEOC2). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. We thank CNES for access to La Crau and their support with the measurements at both La Crau and Gobabeb. The IO-CSIC authors are also grateful to Comunidad de Madrid for funding the program SINFOTON-CM: S2013/MIT-2790

10 pags.; PACS: 06.20.Dk Measurement and error theory; 07.68.+m Photography, photographic instruments; xerography; 42.72.-g Optical sources and standards; 07.60.Dq Photometers, radiometers, and colorimeters, Radiometrically characterizing a camera means relating the response of every pixel of the camera to the radiance emitted by a light source. In order to accomplish this task, not only the responsivities of the pixels have to be characterized, but, in addition, their non-ideal response (dark response or non-linearity) or the radiant flux impinging on the pixel from outside its corresponding viewing solid angle. An extended uniform source developed at the PTB was used to spatially characterize a camera by determining the parameters involved in a response model. The uniformity of the source was optimized using the actual camera to be characterized, and two different procedures were used to estimate the non-uniformity of the source. These procedures are based on varying the distance from the source to the camera and, in consequence, the field-of-view area, allowing the non-uniformity of the source to be identified as the non-correlated spatial variations in the images. © 2014 BIPM & IOP Publishing Ltd.

10 pags., 9 figs. 2 tabs. -- Open Access funded by Creative Commons Atribution Licence 3.0, This work reports a versatile and efficient production of periodic structures of alloy nanoparticles (NPs) with customized diffraction patterns by using the technique of phase mask laser interference. This technique uses interfering single nanosecond laser pulses to induce the periodic dewetting of bilayer (Ag/Au) films on glass produced by pulse laser deposition. Film breaks up into alloy NPs around the regions exposed to intensity maxima and the cold regions placed in the minimum laser intensity are non-transformed. This allows fringes to be produced with a period within the range of 1.7-6.8 μm. Periodic structures of squares, diamonds, rectangles or triangles are produced by accumulating two or three laser pulses with different fringe orientations. As a film parameter, we have analyzed the pattern properties by varying the thickness of the Au layer while keeping that of Ag constant. The diameter of the NPs, their number density, percentage of the transformed region, the interface between transformed and non-transformed region or the minimum period achievable can be tuned by varying the Au concentration. In that way, isolated and big NPs, which are optically characterized by a plasmon resonance, are produced for the thinnest film, whereas a bimodal size distribution of big and small NPs, whose optical transmittance is characterized by IR absorption related with multipolar interactions between the close small NPs, are produced for the highest Au concentration. However, the periodic structure still generates visible diffractive patterns whose diffraction efficiency can increase up to a factor of 4, while their spectral trend dependences can increase or decrease as a function of the Au concentration. These optical behaviors have been explained satisfactorily by taking into account the optical contrast between the regions transformed into NPs and the non-transformed regions. Altogether, this allows the position of the diffraction orders and their relative and absolute spectral efficiency to be customized in a broad range., R. J. Pel´aez acknowledges grant no. JCI-2012-13034 from the Juan de la Cierva program. A. Ferrero, B. Bernad and J. Campos are grateful to the Comunidad de Madrid for funding the program SINFOTON-CM: S2013/MIT- 2790.

NEWRAD 2017, Miraikan Hall, in Odaiba, Tokyo 13 - 16 June, 2017, Numerical simulations are the common method to predict the response of a quantum efficient detector of induced-junction photodiodes at present. As alternative, an analytical model based on Ferrero et al. photocurrent analysis is proposed. Surface and bulk losses are modelled considering design and operation photodiode parameters and the characteristics of the incident beam. At short wavelengths the surface recombination velocity dominates the losses, whereas the bulk doping and reverse bias voltage determine the losses at long wavelengths. The losses predicted by the analytical model and reported simulations by other authors are in the same order of magnitude between 400 nm and 700 nm., This work was supported by the Comunidad de Madrid and the European Union under program S2013/MIT-2790-SINFOTON and by the European Commission under EMRP JRP SIB57-NEWSTAR. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union.

Jeju Island, South Korea, October 21-28, 2017. -- http://www.cie.co.at/news/cie-2017-midterm-meeting-jeju-island-south-korea, Solid-state lighting (SSL) products are already in use by consumers and are rapidly gaining the lighting market. Especially, white Light Emitting Diode (LED) sources are replacing banned incandescent lamps and other lighting technologies in most general lighting applications. The aim of this work is to develop LED-based illuminants that describe typical white LED products based on their Spectral Power Distributions (SPDs). Some of these new illuminants will be recommended in the update of the CIE publication 15 on colorimetry wi th the other typical illuminants, and among them, some could be used to complement the CIE standard illuminant A for calibration use in photometry., The work leading to this study is partly funded by the European Metrology Programme for Innovation and Research (EMPIR) Project 15SIB07 PhotoLED “Future Photometry Based on Solid State Lighting Products”. The EMPIR initiative is co-funded by the European Union’s Horizon 2020 research and innovation programme and the EMPIR Participating States. .

9 pags., 5 figs., 1 tab., The potential of predictable quantum efficient detectors (PQEDs) as optical radiant power primary standard, based on photoelectric effect in silicon semiconductor, has been proved. Until now, the internal quantum efficiency (IQE) of a PQED is only predicted, from the design and setup parameters of the two photodiodes of this radiometer, by means of simulation software for semiconductor devices. This work presents, as alternative method, an analytical model based on Ferrero et al. photocurrent analysis, which considers the different internal regions of the photodiode and the characteristics of the incident beam. The IQE grows with the reverse bias voltage applied to the photodiodes and the lifetime of the charge carriers in the bulk, while IQE decreases when the surface recombination velocity and the doping concentration of the substrate are increased. The IQE results of the analytical model are similar to simulations for wavelengths between 400 nm and 700 nm. Moreover, the analytical model predicts an increase of the IQE with the irradiance, at certain levels of optical power due to the supra-responsivity of the photodiode., This work has been supported by the European Commission through the project SIB57-NEWSTAR under the European Metrology Research Programme (EMRP). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. The authors of CSIC acknowledge support from the Comunidad de Madrid and the European Union under program SINFOTON-CM (S2013/MIT-2790).

6 pags., 3 figs. -- IS&T International Symposium on Electronic Imaging 2019 Color Imaging XXIV: Displaying, Processing, Hardcopy, and Applications, The digital representation of three dimensional objects with different materials has become common not only in the games and movie industry, but also in designer software, e-commerce and other applications. Although the rendered images often seem to be realistic, a closer look reveals that their color accuracy is often insufficient for critical applications. Storage of the angledependent color properties of metallic coatings and other gonioapparent materials demands large amounts of data. Apart from that, also rendering sparkle, gloss and other visual texture phenomena is still a subject of active research. Current approaches are computationally very demanding, and require manual ad-hoc setting of many model parameters. In this paper, we describe a new approach to solve these problems. We combine a multi-spectral physics-based approach to make BRDF representation more efficient. We also account for the common loss in color accuracy due to the varying technical specifications of displays, and we correct for the influence from ambient lighting. The rendering framework presented here is shown to be capable of rendering sparkle and gloss as well, based on objective measurement of these properties. This takes out the subjective phase of manual fine-tuning of model parameters that is characteristic for many current rendering approaches. A feasibility test with the new spectral rendering pipeline shows that is indeed able to produce realistic rendering of color, sparkle, gloss and other texture aspects. The computation time is small enough to make the rendering real-time on an iPad 2017, i.e. with low memory footprint and without high demands on graphic card or data storage., This study was also supported by the Spanish Ministry of Economy and Competitiveness under grant no. DPI2011-30090-C02-02 and the European Union. Khalil Huraibat would also like to thank the Ministry of Economy and Competitiveness for his pre-doctoral fellowship grant (FPI BES- 2016- 077325). The authors are also grateful to EMRP for funding the project “Bidirectional Reflectance Definitions”. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union

The exposure of rats to an enriched environment (EE) has several effects in common with the administration of antidepressants. However, there is still little information about the molecular underpinnings of these effects on rats subjected to experimental models of depression. The aim of this research was to evaluate the effects of EE on rats exposed to the learned helplessness paradigm (LH), a well-known model of the disease. We found that a 21 day exposure to EE reverts helplessness behavior to normal in LH animals. Inmunohistochemical labeling showed that this effect was accompanied by normalization of two structural proteins of hippocampal neurons to control values: the light neurofilament subunit (NFL) and the postsynaptic density 95 (PSD-95) protein, which were decreased in LH animals housed in standard cages. The decrease in the presynaptic protein synaptophysin (SYN) observed in LH animals remained unchanged after exposure to EE. There was no increase in neurogenesis as measured by quantification of double-labeled cells with 5-bromo-2'-deoxyuridine (BrdU) and the neuronal marker beta-tubulin class III. These results show that EE may have behavioral and synaptic effects on animals exposed to an experimental model of depression, and that such actions seem to be independent from neurogenesis.