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Journal articles on the topic 'Synchronized attack'
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Yamuna Bee, Mrs J., E. Naveena, Reshma Elizabeth Thomas, Arathi Chandran, Siva Subramania Raja M, and A. Akhilesh. "Intrusion Detection on Apache Spark Platform in Big data and Machine Learning Techniques." Journal of University of Shanghai for Science and Technology 23, no. 06 (June 22, 2021): 1257–66. http://dx.doi.org/10.51201/jusst/21/06427.
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With the rising cyber-physical power systems and emerging danger of cyber-attacks, the traditional power services are faced with higher risks of being compromised, as vulnerabilities in cyber communications can be broken to cause material damage. Therefore, adjustment needs to be made in the present control scheme plan methods to moderate the impact of possible attacks on service quality. This paper, focuses on the service of synchronized source-load contribution in main frequency regulation, a weakness study is performed with model the attack intrusion process, and the risk review of the service is made by further model the attack impacts on the service’s bodily things. On that basis, the customary synchronized reserve allotment optimization model is adapted and the allocation scheme is correct according to the cyber-attack impact. The proposed alteration methods are validating through a case study, showing efficiency in defensive alongside the cyber-attack impacts.
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Manaseer, Saher, Ahmad K. Al Hwaitat, and Riad Jabri. "Distributed Detection and prevention of Web Threats in Heterogeneous Environment." Modern Applied Science 12, no. 10 (September 9, 2018): 13. http://dx.doi.org/10.5539/mas.v12n10p13.
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The growth of web Applications have increased rapidly due to the huge development of technology with very short turnaround time and with this development the protection from vulnerabilities became very difficult. There is a continuous demand for developing new methods that is able to prevent the fast growth of attacking methods and vulnerabilities. Furthermore there is a great demand to have coordination between different security infrastructure and protection applications to distribution of the attack log in order to prevent the attacker from further attacks to other web hosts. This research proposes a distributed web firewall defensive mechanism which provide a synchronized environment that is consists of several synchronized web application firewalls. Every web application is protected by a web application firewall that send feedback reports that include the type of the attack, The IP Address of the attacker and time of attack to other synchronized firewalls inside the environment to take action against the attacker.
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Wu, Guowei, Xiaojie Chen, Lin Yao, Youngjun Lee, and Kangbin Yim. "An efficient wormhole attack detection method in wireless sensor networks." Computer Science and Information Systems 11, no. 3 (2014): 1127–41. http://dx.doi.org/10.2298/csis130921068w.
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Wireless sensor networks are now widely used in many areas, such as military, environmental, health and commercial applications. In these environments, security issues are extremely important since a successful attack can cause great damage, even threatening human life. However, due to the open nature of wireless communication, WSNs are liable to be threatened by various attacks, especially destructive wormhole attack, in which the network topology is completely destroyed. Existing some solutions to detect wormhole attacks require special hardware or strict synchronized clocks or long processing time. Moreover, some solutions cannot even locate the wormhole. In this paper, a wormhole attack detection method is proposed based on the transmission range that exploits the local neighborhood information check without using extra hardware or clock synchronizations. Extensive simulations are conducted under different mobility models. Simulation results indicate that the proposed method can detect wormhole attacks effectively and efficiently in WSNs.
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O'Connell, Michael, and Aaron Bernard. "A Serious Cause of Panic Attack." Case Reports in Emergency Medicine 2012 (2012): 1–3. http://dx.doi.org/10.1155/2012/393275.
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We report on a case of a patient with atrial fibrillation in the setting of Wolff-Parkinson-White syndrome. The patient underwent synchronized electrical cardioversion, typically considered safe and effective, which resulted in a dangerous complication for the patient (degeneration into ventricular fibrillation). Discussion of common rhythm disturbances in WPW and management strategies are reviewed.
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Butcher, Thomas M. "A ‘synchronized attack’: On Raphael Lemkin's holistic conception of genocide." Journal of Genocide Research 15, no. 3 (September 2013): 253–71. http://dx.doi.org/10.1080/14623528.2013.821221.
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Lisova, Elena, Marina Gutiérrez, Wilfried Steiner, Elisabeth Uhlemann, Johan Åkerberg, Radu Dobrin, and Mats Björkman. "Protecting Clock Synchronization: Adversary Detection through Network Monitoring." Journal of Electrical and Computer Engineering 2016 (2016): 1–13. http://dx.doi.org/10.1155/2016/6297476.
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Nowadays, industrial networks are often used for safety-critical applications with real-time requirements. Such applications usually have a time-triggered nature with message scheduling as a core property. Scheduling requires nodes to share the same notion of time, that is, to be synchronized. Therefore, clock synchronization is a fundamental asset in real-time networks. However, since typical standards for clock synchronization, for example, IEEE 1588, do not provide the required level of security, it raises the question of clock synchronization protection. In this paper, we identify a way to break synchronization based on the IEEE 1588 standard, by conducting a man-in-the-middle (MIM) attack followed by a delay attack. A MIM attack can be accomplished through, for example, Address Resolution Protocol (ARP) poisoning. Using the AVISPA tool, we evaluate the potential to perform a delay attack using ARP poisoning and analyze its consequences showing both that the attack can, indeed, break clock synchronization and that some design choices, such as a relaxed synchronization condition mode, delay bounding, and using knowledge of environmental conditions, can make the network more robust/resilient against these kinds of attacks. Lastly, a Configuration Agent is proposed to monitor and detect anomalies introduced by an adversary performing attacks targeting clock synchronization.
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Manaseer, Saher, and Ahmad K. Al Hwaitat. "Centralized Web Application Firewall Security System." Modern Applied Science 12, no. 10 (September 29, 2018): 164. http://dx.doi.org/10.5539/mas.v12n10p164.
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In this paper we propose a centralized web firewall system for web application security which will provide a new type of synchronized system, which has the ability to detect and prevent a variety of web application attacks for a wide range of hosts at the same time , using an centralized command and control system, the attacked client then sends the information to a centralized command and control server which will distribute the attack information to all of the integrated clients connected to it. The distributed information contains all of the attack information including the type of attack, the IP address of the attacker, and the time of attack. The process of receiving the attacker's information and distributing it through the centralized web firewall is done automatically and immediately at the time of the attack. And all of the receiving clients will take actions against the threat depending on the distributed information such as banning the IP address of the attacker. The main process aims to protect multiple clients from any possible attack from the same attacker or the same type of attack. The system has been implemented to protect a real web application. Experiments showed that the attacks has been successfully prevented on multiple hosts at the time.
This paper came to provide a centralized web firewall system that connect different web firewalls in order to detect and prevent different types of web attacks and work as a fully integrated system with the different clients.
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Ramkumar, B. N., and T. Subbulakshmi. "Tcp Syn Flood Attack Detection and Prevention System using Adaptive Thresholding Method." ITM Web of Conferences 37 (2021): 01016. http://dx.doi.org/10.1051/itmconf/20213701016.
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Transmission Control Protocol Synchronized (SYN) flooding contributes to a major part of the Denial of service attacks (Dos) because of the easy to exploit nature of the TCP three way handshake mechanism. Attackers use this weakness to overflow the TCP queue of the server and make its re-sources consumed resulting it to be unavailable for the requests of legitimate users. So we are in need of a quick and precise defence mechanism to detect the TCP-SYN Flood attack. The main objective of the paper is to propose a detection and prevention mechanism of the TCP-SYN flood attack using adaptive thresholding. Adaptive threshold algorithm (ATA) is used to calculate dynamic threshold .Thus this algorithm helps to overcome the limitations of static thresholding like high false positive ratio and also alert users after violation of the threshold calculated by adaptive thresholding algorithm. The result of the suggested mechanism is very effective in the detection and prevention of the TCP SYN flood attack using adaptive thresholding algorithm.
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Singh, Rupinder, Jatinder Singh, and Ravinder Singh. "WRHT: A Hybrid Technique for Detection of Wormhole Attack in Wireless Sensor Networks." Mobile Information Systems 2016 (2016): 1–13. http://dx.doi.org/10.1155/2016/8354930.
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Wormhole attack is a challenging security threat to wireless sensor networks which results in disrupting most of the routing protocols as this attack can be triggered in different modes. In this paper, WRHT, a wormhole resistant hybrid technique, is proposed, which can detect the presence of wormhole attack in a more optimistic manner than earlier techniques. WRHT is based on the concept of watchdog and Delphi schemes and ensures that the wormhole will not be left untreated in the sensor network. WRHT makes use of the dual wormhole detection mechanism of calculating probability factor time delay probability and packet loss probability of the established path in order to find the value of wormhole presence probability. The nodes in the path are given different ranking and subsequently colors according to their behavior. The most striking feature of WRHT consists of its capacity to defend against almost all categories of wormhole attacks without depending on any required additional hardware such as global positioning system, timing information or synchronized clocks, and traditional cryptographic schemes demanding high computational needs. The experimental results clearly indicate that the proposed technique has significant improvement over the existing wormhole attack detection techniques.
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Ullah, Matti, Warda Aoudjeghout, Cynthia Pimpie, Marc Pocard, and Massoud Mirshahi. "Mitosis in Cancer Cell Increases Immune Resistance via High Expression of HLA-G and PD-L1." Cancers 12, no. 9 (September 18, 2020): 2661. http://dx.doi.org/10.3390/cancers12092661.
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Cancer is a result of “aggressive” division and uncontrolled proliferation of the abnormal cells that survive attack by immune cells. We investigated the expression of HLA-G and PD-L1 with the different stages of cancer cell division along with their role in the interaction of immune cells in vitro. Ovarian cancer (OVCAR-3) and chronic myeloid leukemia cell line (K-562) are used for this study. The correlation of protein expression with percentage of cells in each phase (G1, S and G2 phase) was evaluated through FACS. Cells were synchronized in G1, G2 and mitotic phase to evaluate gene (RT-qPCR) and protein expression (FACS). Real-time immune cell attack (RTICA) analysis with PBMCs (peripheral blood mono-nuclear cells) and cancer cells were performed. We found that cells expressing higher levels of HLA-G and PD-L1 are mainly in G2 phase and those expressing lower levels are mainly in G1 phase. Evidently, the higher expression of the two proteins was observed when synchronized in mitotic phase as compared to low expression when synchronized in G1 phase. RTICA analysis showed the presence of HLA-G delayed the lysis of the cells. In conclusion, the cancer cell can escape from immune cells in division stage that suggests the impact of mitosis index for cancer immunotherapy.
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Radziukevich, M. L., and V. F. Golikov. "Combined formаtion of a cryptographic key using synchronized artificial neural networks." Doklady BGUIR 19, no. 1 (February 23, 2021): 79–87. http://dx.doi.org/10.35596/1729-7648-2021-19-1-79-87.
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А combined method for forming a cryptographic key is proposed in the article. The proposed combined formation consists of two stages: the formation of partially coinciding binary sequences using synchronized artificial neural networks and the elimination of mismatched bits by open comparison of the parities of bit pairs. In this paper, possible vulnerabilities of the basic method of forming a cryptographic key using synchronized artificial neural networks are considered, their danger is assessed, and a correction of the method is proposed to ensure the required confidentiality of the generated shared secret. At the first stage, a deferred brute-force attack is considered. To neutralize this attack, it is proposed to use the convolution function of the results of several independent synchronizations. As a convolution function, the bitwise addition modulo 2 of the vectors of the weights of the networks is used. Due to the correction of the first stage of the basic algorithm, the amount of deferred search exponentially increases, and frequency analysis of binary sequences also becomes ineffective. At the second stage, an attack based on the knowledge of pair parities is considered, taking into account the proposed method for correcting the first stage. The analysis of the influence of network parameters on the process of eliminating the bit mismatch at the second stage is carried out. Statistical modeling of this analysis has been performed. The results obtained showed that the cryptanalyst could not uniquely distinguish the values of the remaining bits. The proposed combined method makes it possible to increase the confidentiality of the generated shared secret and significantly reduce the number of information exchanges in comparison with the Neural key generation technology.
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Zhang, Li, Xinru Mao, and Lin Ding. "Influence of attack angle on vortex-induced vibration and energy harvesting of two cylinders in side-by-side arrangement." Advances in Mechanical Engineering 11, no. 1 (January 2019): 168781401882259. http://dx.doi.org/10.1177/1687814018822598.
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The vortex-induced vibration and energy harvesting of two cylinders in side-by-side arrangement with different attack angles are numerically investigated using two-dimensional unsteady Reynolds-Averaged Navier–Stokes simulations. The Reynolds number ranges from 1000 to 10,000, and the attack angle of free flow is varied from 0° to 90°. Results indicate that the vortex-induced vibration responses with attack angle range of 0°≤ α ≤ 30° are stronger than other attack angle cases. The parallel vortex streets are clearly observed with synchronized vortex shedding. Relatively large attack angle leads to a phase difference between the wake patterns of the two cylinders. Hydrokinetic energy can be obviously harvested when Re > 4000. Compared with the larger attack angle case, the two side-by-side cylinders with smaller attack angle have better performance on energy conversion. The maximum energy conversion efficiency of 21.7% is achieved. The optimum region for energy conversion is 5000 ≤ Re ≤ 7000 and 0°≤ α ≤ 30°.
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Thangarathinam, P., N. Suganya, T. Praddeep, and S. Vignesh. "Synchrophasor Technology for Cyber Security in Smart Grid." International Journal of Students' Research in Technology & Management 3, no. 7 (October 29, 2015): 436. http://dx.doi.org/10.18510/ijsrtm.2015.378.
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Smart grid is controlled by an authority personnel who uses LAN or the internet to control it. By knowing this information any one from outside can control the smart grid using LAN or the internet. This process of hacking the smart grid control is known as aurora attack. The Aurora attack may pose a risk to rotating machinery operating under certain conditions on the electrical grid. The Aurora attack involves opening and closing one or more circuit breakers, resulting in an out-of-synchronism condition that may damage rotating equipment connected to the power grid.This paper focuses on the Aurora attack on a synchronous generator and the existing technology available to mitigate the attack. The root cause of the vulnerability is breakdown in security. The first level prevents the attack with sound security practices. The second level protects the equipment in the event that the security level is compromised. The equipment can be protected using wide-area synchronized phasor measurement and protection system and security considerations.
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Truong, Victor, Alexandre Vervisch-Picois, Jose Rubio Hernan, and Nel Samama. "Characterization of the Ability of Low-Cost GNSS Receiver to Detect Spoofing Using Clock Bias." Sensors 23, no. 5 (March 2, 2023): 2735. http://dx.doi.org/10.3390/s23052735.
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The aim of this paper was to propose a method to characterize the ability of a GNSS user to detect a spoofing attack from the behavior of the clock bias. Spoofing interference is not a new issue, especially in military GNSS, although it is a new challenge for civil GNSS, since it is currently implemented and used in many everyday applications. For this reason, it is still a topical issue, especially for receivers that only have access to high-level data (PVT,CN0). To address this important issue, after conducting a study of the receiver clock polarization calculation process, this led to the development of a very basic Matlab model that emulates a spoofing attack at the computational level. Using this model, we were able to observe that the clock bias is affected by the attack. However, the amplitude of this disturbance depends on two factors: the distance between the spoofer and the target and the synchronization between the clock that generates the spoofing signal and the reference clock of the constellation. To validate this observation, more or less synchronized spoofing attacks were carried out on a fixed commercial GNSS receiver with the use of GNSS signal simulators and also with a moving target. We propose then a method to characterize the capacity of detecting a spoofing attack with the clock bias behavior. We present the application of this method for two commercial receivers of the same manufacturer from different generations.
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Huang, Xiaojie, Yunxia Xia, and Da-Wei Ding. "Distributed Event-Triggered Synchronization for Complex Cyber–Physical Networks under DoS Attacks." Applied Sciences 13, no. 3 (January 29, 2023): 1716. http://dx.doi.org/10.3390/app13031716.
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With the continuous development of the networked society, the ability of cyber attackers is becoming increasingly intelligent, posing a huge threat to complex cyber–physical networks (CCPNs). Therefore, how to design a security strategy for CCPNs under attack has become an urgent problem to be solved, which promotes our work. The problem of the distributed event-triggered synchronization of CCPNs in the presence of denial-of-service (DoS) attacks is investigated in this paper. Firstly, a distributed event-triggered controller is designed such that all nodes of networks are synchronized without DoS attacks by relieving the communication occupancy rate of limited bandwidths. Meanwhile, Zeno and singular triggering behaviors are excluded to illustrate the effectiveness of the proposed event-triggered strategy. Secondly, in view of the continuous switching of CCPNs topologies caused by DoS attacks, an event-triggered control (ETC) strategy is proposed to ensure the synchronization of CCPNs under DoS attacks. Meanwhile, the frequency and duration of tolerable DoS attacks that can ensure the stability of the systems are calculated. Finally, two examples are given to illustrate the effectiveness of the proposed method.
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Chiu, Hon Sun, King-Shan Lui, and Kwan L. Yeung. "DelPHIX: A Simple and Efficient Mechanism for Wormhole Detection in Ad Hoc Networks." Journal of Communications Software and Systems 2, no. 2 (April 5, 2017): 131. http://dx.doi.org/10.24138/jcomss.v2i2.296.
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Data transmission in a mobile ad hoc network is performed within an untrusted wireless environment. It is subjected to many kinds of security attacks. In a wormhole attack, two malicious nodes work together to tunnel packets from one to the other, making other nodes perceive a path to have a smaller hop count. We identify two types of wormhole attacks. In the first type, malicious nodes do not expose themselves in route finding process and legitimate nodes do not know their existence. In the second type, malicious nodes do create route advertisements and legitimate nodes are aware of the existence of malicious nodes, just do not know they are malicious. Existing solutions usually can identify only one kind of attacks. In this paper, we propose a simple and efficient detection method called DelPHIX. Byobserving the delays of different paths to the receiver, the sender is able to detect both kinds of wormhole attacks. This method requires neither synchronized clocks nor special hardware to be equipped in mobile nodes. The performance of DelPHIX is justified by simulations.
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Albert Lusiola, Musoma. "Multi Agency Response to International Terrorism in Kenya: A Comparison of Dusit D2 and Westgate Terror Attacks." African Journal of Empirical Research 2, no. 2 (April 14, 2021): 68–84. http://dx.doi.org/10.51867/ajer.v2i2.23.
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This study sets out to assess responses to international terrorism in Kenya. This stems out of the fact that the terrorism menace has had been a major security challenge facing the country. The study draws a comparison of the Dusit D2 and Westgate terror attacks. Data was collected from a purposive sample of academics as well as serving and retired diplomats, senior police officers and military personnel. Primary data was collected from the respondents using interviews. The findings show that the West gate shopping mall in 2013 and the DusitD2 Hotel attack in January 2019 are replete with major differences. A critical comparison between both attacks shows an immense difference in the response to the terrorist attacks in Westgate Mall and Dust D2. In both cases, there was prior intelligence of the looming attack. However, there was no clear policy framework on intelligence sharing between the various security agencies in Westgate. Additionally, policies on timely multiagency deployment were disjointed in Westgate but improved in Dusit D2. Although the friendly fire was recorded in Westgate, this was not the case in Westgate. There was also a lack of clear policies on hierarchical coordination between different security agencies in Westgate Mall as opposed to Dusit D2. The law had also been more enhanced with the domestication of the 2012 Prevention of Terrorism Act and the creation of the institutions enshrined therein during the Dusit D2 attack. Accountability mechanisms for security agencies had also been improved during the Dusit D2 attack as opposed to Westgate Mall attack where there were cases of indiscipline and looting by state security personnel. Coordination between government officials and security agencies was also smoother in the Dusit D2 attack. Although the terrorists could communicate for some time between themselves and their command center and share publicity information, this was not the case with Dusit D2 where such communication was curtailed immediately. In both attacks though, communication between victims and outside help was poor and unreliable, and false information was passed. This was more prone and documented in the Dusit D2 attack. It is recommended that multiagency response teams should constantly review their operation guidelines and standard operating procedures so as to deal with the ever-changing sophistication in terrorist attacks. The government should put in place ways aimed at checking disparities in capabilities and equipment among various tactical and intelligence teams in Kenya for a uniform response to terrorism. There is a need for multinational frameworks for undertaking financing and creation of joint information infrastructure for security agencies so as to reign in on international terrorism in the East African Region. Training should also be synchronized across security agencies.
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Dass, Prajnamaya, Pranay Kumar Saha, and Hari Om. "Improved Traceable-Resistant Efficient Authentication Schemes for Wireless Networks." International Journal of Business Data Communications and Networking 12, no. 2 (July 2016): 28–61. http://dx.doi.org/10.4018/ijbdcn.2016070103.
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Wireless technology is widely spread everywhere in the real world and has a biggest contribution to mankind. However, with the vitality of wireless architectures, security protocols are vulnerable to attackers outside the system, failure in wireless connectivity and machine failures. Protocols must be streamlined to combat with these abnormal conditions. In this paper, the authors provide a review of an existing protocol by Lee et al. They found that the protocol proposed by Lee et al., Enhanced two factor key exchange protocol in public wireless LANs is vulnerable to traceable attack. It is a serious type of attack where the attacker can target a particular user/client. To ensure security, the authors propose an improved scheme which anonymously provides secure authentication satisfying synchronization, untraceability of user and resists common attacks in a wireless network. As most of the real time security protocols use bio-metric based authentication schemes, they also propose a smartcard based secure authentication scheme for wireless networks. Their proposed schemes are proved safe under the formal security analysis of BAN logic. Both of their protocols are simulated using Automated Validation of Internet Security Protocols and Applications (AVISPA). The simulation of their protocols under On-the-Fly-Model-Checker (OFMC) and Constant Logic based Attack Searcher (CL-AtSe) models of AVISPA results in a SAFE state. The authors have compared their proposed schemes against some of the recently proposed wireless authentication schemes in terms of attack resistivity and operational cost. Experimental results elicit a significant improvement over the existing schemes with low cost. Proposed untraceable, synchronized schemes can be applied for authentication purposes in public wireless networks, client server authentication system etc. with effective cost.
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Matsuzono, Kosuke, Takao Yoshiki, Yosuke Wakutani, Yasuhiro Manabe, Toru Yamashita, Kentaro Deguchi, Yoshio Ikeda, and Koji Abe. "Synchronized Babinski and Chaddock Signs Preceded the MRI Findings in a Case of Repetitive Transient Ischemic Attack." Internal Medicine 52, no. 18 (2013): 2127–29. http://dx.doi.org/10.2169/internalmedicine.52.0190.
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Mukherjee, Saswati, Matangini Chattopadhyay, Samiran Chattopadhyay, and Pragma Kar. "Wormhole Detection Based on Ordinal MDS Using RTT in Wireless Sensor Network." Journal of Computer Networks and Communications 2016 (2016): 1–15. http://dx.doi.org/10.1155/2016/3405264.
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In wireless communication, wormhole attack is a crucial threat that deteriorates the normal functionality of the network. Invasion of wormholes destroys the network topology completely. However, most of the existing solutions require special hardware or synchronized clock or long processing time to defend against long path wormhole attacks. In this work, we propose a wormhole detection method using range-based topology comparison that exploits the local neighbourhood subgraph. The Round Trip Time (RTT) for each node pair is gathered to generate neighbour information. Then, the network is reconstructed by ordinal Multidimensional Scaling (MDS) followed by a suspicion phase that enlists the suspected wormholes based on the spatial reconstruction. Iterative computation of MDS helps to visualize the topology changes and can localize the potential wormholes. Finally, a verification phase is used to remove falsely accused nodes and identify real adversaries. The novelty of our algorithm is that it can detect both short path and long path wormhole links. Extensive simulations are executed to demonstrate the efficacy of our approach compared to existing ones.
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Eslahi, Ali, Shahryar Zeighami, Faisal Ahmed, Seyed Hossein Hosseini, Bahareh Ebrahimi, and Mohammad Hossein Anbardar. "Synchronized Laparoscopic Bilateral Adrenalectomy for Pheochromocytoma in Multiple Endocrine Neoplasia Syndrome: A Case Report." Journal of Kidney Cancer and VHL 9, no. 3 (September 2, 2022): 24–28. http://dx.doi.org/10.15586/jkcvhl.v9i3.239.
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Pheochromocytomas are tumors producing catecholamines that arise from chromaffin cells in the adrenal medulla. They are usually benign in multiple endocrine neoplasia type 2 (MEN2) syndrome, but they tend to present bilaterally in 50–80% of the patients. Few researchers have reported success with simultaneous laparoscopic bilateral adrenalectomy. Hence, we report a 48-year-old woman who presented with a panic attack, headache, and abdominal discomfort that had started 10 years ago. The computed tomography (CT) scan showed a large bilateral cystic lesion in both adrenal glands in favor of pheochromocytomas (30 × 22 mm and 18 × 15 mm on the right side and 40 × 33 mm and 35 × 28 mm on the left side). The patient underwent bilateral laparoscopic adrenalectomy without intraoperative or postoperative complications. The total blood loss was 50 cc, and the operative time was 4 h. The histopathology of the specimen revealed pheochromocytomas of adrenal masses. In conclusion, our case demonstrates that synchronized laparoscopic bilateral adrenalectomy can be a safe and feasible treatment option for pheochromocytomas in MEN2 patients.
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Winter, R. W., K. A. Cornell, L. L. Johnson, M. Ignatushchenko, D. J. Hinrichs, and M. K. Riscoe. "Potentiation of the antimalarial agent rufigallol." Antimicrobial Agents and Chemotherapy 40, no. 6 (June 1996): 1408–11. http://dx.doi.org/10.1128/aac.40.6.1408.
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We have discovered a remarkable synergistic antimalarial interaction between rufigallol and the structurally similar compound exifone. The synergistic effects were produced in chloroquine-susceptible and chloroquine-resistant clones of Plasmodium falciparum. The degree of potentiation as estimated by standard isobolar analysis was approximately 60-fold for experiments initiated with asynchronous parasites. The most pronounced synergism was observed in experiments with synchronized trophozoite-infected erythrocytes, in which the degree of synergy was at least 300-fold. While the mechanism underlying this drug potentiation remains unresolved, it is hypothesized that rufigallol acts in pro-oxidant fashion to produce oxygen radicals inside parasitized erythrocytes. These radicals would attack exifone, thereby initiating its transformation into a more potent compound, a xanthone.
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Karthika, P., and Karmel Arockiasamy. "Simulation of SDN in mininet and detection of DDoS attack using machine learning." Bulletin of Electrical Engineering and Informatics 12, no. 3 (June 1, 2023): 1797–805. http://dx.doi.org/10.11591/eei.v12i3.5232.
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Most contemporary businesses are embracing software defined networking (SDN), a developing architecture that enables an aerial-like perspective of the entire network. SDN operates by virtualizing the network and provides advantages including improved performance, visibility, speed, and scalability. SDN attempts to divide the network control plane from the forwarding plane. The control plane, which includes one or more controllers and incorporates complete intelligence, is thought of as the brain of the SDN. However, SDN has challenges with controller vulnerability, flexibility, and hardware security. But distributed denial of service (DDoS) assaults constitutes a serious threat to the SDN. Transmission control protocol-synchronized (TCP-SYN) floods, a common cyberattack that can harm SDNs, can deplete network resources by opening an excessive number of illegitimate TCP connections. In this research, we provide an OpenFlow port statistic-based architecture for machine learning (ML) enabled TCP-SYN flood detection. This research showed that ML models like support vector machine (SVM), Navie Bayes, and multi-layered perceptron can distinguish between regular traffic and SYN flood traffic and can mitigate the impacts of the attacking node on the network. Results showed that the multilayered perceptron can classify the traffic with highest accuracy of 99.75% for the simulation dataset.
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Marshall, David J. "Predatory and reproductive responses of the estuarine whelk Thais gradata (Caenogastropoda: Muricidae) to novel colonization by Musculista senhousia (Bivalvia: Mytilidae)." Journal of the Marine Biological Association of the United Kingdom 89, no. 7 (June 2, 2009): 1387–93. http://dx.doi.org/10.1017/s0025315409000642.
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Novel predator–prey interactions are becoming increasingly relevant to investigate in the context of current geographical range expansions and biological invasions. This study describes a vigorous attack by a muricid whelk, Thais gradata on a mud-inhabiting mytilid mussel, Musculista senhousia, following new colonization of the mussel in the Brunei estuarine system (Borneo, South-East Asia). This represents only the second reported attack by a gastropod on this globally important invasive mussel species, and the first such attack in its native environment. Whelks migrated from their typical hard surface habitat and barnacle feeding to the sediment, where they aggregated and fed on the mussels. Field data suggest no selection by the whelks of the part of the mussel bed colonized or of the prey size attacked (median shell length = 21 mm). In addition to forming feeding aggregations, the whelks formed non-feeding resting aggregations off the mussel bed (sometimes of more than 80 individuals). These apparently facilitated synchronized mating and consequently the formation of large communal nests of egg capsules (involving approximately 3500 contributing females). During the investigation, the newly-formed mussel colony underwent mass mortality, and the whelks either redistributed on the sediment or returned to feeding on barnacles. The population-level response by the whelks described here maximizes energy transfer from prey resource to whelk propagation. In addition to the whelk's generality of habitat use and feeding behaviour, this is likely to contribute to sustaining populations in a system where prey abundance and distribution is limited by highly variable and extreme physicochemical conditions.
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Huang, Huihui, Xuyang Miao, Zehui Wu, and Qiang Wei. "An Efficient ECC-Based Authentication Scheme against Clock Asynchronous for Spatial Information Network." Mathematical Problems in Engineering 2021 (February 2, 2021): 1–14. http://dx.doi.org/10.1155/2021/8811970.
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With the rapid development of mobile communication technology, the spatial information networks (SIN) have been used for various space tasks’ coverage in commercial, meteorology, emergency, and military scenarios. In SIN, one basic issue is to achieve mutual authentication and secret communication among the participants. Although many researches have designed authentication schemes for SIN, they have not considered the situation where the clock is not synchronized as the broad coverage space in wireless environment. In this paper, we disclose several flaws of Altaf et al.’s scheme (2020), in which the main weakness is that a malicious user can easily obtain the master key of the network control center after launching the offline password-guessing attack. Then, we design an authentication scheme against clock asynchronous for SIN by utilizing elliptic curve cryptosystem (ECC) and identity-based cryptography (IBC). Based on a brief introduction to the main design ideas of our scheme, the security protocol analysis tools of Scyther and AVISPA are used to prove that the scheme can resist various existing active and passive attacks. We further discuss our scheme that provides five essential requirements of security properties to design a robust scheme for SIN and is superior in terms of resistance to security functionality and computational performance by comparison with two other representative schemes. As a result, our scheme will be workable and efficient security for mobile users in the actual environment.
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Hori, Michio, Masanori Kohda, Satoshi Awata, and Satoshi Takahashi. "Dynamics of Laterality in Lake Tanganyika Scale-Eaters Driven by Cross-Predation." Symmetry 11, no. 1 (January 20, 2019): 119. http://dx.doi.org/10.3390/sym11010119.
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Scale-eating cichlid fishes, Perissodus spp., in Lake Tanganyika have laterally asymmetrical bodies, and each population is composed of righty and lefty morphs. Righty morphs attack the right side of prey and lefty morphs do the opposite. This anti-symmetric dimorphism has a genetic basis. Temporal changes in the frequencies of morphs in two cohabiting scale-eating species (Perissodus microlepis and P. straeleni) were investigated over a 31-year period on a rocky shore at the southern end of the lake. Dimorphism was maintained dynamically during the period in both species, and the frequencies oscillated with a period of about four years in a semi-synchronized manner. Recent studies have indicated that this type of anti-symmetric dimorphism is shared widely among fishes, and is maintained by frequency-dependent selection between predator and prey species. The combinations of laterality in each scale-eater and its victim were surveyed. The results showed that “cross-predation”, in which righty predators catch lefty prey and lefty predators catch righty prey, occurred more frequently than the reverse combination (“parallel-predation”). The cause of the predominance of cross-predation is discussed from the viewpoint of the physical and sensory abilities of fishes.
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Leone, M., V. Lucini, D. D'Amico, F. Moschiano, C. Maltempo, F. Fraschini, and G. Bussone. "Twenty-Four-Hour Melatonin and Cortisol Plasma Levels in Relation to Timing of Cluster Headache." Cephalalgia 15, no. 3 (June 1995): 224–29. http://dx.doi.org/10.1046/j.1468-2982.1995.015003224.x.
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The cyclic recurrence of cluster periods and the regular timing of headache occurrence in cluster headache (CH) induced us to study the circadian secretion of melatonin and cortisol in 12 patients with episodic CH, during a cluster period, and compare them with 7 age- and sex-matched healthy controls. Blood was sampled every 2, h for 24 h. All subjects were confined to a dark room from 22.00 to 08.00. Plasma melatonin levels were significantly reduced in CH patients (repeated measures ANOVA p < 0.03; mesor p < 0.02), and the cortisol mesor was significantly increased ( p < 0.03). Amplitudes and acrophases did not differ between the groups. Individual cosinor analysis showed that 4/12 (33.3%) CH patients had no significant melatonin rhythm, and that 5/11 (45.5%) had no cortisol rhythm. Group analysis of cosinor revealed significant rhythmicity of melatonin and cortisol secretion in both groups. In controls, the timing of melatonin and cortisol acrophase significantly correlated with each other, indicating that the biorhythm controllers for the secretion of these hormones were synchronized. Such correlation was not found in the CH patients; mesor, amplitude and acrophase of melatonin and cortisol did not correlate with duration of illness, duration of headache in course, or time since last headache attack.
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Régnière, Jacques, M. Lukas Seehausen, and Véronique Martel. "Modeling Climatic Influences on Three Parasitoids of Low-Density Spruce Budworm Populations. Part 1: Tranosema rostrale (Hymenoptera: Ichneumonidae)." Forests 11, no. 8 (August 5, 2020): 846. http://dx.doi.org/10.3390/f11080846.
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Despite their importance as mortality factors of many insects, the detailed biology and ecology of parasitoids often remain unknown. To gain insights into the spatiotemporal biology of insect parasitoids in interaction with their hosts, modeling of temperature-dependent development, reproduction, and survival is a powerful tool. In this first article of a series of three, we modeled the biology of Tranosema rostrale at the seasonal level with a three-species individual-based model that took into account the temperature-dependent performance of the parasitoid and two of its hosts. The predicted activity of the first adult parasitoid generation closely matched the seasonal pattern of attack on the spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae). The model predicted 1–4 full generations of T. rostrale per year in eastern North America. The generations were generally well synchronized with the occurrence of larvae of a probable alternate host, the obliquebanded leafroller Choristoneura rosaceana (Lepidoptera: Tortricidae), which could be used as an overwintering host. Spatial differences in predicted performance were caused by complex interactions of life-history traits and synchrony with the overwintering host, which led to a better overall performance in environments at higher elevations or along the coasts. Under a climate warming scenario, regions of higher T. rostrale performance were predicted to generally move northward, making especially lower elevations in the southern range less suitable.
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Liu, Yufeng, Jianguo Kong, Xiuping Wang, and Gongbing Shan. "Biomechanical analysis of Yang’s spear turning-stab technique in Chinese martial arts." Physical Activity Review 8, no. 2 (2020): 16–22. http://dx.doi.org/10.16926/par.2020.08.17.
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The Yang’s spear turning-stab was a legendary technique, applied in ancient battles in China. It resulted in numerous famous winnings. The mythical aspect of the technique is a victory in fleeing and back-facing a fighter. Now the skill is a spear technique of Chinese martial arts that is learned and excised by many Chinese Gungfu practitioners. Due to a dearth of scientific study on the skill, the uniqueness and its winning secretes are still unknown. The aim of this study is to demystify the skill by using a synchronized measurement of 3D motion capture (VICON 12 camera system), stab-force measurement (AMTI force platform). Six Gungfu athletes with more than 30 years training experience participated in the study. Both the Yang’s spear turning-stab (used by a fleer) and spear forward-stab (used by a chaser) were measured and biomechanically analyzed. The results reveal that there would be six secrets for its historical successes. They are 1) showing weakness (i.e. pretend to be defeated), 2) shortening the stab for quick turning, 3) hiding the stab for a covert attack, 4) leaving less reaction time for opponent, 5) generating higher stab-force than opponent, and 6) leaning backward for a stable stab-posture. These secrets identify elements necessary for systematic training toward a reliable execution of the skill. This skill shows the delicate characteristics of Chinese martial culture. Learning and training the skill would benefit trainees both physically and culturally.
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Qu, Zhengwei, Xinran Zhang, Yuchen Gao, Chao Peng, Yunjing Wang, and Popov Maxim Georgievitch. "Detection of False Data Injection Attack in AGC System Based on Random Forest." Machines 11, no. 1 (January 9, 2023): 83. http://dx.doi.org/10.3390/machines11010083.
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False data injection attacks change the control effect of automatic generation control systems, which may cause a destructive impact on power systems. In this paper, the data from the regular operation of a system and the data from false data injection attacks in the historical data are studied and classified. The normal operating parameters and abnormal operation parameters under various attack scenarios are collected as samples for training the detection model based on time series. The random forest algorithm model is selected for detection through the comparison of detection effects, and various data training models are accumulated during the operation process to improve the model’s accuracy. Finally, Simulink simulation experiments verify the consistency of the detection results of the simulated attack algorithm. This detection method can realize real-time attack detection and synchronize the detection results to the database with high timeliness. It can be used in systems with rich data samples and has broad applicability.
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Régnière, Jacques, Rémi Saint-Amant, Jean-Claude Thireau, Pierre Therrien, Christian Hébert, and Véronique Martel. "Modeling Climatic Influences on Three Parasitoids of Low-Density Spruce Budworm Populations. Part 2: Meteorus trachynotus (Hymenoptera: Braconidae)." Forests 12, no. 2 (January 28, 2021): 155. http://dx.doi.org/10.3390/f12020155.
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This is the second article of a series of three where we develop temperature-driven models to describe the seasonal interactions between parasitoids and their hosts which we use to explore the impact of climate on their spatiotemporal biology. Here, we model the biology of Meteorus trachynotus (Hymenoptera: Braconidae) with an individual-based model of its daily interactions with two host species. This model predicts the performance of the parasitoid in response to temperature affecting its seasonal development and that of the two hosts. We compare model output with an extensive set of field observations from natural host populations. The predicted activity of the first adult parasitoid generation closely matches the seasonal pattern of attack on the spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae) within the limitations of available data. The model predicts 1–4 full generations of M. trachynotus per year in eastern North America, with generations well synchronized with larvae of a known overwintering host, the obliquebanded leafroller Choristoneura rosaceana. The model predicts the observed density dependence of parasitism on spruce budworm. Predicted performance exhibits spatial variation caused by complex life-history interactions, especially synchrony with the overwintering host. This leads to a better performance in warm but not hot environments at middle latitudes and elevations. The model’s predicted spatial patterns correspond closely to our field observations on the frequency of parasitism on spruce budworm. Under climate change, the model predicts that the performance of M. trachynotus populations will improve in the northern portion of its range.
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Mironov, N. Yu, V. V. Vlodzyanovskiy, Yu A. Yuricheva, S. F. Sokolov, S. P. Golitsyn, L. V. Rosenstraukh, and E. I. Chazov. "Safety and Effectiveness of Electrical and Pharmacological Cardioversion in Persistent Atrial Fibrillation. Part 2: Assessment of Safety." Rational Pharmacotherapy in Cardiology 14, no. 6 (January 5, 2019): 826–30. http://dx.doi.org/10.20996/1819-6446-2018-14-6-826-830.
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Aim. To compare safety of new class III antiarrhythmic drug Refralon with direct current cardioversion (DCC) in patients with persistent atrial fibrillation (AF). Material and methods. 60 patients with persistent AF were randomized to groups of DCC (n=30) and pharmacologic conversion (PCV; n=30). There were no significant differences in age, sex, AF duration, concomitant cardiovascular diseases, CHA2DS2-VASc score and echocardiographic parameters between the groups compared. Initial assessment excluded contraindications to restore sinus rhythm (SR). In DCC group two attempts using biphasic synchronized shocks of 150 J and 170 J were performed. In PCV group patients received up to three subsequent intravenous injections of Refralon 10 μg/kg (maximal dose 30 μg/kg). Results. There were no mortality, stroke, transient ischemic attack, ventricular arrhythmia, asystole longer than 3,0 sec (primary safety criteria) in both groups. Prolongation of QT interval longer than 500 ms observed in 1 of 30 patients (3,3%) in DCC group and in 7 of 30 patients (23,3%) in PCV group. 2 patients (one patient in each group; 3,3%) developed asymptomatic bradycardia after conversion to SR that resolved spontaneously within 30 minutes. 95% confidence interval (95%CI) for secondary safety criteria is [0,02-0,38] for QT prolongation and [-0,04-0,04] for bradycardia. Conclusion. Safety of PCV is noninferior to DCC in patients with persistent AF in terms of primary safety criteria and bradyarrhythmias. More frequent QT interval prolongation to values >500 ms observed in PCV group points to necessity of precautions with use of the drug.
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Barenghi, Alessandro, Gioele Falcetti, and Gerardo Pelosi. "Locating Side Channel Leakage in Time through Matched Filters." Cryptography 6, no. 2 (May 30, 2022): 26. http://dx.doi.org/10.3390/cryptography6020026.
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Side channel attacks provide an effective way to extract secret information from the execution of cryptographic algorithms run on a variety of computing devices. One of the crucial steps for a side channel attack to succeed is the capability to locate the time instant in which the cryptographic primitive being attacked is effectively leaking information on the side channel itself, and synchronize the data obtained from the measurements on that instant. In this work, we propose an efficient and effective solution relying on the digital signal processing technique known as matched filters. We derive our matched filter with a small amount of profiling information which can be obtained from a device matching the one under attack. Our technique reliably identifies the cryptographic operation being computed, even when system interrupts or software multithreading are enabled on our target platform. We validate our approach through a successful attack against an unprotected AES implementation running on a Cortex-M4-based microcontroller.
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Alfraih Abdulaziz Nasser, A., and Wen Bo Chen. "NTP DRDoS Attack Vulnerability and Mitigation." Applied Mechanics and Materials 644-650 (September 2014): 2875–80. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.2875.
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The Network Time Protocol (NTP) is used to synchronize clocks of various computer devices such as personal computers, tablets, and phones based their set time zones. The network of devices that use these NTP servers form a huge distributed network that attracted a number of attacks from late 2013 towards early 2014. This paper presents a hands-on test of the Distributed Reflection Denial of Service (DRDoS) attack by the monlist command, provides more vulnerability in the protocol, and offers mitigation to these vulnerabilities. A Kali Linux server was used to test the monlist command on its localhost. The results showed that a request with a size of 234 bytes got a response of 4,680 bytes. A busy NTP server can return up to 600 addresses which were theoretically calculated to return approximately 48 kilobytes in 100 packets. Consequently, this results in an amplification factor of 206×. The knowledge of the way the attack can be propagated was an important step in thwarting the attack and mitigating more such threats in the same protocol.
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Fujimura, T., Y. Takahagi, H. Nagashima, S. Miyagawa, T. Shigehisa, and H. Murakami. "33 PRODUCTION OF TRANSGENIC-CLONED PIGS CARRYING HDAF, GnT-III AND HETEROZYGOUSLY DISRUPTED ±-1,3-GALACTOSYLTRANSFERASE GENES." Reproduction, Fertility and Development 17, no. 2 (2005): 166. http://dx.doi.org/10.1071/rdv17n2ab33.
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In pig-to-human xenotransplantation, transplants are rapidly rejected by binding of human natural antibodies to porcine xenoantigen, mostly Gal α-1-3Gal oligosaccharides, and subsequent complement attack. To overcome this rejection, we so far have produced transgenic pigs expressing both human CD55/DAF (decay-accelerating factor, a complement-regulatory protein) and GnT-III (N-acetylglucosaminyltransferase III, a sugar chain modifying enzyme). In the present study, we heterozygously disrupted the α-1,3-galactosyltransferase (GT) gene, which catalyses the biosynthesis of Gal α-1-3Gal epitopes, in the fetal fibroblast cells from the DAF/GnT-III transgenic pigs by homologous recombination, and successfully produced GT-knockout pigs by nuclear transfer. Fibroblast cells isolated from Day 30 fetuses of DAF/GnT-III transgenic pigs were transfected with a GT-targeting vector. The targeting event in drug-resistant colonies was confirmed by PCR analysis, and targeted cells were used as nuclear donors. The reconstructed embryos were electrically activated and transferred to estrus-synchronized recipient pigs. At pregnancy Day 27 of gestation, fetuses were collected and their fibroblast cells were isolated for secondary nuclear transfer. The genomic DNA of live-born piglets produced by the secondary nuclear transfer were analyzed for the presence of DAF and GnT-III genes as well as the heterozygous disruption of the GT gene. From a total of 5.5 × 107 cells transfected with the GT-targeting vector, 2,749 drug-resistant colonies were obtained. Eighteen colonies were judged positive for targeting events by PCR analysis. After transfer of 321 cloned embryos reconstructed with the knockout cells to three recipients, four knockout fetuses were obtained from one recipient. Transfer of 633 cloned embryos reconstructed with the knockout fibroblast cells from one knockout fetus to six recipients gave rise to two live knockout piglets. PCR analysis of genomic DNA confirmed that the cloned piglets carried both DAF and GnT-III transgenes as well as the heterozygously disrupted GT gene.
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Quadir, Md Abdul, J. Christy Jackson, J. Prassanna, K. Sathyarajasekaran, K. Kumar, H. Sabireen, Shivam Ubarhande, and V. Vijaya Kumar. "An efficient algorithm to detect DDoS amplification attacks." Journal of Intelligent & Fuzzy Systems 39, no. 6 (December 4, 2020): 8565–72. http://dx.doi.org/10.3233/jifs-189173.
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Domain name system (DNS) plays a critical part in the functioning of the Internet. But since DNS queries are sent using UDP, it is vulnerable to Distributed Denial of Service (DDoS) attacks. The attacker can take advantage of this and spoof the source IP address and direct the response towards the victim network. And since the network does not keep track of the number of requests going out and responses coming in, the attacker can flood the network with these unwanted DNS responses. Along with DNS, other protocols are also exploited to perform DDoS. Usage of Network Time Protocol (NTP) is to synchronize clocks on systems. Its monlist command replies with 600 entries of previous traffic records. This response is enormous compared to the request. This functionality is used by the attacker in DDoS. Since these attacks can cause colossal congestion, it is crucial to prevent or mitigate these types of attacks. It is obligatory to discover a way to drop the spoofed packets while entering the network to mitigate this type of attack. Intelligent cybersecurity systems are designed for the detection of these attacks. An Intelligent system has AI and ML algorithms to achieve its function. This paper discusses such intelligent method to detect the attack server from legitimate traffic. This method uses an algorithm that gets activated by excess traffic in the network. The excess traffic is determined by the speed or rate of the requests and responses and their ratio. The algorithm extracts the IP addresses of servers and detects which server is sending more packets than requested or which are not requested. This server can be later blocked using a firewall or Access Control List (ACL).
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He, Xing, and Michael S. Scordilis. "Efficiently Synchronized Spread-Spectrum Audio Watermarking with Improved Psychoacoustic Model." Research Letters in Signal Processing 2008 (2008): 1–5. http://dx.doi.org/10.1155/2008/251868.
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This paper presents an audio watermarking scheme which is based on an efficiently synchronized spread-spectrum technique and a new psychoacoustic model computed using the discrete wavelet packet transform. The psychoacoustic model takes advantage of the multiresolution analysis of a wavelet transform, which closely approximates the standard critical band partition. The goal of this model is to include an accurate time-frequency analysis and to calculate both the frequency and temporal masking thresholds directly in the wavelet domain. Experimental results show that this watermarking scheme can successfully embed watermarks into digital audio without introducing audible distortion. Several common watermark attacks were applied and the results indicate that the method is very robust to those attacks.
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Yeniçeri, Ramazan, Selçuk Kilinç, and Müştak E. Yalçin. "Attack on a Chaos-Based Random Number Generator Using Anticipating Synchronization." International Journal of Bifurcation and Chaos 25, no. 02 (February 2015): 1550021. http://dx.doi.org/10.1142/s0218127415500212.
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Chaotic systems have been used in random number generation, owing to the property of sensitive dependence on initial conditions and hence the possibility to produce unpredictable signals. Within the types of chaotic systems, those which are defined by only one delay-differential equation are attractive due to their simple model. On the other hand, it is possible to synchronize to the future states of a time-delay chaotic system by anticipating synchronization. Therefore, random number generator (RNG), which employs such a system, might not be immune to the attacks. In this paper, attack on a chaos-based random number generator using anticipating synchronization is investigated. The considered time-delay chaotic system produces binary signals, which can directly be used as a source of RNG. Anticipating synchronization is obtained by incorporating other systems appropriately coupled to the original one. Quantification of synchronization is given by the bit error between the streams produced by the original and coupled systems. It is shown that the bit streams generated by the original system can be anticipated by the coupled systems beforehand.
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Klymiuk, N., A. Baehr, B. Kessler, M. Kurome, A. Wuensch, N. Herbach, R. Wanke, H. Nagashima, and E. Wolf. "425 HIGH-LEVEL EXPRESSION OF LEA29Y IN PANCREATIC ISLETS OF TRANSGENIC PIGS." Reproduction, Fertility and Development 22, no. 1 (2010): 370. http://dx.doi.org/10.1071/rdv22n1ab425.
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Among the candidate organs or tissues for pig-to-primate xenotransplantation, pancreatic islets are probably closest to clinical application. Rejection of islet xenografts occurs mainly by cellular mechanisms; that is, T cells. A candidate molecule to protect porcine islets against the attack by human T cells is CTLA-4Ig, which represents the T-cell-inactivating extracellular domain of the human CTLA-4 protein linked to a region of the human immunoglobulin (Ig). This recombinant soluble fusion protein binds to CD80 and CD86, blocking their interaction with CD28 and thereby inhibiting T-cell proliferation and T-cell-dependent antibody production. The survival of human, rabbit, and porcine islets after transplantation into streptozotocin-treated diabetic mice was found to be prolonged after treatment with CTLA-4Ig. In order to facilitate local protection of pig-to-primate islet xenografts, we generated transgenic pigs expressing LEA29Y, a modification of the original CTLA-4Ig with higher potency, specifically in the pancreatic islets. In LEA29Y, 2 amino acids in the binding region of CTLA-4 are altered. The LEA29Y coding sequence was placed under the control of the 1.3-kb core promoter from the porcine insulin gene (INS), and the polyadenylation signal from the bovine growth hormone gene (GH) was added. The construct was linked with a floxed neomycin resistance cassette and transfected into porcine fetal fibroblasts. The cells were selected and stable clones were pooled and used as donors for nuclear transfer. After electrofusion and activation, embryos were transferred to 2 synchronized gilts; 8 piglets survived to term with 7 of them carrying the transgene. Southern blot analysis suggested that the founder animals contain 1 or 2 independent integration sites. Four founders were autopsied at the age of 3 months to evaluate expression of LEA29Y in the pancreatic islets by immunohistochemistry. The ratio of immunohistochemically stained islet cell profiles to all islet cell profiles in the islet profiles visible in the sections was estimated. The staining intensity was also estimated qualitatively, by grading from weak to strong immunoreactivity (brown color, using DAB as chromogen). Although 2 founders exhibited single LEA29Y-positive islet cells in some pancreatic islet profiles, the other 2 founders showed a high percentage of strongly positive cells in all islet profiles examined, suggesting beta-cell specific expression. Fibroblasts from the latter 2 founders are currently being used for recloning to generate multiple pigs with constitutive expression of LEA29Y in the pancreatic islets. The protective effect of this strategy will be tested by transplanting LEA29Y-expressing porcine islets in diabetic mouse models with a humanized immune system and in diabetic nonhuman primate models. Supported by the Deutsche Forschungsgemeinschaft (FOR 535).
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Gupta, Tanvi, Sumit Kumar, Ankit Tomar, and KamalKant Verma. "DNS Prevention Using 64-Bit Time Synchronized Public Key Encryption to Isolate Phishing Attacks." International Journal of Security and Its Applications 10, no. 8 (August 31, 2016): 395–406. http://dx.doi.org/10.14257/ijsia.2016.10.8.35.
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Pan, Shengyi, Thomas Morris, and Uttam Adhikari. "Classification of Disturbances and Cyber-Attacks in Power Systems Using Heterogeneous Time-Synchronized Data." IEEE Transactions on Industrial Informatics 11, no. 3 (June 2015): 650–62. http://dx.doi.org/10.1109/tii.2015.2420951.
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Kumar, Gulshan, Rahul Saha, Mandeep Singh, and Mritunjay Kumar Rai. "Optimized Packet Filtering Honeypot with Snooping Agents in Intrusion Detection System for WLAN." International Journal of Information Security and Privacy 12, no. 1 (January 2018): 53–62. http://dx.doi.org/10.4018/ijisp.2018010105.
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Wireless LAN networks are considered to be widely used and efficient infrastructure used in different domains of communication. In this paper, we worked on Network Intrusion Detection System (NIDS) to prevent intruder's activities by using snooping agents and honeypot on the network. The idea behind using snooping agents and honeypot is to provide network management in term of monitoring. Honey pot is placed just after the Firewall and intrusion system have strongly coupled synchronize with snooping agents Monitoring is considered at packet level and pattern level of the traffic. Simulation filtered and monitor traffic for highlight the intrusion in the network. Further attack sequence has been created and have shown the effects of attack sequence on scenario which have both honey pot and snoop agent with different network performance parameters like throughput, network load, queuing delay, retransmission attempt and packet. The simulation scenario shows the impact of attack on the network performance.
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Gupta, Kirti, Subham Sahoo, Bijaya Ketan Panigrahi, Frede Blaabjerg, and Petar Popovski. "On the Assessment of Cyber Risks and Attack Surfaces in a Real-Time Co-Simulation Cybersecurity Testbed for Inverter-Based Microgrids." Energies 14, no. 16 (August 12, 2021): 4941. http://dx.doi.org/10.3390/en14164941.
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The integration of variable distributed generations (DGs) and loads in microgrids (MGs) has made the reliance on communication systems inevitable for information exchange in both control and protection architectures to enhance the overall system reliability, resiliency and sustainability. This communication backbone in turn also exposes MGs to potential malicious cyber attacks. To study these vulnerabilities and impacts of various cyber attacks, testbeds play a crucial role in managing their complexity. This research work presents a detailed study of the development of a real-time co-simulation testbed for inverter-based MGs. It consists of a OP5700 real-time simulator, which is used to emulate both the physical and cyber layer of an AC MG in real time through HYPERSIM software; and SEL-3530 Real-Time Automation Controller (RTAC) hardware configured with ACSELERATOR RTAC SEL-5033 software. A human–machine interface (HMI) is used for local/remote monitoring and control. The creation and management of HMI is carried out in ACSELERATOR Diagram Builder SEL-5035 software. Furthermore, communication protocols such as Modbus, sampled measured values (SMVs), generic object-oriented substation event (GOOSE) and distributed network protocol 3 (DNP3) on an Ethernet-based interface were established, which map the interaction among the corresponding nodes of cyber-physical layers and also synchronizes data transmission between the systems. The testbed not only provides a real-time co-simulation environment for the validation of the control and protection algorithms but also extends to the verification of various detection and mitigation algorithms. Moreover, an attack scenario is also presented to demonstrate the ability of the testbed. Finally, challenges and future research directions are recognized and discussed.
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SOLAK, ERCAN. "CRYPTANALYSIS OF OBSERVER BASED DISCRETE-TIME CHAOTIC ENCRYPTION SCHEMES." International Journal of Bifurcation and Chaos 15, no. 02 (February 2005): 653–58. http://dx.doi.org/10.1142/s0218127405012260.
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This paper investigates the weaknesses of cryptosystems that use observer based synchronized chaotic systems. It is shown that known plaintext and chosen plaintext attacks can successfully be launched against such cryptosystems to recover the system parameters and subsequently eavesdrop on the message transmission. The methods employed rely only on the basic mathematical relations that exist between the output sequence and the message sequence of the transmitter system and require very less computations.
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Zhu, Baoshan, Jun Lei, and Shuliang Cao. "Numerical Simulation of Vortex Shedding and Lock-in Characteristics for a Thin Cambered Blade." Journal of Fluids Engineering 129, no. 10 (April 28, 2007): 1297–305. http://dx.doi.org/10.1115/1.2776964.
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In this paper, vortex-shedding patterns and lock-in characteristics that vortex-shedding frequency synchronizes with the natural frequency of a thin cambered blade were numerically investigated. The numerical simulation was based on solving the vorticity-stream function equations with the fourth-order Runge–Kutta scheme in time and the Chakravaythy–Oscher total variation diminishing (TVD) scheme was used to discretize the convective term. The vortex-shedding patterns for different blade attack angles were simulated. In order to confirm whether the vortex shedding would induce blade self-oscillation, numerical simulation was also carried out for blade in a forced oscillation. By changing the pitching frequency and amplitude, the occurrence of lock-in at certain attack angles was determined. Inside the lock-in zone, phase differences between the blade’s pitching displacement and the torque acting on the blade were used to infer the probability of the blade self-oscillation.
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Legett, Henry D., Ikkyu Aihara, and X. E. Bernal. "The dual benefits of synchronized mating signals in a Japanese treefrog: attracting mates and manipulating predators." Philosophical Transactions of the Royal Society B: Biological Sciences 376, no. 1835 (August 23, 2021): 20200340. http://dx.doi.org/10.1098/rstb.2020.0340.
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In dense mating aggregations, such as leks and choruses, acoustic signals produced by competing male conspecifics often overlap in time. When signals overlap at a fine temporal scale the ability of females to discriminate between individual signals is reduced. Yet, despite this cost, males of some species deliberately overlap their signals with those of conspecifics, synchronizing signal production in the chorus. Here, we investigate two hypotheses of synchronized mating signals in a Japanese treefrog ( Buergeria japonica ): (1) increased female attraction to the chorus (the beacon effect hypothesis) and (2) reduced attraction of eavesdropping predators (the eavesdropper avoidance hypothesis). Our results from playback experiments on female frogs and eavesdropping micropredators (midges and mosquitoes) support both hypotheses. Signal transmission and female phonotaxis experiments suggest that away from the chorus, synchronized calls are more attractive to females than unsynchronized calls. At the chorus, however, eavesdroppers are less attracted to calls that closely follow an initial call, while female attraction to individual signals is not affected. Therefore, synchronized signalling likely benefits male B. japonica by both increasing attraction of females to the chorus and reducing eavesdropper attacks. These findings highlight how multiple selective pressures likely promoted the evolution and maintenance of this behaviour. This article is part of the theme issue ‘Synchrony and rhythm interaction: from the brain to behavioural ecology’.
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Youssef, El-Nasser S., Fabrice Labeau, and Marthe Kassouf. "Detection of Load-Altering Cyberattacks Targeting Peak Shaving Using Residential Electric Water Heaters." Energies 15, no. 20 (October 21, 2022): 7807. http://dx.doi.org/10.3390/en15207807.
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The rapid adoption of the smart grid’s nascent load-management capabilities, such as demand-side management and smart home systems, and the emergence of new classes of controllable high-wattage loads, such as energy storage systems and electric vehicles, magnify the smart grid’s exposure to load-altering cyberattacks. These attacks aim at disrupting power grid services by staging a synchronized activation/deactivation of numerous customers’ high-wattage appliances. A proper defense plan is needed to respond to such attacks and maintain the stability of the grid, and would include prevention, detection, mitigation, incident response, and/or recovery strategies. In this paper, we propose a solution to detect load-altering cyberattacks using a time-delay neural network that monitors the grid’s load profile. As a case study, we consider a cyberattack scenario against demand-side management programs that control the loads of residential electrical water heaters in order to perform peak shaving. The proposed solution can be adapted to other load-altering attacks involving different demand-side management programs or other classes of loads. Experiments verify the proposed solution’s efficacy in detecting load-altering attacks with high precision and low false alarm and latency.
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Sang, D.-K., and M.-J. Tahk. "Guidance law switching logic considering the seeker's field-of-view limits." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 223, no. 8 (August 1, 2009): 1049–58. http://dx.doi.org/10.1243/09544100jaero614.
Full textAbstract:
The impact time control guidance (ITCG) method, which has been proposed recently, can be applied successfully to a salvo attack of multiple missiles. Compared to the proportional navigation guidance law, this guidance method makes additional manoeuvres to synchronize the impact times. However, such manoeuvres do not consider the manoeuvrability and the seeker's field-of-view (FOV) of a missile and may cause the target to move out of the missile seeker's FOV; maintaining the seeker lock-on condition during the engagement is critical for missile guidance. To solve this problem, two methods are presented in this article: one is based on the calculation of minimum and maximum flight times considering the missile's manoeuvring limit and the seeker's FOV limit to check the available impact time. The other is based on guidance law switching logic that keeps the target look angle of the seeker constant. These methods can provide the boundary limit of the impact time of the salvo attack and prevent the lock-on failure because of the seeker's FOV limit of the missile during the homing phase when the ITCG is used. This method was applied to the case of a time critical salvo-attack of multiple missiles, which have manoeuvring limit and the seeker's FOV limit, and desired results were obtained.
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Radziukevich, M. L. "A combined method of formation of a cryptographic key with secret modification of the results of synchronization of artificial neural networks." «System analysis and applied information science», no. 3 (October 4, 2021): 51–58. http://dx.doi.org/10.21122/2309-4923-2021-3-51-58.
Full textAbstract:
This article discusses one of the ways to generate a common cryptographic key using synchronized artificial neural networks. This option is based on a combined method of forming a cryptographic key [1]. The proposed combined formation consists of two stages: the formation of partially coinciding binary sequences using synchronized artificial neural networks and the elimination of mismatched bits by open comparison of the parities of bit pairs. The purpose of this article is to increase the cryptographic strength of this method in relation to a cryptanalyst. In this regard, it is proposed to prematurely interrupt the synchronization process at the first stage of the combined method and make changes to the resulting binary sequence by randomly inverting a certain number of bits. To confirm the quality of this method, possible attacks are considered and the scale of enumeration of possible values is illustrated. The results obtained showed that the combined method of forming a cryptographic key with a secret modification of the synchronization results of artificial neural networks, proposed in this article, provides its high cryptographic strength, commensurate with the cryptographic strength of modern symmetric encryption algorithms, with a relatively simple implementation.
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Gopinath, S., A. Pillai, A. G. Diwan, J. V. Pattisapu, and K. Radhakrishnan. "Reiterating the role of corpus callosum in generalization of interictal and ictal epileptiform discharges: a case report with post-callosotomy intracranial electroencephalography in Lennox–Gastaut syndrome." Epilepsy and paroxysmal conditions 13, no. 3 (October 29, 2021): 249–53. http://dx.doi.org/10.17749/2077-8333/epi.par.con.2021.086.
Full textAbstract:
Lennox–Gastaut syndrome (LGS) is an epileptic encephalopathy characterized by delayed mental development and intractable multiple seizure types, predominantly tonic. Drop attacks are the commonest and the most disabling type of seizures. Resective surgery is often not possible in LGS as the electroencephalogram (EEG) abnormalities are usually multifocal and generalized, and magnetic resonance image is often either normal or multilesional. We report a case of LGS with bilateral parieto-occipital gliosis where EEG before and after callosotomy demonstrated synchronized bilateral interictal epileptiform discharges and ictal discharges becoming desynchronized and running down. This phenomenon emphasizes the role of the corpus callosum in secondary bilateral synchrony.