Search Results (136)

We study rainbow solutions to linear equations modulo a prime p, where the residue classes are partitioned into n color classes. Using the Fourier method, we derive a universal lower bound that depends only on the class densities and a single spectral parameter: the Fourier bias (the largest nontrivial Fourier coefficient) of each class. When the biases are at the square-root cancellation scale $p^{-1/2}$ (for random colorings, up to a $\sqrt{logp}$ factor), the bound recovers the optimal growth $p^{n-1}$ with an explicit leading constant and negligible error. Our results complement recent work: in low-bias regimes (pseudorandom or random) they yield sharper quantitative bounds with transparent constants, and the bound requires no extra hypotheses such as coefficient separability. Full article

In Yucatán state, Mexico, Triatoma dimidiata (Latreille, 1811) is the primary vector of Trypanosoma cruzi, the parasite that causes Chagas disease. The vector population presents diverse forms and colorations. Therefore, this study was designed to determine the morphotypes of T. dimidiata based on the taxonomy of the body and external genitalia. Between March 2023 and April 2025, 902 triatomines from 15 municipalities were examined. Three main morphotypes were characterized (I to III). Morphotype II was the most abundant (62.86%) and most distributed in the study area (12 of 15 municipalities), with a notable presence in forests and caves. Morphotypes I and III were found primarily outside houses and in chicken coops. Within the characterized specimens of T. dimidiata sensu lato, morphotype II displays more prominent morphological and structural characteristics. They are smaller compared to morphotypes I and III. In morphotype II, the spiracles are covered by a black spot that extends from the connexival plate to the urosternites. Males had short and robust parameres. The median process of the pygophore is long and slender compared to morphotypes I and III. The female tergite VIII has six sides. The taxonomy should be complemented by a study of the life cycle of each morphotype and analysis of its genome. Full article

The introduction of Maritime Autonomous Surface Ships (MASS) and the accelerating digitalization of ports require precise and dynamic analysis of traffic conditions. However, conventional marine traffic analyses have been limited to low-resolution grids and static density visualizations without fully integrating vessel direction and speed. To address this limitation, this study proposes a traffic flow visualization model that incorporates dynamic maritime traffic structure. The model integrates density, dominant direction, and average speed into a single symbol, thereby complementing the limitations of static analyses. In addition, high-resolution grids of approximately 90 m were applied to enable detailed analysis. AIS data collected between 2022–2023 from the coastal waters of Mokpo, South Korea, were preprocessed, aggregated into grid cells, and analyzed to estimate representative directions (at 10° intervals) as well as average speeds. These results were visualized through color, thickness, length, and direction of arrows. The analysis showed high-density, low-speed traffic patterns and starboard-passage behavior in port approaches and narrow channels, while irregular directions with low density were observed in non-standard routes. The proposed model provides a visual representation of dynamic traffic structures that cannot be revealed by density maps alone, thus offering practical applicability for MASS route planning, VTS operation support, and risk assessment. Full article

Awareness regarding the welfare of captive baboons is rising. Consequently, the best possible medical care is offered to injured animals. To this purpose, knowledge of the species-specific anatomy is a prerequisite. However, detailed anatomical reference works on this species, such as overviews or atlases, are sparse. The existing anatomical literature is scattered in often outdated works or elaborates on a specific detail. Veterinarians responsible for the medical care of captive baboons, therefore, habitually rely on human anatomical atlases. As overviews of the baboon joint morphology are particularly sparse, this first study in a series of three aims to provide a comprehensive overview of the arthrology of the thoracic limb of the hamadryas baboon (Papio hamadryas). The several synovial joints present in the shoulder region, elbow region, and hand are included. Not only the typical connective tissue elements that form the joints but also the associated muscle tendons are depicted. The osseous structures to which these components attach are identified as well. Standard veterinary terminology is used, complemented by human anatomical nomenclature where the former falls short. High-resolution color photographs support the text, allowing this work to serve not only as a dissection guide for veterinary and academic use but also as a baseline for clinical medical care and future research in primate morphology and biomechanics. Full article

This paper presents a digital approach for the identification of apple varieties bred in Kazakhstan using deep learning methods and transfer learning. The main objective of this study is to develop and evaluate an algorithm for automatic varietal classification of apples based on color images obtained under controlled conditions. Five representative cultivars were selected as research objects: Aport Alexander, Ainur, Sinap Almaty, Nursat, and Kazakhskij Yubilejnyj. The fruit samples were collected in the pomological garden of the Kazakh Research Institute of Fruit and Vegetable Growing, ensuring representativeness and taking into account the natural variability of the cultivars. Two convolutional neural network (CNN) architectures—GoogLeNet and SqueezeNet—were fine-tuned using transfer learning with different optimization settings. The data processing pipeline included preprocessing, training and validation set formation, and augmentation techniques to improve model generalization. Network performance was assessed using standard evaluation metrics such as accuracy, precision, and recall, complemented by confusion matrix analysis to reveal potential misclassifications. The results demonstrated high recognition efficiency: the classification accuracy exceeded 95% for most cultivars, while the Ainur variety achieved 100% recognition when tested with GoogLeNet. Interestingly, the Nursat variety achieved the best results with SqueezeNet, which highlights the importance of model selection for specific apple types. These findings confirm the applicability of CNN-based deep learning for varietal recognition of Kazakhstan apple cultivars. The novelty of this study lies in applying neural network models to local Kazakhstan apple varieties for the first time, which is of both scientific and practical importance. The practical contribution of the research is the potential integration of the developed method into industrial fruit-sorting systems, thereby increasing productivity, objectivity, and precision in post-harvest processing. The main limitation of this study is the relatively small dataset and the use of controlled laboratory image acquisition conditions. Future research will focus on expanding the dataset, testing the models under real production environments, and exploring more advanced deep learning architectures to further improve recognition performance. Full article

The famous Four-Color Conjecture (now Theorem) states that any planar graph could be colored using four colors. Hadwiger’s conjecture strengthens the Four-Color Conjecture by asserting that every graph with chromatic number t contains a complete minor of order t. In this paper we investigate Hadwiger’s conjecture for the complements of the Petersen graph and the Clebsch graph; both are strongly regular graphs with independence number two (hence dense graphs). We confirm Hajós’ conjecture, hence Hadwiger’s conjecture, for these graphs. Moreover, we show that for each of these graphs the exact hadwiger number is strictly greater its chromatic number. Full article

Rosa rugosa is an important ornamental and edible species that is valued for its floral colors and essential oils in the cosmetic and pharmaceutical industries. Carotenoids, beyond their health-promoting roles, function as accessory pigments that influence petal coloration, flower quality, and stress responses. However, their accumulation patterns and molecular biosynthesis in R. rugosa remain poorly understood. Here, UPLC-APCI-MS/MS analysis across three developmental stages (bud, semi-open, and full bloom) revealed stage-specific carotenoid accumulation, with phytoene and phytofluene markedly increasing at the semi-open stage. In total, 11 carotenoids were identified, comprising four carotenes and seven xanthophylls. Differential accumulation of metabolites (DAMs) analysis indicated shifts in compounds, including (E/Z)-phytoene, phytofluene, and β-carotene across stages. Genetic complementation assays in Escherichia coli and transient overexpression in rose petals confirmed that RrPSY1 functions as a phytoene synthase. qRT-PCR results showed its upregulation under salt treatment, suggesting a role in enhancing stress tolerance through carotenoid-mediated antioxidant protection. Furthermore, sub-cellular localization experiments confirmed plastid targeting of RrPSY1. Together, these findings clarify the role of RrPSY1 in carotenoid biosynthesis and provide a foundation for future studies on metabolic regulation and biosynthesis of carotenoids in R. rugosa. Full article

There is growing interest from researchers, the food industry, and consumers in reducing or eliminating synthetic preservatives such as nitrites in meat products. In this context, medicinal plants have emerged as promising sources of natural compounds with multifunctional roles. This review summarizes recent advances in the application of medicinal plant extracts as natural antioxidants, antimicrobials, and color-preserving agents in the meat industry. A systematic literature search was conducted using the PubMed and Lens databases, complemented by a bibliometric analysis with the VOS viewer, to identify research trends and key contributors in the field. The incorporation of plant-based ingredients in meat and meat analogues has the potential to enhance flavor, nutritional value, and shelf life while responding to the demand for clean-label and health-oriented products. Particular attention is given to the phytochemical composition, bioactivity, and practical application of selected medicinal plants that have demonstrated efficacy in preserving the oxidative stability, microbial safety, and visual quality of meat. Furthermore, the review highlights emerging plant species with potential in meat preservation and discusses the challenges related to their incorporation into meat matrices. These findings support the strategic use of plant-based bioactive compounds as sustainable and functional alternatives to synthetic additives in meat systems. Full article

Carbohydrates are a primary nutrient for plant growth, and sugar transporter proteins play a crucial role in sugar allocation. In this study, hexose transporter genes encoding in the genome of colored calla lily ‘Jingcai Yangguang’ (Zantedeschia elliottiana cv. Jingcai Yangguang) were identified, and their expression patterns following infection by Pectobacterium carotovora subsp. Carotovora were investigated. Additionally, the transport characteristics of three hexose transporters, ZeSTP7, ZeSTP15, and ZeSTP17, were determined. The results showed that the sugar transporter protein family in Z. elliottiana comprises 18 members, most of which possess 12 transmembrane domains. Phylogenetic analysis revealed that the ZeSTP gene family was divided into five subgroups. Tandem gene duplication events were identified on the 16 chromosomes of Z. elliottiana, with multiple tandemly duplicated genes detected. Comparative analysis of synteny between species identified ZeSTP8 and OsSTP22 as homologous gene pairs, while OsSTP6 (OsMST6) was identified as a homologous gene pair with both ZeSTP14 and ZeSTP17. Following infection by P. carotovora subsp. carotovora, the transcript levels of ZeSTP7, ZeSTP15, and ZeST17 were all significantly elevated. Yeast mutant hexose complementation tests indicated that ZeSTP7 could transport glucose and galactose, whereas ZeSTP15 and ZeSTP17 exhibited limited transport capacity in this respect. This study provides a systematic identification and analysis of hexose transporter genes at the genome-wide level, highlighting the role of ZeSTP genes in the response of colored calla lily to soft rot and laying a theoretical foundation for further understanding the functions of sugar transporter genes. Full article

Multiple sclerosis (MS), a chronic disease of the central nervous system, is known to cause structural and vascular changes in the retina. Although optical coherence tomography (OCT) and fundus photography can detect retinal thinning and circulatory abnormalities, these findings are not specific to MS. This study explores the potential of Infrared Scanning-Laser-Ophthalmoscopy (IR-SLO) imaging to uncover vascular morphological features that may serve as MS-specific biomarkers. Using an age-matched, subject-wise stratified k-fold cross-validation approach, a deep learning model originally designed for color fundus images was adapted to segment optic disc, optic cup, and retinal vessels in IR-SLO images, achieving Dice coefficients of 91%, 94.5%, and 97%, respectively. This process included tailored pre- and post-processing steps to optimize segmentation accuracy. Subsequently, clinically relevant features were extracted. Statistical analyses followed by SHapley Additive exPlanations (SHAP) identified vessel fractal dimension, vessel density in zones B and C (circular regions extending 0.5–1 and 0.5–2 optic disc diameters from the optic disc margin, respectively), along with vessel intensity and width, as key differentiators between MS patients and healthy controls. These findings suggest that IR-SLO can non-invasively detect retinal vascular biomarkers that may serve as additional or alternative diagnostic markers for MS diagnosis, complementing current invasive procedures. Full article

Natural colorants, with their sustainable origins, offer a promising alternative for various applications. Advanced studies have unveiled the remarkable properties, resilience, and durability of these ancient dyes, which our ancestors developed through sustainable material processing. This serves as a testament to the potential of sustainable solutions in our field. As part of our research, we prepared three medieval temperas using gum arabic, parchment glue, and casein glue. These tempera were explicitly designed to protect the purples obtained from Chrozophora tinctoria extracts. A comprehensive multi-analytical approach guides our research on natural colorants. Central to this approach is the use of molecular fluorescence by microspectrofluorimetry, a key tool in our study. By analyzing the emission and excitation spectra in the visible range, we can identify specific formulations. This method is further supported by fingerprinting techniques, including Fourier Transform Infrared Spectroscopy (FTIR) and High-Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD). These are further complemented by Fiber Optics Reflectance Spectroscopy (FORS) and colorimetry. Building on our understanding of orcein purples, we have extended our research to purples derived from Chrozophora tinctoria extracts. Our findings reveal the unique properties of Chrozophora tinctoria, which can be accurately distinguished from orcein purples, highlighting the distinctiveness of each. Full article

The eye is one of our five sense organs, where optical and neural structures are integrated. It works in synchrony with the brain, enabling the formation of meaningful images. However, lack of function, complete absence or structural abnormalities of cone cells in the cone cells in the retina causes the emergence of types of Color Vision Deficiency (CVD). This deficiency is characterized by the lack of clear vision in the use of colors in the same region of the spectrum, and greatly affects the quality of life of the patient. Therefore, it is important to develop filters that enable colors to be combined successfully. In this study, an original filter design was improved, built on a five-stage systematic structure that complements and supports itself. But optimization regarding performance value needs to be tested with objective methods independent of human decision. Therefore, in order to provide performance analyses based on objective evaluation criteria, original and enhanced images simulated by patients with seven different Color Vision Deficiency (CVD) types were classified with the MobileNet transfer learning model. The classification results show that the developed final filter greatly improves the differences in color perception levels in both eyes. Thus, color stimulation between the two eyes is more balanced, and perceptual symmetry is created. With perceptual symmetry, environmental colors are perceived more consistently and distinguishably, and the visual difficulties encountered by color blind individuals in daily life are reduced. Full article

Oak wood color plays a critical role in veneer production, where visual consistency directly affects material value. However, production choices are still often based on experience rather than systematic scientific data. Although many studies have examined individual factors affecting wood color, such as species or drying conditions, few have brought together ecological and industrial perspectives. This review addresses that gap by examining how habitat, species characteristics, and processing parameters influence color variation in Quercus robur and Quercus petraea. A structured literature review was conducted using Web of Science, Scopus, and Google Scholar, complemented by industry observations. The results show that site-specific factors—such as soil type, forest type, and regional climate—can significantly affect oak wood color, in some cases more than genetic differences. Drying methods, wood age, and log storage also contribute to variations in color and homogeneity. These findings highlight the potential for better raw material selection and processing strategies, leading to improved quality, sustainability, and economic efficiency in veneer production. Remaining knowledge gaps—particularly in predictive modeling and veneer-specific studies—point to important areas for future research. Full article

Understanding and mapping ephemeral gullies (EGs) are vital for enhancing agricultural productivity and achieving food security. This study proposes an upscaling-based strategy to refine the predictive mapping of EGs, utilizing high-resolution Pléiades Neo (0.6 m) and medium-resolution Sentinel-2 (10 m) satellite imagery, alongside ground-truth EGs mapping in Niagara Region, Canada. The research involved generating spectral feature maps using Blue, Green, Red, and Near-infrared spectral bands, complemented by indices indicative of surface wetness, vegetation, color, and soil texture. Employing the Random Forest (RF) algorithm, this study executed three distinct strategies for EGs identification. The first strategy involved direct calibration using Sentinel-2 spectral features for 10 m resolution mapping. The second strategy utilized high-resolution Pléiades Neo data for model calibration, enabling EGs mapping at resolutions of 0.6, 2, 4, 6, and 8 m. The third, or upscaling strategy, applied the high-resolution calibrated model to medium-resolution Sentinel-2 imagery, producing 10 m resolution EGs maps. The accuracy of these maps was evaluated against actual data and compared across strategies. The findings highlight the Variable Importance Measure (VIM) of different spectral features in EGs identification, with normalized near-infrared (Norm NIR) and normalized red reflectance (Norm Red) exhibiting the highest and lowest VIM, respectively. Vegetation-related indices demonstrated a higher VIM compared to surface wetness indices. The overall classification error of the upscaling strategy at spatial resolutions of 0.6, 2, 4, 6, 8, and 10 m (Upscaled), as well as that of the direct Sentinel-2 model, were 7.9%, 8.2%, 9.1%, 10.3%, 11.2%, 12.5%, and 14.5%, respectively. The errors for EGs maps at various resolutions revealed an increase in identification error with higher spatial resolution. However, the upscaling strategy significantly improved the accuracy of EGs identification in medium spatial resolution scenarios. This study not only advances the methodology for EGs mapping but also contributes to the broader field of precision agriculture and environmental management. By providing a scalable and accessible approach to EGs mapping, this research supports enhanced soil conservation practices and sustainable land management, addressing key challenges in agricultural sustainability and environmental stewardship. Full article

Electrochromic devices have garnered significant interest owing to their promising applications in smart multifunctional electrochromic energy storage systems (EESDs) and their emerging next-generation electronic technologies. Tungsten oxide (WO₃), possessing both electrochromic and pseudocapacitive characteristics, offers great potential for developing multifunctional devices with enhanced performance. However, achieving an efficient and straightforward synthesis of WO₃ electrochromic films, while simultaneously ensuring high coloration efficiency and energy storage capability, remains a significant challenge. In this work, a low-temperature hydrothermal approach is employed to directly grow hexagonal-phase WO₃ films on FTO substrates. This process utilizes sorbitol to promote nucleation and rubidium sulfate to regulate crystal growth, enabling a one-step in situ fabrication strategy. To complement the high-performance WO₃ cathode, a composite PB/SnO₂ film was designed as the anode, offering improved electrochromic properties and enhanced stability. The assembled EESD exhibited fast bleaching/coloration response and a high coloration efficiency of 101.2 cm² C⁻¹. Furthermore, it exhibited a clear and reversible change in optical properties, shifting from a transparent state to a deep blue color, with a transmittance modulation reaching 81.47%. Full article