The Bird-like Flapping-wing Air Vehicle (BFAV) is a robotic innovation that emulates the flight patterns of birds. In comparison to fixed-wing and rotary-wing air vehicles, the BFAV offers superior attributes such as stealth, enhanced maneuverability, strong adaptability, and low noise, which render the BFAV a promising prospect for numerous applications. Consequently, it represents a crucial direction of research in the field of air vehicles for the foreseeable future. However, the flapping-wing vehicle is a nonlinear and unsteady system, posing significant challenges for BFAV to achieve autonomous flying since it is difficult to analyze and characterize using traditional methods and aerodynamics. Hence, flight control as a major key for flapping-wing air vehicles to achieve autonomous flight garners considerable attention from scholars. This paper presents an exposition of the flight principles of BFAV, followed by a comprehensive analysis of various significant factors that impact bird flight. Subsequently, a review of the existing literature on flight control in BFAV is conducted, and the flight control of BFAV is categorized into three distinct components: position control, trajectory tracking control, and formation control. Additionally, the latest advancements in control algorithms for each component are deliberated and analyzed. Ultimately, a projection on forthcoming directions of research is presented. Researchers have drawn inspiration from flying animals to create various flight systems, including fixed-wing, rotary-wing, and flapping-wing systems ,2. ThereFlapping-wing air vehicles have become a research hotspot ,15 in reSome of the most representative studies are the bionic rainbird “BionicSwift” from the German Festo and “Cloudy Owl” from Northwestern Polytechnical University. Festo’s bionic swift, “BionicSwift”, has a body length of 44.5 cm, a wingspan of 68 cm, and a weight of only 42 g. The bionic air vehicle is quick and flexible and can make tight maneuvers and flying loops. Additionally, actual flight tests have shown that five BionicSwifts may maneuver in unison and autonomously in the designated airspace while engaging with the radio-based indoor GPS. To push the boundaries of endurance, load capacity, and environmental adaptability, Prof. Song Bifeng’s team has been designing more bionic and effective flapping-wing air vehicles. The team’s “Cloudy Owl” flapping-wing air vehicle achieved a new world record in 2022 by successfully flying an autonomous course for 154 min and making a soft landing.Flight control, as an integral part of the research on flapping-wing air vehicles, is the basis for the realization of autonomous flight, trajectory orchestration, and other capabilities of the air vehicle. A highly bird-like flapping-wing air vehicle not only needs to mimic the shape and flight mode of a bird but also needs to be more capable of accomplishing complex flight maneuvers such as turning, diving, and flipping like a bird. In consideration of the fact that the flapping-wing air vehicle is a nonlinear and unsteady system, it is susceptible to factors such as environmental disturbances. Moreover, the mass and size of the flapping-wing system greatly limit energy, sensors, and airborne processing, leading to a sharp decline in performance. Hence, it is imperative to use well-defined flight control algorithms to improve the stability of the system. The key way to obtain fine vehicle control and make the flapping-wing air vehicle fly more nimbly, steadily, and safely is through effective and precise algorithms. Therefore, excellent flight control algorithms are crucial to flapping-wing air vehicles’ flight performance and application prospects. Based on this background, this paper investigates the flight control algorithm of BFAV with nonlinearity, parameter coupling, and uncertainty and summarizes the research progress of the BFAV flight control algorithm so far.The structure of this essay is as follows . The firThe remarkable flying capabilities of insects and birds in their natural habitats have been extensively studied . In an eThe wing, which is the most vital component of avian flight, is a complex structure consisting of primary and secondary flight feathers, covering feathers, and down feathers that span the entire wing. This intricate structure can be divided into two distinct parts, namely the inner and outer wings , as depiThe wing is an integral part of a flapping-wing air vehicle. The different forms of wing bending during flapping make the wings flexible and contribute significantly to the aerodynamic efficiency of flapping motion . FurtherThe aerial flight environment is complex and variable nonetheless, as it incorporates unstable flows from a variety of origins, such as wind gusts and turbulence that may be suffered during flight . When coIn conclusion, the geometry of avian wings and their deformation, the arrangement of feathers, and the synergistic cooperation between wings and tail are critical determinants of avian flight. The predominant mechanism of flight control is achieved through the flapping of wings and tail in unison, as no appropriate material has been identified for the distributed control of the wings of a flapping-wing air vehicle, precluding the autonomous arrangement of feathers akin to that of birds. Despite the potential benefits of this mechanism, its practical application is still fraught with numerous challenges. One such challenge is the intricate interplay between the non-constant wing wake flow and the wake, which often eludes explicit modeling . This coThe control algorithm of BFAV has been a popular subject of study in the academic realm. The flight control algorithm can be categorized into three primary components: position control, trajectory tracking control, and formation control. Position control is the fundamental element of the control system, encompassing attitude and height control, which guarantee the air vehicle’s maintenance of the correct attitude and height during flight. Trajectory tracking control directs the air vehicle to follow a predetermined trajectory and can be utilized for various tasks such as cruise and search. Eventually, the implementation of formation control will allow for collaborative flight among multiple BFAVs, thereby enabling the execution of mission assignments, cluster searches, and other related activities. Attitude control is essential for achieving precise orientation and tracking flight for all types of air vehicles . The adjThe bionic flapping-wing vehicle is widely recognized as a nonlinear and unsteady system , charactThe stable and precise control of flight altitude is a crucial aspect of flapping-wing air vehicle flight control, as acknowledged in the literature . AccuratThe PID control technique is a conventional method for controlling the height of flapping-wing air vehicles in flight control studies, but its effectiveness is restricted when applied to complex nonlinear systems and complex signal tracking. Consequently, researchers have shifted their focus towards utilizing more advanced control algorithms, such as the adaptable neural network algorithm. In this regard, AI-Mahasneh et al. developed an adaptive control system that employs a generalized regression neural network (GRNN) as the height controller for FWMAVs . Upon coThe utilization of trajectory tracking control in pre-planning and optimizing the flight trajectory of BFAVs based on attitude and height control can enhance the stability and accuracy of the air vehicle during flight. Consequently, trajectory tracking control assumes a crucial role in the operation of flapping-wing air vehicles.The control algorithm for trajectory tracking in a flapping-wing air vehicle necessitates consideration of various factors involved in the flight itself, such as nonlinear modeling, time-varying disturbances, and unidentified external uncertainties, which can potentially impact the stability and precision of the control system. Research has shown that neural network techniques are proficient in managing nonlinear systems with exceptional approximation ,56. He eModel-based controllers  enable tFurthermore, practical applications of FWMAVs are often impeded by challenges such as input deadband  and inpuThe completion of intricate missions often requires the use of multiple flapping-wing air vehicles, as relying on a single vehicle can prove challenging. The advancement of group intelligence has led to increased interest in the cluster formation technology of these vehicles. Formation flying is a flight strategy that maximizes the utilization of airflow and aerodynamic effects through the formation of multiple vehicles in flight with predetermined positional alignments and attitudes. For instance, a rear vehicle may utilize vortices generated by a front vehicle in the formation to reduce its own resistance and energy consumption. Furthermore, interactions among the vehicles have the potential to significantly decrease air resistance and enhance overall flight efficacy. Therefore, flapping-wing air vehicles’ cluster formation transformation, by emulating the characteristics and laws of bird clusters, can achieve optimal and balanced energy consumption and enhance long-distance endurance, as evidenced by previous research .Significant avian species undergo extensive migration with the changing of the seasons. Wild geese, for example, migrate in formations that take the shape of “V,” “I,” or “L.” Among these formations, the “V” formation is deemed the most effective for achieving group energy savings, a phenomenon known as the “Wild Geese Queue Effect” ,72. NumeAn optimal flight arrangement has the potential to mitigate the energy consumption of the collective and enhance its range. Nevertheless, the alterations in airflow during the flight are multifaceted, and the crux of formation flight lies in the ability to promptly adapt to environmental changes. The realization of collaborative control of multiple air vehicles is the prerequisite guarantee for the completion of excellent flight arrangements and the realization of formation flight. In contrast to the flight control of a solitary flapping-wing air vehicle, the management of formation flight necessitates not only the appropriate control of each air vehicle but also the synchronized administration of multiple air vehicles to avert collisions during formation alterations. The primary techniques for formation control comprise the leader-follower method, the behavior-based method, the virtual structure method, and the consistency method. The advantages and disadvantages of each of the four control approaches are enumerated in Furthermore, communication and obstacle circumvention have emerged as primary concerns in the realm of formation control. The existing literature has identified artificial potential fields  and distIn general, formation flight of BFAVs has not received enough attention due to the fact that the technology of flapping-wing vehicles is not as advanced as that of fixed-wing and rotary-wing vehicles. While the control algorithms for formation flight have been extensively researched and applied in the context of rotor-system air vehicles, the utilization of such techniques on BFAV’s physical air vehicles has been comparatively limited. Therefore, further research in this domain is warranted.There is a close connection and interaction among these three primary controls, namely position control, trajectory tracking control, and formation control. Position control is the basis of trajectory tracking control and formation control, which are critical to the flight stability of BFAV. Trajectory tracking control and formation control need the support of position control to achieve more complex missions. Hence, these three controls are interrelated in BFAV control research and can cooperate for optimal flying performance.Control of flexible wing deformation. Due to the BFAV’s enormous wingspan, the elastic deformation caused by the flexible wing during flutter will not only affect its aerodynamic performance but also the stability of the system. He et al. created a dynamic model of the flexible wing and applied the Lyapunov direct approach to ensure the stability of the flexible wing system . And theReconfiguration of the controller. The traditional single-control algorithm can hardly meet the flight control requirements of a flapping-wing air vehicle in different flight modes, environmental situations, and missions under a nonlinear, non-constant system. Therefore, the controller of the flapping-wing air vehicle can be modified to extend the applicability and scenarios of BFAV. Aids based on different strategies, such as switching strategy, adaptive strategy, etc., can be used to help the air vehicle choose different controllers or numerous controllers in conjunction with one another to improve the adaptability and scalability of flight control. This is a direction worth exploring.Multi-vehicle synergy and intelligent formation. Flapping-wing air vehicles are not as mature as fixed-wing and rotary-wing air vehicles. Consequently, the accomplishment of high-precision and highly maneuverable missions by a single physical flapping-wing air vehicle is rare, and the instances of such vehicles performing multi-engine synergy and intelligent formation are even scarcer. However, the efficacy and success rate of a single air vehicle are limited when undertaking challenging tasks, such as inspecting vast areas. The integration of intelligent information and multi-vehicle coordination has the potential to enhance the scope of task execution and the reliability of task fulfillment . ConsequBionics as an interdisciplinary discipline has garnered increasing attention in recent years. Within this domain, research on flapping-wing air vehicles (BFAV) has emerged as a hotpot of investigation. While some progress has been made in developing flight control algorithms for BFAVs, achieving high precision and maneuverability in physical air vehicles remains challenging due to the complexity of their models and the multitude of factors that affect control. In light of these findings, this paper presents several perspectives on the future research trajectory for BFAVs:The flight control techniques employed by BFAV are subject to ongoing enhancement to effectively address diverse application scenarios and associated demands in the future. This essay provides three promising avenues for research and exploration: flexible wing deformation control, controller reconfiguration, multi-vehicle collaboration, and intelligent formation.


The rapid urbanization and the increasing need for sustainable development have led to the emergence of green roof landscapes in ocean cities. These rooftop gardens provide numerous environmental benefits and contribute to the overall well-being of urban dwellers. However, optimizing the design and interaction experience of green roof landscapes requires the integration of intelligent technologies. This paper explores the application of computer visual design techniques, specifically 3DMAX modeling and virtual reality, in the intelligent interaction design of green roof landscape plants in ocean cities. Designers can use computer visual design (3DMAX) and other technologies to interact intelligently with the roof landscape in order to improve landscape design. Through case studies, this indicated that computer vision is excellent for image processing of rooftop landscapes and also demonstrates a high degree of compatibility between computer vision and green rooftop landscape plant design in marine cities. This paper highlights the significance of intelligent interaction design and computer visual design techniques in optimizing the integration of green roof landscape plants in ocean cities. It emphasizes the potential of 3DMAX modeling and VR technology in creating immersive and engaging experiences for designers, users, and stakeholders alike. The findings contribute to the growing body of knowledge in the field of sustainable urban development and provide insights for designers, policymakers, and researchers seeking to enhance green roof landscapes in ocean cities. The dissertation highlights the potential of using computer vision design techniques to enhance the roof garden landscaping process and advocates for more efficient and effective ways to design, visualize, and improve rooftop gardens by utilizing software equipped with computer vision technology such as 3DMAX, ultimately contributing to the advancement of sustainable urban landscapes. Marine city roof landscape plants not only have excellent cooling and insulation effects but also can beautify the environment, purify the air, improve the local microclimate, and greatly increase the green coverage rate of the city . They arInteraction design is a multidisciplinary field that focuses on creating meaningful and engaging interactions between users and products, systems, or environments. In the context of green roof landscapes, interaction design involves the deliberate shaping of the user’s experience and interactions within the garden space. It encompasses various elements including spatial arrangement, plant selection, sensory stimuli, and user-centered considerations .More and more people are studying green roof landscape plants in ocean cities. “Virtual Reality Applications in Landscape Architecture: A Review” by Elsayed et al. (2020) explored the use of virtual reality (VR) in landscape architecture, including green roof design and interaction . It disc“Computer Vision-Based Techniques for Plant Phenotyping in Green Roofs” by Alsadik et al. (2020) focused on the application of computer vision techniques for plant phenotyping in green roofs . It explThe research methodology of this paper involves a combination of literature review, case studies, and empirical analysis. The literature review provides a comprehensive understanding of the existing knowledge and research in the field of intelligent interaction design and computer visual design techniques . Case stBy employing intelligent interaction design principles, rooftop gardens can offer more than just a visual spectacle. They can become immersive and interactive spaces that stimulate curiosity, learning, and a deeper connection with nature. Intelligent interaction design takes into account the diverse needs and preferences of users, fostering engagement, and promoting a sense of well-being . For insFurthermore, interaction design can be enhanced through the integration of computer visual design techniques such as 3D modeling and virtual reality. These technologies enable designers and users to visualize and interact with green roof landscapes in a dynamic and immersive manner. Three-dimensional modeling allows for realistic representations of the garden space, facilitating the evaluation of plant placements, spatial arrangements, and overall design concepts. VR technology, on the other hand, offers users the opportunity to virtually explore and interact with the rooftop garden, offering a deeper understanding of the plant ecosystem and experience of the space from different perspectives .Computer vision is also a commonly used technology nowadays, and its use regarding green rooftop landscape plants in ocean cities is also a trend. Computer vision has excellent image-processing functions, which can identify the distribution of various samples in the landscape. This is very helpful for the design of rooftop landscape plants in ocean cities. In this experiment, computer vision technology was also used to identify the greening rate of green rooftop landscape plants in ocean cities. From the results, it can be found that computer vision is still very effective in analyzing the greening of green landscape plants in marine cities .The use of new tools and design methods utilizing computer methods in green roof planting landscape design helps designers to create more precise and knowledge-based greening designs. This article describes the application of computer vision design techniques, especially in the field of roof garden landscaping, using software such as 3DMax2020. This involves using the capabilities of such software to digitally model and visualize roof garden layouts, plant arrangements, and other landscape elements. These tools, often rooted in computer vision principles, empower designers and architects to meticulously simulate, model, and visualize every intricate facet of landscapes, structures, and objects. By incorporating these techniques into green roof landscaping, we aim to facilitate a more precise, informed, and knowledge-driven approach to greening design.Just like other architectural landscapes and forests, the green roof landscape of ocean cities is a combination of water, mountains, and rocks based on terrain and natural features to form a garden. In urban greening, roof greening accounts for a large proportion and is also known as a plant that leaves the soil environment. With the increase of buildings and population, people’s desire for natural greening has become more urgent . InstituIn addition to designing according to the technical principles of architectural design, roof greening in ocean cities also needs to consider the structure of the roof, the waterproof and drainage structure of the roof, the growth characteristics of plants, and the growth techniques of plants. These are all technical requirements for creating roof landscapes. The key to the success of roof greening construction lies in the bearing capacity of the roof, the ability of the roof for drainage and waterproofing, and the combination of greening plant species . In ordeNatural layout: Most of the plants in the roof landscape are arranged in a natural way so that the roof landscape can form a natural garden effect. The natural layout of the roof landscape is meant to match the roof landscape with the surrounding buildings and water bodies and then combine trees and flowers to form a dense natural landscape . Rule-based layout: In rule-based layout, the designer needs to pay attention to the decoration of plants so that the plants in the garden form a regular and hierarchical plant configuration. This plant configuration has a fresh and solemn landscape atmosphere, which can give people a good feeling. Mixed layout: The mixed roof landscape not only possesses the landscape characteristics of natural and regular layout but also has its own unique style. In the changes of spatial composition points and surfaces, it forms a variety of spatial levels. This type of rooftop landscape is designed to enhance the continuity of the plant landscape and emphasize the diversity of landscape plants, thereby closely combining different types, styles, and landscapes to form an extremely beautiful rooftop landscape . The composition of the green roof landscape in marine cities is shown in Enhancing urban climates in ocean cities: Rooftop landscape plants have demonstrated their capacity to contribute significantly to urban climate improvements. These plants play a pivotal role in absorbing particulate dust and mitigating the presence of toxic gases in the atmosphere, simultaneously regulating the humidity levels within urban environments. Moreover, they serve as effective buffers for reducing noise pollution in residential zones, showcasing a notable noise-reduction efficacy. Through the process of photosynthesis, green plants exhibit an impressive ability to sequester substantial quantities of carbon dioxide from the surrounding atmosphere, thereby acting as a countermeasure against the formation of urban “heat islands”. Additionally, these rooftop plants offer a protective function, preserving the integrity of the waterproofing layer on rooftops, consequently extending the operational lifespan of the roofs .Beautifying the urban air landscape: The development of ocean urbanization is very rapid. If different forms of rooftop landscape plants can be arranged at the top of these buildings, then above the city, there would not be just a lifeless concrete roof. Relevant data show that if there is green comprises 25% of the sight line, it can make people feel happy. The existence of rooftop landscape plants can precisely meet this demand, which can regulate people’s psychological state and effectively improve the mental outlook of urban populations . The mulHaving a good insulation effect: Due to direct sunlight in summer, roofs without greenery have much higher temperatures than the outside. Moreover, due to the color and material of the roofs, the heating rate varies, with some roofs reaching a heating rate of over 80%. However, on a roof with green vegetation, the surface temperature of the roof can be effectively reduced due to the blocking of heat by leaves and the emission of heat by transpiration. Therefore, the indoor temperature of the building can be effectively controlled in the hot summer . If the Computer visual design techniques encompass various methods and tools used to create and manipulate visual elements in digital environments. Two key technologies in this realm are 3D modeling and virtual reality (VR). Three-dimensional modeling involves the creation of three-dimensional digital representations of objects or spaces, allowing for a realistic and interactive visualization. VR, on the other hand, immerses users (or the design team responsible for creating and implementing the rooftop garden design) in a simulated environment, enabling them to interact with and experience a virtual world .In computer vision, image processing refers to the analysis and manipulation of digital images using algorithms and computational methods. It involves tasks such as image enhancement, segmentation, feature extraction, and object recognition. By extracting meaningful information from images, computer vision techniques enable the understanding and interpretation of visual data. The data-preparation stage of the computer vision system is shown in The method of computer vision image processing is shown in Computer visual design techniques refer to the utilization of advanced software tools, often based on computer vision technology, to create and manipulate visual elements in a digital environment. These techniques enable designers and architects to simulate, model, and visualize various aspects of landscapes, structures, and objects in a highly detailed and interactive manner.In this thesis, highlighting the application of computer visual design techniques, specifically using software like 3DMax, in the field of rooftop garden landscaping. This involves using the capabilities of such software to digitally model and visualize rooftop garden layouts, plant arrangements, and other landscape elements. The software’s computer vision capabilities can assist in various ways:Three-dimensional modeling: Computer visual design software like 3DMax allows designers to create detailed three-dimensional models of rooftop landscapes. This modeling can encompass everything from the layout of plants and structures to the overall spatial arrangement, providing an accurate representation of how the final garden would look.Realistic visualization: These software tools enable the creation of high-fidelity visualizations that closely resemble real-world conditions. Designers can incorporate realistic textures, lighting, and environmental factors, giving stakeholders a clear and vivid understanding of the proposed rooftop garden’s appearance.Simulation and analysis: Computer visual design software often includes simulation features that can be used to analyze different scenarios. For rooftop garden landscaping, this could involve simulating the growth of plants over time, assessing factors like sunlight exposure, wind patterns, and how the garden might evolve seasonally.Iterative design: The digital nature of these techniques allows for quick and easy modifications to the design. Designers can experiment with various plant placements, materials, and layout configurations, rapidly refining their ideas to achieve the desired outcome.Stakeholder communication: These visualizations can serve as effective communication tools between designers, clients, and other stakeholders. By providing a realistic preview of the proposed rooftop garden, these techniques facilitate better understanding and decision making.In essence, this thesis underscores the potential of utilizing computer visual design techniques to enhance the process of rooftop garden landscaping. By harnessing software equipped with computer vision technology, such as 3ds Max, designers can advocate for a more efficient and effective approach to designing, visualizing, and refining rooftop gardens, ultimately contributing to the advancement of sustainable urban landscapes.The landscape design process for roof gardens involves a series of systematic steps aimed at conceptualizing, planning, and creating green spaces on the rooftops of buildings. This paper emphasizes the utilization of computer visual design techniques, particularly software with computer vision technology like 3ds Max, to enhance and facilitate this process. The following is an overview of the typical steps in the landscape design process for roof gardens:Site analysis and assessment: The process begins with a comprehensive evaluation of the rooftop’s characteristics. This includes assessing factors such as sunlight exposure, wind patterns, structural integrity, load-bearing capacity, and existing utilities. Computer visual design techniques can aid in creating accurate digital models of the rooftop, allowing designers to analyze these factors in detail.Conceptualization and ideation: Designers brainstorm and develop initial ideas for the rooftop garden. This phase involves considering the client’s preferences, functional requirements, and aesthetic goals. Computer visual design software enables the creation of digital sketches and preliminary visualizations that help translate conceptual ideas into tangible representations.Design development: The chosen concepts are refined and developed further. This involves specifying plant selections, hardscape elements (such as pathways and seating areas), and other design elements. Computer visual design techniques allow for the creation of detailed 3D models that provide a realistic preview of the garden’s layout, helping designers and clients visualize the final outcome.Visualization and simulation: This step involves using computer visual design tools to create high-quality visualizations and simulations. Designers can apply realistic textures, lighting, and environmental effects to the digital models. Additionally, simulations can be used to predict how plants will grow over time, how shadows will change during different times of the day, and how the garden will evolve with the changing seasons.Refinement and iteration: Computer visual design software allows for easy modifications to the design. Designers can experiment with various plant arrangements, colors, materials, and spatial configurations. Iterative refinement ensures that the design aligns with the client’s vision and functional requirements.Documentation and communication: Detailed plans, sections, and elevations are generated using the software tools. These documents serve as crucial references for construction and installation. Additionally, the high-quality visualizations facilitate effective communication with clients, stakeholders, and contractors, ensuring a shared understanding of the design intent.Implementation and maintenance: Once the design is finalized, the actual construction of the rooftop garden takes place. Proper installation of plants and hardscape elements follows the detailed plans and specifications generated during the design phase. Ongoing maintenance ensures the garden thrives and continues to contribute positively to the urban environment.The application of computer visual design techniques, specifically 3D modeling and VR, offers numerous benefits and applications in the field of interaction design, particularly in rooftop gardens .Enhanced visualization: 3D modeling enables designers and users to visualize rooftop gardens in a realistic and immersive manner. It allows for a better understanding of spatial arrangements, plant placements, and design concepts. Users can explore the garden from different perspectives, fostering a deeper connection with the space and facilitating informed design decisions .Interactive exploration: VR technology provides an unparalleled opportunity for users to interact with rooftop gardens. By simulating the experience of being in the garden, users can virtually walk through the space, interact with plants, and experience various design elements. This interactive exploration promotes engagement and enables users to envision the potential of the rooftop garden .Iterative design process: Computer visual design techniques facilitate a more iterative and collaborative design process. Designers can create, modify, and refine 3D models of the rooftop garden, allowing for quick prototyping and testing of different design iterations. Users can provide feedback and actively participate in the design process, resulting in more user-centered and optimized designs.Educational and informative experiences: Computer visual design techniques can be leveraged to create educational and informative experiences in rooftop gardens. Through 3D modeling and VR, users can learn about different plant species, their characteristics, and their ecological relationships . This inUser engagement and well-being: The immersive and engaging nature of computer visual design techniques enhances user experiences in rooftop gardens. By incorporating interactive elements such as touch-based interactions or gamified activities, users can actively engage with the environment, fostering a sense of well-being, curiosity, and connection with nature.Computer visual design techniques, including 3D modeling and VR technologies, offer numerous benefits and applications in the field of interaction design for rooftop gardens. They enable enhanced visualization, interactive exploration, iterative design processes, educational experiences, and increased user engagement. By leveraging these technologies, rooftop gardens can provide immersive and engaging experiences that promote sustainable design and improve the overall well-being of users .The Alibaba office building headquarters is a landmark building located in Hangzhou, China, and is home to the headquarters of Internet giant Alibaba. The building was designed by the internationally recognized architectural firm, Foster + Partners, and is an office and a commercial, cultural, and recreational complex. There are 15 roof gardens in the overall park, with a minimum area of 390 square meters and a maximum area of 878 square meters As in .This paper takes the rooftop garden of Alibaba’s headquarters building as a case study to conduct in-depth research on the application of computer visual design techniques, specifically computer vision and 3D rendering, in the intelligent interaction design of green roof landscape plants in ocean cities. The aim is to explore the potential of these technologies in optimizing the integration of green roof landscape plants and improving the overall landscape design.To begin, computer vision techniques were employed to analyze and process images of the rooftop garden. By capturing high-resolution images and utilizing image-processing algorithms, various aspects of the rooftop garden, such as plant composition, spatial arrangement, and overall greening rate, were measured and evaluated. Computer vision enabled efficient and accurate data collection, providing valuable insights into the effectiveness of green roof landscapes in marine cities. Next, 3D rendering techniques were utilized to create detailed and realistic representations of the rooftop garden. By translating design drawings and plant simulations into three-dimensional models, designers are able to visualize and analyze the interactive design aspects of the plant landscapes. Herein, this included evaluating the placement of different plant species, assessing their visual impact, and understanding the ecological relationships within the rooftop garden.The research focuses on several key aspects. Firstly, the greening rate of plants in the rooftop garden was measured and analyzed using computer vision techniques. By quantifying the coverage and distribution of plants, the effectiveness of the green roof landscape in providing environmental benefits, such as heat insulation and carbon sequestration, was able to be assessed. Furthermore, the composition of the rooftop garden’s plant species was examined. Computer vision techniques aided in identifying and categorizing the various plants present in the rooftop garden. This analysis provided valuable information on the biodiversity and ecological balance of the green roof landscape. It also enables designers to make informed decisions regarding plant selection, considering factors such as adaptability to marine climates, resistance to saltwater exposure, and compatibility with the overall design concept. The interactive design of the plant landscapes was explored based on the 3D rendering models. By virtually experiencing the rooftop garden through VR technology, designers, users, and stakeholders can engage in interactive exploration and provide feedback on the design. This user-centered approach fosters participatory design, allowing for adjustments and improvements to be made based on user preferences and needs.Ocean city data and computer technology have become important sources and methods for measuring landscape quality . With thMachine learning is often used in computer vision algorithms. Machine learning utilizes the set Q as training data. The best assumption in the assumed space is h, and N(h) is used to represent the initial probability of hypothesis h before the untrained dataset Q, while P(Q) reflects the probability of hypothesis h holding after setting the training data Q. The calculation method for probability is shown in Formula (1): In the process of machine learning, the assumption of maximum likelihood is called the maximum posterior hypothesis, and the calculation method is shown in Formula (2): By combining Formulas (1)–(3), the following can be obtained: Computer vision techniques offer a powerful means to extract valuable landscape features through the utilization of image segmentation algorithms. One particularly useful metric is the green view index (GVI), which provides a quantitative measure of the greening level in ocean cities’ landscapes. By quantifying the panoramic green view rate, it is possible to assess the aesthetic value of these cities and understand the significant impact of greening rates on people’s overall life satisfaction and well-being . And theThe analysis of the data presented in These experimental findings shed light on the greening rates of green roof landscape plants in the Alibaba corporate headquarters building roof garden, indicating a moderate level of greening. The results highlight the effectiveness of computer vision in observing and evaluating the greening levels of ocean city rooftop landscapes through advanced image-processing techniques and other technologies. This reflects the success of intelligent interaction enabled by computer vision, which played a significant role in obtaining relatively accurate greening rate measurements.The experiment’s outcomes further emphasize the significance of intelligent interaction design and computer visual design techniques in optimizing the integration of green roof landscape plants in ocean cities. By leveraging computer vision, designers can interact intelligently with the rooftop landscape, gaining precise measurements of greening rates. This intelligent interaction allows designers, users, and stakeholders to make informed decisions regarding landscape design, fostering the creation of aesthetically pleasing and environmentally beneficial green roof environments.The analysis of the roof gardens’ ornamental intensity reveals that among the studied samples, there are four roof gardens categorized as having strong ornamental qualities, nine classified as medium, and two classified as weak Analysis of Plant Landscape and Human Interaction:Through computer vision image-processing techniques, the greening rate of the rooftop garden at Alibaba’s headquarters building was accurately determined. These findings demonstrate the effectiveness of computer vision in accurately assessing and quantifying the greening rate of green roof landscape plants in ocean cities. The intelligent interaction of computer vision in image processing has proven to be highly beneficial in evaluating and optimizing the integration of green roof landscape plants, leading to a more sustainable and aesthetically pleasing urban environment. The specific results of the analysis are as follows:The rooftop garden of Alibaba’s headquarters building features a diverse plant landscape carefully curated to provide both aesthetic value and functional benefits. The designers employed 3D modeling and VR technology to create an immersive experience for users and stakeholders. By conducting in-depth case studies, the analysis revealed a strong alignment between computer vision and green rooftop landscape plant design in marine cities, further emphasizing the significance of intelligent interaction design and computer visual design techniques .(2)The plant landscape design in the rooftop garden incorporates four functional modules: negotiation space, observation deck, multi-person party area, and VR virtual experience zone. Each module is strategically placed to enhance the interaction between visitors and plants, fostering a deeper connection with nature. The rooftop garden features a variety of plant species, including weeping willow, camphor trees, magnolia, cattails, and more, each chosen to create a specific ambiance and offer a range of sensory experiences.The design also considers the rooftop garden’s accessibility, line-of-sight permeability, boundary richness, and interactivity. For instance, the semi-open waterfront space is adorned with water’s-edge plants like lotus and cattails, creating a beautiful and natural water landscape that allows for close interaction with the garden. Meanwhile, the semi-enclosed space is densely planted with yew, magnolia, and camphor trees, forming a hidden and secluded landscape, providing visitors with a sense of tranquility and enclosure.(3)Plant Landscape Lighting Design and Human Interaction:The rooftop garden’s plant landscape lighting design significantly contributes to the interactivity between people and the environment, particularly during nighttime hours. This lighting design takes into account human physiological and psychological characteristics, emphasizing a human-centric approach. By thoughtfully selecting light sources and lamp positions based on plant height and characteristics, the lighting design effectively showcases the rooftop garden’s unique features .Using light superposition, flow, translucency, and refraction, the plant landscape lighting design creates a mesmerizing visual experience that captivates visitors. The lighting fixtures are strategically hidden through various methods, allowing the light to flow through the foliage or create enchanting silhouettes, fostering a harmonious connection between light and nature.The lighting design also adapts to the changing seasons and weather conditions, allowing visitors to experience the rooftop garden’s different scenes throughout the year. During spring, the focus is on illuminating lush crowns and leaves, while winter highlights the striking branches and tree trunks. This thoughtful adjustment enhances the rooftop garden’s interactivity, making visitors feel closer to nature and creating a sense of wonder and awe.In conclusion, the application of computer visual design techniques, 3D modeling, and VR technology in the intelligent interaction design of green roof landscape plants in ocean cities offers numerous benefits. From accurately assessing the greening rate to curating a diverse and interactive plant landscape and employing sophisticated lighting design, these intelligent technologies enhance the overall experience of green rooftop gardens. As urbanization continues, these findings provide valuable insights for designers, policymakers, and researchers seeking to create sustainable and engaging green spaces in ocean cities.In line with current design trends for green roof landscapes in coastal cities, the dominant approach is visual design using new 3D2020 software. Through analysis of the climate conditions in marine cities, we aimed to understand the optimal design of roof gardens, including spatial requirements and plant arrangements. We used interactive software to simulate visitors’ movements within the garden and generate ideas for an interactive experience. Abbreviations are defined on first use. In this paper, we examine the process of designing green roof landscapes using 3D software. We focus on two representative cases and conducted a comparative analysis with three additional cases to enhance the results. To gather information for the 3D design, we conducted a literature survey and used a specialized program design. According to the research cases presented in the previous section, this section analyzes the three-dimensional effects of various forms of green roofs. The following This papers analyze four representative green roofs for their three-dimensional effects and uses 3D and VR technology for further explanation. The rooftop garden landscape design for the 361° office building in Xiamen is as displayed in As indicated in As presented in (1)It is necessary to enhance the theory of roof garden design by adhering to correct design.The three case studies of green roof development yield the following conclusions:First, the concept of appropriate ecological design is based on the climatic conditions of the region and selecting vegetation that suits the roof’s planting site. Second, the concept of sustainable development design is also important. Rooftop garden landscape design is a viable option, as shown by Alibaba’s success story. However, it is not necessary to adopt all popular foreign elements, which can increase costs and be an imprudent behavior. It is important to consider the impact on expenses before making such decisions. To ensure the seamless integration of such imported goods into China’s urban development, it is also essential to implement a sustainable development strategy for rooftop gardening. This must be carried out in a progressive and steady manner, taking into account national conditions and economic development.(2)It is crucial to carefully select plants that are suitable for the region’s growth and development.Firstly, the high location of the roof suggests the choice plants that thrive in direct sunlight and have a well-developed root system. Secondly, given the limited weight-bearing capacity, it is advisable to opt for lightweight flowers or herbaceous plants. Thirdly, since the soil layer on the roof is shallow and lacks water-storage capacity, drought-resistant vegetation is a suitable choice.(3)Computer-aided three-dimensional technology can be utilized to optimize the landscape design in accordance with the building’s form and function.The landscape design for the roof garden failed to consider the building group’s shape and did not establish clear design standards beforehand. To enhance the design program, it is recommended to lay out the landscape design in accordance with the building group’s shape and function. The intention of this approach is to adapt to the local conditions. Combined with the form and function of the building complex, a garden landscape must be designed that is harmonious with the surrounding environment and fully reflects the functional characteristics of the building. It must adopt a natural layout that reflects the coordination and integration of the building with the garden landscape or adopt a conventional approach that emphasizes landscape decoration and arrangement to enhance the landscape level and compensate for spatial constraints. However, in selecting garden vignettes, weight and volume restrictions due to the roof’s load-bearing capacity necessitate a considered approach. Alternatively, the designer may change the materials used for garden vignettes, such as employing lighter volcanic rock for rockeries. Adjusting the landscape of the roof garden can be achieved through manipulating color, shape, proportion, and texture by means of a computer.(1)Generalization and General Design of Analytical Studies:A fundamental consideration in research involving case studies represents the extent to which the findings can be extrapolated to wider contexts, thereby contributing to universal design principles and practices. In the context of the study titled “Computer Vision Interaction Design in Sustainable Urban Development: A Case Study of Roof Garden Landscape Plants in Marine Cities”, it is pertinent to address the generalizability of the case study findings.The case study focused on the rooftop garden of the Alibaba headquarters building, examining the integration of computer visual design techniques, 3D modeling, and VR technology in the intelligent interaction design of green roof landscape plants. While this case study is insightful and provides a specific example of effective integration, it is essential to discuss the potential for broader applicability. Therefore, this study comparatively analyzes the roof gardens of two other ocean cities. The study of three cases makes the research conclusion more rigorous and scientific.Universal design implications: The insights derived from the case study hold potential implications for the broader domain of green roof landscape design in ocean cities. The principles and methodologies employed, such as accurately assessing greening rates, curating diverse plant landscapes, and employing sophisticated lighting design, can serve as foundational concepts applicable to other similar projects. At the same time, comprehensive design is carried out from aspects such as color, shape, proportion, texture, and so on.Key considerations for generalization: It is crucial to recognize that the success and generalizability of case study findings depend on various factors, including the context, scope, and specific characteristics of the target projects. The generalizability of our findings rests on the alignment of factors such as climate, geographical location, urban planning regulations, and user preferences.While our case study offers a specific example of intelligent interaction design in a green roof landscape, its generalizability to universal design principles requires careful consideration of contextual factors. Our study serves as a foundation, and its findings can be interpreted alongside existing research to ascertain their broader applicability in enhancing green roof landscapes in various marine cities.(2)Analysis of the Spatial Structure Presented in the Case Study:Landscape typology of the rooftop garden: The landscape typology of the rooftop garden can be categorized as a “Multifunctional Urban Oasis”. This typology encapsulates the fusion of ecological, aesthetic, and interactive elements within an urban context. The garden serves as a retreat within the bustling city, offering not only visual delight but also functional benefits such as temperature regulation, air purification, and biodiversity enhancement. The negotiation spaces, observation deck, party area, and virtual experience zone each contribute to this multifaceted typology, providing opportunities for relaxation, connection with nature, and engagement.The case study centers around the rooftop garden of the Alibaba headquarters building, a landmark in Hangzhou, China. This case is compared with the other two cases. This garden showcases a thoughtfully designed spatial structure that integrates various functional modules, plant species, and interactive elements. The spatial arrangement exhibits a purposeful division of zones, each contributing to the overall user experience and interaction with the green roof landscape.Scope of application of the case study: The scope of this case study is centered around showcasing the integration of intelligent technologies, specifically computer visual design techniques, in the design and interaction of green roof landscapes in ocean cities. While the case study’s primary focus is on the rooftop garden of the Alibaba headquarters building, its implications extend beyond this specific location. The principles, methodologies, and findings presented offer valuable insights for designers, researchers, and policymakers seeking to enhance green roof landscapes in diverse marine cities facing similar urbanization and sustainability challenges.By utilizing computer vision and 3D rendering techniques, the study addresses key aspects of green roof design: greening rate assessment, plant species composition, interactive design, and lighting considerations. The case study’s scope of application encompasses not only rooftop gardens in marine cities but also potentially any urban environment that aims to leverage intelligent technologies for sustainable and engaging green spaces.Prior this study, existing research has explored various aspects of green roof landscapes and their benefits in urban environments. Many studies have focused on the environmental advantages of green roofs, such as their ability to mitigate heat-island effects, improve air quality, and reduce stormwater runoff . AdditioSecondly, this research places a strong emphasis on the integration of intelligent technologies, particularly computer visual design techniques, 3D modeling, and VR technology, in the design process. By leveraging these tools, designers can interact intelligently with the rooftop landscape, leading to more informed decisions and better outcomes. This integration of technology and design aligns with the growing trend of smart urban development and highlights the potential for creating innovative and sustainable green roof landscapes .While this study provides valuable insights into the application of computer visual design techniques and intelligent interaction design in green roof landscapes, there are certain areas that warrant further exploration. Firstly, the research primarily focuses on the case study of the Alibaba headquarters building. Although there are also comparative analyses of two other cases, this may limit the generalizability of the findings. Future research could include a broader range of case studies from various ocean cities to enhance the comprehensiveness of the results.Additionally, the study primarily emphasizes the greening rate and aesthetic aspects of rooftop gardens. Future research could delve deeper into the functional aspects of green roof landscapes, such as their role in providing habitat for biodiversity, supporting urban agriculture, and contributing to energy efficiency and building performance. Understanding the multifaceted benefits of rooftop gardens will enable a more holistic approach to their design and integration into urban environments. As technology continues to evolve, there may be opportunities to explore emerging computer visual design techniques and other intelligent technologies that could further enhance the interaction design of green roof landscapes. Integrating advancements in artificial intelligence, data analytics, and sensor technologies could open new avenues for optimizing the performance and user experience of rooftop gardens.The conclusions drawn from this research are well defined within a focused and referenceable research scope. Through a comprehensive analysis of the rooftop garden at the Alibaba headquarters building and a comparative analysis of the other two cases, this study effectively demonstrates the applicability and benefits of integrating computer visual design techniques, particularly 3D modeling and virtual reality, in the intelligent interaction design of green roof landscape plants in marine cities. This article studied the intelligent interaction of green rooftop landscape plants in marine cities using computer vision technology. This can enable more reasonable design of landscape plant layout. This article tested the distribution of greening rates of various rooftop landscapes under computer vision through experiments. These greening rate data can provide a reference for landscape design. This research delves into the realm of intelligent interaction design of green roof landscape plants in ocean cities, leveraging the power of computer visual design techniques and 3D modeling. The rapid urbanization and the growing demand for sustainable development have given rise to the emergence of green roof landscapes, which not only provide significant environmental benefits but also contribute to the overall well-being of urban dwellers.The integration of intelligent technologies is paramount in optimizing the design and interaction experience of green roof landscapes. Through case studies and extensive analysis, we have established that computer vision, particularly in the image processing of rooftop landscapes, offers remarkable accuracy in assessing and quantifying the greening rate of green roof landscape plants. This valuable information empowers designers and policymakers to create more effective and sustainable urban environments.The application of 3DMAX modeling and VR technology enriches the design process by providing designers, users, and stakeholders with immersive and engaging experiences. By simulating and visualizing the rooftop gardens, designers can interact intelligently with the space and make well-informed decisions to enhance the landscape design effectively. The compatibility between computer vision and green rooftop landscape plant design in marine cities underscores the potential of these technologies in shaping aesthetically pleasing and functional green spaces.The specific conclusions obtained within this scope include the following:Effectiveness of computer vision design aids: The efficiency of computer vision design technology is prominently demonstrated through its utilization in the analysis of greening rates via 3DMAX renderings. This approach offers a precise and dependable method for assessing and quantifying the extent of greenery within rooftop landscape plants. Moreover, within the domain of plant landscape design, the versatility of this technology allows for real-time adjustments to design schemes in alignment with specific requirements. As a result, the overall efficacy of the design process is significantly enhanced.Alignment with design: The alignment between computer visual design techniques and green rooftop landscape plant design in marine cities is clearly demonstrated. Through in-depth case studies, we highlight the significance of intelligent interaction design and computer visual design techniques in enhancing user experiences with green rooftop gardens.Scope of application: Our study’s conclusions are specifically applicable to the integration of computer visual design techniques, 3D modeling, and VR technology in green roof landscaping within ocean cities. The findings provide valuable insights for designers, policymakers, and researchers working on sustainable urban development in similar marine environments.Enhanced interaction design: Through in-depth case studies, the study affirms a strong alignment between computer visual design techniques and the effective design of green rooftop landscapes in marine cities. The utilization of 3D modeling and virtual reality facilitates immersive experiences for designers, users, and stakeholders. This finding underscores the potential for intelligent technologies to enhance human interaction with green spaces.Ecological considerations: The research recognizes the importance of plant species composition and ecological balance in green roof landscape design. The study’s application of computer vision in identifying and categorizing plant species informs the selection process for plants that thrive in marine climates, thus contributing to sustainable and resilient designs.User-centered approach: The investigation underscores the significance of a human-centric approach in landscape lighting design. By thoughtfully adapting lighting to seasonal changes and physiological factors, the research showcases the potential of computer visual design techniques to create captivating visual experiences that foster a stronger connection between visitors and the natural environment.Applicability to ocean cities: The study’s scope is clearly defined within the context of marine cities, catering to the specific challenges and opportunities posed.


We have recently proposed experimental design guidelines and areas of study for preclinical rodent models of gender-affirming hormone therapy in neuroscience. These guidelines also apply to any field subject to the influences of gonadal steroid hormones, including metabolism and growth, cancer, and physiology. This perspective briefly describes our suggestions for these fields. Studying the effects of exogenous steroid hormones will have translational benefits for the community. We also discuss the need for equitable practices for cisgender scientists who wish to implement these guidelines and engage with the community. It is necessary that community-informed practices are implemented in preclinical research to maximize the benefit to transgender, nonbinary, and/or gender diverse (TNG) healthcare, which is currently in jeopardy in the United States, Europe, and across the globe. In the decades since, the use of these hormones as gender-affirming hormone therapy (GAHT) became widespread among transgender individuals for biomedical sex/gender transition  exert their effects by acting as ligands to their cognate receptors. The most well-studied of the hormone receptors are the canonical nuclear receptors: estrogen receptor alpha and beta , androgen receptor (AR), and progesterone receptors . These receptors are expressed at varying levels throughout the brain, with notably denser expression in subcortical regions important for social behavior, stress responses, metabolism, mood/affect, memory, and cognition. Therefore, understanding the mechanisms by which gonadal hormones influence these aspects of neural function is fundamental for improving GAHT.Nuclear hormone receptors regulate gene expression to drive changes in neural circuit wiring, synaptic strength, and neural activity. When bound with their ligand, these receptors interact with the genome, acting as transcription factors and modifying chromatin profiles . Recent Membrane-bound hormone receptors are found on both the plasma membrane and the surface of organelles. Once ligand-bound, these receptors are often thought to initiate molecular cascades, leading to changes in cell function and behavior. The timescale of action is hypothesized to lead to parallel mechanisms of intracellular action in concert with nuclear receptor activation. Future research on GAHT could illuminate the interplay between membrane-bound receptors and nuclear receptors and interrogate how each receptor-type distinctly affects cellular function in multiple tissue-types.Cognition, memory, and learning are influenced by gonadal hormones, and many of the brain regions involved in cognition express steroid receptors. However, evidence that estrogen replacement therapies can protect against cognitive decline remains controversial. Studies in cisgender humans partially support the hypothesis that steroids influence cognition and memory in older adults across sex. The influence of GAHT on cognitive measures in transgender, nonbinary, and/or gender diverse (TNG) people—in youth seeking to delay puberty or in older TNG individuals with years of GAHT—remains largely unknown. More clinical and preclinical studies are needed to assess the mechanisms of GAHT on cognition and memory and the interactions of GAHT and social/minority stressors in young and aging TNG populations.Hormonal milieus interacting with multiple brain regions lead to differences in the etiology, symptomology, and effectiveness of treatments for mood and stress disorders. Evidence that GAHT alters stress reactivity in clinical settings suggests that it has direct actions on stress circuitry, which may impact the mental health needs of individuals treated with GAHT. However, studies examining GAHT-associated mental health run the risk of pathologizing GAHTs. Therefore, we propose 2 lines of inquiry to pursue through animal models of mood and stress disorders. The first compares GAHT-treated animals to untreated controls, which may identify the direct action of GAHT on mood and stress-related brain regions. The second examines the mental health outcomes using animal models of mood and stress disorder by comparing GAHT-treated animals differentially exposed to an additional variable. Gender-based discrimination and perception of the contemporary geopolitical climate are related to elevated biomarkers of allostatic load in transgender populations. Such factors can be conceived as chronic psychosocial stressors; as such, particular focus should be given to rodent models of chronic psychosocial stress.Although steroidal hormones and their effects on general metabolism and physiology are historically well-studied, much remains to be studied about GAHT and its long-term outcomes on growth, overall metabolism, and bone health. Both estrogens and androgens are thought to regulate feeding behaviors, homeostatic control of thermoregulation, and overall body mass. However, as few studies have examined the effects of E-GAHT and T-GAHT on long-term body composition and growth, we propose preclinical studies to understand how varying regimens of GAHT lead to changes in body weight and the localization of fat accumulation before and after GAHT. These studies would allow for further tailoring of GAHT regimens to increase satisfactory transition outcomes in TNG populations. Additionally, bone health is thought to be regulated in part by circulating steroidal hormones. Age-dependent bone loss is partially attributed to a dysregulation of gonadal steroids. To address this, we propose longitudinal studies that examine the effects of GAHT on bone health in older TNG individuals and the maintenance of bone growth in young and middle-aged TNG individuals.While much of our focus has been on neurobiology, our models can be easily applied to other endocrine-sensitive physiological and pathophysiological processes, such as cancer. While much has been written about health disparities in the TNG community in the context of cancer, the influence of GAHT on the prevalence of or risk for endocrine cancers is understudied. Furthermore, the mechanisms underlying these effects can only be postulated due to the lack of preclinical studies in animal and cellular models. Questions that can be addressed by the proposed models include both short-term and long-term treatment with both E-GAHT and T-GAHT in young adult and aged rodents, activation of cellular processes by both treatment types on ER/PR-positive breast cancer cells, the influence of E-GAHT on prostate cancers, and the long-term effects of pubertal delay on endocrine cancers, including intestinal and reproductive cancers.We must recognize that animal GAHT models are limited in their ability to fully study the uniquely human experience of gender-affirming treatments. However, these models can improve our knowledge of how GAHTs influence physiological and neurological processes. It is imperative to understand that GAHT and the social stressors discussed could have reciprocal influences on their actions and should be individually and synergistically studied. There remain significant barriers to healthcare and to STEM careers for TNG people, which are amplified by current political decisions. As such, studies using the proposed preclinical models of GAHT must incorporate collaborations with TNG community members, either in the lab or through community outreach. As transgender, nonbinary, and gender diverse identities are increasingly common, the prevalence of binary classifications significantly hinders meaningful research, particularly when applied to the human condition. The TNG community has identified GAHT research priorities for GAHT  to ensurJournal of the Endocrine Society. The remaining authors have nothing to disclose.T.A.R. is an Editorial Board member for the


Charcot neuroarthropathy (CN) is a chronic, destructive, and painless damage of the skeletal system that affects the life quality of patients. CN, with an unclear mechanism, is characterized with invasive destruction of bones and a serious abnormality of bone metabolism. Unfortunately, development of an effective prevention and treatment strategy for CN is still a great challenge. Of note, recent studies providing an insight into the molecular mechanisms of bone metabolism and homeostasis have propelled development of novel CN therapeutic strategies. Therefore, this review aims to shed light on the pathogenesis, diagnosis, and treatment of CN. In particular, we highlight the eminent role of the osteoprotegerin (OPG)-receptor activator of nuclear factor-κB (RANK)-RANK ligand (RANKL) system in the development of CN. Furthermore, we summarize and discuss the diagnostic biomarkers of CN as well as the potential pharmacological mechanisms of current treatment regimens from the perspective of bone metabolism. We believe that this review will enhance the current state of knowledge on the diagnosis, prevention, and therapeutic efficacy of CN. The incidence of diabetes has steadily surged among the aging population all over the world . ChronicCN was first described in a Spanish article by The studies published so far have improved our understanding of CN pathogenesis as well as the progress in its diagnosis and treatment. In fact, recent advances in the knowledge of the molecular mechanisms of bone metabolism and homeostasis have provided a promising direction for scheduling new CN therapeutic strategies. However, the underlying mechanisms and the actual efficacy of current therapeutic strategies for CN are yet to be elucidated. During the novelty retrieval via Web of Science search engine, we set “Charcot Neuroarthropathy” and “Charcot Neuroarthropathy AND Pathogenesis AND Bone metabolism” as search topics, which led to a dramatic decrease in the number of publications from 650 to 28 . Thus, tRecently, several comprehensive reviews have summarized and discussed the excellent stride of bone metabolism in CN development . Howevervia increased expression of cytokines and further aggravate bone resorption  was found to be highly involved in the development of diabetic CN. In particular, there was a positive correlation with G alleles for both the OPG 1181G>C and 245T>G variants in CN patients as compared to patients with diabetic neuropathy and healthy controls  could serve as beneficial agents for the treatment of CN. However, clinical data and verification of efficacy of these agents are highly desired. In addition, certain anti-inflammatory therapies, including inhibitors of RANKL, NF-κB, and IL-1β, have already been applied in animal experiments to ameliorate inflammation in arthritis .The interaction between diabetes, neuropathy, and excessive inflammatory response is one of the main causes for CN development that can lead to bone absorption and joint deformity . OxidatiDiabetes is associated with an increase rate of lipoperoxidation, while vascular calcification (VC) is linked with upregulation in oxidized low-density lipoprotein expression . In a prConsidering the tremendous surge in its incidence and prevalence, diabetes has become the most common cause of CN affecting the foot and ankle. From the perspective of bone metabolism, the main goal of pharmacological intervention involves suppression of excessive inflammation and bone resorption. Therapeutic strategies targeting inhibition of osteoclast function and pro-inflammatory signaling can provide a promising direction for CN treatment. Anti-resorptive treatments, especially with BPs, have been used in animal models and randomized clinical trials. Although there is no evident verification of an ideal dosage regime and true long-term validity, clinical trial results suggest improved symptom control, a more rapid decrease in the foot temperature, and a marked decline in bone resorption marker levels without any serious side-effects. While evidence suggests the direct involvement of monocytes in the pathogenesis of CN, further research focused on the monocyte-to-osteoclast differentiation process may give us a better insight into early prevention strategies for this pathogenic condition. Early diagnosis is still the best strategies for the management of patients with CN. In patients with diabetes and lower extremity neuropathy, any delicate injury deserves necessary observation due to the tendency of the limb to proceed to a Charcot’s process . In summ


The potential of perinatal tissues to provide cellular populations to be used in different applications of regenerative medicine is well established. Recently, the efforts of researchers are being addressed regarding the evaluation of cell products  to be used as an alternative to cellular infusion. The data regarding the effective recapitulation of most perinatal cells’ properties by their secreted complement point in this direction. EVs secreted from perinatal cells exhibit key therapeutic effects such as tissue repair and regeneration, the suppression of inflammatory responses, immune system modulation, and a variety of other functions. Although the properties of EVs from perinatal derivatives and their significant potential for therapeutic success are amply recognized, several challenges still remain that need to be addressed. In the present review, we provide an up-to-date analysis of the most recent results in the field, which can be addressed in future research in order to overcome the challenges that are still present in the characterization and utilization of the secreted complement of perinatal cells and, in particular, mesenchymal stromal cells. In the last decade, significant advances have been made to fully assess the biology of mesenchymal stromal cells (MSCs) derived from perinatal tissues. The term “perinatal” defines birth-associated tissues and other fetal annexes , obtained immediately after birth. To date, many applications of perinatal MSCs for clinical purposes have been studied with promising results, mainly due to their unique immune and differentiative properties . DespiteThe secretome is enriched with extracellular vesicles (EVs), secreted by cells through the development of multivesicular bodies or by cell membrane shedding ,13. TheyThe increasing interest in the therapeutic benefits obtained by using the EVs released by parental MSCs in various diseases reinforces the hypothesis of the usefulness of MSC secretomes as a new therapeutic strategy.Perinatal tissues represent a plentiful source of promising cell types. Among the organs that may be used as a source of perinatal cells, the placenta is of key importance for its role in fetal nutrition and development, acting as a functional interface between the mother and fetus, either via the exchange of nutrients or via its immune and endocrine roles . The forThe placenta is usually discarded post-partum and easily obtained with a virtually limitless availability, free from ethical issues, and provides efficient MSC recovery without invasive procedures . Differewww.ClinicalTrials.gov database accessed on 30 July 2023. One of these (NCT04213248) investigates the ability of umbilical cord-derived EVs to reduce dry eye symptoms in patients with chronic graft-versus-host disease (cGVHD). Another study (NCT04202770) evaluates the potential of liquid amniotic-derived EVs in the treatment of depression and neurodegenerative dementia, while another study (NCT04384445) evaluates their ability to suppress the activation of cytokines or intervene in other adverse events in COVID-19 patients with severe symptoms. In line with this, we herein summarize the current studies in the literature regarding cell-free therapeutic options by employing EVs derived from perinatal MSCs in the context of several pathological conditions.MSCs are involved dynamically and actively in feto-maternal communication by releasing several molecules into the maternal circulation (including hormones and proteins) as well as EVs . The thedecidua basalis is the implantation site of the embryo and where the decidua interacts with the trophoblasts responsible for the forming of the basal plate; the decidua capsularis, enriched in decidual cells and some small vessels, is towards the uterus in contact with the chorion; and the decidua parietalis is an elongation of the decidua capsularis replacing the endometrium and merges with the capsularis, within the fourth month of gestation, in parallel with the reduction in uterine cavity width [decidua basalis and decidua parietalis tissue. Generally, hD-MSCs have a shape similar to fibroblastic cells, the ability to adhere to plastic, and the presence of surface markers typical of MSCs, including HLA-ABC. Between the markers that are not expressed by hD-MSCs, studies have reported CD 40, CD80, CD83, CD-86, and HLA-DR [As mentioned previously, perinatal tissues are obtained from term placentas and fetal annexes . The matty width . Dependid HLA-DR . Moreoved HLA-DR . From thd HLA-DR .Placental tissue-derived EVs can be produced regardless of physiological or pathological condition; indeed, the biogenesis and release of EVs from the placenta may be regulated by changes in the cellular microenvironment, such as oxygen tension and glucose concentration ,50. StudAlthough the main roles of placental MSC-derived EVs have been studied in the maternal–fetal communication, it is interesting moreover to highlight their role in other conditions. For instance, it was shown that placental MSC-derived EVs alleviated oxidative stress and restored the biological activity in renal ischemia–reperfusion injury models by regulating mitochondrial structure and function . AnotherThe fetal portion of the placenta is represented by the chorion, which underlines the decidua basalis grouping all the layers that enclose the embryo. It originates from the trophoblast, which unites with the extraembryonic mesoderm . The so-The chorion per se does not generate blood vessels per se but represents the tissue in which the connecting vessels between the placental villi and the connective stalk (which later will give rise to the UC) are located . Silini During gestation, trophoblast cells perform key functions that depend on an increasing number of structural and functional changes occurring at their expense and mediated by the secretion of EVs . For insRegarding MSCs derived from chorionic villi and chorion laeve, this distinction is only related to the different regions of origin, as these cell subpopulations do not differ from each other in their cellular characteristics and immunophenotypes . Studies4) in a mouse model [Of note, MSC-derived EVs are also able to mediate many functions in pathological conditions: for example, MSC-derived EVs favored liver regeneration through antifibrotic and autophagic mechanisms in a hepatic failure model  and allese model  Table 24 in a mose model  . Instead, the portion of the membrane that lines the chorionic plate has been named the human placental amniotic membrane (hPAM). The dramatic growth of the amniotic cavity, starting at the fourth week of development, increases the contact between the hAM and the chorion, leading to the formation of the human amnio-chorionic membrane (hACM). Overall, the hACM constitutes the union between the fetal membranes with the chorionic plate [The human amniotic membrane (hAM) lines the amniotic cavity containing the amniotic fluid (AF). Due to the extension and cellular heterogeneity of the amniotic membrane, a subdivision in different zones has been proposed: the peripheral part of the membrane that lines the ic plate . Specifiic plate . Moreoveic plate . The hAMic plate . Furtheric plate ,83,84,85ic plate . hCM-deric plate .Thence, hAM- and AM-derived cells, at the end of pregnancy, represent a highly abundant and accessible tissue that could be useful for diverse therapeutic applications . hAECs hIn immortalized human proximal tubular cells, hAEC-derived EVs ameliorated renal tissue damage, preventing apoptosis, as well as capillary rarefaction together with immunomodulation activity . SimilarhAMSCs-derived EVs’ functional and molecular characterization remain fragmentary, thus delaying their translation into clinical practice. Recently, hAMSC-derived EVs were observed to mediate the healing of inflamed and diseased joints and tendons due to the fact that they possess teno/chondroprotective characteristics, as well as the ability to induce the polarization of M2 macrophages and the inhibition of inflammatory T cells, with consequent promotion of Treg . In thisRecently, EVs derived from the conditioned medium of hCMSCs (hCMSC-EVs) have been isolated and characterized, demonstrating that EVs and their contents can be taken up by different types of mesenchymal cells  during the osteoarthritic process, suggesting their perspective role in the treatment of disease .At around the seventh/eighth day of embryonic development, between the membrane that directly covers the embryo  and the embryo itself, a small space is formed, which will give rise to the amniotic cavity filled with AF . ImportaIn relation to the therapeutic utility of hAF-MSCs, various beneficial effects are known to be mediated by secreted EVs (hAFMSC-derived EVs). Balbi and coworkers showed that hAFMSC-derived EVs act as functional mediators of proliferative, antiapoptotic, immunomodulatory, proangiogenic, and anti-inflammatory processes, which are key properties for regenerative therapy. In particular, they have shown that hAFMSC-derived EVs modulate the expression of inflammatory  and pro-resolving (Il-10) cytokines, as well as blocking the infiltration of immunoglobulins into inflamed muscle tissue . In TablAs shown in It is known that hAFMSC-derived EVs provide information specific to normal and abnormal parturition. In this regard, a proteomic profile analysis, with the enrichment of key inflammatory markers, allowed us to distinguish hAFMSC-derived EVs isolated from patients who had spontaneous preterm birth or premature rupture of membranes compared with those who delivered at term . FurtherInterestingly, it has been reported that other features of hAFMSC-derived EVs may reside in their anti-apoptotic, pro-angiogenic, and immune-modulatory activities, prospectively of interest in anticancer therapy. For example, hAFMSC-derived EVs were shown to inhibit apoptosis and support the survival of damaged granulosa cells, thus preventing ovarian follicles from atresia in mice following chemotherapy .The hUC connects the embryo, and then the fetus, to the placenta, allowing the exchange of nutrients and gasses during gestation. The UC is formed when the body stalk , umbilical blood vessels, and allantoid duct along with the umbilical coelom are surrounded by diffuse amnion. The extraembryonic mesoderm of all the ducts in the UC merges together, giving rise to a mucoid connective tissue called “Wharton’s jelly”  described for the first time by Thomas Wharton in 1656 . This pa4-induced liver fibrosis in vivo model by mediating hepatic protection and inhibiting the detrimental epithelial-to-mesenchymal transition of hepatocytes [The cells can be isolated in both the UC blood UCB and UC tissue . hUC-MSCatocytes . As descSimilarly, hUCMSC-derived EVs have provided evidence of their ability to accelerate the functional and morphological recovery of cisplatin-induced acute kidney injury by promoting proliferation and damage repair once incorporated into damaged epithelium, a result that has been observed both in vitro and in vivo . InteresIn lung cancer cell lines, hUCMSC-derived EVs are capable of promoting migration and invasion by transferring miR-410 . InsteadIn perinatal brain injury treatment, WJ-MSCs have been shown to reduce neuroinflammation and induce neuro-regeneration . The effPerinatal MSCs are emerging as a strong candidate for a new source of MSCs that could be suitable to replace adult MSCs as they can be procured by noninvasive procedures and there are no ethical controversies surrounding them. It is beyond doubt that most of the perinatal sources of stem cells that we have reviewed here present key improvements over adult MSCs in terms of availability, proliferation rate, efficacy, and safety for both donor and recipient ,170,171.Overall, EVs secreted from perinatal MSCs exhibit key therapeutic effects such as tissue repair and regeneration, the suppression of inflammatory responses, immune system modulation, and a variety of other functions. Although the properties of MSCs-derived perinatal EVs and their significant potential for therapeutic success are recognized, several challenges still remain that need to be addressed. First of all, from a practical point of view, the standard methodologies for the isolation and large-scale production of EVs, as well as their characterization and administration, require standardized protocols to be applied as effective, safe, and potent cell-free therapies. Overall, the knowledge in the research underlining the therapeutic mechanism of action of perinatal MSC-derived EVs, together with the development of preclinical models to test their therapeutic efficacy could contribute to new findings on the applicability of perinatal MSC-derived EVs necessary to achieve translation and successful clinical implementation.