Multi-layered Defense Research Articles

Development of Thin and Lightweight Bulletproof Windows Using Strengthened SLS Glass by Ion Exchange

Soda-lime silicate (SLS) glass was strengthened by ion exchange for application of thin and lightweight bulletproof windows. The optimal conditions for ion exchanged SLS glass (thickness of 3 and 10 mm) at 480℃ were 10 and 17 min, respectively. The Vickers hardness values of the strengthened SLS glass samples with thicknesses of 3 and 10 mm were 5.9 ± 0.22 and 6.7 ± 0.17 GPa, respectively, which values were about 22% higher than those of parent SLS glass. By laminating a multilayer defense film and polycarbonate sheet with ion exchanged SLS glass, we were able to make a thin and lightweight bulletproof window (24.25 mm, 4.57 kg, 50.06 kg/㎡, V 50 901.8 m/s). As a result, the thickness of the bulletproof window was decreased by about 39% from 40 to 24.25 mm. The light transmittance in the visible range satisfied the standard (over 76%) for bulletproof windows.

Improvement in ballistic impact resistance of a transparent bulletproof material laminated with strengthened soda-lime silicate glass

This study evaluates the ballistic impact resistance of soda-lime silicate glass strengthened by ion exchange for application in lightweight and thin bulletproof materials. The maximum flexural strength values of the strengthened glass with thicknesses of 3, 4, 8, and 10 mm were 0.63, 0.68, 0.73, and 0.77 GPa, respectively, values that were 3.5 times higher than that of the parent glass. By laminating polycarbonate and multilayer defense film with the strengthened glass, we achieved a ballistic limit velocity of 973.8 m/s, which was 16% higher than the standard. Also, the transmittance satisfied the standard for bulletproof windows.

Induced systemic resistance responses in perennial ryegrass against Magnaporthe oryzae elicited by semi-purified surfactin lipopeptides and live cells of Bacillus amyloliquefaciens.

The suppressive ability of several strains of cyclic lipopeptide-producing Bacillus rhizobacteria to grey leaf spot disease caused by Magnaporthe oryzae has been documented previously; however, the underlying mechanism(s) involved in the induced systemic resistance (ISR) activity in perennial ryegrass (Lolium perenne L.) remains unknown. Root-drench application of solid-phase extraction (SPE)-enriched surfactin and live cells of mutant Bacillus amyloliquefaciens strain FZB42-AK3 (produces surfactin, but not bacillomycin D and fengycin) significantly reduced disease incidence and severity on perennial ryegrass. The application of the treatments revealed a pronounced multilayered ISR defence response activation via timely and enhanced accumulation of hydrogen peroxide (H2O2), elevated cell wall/apoplastic peroxidase activity, and deposition of callose and phenolic/polyphenolic compounds underneath the fungal appressoria in naïve leaves, which was significantly more intense in treated plants than in mock-treated controls. Moreover, a hypersensitive response (HR)-type reaction and enhanced expression of LpPrx (Prx, peroxidase), LpOXO4 (OXO, oxalate oxidase), LpPAL (PAL, phenylalanine ammonia lyase), LpLOXa (LOX, lipoxygenase), LpTHb (putative defensin) and LpDEFa (DEFa, putative defensin) in perennial ryegrass were associated with SPE-enriched surfactin and live AK3 cell treatments, acting as a second layer of defence when pre-invasive defence responses failed. The results indicate that ISR activity following surfactin perception may sensitize H2O2 -mediated defence responses, thereby providing perennial ryegrass with enhanced protection against M. oryzae.

The mRNA decay factor PAT1 functions in a pathway including MAP kinase 4 and immune receptor SUMM2.

Multi-layered defense responses are activated in plants upon recognition of invading pathogens. Transmembrane receptors recognize conserved pathogen-associated molecular patterns (PAMPs) and activate MAP kinase cascades, which regulate changes in gene expression to produce appropriate immune responses. For example, Arabidopsis MAP kinase 4 (MPK4) regulates the expression of a subset of defense genes via at least one WRKY transcription factor. We report here that MPK4 is found in complexes in vivo with PAT1, a component of the mRNA decapping machinery. PAT1 is also phosphorylated by MPK4 and, upon flagellin PAMP treatment, PAT1 accumulates and localizes to cytoplasmic processing (P) bodies which are sites for mRNA decay. Pat1mutants exhibit dwarfism and de-repressed immunity dependent on the immune receptor SUMM2. Since mRNA decapping is a critical step in mRNA turnover, linking MPK4 to mRNA decay via PAT1 provides another mechanism by which MPK4 may rapidly instigate immune responses.

The multilayered innate immune defense of the gut.

In the wild, the fruit fly Drosophila melanogaster thrives on rotten fruit. The digestive tract maintains a powerful gut immune barrier to regulate the ingested microbiota, including entomopathogenic bacteria. This gut immune barrier includes a chitinous peritrophic matrix that isolates the gut contents from the epithelial cells. In addition, the epithelial cells are tightly sealed by septate junctions and can mount an inducible immune response. This local response can be activated by invasive bacteria, or triggered by commensal bacteria in the gut lumen. As with chronic inflammation in mammals, constitutive activation of the gut innate immune response is detrimental to the health of flies. Accordingly, the Drosophila gut innate immune response is tightly regulated to maintain the endogenous microbiota, while preventing infections by pathogenic microorganisms.

MLDS: Multi-Layer Defense System for Preventing Advanced Persistent Threats

Here we report on the issue of Advanced Persistent Threats (APT), which use malware for the purpose of leaking the data of large corporations and government agencies. APT attacks target systems continuously by utilizing intelligent and complex technologies. To overthrow the elaborate security network of target systems, it conducts an attack after undergoing a pre-reconnaissance phase. An APT attack causes financial loss, information leakage, etc. They can easily bypass the antivirus system of a target system. In this paper, we propose a Multi-Layer Defense System (MLDS) that can defend against APT. This system applies a reinforced defense system by collecting and analyzing log information and various information from devices, by installing the agent on the network appliance, server and end-user. It also discusses how to detect an APT attack when one cannot block the initial intrusion while continuing to conduct other activities. Thus, this system is able to minimize the possibility of initial intrusion and damages of the system by promptly responding through rapid detection of an attack when the target system is attacked.

Nonhost Resistance of Arabidopsis thaliana Against Alternaria alternata Involves both Pre- and Postinvasive Defenses but Is Collapsed by AAL-Toxin in the Absence of LOH2

The tomato pathotype of Alternaria alternata causes Alternaria stem canker on tomato depending upon the production of the host-specific AAL-toxin. Host defense mechanisms to A. alternata, however, are largely unknown. Here, we elucidate some of the mechanisms of nonhost resistance to A. alternata using Arabidopsis mutants. Wild-type Arabidopsis showed either no symptoms or a hypersensitive reaction (HR) when inoculated with both strains of AAL-toxin-producing and non-producing A. alternata. Yet, when these Arabidopsis penetration (pen) mutants, pen2 and pen3, were challenged with both strains of A. alternata, fungal penetration was possible. However, further fungal development and conidiation were limited on these pen mutants by postinvasion defense with HR-like cell death. Meanwhile, only AAL-toxin-producing A. alternata could invade lag one homologue (loh)2 mutants, which have a defect in the AAL-toxin resistance gene, subsequently allowing the fungus to complete its life cycle. Thus, the nonhost resistance of Arabidopsis thaliana to A. alternata consists of multilayered defense systems that include pre-invasion resistance via PEN2 and PEN3 and postinvasion resistance. However, our study also indicates that the pathogen is able to completely overcome the multilayered nonhost resistance if the plant is sensitive to the AAL-toxin, which is an effector of the toxin-dependent necrotrophic pathogen A. alternata.

More beneath the surface? Root versus shoot antifungal plant defenses

Let's get dirty! Plant roots are deeply embedded in clammy soil, and working with them means digging into the mud, hoping not to crush the fragile root branches and flimsy root hairs. In short, working with roots can be a tedious activity. This might partly explain why, over decades, roots could maintain a subsistence fairly hidden from the scrutinizing eyes of plant researchers—until the past few years. Plant breeding has been mainly driven by the search for aboveground traits; as a consequence, roots are now even claimed to be a potential key for a second green revolution (Gewin, 2010). Promising studies aiming to improve crop yields focus on root architecture and the genetics underlying root development. For instance, wheat lines exhibiting deeper and fast-growing roots were isolated and crossed with commercial cultivars, in the hope of generating drought-tolerant lines (Kirkegaard et al., 2007). Similarly, drought-stressed maize lines were shown to have a higher yield when specifically adapting their root structure by building an intercellular air space compared to maize varieties that were not able to adapt their root architecture (Zhu et al., 2010). As if handling abiotic stress would not be already a substantial task, roots are also garrisoned at the frontline against pathogens and pests. Soil-borne pathogens such as Fusarium, Pythium, or Phytophthora are infamous for being vicious parasites that can devastate entire harvests (Okubara and Paulitz, 2005). However, the lack of a convenient accessibility of root systems renders the task of controlling such pathogens more than challenging. Consequently, the knowledge about belowground defense responses is limited, in contrast to well-dissected aboveground mechanisms (Rasmann and Agrawal, 2008). Moreover, studies comparing root and shoot immune responses are scarce. In animal model systems, organ-specific antifungal immune responses are a well-known phenomenon (Lionakis et al., 2011). In plant-microbe models, pathological studies were historically mainly focused on either roots or shoots. Recent studies highlight an organ-specific immunity against fungal pathogens, pointing toward the fact that plants employ a “defense in depth,” a multi-layered organ-specific local and systemic defense system. Elucidating such a defense in depth for given pathosystems will be an important task for future studies in plant pathology.

Why multi-layered security is still the best defence

As if protecting resources in the age of Bring Your Own Device (BYOD) wasn't already hard enough, the beleaguered, unsung heroes of corporate IT security increasingly have to look beyond the plethora of user-access devices and consider the security of equipment such as printers, fax machines, and even the routers and switches with which the network is built. As if protecting resources in the age of Bring Your Own Device (BYOD) wasn't already hard enough, the beleaguered unsung heroes of corporate IT security increasingly have to look beyond the plethora of user-access devices and consider the security of equipment such as printers, fax machines and even routers and switches. The notion of a multi-tiered defence has somewhat gone out of fashion. However, corporate networks are becoming more complex and the nature of the threats is evolving. Simon Denman of NETASQ looks at the current threat landscape and argues that a multi-layered defence is still the best way of securing the corporate network.

Lectin-Mediated Resistance Impairs Plant Virus Infection at the Cellular Level

Plants possess a multilayered defense response, known as plant innate immunity, to infection by a wide variety of pathogens. Lectins, sugar binding proteins, play essential roles in the innate immunity of animal cells, but the role of lectins in plant defense is not clear. This study analyzed the resistance of certain Arabidopsis thaliana ecotypes to a potexvirus, plantago asiatica mosaic virus (PlAMV). Map-based positional cloning revealed that the lectin gene JACALIN-TYPE LECTIN REQUIRED FOR POTEXVIRUS RESISTANCE1 (JAX1) is responsible for the resistance. JAX1-mediated resistance did not show the properties of conventional resistance (R) protein-mediated resistance and was independent of plant defense hormone signaling. Heterologous expression of JAX1 in Nicotiana benthamiana showed that JAX1 interferes with infection by other tested potexviruses but not with plant viruses from different genera, indicating the broad but specific resistance to potexviruses conferred by JAX1. In contrast with the lectin gene RESTRICTED TEV MOVEMENT1, which inhibits the systemic movement of potyviruses, which are distantly related to potexviruses, JAX1 impairs the accumulation of PlAMV RNA at the cellular level. The existence of lectin genes that show a variety of levels of virus resistance, their targets, and their properties, which are distinct from those of known R genes, suggests the generality of lectin-mediated resistance in plant innate immunity.

New Synthesis -- Plant Defense Signaling: New Opportunities for Studying Chemical Diversity

Higher plants have evolved multilayered defense signaling systems that are based on the generation and perception of small molecules. These signaling pathways provide warning of incoming danger, triggering not only local resistance responses but also long-distance signals that lead to the protection of the whole plant against subsequent attack. This induced resistance againstpathogensandherbivores often involves the production of alkaloids, terpenes, phenolics, and other small molecules with toxic and deterrent properties. However, although there are thousands of known plant metabolites with direct defensive functions, relatively few signaling molecules have been identified. Among these, salicylate, jasmonate, and related metabolites are the most extensively studied, and likely have universal functions as components of pathways leading to the induction of both local and systemic plant defense responses. Salicylate and jasmonate-dependent signaling pathways in plants are presumed to have their evolutionary origins in the production of metabolites with a direct defensive function. Salicin, a metabolic precursor of salicylate, has a protective function in plants such as willows,andlipidintermediatesinjasmonatebiosynthesis alsohavebeen implicated in plant defense. For plants under attack, the induction of a local defense response is a reliable indicator of pests or pathogens that have the potential to spread more widely. Small molecules that are phloem mobile or even volatile, e.g., methyl salicylate and methyl jasmonate, provide an efficient means for propagating a systemic signal. Thus, by eliciting additional defenses and turning on signaling pathways, secondarymetabolites(SMs)cancontributetoasignalamplificationloop

Multi-Layer Model for Network Fault Detection Based on Artificial Immune

In order to reduce the fault detection rate and improve the self-adaptive capability in network fault detection, an artificial immune mechanism which is inspired by multi-layer defense of a biological immune system is proposed to perform network fault detection. The immune model is composed of three parts: the inherent detection layer, fuzzy judgment layer and adaptive detection layer. Dendritic cells can influence the reaction of coordinating T-cells, which can be activate or tolerate so that induce adaptive immune responses and affirm the type of adaptive response. Inherent detection layer and fuzzy judgment layer interact with each other to reduce the error detection rate, while the adaptive detection layer is capable of learning unknown fault patterns.

Reactive oxygen species in the normal and acutely injured liver

Reactive oxygen species in the normal and acutely injured liver

The war of the worlds

The war of the worlds

An Outlook on the Localisation and Structure-Function Relationships of R Proteins in Solanum

The co-evolution of plants and plant-pathogens shaped a multi-layered defence system in plants, in which Resistance proteins (R proteins) play a significant role. A fundamental understanding of the functioning of these R proteins and their position in the broader defence system of the plant is essential. Sub-project 3 of the BIOEXPLOIT programme studies how R proteins are activated upon effector recognition and how recognition is conveyed in resistance signalling pathways, using the solanaceous R proteins Rx1 (from S. tuberosum spp. andigena; conferring extreme resistance against Potato Virus X), I-2 (from S. lycopersicon; mediating resistance to Fusarium oxysporum) and Mi-1.2 (from S. lycopersicon; conferring resistance to Meloidogyne incognita) as model systems. The results obtained in this project will serve as a model for other R proteins and will be translated to potential applications or alternative strategies for disease resistance. These include the modification of the recognition specificity of R proteins with the aim to obtain broad spectrum resistance to major pathogens in potato.

How cigarette smoke skews immune responses to promote infection, lung disease and cancer

A complex and multilayered immune defence system protects the host against harmful agents and maintains tissue homeostasis. Cigarette smoke exposure markedly impacts the immune system, compromising the host's ability to mount appropriate immune and inflammatory responses and contributing to smoking-related pathologies. These adverse effects on the immune system not only occur in active smokers, but also in those exposed to smoke passively in contaminated environments, and may persist for decades after exposure has ended.

The Role of Mitochondria in Reactive Oxygen Species Metabolism and Signaling

Oxidative stress is considered a major contributor to the etiology of both "normal" senescence and severe pathologies with serious public health implications. Several cellular sources, including mitochondria, are known to produce significant amounts of reactive oxygen species (ROS) that may contribute to intracellular oxidative stress. Mitochondria possess at least 10 known sites that are capable of generating ROS, but they also feature a sophisticated multilayered ROS defense system that is much less studied. This review summarizes the current knowledge about major components involved in mitochondrial ROS metabolism and factors that regulate ROS generation and removal at the level of mitochondria. An integrative systemic approach is applied to analysis of mitochondrial ROS metabolism, which is "dissected" into ROS generation, ROS emission, and ROS scavenging. The in vitro ROS-producing capacity of several mitochondrial sites is compared in the metabolic context and the role of mitochondria in ROS-dependent intracellular signaling is discussed.

Molecular characterization of a pepper C2 domain-containing SRC2 protein implicated in resistance against host and non-host pathogens and abiotic stresses

Plants guard themselves against pathogen attack using multi-layered defense mechanism. Calcium represents an important secondary messenger during such defense responses. Upon examination of a pepper cDNA library, we observed that the gene CaSRC2-1 (Capsicum annum SRC2-1) was upregulated significantly in response to infection with the type II non-host pathogen Xanthomonas axonopodis pv. glycines 8 ra, which elicits a hypersensitive response. CaSRC2-1 encodes a protein that contains a C2 domain and it exhibits a high degree of homology to the protein Soybean genes regulated by cold 2 (SRC2). However, little is known about how SRC2 expression is elicited by biotic stresses such as pathogen challenge. Further sequence analysis indicated that the CaSRC2-1 C2 domain is unique and contain certain amino acids that are conserved within the C2 domains of other plants and animals. CaSRC2-1 transcription was up-regulated under both biotic and abiotic stress conditions, including bacterial and viral pathogen infection, CaCl(2) and cold treatment, but unaffected by treatment with plant defense-related chemicals such as salicylic acid, methyl jasmonic acid, ethephone, and abscisic acid. Intriguingly, under steady state conditions, CaSRC2-1 was expressed only in the root system. A CaSRC2-1-GFP fusion protein was used to determine localization to the plasma membrane. A fusion protein lacking the C2 domain failed to target the membrane but remained in the cytoplasm, indicating that the C2 domain plays a critical role in localization. Thus, CaSRC2-1 encodes a novel C2 domain-containing protein that targets the plasma membrane and plays a critical role in the abiotic stress and defense responses of pepper plants.

Tractable approximations to multistage decisions in air defence scenarios

Simulations are commonly used to investigate the control and resource allocation problems associated with pitting aircraft against ground based air defences. Such simulations rapidly become computationally intractable as units are added. Previous work described an envelope method that retains computational tractability if the lowest and highest cost target sequences can be defined a priori and used to establish solution bounds. This approach must be modified to be applied to the more common case where there are no obvious best or worst sequences of targets. We show that these bounding sequences can be approximated by using binary comparisons and by basing decisions on a heuristic. This approach compares well with exact results in some computationally tractable situations. References R. E. Ball, The Fundamentals of Aircraft Combat Survivability Analysis and Design (American Institute of Aeronautics and Astronautics, 1985). D. Ghose, M. Krichman, J. L. Speyer and J. S. Shamma, Modeling and analysis of air campaign resource allocation: A spatio-temporal decomposition approach, IEEE Transactions on systems, man and cybernetics- Part A: Systems and humans 32 (2002) 403--418. Jose B. Cruz Jr, Marwan A. Simaan, Aga Gacic, Huihui Jiang, Bruno Letellier, Ming Li and Yong Liu, Game-theoretic modeling and control of a military air operation, IEEE Transactions on aerospace and electronic systems 37 (2001) 1393--1405. Eric V. Larson and Glenn A. Kent, A new methodology for assessing multilayer missile defence options, Monograph Report, RAND Corporation (1994) . W. McEneany, B. Fitzpatrick and I. Lauko, Stochastic game approach to air operations, IEEE Transactions on Aerospace and Electronic Systems 40 (2004) 1191--1216. A. H. Pincombe and B. M. Pincombe, A Markov decision model for tactical military engagements, Proceedings of ASOR2001 (2001) . A. H. Pincombe and B. M. Pincombe, A Markov based method for military analysis, Bulletin of the Australian Society for Operations Research 22 (2003) . A. H. Pincombe and B. M. Pincombe, Markov modelling on the effectiveness of sanctions: A case study of the Falklands war, in Proceedings of the 13th Biennial Computational Techniques and Applications Conference, CTAC-2006 (eds. Wayne Read and A. J. Roberts), Volume 48 of ANZIAM J., http://anziamj.austms.org.au/ojs/index.php/ANZIAMJ/article/view/80 [November 14, 2007], C527--C541. A. Tversky and I. Simonson, Context-dependent preferences, Management Science 39 (1993) 1179--1189. Yong Liu, Marwan A. Simaan and Jose B. Cruz Jr, An application of dynamic Nash task assignment strategies to multi-team military air operations, Automatica 39 (2003) 1469--1479.

Conceptualising social engineering attacks through system archetypes

At the highest abstraction level, an attempt by a social engineer to exploit a victim organisation either attempts to achieve some specific target (denial of service, steal an asset, tap some particular information) or it wishes to maximise an outcome, such as to disable the organisation by a terrorist attack or establish a permanent parasitic relationship (long-term espionage). Seen as dynamic processes, the first kind of exploit is a controlling ('balancing') feedback loop, while the second kind is a reinforcing feedback loop. Each type of exploit meets a first line of defence in control processes or in escalating ('reinforcing') processes of resistance. The possible combinations of the two modes of attack and the two modes of defence yield four archetypes of exploit and natural defence. Predictably, the social engineer would seek to outsmart the first line of defence; it is shown that each archetype implies a particular strategy to do so. Anticipation of these modes of attack must be the starting point for an effective multilayered defence against social engineering attacks.