Non-volatile dynamically switchable color display via chalcogenide stepwise cavity resonators

High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching.Antimony trisulfide(Sb_(2)S_(3))is a newly rising chalcogenide material that possesses prompt and significant transition of its optical characteristics in the visible region between amorphous and crystalline phases,which holds the key to color-varying devices.Herein,we proposed a dynamically switchable color printing method using Sb_(2)S_(3)-based stepwise pixelated Fabry-Pérot(FP)cavities with various cavity lengths.The device was fabricated by employing a direct laser patterning that is a less timeconsuming,more approachable,and low-cost technique.As switching the state of Sb_(2)S_(3) between amorphous and crystalline,the multi-color of stepwise pixelated FP cavities can be actively changed.The color variation is due to the profound change in the refractive index of Sb_(2)S_(3) over the visible spectrum during its phase transition.Moreover,we directly fabricated sub-50 nm nano-grating on ultrathin Sb_(2)S_(3) laminate via microsphere 800-nm femtosecond laser irradiation in far field.The minimum feature size can be further decreased down to~45 nm(λ/17)by varying the thickness of Sb_(2)S_(3) film.Ultrafast switchable Sb_(2)S_(3) photonic devices can take one step toward the next generation of inkless erasable papers or displays and enable information encryption,camouflaging surfaces,anticounterfeiting,etc.Importantly,our work explores the prospects of rapid and rewritable fabrication of periodic structures with nano-scale resolution and can serve as a guideline for further development of chalcogenide-based photonics components.

Coupling of reduced inorganic fertilizer with plant-based organic fertilizer as a promising fertilizer management strategy for colored rice in tropical regions

Colored rice is a type of high-quality,high-added-value rice that has attracted increasing attention in recent years.The use of large amounts of inorganic nitrogen fertilizer in rice fields results in low fertilizer use efficiency and high environmental pollution.Organic fertilizer is a promising way to improve soil quality and sustain high yields.However,most studies focus on the effect of animal-based organic fertilizers.The effects of different ratios of plantbased organic fertilizer and inorganic fertilizer on the grain yield and quality of colored rice have rarely been reported.Therefore,a two-year field experiment was conducted in 2020 and 2021 to study the effects of replacing inorganic N fertilizers with plant-based organic fertilizers on the yield,nitrogen use efficiency(NUE),and anthocyanin content of two colored rice varieties in a tropical region in China.The experimental treatments included no nitrogen fertilization(T1),100% inorganic nitrogen fertilizer(T2),30%inorganic nitrogen fertilizer substitution with plant-based organic fertilizer(T3),60%inorganic nitrogen fertilizer substitution with plant-based organic fertilizer(T4),and 100% plantbased organic fertilizer(T5).The total nitrogen provided to all the treatments except T1 was the same at 120 kg ha-1.Our results showed that the T3 treatment enhanced the grain yield and anthocyanin content of colored rice by increasing nitrogen use efficiency compared with T2.On average,grain yields were increased by 9 and 8%,while the anthocyanin content increased by 16 and 10% in the two colored rice varieties under T3 across the two years,respectively,as compared with T2.Further study of the residual effect of partial substitution of inorganic fertilizers showed that the substitution of inorganic fertilizer with plant-based organic fertilizer improved the soil physiochemical properties,and thus increased the rice grain yield,in the subsequent seasons.The highest grain yield of the subsequent rice crop was observed under the T5 treatment.Our results suggested that the application of plantbased organic fertilizers can sustain the production of colored rice with high anthocyanin content in tropical regions,which is beneficial in reconciling the relationship between rice production and environmental protection.

Intelligent diagnosis of retinal vein occlusion based on color fundus photographs

AIM:To develop an artificial intelligence(AI)diagnosis model based on deep learning(DL)algorithm to diagnose different types of retinal vein occlusion(RVO)by recognizing color fundus photographs(CFPs).METHODS:Totally 914 CFPs of healthy people and patients with RVO were collected as experimental data sets,and used to train,verify and test the diagnostic model of RVO.All the images were divided into four categories[normal,central retinal vein occlusion(CRVO),branch retinal vein occlusion(BRVO),and macular retinal vein occlusion(MRVO)]by three fundus disease experts.Swin Transformer was used to build the RVO diagnosis model,and different types of RVO diagnosis experiments were conducted.The model’s performance was compared to that of the experts.RESULTS:The accuracy of the model in the diagnosis of normal,CRVO,BRVO,and MRVO reached 1.000,0.978,0.957,and 0.978;the specificity reached 1.000,0.986,0.982,and 0.976;the sensitivity reached 1.000,0.955,0.917,and 1.000;the F1-Sore reached 1.000,0.9550.943,and 0.887 respectively.In addition,the area under curve of normal,CRVO,BRVO,and MRVO diagnosed by the diagnostic model were 1.000,0.900,0.959 and 0.970,respectively.The diagnostic results were highly consistent with those of fundus disease experts,and the diagnostic performance was superior.CONCLUSION:The diagnostic model developed in this study can well diagnose different types of RVO,effectively relieve the work pressure of clinicians,and provide help for the follow-up clinical diagnosis and treatment of RVO patients.

Physiological and psychological responses to tended plant communities with varying color characteristics

Exposure to plants has been reported to promote health and reduce stress,and plant color has direct impacts on physical and mental health.We used images of common types of tended plant communities in Shenyang,China,with combinations of yellow,green,and red foliage,as experimental stimuli.A total of 27 images were used as visual stimuli.We used electroencephalography to measureαwave activity(8-13 Hz)in 40 subjects while they viewed visual stimuli.These data were combined with subjective questionnaire data to analyze the relaxing effect of images of tended plant communities with different color types and proportions on people.The results revealed that,although there were slight differences between the electroencephalography and psychological findings,women were significantly more relaxed than men after viewing the images.Physiological and psychological responses varied with the types and proportions of colors in the tended plant communities:those of foliage with combinations of two or three colors induced stronger responses than images with a single color.Specifically,(1)for one-color plant communities,green or yellow plant communities induced a stronger relaxation effect than red plant communities;(2)for two-color plant communities,the optimal color proportion was 55%+45%,and the green+yellow and green+red color combinations induced a stronger relaxation effect;(3)for three-color plant communities,the relaxation effect was strongest when the color proportion was 55%green+25%yellow+20%red.These data would provide a plant color matching in future plant landscape design,which may be helpful for creating healthy and relaxing environments.

Unsupervised Color Segmentation with Reconstructed Spatial Weighted Gaussian Mixture Model and Random Color Histogram

Image classification and unsupervised image segmentation can be achieved using the Gaussian mixture model.Although the Gaussian mixture model enhances the flexibility of image segmentation,it does not reflect spatial information and is sensitive to the segmentation parameter.In this study,we first present an efficient algorithm that incorporates spatial information into the Gaussian mixture model(GMM)without parameter estimation.The proposed model highlights the residual region with considerable information and constructs color saliency.Second,we incorporate the content-based color saliency as spatial information in the Gaussian mixture model.The segmentation is performed by clustering each pixel into an appropriate component according to the expectation maximization and maximum criteria.Finally,the random color histogram assigns a unique color to each cluster and creates an attractive color by default for segmentation.A random color histogram serves as an effective tool for data visualization and is instrumental in the creation of generative art,facilitating both analytical and aesthetic objectives.For experiments,we have used the Berkeley segmentation dataset BSDS-500 and Microsoft Research in Cambridge dataset.In the study,the proposed model showcases notable advancements in unsupervised image segmentation,with probabilistic rand index(PRI)values reaching 0.80,BDE scores as low as 12.25 and 12.02,compactness variations at 0.59 and 0.7,and variation of information(VI)reduced to 2.0 and 1.49 for the BSDS-500 and MSRC datasets,respectively,outperforming current leading-edge methods and yielding more precise segmentations.

Identification and effective regulation of scarb1 gene involved in pigmentation change in autotetraploid Carassius auratus

The autotetraploid Carassius auratus(4nRR,4n=200,RRRR)is derived from whole-genome duplication of Carassius auratus red var.(RCC,2n=100,RR).In the current study,we demonstrated that chromatophores and pigment changes directly caused the coloration and variation of 4nRR skin(red in RCC,brownish-yellow in4nRR).To further explore the molecular mechanisms underlying coloration formation and variation in 4nRR,we performed transcriptome profiling and molecular functional verification in RCC and 4nRR.Results revealed that scarb1,associated with carotenoid metabolism,underwent significant down-regulation in 4nRR.Efficient editing of this candidate pigment gene provided clear evidence of its significant role in RCC coloration.Subsequently,we identified four divergent scarb1 homeologs in 4nRR:two original scarb1 homeologs from RCC and two duplicated ones.Notably,three of these homeologs possessed two highly conserved alleles,exhibiting biased and allelespecific expression in the skin.Remarkably,after precise editing of both the original and duplicated scarb1homeologs and/or alleles,4nRR individuals,whether singly or multiply mutated,displayed a transition from brownishyellow skin to a cyan-gray phenotype.Concurrently,the proportional areas of the cyan-gray regions displayed a gene-dose correlation.These findings illustrate the subfunctionalization of duplicated scarb1,with all scarb1genes synergistically and equally contributing to the pigmentation of 4nRR.This is the first report concerning the functional differentiation of duplicated homeologs in an autopolyploidfish,substantiallyenrichingour understanding of coloration formation and change within this group of organisms.

Self‑Healing Dynamic Hydrogel Microparticles with Structural Color for Wound Management

Chronic diabetic wounds confront a significant medical challenge because of increasing prevalence and difficult-healing circumstances.It is vital to develop multifunctional hydrogel dressings,with well-designed morphology and structure to enhance flexibility and effectiveness in wound management.To achieve these,we propose a self-healing hydrogel dressing based on structural color microspheres for wound management.The microsphere comprised a photothermal-responsive inverse opal framework,which was constructed by hyaluronic acid methacryloyl,silk fibroin methacryloyl and black phosphorus quantum dots(BPQDs),and was further re-filled with a dynamic hydrogel.The dynamic hydrogel filler was formed by Knoevenagel condensation reaction between cyanoacetate and benzaldehyde-functionalized dextran(DEX-CA and DEX-BA).Notably,the composite microspheres can be applied arbitrarily,and they can adhere together upon near-infrared irradiation by leveraging the BPQDs-mediated photothermal effect and the thermoreversible stiffness change of dynamic hydrogel.Additionally,eumenitin and vascular endothelial growth factor were co-loaded in the microspheres and their release behavior can be regulated by the same mechanism.Moreover,effective monitoring of the drug release process can be achieved through visual color variations.The microsphere system has demonstrated desired capabilities of controllable drug release and efficient wound management.These characteristics suggest broad prospects for the proposed composite microspheres in clinical applications.

A novel histone methyltransferase gene Cg SDG40 positively regulates carotenoid biosynthesis during citrus fruit ripening

The flesh color of pummelo(Citrus maxima)fruits is highly diverse and largely depends on the level of carotenoids,which are beneficial to human health.It is vital to investigate the regulatory network of carotenoid biosynthesis to improve the carotenoid content in pummelo.However,the molecular mechanism underlying carotenoid accumulation in pummelo is not fully understood.In this study,we identified a novel histone methyltransferase gene,CgSDG40,involved in carotenoid regulation by analyzing the flesh transcriptome of typical white-fleshed pummelo,red-fleshed pummelo and extreme-colored F1 hybrids from a segregated pummelo population.Expression of CgSDG40 corresponded to flesh color change and was highly coexpressed with CgPSY1.Interestingly,CgSDG40 and CgPSY1 are located physically adjacent to each other on the chromosome in opposite directions,sharing a partially overlapping promoter region.Subcellular localization analysis indicated that CgSDG40 localizes to the nucleus.Overexpression of CgSDG40 significantly increased the total carotenoid content in citrus calli relative to that in wild type.In addition,expression of CgPSY1 was significantly activated in overexpression lines relative to wild type.Taken together,our findings reveal a novel histone methyltransferase regulator,CgSDG40,involved in the regulation of carotenoid biosynthesis in citrus and provide new strategies for molecular design breeding and genetic improvement of fruit color and nutritional quality.

Fine-mapping and primary analysis of candidate genes associated with seed coat color in mung bean(Vigna radiata L.)

Seed coat color affects the appearance and commodity quality of mung beans(Vigna radiata L.).The substances that affect mung bean seed coat color are mainly flavonoids,which have important medicinal value.Mapping the seed coat color gene in mung beans would facilitate the development of new varieties and improve their value.In this study,an F2 mapping population consisting of 546 plants was constructed using Jilv9(black seed coat)and BIS9805(green seed coat).Using bulk segregated analysis(BSA)sequencing and kompetitive allele-specific PCR(KASP)markers,the candidate region related to seed coat color was finally narrowed to 0.66 Mb on chromosome(Chr.)4 and included eight candidate genes.Combined transcriptome and metabolome analyses showed that three of the eight candidate genes(LOC106758748,LOC106758747,and LOC106759075)were differentially expressed,which may have caused the differences in flavonoid metabolite content between Jilv9 and BIS9805.These findings can provide a research basis for cloning the genes related to seed coat color and accelerate molecular markerassisted selection breeding in mung beans.

A chromosome-level genome assembly for Chinese plum‘Wushancuili'reveals the molecular basis of its fruit color and susceptibility to rain-cracking

Chinese plum(Prunus salicina Lindl.)originates from China and makes a large contribution to the global production of plums.The P.salicina‘Wushancuili'has a green coloration and high fruit quality and is economically important in eliminating poverty and protecting ecology in the Yangtze River Three Gorges Reservoir.However,rain-induced cracking(rain-cracking,literally skin cracking caused by rain)is a limitation to‘Wushancuili'fruit production and causes severe losses.This study reported a high-quality‘Wushancuili'genome assembly consisting of a 302.17-Mb sequence with eight pseudo-chromosomes and a contig N50 of 23.59 Mb through the combination of Illumina sequencing,Pacific Biosciences HiFiⅢsequencing,and high-throughput chromosome conformation capture technology.A total of 25109 protein-coding genes are predicted and 54.17%of the genome is composed of repetitive sequences.‘Wushancuili'underwent a remarkable orthoselection during evolution.Gene identification revealed that loss-of-function in four core MYB10 genes results in the anthocyanin deficiency and absence of red color,revealing the green coloration due to the residual high chlorophyll in fruit skin.Besides,the occurrence of cracking is assumed to be closely associated with cell wall modification and frequently rain-induced pathogen enrichment through transcriptomic analysis.The loss of MYB10 genes might render fruit more susceptible to pathogen-mediated cracking by weakening the epidermal strength and reactive oxygen species(ROS)scavenging.Our findings provided fundamental knowledge regarding fruit coloration and rain-cracking and will facilitate genetic improvement and cultivation management in Chinese plums.

Reconfigurable and polarization-dependent optical filtering for transflective full-color generation utilizing low-loss phase-change materials

All-dielectric metasurface, which features low optical absorptance and high resolution, is becoming a promising candidate for full-color generation. However, the optical response of current metamaterials is fixed and lacks active tuning. In this work, we demonstrate a reconfigurable and polarization-dependent active color generation technique by incorporating low-loss phase change materials(PCMs) and CaF_2 all-dielectric substrate. Based on the strong Mie resonance effect and low optical absorption structure, a transflective, full-color with high color purity and gamut value is achieved. The spectrum can be dynamically manipulated by changing either the polarization of incident light or the PCM state. High transmittance and reflectance can be simultaneously achieved by using low-loss PCMs and substrate. The novel active metasurfaces can bring new inspiration in the areas of optical encryption, anti-counterfeiting, and display technologies.

Unraveling the regulatory network of flower coloration in soybean:Insights into roles of GmMYBA3 and GmMYBR1

Anthocyanins play crucial roles in pollen protection and pollinator attraction in flowering plants.However,the mechanisms underlying flower color determination and whether floral anthocyanin regulators participate in other processes remain largely unresolved in soybeans(Glycine max).In this study,we investigated the genetic components and mechanisms governing anthocyanin biosynthesis in soybean flowers.Molecular and genetic studies have characterized two antagonistic regulators,the positive activator GmMYBA3 and the negative repressor GmMYBR1,that modulate the gene expression of anthocyanin biosynthesis in soybean flowers.Further findings revealed a regulatory interplay between GmMYBA3 and GmMYBR1 bridged by GmTT8a,highlighting the complexity of anthocyanin regulation in different soybean organs.Exploration of additional soybean cultivars demonstrated the universality of GmMYBA3 and GmMYBR1 in regulating floral anthocyanin biosynthesis-related genes,with GmF3’5’H identified as a crucial determinant of white flower color.This study provides a molecular mechanism underlying soybean flower color determination,paving the way for the molecular modification of soybean flowers to probably enhance their resistance to abiotic stresses and attractiveness to pollinators.

MXenes for Bioinspired Soft Actuators:Advancements in Angle-Independent Structural Colors and Beyond

Soft actuators have garnered substantial attention in current years in view of their potential appliances in diverse domains like robotics,biomedical devices,and biomimetic systems.These actuators mimic the natural movements of living organisms,aiming to attain enhanced flexibility,adaptability,and versatility.On the other hand,angle-independent structural color has been achieved through innovative design strategies and engineering approaches.By carefully controlling the size,shape,and arrangement of nanostructures,researchers have been able to create materials exhibiting consistent colors regardless of the viewing angle.One promising class of materials that holds great potential for bioinspired soft actuators is MXenes in view of their exceptional mechanical,electrical,and optical properties.The integration of MXenes for bioinspired soft actuators with angle-independent structural color offers exciting possibilities.Overcoming material compatibility issues,improving color reproducibility,scalability,durability,power supply efficiency,and cost-effectiveness will play vital roles in advancing these technologies.This perspective appraises the development of bioinspired MXene-centered soft actuators with angleindependent structural color in soft robotics.

Novel self-embedding holographic watermarking image encryption protection scheme

For digital image transmission security and information copyright,a new holographic image self-embedding watermarking encryption scheme is proposed.Firstly,the plaintext is converted to the RGB three-color channel,the corresponding phase hologram is obtained by holographic technology and the watermark is self-embedded in the frequency domain.Secondly,by applying the Hilbert transform principle and genetic center law,a complete set of image encryption algorithms is constructed to realize the encryption of image information.Finally,simulation results and security analysis indicate that the scheme can effectively encrypt and decrypt image information and realize the copyright protection of information.The introduced scheme can provide some support for relevant theoretical research,and has practical significance.

Ionically Imprinting-Based Copper(Ⅱ)Label-Free Detection for Preventing Hearing Loss

Copper is a microelement with important physiological functions in the body.However,the excess copper ion(Cu^(2+))may cause severe health problems,such as hair cell apoptosis and the resultant hearing loss.Therefore,the assay of Cu^(2+)is important.We integrate ionic imprinting technology(IIT)and structurally colored hydrogel beads to prepare chitosan-based ionically imprinted hydrogel beads(IIHBs)as a low-cost and high-specificity platform for Cu^(2+)detection.The IIHBs have a macroporous microstructure,uniform size,vivid structural color,and magnetic responsiveness.When incubated in solution,IIHBs recognize Cu^(2+)and exhibit a reflective peak change,thereby achieving label-free detection.In addition,benefiting from the IIT,the IIHBs display good specificity and selectivity and have an imprinting factor of 19.14 at 100μmol·L^(-1).These features indicated that the developed IIHBs are promising candidates for Cu^(2+)detection,particularly for the prevention of hearing loss.

Identification of Shell Color-Associated Genes Using Mantle Branch-Specific RNA Sequencing of Yellow-Colored Line of Pearl Oyster Pinctada fucata martensii

The yellow-colored line of pearl oyster Pinctada fucata martensii displays a yellow prismatic layer and a white nacreous layer that can be used as an ideal model for research on shell color formation.Micro-Raman spectroscopy and transcriptome analyses were performed to explore the potential molecular mechanism underlying the phenotype differentiation.The micro-Raman spectroscopy results indicate that the prismatic layer exhibits distinct characteristic peaks of carotenoids,while these peaks are not prominent in the nacreous layer.In the transcriptome comparison of the central zone of mantle and mantle edge tissue,which function in nacreous and prismatic layer formation,respectively,935 significantly differentially expressed genes(DEGs)were identified,with 385 genes upregulated and 227 genes downregulated(|log_(2)(Fold change)|>1 and false discovery rate<0.05)in the mantle edge tissue.Among these genes,some were associated with melanoma/melanogenesis,such as tyrosinase,zinc metalloprotease,glutathione S-transferase,and ATP-binding cassette sub-family;some were associated with the carotenoid-related pathway,including scavenger receptors,cytochrome P450 and lipoprotein receptor.Genes associated with porphyrin metabolism,including porphobilinogen deaminase,and copper/zinc superoxide dismutase,and genes associated with shell matrix protein,including amorphous calcium carbonate binding protein,shematrin,PIF,and collagen,also exhibited significantly different expressions.It is speculated that the different colours between prismatic layer and nacreous layer in the yellow-colored line of P.f.martensii might be resulted from melanin,carotenoids and porphyrin metabolism,while genes related to shell structure and biomineralization might also affect coloration.Our results provide new insights to understand the mechanism of shell color formation in mollusca.

Quantitative trait loci identification reveals zinc finger protein CONSTANS-LIKE 4 as the key candidate gene of stigma color in watermelon(Citrullus lanatus)

Stigma color is a critical agronomic trait in watermelon that plays an important role in pollination.However,there are few reports on the regulation of stigma color in watermelon.In this study,a genetic analysis of the F2 population derived from ZXG1553(P1,with orange stigma)and W1-17(P2,with yellow stigma)indicated that stigma color is a quantitative trait and the orange stigma is recessive compared with the yellow stigma.Bulk segregant analysis sequencing(BSA-seq)revealed a 3.75 Mb segment on chromosome 6 that is related to stigma color.Also,a major stable effective QTL Clqsc6.1(QTL stigma color)was detected in two years between cleaved amplified polymorphic sequencing(CAPS)markers Chr06_8338913 and Chr06_9344593 spanning a~1.01 Mb interval that harbors 51 annotated genes.Cla97C06G117020(annotated as zinc finger protein CONSTANS-LIKE 4)was identified as the best candidate gene for the stigma color trait through RNA-seq,quantitative real-time PCR(qRT-PCR),and gene structure alignment analysis among the natural watermelon panel.The expression level of Cla97C06G117020 in the orange stigma accession was lower than in the yellow stigma accessions with a significant difference.A nonsynonymous SNP site of the Cla97C06G117020 coding region that causes amino acid variation was related to the stigma color variation among nine watermelon accessions according to their re-sequencing data.Stigma color formation is often related to carotenoids,and we also found that the expression trend of ClCHYB(annotated asβ-carotene hydroxylase)in the carotenoid metabolic pathway was consistent with Cla97C06G117020,and it was expressed in low amounts in the orange stigma accession.These data indicated that Cla97C06G117020 and ClCHYB may interact to form the stigma color.This study provides a theoretical basis for gene fine mapping and mechanisms for the regulation of stigma color in watermelon.

CmMYB3-like negatively regulates anthocyanin biosynthesis and flower color formation during the post-flowering stage in Chrysanthemum morifolium

Color fading caused by a decrease in anthocyanin accumulation during the post-flowering stage significantly affects postharvest quality of chrysanthemum.However,the underlying mechanism by which anthocyanin accumulation decreases during the post-flowering stage still unclear,which greatly restricts design of molecular breeding in chrysanthemum.Here,a chrysanthemum SG7 R2R3 MYB transcription factor(TF),CmMYB3-like,was identified to have a function in regulating anthocyanin biosynthesis during the post-flowering stage.Quantitative real time PCR(qRT-PCR)assays showed that the expression of CmMYB3-like was gradually downregulated when anthocyanin content increased during the flowering stage and was significantly upregulated during the post-flowering stage.Genetic transformation of chrysanthemum and dual-luciferase assays in N.benthamiana leaves showed that CmMYB3-like suppressed anthocyanin accumulation by inhibiting the transcription of CmCHS and CmANS directly and that of CmF3H indirectly.However,overexpression or suppression of CmMYB3-like did not affect the biosynthesis of flavones or flavonols.Genetic transformation of chrysanthemum revealed that the overexpression of CmMYB3-like inhibited anthocyanin accumulation,but its suppression prevented the decrease in anthocyanin accumulation during the post-flowering stage.Our results revealed a crucial role of CmMYB3-like in regulating the color of petals during the post-flowering stage and provided a target gene for molecular design breeding to improve the postharvest quality of chrysanthemum.

Adaptive Segmentation for Unconstrained Iris Recognition

In standard iris recognition systems,a cooperative imaging framework is employed that includes a light source with a near-infrared wavelength to reveal iris texture,look-and-stare constraints,and a close distance requirement to the capture device.When these conditions are relaxed,the system’s performance significantly deteriorates due to segmentation and feature extraction problems.Herein,a novel segmentation algorithm is proposed to correctly detect the pupil and limbus boundaries of iris images captured in unconstrained environments.First,the algorithm scans the whole iris image in the Hue Saturation Value(HSV)color space for local maxima to detect the sclera region.The image quality is then assessed by computing global features in red,green and blue(RGB)space,as noisy images have heterogeneous characteristics.The iris images are accordingly classified into seven categories based on their global RGB intensities.After the classification process,the images are filtered,and adaptive thresholding is applied to enhance the global contrast and detect the outer iris ring.Finally,to characterize the pupil area,the algorithm scans the cropped outer ring region for local minima values to identify the darkest area in the iris ring.The experimental results show that our method outperforms existing segmentation techniques using the UBIRIS.v1 and v2 databases and achieved a segmentation accuracy of 99.32 on UBIRIS.v1 and an error rate of 1.59 on UBIRIS.v2.

The protective effect of cyclodextrin on the color quality and stability of Cabernet Sauvignon red wine

The impact of cyclodextrins(CDs)on wine quality and stability remains largely unknown.This study systematically assessed the protective effect of the post-fermentation addition of CDs on color stability of red wine from the viewpoints of color characteristics,copigmentation and phenolic profiles.The grey relational analysis(GRA)and principal component analysis(PCA)methods were employed to dissect the key effective determinants related to color quality.The addition of CDs induced a significant hyperchromic effect of 8.19-25.40%,a significant bathochromic effect and an enhancement of the color intensity.Furthermore,the evolution of anthocyanin forms and the content of monomeric anthocyanins revealed that β-CD is a superior favorable cofactor during wine aging,but for long-term aging,2-HP-β-CD and 2-HP-γ-CD are more beneficial in promoting the formation of polymerized anthocyanins and color stability.This work provides an important reference for the use of CDs to enhance the color quality and stability of red wines.