The 5th generation of mobile networks has come to the market bringing the promise of disruptive performances as low latency, availability and reliability, imposing the development of the so-called “killer applications”. This contribution presents a 5G use case in the context of Structural Health Monitoring which guarantees an unprecedented level of reliability when exploited for public safety purposes as Earthquake Early Warning. The interest on this topic is at first justified through a deep market analysis, and subsequently declined in terms of public safety benefits. A specific sensor board, guaranteeing real-time processing and 5G connectivity, is presented as the foundation on which the architecture of the network is designed and developed. Advantages of 5G-enabled urban safety are then discussed and proven in the experimentation results, showing that the proposed architecture guarantees lower latency delays and overcome the impairments of cloud solutions especially in terms of delays variability. The fifth generation (5G) of the mobile access technology is changing the mobile communication business ecosystem by introducing specific services that can be operated by different stakeholders in various fields, i.e., public safety, healthcare, energy, manufacturing, media and entertainment, financial services, public transport, retail, automotive, and agriculture.This contribution focuses on the public safety vertical. These kinds of applications are referred to as Public Protection and Disaster Relief (PPDR) and, based on the 5G Observatory, only five trials, out of 181, were dedicated to PPDR [These applications require communications efficiency, especially under harsh conditions when the safety of critical infrastructures may not be guaranteed due to catastrophic events. This pushes the investigation toward solutions that are able to guarantee all the services to properly address the crisis.Introducing 5G in this context means overcoming the limited flexibility and scalability of legacy systems that are mainly due to hardware-based networks functions exploitation and the absence of a proper orchestrator . This isMoreover, the shared infrastructure approach and the use of public instead of dedicated networks, both offered by the 5G scenario, have the potential to overcome the problem of affordability and economy of scale, which has caused the public safety sector to remain many technological generations behind the public communication solutions.Various trials to exploit the previously discussed potentials have been designed and developed in recent years. The 5GENESIS ICT-17-2018) platform was tested in Malaga by furnishing the local police commercial mobile phones for live videos exchange to receive and transmit live video in the coverage area of the deployed 5G network. A comprehensive document on experimental results is not yet available, but the experimentation methodology is described in . A solut-2018 plaMany other projects concerning with PPDR solutions though 5G technologies could be cited as successful examples, but based on the authors’ understanding, the solution integrating two widely different applications that is experimented here, and whose architecture was proposed in , is not sensor services and within the use case category of higher reliability, availability, and lower latency.In this paper, the first experimental outcomes of an application related to a 5G-enabled IoT for public safety is presented. Generally, 5G-enabled IoT consists of various types of IoT devices sending data through a very efficient communication infrastructure guaranteeing low latency while conceiving with public safety or generally speaking, safety applications. The described solution for Structural Health Monitoring (SHM) of buildings and infrastructures addresses both normal and emergency conditions, and it is one of the outcomes of the experimentation within the 5G trial in the city of L’Aquila  . SpecifiThe remainder of the paper is organized as follows: in operation evaluation,data acquisition, normalization and cleansing,feature selection and information condensation,statistical model development for feature discrimination.Based on , the SHMHow these four steps are implemented clearly depends on the specific application , imposing specific constraints. For instance, measurements’ synchronization is required while conceiving with dynamic analysis oriented monitoring , while tSince SHM systems deal with safety of buildings and people, reliability represents a key requirement. On the other hand, the massive deployment of sensors stresses energy efficiency to guarantee sufficient lifetime to battery powered devices. Energy efficiency can be achieved by the design of low power devices and efficient power management strategies. Buildings are monitored by exploiting data coming from the deployed sensors in order to evaluate their performance over time, for instance in terms of safety, thus allowing the design of a proper restoration plan, to reduce their vulnerability. When a catastrophic event arises, constantly tracked structures are able to activate proper mechanisms for emergency response.Traditional systems are based on wired grids of sensors deployed along a structure and have a high cost, considerable size and poor flexibility.In recent years, a significant opportunity in the field of SHM technologies has been represented by the gradual growth of Wireless Sensor Networks (WSNs). Indeed, they offer the opportunity of reducing deployment costs and improving service flexibility by eliminating connection cables. Moreover, the reduction or even the total absence of cabled connections allows WSNs to be suitable for installation in buildings of historical or artistic relevance where wireless nodes can be properly hidden.Furthermore, WSN nodes can be configured to analyze sensors measurements and eventually trigger alarm signals in case of damage detected.For example, in the use case discussed in One of the advantages of the scenario proposed in this paper is given by the exploitation of a SHM system, commonly intended for long-term purposes with relaxed constraints, for public safety. In this section, the importance of SHM from an economic point of view is demonstrated, which gives added value to the feasibility of the proposed scenario.On a global level, the size of the market referable to SHM in 2020 is US$1.5 billion, and it is in a growing phase: the market is expected to reach a value of US$2.9 million in 2025 with a compound annual growth rate of 14.1 percent in this period . At presA further segmentation element is represented by the type of connection between sensors, wired or wireless. From this point of view, the research highlights how the market is moving towards a wireless approach, to overcome the limits of wired technologies , as shown by the growth rate about 5 percent in favor of wireless technology.A last analysis is related to the registered patents for SHM with the aim of highlighting the trends and the distribution of patented technologies.measurement mainly concerns the concepts of “deformation” and “vibration”;there is considerable interest in solutions related to the use of optical fiber;in terms of applications, the most represented categories are those related to the aeronautical sector, civil engineering and bridge monitoring;the category related to “measured data” highlights a multiplicity of variables considered in the patented solutions for the purposes of structural monitoring.Results shown in Moreover, the analysis found that the total number of patents worldwide (3035) is not particularly high and the 42 percent of world patents are held by 10 players.The development of 5G networks is of particular interest to the broad issue of mission critical services and emergency management systems. Traditionally, public safety communications services have been implemented through Personal Mobile Radio (PMR) systems. However, media transmission can be useful in many critical scenarios, but current PMR systems cannot support these types of services . TherefoWith particular focus on SHM, a challenging application is the utilization of the sensors not only for a monitoring purpose, but also for the early detection and notification of seismic events. This application, known as Earthquake Early Warning (EEW), has been studied and tested with the limitations of the dedicated communications systems described above . Howeverrisk region is defined as the area where the seismic wave arrives before the early warning, i.e., risk region by offering higher throughput and low latency and by leveraging the density of connected devices in contrast to legacy EEW systems with sensing stations placed at a distance of 10–30 km. It is worth mentioning that, due to the time required to collect the minimum data to detect the seismic event, there is a not compressible blind area, highlighted in dark grey in ., te<tw . The adoThe exploitation of a system able to support both SHM and EEW scenarios relies on the setup of monitoring sensor networks at a building level able to collect data that characterize the structural behavior of the buildings. The same data will be used to detect a severe seismic event in order to generate an EEW-message.An ad-hoc sensor board has been developed by authors in order to demonstrate the capabilities of such kind of systems designed as a high performance device for real-time SHM of buildings and infrastructures . It is bThe board is equipped with a 4-channel 24-bit ADC able of sampling at 100 Hz. However, on-board data processing capabilities allow for minimizing the total amount of data to be transmitted. It also provides the possibility to handle measurements coming from other kinds of sensors like tilt-meters and crack-meters. The integrated temperature sensor allows for evaluating the thermal effect on the structure and on the sensor, thus allowing for distinguishing thermally induced variations from real measurements.Data acquired from the sensors feed a data-driven model, based on System Identification from Control Theory and Machine Learning (ML) from Computer Science, . Using sAn enabling paradigm to meet performance and security requirements of SHM and EEW is represented by network slicing that is a tool for the implementation of vertical and transparent support of services with different requirements  in terms of throughput, latency, and reliability through a shared physical infrastructure.mobile segment, the transport segment and the core segment. The definition of the slices hosting respectively the SHM and EEW services involves the configuration of those three segments to adequately handle the traffic belonging to the slices. In particular, the mobile segment has to efficiently manage radio resources. While the monitoring traffic of SHM can be handled with a best effort approach, the EEW traffic is characterized by more stringent requirements.Referring to the architecture shown in Due to the uRLLC nature of the EEW slice, the mobile network can adopt a series of strategies to reduce the experienced latency of early warning messages such as: grant free transmission, slot duration reduction, semi persistent scheduling, and uRLLC-eMBB multiplexing. Transport segment has to forward the traffic pertaining to the slices through the radio access network segments , making use of the packet and optical network infrastructures.With respect to previous mobile communications technologies, 5G allows for offering specific reliability levels per service. This can be achieved by leveraging multi-connectivity, i.e., the possibility to connect to multiple radio access points, ad-hoc transmission strategies , and by Referring to the core segment, computation elements also referred to as Virtual Network Functions (VNFs) have to be orchestrated according to service metrics.The configuration of network and computing resources for different slices is performed through the use of SDN controller for the network configuration and MANagament and Orchestration (MANO) for the reservation of computing resources and the deployment of the VNFs.On this hand, MEC represents a useful tool to redirect the traffic belonging to a specific service towards the edge of the network and closer to the terminals by enabling different types of applications such as novel multimedia services , enhanceDifferently from the previous mobile generation 4G, 5G natively supports service deployment at the edge thanks to the introduction of the novel User Plane Function (UPF), which represents an anchor element between the mobile and data network. As shown in The considered scenario adopts the Message Queue Telemetry Transport (MQTT) protocol at the application layer, which is based on the publish/subscribe pattern. Based on this pattern, buildings act as publishers and send early warning messages or monitoring data to a so-called “broker”. The broker sends collected data to the subscribers, which are represented by the buildings interested by the critical event. A graphical representation of this process is given in The test-bed adopted for the 5G use case that took place in the city of L’Aquila, addressing the SHM and EEW scenario, implements the architecture shown in The edge cloud was located within the city of L’Aquila, and it was reachable by the gNodeB through the metro network. The remote cloud was located in proximity of the city of Rome , and it was reachable through the operator’s national backbone network.As shown in Tests have been conducted using a steel test frame, shown in A commercially available traffic generator was utilized to perform network latency measurements and characterize the delay introduced by the network infrastructure for the metro network connecting the base station to the edge cloud and operator’s national backbone utilized to reach the Remote Cloud. Measured network latencies at the metro network (in ms) follow a Gaussian distribution Sensors data were subsequently sent to the edge and remote cloud and delays were assessed. Publish messages were generated every 10 ms by the publisher, with MQTT QoS set to zero. An ad-hoc client software was developed to emulate the behaviour of the sensor board and measure latency at the application layer. To measure the latency at the application layer, a time-stamp-based mechanism was introduced in the exchange of messages between application components, and GPS was utilized to synchronize the machines involved in the measurements. Measured delays at the application layer approximately follow a Gaussian distribution with In terms of seismic waves and EEW messages propagation times, it could be difficult to evaluate the impact of the reduction of the elapsed time to propagate the information wave related to the EEW message because it depends on many aspects characterizing the seismic wave propagation such as geological conditions, constructions density, population density and many others. However, considering that the average speed of a superficial seismic wave is about 8 Km/s , the deThe geographical distribution of the buildings may involve multiple edge computing nodes. Redundancy of MEC infrastructures represents an open research challenge and different strategies can be implemented to reduce, for example, the need for coordination (and delay) among edge nodes, considering different metrics, e.g., cost, risk, bandwidth usage, etc., .Moreover, in terms of availability and reliability, the remote cloud scenario is exposed to severe service degradation or outages, related or not to the seismic event, due to its design principle  not compliant with PPDR services requirements. On the contrary, an MEC solution is able to bypass unpredictable drawbacks that would indeed introduce unacceptable latencies providing to network operators a viable way to increase PPDR Service Level Agreement (SLA) compliancy.Finally, an MEC approach allows an end-to-end control of the traffic of the EEW service and enables the network operator to apply traffic-specific policies to ensure guaranteed performance (in contrast with the remote cloud approach). As a lesson learned, critical applications with a public safety scope as the EEW also have to deal with multi-operator strategies to make elaboration at the edge available for users belonging to a multiplicity of operators.This contribution discussed the potential role of 5G for public safety applications, presenting a scenario allowing the implementation of both SHM and EEW solutions based on a common sensor device and a shared communication infrastructure.The concept of SHM is at first decreased in terms of definition and future directions and subsequently a market analysis is presented to demonstrate the market demand for buildings’ monitoring solutions. The scenario involving SHM for public safety is then presented and its challenges discussed. The latter issues are partially solved by a specific implementation of a sensor board allowing the variety of sensors and connectivity technologies that may be needed in this context. Then, novel architectural solutions able to respond to the discussed challenges are presented. Results demonstrate that public safety issues, especially when specified in terms of EEW, may gather significant advantages in terms of latency reduction and reliability, when novel technologies, such as 5G, MEC, and network slicing, are used.As a matter of future works, the potential of the presented scenario should be analysed by focusing on the opportunity offered by the sixth generation (6G), together with IoT and ML for implementing a truly smart city .


As automated driving technology continues to develop, studies are being conducted to develop various scenarios for assessing the functional safety, failure safety, and mobility of automated vehicles (AVs). As the commercialization of AVs progresses, it is necessary to develop a set of test scenarios for new car assessment programs (NCAPs), so as to provide information on the safety and reliability of AVs to consumers. To provide valuable information regarding newly emerged AVs to consumers who are willing to purchase them, it is necessary to derive specific and well-defined test scenarios based on the safety-in-use. Accordingly, to apply NCAPs to AVs, this study established test scenarios targeting freeways where AVs were expected to be commercialized. To this end, based on freeway traffic accident data and opinions of traffic safety and AV experts, we derived possible dangerous situations when an AV is maintaining a lane on a freeway. Functional scenarios were defined based on the derived dangerous situations. The priority of the defined functional scenarios was set using the analytic hierarchy process (AHP). Accordingly, this study presents a logical and concrete scenario construction methodology for deriving the ranges and values of test parameters for functional scenarios. As various organizations such as automobile original equipment manufacturers  and IT companies , universities, and start-ups accelerate the development of automated vehicle (AV) technology, AVs are getting closer to commercialization –3. As inHowever, as AV commercialization approaches, there is an increasing demand to provide safety assessment results for AV to consumers through the new car assessment programs (NCAP). An NCAP is a system for inducing rational purchases by delivering safety assessment results for automobiles to consumers. In an NCAP, tests such as head-on collision, side impact, and rollover are performed according to a protocol to evaluate the safety of a vehicle, and the results are scored and then disclosed to consumers. Studies related to the passive and active safety of automobiles must have high accuracy and reliability, as they are directly related to human life. Currently, NCAPs are evaluating advanced driver assistance system (ADAS)-related functions in autonomous driving technologies and are expected that will soon conduct safety assessments of AVs , 7. In tTherefore, this study aimed to derive a safety assessment scenario development methodology for testing AVs in the KNCAP, targeting Level 3 AVs as defined by SAE . To provIn this study, the spatial range for the AV test scenario development was set to maintaining the AV within the main lanes among the freeways in Korea, except for on ramps and tollgates. In this study, the freeway traffic accident data from general automobiles and expert opinions were considered together to develop the scenarios. The temporal range of the traffic accident data was from 2012 to 2014. The temporal range of traffic accident data was relatively old, as the Korean National Police Agency (KNPA) does not disclose recent traffic accident data. In addition, this study built the AV test scenarios based on the functional, logical, and concrete scenario concepts presented by the PEGASUS project , 10.Section 2 examines related trends and studies. Section 3 defines the need for AV tests, and describes the direction for the safety assessment. Section 4 details the development of the test scenario derivation methodology and scenario framework for testing AVs, and the development of test scenarios according to the framework. Section 5 presents the results from the test scenarios. Section 6 presents the conclusions and directions for future development.The PEGASUS project is a project for the establishment of generally accepted quality criteria, tools and methods, as well as scenarios and situations, for the release of highly automated driving functions. It is organized under the leadership of the German Federal Ministry for Economic Affairs and Energy , 10. In In 2016, the National Highway Traffic Safety Administration (under the U.S. Department of Transportation) presented guidelines for evaluating the design, development, and operation of AVs through the announcement of the “Federal Automated Vehicles Policy” . RecentlThe SAKURA project proposes an engineering framework for AV safety assessment scenario development in Japan . The proThe CETRAN (Excellent Center for Autonomous Vehicle Testing and Research) is a project to develop standards and behavioral capabilities to promote the application of autonomous vehicles in Singapore’s urban environment. Therefore, CETRAN develops a test methodology for adopting and introducing technologies related to autonomous vehicles. Regarding scenarios, a data-based approach is presented, focusing on qualitative explanations of scenarios, and scenario categories are classified by introducing appropriate tags . The sceThe Association for Standardization of Automation and Measuring Systems (ASAM) promotes the standardization of tool chains for use in vehicle development and testing . The ASAAmong WP.29, the "Working Party on Automated/Autonomous and Connected Vehicle" introduced a new assessment/test method (NATM) master document for evaluating automated driving systems (ADSs). The NATM builds scenario catalogs for situations requiring safety assessments, and validates them through simulation/virtual testing, track testing, real-world testing, audit/assessment, and in-service monitoring and reporting; this type of approach is called a "multi-pillar approach" . The NATYang et al.  proposedGelder et al.  proposedSo et al.  presenteTakács et al.  presenteErdogan et al.  indicateAs a result of reviewing the related studies, it can be seen that many studies have proposed diverse methods for creating scenarios related to the assessment and auditing of AVs, but it is difficult to find studies on developing test scenarios for applying NCAPs to AVs. As AV safety is a matter directly related to life, research is needed to develop NCAP evaluation scenarios for AVs to increase such safety. Therefore, unlike previous studies, this study intends to establish scenarios based on safety-in-use and examples of situations threatening AVs when driving, and to introduce a spatial scope into freeway and NCAP assessments.An NCAP evaluates the safety of vehicles sold in the market and aims to provide consumers with an easy-to-understand result , 32. As In the case of the KNCAP, it provides safety information by assessing the ADASs of Level 2 vehicles, and research on how to assess Level 3 AVs is currently in progress. In addition, if the NCAP for Level 2 vehicles is centered on functional safety, the evaluation of level 3 AVs needs to focus on comprehensive driving safety, take-overs, and minimum risk maneuvering. Therefore, it is considered that the biggest difference in assessments for Level 2 vehicles with ADAS and Level 3 AVs is in the test scenarios. Accordingly, to systematically and objectively evaluate AVs in the KNCAP, it is necessary to derive test scenarios, after establishing a test scenario development direction reflecting the domestic traffic conditions.In Korea, there are “Rules on the Performance and Standards of Automobiles and Auto-Parts,” called safety standards, and “Enforcement Rules for Performance and Standards of Automobiles and Auto-Parts," called enforcement regulations. The safety standards suggest the minimum levels of safety and performance required from automobiles . The enfNevertheless, in an NCAP, it is necessary to implement a more challenging assessment than those for the safety standards and enforcement regulations, so as to promote safety technology development, rather than minimum safety guarantees. In the case of enforcement regulations, it is generally simply evaluated whether the AV functionality works under normal driving conditions. Therefore, it is considered that the KNCAP should be differentiated from safety standards and enforcement regulations, e.g., by comprehensively assessing the defensive driving abilities of AVs in more realistic and challenging situations. In other words, it is considered necessary to develop NCAP test scenarios focusing on situations that drivers actually experience while driving on freeways, such as a situation that conflicts with that of another vehicle on the freeway, or a dangerous situation where the next action of the AV must be quickly decided. In addition, the actual situation needs to be considered in terms of the transportation facilities. For example, it is necessary to evaluate whether an AV drives well not only in a normal lane but also in a partially damaged lane.In this study, in order to develop the KNCAP AV test scenarios, the methodology of the most recent trends, PEGASUS project, SAKURA project, and CETRAN was benchmarked through literature review. Especially, the PEGASUS project’s functional, logical, concrete scenario development method, concepts and six-layer format were benchmarked, and data suitable for the Korean situation were collected and analyzed to develop scenarios suitable for Korea. A description of the benchmarked methodologies was written in the Literature Review part of Section 2. Section 4 deals with the development methodology of the newly derived scenario.This study presents an AV test scenario development methodology that can be used in the KNCAP. Based on the scenario definition method of the PEGASUS project and its six-layer format, an internationally operable and sustainable scenario development framework was established. The scenario development framework aimed to promote a systematic and objective assessment of freeway lane-keeping performance. As can be seen in To assess the safety of AVs, it is best to use AV traffic accident data. However, the existing AV traffic accident data suitable for domestic traffic conditions remains insufficient. Therefore, the KNPA’s traffic accident data for general automobiles were used. The KNPA’s traffic accident data comprised 58 pieces of information, including those concerning the time, place, accident type, vehicle model, and descriptions. A total of 10,364 cases of freeway traffic accidents were collected between 2012 and 2014. Among them, to extract only the spatial range set in this study, 8,225 traffic accidents were extracted by spatial calculation using QGIS 3.10, and traffic accidents that occurred on ramps and tollgates were excluded. Of the 8,225 traffic accident data, 6,951 traffic accident data were ultimately selected after excluding traffic accidents caused by drunk driving. Using data from the 6,951 traffic accidents, we derived the dangerous situations that AVs will experience on actual freeways in the future.In addition, information such as the design speed, lane width, and curvature was collected using freeway geometry data provided by the Korea Expressway Corporation (KEC). Information such as the lane size was collected using the rules on road structure and facility standards from the Ministry of Land, Infrastructure, and Transportation (MOLIT). The road lighting standard information was provided by the Korea Standards Association (KSA). For freeway environmental condition data, information on the domestic precipitation and fog was provided by the Korea Meteorological Administration (KMA). Finally, information concerning, e.g., accident locations, moving distances, vehicle speeds, and time-to-collision (TTC) was collected through an image analysis of dash-cam data owned by domestic insurance companies.The functional scenario is a stage for presenting conceptual explanations of roads, environments, and situations; hence, the description of the situation is key. In this study, the description of the situation was derived using the "descriptions" from among the freeway traffic accident data of the KNPA, and the opinions of experts in AVs and traffic safety. The descriptions followed a format such as "#1 vehicle did not notice that #2 vehicle had stopped, so #1 vehicle struck the rear of #2 vehicle with the front bumper of #1 vehicle." The description described the traffic accident process in detail, such as the cause of the accident, how the collision progressed, and which parts between vehicles collided. The accident process was described in the text; therefore, the text of the situation information was analyzed using a text mining technique. As a result of the text mining process, traffic accidents were classified into eight accident categories. Eight accident categories are traffic accidents while driving at high speed, while driving at low speed, traffic accidents owing to stationary object, owing to cut-in, owing to cut-out, traffic accidents caused by reverse vehicle, other traffic accidents, and not applicable traffic accidents. The frequency of occurrence was calculated according to the classified categories, and possible dangerous situations were derived through a detailed analysis. By listening to the opinions of experts in AVs and traffic safety, additional dangerous situations potentially occurring for AVs were identified. The derived dangerous situations were reviewed as functional scenarios for the NCAP.The constructed functional scenario proceeds to a logical scenario and concrete scenario, and the amount of information exponentially increases. It is practically impossible to evaluate all scenarios; therefore, it is necessary to construct representative scenarios through verification and priority derivation. To this end, experts in AVs and traffic safety were consulted to establish the priority of the functional scenarios based on an analytic hierarchy process (AHP). The priority-building procedure for the functional scenarios was as follows.The priority evaluation items for the AHP are derived, as shown in The priority evaluation items are standardized to a value between 0 and 1 according to the survey results of the experts and are used as weights.Experts indicate their survey scores on a 5-point Likert scale for each constructed functional scenario.The comprehensive scores are calculated by multiplying the score for each scenario by the calculated weight.The higher the total score finally derived, the higher the priority.In the logical scenario, it is essential to select the evaluation-related parameters based on the built functional scenarios, and to derive the range of each parameter value. In this study, the logical scenario was used to analyze the collected data and define the parameters and ranges potentially affecting the AV maneuvers in the situation, based on the six-layer format. The reason for using the six-layer format was that the parameters to be considered in a scenario could be easily organized according to the characteristics of each parameter.In the concrete scenario, it is essential to present the parameter values to be used in the test, so as to ensure the reproducibility of the experiment. Accordingly, a representative value of the parameter was selected within a range, such that the experimenter could easily adjust the difficulty according to the purpose of the experiment and achieve the purpose of the experimental situation.In the section 4, the methodology of how to develop scenarios in this study was derived by benchmarking the PEGASUS project’s concept. This chapter contains examples of the process of constructing an actual test scenario according to the derived methodology. In this study, unlike the existing PEGASUS project, there is a difference in that a safety-in-use scenario based on traffic accident data was derived along with expert opinions.The dangerous situations that AVs could face during lane keeping on a freeway were derived based on two types of data. The first used the descriptions from the KNPA freeway traffic accident data. The texts in the descriptions of the preprocessed 6,951 traffic accident data were classified and defined into eight categories, as shown in The second type of data reflected the opinions of freeway safety experts and AV experts. The freeway safety experts comprised the KEC employees who managed traffic at freeway sites, and researchers majoring in freeway safety management. The AV experts consisted of the Korea Automobile Testing & Research Institute (KATRI) researchers in charge of AV temporary driving permits and the NCAP, along with AV developers and AV testers. The expert opinions were used to derive dangerous situations, such as situations in which accident avoidance was expected to be difficult from an AV perspective, or threat situations in which it was difficult to avoid an accident even if a human driver was driving (as determined from an engineering perspective).After a detailed analysis of specific situations during freeway driving, the functional scenarios for the NCAP test were finally developed by comparing them with the current enforcement regulations. The developed functional scenarios are presented from Figs In Finally, the situation with the highest priority was determined; it was a situation in which the driving lane of the AV was not congested and a target vehicle suddenly cut in from the queue of a heavily congested adjacent lane, with a total score of 4.27.In this stage, the parameters and range of parameter values requiring consideration for all functional scenarios were selected. The corresponding parameters and values were necessary for the development of the logical and concrete scenarios. As for the range of parameters and values, the parameters and related data sources required for each layer defined in the PEGASUS project were investigated and analyzed, as shown in According to the analysis above, the representative scenario with the highest priority was a situation in which the driving lane of the AV was not congested, and a target vehicle suddenly cut in from the queue of a heavily congested adjacent lane. It is difficult to derive various concrete scenarios for all of the functional scenarios. In this study, logical and concrete scenarios were constructed for the previously selected functional scenario. For the development of the logical scenario, the ranges were only set for the parameters related to the scenario among the previously selected parameters. In addition, the value of a parameter for creating a concrete scenario was derived based on the value most frequently used on average. An example of a concrete scenario was presented earlier. In fact, for individual functional scenarios, many concrete scenarios can be created to describe various situations by changing the parameter values in the logical scenario within the corresponding range, or by changing the locations of the target vehicles or neighboring vehicles. The work of generating such a concrete scenario can be conducted according to a systematic procedure; alternatively, such a scenario can be created by setting values at random within the parameter ranges of the logical scenario. The latter case is thought to be frequently used in simulation-based tests using vehicle-in-the-loop or hardware-in-the-loop simulations. In this case, it is necessary to select valid values by considering the relationships between parameters to perform a meaningful experiment. A scenario in which the range of effective values is reduced after considering the relationships with other parameters is called a test case. The process of creating a concrete scenario in this way may vary depending on the experimental method, such as whether it is based on a proving ground, real road, or simulation.With the introduction of AV approaches, there is a need to provide information on the safety of AVs to people who want to purchase AVs. Vehicle safety information is currently provided through NCAPs. An NCAP encourages car manufacturers to develop safety technologies and, through evaluation results, contributes to helping consumers choose a safer car when purchasing a car. However, as the KNCAP currently only provides safety information for general vehicles equipped with ADASs, it will be necessary to provide safety information for AVs in the near future.In this study, a methodology was established for deriving NCAP test scenarios for providing AV safety information. Prior to establishing the methodology, the necessity and direction of the AV NCAP test were established. In Korea, safety standards and enforcement regulations related to maintaining lanes on freeways have been developed for Level 3 AVs. Accordingly, it was determined that a more challenging assessment should be conducted to differentiate from the NCAP test. Therefore, the AV test scenario of this study was derived based on an assessment of situations in which the AV responds when another vehicle is driving. The NCAP evaluation scenario referred to the format of the PEGASUS project to establish an internationally compatible and sustainable assessment methodology. A sustainable assessment methodology was constructed by gradually specifying the scenario, and the variables necessary for the experiment were divided into six layers to secure systematization. In this study, the detailed situations of general automobile accident data were classified into eight categories. By reflecting the detailed classifications of accident data and opinions of experts, it was possible to derive the dangerous situations for AVs, and to build a functional scenario. After deriving a functional scenario, it was considered that the evaluation scenario construction is sustainable, based on verification using the AHP and the derived priorities. In addition, it was determined that the variables of the logical and concrete scenarios could be used continuously, e.g., through continuous updates.S1 File(ZIP)Click here for additional data file.


This Research Topic comprises papers related to rare bone diseases, osteoporosis and osteoarthritis, illustrating the wide spectrum covered by the Bone Research section of Frontiers in Endocrinology.Laurent et al. present consensus recommendations for the diagnosis and Management of X-linked hypophosphatemia (XLH) in Belgium. In this disease, PHEX mutations determined the increase of the levels of the hormone fibroblast growth factor 23 (FGF23), with consequent renal phosphate wasting, altered skeletal and dental mineralization. Though evidence-based guidelines in this area have previously been published, there is a need to translate the principles on which these are based to more practical recommendations at a national level, in this instance a relatively well funded mixed state and private healthcare system. The broad but nevertheless detailed and practical overview of the clinical aspects of diagnosis and management of XLH presented in this article provides useful guidance for management of these patients. Guidance on the use of burosumab in children with XLH is particularly timely, given the recent EMA market authorization of this new FGF23 antibody treatment, which has the potential to transform the lives of those living with this condition.Starup-Linde et al. examined the role of osteoglycin in the altered bone turnover associated to type 1 and type 2 diabetes , based on studies in mice suggesting that osteoglycin exerts endocrine effects on bone and pancreas. Osteoglycin is a proteoglycan derived from bone, cartilage and myocytes; it enhances bone formation and mineralization. The authors did not find significant differences for osteoglycin levels between T1D and T2D patients, but interestingly they showed that osteoglycin levels in diabetic patients were unrelated to metabolic markers of diabetes and bone turnover markers, arguing against such a role. A related study by Cherian et al. examined whether two adipomyokines, irisin and Meteorin-like (METRNL), play a role in altered bone remodeling in individuals with obesity and T2D. Irisin and Meteorin-like (METRNL) contribute to increased thermogenesis following exercise and cold exposure, and affect bone cell activity. Levels of irisin and METRNL were found to be related to several molecules with osteogenic properties, suggesting that adipomyokines might affect the development of bone and muscle complications associated with obesity and T2D.Two articles report findings from clinical studies aiming to examine the basis for increased fracture risk in diabetes, by studying mechanisms contributing to cross talk between bone and energy metabolism. Samvelyan et al. used a murine model to examine the pathogenesis of osteoarthritis. Specifically, the authors examined whether altered growth plate dynamics contribute to the development of osteoarthritis in the destabilisation of medial meniscus (DMM) model, as well as in a non-surgical loading model. In both models, development of osteoarthritis was associated with switching of articular chondrocytes to a hypertrophic chondrocyte phenotype, associated with morphological changes including growth plate bridging. Consistently, the authors demonstrated the increased expression of hypertrophy markers Col10a1 and MMP13 in the growth plate of osteoarthritis models. Additionally, epiphyseal trabecular bone abnormalities were associated to morphological changes of the growth plate. Thus, these results further support the role that the altered growth plate with the consequent bone disease may play in the development of osteoarthritis.The study by Taken together, these four papers exemplify the range of insights in the bone field in 2021.All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Descriptive, bivariate analyses, and multivariate linear regression were performed. Focus groups (FGs) delved into aspects of relevance regarding QOL and determinants, through qualitative content analysis and triangulation of information. The median score in the four WHOQOL-BREF dimensions surpasses 50 points, with the highest score being in the psychological dimension (62.5 ± 16.7). According to the multivariate linear regression models, the variables significantly associated with QOL scores were playing sports, being married/living together, normal BMI, low social support, and medium/low socioeconomic status. The qualitative results explained the determinants of QOL in the personal, academic, and social dimensions of the participants. The discourses showed that the postgraduate course represents a resignification of their life, where their QOL is affected by the difficulties of their academic development, by the difficulty of reconciling the personal academic load with their affective, work, and social life, and by the stress they experience in their staff process. In conclusion, the participants’ QOL was moderate and affected by different factors. The findings highlighted the importance of mental health promotion and well-being strategies in students of orthodontic postgraduate training programs in Colombia for improving QOL.This study analyzed the academic, sociodemographic, and labor conditions related to the quality of life (QOL) of orthodontics postgraduate students in Colombia. A mixed study  was conducted. An online cross-sectional survey ( Quality of life (QOL) as an individual and societal concept is not a new concept . DiffereHealth personnel could be exposed to personal, social, and labor situations that impact their QOL ,5,6. In Postgraduate students in clinical dental areas are presented with high demands and academic loads, and the QOL could be affected by personal and social situations and thus impact their physical and mental health status. A simple literature search on PubMed about the topic can reveal that there are some factors to study in this population. For instance, in dental students, the presence of anxiety and sleep disorders are considered as factors related to the QOL . SimilarThe study of complex phenomena through modern methodologies that capture social reality from different perspectives is an important challenge for dentistry. In this sense, both qualitative research  and mixeAccordingly, this study aims to analyze the academic, sociodemographic, and labor conditions related to the QOL of orthodontic postgraduate students in Colombia.A sequential explanatory design (mixed-methods study) was conducted . This meAn online survey was applied for orthodontic students in Colombia. No-probabilistic sampling methods were carried out, and participants who freely and voluntarily answered the survey were included. For that purpose, diverse strategies were applied such as emails provided by universities, use of social networks (Facebook and WhatsApp) and using snowballing sampling methods through referrals and forwarding of the questionnaire to other students. The final sample was 84 . The questionnaire was self-administered by using the Google Forms tool (available upon request). All surveys were anonymous and confidential. A pilot study was conducted with a sample of 10 dentists to improve interpretability and evaluate the completion time and internal consistency.The primary outcome was quality of life (QOL), as measured by the WHOQOL-BREF . This isCronbach alpha coefficients were calculated using the WHOQOL-BREF, GHQ-12 and Duke-UNC-11 instruments of the sample to assess their reliability. The following values were obtained: (1) WHOQOL-BREF: 0.717; (2) GHQ-12: 0.855; and (3) Duke-UNC-11: 0.916 . ® was used to carry out all of the analyses.All variables underwent descriptive analysis. The normality distribution of the quantitative variables was evaluated (Kolmogorov–Smirnov test). Bivariate analysis has been performed for QOL domain scores with explanatory variables according to their nature . A linear multivariate regression analysis was carried out in order to evaluate the association of the explanatory variables on each of the dimensions of WHOQOL-BREF and to identify possible predictors of their scores. Belonging was determined by evaluating the compliance with the assumptions of linearity, non-collinearity and normality, constant variance, and correlation of residuals. All of the analyses used a level of statistical significance of <0.05. SPSS software version 22.0-IBMA qualitative approach (under the focused ethnographic perspective) was conducted using three focus groups (FGs) and 17 orthodontics students that previously completed the survey participated (selected for convenience). The research team produced a guide for use in the FGs that indicated a series of topics related to the QOL and its determinants. Similarly, some relevant quantitative findings are deepened through the opinion of participants, and the information that was confusing or contradictory was expanded. The FGs were conducted by one member of the research team (A.A.A-S.), who is a Ph.D. in public health and has expertise in qualitative methods. The FGs lasted between 60 and 90 min and were digitally recorded and transcribed verbatim. Concerning the situation of the COVID-19 pandemic, and to obtain the participation of periodontists from various parts of Colombia, remote means (Microsoft Teams) were used.Analysis of the narrative content led to the identification of important text elements and information trends found in the participants’ speeches. Analyses of the data were conducted by all authors and were reviewed and compared. Atlas.Ti 8.0 software was used for analyzing the transcribed data. The text fragments were tagged under 126 codes and then grouped into 3 categories.The integration of the two sub-studies were integrated using triangulation ,23. Two Individuals gave their consent, which was explained on the first page of the survey and was read and approved for the FGs. Confidentiality was ensured throughout the research process, in compliance with standard regulations. The study protocol was approved by the Bioethics Research Committee of the Faculty of Dentistry of the University of Antioquia .Regarding QOL according to the WHOQOL-BREF instrument, the median score in the four dimensions surpasses 50 points, with the highest score being in the psychological dimension (62.5 ± 16.7). Finally, regarding health and social support indicators, only a third indicated that they practice sports, a quarter reported overweight/obesity, a third perceived their general health as poor, a little more than half referred to their mental health as poor, and a little more than 10% perceived low social support .A multivariate analysis by linear regression showcased the potential factors explaining QOL that were significantly associated. For the physical dimension, social support is negatively related to QOL . In the psychological dimension, playing sports, marital status (being married), and having a normal body mass index were positively associated (increase QOL scores), whereas social support was negatively associated. As for the social relationships dimension, playing sports was positively associated, while living alone was negatively associated. Finally, on analyzing the environmental dimension, it was found that playing sports and marital status (being married) were positively associated with QOL, while having low social support, a medium or low socioeconomic stratum, and living alone were negatively associated .The analysis of the focus groups (FGs) deepened the aspects observed in the quantitative results. From the participants’ perspectives, it was possible to establish two main categories, which are discussed below:“So those specific life conditions and those specific commitments from the, let’s say, personal point of view are the most important factor that makes the difference between the quality-of-life perception of different residents, considering that we all have something in common at this moment, which is the residency or the postgraduate degree, but there are certain things in each one’s life that can create those differences in regard to the perception of quality”.(FG 3)Quality of life denotes a multidimensional and dynamic concept. The participants’ discourses made it possible to establish in common 20 keywords that define QOL  as well “I want to say something that has to do with the academic part obviously and it’s the patients, because I don’t know if in your universities it is like this, but in mine we have to get the patients, so you have to constantly be after people, looking for someone to be your patient and in the university, supposedly people goes there, but that’s a lie, no one goes there and it doesn’t matter to them if you got them, if you paid to them, if you didn’t, but is very difficult”.(FG 2)From the participants’ experience, the postgraduate course in orthodontics is a personal, academic, and professional project, as shown in However, despite the difficulties, the participants considered that an adaptation process can be carried out in which support networks play an important role and that studying for a postgraduate degree is an opportunity for personal and professional growth and improvement, helping them advance one step further in their professional training in comparison to general dentists .The participants reported QOL scores in different dimensions that range between 50 points for the physical dimension and 63 points for the psychological dimension. However, the bivariate and multivariate analyses show that the QOL is associated with different academic, sociodemographic, occupational, and health factors that exert a positive or negative influence. Although the QOL is perceived as moderate, the participants’ discourses in the FGs showed that the postgraduate course is a personal and academic project where a deterioration of mental health and QOL is evidenced, where subjective and those related to the educational context intervene, and other factors such as difficulties in reconciling family and social life with a higher academic and scientific workload also impacted on the decreasing of QOL. This situation makes the postgraduate experience, on the one hand, rewarding for achieving a step in their professional life, but on the other hand, a process of constant change and adaptation that causes frustration in certain specific aspects.The scores given in the different domains in the QOL by orthodontic postgraduate students show a close relationship with their particular experiences and the groups in which they are inserted and have social cohesion. Thus, when these results were compared with other contexts, certain differences are made evident. For example, the QOL scores in our study were much lower when compared to a study conducted with orthodontists who had already graduated from the city of Medellin (Colombia) . The samThe QOL from the perception in the speeches of the participants is defined as multifactorial and multi-dimensional. Studying orthodontics becomes an academic and personal process where specific factors come together that affect QOL positively or negatively. For instance, a qualitative study conducted in Germany  found thSocial support networks  are essential QOL predictors in the study population. In multivariate models, the perception of low social support and living alone are associated with lower QOL scores, while being married/cohabitated is associated with higher QOL scores. This situation was corroborated by the qualitative findings in the FGs, where the participants’ discourses highlighted the support of friends and family as satisfying elements of QOL. In this regard, a study conducted on Chilean university students shows how social support plays a protective role for symptoms related to stress and anxiety , and a sQuantitative analyzes carried out in the students’ sample and the discourses provided in the FGs show a close relationship between the QOL and health indicators. In fact, one third of the participants reported poor self-perceived health, more than half reported poor mental health, and the majority reported the postgraduate studies as stressful . Multivariate models show a normal BMI and practicing sports as positive predictors for QOL. A Chinese study conducted on medical and dental students found that physical fitness and lifestyle are significant contributors to academic performance . HoweverQualitative findings show that QOL could be affected by the COVID-19 pandemic. Specifically, in the academic field, an adaptation process was presented in the teaching–learning forms and the patient care protocols in this training process. This is an emerging fact since the survey did not contemplate specific variables that measured the impact of the pandemic, and this was not a specific objective of the study. In this regard, research conducted with dental students in Turkey shows how online teaching mechanisms taught during the pandemic impacted increased stress, anxiety, and the presence of factors that negatively affected the QOL . In a crIn the interpretation of the findings, is important to highlight the importance of discussing the main strengths and limitations of this study. We recognize that, to the best of our knowledge, this is the first study focused on a particular group of orthodontic students in Colombia. The mixed methods approach allowed us to understand the factors affecting the QOL in the target population, transcending the classic biomedical point of view of seeing health–disease processes and allowing the social construction of the research problem. In addition, the data collection instruments were carefully planned and have internal validity processes, both by a pilot test and by the consistency and validation of the QOL questionnaire, as well as with the reliability and rigor in the FGs used. Nevertheless, the nature of the study design does not allow for the establishment of causal relationships, but rather associations between variables in the cross-sectional sub-study and understanding of relationships between categories of analysis in the qualitative sub-study. This type of non-probabilistic sample does not permit the results to be inferred from the general population of orthodontic students. Lastly, it seems important to mention that the findings could be affected by the time of the survey and the semiannual/annual calendar of academic activities in the different institutions where the students are enrolled.Accepting the above limitations, this study is constituted as an input to know the social, health, and QOL aspects in specific scenarios. Complementary studies are required in Colombia, which, through more representative samples and involving other questionnaires and social, physical, and mental health indicators, allow us to understand the reality experienced by students of clinical specialties in dentistry. Further research should delve into aspects related to the curricula in the training of students of clinical specialties in dentistry from the perspective of other authors .From the perspective of the students participating in the study, QOL is perceived as moderate and is conditioned by sociodemographic factors, academic aspects during their training, and their physical and mental health situations. The predictor variables for QOL were social support, socioeconomic status, marital status, type of family, BMI, and sport practice. The postgraduate course is an academic and personal project that highlights particular and general situations and that has a role in the deterioration of the QOL, but, in turn, will allow them, in the long term, to improve their economic conditions, which will have an impact on a better QOL in the near future. Some satisfiers were found that deserve to be considered to generate strategies that contribute to the general well-being of these students from holistic and integral approaches.


Religious mass gatherings, especially pilgrimages of various faiths, involve overcrowding and the international movement of people, exposing individuals to significant health risks, such as the spread of infectious diseases, crowds, exposure to bad weather, physical stress, or risks due to pre-existing medical conditions. This paper aims to review the literature related to health care research on religious mass gatherings, with special reference to the role of awareness creation, training, and risk awareness for individuals during Hajj. The results indicated that the research on health risks associated with large-scale gatherings showed that some countries (which witness religious gatherings) follow effective preventive measures to reduce health risks, while some countries did not . It also showed that most studies overlooked identifying the causes of infectious diseases and determining the perceptions of participants in mass gatherings. While it showed that environmental factors strongly influence the emergence of infectious diseases among individuals, the results also showed the scarcity of research that revolves around the awareness of community members, the health risks of mass gatherings, preventive measures against diseases, and the main effects on individuals’ perceptions of risks. The results also showed a lack of research evidence on how pilgrims perceive risks, adopt information, and interact with their willingness to be trained in preventive measures. Healthcare is one of the essential elements to consider in planning for mass gatherings. Even in events in which everything is managed smoothly, it has been noted that approximately 1.5% of people will require medical assistance, associated both with different kind of ‘physical stress’ or ‘pre-existing’ medical conditions . CrowdedWhile the concept of mass gathering medicine is not new, it has especially become a topic of discussion in recent years. According to Alrabeeah et al. , mass gaDisaster risk in mass gathering events is typically from hazards interacting with existing individual vulnerabilities, and much of the current research is concentrated on the transmission of travel-related infectious diseases . MoreoveAs the current literature continues to expand and its relevance increases, there is a strong need to define the existing gaps in research and the areas in need of strengthening to improve practices associated with the implementation of the SFDRR. There is a need to focus on the physical dynamics at mass gatherings and how they influence the spreading of contagious illnesses. Additionally, the role played by awareness, training, and risk perception in the spreading of these illnesses also needs to be defined.This review focuses on a specific category of mass gatherings that are particularly extensive for their participation and are concentrated on specific geographical locations: religious events. Most people around the world profess religions, according to a report issued by the Pew Research Center, in 2012. It showed that the global religious scene contains more than 5.8 billion people professing religions. The religious diversity is panoramic, and includes three main religious sects: Christianity, Islam, and Hinduism. The Pew study found that there are 2.2 billion Christians around the world (32% of the world’s population), 1.6 billion Muslims (23% of the world’s population), 1.0 billion Hindus (15% of the world’s population), half a billion Buddhists, and 14 million Jews who follow Judaism .Studies related to religion show that the Muslim population is the fastest growing in the world with an expected rate of 35% in the next 20 years. The global Muslim population is expected to reach 2.2 billion by 2030, more than double the rate of the non-Muslim population. In 2019 alone, the Hajj attracted over 2.5 million pilgrims, while the Kumbh Mela was attended by approximately 150 million people . In addiThe next sections develop a “traditional or narrative literature review” that is designed to be replicable in the future . The firAs a second step, the abstract sections of the sources identified were analyzed to reveal other relevant keywords that could be associated with the same content. Several new keywords were also identified including “infectious disease risk” and “non-infectious disease risks.” Again, a further and more focused analysis was concentrated adding the name of the case studies to each of the keywords. A clear focus of the literature was concentrated on the three largest religious gatherings, the Hajj, the Kumbh Mela, and the Arba’een pilgrimage, that are reported in the sections below. The final step in conducting the review involved a cross-check of the bibliography in the papers included to identify possible recurrent citations. What emerged was a concentration of the literature on the Hajj event, which will be discussed in more detail. This can be explained by more information being provided by Saudi authorities and the yearly recurrence of the event.Hajj is a yearly event that attracts approximately three million Muslims from all over the world, and it represents more than just a physical journey. The annual mass gathering is one of the five pillars under Islam . The priThe Hajj is unfortunately faced by several high-profile risks. This stems from the fact that this mass gathering has several unique characteristics that creates a conducive environment for health risks. The first of these characteristics is the size of the pilgrim crowds. In fact, elevated population densities of up to nine people per square meter have previously been recorded during the mass gathering . Such coThe sheer size of the crowds at Hajj greatly stretches the limited public health resources available during the Hajj. It is important to note that the Saudi government avails a lot of public health resources for the mass gathering . In addiAnother factor that increases the degree of health risk during the Hajj is the climate of Mecca. Saudi Arabia is well known to be a desert nation. As such, it is not surprising that Mecca, one of the country’s interior cities, largely has a semi-arid climate. Even during the winter, temperature levels rarely go significantly low, while in the summer they can hit highs of up to 45 °C . As suchLastly, the diversity of the pilgrim population during the Hajj also increases the level of health risk during the mass gathering. Hajj pilgrims are drawn from all over the world. While this is a fact to be celebrated from a religious standpoint, it creates several complexities from the public health standpoint. Understandably, these pilgrims have widely unique and diverse medical backgrounds. Some originate from regions where certain disease strains are not found in other parts of the world . AdditioUnfortunately, infectious-related health risks are quite common during the Hajj. The spread and dissemination of infectious diseases is highly reliant on close contact and interaction . Owing tUndoubtedly, the most common infectious diseases during the Hajj are respiratory infections, particularly upper respiratory tract infections. For example, it is reported that up to a third of all pilgrims that embark on the Hajj experience respiratory symptoms associated with the influenza virus . This haThe ease with which upper respiratory tract infections spread during the Hajj has led to the fear that viral pandemic could occur at the mass gathering. In fact, in the last few years, Saudi public health authorities have been forced to implement strict infectious control measures in response to COVID-19, SARS, H1N1, and the MERS Coronavirus .Lower respiratory tract infections, while not as prevalent as upper respiratory tract infections, account for a significant portion of hospital admissions during the Hajj. In fact, as highlighted earlier, pneumonia has been the leading cause of pilgrim hospital admission during several Hajj editions. In 2003, for example, approximately 39% of the pilgrims admitted during the mass gathering were suffering from pneumonia . AdditioInfectious gastrointestinal diseases are often also reported during the Hajj. Fortunately, however, these infections do not have particularly high mortality and morbidity rates. Many of the pilgrims that embark on the Hajj in fact experience traveler’s diarrhea . The occUnfortunately, meningococcal disease has also historically also been an infectious health concern during the Hajj. The infectious nature of this disease is typically at an elevated level during the Hajj owing to overcrowding, elevated carrier rates, and high humidity . As a reSome of the rituals associated with the Hajj can expose pilgrims to the risk of contracting infectious blood-borne disease. At the end of every Hajj cycle, male pilgrims will typically shave their heads to signify a successfully completed pilgrimage . UnfortuMore recently, public health officials in and out of Saudi Arabia have become aware of the potential risk for the global spread of antibiotic resistant bacteria through mass gatherings such as the Hajj. Antimicrobial resistance develops when microbial organisms, such as bacteria, survive exposure to an antimicrobial drug, such as an antibiotic, by changing . While gWhile infectious diseases are by far the most prevalent health risks during the Hajj, they unfortunately are not the only ones. Non-infectious-related health risks occur far less frequently but account for a significantly greater proportion of the mortality during the annual pilgrimage . Sadly, Since 2019, after the outbreak of COVID-19 around the world, the Kingdom of Saudi Arabia has taken strict measures to curb the spread of COVID-19 within the Kingdom. In 2020, the Kingdom cancelled many religious gatherings, halting Umrah ceremonies in early March, halted all international flights, and restricting internal movement . In 2020Cognizant of the various health risks that exists at the Hajj, every year the Saudi Ministry of Health publishes an updated list of preventative health guidelines and recommendations that pilgrims are expected to adhere to. The most recently published update was in readiness for the 1439H (2018) Hajj season. Among the diseases of special importance highlighted in the update was yellow fever. The ministry instructed that all pilgrims from yellow fever-endemic countries in Africa and the Americas should show a valid yellow fever vaccination certificate [Further, with regards to seasonal influenza, the ministry did not require all pilgrims to get vaccinated, but rather recommended that they did. It especially advised that persons with compromised immunities, coupled with young children, pregnant women, and the elderly, receive the vaccine. Lastly, pilgrims from countries affected by the Zika virus disease or dengue fever were required to show certification that they have completed disinfection measures . A majorLastly, the Ministry of Health encourages that pilgrims be in good physical condition and actively seek out health education. As stated on numerous occasions, the Hajj can be a very tiring journey, especially considering the hot climate in Mecca. As such, the ministry encourages fellow governments to only grant those pilgrims in the best physical condition to complete the pilgrimage the permission to embark on Hajj . Those wIn addition to these preventative measures provided by the Saudi Ministry of Health, several international organizations and governments also provide recommendations for pilgrims. For example, the Centre for Disease Control and Prevention (CDC), publishes a detailed overview of the Hajj pilgrimage on its website, including the various health issues that exist, to prepare American pilgrims . EquallyThe socio-medical model of interaction shows that pilgrim behavior also plays a major role in the mitigation of health risks at the Hajj . A signiArguably the greatest success experienced concerning adherence to recommended preventative health measures has been with the uptake of the meningococcal disease vaccine. According to Memish et al. , the comKumbh Mela is a mass gathering held in India. As with the Hajj, the Kumbh Mela is a religious mass gathering. However, it is based on Hindu mythology as opposed to Islam . Its mytThere are several factors in the Kumbh Mela that make the mass gathering susceptible to health risks. Arguably the greatest vulnerability is the large number of participants. At approximately 100 million participants, the Kumbh Mela is approximately 30 times larger than the Hajj . AdditioAfter 2019, and after COVID-19 entered India in early 2020, the virus spread across India like wildfire, due to India’s overpopulation, disparity in education level, and low income. Large numbers of infections were recorded, despite the increasing efforts to follow measures to protect against the virus, such as maintaining social distancing, wearing masks, and using hand sanitizers .Cholera is the most prevalent infectious disease risk at the Kumbh Mela. During this mass gathering event, millions repeatedly and concurrently take holy baths in the river. Some of the participants also relieve themselves in the water, while others drink the same river waters. As such, should the water be contaminated, millions can easily become infected. A high number of bathers, coupled with hot weather, facilitates the growth of vibrio cholerae . AdditioOther infectious disease that are spread through contaminated water are also prevalent at the Kumbh Mela. While deadly cholera outbreaks were common before the mid-20th century, no outbreaks have been reported since . HoweverWhile infectious respiratory diseases are not linked with significant mortality at the Kumbh Mela, they are still very prevalent. Overcrowding, stress, and exhaustion, facilitate the spread of upper respiratory tract infections such as influenza. Additionally, the use of wood fuel and cow dung to create fires has caused many to seek treatment for persistent coughs. In fact, approximately 23% of the 15,000 patients treated during the event received treatment for cough-related respiratory infections during the 2013 Kumbh Mela edition . FurtherFurther, some of the rituals undertaken at the Kumbh Mela expose some visitors to blood-borne diseases. Some visitors undergo initiation to become sadhus (monks) at the mass gathering. While many of the rituals involved in this initiation are not shown openly, the initiates are required to shave their heads . Given tAs with the Hajj, the Kumbh Mela is also faced by a significant risk of human stampedes. While this mass gathering does not occur within a fixed structural boundary, the movement of pilgrim is mainly limited to the banks of rivers . As suchRegarding the COVID-19 pandemic, the Indian government followed several measures to contain the spread of the virus; a nationwide lockdown was imposed at the beginning of 2020. India succeeded in reducing the number of cases at that time but depending on the economic and social conditions in India, the lockdown was gradually eased, which pushed the number of injuries rapidly upwards in the middle of 2020. Consequently, religious gatherings such as the Kumbh Mela are creating a major public health risk with a catastrophic increase in COVID-19 cases. Consequently, different dates for bathing/toothing were announced and the upper body of the grooves showed some willingness to hold the Kumbh Mela in a restricted manner. It was recommended that the number of participants in the Kumbh Mela be restricted in 2021 .In recent years, due to the strong commitment of the public health authorities in India, the Kumbh Hela has not had a significant accident . There hThe current literature shows very little research into the adherence preventative health measures by governmental authorities. That said, some studies have shown that despite government insistence against it, many pilgrims continue to drink water from the rivers as they consider it is holy . AdditioThe annual Arba’een pilgrimage is held every year in Karbala, Iraq, and challenges the Hajj in size . The masThese challenges at the annual mass gathering event are partially caused by the defects of the health infrastructure in Iraq. Years of war have left large sections of the country destroyed, including many that touch on the healthcare system . AdditioDespite the unavailability of significant research evidence, the Arba’een pilgrimage is believed to have infectious disease risks. According to Karampourian et al. , this laResearch has also shown the level of risk perception among Arba’een pilgrimage to be worryingly low. Many of those who embark on the pilgrimage do not have sufficient knowledge on public and private health. As a result, many continue to engage in risky health behaviors such as unhygienic beliefs and the refusal to take medication . This loReligious gatherings for Christian groups include World Youth Day, which is held every two or three years in the Catholic Church, and nearly a quarter of a million Catholic youths in different cities attend an event hosted by the Pope. For example, the closing mass for World Youth Day in 1995 attracted 5 million participants in the Philippines. In 2015, 6 million people also gathered for World Youth Day in the Philippines, led by Pope Francis .The Christian pilgrimage in France, the most famous, attracts more than 5 million in the city of Lourdes, and it is a year-round event. Lourdes, a small city in the southern Pyrenees, is the second most visited French city after Paris. It is the third most important pilgrimage site in the world of Catholics after the Holy Land and Rome . BecauseNow, with the occurrence of the COVID-19 pandemic, most countries have gone on to impose closures and bans for certain periods between 2019 until now, to limit the spread of the virus. It also limited the number of people in religious gatherings with the imposition of social distancing and the use of protection methods such as wearing masks and gloves and frequent sterilization. In St. Peter’s Basilica (Vatican), Pope Francis’ Easter Sunday mass was held in April 2020 without the audience and broadcast live on TV . Additionally, Protestant churches around the world held Easter through live broadcasts without church attendance. Most places of worship in the world have suspended physical worship and regular prayers and replaced their services to internet broadcasting .This review showed that public health risks during religious and mass gatherings have been investigated extensively, as to the pre-travel requirements, but there are still some evident gaps in these studies. It can be noted much of the current research has focused on the Hajj and some insights from other mass gatherings have been overlooked, as well as other causes that affect infectious diseases in mass groups. This may be due to the fact that Hajj is an annual routine that happens every once in a while, and because most of the world’s population embrace religions, and finally because Hajj is linked to a specific place to perform it and therefore includes travel and climate and environmental change, which may cause diseases, or mutations of viruses due to mixing people from different parts of the world.One of the main causes is the strong evidence of climate change studies, which are showing disease emergence from land and climate change that are affecting mass groups with emerging diseases. Emergence or resurgence of numerous infectious diseases are strongly influenced by environmental factors such as climate or land use change . As the Half of the population live in large cities, with 8.9 million people in London, U.K. In the 9th largest section of London is Notting Hill Carnival, in central London, with one million people gathering in just two days, in an area that already has over 750,000 thousand people living there . This tyA common gap in all the case studies analyzed is the limited evidence associated with risk. Indeed, the literature on disaster reduction suggests considering this element as a critical component to address vulnerabilities in emergency planning . In otheEven in the Hajj, much of the research has concentrated on the causes and consequences of infectious disease risks. Much less, evidence has not been commensurate in looking into how pilgrims perceive health risks at mass gatherings and specifically the Hajj. Johansson et al. have stated the concern is a macroscopic (crowd) level, rather than an individual level, or a microscopic level . In otheThis is common with the analyses developed on the Kumbh Mela, where numerous inferences have been made about the behaviors of pilgrims without a commensurate look into how they perceive health risks . As highThese gaps suggest focusing on the current state of art on the hazard, exposure, and physical vulnerability components of disaster risk. Instead, it is missing the understanding of vulnerability as a process where environmental, social, and economic factors interact dynamically . In our While there are numerous models that attempt to explain the differential use of preventive behavior, one of the most consistently and widely used is the health belief model (HBM) . This moSeveral psychological outcomes are associated with mass gatherings, which include empowerment, mood improvement, and self-esteem . In turnIn conclusion, The literature on crowd medicine has developed in recent years, analyzing various approaches to mitigating health risks. However, current research has largely focused on the epidemiological and physical conditions that influence these health risks, such as the risks of infectious diseases. This state-of-the-art review highlighted the health risks of religious congregations. Due to the importance of religion, and the presence of large numbers of people belonging to different religious sects, mass religious gatherings are frequent in the Christian, Islamic, Hindu, and other worlds. These gatherings include the international movement of pilgrims, which has proven the danger of the globalization of infectious diseases, especially COVID-19, in addition to the introduction of viruses, and drug-resistant bacteria.However, there is insufficient evidence on how pilgrims perceive risks, the factors that influence the dissemination of information, and how these elements affect preparedness and training. However, most countries that witness religious gatherings , impose strategies to limit the spread of diseases and injuries, and use monitoring and regulatory protocols, to make these gatherings safer. During the years 2020 and 2021, with the outbreak of COVID-19, most countries of the world imposed strict measures to limit the spread of the virus, including mass religious gatherings.These measures ranged from stopping the gathering and replacing it with methods of broadcasting via the Internet and television, or restricting the number of people in the gathering with the application of social distancing and the use of masks and hand sterilization. Despite the recommendations contained in documents such as the SFDRR, countries in the third world still do not provide a satisfactory level in managing religious gatherings and mitigating their health risks. Thus, the social and environmental drivers associated with health risks are not well understood in their effects on vulnerability mitigation and risk reduction in general. In other words, future research will benefit by optimizing the context in the current framework for disaster reduction, to address potential drivers and root causes. Finally, we hope that mass gathering regulators in general will use new methods for disease control and prevention, using new digital technologies to detect risks.


Leiomyomas are benign tumors that originate on the smooth muscle, usually found in the uterus, gastrointestinal tract and skin. This type of tumor rarely occurs in the oral cavity, specially because of the lack of smooth muscle in this areaOur goal with this paper is to report on a case of a patient with a painful tongue leiomyoma.A 34 year old man, with the Acquired Immunedeficiency Syndrome (AIDS), visited the physician, complaining of a spontaneous stinging pain in the oral cavity for 2 years. During exam we saw a reddish mass, of regular contours, measuring about one centimeter in diameter, located on the tongue base. Tecnecium-99 scintigraphy used to assess the presence of ectopic thyroid tissue was negative.The tumor was biopsied and the pathology  showed aLeiomyomas may be divided according to the World Health Organization in three types: angioleiomyomas, solid leiomyomas and leiomyoblastomas. The most common type in the oral cavity is the angioleiomyoma, with 74% prevalence rate, followed by the solid leiomyoma, the most common in the tongue, with 25%3 prevalence. The smooth muscle tumor origin in the oral cavity could be in the middle layer of the arteries, ectopic smooth muscle tissues or the tongue taste budsIts occurrence on the tongue was reported in only 23 cases in the English literatureWe did not find other cases of painful leiomyomas in AIDS patients.Tongue base leiomyoma differential diagnosis must be carried out bearing in mind the other tumors that may affect this region, and be specially based on histopathology. Pain, although rare, may be its major manifestation, such as the one reported here. This is its first publication of an occurrence in an AIDS patient.