Passive Defense Strategy Research Articles

Novel multiphoton intravital imaging enables real-time study of Helicobacter pylori interaction with neutrophils and macrophages in the mouse stomach.

Helicobacter pylori (H. pylori) is a bacterial pathogen that exclusively colonizes the human gastric mucosa and can cause persistent infection. In this process, H. pylori employs various strategies to avoid recognition by the human immune system. These range from passive defense strategies (e.g., altered LPS or flagellin structures) that prevent recognition by pattern recognition receptors (PRRs) to more active approaches, such as inhibition of IL-2 secretion and proliferation of T cells via VacA. Despite the growing evidence that H. pylori actively manipulates the human immune system for its own benefit, the direct interaction of H. pylori with immune cells in situ is poorly studied. Here, we present a novel intravital imaging model of the murine stomach gastric mucosa and show for the first time the in situ recruitment of neutrophils during infection and a direct H. pylori-macrophage interaction. For this purpose, we applied multiphoton intravital microscopy adapted with live drift correction software (VivoFollow) on LysM-eGFP and CX3CR1-eGFP reporter mice strains in which specific subsets of leukocytes are fluorescently labeled. Multiphoton microscopy is proving to be an excellent tool for characterizing interactions between immune cells and pathogens in vivo.

Dynamic Reconfiguration for Resilient State Estimation Against Cyber Attacks

The increasing complexity and connectivity of critical infrastructures makes it increasingly likely that they will be subject to malicious attacks that compromise operation. Recent studies have shown that these systems are vulnerable to a wide range of cyber-attacks, including False Data Injection (FDI) attacks that bypasses conventional detection techniques. Conventional security monitoring, protection, and control tools are based primarily on passive defense strategies. In this paper, we propose an approach for active defense that improves system security and the detection rate of FDI attacks. The key insight for this approach is that emerging micro-grids can utilize distributed energy resources to dynamically reconfigure the system (e.g. power flow paths), across multiple acceptable configurations. Instead of using information from only a single static configuration to detect FDI attacks, our proposed approach uses <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dynamic reconfiguration</i> to compare measured and estimated states under multiple configurations to accurately detect FDI attacks. We describe an implementation and supporting infrastructure for a secure reconfigurable microgrid. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Dynamic reconfiguration</i> also makes it more difficult for attackers to gain knowledge on the system's parameters, which increases the difficulty for attackers to construct hidden attack vectors. We evaluate our approach in the specific scenario of emerging micro-grids. We develop a novel technique for state estimation using multiple configurations and demonstrate that this approach significantly improves FDI detection accuracy.

Robust Communicative Multi-Agent Reinforcement Learning with Active Defense

Communication in multi-agent reinforcement learning (MARL) has been proven to effectively promote cooperation among agents recently. Since communication in real-world scenarios is vulnerable to noises and adversarial attacks, it is crucial to develop robust communicative MARL technique. However, existing research in this domain has predominantly focused on passive defense strategies, where agents receive all messages equally, making it hard to balance performance and robustness. We propose an active defense strategy, where agents automatically reduce the impact of potentially harmful messages on the final decision. There are two challenges to implement this strategy, that are defining unreliable messages and adjusting the unreliable messages' impact on the final decision properly. To address them, we design an Active Defense Multi-Agent Communication framework (ADMAC), which estimates the reliability of received messages and adjusts their impact on the final decision accordingly with the help of a decomposable decision structure. The superiority of ADMAC over existing methods is validated by experiments in three communication-critical tasks under four types of attacks.

Research on active defense decision-making method for cloud boundary networks based on reinforcement learning of intelligent agent

The cloud boundary network environment is characterized by a passive defense strategy, discrete defense actions, and delayed defense feedback in the face of network attacks, ignoring the influence of the external environment on defense decisions, thus resulting in poor defense effectiveness. Therefore, this paper proposes a cloud boundary network active defense model and decision method based on the reinforcement learning of intelligent agent, designs the network structure of the intelligent agent attack and defense game, and depicts the attack and defense game process of cloud boundary network; constructs the observation space and action space of reinforcement learning of intelligent agent in the non-complete information environment, and portrays the interaction process between intelligent agent and environment; establishes the reward mechanism based on the attack and defense gain, and encourage intelligent agents to learn more effective defense strategies. the designed active defense decision intelligent agent based on deep reinforcement learning can solve the problems of border dynamics, interaction lag, and control dispersion in the defense decision process of cloud boundary networks, and improve the autonomy and continuity of defense decisions.

Active and Passive Defense Strategies of Cyber-Physical Power System against Cyber Attacks Considering Node Vulnerability

Vulnerable parts in the cyber-physical power system can be maliciously attacked to trigger cascading failures. This paper proposes a defense framework with active and passive defense hybrid strategies. First, a comprehensive vulnerability assessment index is presented to identify vital nodes contributing to failure extension. The proposed index is based on both physical characteristics and topology. Physical characteristic is assessed through the optimal power flow to calculate the load losses. The topology index is obtained by the attacking node and calculating the nodes lost at the steady state. Then, the active and passive defense strategies are established. Deploying false nodes based on the comprehensive vulnerability index is set as the active defense strategy. Changing from centralized control mode to centralized-distributed control mode is the passive defense strategy. The system can defend against attacks with active and passive strategies effectively in the attacking experiments. Finally, we have made a profound study of the first-order percolation problem. The first-order percolation disappears under the active and passive defense strategies in a scale-free network, while the small world network transfers from the first-order percolation to the second-order percolation. The findings indicated that the diverse results resulted from their structure.

Large-sized Late Turonian–Early Coniacian (Late Cretaceous) inoceramid bivalves from Germany: taxonomic issues, temporal framework and palaeoecological implications

A systematic-stratigraphic revision of selected large Late Turonian–Early Coniacian inoceramids of the lamarcki group from Germany showed that both historical specimens of Goldfuss (1836), introduced as Inoceramus annulatus and later becoming the types of Late Turonian I. lamarcki stuemckei Heinz, 1928a and Early Coniacian I. annulatus Goldfuss, 1836, respectively, are of Late Turonian age. I. stuemckei Heinz, 1928a, as emended herein, is well represented by its lectotype. Bulky isolated hinges from Upper Turonian strata, used by Heinz (1932a) to erect Heroceramus hercules, are just fragments of contemporaneous large I. stuemckei; H. hercules is thus invalid. The common Late Turonian I. stuemckei occurs facies-independent from near- to offshore settings and its first common appearance is an excellent marker for the substage base. I. annulatus Goldfuss, 1836 was later applied to very large forms first appearing in the mid-Early Coniacian. Thus, I. annulatus sensu Walaszczyk and Wood (1998) is poorly represented by its medium-sized latest Turonian lectotype, causing some nomenclatorial issues. I. stuemckei (heightmax 500 mm) and I. annulatus (heightmax one metre) are characterized by a stratigraphically abrupt shell enlargement and hinge buttressing across the Middle/Upper Turonian boundary and within the Early Coniacian, respectively. This shift to larger sizes, a common passive defense strategy against predation, is accompanied by widespread evidence for increased Late Turonian predation pressure by marine durophages. We thus speculate that the size increase in Late Turonian–Early Coniacian inoceramid bivalves is part of an escalating arms race between prey and predators, ultimately triggering Late Cretaceous inoceramid gigantism.

Signal Emulation Attack and Defense for Smart Home IoT

Internet of Things (IoT) is transforming every corner of our daily life and plays important roles in the smart home. Depending on different requirements on wireless transmission, dedicated wireless protocols have been adopted on various types of IoT devices. Recent advances in Cross-Technology Communication (CTC) enable direct communication across those wireless protocols, which will greatly improve the spectrum utilization efficiency. However, it incurs serious security concerns on heterogeneous IoT devices. In this paper, we identify a new physical-layer attack, cross-technology signal emulation attack, where a WiFi device eavesdrops a ZigBee packet on the fly, and further manipulates the ZigBee device by emulating a ZigBee signal. To defend against this attack, we propose two defense strategies with the help of a commonly found WiFi router. Particularly, the passive defense strategy focuses on misleading the ZigBee signal eavesdropping, while the proactive approach develops a real-time detection mechanism on distinguishing between a common ZigBee signal and an emulated signal. We implement the complete attacking process and defense strategies with TI CC26x2R LaunchPad, USRP-N210 platform, and a self-designed prototype. Extensive experiments have demonstrated the existence of the attack, and the feasibility, effectiveness, and accuracy of the proposed defense strategies.

Reinforcement-learning-based dynamic defense strategy of multistage game against dynamic load altering attack

As the current power grid is highly interconnected and more information and communication technologies (ICTs) are being deployed recently, it could be the target of malicious cyber-physical attacks. Dynamic load altering attacks (D-LAAs), as a special case of load altering attacks, could be performed to interfere the demand response and ultimately force certain generators off-line. Cascading failures due to transmission line overloads may also be triggered. In this paper, we propose a new dynamic defense strategy against D-LAAs through a multistage game between the attacker and the defender which is solved by minimax-q learning. Different from the static game, the multistage game considers the attacker and defender’s action sequences and the optimal strategies at each state are learned. After each time step, the cascading failure is measured, and the load shedding is used as the feedback for the attacker to generate the next action strategy. The performance of the proposed model is evaluated on the IEEE 39-bus system. Comparisons between the dynamic defense strategy and the passive defense strategy are conducted, and the results verify the advantage of the proposed dynamic defense strategy. To improve the power system resilience, this defense strategy can be deployed in advance when such cyber-physical attacks are anticipated.

Load altering attack-tolerant defense strategy for load frequency control system

Cyber attacks become emerging threats to every information-oriented energy management system. By violating the cyber systems, the hacker can disrupt the security and stability due to the strong coupling between the cyber and physical facilities. In this paper, one type of cyber attacks designated as the load altering attack is studied for the power system frequency control, and corresponding defense strategies are proposed to improve the frequency control performance. Considering the difficulty of the application of model-based controller into large-scale power systems, a novel model-free defense framework is for the first time presented. Under this framework, both active defense and passive defense strategies are designed. The former assumes that the defender has the initiative to learn different attack scenarios. Adaptive defense strategies are implemented using the online attack identification information and off-line trained strategy pool. The latter assumes that the defender passively tolerates various attack scenarios via the pre-trained off-line strategy. Both approaches prove to be effective through validation based on the IEEE benchmark systems. The proposed defense framework and defense strategies can be extended to other energy control systems to enhance their attack tolerance capability.

Grapevine comparative early transcriptomic profiling suggests that Flavescence dor\xe9e phytoplasma represses plant responses induced by vector feeding in susceptible varieties

BackgroundFlavescence dorée is the most serious grapevine yellows disease in Europe. It is caused by phytoplasmas which are transmitted from grapevine to grapevine by the leafhopper Scaphoideus titanus. Differences in susceptibility among grapevine varieties suggest the existence of specific genetic features associated with resistance to the phytoplasma and/or possibly with its vector. In this work, RNA-Seq was used to compare early transcriptional changes occurring during the three-trophic interaction between the phytoplasma, its vector and the grapevine, represented by two different cultivars, one very susceptible to the disease and the other scarcely susceptible.ResultsThe comparative analysis of the constitutive transcriptomic profiles suggests the existence of passive defense strategies against the insect and/or the phytoplasma in the scarcely-susceptible cultivar. Moreover, the attack by the infective vector on the scarcely-susceptible variety prompted immediate and substantial transcriptomic changes that led to the rapid erection of further active defenses. On the other hand, in the most susceptible variety the response was delayed and mainly consisted of the induction of phytoalexin synthesis. Surprisingly, the jasmonic acid- and ethylene-mediated defense reactions, activated by the susceptible cultivar following FD-free insect feeding, were not detected in the presence of the phytoplasma-infected vector.ConclusionsThe comparison of the transcriptomic response in two grapevine varieties with different levels of susceptibility to Flavescence dorèe highlighted both passive and active defense mechanisms against the vector and/or the pathogen in the scarcely-susceptible variety, as well as the capacity of the phytoplasmas to repress the defense reaction against the insect in the susceptible variety.

Positive or negative? The shell alters the relationship among behavioral defense strategy, energy metabolic levels and antioxidant capacity in freshwater turtles

BackgroundThe relationships among energy metabolic levels, behavioral and other physiological traits help to determine the trade-off of energy allocation between different traits and the evolution of life-history driven by natural selection. However, these relationships may be distinctive in selected animal taxa because of their unique traits. In the present study, the relationships among energy metabolic levels, behavioral defense strategies, and antioxidant capacity were explored in three freshwater turtle species with different shell morphologies, by assessing responses to attack, righting time, shell morphology, whole-organism metabolic rates, tissue metabolic enzyme activities and antioxidant levels.ResultsThe Chinese three-keeled pond turtles, Chinemys reevesii, showed a passive defense strategy, relatively larger shells, a higher resting metabolic rate (RMR) and higher antioxidant levels compared to the snapping turtle, Chelydra serpentina, or the Chinese soft-shelled turtle, Pelodiscus sinensis. These latter two species both showed an active defense strategy, a higher factorial aerobic scope and better muscle anaerobic metabolic capacity but relatively smaller shells, lower RMR and antioxidant capacity.ConclusionOur results indicate a negative relationship between RMR and activity levels in behavioral defense strategies along small-big shell continuum among the three turtle species. We also found a positive relationship between antioxidant capacity and energy metabolism but a negative one between antioxidant capacity and activity levels in defense strategies. The present study indicated a role of turtle shell in forming unique relationship between energy metabolic levels and behaviors in freshwater turtle taxa and a possible trade-off between the maintenance of physiological homeostasis and activity levels in energy allocation.

A Comparative Study of the Application of Passive Defense Strategies from the Perspective of Urban Design at International Airports: International Airports of Ben-Gurion, Munich and Singapore Changi

Billions are spent every year to construct vital infrastructures around the world. On the other hand, we witness terrorist crimes and the killing of innocent people and causing serious physical and psychological damages to them every day in every corner of the world. Unfortunately, today this trend has not been stopped and likely will continue. So, due to the fact that the most important issue in urban design is human and the most important goal is to create safe and stable places for them, it can be concluded that in critical infrastructure such as airports, which are a priority to strategies to deal with terrorist threats, public areas vulnerabilities against terrorist threats have to be investigated to understand the weaknesses of the target infrastructures. So, determining its attractiveness for the invasion, civil defense measures can be taken to reduce vulnerability. In this regard, urban design principles should be applied to reduce the blast effects and to minimize the damage in the public areas of airports. In this study, by implementing an analytical-descriptive methodology, we attempt to identify urban design guidelines resistant to terrorist bombings in public areas of airport environments. The findings of this study show that in achieving terrorist blast-resistant urban design, deployment of strategies in the field of building components, atmosphere, design, and urban landscape will reduce the vulnerability of airports.

Bold fish, shy fish: it's all in the metabolism

![Graphic][1] To flee, or not to flee? The answer to that question may lie in physiology. Whether an animal adopts an active or passive defense strategy when faced with danger is related to its behavioral phenotype, or ‘personality’. For example, bold individuals typically behave actively

Evaluation of passive defense strategy on sustainable urban development with emphasis on the prevention of natural hazards (flood) _ Case Study: Noshahr

Abstract. Today, along with the rapid increase in urban population centers of biological and excessive growth, the death toll from natural disasters and artificial rising. The recent disaster in decades, as crises such as floods, storms, droughts, wars and social crises have appeared, Safety of cities in every part of the world is endangered. Given the interconnectedness and interdependence of urban elements together, including all the factors in a city's urban vulnerability. In other words, disasters affect all parts of the city. Urban systems are affected by the vulnerability of disasters, including floods. Reduce the vulnerability of urban cities at different levels, is one of the main priorities and measures of passive defense. Therefore, this article is trying to take advantage of the views of experts to review the role of Urban Development in passive defense planning with a focus on natural hazards, floods in the city of Noshahr City. The research method is descriptive analysis and population experts are administrative units of Noshahr in 1393. In this study, a questionnaire has been prepared in which 16 specialized research question has been raised in four areas.

Assessment of Mobbing Behaviors Exposed by the Academic Personnel Working in a University, in Turkey

Objective: To determine psychological violence behaviors (mobbing) exposed by academic personnel working in Erciyes University, Turkey. Methods: A questionnaire-based cross sectional study was performed in June 2010 in Erciyes University. No sampling methods were used, questionnaires were delivered by mail to all academicians and 450 of 850 (53.0%) questionnaires were returned. We used the Mobbing Perception Scale (MPS) for data collection. Results: A total of 58.2% of the academicians experienced recurrent physiological violence at least once a week in the workplace and 16.6% stated that they were directly exposed to mobbing behavior every day (>1 point) in the past year, 44.7% reported “assault to their professional status”, 42.8% reported “assault to personality”, 39.9 % reported “isolation from work”, 13.0% reported “direct negative behavior”. The most commonly (30.4%) experienced behavior was; “groundless talk about the person in question”. Mobbing was not associated with demographic and professional variables. The main source of mobbing was the managers. Also 68.0% of the victims resorted to passive defense strategies, and only 2.5% took legal action. Conclusion: Workplace mobbing is a critical problem for academicians in our university. The level of directly mobbing behavior was substantially high. The most common threatening behavior was “assault to professional status”. The primary mobbers were the managers. A great of majority academicians had not been received professional help and they internalized the mobbing. The findings indicated that levels of awareness of mobbing have increased among academicians.

A Study on a Legal Framework of Smart Water Grid

It is high time that state, local government, public institution, company and people should establish a new paradigm in order to overcome water shortage due to global population growth, urbanization and climate change etc. This means that we should establish strategies for water management in a dimension of securing state competitiveness of a dynamic force for new growth as well as prevention of disaster through integrated smart water management, turning away from passive defense strategy to water crisis. Smart Water Management that refers to implement intelligent water information systems by IT convergence is considered a new paradigm. Smart Water Grid (hereinafter “SWG”) is the core of this water management policy. In this paper, we try to study the Smart Water policy, especially SWG, and legislation development trends in major advanced countries such as U.S.A., EU, Singapore, Australia and Japan etc. In the conclusion, we suggest a proposal for structuring a legal framework of SWG in an era of climate change.

WIRELESS MESH NETWORK CROSS-LAYER INTRUSION DETECTION

Intrusion is something which is unsolicited activity and which might be used to interrupt the functions of wireless network. If we talk about wireless networks, having centralized monitoring policy; therefore it is very much easy to detect and eliminate intrusions efficiently. But when we look forward to wireless scenario, especially in the multi hop wireless network, intrusion activities are more because of the lack of centralized monitoring policy. Wireless network is very much vulnerable to different kinds of attacks and intrusions at different OSI layer due to mainly co-operation among their noses. Intrusion detection is the most fundamental component of defense in depth strategy, are capable to identify security attacks and raise an alarm to inform authorities. Intrusion detection system, a passive defense strategy informs about attacks to network administrator because the attacks come easy to wireless network. Intrusion detection system is a second line of defense. Lots of IDSs are proposed in the literature, capable to detect attacks in a particular layer of the OSI model. Here we are proposing Cross layer IDSs, which is capable to detect multiple layer possible attacks.

US Policy on Active Cyber Defense

Today cyberspace is playing a pivotal role in many sectors of society and has become an integral part in the lives of individuals. Much of the critical infrastructure responsible for basic facilities such as water, energy, food, gas and electricity has become heavily integrated with cyberspace. As a result, securing cyberspace has become an issue of high national priority for many governments around the world and the US is no exception. For quite some time, this has been achieved through passive cyber defense strategies. Unfortunately, in recent years, these strategies have proved ineffective in accomplishing this goal, requiring a shift in strategy from passive to active cyber defense strategies. We examine the US policy on active cyber defense and the circumstances under which active cyber defense may be utilized by the US Government or those acting on its behalf. It can be difficult in some circumstances to distinguish active cyber defense from cyber offense. As may therefore be expected, the utilization of active cyber defense has the potential for creation of political, ethical as well as legal, and operational risks. In a brief comparison of US policy on active cyber defense with a few selected cybersecurity policies of other states the US policy is on the aggressive end of the spectrum, at least among the democratic states.

Does a Persistent Defense Strategy Pay Off? An Analysis of Insurance Company Defense Expenditures

Evidence from the property-casualty insurance industry suggests that some insurers tend to settle claims quickly and out of court, while others vigorously defend all claims. While we expect this tendency to vary across lines due to the differential exposures to liability claims, we propose that insurer defense behaviors are not random, but reflect strategies that vary according to market conditions and insured preferences. We consider the extent to which financial and operating characteristics play a differential role for those insurers who select more aggressive or passive defense strategies, and propose that an alignment of insurer and consumer preference is a primary determinant of insurers’ defense strategies. Using insurer defense cost data from 1998-2008, we perform a multi-step analysis to assess the relationships between insurer and market characteristics to defense strategies and assess whether persistence in a particular defense strategy proves to be profitable.

Genetic structure of hereditary catalepsy in mice

Catalepsy or pronounced freezing is a natural passive defense strategy in animals and a syndrome of some mental disorders in human. Hereditary catalepsy was shown to be associated with depressive-like features in rats and mice. The loci underlying the difference in predisposition to catalepsy between catalepsy-prone CBA/lacJ and catalepsy-resistant AKR/J mice were mapped using congenic line and selective breeding approaches. Three congenic mouse lines (AKR.CBA-D13Mit76C, AKR.CBA-D13Mit76A and AKR.CBA-D13Mit78) carrying the 59- to 70-, 61- to 70- and 71- to 75-cm fragments of chromosome 13 transferred from the CBA to the AKR genome were created by nine successive backcrossing of (CBA x AKR)F(1) on AKR strain. Because catalepsy was found only in the AKR.CBA-D13Mit76C and AKR.CBA-D13Mit76A mice, the major gene of catalepsy was mapped on the fragment of 61-70 cm. Selective breeding of the (CBA x (CBA x AKR))BC backcross generation for high predisposition to catalepsy showed numerous genome-wide distributed CBA-derived alleles as well as the AKR-derived alleles mapped on chromosome 17 and on the proximal parts of chromosomes 10 and 19 that increased the cataleptogenic effect of the major gene.