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1.
Opt Express ; 29(5): 7589-7600, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33726257

RESUMO

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.

2.
Opt Express ; 26(23): 30116-30127, 2018 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-30469891

RESUMO

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.

3.
Appl Opt ; 56(7): 1996-2006, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28248401

RESUMO

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.

4.
J Opt Soc Am A Opt Image Sci Vis ; 33(10): 1978-1988, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-27828101

RESUMO

Coatings with diffraction pigments present high iridescence, which needs to be characterized in order to describe their appearance. The spectral bidirectional reflectance distribution functions (BRDFs) of six coatings with SpectraFlair diffraction pigments were measured using the robot-arm-based goniospectrophotometer GEFE, designed and developed at CSIC. Principal component analysis has been applied to study the coatings of BRDF data. From data evaluation and based on theoretical considerations, we propose a relevant geometric factor to study the spectral reflectance and color gamut variation of coatings with diffraction pigments. At fixed values of this geometric factor, the spectral BRDF component due to diffraction is almost constant. Commercially available portable goniospectrophotometers, extensively used in several industries (automotive and others), should be provided with more aspecular measurement angles to characterize the complex reflectance of goniochromatic coatings based on diffraction pigments, but they would not require either more than one irradiation angle or additional out-of-plane geometries.

5.
J Opt Soc Am A Opt Image Sci Vis ; 32(1): 1-11, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26366484

RESUMO

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.

6.
J Opt Soc Am A Opt Image Sci Vis ; 31(2): 436-47, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24562043

RESUMO

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.


Assuntos
Luz , Espalhamento de Radiação , Absorção , Cor
7.
Rev Esp Anestesiol Reanim ; 57(4): 245-9, 2010 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-20499805

RESUMO

We report 2 cases of pulmonary torsion discovered during the early postoperative recovery of patients who had undergone lobectomy. Early diagnosis, based on chest radiography and confirmed by computed tomography, meant we were able to avoid major surgical resection and the development of further complications. Pulmonary torsion is a rare but potentially serious abnormality. Prompt diagnosis is the key to preventing tissue injury and complications such as necrotizing pneumonitis, thromboembolic disease, or septic shock. Among the diagnostic tests that can be carried out if there is good reason to suspect torsion, we emphasize simple chest radiography and fiberoptic bronchoscopy, supported by computed tomography or arteriography, even though a firm diagnosis requires surgical exploration of the affected lung. Definitive treatments range from reversing the torsion and securing the lung to resecting the lung if the parenchymal tissue has been fully compromised.


Assuntos
Pneumopatias/etiologia , Pneumonectomia/efeitos adversos , Anormalidade Torcional/etiologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
8.
Clin Chim Acta ; 398(1-2): 70-4, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18786524

RESUMO

BACKGROUND: Peroxisome Proliferator-Activated Receptors (PPARs) and its co-activators are regulatory elements of the cellular lipid homeostasis and have been associated with feeding behavior modulation. Animal models suggest that these genes may be involved in alcohol consumption regulation. However, no studies in humans exist. Our aim is to estimate the possible association between polymorphisms in the PPAR-alpha, PPAR-gamma and PPAR-gamma co-activator 1A (PGC-1A) genes and alcohol consumption in humans. METHODS: We have conducted a cross-sectional study between the PPAR-alpha L162V, PPAR-gamma P12A and PGC-1A G482S polymorphisms, and alcohol consumption in a general Mediterranean Spanish population (303 men and 443 women). RESULTS: We have found an association between the L162V polymorphism and alcohol consumption in which, carriers of the V allele were more prevalent among alcohol consumers (19.4% vs. 9.8%; OR 2.69; 95% CI: 1.31-5.54, p=0.007). The G482S polymorphism showed a significantly higher frequency in the group of high alcohol drinkers than in non-high alcohol drinkers (33.4% vs. 20.6%; OR 2.28; 95% CI: 1.07-4.88, p=0.034). Mean alcohol consumption was higher as the number of G alleles increased (GG 8.6+/-12.8 g/day, GS 6.6+/-9.2 g/day, SS 5.6+/-7.8 g/day, p=0.003). These results remained statistically significant after covariate adjustment. CONCLUSIONS: PPAR-alpha L162V and PGC-1A G482S polymorphisms are associated with alcohol consumption in the Mediterranean population.


Assuntos
Consumo de Bebidas Alcoólicas/genética , Proteínas de Choque Térmico/genética , PPAR alfa/genética , Fatores de Transcrição/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/psicologia , Alelos , Estudos Transversais , DNA/genética , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Região do Mediterrâneo , Pessoa de Meia-Idade , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Polimorfismo Genético/genética , Polimorfismo de Nucleotídeo Único , Fatores Socioeconômicos , Espanha/epidemiologia , Adulto Jovem
9.
Opt Express ; 15(12): 7810-7, 2007 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-19547108

RESUMO

This work uses the S-CIELAB color model to compare images that have been calibrated and processed using a colorimetric dithering method which simulates increments in viewing distance. Firstly, we obtain XYZ calibrated images by applying the appropriate color transformations to the original images. These transformations depend on whether the image is viewed on a display device or encoded by a capture device, for example. Secondly, we use a colorimetric dithering method consisting of a partitive additive mixing of XYZ tristimulus values. The number of dithered pixels depends on simulated viewing distance. The dithered tristimulus values are transformed to digital data to observe the dithering effects in the image. Finally, we predict color differences using the S-CIELAB model as color appearance model for images. Moreover, this paper proposes some applications of this method to artistic and industrial problems where one must compare two images that appear different at close viewing distance, but match when they are seen from afar.

10.
Clin Chim Acta ; 386(1-2): 53-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17716640

RESUMO

BACKGROUND: The increasing number of samples from the biomedical genetic studies and the number of centers participating in the same involves increasing risk of mistakes in the different sample handling stages. We have evaluated the usefulness of the amelogenin test for quality control in sample identification. METHODS: Amelogenin test (frequently used in forensics) was undertaken on 1224 individuals participating in a biomedical study. Concordance between referred sex in the database and amelogenin test was estimated. Additional sex-error genetic detecting systems were developed. RESULTS: The overall concordance rate was 99.84% (1222/1224). Two samples showed a female amelogenin test outcome, being codified as males in the database. The first, after checking sex-specific biochemical and clinical profile data was found to be due to a codification error in the database. In the second, after checking the database, no apparent error was discovered because a correct male profile was found. False negatives in amelogenin male sex determination were discarded by additional tests, and feminine sex was confirmed. A sample labeling error was revealed after a new DNA extraction. CONCLUSION: The amelogenin test is a useful quality control tool for detecting sex-identification errors in large genomic studies, and can contribute to increase its validity.


Assuntos
Amelogenina/análise , Amelogenina/genética , DNA/análise , Medicina Legal/métodos , Análise para Determinação do Sexo/métodos , DNA/química , Bases de Dados de Ácidos Nucleicos , Eletroforese em Gel de Poliacrilamida , Feminino , Genômica , Humanos , Masculino , Controle de Qualidade , Ensaios Clínicos Controlados Aleatórios como Assunto , Reprodutibilidade dos Testes
12.
Annu Int Conf IEEE Eng Med Biol Soc ; 2015: 3586-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26737068

RESUMO

Assistive ambulatory devices are used for gait rehabilitation and assistance. In both cases, their benefit is greater when they are used properly. As for canes, embedded sensors can be used for monitoring purposes. In this paper, a custom tactile handle equipping a cane is described. It is composed of cost-effective commercially available pressure sensors. Experimental results involving 10 subjects show that the developed handle can provide information on the cane orientation as well as on the load applied to it during assisted gait. These data can help monitoring the cane usage and misuses detection.


Assuntos
Bengala , Adulto , Marcha , Humanos , Monitorização Ambulatorial , Pressão , Tecnologia Assistiva , Adulto Jovem
13.
Vision Res ; 37(13): 1829-44, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9274768

RESUMO

In agreement with the principles of the relativistic model proposed by Creutzfeldt et al., with the photometric rule (lightness anchoring rule) and with the influence of simultaneous contrast in the appearance of a visual scene, we propose a first-stage mechanism yielding substantial colour constancy. We have defined a set of first-stage colour descriptors, and to test their utility, we have performed a simulation using a Machine Vision System (MVS). The statistical stability of the descriptors for Munsell samples under different illuminants is good.


Assuntos
Algoritmos , Percepção de Cores/fisiologia , Humanos , Modelos Neurológicos , Espectrofotometria
14.
IEEE Trans Neural Netw ; 14(5): 1375-92, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-18244584

RESUMO

This paper presents a mixed-signal neuro-fuzzy controller chip which, in terms of power consumption, input-output delay, and precision, performs as a fully analog implementation. However, it has much larger complexity than its purely analog counterparts. This combination of performance and complexity is achieved through the use of a mixed-signal architecture consisting of a programmable analog core of reduced complexity, and a strategy, and the associated mixed-signal circuitry, to cover the whole input space through the dynamic programming of this core. Since errors and delays are proportional to the reduced number of fuzzy rules included in the analog core, they are much smaller than in the case where the whole rule set is implemented by analog circuitry. Also, the area and the power consumption of the new architecture are smaller than those of its purely analog counterparts simply because most rules are implemented through programming. The paper presents a set of building blocks associated to this architecture, and gives results for an exemplary prototype. This prototype, called multiplexing fuzzy controller (MFCON), has been realized in a CMOS 0.7 /spl mu/m standard technology. It has two inputs, implements 64 rules, and features 500 ns of input to output delay with 16-mW of power consumption. Results from the chip in a control application with a dc motor are also provided.

15.
Actas Urol Esp ; 14(6): 452-4, 1990.
Artigo em Espanhol | MEDLINE | ID: mdl-2080739

RESUMO

Ureteral triplicity is a rare abnormality of which there are less than a hundred cases reported up to date. The possible absence of clinical signs can explain why this malformation passes unnoticed specially when there are blind branches and dysplastic renal segments. The paper presents the case of a 43 year-old male, attending the clinic on a testicle tumour consultation, in which in spite of the previously mentioned circumstances a preoperative diagnosis of trifid ureter with ipsilateral ureterocele and renal dysplasia was reached owing to the use of C.A.T.


Assuntos
Anormalidades Múltiplas , Disgerminoma/complicações , Rim/anormalidades , Neoplasias Testiculares/complicações , Ureter/anormalidades , Ureter/diagnóstico por imagem , Ureterocele/complicações , Adulto , Humanos , Masculino , Tomografia Computadorizada por Raios X , Ureterocele/patologia
16.
Actas Urol Esp ; 17(6): 376-9, 1993 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-8368105

RESUMO

Presentation of two cases of renal abscess formation in patients with stage IV C-1 AIDS and active associated tuberculosis. The microorganism isolated in the first case was S. aureus. Culture of the second cases was artefacted since antibiotic administration had already been started. Also, both patients showed abdominal abscesses, at spleen and liver level in the first case, and prostatic level in the second case, both compatible with Mycobacterium tuberculosis dissemination. Both cases showed a lethal evolution. The role played by the immunodeficiency as a precipitating agent in the extrapulmonary tuberculosis and in the formation of renal abscesses is analyzed.


Assuntos
Abscesso/complicações , Síndrome da Imunodeficiência Adquirida/complicações , Bacteriemia/complicações , Nefropatias/complicações , Infecções Estafilocócicas/complicações , Tuberculose/complicações , Adulto , Humanos , Masculino
18.
Alcohol ; 45(2): 131-6, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21303710

RESUMO

Neuropeptide Y (NPY) is a neurotransmitter widely distributed in the central nervous system. Several studies have demonstrated that increases of NPY are associated with reduced alcohol intake and anxiety manifestations. The Leu7Pro polymorphism in the NPY has been associated with alcohol consumption, but evidence is scarce. In the Spanish Mediterranean population, this variant is not polymorphic. Thus, our aim is to identify novel functional variants in the NPY and to investigate the impact of these markers and others previously described on alcohol consumption in this population. A total of 911 subjects (321 men and 590 women) from the Spanish Mediterranean population were recruited. Alcohol consumption, and demographic and lifestyle variables were measured. Nucleotide sequence determination and SNP analyses were carried out. Only one exonic SNP was detected by direct sequencing (1258 G>A or rs9785023; allele frequency 0.47). From the intronic markers chosen (483 A>G or rs13235938, 2517 A>G or rs4722342, and 7065 A>G or rs4722343), only the two latter ones were polymorphic (allele frequencies 0.46 and 0.04, respectively), and none of them were associated with alcohol consumption. However, the 1258 G>A SNP was associated (recessive pattern) with higher alcohol intake. This association was particularly relevant in men with high alcohol intake (59.1±5.0 g/day in AA as opposed to 40.6±7.5 in the G carriers, P=.022) and women with moderate alcohol intake (7.3±5.5 g/day in AA as opposed to 4.6±3.9g/day in G carriers, P=.048). The 1258 G>A polymorphism in the NPY is associated with higher alcohol consumption in the Mediterranean population.


Assuntos
Consumo de Bebidas Alcoólicas/genética , Neuropeptídeo Y/genética , Grupos Populacionais/genética , Adulto , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Região do Mediterrâneo , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Análise de Sequência , Espanha
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