Search Results (88)

With the global increase in maritime activities, the frequency of maritime accidents has risen, underscoring the urgent need for faster and more efficient search and rescue (SAR) solutions. This study presents an intelligent unmanned aerial vehicle (UAV)-based maritime rescue system that combines GPS-driven dynamic path planning with vision-based dual-target detection and tracking. Developed within the Gazebo simulation environment and based on modular ROS architecture, the system supports stable takeoff and smooth transitions between multi-rotor and fixed-wing flight modes. An external command module enables real-time waypoint updates. This study proposes three path-planning schemes based on the characteristics of drones. Comparative experiments have demonstrated that the triangular path is the optimal route. Compared with the other schemes, this path reduces the flight distance by 30–40%. Robust target recognition is achieved using a darknet-ROS implementation of the YOLOv4 model, enhanced with data augmentation to improve performance in complex maritime conditions. A monocular vision-based ranging algorithm ensures accurate distance estimation and continuous tracking of rescue vessels. Furthermore, a dual-target-tracking algorithm—integrating motion prediction with color-based landing zone recognition—achieves a 96% success rate in precision landings under dynamic conditions. Experimental results show a 4% increase in the overall mission success rate compared to traditional SAR methods, along with significant gains in responsiveness and reliability. This research delivers a technically innovative and cost-effective UAV solution, offering strong potential for real-world maritime emergency response applications. Full article

Gynopara is a specific winged type in the life history of Aphis gossypii. As a key reproduction mode between parthenogenesis and sexual reproduction, it lays sexual females in late autumn. However, little is known about gynoparae because of its rare presence in the wild and the lack of its detailed descriptions. In this study, we investigated the morphological characteristics, ovary maturation process, and key signaling pathways during the development of gynoparae of A. gossypii. With the extension of development stage, the gynoparae exhibited gradually enlarged and thickened abdomen, deepened color. Obviously differentiated wing primordia in the second instar nymphs. Two nested U-shaped zones containing a series of waxy secreta spots were present on the abdomen of the fourth instar nymphs, and these morphological characteristics could be used as important markers for identifying gynoparae. Temporal transcriptomic analysis suggested that juvenile hormone (JH) might be involved in regulating the development of gynoparae. After the application JH analog kinoprene to the first instar nymphs, almost all treated individuals failed to complete wing differentiation, and most lost the ability to produce progeny, suggesting the destructive effect of JH on wing differentiation and reproduction of gynoparae. Moreover, exogenous addition of kinoprene also significantly altered the expression levels of four key genes responsible for the synthesis and degradation of JH. Our findings reveal the mechanism by which JH regulated wing differentiation and reproductive capacity of gynoparae, which lay a foundation for the further research on reproduction mode switch in aphids in the future. Full article

The variability in shape and coloration patterns associated with strategies of crypsis increases the environmental entropy and makes it more difficult for a potential predator to learn a certain prey to locate. To demonstrate this concept, we composed images of the wings of two Hemerobiidae species (Gayomyia falcata and Megalomus stangei) on a leaf background and then optically analyzed them by calculating the entropy of the images (in color as well as grayscale). For comparison, we colored the wings of Hemerobiidae artificially, and the analysis was repeated with these non-cryptic wings. The results indicate that the artificially colored wings reduce the entropy of the image, facilitating the location of the specimen, while the natural wings increase the entropy, thus hiding the presence of the specimen. In this context, the more morphological and chromatic diversity that the wings show, the greater the increase in entropy. Full article

While marking queens is an optional rather than mandatory technique, it is increasingly becoming a standard practice in modern beekeeping. Finding queens in strong colonies and large apiaries is a time-consuming process. The visible and durable marking of the queen enables it to be seen more quickly, directly improving productivity in apiary management. This study examined a new technique for marking queens using an oil-based marker, which involved marking not only the thorax (as a standard technique) but also the wings and abdomen. The durability of the marking was assessed by measuring color retention at the start of the experiment and after five months. Two groups of queens were formed: an experimental group, marked with the new technique on three body parts—Group O (n = 12) and a control group of unmarked queens—Group N (n = 12). The most durable color retention was observed on the thorax (54.4%) and abdomen (14.4%), while retention on the wings was weaker (2.4%), necessitating reapplication during the season. Considering the proportion of the total marked area, abdomen marking gave better results (9.5%) compared to the thorax (5.4%) and wings (0.6%) marking. The application of this marking technique showed no negative effects on queen acceptance, survival, or supersedure. Marking three body parts can increase the queen’s visibility in a non-invasive way, improving work efficiency. Full article

Among the several usages of unmanned aerial vehicles (UAVs), a wireless relay system is one of the most promising applications. Specifically, a small fixed-wing UAV is suitable to establish the system promptly. In the system, an antenna pointing control system directs an onboard antenna to a ground station in order to form and maintain a communication link between the UAV and the ground station. In this paper, we propose a sensor system to detect the direction of the ground station from the UAV by using color marker patterns for the antenna pointing control system. The sensor detects the difference between the antenna pointing direction and the ground station direction. The sensor is characterized by the usage of both the color information of multiple color markers and color marker pattern matching. These enable the detection of distant, low-resolution markers, a high accuracy of marker detection, and robust marker detection against motion blur. In this paper, we describe the detailed algorithm of the sensor, and its performance is evaluated by using the prototype sensor system. Experimental performance evaluation results showed that the proposed method had a minimum detectable drawing size of 10.2 pixels, a motion blur tolerance of 0.0175, and a detection accuracy error of less than 0.12 deg. This performance indicates that the method has a minimum detectable draw size that is half that of the ArUco marker (a common AR marker), is 15.9 times more tolerant of motion blur than the ArUco marker, and has a detection accuracy error twice that of the ArUco marker. The color markers in the proposed method can be placed farther away or be smaller in size than ArUco markers, and they can be detected by the onboard camera even if the aircraft’s attitude changes significantly. The proposed method using color marker patterns has the potential to improve the operational flexibility of radio relay systems utilizing UAVs and is expected to be further developed in the future. Full article

Acanthococcus ironsidei (Williams) (Hemiptera: Eriococcidae) is an invasive pest of macadamia, Macadamia integrifolia, in Hawai’i, causing death to macadamia trees and decreased nut productivity. Monitoring relies on wrapping double-sided sticky tapes over tree branches to trap dispersing crawlers (i.e., mobile immature stage), but this is tedious for growers, especially in large orchards. From September to November 2022 and December 2022 to February 2023, at two commercial macadamia orchards on Hawai’i Island, the use of colored sticky cards was assessed for improving the monitoring of A. ironsidei and to investigate the Hymenopteran parasitoid complex that inhabits macadamia canopies. At each study site, four different colored sticky cards (yellow, lime green, dark green, and white) were placed on the lower canopy of five trees, and on each tree, a transparent double-sided sticky tape was deployed. At bi-weekly intervals, the sticky cards were replaced and re-randomized on each tree, and the double-sided sticky tapes were replaced. The results showed that the sticky cards captured both A. ironsidei crawlers and (winged) male adults, while the double-sided sticky tapes captured only crawlers. The trap color did not have significant effects on the captures of A. ironsidei male adults at the sites, while the captures of crawlers on sticky cards were lowest on the dark green sticky traps at one site. The captures of A. ironsidei adult males on white sticky traps were generally correlated with the number of crawlers captured on the double-sided sticky tapes. The parasitoid complex captured had disparities in the attraction to color; however, the yellow, lime green and dark green colors were seemingly more effective for monitoring Encarsia lounsburyi (Berlese & Paoli), a reported parasitoid of A. ironsidei. These results have useful practical implications for improved monitoring of A. ironsidei crawlers, male adults and associated natural enemies. Full article

Flower color serves as a vital ornamental feature of landscape plants; Sophora japonica L. mutant ‘AM’ exhibits the different colors from the common S. japonica. ‘AM’, presenting with a light purple-red wing and keel and yellowish-white flag petals, while common S. japonica is yellow and white. The metabolites contributing to this color specificity in red-flowered S. japonica ‘AM’ are not yet fully understood. In this study, the flag, wing, and keel petals were collected from ‘AM’ at various phases, including the flower bud phase, initial flowering phase, full bloom phase, and final flowering phase, for conducting the metabolic assays targeting anthocyanins. Subsequently, we identified 45 anthocyanin-related metabolites, including nine flavonoids and 36 anthocyanins. Ten major floral chromoside metabolites were found to affect the coloration differences among the petals, where the most abundant anthocyanin was cyanidin-3-O-glucoside (Cy3G), which was much higher in the keel petal (LGB) and wing petal (YB) than in the flag petal (QB), and similarly, during the four periods of different petal types, the Cy3G content was higher in the initial flowering stage (S2), the full bloom stage (S3), and the final flowering stage (S4) than the flower bud stage (S1), which was in accordance with the trend of the observed petal floral color phenotypic difference measurement correlation. This suggested that the Cy3G accumulation was the primary factor driving the distinct coloration of varying types of petals. These findings could contribute to the understanding of the biochemical mechanisms underlying S. japonica petal coloration and may support future efforts in flower color improvement. Full article

Insects can repair wounds and regenerate body parts in response to physical damage. Wound healing in butterfly pupal wing tissues is developmentally interesting because ectopic color patterns develop during healing, suggesting that normal and damage-induced color patterns may use similar mechanisms. Here we physiologically investigated wound healing and ectopic color pattern formation in butterfly pupal wing tissues using the blue pansy butterfly Junonia orithya. In response to physical puncture damage, various ectopic color patterns are formed around the damage site. After the wounding operation, we observed hemocytes migrating over long distances along the wing veins (lacunae) toward the damage site, where hemocytes and epidermal cells formed cellular clusters. Calcium oscillations were observed in cells at and near the damage site. Calcium oscillations were transiently affected by ruthenium red, an inhibitor of calcium transporters and channels, and ruthenium red caused various abnormalities in the scales of adult wings. These results suggest that cell migration, cluster formation, and calcium oscillations play important roles in wound healing and scale development at and near the damage site. Ectopic color patterns may develop in response to local calcium oscillations as a consequence of the evolutionary co-option of the healing process for normal development. Full article

Background: The development of microsurgical techniques has enabled reconstructive versatility in various clinical scenarios. Supermicrosurgery is an advanced microsurgical technique ensuring precise reconstructions by operating on small-caliber vessels and nerves, with applications in reconstructive surgeries. Objectives: This study aims to compare the effectiveness of four low-cost training models, thereby improving surgical precision and reducing the learning curve for novice surgeons. Materials and Methods: We conducted a prospective non-randomized study comparing the classic anastomosis technique, the intravascular stenting (IVaS) technique, the color contrast (CC) technique, and our newly introduced double-contrast (DC) technique, which combines IVaS with CC. We used a non-living experimental model represented by chicken wings, analyzing the vessel preparation and anastomosis time, anastomosis patency, and back wall biting through a standardized protocol. We performed 120 end-to-end anastomoses in total, with vessel diameters ranging from 0.5 to 0.8 mm. Results: CC demonstrated superior time efficiency and success rates, reaffirming it as a reliable option in supermicrosurgery, while DC showed slightly better time efficiency and patency compared to both IVaS alone and the classic method. CC outperformed the others in anastomosis time, patency, and back wall catching, reaffirming its reliability in supermicrosurgery. Conclusions: Although DC did not significantly improve patency, it reduced back wall engagement. This makes the DC technique beneficial for trainees working on vessels under 0.5 mm in diameter, where stenting is often required, improving surgical precision and reducing the learning curve, leading to better outcomes in supermicrosurgery. Full article

Repeated expeditions across various regions of Georgia in the early 2000s led to the identification of 434 wild grapevine individuals (Vitis vinifera L. subsp. sylvestris (C.C. Gmel.) Hegi) across 127 different sites, with 45% of these sites containing only a single vine and only 7% more than 9 vines. A total of 70 accessions were propagated in a germplasm collection, 41 of them were descripted from the ampelographic point of view and 32 from the phenological one. The geographical and ecological analysis confirmed that wild grapevines primarily grow in humid environments with warm and fully humid climates, often near rivers. They favor deep, fertile, and evolved soils, mainly alluvial and cinnamonic types (80%), with a marginal presence on strongly eroded soils. Their main natural vegetations are forests and open woodlands, with some individuals in the Southeast found in steppes. The altitudinal range spans from 0 to 1200 m, with 80% of vines distributed between 400 and 900 m. The phenological analysis revealed significant differences among the accessions but no difference among populations, with only a slight variation in bud-break timing, indicating a high level of synchronicity overall. Flowering timing proved to be the most uniform stage, suggesting minimal environmental pressure on genetic adaptation. The mature leaf morphology exhibited significant polymorphism, though leaves were generally three- or five-lobed, weak-wrinkling, and -blistering, with a low density of hairs. Bunch and berry morphology were more uniform. Bunches were consistently very small, cylindrical, and never dense or winged. Berries were also very small, mostly globular, always blue-black in color, and non-aromatic. A striking feature was the frequency of red flesh coloration, which ranged from weak to strong, with uncolored flesh being rare. The Georgian population of wild grapevines was found to be fragmented, often consisting of scattered single individuals or small groups. Therefore, we believe it is urgent for Georgia to implement specific protection measures to preserve this vital genetic resource. Full article

The food industry continuously prioritizes methods and technologies to ensure product quality and safety. Traditional approaches, which rely on conventional algorithms that utilize predefined features, have exhibited limitations in representing the intricate characteristics of food items. Recently, a significant shift has emerged with the introduction of convolutional neural networks (CNNs). These networks have emerged as powerful and versatile tools for feature extraction, standing out as a preferred choice in the field of deep learning. The main objective of this study is to evaluate the effectiveness of convolutional neural networks (CNNs) when applied to the classification of chicken meat products by comparing different image preprocessing approaches. This study was carried out in three phases. In the first phase, the original images were used without applying traditional filters or color modifications, processing them solely with a CNN. In the second phase, color filters were applied to help separate the images based on their chromatic characteristics, while still using a CNN for processing. Finally, in the third phase, additional filters, such as Histogram of Oriented Gradients (HOG), Local Binary Pattern (LBP), and saliency, were incorporated to extract complementary features from the images, without discontinuing the use of a CNN for processing. Experimental images, sourced from the Pygsa Group databases, underwent preprocessing using these filters before being input into a CNN-based classification architecture. The results show that the developed models outperformed conventional methods, significantly improving the ability to differentiate between chicken meat types, such as yellow wing, white wing, yellow thigh, and white thigh, with the training accuracy reaching 100%. This highlights the potential of CNNs, especially when combined with advanced architectures, for efficient detection and analysis of complex food matrices. In conclusion, these techniques can be applied to food quality control and other detection and analysis domains. Full article

Butterfly wing scales feature complex nanostructures that influence wing coloration and various mechanical and optical properties. This configuration plays a key role in ecological interactions, flight conditions, and thermoregulation, facilitated by interactions with environmental electromagnetic energy. In tropical forests, butterflies occupy distinct vertical habitats, experiencing significant light and temperature variations. While wing nanostructures have been widely studied, their variation across different vertical flight preferences remains underexplored. This study investigates the wing nanostructures of 12 tropical butterfly species from the Nymphalidae family, focusing on their optical, morphological, and thermal properties across different forest strata. We analyzed the optical response through diffuse reflectance in the UV, Vis, and NIR ranges, correlating these findings with nanostructural configuration and thermal stability using thermogravimetric analysis (TGA). Our results reveal a significant correlation between flight stratification and wing optical responses, alongside distinct nanostructural features within each stratum. This study demonstrates the variability in butterfly wing nanostructures along the vertical stratification of the forest to cope with environmental conditions, raising new questions for future research on eco-evolutionary flight and thermal adaptations. Additionally, this underscores the importance of understanding how these structural adaptations influence butterfly interactions with their environment and their evolutionary success across different forest strata. Full article

Colloidal Cu₂O nanoparticles can exhibit both photocatalytic activity under visible light illumination and resonant Mie scattering, but, for their practical application, they have to be immobilized on a substrate. Butterfly wings, with complex hierarchical photonic nanoarchitectures, constitute a promising substrate for the immobilization of nanoparticles and for the tuning of their optical properties. The native wax layer covering the wing scales of Polyommatus icarus butterflies was removed by simple ethanol pretreatment prior to the deposition of Cu₂O nanoparticles, which allowed reproducible deposition on the dorsal blue wing scale nanoarchitectures via drop casting. The samples were investigated by optical and electron microscopy, attenuated total reflectance infrared spectroscopy, UV–visible spectrophotometry, microspectrophotometry, and hyperspectral spectrophotometry. It was found that the Cu₂O nanoparticles integrated well into the photonic nanoarchitecture of the P. icarus wing scales, they exhibited Mie resonance on the glass slides, and the spectral signature of this resonance was absent on Si(100). A novel bio-nanohybrid photonic nanoarchitecture was produced in which the spectral properties of the butterfly wings were tuned by the Cu₂O nanoparticles and their backscattering due to the Mie resonance was suppressed despite the low refractive index of the chitinous substrate. Full article

The pale grass blue, Pseudozizeeria maha, is a small lycaenid butterfly widely distributed across Asia. Due to its exclusively diurnal lifestyle and conspicuous sexual dimorphism in wing coloration, vision has traditionally been regarded as the primary sensory system driving various behaviors. However, non-visual sensory systems related to sex-specific behavioral responses, such as antennae, have received far less attention. This study investigated the morphological characteristics and sensilla types of the antennae in adult P. maha using scanning electron microscopy, with a focus on potential sexual dimorphism. The antennae of adult P. maha are clavate, with no significant sexual differences in overall morphology. Six types of antennal sensilla were identified: Böhm bristles, sensilla squamiformia, sensilla trichodea, sensilla chaetica, sensilla basiconica, and sensilla coeloconica, with no sexual dimorphism observed in their morphological types or dimensions. Remarkably, the sensilla coeloconica exhibit significant sexual dimorphism, with a more prominent presence in females. This finding suggests that female P. maha may rely more on olfactory cues for some sex-specific behaviors, such as oviposition site selection. Full article

One of the important genes for eyespot development in butterfly wings is Distal-less. Its function has been evaluated via several methods, including CRISPR/Cas9 genome editing. However, functional inhibition may be performed at the right time at the right place using a different method. Here, we used a novel protein delivery method for pupal wing tissues in vivo to inactivate a target protein, Distal-less, with a polyclonal anti-Distal-less antibody using the blue pansy butterfly Junonia orithya. We first demonstrated that various antibodies including the anti-Distal-less antibody were delivered to wing epithelial cells in vivo in this species. Treatment with the anti-Distal-less antibody reduced eyespot size, confirming the positive role of Distal-less in eyespot development. The treatment eliminated or deformed a parafocal element, suggesting a positive role of Distal-less in the development of the parafocal element. This result also suggested the integrity of an eyespot and its corresponding parafocal element as the border symmetry system. Taken together, these findings demonstrate that the antibody-mediated protein knockdown method is a useful tool for functional assays of proteins, such as Distal-less, expressed in pupal wing tissues, and that Distal-less functions for eyespots and parafocal elements in butterfly wing color pattern development. Full article