Single Color Research Articles

The use of LEDs as a light source for fluorescence pressure measurements

ABSTRACT We discuss the use of commercial high power light emitting diodes (LEDs) as a light source for fluorescence pressure measurements. The relatively broad light emitting spectra of single color LEDs (in comparison with lasers) do not prevent producing narrow fluorescence lines at least for two widely used pressure indicator materials, namely ruby () and strontium tetraborate (). Strongest responses of both pressure gauges were detected for the green color LEDs with the average wavelength . LEDs might be easily implemented for producing fiber-coupled, as well as the parallel light sources. LEDs were found to be efficient to replace laser sources in piston-cylinder cell and diamond anvil cell fluorescence pressure measurement setups.

Oxygen-saturation-related functional parameter as a biomarker for diabetes mellitus-extraction method and clinical validation.

Purpose: To develop a computational method for oxygen-saturation-related functional parameter analysis of retinal vessels based on traditional color fundus photography, and to explore their characteristic alterations in type 2 diabetes mellitus (DM). Methods: 50 type 2 DM patients with no-clinically detectable retinopathy (NDR) and 50 healthy subjects were enrolled in the study. An optical density ratio (ODR) extraction algorithm based on the separation of oxygen-sensitive and oxygen-insensitive channels in color fundus photography was proposed. With precise vascular network segmentation and arteriovenous labeling, ODRs were acquired from different vascular subgroups, and the global ODR variability (ODRv) was calculated. Student's t-test was used to analyze the differences of the functional parameters between groups, and regression analysis and receiver operating characteristic (ROC) curves were used to explore the discrimination efficiency of DM patients from healthy subjects based on these functional parameters. Results: There was no significant difference in the baseline characteristics between the NDR and healthy normal groups. The ODRs of all vascular subgroups except the micro venule were significantly higher (, respectively) while ODRv was significantly lower () in NDR group than that in healthy normal group. In the regression analysis, the increased ODRs except micro venule and decreased ODRv were significantly correlated with the incidence of DM, and the C-statistic for discrimination DM with all ODR is 0.777 (95% CI 0.687-0.867, ). Conclusion: A computational method to extract the retinal vascular oxygen-saturation-related optical density ratios (ODRs) with single color fundus photography was developed, and increased ODRs and decreased ODRv of retinal vessels could be new potential image biomarkers of DM.

Form and color visual perception in green exercise: Positive effects on attention, mood, and self-esteem

Physical activity performed in a natural environment, especially among green spaces, is associated with mental health benefits. Yet few studies have explored the separable influences of visual perception on the effects of green exercise. The present study assessed the extent to which two components of visual perception (form and color) contributed to mental health benefits by separating the form and color characteristics of an image of a green tree. In total, 76 healthy college students (18–24 years of age) engaged in incremental cycling exercise at a moderate intensity while viewing an image in front of them on a large screen. Participants were randomly assigned to one of four groups in which the image they viewed was a green tree, an achromatic tree, a formless color green, or a formless achromatic color. Before and after cycling (test time), participants’ selective attention, mood state, and self-esteem were assessed using the Perception and Attention Function battery and the Chinese versions of the Profile of Mood States scale and the Rosenberg Self-Esteem Scale, respectively. Significant interactions detected between test time and form perception indicated that scores in total mood disturbance decreased and scores in the esteem subscale and self-esteem scale increased after cycling while viewing trees. A significant interaction between test time and color perception indicated that anger decreased in the two green color conditions. A significant interaction of color perception by form perception by test time was associated with a significant decrease in response times on the attention task after cycling among participants who viewed the green tree. Our findings are important for interpreting mechanisms underlying characteristics attributable to environmental benefits and revealed that single (color or form) or combined (color and form) visual perception improved the mental health benefits of exercise. These findings may also inform the design and planning of urban green spaces to maximize green exercise effects.

Polarization study of single color centers in aluminum nitride

Color centers in wide-bandgap semiconductors are a promising class of solid-state quantum light source, many of which operate at room temperature. We examine a family of color centers in aluminum nitride, which emits close to 620 nm. We present a technique to rapidly map an ensemble of these single photon emitters, identifying all emitters, not just those with absorption dipole parallel to the laser polarization. We demonstrate a fast technique to determine their absorption polarization orientation in the c-plane, finding they are uniformly distributed in orientation, in contrast to many other emitters in crystalline materials.

DNA Barcoding of Selected Freshwater Fishes in New Calabar River, Rivers State, Nigeria

The major environmental crisis is the loss of biodiversity and the decline is predominant in the fish population. Although taxonomic history began 250 years ago, there are still undiscovered members of species and new species are waiting to be uncovered. The failure of the traditional taxonomic method to address this issue has resulted to the adoption of a molecular approach-DNA barcoding. It was proposed that DNA barcoding using the mitochondrion cytochrome oxidase subunit I (COI) gene has the capability to serve as a barcode for fish. The aim of this study was to use DNA barcoding in the identification of fish species in the New Calabar River, Rivers State. BLAST result showed the correlation between the sequence queried and the biological sequences with the NCBI database. The names of the samples, percentage ID, predicted organisms, and GenBank Accession numbers were clearly identified. A total of 18 sequences (all > 600bp) belonging to 8 species, 7 genera, 7 families, and 5 orders were validated and submitted to the NCBI database. Each nucleotide peak was represented by a single colour with various percentage occurrences. Two (22%) out of the 9 original samples analyzed corresponded with the predicted organisms from the BLAST result.) There were a total of 712 positions in the final dataset. Evolutionary analyses were conducted in MEGA11. Pairwise sequence alignment showed different consensus positions and a total of 30 mutations. There was one insertion from Polynemus dubius and 29 substitutions (transition-15 and transversion-14) mutations. No deletion and nonsense codons were detected in all the amplified sequences. This work will facilitate more research in other keys areas such as the identification of mislabeled fish products, illegal trading of endangered species, and effective tracking of fish biodiversity.

Preparation and Orthogonal Analysis for Dual-Responsive Electrochromic Polymer Dispersed Liquid Crystal Devices.

In this work, we provide a fabrication method for dual-responsive electrochromic (EC) polymer dispersed liquid crystal (PDLC) devices. The EC PDLC device was developed by combing the PDLC technique and a colored complex formed via a redox reaction without a specific EC molecule in a simple preparation method. The mesogen played dual roles in the device for scattering in the form of microdroplets and participating in the redox reactions. Orthogonal experiments were performed with the acrylate monomer concentration, the ionic salt concentration, and the cell thickness as factors to investigate the electro-optical performance for the achievement of optimized fabrication conditions. The optimized device presented four switchable states modulated by external electric fields. The light transmittance of the device was changed by an alternative current (AC) electric field while the color change was realized by a direct current (DC) electric field. Variations of mesogen and ionic salt species can modulate the color and hue of devices, which solves the disadvantage of a single color for traditional EC devices. This work lays the foundation for realizing patterned multi-colored patterned displays and anti-counterfeiting via screen printing and inkjet printing techniques.

Emocolor: An assistant design method for emotional color matching based on semantics and images

AbstractMuch research has been done on the relationship between emotions and colors, and many color scheme recommendation tools have been developed. These tools can often help recommend a suitable color scheme to express a certain emotion, but it is still difficult to design satisfying schemes based on such recommendations. In this study, based on the Color Scheme Bible, Compact Edition, we developed Emocolor, which allows professionals to generate a large number of color schemes based on emotional words or emotional images. It is also used to iteratively optimize the generated color schemes based on an interactive genetic algorithm to find the color scheme design that best matches the user's emotion. Through the evaluation of tram color schemes based on emotional words, Emocolor can effectively generate tram color schemes that match users’ emotions. It can also effectively transfer the emotion of an image with a single dominant color to a tram color scheme. In short, Emocolor can help professionals describe the relationship between emotion and color in a more accurate way and design emotional color schemes. Emocolor can be applied in advertising design, product design, interior design, and other fields.

Object-Occluded Human Shape and Pose Estimation With Probabilistic Latent Consistency.

Occlusions between human and objects, especially for the activities of human-object interactions, are very common in practical applications. However, most of the existing approaches for 3D human shape and pose estimation require that human bodies are well captured without occlusions or with minor self-occlusions. In this paper, we focus on the problem of directly estimating the object-occluded human shape and pose from single color images. Our key idea is to utilize a partial UV map to represent an object-occluded human body, and the full 3D human shape estimation is ultimately converted as an image inpainting problem. We propose a novel two-branch network architecture to train an end-to-end regressor via a latent distribution consistency, which also includes a novel visible feature sub-net to extract the human information from object-occluded color images. To supervise the network training, we further build a novel dataset named as 3DOH50K. Several experiments are conducted to reveal the effectiveness of the proposed method. Experimental results demonstrate that the proposed method achieves state-of-the-art compared with previous methods. The dataset and codes are publicly available at https://www.yangangwang.com/papers/ZHANG-OOH-2020-03.html.

Oriented Surface‐Anchored Metal–Organic Frameworks (SurMOFs) as Electrochromic Thin Films

AbstractNovel electrochromic hybrid thin films are synthesized following a liquid‐phase epitaxy in a layer‐by‐layer fashion, yielding highly oriented surface‐anchored metal–organic frameworks (SurMOFs). The initial orange color of this {Zn2(PDICl4)2} crystalline thin films is reversibly switched by electrochemical reduction. In a lithium‐based electrolyte, a dark blue color is obtained in few seconds with a color efficiency of 104.8 cm2 C−1 (λ = 645 nm). Interestingly, the color of the reduced state is easily modulated by changing the electrolyte composition. Clearly, two different mechanisms are implicated and the reduced species responsible of the color are identified. Taking advantage of this unusual property, electrochromic devices with a novel configuration are designed leading to an original prototype capable of reversibly switching from a single initial orange color to two different colors simultaneously, namely dark blue and cyan.

배색의 증가에 따른 단맛 연상 예측

Color is an important visual information that evokes the association of taste, and most product colors consists of color combinations to enhance power of information delivery and have a great influence on the association of the users. Previous studies on color combinations and taste have shown that the additive relationship between single color and color combinations is established in the association of sweetness for two color combinations. In this study, we tried to find out whether additivity is established in sweetness association from single color to three-color coloration, and whether it is possible to make a quantitative prediction of sweetness based on the existing color emotion prediction formula. First, 10 colors (R, YR, Y, G, B, PB, P, Pk, Wh, Bk) were composed of single color, two color and three color combinations, respectively, in the flat sample. Then, subjects were asked to evaluate the sweetness association of each stimulus. According to the average of the response values, sweetness association was classified into sweetness association, neutral association, and non-association color combinations. As a result, in both single color and multicolor combinations, the colors that predominantly act on sweetness association and non-association matched, indicating that the association of the sweetness of multicolor combinations has a great influence on the association of fewer colors or single color. Therefore, the sweet association could be predicted by the color emotion prediction formula, and it was confirmed that single and multi colors established an additional relationship between two and three color combinations. Through this study, it is intended to provide more efficiency in food package design by predicting sweetness association with a color emotion prediction model.

Color constancy from a pure color view.

Great efforts have been made on illuminant estimation in both academia and industry, leading to the development of various statistical- and learning-based methods. Little attention, however, has been given to images that are dominated by a single color (i.e., pure color images), though they are not trivial to smartphone cameras. In this study, a pure color image dataset, "PolyU Pure Color," was developed. A lightweight feature-based multilayer perceptron (MLP) neural network model-"Pure Color Constancy (PCC)"-was also developed for estimating the illuminant of pure color images using four color features (i.e., the chromaticities of the maximal, mean, brightest, and darkest pixels) of an image. The proposed PCC method was found to have significantly better performance for pure color images in the PolyU Pure Color dataset and comparable performance for normal images in two existing image datasets, in comparison to the various state-of-the-art learning-based methods, with a good cross-sensor performance. Such good performance was achieved with a much smaller number of parameters (i.e., around 400) and a very short processing time (i.e., around 0.25 ms) for an image using an unoptimized Python package. This makes the proposed method possible for practical deployments.

What do clean and dirty hands of primary school pupils look like?

ABSTRACT The current pandemic has highlighted the importance of hand hygiene as a preventive measure to avoid the transmission of diseases. It is a habit that should be reinforced during childhood, so that it lasts into adulthood. The main objective was to analyse and describe, through drawing, the mental schemas that 6-12 year-old pupils have about clean and dirty hands and their relationship with microorganisms. A descriptive and qualitative study was carried out with 260 participants in which their drawings were analysed according to thecategories: colouring, shape and/or presence of wounds, viruses or living beings, localisation and presence of accessories. The results show that dirty hands are represented coloured in sections combining various shapes and, in some cases, living beings or viruses can be found. Among 11–12 year-old students there are very few cases where dirt is represented as dots or reference is made to microscopic size, with neutral and warm colours being the most used. Clean hands are represented by the silhouette of the hand in a single colour. Sometimes accessories are added to reinforce the idea of cleanliness and it is not conceivable that a clean hand could harbour microorganisms or dirt.

Scalable manufacturing of quantum light emitters in silicon under rapid thermal annealing.

Quantum light sources play a fundamental role in quantum technologies ranging from quantum networking to quantum sensing and computation. The development of these technologies requires scalable platforms, and the recent discovery of quantum light sources in silicon represents an exciting and promising prospect for scalability. The usual process for creating color centers in silicon involves carbon implantation into silicon, followed by rapid thermal annealing. However, the dependence of critical optical properties, such as the inhomogeneous broadening, the density, and the signal-to-background ratio, on centers implantation steps is poorly understood. We investigate the role of rapid thermal annealing on the dynamic of the formation of single color centers in silicon. We find that the density and the inhomogeneous broadening greatly depend on the annealing time. We attribute the observations to nanoscale thermal processes occurring around single centers and leading to local strain fluctuations. Our experimental observation is supported by theoretical modeling based on first principles calculations. The results indicate that annealing is currently the main step limiting the scalable manufacturing of color centers in silicon.

Fine Mapping and Identification of SmAPRR2 Regulating Rind Color in Eggplant (Solanum melongena L.)

Rind color is an economically important agronomic trait in eggplant that impacts consumer preferences. In this study, bulked segregant analysis and competitive allele-specific PCR were employed to identify the candidate gene for eggplant rind color through constructing a 2794 F2 population generated from a cross between "BL01" (green pericarp) and "B1" (white pericarp). Genetic analysis of rind color revealed that a single dominant gene controls green color of eggplant peel. Pigment content measurement and cytological observations demonstrated that chlorophyll content and chloroplast number in BL01 were higher than in B1. A candidate gene (EGP19168.1) was fine-mapped to a 20.36 Kb interval on chromosome 8, which was predicted to encode the two-component response regulator-like protein Arabidopsis pseudo-response regulator2 (APRR2). Subsequently, allelic sequence analysis revealed that a SNP deletion (ACT→AT) in white-skinned eggplant led to a premature termination codon. Genotypic validation of 113 breeding lines using the Indel marker closely linked to SmAPRR2 could predict the skin color (green/white) trait with an accuracy of 92.9%. This study will be valuable for molecular marker-assisted selection in eggplant breeding and provides theoretical foundation for analyzing the formation mechanism of eggplant peel color.

Fabrication of single color centers in sub-50 nm nanodiamonds using ion implantation

Abstract Diamond color centers have been widely studied in the field of quantum optics. The negatively charged silicon vacancy (SiV−) center exhibits a narrow emission linewidth at the wavelength of 738 nm, a high Debye–Waller factor, and unique spin properties, making it a promising emitter for quantum information technologies, biological imaging, and sensing. In particular, nanodiamond (ND)-based SiV− centers can be heterogeneously integrated with plasmonic and photonic nanostructures and serve as in vivo biomarkers and intracellular thermometers. Out of all methods to produce NDs with SiV− centers, ion implantation offers the unique potential to create controllable numbers of color centers in preselected individual NDs. However, the formation of single color centers in NDs with this technique has not been realized. We report the creation of single SiV− centers featuring stable high-purity single-photon emission through Si implantation into NDs with an average size of ∼20 nm. We observe room temperature emission, with zero-phonon line wavelengths in the range of 730–800 nm and linewidths below 10 nm. Our results offer new opportunities for the controlled production of group-IV diamond color centers with applications in quantum photonics, sensing, and biomedicine.

Apollo-IRE1: A genetically encoded sensor for live cell and multiplexed imaging of ER stress.

Several metabolic diseases, such as Alzheimer's, diabetes, and arthritis, are caused in part by the cellular accumulation of improperly folded proteins in the Endoplasmic Reticulum (ER). In response to protein misfolding, a transmembrane stress-sensor called IRE1α activates the Unfolded Protein Response (UPR) to maintain protein folding homeostasis. To measure ER stress response in living beta-cells with spatial and temporal resolution, we developed a genetically encoded sensor based on fluorescent protein-tagged IRE1α. This sensor homo-oligomerizes to dimeric and tetrameric conformations under early and chronic ER stress, respectively, resulting in homoFRET and an associated decrease in steady-state fluorescence anisotropy (i.e., decreased IRE1 anisotropy/polarisation of fluorescence due oligomerization (Apollo-IRE1)). Apollo-IRE1 responds to chemical and physiological (high glucose) stress in a rat beta-cell line (INS-1E) and mouse islets. Preliminary data suggest that UPR-associated XBP1 mRNA splicing is highly correlated with sensor response. Furthermore, individual cells with the highest sensor response (correlating to late-stage UPR) show elevated levels of pro-apoptotic protein TXNIP. The single colour design of Apollo sensors also makes them ideal for multiplexing, offering an exciting opportunity to explore multiparametric analysis of cellular metabolic characteristics. To demonstrate the multiplexing capability of Apollo-IRE1, we will explore simultaneously imaging of a sensor for NADPH (Apollo-NADP+) and by immunofluorescence with other ER stress markers. These data validate and demonstrate the utility of Apollo-IRE1 in sensing early and chronic ER stress through live cell imaging and multiplexed analysis.

Tire appearance defect detection method via combining HOG and LBP features

Tire appearance defect detection based on machine vision is an effective technology to improve the tire production quality. The detection process can be completed by the way of non-destructive testing. Therefore, more and more researchers are paying attention to this technology. However, tires are characterized by single block colors and various defects. It is a great challenge to accurately detect tire appearance defects. To complete the task of detecting tire defects, this paper presents a novel tire appearance defect detection method via combining histogram of oriented gradients (HOG) and local binary pattern (LBP) features. First, we construct a tire image dataset to provide defective and normal tire images. Then, histogram of oriented gradients and local binary pattern features of tire images are, respectively, extracted and used to train the support vector machine (SVM) classifier. Finally, the support vector machine classifier calculates the prediction scores of the test images via combining the histogram of oriented gradients and local binary pattern features. These scores can be utilized to determine whether the test image is a defective or a normal tire image, and the goal of tire appearance defect detection is achieved. Conducted on the tire image dataset, our method has verified the effectiveness of detecting tire detects, and the mean accuracy is improved more than 1.6% than the algorithm that only uses the histogram of oriented gradients or local binary pattern feature. The experimental results demonstrate that the combination of HOG and LBP features can increase tire appearance defect detection accuracy.

Evaluation of automatic discrimination between benign and malignant prostate tissue in the era of high precision digital pathology

BackgroundProstate cancer is a major health concern in aging men. Paralleling an aging society, prostate cancer prevalence increases emphasizing the need for efficient diagnostic algorithms.MethodsRetrospectively, 106 prostate tissue samples from 48 patients (mean age, 66pm 6.6 years) were included in the study. Patients suffered from prostate cancer (n = 38) or benign prostatic hyperplasia (n = 10) and were treated with radical prostatectomy or Holmium laser enucleation of the prostate, respectively. We constructed tissue microarrays (TMAs) comprising representative malignant (n = 38) and benign (n = 68) tissue cores. TMAs were processed to histological slides, stained, digitized and assessed for the applicability of machine learning strategies and open–source tools in diagnosis of prostate cancer. We applied the software QuPath to extract features for shape, stain intensity, and texture of TMA cores for three stainings, H&E, ERG, and PIN-4. Three machine learning algorithms, neural network (NN), support vector machines (SVM), and random forest (RF), were trained and cross-validated with 100 Monte Carlo random splits into 70% training set and 30% test set. We determined AUC values for single color channels, with and without optimization of hyperparameters by exhaustive grid search. We applied recursive feature elimination to feature sets of multiple color transforms.ResultsMean AUC was above 0.80. PIN-4 stainings yielded higher AUC than H&E and ERG. For PIN-4 with the color transform saturation, NN, RF, and SVM revealed AUC of 0.93pm 0.04, 0.91pm 0.06, and 0.92pm 0.05, respectively. Optimization of hyperparameters improved the AUC only slightly by 0.01. For H&E, feature selection resulted in no increase of AUC but to an increase of 0.02–0.06 for ERG and PIN-4.ConclusionsAutomated pipelines may be able to discriminate with high accuracy between malignant and benign tissue. We found PIN-4 staining best suited for classification. Further bioinformatic analysis of larger data sets would be crucial to evaluate the reliability of automated classification methods for clinical practice and to evaluate potential discrimination of aggressiveness of cancer to pave the way to automatic precision medicine.

Controlled mechano-luminescence properties of SrGa2O4:Tb3+ co-doping with Dy3+ and Eu3+ ions.

Trap-controlled mechano-luminescence (ML) featuring photon emission under mechanical stimuli provides promising applications such as dynamic imaging of force, integrated optical sensing, information storage, and anti-counterfeiting encryption. However, the corresponding emission with a single color still limits the application of ML materials. Here, a trap-controlled ML phosphor of SrGa2O4:Tb3+ (SGO:Tb3+) with a green-emission is investigated with an adjustable ML color. The relationship between ML and thermoluminescence (TL) is verified by co-doping with Dy3+ and Eu3+ ions for the manipulation of the constructed traps. Accordingly, the as-explored ML phosphor with multicolor output is employed to create encrypted anticounterfeiting patterns, which produces bright and spatially resolvable optical codes under the single-point dynamic pressure of a ballpoint pen. Hence, it provides a new approach to achieve ML with multicolor and gives us an insight into understanding the mechanism of the ML procedure.

Additivity Constrained Linearisation of Camera Calibration Data.

When characterising a digital camera spectrally or colourimetrically, the camera response to a generally diffusely reflecting colour chart is often employed. The recorded responses to the light incident from each colour patch are typically not linearly related to the power of the irradiance on the chart, and the irradiance varies with position on the chart. This necessitates a linearisation of the responses. We present a new single image colour chart-based estimation method of responses, that are linearly related to camera response values known as ground truth. The method estimates the spatial geometry of the irradiance incident on the chart attenuated by lens vignetting and compensates individually for volumetric and per colour channel non-linearities, including compensation for physical scene and camera properties in a pipeline of successive signal transformations between the estimated linear and the given recorded responses. The estimation is controlled by introducing a novel Additivity Principle of linear responses, which is derived from the spectral reflectances of the coloured surfaces on the colour chart, observing that linear relations of the spectral reflectances are equal to the relations of the corresponding linear responses. Crucially, the additivity principle is not subject to metamerism. The method is fundamentally solely reliant on a one-shot set of one triplet of response values sampled from each patch of a colour chart with known spectral reflectances, where rendition level, gray scale, illuminant, camera sensor curves, irradiance geometry, vignetting, moderate specular reflection, colour space, colour correction, gamut correction and noise level are unknown.