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Search Results (211)

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14 pages, 2031 KiB  
Article
Unraveling Plastic Pollution in Protected Terrestrial Raptors Using Regurgitated Pellets
by Chloe Wayman, Francisca Fernández-Piñas, Irene López-Márquez, Rocío Fernández-Valeriano, Juan José Iglesias-Lebrija, Fernando González-González, Roberto Rosal and Miguel González-Pleiter
Microplastics 2024, 3(4), 671-684; https://doi.org/10.3390/microplastics3040041 - 8 Nov 2024
Viewed by 537
Abstract
The threat of plastic pollution has escalated to unprecedented levels, with particular concern surrounding microplastics (MPs) and artificial fibers or particles (AFs) due to their wide distribution across ecosystems and their bioavailability to wildlife. Although research on the impact of plastic on wild [...] Read more.
The threat of plastic pollution has escalated to unprecedented levels, with particular concern surrounding microplastics (MPs) and artificial fibers or particles (AFs) due to their wide distribution across ecosystems and their bioavailability to wildlife. Although research on the impact of plastic on wild birds is rapidly growing, knowledge of terrestrial species remains limited, especially regarding raptors, which have been significantly understudied. Here, we investigated the prevalence of MPs and AFs in regurgitated pellets from six protected terrestrial raptor species, namely the Cinereous Vulture (Aegypius monachus), the Bonelli’s Eagle (Aquila fasciata), the Little Owl (Athene noctua), the Lesser Kestrel (Falco naumanni), the Red Kite (Milvus milvus), and the Barn Owl (Tyto alba), collected between 2022 and 2023. Our analysis revealed that 68% of the pellets contained MPs (47 out of 69), and 81% contained AFs (56 out of 69). Additionally, two macroplastics were found inside the pellets: a cable tie in a Red Kite and a bird identification ring in a Cinereous Vulture. The concentrations (mean ± standard error of the mean) were 2.39 ± 0.39 MPs/pellet and 5.16 ± 0.72 AFs/pellet. The concentration of MPs and AFs varied significantly among some of the studied species; however, no significant differences were observed among urban, rural, and protected areas. This could indicate that contamination levels are mainly related to the type of species. Fibers emerged as the predominant contaminant shape, with six different polymers identified, among which PET, PE, and acrylics were the most prevalent. These findings highlight that plastic pollution has reached protected terrestrial raptors and that the impact of plastic on their life cycles needs to be assessed. Full article
(This article belongs to the Collection Current Opinion in Microplastics)
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<p>Geographical locations of sampling sites where regurgitated pellets of each protected terrestrial raptor species were found, collected between 2022 and 2023.</p>
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<p>Macroplastics found in the regurgitated pellet of a Red Kite (<b>A</b>) and Cinereous Vulture (<b>B</b>). The photographs were taken by the authors.</p>
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<p>The chemical compositions of the MPs found in the pellets identified by micro-FTIR.</p>
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<p>A boxplot of the total microparticles per regurgitated pellets of different bird species. In the upper panel (<b>A</b>), the total MPs/pellet is shown, and in the lower panel (<b>B</b>), the AFs/pellet is shown. Different letters indicate significant differences among MPs/pellet (<b>A</b>) or AF/pellet (<b>B</b>) in each specie (<span class="html-italic">p</span> &lt; 0.05).</p>
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23 pages, 7669 KiB  
Article
Thermal Performance of Novel Eco-Friendly Prefabricated Walls for Thermal Comfort in Temperate Climates
by Rafael Alavez-Ramirez, Fernando Chiñas-Castillo, Jacobo Martínez-Reyes, Jose Luis Caballero-Montes, Magdaleno Caballero-Caballero, Valentin Juventino Morales-Dominguez, Margarito Ortiz-Guzman, Luis Humberto Robledo-Taboada, Erick Adrian Juarez-Arellano and Laura Elvira Serrano-De la Rosa
Sustainability 2024, 16(21), 9349; https://doi.org/10.3390/su16219349 - 28 Oct 2024
Viewed by 687
Abstract
The global threat of climate change has become increasingly severe, with the efficiency of buildings and the environment being significantly impacted. It is necessary to develop bioclimatic architectural systems that can effectively reduce energy consumption while bringing thermal comfort, reducing the impact of [...] Read more.
The global threat of climate change has become increasingly severe, with the efficiency of buildings and the environment being significantly impacted. It is necessary to develop bioclimatic architectural systems that can effectively reduce energy consumption while bringing thermal comfort, reducing the impact of external temperatures. This study presents the results of a real-scale experimental house prototype, MHTITCA, using a unique design composed of novel eco-friendly prefabricated channel walls filled with a blend of soil, sawdust, and cement for walls and roofs. The experimental analysis performed in this study was based on dynamic climatology. A solar orientation chart of the place was constructed to identify the solar radiation intensity acting on the house. Measurements of roof surface temperatures were conducted to determine temperature damping and temperature wave lag. Monthly average temperature and direct solar radiation data of the site were considered. Compared to other alternative house prototypes, the system maximizes thermal comfort in high-oscillation temperate climates. Temperature measurements were taken inside and outside to evaluate the thermal performance. A thermal insulating layer was added outside the wall and the envelope to improve the prototype’s thermal comfort and reduce the decrement factor even more. This MHTITCA house prototype had 85% thermal comfort, 0% overheating, and 15% low heating. This eco-friendly prototype design had the best thermal performance, achieving a thermal lag of twelve hours, a reduced decrement factor of 0.109, and preventing overheating in areas with high thermal fluctuations. Comparatively, the other prototypes examined provided inferior thermal comfort. The suggested MHTITCA system can be an energy-saving and passive cooling option for thermal comfort in low-cost houses in temperate climates with high thermal oscillations in urban or rural settings. Full article
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<p>Bioclimatic classification of the Mexican Republic [<a href="#B22-sustainability-16-09349" class="html-bibr">22</a>].</p>
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<p>Preparation of prefabricated channels: (<b>a</b>) for the walls and (<b>b</b>) for the roof.</p>
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<p>MHTIT experimental module: (<b>a</b>) MHTIT prototype and (<b>b</b>) isometric view of the MHTIT.</p>
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<p>Isometric view of the MMTLM house with reinforced mortar walls, empty milk cartons (Tetra Pak), and a reinforced mortar slab.</p>
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<p>Isometric view of the MBSCLM house with compacted soil block walls and a reinforced mortar slab.</p>
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<p>Isometric view of the MMLM house with reinforced mortar.</p>
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<p>Monthly temperatures in the city of Oaxaca.</p>
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<p>Rainy season in Oaxaca.</p>
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<p>Hourly temperatures in Oaxaca.</p>
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<p>Hourly humidity in Oaxaca.</p>
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<p>Psychrometric chart for Oaxaca.</p>
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<p>Olgyay’s solar graph for Oaxaca.</p>
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<p>Evans’ comfort triangle of Oaxaca.</p>
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<p>Interior temperatures in April 2023: (<b>a</b>) All four prototype systems: MHTIT, MMTLM, MMLM, and MBSCLM. (<b>b</b>) MMLM vs. T<sub>Ext</sub>; (<b>c</b>) MBSCLM vs. T<sub>Ext</sub>; (<b>d</b>) MMTLM vs. T<sub>Ext</sub>.</p>
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<p>Comparative of the hybrid system with thermal insulation (MHTITCA) and without thermal insulation (MHTIT).</p>
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<p>Hottest day of the systems under study.</p>
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<p>Thermal damping and time lag of the MHTITCA system.</p>
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<p>Decrement factor and wall thickness of the present study vs. past studies.</p>
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<p>Thermal lag and wall thickness vs. past studies.</p>
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23 pages, 934 KiB  
Article
Cyber Resilience Limitations in Space Systems Design Process: Insights from Space Designers
by Syed Shahzad, Keith Joiner, Li Qiao, Felicity Deane and Jo Plested
Systems 2024, 12(10), 434; https://doi.org/10.3390/systems12100434 - 15 Oct 2024
Viewed by 861
Abstract
Space technology is integral to modern critical systems, including navigation, communication, weather, financial services, and defence. Despite its significance, space infrastructure faces unique cyber resilience challenges exacerbated by the size, isolation, cost, persistence of legacy systems, and lack of comprehensive cyber resilience engineering [...] Read more.
Space technology is integral to modern critical systems, including navigation, communication, weather, financial services, and defence. Despite its significance, space infrastructure faces unique cyber resilience challenges exacerbated by the size, isolation, cost, persistence of legacy systems, and lack of comprehensive cyber resilience engineering standards. This paper examines the engineering challenges associated with incorporating cyber resilience into space design, drawing on insights and experiences from industry experts. Through qualitative interviews with engineers, cybersecurity specialists, project managers, and testers, we identified key themes in engineering methodologies, cybersecurity awareness, and the challenges of integrating cyber resilience into space projects. Participants emphasised the importance of incorporating cybersecurity considerations from the earliest stages of design, advocating for principles such as zero-trust architecture and security by design. Our findings reveal that experts favour Model-Based Systems Engineering (MBSE) and Agile methodologies, highlighting their synergy in developing flexible and resilient systems. The study also underscores the tension between principles-based standards, which offer flexibility but can lead to inconsistent implementation, and compliance-based approaches, which provide clear measures but may struggle to adapt to evolving threats. Additionally, the research recognises significant barriers to achieving cyber resilience, including insider threats, the complexity of testing and validation, and budget constraints. Effective stakeholder engagement and innovative funding models are crucial for fostering a culture of cybersecurity awareness and investment in necessary technologies. This study highlights the need for a comprehensive cyber resilience framework that integrates diverse engineering methodologies and proactive security measures, ensuring the resilience of space infrastructure against emerging cyber threats. Full article
(This article belongs to the Special Issue Cyber Security Challenges in Complex Systems)
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<p>Deductive codes of interview questions.</p>
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<p>Flow chart of the research procedure.</p>
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<p>Major themes from thematic analysis of interview data.</p>
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<p>Inductive code frequency.</p>
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<p>New themes found in inductive codes.</p>
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25 pages, 5245 KiB  
Article
Enhancing Syslog Message Security and Reliability over Unidirectional Fiber Optics
by Alin-Adrian Anton, Petra Csereoka, Eugenia Ana Capota and Răzvan-Dorel Cioargă
Sensors 2024, 24(20), 6537; https://doi.org/10.3390/s24206537 - 10 Oct 2024
Viewed by 635
Abstract
Standard log transmission protocols do not offer a robust way of segregating the log network from potential threats. A secure log transmission system and the realization of a data diode using affordable components are proposed. Unidirectional data flow prevents unauthorized access and eavesdropping, [...] Read more.
Standard log transmission protocols do not offer a robust way of segregating the log network from potential threats. A secure log transmission system and the realization of a data diode using affordable components are proposed. Unidirectional data flow prevents unauthorized access and eavesdropping, ensuring the integrity and confidentiality of sensitive log data. The system uses an encryption protocol that requires that the upstream and the downstream of the data diode are perfectly synchronized, mitigating replay attacks. It has been shown that message amplification can mitigate UDP packet loss, but this is only required when the data diode traffic is congested. The implementation of the encryption algorithm is suitable for resource-constrained devices and it has been shown to produce random-looking output even on a reduced number of rounds when compared to the parent cipher. Several improvements have been made to the original encryption algorithm for which an actual implementation was missing. Free software and datasets have been made available to reproduce the results. The complete solution is easy to reproduce in order to secure the segregation of a log network inside any scenario where logging is required by the law and log tampering must be prevented. Full article
(This article belongs to the Special Issue Sensing in Internet of Things and Smart Sensor Networks)
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Graphical abstract

Graphical abstract
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<p>Generalized cloud log forensics as proposed in [<a href="#B21-sensors-24-06537" class="html-bibr">21</a>] (reconstruction of Figure 4 Page 12).</p>
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<p>Differences between Speck-R [<a href="#B39-sensors-24-06537" class="html-bibr">39</a>] (<b>a</b>) and Enhanced Speck-R (<b>b</b>).</p>
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<p>Connection schematics for a gigabit ethernet data diode using 3 off-the-shelf media converters.</p>
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<p>Gigabit ethernet data diode using 3 off-the-shelf media converters.</p>
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<p>Fast ethernet data diode schematics made using only 2 media converters.</p>
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<p>Fast ethernet data diode with 2 media converters.</p>
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<p>Solution architecture for safely concentrating logs via UDP through a data diode for live tailing with an SIEM or SOAR in a network with a higher security level.</p>
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<p>Line message format where the first 8 bytes are a uint64_t counter and the rest are a list of printable characters.</p>
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<p>Sender and receiver programs. (<b>a</b>) Sender program in Algorithm 5; (<b>b</b>) receiver program in Algorithm 6.</p>
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<p>Combined data diodes for scaling the program over several unidirectional links. (<b>a</b>) parallel unidirectional connections used in a round-robin fashion; (<b>b</b>) several self-made gigabit data diodes in a 2U rack case.</p>
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30 pages, 10558 KiB  
Article
A Numerical Evaluation for Estimating the Consequences on Users and Rescue Teams Due to the Fire of an Electric Bus in a Road Tunnel
by Ciro Caliendo, Isidoro Russo and Gianluca Genovese
Appl. Sci. 2024, 14(20), 9191; https://doi.org/10.3390/app14209191 - 10 Oct 2024
Viewed by 636
Abstract
E-mobility is progressively penetrating the European market with the ever-increasing registration of new battery electric vehicles (BEVs). Although BEVs can significantly contribute to achieving the goal of sustainable road transport, they pose new challenges related to the complexity of managing battery fire events, [...] Read more.
E-mobility is progressively penetrating the European market with the ever-increasing registration of new battery electric vehicles (BEVs). Although BEVs can significantly contribute to achieving the goal of sustainable road transport, they pose new challenges related to the complexity of managing battery fire events, especially in confined spaces such as road tunnels. In this regard, while fires of BEVs with small-sized batteries (i.e., cars and vans) have been widely studied, the consequences of fires involving battery electric buses (BEBs), which are equipped with larger-capacity traction batteries, have not yet been sufficiently investigated. In this context, 3D computational fluid dynamics (CFD) simulations were performed to quantitatively assess the threat that a BEB might pose to the safety of users and rescue teams when it catches fire in a bi-directional road tunnel. In this respect, a comparison was also carried out with the consequences of the fire of a similar internal combustion engine bus (ICEB). Since the environmental conditions inside a tunnel, apart from its geometry, depend on both the traffic flow and type of ventilation, the safety of the users and rescue teams in the event of a BEB fire was evaluated by considering the tunnel under conditions of congested traffic, as well as natural or longitudinal mechanical ventilation. The results showed that the fire of the BEB, compared to that of its ICEB counterpart, worsened the environmental conditions inside the tunnel, especially in terms of toxic gas concentrations. This caused a reduction in the safety level of the users when considering the scenarios of both the naturally and mechanically ventilated tunnel. Moreover, in the case of natural ventilation, the BEB fire was found to cause a higher reduction in the safety level of the rescue teams. Full article
(This article belongs to the Section Civil Engineering)
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<p>Geometric features of the examined bi-directional road tunnel, with a view of the bus fire, jet fans, and vehicles in the queue. The unit of measurement of geometric quantities is the meter.</p>
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<p>Flow chart of the methodology.</p>
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<p>Comparison between the HF concentrations predicted by the FDS code and those provided by Willstrand et al. [<a href="#B13-applsci-14-09191" class="html-bibr">13</a>] in the event of a BEV fire in an enclosed garage.</p>
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<p>Grid sensitivity analysis: predictions of temperatures and HF concentrations, as a function of the cell size, at points <span class="html-italic">A</span>, <span class="html-italic">B</span>, and <span class="html-italic">C</span> after <span class="html-italic">t</span> = 15 min from the start of the BEB fire, considering the scenario of longitudinal mechanical ventilation.</p>
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<p>Arrangement of the queued equivalent cars on both sides of the bus in flames, with a view of the escape routes and emergency exit.</p>
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<p>Spatial distributions downstream of the fire related to the HF concentration at the height of breathing along the escape route toward Portal <span class="html-italic">B</span> for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions downstream of the fire related to the CO concentration at the height of breathing along the escape route toward Portal <span class="html-italic">B</span> for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions downstream of the fire related to the CO<sub>2</sub> concentration at the height of breathing along the escape route toward Portal <span class="html-italic">B</span> for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions downstream of the fire related to the temperature at the height of breathing along the escape route toward Portal <span class="html-italic">B</span> for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions downstream of the fire related to the radiant heat flux at the height of breathing along the escape route toward Portal <span class="html-italic">B</span> for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions downstream of the fire related to the visibility distance at the height of breathing along the escape route toward Portal <span class="html-italic">B</span> for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions downstream of the fire related to the FED<sub>toxic gases</sub> at the height of breathing along the escape route toward Portal <span class="html-italic">B</span> for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions related to the HF concentration at the height of breathing along the escape route downstream and upstream of the bus in flames for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions related to the CO concentration at the height of breathing along the escape route downstream and upstream of the bus in flames for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions related to the CO<sub>2</sub> concentration at the height of breathing along the escape route downstream and upstream of the bus in flames for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions related to the temperature at the height of breathing along the escape route downstream and upstream of the bus in flames for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions related to the radiant heat flux at the height of breathing along the escape route downstream and upstream of the bus in flames for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions related to the visibility distance at the height of breathing along the escape route downstream and upstream of the bus in flames for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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<p>Spatial distributions related to the FED<sub>toxic gases</sub> at the height of breathing along the escape route downstream and upstream of the bus in flames for both BEB and ICEB fires, in both cases of ventilation investigated.</p>
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10 pages, 2936 KiB  
Article
Wildfire Spread Prediction Using Attention Mechanisms in U2-NET
by Hongtao Xiao, Yingfang Zhu, Yurong Sun, Gui Zhang and Zhiwei Gong
Forests 2024, 15(10), 1711; https://doi.org/10.3390/f15101711 - 27 Sep 2024
Viewed by 643
Abstract
Destructive wildfires pose a serious threat to ecosystems, economic development, and human life and property safety. If wildfires can be extinguished in a relatively short period of time after they occur, the losses caused by wildfires will be greatly reduced. Although deep learning [...] Read more.
Destructive wildfires pose a serious threat to ecosystems, economic development, and human life and property safety. If wildfires can be extinguished in a relatively short period of time after they occur, the losses caused by wildfires will be greatly reduced. Although deep learning methods have been shown to have powerful feature extraction capabilities, many current models still have poor generalization performance when faced with complex tasks. To this end, in this study, we considered introducing attention modules both inside and outside the nested U-shaped structure and trained a neural network model based on the U2-Net architecture to enable the model to suppress the activation of irrelevant areas. Compared with baseline models such as U-Net, our model has made great progress on the test set, with an F1 score improvement of at least 2.8%. The experimental results indicate that the model we proposed has certain practicality and can provide a significant scientific basis for forest fire management and emergency decision-making. Full article
(This article belongs to the Section Natural Hazards and Risk Management)
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<p>The architecture diagram of Attention U2-Net.</p>
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<p>The process of attentional mechanisms in Attention U2-Net.</p>
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<p>Sample data visualization. Each row represents a sample. In addition to the label value and the predicted value, we also show the weather conditions in the area. The brighter the color, the larger the value.</p>
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<p>The effect of each comparison model. (<b>a</b>–<b>d</b>) show the effects of the U-Net, Attention U-Net, ResUNet, and U2-Net models on the test set samples. Each row represents a sample. In addition to the label value and the predicted value, we also show the weather conditions in the area. The brighter the color, the larger the value.</p>
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<p>The effect of our model. Each row represents a sample. In addition to the label value and the predicted value, we also show the weather conditions in the area. The brighter the color, the larger the value.</p>
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12 pages, 2770 KiB  
Article
Experimental Study on the Transport Behavior of Micron-Sized Sand Particles in a Wellbore
by Huizeng Zhang, Zhiming Yin, Yingwen Ma, Mingchun Wang, Bin Wang, Chengcheng Xiao, Tie Yan and Jingyu Qu
Processes 2024, 12(10), 2075; https://doi.org/10.3390/pr12102075 - 25 Sep 2024
Viewed by 444
Abstract
In the process of natural gas hydrate extraction, especially in offshore hydrate extraction, the multiphase flow inside the wellbore is complex and prone to flow difficulties caused by reservoir sand production, leading to pipeline blockage accidents, posing a threat to the safety of [...] Read more.
In the process of natural gas hydrate extraction, especially in offshore hydrate extraction, the multiphase flow inside the wellbore is complex and prone to flow difficulties caused by reservoir sand production, leading to pipeline blockage accidents, posing a threat to the safety of hydrate extraction. This paper presents experimental research on the migration characteristics of micrometer-sized sand particles entering the wellbore, detailing the influence of key parameters such as sand particle size, sand ratio, wellbore deviation angle, fluid velocity, and fluid viscosity on the sand bed height. It establishes a predictive model for the deposition height of micrometer-sized sand particles. The model’s predicted results align well with experimental findings, and under the experimental conditions of this study, the model’s average prediction error for the sand bed height is 12.47%, indicating that the proposed model demonstrates a high level of accuracy in predicting the bed height. The research results can serve as a practical basis and engineering guidance for reducing the risk of natural gas hydrate and sand blockages, determining reasonable extraction procedures, and ensuring the safety of wellbore flow. Full article
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<p>Schematic of the experimental setup for studying the transport and sedimentation of micrometer-scale particles, detailing the apparatus and its components.</p>
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<p>Malvern Mastersizer 3000 laser diffraction particle size analyzer.</p>
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<p>Schematic diagram of wellbore–sand bed height geometric relationship.</p>
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<p>Visual representation of key experimental phenomena observed during the flow of micron-sized sand particles in pipes.</p>
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<p>Variation in reservoir sand bed height with changes in sand ratio.</p>
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<p>Relationship between wellbore deviation angle and reservoir sand bed height.</p>
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<p>Effect of fluid flow velocity on the reservoir sand bed height.</p>
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<p>Impact of particle size on the reservoir sand bed height.</p>
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<p>Influence of fluid’s apparent viscosity on the height of the sand bed.</p>
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<p>Comparison between experimental and model-predicted values for sediment concentration.</p>
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15 pages, 5267 KiB  
Article
Investigating the Energy Dissipation Mechanism of Piano Key Weir: An Integrated Approach Using Physical and Numerical Modeling
by Zixiang Li, Fan Yang, Changhai Han, Ziwu Fan, Kaiwen Yu, Kang Han and Jingxiu Wu
Water 2024, 16(18), 2620; https://doi.org/10.3390/w16182620 - 15 Sep 2024
Viewed by 529
Abstract
The enormous energy carried by discharged water poses a serious threat to the Piano Key Weir (PKW) and its downstream hydraulic structures. However, previous research on energy dissipation in PKWs has mainly focused downstream effects, and the research methods have been largely limited [...] Read more.
The enormous energy carried by discharged water poses a serious threat to the Piano Key Weir (PKW) and its downstream hydraulic structures. However, previous research on energy dissipation in PKWs has mainly focused downstream effects, and the research methods have been largely limited to physical model experiments. To deeply investigate the discharge capacity and hydraulic characteristics of PKW, this study established a PKW model with universally applicable geometric parameters. By combining physical model experiments and numerical simulations, the flow pattern of the PKW, the discharge at the overflow edges, and the variation in the energy dissipation were revealed for different water heads. The results showed that the discharge of the side wall constitutes the majority of the total discharge at low water heads, resulting in a relatively high overall discharge efficiency. As the water head increases, the proportion of discharge from the inlet and outlet keys increases, while the proportion from the side wall decreases. This change results in less discharge from the side wall and a consequent reduction in the overall discharge efficiency. The PKW exhibits superior energy dissipation efficiency under low water heads. However, this efficiency exhibits an inverse relationship with an increasing water head. The overall energy dissipation efficiency can reach 40% to 70%. Additionally, the collision of the water flows inside the outlet chamber and the mixing of the overflow jet play a primary role in energy dissipation. The findings of this study have significant implications for hydraulic engineering construction and PKW operational safety. Full article
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<p>Schematics of the PKW and the laboratory equipment.</p>
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<p>The main geometric parameters of the Type A PKW.</p>
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<p>Overview of the simulation region and settings.</p>
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<p>Comparison between the simulated and measured values of the water surface profiles under three water head conditions.</p>
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<p>Experimental flow pattern of the PKW for (<b>a</b>) <span class="html-italic">H</span>/<span class="html-italic">P</span> = 0.09, (<b>b</b>) <span class="html-italic">H</span>/<span class="html-italic">P</span> = 0.20, and (<b>c</b>) <span class="html-italic">H</span>/<span class="html-italic">P</span> = 0.34.</p>
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<p>(<b>a</b>) Discharge proportion and (<b>b</b>) discharge efficiency of the three overflow edges.</p>
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<p>Relationship between (<b>a</b>) the energy and (<b>b</b>) the energy dissipation rate with the water head.</p>
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<p>Energy variation curves along the route.</p>
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<p>The vector in front of (<b>a</b>) the inlet key and (<b>b</b>) the outlet key of the PKW.</p>
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<p>Water overflows through the side wall for (<b>a</b>) the low water head and (<b>b</b>) the high water head.</p>
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<p>The turbulence dissipation (<b>a</b>) at the top of the PKW and (<b>b</b>) at the bottom of the PKW.</p>
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13 pages, 2279 KiB  
Article
Metagenomics Insight into Veterinary and Zoonotic Pathogens Identified in Urban Wetlands of Los Lagos, Chile
by Catherine Opitz-Ríos, Alvaro Burgos-Pacheco, Francisca Paredes-Cárcamo, Javier Campanini-Salinas and Daniel A. Medina
Pathogens 2024, 13(9), 788; https://doi.org/10.3390/pathogens13090788 - 12 Sep 2024
Viewed by 1069
Abstract
Wetlands are ecosystems that are essential to ecological balance and biodiversity; nevertheless, human activity is a constant threat to them. Excess nutrients are caused by intensive livestock and agricultural operations, pollution, and population growth, which in turn leads to uncontrolled microbiological development. This [...] Read more.
Wetlands are ecosystems that are essential to ecological balance and biodiversity; nevertheless, human activity is a constant threat to them. Excess nutrients are caused by intensive livestock and agricultural operations, pollution, and population growth, which in turn leads to uncontrolled microbiological development. This impairment in water quality can constitute a risk to animal, human, and environmental health. To thoroughly characterize the microbial communities, shotgun metagenomics was used to characterize the taxonomic and functional pattern of microorganisms that inhabit urban wetlands in the Los Lagos Region of Chile. The main objective was to identify microorganisms of veterinary relevance, assess their potential antibiotic resistance, and characterize the main virulence mechanism. As expected, a high diversity of microorganisms was identified, including bacteria described as animal or human pathogens, such as Pasteurella multocida, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. Also, a diverse repertory of antimicrobial-resistant genes (ARGs) was detected in metagenomic assembled sequences and inside the sequence of mobile genetic elements, genes that confer mainly resistance to beta-lactams, consistent with the families of antibiotics most used in Chile. In addition, a diverse collection of virulence mechanisms was also identified. Given the significance of the relationship between environmental, animal, and human health—a concept known as One Health—there is a need to establish molecular surveillance programs that monitor the environmental biohazard elements using molecular tools. This work is the first report of the presence of these harmful biological elements in urban wetlands subjected to anthropogenic pressure, located in the south of Chile. Full article
(This article belongs to the Special Issue Spatio-Temporal Analysis of Veterinary Infectious Diseases)
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<p><b>Taxonomy abundance at the species level is represented as a stacked bar plot of each sample.</b> The color pattern of each bar shows the microbial community structure, while the amplitude of each color represents the percentage of abundance of the assigned taxonomy. Remarkable taxa with the most abundance was <span class="html-italic">Pseudomonas</span> sp. SCA2728.1_7 on the Mirasol wetland, represented by the dark blue color, <span class="html-italic">Serratia liquefaciens</span> on Antiñir, denoted by olive color, <span class="html-italic">Pseudomonas fragi</span> on Teodosio2 represented by cyan color, while on Teodosio1 the most abundant specie was <span class="html-italic">Pseudomonas psychrophile</span>, denoted by tomato color.</p>
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<p>Heatmap of bacteria species identified that are included in the list of notifiable diseases. The relative abundance of bacterial species in the cities of Osorno, Llanquihue, Puerto Varas, and Puerto Montt is represented by the colors white (low abundance), yellow (middle abundance), and red (high abundance). The wetland with the highest relative abundance of microorganisms, represented by an intense red color, is the La Paloma wetland, located in the city of Puerto Montt. Conversely, the wetland with the lowest abundance is the Luis Ebel wetland, also in the city of Puerto Montt.</p>
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<p>Heatmap of bacterial species relevant in veterinary and human medicine. The relative abundance of bacterial species in wetlands of the cities of Osorno, Llanquihue, Puerto Varas, and Puerto Montt is presented. The wetland with the highest relative abundance of infectious bacterial species, represented by an intense red color, is the La Paloma wetland in the city of Puerto Montt. Conversely, the wetlands with the lowest abundance are Las Ranas in the city of Llanquihue, Luis Ebel in the city of Puerto Montt, and La Marina in the city of Puerto Varas.</p>
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<p>Identified antimicrobial resistances and classification by antimicrobial families or by antimicrobial compounds in urban wetlands of the Los Lagos region. A wide diversity of ARGs were identified using the NCBI database, with the highest frequency corresponding to the Teodosio Sarao wetland in the city of Llanquihue, followed by the Luis Ebel wetland in the city of Puerto Montt. The number denotes the different genes for the same resistance.</p>
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20 pages, 3903 KiB  
Review
Artificial Intelligence-Driven Analysis of Antimicrobial-Resistant and Biofilm-Forming Pathogens on Biotic and Abiotic Surfaces
by Akanksha Mishra, Nazia Tabassum, Ashish Aggarwal, Young-Mog Kim and Fazlurrahman Khan
Antibiotics 2024, 13(8), 788; https://doi.org/10.3390/antibiotics13080788 - 22 Aug 2024
Cited by 2 | Viewed by 1901
Abstract
The growing threat of antimicrobial-resistant (AMR) pathogens to human health worldwide emphasizes the need for more effective infection control strategies. Bacterial and fungal biofilms pose a major challenge in treating AMR pathogen infections. Biofilms are formed by pathogenic microbes encased in extracellular polymeric [...] Read more.
The growing threat of antimicrobial-resistant (AMR) pathogens to human health worldwide emphasizes the need for more effective infection control strategies. Bacterial and fungal biofilms pose a major challenge in treating AMR pathogen infections. Biofilms are formed by pathogenic microbes encased in extracellular polymeric substances to confer protection from antimicrobials and the host immune system. Biofilms also promote the growth of antibiotic-resistant mutants and latent persister cells and thus complicate therapeutic approaches. Biofilms are ubiquitous and cause serious health risks due to their ability to colonize various surfaces, including human tissues, medical devices, and food-processing equipment. Detection and characterization of biofilms are crucial for prompt intervention and infection control. To this end, traditional approaches are often effective, yet they fail to identify the microbial species inside biofilms. Recent advances in artificial intelligence (AI) have provided new avenues to improve biofilm identification. Machine-learning algorithms and image-processing techniques have shown promise for the accurate and efficient detection of biofilm-forming microorganisms on biotic and abiotic surfaces. These advancements have the potential to transform biofilm research and clinical practice by allowing faster diagnosis and more tailored therapy. This comprehensive review focuses on the application of AI techniques for the identification of biofilm-forming pathogens in various industries, including healthcare, food safety, and agriculture. The review discusses the existing approaches, challenges, and potential applications of AI in biofilm research, with a particular focus on the role of AI in improving diagnostic capacities and guiding preventative actions. The synthesis of the current knowledge and future directions, as described in this review, will guide future research and development efforts in combating biofilm-associated infections. Full article
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<p>The biofilms created by bacterial pathogens are present on various human body tissues, medical equipment, such as catheters or prostheses, and in the environment. It acts as a reservoir for potential infections that may occur in the future. The common bacterial species that are associated with diseases caused by biofilms are depicted in a schematic figure on the left. The arrows in the diagram indicate where these bacteria are located throughout the body. When it comes to the development of biofilm, attachment, maturation, and separation are all essential components (bottom right). Multiple components contribute to this multistep process, including bacterial surface chemicals, secreted matrix effectors, ambient components, and stressors. Therefore, the regulation of bacterial biofilm (located on the lower right) necessitates the utilization of intricate positive and negative regulatory mechanisms. Second messengers such as Bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) are examples of these mechanisms. Quorum sensing (QS), regulatory sRNAs, alternative sigma factors, two-component systems, and other mechanisms are also included. Reprinted from [<a href="#B26-antibiotics-13-00788" class="html-bibr">26</a>], Copyright © 2021 by the authors and Shared Science Publishers OG. Enterohemorrhagic <span class="html-italic">Escherichia coli</span> (EHEC), extracellular DNA (eDNA), and small RNAs (sRNAs).</p>
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<p>Global annual economic burden of various market sectors with biofilm-associated technologies (all values are in billions of dollars). The information obtained from [<a href="#B68-antibiotics-13-00788" class="html-bibr">68</a>].</p>
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<p>Global annual economic burden of various biofilm-associated infections on the health sector (all values are in billions of dollars). The information obtained from [<a href="#B68-antibiotics-13-00788" class="html-bibr">68</a>].</p>
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<p>Basic block diagram of machine learning and deep learning. Reprinted from [<a href="#B105-antibiotics-13-00788" class="html-bibr">105</a>]. Copyright © 2021 by the authors and Licensee, J Big Data.</p>
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<p>Internal workflow diagram of deep learning. Reprinted from the [<a href="#B105-antibiotics-13-00788" class="html-bibr">105</a>] Copyright © 2021 by the authors and Licensee, J Big Data.</p>
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<p>Deep learning architecture represents the detection of microorganisms from microscopic images.</p>
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<p>(<b>a</b>) A method was devised to segment biofilm from surfaces in SEM images. (<b>b</b>) Close-up images illustrate the surface before and after pre-processing, where outliers were eliminated to smooth scratches on the surface, facilitating improved segmentation. (<b>c</b>) An overlay demonstrates the segmented area (highlighted in blue) overlaid onto the SEM image, showcasing precise biofilm detection. Reprinted from [<a href="#B121-antibiotics-13-00788" class="html-bibr">121</a>]. Copyright © 2016 by the authors and Licensee, Scientific Reports.</p>
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<p>Confocal laser scanning microscopy allowed nanosensor fluorescence imaging in reference buffers. (<b>a</b>) FITC (green) and NR (red) nanosensor fluorescence were observed in 8 reference buffers. Z-stack imaging captured biofilm depth at each pH. Representative 2D pictures with overlays improve clarity. A 100 µm scale bar is used for all pictures. (<b>b</b>) FITC/NR fluorescence intensity (FI) was plotted versus pH. Error bars represent standard deviation, while blue-shaded regions represent fitted curve confidence intervals. Reprinted from [<a href="#B146-antibiotics-13-00788" class="html-bibr">146</a>]. Copyright © 2022 by the authors and Licensee, Scientific Reports.</p>
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18 pages, 7741 KiB  
Article
The Food Additive Benzaldehyde Confers a Broad Antibiotic Tolerance by Modulating Bacterial Metabolism and Inhibiting the Formation of Bacterial Flagella
by Xia Xiao, Can Ma, Han Zhang, Wei Liu, Yanhu Huang, Chuang Meng and Zhiqiang Wang
Int. J. Mol. Sci. 2024, 25(16), 8843; https://doi.org/10.3390/ijms25168843 - 14 Aug 2024
Viewed by 716
Abstract
The rise of antibiotic tolerance in bacteria harboring genetic elements conferring resistance to antibiotics poses an increasing threat to public health. However, the primary factors responsible for the emergence of antibiotic tolerance and the fundamental molecular mechanisms involved remain poorly comprehended. Here, we [...] Read more.
The rise of antibiotic tolerance in bacteria harboring genetic elements conferring resistance to antibiotics poses an increasing threat to public health. However, the primary factors responsible for the emergence of antibiotic tolerance and the fundamental molecular mechanisms involved remain poorly comprehended. Here, we demonstrate that the commonly utilized food additive Benzaldehyde (BZH) possesses the capacity to induce a significant level of fluoroquinolone tolerance in vitro among resistant Escherichia coli. Our findings from animal models reveal that the pre-administration of BZH results in an ineffective eradication of bacteria through ciprofloxacin treatment, leading to similar survival rates and bacterial loads as observed in the control group. These results strongly indicate that BZH elicits in vivo tolerance. Mechanistic investigations reveal several key factors: BZH inhibits the formation of bacterial flagella and releases proton motive force (PMF), which aids in expelling antibiotics from within cells to reducing their accumulation inside. In addition, BZH suppresses bacterial respiration and inhibits the production of reactive oxygen species (ROS). Moreover, exogenous pyruvate successfully reverses BZH-induced tolerance and restores the effectiveness of antibiotics, highlighting how crucial the pyruvate cycle is in combating antibiotic tolerance. The present findings elucidate the underlying mechanisms of BZH-induced tolerance and highlight potential hazards associated with the utilization of BZH. Full article
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<p>The bactericidal activity of antibiotics against pathogens is reduced by the presence of benzaldehyde. (<b>A</b>–<b>D</b>) Pre-culturing benzaldehyde with bacteria for 3 h resulted in a dose-dependent decrease in the effectiveness of ciprofloxacin against wild-type strains that are resistant to ciprofloxacin. (<b>E</b>–<b>G</b>) Benzaldehyde reduced the bactericidal activity of three bactericidal antibiotics (kanamycin, meropenem, and ceftiofur) against <span class="html-italic">E. coli</span> CX93T. (<b>H</b>) The minimum duration to achieve a 99% reduction in the bacterial population (MDK<sub>99</sub>) of ciprofloxacin against <span class="html-italic">E. coli</span> CX93T. All data obtained from biological experiments conducted in triplicate are reported as mean values with standard deviations (±SD). Statistical significance was determined using non-parametric one-way ANOVA, and the levels of significance were denoted as * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001, and **** <span class="html-italic">p</span> &lt; 0.0001.</p>
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<p>Transcriptome analysis of <span class="html-italic">E. coli</span> following exposure to benzaldehyde. (<b>A</b>) Volcano plot illustrating the differential expression of genes. The mRNA fold changes (Log<sub>2</sub>(FC)) in <span class="html-italic">E. coli</span> CX93T compared to <span class="html-italic">E. coli</span> CX93T treated with benzaldehyde, along with their corresponding significance values represented as log<sub>10</sub> (<span class="html-italic">p</span> value). (<b>B</b>,<b>C</b>) Analysis of gene functional enrichment, including KEGG and GO enrichment; (<b>D</b>) RT-PCR results demonstrating the transcription levels of genes associated with bacterial flagella and chemotaxis.</p>
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<p>Benzaldehyde inhibits the formation of bacterial flagella and reduces intracellular antibiotic accumulation levels. (<b>A</b>,<b>B</b>) The surface morphology observed using scanning electron microscope in the absence (A) and presence (<b>B</b>) of benzaldehyde; (<b>C</b>,<b>D</b>) benzaldehyde inhibited swimming motility of <span class="html-italic">E. coli</span> CX93T in a dose dependent manner; (<b>E</b>,<b>F</b>) benzaldehyde dissipated the Δ<span class="html-italic">ψ</span> (<b>E</b>), while showed no effect on ΔpH; (<b>G</b>) benzaldehyde decreased the intracellular accumulation of ciprofloxacin. ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001, and **** <span class="html-italic">p</span> &lt; 0.0001.</p>
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<p>Benzaldehyde decelerates the TCA cycle and bacterial metabolism. (<b>A</b>) Benzaldehyde inhibited bacterial respiration; (<b>B</b>) the respiration rate increase induced through ciprofloxacin was inhibited by benzaldehyde; (<b>C</b>) benzaldehyde downregulated the intracellular ATP level. (<b>D</b>) Benzaldehyde increased the level of NAD<sup>+</sup>; (<b>E</b>) benzaldehyde increased the ratio of NAD<sup>+</sup>/NADH. The mean ± SD values presented in this study were derived from three separate experiments. Statistical analysis revealed no difference (ns <span class="html-italic">p</span> &gt; 0.05) a highly significant difference (**** <span class="html-italic">p</span> &lt; 0.0001).</p>
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<p>Pyruvate plays a critical role in benzaldehyde-induced tolerance. (<b>A</b>) The intracellular pyruvate concentration decreased in a manner dependent on the concentration of benzaldehyde; (<b>B</b>) the exogenous addition of pyruvate reversed the downregulation of genes related to bacterial flagella and chemotaxis caused by benzaldehyde; (<b>C</b>,<b>D</b>) the surface morphology of benzaldehyde-pretreated <span class="html-italic">E. coli</span> CX93T was examined using a scanning electron microscope in the presence (<b>D</b>) and absence (<b>C</b>) of pyruvate; (<b>E</b>) the exogenous addition of pyruvate successfully reinstated the bactericidal effect of antibiotics against benzaldehyde pretreated bacteria. The levels of significance were denoted as * <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001, and **** <span class="html-italic">p</span> &lt; 0.0001.</p>
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<p>Benzaldehyde mitigates the oxidative damage caused by ciprofloxacin in bacteria. (<b>A</b>,<b>B</b>) The ROS level induced by benzaldehyde (<b>A</b>) or ciprofloxacin in combination with benzaldehyde (<b>B</b>); (<b>C</b>,<b>D</b>) the superoxide dismutase (SOD) activity under the treatment of benzaldehyde (<b>C</b>) or ciprofloxacin in combination with benzaldehyde (<b>D</b>). The levels of significance were denoted as ns <span class="html-italic">p</span> &gt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01, *** <span class="html-italic">p</span> &lt; 0.001, and **** <span class="html-italic">p</span> &lt; 0.0001.</p>
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<p>The in vivo effectiveness of ciprofloxacin is diminished upon administration of benzaldehyde. (<b>A</b>) Protocols for conducting experiments on the infection model of <span class="html-italic">G. mellonella</span> larvae. The survival rates of <span class="html-italic">G. mellonella</span> larvae (n = 12) infected with <span class="html-italic">E. coli</span> CX93T (10<sup>5</sup> CFUs) were evaluated following co-culturing without (<b>B</b>) and with benzaldehyde (400 μg/mL, (<b>C</b>)) for a duration of three hours, followed by treatment with a single dose of ciprofloxacin (50 mg/kg). (<b>D</b>) Design of the experimental procedures for inducing peritonitis-sepsis infection in mice. (<b>E</b>,<b>F</b>) The survival rate curve of mice (n = 12) that were pre-administered with either PBS (<b>E</b>) or benzaldehyde (100 mg/kg, (<b>F</b>)) for a consecutive period of 5 days is depicted. Subsequently, the mice were intraperitoneally infected with <span class="html-italic">E. coli</span> CX93T and treated with either PBS or ciprofloxacin (40 mg/kg). (<b>G</b>,<b>H</b>) The levels of bacteria in the liver and kidney of mice, which were administered with PBS (<b>G</b>) or benzaldehyde (100 mg/kg, (<b>H</b>)) before infection as previously mentioned. (<b>I</b>) The HE staining results of liver and kidney under various treatment conditions. The levels of significance were denoted as ns <span class="html-italic">p</span> &gt; 0.05 and **** <span class="html-italic">p</span> &lt; 0.0001.</p>
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13 pages, 2822 KiB  
Article
Disinfection Efficacy and Eventual Harmful Effect of Chemical Peracetic Acid (PAA) and Probiotic Phaeobacter inhibens Tested on Isochrisys galbana (var. T-ISO) Cultures
by Elia Casoni, Gloria Contis, Leonardo Aguiari, Michele Mistri and Cristina Munari
Water 2024, 16(16), 2257; https://doi.org/10.3390/w16162257 - 10 Aug 2024
Viewed by 1090
Abstract
One of the main threats to aquaculture is represented by microbial pathogens, causing mass mortality episodes in hatcheries, which result in huge economic losses. Among the many disinfection methods applied to reduce this issue, the use of chemicals and beneficial microorganisms (probiotics) seems [...] Read more.
One of the main threats to aquaculture is represented by microbial pathogens, causing mass mortality episodes in hatcheries, which result in huge economic losses. Among the many disinfection methods applied to reduce this issue, the use of chemicals and beneficial microorganisms (probiotics) seems to be the most efficient. The aim of this study is to test the efficacy of two of them: a chemical, peracetic acid (PAA), and a probiotic, Phaeobacter inhibens. Tests were run on microalgae of the species Isochrysis galbana (var T-ISO). For both remedies, the microalgae survival rate and final cell concentration (cell/mL) were monitored. PAA analysis tested six different concentrations of the chemical: 7.5 µg, 10 µg/L, 20 µg/L, 30 µg/L, 40 µg/L, and 60 µg/L. Meanwhile, P. inhibens was tested with a concentration of 104 CFU/mL. Analysis for both the remedies was conducted on a laboratory scale using glass flasks, and on an industrial scale inside photobioreactors (PBRs). Among all the treatments, the one with PAA dosed with a concentration of 60 µg/L gave the best results, as the culture reached a final density of 8.61 × 106 cell/mL. However, none of the remedies involved in the experiment harmed microalgae or their growth. The results match perfectly with the condition requested for the tested remedies: to obtain an optimal breakdown of pathogens without interfering with culture growth. These features make PAA and P. inhibens good candidates for disinfection methods in aquaculture facilities. Full article
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<p><span class="html-italic">I. galbana</span> growth expressed as 10<sup>6</sup> cell/mL (±SD) (<b>left graphs</b>) and relative pH variation (±SD) (<b>right graphs</b>) for every treatment tested in the laboratory trial involving PAA. Each graph shows the results of two treatments and the control group (CTRL): (<b>a</b>) 7.5 µg/L and 10 µg/L treatments; (<b>b</b>) 20 µg/L and 30 µg/L treatments; (<b>c</b>) 40 µg/L and 60 µg/L treatments. The trial lasted from T0 (0 h) to T2 (48 h).</p>
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<p><span class="html-italic">I. galbana</span> average specific growth rate (µ) related to every treatment tested in each trial, expressed as 10<sup>6</sup> cell/mL/h. (<b>a</b>) PAA laboratory trial: the blue square contains the treatments with µ values grouping under the 0.025 × 10<sup>6</sup> cell/mL/h threshold (bold horizontal line); the red square contains the µ values grouping above the 0.025 × 10<sup>6</sup> cell/mL/h. No statistical differences were detected among treatments. (<b>b</b>) <span class="html-italic">P. inhibens</span> laboratory trial. No statistical differences were detected among treatments. (<b>c</b>) PBR trial: different letters (“x”, “y”) indicate a significant statistical difference, according to Tukey’s HSD test (<span class="html-italic">p</span>-value &lt; 0.05).</p>
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<p><span class="html-italic">I. galbana</span> growth related to the laboratory trial involving <span class="html-italic">P. inhibens</span> strain DSM17395, expressed as 10<sup>6</sup> cell/mL (±SD). The trial lasted from T0 (0 h) to T3 (72 h).</p>
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<p>Growth curve and pH variation related to the PBR trial involving the 60 µg/L PAA treatment, <span class="html-italic">P. inhibens</span> treatment, and a control group. The results for cell growth are expressed as 10<sup>6</sup> cell/mL (±SD). The trial lasted from T0 (0 h) to T2 (48 h).</p>
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<p>Rapid efficacy evaluation test results, to assess the presence/absence of pathogen bacteria belonging to genus <span class="html-italic">Vibrio</span> in cultures analyzed during the PBR trial: (<b>a</b>) PBR control group; (<b>b</b>) PBR treated with PAA; (<b>c</b>) PBR treated with probiotic <span class="html-italic">P. inhibens</span>.</p>
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30 pages, 5833 KiB  
Review
A Survey: Security Vulnerabilities and Protective Strategies for Graphical Passwords
by Zena Mohammad Saadi, Ahmed T. Sadiq, Omar Z. Akif and Alaa K. Farhan
Electronics 2024, 13(15), 3042; https://doi.org/10.3390/electronics13153042 - 1 Aug 2024
Cited by 1 | Viewed by 1125
Abstract
As technology advances and develops, the need for strong and simple authentication mechanisms that can help protect data intensifies. The contemporary approach to giving access control is through graphical passwords comprising images, patterns, or graphical items. The objective of this review was to [...] Read more.
As technology advances and develops, the need for strong and simple authentication mechanisms that can help protect data intensifies. The contemporary approach to giving access control is through graphical passwords comprising images, patterns, or graphical items. The objective of this review was to determine the documented security risks that are related to the use of graphical passwords, together with the measures that have been taken to prevent them. The review was intended to present an extensive literature review of the subject matter on graphical password protection and to point toward potential future research directions. Many attacks, such as shoulder surfing attacks, SQL injection attacks, and spyware attacks, can easily exploit the graphical password scheme, which is one of the most widely used. To counter these security threats, several measures have been suggested, but none of the security attacks can be completely overcome. Each of the proposed measures has its pros and cons. This study begins by elucidating some of the graphical password schemes studied between 2012 and 2023, delving into potential threats and defense mechanisms associated with these schemes. Following a thorough identification and selection process, five of the reviewed papers explain the threat of shoulder surfing and spyware attacks on graphical password schemes, while two explain the threat of brute force attacks. One paper focuses on dictionary attacks, while four other papers address social engineering, SQL injection attacks, and guessing attacks as potential threats to graphical password schemes. In addition, the papers recognize other forms of attacks, such as video recording attacks, filtering attacks, reverse engineering attacks, multiple observation attacks, key/mouse logger attacks, insider attacks, computer vision attacks, image gallery attacks, sonar attacks, reply attacks, data interception attacks, and histogram manipulation attacks. These attacks are examined in three, three, eight, one, four, one, one, one, one, one, one, and one papers, respectively. Moreover, out of all such countermeasures, most of them are based on three categories—randomization, obfuscation, and password space complexity—which are the most commonly employed strategies for improving graphical password schemes. Full article
(This article belongs to the Special Issue AI in Cybersecurity, 2nd Edition)
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<p>Where You See is What You Enter (WYSWYE; adapted from [<a href="#B4-electronics-13-03042" class="html-bibr">4</a>]) user interface. (<b>a</b>) Users must mentally cross out each row and column from the challenge grid that does not have the password images—in this example, an apple, a dog, ice cream, and television. (<b>b</b>) Users must determine where the password images are located in the grid with fewer challenges. (<b>c</b>) Users must click where the password images are located in the response grid. (<b>d</b>) Sample notations that are used in the challenge and response grids to highlight WYSWYE’s shortcomings [<a href="#B3-electronics-13-03042" class="html-bibr">3</a>].</p>
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<p>The Gokhale and Waghmare system’s user interface [<a href="#B7-electronics-13-03042" class="html-bibr">7</a>].</p>
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<p>The system’s user interface by Por et al. [<a href="#B9-electronics-13-03042" class="html-bibr">9</a>].</p>
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<p>The system’s user interface by Sun et al. [<a href="#B12-electronics-13-03042" class="html-bibr">12</a>].</p>
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<p>A combination of graphical password recognition and recall schemes [<a href="#B13-electronics-13-03042" class="html-bibr">13</a>].</p>
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<p>A hybrid textual-graphical authentication scheme [<a href="#B14-electronics-13-03042" class="html-bibr">14</a>].</p>
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<p>The first stage of login verification [<a href="#B15-electronics-13-03042" class="html-bibr">15</a>]. (<b>a</b>) Primary interface; (<b>b</b>) The system passes implicitly “8,T” as a user login indicator.</p>
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<p>(<b>a</b>) User’s password image. (<b>b</b>) Click points chosen by the user indicated by circles. (<b>c</b>) Image presented with a grid of alphabets. (<b>d</b>) Secret token ‘GC’ aligned over the first click point [<a href="#B16-electronics-13-03042" class="html-bibr">16</a>].</p>
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<p>Path tolerance example [<a href="#B17-electronics-13-03042" class="html-bibr">17</a>].</p>
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<p><span class="html-italic">GRA-PIN scheme</span> [<a href="#B18-electronics-13-03042" class="html-bibr">18</a>].</p>
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<p><span class="html-italic">GRA-PIN scheme</span> [<a href="#B18-electronics-13-03042" class="html-bibr">18</a>].</p>
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<p>Selection of verification grids and password path in the registration phase [<a href="#B19-electronics-13-03042" class="html-bibr">19</a>].</p>
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<p>Multi-factor authentication (MFA) [<a href="#B18-electronics-13-03042" class="html-bibr">18</a>]. (<b>a</b>) Image loading screen; (<b>b</b>) The image upload screen once the user has uploaded 9 images.</p>
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<p>The system architecture of the choice-based graphical password scheme [<a href="#B20-electronics-13-03042" class="html-bibr">20</a>].</p>
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<p>Related graphical password schemes with security attacks.</p>
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22 pages, 3305 KiB  
Article
Behind the Code: Identifying Zero-Day Exploits in WordPress
by Mohamed Azarudheen Mohamed Mohideen, Muhammad Shahroz Nadeem, James Hardy, Haider Ali, Umair Ullah Tariq, Fariza Sabrina, Muhammad Waqar and Salman Ahmed
Future Internet 2024, 16(7), 256; https://doi.org/10.3390/fi16070256 - 19 Jul 2024
Viewed by 1370
Abstract
The rising awareness of cybersecurity among governments and the public underscores the importance of effectively managing security incidents, especially zero-day attacks that exploit previously unknown software vulnerabilities. These zero-day attacks are particularly challenging because they exploit flaws that neither the public nor developers [...] Read more.
The rising awareness of cybersecurity among governments and the public underscores the importance of effectively managing security incidents, especially zero-day attacks that exploit previously unknown software vulnerabilities. These zero-day attacks are particularly challenging because they exploit flaws that neither the public nor developers are aware of. In our study, we focused on dynamic application security testing (DAST) to investigate cross-site scripting (XSS) attacks. We closely examined 23 popular WordPress plugins, especially those requiring user or admin interactions, as these are frequent targets for XSS attacks. Our testing uncovered previously unknown zero-day vulnerabilities in three of these plugins. Through controlled environment testing, we accurately identified and thoroughly analyzed these XSS vulnerabilities, revealing their mechanisms, potential impacts, and the conditions under which they could be exploited. One of the most concerning findings was the potential for admin-side attacks, which could lead to multi-site insider threats. Specifically, we found vulnerabilities that allow for the insertion of malicious scripts, creating backdoors that unauthorized users can exploit. We demonstrated the severity of these vulnerabilities by employing a keylogger-based attack vector capable of silently capturing and extracting user data from the compromised plugins. Additionally, we tested a zero-click download strategy, allowing malware to be delivered without any user interaction, further highlighting the risks posed by these vulnerabilities. The National Institute of Standards and Technology (NIST) recognized these vulnerabilities and assigned them CVE numbers: CVE-2023-5119 for the Forminator plugin, CVE-2023-5228 for user registration and contact form issues, and CVE-2023-5955 for another critical plugin flaw. Our study emphasizes the critical importance of proactive security measures, such as rigorous input validation, regular security testing, and timely updates, to mitigate the risks posed by zero-day vulnerabilities. It also highlights the need for developers and administrators to stay vigilant and adopt strong security practices to defend against evolving threats. Full article
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<p>The experimental method employed to uncover vulnerabilities and exploits.</p>
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<p>A typical DAST process followed to test vulnerabilities.</p>
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<p>The JavaScript code added to the plugin enabling XSS attack.</p>
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<p>User registration web form with XSS.</p>
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<p>The XSS triggered the JavaScript code execution, shows that a more potent javascript can be executed as well.</p>
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<p>A keylogger being attached to the plugin from the admin side, showcasing how easy it is for an insider to affect web applications with malicious code.</p>
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<p>Malware file successfully download on the client side through XSS vulnerability.</p>
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<p>Sample output showcasing sensitive user information captured by the keylogger.</p>
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<p>Sample output displaying the system specifications of the user machine.</p>
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28 pages, 6189 KiB  
Article
Cyber Evaluation and Management Toolkit (CEMT): Face Validity of Model-Based Cybersecurity Decision Making
by Stuart Fowler, Keith Joiner and Siqi Ma
Systems 2024, 12(7), 238; https://doi.org/10.3390/systems12070238 - 1 Jul 2024
Viewed by 1158
Abstract
The Cyber Evaluation and Management Toolkit (CEMT) is an open-source university research-based plugin for commercial digital model-based systems engineering tools that streamlines conducting cybersecurity risk evaluations for complex cyber-physical systems. The authors developed this research tool to assist the Australian Defence Force (ADF) [...] Read more.
The Cyber Evaluation and Management Toolkit (CEMT) is an open-source university research-based plugin for commercial digital model-based systems engineering tools that streamlines conducting cybersecurity risk evaluations for complex cyber-physical systems. The authors developed this research tool to assist the Australian Defence Force (ADF) with the cybersecurity evaluation of complicated systems operating in an increasingly contested and complex cyber environment. This paper briefly outlines the functionality of the CEMT including the inputs, methodology, and outputs required to apply the toolkit using a sample model of the process applied to a generic insider threat attack. A face validity trial was conducted on the CEMT, surveying subject-matter experts in the field of complex cybersecurity analysis and risk assessment to present the generic case study and gather data on the expected benefits of a real-world implementation of the process. The results of the face validity broadly supports the effectiveness and usability of the CEMT, providing justification for industry research trials of the CEMT. Full article
(This article belongs to the Special Issue Decision Making with Model-Based Systems Engineering)
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<p>Generic process for making cybersecurity risk decisions under a compliance-driven risk assessment paradigm.</p>
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<p>Threat-based cybersecurity engineering context.</p>
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<p>High level approach for our model-based implementation of threat-based cybersecurity engineering.</p>
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<p>CEMT misuse case diagram from the generic sample model.</p>
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<p>Intermediate CEMT mal-activity diagram for the Insider Threat misuse case.</p>
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<p>Intermediate CEMT mal-activity diagram for the Exploit System Access mal-activity.</p>
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<p>Detailed CEMT mal-activity diagram for the Access Sensitive Data mal-activity.</p>
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<p>Partial CEMT attack tree—forward diagram from the CEMT sample model.</p>
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<p>Partial CEMT parametric risk diagram from the CEMT sample model.</p>
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<p>Simulation histogram for the CEMT parametric risk diagram.</p>
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<p>Responses to the question: “What is your main area of expertise?” Bars indicate the number of respondents, out of the 20 respondents, that provided that particular response.</p>
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<p>Responses to the question: “What option best describes your expected role in a cyberworthiness assessment process?” Bars indicate the number of respondents, out of the 20 respondents, that provided that particular response.</p>
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<p>Summary results of the CEMT face validity survey. Bars indicate the number of respondents, out of the 20 respondents, that provided that particular response.</p>
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<p>Overall rating of the threat-based cybersecurity engineering approach using the CEMT, based on responses to the face validity survey. Number in each pie segment indicates the number of respondents, out of the 20 respondents, that provided that particular response.</p>
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<p>Significance of the CEMT approach across five key attributes of model-based security assessments.</p>
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