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Sample records for evade complement attack

  1. Pasteurella pneumotropica evades the human complement system by acquisition of the complement regulators factor H and C4BP.

    Directory of Open Access Journals (Sweden)

    Alfredo Sahagún-Ruiz

    Full Text Available Pasteurella pneumotropica is an opportunist Gram negative bacterium responsible for rodent pasteurellosis that affects upper respiratory, reproductive and digestive tracts of mammals. In animal care facilities the presence of P. pneumotropica causes severe to lethal infection in immunodeficient mice, being also a potential source for human contamination. Indeed, occupational exposure is one of the main causes of human infection by P. pneumotropica. The clinical presentation of the disease includes subcutaneous abscesses, respiratory tract colonization and systemic infections. Given the ability of P. pneumotropica to fully disseminate in the organism, it is quite relevant to study the role of the complement system to control the infection as well as the possible evasion mechanisms involved in bacterial survival. Here, we show for the first time that P. pneumotropica is able to survive the bactericidal activity of the human complement system. We observed that host regulatory complement C4BP and Factor H bind to the surface of P. pneumotropica, controlling the activation pathways regulating the formation and maintenance of C3-convertases. These results show that P. pneumotropica has evolved mechanisms to evade the human complement system that may increase the efficiency by which this pathogen is able to gain access to and colonize inner tissues where it may cause severe infections.

  2. Edwardsiella tarda Tunes Tricarboxylic Acid Cycle to Evade Complement-Mediated Killing

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    Zhi-xue Cheng

    2017-12-01

    Full Text Available Evasion of complement-mediated killing is a common phenotype for many different types of pathogens, but the mechanism is still poorly understood. Most of the clinic isolates of Edwardsiella tarda, an important pathogen infecting both of human and fish, are commonly found serum-resistant. To explore the potential mechanisms, we applied gas chromatography-mass spectrometry (GC-MS-based metabolomics approaches to profile the metabolomes of E. tarda EIB202 in the presence or absence of serum stress. We found that tricarboxylic acid (TCA cycle was greatly enhanced in the presence of serum. The quantitative real-time PCR (qRT-PCR and enzyme activity assays validated this result. Furthermore, exogenous succinate that promotes the TCA cycle increased serum resistance, while TCA cycle inhibitors (bromopyruvate and propanedioic acid that inhibit TCA cycle, attenuated serum resistance. Moreover, the enhanced TCA cycle increased membrane potential, thus decreased the formation of membrane attack complex at cell surface, resulting serum resistance. These evidences suggested a previously unknown membrane potential-dependent mechanism of serum resistance. Therefore, our findings reveal that pathogen mounts a metabolic trick to cope with the serum complement-mediated killing.

  3. Complement Attack against Aspergillus and Corresponding Evasion Mechanisms

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    Cornelia Speth

    2012-01-01

    Full Text Available Invasive aspergillosis shows a high mortality rate particularly in immunocompromised patients. Perpetually increasing numbers of affected patients highlight the importance of a clearer understanding of interactions between innate immunity and fungi. Innate immunity is considered to be the most significant host defence against invasive fungal infections. Complement represents a crucial part of this first line defence and comprises direct effects against invading pathogens as well as bridging functions to other parts of the immune network. However, despite the potency of complement to attack foreign pathogens, the prevalence of invasive fungal infections is increasing. Two possible reasons may explain that phenomenon: First, complement activation might be insufficient for an effective antifungal defence in risk patients (due to, e.g., low complement levels, poor recognition of fungal surface, or missing interplay with other immune elements in immunocompromised patients. On the other hand, fungi may have developed evasion strategies to avoid recognition and/or eradication by complement. In this review, we summarize the most important interactions between Aspergillus and the complement system. We describe the various ways of complement activation by Aspergillus and the antifungal effects of the system, and also show proven and probable mechanisms of Aspergillus for complement evasion.

  4. Complement Attack against Aspergillus and Corresponding Evasion Mechanisms

    Science.gov (United States)

    Speth, Cornelia; Rambach, Günter

    2012-01-01

    Invasive aspergillosis shows a high mortality rate particularly in immunocompromised patients. Perpetually increasing numbers of affected patients highlight the importance of a clearer understanding of interactions between innate immunity and fungi. Innate immunity is considered to be the most significant host defence against invasive fungal infections. Complement represents a crucial part of this first line defence and comprises direct effects against invading pathogens as well as bridging functions to other parts of the immune network. However, despite the potency of complement to attack foreign pathogens, the prevalence of invasive fungal infections is increasing. Two possible reasons may explain that phenomenon: First, complement activation might be insufficient for an effective antifungal defence in risk patients (due to, e.g., low complement levels, poor recognition of fungal surface, or missing interplay with other immune elements in immunocompromised patients). On the other hand, fungi may have developed evasion strategies to avoid recognition and/or eradication by complement. In this review, we summarize the most important interactions between Aspergillus and the complement system. We describe the various ways of complement activation by Aspergillus and the antifungal effects of the system, and also show proven and probable mechanisms of Aspergillus for complement evasion. PMID:22927844

  5. Trypanosoma cruzi Evades the Complement System as an Efficient Strategy to Survive in the Mammalian Host: The Specific Roles of Host/Parasite Molecules and Trypanosoma cruzi Calreticulin

    Science.gov (United States)

    Ramírez-Toloza, Galia; Ferreira, Arturo

    2017-01-01

    American Trypanosomiasis is an important neglected reemerging tropical parasitism, infecting about 8 million people worldwide. Its agent, Trypanosoma cruzi, exhibits multiple mechanisms to evade the host immune response and infect host cells. An important immune evasion strategy of T. cruzi infective stages is its capacity to inhibit the complement system activation on the parasite surface, avoiding opsonizing, immune stimulating and lytic effects. Epimastigotes, the non-infective form of the parasite, present in triatomine arthropod vectors, are highly susceptible to complement-mediated lysis while trypomastigotes, the infective form, present in host bloodstream, are resistant. Thus T. cruzi susceptibility to complement varies depending on the parasite stage (amastigote, trypomastigotes or epimastigote) and on the T. cruzi strain. To avoid complement-mediated lysis, T. cruzi trypomastigotes express on the parasite surface a variety of complement regulatory proteins, such as glycoprotein 58/68 (gp58/68), T. cruzi complement regulatory protein (TcCRP), trypomastigote decay-accelerating factor (T-DAF), C2 receptor inhibitor trispanning (CRIT) and T. cruzi calreticulin (TcCRT). Alternatively, or concomitantly, the parasite captures components with complement regulatory activity from the host bloodstream, such as factor H (FH) and plasma membrane-derived vesicles (PMVs). All these proteins inhibit different steps of the classical (CP), alternative (AP) or lectin pathways (LP). Thus, TcCRP inhibits the CP C3 convertase assembling, gp58/68 inhibits the AP C3 convertase, T-DAF interferes with the CP and AP convertases assembling, TcCRT inhibits the CP and LP, CRIT confers ability to resist the CP and LP, FH is used by trypomastigotes to inhibit the AP convertases and PMVs inhibit the CP and LP C3 convertases. Many of these proteins have similar molecular inhibitory mechanisms. Our laboratory has contributed to elucidate the role of TcCRT in the host-parasite interplay

  6. Trypanosoma cruzi Evades the Complement System as an Efficient Strategy to Survive in the Mammalian Host: The Specific Roles of Host/Parasite Molecules and Trypanosoma cruzi Calreticulin

    Directory of Open Access Journals (Sweden)

    Galia Ramírez-Toloza

    2017-09-01

    Full Text Available American Trypanosomiasis is an important neglected reemerging tropical parasitism, infecting about 8 million people worldwide. Its agent, Trypanosoma cruzi, exhibits multiple mechanisms to evade the host immune response and infect host cells. An important immune evasion strategy of T. cruzi infective stages is its capacity to inhibit the complement system activation on the parasite surface, avoiding opsonizing, immune stimulating and lytic effects. Epimastigotes, the non-infective form of the parasite, present in triatomine arthropod vectors, are highly susceptible to complement-mediated lysis while trypomastigotes, the infective form, present in host bloodstream, are resistant. Thus T. cruzi susceptibility to complement varies depending on the parasite stage (amastigote, trypomastigotes or epimastigote and on the T. cruzi strain. To avoid complement-mediated lysis, T. cruzi trypomastigotes express on the parasite surface a variety of complement regulatory proteins, such as glycoprotein 58/68 (gp58/68, T. cruzi complement regulatory protein (TcCRP, trypomastigote decay-accelerating factor (T-DAF, C2 receptor inhibitor trispanning (CRIT and T. cruzi calreticulin (TcCRT. Alternatively, or concomitantly, the parasite captures components with complement regulatory activity from the host bloodstream, such as factor H (FH and plasma membrane-derived vesicles (PMVs. All these proteins inhibit different steps of the classical (CP, alternative (AP or lectin pathways (LP. Thus, TcCRP inhibits the CP C3 convertase assembling, gp58/68 inhibits the AP C3 convertase, T-DAF interferes with the CP and AP convertases assembling, TcCRT inhibits the CP and LP, CRIT confers ability to resist the CP and LP, FH is used by trypomastigotes to inhibit the AP convertases and PMVs inhibit the CP and LP C3 convertases. Many of these proteins have similar molecular inhibitory mechanisms. Our laboratory has contributed to elucidate the role of TcCRT in the host

  7. Regulation of complement membrane attack complex formation in myocardial infarction.

    OpenAIRE

    Väkevä, A.; Laurila, P; Meri, S.

    1993-01-01

    Recent studies have suggested that the complement (C) system is involved in the development of tissue injury of myocardial infarction. As it is not known why the strictly controlled C system starts to react against autologous heart tissue, we have analyzed the expression of various membrane regulators of C (CR1, DAF, MCP, CD59, C8 binding protein) and the pattern of deposition of C components and plasma C regulators (C4b binding protein and vitronectin) in normal (n = 7) and infarcted (n = 13...

  8. Hepatitis C virus suppresses C9 complement synthesis and impairs membrane attack complex function.

    Science.gov (United States)

    Kim, Hangeun; Meyer, Keith; Di Bisceglie, Adrian M; Ray, Ranjit

    2013-05-01

    Hepatitis C virus (HCV) proteins inhibit complement component expression, which may attenuate immunity against infection. In this study, we examined whether HCV regulates the membrane attack complex (MAC) via complement component C9. MAC is composed of C5b to C9 (C5b-9) and mediates cell lysis of invaded pathogens. Liver biopsy specimens from chronically HCV-infected patients exhibited a lower level of C9 mRNA expression than liver biopsy specimens from unrelated disease or healthy control human liver RNA. Hepatocytes infected with cell culture-grown HCV or expressing HCV core protein also displayed significant repression of C9 mRNA and protein levels. Promoter analysis suggested that the T cell factor-4 (TCF-4E) transcription factor is responsible for HCV core-mediated C9 promoter regulation. Sera from chronically HCV-infected patients displayed a lower level of C5b-9 and a reduced antimicrobial effect on model organisms compared to unrelated patient sera or sera from healthy volunteers. Together, these results for C9 regulation by HCV core protein coupled with functional impairment of the membrane attack complex underscore HCV-mediated attenuation of immune mechanisms.

  9. Complement

    Science.gov (United States)

    ... in the liquid portion of your blood. The complement system is a group of proteins that move freely ... a role in the development of inflammation. The complement system protects the body from infections, dead cells and ...

  10. CR2-mediated activation of the complement alternative pathway results in formation of membrane attack complexes on human B lymphocytes

    DEFF Research Database (Denmark)

    Nielsen, C H; Marquart, H V; Prodinger, W M

    2001-01-01

    Normal human B lymphocytes activate the alternative pathway of complement via complement receptor type 2 (CR2, CD21), that binds hydrolysed C3 (iC3) and thereby promotes the formation of a membrane-bound C3 convertase. We have investigated whether this might lead to the generation of a C5...... convertase and consequent formation of membrane attack complexes (MAC). Deposition of C3 fragments and MAC was assessed on human peripheral B lymphocytes in the presence of 30% autologous serum containing 4.4 mM MgCl2/20 mM EGTA, which abrogates the classical pathway of complement without affecting...

  11. CR2-mediated activation of the complement alternative pathway results in formation of membrane attack complexes on human B lymphocytes

    DEFF Research Database (Denmark)

    Nielsen, C H; Marquart, H V; Prodinger, W M

    2001-01-01

    convertase and consequent formation of membrane attack complexes (MAC). Deposition of C3 fragments and MAC was assessed on human peripheral B lymphocytes in the presence of 30% autologous serum containing 4.4 mM MgCl2/20 mM EGTA, which abrogates the classical pathway of complement without affecting...

  12. Inhibition of the Membrane Attack Complex by Dengue Virus NS1 through Interaction with Vitronectin and Terminal Complement Proteins.

    Science.gov (United States)

    Conde, Jonas Nascimento; da Silva, Emiliana Mandarano; Allonso, Diego; Coelho, Diego Rodrigues; Andrade, Iamara da Silva; de Medeiros, Luciano Neves; Menezes, Joice Lima; Barbosa, Angela Silva; Mohana-Borges, Ronaldo

    2016-11-01

    Dengue virus (DENV) infects millions of people worldwide and is a major public health problem. DENV nonstructural protein 1 (NS1) is a conserved glycoprotein that associates with membranes and is also secreted into the plasma in DENV-infected patients. The present study describes a novel mechanism by which NS1 inhibits the terminal complement pathway. We first identified the terminal complement regulator vitronectin (VN) as a novel DENV2 NS1 binding partner by using a yeast two-hybrid system. This interaction was further assessed by enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) assay. The NS1-VN complex was also detected in plasmas from DENV-infected patients, suggesting that this interaction occurs during DENV infection. We also demonstrated that the DENV2 NS1 protein, either by itself or by interacting with VN, hinders the formation of the membrane attack complex (MAC) and C9 polymerization. Finally, we showed that DENV2, West Nile virus (WNV), and Zika virus (ZIKV) NS1 proteins produced in mammalian cells inhibited C9 polymerization. Taken together, our results points to a role for NS1 as a terminal pathway inhibitor of the complement system. Dengue is the most important arthropod-borne viral disease nowadays and is caused by dengue virus (DENV). The flavivirus NS1 glycoprotein has been characterized functionally as a complement evasion protein that can attenuate the activation of the classical, lectin, and alternative pathways. The present study describes a novel mechanism by which DENV NS1 inhibits the terminal complement pathway. We identified the terminal complement regulator vitronectin (VN) as a novel DENV NS1 binding partner, and the NS1-VN complex was detected in plasmas from DENV-infected patients, suggesting that this interaction occurs during DENV infection. We also demonstrated that the NS1-VN complex inhibited membrane attack complex (MAC) formation, thus interfering with the complement terminal pathway. Interestingly

  13. Targeting the Human Complement Membrane Attack Complex to Selectively Kill Prostate Cancer Cells

    Science.gov (United States)

    2013-10-01

    reproductive tract of the fe- male. In this regard, seminal plasma is devoid of complement ac- tivity and actually has a strong anti-complement activity (8...article: EA, Ab-sensitized sheep erythrocyte; ES, sheep erythrocyte; PSA, prostate-specific Ag; PVDF, polyvinylidene difluoride. Copyright 2013 by The...addition of sample loading buffer. Proteins were separated by SDS-PAGE and transferred to PVDF membrane as described above. C3b/iC3b deposition assay Sheep

  14. Synergistic enhancement of chemokine generation and lung injury by C5a or the membrane attack complex of complement

    DEFF Research Database (Denmark)

    Czermak, B J; Lentsch, A B; Bless, N M

    1999-01-01

    Complement plays an important role in many acute inflammatory responses. In the current studies it was demonstrated that, in the presence of either C5a or sublytic forms of the complement-derived membrane attack complex (MAC), rat alveolar macrophages costimulated with IgG immune complexes...... demonstrated synergistic production of C-X-C (macrophage inflammatory protein-2 and cytokine-induced neutrophil chemoattractant) and C-C (macrophage inflammatory protein-1alpha and monocyte chemoattractant-1) chemokines. In the absence of the costimulus, C5a or MAC did not induce chemokine generation....... In in vivo studies, C5a and MAC alone caused limited or no intrapulmonary generation of chemokines, but in the presence of a costimulus (IgG immune complexes) C5a and MAC caused synergistic intrapulmonary generation of C-X-C and C-C chemokines but not of tumor necrosis factor alpha. Under these conditions...

  15. Down-regulation of human complement factor H sensitizes non-small cell lung cancer cells to complement attack and reduces in vivo tumor growth.

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    Ajona, Daniel; Hsu, Yi-Fan; Corrales, Leticia; Montuenga, Luis M; Pio, Ruben

    2007-05-01

    Malignant cells are often resistant to complement activation through the enhanced expression of complement inhibitors. In this work, we examined the protective role of factor H, CD46, CD55, and CD59 in two non-small cell lung cancer cell lines, H1264 and A549, upon activation of the classical pathway of complement. Complement was activated with polyclonal Abs raised against each cell line. After blocking factor H activity with a neutralizing Ab, C3 deposition and C5a release were more efficient. Besides, a combined inhibition of factor H and CD59 significantly increased complement-mediated lysis. CD46 and CD55 did not show any effect in the control of complement activation. Factor H expression was knockdown on A549 cells using small interfering RNA. In vivo growth of factor H-deficient cells in athymic mice was significantly reduced. C3 immunocytochemistry on explanted xenografts showed an enhanced activation of complement in these cells. Besides, when mice were depleted of complement with cobra venom factor, growth was recovered, providing further evidence that complement was important in the reduction of in vivo growth. In conclusion, we show that expression of the complement inhibitor factor H by lung cancer cells can prevent complement activation and improve tumor development in vivo. This may have important consequences in the efficiency of complement-mediated immunotherapies.

  16. Hõimupäevad

    Index Scriptorium Estoniae

    2003-01-01

    Avatakse EKA Saamimaa uurimisreisi temaatikal põhinev näitus "Nelja tuule retk", ungari foto- ja etnograafi Laszlo Kunkovacsi fotonäitus "Ungari karjusekultuur". ERMis on avatud ülevaatenäitus "EKA soomeugri joonised ERMis". Hõimupäevade muusikaprojektidest, mis leiavad seekord aset koostöös "Jazzkaare" projektiga "Piirideta Põhjala"

  17. Hepatitis B virus X protein up-regulates C4b-binding protein α through activating transcription factor Sp1 in protection of hepatoma cells from complement attack.

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    Feng, Guoxing; Li, Jiong; Zheng, Minying; Yang, Zhe; Liu, Yunxia; Zhang, Shuqin; Ye, Lihong; Zhang, Weiying; Zhang, Xiaodong

    2016-05-10

    Hepatitis B virus X protein (HBx) plays crucial roles in the development of hepatocellular carcinoma (HCC). We previously showed that HBx protected hepatoma cells from complement attack by activation of CD59. Moreover, in this study we found that HBx protected hepatoma cells from complement attack by activation of C4b-binding protein α (C4BPα), a potent inhibitor of complement system. We observed that HBx were positively correlated with those of C4BPα in clinical HCC tissues. Mechanistically, HBx activated the promoter core region of C4BPα, located at -1199/-803nt, through binding to transcription factor Sp1. In addition, chromatin immunoprecipitation (ChIP) assays showed that HBx was able to bind to the promoter of C4BPα, which could be blocked by Sp1 silencing. Functionally, knockdown of C4BPα obviously increased the deposition of C5b-9, a complex of complement membrane attack, and remarkably abolished the HBx-induced resistance of hepatoma cells from complement attack in vitro and in vivo. Thus, we conclude that HBx up-regulates C4BPα through activating transcription factor Sp1 in protection of liver cancer cells from complement attack. Our finding provides new insights into the mechanism by which HBx enhances protection of hepatoma cells from complement attack.

  18. The classical and alternative pathways of complement activation play distinct roles in spontaneous C3 fragment deposition and membrane attack complex (MAC) formation on human B lymphocytes

    DEFF Research Database (Denmark)

    Leslie, Robert Graham Quinton; Nielsen, Claus Henrik

    2004-01-01

    The contributions of the classical (CP) and alternative (AP) pathways of complement activation to the spontaneous deposition of C3 fragments and the formation of membrane attack complexes (MAC) on human B lymphocytes, were assessed by incubating peripheral blood mononuclear cells with autologous......, however, in the nature of the fragments deposited as a result of CP and AP activation: C3b fragments deposited via the CP were extensively ( approximately 90%) converted to the terminal degradation product, C3dg, whereas about 50% of those deposited by the AP persisted as C3b/iC3b fragments. The extent...

  19. The role of complement receptors type 1 (CR1, CD35) and 2 (CR2, CD21) in promoting C3 fragment deposition and membrane attack complex formation on normal peripheral human B cells

    DEFF Research Database (Denmark)

    Nielsen, Claus Henrik; Pedersen, Morten Løbner; Marquart, Hanne Vibeke Hansen

    2002-01-01

    Normal human B lymphocytes are known to activate the alternative pathway (AP) of complement, leading to C3-fragment deposition and membrane attack complex (MAC) formation. The process is mediated via complement receptor type 2 (CR2, CD21), with complement receptor type 1 (CR1, CD35) playing......, the presence of extrinsic CR1, on E, may serve to limit spontaneous MAC formation and thereby ensure cell survival in the circulation....

  20. Lutein supplementation leads to decreased soluble complement membrane attack complex sC5b-9 plasma levels

    National Research Council Canada - National Science Library

    Tian, Yuan; Kijlstra, A; Veen, van der, RLP; Makridaki, M; Murray, Ian J; Berendschot, TTJM Tos

    2015-01-01

    ... in drusen (Hageman et al. ). These findings were supported by studies showing an increase in the level of various complement activation products in the circulation of AMD patients (Donoso et al. ; Scholl et al. ; Reynolds et al. ; Hecker et al. ) and provided further evidence for a systemic inflammatory component to the disease pathogenesis...

  1. Interdiction of a Markovian evader

    Energy Technology Data Exchange (ETDEWEB)

    Hagberg, Aric [Los Alamos National Laboratory; Izraelevitz, David [Los Alamos National Laboratory; Pan, Feng [Los Alamos National Laboratory; Gutfraind, Alexander [CORNELL UNIV

    2008-01-01

    Network interdiction is a combinatorial optimization problem on an activity network arising in a number of important security-related applications. It is classically formulated as a bilevel maximin problem representing an 'interdictor' and an 'evader'. The evader tries to move from a source node to the target node along the shortest or safest path while the interdictor attempts to frustrate this motion by cutting edges or nodes. The interdiction objective is to find the optimal set of edges to cut given that there is a finite interdiction budget and the interdictor must move first. We reformulate the interdiction problem for stochastic evaders by introducing a model in which the evader follows a Markovian random walk guided by the least-cost path to the target. This model can represent incomplete knowledge about the evader and the graph as well as partial interdiction. We formulate the optimization problem for this model and show how, by exploiting topological ordering of the nodes, one can achieve an order-of-magnitude speedup in computing the objective function. We also introduce an evader-motion-based heuristic that can significantly improve solution quality by providing a global view of the network to approximation methods.

  2. Trichinella spiralis Paramyosin Binds Human Complement C1q and Inhibits Classical Complement Activation.

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    Ran Sun

    2015-12-01

    Full Text Available Trichinella spiralis expresses paramyosin (Ts-Pmy as a defense mechanism. Ts-Pmy is a functional protein with binding activity to human complement C8 and C9 and thus plays a role in evading the attack of the host's immune system. In the present study, the binding activity of Ts-Pmy to human complement C1q and its ability to inhibit classical complement activation were investigated.The binding of recombinant and natural Ts-Pmy to human C1q were determined by ELISA, Far Western blotting and immunoprecipitation, respectively. Binding of recombinant Ts-Pmy (rTs-Pmy to C1q inhibited C1q binding to IgM and consequently inhibited C3 deposition. The lysis of antibody-sensitized erythrocytes (EAs elicited by the classical complement pathway was also inhibited in the presence of rTs-Pmy. In addition to inhibiting classical complement activation, rTs-Pmy also suppressed C1q binding to THP-1-derived macrophages, thereby reducing C1q-induced macrophages migration.Our results suggest that T. spiralis paramyosin plays an important role in immune evasion by interfering with complement activation through binding to C1q in addition to C8 and C9.

  3. Evader Interdiction and Collateral Damage

    Energy Technology Data Exchange (ETDEWEB)

    Gutfraind, Alexander [Los Alamos National Laboratory

    2011-01-01

    In network interdiction problems, evaders (hostile agents or data packets) are moving through a network towards their targets and we wish to choose sensor placement locations in order to intercept them before they reach their destinations. Sensor locations should be chosen economically, balancing security gains with cost, including the inconvenience sensors inflict upon innocent travelers. We give optimal sensor allocation algorithms for several classes of special graphs and hardness and optimal approximation results for general graphs, including for deterministic or Markov chain-based and oblivious or reactive evaders. In a similar-sounding but much different problem setting posed by [10] where the innocent travelers can also be reactive, we again give optimal algorithms for special cases and hardness and (essentially) optimal approximation results on general graphs.

  4. Exploitation of complement regulatory proteins by Borrelia and Francisella.

    Science.gov (United States)

    Madar, Marian; Bencurova, Elena; Mlynarcik, Patrik; Almeida, André M; Soares, Renata; Bhide, Katarina; Pulzova, Lucia; Kovac, Andrej; Coelho, Ana V; Bhide, Mangesh

    2015-06-01

    Pathogens have developed sophisticated mechanisms of complement evasion such as binding to the host complement regulatory proteins (CRPs) on their surface or expression of CRP mimicking molecules. The ability of pathogens to evade the complement system has been correlated with pathogenesis and host selectivity. Hitherto, little work has been undertaken to determine whether Borrelia and Francisella exploit various CRPs to block complement attack. Seventeen Borrelia (twelve species) and six Francisella (three subspecies) strains were used to assess their ability to bind human, sheep and cattle CRPs or mimic membrane associated complement regulators. A series of experiments including affinity ligand binding experiments, pull-down assays and mass spectrometry based protein identification, revealed an array of CRP binding proteins of Borrelia and Francisella. Unlike Francisella, Borrelia strains were able to bind multiple human CRPs. Three strains of Borrelia (SKT-4, SKT-2 and HO14) showed the presence of a human CD46-homologous motif, indicating their ability to possess putative human CD46 mimicking molecules. Similarly, five strains of Borrelia and two strains of Francisella may have surface proteins with human CD59-homologous motifs. Among ovine and bovine CRPs, the only CRP bound by Francisella (LVS, Tul4 strain) was vitronectin, while ovine C4BP, ovine factor H and bovine factor H were bound to Borrelia strains SKT-2, DN127 and Co53. This study presents an array of proteins of Borrelia and Francisella that bind CRPs or may mimic membrane-CRPs, thus enabling multiphasic complement evasion strategies of these pathogens.

  5. The novel complement inhibitor human CUB and Sushi multiple domains 1 (CSMD1) protein promotes factor I-mediated degradation of C4b and C3b and inhibits the membrane attack complex assembly.

    Science.gov (United States)

    Escudero-Esparza, Astrid; Kalchishkova, Nikolina; Kurbasic, Emila; Jiang, Wen G; Blom, Anna M

    2013-12-01

    CUB and Sushi multiple domains 1 (CSMD1) is a transmembrane protein containing 15 consecutive complement control protein (CCP) domains, which are characteristic for complement inhibitors. We expressed a membrane-bound fragment of human CSMD1 composed of the 15 C-terminal CCP domains and demonstrated that it inhibits deposition of C3b by the classical pathway on the surface of Chinese hamster ovary cells by 70% at 6% serum and of C9 (component of membrane attack complex) by 90% at 1.25% serum. Furthermore, this fragment of CSMD1 served as a cofactor to factor I-mediated degradation of C3b. In all functional assays performed, well-characterized complement inhibitors were used as positive controls, whereas Coxsackie adenovirus receptor, a protein with no effect on complement, was a negative control. Moreover, attenuation of expression in human T47 breast cancer cells that express endogenous CSMD1 significantly increased C3b deposition on these cells by 45% at 8% serum compared with that for the controls. Furthermore, by expressing a soluble 17-21 CCP fragment of CSMD1, we found that CSMD1 inhibits complement by promoting factor I-mediated C4b/C3b degradation and inhibition of MAC assembly at the level of C7. Our results revealed a novel complement inhibitor for the classical and lectin pathways.

  6. Optimal interdiction of unreactive Markovian evaders

    Energy Technology Data Exchange (ETDEWEB)

    Hagberg, Aric [Los Alamos National Laboratory; Pan, Feng [Los Alamos National Laboratory; Gutfraind, Alex [CORNELL UNIV.

    2009-01-01

    The interdiction problem arises in a variety of areas including military logistics, infectious disease control, and counter-terrorism. In the typical formulation of network interdiction. the task of the interdictor is to find a set of edges in a weighted network such that the removal of those edges would increase the cost to an evader of traveling on a path through the network. Our work is motivated by cases in which the evader has incomplete information about the network or lacks planning time or computational power, e.g. when authorities set up roadblocks to catch bank robbers, the criminals do not know all the roadblock locations or the best path to use for their escape. We introduce a model of network interdiction in which the motion of one or more evaders is described by Markov processes on a network and the evaders are assumed not to react to interdiction decisions. The interdiction objective is to find a node or set. of size at most B, that maximizes the probability of capturing the evaders. We prove that similar to the classical formulation this interdiction problem is NP-hard. But unlike the classical problem our interdiction problem is submodular and the optimal solution can be approximated within 1-lie using a greedy algorithm. Additionally. we exploit submodularity to introduce a priority evaluation strategy that speeds up the greedy algorithm by orders of magnitude. Taken together the results bring closer the goal of finding realistic solutions to the interdiction problem on global-scale networks.

  7. Microbes bind complement inhibitor factor H via a common site.

    Directory of Open Access Journals (Sweden)

    T Meri

    Full Text Available To cause infections microbes need to evade host defense systems, one of these being the evolutionarily old and important arm of innate immunity, the alternative pathway of complement. It can attack all kinds of targets and is tightly controlled in plasma and on host cells by plasma complement regulator factor H (FH. FH binds simultaneously to host cell surface structures such as heparin or glycosaminoglycans via domain 20 and to the main complement opsonin C3b via domain 19. Many pathogenic microbes protect themselves from complement by recruiting host FH. We analyzed how and why different microbes bind FH via domains 19-20 (FH19-20. We used a selection of FH19-20 point mutants to reveal the binding sites of several microbial proteins and whole microbes (Haemophilus influenzae, Bordetella pertussis, Pseudomonas aeruginosa, Streptococcus pneumonia, Candida albicans, Borrelia burgdorferi, and Borrelia hermsii. We show that all studied microbes use the same binding region located on one side of domain 20. Binding of FH to the microbial proteins was inhibited with heparin showing that the common microbial binding site overlaps with the heparin site needed for efficient binding of FH to host cells. Surprisingly, the microbial proteins enhanced binding of FH19-20 to C3b and down-regulation of complement activation. We show that this is caused by formation of a tripartite complex between the microbial protein, FH, and C3b. In this study we reveal that seven microbes representing different phyla utilize a common binding site on the domain 20 of FH for complement evasion. Binding via this site not only mimics the glycosaminoglycans of the host cells, but also enhances function of FH on the microbial surfaces via the novel mechanism of tripartite complex formation. This is a unique example of convergent evolution resulting in enhanced immune evasion of important pathogens via utilization of a "superevasion site."

  8. Skulptuuripäevad Pärnus

    Index Scriptorium Estoniae

    2003-01-01

    4.-15. VIII Pärnus Vallikääru aasal 3. rahvusvahelised skulptuuripäevad "Pärnu positiivne märk". Osalevad Serge Samyn (Prantsusmaa), Kestutis Lanauskaټ (Leedu), Asa Hauksdottir (Island), Meeland Sepp, Toomas Kuusing, Toomas Altnurme, Rait Pärg (korraldaja). Lastele vanuses 7-15 avatud töötuba juhendab Eneken Maripuu

  9. Maakunsti päevad Rakveres

    Index Scriptorium Estoniae

    2000-01-01

    5.-10. VI Rakvere tammikus rahvusvahelised maakunsti päevad. Korraldaja Anne Kokkov. Rakvere muuseumis lõppes naivistliku kunstniku Berta Mändla näitus "Berta jutustab". Muuseumi teisi üritusi. Richard Sagritsa ateljees Karepal väljapanek kunstniku ja tema kaasaegsete loomingust.

  10. The Bordetella pertussis Bps Polysaccharide Enhances Lung Colonization by Conferring Protection from Complement-mediated Killing

    Science.gov (United States)

    Ganguly, Tridib; Johnson, John B.; Kock, Nancy D.; Parks, Griffith D.; Deora, Rajendar

    2014-01-01

    Summary Bordetella pertussis is a human-restricted Gram-negative bacterial pathogen that causes whooping cough or pertussis. Pertussis is the leading vaccine preventable disease that is resurging in the USA and other parts of the developed world. There is an incomplete understanding of the mechanisms by which B. pertussis evades killing and clearance by the complement system, a first line of host innate immune defense. The present study examined the role of the Bps polysaccharide to resist complement activity in vitro and in the mouse respiratory tract. The isogenic bps mutant strain containing a large non polar in-frame deletion of the bpsA-D locus was more sensitive to serum and complement mediated killing than the WT strain. As determined by western blotting, flow cytometry and electron microscopic studies, the heightened sensitivity of the mutant strain was due to enhanced deposition of complement proteins and the formation of membrane attack complex, the end product of complement activation. Bps was sufficient to confer complement resistance as evidenced by a Bps-expressing E. coli being protected by serum killing. Additionally, western blotting and flow cytometry assays revealed that Bps inhibited the deposition of complement proteins independent of other B. pertussis factors. The bps mutant strain colonized the lungs of complement-deficient mice at higher levels than that observed in C57Bl/6 mice. These results reveal a previously unknown interaction between Bps and the complement system in controlling B. pertussis colonization of the respiratory tract. These findings also make Bps a potential target for the prevention and therapy of whooping cough. PMID:24438122

  11. How eukaryotic filamentous pathogens evade plant recognition.

    Science.gov (United States)

    Oliveira-Garcia, Ely; Valent, Barbara

    2015-08-01

    Plant pathogenic fungi and oomycetes employ sophisticated mechanisms for evading host recognition. After host penetration, many fungi and oomycetes establish a biotrophic interaction. It is assumed that different strategies employed by these pathogens to avoid triggering host defence responses, including establishment of biotrophic interfacial layers between the pathogen and host, masking of invading hyphae and active suppression of host defence mechanisms, are essential for a biotrophic parasitic lifestyle. During the infection process, filamentous plant pathogens secrete various effectors, which are hypothesized to be involved in facilitating effective host infection. Live-cell imaging of fungi and oomycetes secreting fluorescently labeled effector proteins as well as functional characterization of the components of biotrophic interfaces have led to the recent progress in understanding how eukaryotic filamentous pathogens evade plant recognition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. The Bordetella pertussis Bps polysaccharide enhances lung colonization by conferring protection from complement-mediated killing.

    Science.gov (United States)

    Ganguly, Tridib; Johnson, John B; Kock, Nancy D; Parks, Griffith D; Deora, Rajendar

    2014-07-01

    Bordetella pertussis is a human-restricted Gram-negative bacterial pathogen that causes whooping cough or pertussis. Pertussis is the leading vaccine preventable disease that is resurging in the USA and other parts of the developed world. There is an incomplete understanding of the mechanisms by which B. pertussis evades killing and clearance by the complement system, a first line of host innate immune defence. The present study examined the role of the Bps polysaccharide to resist complement activity in vitro and in the mouse respiratory tract. The isogenic bps mutant strain containing a large non-polar in-frame deletion of the bpsA-D locus was more sensitive to serum and complement mediated killing than the WT strain. As determined by Western blotting, flow cytometry and electron microscopic studies, the heightened sensitivity of the mutant strain was due to enhanced deposition of complement proteins and the formation of membrane attack complex, the end-product of complement activation. Bps was sufficient to confer complement resistance as evidenced by a Bps-expressing Escherichia coli being protected by serum killing. Additionally, Western blotting and flow cytometry assays revealed that Bps inhibited the deposition of complement proteins independent of other B. pertussis factors. The bps mutant strain colonized the lungs of complement-deficient mice at higher levels than that observed in C57Bl/6 mice. These results reveal a previously unknown interaction between Bps and the complement system in controlling B. pertussis colonization of the respiratory tract. These findings also make Bps a potential target for the prevention and therapy of whooping cough. © 2014 John Wiley & Sons Ltd.

  13. Exploitation of the complement system by oncogenic Kaposi's sarcoma-associated herpesvirus for cell survival and persistent infection.

    Directory of Open Access Journals (Sweden)

    Myung-Shin Lee

    2014-09-01

    Full Text Available During evolution, herpesviruses have developed numerous, and often very ingenious, strategies to counteract efficient host immunity. Specifically, Kaposi's sarcoma-associated herpesvirus (KSHV eludes host immunity by undergoing a dormant stage, called latency wherein it expresses a minimal number of viral proteins to evade host immune activation. Here, we show that during latency, KSHV hijacks the complement pathway to promote cell survival. We detected strong deposition of complement membrane attack complex C5b-9 and the complement component C3 activated product C3b on Kaposi's sarcoma spindle tumor cells, and on human endothelial cells latently infected by KSHV, TIME-KSHV and TIVE-LTC, but not on their respective uninfected control cells, TIME and TIVE. We further showed that complement activation in latently KSHV-infected cells was mediated by the alternative complement pathway through down-regulation of cell surface complement regulatory proteins CD55 and CD59. Interestingly, complement activation caused minimal cell death but promoted the survival of latently KSHV-infected cells grown in medium depleted of growth factors. We found that complement activation increased STAT3 tyrosine phosphorylation (Y705 of KSHV-infected cells, which was required for the enhanced cell survival. Furthermore, overexpression of either CD55 or CD59 in latently KSHV-infected cells was sufficient to inhibit complement activation, prevent STAT3 Y705 phosphorylation and abolish the enhanced survival of cells cultured in growth factor-depleted condition. Together, these results demonstrate a novel mechanism by which an oncogenic virus subverts and exploits the host innate immune system to promote viral persistent infection.

  14. Saliva of Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) inhibits classical and alternative complement pathways.

    Science.gov (United States)

    Silva, Naylene C S; Vale, Vladimir F; Franco, Paula F; Gontijo, Nelder F; Valenzuela, Jesus G; Pereira, Marcos H; Sant'Anna, Mauricio R V; Rodrigues, Daniel S; Lima, Walter S; Fux, Blima; Araujo, Ricardo N

    2016-08-11

    Rhipicephalus (Boophilus) microplus is the main ectoparasite affecting livestock worldwide. For a successful parasitism, ticks need to evade several immune responses of their hosts, including the activation of the complement system. In spite of the importance of R. microplus, previous work only identified one salivary molecule that blocks the complement system. The current study describes complement inhibitory activities induced by R. microplus salivary components and mechanisms elicited by putative salivary proteins on both classical and alternative complement pathways. We found that R. microplus saliva from fully- and partially engorged females was able to inhibit both pathways. Saliva acts strongly at the initial steps of both complement activation pathways. In the classical pathway, the saliva blocked C4 cleavage, and hence, deposition of C4b on the activation surface, suggesting that the inhibition occurs at some point between C1q and C4. In the alternative pathway, saliva acts by binding to initial components of the cascade (C3b and properdin) thereby preventing the C3 convertase formation and reducing C3b production and deposition as well as cleavage of factor B. Saliva has no effect on formation or decay of the C6 to C8 components of the membrane attack complex. The saliva of R. microplus is able to inhibit the early steps of classical and alternative pathways of the complement system. Saliva acts by blocking C4 cleavage and deposition of C4b on the classical pathway activation surface and, in the alternative pathway, saliva bind to initial components of the cascade (C3b and properdin) thereby preventing the C3 convertase formation and the production and deposition of additional C3b.

  15. Cysteine proteinase from Streptococcus pyogenes enables evasion of innate immunity via degradation of complement factors.

    Science.gov (United States)

    Honda-Ogawa, Mariko; Ogawa, Taiji; Terao, Yutaka; Sumitomo, Tomoko; Nakata, Masanobu; Ikebe, Kazunori; Maeda, Yoshinobu; Kawabata, Shigetada

    2013-05-31

    Streptococcus pyogenes is an important human pathogen that causes invasive diseases such as necrotizing fasciitis, sepsis, and streptococcal toxic shock syndrome. We investigated the function of a major cysteine protease from S. pyogenes that affects the amount of C1-esterase inhibitor (C1-INH) and other complement factors and aimed to elucidate the mechanism involved in occurrence of streptococcal toxic shock syndrome from the aspect of the complement system. First, we revealed that culture supernatant of a given S. pyogenes strain and recombinant SpeB degraded the C1-INH. Then, we determined the N-terminal sequence of the C1-INH fragment degraded by recombinant SpeB. Interestingly, the region containing one of the identified cleavage sites is not present in patients with C1-INH deficiency. Scanning electron microscopy of the speB mutant incubated in human serum showed the abnormal superficial architecture and irregular oval structure. Furthermore, unlike the wild-type strain, that mutant strain showed lower survival capacity than normal as compared with heat-inactivated serum, whereas it had a significantly higher survival rate in serum without the C1-INH than in normal serum. Also, SpeB degraded multiple complement factors and the membrane attack complex. Flow cytometric analyses revealed deposition of C9, one of the components of membrane the attack complex, in greater amounts on the surface of the speB mutant, whereas lower amounts of C9 were bound to the wild-type strain surface. These results suggest that SpeB can interrupt the human complement system via degrading the C1-INH, thus enabling S. pyogenes to evade eradication in a hostile environment.

  16. Complement and Antibody-Mediated Enhancement of Erythrocyte Invasion by Plasmodium Falciparum

    Science.gov (United States)

    2016-04-01

    Keywords: Malaria Complement Red blood cells Merozoites CR11. Introduction Malaria , a mosquito-borne infectious disease caused by eukaryotic intracellular... malaria kills hundreds of thousands of people every year. A vaccine that blocks red blood cell (RBC) invasion has been an elusive goal. Although...to use complement to invade RBCs and, thus, hijack the complement system and evade the host immune response. 15. SUBJECT TERMS Malaria , complement

  17. Viral mimicry of the complement system

    Indian Academy of Sciences (India)

    The complement system is a potent innate immune mechanism consisting of cascades of proteins which are designed to fight against and annul intrusion of all the foreign pathogens. Although viruses are smaller in size and have relatively simple structure, they are not immune to complement attack. Thus, activation of the ...

  18. Evolution of the complement system.

    Science.gov (United States)

    Nonaka, Masaru

    2014-01-01

    The mammalian complement system constitutes a highly sophisticated body defense machinery comprising more than 30 components. Research into the evolutionary origin of the complement system has identified a primitive version composed of the central component C3 and two activation proteases Bf and MASP in cnidaria. This suggests that the complement system was established in the common ancestor of eumetazoa more than 500 million years ago. The original activation mechanism of the original complement system is believed to be close to the mammalian lectin and alternative activation pathways, and its main role seems to be opsonization and induction of inflammation. This primitive complement system has been retained by most deuterostomes without major change until the appearance of jawed vertebrates. At this stage, duplication of the C3, Bf and MASP genes as well as recruitment of membrane attack components added the classical and lytic pathways to the primitive complement system, converting it to the modern complement system. In contrast, the complement system was lost multiple times independently in the protostome lineage.

  19. An Approach to Detect Malicious Behaviors by Evading Stalling Code

    OpenAIRE

    Chao Dai; Xiaonan Liu; Chao You; Yichi Zhang; Jianmin Pang

    2012-01-01

    Since malwares contain stalling codes, malicious behaviors can’t be detected in emulated analysis environment. This paper proposes an approach to detect malicious behaviors by evade stalling codes. First, we executed a malware in the emulated analysis environment, and saved every executed instruction in a trace file; Second, we began to detect stalling codes with the trace file, and constructed stalling code evasive points; At last, we executed the malware again and evade stalling codes with ...

  20. Heart Attack

    Science.gov (United States)

    Each year almost 800,000 Americans have a heart attack. A heart attack happens when blood flow to the heart suddenly ... it's important to know the symptoms of a heart attack and call 9-1-1 if you or ...

  1. Attack surfaces

    DEFF Research Database (Denmark)

    Gruschka, Nils; Jensen, Meiko

    2010-01-01

    The new paradigm of cloud computing poses severe security risks to its adopters. In order to cope with these risks, appropriate taxonomies and classification criteria for attacks on cloud computing are required. In this work-in-progress paper we present one such taxonomy based on the notion...... of attack surfaces of the cloud computing scenario participants....

  2. Täna algavad Eesti Muusika Päevad

    Index Scriptorium Estoniae

    2004-01-01

    Eesti Muusika Päevade raames toimunud üritustest 21. aprillini: ERSO sümfooniakontserdist Estonia kontserdisaalis, Jüri Reinvere radiofoonilise ooperi "Vastaskallas" esiettekandest Tallinna Linnateatri Hobuveski saalis, kontserdist Kunstihoone Vabaduse väljakul (esitusel Urmas Sisaski uus "Tähistaeva tsükkel" - "Eesti rahvataevas"), lastekontserdist "Kodumaine viis" Estonia kontserdisaalis

  3. Kallikrein Cleaves C3 and Activates Complement.

    Science.gov (United States)

    Irmscher, Sarah; Döring, Nadia; Halder, Luke D; Jo, Emeraldo A H; Kopka, Isabell; Dunker, Christine; Jacobsen, Ilse D; Luo, Shanshan; Slevogt, Hortense; Lorkowski, Stefan; Beyersdorf, Niklas; Zipfel, Peter F; Skerka, Christine

    2017-12-14

    The human plasma contact system is an immune surveillance system activated by the negatively charged surfaces of bacteria and fungi and includes the kallikrein-kinin, the coagulation, and the fibrinolytic systems. Previous work shows that the contact system also activates complement, and that plasma enzymes like kallikrein, plasmin, thrombin, and FXII are involved in the activation process. Here, we show for the first time that kallikrein cleaves the central complement component C3 directly to yield active components C3b and C3a. The cleavage site within C3 is identical to that recognized by the C3 convertase. Also, kallikrein-generated C3b forms C3 convertases, which trigger the C3 amplification loop. Since kallikrein also cleaves factor B to yield Bb and Ba, kallikrein alone can trigger complement activation. Kallikrein-generated C3 convertases are inhibited by factor H; thus, the kallikrein activation pathway merges with the amplification loop of the alternative pathway. Taken together, these data suggest that activation of the contact system locally enhances complement activation on cell surfaces. The human pathogenic microbe Candida albicans activates the contact system in normal human serum. However, C. albicans immediately recruits factor H to the surface, thereby evading the alternative and likely kallikrein-mediated complement pathways. © 2017 S. Karger AG, Basel.

  4. The role of complement receptors type 1 (CR1, CD35) and 2 (CR2, CD21) in promoting C3 fragment deposition and membrane attack complex formation on normal peripheral human B cells

    DEFF Research Database (Denmark)

    Nielsen, Claus Henrik; Pedersen, Morten Løbner; Marquart, Hanne Vibeke

    2002-01-01

    a subsidiary role. In this study, we examine the relative contributions of CR1 and CR2 to the deposition of C3 fragments and MAC on B lymphocytes under circumstances where all complement pathways are operational. C3-fragment deposition and MAC formation were assessed on human peripheral B lymphocytes...... in significant reduction of both C3-fragment deposition (22.0+/-14.5%) and MAC formation (47.4+/-13.8%). Both the lack of CR2 influence on MAC formation and the promotion of C3-fragment deposition by CR1 are in striking contrast to the situation where only the AP is operational. The presence of erythrocytes (E...

  5. Complement component 4

    Science.gov (United States)

    ... certain protein. This protein is part of the complement system. The complement system is a group of proteins that move freely ... a role in the development of inflammation. The complement system protects the body from infections, dead cells and ...

  6. Heart Attack

    Science.gov (United States)

    ... pain Fatigue Heart attack Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  7. Heart attack

    Science.gov (United States)

    ... heart attack. A stent is a small, metal mesh tube that opens up (expands) inside a coronary ... e228. PMID: 25260718 www.ncbi.nlm.nih.gov/pubmed/25260718 . Anderson JL. ST segment elevation acute myocardial ...

  8. Borrelia recurrentis employs a novel multifunctional surface protein with anti-complement, anti-opsonic and invasive potential to escape innate immunity.

    Directory of Open Access Journals (Sweden)

    Sonja Grosskinsky

    Full Text Available Borrelia recurrentis, the etiologic agent of louse-borne relapsing fever in humans, has evolved strategies, including antigenic variation, to evade immune defence, thereby causing severe diseases with high mortality rates. Here we identify for the first time a multifunctional surface lipoprotein of B. recurrentis, termed HcpA, and demonstrate that it binds human complement regulators, Factor H, CFHR-1, and simultaneously, the host protease plasminogen. Cell surface bound factor H was found to retain its activity and to confer resistance to complement attack. Moreover, ectopic expression of HcpA in a B. burgdorferi B313 strain, deficient in Factor H binding proteins, protected the transformed spirochetes from complement-mediated killing. Furthermore, HcpA-bound plasminogen/plasmin endows B. recurrentis with the potential to resist opsonization and to degrade extracellular matrix components. Together, the present study underscores the high virulence potential of B. recurrentis. The elucidation of the molecular basis underlying the versatile strategies of B. recurrentis to escape innate immunity and to persist in human tissues, including the brain, may help to understand the pathological processes underlying louse-borne relapsing fever.

  9. The Complement System

    OpenAIRE

    Sarma, J. Vidya; Ward, Peter A.

    2010-01-01

    The complement system consists of a tightly regulated network of proteins that play an important role in host defense and inflammation. Complement activation results in opsonization of pathogens and their removal by phagocytes, as well as cell lysis. Inappropriate complement activation and complement deficiencies are the underlying cause of the pathophysiology of many diseases such as systemic lupus erythematosus and asthma. This review represents an overview of the complement system in an ef...

  10. About Heart Attacks

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More About Heart Attacks Updated:Jan 27,2017 A heart attack is ... coronary artery damage leads to a heart attack . Heart Attack Questions and Answers What is a heart attack? ...

  11. Molecular interplay between bacteria and the terminal complement pathway

    NARCIS (Netherlands)

    Berends, E.T.M.

    2015-01-01

    The plasma proteins of the complement system fulfill important immune defense functions, including opsonization of bacteria for phagocytosis, generation of chemo-attractants and direct bacterial killing via assembly of the Membrane Attack Complex (MAC or C5b-9 complex). The terminal complement

  12. The role of the complement system in cancer.

    Science.gov (United States)

    Afshar-Kharghan, Vahid

    2017-03-01

    In addition to being a component of innate immunity and an ancient defense mechanism against invading pathogens, complement activation also participates in the adaptive immune response, inflammation, hemostasis, embryogenesis, and organ repair and development. Activation of the complement system via classical, lectin, or alternative pathways generates anaphylatoxins (C3a and C5a) and membrane attack complex (C5b-9) and opsonizes targeted cells. Complement activation end products and their receptors mediate cell-cell interactions that regulate several biological functions in the extravascular tissue. Signaling of anaphylatoxin receptors or assembly of membrane attack complex promotes cell dedifferentiation, proliferation, and migration in addition to reducing apoptosis. As a result, complement activation in the tumor microenvironment enhances tumor growth and increases metastasis. In this Review, I discuss immune and nonimmune functions of complement proteins and the tumor-promoting effect of complement activation.

  13. Complement system in zebrafish.

    Science.gov (United States)

    Zhang, Shicui; Cui, Pengfei

    2014-09-01

    Zebrafish is recently emerging as a model species for the study of immunology and human diseases. Complement system is the humoral backbone of the innate immune defense, and our knowledge as such in zebrafish has dramatically increased in the recent years. This review summarizes the current research progress of zebrafish complement system. The global searching for complement components in genome database, together with published data, has unveiled the existence of all the orthologues of mammalian complement components identified thus far, including the complement regulatory proteins and complement receptors, in zebrafish. Interestingly, zebrafish complement components also display some distinctive features, such as prominent levels of extrahepatic expression and isotypic diversity of the complement components. Future studies should focus on the following issues that would be of special importance for understanding the physiological role of complement components in zebrafish: conclusive identification of complement genes, especially those with isotypic diversity; analysis and elucidation of function and mechanism of complement components; modulation of innate and adaptive immune response by complement system; and unconventional roles of complement-triggered pathways. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. The secreted Candida albicans protein Pra1 disrupts host defense by broadly targeting and blocking complement C3 and C3 activation fragments.

    Science.gov (United States)

    Luo, Shanshan; Dasari, Prasad; Reiher, Nadine; Hartmann, Andrea; Jacksch, Susanne; Wende, Elisabeth; Barz, Dagmar; Niemiec, Maria Joanna; Jacobsen, Ilse; Beyersdorf, Niklas; Hünig, Thomas; Klos, Andreas; Skerka, Christine; Zipfel, Peter F

    2018-01-01

    Candida albicans the most frequently isolated clinical fungal pathogen can cause local as well as systemic and life-threatening infections particularly in immune-compromised individuals. A better and more detailed understanding how C. albicans evades human immune attack is therefore needed for identifying fungal immune-evasive proteins and develop new therapies. Here, we identified Pra1, the pH-regulated C. albicans antigen as a hierarchical complement inhibitor that targets C3, the central human complement component. Pra1 cleaved C3 at a unique site and further inhibited effector function of the activation fragments. The newly formed C3a-like peptide lacked the C-terminal arginine residue needed for C3a-receptor binding and activation. Moreover, Pra1 also blocked C3a-like antifungal activity as shown in survival assays, and the C3b-like molecule formed by Pra1 was degraded by the host protease Factor I. Pra1 also bound to C3a and C3b generated by human convertases and blocked their effector functions, like C3a antifungal activity shown by fungal survival, blocked C3a binding to human C3a receptor-expressing HEK cells, activation of Fura2-AM loaded cells, intracellular Ca2+ signaling, IL-8 release, C3b deposition, as well as opsonophagocytosis and killing by human neutrophils. Thus, upon infection C. albicans uses Pra1 to destroy C3 and to disrupt host complement attack. In conclusion, candida Pra1 represents the first fungal C3-cleaving protease identified and functions as a fungal master regulator of innate immunity and as a central fungal immune-escape protein. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Pyoverdine, the Major Siderophore in Pseudomonas aeruginosa, Evades NGAL Recognition

    Directory of Open Access Journals (Sweden)

    Mary E. Peek

    2012-01-01

    Full Text Available Pseudomonas aeruginosa is the most common pathogen that persists in the cystic fibrosis lungs. Bacteria such as P. aeruginosa secrete siderophores (iron-chelating molecules and the host limits bacterial growth by producing neutrophil-gelatinase-associated lipocalin (NGAL that specifically scavenges bacterial siderophores, therefore preventing bacteria from establishing infection. P. aeruginosa produces a major siderophore known as pyoverdine, found to be important for bacterial virulence and biofilm development. We report that pyoverdine did not bind to NGAL, as measured by tryptophan fluorescence quenching, while enterobactin bound to NGAL effectively causing a strong response. The experimental data indicate that pyoverdine evades NGAL recognition. We then employed a molecular modeling approach to simulate the binding of pyoverdine to human NGAL using NGAL’s published crystal structures. The docking of pyoverdine to NGAL predicted nine different docking positions; however, neither apo- nor ferric forms of pyoverdine docked into the ligand-binding site in the calyx of NGAL where siderophores are known to bind. The molecular modeling results offer structural support that pyoverdine does not bind to NGAL, confirming the results obtained in the tryptophan quenching assay. The data suggest that pyoverdine is a stealth siderophore that evades NGAL recognition allowing P. aeruginosa to establish chronic infections in CF lungs.

  16. Back-action Evading Measurements of a Nanomechanical Resonator

    Science.gov (United States)

    Ndukum, Tchefor; Rocheleau, Tristan; Schwab, Keith

    2010-03-01

    By driving a 5GHz superconducting, co-planar waveguide (CPW) resonator coupled to a radio-frequency nanomechanical resonator with both red and blue-detuned, phase coherent microwave signals, we have demonstrated amplifier noise back-action evading (BAE) detection of one quadrature of nanomechanical motion. With this quantum non-demolition (QND) scheme we have shown precise measurements of a single motional quadrature with additive measurement noise of 4 times the zero point amplitude, and a reduction in sensitivity to injected measurement noise of a factor of 43 in comparison to a single tone, non-BAE measurement. By increasing the CPW frequency to 7.5GHz, quadrupling the coupling strength and improving the (internal) quality factor of the CPW, we expect to be able to demonstrate sensitivity to one quadrature with additive measurement noise below the zero-point level, a necessary ingredient to produce and measure squeezed states of motion.

  17. Back action evading quantum limited measurements of a nanomechanical resonator

    Science.gov (United States)

    Ndukum, Tchefor; Rocheleau, Tristan; Hertzberg, Jared; Schwab, Keith

    2009-03-01

    By driving a 5GHz superconducting, co-planar waveguide (CPW) resonator coupled to a radio-frequency nanomechanical resonator with both red- and blue-detuned, phase coherent microwave signals, we demonstrate amplifier noise back action evading(BAE) detection of one quadrature of nanomechanical motion. With this method we show precise measurements of a single motional quadrature with additive measurement noise of 4 times the zero point amplitude, and a reduction in sensitivity to injected measurement noise of a factor of 43 in comparison to a single tone, non-BAE measurement. We have also found a parametric instability which limits the coupling strength possible in our device, which will be described elsewhere. With straightforward improvements to the microwave resonator, we expect to be able to demonstrate sensitivity to one quadrature with additive measurement noise below the zero-point level, a necessary ingredient to produce and measure squeezed states of motion.

  18. Polyphosphate suppresses complement via the terminal pathway.

    Science.gov (United States)

    Wat, Jovian M; Foley, Jonathan H; Krisinger, Michael J; Ocariza, Linnette Mae; Lei, Victor; Wasney, Gregory A; Lameignere, Emilie; Strynadka, Natalie C; Smith, Stephanie A; Morrissey, James H; Conway, Edward M

    2014-01-30

    Polyphosphate, synthesized by all cells, is a linear polymer of inorganic phosphate. When released into the circulation, it exerts prothrombotic and proinflammatory activities by modulating steps in the coagulation cascade. We examined the role of polyphosphate in regulating the evolutionarily related proteolytic cascade complement. In erythrocyte lysis assays, polyphosphate comprising more than 1000 phosphate units suppressed total hemolytic activity with a concentration to reduce maximal lysis to 50% that was 10-fold lower than with monophosphate. In the ion- and enzyme-independent terminal pathway complement assay, polyphosphate suppressed complement in a concentration- and size-dependent manner. Phosphatase-treated polyphosphate lost its ability to suppress complement, confirming that polymer integrity is required. Sequential addition of polyphosphate to the terminal pathway assay showed that polyphosphate interferes with complement only when added before formation of the C5b-7 complex. Physicochemical analyses using native gels, gel filtration, and differential scanning fluorimetry revealed that polyphosphate binds to and destabilizes C5b,6, thereby reducing the capacity of the membrane attack complex to bind to and lyse the target cell. In summary, we have added another function to polyphosphate in blood, demonstrating that it dampens the innate immune response by suppressing complement. These findings further establish the complex relationship between coagulation and innate immunity.

  19. Malaria parasite evasion of classical complement pathway attack

    DEFF Research Database (Denmark)

    Larsen, Mads Delbo; Ditlev, Sisse; Olmos, Rafael Bayarri

    2017-01-01

    Background: The most severe form of malaria is caused by the intraerythrocytic protozoan parasite Plasmodium falciparum. The parasite exports multiple proteins to the erythrocyte membrane, including members of the protein family P. falciparum erythrocyte membrane protein 1 (PfEMP-1). Expression...

  20. Can Nondeterminism Help Complementation?

    Directory of Open Access Journals (Sweden)

    Yang Cai

    2012-10-01

    Full Text Available Complementation and determinization are two fundamental notions in automata theory. The close relationship between the two has been well observed in the literature. In the case of nondeterministic finite automata on finite words (NFA, complementation and determinization have the same state complexity, namely Theta(2^n where n is the state size. The same similarity between determinization and complementation was found for Buchi automata, where both operations were shown to have 2^Θ(n lg n state complexity. An intriguing question is whether there exists a type of omega-automata whose determinization is considerably harder than its complementation. In this paper, we show that for all common types of omega-automata, the determinization problem has the same state complexity as the corresponding complementation problem at the granularity of 2^Θ(..

  1. Complement activation, endothelial dysfunction, insulin resistance and chronic heart failure

    DEFF Research Database (Denmark)

    Bjerre, M.; Kistorp, C.; Hansen, T.K.

    2010-01-01

    , IR was an independent predictor of sMAC in the CHF group beta = 0.37 (p complement system and thus......Objectives. Patients with chronic heart failure (CHF) have an exaggerated immune response, endothelial damage/dysfunction, and increased risk of diabetes mellitus (DM). The inter-relationship(s) between indices of complement activation (soluble membrane attack complex, sMAC), inflammation (hs...

  2. Complement factor H in host defense and immune evasion.

    Science.gov (United States)

    Parente, Raffaella; Clark, Simon J; Inforzato, Antonio; Day, Anthony J

    2017-05-01

    Complement is the major humoral component of the innate immune system. It recognizes pathogen- and damage-associated molecular patterns, and initiates the immune response in coordination with innate and adaptive immunity. When activated, the complement system unleashes powerful cytotoxic and inflammatory mechanisms, and thus its tight control is crucial to prevent damage to host tissues and allow restoration of immune homeostasis. Factor H is the major soluble inhibitor of complement, where its binding to self markers (i.e., particular glycan structures) prevents complement activation and amplification on host surfaces. Not surprisingly, mutations and polymorphisms that affect recognition of self by factor H are associated with diseases of complement dysregulation, such as age-related macular degeneration and atypical haemolytic uremic syndrome. In addition, pathogens (i.e., non-self) and cancer cells (i.e., altered-self) can hijack factor H to evade the immune response. Here we review recent (and not so recent) literature on the structure and function of factor H, including the emerging roles of this protein in the pathophysiology of infectious diseases and cancer.

  3. The Emerging Role of Complement Lectin Pathway in Trypanosomatids: Molecular Bases in Activation, Genetic Deficiencies, Susceptibility to Infection, and Complement System-Based Therapeutics

    Directory of Open Access Journals (Sweden)

    Ingrid Evans-Osses

    2013-01-01

    Full Text Available The innate immune system is evolutionary and ancient and is the pivotal line of the host defense system to protect against invading pathogens and abnormal self-derived components. Cellular and molecular components are involved in recognition and effector mechanisms for a successful innate immune response. The complement lectin pathway (CLP was discovered in 1990. These new components at the complement world are very efficient. Mannan-binding lectin (MBL and ficolin not only recognize many molecular patterns of pathogens rapidly to activate complement but also display several strategies to evade innate immunity. Many studies have shown a relation between the deficit of complement factors and susceptibility to infection. The recently discovered CLP was shown to be important in host defense against protozoan microbes. Although the recognition of pathogen-associated molecular patterns by MBL and Ficolins reveal efficient complement activations, an increase in deficiency of complement factors and diversity of parasite strategies of immune evasion demonstrate the unsuccessful effort to control the infection. In the present paper, we will discuss basic aspects of complement activation, the structure of the lectin pathway components, genetic deficiency of complement factors, and new therapeutic opportunities to target the complement system to control infection.

  4. Complement component 3 (C3)

    Science.gov (United States)

    ... certain protein. This protein is part of the complement system. The complement system is a group of proteins that move freely ... a role in the development of inflammation. The complement system protects the body from infections, dead cells and ...

  5. Bacterial self-defence: how Escherichia coli evades serum killing.

    Science.gov (United States)

    Miajlovic, Helen; Smith, Stephen G

    2014-05-01

    The ability to survive the bactericidal action of serum is advantageous to extraintestinal pathogenic Escherichia coli that gain access to the bloodstream. Evasion of the innate defences present in serum, including complement and antimicrobial peptides, involves multiple factors. Serum resistance mechanisms utilized by E. coli include the production of protective extracellular polysaccharide capsules and expression of factors that inhibit or interfere with the complement cascade. Recent studies have also highlighted the importance of structural integrity of the cell envelope in serum survival. These survival strategies are outlined in this review with particular attention to novel findings and recent insights into well-established resistance mechanisms. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  6. Complementing the sugar code: role of GAGs and sialic acid in complement regulation

    Directory of Open Access Journals (Sweden)

    Alex eLangford-Smith

    2015-02-01

    Full Text Available Sugar molecules play a vital role on both microbial and mammalian cells, where they are involved in cellular communication, govern microbial virulence and modulate host immunity and inflammatory responses. The complement cascade, as part of a host’s innate immune system, is a potent weapon against invading bacteria but has to be tightly regulated to prevent inappropriate attack and damage to host tissues. A number of complement regulators, such as factor H and properdin, interact with sugar molecules, such as glycosaminoglycans and sialic acid, on host and pathogen membranes and direct the appropriate complement response by either promoting the binding of complement activators or inhibitors. The binding of these complement regulators to sugar molecules can vary from location to location, due to their different specificities and because distinct structural and functional subpopulations of sugars are found in different human organs, such as the brain, kidney and eye. This review will cover recent studies that have provided important new insights into the role of glycosaminoglycans and sialic acid in complement regulation and how sugar recognition may be compromised in disease

  7. The role of the complement system in diabetic nephropathy

    DEFF Research Database (Denmark)

    Flyvbjerg, Allan

    2017-01-01

    -threatening disease. An increasing body of evidence points toward a role of the complement system in the pathogenesis of diabetic nephropathy. For example, circulating levels of mannose-binding lectin (MBL), a pattern recognition molecule of the innate immune system, have emerged as a robust biomarker...... for the development and progression of this disease, and evidence suggests that MBL, H-ficolin, complement component C3 and the membrane attack complex might contribute to renal injury in the hyperglycaemic mileu. New approaches to modulate the complement system might lead to the development of new agents to prevent...

  8. Sissejuhatus Tubinasse : Marianne Kõrveri "Äraoldud päevade summa" / Tõnu Karjatse

    Index Scriptorium Estoniae

    Karjatse, Tõnu

    2005-01-01

    Muusikaline dokumentaalfilm "Äraoldud päevade summa" helilooja Eduard Tubinast : stsenarist ja tekstide autor Jüri Reinvere : režissöör Marianne Kõrver : Exitfilm - Eesti Televisioon - SVT (Rootsi)

  9. Tartu Kevadpäevad 2008 : Nädalajagu muusikat igale maitsele / Signe Tamberg

    Index Scriptorium Estoniae

    Tamberg, Signe

    2008-01-01

    Tartu Kevadpäevad 2008 muusikaprogrammis: 34. tudengilaulu võistlusest 29. apr. Tartu Sadamateatris, öölaulupeost 28. apr. Kassitoome orus, kontsertidest "Rokime!" 2. mail ja "Folgime" 3. mail Raekoja platsil

  10. Linear Pursuit Differential Game under Phase Constraint on the State of Evader

    Directory of Open Access Journals (Sweden)

    Askar Rakhmanov

    2016-01-01

    Full Text Available We consider a linear pursuit differential game of one pursuer and one evader. Controls of the pursuer and evader are subjected to integral and geometric constraints, respectively. In addition, phase constraint is imposed on the state of evader, whereas pursuer moves throughout the space. We say that pursuit is completed, if inclusion y(t1-x(t1∈M is satisfied at some t1>0, where x(t and y(t are states of pursuer and evader, respectively, and M is terminal set. Conditions of completion of pursuit in the game from all initial points of players are obtained. Strategy of the pursuer is constructed so that the phase vector of the pursuer first is brought to a given set, and then pursuit is completed.

  11. Uudised : Voices of Europe tuleb Pärdi teosega. Puhkpillipäevad Võrus / Ingrid Peek

    Index Scriptorium Estoniae

    Peek, Ingrid

    2000-01-01

    1. sept. Tallinnas Kaarli kirikus toimuvast kontserdist, kus tuleb ettekandele Pärdi teos "Which was the son of...". 15. aug. avatakse Võrus V noorte puhkpillimängijate suvekool ja Võru vaskpillipäevad

  12. Eesti Suusapäevad Jay Peak´is / Peeter Teedla ; fotod: Peeter Teedla

    Index Scriptorium Estoniae

    Teedla, Peeter

    2006-01-01

    märtsikuu esimesel nädalalõpul idaranniku eestlaste suusapäevad, osavõtjaid 156, paljud perekondade ja väikeste lastega, organiseerijaks Kristin Raamot. Peeti murdmaasuusatamise - ja slaalomivõistlused

  13. Symmetric Complementation. Revision

    Science.gov (United States)

    1981-01-01

    has efficient decision algorithms if the machine is both space and complementation bounded. Michael Sipser has also suggested an equivalent machine...Vassos Hadzilacos, Joe Halpern, Harry Lewis, A. Prasad, Michael Sipser , and Paul Spirakis for a careful reading and many useful comnents on

  14. [Case of law-evading herbs poisoning that induced shock and myocardial damage].

    Science.gov (United States)

    Nakamura, Yoshihiko; Nakano, Minoru; Nakamura, Mitsunobu; Miyazaki, Dai; Okamori, Satoshi; Akuzawa, Hisashi; Yuasa, Masahiro

    2014-12-01

    Law-evading herbs may induce poisoning symptoms, especially when they contain synthetic cannabinoids. However, their detailed pharmacological effects have not yet been clarified. Some reports have previously described symptoms of poisoning, but only a few reports have so far described shock and myocardial damage (MD). We experienced a case of shock and MD in a patient who had smoked law-evading herbs. A 61-year-old male presented at an emergency department 8 hours after smoking law-evading herbs (Rush Trip, High Men Monster) with chest pain. A vasopressor agent was administered to treat shock and antiarrhythmic drugs were administered due to ventricular arrhythmia. The contents of the law-evading herbs were unknown, so an in-hospital follow-up was conducted to treat the patient's symptoms. The follow-up blood test showed an increased level of cardiac enzymes, which thereafter demonstrated a spontaneous remission. The systemic conditions tended to improve and the patient was discharged from the hospital on the 5th hospital day. The contents of the law-evading herbs in question were thereafter,analyzed, and synthetic cannabinoids (JWH-210, JWH-081 and JWH-122) as well as caffeine were detected. The cause for the poisoning symptoms were suspected to be the presence of synthetic cannabinoids and caffeine. Such law-evading herbs may contain synthetic cannabinoids and caffeine which both may induce shock and MD.

  15. How Escherichia coli Circumvent Complement-Mediated Killing

    Directory of Open Access Journals (Sweden)

    Angela S. Barbosa

    2017-04-01

    Full Text Available Complement is a crucial arm of the innate immune response against invading bacterial pathogens, and one of its main functions is to recognize and destroy target cells. Similar to other pathogens, Escherichia coli has evolved mechanisms to overcome complement activation. It is well known that capsular polysaccharide may confer resistance to complement-mediated killing and phagocytosis, being one of the strategies adopted by this bacterium to survive in serum. In addition, proteases produced by E. coli have been shown to downregulate the complement system. Pic, an autotransporter secreted by different pathogens in the Enterobacteriaceae family, is able to cleave C2, C3/C3b, and C4/C4b and works synergistically with human Factor I and Factor H (FH, thereby promoting inactivation of C3b. Extracellular serine protease P, a serine protease of enterohemorrhagic E. coli (EHEC, downregulates complement activation by cleaving C3/C3b and C5. StcE, a metalloprotease secreted by EHEC, inhibits the classical complement-mediated cell lysis by potentiating the action of C1 inhibitor, and the periplasmic protease Prc contributes to E. coli complement evasion by interfering with the classical pathway activation and by preventing membrane attack complex deposition. Finally, it has been described that E. coli proteins interact with negative complement regulators to modulate complement activation. The functional consequences resulting from the interaction of outer membrane protein A, new lipoprotein I, outer membrane protein W, and Stx2 with proteins of the FH family and C4b-binding protein (C4BP are discussed in detail. In brief, in this review, we focused on the different mechanisms used by pathogenic E. coli to circumvent complement attack, allowing these bacteria to promote a successful infection.

  16. Solidarity under Attack

    DEFF Research Database (Denmark)

    Meret, Susi; Goffredo, Sergio

    2017-01-01

    https://www.opendemocracy.net/can-europe-make-it/susi-meret-sergio-goffredo/solidarity-under-attack......https://www.opendemocracy.net/can-europe-make-it/susi-meret-sergio-goffredo/solidarity-under-attack...

  17. Social engineering attack framework

    CSIR Research Space (South Africa)

    Mouton, F

    2014-07-01

    Full Text Available link. A social engineering attack targets this weakness by; using various manipulation techniques in order to elicit sensitive; information. The field of social engineering is still in its infancy; stages with regards to formal definitions and attack...

  18. Pericarditis - after heart attack

    Science.gov (United States)

    ... include: A previous heart attack Open heart surgery Chest trauma A heart attack that has affected the thickness of your heart muscle Symptoms Symptoms include: Anxiety Chest pain from the swollen pericardium rubbing on the ...

  19. Heart attack first aid

    Science.gov (United States)

    First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... A heart attack occurs when the blood flow that carries oxygen to the heart is blocked. The heart muscle ...

  20. Transient Ischemic Attack

    Medline Plus

    Full Text Available ... Ischemic Attack TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an artery for a short time. The only difference between a stroke ...

  1. Analysis of the complement sensitivity of oral treponemes and the potential influence of FH binding, FH cleavage and dentilisin activity on the pathogenesis of periodontal disease.

    Science.gov (United States)

    Miller, D P; McDowell, J V; Bell, J K; Goetting-Minesky, M P; Fenno, J C; Marconi, R T

    2014-10-01

    Treponema denticola, a periopathogen, evades complement-mediated killing by binding the negative complement regulatory protein factor H (FH) to its surface via the FhbB protein. Paradoxically, bound FH is cleaved by T. denticola's dentilisin protease, a process hypothesized to trigger localized dysregulation of complement activation in periodontal pockets. The ability of other oral treponemes to evade complement-mediated killing and bind and cleave FH has not been assessed. In this report, we demonstrate that representative isolates of Treponema socranskii, Treponema medium, Treponema pectinovorum and Treponema maltophilum are also serum resistant, whereas Treponema vincentii and Treponema amylovorum are serum sensitive. Although T. denticola's ability to evade complement-mediated killing is strictly dependent on FH binding, other serum-resistant treponemal species lack FhbB and do not bind FH, indicating an FH-independent mechanism of complement evasion. To assess the influence of FhbB sequence variation on FH binding and cleavage by T. denticola, fhbB sequences were determined for 30 isolates. Three distinct phyletic types were identified. All T. denticola strains bound FH and were serum resistant, but differences in binding kinetics, dentilisin activity and FH cleavage ability were observed. Based on these analyses, we hypothesize that the composition of the T. denticola population is a determining factor that influences the progression and severity of periodontal disease. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Role of complement in in vitro and in vivo lung inflammatory reactions

    DEFF Research Database (Denmark)

    Czermak, B J; Lentsch, A B; Bless, N M

    1998-01-01

    Complement is one of the integral buttresses of the inflammatory response. In addition to host defense activities, proinflammatory properties of several complement components are described. This overview elucidates the role of complement in inflammatory reactions in vitro and in vivo, focusing...... on the complement activation products, C5a, and the membrane attack complex, C5b-9. Using several approaches, the impact of these complement components in mechanisms relevant to neutrophil recruitment is emphasized. In addition, the participation of complement in endothelial superoxide generation and its essential...... requirement for full expression of lung injury is demonstrated, as are the involved intracellular signal transduction pathways. Understanding the mechanisms of complement-induced proinflammatory effects may provide a basis for future therapeutic blockade of complement and/or its activation products....

  3. Complement susceptibility in glutamine deprived breast cancer cells

    Directory of Open Access Journals (Sweden)

    Boackle Robert J

    2007-07-01

    Full Text Available Abstract Background Membrane complement regulatory proteins (mCRPs inhibit complement-mediated killing of human cells by human complement, a property that confers protection from complement to malignant breast cancer cells and that thwarts some immunotherapies. Metabolic mechanisms may come into play in protecting cancer cells from the complement system subsequent to relatively low levels of complement deposition. Results In differentiating these mechanisms, two types of human breast cancer cell lines, MCF7 (adenocarcinoma and Bcap37 (medullary carcinoma were cell-cycle synchronized using glutamine-deprivation followed by restoration. These cells were examined for the expression of two mCRPs (CD59 and CD55, and for subsequent susceptibility to antibody-mediated complement-induced membrane damage. After glutamine restoration, MCF7 and Bcap37 cells were synchronized into the G2/M phase and an average increased expression of CD59 and CD55 occurred with a corresponding resistance to complement-mediated damage. Blocking CD59 inhibitory function with monoclonal antibody revealed that CD59 played a key role in protecting unsynchronized Bcap37 and MCF7 cancer cells from the complement membrane attack complex. Interestingly, glutamine-deprivation did not significantly affect the expression of proteins e.g., the surface level of CD59 or CD55, but did increase the susceptibility to complement-mediated killing. One possible explanation is that glutamine-deprivation may have slowed the turnover rate of mCRPs, preventing the cells from replacing pre-existing mCRPs, as they became neutralized by covalent C4b and C3b depositions. Conclusion Taken together the findings are consistent with the conclusion that future immunotherapies should aim to achieve a highly specific and profound activation and deposition of complement as well as to disrupt the synthesis and expression of CD59 and CD55 by the cancer cells.

  4. Pseudomonas aeruginosa alkaline protease blocks complement activation via the classical and lectin pathways.

    Science.gov (United States)

    Laarman, Alexander J; Bardoel, Bart W; Ruyken, Maartje; Fernie, Job; Milder, Fin J; van Strijp, Jos A G; Rooijakkers, Suzan H M

    2012-01-01

    The complement system rapidly detects and kills Gram-negative bacteria and supports bacterial killing by phagocytes. However, bacterial pathogens exploit several strategies to evade detection by the complement system. The alkaline protease (AprA) of Pseudomonas aeruginosa has been associated with bacterial virulence and is known to interfere with complement-mediated lysis of erythrocytes, but its exact role in bacterial complement escape is unknown. In this study, we analyzed how AprA interferes with complement activation and whether it could block complement-dependent neutrophil functions. We found that AprA potently blocked phagocytosis and killing of Pseudomonas by human neutrophils. Furthermore, AprA inhibited opsonization of bacteria with C3b and the formation of the chemotactic agent C5a. AprA specifically blocked C3b deposition via the classical and lectin pathways, whereas the alternative pathway was not affected. Serum degradation assays revealed that AprA degrades both human C1s and C2. However, repletion assays demonstrated that the mechanism of action for complement inhibition is cleavage of C2. In summary, we showed that P. aeruginosa AprA interferes with classical and lectin pathway-mediated complement activation via cleavage of C2.

  5. Material properties in complement activation

    DEFF Research Database (Denmark)

    Moghimi, S. Moein; Andersen, Alina Joukainen; Ahmadvand, Davoud

    2011-01-01

    Uncontrolled complement activation can induce many inflammatory and life threatening conditions. Accordingly, the role of complement in initiation of adverse reactions to polymers and nanoparticulate drug carriers is receiving increasing attention and has prompted extensive ‘structure-immune perf......Uncontrolled complement activation can induce many inflammatory and life threatening conditions. Accordingly, the role of complement in initiation of adverse reactions to polymers and nanoparticulate drug carriers is receiving increasing attention and has prompted extensive ‘structure...

  6. Composite Dos Attack Model

    Directory of Open Access Journals (Sweden)

    Simona Ramanauskaitė

    2012-04-01

    Full Text Available Preparation for potential threats is one of the most important phases ensuring system security. It allows evaluating possible losses, changes in the attack process, the effectiveness of used countermeasures, optimal system settings, etc. In cyber-attack cases, executing real experiments can be difficult for many reasons. However, mathematical or programming models can be used instead of conducting experiments in a real environment. This work proposes a composite denial of service attack model that combines bandwidth exhaustion, filtering and memory depletion models for a more real representation of similar cyber-attacks. On the basis of the introduced model, different experiments were done. They showed the main dependencies of the influence of attacker and victim’s properties on the success probability of denial of service attack. In the future, this model can be used for the denial of service attack or countermeasure optimization.

  7. An Investigation Into Australian Personal Tax Evaders - Their Attitudes Towards Compliance And The Penalties For Non-Compliance

    National Research Council Canada - National Science Library

    Ken Devos

    2009-01-01

    .... This study investigates the relationship that exists between selected tax compliance variables and the attitudes and behaviour of Australian personal 'tax evaders' towards compliance and the penalties...

  8. Complementing Gender Analysis Methods.

    Science.gov (United States)

    Kumar, Anant

    2016-01-01

    The existing gender analysis frameworks start with a premise that men and women are equal and should be treated equally. These frameworks give emphasis on equal distribution of resources between men and women and believe that this will bring equality which is not always true. Despite equal distribution of resources, women tend to suffer and experience discrimination in many areas of their lives such as the power to control resources within social relationships, and the need for emotional security and reproductive rights within interpersonal relationships. These frameworks believe that patriarchy as an institution plays an important role in women's oppression, exploitation, and it is a barrier in their empowerment and rights. Thus, some think that by ensuring equal distribution of resources and empowering women economically, institutions like patriarchy can be challenged. These frameworks are based on proposed equality principle which puts men and women in competing roles. Thus, the real equality will never be achieved. Contrary to the existing gender analysis frameworks, the Complementing Gender Analysis framework proposed by the author provides a new approach toward gender analysis which not only recognizes the role of economic empowerment and equal distribution of resources but suggests to incorporate the concept and role of social capital, equity, and doing gender in gender analysis which is based on perceived equity principle, putting men and women in complementing roles that may lead to equality. In this article the author reviews the mainstream gender theories in development from the viewpoint of the complementary roles of gender. This alternative view is argued based on existing literature and an anecdote of observations made by the author. While criticizing the equality theory, the author offers equity theory in resolving the gender conflict by using the concept of social and psychological capital.

  9. Nocturnal panic attacks

    OpenAIRE

    Lopes Fabiana L.; Nardi Antonio E.; Nascimento Isabella; Valença Alexandre M.; Zin Walter A

    2002-01-01

    The panic-respiration connection has been presented with increasing evidences in the literature. We report three panic disorder patients with nocturnal panic attacks with prominent respiratory symptoms, the overlapping of the symptoms with the sleep apnea syndrome and a change of the diurnal panic attacks, from spontaneous to situational pattern. The implication of these findings and awareness to the distinct core of the nocturnal panic attacks symptoms may help to differentiate them from sle...

  10. Transient Ischemic Attack

    Medline Plus

    Full Text Available ... stroke symptoms. Popular Topics TIA Cardiac Catheter Cholesterol Heart Attack Stent © 2018, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. ...

  11. Seven Deadliest Network Attacks

    CERN Document Server

    Prowell, Stacy; Borkin, Mike

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting networks? Then you need Seven Deadliest Network Attacks. This book pinpoints the most dangerous hacks and exploits specific to networks, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks detailed in this book include: Denial of Service War Dialing Penetration "Testing" Protocol Tunneling Spanning Tree At

  12. Seven deadliest USB attacks

    CERN Document Server

    Anderson, Brian

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting USB technology? Then you need Seven Deadliest USB Attacks. This book pinpoints the most dangerous hacks and exploits specific to USB, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks detailed in this book include: USB Hacksaw USB Switchblade USB Based Virus/Malicous Code Launch USB Device Overflow RAMdum

  13. Seven Deadliest Microsoft Attacks

    CERN Document Server

    Kraus, Rob; Borkin, Mike; Alpern, Naomi

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting Microsoft products? Then you need Seven Deadliest Microsoft Attacks. This book pinpoints the most dangerous hacks and exploits specific to Microsoft applications, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Windows Operating System-Password AttacksActive Directory-Escalat

  14. Heart attack - discharge

    Science.gov (United States)

    ... attack Heart bypass surgery Heart bypass surgery - minimally invasive Heart pacemaker High blood cholesterol levels High blood pressure Implantable cardioverter-defibrillator Smoking - tips on how to ...

  15. Transient Ischemic Attack

    Medline Plus

    Full Text Available ... stroke symptoms. Popular Topics TIA Cardiac Catheter Cholesterol Heart Attack Stent © 2017, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. ...

  16. The hypervariable region of Streptococcus pyogenes M protein escapes antibody attack by antigenic variation and weak immunogenicity

    DEFF Research Database (Denmark)

    Lannergård, Jonas; Gustafsson, Caj Ulrik Mattias; Waldemarsson, Johan

    2011-01-01

    Sequence variation of antigenic proteins allows pathogens to evade antibody attack. The variable protein commonly includes a hypervariable region (HVR), which represents a key target for antibodies and is therefore predicted to be immunodominant. To understand the mechanism(s) of antibody evasion...

  17. Eesti Muusika Päevad 2000 : ECPNMi juhatus Tallinnas / Consuelo Diez ; interv. Evelin Kõrvits

    Index Scriptorium Estoniae

    Diez, Consuelo

    2000-01-01

    28.-30. apr. pidas Tallinnas aastakoosolekut ning külastas Eesti Muusika Päevade kontserte ECPNMi (European Conference of Promoters of New Music) juhatus. ECPNMi juhatuse liikmed räägivad uue muusika üritustest oma riikides, muljeid eesti muusika päevadelt

  18. Märtsipäevade valupisaraid peab lastele näitama / Anu Bollverk

    Index Scriptorium Estoniae

    Bollverk, Anu

    2009-01-01

    1949. aasta märtsiküüditamisele pühendatud mälestuspäevast Koeru kultuurimajas ning sealse huviteatri poolt ette kantud Herbert Lasti näidendist "Valupisarais märtsipäevad" (lavastajad Herbert Last ja Uno Aav)

  19. Eesti muusika päevad - üks kord aastas, kõigile / Jelena Gandshu

    Index Scriptorium Estoniae

    Gandshu, Jelena

    2008-01-01

    Muusikateadlased Jelena Gandshu ja Gerhard Lock, heliloojad Age Hirv ja Liis Jürgens 3.-10. aprillini toimunud Eesti muusika päevade kontsertidest: kinos Sõprus "Sensatsioon!!!", Kultuuritehases Polymer "Cellissimo", Estonia kontserdisaalis ERSO "Sümfoonilised hääled", Tallinna raekojas Mihkel Poll ja Oliver Kuusik, Katariina kirikus PaukenfEst, Nigulistes Jüri Reinvere autorikontsert. Järgneb

  20. Matemaatikaõpetajate pidupäevad Tartus / Viia Keeru, Tiit Lepmann

    Index Scriptorium Estoniae

    Keeru, Viia

    2009-01-01

    36. matemaatikaõpetajate päevadest, mis pühendati professor Olaf Prinitsa 85. sünniaastapäevale. Päevade lõpus selgusid tänavused professor G. Rägo nimelise medali laureaadid, kelle seas olid ka TLÜ Haapsalu Kolledži lektor Sirje Piht ja TLÜ matemaatika didaktika dotsent Madis Lepik

  1. Nüüdismuusika päevad pakuvad põnevat kuulamist

    Index Scriptorium Estoniae

    2005-01-01

    Pärnu nüüdismuusika päevade "Muusika ja arhitektuur" raames 20. jaan. esinevad loengutega Endla teatri sammassaalis arhitektid Veronika Valk ja Leonhard Lapin ning muusikateadlased Gerhard Lock ja Jaan Ross. Toivo Tulevi autorikontserdist Agape keskuses

  2. Complement system in lung disease.

    Science.gov (United States)

    Pandya, Pankita H; Wilkes, David S

    2014-10-01

    In addition to its established contribution to innate immunity, recent studies have suggested novel roles for the complement system in the development of various lung diseases. Several studies have demonstrated that complement may serve as a key link between innate and adaptive immunity in a variety of pulmonary conditions. However, the specific contributions of complement to lung diseases based on innate and adaptive immunity are just beginning to emerge. Elucidating the role of complement-mediated immune regulation in these diseases will help to identify new targets for therapeutic interventions.

  3. Plants under dual attack

    NARCIS (Netherlands)

    Ponzio, C.A.M.

    2016-01-01

    Though immobile, plants are members of complex environments, and are under constant threat from a wide range of attackers, which includes organisms such as insect herbivores or plant pathogens. Plants have developed sophisticated defenses against these attackers, and include chemical responses such

  4. Transient Ischemic Attack

    Medline Plus

    Full Text Available Transient Ischemic Attack TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an artery for a short time. The only ... TIA is that with TIA the blockage is transient (temporary). TIA symptoms occur rapidly and last a ...

  5. Genetics Home Reference: complement component 8 deficiency

    Science.gov (United States)

    ... of the body's immune response known as the complement system . The complement system is a group of proteins that work together ... complement component 8 deficiency Merck Manual Consumer Version: Complement System Orphanet: Immunodeficiency due to a late component of ...

  6. Terminal complexes of the complement system: new structural insights and their relevance to function.

    Science.gov (United States)

    Morgan, Bryan Paul; Walters, David; Serna, Marina; Bubeck, Doryen

    2016-11-01

    Complement is a key component of innate immunity in health and a powerful driver of inflammation and tissue injury in disease. The biological and pathological effects of complement activation are mediated by activation products. These come in two flavors: (i) proteolytic fragments of complement proteins (C3, C4, C5) generated during activation that bind specific receptors on target cells to mediate effects; (ii) the multimolecular membrane attack complex generated from the five terminal complement proteins that directly binds to and penetrates target cell membranes. Several recent publications have described structural insights that have changed perceptions of the nature of this membrane attack complex. This review will describe these recent advances in understanding of the structure of the membrane attack complex and its by-product the fluid-phase terminal complement complex and relate these new structural insights to functional consequences and cell responses to complement membrane attack. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Mathematical Attacks on RSA Cryptosystem

    OpenAIRE

    Imad K. Salah; Abdullah Darwish; Saleh Oqeili

    2006-01-01

    In this paper some of the most common attacks against Rivest, Shamir, and Adleman (RSA) cryptosystem are presented. We describe the integer factoring attacks, attacks on the underlying mathematical function, as well as attacks that exploit details in implementations of the algorithm. Algorithms for each type of attacks are developed and analyzed by their complexity, memory requirements and area of usage.

  8. The renaissance of complement therapeutics.

    Science.gov (United States)

    Ricklin, Daniel; Mastellos, Dimitrios C; Reis, Edimara S; Lambris, John D

    2018-01-01

    The increasing number of clinical conditions that involve a pathological contribution from the complement system - many of which affect the kidneys - has spurred a regained interest in therapeutic options to modulate this host defence pathway. Molecular insight, technological advances, and the first decade of clinical experience with the complement-specific drug eculizumab, have contributed to a growing confidence in therapeutic complement inhibition. More than 20 candidate drugs that target various stages of the complement cascade are currently being evaluated in clinical trials, and additional agents are in preclinical development. Such diversity is clearly needed in view of the complex and distinct involvement of complement in a wide range of clinical conditions, including rare kidney disorders, transplant rejection and haemodialysis-induced inflammation. The existing drugs cannot be applied to all complement-driven diseases, and each indication has to be assessed individually. Alongside considerations concerning optimal points of intervention and economic factors, patient stratification will become essential to identify the best complement-specific therapy for each individual patient. This Review provides an overview of the therapeutic concepts, targets and candidate drugs, summarizes insights from clinical trials, and reflects on existing challenges for the development of complement therapeutics for kidney diseases and beyond.

  9. The renaissance of complement therapeutics

    Science.gov (United States)

    Ricklin, Daniel; Mastellos, Dimitrios C.; Reis, Edimara S.; Lambris, John D.

    2018-01-01

    The increasing number of clinical conditions that involve a pathological contribution from the complement system — many of which affect the kidneys — has spurred a regained interest in therapeutic options to modulate this host defence pathway. Molecular insight, technological advances, and the first decade of clinical experience with the complement-specific drug eculizumab, have contributed to a growing confidence in therapeutic complement inhibition. More than 20 candidate drugs that target various stages of the complement cascade are currently being evaluated in clinical trials, and additional agents are in preclinical development. Such diversity is clearly needed in view of the complex and distinct involvement of complement in a wide range of clinical conditions, including rare kidney disorders, transplant rejection and haemodialysis-induced inflammation. The existing drugs cannot be applied to all complement-driven diseases, and each indication has to be assessed individually. Alongside considerations concerning optimal points of intervention and economic factors, patient stratification will become essential to identify the best complement-specific therapy for each individual patient. This Review provides an overview of the therapeutic concepts, targets and candidate drugs, summarizes insights from clinical trials, and reflects on existing challenges for the development of complement therapeutics for kidney diseases and beyond. PMID:29199277

  10. Streptococcus pyogenes Endopeptidase O Contributes to Evasion from Complement-mediated Bacteriolysis via Binding to Human Complement Factor C1q.

    Science.gov (United States)

    Honda-Ogawa, Mariko; Sumitomo, Tomoko; Mori, Yasushi; Hamd, Dalia Talat; Ogawa, Taiji; Yamaguchi, Masaya; Nakata, Masanobu; Kawabata, Shigetada

    2017-03-10

    Streptococcus pyogenes secretes various virulence factors for evasion from complement-mediated bacteriolysis. However, full understanding of the molecules possessed by this organism that interact with complement C1q, an initiator of the classical complement pathway, remains elusive. In this study, we identified an endopeptidase of S. pyogenes, PepO, as an interacting molecule, and investigated its effects on complement immunity and pathogenesis. Enzyme-linked immunosorbent assay and surface plasmon resonance analysis findings revealed that S. pyogenes recombinant PepO bound to human C1q in a concentration-dependent manner under physiological conditions. Sites of inflammation are known to have decreased pH levels, thus the effects of PepO on bacterial evasion from complement immunity was analyzed in a low pH condition. Notably, under low pH conditions, PepO exhibited a higher affinity for C1q as compared with IgG, and PepO inhibited the binding of IgG to C1q. In addition, pepO deletion rendered S. pyogenes more susceptible to the bacteriocidal activity of human serum. Also, observations of the morphological features of the pepO mutant strain (ΔpepO) showed damaged irregular surfaces as compared with the wild-type strain (WT). WT-infected tissues exhibited greater severity and lower complement activity as compared with those infected by ΔpepO in a mouse skin infection model. Furthermore, WT infection resulted in a larger accumulation of C1q than that with ΔpepO. Our results suggest that interaction of S. pyogenes PepO with C1q interferes with the complement pathway, which enables S. pyogenes to evade complement-mediated bacteriolysis under acidic conditions, such as seen in inflammatory sites. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Nocturnal panic attacks

    Directory of Open Access Journals (Sweden)

    Lopes Fabiana L.

    2002-01-01

    Full Text Available The panic-respiration connection has been presented with increasing evidences in the literature. We report three panic disorder patients with nocturnal panic attacks with prominent respiratory symptoms, the overlapping of the symptoms with the sleep apnea syndrome and a change of the diurnal panic attacks, from spontaneous to situational pattern. The implication of these findings and awareness to the distinct core of the nocturnal panic attacks symptoms may help to differentiate them from sleep disorders and the search for specific treatment.

  12. Heart Attack Payment - State

    Data.gov (United States)

    U.S. Department of Health & Human Services — Payment for heart attack patients measure – state data. This data set includes state-level data for payments associated with a 30-day episode of care for heart...

  13. Heart Attack Payment - Hospital

    Data.gov (United States)

    U.S. Department of Health & Human Services — Payment for heart attack patients measure – provider data. This data set includes provider data for payments associated with a 30-day episode of care for heart...

  14. Transient Ischemic Attack

    Medline Plus

    Full Text Available ... TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an ... a short time. The only difference between a stroke and TIA is that with TIA the blockage ...

  15. Transient Ischemic Attack

    Medline Plus

    Full Text Available ... immediately for any stroke symptoms. Popular Topics TIA Cardiac Catheter Cholesterol Heart Attack Stent © 2018, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. ...

  16. Heart Attack Payment - National

    Data.gov (United States)

    U.S. Department of Health & Human Services — Payment for heart attack patients measure – national data. This data set includes national-level data for payments associated with a 30-day episode of care for heart...

  17. Cooperating attackers in neural cryptography.

    Science.gov (United States)

    Shacham, Lanir N; Klein, Einat; Mislovaty, Rachel; Kanter, Ido; Kinzel, Wolfgang

    2004-06-01

    A successful attack strategy in neural cryptography is presented. The neural cryptosystem, based on synchronization of neural networks by mutual learning, has been recently shown to be secure under different attack strategies. The success of the advanced attacker presented here, called the "majority-flipping attacker," does not decay with the parameters of the model. This attacker's outstanding success is due to its using a group of attackers which cooperate throughout the synchronization process, unlike any other attack strategy known. An analytical description of this attack is also presented, and fits the results of simulations.

  18. Facial Dog Attack Injuries

    OpenAIRE

    Lin, Wei; Patil, Pavan Manohar

    2013-01-01

    The exposed position of the face makes it vulnerable to dog bite injuries. This fact combined with the short stature of children makes them a high-risk group for such attacks. In contrast to wounds inflicted by assaults and accidents, dog bite wounds are deep puncture type wounds compounded by the presence of pathologic bacteria from the saliva of the attacking dog. This, combined with the presence of crushed, devitalized tissue makes these wounds highly susceptible to infection. Key to succe...

  19. Launch under attack

    Energy Technology Data Exchange (ETDEWEB)

    Steinbruner, J.

    1984-01-01

    The strategy of launch under attack calls for launching nuclear weapons on warning that attacking weapons are on their way. The political pressures for adopting this strategy are symptomatic of an increasing instability in the nuclear balance. The author describes a Brookings Institute model, which indicates that the problems of decentralized control and precise timing could lead to failures in retargeting procedures. The major concern is that the strategy imposes powerful incentives for preemption as the most promising means of conducting nuclear war.

  20. evad : [luuletused] / Philip Larkin ; inglise keelest tlk. Maarja Kangro

    Index Scriptorium Estoniae

    Larkin, Philip

    2007-01-01

    Sisu: Päevad ; Mitte midagi öelda ; See olgu värss ; Uurimus lugemisharjumustest ; Hommage valitsusele ; Vesi ; Vajakud ; Viige üks koju lastele ; Jutt voodis ; Kõrged aknad ; Sa jätkad elu ; Kui. Orig.: Days ; Nothing to be said ; This be the verse ; A study of reading habits ; Homage to a government ; Water ; Wants ; Take one home for the kiddies ; Talking in bed ; High windows ; Continuing to live ; If

  1. DO PENALTIES AND ENFORCEMENT MEASURES MAKE TAXPAYERS MORE COMPLIANT? THE VIEW OF AUSTRALIAN TAX EVADERS

    OpenAIRE

    Dr Ken Devos

    2013-01-01

    The tax compliance literature indicates that many factors, including, economic, social, psychological and demographic, impact upon the compliance behaviour of individual taxpayers. This study explores the relationship, if any, that exists between selected tax compliance and demographic variables and the compliance behaviour of Australian individual tax evaders. The study employed a mixed method research approach comprising both a survey and interviews. The findings revealed that tax law enfor...

  2. The attack navigator

    DEFF Research Database (Denmark)

    Probst, Christian W.; Willemson, Jan; Pieters, Wolter

    2016-01-01

    The need to assess security and take protection decisions is at least as old as our civilisation. However, the complexity and development speed of our interconnected technical systems have surpassed our capacity to imagine and evaluate risk scenarios. This holds in particular for risks that are c......The need to assess security and take protection decisions is at least as old as our civilisation. However, the complexity and development speed of our interconnected technical systems have surpassed our capacity to imagine and evaluate risk scenarios. This holds in particular for risks...... that are caused by the strategic behaviour of adversaries. Therefore, technology-supported methods are needed to help us identify and manage these risks. In this paper, we describe the attack navigator: a graph-based approach to security risk assessment inspired by navigation systems. Based on maps of a socio......-technical system, the attack navigator identifies routes to an attacker goal. Specific attacker properties such as skill or resources can be included through attacker profiles. This enables defenders to explore attack scenarios and the effectiveness of defense alternatives under different threat conditions....

  3. Value of Plasmatic Membrane Attack Complex as a Marker of Severity in Acute Kidney Injury

    OpenAIRE

    Rodríguez, Eva; Riera, Marta; Barrios, Clara; Pascual, Julio

    2014-01-01

    The aim of this study was to determine if complement pathway is activated in AKI; for this purpose, we measured, through ELISA sandwich, the terminal lytic fraction of the complement system, called membrane attack complex (C5b-C9), in AKI patients compared with patients with similar clinical conditions but normal renal function. Our data showed that complement system is activated in AKI. Plasmatic MAC concentrations were significantly higher in AKI patients than in those with normal renal fun...

  4. Muusika : Jeremija nutulaulud palmipuudepühal. Jätkub "Musica Grande". Lihavõttetervitus Barcelonast. Rannap "Selges eesti helikeeles". Juba XIII trompetipäevad. III klavessiinipäevad / Jaan-Eik Tulve

    Index Scriptorium Estoniae

    Tulve, Jaan-Eik, 1967-

    2002-01-01

    Vox Clamantise kontsertidest Tartus ja Tallinnas. Jätkub sari "Musica Grande" kontsertidega Tartus ja Tallinnas pealkirjaga "Kontsertlik". Eestisse sõidab esinema üks Hispaania tippkoore Coral Cantiga Barcelonast. Rein Rannapi tänavusest suurprojektist, klaveriõhtust "Selges eesti helikeeles". 1. - 7. aprillini toimuvad EMA rahvusvahelised trompetipäevad. 4. - 7. aprillini korraldab Eesti Klavessiinisõprade Tsunft III klavessiinipäevad

  5. Cyber Attacks, Information Attacks, and Postmodern Warfare

    Directory of Open Access Journals (Sweden)

    Valuch Jozef

    2017-06-01

    Full Text Available The aim of this paper is to evaluate and differentiate between the phenomena of cyberwarfare and information warfare, as manifestations of what we perceive as postmodern warfare. We describe and analyse the current examples of the use the postmodern warfare and the reactions of states and international bodies to these phenomena. The subject matter of this paper is the relationship between new types of postmodern conflicts and the law of armed conflicts (law of war. Based on ICJ case law, it is clear that under current legal rules of international law of war, cyber attacks as well as information attacks (often performed in the cyberspace as well can only be perceived as “war” if executed in addition to classical kinetic warfare, which is often not the case. In most cases perceived “only” as a non-linear warfare (postmodern conflict, this practice nevertheless must be condemned as conduct contrary to the principles of international law and (possibly a crime under national laws, unless this type of conduct will be recognized by the international community as a “war” proper, in its new, postmodern sense.

  6. Identification and functional characterisation of Complement Regulator Acquiring Surface Protein-1 of serum resistant Borrelia garinii OspA serotype 4

    Directory of Open Access Journals (Sweden)

    Zipfel Peter F

    2010-02-01

    Full Text Available Abstract Background B. burgdorferi sensu lato (sl is the etiological agent of Lyme borreliosis in humans. Spirochetes have adapted themselves to the human immune system in many distinct ways. One important immune escape mechanism for evading complement activation is the binding of complement regulators Factor H (CFH or Factor H-like protein1 (FHL-1 to Complement Regulator-Acquiring Surface Proteins (CRASPs. Results We demonstrate that B. garinii OspA serotype 4 (ST4 PBi resist complement-mediated killing by binding of FHL-1. To identify the primary ligands of FHL-1 four CspA orthologs from B. garinii ST4 PBi were cloned and tested for binding to human CFH and FHL-1. Orthologs BGA66 and BGA71 were found to be able to bind both complement regulators but with different intensities. In addition, all CspA orthologs were tested for binding to mammalian and avian CFH. Distinct orthologs were able to bind to CFH of different animal origins. Conclusions B. garinii ST4 PBi is able to evade complement killing and it can bind FHL-1 to membrane expressed proteins. Recombinant proteins BGA66 can bind FHL-1 and human CFH, while BGA71 can bind only FHL-1. All recombinant CspA orthologs from B. garinii ST4 PBi can bind CFH from different animal origins. This partly explains the wide variety of animals that can be infected by B. garinii.

  7. Cooperating attackers in neural cryptography

    Science.gov (United States)

    Shacham, Lanir N.; Klein, Einat; Mislovaty, Rachel; Kanter, Ido; Kinzel, Wolfgang

    2004-06-01

    A successful attack strategy in neural cryptography is presented. The neural cryptosystem, based on synchronization of neural networks by mutual learning, has been recently shown to be secure under different attack strategies. The success of the advanced attacker presented here, called the “majority-flipping attacker,” does not decay with the parameters of the model. This attacker’s outstanding success is due to its using a group of attackers which cooperate throughout the synchronization process, unlike any other attack strategy known. An analytical description of this attack is also presented, and fits the results of simulations.

  8. Seven Deadliest Wireless Technologies Attacks

    CERN Document Server

    Haines, Brad

    2010-01-01

    How can an information security professional keep up with all of the hacks, attacks, and exploits? One way to find out what the worst of the worst are is to read the seven books in our Seven Deadliest Attacks Series. Not only do we let you in on the anatomy of these attacks but we also tell you how to get rid of them and how to defend against them in the future. Countermeasures are detailed so that you can fight against similar attacks as they evolve. Attacks featured in this book include:Bluetooth AttacksCredit Card, Access Card, and Passport AttacksBad Encryption

  9. Complement 3d: from molecular adjuvant to target of immune escape mechanisms.

    Science.gov (United States)

    Bergmann-Leitner, Elke S; Leitner, Wolfgang W; Tsokos, George C

    2006-11-01

    C3d is a fragment of the complement factor C3 and is generated in the course of complement activation. When bound to antigen in single or multiple copies, the B cell receptor and complement receptor 2 become co-crosslinked resulting in decreased or increased B cell responses depending on the valence of the antigen-C3d construct. When antigen-C3d constructs are used for the purpose of generating a protective immune response (vaccines), they may either enhance the expected response or suppress it depending on the nature of the antigen. Various pathogens use C3d to evade the immune system by inhibiting complement activation, invading and homing in host cells or masking immunogenic areas of pathogen proteins. Therefore, future vaccination strategies for infectious diseases and cancer employing C3d as a molecular adjuvant need to be carefully evaluated before choosing a target antigen in order to take advantage of the adjuvant effect of the complement component while avoiding potential vaccine complications associated with immune escape mechanisms.

  10. The political attack ad

    Directory of Open Access Journals (Sweden)

    Palma Peña-Jiménez, Ph.D.

    2011-01-01

    Full Text Available During election campaigns the political spot has a clear objective: to win votes. This message is communicated to the electorate through television and Internet, and usually presents a negative approach, which includes a direct critical message against the opponent, rather than an exposition of proposals. This article is focused on the analysis of the campaign attack video ad purposely created to encourage the disapproval of the political opponent among voters. These ads focus on discrediting the opponent, many times, through the transmission of ad hominem messages, instead of disseminating the potential of the political party and the virtues and manifesto of its candidate. The article reviews the development of the attack ad since its first appearance, which in Spain dates back to 1996, when the famous Doberman ad was broadcast, and examines the most memorable campaign attack ads.

  11. Genetics Home Reference: complement component 2 deficiency

    Science.gov (United States)

    ... of the body's immune response known as the complement system . The complement system is a group of proteins that work together ... in the pathway that turns on (activates) the complement system when foreign invaders, such as bacteria, are detected. ...

  12. The role of complement in ocular pathology

    OpenAIRE

    Bora, Nalini S.; Jha, Purushottam; Bora, Puran S.

    2008-01-01

    Functionally active complement system and complement regulatory proteins are present in the normal human and rodent eye. Complement activation and its regulation by ocular complement regulatory proteins contribute to the pathology of various ocular diseases including keratitis, uveitis and age-related macular degeneration. Furthermore, a strong relationship between age-related macular degeneration and polymorphism in the genes of certain complement components/complement regulatory proteins is...

  13. Complement-Mediated Regulation of Apolipoprotein E in Cultured Human RPE Cells.

    Science.gov (United States)

    Yang, Ping; Skiba, Nikolai P; Tewkesbury, Grace M; Treboschi, Victoria M; Baciu, Peter; Jaffe, Glenn J

    2017-06-01

    Complement activation is implicated in the pathogenesis of age-related macular degeneration (AMD). Apolipoprotein E (ApoE) and complement activation products such as membrane attack complex (MAC) are present in eyes of individuals with AMD. Herein, we investigated the effect of complement activation on induction of ApoE accumulation in human retinal pigment epithelial (RPE) cells. Cultured human RPE cells were primed with a complement-fixing antibody followed by treatment with C1q-depleted (C1q-Dep) human serum to elicit alternative pathway complement activation. Controls included anti-C5 antibody-treated serum and heat-inactivated C1q-Dep. Total protein was determined on RPE cell extracts, conditioned media, and extracellular matrix (ECM) by Western blot. ApoE and MAC colocalization was assessed on cultured RPE cells and human eyes by immunofluorescent stain. ApoE mRNA expression was evaluated by quantitative PCR (qPCR). Complement challenge upregulated cell-associated ApoE, but not apolipoprotein A1. ApoE accumulation was blocked by anti-C5 antibody and enhanced by repetitive complement challenge. ApoE mRNA levels were not affected by complement challenge. ApoE was frequently colocalized with MAC in complement-treated cells and drusen from human eyes. ApoE was released into complement-treated conditioned media after a single complement challenge and accumulated on ECM after repetitive complement challenge. Complement challenge induces time-dependent ApoE accumulation in RPE cells. An understanding of the mechanisms by which complement affects RPE ApoE accumulation may help to better explain drusen composition, and provide insights into potential therapeutic targets.

  14. Mesenchymal stem cells engineered to inhibit complement-mediated damage.

    Directory of Open Access Journals (Sweden)

    Melisa A Soland

    Full Text Available Mesenchymal stem cells (MSC preferentially migrate to damaged tissues and, due to their immunomodulatory and trophic properties, contribute to tissue repair. Although MSC express molecules, such as membrane cofactor protein (CD46, complement decay-accelerating factor (CD55, and protectin (CD59, which confer protection from complement-mediated lysis, MSC are recruited and activated by anaphylatoxins after transplantation, potentially causing MSC death and limiting therapeutic benefit. We have previously demonstrated that transduction of MSC with a retrovirus encoding HCMV-US proteins resulted in higher levels of MSC engraftment due to decreased HLA-I expression. Here, we investigate whether engineering MSC to express US2 (MSC-US2, US3 (MSC-US3, US6 (MSC-US6, or US11 (MSC-US11 HCMV proteins can alter complement recognition, thereby better protecting MSC from complement attack and lysis. HCMV-US proteins increased MSC CD59 expression at different levels as determined by flow cytometric evaluation of the median fluorescence intensity ratio (MFI. A significant increase in CD59 expression was seen in MSC-US2, MSC-US3, and MSC-US6, but not in MSC-US11. Only MSC-US2 displayed increased expression of CD46, while US2 and US3 proteins were both able to augment the percentage of MSC expressing this molecule. Regardless of the HCMV protein expressed, none changed CD55 MFI; however, expression of US6, US11, and US2 each increased the percentage of MSC that were positive for this molecule. Because US2 protein was the most efficient in up-regulating all three complement regulatory proteins, we used a functional complement-mediated cytotoxicity assay to investigate whether MSC-US2 were protected from complement-mediated lysis. We demonstrated that over-expression of the US2 protein reduced complement lysis by 59.10±12.89% when compared to untransduced MSC. This is the first report, to our knowledge, describing a role of HCMV-US proteins in complement evasion

  15. Force Dynamics of Verb Complementation

    Directory of Open Access Journals (Sweden)

    Jacek Woźny

    2015-12-01

    Full Text Available Force Dynamics of Verb Complementation The concepts of motion and force are both extensively discussed in cognitive linguistics literature. But they are discussed separately. The first usually in the context of ‘motion situations’ (Talmy, Slobin, Zlatev, the other as part of the Force Dynamics framework, which was developed by Talmy. The aim of this paper is twofold: first, to argue that the concepts of force and motion should not be isolated but considered as two inseparable parts of force-motion events. The second goal is to prove that the modified Force Dynamics (force-motion framework can be used for precise characterization of the verb complementation patterns. To this end, a random sample of 50 sentences containing the verb ‘went’ is analyzed, demonstrating the differences between the categories of intensive and intransitive complementation with respect to the linguistically coded parameters of force and motion.

  16. Heart Attack Recovery FAQs

    Science.gov (United States)

    ... smolder — that can be destructive. If you think counseling would help your family deal with your heart attack more ... your lifestyle habits through exercise training, education and counseling to ... or with the help of your doctor, nurse, dietitian or other healthcare ...

  17. Fatal crocodile attack.

    Science.gov (United States)

    Chattopadhyay, Saurabh; Shee, Biplab; Sukul, Biswajit

    2013-11-01

    Attacks on human beings by various animals leading to varied types of injuries and even death in some cases are not uncommon. Crocodile attacks on humans have been reported from a number of countries across the globe. Deaths in such attacks are mostly due to mechanical injuries or drowning. Bites by the crocodiles often cause the limbs to be separated from the body. The present case refers to an incident of a fatal attack by a crocodile on a 35 years old female where only the mutilated head of the female was recovered. Multiple lacerated wounds over the face and scalp along with fracture of the cranial bones was detected on autopsy. Two distinct bite marks in the form of punched in holes were noted over the parietal and frontal bones. Injuries on the head with its traumatic amputation from the body were sufficient to cause death. However, the presence of other fatal injuries on the unrecovered body parts could not be ruled out. Copyright © 2013 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  18. Temporal Cyber Attack Detection.

    Energy Technology Data Exchange (ETDEWEB)

    Ingram, Joey Burton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Draelos, Timothy J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Galiardi, Meghan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Doak, Justin E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-11-01

    Rigorous characterization of the performance and generalization ability of cyber defense systems is extremely difficult, making it hard to gauge uncertainty, and thus, confidence. This difficulty largely stems from a lack of labeled attack data that fully explores the potential adversarial space. Currently, performance of cyber defense systems is typically evaluated in a qualitative manner by manually inspecting the results of the system on live data and adjusting as needed. Additionally, machine learning has shown promise in deriving models that automatically learn indicators of compromise that are more robust than analyst-derived detectors. However, to generate these models, most algorithms require large amounts of labeled data (i.e., examples of attacks). Algorithms that do not require annotated data to derive models are similarly at a disadvantage, because labeled data is still necessary when evaluating performance. In this work, we explore the use of temporal generative models to learn cyber attack graph representations and automatically generate data for experimentation and evaluation. Training and evaluating cyber systems and machine learning models requires significant, annotated data, which is typically collected and labeled by hand for one-off experiments. Automatically generating such data helps derive/evaluate detection models and ensures reproducibility of results. Experimentally, we demonstrate the efficacy of generative sequence analysis techniques on learning the structure of attack graphs, based on a realistic example. These derived models can then be used to generate more data. Additionally, we provide a roadmap for future research efforts in this area.

  19. BIRD ATTACK OCULAR INJURIES.

    Science.gov (United States)

    Tabatabaei, Seyed Ali; Soleimani, Mohammad; Behrouz, Mahmoud Jabbarvand

    2017-03-29

    To report 30 patients with bird attack-related eye injuries. This study was performed among patients coming to Farabi Eye Hospital, Tehran, Iran, from 2010 to 2015 with a history of bird attack causing eye injury. The inclusion criteria were a history of bird attack by pecking causing eye injury and having treatment and follow-up record for at least 6 months after treatment. The primary eye examinations included a full ophthalmic examination including evaluation of uncorrected visual acuity and best-corrected visual acuity (BCVA), anterior segment slit lamp biomicroscopy, and photography. For all patients with penetrating injury, primary repair was undertaken. Thirty patients (10 females and 20 males) with a mean age of 23.3 ± 18.5 years entered the study. The most common zone of injury was zone 1 (P < 0.001), and lensectomy was not needed in majority of patients (P < 0.001). The most common bird causing the injury was mynah (P < 0.001). Those patients with baseline BCVA of less than 20/200 or those with endophthalmitis had statistically worse final BCVA after treatment. Patients attacked by mynah bird had significantly better pretreatment uncorrected visual acuity and BCVA. The most common bird causing the eye injury among the sample of patients from Iran was mynah, which differs with previous studies indicating the rooster attack as the most common cause of eye injury. The authors also found that the most common zone of injury was zone 1, and the presence of endophthalmitis and lower baseline BCVA were significant risk factors for worse visual outcomes.

  20. Complement System Part I – Molecular Mechanisms of Activation and Regulation

    Science.gov (United States)

    Merle, Nicolas S.; Church, Sarah Elizabeth; Fremeaux-Bacchi, Veronique; Roumenina, Lubka T.

    2015-01-01

    Complement is a complex innate immune surveillance system, playing a key role in defense against pathogens and in host homeostasis. The complement system is initiated by conformational changes in recognition molecular complexes upon sensing danger signals. The subsequent cascade of enzymatic reactions is tightly regulated to assure that complement is activated only at specific locations requiring defense against pathogens, thus avoiding host tissue damage. Here, we discuss the recent advances describing the molecular and structural basis of activation and regulation of the complement pathways and their implication on physiology and pathology. This article will review the mechanisms of activation of alternative, classical, and lectin pathways, the formation of C3 and C5 convertases, the action of anaphylatoxins, and the membrane-attack-complex. We will also discuss the importance of structure–function relationships using the example of atypical hemolytic uremic syndrome. Lastly, we will discuss the development and benefits of therapies using complement inhibitors. PMID:26082779

  1. Bluetooth security attacks comparative analysis, attacks, and countermeasures

    CERN Document Server

    Haataja, Keijo; Pasanen, Sanna; Toivanen, Pekka

    2013-01-01

    This overview of Bluetooth security examines network vulnerabilities and offers a comparative analysis of recent security attacks. It also examines related countermeasures and proposes a novel attack that works against all existing Bluetooth versions.

  2. The role of the complement system in hereditary angioedema.

    Science.gov (United States)

    Csuka, Dorottya; Veszeli, Nóra; Varga, Lilian; Prohászka, Zoltán; Farkas, Henriette

    2017-09-01

    Hereditary angioedema (HAE) is a rare, but potentially life-threatening disorder, characterized by acute, recurring, and self-limiting edematous episodes of the face, extremities, trunk, genitals, upper airways, or the gastrointestinal tract. HAE may be caused by the deficiency of C1-inhibitor (C1-INH-HAE) but another type of the disease, hereditary angioedema with normal C1-INH function (nC1-INH-HAE) was also described. The patient population is quite heterogeneous as regards the location, frequency, and severity of edematous attacks, presenting large intra- and inter-individual variation. Here, we review the role of the complement system in the pathomechanism of HAE and also present an overview on the complement parameters having an importance in the diagnosis or in predicting the severity of HAE. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Complement: Alive and Kicking Nanomedicines

    DEFF Research Database (Denmark)

    Andersen, Alina Joukainen; Hashemi, S.H.; Andresen, Thomas Lars

    2009-01-01

    Administration of liposome- and polymer-based clinical nanomedicines, as well as many other proposed multifunctional nanoparticles, often triggers hypersensitivity reactions without the involvement of IgE. These anaphylactic reactions are believed to be secondary to activation of the complement...

  4. The lectin pathway of complement

    DEFF Research Database (Denmark)

    Ballegaard, Vibe Cecilie Diederich; Haugaard, Anna Karen; Garred, P

    2014-01-01

    The pattern recognition molecules of the lectin complement pathway are important components of the innate immune system with known functions in host-virus interactions. This paper summarizes current knowledge of how these intriguing molecules, including mannose-binding lectin (MBL), Ficolin-1, -2...

  5. Life After a Heart Attack

    Science.gov (United States)

    ... been stable for a few weeks. Anxiety and Depression After a Heart Attack After a heart attack, ... 2009, this project provided six awards at five academic institutions to identify genetic connections to heart, lung, ...

  6. The Complement System and Ocular Diseases

    OpenAIRE

    Jha, Purushottam; Bora, Puran S.; Bora, Nalini S.

    2007-01-01

    In the normal eye, the complement system is continuously activated at low levels and both membrane-bound and soluble intraocular complement regulatory proteins tightly regulate this spontaneous complement activation. This allows protection against pathogens without causing any damage to self-tissue and vision loss. The complement system and complement regulatory proteins control the intraocular inflammation in autoimmune uveitis and play an important role in the development of corneal inflamm...

  7. When women attack.

    Science.gov (United States)

    McLaughlin, Bryan; Davis, Catasha; Coppini, David; Kim, Young Mie; Knisely, Sandra; McLeod, Douglas

    2015-01-01

    The common assumption that female candidates on the campaign trail should not go on the attack, because such tactics contradict gender stereotypes, has not received consistent support. We argue that in some circumstances gender stereotypes will favor female politicians going negative. To test this proposition, this study examines how gender cues affect voter reactions to negative ads in the context of a political sex scandal, a context that should prime gender stereotypes that favor females. Using an online experiment involving a national sample of U.S. adults (N = 599), we manipulate the gender and partisan affiliation of a politician who attacks a male opponent caught in a sex scandal involving sexually suggestive texting to a female intern. Results show that in the context of a sex scandal, a female candidate going on the attack is evaluated more positively than a male. Moreover, while female participants viewed the female sponsor more favorably, sponsor gender had no effect on male participants. Partisanship also influenced candidate evaluations: the Democratic female candidate was evaluated more favorably than her Republican female counterpart.

  8. Attack Trees with Sequential Conjunction

    NARCIS (Netherlands)

    Jhawar, Ravi; Kordy, Barbara; Mauw, Sjouke; Radomirović, Sasa; Trujillo-Rasua, Rolando

    2015-01-01

    We provide the first formal foundation of SAND attack trees which are a popular extension of the well-known attack trees. The SAND at- tack tree formalism increases the expressivity of attack trees by intro- ducing the sequential conjunctive operator SAND. This operator enables the modeling of

  9. Replacement Attack: A New Zero Text Watermarking Attack

    Science.gov (United States)

    Bashardoost, Morteza; Mohd Rahim, Mohd Shafry; Saba, Tanzila; Rehman, Amjad

    2017-03-01

    The main objective of zero watermarking methods that are suggested for the authentication of textual properties is to increase the fragility of produced watermarks against tampering attacks. On the other hand, zero watermarking attacks intend to alter the contents of document without changing the watermark. In this paper, the Replacement attack is proposed, which focuses on maintaining the location of the words in the document. The proposed text watermarking attack is specifically effective on watermarking approaches that exploit words' transition in the document. The evaluation outcomes prove that tested word-based method are unable to detect the existence of replacement attack in the document. Moreover, the comparison results show that the size of Replacement attack is estimated less accurate than other common types of zero text watermarking attacks.

  10. From Malware Signatures to Anti-Virus Assisted Attacks

    OpenAIRE

    Wressnegger, Christian; Freeman, Kevin; Yamaguchi, Fabian; Rieck, Konrad

    2016-01-01

    Although anti-virus software has significantly evolved over the last decade, classic signature matching based on byte patterns is still a prevalent concept for identifying security threats. Anti-virus signatures are a simple and fast detection mechanism that can complement more sophisticated analysis strategies. However, if signatures are not designed with care, they can turn from a defensive mechanism into an instrument of attack. In this paper, we present a novel method for automatically de...

  11. Structural Learning of Attack Vectors for Generating Mutated XSS Attacks

    Directory of Open Access Journals (Sweden)

    Yi-Hsun Wang

    2010-09-01

    Full Text Available Web applications suffer from cross-site scripting (XSS attacks that resulting from incomplete or incorrect input sanitization. Learning the structure of attack vectors could enrich the variety of manifestations in generated XSS attacks. In this study, we focus on generating more threatening XSS attacks for the state-of-the-art detection approaches that can find potential XSS vulnerabilities in Web applications, and propose a mechanism for structural learning of attack vectors with the aim of generating mutated XSS attacks in a fully automatic way. Mutated XSS attack generation depends on the analysis of attack vectors and the structural learning mechanism. For the kernel of the learning mechanism, we use a Hidden Markov model (HMM as the structure of the attack vector model to capture the implicit manner of the attack vector, and this manner is benefited from the syntax meanings that are labeled by the proposed tokenizing mechanism. Bayes theorem is used to determine the number of hidden states in the model for generalizing the structure model. The paper has the contributions as following: (1 automatically learn the structure of attack vectors from practical data analysis to modeling a structure model of attack vectors, (2 mimic the manners and the elements of attack vectors to extend the ability of testing tool for identifying XSS vulnerabilities, (3 be helpful to verify the flaws of blacklist sanitization procedures of Web applications. We evaluated the proposed mechanism by Burp Intruder with a dataset collected from public XSS archives. The results show that mutated XSS attack generation can identify potential vulnerabilities.

  12. Complement genetics and host defence.

    Science.gov (United States)

    Lachmann, P J

    1990-12-01

    There is a surprisingly high frequency of allelic variation in complement proteins. The best candidate for a true selective polymorphism is that of C3. For C4 and factor B within the MHC it is more difficult to identify the effects of individual alleles. No evidence suggests other alleles of C4 (and C2) than the null alleles (or the two isoproteins C4A and C4B) to have any functional differences with resistance. Thus, the major functions of complement, as shown by the effects of deficiency, are to resist infection against bacteria and particularly against Neisseria, and to prevent immune complex disease. There are also undoubtedly balancing contributions to the pathogenesis of some infections and to all immune complex disease. Data from studies of C4 polymorphism and from the presence of control proteins on micro-organisms suggest there may be in addition more subtle contributions to immunity against a variety of other infections.

  13. Seven Deadliest Unified Communications Attacks

    CERN Document Server

    York, Dan

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting Unified Communications technology? Then you need Seven Deadliest Unified Communication Attacks. This book pinpoints the most dangerous hacks and exploits specific to Unified Communications, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks featured in this book include: UC Ecosystem Attacks Insecure Endpo

  14. The atherogenic bacterium Porphyromonas gingivalis evades circulating phagocytes by adhering to erythrocytes

    DEFF Research Database (Denmark)

    Belstrøm, Daniel; Holmstrup, Palle; Damgaard, Christian

    2011-01-01

    A relationship between periodontitis and coronary heart disease has been investigated intensively. A pathogenic role for the oral bacterium Porphyromonas gingivalis has been suggested for both diseases. We examined whether complement activation by P. gingivalis strain ATCC 33277 allows the bacter......A relationship between periodontitis and coronary heart disease has been investigated intensively. A pathogenic role for the oral bacterium Porphyromonas gingivalis has been suggested for both diseases. We examined whether complement activation by P. gingivalis strain ATCC 33277 allows...

  15. A hot L1 retrotransposon evades somatic repression and initiates human colorectal cancer

    Science.gov (United States)

    Scott, Emma C.; Gardner, Eugene J.; Masood, Ashiq; Chuang, Nelson T.; Vertino, Paula M.; Devine, Scott E.

    2016-01-01

    Although human LINE-1 (L1) elements are actively mobilized in many cancers, a role for somatic L1 retrotransposition in tumor initiation has not been conclusively demonstrated. Here, we identify a novel somatic L1 insertion in the APC tumor suppressor gene that provided us with a unique opportunity to determine whether such insertions can actually initiate colorectal cancer (CRC), and if so, how this might occur. Our data support a model whereby a hot L1 source element on Chromosome 17 of the patient's genome evaded somatic repression in normal colon tissues and thereby initiated CRC by mutating the APC gene. This insertion worked together with a point mutation in the second APC allele to initiate tumorigenesis through the classic two-hit CRC pathway. We also show that L1 source profiles vary considerably depending on the ancestry of an individual, and that population-specific hot L1 elements represent a novel form of cancer risk. PMID:27197217

  16. Evading the pulsar constraints on the cosmic string tension in supergravity inflation

    Energy Technology Data Exchange (ETDEWEB)

    Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Miyamoto, Yuhei [Tokyo Univ. (Japan). Dept. of Physics; Tokyo Univ. (JP). Research Center for the Early Universe (RESCEU); Yokoyama, Jun' ichi [Tokyo Univ. (JP). Research Center for the Early Universe (RESCEU); Tokyo Univ., Kashiwa, Chiba (JP). Inst. for the Physics and Mathematics of the Universe (IPMU)

    2012-04-15

    The cosmic string is a useful probe of the early Universe and may give us a clue to physics at high energy scales where any artificial particle accelerators cannot reach. Although one of the most promising tools is the cosmic microwave background, the constraint from gravitational waves is becoming so stringent that one may not hope to detect its signatures in the cosmic microwave background. In this paper, we construct a scenario that contains cosmic strings observable in the cosmic microwave background while evading the constraint imposed by the recent pulsar timing data. We argue that cosmic strings with relatively large tension are allowed by delaying the onset of the scaling regime. We also show that this scenario is naturally realized in the context of chaotic inflation in supergravity, where the phase transition is governed by the Hubble induced mass.

  17. Attacks on computer systems

    Directory of Open Access Journals (Sweden)

    Dejan V. Vuletić

    2012-01-01

    Full Text Available Computer systems are a critical component of the human society in the 21st century. Economic sector, defense, security, energy, telecommunications, industrial production, finance and other vital infrastructure depend on computer systems that operate at local, national or global scales. A particular problem is that, due to the rapid development of ICT and the unstoppable growth of its application in all spheres of the human society, their vulnerability and exposure to very serious potential dangers increase. This paper analyzes some typical attacks on computer systems.

  18. Can You Recognize a Heart Attack? Quiz

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Can You Recognize a Heart Attack? Updated:Sep 16, ... a Heart Attack Heart Attack Symptoms in Women “Can you recognize a heart attack?” Quiz • Understand Your ...

  19. The complement system and adverse pregnancy outcomes.

    Science.gov (United States)

    Regal, Jean F; Gilbert, Jeffrey S; Burwick, Richard M

    2015-09-01

    Adverse pregnancy outcomes significantly contribute to morbidity and mortality for mother and child, with lifelong health consequences for both. The innate and adaptive immune system must be regulated to insure survival of the fetal allograft, and the complement system is no exception. An intact complement system optimizes placental development and function and is essential to maintain host defense and fetal survival. Complement regulation is apparent at the placental interface from early pregnancy with some degree of complement activation occurring normally throughout gestation. However, a number of pregnancy complications including early pregnancy loss, fetal growth restriction, hypertensive disorders of pregnancy and preterm birth are associated with excessive or misdirected complement activation, and are more frequent in women with inherited or acquired complement system disorders or complement gene mutations. Clinical studies employing complement biomarkers in plasma and urine implicate dysregulated complement activation in components of each of the adverse pregnancy outcomes. In addition, mechanistic studies in rat and mouse models of adverse pregnancy outcomes address the complement pathways or activation products of importance and allow critical analysis of the pathophysiology. Targeted complement therapeutics are already in use to control adverse pregnancy outcomes in select situations. A clearer understanding of the role of the complement system in both normal pregnancy and complicated or failed pregnancy will allow a rational approach to future therapeutic strategies for manipulating complement with the goal of mitigating adverse pregnancy outcomes, preserving host defense, and improving long term outcomes for both mother and child. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Recent "phishing" attacks

    CERN Multimedia

    IT Department

    2009-01-01

    Over the last few weeks there has been a marked increase in the number of attacks on CERN made by cybercriminals. Typical attacks arrive in the form of e-mail messages purporting to come from the CERN Help Desk, Mail Service, or some similarly official-sounding entity and suggest that there is a problem with your account, such as it being over-quota. They then ask you to click on a link or to reply and give your password. Please don’t! Be cautious of any unexpected messages containing web links even if they appear to come from known contacts. If you happen to click on such a link and if your permission is requested to run or install software, always decline it. NEVER provide your password or other details if these are requested. These messages try to trick you into clicking on Web links which will help them to install malicious software on your computer, and anti-virus software cannot be relied on to detect all cases. In case of questions on this topic, you may contact mailto:helpdesk@cern.ch. CERN Comput...

  1. Tallinna Merepäevade turismikonverents käsitles mere ja linna kohtumispaiga arenguid ja arendamist / Ain Hinsberg

    Index Scriptorium Estoniae

    Hinsberg, Ain

    2013-01-01

    Tallinna Sadama, linnavalitsuse, Viking Line ja EHTE poolt 12. juulil Admiraliteedi basseiniääres Merepäevade paviljonis korraldatud konverentsist "Mere ja linna kohtumispaik kui linnaruum ja sihtkoht", kus esinesid Allan Kiil, Tiit Kask, Duncan Frazer Inglismaalt, Satu Lehtonen Soomest, Anu Hallik-Jürgenstein, Peeter Pere, Heikki Mäki, Evelyn Sepp ja Ahto Ader

  2. Formulation of a Cooperative-Confinement-Escape problem of multiple cooperative defenders against an evader escaping from a circular region

    Science.gov (United States)

    Li, Wei

    2016-10-01

    In this paper, we propose and formulate the Cooperative-Confinement-Escape (CCE) problem of multiple cooperative defenders against an evader escaping from a circular region, in which the defenders are moving on the circle with attempt to prevent possible escape of a single evader who is initially located inside the circle. The main contributions are summarized as follows: (1) we first provide an effective formulation of the CCE problem, which is an emphasis of this paper, with design of two nonlinear control strategies for the cooperative defenders and the adversarial evader, respectively. Particularly, we consider to include a proper interaction between each pair of the nearest-neighbor defenders, and an adaptive trajectory prediction mechanism in the strategies of the defenders to increase the chance of successful confinement. (2) For the first attempt on analyzing the CCE dynamics which is unavoidably strongly nonlinear, we analyze the minimum energy of the evader for possible escape. (3) For understanding of the behaviors of the system under different parameters, (i) we illustrate the effectiveness of the confinement strategy using the adaptive trajectory prediction mechanism, and (ii) the physical roles of the system parameters with respect to the system dynamics, some of which may be unexpected or not straightforward. A separate paper will be presented for systematic analysis of the agents' behaviors with respect to the large intervals of the parameter settings.

  3. Lübecki filmipäevad 1999 ja Thomas Manni ekraniseering 1923 / Lauri Kärk

    Index Scriptorium Estoniae

    Kärk, Lauri, 1954-

    1999-01-01

    4.-7. novembrini Lübeckis toimunud Põhjamaade filmipäevade 41. Nordische Filmtage huvitavamatest filmidest, nagu Thomas Manni "Buddenbrookide" ekraniseering 1923. aastast (režissöör Gerhard Lamprecht) ja Rasmus Gerlachi dokumentaal "Operaator Kaufman" Dziga Vertovist ja tema kahest, samuti kino alal tegutsenud vennast

  4. The role of the complement system in diabetic nephropathy.

    Science.gov (United States)

    Flyvbjerg, Allan

    2017-05-01

    The development of type 1 and type 2 diabetes mellitus has a substantial negative impact on morbidity and mortality and is responsible for substantial individual and socioeconomic costs worldwide. One of the most serious consequences of diabetes mellitus is the development of diabetic angiopathy, which manifests clinically as microvascular and macrovascular complications. One microvascular complication, diabetic nephropathy, is the most common cause of end-stage renal disease in developed countries. Although several available therapeutic interventions can delay the onset and progression of diabetic nephropathy, morbidity associated with this disease remains high and new therapeutic approaches are needed. In addition, not all patients with diabetes mellitus will develop diabetic nephropathy and thus new biomarkers are needed to identify individuals who will develop this life-threatening disease. An increasing body of evidence points toward a role of the complement system in the pathogenesis of diabetic nephropathy. For example, circulating levels of mannose-binding lectin (MBL), a pattern recognition molecule of the innate immune system, have emerged as a robust biomarker for the development and progression of this disease, and evidence suggests that MBL, H-ficolin, complement component C3 and the membrane attack complex might contribute to renal injury in the hyperglycaemic mileu. New approaches to modulate the complement system might lead to the development of new agents to prevent or slow the progression of diabetic nephropathy.

  5. Complement activation and inhibition: a delicate balance

    DEFF Research Database (Denmark)

    Sjöberg, A P; Trouw, L A; Blom, A M

    2009-01-01

    proteins, pentraxins, amyloid deposits, prions and DNA, all bind the complement activator C1q, but also interact with complement inhibitors C4b-binding protein and factor H. This contrasts to the interaction between C1q and immune complexes, in which case no inhibitors bind, resulting in full complement...

  6. HIV Coinfection Enhances Complement Activation During Sepsis

    NARCIS (Netherlands)

    Huson, Michaëla A. M.; Wouters, Diana; van Mierlo, Gerard; Grobusch, Martin P.; Zeerleder, Sacha S.; van der Poll, Tom

    2015-01-01

    Human immunodeficiency virus (HIV)-induced complement activation may play a role in chronic immune activation in patients with HIV infection and influence the complement system during acute illness. We determined the impact of HIV infection on the complement system in patients with asymptomatic HIV

  7. Cyber Attacks and Combat Behavior

    Directory of Open Access Journals (Sweden)

    Carataș Maria Alina

    2017-01-01

    Full Text Available Cyber terrorism is an intangible danger, a real over the corner threat in the life of individuals,organizations, and governments and is getting harder to deal with its damages. The motivations forthe cyber-attacks are different, depending on the terrorist group, from cybercrime to hacktivism,attacks over the authorities’ servers. Organizations constantly need to find new ways ofstrengthening protection against cyber-attacks, assess their cyber readiness, expand the resiliencecapacity and adopts international security regulations.

  8. Tracing Technique for Blaster Attack

    OpenAIRE

    S., Siti Rahayu; Y., Robiah; S., Shahrin; A., Faizal M.; M, Mohd Zaki; R, Irda

    2009-01-01

    Blaster worm of 2003 is still persistent, the infection appears to have successfully transitioned to new hosts as the original systems are cleaned or shut off, suggesting that the Blaster worm, and other similar worms, will remain significant Internet threats for many years after their initial release. This paper is to propose technique on tracing the Blaster attack from various logs in different OSI layers based on fingerprint of Blaster attack on victim logs, attacker logs and IDS alert log...

  9. Attacks on RFID Identification Systems

    Directory of Open Access Journals (Sweden)

    D. M. Mikhaylov

    2010-09-01

    Full Text Available This article is about attacks on RFID systems. Currently antivirus developers are not developing systems that protect from viruses that could exist on RFID tags. Such viruses are considered as not existing because the RFID tag memory is very small. Unfortunately such viruses exist. This article is concerned to such viruses and attacks that hackers could do using such viruses. Based on this article methods to prevent RFID-viruses attacks could be developed.

  10. Seven Deadliest Social Network Attacks

    CERN Document Server

    Timm, Carl

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting social networks? Then you need Seven Deadliest Social Network Attacks. This book pinpoints the most dangerous hacks and exploits specific to social networks like Facebook, Twitter, and MySpace, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. Attacks detailed in this book include: Social Networking Infrastruct

  11. Seven Deadliest Web Application Attacks

    CERN Document Server

    Shema, Mike

    2010-01-01

    Do you need to keep up with the latest hacks, attacks, and exploits effecting web applications? Then you need Seven Deadliest Web Application Attacks. This book pinpoints the most dangerous hacks and exploits specific to web applications, laying out the anatomy of these attacks including how to make your system more secure. You will discover the best ways to defend against these vicious hacks with step-by-step instruction and learn techniques to make your computer and network impenetrable. .. .. Attacks detailed in this book include: ..: ..; Cross-Site Scripting (XSS) ..; Cross-Site Request Fo

  12. Attacker profiling in quantitative security assessment based on attack trees

    NARCIS (Netherlands)

    Lenin, Aleksandr; Willemson, Jan; Sari, Dyan Permata

    2014-01-01

    We present the results of research of limiting adversarial budget in attack games, and, in particular, in the failure-free attack tree models presented by Buldas-Stepanenko in 2012 and improved in 2013 by Buldas and Lenin. In the previously presented models attacker’s budget was assumed to be

  13. Complement the hemostatic system: an intimate relationship.

    Science.gov (United States)

    Weitz, Ilene Ceil

    2014-05-01

    The complement system is important part of our innate immune system and interacts directly with the hemostatic system. Disorders of complement activation or dysregulation resulting in excess complement generation, such as Paroxysmal Nocturnal Hemoglobinuria (PNH), atypical Hemolytic uremic Syndrome (aHUS) and antiphospholipid syndrome (APLS) have been associated with significant thrombophilia. Terminal Complement (C5b-9) deposition on endothelial and tumor cell membranes has also been reported in a variety of cancer. Recent developments in complement inhibition have given us new insights into the mechanism of thrombosis in these disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Spontaneous complement activation on human B cells results in localized membrane depolarization and the clustering of complement receptor type 2 and C3 fragments

    DEFF Research Database (Denmark)

    Løbner, Morten; Leslie, Robert G Q; Prodinger, Wolfgang M

    2009-01-01

    While our previous studies have demonstrated that complement activation induced by complement receptors type 2 (CR2/CD21) and 1 (CR1/CD35) results in C3-fragment deposition and membrane attack complex (MAC) formation in human B cells, the consequences of these events for B-cell functions remain...... requires activation of complement via the alternative pathway, as indicated by total inhibition upon neutralization of factor D, and is abrogated by combined blockade of CR1 and CR2, but not of either receptor alone. The membrane depolarization is not associated with the apoptosis of B cells, as examined...... by co-staining with APO-2.7 or by the TdT-mediated biotin-dUTP nick-end labelling (TUNEL) assay. Confocal microscopy revealed that depolarization and C3 deposition, unlike MAC deposition, are limited to restricted areas on the B-cell surface. Double staining revealed a close association between the C3...

  15. DYNAMICS OF ACTIVITY OF SOME COMPONENTS OF COMPLEMENT IN TREATMENT OF ATOPIC DERMATITIS IN CHILDREN

    Directory of Open Access Journals (Sweden)

    S. S. Andina

    2014-01-01

    Full Text Available The article describes immunoassay methods of determining the functional activity of the components C3 and C9 and C1 inhibitor for diagnostic and prognostic purposes in the treatment of patients. The activity of these components, as well as the activity and the amount of C1 inhibitor in the blood serum of children aged 6 months to 18 years suffering from atopic dermatitis have been analyzed before and after treatment to determine the involvement of the complement system in the pathogenesis of this disease. The developed methods of enzyme immunoassay for determination of the functional components of the complement system have shown high sensitivity and reliability. The activity of C9 component involved in the membrane attack of the complement was significantly below normal in children with atopic dermatitis. That indicates the involvement of membrane attack complex components in the skin necrotic processes. Component C3 activity is also reduced. C3 is the key component of the activation cascade involved in the inflammatory processes. Specific activity of C1 inhibitor increased before and during the treatment, indicating an increased biosynthesis of this acute phase protein. Positive tendency towards the normalization of the status of complement after treatment has been observed. Data obtained in this study indicate the involvement of complement system in the pathological process of atopic dermatitis in children.

  16. Invisible Trojan-horse attack

    DEFF Research Database (Denmark)

    Sajeed, Shihan; Minshull, Carter; Jain, Nitin

    2017-01-01

    We demonstrate the experimental feasibility of a Trojan-horse attack that remains nearly invisible to the single-photon detectors employed in practical quantum key distribution (QKD) systems, such as Clavis2 from ID Quantique. We perform a detailed numerical comparison of the attack performance...

  17. Heart Attack Symptoms in Women

    Science.gov (United States)

    ... and Conditions and Privacy Policy Go Red For Women® presents: View our first-ever short film (opens in new window) by Elizabeth Banks and share with the women you love. Heart Attack • Home • About Heart Attacks ...

  18. [Heart-attack in pregnancy].

    Science.gov (United States)

    Výtisková, T; Suchá, D; Fučíková, Z

    To describe hear-attack on crystal meth addicted pregnant woman. Case report. Acute heart-attack during pregnancy means unexpected obstetric complication. The consequences could be fatal for the mother and the fetus. Although good delivery management and treatment could reduce morbidity and mortality to a minimum.

  19. Trichobothrial mediation of an aquatic escape response: Directional jumps by the fishing spider, Dolomedes triton, foil frog attacks

    Directory of Open Access Journals (Sweden)

    Robert B. Suter

    2003-07-01

    Full Text Available Fishing spiders (Pisauridae frequent the surfaces of ponds and streams and thereby expose themselves to predation by a variety of aquatic and semi-aquatic vertebrates. To assess the possibility that the impressive jumps of fishing spiders from the water surface function in evading attacks by frogs, attacks by bullfrogs (Rana catesbiana and green frogs (R. clamitans on Dolomedes triton were studied. Both the attack dynamics of the frogs and the evasive behaviors of the spiders were recorded at 250 frames per second. A freeze-dried bullfrog, propelled toward spiders with acceleration, posture, and position that approximated the natural attack posture and dynamics, was used to assess the spiders' behavior. Qualitatively, the spiders responded to these mock-attacks just as they had to attacks by live frogs: jumping (N=29 jumps, 56.9% of instances, rearing the legs nearest the attacking frog (N=15, 29.4%, or showing no visible response (N=7, 13.7%. Spiders that jumped always did so away (in the vertical plane from the attack (mean =137° vs. vertical at 90° or horizontally toward the frog at 0°. The involvement of the trichobothria (leg hairs sensitive to air movements, and the eyes as sensory mediators of the evasion response was assessed. Spiders with deactivated trichobothria were significantly impaired relative to intact and sham-deactivated spiders, and relative to spiders in total darkness. Thus, functional trichobothria, unlike the eyes, are both necessary and sufficient mediators of the evasion response. Measurements of air flow during frog attacks suggest that an exponential rise in flow velocity is the airborne signature of an attack.

  20. Invisible Trojan-horse attack.

    Science.gov (United States)

    Sajeed, Shihan; Minshull, Carter; Jain, Nitin; Makarov, Vadim

    2017-08-21

    We demonstrate the experimental feasibility of a Trojan-horse attack that remains nearly invisible to the single-photon detectors employed in practical quantum key distribution (QKD) systems, such as Clavis2 from ID Quantique. We perform a detailed numerical comparison of the attack performance against Scarani-Ac´ın-Ribordy-Gisin (SARG04) QKD protocol at 1924 nm versus that at 1536 nm. The attack strategy was proposed earlier but found to be unsuccessful at the latter wavelength, as reported in N. Jain et al., New J. Phys. 16, 123030 (2014). However at 1924 nm, we show experimentally that the noise response of the detectors to bright pulses is greatly reduced, and show by modeling that the same attack will succeed. The invisible nature of the attack poses a threat to the security of practical QKD if proper countermeasures are not adopted.

  1. Superposition Attacks on Cryptographic Protocols

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Funder, Jakob Løvstad; Nielsen, Jesper Buus

    2011-01-01

    string model. While our protocol is classical, it is sound against a cheating unbounded quantum prover and computational zero-knowledge even if the verifier is allowed a superposition attack. Finally, we consider multiparty computation and show that for the most general type of attack, simulation based......Attacks on classical cryptographic protocols are usually modeled by allowing an adversary to ask queries from an oracle. Security is then defined by requiring that as long as the queries satisfy some constraint, there is some problem the adversary cannot solve, such as compute a certain piece...... of information. In this paper, we introduce a fundamentally new model of quantum attacks on classical cryptographic protocols, where the adversary is allowed to ask several classical queries in quantum superposition. This is a strictly stronger attack than the standard one, and we consider the security...

  2. [The current situation of aggravated intoxication with "kiken" drugs (law-evading drugs)].

    Science.gov (United States)

    Akashi, Akiko; Kashiura, Masahiro; Mikami, Manabu; Hamabe, Yuichi

    2016-03-01

    The intoxication caused by "kiken" drugs (law-evading drugs), such as synthetic cannabinoids, cathinones, and methoxetamine, has recently increased in Japan. We retrospectively examined the characteristics of patients poisoned with the "kiken" drugs. We included patients who presented at the emergency department at the Tokyo Metropolitan Bokutoh Hospital from January 2011 to December 2014. Eighteen patients admitted between January 2011 and December 2013 were included in the early period group and 10 patients admitted between January and December 2014 were categorized into the late period group. The number of the patients transported to our emergency department between 2011 and 2014 increased annually. Patients were mainly admitted between May and October 2014; no patients were admitted after November 2014. The patients' age, history of previous mental disease, habitual use, Triage DOA results, serum creatinine values on admission, and respiratory management differed significantly between the groups. However, the median serum creatinine values of both groups on admission were within the normal level. Patients poisoned with the "kiken" drugs showed more severe symptoms, higher rate of habitual use, and higher average age. The annual increase in the number of the patients observed thus far is expected to decrease in the future. Maintenance of the law and expansion of medical institutions that treat patients addicted to the "kiken" drugs are warranted.

  3. Henipaviruses Employ a Multifaceted Approach to Evade the Antiviral Interferon Response

    Directory of Open Access Journals (Sweden)

    Megan L. Shaw

    2009-12-01

    Full Text Available Hendra and Nipah virus, which constitute the genus Henipavirus, are zoonotic paramyxoviruses that have been associated with sporadic outbreaks of severe disease and mortality in humans since their emergence in the late 1990s. Similar to other paramyxoviruses, their ability to evade the host interferon (IFN response is conferred by the P gene. The henipavirus P gene encodes four proteins; the P, V, W and C proteins, which have all been described to inhibit the antiviral response. Further studies have revealed that these proteins have overlapping but unique properties which enable the virus to block multiple signaling pathways in the IFN response. The best characterized of these is the JAK-STAT signaling pathway which is targeted by the P, V and W proteins via an interaction with the transcription factor STAT1. In addition the V and W proteins can both limit virus-induced induction of IFN but they appear to do this via distinct mechanisms that rely on unique sequences in their C-terminal domains. The ability to generate recombinant Nipah viruses now gives us the opportunity to determine the precise role for each of these proteins and address their contribution to pathogenicity. Additionally, the question of whether these multiple anti-IFN strategies are all active in the different mammalian hosts for henipaviruses, particularly the fruit bat reservoir, warrants further exploration.

  4. Stealth nanotubes: strategies of shielding carbon nanotubes to evade opsonization and improve biodistribution

    Science.gov (United States)

    Kotagiri, Nalinikanth; Kim, Jin-Woo

    2014-01-01

    Carbon nanotubes (CNTs) have recently been in the limelight for their potential role in disease diagnostics and therapeutics, as well as in tissue engineering. Before these medical applications can be realized, there is a need to address issues like opsonization, phagocytosis by macrophages, and sequestration to the liver and spleen for eventual elimination from the body; along with equally important issues such as aqueous solubility, dispersion, biocompatibility, and biofunctionalization. CNTs have not been shown to be able to evade such biological obstacles, which include their nonspecific attachments to cells and other biological components in the bloodstream, before reaching target tissues and cells in vivo. This will eventually determine their longevity in circulation and clearance rate from the body. This review article discusses the current status, challenges, practical strategies, and implementations of coating CNTs with biocompatible and opsonin-resistant moieties, rendering CNTs transparent to opsonins and deceiving the innate immune response to make believe that the CNTs are not foreign. A holistic approach to the development of such “stealth” CNTs is presented, which encompasses not only several biophysicochemical factors that are not limited to surface treatment of CNTs, but also extraneous biological factors such as the protein corona formation that inevitably controls the in vivo fate of the particles. This review also discusses the present and potential applications, along with the future directions, of CNTs and their hybrid-based nanotheranostic agents for multiplex, multimodal molecular imaging and therapy, as well as in other applications, such as drug delivery and tissue engineering. PMID:24872705

  5. Quantum back-action-evading measurement of motion in a negative mass reference frame

    Science.gov (United States)

    Møller, Christoffer B.; Thomas, Rodrigo A.; Vasilakis, Georgios; Zeuthen, Emil; Tsaturyan, Yeghishe; Balabas, Mikhail; Jensen, Kasper; Schliesser, Albert; Hammerer, Klemens; Polzik, Eugene S.

    2017-07-01

    Quantum mechanics dictates that a continuous measurement of the position of an object imposes a random quantum back-action (QBA) perturbation on its momentum. This randomness translates with time into position uncertainty, thus leading to the well known uncertainty on the measurement of motion. As a consequence of this randomness, and in accordance with the Heisenberg uncertainty principle, the QBA puts a limitation—the so-called standard quantum limit—on the precision of sensing of position, velocity and acceleration. Here we show that QBA on a macroscopic mechanical oscillator can be evaded if the measurement of motion is conducted in the reference frame of an atomic spin oscillator. The collective quantum measurement on this hybrid system of two distant and disparate oscillators is performed with light. The mechanical oscillator is a vibrational ‘drum’ mode of a millimetre-sized dielectric membrane, and the spin oscillator is an atomic ensemble in a magnetic field. The spin oriented along the field corresponds to an energetically inverted spin population and realizes a negative-effective-mass oscillator, while the opposite orientation corresponds to an oscillator with positive effective mass. The QBA is suppressed by -1.8 decibels in the negative-mass setting and enhanced by 2.4 decibels in the positive-mass case. This hybrid quantum system paves the way to entanglement generation and distant quantum communication between mechanical and spin systems and to sensing of force, motion and gravity beyond the standard quantum limit.

  6. Close, but no cigar: certain cigars are pseudo-cigarettes designed to evade regulation.

    Science.gov (United States)

    Delnevo, Cristine D; Hrywna, Mary; Giovenco, Daniel P; Miller Lo, Erin J; O'Connor, Richard J

    2017-05-01

    An abundance of evidence suggests that the tobacco industry's response to increased regulation imposed on cigarettes has been the development of little cigars and filtered cigars which are tobacco products that are merely cigarettes in disguise. Emphasising these products' physical attributes, the tobacco industry has offered cigar products to its consumers as pseudo-cigarettes. For decades, tobacco manufacturers' response to increased cigarette regulation and taxation has been to exploit policy loopholes by offering these little cigars and filtered cigars pseudo-cigarettes that are exempted from this regulatory oversight. As a result, in spite of increased regulations and taxes on cigarettes, smokers can purchase cigars that are almost physically indistinguishable from their cigarettes at a lower cost. This commentary describes the recent evolution of the cigar market in response to federal regulation, and highlights historical cigar industry attempts to evade taxation, capitalise on product features that are off-limits to cigarettes, and capture the shrinking market of cigarette smokers. We present the case that little cigars and filtered cigars, differing very little physically from cigarettes, are products deserving the same regulatory scrutiny. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  7. Evading plant immunity: feedback control of the T3SS in Pseudomonas syringae

    Science.gov (United States)

    Waite, Christopher; Schumacher, Jörg; Jovanovic, Milija; Bennett, Mark; Buck, Martin

    2017-01-01

    Microbes are responsible for over 10% of the global yield losses in staple crops such as wheat, rice, and maize. Understanding the decision-making strategies that enable bacterial plant pathogens to evade the host immune system and cause disease is essential for managing their ever growing threat to food security. Many utilise the needle-like type III secretion system (T3SS) to suppress plant immunity, by injecting effector proteins that inhibit eukaryotic signalling pathways into the host cell cytoplasm. Plants can in turn evolve resistance to specific pathogens via recognition and blocking of the T3SS effectors, so leading to an ongoing co-evolutionary ‘arms race’ between pathogen and host pairs. The extracytoplasmic function sigma factor HrpL co-ordinates the expression of the T3SS regulon in the leaf-dwelling Pseudomonas syringae and similar pathogens. Recently, we showed that association of HrpL with a target promoter directly adjacent to the hrpL gene imposes negative autogenous control on its own expression level due to overlapping regulatory elements. Our results suggest that by down-regulating T3SS function, this fine-tuning mechanism enables P. syringae to minimise effector-mediated elicitation of plant immunity. PMID:28435841

  8. Evading Quantum Mechanics: Engineering a Classical Subsystem within a Quantum Environment

    Directory of Open Access Journals (Sweden)

    Mankei Tsang

    2012-09-01

    Full Text Available Quantum mechanics is potentially advantageous for certain information-processing tasks, but its probabilistic nature and requirement of measurement backaction often limit the precision of conventional classical information-processing devices, such as sensors and atomic clocks. Here we show that, by engineering the dynamics of coupled quantum systems, it is possible to construct a subsystem that evades the measurement backaction of quantum mechanics, at all times of interest, and obeys any classical dynamics, linear or nonlinear, that we choose. We call such a system a quantum-mechanics-free subsystem (QMFS. All of the observables of a QMFS are quantum-nondemolition (QND observables; moreover, they are dynamical QND observables, thus demolishing the widely held belief that QND observables are constants of motion. QMFSs point to a new strategy for designing classical information-processing devices in regimes where quantum noise is detrimental, unifying previous approaches that employ QND observables, backaction evasion, and quantum noise cancellation. Potential applications include gravitational-wave detection, optomechanical-force sensing, atomic magnetometry, and classical computing. Demonstrations of dynamical QMFSs include the generation of broadband squeezed light for use in interferometric gravitational-wave detection, experiments using entangled atomic-spin ensembles, and implementations of the quantum Toffoli gate.

  9. The Role of Complement in Tumor Growth

    Science.gov (United States)

    Pio, Ruben; Corrales, Leticia; Lambris, John D.

    2015-01-01

    Complement is a central part of the immune system that has developed as a first defense against non-self cells. Neoplastic transformation is accompanied by an increased capacity of the malignant cells to activate complement. In fact, clinical data demonstrate complement activation in cancer patients. On the basis of the use of protective mechanisms by malignant cells, complement activation has traditionally been considered part of the body's immunosurveillance against cancer. Inhibitory mechanisms of complement activation allow cancer cells to escape from complement-mediated elimination and hamper the clinical efficacy of monoclonal antibody–based cancer immunotherapies. To overcome this limitation, many strategies have been developed with the goal of improving complement-mediated effector mechanisms. However, significant work in recent years has identified new and surprising roles for complement activation within the tumor microenvironment. Recent reports suggest that complement elements can promote tumor growth in the context of chronic inflammation. This chapter reviews the data describing the role of complement activation in cancer immunity, which offers insights that may aid the development of more effective therapeutic approaches to control cancer. PMID:24272362

  10. The complement system in human cardiometabolic disease.

    Science.gov (United States)

    Hertle, E; Stehouwer, C D A; van Greevenbroek, M M J

    2014-10-01

    The complement system has been implicated in obesity, fatty liver, diabetes and cardiovascular disease (CVD). Complement factors are produced in adipose tissue and appear to be involved in adipose tissue metabolism and local inflammation. Thereby complement links adipose tissue inflammation to systemic metabolic derangements, such as low-grade inflammation, insulin resistance and dyslipidaemia. Furthermore, complement has been implicated in pathophysiological mechanisms of diet- and alcohol induced liver damage, hyperglycaemia, endothelial dysfunction, atherosclerosis and fibrinolysis. In this review, we summarize current evidence on the role of the complement system in several processes of human cardiometabolic disease. C3 is the central component in complement activation, and has most widely been studied in humans. C3 concentrations are associated with insulin resistance, liver dysfunction, risk of the metabolic syndrome, type 2 diabetes and CVD. C3 can be activated by the classical, the lectin and the alternative pathway of complement activation; and downstream activation of C3 activates the terminal pathway. Complement may also be activated via extrinsic proteases of the coagulation, fibrinolysis and the kinin systems. Studies on the different complement activation pathways in human cardiometabolic disease are limited, but available evidence suggests that they may have distinct roles in processes underlying cardiometabolic disease. The lectin pathway appeared beneficial in some studies on type 2 diabetes and CVD, while factors of the classical and the alternative pathway were related to unfavourable cardiometabolic traits. The terminal complement pathway was also implicated in insulin resistance and liver disease, and appears to have a prominent role in acute and advanced CVD. The available human data suggest a complex and potentially causal role for the complement system in human cardiometabolic disease. Further, preferably longitudinal studies are needed to

  11. A Strategic Analysis of Information Sharing Among Cyber Attackers

    Directory of Open Access Journals (Sweden)

    Kjell Hausken

    2015-10-01

    Full Text Available We build a game theory model where the market design is such that one firm invests in security to defend against cyber attacks by two hackers. The firm has an asset, which is allocated between the three market participants dependent on their contest success. Each hacker chooses an optimal attack, and they share information with each other about the firm’s vulnerabilities. Each hacker prefers to receive information, but delivering information gives competitive advantage to the other hacker. We find that each hacker’s attack and information sharing are strategic complements while one hacker’s attack and the other hacker’s information sharing are strategic substitutes. As the firm’s unit defense cost increases, the attack is inverse U-shaped and reaches zero, while the firm’s defense and profit decrease, and the hackers’ information sharing and profit increase. The firm’s profit increases in the hackers’ unit cost of attack, while the hackers’ information sharing and profit decrease. Our analysis also reveals the interesting result that the cumulative attack level of the hackers is not affected by the effectiveness of information sharing between them and moreover, is also unaffected by the intensity of joint information sharing. We also find that as the effectiveness of information sharing between hackers increases relative to the investment in attack, the firm’s investment in cyber security defense and profit are constant, the hackers’ investments in attacks decrease, and information sharing levels and hacker profits increase. In contrast, as the intensity of joint information sharing increases, while the firm’s investment in cyber security defense and profit remain constant, the hackers’ investments in attacks increase, and the hackers’ information sharing levels and profits decrease. Increasing the firm’s asset causes all the variables to increase linearly, except information sharing which is constant. We extend

  12. Differential capacity for complement receptor-mediated immune evasion by Porphyromonas gingivalis depending on the type of innate leukocyte.

    Science.gov (United States)

    Hajishengallis, G; Krauss, J L; Jotwani, R; Lambris, J D

    2017-04-01

    The complement system plays a central role in immunity and inflammation, although certain pathogens can exploit complement to undermine protective immunity. In this context, the periodontal keystone pathogen Porphyromonas gingivalis was previously shown by our group to evade killing by neutrophils or macrophages through exploitation of complement C5a receptor 1 (C5aR1) and complement receptor 3 (CR3). Here, we examined whether P. gingivalis uses complement receptors to also subvert killing by dendritic cells. In line with earlier independent studies, intracellular viable P. gingivalis bacteria could be recovered from mouse bone-marrow-derived dendritic cells (BMDC) or human monocyte-derived dendritic cells (MDDC) exposed to the pathogen. However, in the presence of C5a, the intracellular survival of P. gingivalis was significantly decreased in a C5aR1-dependent way. Further work using wild-type and receptor-knockout BMDC showed that, in the presence of C3a, the C3a receptor (C3aR) similarly enhanced the intracellular killing of P. gingivalis. In contrast, C5aR2, an alternative receptor for C5a (G protein-coupled receptor 77), was associated with increased intracellular P. gingivalis viable counts, consistent with the notion that C5aR2 functions as a negative regulator of C5aR1 activity. Moreover, P. gingivalis failed to use CR3 as a phagocytic receptor in BMDC, in contrast to our earlier findings in macrophages where CR3-mediated uptake promotes P. gingivalis survival. Collectively, these data show that complement receptors mediate cell-type-specific effects on how innate leukocytes handle P. gingivalis, which appears to exploit complement to preferentially evade those cells (neutrophils and macrophages) that are most often encountered in its predominant niche, the periodontal pocket. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Targeting the Human Complement Membrane Attack Complex to Selectively Kill Prostate Cancer Cells

    Science.gov (United States)

    2012-10-01

    fragment in green, PAC5-7 insert in yellow. A plasmid containing PAC-7 was transfected into COS-7 and HEK293T cells and conditioned media...This DNA was purified and transfected into HEK293T cells. Virus production was monitored by GFP expression. After a series of viral amplifications a...high titer virus stock was made. Recombinant PAC5-7 can be expressed by adding viral stock to feeder HEK293 cells. A series of viral transfections

  14. A novel trifunctional IgG-like bispecific antibody to inhibit HIV-1 infection and enhance lysis of HIV by targeting activation of complement

    Directory of Open Access Journals (Sweden)

    Tomlinson Stephen

    2010-06-01

    Full Text Available Abstract Background The complement system is not only a key component of innate immunity but also provides a first line of defense against invading pathogens, especially for viral pathogens. Human immunodeficiency virus (HIV, however, possesses several mechanisms to evade complement-mediated lysis (CoML and exploit the complement system to enhance viral infectivity. Responsible for this intrinsic resistance against complement-mediated virolysis are complement regulatory membrane proteins derived from the host cell that inherently downregulates complement activation at several stages of the cascade. In addition, HIV is protected from complement-mediated lysis by binding soluble factor H (fH through the viral envelope proteins, gp120 and gp41. Whereas inhibition of complement activity is the desired outcome in the vast majority of therapeutic approaches, there is a broader potential for complement-mediated inhibition of HIV by complement local stimulation. Presentation of the hypothesis Our previous studies have proven that the complement-mediated antibody-dependent enhancement of HIV infection is mediated by the association of complement receptor type 2 bound to the C3 fragment and deposited on the surface of HIV virions. Thus, we hypothesize that another new activator of complement, consisting of two dsFv (against gp120 and against C3d respectively linked to a complement-activating human IgG1 Fc domain ((anti-gp120 × anti-C3d-Fc, can not only target and amplify complement activation on HIV virions for enhancing the efficiency of HIV lysis, but also reduce the infectivity of HIV through blocking the gp120 and C3d on the surface of HIV. Testing the hypothesis Our hypothesis was tested using cell-free HIV-1 virions cultivated in vitro and assessment of virus opsonization was performed by incubating appropriate dilutions of virus with medium containing normal human serum and purified (anti-gp120 × anti-C3d-Fc proteins. As a control group, viruses

  15. Complement Diagnostics: Concepts, Indications, and Practical Guidelines

    Directory of Open Access Journals (Sweden)

    Bo Nilsson

    2012-01-01

    Full Text Available Aberrations in the complement system have been shown to be direct or indirect pathophysiological mechanisms in a number of diseases and pathological conditions such as autoimmune disease, infections, cancer, allogeneic and xenogeneic transplantation, and inflammation. Complement analyses have been performed on these conditions in both prospective and retrospective studies and significant differences have been found between groups of patients, but in many diseases, it has not been possible to make predictions for individual patients because of the lack of sensitivity and specificity of many of the assays used. The basic indications for serological diagnostic complement analysis today may be divided into three major categories: (a acquired and inherited complement deficiencies; (b disorders with complement activation; (c inherited and acquired C1INH deficiencies. Here, we summarize indications, techniques, and interpretations for basic complement analyses and present an algorithm, which we follow in our routine laboratory.

  16. Complement defects in patients with chronic rhinosinusitis

    DEFF Research Database (Denmark)

    Gaunsbaek, Maria Quisgaard; Lange, Bibi; Kjeldsen, Anette D

    2012-01-01

    The complement system is an important part of our immune system, and complement defects lead generally to increased susceptibility to infections and autoimmune diseases. We have studied the role of complement activity in relation with chronic rhinosinusitis (CRS), and more specifically studied...... was significantly higher among CRS patients than among healthy control subjects. A majority of Mannan-binding lectin deficient CRS patients was observed. The presence of complement defects had no influence on the severity of subjective symptoms. Our studies show that defects in the complement system collectively...... whether complement defects collectively predispose individuals for CRS or affect CRS severity. The participants comprised 87 CRS patients randomly selected from the general population, and a control group of 150 healthy blood donors. The CRS patients were diagnosed according to the European Position Paper...

  17. Complement pathways and meningococcal disease : diagnostic aspects

    DEFF Research Database (Denmark)

    Sjöholm, A G; Truedsson, L; Jensenius, Jens Christian

    2001-01-01

    Complement is an immunological effector system that bridges innate and acquired immunity in several ways. There is a striking association between susceptibility to meningococcal disease and various forms of complement deficiency (1,2). In defense against bacterial infection, the most important...... function of complement is probably to serve as a mediator of antibody-dependent immunity. Specific antibodies can trigger activation of the classical and the alternative pathways of complement activation (3-5). It is well known that antibody-independent mechanisms interfere with alternative pathway...... activation on the bacterial surface (6,7). The newly discovered mannan-binding lectin (MBL) pathway of complement activation appears to be protective against many types of infection (8) and adds previously unsuspected aspects of innate immunity to complement-mediated defense. Interestingly, immune responses...

  18. Role of Complement in Autoimmune Hemolytic Anemia.

    Science.gov (United States)

    Berentsen, Sigbjørn

    2015-09-01

    The classification of autoimmune hemolytic anemias and the complement system are reviewed. In autoimmune hemolytic anemia of the warm antibody type, complement-mediated cell lysis is clinically relevant in a proportion of the patients but is hardly essential for hemolysis in most patients. Cold antibody-mediated autoimmune hemolytic anemias (primary cold agglutinin disease, secondary cold agglutinin syndrome and paroxysmal cold hemoglobinuria) are entirely complement-mediated disorders. In cold agglutinin disease, efficient therapies have been developed in order to target the pathogenic B-cell clone, but complement modulation remains promising in some clinical situations. No established therapy exists for secondary cold agglutinin syndrome and paroxysmal cold hemoglobinuria, and the possibility of therapeutic complement inhibition is interesting. Currently, complement modulation is not clinically documented in any autoimmune hemolytic anemia. The most relevant candidate drugs and possible target levels of action are discussed.

  19. The Lectin Pathway of Complement and Biocompatibility

    DEFF Research Database (Denmark)

    Hein, Estrid; Garred, Peter

    2015-01-01

    activation, the coagulation system and the complement system. The complement system is an important part of the initial immune response and consists of fluid phase molecules in the blood stream. Three different activation pathways can initiate the complement system, the lectin, the classical...... been broadly documented. However, the specific role of lectin pathway and the pattern recognition molecules initiating the pathway has only been transiently investigated. Here we review the current data on the field....

  20. Role of Complement in Autoimmune Hemolytic Anemia

    OpenAIRE

    Berentsen, Sigbj?rn

    2015-01-01

    Summary The classification of autoimmune hemolytic anemias and the complement system are reviewed. In autoimmune hemolytic anemia of the warm antibody type, complement-mediated cell lysis is clinically relevant in a proportion of the patients but is hardly essential for hemolysis in most patients. Cold antibody-mediated autoimmune hemolytic anemias (primary cold agglutinin disease, secondary cold agglutinin syndrome and paroxysmal cold hemoglobinuria) are entirely complement-mediated disorder...

  1. Allergens might trigger migraine attacks.

    Science.gov (United States)

    Bektas, Hesna; Karabulut, Hayriye; Doganay, Beyza; Acar, Baran

    2017-03-01

    Migraine is a common primary headache disorder. The mechanisms underlying the onset of a migraine attack are not completely understood. Environmental changes and a number of other factors could induce migraine attacks. The aim of this study was to investigate the relationship between the frequency of migraine attacks and allergens. Migraine patients without aura, and healthy individuals similar in age and gender without a history of headache and allergy were prospectively included in the study. The duration of migraine, the frequency of migraine attacks, the medication history, and the symptoms during attacks were questioned. Migraine disability assessment score (MIDAS) and visual analog scale (VAS) scores were obtained. Allergen extracts including dust, fungi, insect, animal epithelium, pollens, and food allergens were applied for allergy tests. 49 migraine patients and 49 healthy individuals were enrolled in the study. There was no significant difference in terms of age and gender. The median migraine disease duration, the number of attacks in a month, and the duration of attacks were, respectively, 5.5 years (1-44), 4 (1-10) day/month, and 24 (4-72) h. The mean MIDAS grade was 2.45 ± 0.14 (1-4), and mean VAS score was 7.89 ± 0.27 (4-10). The positivity of allergy tests was 55.1 % (27/49) in the migraine group and 32.7 % (16/49) in the control group (p < 0.05). The allergy tests were positive for house dust, red birch, hazel tree, olive tree, nettle, and wheat. The frequency of migraine attacks was higher in allergy-test-positive patients than in negative ones in the migraine group (p = 0.001). The migraine patients who had frequent attacks should be examined for allergies.

  2. WILD PIG ATTACKS ON HUMANS

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, J.

    2013-04-12

    Attacks on humans by wild pigs (Sus scrofa) have been documented since ancient times. However, studies characterizing these incidents are lacking. In an effort to better understand this phenomenon, information was collected from 412 wild pig attacks on humans. Similar to studies of large predator attacks on humans, data came from a variety of sources. The various attacks compiled occurred in seven zoogeographic realms. Most attacks occurred within the species native range, and specifically in rural areas. The occurrence was highest during the winter months and daylight hours. Most happened under non-hunting circumstances and appeared to be unprovoked. Wounded animals were the chief cause of these attacks in hunting situations. The animals involved were typically solitary, male and large in size. The fate of the wild pigs involved in these attacks varied depending upon the circumstances, however, most escaped uninjured. Most human victims were adult males traveling on foot and alone. The most frequent outcome for these victims was physical contact/mauling. The severity of resulting injuries ranged from minor to fatal. Most of the mauled victims had injuries to only one part of their bodies, with legs/feet being the most frequent body part injured. Injuries were primarily in the form of lacerations and punctures. Fatalities were typically due to blood loss. In some cases, serious infections or toxemia resulted from the injuries. Other species (i.e., pets and livestock) were also accompanying some of the humans during these attacks. The fates of these animals varied from escaping uninjured to being killed. Frequency data on both non-hunting and hunting incidents of wild pig attacks on humans at the Savannah River Site, South Carolina, showed quantitatively that such incidents are rare.

  3. Shark Attack Project - Marine Attack at Towed Hydrophone Arrays

    National Research Council Canada - National Science Library

    Kalmijn, Adrianus J

    2005-01-01

    The original objective of the SIO Marine Attack project was to identify the electric and magnetic fields causing sharks to inflict serious damage upon the towed hydrophone arrays of US Navy submarines...

  4. Multiculturalism & The Charlie Hebdo Attack

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2016-01-01

    The attack on Charlie Hebdo has by many been linked to multiculturalism. But it is unclear exactly how the connection between multiculturalism and the attack should be understood and whether there indeed is such a connection. The article discusses this by distinguishing between different senses...... of multiculturalism and different ways in which one might think that there is a link between multiculturalism and the attack. On this basis the resulting claims are discussed as to whether they are in fact plausible, which many of them turn out not to be....

  5. Automated Generation of Attack Trees

    DEFF Research Database (Denmark)

    Vigo, Roberto; Nielson, Flemming; Nielson, Hanne Riis

    2014-01-01

    -prone and impracticable for large systems. Nonetheless, the automated generation of attack trees has only been explored in connection to computer networks and levering rich models, whose analysis typically leads to an exponential blow-up of the state space. We propose a static analysis approach where attack trees...... interesting quantitative problems, that can be solved through an encoding into Satisfiability Modulo Theories. The flexibility and effectiveness of the approach is demonstrated on the study of a national-scale authentication system, whose attack tree is computed thanks to a Java implementation...

  6. The Cyber-Physical Attacker

    DEFF Research Database (Denmark)

    Vigo, Roberto

    2012-01-01

    The world of Cyber-Physical Systems ranges from industrial to national interest applications. Even though these systems are pervading our everyday life, we are still far from fully understanding their security properties. Devising a suitable attacker model is a crucial element when studying...... the security properties of CPSs, as a system cannot be secured without defining the threats it is subject to. In this work an attacker scenario is presented which addresses the peculiarities of a cyber-physical adversary, and we discuss how this scenario relates to other attacker models popular in the security...

  7. Emakeelepäevad Riias jätkuvad / Tõnu Karma ; fotod: M. Kulli ja Tõnu Karma

    Index Scriptorium Estoniae

    Karma, Tõnu

    2003-01-01

    12. märtsil 1989. aastal emakeelepäeva tähistamisest Riias, korraldajaks Läti Eesti Selts, ja sama aasta juunis rahvaluulepäevade pidamist, millega tähistati Jakob Hurda 150. sünniaastapäeva, Kristjan Jaak Petersoni 200. sünniaastapäeva tähistamisest ja mälestuskivi püstitamisest Jakobi kalmistule

  8. Some legal challenges posed by remote attack

    National Research Council Canada - National Science Library

    William Boothby

    2012-01-01

      Abstract Attacking from a distance is nothing new, but with the advent of certain new technologies, attacks can be undertaken in which the attacker remains very remote from the scene where force will be employed...

  9. Social Engineering Attack Detection Model: SEADMv2

    CSIR Research Space (South Africa)

    Mouton, F

    2015-10-01

    Full Text Available and is only able to cater for social engineering attacks that use bidirectional communication. Previous research discovered that social engineering attacks can be classified into three different categories, namely attacks that utilise bidirectional...

  10. A Distributed Middleware Architecture for Attack-Resilient Communications in Smart Grids: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yifu; Wei, Jin; Hodge, Bri-Mathias

    2017-05-24

    Distributed energy resources (DERs) are being increasingly accepted as an excellent complement to traditional energy sources in smart grids. Because most of these generators are geographically dispersed, dedicated communications investments for every generator are capital-cost prohibitive. Real-time distributed communications middleware - which supervises, organizes, and schedules tremendous amounts of data traffic in smart grids with high penetrations of DERs - allows for the use of existing network infrastructure. In this paper, we propose a distributed attack-resilient middleware architecture that detects and mitigates the congestion attacks by exploiting the quality of experience measures to complement the conventional quality of service information to effectively detect and mitigate congestion attacks. The simulation results illustrate the efficiency of our proposed communications middleware architecture.

  11. A Distributed Middleware Architecture for Attack-Resilient Communications in Smart Grids

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, Brian S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wu, Yifu [University of Akron; Wei, Jin [University of Akron

    2017-07-31

    Distributed Energy Resources (DERs) are being increasingly accepted as an excellent complement to traditional energy sources in smart grids. As most of these generators are geographically dispersed, dedicated communications investments for every generator are capital cost prohibitive. Real-time distributed communications middleware, which supervises, organizes and schedules tremendous amounts of data traffic in smart grids with high penetrations of DERs, allows for the use of existing network infrastructure. In this paper, we propose a distributed attack-resilient middleware architecture that detects and mitigates the congestion attacks by exploiting the Quality of Experience (QoE) measures to complement the conventional Quality of Service (QoS) information to detect and mitigate the congestion attacks effectively. The simulation results illustrate the efficiency of our proposed communications middleware architecture.

  12. Soluble form of membrane attack complex independently predicts mortality and cardiovascular events in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Lindberg, Søren; Pedersen, Sune H; Mogelvang, Rasmus

    2012-01-01

    The complement system is an important mediator of inflammation, which plays a pivotal role in atherosclerosis and acute myocardial infarction (AMI). Animal studies suggest that activation of the complement cascade resulting in the formation of soluble membrane attack complex (sMAC), contributes...

  13. Dengue Virus Evades AAV-Mediated Neutralizing Antibody Prophylaxis in Rhesus Monkeys.

    Science.gov (United States)

    Magnani, Diogo M; Ricciardi, Michael J; Bailey, Varian K; Gutman, Martin J; Pedreño-Lopez, Núria; Silveira, Cassia G T; Maxwell, Helen S; Domingues, Aline; Gonzalez-Nieto, Lucas; Su, Qin; Newman, Ruchi M; Pack, Melissa; Martins, Mauricio A; Martinez-Navio, José M; Fuchs, Sebastian P; Rakasz, Eva G; Allen, Todd M; Whitehead, Stephen S; Burton, Dennis R; Gao, Guangping; Desrosiers, Ronald C; Kallas, Esper G; Watkins, David I

    2017-10-04

    Development of vaccines against mosquito-borne Flaviviruses is complicated by the occurrence of antibody-dependent enhancement (ADE), which can increase disease severity. Long-term delivery of neutralizing antibodies (nAbs) has the potential to effectively block infection and represents an alternative to vaccination. The risk of ADE may be avoided by using prophylactic nAbs harboring amino acid mutations L234A and L235A (LALA) in the immunoglobulin G (IgG) constant region. Here, we used recombinant adeno-associated viruses (rAAVs) to deliver the anti-dengue virus 3 (DENV3) nAb P3D05. While the administration of rAAV-P3D05-rhesus immunoglobulin G1 (rhIgG1)-LALA to rhesus macaques engendered DENV3-neutralizing activity in serum, it did not prevent infection. The emergence of viremia following DENV3 challenge was delayed by 3-6 days in the rAAV-treated group, and replicating virus contained the envelope mutation K64R. This neutralization-resistant variant was also confirmed by virus outgrowth experiments in vitro. By delivering P3D05 with unmutated Fc sequences, we further demonstrated that DENV3 also evaded wild-type nAb prophylaxis, and serum viral loads appeared to be higher in the presence of low levels of unmutated P3D05-rhIgG1. Our study shows that a vectored approach for long-term delivery of nAbs with the LALA mutations is promising, but prophylaxis using a single nAb is likely insufficient at preventing DENV infection and replication. Copyright © 2017 The American Society of Gene and Cell Therapy. All rights reserved.

  14. Optimized AAV rh.10 Vectors That Partially Evade Neutralizing Antibodies during Hepatic Gene Transfer

    Directory of Open Access Journals (Sweden)

    Ruchita Selot

    2017-07-01

    Full Text Available Of the 12 common serotypes used for gene delivery applications, Adeno-associated virus (AAVrh.10 serotype has shown sustained hepatic transduction and has the lowest seropositivity in humans. We have evaluated if further modifications to AAVrh.10 at its phosphodegron like regions or predicted immunogenic epitopes could improve its hepatic gene transfer and immune evasion potential. Mutant AAVrh.10 vectors were generated by site directed mutagenesis of the predicted targets. These mutant vectors were first tested for their transduction efficiency in HeLa and HEK293T cells. The optimal vector was further evaluated for their cellular uptake, entry, and intracellular trafficking by quantitative PCR and time-lapse confocal microscopy. To evaluate their potential during hepatic gene therapy, C57BL/6 mice were administered with wild-type or optimal mutant AAVrh.10 and the luciferase transgene expression was documented by serial bioluminescence imaging at 14, 30, 45, and 72 days post-gene transfer. Their hepatic transduction was further verified by a quantitative PCR analysis of AAV copy number in the liver tissue. The optimal AAVrh.10 vector was further evaluated for their immune escape potential, in animals pre-immunized with human intravenous immunoglobulin. Our results demonstrate that a modified AAVrh.10 S671A vector had enhanced cellular entry (3.6 fold, migrate rapidly to the perinuclear region (1 vs. >2 h for wild type vectors in vitro, which further translates to modest increase in hepatic gene transfer efficiency in vivo. More importantly, the mutant AAVrh.10 vector was able to partially evade neutralizing antibodies (~27–64 fold in pre-immunized animals. The development of an AAV vector system that can escape the circulating neutralizing antibodies in the host will substantially widen the scope of gene therapy applications in humans.

  15. Optimized AAV rh.10 Vectors That Partially Evade Neutralizing Antibodies during Hepatic Gene Transfer.

    Science.gov (United States)

    Selot, Ruchita; Arumugam, Sathyathithan; Mary, Bertin; Cheemadan, Sabna; Jayandharan, Giridhara R

    2017-01-01

    Of the 12 common serotypes used for gene delivery applications, Adeno-associated virus (AAV)rh.10 serotype has shown sustained hepatic transduction and has the lowest seropositivity in humans. We have evaluated if further modifications to AAVrh.10 at its phosphodegron like regions or predicted immunogenic epitopes could improve its hepatic gene transfer and immune evasion potential. Mutant AAVrh.10 vectors were generated by site directed mutagenesis of the predicted targets. These mutant vectors were first tested for their transduction efficiency in HeLa and HEK293T cells. The optimal vector was further evaluated for their cellular uptake, entry, and intracellular trafficking by quantitative PCR and time-lapse confocal microscopy. To evaluate their potential during hepatic gene therapy, C57BL/6 mice were administered with wild-type or optimal mutant AAVrh.10 and the luciferase transgene expression was documented by serial bioluminescence imaging at 14, 30, 45, and 72 days post-gene transfer. Their hepatic transduction was further verified by a quantitative PCR analysis of AAV copy number in the liver tissue. The optimal AAVrh.10 vector was further evaluated for their immune escape potential, in animals pre-immunized with human intravenous immunoglobulin. Our results demonstrate that a modified AAVrh.10 S671A vector had enhanced cellular entry (3.6 fold), migrate rapidly to the perinuclear region (1 vs. >2 h for wild type vectors) in vitro, which further translates to modest increase in hepatic gene transfer efficiency in vivo. More importantly, the mutant AAVrh.10 vector was able to partially evade neutralizing antibodies (~27-64 fold) in pre-immunized animals. The development of an AAV vector system that can escape the circulating neutralizing antibodies in the host will substantially widen the scope of gene therapy applications in humans.

  16. Genetic attack on neural cryptography.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Naeh, Rivka; Kanter, Ido

    2006-03-01

    Different scaling properties for the complexity of bidirectional synchronization and unidirectional learning are essential for the security of neural cryptography. Incrementing the synaptic depth of the networks increases the synchronization time only polynomially, but the success of the geometric attack is reduced exponentially and it clearly fails in the limit of infinite synaptic depth. This method is improved by adding a genetic algorithm, which selects the fittest neural networks. The probability of a successful genetic attack is calculated for different model parameters using numerical simulations. The results show that scaling laws observed in the case of other attacks hold for the improved algorithm, too. The number of networks needed for an effective attack grows exponentially with increasing synaptic depth. In addition, finite-size effects caused by Hebbian and anti-Hebbian learning are analyzed. These learning rules converge to the random walk rule if the synaptic depth is small compared to the square root of the system size.

  17. What Causes a Heart Attack?

    Science.gov (United States)

    ... heart attack at age 36, it stopped her "dead in her tracks." Jennifer reminds us how heart disease takes too many of our moms, sisters, and friends from us every day. The more we share our stories, the faster ...

  18. What Is a Heart Attack?

    Science.gov (United States)

    ... blood pressure and excess protein in the urine. Preeclampsia is linked to an increased lifetime risk of heart disease, including CHD, heart attack, heart failure , and high blood pressure. Screening and Prevention Lowering your risk factors for coronary heart disease ...

  19. The relapsing fever spirochete Borrelia miyamotoi resists complement-mediated killing by human serum.

    Science.gov (United States)

    Teegler, Axel; Herzberger, Pia; Margos, Gabriele; Fingerle, Volker; Kraiczy, Peter

    2014-10-01

    Borrelia miyamotoi, a relapsing fever spirochete transmitted by ixodid ticks, is able to cause infections associated with systemic complaints, including malaise and fever, as well as meningoencephalitis in immunocompromised patients. In order to elucidate immune evasion of previously difficult to cultivate B. miyamotoi, we have examined the ability of this newly emerging human pathogen to escape the complement system. Growth inhibition assays revealed that B. miyamotoi is strongly resistant to complement-mediated bacteriolysis. Investigating complement activation, we found that B. miyamotoi showed reduced deposition of components C3, C5, C7, C8, C9 as well as the membrane attack complex (MAC) on the borrelial surface. In addition, no aberrations in cell morphology were observed after incubation of B. miyamotoi in active human serum, confirming the findings of the growth inhibition assay. The data presented here provide strong evidence that B. miyamotoi overcome human complement by affecting the central complement component C3, thereby inhibiting formation of the C3 convertase and downstream activation of the complement cascade. Copyright © 2014 Elsevier GmbH. All rights reserved.

  20. Functional Analyses of Complement Convertases Using C3 and C5-Depleted Sera

    Science.gov (United States)

    Okroj, Marcin; Holmquist, Emelie; King, Ben C.; Blom, Anna M.

    2012-01-01

    C3 and C5 convertases are central stages of the complement cascade since they converge the different initiation pathways, augment complement activation by an amplification loop and lead to a common terminal pathway resulting in the formation of the membrane attack complex. Several complement inhibitors attenuate convertase formation and/or accelerate dissociation of convertase complexes. Functional assays used to study these processes are often performed using purified complement components, from which enzymatic complexes are reconstituted on the surface of erythrocytes or artificial matrices. This strategy enables identification of individual interactions between convertase components and putative regulators but carries an inherent risk of detecting non-physiological interactions that would not occur in a milieu of whole serum. Here we describe a novel, alternative method based on C3 or C5-depleted sera, which support activation of the complement cascade up to the desired stages of convertases. This approach allows fast and simple assessment of the influence of putative regulators on convertase formation and stability. As an example of practical utility of the assay, we performed studies on thioredoxin-1 in order to clarify the mechanism of its influence on complement convertases. PMID:23071769

  1. Functional analyses of complement convertases using C3 and C5-depleted sera.

    Directory of Open Access Journals (Sweden)

    Marcin Okroj

    Full Text Available C3 and C5 convertases are central stages of the complement cascade since they converge the different initiation pathways, augment complement activation by an amplification loop and lead to a common terminal pathway resulting in the formation of the membrane attack complex. Several complement inhibitors attenuate convertase formation and/or accelerate dissociation of convertase complexes. Functional assays used to study these processes are often performed using purified complement components, from which enzymatic complexes are reconstituted on the surface of erythrocytes or artificial matrices. This strategy enables identification of individual interactions between convertase components and putative regulators but carries an inherent risk of detecting non-physiological interactions that would not occur in a milieu of whole serum. Here we describe a novel, alternative method based on C3 or C5-depleted sera, which support activation of the complement cascade up to the desired stages of convertases. This approach allows fast and simple assessment of the influence of putative regulators on convertase formation and stability. As an example of practical utility of the assay, we performed studies on thioredoxin-1 in order to clarify the mechanism of its influence on complement convertases.

  2. Harvesting Smartphone Privacy Through Enhanced Juice Filming Charging Attacks

    DEFF Research Database (Denmark)

    Meng, Weizhi; Fei, Fei; Li, Wenjuan

    2017-01-01

    The increasingly high demand for smartphone charging in people’s daily lives has apparently encouraged much more public charging stations to be deployed in various places (e.g., shopping malls, airports). However, these public charging facilities may open a hole for cyber-criminals to infer private...... information and data from smartphone users. Juice filming charging (JFC) attack is a particular type of charging attacks, which is capable of stealing users’ sensitive information from both Android OS and iOS devices, through automatically monitoring and recording phone screen during the whole charging period...... one in collecting users’ information at large and extracting sensitive data with a higher accuracy. Our work aims to complement existing results and stimulate more efforts in defending smartphones against charging threats....

  3. CAS, interdiction, and attack helicopters

    OpenAIRE

    Groenke, Andrew S.

    2005-01-01

    Within days of a major failed strike by attack helicopters during Operation Iraqi Freedom (OIF) analysts were questioning the value of such platforms on the modern battlefield. As OIF moved from combat to stability operations, helicopter losses from enemy action actually increased seemingly strengthening the argument of those who see the helicopter as unsuitable to some combat operations. Attack helicopter operations have diverged into two distinct categories, interdiction and close air sup...

  4. Software-based Microarchitectural Attacks

    OpenAIRE

    Gruss, Daniel

    2017-01-01

    Modern processors are highly optimized systems where every single cycle of computation time matters. Many optimizations depend on the data that is being processed. Software-based microarchitectural attacks exploit effects of these optimizations. Microarchitectural side-channel attacks leak secrets from cryptographic computations, from general purpose computations, or from the kernel. This leakage even persists across all common isolation boundaries, such as processes, containers, and virtual ...

  5. Review on complement analysis method and the roles of glycosaminoglycans in the complement system.

    Science.gov (United States)

    Li, Lian; Li, Yan; Ijaz, Muhammad; Shahbaz, Muhammad; Lian, Qianqian; Wang, Fengshan

    2015-12-10

    Complement system is composed of over 30 proteins and it plays important roles in self-defence and inflammation. There are three activation pathways, including classical pathway, alternative pathway and lectin pathway, in complement system, and they are associated with many diseases such as osteoarthritis and age-related macular degeneration. Modulation of the complement system may be a promising strategy in the treatment of related diseases. Glycosaminoglycans are anionic linear polysaccharides without branches. They are one kind of multi-functional macromolecules which have great potential in regulating complement system. This review is organized around two aspects between the introduction of complement system and the interaction of glycosaminoglycans with complement system. Three complement activation pathways and the biological significance were introduced first. Then functional analysis methods were compared to provide a strategy for potential glycosaminoglycans screen. Finally, the roles of glycosaminoglycans played in the complement system were summed up. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Viral mimicry of the complement system

    Indian Academy of Sciences (India)

    Unknown

    et al 2002), hepatitis C virus (Ishii et al 2001) and HIV. (Ezekowitz et al 1989; Saifuddin et al 2000). Activation of the complement system in the absence of proper regulation can lead to virus neutralization. The various mechanisms which are known to inactivate viruses are: (i) neutralization by complement dependant ...

  7. Complement Clause Formation In Leteh | Ansah | Contemporary ...

    African Journals Online (AJOL)

    This paper explores the complementation phenomenon in Leteh. The discussion is done within the framework of Basic Linguistic Theory (Dixon 1997), and further appeals to the theory of grammaticalization to explain the multiple functions of Leteh complementizers. Leteh is a South Guan (Kwa, Niger-Congo) language ...

  8. The complement system in systemic autoimmune disease

    NARCIS (Netherlands)

    Chen, Min; Daha, Mohamed R.; Kallenberg, Cees G. M.

    Complement is part of the innate immune system. Its major function is recognition and elimination of pathogens via direct killing and/or stimulation of phagocytosis. Activation of the complement system is, however, also involved in the pathogenesis of the systemic autoimmune diseases. Activation via

  9. Complement activation by Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jensen, E T; Kharazmi, A; Garred, P

    1993-01-01

    In chronic infections, such as the bronchopulmonary Pseudomonas aeruginosa infection in cystic fibrosis (CF) patients, bacteria persist despite an intact host immune defense and frequent antibiotic treatment. An important reason for the persistence of the bacteria is their capacity for the biofilm...... mode of growth. In this study we investigated the role of biofilms in activation of complement, a major contributor to the inflammatory process. Complement activation by P. aeruginosa was examined in a complement consumption assay, production of C3 and factor B conversion products assessed by crossed...... immuno-electrophoresis, C5a generation tested by a PMN chemotactic assay, and terminal complement complex formation measured by ELISA. Two of the four assays showed that P. aeruginosa grown in biofilm activated complement less than planktonic bacteria, and all assays showed that activation by intact...

  10. Porphyromonas gingivalis manipulates complement and TLR signaling to uncouple bacterial clearance from inflammation and promote dysbiosis

    Science.gov (United States)

    Maekawa, Tomoki; Krauss, Jennifer L.; Abe, Toshiharu; Jotwani, Ravi; Triantafilou, Martha; Triantafilou, Kathy; Hashim, Ahmed; Hoch, Shifra; Curtis, Michael A.; Nussbaum, Gabriel; Lambris, John D.; Hajishengallis, George

    2014-01-01

    SUMMARY Certain low-abundance bacterial species, such as the periodontitis-associated oral bacterium Porphyromonas gingivalis can subvert host immunity to remodel a normally symbiotic microbiota into a dysbiotic, disease-provoking state. However, such pathogens also exploit inflammation to thrive in dysbiotic conditions. How these bacteria evade immunity while maintaining inflammation is unclear. As previously reported, P. gingivalis remodels the oral microbiota into a dysbiotic state by exploiting complement. Now we show that in neutrophils P. gingivalis disarms a host-protective TLR2-MyD88 pathway via proteasomal degradation of MyD88, whereas it activates an alternate TLR2-Mal-PI3K pathway. This alternate TLR2-Mal-PI3K pathway blocks phagocytosis, provides ‘bystander’ protection to otherwise susceptible bacteria, and promotes dysbiotic inflammation in vivo. This mechanism to disengage bacterial clearance from inflammation required an intimate crosstalk between TLR2 and the complement receptor C5aR, and can contribute to the persistence of microbial communities that drive dysbiotic diseases. PMID:24922578

  11. Yersinia enterocolitica serum resistance proteins YadA and ail bind the complement regulator C4b-binding protein.

    Directory of Open Access Journals (Sweden)

    Vesa Kirjavainen

    Full Text Available Many pathogens are equipped with factors providing resistance against the bactericidal action of complement. Yersinia enterocolitica, a Gram-negative enteric pathogen with invasive properties, efficiently resists the deleterious action of human complement. The major Y. enterocolitica serum resistance determinants include outer membrane proteins YadA and Ail. Lipopolysaccharide (LPS O-antigen (O-ag and outer core (OC do not contribute directly to complement resistance. The aim of this study was to analyze a possible mechanism whereby Y. enterocolitica could inhibit the antibody-mediated classical pathway of complement activation. We show that Y. enterocolitica serotypes O:3, O:8, and O:9 bind C4b-binding protein (C4bp, an inhibitor of both the classical and lectin pathways of complement. To identify the C4bp receptors on Y. enterocolitica serotype O:3 surface, a set of mutants expressing YadA, Ail, O-ag, and OC in different combinations was tested for the ability to bind C4bp. The studies showed that both YadA and Ail acted as C4bp receptors. Ail-mediated C4bp binding, however, was blocked by the O-ag and OC, and could be observed only with mutants lacking these LPS structures. C4bp bound to Y. enterocolitica was functionally active and participated in the factor I-mediated degradation of C4b. These findings show that Y. enterocolitica uses two proteins, YadA and Ail, to bind C4bp. Binding of C4bp could help Y. enterocolitica to evade complement-mediated clearance in the human host.

  12. GLUCOCORTICOSTEROIDS' EFFECT UPON THE COMPLEMENT LEVEL

    Directory of Open Access Journals (Sweden)

    Voja Pavlovic

    2001-03-01

    Full Text Available The effect of high doses of cortisol upon the level of the overall complements'hemolytic activity and particular complements' components is studies. The experimentsinvolved guinea pigs of male sex of the body mass from 300 to 400 g, namelythose that have not been treated by anything so far. The doses of hydrocortisone(Hemofarm DD were also used for the experiment. The overall complements'activity was determined by testing the capabilities of a series of various solutions ofthe guinea pigs' serum to separate sheep erythrocytes that were made sensitive byrabbit anti-erythrocyte antibodies. The determination of the C1, C2, C3 and C4complements' components was done by the method of the quantitative diffusion ofthe radial type by using the Partigen blocks Behringwerke AG. The series comprised25 guinea pigs of male sex. The low cortisol level rapidly increase the overallhemolytic activity of the complements of the C1 est erase concentration. Along withthe cortisol dose increase the overall hemolytic complements' activity is dropping aswell as that of the C1, C2, C3 and C4 complements' components.

  13. A computer network attack taxonomy and ontology

    CSIR Research Space (South Africa)

    Van Heerden, RP

    2012-01-01

    Full Text Available of attacks, means that an attack could be mitigated accordingly. The authors extend a previous, initial taxonomy of computer network attacks which forms the basis of a proposed network attack ontology in this paper. The objective of this ontology...

  14. Analytical Characterization of Internet Security Attacks

    Science.gov (United States)

    Sellke, Sarah H.

    2010-01-01

    Internet security attacks have drawn significant attention due to their enormously adverse impact. These attacks includes Malware (Viruses, Worms, Trojan Horse), Denial of Service, Packet Sniffer, and Password Attacks. There is an increasing need to provide adequate defense mechanisms against these attacks. My thesis proposal deals with analytical…

  15. Time-dependent analysis of attacks

    NARCIS (Netherlands)

    Arnold, Florian; Hermanns, H.; Pulungan, Reza; Stoelinga, Mariëlle Ida Antoinette

    The success of a security attack crucially depends on time: the more time available to the attacker, the higher the probability of a successful attack; when given enough time, any system can be compromised. Insight in time-dependent behaviors of attacks and the evolution of the attacker’s success as

  16. RESIST SRP AGAINST WORMHOLE ATTACK

    Directory of Open Access Journals (Sweden)

    Marjan Kuchaki Rafsanjani

    2013-06-01

    Full Text Available Ad-hoc networks refer to temporary or interim networks which form for special purposes. Actually they are wireless networks with mobile nodes. These networks use no network assisting element for path routing and in these networks available nodes are responsible for path routing. Therefore when malicious nodes want to find a way to interfere with the path routing then the existence of a secure route protocol (SRP can prevent the interference. SRP protocol is one of the secure algorithms of path routing protocol but it is notresistant against wormhole attack. Wormhole attack is considered as a subtle attack in which two malicious nodes make a short connection in network's topology through private or implicit connection and represent two non neighbor nodes as neighbors and prevent the correctoperation of path routing protocol by using this method. One of the methods of preventing wormhole attack is by using packet leashes. We try to decrease the wormhole attack occurrence in this routing protocol by a kind of packet leashes called temporal leashes. We alsowill minimize problems resulting from using temporal leashes by different methods and modifications in its structure.

  17. Network robustness under large-scale attacks

    CERN Document Server

    Zhou, Qing; Liu, Ruifang; Cui, Shuguang

    2014-01-01

    Network Robustness under Large-Scale Attacks provides the analysis of network robustness under attacks, with a focus on large-scale correlated physical attacks. The book begins with a thorough overview of the latest research and techniques to analyze the network responses to different types of attacks over various network topologies and connection models. It then introduces a new large-scale physical attack model coined as area attack, under which a new network robustness measure is introduced and applied to study the network responses. With this book, readers will learn the necessary tools to evaluate how a complex network responds to random and possibly correlated attacks.

  18. Complement receptors in myeloid cell adhesion and phagocytosis

    OpenAIRE

    Dustin, Michael L.

    2016-01-01

    Myeloid cells make extensive use of the complement system in the context of recruitment, phagocytosis and other effector functions. There are several types of complement receptors on myeloid cells including G-proteins coupled receptors for localizing the source of complement activation, and three sets of type I transmembrane proteins that link complement to phagocytosis-complement receptor 1, a single chain type I membrane protein with tandem complement regulatory repeats, complement receptor...

  19. Transnationalism and integration : complements or Substitutes?

    NARCIS (Netherlands)

    Dekker, B.; Siegel, M.

    2013-01-01

    This paper investigates the relationship between transnational practices and integration by testing whether they are substitutes or complements. For this purpose, we use a multidimensional transnationalism index. The index includes three dimensions of transnational practices, including migrants'

  20. Autocrine Effects of Tumor-Derived Complement

    Directory of Open Access Journals (Sweden)

    Min Soon Cho

    2014-03-01

    Full Text Available We describe a role for the complement system in enhancing cancer growth. Cancer cells secrete complement proteins that stimulate tumor growth upon activation. Complement promotes tumor growth via a direct autocrine effect that is partially independent of tumor-infiltrating cytotoxic T cells. Activated C5aR and C3aR signal through the PI3K/AKT pathway in cancer cells, and silencing the PI3K or AKT gene in cancer cells eliminates the progrowth effects of C5aR and C3aR stimulation. In patients with ovarian or lung cancer, higher tumoral C3 or C5aR mRNA levels were associated with decreased overall survival. These data identify a role for tumor-derived complement proteins in promoting tumor growth, and they therefore have substantial clinical and therapeutic implications.

  1. Complement and Immunoregulation in Tissue Injury

    Science.gov (United States)

    2015-12-01

    transplantation, cardiovascular and autoimmune diseases . The complement system is an important mediator of IR injury in various organs including...on epithelial cells. Because of its ability to mobilize neutrophils, IL-17A is important in the pathogenesis of autoimmune diseases , and in chronic...intestine, kidney , liver, lungs and heart. In mesenteric IR complement activation and deposition have been recognized as key components for the initiation

  2. Surviving mousepox infection requires the complement system.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Moulton

    2008-12-01

    Full Text Available Poxviruses subvert the host immune response by producing immunomodulatory proteins, including a complement regulatory protein. Ectromelia virus provides a mouse model for smallpox where the virus and the host's immune response have co-evolved. Using this model, our study investigated the role of the complement system during a poxvirus infection. By multiple inoculation routes, ectromelia virus caused increased mortality by 7 to 10 days post-infection in C57BL/6 mice that lack C3, the central component of the complement cascade. In C3(-/- mice, ectromelia virus disseminated earlier to target organs and generated higher peak titers compared to the congenic controls. Also, increased hepatic inflammation and necrosis correlated with these higher tissue titers and likely contributed to the morbidity in the C3(-/- mice. In vitro, the complement system in naïve C57BL/6 mouse sera neutralized ectromelia virus, primarily through the recognition of the virion by natural antibody and activation of the classical and alternative pathways. Sera deficient in classical or alternative pathway components or antibody had reduced ability to neutralize viral particles, which likely contributed to increased viral dissemination and disease severity in vivo. The increased mortality of C4(-/- or Factor B(-/- mice also indicates that these two pathways of complement activation are required for survival. In summary, the complement system acts in the first few minutes, hours, and days to control this poxviral infection until the adaptive immune response can react, and loss of this system results in lethal infection.

  3. Complement Recognition Pathways in Renal Transplantation.

    Science.gov (United States)

    Nauser, Christopher L; Farrar, Conrad A; Sacks, Steven H

    2017-09-01

    The complement system, consisting of soluble and cell membrane-bound components of the innate immune system, has defined roles in the pathophysiology of renal allograft rejection. Notably, the unavoidable ischemia-reperfusion injury inherent to transplantation is mediated through the terminal complement activation products C5a and C5b-9. Furthermore, biologically active fragments C3a and C5a, produced during complement activation, can modulate both antigen presentation and T cell priming, ultimately leading to allograft rejection. Earlier work identified renal tubule cell synthesis of C3, rather than hepatic synthesis of C3, as the primary source of C3 driving these effects. Recent efforts have focused on identifying the local triggers of complement activation. Collectin-11, a soluble C-type lectin expressed in renal tissue, has been implicated as an important trigger of complement activation in renal tissue. In particular, collectin-11 has been shown to engage L-fucose at sites of ischemic stress, activating the lectin complement pathway and directing the innate immune response to the distressed renal tubule. The interface between collectin-11 and L-fucose, in both the recipient and the allograft, is an attractive target for therapies intended to curtail renal inflammation in the acute phase. Copyright © 2017 by the American Society of Nephrology.

  4. The Vi capsular polysaccharide enables Salmonella enterica serovar typhi to evade microbe-guided neutrophil chemotaxis.

    Directory of Open Access Journals (Sweden)

    Tamding Wangdi

    2014-08-01

    Full Text Available Salmonella enterica serovar Typhi (S. Typhi causes typhoid fever, a disseminated infection, while the closely related pathogen S. enterica serovar Typhimurium (S. Typhimurium is associated with a localized gastroenteritis in humans. Here we investigated whether both pathogens differ in the chemotactic response they induce in neutrophils using a single-cell experimental approach. Surprisingly, neutrophils extended chemotactic pseudopodia toward Escherichia coli and S. Typhimurium, but not toward S. Typhi. Bacterial-guided chemotaxis was dependent on the presence of complement component 5a (C5a and C5a receptor (C5aR. Deletion of S. Typhi capsule biosynthesis genes markedly enhanced the chemotactic response of neutrophils in vitro. Furthermore, deletion of capsule biosynthesis genes heightened the association of S. Typhi with neutrophils in vivo through a C5aR-dependent mechanism. Collectively, these data suggest that expression of the virulence-associated (Vi capsular polysaccharide of S. Typhi obstructs bacterial-guided neutrophil chemotaxis.

  5. Creative Persuasion: A Study on Adversarial Behaviors and Strategies in Phishing Attacks

    Directory of Open Access Journals (Sweden)

    Prashanth Rajivan

    2018-02-01

    Full Text Available Success of phishing attacks depend on effective exploitation of human weaknesses. This research explores a largely ignored, but crucial aspect of phishing: the adversarial behavior. We aim at understanding human behaviors and strategies that adversaries use, and how these may determine the end-user response to phishing emails. We accomplish this through a novel experiment paradigm involving two phases. In the adversarial phase, 105 participants played the role of a phishing adversary who were incentivized to produce multiple phishing emails that would evade detection and persuade end-users to respond. In the end-user phase, 340 participants performed an email management task, where they examined and classified phishing emails generated by participants in phase-one along with benign emails. Participants in the adversary role, self-reported the strategies they employed in each email they created, and responded to a test of individual creativity. Data from both phases of the study was combined and analyzed, to measure the effect of adversarial behaviors on end-user response to phishing emails. We found that participants who persistently used specific attack strategies (e.g., sending notifications, use of authoritative tone, or expressing shared interest in all their attempts were overall more successful, compared to others who explored different strategies in each attempt. We also found that strategies largely determined whether an end-user was more likely to respond to an email immediately, or delete it. Individual creativity was not a reliable predictor of adversarial performance, but it was a predictor of an adversary's ability to evade detection. In summary, the phishing example provided initially, the strategies used, and the participants' persistence with some of the strategies led to higher performance in persuading end-users to respond to phishing emails. These insights may be used to inform tools and training procedures to detect phishing

  6. Mitigating Higher Ed Cyber Attacks

    Science.gov (United States)

    Rogers, Gary; Ashford, Tina

    2015-01-01

    In this presentation we will discuss the many and varied cyber attacks that have recently occurred in the higher ed community. We will discuss the perpetrators, the victims, the impact and how these institutions have evolved to meet this threat. Mitigation techniques and defense strategies will be covered as will a discussion of effective security…

  7. Television Journalism During Terror Attacks

    DEFF Research Database (Denmark)

    Mogensen, Kirsten

    This article views television news coverage of ongoing terrorist attacks and their immediate aftermath as a special genre within journalism, and describes norms connected with the genre. The description is based on qualitative analyses of the coverage on the major American networks in the fi rst 24...

  8. Television journalism during terror attacks

    DEFF Research Database (Denmark)

    Mogensen, Kirsten

    2008-01-01

    This article views television news coverage of ongoing terrorist attacks and their immediate aftermath as a special genre within journalism, and describes norms connected with the genre. The description is based on qualitative analyses of the coverage on major American networks the first 24 hours...

  9. The Timing of Terrorist Attacks

    DEFF Research Database (Denmark)

    Jensen, Thomas

    2016-01-01

    I use a simple optimal stopping model to derive policy relevant insights on the timing of one-shot attacks by small autonomous terrorist units or “lone wolf” individuals. A main insight is that an increase in proactive counterterrorism measures can lead to a short term increase in the number...

  10. Molecules Great and Small: The Complement System.

    Science.gov (United States)

    Mathern, Douglas R; Heeger, Peter S

    2015-09-04

    The complement cascade, traditionally considered an effector arm of innate immunity required for host defense against pathogens, is now recognized as a crucial pathogenic mediator of various kidney diseases. Complement components produced by the liver and circulating in the plasma undergo activation through the classical and/or mannose-binding lectin pathways to mediate anti-HLA antibody-initiated kidney transplant rejection and autoantibody-initiated GN, the latter including membranous glomerulopathy, antiglomerular basement membrane disease, and lupus nephritis. Inherited and/or acquired abnormalities of complement regulators, which requisitely limit restraint on alternative pathway complement activation, contribute to the pathogenesis of the C3 nephropathies and atypical hemolytic uremic syndrome. Increasing evidence links complement produced by endothelial cells and/or tubular cells to the pathogenesis of kidney ischemia-reperfusion injury and progressive kidney fibrosis. Data emerging since the mid-2000s additionally show that immune cells, including T cells and antigen-presenting cells, produce alternative pathway complement components during cognate interactions. The subsequent local complement activation yields production of the anaphylatoxins C3a and C5a, which bind to their respective receptors (C3aR and C5aR) on both partners to augment effector T-cell proliferation and survival, while simultaneously inhibiting regulatory T-cell induction and function. This immune cell-derived complement enhances pathogenic alloreactive T-cell immunity that results in transplant rejection and likely contributes to the pathogenesis of other T cell-mediated kidney diseases. C5a/C5aR ligations on neutrophils have additionally been shown to contribute to vascular inflammation in models of ANCA-mediated renal vasculitis. New translational immunology efforts along with the development of pharmacologic agents that block human complement components and receptors now permit

  11. Rodent complementation group 8 (ERCC8) corresponds to Cockayne syndrome complementation group A.

    Science.gov (United States)

    Itoh, T; Shiomi, T; Shiomi, N; Harada, Y; Wakasugi, M; Matsunaga, T; Nikaido, O; Friedberg, E C; Yamaizumi, M

    1996-02-15

    US31 is a UV-sensitive mutant cell line (rodent complementation group 8) derived from a mouse T cell line L5178Y. We analyzed removal kinetics for UV-induced cyclobutane pyrimidine dimers and (6-4) photoproducts in US31 cells using monoclonal antibodies against these photoproducts. While nearly all (6-4) photoproducts were repaired within 6 h after UV-irradiation, more than 70% of cyclobutane pyrimidine dimers remained unrepaired even 24 h after UV-irradiation. These kinetics resembled those of Cockayne syndrome (CS) cells. Since US31 cells had a low efficiency of cell fusion and transfection, which hampered both complementation tests and gene cloning, we constructed fibroblastic complementation group 8 cell line 6L1030 by fusion of US31 cells with X-irradiated normal mouse fibroblastic LTA cells. Complementation tests by cell fusion and transfection using 6L1030 cells revealed that rodent complementation group 8 corresponded to CS complementation group A.

  12. JFCGuard: Detecting juice filming charging attack via processor usage analysis on smartphones

    DEFF Research Database (Denmark)

    Meng, Weizhi; Jiang, Lijun; Wang, Yu

    2017-01-01

    Smartphones have become necessities in people' lives, so that many more public charging stations are under deployment worldwide to meet the increasing demand of phone charging (i.e., in airports, subways, shops, etc). However, this situation may expose a hole for cyber-criminals to launch various......, to detect JFC attack based on processor usage analysis for smartphone users. In the evaluation, we perform a user study with over 250 participants and the results demonstrate that JFCGuard can identify JFC attack in an effective way. Our work aims to complement existing research results and stimulate more...

  13. Trojan Horse Attacking Strategy on Quantum Cryptography

    Science.gov (United States)

    Zeng, Guihua

    2003-08-01

    Trojan horse attacking strategy on quantum cryptography is investigated, three aspects are involved. First, the mechanism for the Trojan horse attacking strategy on quantum cryptography as well as classic cryptography is studied. Then the fragility of the quantum cryptographic algorithm employing EPR pairs as key against the Trojan horse attacking strategy is analyzed. To prevent the Trojan horse attacking strategy, an improvement scheme which makes use of non-orthogonal entangled states is proposed, results show the improvement scheme is robust to the Trojan horse attacking strategy without reducing the security on other kinds of attacking strategies.

  14. Complement in therapy and disease: Regulating the complement system with antibody-based therapeutics.

    Science.gov (United States)

    Melis, Joost P M; Strumane, Kristin; Ruuls, Sigrid R; Beurskens, Frank J; Schuurman, Janine; Parren, Paul W H I

    2015-10-01

    Complement is recognized as a key player in a wide range of normal as well as disease-related immune, developmental and homeostatic processes. Knowledge of complement components, structures, interactions, and cross-talk with other biological systems continues to grow and this leads to novel treatments for cancer, infectious, autoimmune- or age-related diseases as well as for preventing transplantation rejection. Antibodies are superbly suited to be developed into therapeutics with appropriate complement stimulatory or inhibitory activity. Here we review the design, development and future of antibody-based drugs that enhance or dampen the complement system. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Reliability of a Field Test of Defending and Attacking Agility in Australian Football and Relationships to Reactive Strength.

    Science.gov (United States)

    Young, Warren B; Murray, Mitch P

    2017-02-01

    Young, WB and Murray, MP. Reliability of a field test of defending and attacking agility in Australian football and relationships to reactive strength. J Strength Cond Res 31(2): 509-516, 2017-Defending and attacking agility tests for Australian football do not exist, and it is unknown whether any physical qualities correlate with these types of agility. The purposes of this study were to develop new field tests of defending and attacking agility for Australian Rules football, to determine whether they were reliable, and to describe the relationship between the agility tests to determine their specificity. Because the reactive strength (RS) of the lower limb muscles has been previously correlated with change-of-direction speed, we also investigated the relationship between this quality and the agility tests. Nineteen male competitive recreational-level Australian Rules football players were assessed on the agility tests and a drop jump test to assess RS. Interday and interrater reliability was also assessed. The agility tests involved performing 10 trials of one-on-one agility tasks against 2 testers (opponents), in which the objective was to be in a position to tackle (defending) or to evade (attacking) the opponent. Both agility tests had good reliability (intraclass correlation > 0.8, %CV 0.05], and interrater reliability was very high [r = 0.997, p < 0.001]). The common variance between the agility tests was 45%, indicating that they represented relatively independent skills. There was a large correlation between RS and defending agility (r = 0.625, p = 0.004), and a very large correlation with attacking agility (r = 0.731, p < 0.001). Defending and attacking agility have different characteristics, possibly related to the footwork, physical, and cognitive demands of each. Nonetheless, RS seems to be important for agility, especially for attacking agility.

  16. Quantification of complement system activation by measuring C5b-9 cell surface deposition using a cell-ELISA technique.

    Science.gov (United States)

    Jeon, Hyungtaek; Lee, Ji-Su; Yoo, Seungmin; Lee, Myung-Shin

    2014-12-15

    The complement system is an important aspect of immune defense against microbial invasion. Eukaryotic cells express various complement regulatory proteins to protect them from uncontrolled complement activation. However, some eukaryotic cells possess constitutive complement system activation that does not require specific triggering factors, which is known to have unexpected effects on cell proliferation and survival. This area of research is still preliminary and a standard method to measure complement system activation in eukaryotic cells has yet to be identified. Here, we present a quantitative in vitro method to measure complement system activation in eukaryotic cells by detecting C5b-9, the membrane attack complex, on cell surfaces. The results obtained using this assay correlated with C3b deposition measured using flow cytometry and C5b-9 deposition detected using an immunofluorescence assay. Furthermore, we showed that various cancer cell lines displayed different levels of complement system activation by using this assay. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Crony Attack: Strategic Attack’s Silver Bullet

    Science.gov (United States)

    2006-11-01

    by distributing a large amount of private goods to the selectorate—the cronies—can be termed kleptocracies . Many govern- ments do indeed resemble...where the high-private goods kleptocracy is a good model. Furthermore, while not an example of crony attack to affect policy change (as opposed to...information about those nearest to the leader. The relationships part is only the start. Kleptocracies , like orga- nized crime leaders, are clever

  18. Platelets and the complement cascade in atherosclerosis.

    Science.gov (United States)

    Patzelt, Johannes; Verschoor, Admar; Langer, Harald F

    2015-01-01

    Atherosclerosis and its late sequels are still the number one cause of death in western societies. Platelets are a driving force not only during the genesis of atherosclerosis, but especially in its late stages, as evidenced by complications such as arterial thrombosis, myocardial infarction, and ischemic stroke. Atherosclerosis is increasingly recognized as an inflammatory disease, influenced by various immune mechanisms. The complement system is part of our innate immune system, and its diverse roles in atherosclerosis have become evident over the past years. In this review we identify points of intersection between platelets and the complement system and discuss their relevance for atherosclerosis. Specifically, we will focus on roles for platelets in the onset as well as progression of the disease, a possible dual role for complement in the genesis and development of atherosclerosis, and review emerging literature revealing previously unrecognized cross-talk between platelets and the complement system and discuss its possible impact for atherosclerosis. Finally, we identify limitations of current research approaches and discuss perspectives of complement modulation in the control of the disease.

  19. Influenza virus uses its neuraminidase protein to evade the recognition of two activating NK cell receptors.

    Science.gov (United States)

    Bar-On, Yotam; Seidel, Einat; Tsukerman, Pinchas; Mandelboim, Michal; Mandelboim, Ofer

    2014-08-01

    Natural Killer (NK) cells play a central role in the defense against viral infections and in the elimination of transformed cells. The recognition of pathogen-infected and tumor cells is controlled by inhibitory and activating receptors. We have previously shown that among the activating (killer) NK cell receptors the natural cytotoxicity receptors, NKp44 and NKp46, interact with the viral hemagglutinin (HA) protein expressed on the cell surface of influenza-virus-infected cells. We further showed that the interaction between NKp44/NKp46 and viral HA is sialic-acid dependent and that the recognition of HA by NKp44 and NKp46 leads to the elimination of the infected cells. Here we demonstrate that the influenza virus developed a counter-attack mechanism and that the virus uses its neuraminidase (NA) protein to prevent the recognition of HA by both the NKp44 and NKp46 receptors, resulting in reduced elimination of the infected cells by NK cells. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Timing Is Everything with Heart Attacks

    Science.gov (United States)

    ... and certain time periods. The study was published online recently in the American Heart Journal . Previous research has suggested that highly stressful events, such as earthquakes and World Cup soccer games, may trigger heart attacks. Stress-related heart attacks ...

  1. Stochastic Model of TCP SYN Attacks

    Directory of Open Access Journals (Sweden)

    Simona Ramanauskaitė

    2011-08-01

    Full Text Available A great proportion of essential services are moving into internet space making the threat of DoS attacks even more actual. To estimate the real risk of some kind of denial of service (DoS attack in real world is difficult, but mathematical and software models make this task easier. In this paper we overview the ways of implementing DoS attack models and offer a stochastic model of SYN flooding attack. It allows evaluating the potential threat of SYN flooding attacks, taking into account both the legitimate system flow as well as the possible attack power. At the same time we can assess the effect of such parameters as buffer capacity, open connection storage in the buffer or filte­ring efficiency on the success of different SYN flooding attacks. This model can be used for other type of memory depletion denial of service attacks.Article in Lithuanian

  2. Lifestyle Changes for Heart Attack Prevention

    Science.gov (United States)

    ... help prevent your first heart attack. Heart-Healthy Lifestyle Changes A heart-healthy lifestyle can help prevent ... to flow to the heart muscle. Heart-Healthy Lifestyle Changes Treatment for a heart attack usually includes ...

  3. Social engineering attack examples, templates and scenarios

    CSIR Research Space (South Africa)

    Mouton, Francois

    2016-06-01

    Full Text Available link. A social engineering attack targets this weakness by using various manipulation techniques to elicit sensitive information. The field of social engineering is still in its early stages with regard to formal definitions, attack frameworks...

  4. Being active after a heart attack (image)

    Science.gov (United States)

    ... best activity when you start exercising after a heart attack. Start slowly, and increase the amount of time ... best activity when you start exercising after a heart attack. Start slowly, and increase the amount of time ...

  5. Three complementation groups in Cockayne syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, A.R. (Sussex Univ., Brighton (UK). M.R.C. Cell Mutation Unit)

    1982-12-01

    After 16 Jm/sup -2/ of UV-irradiation non-dividing normal cells recover normal rates of RNA synthesis within 24 h, whereas in cells from donors with Cockayne syndrome (CS) the rate of RNA synthesis gradually declines. Cultures of a mixed population from 2 CS donors were fused with polyethylene glycol: subsequently they were UV-irradiated and RNA synthesis was measured autoradiographically in mono-, bi-, and multinuclear cells. Genetic complementation was indicated by high levels of RNA synthesis in bi- and multinuclear cells when compared with mononuclear cells. Using this assay, 11 CS strains have been assigned to three complementation groups: 2 into group A, 8 into group B and 1 into group C. The strain in group C is derived from an individual who also had xeroderma pigmentosum (XP), and was the sole known representative of XP-complementation group B.

  6. The Complement System in Lupus Nephritis.

    Science.gov (United States)

    Birmingham, Daniel J; Hebert, Lee A

    2015-09-01

    The complement system is composed of a family of soluble and membrane-bound proteins that historically has been viewed as a key component of the innate immune system, with a primary role of providing a first-line defense against microorganisms. Although this role indeed is important, complement has many other physiological roles, including the following: (1) influencing appropriate immune responses, (2) disposing of waste in the circulation (immune complexes, cellular debris), and (3) contributing to damage of self-tissue through inflammatory pathways. These three roles are believed to be significant factors in the pathogenesis of systemic lupus erythematosus, particularly its renal manifestation (lupus nephritis), contributing both protective and damaging effects. In this review, we provide an overview of the human complement system and its functions, and discuss its intricate and seemingly contradictory roles in the pathogenesis of lupus nephritis. Copyright © 2015. Published by Elsevier Inc.

  7. Intermittent hypoendorphinaemia in migraine attack.

    Science.gov (United States)

    Baldi, E; Salmon, S; Anselmi, B; Spillantini, M G; Cappelli, G; Brocchi, A; Sicuteri, F

    1982-06-01

    Beta-endorphin (RIA method, previous chromatographic extraction) was evaluated in plasma of migraine sufferers in free periods and during attacks. Decreased levels of the endogenous opioid peptide were found in plasma sampled during the attacks but not in free periods. Even chronic headache sufferers exhibited significantly lowered levels of beta-endorphin, when compared with control subjects with a negative personal and family history of head pains. The mechanism of the hypoendorphinaemia is unknown: lowered levels of the neuropeptide, which controls nociception, vegetative functions and hedonia, could be important in a syndrome such as migraine, characterized by pain, dysautonomia and anhedonia. The impairment of monoaminergic synapses ("empty neuron" condition) constantly present in sufferers from serious headaches, could be due to the fact that opioid neuropeptides, because of a receptoral or metabolic impairment, poorly modulate the respective monoaminergic neurons, resulting in imbalance of synaptic neurotransmission.

  8. Novel biological networks modulated by complement.

    Science.gov (United States)

    Mastellos, Dimitrios; Andronis, Christos; Persidis, Andreas; Lambris, John D

    2005-06-01

    The almost complete deciphering of the human genome has paved the way for the application of new technology platforms in understanding the contribution of complex biological pathways to human pathophysiology and disease. In the post-genomic era, the concept of systems biology has gained significant momentum and biomedical research is now being conducted on an integrated and cross-disciplinary platform that pulls together its resources from diverse fields such as computational biology, bioinformatics, functional genomics, structural biology, and proteomics. In this perspective, the identity of established biologic systems is being re-examined in the light of novel findings that suggest novel associations between otherwise unrelated pathways and individual proteins. Complement exemplifies such a system that, transcending its innate immune identity, has forged functional associations with multiple pathways and networks in modulating basic biologic processes. In the present article, we provide a global overview of these unusual system associations of complement with the aid of a powerful and high-throughput bioinformatics platform. Using a novel approach called systems literature analysis that allows the rapid extraction of text-based associations between genes and pathways from the ever expanding scientific article database, we have selected a broad range of biologic processes modulated by complement proteins and have constructed an integrated map of complement-mediated networks that incorporates well over 85 diverse biologic pathways. Expanding the complement cascade beyond its approximately 35 designated components, we discuss protein-protein interactions involving novel ligands and associations with signaling cascades and cellular networks that affect both inflammatory and non-inflammatory processes. This integrated consideration of complement within a unified 'systems biology' framework underscores the concept that innate immunity goes well beyond the protection

  9. Network Attack Reference Data Set

    Science.gov (United States)

    2004-12-01

    fingerprinting tools include QueSO [10] (literally translates to “what OS”) and nmap [11], however there are a number of additional tools available for...Network Attack Reference Data Set J. McKenna and J. Treurniet Defence R&D Canada √ Ottawa TECHNICAL...collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources

  10. Joint Direct Attack Munition (JDAM)

    Science.gov (United States)

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-503 Joint Direct Attack Munition (JDAM) As of FY 2017 President’s Budget Defense Acquisition...Mission and Description 6 Executive Summary 7 Threshold Breaches 8 Schedule 9 Performance 12 Track to Budget 14 Cost and Funding...15 Low Rate Initial Production 26 Foreign Military Sales 27 Nuclear Costs 29 Unit Cost 30 Cost Variance 33 Contracts 36

  11. Dual Stage SQL Injection Attacks

    OpenAIRE

    Eve, Martin Paul

    2009-01-01

    I came across quite an interesting SQL Injection scenario today. The software in which the vulnerability resides will remain anonymous until fixed, but an abstracted version of the scenario can safely be outlined below.\\ud \\ud The objective of the software is to restrict user accounts to certain IP addresses when accessing a bulletin board. This shows how this can be bypassed using a dual-stage SQL injection attack.

  12. New Multi-step Worm Attack Model

    OpenAIRE

    Robiah, Y.; Rahayu, S. Siti; Shahrin, S.; Faizal, M. A.; Zaki, M. Mohd; Marliza, R.

    2010-01-01

    The traditional worms such as Blaster, Code Red, Slammer and Sasser, are still infecting vulnerable machines on the internet. They will remain as significant threats due to their fast spreading nature on the internet. Various traditional worms attack pattern has been analyzed from various logs at different OSI layers such as victim logs, attacker logs and IDS alert log. These worms attack pattern can be abstracted to form worms' attack model which describes the process of worms' infection. Fo...

  13. Classifying network attack scenarios using an ontology

    CSIR Research Space (South Africa)

    Van Heerden, RP

    2012-03-01

    Full Text Available ). ?Spear Phishing? refers to targeted social engineering-type email attacks (Jagatic, 2007). ?Physical? refers to manual methods to gain access, for example physically removing the hard drive or breaking the access door to enter a secure server room... the size and utility of the target. The "Target" class is the physical device or entity targeted by an attack. The "Vulnerability" class describes a target vulnerability used by the attacker. The "Phase" class represents an attack model that subdivides...

  14. Terror attacks influence driving behavior in Israel

    Science.gov (United States)

    Stecklov, Guy; Goldstein, Joshua R.

    2004-01-01

    Terror attacks in Israel produce a temporary lull in light accidents followed by a 35% spike in fatal accidents on Israeli roads 3 days after the attack. Our results are based on time-series analysis of Israeli traffic flows, accidents, and terror attacks from January 2001 through June 2002. Whereas prior studies have focused on subjective reports of posttraumatic stress, our study shows a population-level behavioral response to violent terror attacks. PMID:15448203

  15. Attack Graph Construction for Security Events Analysis

    Directory of Open Access Journals (Sweden)

    Andrey Alexeevich Chechulin

    2014-09-01

    Full Text Available The paper is devoted to investigation of the attack graphs construction and analysis task for a network security evaluation and real-time security event processing. Main object of this research is the attack modeling process. The paper contains the description of attack graphs building, modifying and analysis technique as well as overview of implemented prototype for network security analysis based on attack graph approach.

  16. Distance hijacking attacks on distance bounding protocols

    OpenAIRE

    Cremers, Cas; Rasmussen, Kasper Bonne; Čapkun, Srdjan

    2011-01-01

    Distance bounding protocols are typically analyzed with respect to three types of attacks: Distance Fraud, Mafia Fraud, and Terrorist Fraud. We define a fourth main type of attacks on distance bounding protocols, called Distance Hijacking attacks. We show that many proposed distance bounding protocols are vulnerable to these attacks, and we propose solutions to make these protocols resilient to Distance Hijacking. Additionally, we generalize Distance Hijacking to Location Hijacking, to which ...

  17. Complement-mediated solubilization of immune complexes. Solubilization inhibition and complement factor levels in SLE patients

    DEFF Research Database (Denmark)

    Baatrup, Gunnar; Petersen, Ivan; Kappelgaard, E

    1984-01-01

    Thirty-two of 36 serum samples from 19 SLE patients showed reduced capacity to mediate complement-dependent solubilization of immune complexes (IC). SLE patients with nephritis exerted the lowest complement-mediated solubilization capacity (CMSC) whereas sera from patients with inactive disease...

  18. Porcine complement regulators protect aortic smooth muscle cells poorly against human complement-induced lysis and proliferation: consequences for xenotransplantation.

    Science.gov (United States)

    Capey, Steven; van den Berg, Carmen W

    2005-05-01

    Accelerated atherosclerosis after transplantation has been observed and is characterized by smooth muscle cell proliferation in the graft. Porcine cells are frequently used in models of atherosclerosis and porcine organs are considered for use in transplantation. Complement (C) activation is known to play a major role in rejection of xenografts and is also considered to play a role in the development of atherosclerosis. The aim of this study was to investigate the expression and function of membrane bound regulators of complement (CReg) on porcine aortic smooth muscle cells (PASMC). The PASMC were assessed for expression of CReg and susceptibility to lysis by human C by flow-cytometry. The effect of various cytokines on CReg expression and C-susceptibility was investigated. The ability of human C to induce cell proliferation was assessed using the Alamar blue assay. The PASMC only express the CReg membrane cofactor protein (MCP) and CD59 on their cell surface. MCP expression was increased by interleukin (IL)-4. In contrast to porcine aortic endothelial cells (PAEC), PASMC were found to be surprisingly sensitive to C-mediated lysis, mainly due to a low level of expression of CD59. Human C-induced proliferation of PASMC, which was dependent on complete membrane attack complex (MAC) formation. Endogenously expressed CReg on PASMC poorly protect these cells to human C. Human C can induce proliferation of PASMC. In order to prevent accelerated atherosclerosis in porcine xenografts, increased levels of CReg not only have to be obtained on the endothelial cells but also on the smooth muscle cells.

  19. Complement propriety and conspiracy in nanomedicine

    DEFF Research Database (Denmark)

    Moghimi, Seyed Moein

    2016-01-01

    The complement system is the first line of body's defense against intruders and it acts as a functional bridge between innate and adaptive arms of the immune system. This commentary examines the key roles of complement activation in response to nanomedicine administration, including nucleic acid...... complexes. These comprise beneficial (eg, adjuvanticity) as well as adverse effects (eg, infusion-related reactions). Pigs (and sheep) are often used as predictive models of nanomedicine-mediated infusion-related reactions in humans. The validity of these models in relation to human responses is questioned...

  20. The Epidermal Growth Factor Receptor Is a Regulator of Epidermal Complement Component Expression and Complement Activation

    DEFF Research Database (Denmark)

    Abu-Humaidan, Anas H A; Ananthoju, Nageshwar; Mohanty, Tirthankar

    2014-01-01

    The complement system is activated in response to tissue injury. During wound healing, complement activation seems beneficial in acute wounds but may be detrimental in chronic wounds. We found that the epidermal expression of many complement components was only increased to a minor extent in skin...... components in keratinocytes and epidermis following stimulation with proinflammatory cytokines. Importantly, EGFR inhibition of cultured keratinocytes either alone or in combination with proinflammatory stimulus promoted activation of the complement system after incubation with serum. In keratinocytes...... wounds in vivo and in cultured keratinocytes after exposure to supernatant from stimulated mononuclear cells. In contrast, the epidermal expression of complement components was downregulated in ex vivo injured skin lacking the stimulation from infiltrating inflammatory cells but with intact injury...

  1. Cyberprints: Identifying Cyber Attackers by Feature Analysis

    Science.gov (United States)

    Blakely, Benjamin A.

    2012-01-01

    The problem of attributing cyber attacks is one of increasing importance. Without a solid method of demonstrating the origin of a cyber attack, any attempts to deter would-be cyber attackers are wasted. Existing methods of attribution make unfounded assumptions about the environment in which they will operate: omniscience (the ability to gather,…

  2. Attack Tree Generation by Policy Invalidation

    DEFF Research Database (Denmark)

    Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, Rene Rydhof

    2015-01-01

    through brainstorming of experts. In this work we formalize attack tree generation including human factors; based on recent advances in system models we develop a technique to identify possible attacks analytically, including technical and human factors. Our systematic attack generation is based...

  3. Attacks and countermeasures on AES and ECC

    DEFF Research Database (Denmark)

    Tange, Henrik; Andersen, Birger

    2013-01-01

    AES (Advanced Encryption Standard) is widely used in LTE and Wi-Fi communication systems. AES has recently been exposed to new attacks which have questioned the overall security of AES. The newest attack is a so called biclique attack, which is using the fact that the content of the state array...

  4. Automated classification of computer network attacks

    CSIR Research Space (South Africa)

    Van Heerden, R

    2013-11-01

    Full Text Available In this paper we demonstrate how an automated reasoner, HermiT, is used to classify instances of computer network based attacks in conjunction with a network attack ontology. The ontology describes different types of network attacks through classes...

  5. 47 CFR 76.1612 - Personal attack.

    Science.gov (United States)

    2010-10-01

    ... CABLE TELEVISION SERVICE Notices § 76.1612 Personal attack. (a) When, during origination cablecasting of issues of public importance, an attack is made upon the honesty, character, integrity, or like personal... 47 Telecommunication 4 2010-10-01 2010-10-01 false Personal attack. 76.1612 Section 76.1612...

  6. Therapeutic complement inhibition in complement-mediated hemolytic anemias: Past, present and future.

    Science.gov (United States)

    Risitano, Antonio M; Marotta, Serena

    2016-06-01

    The introduction in the clinic of anti-complement agents represented a major achievement which gave to physicians a novel etiologic treatment for different human diseases. Indeed, the first anti-complement agent eculizumab has changed the treatment paradigm of paroxysmal nocturnal hemoglobinuria (PNH), dramatically impacting its severe clinical course. In addition, eculizumab is the first agent approved for atypical Hemolytic Uremic Syndrome (aHUS), a life-threatening inherited thrombotic microangiopathy. Nevertheless, such remarkable milestone in medicine has brought to the fore additional challenges for the scientific community. Indeed, the list of complement-mediated anemias is not limited to PNH and aHUS, and other human diseases can be considered for anti-complement treatment. They include other thrombotic microangiopathies, as well as some antibody-mediated hemolytic anemias. Furthermore, more than ten years of experience with eculizumab led to a better understanding of the individual steps of the complement cascade involved in the pathophysiology of different human diseases. Based on this, new unmet clinical needs are emerging; a number of different strategies are currently under development to improve current anti-complement treatment, trying to address these specific clinical needs. They include: (i) alternative anti-C5 agents, which may improve the heaviness of eculizumab treatment; (ii) broad-spectrum anti-C3 agents, which may improve the efficacy of anti-C5 treatment by intercepting the complement cascade upstream (i.e., preventing C3-mediated extravascular hemolysis in PNH); (iii) targeted inhibitors of selective complement activating pathways, which may prevent early pathogenic events of specific human diseases (e.g., anti-classical pathway for antibody-mediated anemias, or anti-alternative pathway for PNH and aHUS). Here we briefly summarize the status of art of current and future complement inhibition for different complement-mediated anemias

  7. Mesenchymal stromal cells engage complement and complement receptor bearing innate effector cells to modulate immune responses.

    Directory of Open Access Journals (Sweden)

    Guido Moll

    Full Text Available Infusion of human third-party mesenchymal stromal cells (MSCs appears to be a promising therapy for acute graft-versus-host disease (aGvHD. To date, little is known about how MSCs interact with the body's innate immune system after clinical infusion. This study shows, that exposure of MSCs to blood type ABO-matched human blood activates the complement system, which triggers complement-mediated lymphoid and myeloid effector cell activation in blood. We found deposition of complement component C3-derived fragments iC3b and C3dg on MSCs and fluid-phase generation of the chemotactic anaphylatoxins C3a and C5a. MSCs bound low amounts of immunoglobulins and lacked expression of complement regulatory proteins MCP (CD46 and DAF (CD55, but were protected from complement lysis via expression of protectin (CD59. Cell-surface-opsonization and anaphylatoxin-formation triggered complement receptor 3 (CD11b/CD18-mediated effector cell activation in blood. The complement-activating properties of individual MSCs were furthermore correlated with their potency to inhibit PBMC-proliferation in vitro, and both effector cell activation and the immunosuppressive effect could be blocked either by using complement inhibitor Compstatin or by depletion of CD14/CD11b-high myeloid effector cells from mixed lymphocyte reactions. Our study demonstrates for the first time a major role of the complement system in governing the immunomodulatory activity of MSCs and elucidates how complement activation mediates the interaction with other immune cells.

  8. Testing the ability of viral haemorrhagic septicaemia virus to evade the protective immune response induced in rainbow trout by DNA vaccination

    DEFF Research Database (Denmark)

    Sepulveda, Dagoberto; Lorenzen, Niels

    2013-01-01

    glycoprotein, the only surface protein of the VHSV, has been successful as an experimental prophylactic treatment against this disease, because it induces a strong innate (interferon) and adaptive (cellular and humoral) immune response. However, since RNA viruses are known to possess high variability......, this work aims to evaluate whether VHSV is able to evade the protective immune response induced by the DNA vaccination. Earlier studies have demonstrated that VHSV can evade the neutralizing effect of monoclonal antibodies by mutations in the glycoprotein gene. One approach of the present study is therefore...

  9. Calculating Adversarial Risk from Attack Trees: Control Strength and Probabilistic Attackers

    NARCIS (Netherlands)

    Pieters, Wolter; Davarynejad, Mohsen

    2015-01-01

    Attack trees are a well-known formalism for quantitative analysis of cyber attacks consisting of multiple steps and alternative paths. It is possible to derive properties of the overall attacks from properties of individual steps, such as cost for the attacker and probability of success. However, in

  10. Genetic evidence for involvement of classical complement pathway in induction of experimental autoimmune myasthenia gravis.

    Science.gov (United States)

    Tüzün, Erdem; Scott, Benjamin G; Goluszko, Elzbieta; Higgs, Stephen; Christadoss, Premkumar

    2003-10-01

    Abs to acetylcholine receptor (AChR) and complement are the major constituents of pathogenic events causing neuromuscular junction destruction in both myasthenia gravis (MG) and experimental autoimmune MG (EAMG). To analyze the differential roles of the classical vs alternative complement pathways in EAMG induction, we immunized C3(-/-), C4(-/-), C3(+/-), and C4(+/-) mice and their control littermates (C3(+/+) and C4(+/+) mice) with AChR in CFA. C3(-/-) and C4(-/-) mice were resistant to disease, whereas mice heterozygous for C3 or C4 displayed intermediate susceptibility. Although C3(-/-) and C4(-/-) mice had anti-AChR Abs in their sera, anti-AChR IgG production by C3(-/-) mice was significantly suppressed. Both C3(-/-) and C4(-/-) mice had reduced levels of B cells and increased expression of apoptotis inducers (Fas ligand, CD69) and apoptotic cells in lymph nodes. Immunofluorescence studies showed that the neuromuscular junction of C3(-/-) and C4(-/-) mice lacked C3 or membrane attack complex deposits, despite having IgG deposits, thus providing in vivo evidence for the incapacity of anti-AChR IgGs to induce full-blown EAMG without the aid of complements. The data provide the first direct genetic evidence for the classical complement pathway in the induction of EAMG induced by AChR immunization. Accordingly, severe MG and other Ab- and complement-mediated diseases could be effectively treated by inhibiting C4, thus leaving the alternative complement pathway intact.

  11. New insights into the reaction of Schistosoma mansoni cercaria to the human complement system.

    Science.gov (United States)

    Da'dara, Akram A; Krautz-Peterson, Greice

    2014-10-01

    Schistosomes are parasitic worms that have a complex life cycle. The larval stage cercaria, infectious to mammals, is described as highly susceptible to the complement system, largely due to the glycocalyx that covers the cercarial membrane. In an attempt to have a more complete understanding of cercaria reaction to the complement system, three different approaches were used. Live cercariae exposed to normal human serum (NHS) as source of complement factors were assessed for (i) membrane attack complex (MAC) deposition on the parasite surface, (ii) cercaria survival rate by Hoechst staining of parasite DNA, and (iii) transformation into schistosomula by detection of the glucose transporter protein 4 (SGTP4), a marker for new tegument formation. We found that 82-95% of cercariae directly exposed to NHS for 18 h were viable and retained their ability to shed the glycocalyx, suggesting minimal tegument damage. In contrast, inhibition of glycocalyx shedding using eserine caused significant MAC binding and parasite death. Culturing complement-exposed cercariae to measure long-term survival showed that more parasites died over time, reaching a survival rate of 18-31% by day 6 in culture. The reason for this slow death is unknown, but the surviving parasites were able to form a new tegument as shown by detection of SGTP4 on the parasite surface. Furthermore, we found that complement activation significantly damaged the acetabular gland ducts and lysed secretory vesicles released by transforming cercariae. These findings should contribute for future in vivo studies of the effects of the complement system in skin migrating cercariae.

  12. Optomechanical effects of two-level systems in a back-action evading measurement of micro-mechanical motion

    Science.gov (United States)

    Suh, J.; Weinstein, A. J.; Schwab, K. C.

    2013-07-01

    We show that the two-level systems (TLS) in lithographic superconducting circuits act as a power-dependent dielectric leading to non-linear responses in a parametrically coupled electromechanical system. Driven TLS shift the microwave resonance frequency and modulate the mechanical resonance through the optical spring effect. By pumping with two tones in a back-action evading measurement, these effects produce a mechanical parametric instability which limits single quadrature imprecision to 1.4 xzp. The microwave resonator noise is also consistent to a TLS-noise model. These observations suggest design strategies for minimizing TLS effects to improve ground-state cooling and quantum non-demolition measurements of motion.

  13. Graphs whose complement and square are isomorphic

    DEFF Research Database (Denmark)

    Milanic, M.; Pedersen, Anders Sune; Pellicer, D.

    2014-01-01

    We study square-complementary graphs, that is, graphs whose complement and square are isomorphic. We prove several necessary conditions for a graph to be square-complementary, describe ways of building new square-complementary graphs from existing ones, construct infinite families of square-compl...

  14. Synapse remodeling, compliments of the complement system.

    Science.gov (United States)

    Fourgeaud, Lawrence; Boulanger, Lisa M

    2007-12-14

    A growing body of evidence indicates that some proteins known for their immune functions also have distinct nonimmune functions in the normal uninjured central nervous system. In this issue, Stevens et al. (2007) demonstrate an unexpected requirement for molecules of the complement cascade in the remodeling of synaptic connections in the developing visual system.

  15. Complement activation and regulation in preeclamptic placenta

    Directory of Open Access Journals (Sweden)

    A. Inkeri eLokki

    2014-07-01

    Full Text Available Preeclampsia (PE is a common disorder of pregnancy originating in the placenta. We examined whether excessive activation or poor regulation of the complement system at the maternal-fetal interface could contribute to the development of PE. Location and occurrence of complement components and regulators in placentae were analyzed. Cryostat sections of placentae were processed from 7 early-onset PE (diagnosis <34 weeks of gestation, 5 late-onset PE and 10 control pregnancies and immunostained for 6 complement activators and 6 inhibitors. Fluorescence was quantified and compared between PE and control placentae. Gene copy numbers of complement components C4A and C4B were assessed by a quantitative PCR method. Maternal C4 deficiencies (≥1 missing or non-functional C4 were most common in the early-onset PE group (71%, and more frequent in late-onset PE compared to healthy controls (60% vs. 38%. Complement C1q deposition differed significantly between control and patient groups: controls and early-onset PE patients had more C1q than late-onset PE patients (mean p=0.01 and p=0.005, respectively. C3 activation was analyzed by staining for C3b/iC3b and C3d. C3d was mostly specific to the basal syncytium and C3b/iC3b diffuse in other structures, but there were no clear differences between the study groups. Activated C4 and membrane-bound regulators CD55, CD46 and CD59 were observed abundantly in the syncytiotrophoblast. Syncytial knots, structures enriched in PE, stained specifically for the classical pathway inhibitor C4bp, whereas the key regulator alternative pathway, Factor H showed a wider distribution in the placenta. Differences in C1q deposition between late- and early-onset PE groups may be indicative of the different aetiology of PE symptoms in these patients. Irregular distribution of the complement regulators C4bp and FH in the PE placenta and a higher frequency of C4A deficiencies suggest a disturbed balance between complement activation

  16. Non-specific adsorption of complement proteins affects complement activation pathways of gold nanomaterials.

    Science.gov (United States)

    Quach, Quang Huy; Kah, James Chen Yong

    2017-04-01

    The complement system is a key humoral component of innate immunity, serving as the first line of defense against intruders, including foreign synthetic nanomaterials. Although gold nanomaterials (AuNMs) are widely used in nanomedicine, their immunological response is not well understood. Using AuNMs of three shapes commonly used in biomedical applications: spherical gold nanoparticles, gold nanostars and gold nanorods, we demonstrated that AuNMs activated whole complement system, leading to the formation of SC5b-9 complex. All three complement pathways were simultaneously activated by all the AuNMs. Recognition molecules of the complement system interacted with all AuNMs in vitro, except for l-ficolin, but the correlation between these interactions and corresponding complement pathway activation was only observed in the classical and alternative pathways. We also observed the mediating role of complement activation in cellular uptake of all AuNMs by human U937 promonocytic cells, which expresses complement receptors. Taken together, our results highlighted the potential immunological challenges for clinical applications of AuNMs that were often overlooked.

  17. Whispering through DDoS attack

    Directory of Open Access Journals (Sweden)

    Miralem Mehic

    2016-03-01

    Full Text Available Denial of service (DoS attack is an attempt of the attacker to disable victim's machine by depleting network or computing resources. If this attack is performed with more than one machine, it is called distributed denial of service (DDoS attack. Covert channels are those channels which are used for information transmission even though they are neither designed nor intended to transfer information at all. In this article, we investigated the possibility of using of DDoS attack for purposes of hiding data or concealing the existing covert channel. In addition, in this paper we analyzed the possibility of detection of such covert communication with the well-known statistical method. Also, we proposed the coordination mechanisms of the attack which may be used. A lot of research has been done in order to describe and prevent DDoS attacks, yet research on steganography on this field is still scarce.

  18. Network Protection Against DDoS Attacks

    Directory of Open Access Journals (Sweden)

    Petr Dzurenda

    2015-03-01

    Full Text Available The paper deals with possibilities of the network protection against Distributed Denial of Service attacks (DDoS. The basic types of DDoS attacks and their impact on the protected network are presented here. Furthermore, we present basic detection and defense techniques thanks to which it is possible to increase resistance of the protected network or device against DDoS attacks. Moreover, we tested the ability of current commercial Intrusion Prevention Systems (IPS, especially Radware DefensePro 6.10.00 product against the most common types of DDoS attacks. We create five scenarios that are varied in type and strength of the DDoS attacks. The attacks intensity was much greater than the normal intensity of the current DDoS attacks.

  19. SQL Injection Attacks and Defense

    CERN Document Server

    Clarke, Justin

    2012-01-01

    SQL Injection Attacks and Defense, First Edition: Winner of the Best Book Bejtlich Read Award "SQL injection is probably the number one problem for any server-side application, and this book unequaled in its coverage." -Richard Bejtlich, Tao Security blog SQL injection represents one of the most dangerous and well-known, yet misunderstood, security vulnerabilities on the Internet, largely because there is no central repository of information available for penetration testers, IT security consultants and practitioners, and web/software developers to turn to for help. SQL Injection Att

  20. Coronary Artery Dissection: Not Just a Heart Attack

    Science.gov (United States)

    ... Aneurysm More Coronary Artery Dissection: Not Just a Heart Attack Updated:Oct 4,2016 Sometimes a heart attack ... Disease Go Red For Women Types of aneurysms Heart Attack • Home • About Heart Attacks Acute Coronary Syndrome (ACS) ...

  1. Characterization of early and terminal complement proteins associated with polymorphonuclear leukocytes in vitro and in vivo after spinal cord injury

    Directory of Open Access Journals (Sweden)

    Galvan Manuel D

    2008-06-01

    Full Text Available Abstract Background The complement system has been suggested to affect injury or disease of the central nervous system (CNS by regulating numerous physiological events and pathways. The activation of complement following traumatic CNS injury can also result in the formation and deposition of C5b-9 membrane attack complex (C5b-9/MAC, causing cell lysis or sublytic effects on vital CNS cells. Although complement proteins derived from serum/blood-brain barrier breakdown can contribute to injury or disease, infiltrating immune cells may represent an important local source of complement after injury. As the first immune cells to infiltrate the CNS within hours post-injury, polymorphonuclear leukocytes (PMNs may affect injury through mechanisms associated with complement-mediated events. However, the expression/association of both early and terminal complement proteins by PMNs has not been fully characterized in vitro, and has not observed previously in vivo after traumatic spinal cord injury (SCI. Method We investigated the expression of complement mRNAs using rt-PCR and the presence of complement proteins associated with PMNs using immunofluroescence and quantitative flow cytometry. Results Stimulated or unstimulated PMNs expressed mRNAs encoding for C1q, C3, and C4, but not C5, C6, C7 or C9 in culture. Complement protein C1q or C3 was also detected in less than 30% of cultured PMNs. In contrast, over 70% of PMNs that infiltrated the injured spinal cord were associated with C1q, C3, C7 and C5b-9/MAC 3 days post-SCI. The localization/association of C7 or C5b-9/MAC with infiltrating PMNs in the injured spinal cord suggests the incorporation or internalization of C7 or C5b-9/MAC bound cellular debris by infiltrating PMNs because C7 and C5b-9/MAC were mostly localized to granular vesicles within PMNs at the spinal cord epicenter region. Furthermore, PMN presence in the injured spinal cord was observed for many weeks post-SCI, suggesting that this

  2. Structural Basis for Recognition of the Pore-Forming Toxin Intermedilysin by Human Complement Receptor CD59

    Directory of Open Access Journals (Sweden)

    Steven Johnson

    2013-05-01

    Full Text Available Pore-forming proteins containing the structurally conserved membrane attack complex/perforin fold play an important role in immunity and host-pathogen interactions. Intermedilysin (ILY is an archetypal member of a cholesterol-dependent cytolysin subclass that hijacks the complement receptor CD59 to make cytotoxic pores in human cells. ILY directly competes for the membrane attack complex binding site on CD59, rendering cells susceptible to complement lysis. To understand how these bacterial pores form in lipid bilayers and the role CD59 plays in complement regulation, we determined the crystal structure of human CD59 bound to ILY. Here, we show the ILY-CD59 complex at 3.5 Å resolution and identify two interfaces mediating this host-pathogen interaction. An ILY-derived peptide based on the binding site inhibits pore formation in a CD59-containing liposome model system. These data provide insight into how CD59 coordinates ILY monomers, nucleating an early prepore state, and suggest a potential mechanism of inhibition for the complement terminal pathway.

  3. Muusikamaailm : Festivalil Schwetzingenis. Ellingtoni sajandi tähistamine. Linz saab uue ooperimaja. Isaac Stern viiulita Saksamaal. Muusikapäevad Luksemburgis / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    1999-01-01

    30. apr.-7. juunini toimuvast muusikafestivalist Schwetzingenis. D. Ellingtoni 100. sünniaastapäeva tähistamisest maailmas. Valmis Linzi uue ooperimaja planeering. I. Stern juhatas kümnepäevast seminari Kölni Kõrgema Muusikakooli juures. Rahvusvahelise Nüüdismuusika Ühingu (ISCM) iga-aastased maailma muusikapäevad toimuvad 2000. aastal Luksemburgis

  4. A metalloproteinase karilysin present in the majority of Tannerella forsythia isolates inhibits all pathways of the complement system

    DEFF Research Database (Denmark)

    Jusko, Monika; Potempa, Jan; Karim, Abdulkarim Y

    2012-01-01

    Tannerella forsythia is a poorly studied pathogen despite being one of the main causes of periodontitis, which is an inflammatory disease of the supporting structures of the teeth. We found that despite being recognized by all complement pathways, T. forsythia is resistant to killing by human...... complement, which is present at up to 70% of serum concentration in gingival crevicular fluid. Incubation of human serum with karilysin, a metalloproteinase of T. forsythia, resulted in a decrease in bactericidal activity of the serum. T. forsythia strains expressing karilysin at higher levels were more...... resistant than low-expressing strains. Furthermore, the low-expressing strain was significantly more opsonized with activated complement factor 3 and membrane attack complex from serum compared with the other strains. The high-expressing strain was more resistant to killing in human blood. The protective...

  5. Shoulder injuries from attacking motion

    Science.gov (United States)

    Yanagi, Shigeru; Nishimura, Tetsu; Itoh, Masaru; Wada, Yuhei; Watanabe, Naoki

    1997-03-01

    Sports injuries have bothered professional players. Although many medical doctors try to treat injured players, to prevent sports injuries is more important. Hence, it is required to clear a kinematic mechanism of the sport injuries. A shoulder of volleyball attacker or baseball pitcher is often inured by playing motion. The injuries are mainly caused at the end of long head tendon, which is located in the upper side of scapula. Generally, a muscle and tendon have enough strength against tensile force, however, it seems that they are sometimes defeated by the lateral force. It is imagined that the effect of the lateral force has a possibility of injuring the tendon. If we find the influence of the lateral force on the injured portion, the mechanism of injuries must be cleared. In our research, volleyball attacking motion is taken by high speed video cameras. We analyze the motion as links system and obtain an acceleration of an arm and a shoulder from video image data. The generated force at a shoulder joint is calculated and resolved into the lateral and longitudinal forces. Our final goal is to discuss a possibility that the lateral force causes the injuries.

  6. Tanker avionics and aircrew complement evaluation.

    Science.gov (United States)

    Moss, R W; Barbato, G J

    1982-11-01

    This paper describes an effort to determine control and display criteria for operating SAC's KC-135 tanker with a reduced crew complement. The Tanker Avionics and Aircrew Complement Evaluation (TAACE) Program was a four-phase effort addressing the control and display design issues associated with operating the tanker without the navigator position. Discussed are: the mission analysis phase, during which the tanker's operational responsibilities were defined and documented; the design phase, during which alternative crew station design concepts were developed; the mockup evaluation phase, which accomplished initial SAC crew member assessment of cockpit designs; and the simulation phase, which validated the useability of the crew system redesign. The paper also describes a recommended crew station configuration and discusses some of the philosophy underlying the selection of cockpit hardware and systems.

  7. Complement and Immunoregulation in Tissue Injury

    Science.gov (United States)

    2014-10-01

    components of the immune response. To date there is no specific therapy that has yet gained widespread clinical use for the prevention and treatment of...lymphocyte depletion and inhibition of complement activation. Despite significant advances in this field, no agent or 9 therapy has yet gained widespread...relative to ß actin expression. 11 Figure 3: Proposed schema illustrates the protective role of R-spondin3 in endothelial cells under hypoxic stress

  8. DDOS ATTACK DETECTION SIMULATION AND HANDLING MECHANISM

    Directory of Open Access Journals (Sweden)

    Ahmad Sanmorino

    2013-11-01

    Full Text Available In this study we discuss how to handle DDoS attack that coming from the attacker by using detection method and handling mechanism. Detection perform by comparing number of packets and number of flow. Whereas handling mechanism perform by limiting or drop the packets that detected as a DDoS attack. The study begins with simulation on real network, which aims to get the real traffic data. Then, dump traffic data obtained from the simulation used for detection method on our prototype system called DASHM (DDoS Attack Simulation and Handling Mechanism. From the result of experiment that has been conducted, the proposed method successfully detect DDoS attack and handle the incoming packet sent by attacker.

  9. Securing internet by eliminating DDOS attacks

    Science.gov (United States)

    Niranchana, R.; Gayathri Devi, N.; Santhi, H.; Gayathri, P.

    2017-11-01

    The major threat caused to the authorised usage of Internet is Distributed Denial of Service attack. The mechanisms used to prevent the DDoS attacks are said to overcome the attack’s ability in spoofing the IP packets source addresses. By utilising Internet Protocol spoofing, the attackers cause a consequential load over the networks destination for policing attack packets. To overcome the IP Spoofing level on the Internet, We propose an Inter domain Packet Filter (IPF) architecture. The proposed scheme is not based on global routing information. The packets with reliable source addresses are not rejected, the IPF frame work works in such a manner. The spoofing capability of attackers is confined by IPF, and also the filter identifies the source of an attack packet by minimal number of candidate network.

  10. Model checking exact cost for attack scenarios

    DEFF Research Database (Denmark)

    Aslanyan, Zaruhi; Nielson, Flemming

    2017-01-01

    Attack trees constitute a powerful tool for modelling security threats. Many security analyses of attack trees can be seamlessly expressed as model checking of Markov Decision Processes obtained from the attack trees, thus reaping the benefits of a coherent framework and a mature tool support....... However, current model checking does not encompass the exact cost analysis of an attack, which is standard for attack trees. Our first contribution is the logic erPCTL with cost-related operators. The extended logic allows to analyse the probability of an event satisfying given cost bounds and to compute...... the exact cost of an event. Our second contribution is the model checking algorithm for erPCTL. Finally, we apply our framework to the analysis of attack trees....

  11. Relationship of serum complement levels to events of the malarial paroxysm.

    Science.gov (United States)

    Neva, F A; Howard, W A; Glew, R H; Krotoski, W A; Gam, A A; Collins, W E; Atkinson, J P; Frank, M M

    1974-08-01

    Malarial paroxysms due to Plasmodium vivax were studied for alterations in whole serum complement (C') and certain C' components. The objective was to relate C' values with events of the parasite cycle during schizogony and with the febrile pattern. Substantial decreases in C' were found in 9 of 18 paroxysms studied during relapse. In contrast, only one of 22 paroxysms occuring during the primary attack was associated with a striking depression in C', and this case exhibited certain characteristics of a relapse paroxysm. The mean change in C' levels during paroxysms in relapse (-23%) was significantly different from paroxysms of the primary attack (-2%). Depletion of C' was associated directly with degree of parasitemia and presence of complement-fixing (CF) antibody. Lowest levels of C' were found within a few hours after completion of schizont repture and peak fever. C4 levels reflected changes in whole serum C' and appeared to be a more sensitive indicator of C' alterations during malaria. While the alterations in C4 as well as C1 and C2 indicated that the classical C' pathway was involved, some preliminary results showed little or no depletion of late components, C3 and C6. Overall results are compatible with C' activation and depletion during or soon after schizont repture if parasite density is sufficiently high and if CF antibody is present.

  12. Distance hijacking attacks on distance bounding protocols

    OpenAIRE

    Cremers, Cas; Rasmussen, Kasper Bonne; Čapkun, Srdjan

    2011-01-01

    Distance bounding protocols are typically analyzed with respect to three types of attacks: Distance Fraud, Mafia Fraud, and Terrorist Fraud. We define and analyze a fourth main type of attack on distance bounding protocols, called Distance Hijacking. We show that many proposed distance bounding protocols are vulnerable to this type of attack, and we propose solutions to make these protocols resilient to Distance Hijacking. We further show that verifying distance bounding protocols using exist...

  13. Expression of innate immune complement regulators on brain epithelial cells during human bacterial meningitis

    Directory of Open Access Journals (Sweden)

    Gasque Philippe

    2006-09-01

    Full Text Available Abstract Background In meningitis, the cerebrospinal fluid contains high levels of innate immune molecules (e.g. complement which are essential to ward off the infectious challenge and to promote the infiltration of phagocytes (neutrophils, monocytes. However, epithelial cells of either the ependymal layer, one of the established niche for adult neural stem cells, or of the choroid plexus may be extremely vulnerable to bystander attack by cytotoxic and cytolytic complement components. Methods In this study, we assessed the capacity of brain epithelial cells to express membrane-bound complement regulators (ie, CD35, CD46, CD55 and CD59 in vitro and in situ by immunostaining of control and meningitis human brain tissue sections. Results Double immunofluorescence experiments for ependymal cell markers (GFAP, S100, ZO-1, E-cadherin and complement regulators indicated that the human ependymal cell line model was strongly positive for CD55, CD59 compared to weak stainings for CD46 and CD35. In tissues, we found that CD55 was weakly expressed in control choroid plexus and ependyma but was abundantly expressed in meningitis. Anti-CD59 stained both epithelia in apical location while increased CD59 staining was solely demonstrated in inflamed choroid plexus. CD46 and CD35 were not detected in control tissue sections. Conversely, in meningitis, the ependyma, subependyma and choroid plexus epithelia were strongly stained for CD46 and CD35. Conclusion This study delineates for the first time the capacity of brain ependymal and epithelial cells to respond to and possibly sustain the innate complement-mediated inflammatory insult.

  14. Snow fall and heart attacks.

    Science.gov (United States)

    Persinger, M A; Ballance, S E; Moland, M

    1993-03-01

    Total numbers of daily hospital admissions for cardiac emergencies were obtained from 3 hospitals within the Sudbury Basin in Canada for November through March for each of 4 consecutive years (1983-1986). Major diagnostic categories were also differentiated. No statistically significant correlations were found between the amount of snowfall during the day of or the days before or after admissions for the major categories of cardiac emergency. Specific analyses, conducted to reveal possible recondite associations between extreme or cumulative snowfalls and the most extreme days of cardiac emergencies, indicated a chance association. We conclude that the occurrence of heart attacks is independent of snowfall but that, when they occur, they are attributed to shoveling if there has been a recent major snow storm.

  15. Cache timing attacks on recent microarchitectures

    DEFF Research Database (Denmark)

    Andreou, Alexandres; Bogdanov, Andrey; Tischhauser, Elmar Wolfgang

    2017-01-01

    AES or similar algorithms in virtualized environments. This paper applies variants of this cache timing attack to Intel's latest generation of microprocessors. It enables a spy-process to recover cryptographic keys, interacting with the victim processes only over TCP. The threat model is a logically...... separated but CPU co-located attacker with root privileges. We report successful and practically verified applications of this attack against a wide range of microarchitectures, from a two-core Nehalem processor (i5-650) to two-core Haswell (i7-4600M) and four-core Skylake processors (i7-6700). The attack...

  16. Predator versus prey: locust looming-detector neuron and behavioural responses to stimuli representing attacking bird predators.

    Science.gov (United States)

    Santer, Roger D; Rind, F Claire; Simmons, Peter J

    2012-01-01

    Many arthropods possess escape-triggering neural mechanisms that help them evade predators. These mechanisms are important neuroethological models, but they are rarely investigated using predator-like stimuli because there is often insufficient information on real predator attacks. Locusts possess uniquely identifiable visual neurons (the descending contralateral movement detectors, DCMDs) that are well-studied looming motion detectors. The DCMDs trigger 'glides' in flying locusts, which are hypothesised to be appropriate last-ditch responses to the looms of avian predators. To date it has not been possible to study glides in response to stimuli simulating bird attacks because such attacks have not been characterised. We analyse video of wild black kites attacking flying locusts, and estimate kite attack speeds of 10.8±1.4 m/s. We estimate that the loom of a kite's thorax towards a locust at these speeds should be characterised by a relatively low ratio of half size to speed (l/|v|) in the range 4-17 ms. Peak DCMD spike rate and gliding response occurrence are known to increase as l/|v| decreases for simple looming shapes. Using simulated looming discs, we investigate these trends and show that both DCMD and behavioural responses are strong to stimuli with kite-like l/|v| ratios. Adding wings to looming discs to produce a more realistic stimulus shape did not disrupt the overall relationships of DCMD and gliding occurrence to stimulus l/|v|. However, adding wings to looming discs did slightly reduce high frequency DCMD spike rates in the final stages of object approach, and slightly delay glide initiation. Looming discs with or without wings triggered glides closer to the time of collision as l/|v| declined, and relatively infrequently before collision at very low l/|v|. However, the performance of this system is in line with expectations for a last-ditch escape response.

  17. Cued Panic Attacks in Body Dysmorphic Disorder

    Science.gov (United States)

    Phillips, Katharine A.; Menard, William; Bjornsson, Andri S.

    2013-01-01

    Background Body dysmorphic disorder (BDD) is a common and often severe disorder. Clinical observations suggest that panic attacks triggered by BDD symptoms may be common. However, to our knowledge, no study has examined such panic attacks in BDD. We investigated the prevalence, clinical features, and correlates of BDD-triggered panic attacks in individuals with this disorder. Methods Panic attacks and other variables were assessed using reliable and valid measures in 76 individuals with lifetime DSM-IV BDD. Results 28.9% (95% CI, 18.5%–39.4%) of participants reported lifetime panic attacks triggered by BDD symptoms. The most common triggers of such attacks were feeling that others were looking at or scrutinizing the perceived appearance defects (61.9%), looking in the mirror at perceived defects (38.1%), and being in bright light where perceived defects would be more visible (23.8%). The most common panic attack symptoms were palpitations (86.4%), sweating (66.7%), shortness of breath (63.6%), trembling or shaking (63.6%), and fear of losing control or going crazy (63.6%). Compared to participants without such panic attacks, those with BDD-triggered panic attacks had more severe lifetime BDD, social anxiety, and depressive symptoms, as well as poorer functioning and quality of life on a number of measures. They were also less likely to be employed and more likely to have been psychiatrically hospitalized and to have had suicidal ideation due to BDD. Conclusions Panic attacks triggered by BDD-related situations appear common in individuals with this disorder. BDD-triggered panic attacks were associated with greater symptom severity and morbidity. PMID:23653076

  18. Genetic, molecular and functional analyses of complement factor I deficiency

    DEFF Research Database (Denmark)

    Nilsson, S.C.; Trouw, L.A.; Renault, N.

    2009-01-01

    Complete deficiency of complement inhibitor factor I (FI) results in secondary complement deficiency due to uncontrolled spontaneous alternative pathway activation leading to susceptibility to infections. Current genetic examination of two patients with near complete FI deficiency and three patie...

  19. Role of complement in graft rejection after organ transplantation

    NARCIS (Netherlands)

    Bos, Ineke G. A.; ten Berge, Ineke J. M.; Hack, C. Erik

    2002-01-01

    Activation of the complement system may significantly contribute to the inflammatory reaction after solid organ transplantation. In allotransplantation, the complement system may be activated by ischemia/reperfusion and, possibly, by antibodies directed against the graft. In xenotransplantation from

  20. Complement Inhibitory Proteins and Their Role in Tumorigenesis

    National Research Council Canada - National Science Library

    Tomlinson, Stephen

    2001-01-01

    Complement is a major effector mechanism of the immune system. Membrane complement inhibitors on the surface of breast tumor cells, may play a crucial role in determining tumorigenesis and the outcome of antibody-mediated immunotherapy...

  1. Small RNA-mediated Cry toxin silencing allows Bacillus thuringiensis to evade Caenorhabditis elegans avoidance behavioral defenses

    Science.gov (United States)

    Peng, Donghai; Luo, Xiaoxia; Zhang, Ni; Guo, Suxia; Zheng, Jinshui; Chen, Ling

    2018-01-01

    Abstract Pathogen avoidance behavior protects animal hosts against microbial pathogens. Pathogens have evolved specific strategies during coevolution in response to such host defenses. However, these strategies for combatting host avoidance behavioral defenses remain poorly understood. Here, we used Caenorhabditis elegans and its bacterial pathogen Bacillus thuringiensis as a model and determined that small RNA (sRNA)-mediated Cry toxin silencing allowed pathogens to evade host avoidance behavioral defenses. The B. thuringiensis strain YBT-1518, which encodes three nematicidal cry genes, is highly toxic to C. elegans. However, the expression of the most potent toxin, Cry5Ba, was silenced in this strain when YBT-1518 was outside the host. Cry5Ba silencing was due to the sRNA BtsR1, which bound to the RBS site of the cry5Ba transcript via direct base pairing and inhibited Cry5Ba expression. Upon ingestion by C. elegans, Cry5Ba was expressed in vivo by strain YBT-1518. Cry5Ba silencing may allow B. thuringiensis to avoid nematode behavioral defenses and then express toxins once ingested to kill the host and gain a survival advantage. Our work describes a novel model of sRNA-mediated regulation to aid pathogens in combating host avoidance behavioral defenses. PMID:29069426

  2. The West Nile virus assembly process evades the conserved antiviral mechanism of the interferon-induced MxA protein

    Energy Technology Data Exchange (ETDEWEB)

    Hoenen, Antje [School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane (Australia); Gillespie, Leah [Department of Microbiology, La Trobe University, Melbourne (Australia); Department of Microbiology and Immunology, University of Melbourne, Melbourne (Australia); Morgan, Garry; Heide, Peter van der [Institute for Molecular Bioscience, University of Queensland, Brisbane (Australia); Khromykh, Alexander [School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane (Australia); Australian Infectious Diseases Research Centre, University of Queensland, Brisbane (Australia); Mackenzie, Jason, E-mail: jason.mackenzie@unimelb.edu.au [Department of Microbiology, La Trobe University, Melbourne (Australia); Department of Microbiology and Immunology, University of Melbourne, Melbourne (Australia)

    2014-01-05

    Flaviviruses have evolved means to evade host innate immune responses. Recent evidence suggests this is due to prevention of interferon production and signaling in flavivirus-infected cells. Here we show that the interferon-induced MxA protein can sequester the West Nile virus strain Kunjin virus (WNV{sub KUN}) capsid protein in cytoplasmic tubular structures in an expression-replication system. This sequestering resulted in reduced titers of secreted WNV{sub KUN} particles. We show by electron microscopy, tomography and 3D modeling that these cytoplasmic tubular structures form organized bundles. Additionally we show that recombinant ER-targeted MxA can restrict production of infectious WNV{sub KUN} under conditions of virus infection. Our results indicate a co-ordinated and compartmentalized WNV{sub KUN} assembly process may prevent recognition of viral components by MxA, particularly the capsid protein. This recognition can be exploited if MxA is targeted to intracellular sites of WNV{sub KUN} assembly. This results in further understanding of the mechanisms of flavivirus evasion from the immune system. - Highlights: • We show that the ISG MxA can recognize the West Nile virus capsid protein. • Interaction between WNV C protein and MxA induces cytoplasmic fibrils. • MxA can be retargeted to the ER to restrict WNV particle release. • WNV assembly process is a strategy to avoid MxA recognition.

  3. Upregulated Op18/stathmin activity causes chromosomal instability through a mechanism that evades the spindle assembly checkpoint

    Energy Technology Data Exchange (ETDEWEB)

    Holmfeldt, Per; Sellin, Mikael E. [Department of Molecular Biology, Umea University, SE-901 87 Umea (Sweden); Gullberg, Martin, E-mail: Martin.Gullberg@molbiol.umu.se [Department of Molecular Biology, Umea University, SE-901 87 Umea (Sweden)

    2010-07-15

    Op18/stathmin (Op18) is a microtubule-destabilizing protein that is phosphorylation-inactivated during mitosis and its normal function is to govern tubulin subunit partitioning during interphase. Human tumors frequently overexpress Op18 and a tumor-associated Q18{yields}E mutation has been identified that confers hyperactivity, destabilizes spindle microtubules, and causes mitotic aberrancies, polyploidization, and chromosome loss in K562 leukemia cells. Here we determined whether wild-type and mutant Op18 have the potential to cause chromosomal instability by some means other than interference with spindle assembly, and thereby bypassing the spindle assembly checkpoint. Our approach was based on Op18 derivatives with distinct temporal order of activity during mitosis, conferred either by differential phosphorylation inactivation or by anaphase-specific degradation through fusion with the destruction box of cyclin B1. We present evidence that excessive Op18 activity generates chromosomal instability through interference occurring subsequent to the metaphase-to-anaphase transition, which reduces the fidelity of chromosome segregation to spindle poles during anaphase. Similar to uncorrected merotelic attachment, this mechanism evades detection by the spindle assembly checkpoint and thus provides an additional route to chromosomal instability.

  4. Cooperative option of pursuit game with two pursuers and one evader. A strong stability of division variety

    Directory of Open Access Journals (Sweden)

    Viktor D. Shiryayev

    2017-06-01

    Full Text Available Introduction: The article deals with a simple differential game on the plane of pursuit with two consistently active players and one evader E; the game is considered in the form of the characteristic function. Materials and Methods: The geometric constructions and methods are used for solving the problem. The security zone of the escapee is bounded by the Apollonius circle, the pursuit team uses a strategy of parallel approach. Results: A method of finding the optimal players strategies and the optimal players’ trajectory is proposed. The way of forming the characteristic function is provided. All the variety of division is considered as a solution. However, the use of the results of cooperative theory of differential games is impossible without solving the problems associated with the specifics of differential equations of motion. Foremost, it is the problem of dynamic stability of optimality principles. The article introduces an auxiliary function of making the redistribution of winnings in time, keeping his total winnings throughout the game. The dynamic stability of the cooperative solution is determined with the help of this function. Strong dynamic stability of the entire set of solutions is shown. Discussion and Conclusions: The obtained results are consistent with similar research of other authors. Further research in this field can be used in the development of methods for “regularization” of optimality principles, for which the condition of dynamic stability is always fulfilled.

  5. Intrusion detection systems: complement to firewall security system ...

    African Journals Online (AJOL)

    The main purpose with firewall is to protect against unauthorized external attacks but it will normally leave the network unprotected from internal attacks or intrusions. Fire walls and access control have been the most important components used in order to secure network and its resources. They work to prevent attacks from ...

  6. On Wiener index of graph complements

    Directory of Open Access Journals (Sweden)

    Jaisankar Senbagamalar

    2014-06-01

    Full Text Available Let $G$ be an $(n,m$-graph. We say that $G$ has property $(ast$ if for every pair of its adjacent vertices $x$ and $y$, there exists a vertex $z$, such that $z$ is not adjacent to either $x$ or $y$. If the graph $G$ has property $(ast$, then its complement $overline G$ is connected, has diameter 2, and its Wiener index is equal to $binom{n}{2}+m$, i.e., the Wiener index is insensitive of any other structural details of the graph $G$. We characterize numerous classes of graphs possessing property $(ast$, among which are trees, regular, and unicyclic graphs.

  7. Begin and start: aspect and complement choice

    Directory of Open Access Journals (Sweden)

    Tünde Nagy

    2008-01-01

    Full Text Available The paper offers a semantic analysis of begin and start and their non-finite complementation: the to-infinitive and –ing constructions. The core idea of the paper is that the aspectual constructions ‘begin+ to infinitive’, ‘begin + ing’, ‘start+ to infinitive’, and ‘start+ ing’ have both a schematic and a prototypical meaning, and that the subtle differences between them are motivated by several factors, like viewing (perfectivity vs. imperfectivity, temporality (future orientation vs. ongoing reading dynamicity (graduality vs. abruptness, agentivity, etc.

  8. Generating attacks in SysML activity diagrams by detecting attack surfaces

    NARCIS (Netherlands)

    Ouchani, Samir; Lenzini, Gabriele

    In the development process of a secure system is essential to detect as early as possible the system’s vulnerable points, the so called attack surfaces, and to estimate how feasible it would be that known attacks breach through them. Even if attack surfaces can be sometimes detected automatically,

  9. Attack Trees for Practical Security Assessment: Ranking of Attack Scenarios with ADTool 2.0

    NARCIS (Netherlands)

    Gadyatskaya, Olga; Jhawar, Ravi; Kordy, P.T.; Lounis, Karim; Mauw, Sjouke; Trujillo-Rasua, Rolando

    2016-01-01

    In this tool demonstration paper we present the ADTool2.0: an open-source software tool for design, manipulation and analysis of attack trees. The tool supports ranking of attack scenarios based on quantitative attributes entered by the user; it is scriptable; and it incorporates attack trees with

  10. [The complement system as a main actor in the pathogenesis of obstetric antiphospholipid syndrome].

    Science.gov (United States)

    Alijotas-Reig, Jaume

    2010-01-23

    Pregnancy losses are the main obstetrical complications of the obstetric antiphospholipid syndrome (obstetric-APS). Classically, they have been strongly attributed to thrombosis and further placental infarcts. But in some cases is not possible to show evidence of decidual thrombosis or placental vasculopathy, and sometimes inflammatory signs are present. Besides, the prevalence of systemic thrombosis is low in obstetric APS patients. Some cases have low plasma C4/C3 levels. Animal models show a local inflammatory mechanism. The beta2-glycoprotein-I/anti-beta2-glycoprotein-I complexes activate both, classical and alternative complement pathways. Complement proteins may injure trophoblast cells, recruiting and activating monocytes and neutrophils. Free radicals and proteolytic enzymes could also attack trophoblastic cells. In addition, an amplifier loop between the tissue factor, inflammatory cells and complement proteins could exist. Overall, these diverse mechanisms may explain both, inflammatory and thrombophilic placental alterations. In the end, the role played in this binomial by certain pro-inflammatory cytokines, mainly TNF-alpha, remains to clarify. Copyright 2009 Elsevier España, S.L. All rights reserved.

  11. British used Congreve Rockets to Attack Napoleon

    Science.gov (United States)

    2004-01-01

    Sir William Congreve developed a rocket with a range of about 9,000 feet. The incendiary rocket used black powder, an iron case, and a 16-foot guide stick. In 1806, British used Congreve rockets to attack Napoleon's headquarters in France. In 1807, Congreve directed a rocket attack against Copenhagen.

  12. Playing Attack and Defense with Trusted Storage

    DEFF Research Database (Denmark)

    Gonzalez, Javier; Bonnet, Philippe; Bouganim, Luc

    2014-01-01

    provide trusted storage? This is the question we tackle in this demonstration. We describe how secure devices, equipped with a trusted execution environment, differ from general purpose devices. We illustrate with our demonstration scenario, that it is much more difficult to attack a storage service...... running on a secure device, than to attack the same service running on a general purpose device....

  13. Evaluation of Crosstalk Attacks in Access Networks

    DEFF Research Database (Denmark)

    Wagner, Christoph; Eiselt, Michael; Grobe, Klaus

    2016-01-01

    WDM-PON systems regained interest as low-cost solution for metro and access networks. We present a comparative analysis of resilience of wavelength-selective and wavelength-routed architectures against crosstalk attackers. We compare the vulnerability of these architectures against attacks...

  14. Micromechanics of high temperature hydrogen attack

    NARCIS (Netherlands)

    Schlögl, Sabine M.; Giessen, Erik van der

    1999-01-01

    Hydrogen attack is a material degradation process that occurs at elevated temperatures in hydrogen-rich environments, such as found in petro-chemical installations. Weldments in components such as reactor vessels are particularly susceptible to hydrogen attack. This paper discusses a multi-scale

  15. Drammer : Deterministic Rowhammer attacks on mobile platforms

    NARCIS (Netherlands)

    Van Der Veen, Victor; Fratantonio, Yanick; Lindorfer, Martina; Gruss, Daniel; Maurice, Clémentine; Vigna, Giovanni; Bos, Herbert; Razavi, Kaveh; Giuffrida, Cristiano

    2016-01-01

    Recent work shows that the Rowhammer hardware bug can be used to craft powerful attacks and completely subvert a system. However, existing efforts either describe probabilistic (and thus unreliable) attacks or rely on special (and often unavailable) memory management features to place victim objects

  16. Rotational Rebound Attacks on Reduced Skein

    DEFF Research Database (Denmark)

    Khovratovich, Dmitry; Nikolic, Ivica; Rechberger, Christian

    2010-01-01

    In this paper we combine a recent rotational cryptanalysis with the rebound attack, which results in the best cryptanalysis of Skein, a candidate for the SHA-3 competition. The rebound attack approach was so far only applied to AES-like constructions. For the first time, we show that this approach...

  17. Revisiting attacker model for smart vehicles

    NARCIS (Netherlands)

    Petit, Jonathan; Feiri, Michael; Kargl, Frank

    Because of the potential impact on user's life in cooperative automated safety applications, the security of Vehicle-to-X communication (V2X) is mandatory. However, the current attacker model used in literature is often too network-oriented, and it is unclear what realistic attacks could be. In this

  18. The Production of Complement Clauses in Children with Language Impairment

    Science.gov (United States)

    Steel, Gillian; Rose, Miranda; Eadie, Patricia

    2016-01-01

    Purpose: The purpose of this research was to provide a comprehensive description of complement-clause production in children with language impairment. Complement clauses were examined with respect to types of complement structure produced, verb use, and both semantic and syntactic accuracy. Method: A group of 17 children with language impairment…

  19. The Complement System in Dialysis : A Forgotten Story?

    NARCIS (Netherlands)

    Poppelaars, Felix; Faria, Bernardo; da Costa, Mariana Gaya; Franssen, Casper F. M.; van Son, Willem J.; Berger, Stefan P.; Daha, Mohamed R.; Seelen, Marc A.

    2018-01-01

    Significant advances have lead to a greater understanding of the role of the complement system within nephrology. The success of the first clinically approved complement inhibitor has created renewed appreciation of complement-targeting therapeutics. Several clinical trials are currently underway to

  20. 21 CFR 866.5240 - Complement components immunological test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Complement components immunological test system... SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems § 866.5240 Complement components immunological test system. (a) Identification. A complement components...

  1. The Ancient Complement System: Role in Physiology and Defense

    NARCIS (Netherlands)

    Kuipers, Saskia

    2003-01-01

    The Ancient Complement System: Role in Microbial Clearance, Lipid Transport and Prevention of Autoimmunity This study concentrates on the complement system, which is part of the nonspecific or ‘innate’ immune system. The complement system may be considered a primordial enzyme system that was,

  2. Pathogenic role of complement in renal ischemia/reperfusion injury

    NARCIS (Netherlands)

    Pol, Pieter van der

    2013-01-01

    The aim of the research described in this thesis was to study the role of complement in renal ischemia/reperfusion injury (IRI) and to delineate the contribution of the different complement pathways involved. So far, in human renal IRI, the activation pathways of complement by ischemic proximal

  3. Complement-mediated solubilization of immune complexes and their interaction with complement C3 receptors

    DEFF Research Database (Denmark)

    Petersen, Ivan; Baatrup, Gunnar; Jepsen, H H

    1985-01-01

    Some of the molecular events in the complement (C)-mediated solubilization of immune complexes (IC) have been clarified in recent years. The solubilization is primarily mediated by alternative C pathway proteins whereas factors in the classical pathway accelerate the process. Components of the me......Some of the molecular events in the complement (C)-mediated solubilization of immune complexes (IC) have been clarified in recent years. The solubilization is primarily mediated by alternative C pathway proteins whereas factors in the classical pathway accelerate the process. Components...

  4. Automatic Classification of Attacks on IP Telephony

    Directory of Open Access Journals (Sweden)

    Jakub Safarik

    2013-01-01

    Full Text Available This article proposes an algorithm for automatic analysis of attack data in IP telephony network with a neural network. Data for the analysis is gathered from variable monitoring application running in the network. These monitoring systems are a typical part of nowadays network. Information from them is usually used after attack. It is possible to use an automatic classification of IP telephony attacks for nearly real-time classification and counter attack or mitigation of potential attacks. The classification use proposed neural network, and the article covers design of a neural network and its practical implementation. It contains also methods for neural network learning and data gathering functions from honeypot application.

  5. Use of Attack Graphs in Security Systems

    Directory of Open Access Journals (Sweden)

    Vivek Shandilya

    2014-01-01

    Full Text Available Attack graphs have been used to model the vulnerabilities of the systems and their potential exploits. The successful exploits leading to the partial/total failure of the systems are subject of keen security interest. Considerable effort has been expended in exhaustive modeling, analyses, detection, and mitigation of attacks. One prominent methodology involves constructing attack graphs of the pertinent system for analysis and response strategies. This not only gives the simplified representation of the system, but also allows prioritizing the security properties whose violations are of greater concern, for both detection and repair. We present a survey and critical study of state-of-the-art technologies in attack graph generation and use in security system. Based on our research, we identify the potential, challenges, and direction of the current research in using attack graphs.

  6. Protecting Cryptographic Memory against Tampering Attack

    DEFF Research Database (Denmark)

    Mukherjee, Pratyay

    . In practice such attacks can be executed easily, e.g. by heating the device, as substantiated by numerous works in the past decade. Tampering attacks are a class of such physical attacks where the attacker can change the memory/computation, gains additional (non-black-box) knowledge by interacting...... with the faulty device and then tries to break the security. Prior works show that generically approaching such problem is notoriously difficult. So, in this dissertation we attempt to solve an easier question, known as memory-tampering, where the attacker is allowed tamper only with the memory of the device...... but not the computation. Such weaker model can still be practically useful and moreover, may provide nice building-blocks to tackle full-fledged tampering in future. In this dissertation we study different models of memory-tampering and provide a number of solutions with different flavors. Mainly we took two different...

  7. Two Improved Multiple-Differential Collision Attacks

    Directory of Open Access Journals (Sweden)

    An Wang

    2014-01-01

    Full Text Available In CHES 2008, Bogdanov proposed multiple-differential collision attacks which could be applied to the power analysis attacks on practical cryptographic systems. However, due to the effect of countermeasures on FPGA, there are some difficulties during the collision detection, such as local high noise and the lack of sampling points. In this paper, keypoints voting test is proposed for solving these problems, which can increase the success ratio from 35% to 95% on the example of one implementation. Furthermore, we improve the ternary voting test of Bogdanov, which can improve the experiment efficiency markedly. Our experiments show that the number of power traces required in our attack is only a quarter of the requirement of traditional attack. Finally, some alternative countermeasures against our attacks are discussed.

  8. Early Neoplastic Progression Is Complement Independent

    Directory of Open Access Journals (Sweden)

    Karin E. de Visser

    2004-11-01

    Full Text Available Infiltration of leukocytes into premalignant tissue is a common feature of many epithelial neoplasms and is thought to contribute to cancer development. However, the molecular and cellular regulatory mechanisms underlying activation of innate host responses to enhanced neoplastic cell proliferation are largely unknown. Considering the importance of the complement system in regulating inflammation during acute pathologic tissue remodeling, we examined the functional significance of complement component 3 (C3 as a regulator of inflammatory cell infiltration and activation during malignant progression by using a transgenic mouse model of multistage epithelial carcinogenesis, e.g., HPV16 mice. Whereas abundant deposition of C3 is a characteristic feature of premalignant hyperplasias and dysplasias coincident with leukocyte infiltration in neoplastic tissue, genetic elimination of C3 neither affects inflammatory cell recruitment toward neoplastic skin nor impacts responding pathways downstream of inflammatory cell activation, e.g., keratinocyte hyperproliferation or angiogenesis. Taken together, these data suggest that complementindependent pathways are critical for leukocyte recruitment into neoplastic tissue and leukocytemediated potentiation of tumorigenesis.

  9. Participial Perception Verb Complements in Old English

    Directory of Open Access Journals (Sweden)

    Lowrey Brian

    2014-12-01

    Full Text Available In this paper, I shall examine the complements of perception verbs in Old English involving a noun phrase and a present participle. What kind of perception is described by these structures? Do they evoke the perception of an event, or that of an entity? It will be shown here that there are good reasons to believe that an NP + present participle sequence could function as the equivalent of the traditional “AcI” construction when used with perception verbs. I shall also attempt to determine to what extent the syntax of this construction matches the semantics: is the internal argument of the perception verb the NP alone, or some kind of combination of the NP and the participle? This question is particularly interesting in the light of Declerck’s (1982 remarks on participle perception verb complements in modern English. Finally, I shall take a look at morphological parametres: sometimes the participle inflects to agree with the NP, whereas on other occasions it does not. What might the implications of this kind of variation be?

  10. Uudised : Üheteistkümnendad trompetipäevad. Eesti Muusikanõukogus. Tüüri "Motus I" Londonis / Kadri Ruudi

    Index Scriptorium Estoniae

    Ruudi, Kadri

    2000-01-01

    4.-15. apr. toimuvad EMA XI trompetipäevad. 14.-19. märtsil viibis Eestis IMC asepresident F. Müller-Heuser, 22. märtsil toimus EMN juhatuse koosolek. 19. märtsil andis Londoni South Bank Centre'is kontserdi P. Carneiro, kes tõi Inglismaal esiettekandele ka E.-S. Tüüri teose "Motus I"

  11. Theoretical implications of complement structure acquisition in Korean.

    Science.gov (United States)

    Kim, Y J

    1989-10-01

    The acquisition of complement phrasal constructions in Korean is examined in spontaneous speech data from two children, who were observed from one and a half to three years of age. In spite of typological differences between English and Korean, both syntactic and semantic characteristics are found to be shared by children acquiring complement constructions in the two languages. However, certain language-specific features of Korean complement structures make it possible to address theoretical points concerning the structure of infinitival complements which cannot be resolved with the acquisition data on English. The error pattern in the acquisition of certain 'subject-equi' verbs in Korean poses problems both for LFG and GB accounts of the constituent structure of infinitival complements and the acquisition of those constructions. On the basis of the Korean data, I propose that base-generated VP complements are acquired first, with semantically motivated reanalysis of previously acquired infinitival complement structures occurring at a later stage.

  12. The Complement System and Antibody-Mediated Transplant Rejection.

    Science.gov (United States)

    Stites, Erik; Le Quintrec, Moglie; Thurman, Joshua M

    2015-12-15

    Complement activation is an important cause of tissue injury in patients with Ab-mediated rejection (AMR) of transplanted organs. Complement activation triggers a strong inflammatory response, and it also generates tissue-bound and soluble fragments that are clinically useful markers of inflammation. The detection of complement proteins deposited within transplanted tissues has become an indispensible biomarker of AMR, and several assays have recently been developed to measure complement activation by Abs reactive to specific donor HLA expressed within the transplant. Complement inhibitors have entered clinical use and have shown efficacy for the treatment of AMR. New methods of detecting complement activation within transplanted organs will improve our ability to diagnose and monitor AMR, and they will also help guide the use of complement inhibitory drugs. Copyright © 2015 by The American Association of Immunologists, Inc.

  13. A vital role for complement in heart disease

    DEFF Research Database (Denmark)

    Lappegård, Knut T; Garred, Peter; Jonasson, Lena

    2014-01-01

    fibrillation often share risk factors both with coronary heart disease and heart failure, and there is some evidence implicating complement activation in atrial fibrillation. Moreover, Chagas heart disease, a protozoal infection, is an important cause of heart failure in Latin America, and the complement......Heart diseases are common and significant contributors to worldwide mortality and morbidity. During recent years complement mediated inflammation has been shown to be an important player in a variety of heart diseases. Despite some negative results from clinical trials using complement inhibitors......, emerging evidence points to an association between the complement system and heart diseases. Thus, complement seems to be important in coronary heart disease as well as in heart failure, where several studies underscore the prognostic importance of complement activation. Furthermore, patients with atrial...

  14. Protecting complex infrastructures against multiple strategic attackers

    Science.gov (United States)

    Hausken, Kjell

    2011-01-01

    Infrastructures are analysed subject to defence by a strategic defender and attack by multiple strategic attackers. A framework is developed where each agent determines how much to invest in defending versus attacking each of multiple targets. A target can have economic, human and symbolic values, which generally vary across agents. Investment expenditure functions for each agent can be linear in the investment effort, concave, convex, logistic, can increase incrementally, or can be subject to budget constraints. Contest success functions (e.g., ratio and difference forms) determine the probability of a successful attack on each target, dependent on the relative investments of the defender and attackers on each target, and on characteristics of the contest. Targets can be in parallel, in series, interlinked, interdependent or independent. The defender minimises the expected damage plus the defence expenditures. Each attacker maximises the expected damage minus the attack expenditures. The number of free choice variables equals the number of agents times the number of targets, or lower if there are budget constraints. Each agent is interested in how his investments vary across the targets, and the impact on his utilities. Alternative optimisation programmes are discussed, together with repeated games, dynamic games and incomplete information. An example is provided for illustration.

  15. Interpain A, a cysteine proteinase from Prevotella intermedia, inhibits complement by degrading complement factor C3.

    Directory of Open Access Journals (Sweden)

    Michal Potempa

    2009-02-01

    Full Text Available Periodontitis is an inflammatory disease of the supporting structures of the teeth caused by, among other pathogens, Prevotella intermedia. Many strains of P. intermedia are resistant to killing by the human complement system, which is present at up to 70% of serum concentration in gingival crevicular fluid. Incubation of human serum with recombinant cysteine protease of P. intermedia (interpain A resulted in a drastic decrease in bactericidal activity of the serum. Furthermore, a clinical strain 59 expressing interpain A was more serum-resistant than another clinical strain 57, which did not express interpain A, as determined by Western blotting. Moreover, in the presence of the cysteine protease inhibitor E64, the killing of strain 59 by human serum was enhanced. Importantly, we found that the majority of P. intermedia strains isolated from chronic and aggressive periodontitis carry and express the interpain A gene. The protective effect of interpain A against serum bactericidal activity was found to be attributable to its ability to inhibit all three complement pathways through the efficient degradation of the alpha-chain of C3 -- the major complement factor common to all three pathways. P. intermedia has been known to co-aggregate with P. gingivalis, which produce gingipains to efficiently degrade complement factors. Here, interpain A was found to have a synergistic effect with gingipains on complement degradation. In addition, interpain A was able to activate the C1 complex in serum, causing deposition of C1q on inert and bacterial surfaces, which may be important at initial stages of infection when local inflammatory reaction may be beneficial for a pathogen. Taken together, the newly characterized interpain A proteinase appears to be an important virulence factor of P. intermedia.

  16. Neisseria gonorrhoeae Evades Calprotectin-Mediated Nutritional Immunity and Survives Neutrophil Extracellular Traps by Production of TdfH.

    Science.gov (United States)

    Jean, Sophonie; Juneau, Richard A; Criss, Alison K; Cornelissen, Cynthia N

    2016-10-01

    Neisseria gonorrhoeae successfully overcomes host strategies to limit essential nutrients, termed nutritional immunity, by production of TonB-dependent transporters (TdTs)-outer membrane proteins that facilitate nutrient transport in an energy-dependent manner. Four gonococcal TdTs facilitate utilization of iron or iron chelates from host-derived proteins, including transferrin (TbpA), lactoferrin (LbpA), and hemoglobin (HpuB), in addition to xenosiderophores from other bacteria (FetA). The roles of the remaining four uncharacterized TdTs (TdfF, TdfG, TdfH, and TdfJ) remain elusive. Regulatory data demonstrating that production of gonococcal TdfH and TdfJ are unresponsive to or upregulated under iron-replete conditions led us to evaluate the role of these TdTs in the acquisition of nutrients other than iron. In this study, we found that production of gonococcal TdfH is both Zn and Zur repressed. We also found that TdfH confers resistance to calprotectin, an immune effector protein highly produced in neutrophils that has antimicrobial activity due to its ability to sequester Zn and Mn. We found that TdfH directly binds calprotectin, which enables gonococcal Zn accumulation in a TdfH-dependent manner and enhances bacterial survival after exposure to neutrophil extracellular traps (NETs). These studies highlight Zn sequestration by calprotectin as a key functional arm of NET-mediated killing of gonococci. We demonstrate for the first time that N. gonorrhoeae exploits this host strategy in a novel defense mechanism, in which TdfH production hijacks and directly utilizes the host protein calprotectin as a zinc source and thereby evades nutritional immunity. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. Rice OsFLS2-Mediated Perception of Bacterial Flagellins Is Evaded by Xanthomonas oryzae pvs. oryzae and oryzicola.

    Science.gov (United States)

    Wang, Shanzhi; Sun, Zhe; Wang, Huiqin; Liu, Lijuan; Lu, Fen; Yang, Jun; Zhang, Min; Zhang, Shiyong; Guo, Zejian; Bent, Andrew F; Sun, Wenxian

    2015-07-01

    Bacterial flagellins are often recognized by the receptor kinase FLAGELLIN SENSITIVE2 (FLS2) and activate MAMP-triggered immunity in dicotyledonous plants. However, the capacity of monocotyledonous rice to recognize flagellins of key rice pathogens and its biological relevance remain poorly understood. We demonstrate that ectopically expressed OsFLS2 in Arabidopsis senses the eliciting flg22 peptide and in vitro purified Acidovorax avenae (Aa) flagellin in an expression level-dependent manner, but does not recognize purified flagellins or derivative flg22(Xo) peptides of Xanthomonas oryzae pvs. oryzae (Xoo) and oryzicola (Xoc). Consistently, the flg22 peptide and purified Aa flagellin, but not Xoo/Xoc flagellins, induce various immune responses such as defense gene induction and MAPK activation in rice. Perception of flagellin by rice does induce strong resistance to Xoo infection, as shown after pre-treatment of rice leaves with Aa flagellin. OsFLS2 was found to differ from AtFLS2 in its perception specificities or sensitivities to different flg22 sequences. In addition, post-translational modification of Xoc flagellin was altered by deletion of glycosyltransferase-encoding rbfC, but this had little effect on Xoc motility and rpfC mutation did not detectably reduce Xoc virulence on rice. Deletion of flagellin-encoding fliC from Xoo/Xoc blocked swimming motility but also did not significantly alter Xoo/Xoc virulence. These results suggest that Xoo/Xoc carry flg22-region amino acid changes that allow motility while evading the ancient flagellin detection system in rice, which retains recognition capacity for other bacterial pathogens. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  18. Masturbation and Partnered Sex: Substitutes or Complements?

    Science.gov (United States)

    Regnerus, Mark; Price, Joseph; Gordon, David

    2017-10-01

    Drawing upon a large, recent probability sample of American adults ages 18-60 (7648 men and 8090 women), we explored the association between sexual frequency and masturbation, evaluating the evidence for whether masturbation compensates for unavailable sex, complements (or augments) existing paired sexual activity, or bears little association with it. We found evidence supporting a compensatory relationship between masturbation and sexual frequency for men, and a complementary one among women, but each association was both modest and contingent on how content participants were with their self-reported frequency of sex. Among men and women, both partnered status and their sexual contentment were more obvious predictors of masturbation than was recent frequency of sex. We conclude that both hypotheses as commonly evaluated suffer from failing to account for the pivotal role of subjective sexual contentment in predicting masturbation.

  19. Genetic complementation groups in cockayne syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, K.; Kawai, K.; Kumahara, Y.; Ikenaga, M.; Okada, Y.

    1981-07-01

    Skin fibroblasts from patients with cockayne syndrome (CS cell) exhibited marked ultraviolet (UV) sensitivity as measured by colony-forming ability. Further, recovery of semiconservative DNA synthesis following UV irradiation was absent in CS cells, as it is in xeroderma pigmentosum cells. We found that the rate of semiconservative DNA synthesis measured at 12 h after 12 J/m2 of UV irradiation had recovered to nearly normal levels in binuclear cells obtained by the fusion of CS strains CS3BE (GM 1856) and CS7SE (GM1428) and of CS3BE (GM1856) and CS1BE (GM1629), but not of C57SE (GM1428) and CS1BE (GM1629). These results indicate that there are at least two genetic complementation groups in CS.

  20. Lectin Complement Pathway Proteins in Healthy Individuals

    DEFF Research Database (Denmark)

    Troldborg, Anne; Hansen, Annette Gudmann; Hansen, Søren W K

    2017-01-01

    Since the discovery of the lectin pathway of complement activation, numerous clinical cohorts have been examined for one or more of the proteins, with the intention of uncovering the functions of the proteins or with the aim of discovering new biomarkers or diagnostic tools. To unveil the abnormal......, it is pivotal to know the normal. Our aim was to describe the concentrations of the eleven known proteins of the lectin pathway in serum and plasma and to uncover possible gender differences, age and diurnal variations, which must be taken into account for investigations in different cohorts. We examined...... the concentrations of all lectin pathway proteins (mannan-binding lectin (MBL), H-ficolin, L-ficolin, M-ficolin, collectin-K1, collectin-L1, MBL-associated serine protease 2 (MASP-2), MASP-3, MBL associated protein of 44 kDa (MAp44) and MAp19 in 300 Danish blood donors in serum and EDTA plasma in established assays...

  1. Acidosis activates complement system in vitro

    Directory of Open Access Journals (Sweden)

    Michael Emeis

    1998-01-01

    Full Text Available We investigated the in vitro effect of different form s of acidosis (pH 7.0 on the formation of anaphylatoxins C3a and C5a. Metabolic acidosis due to addition of hydrochloric acid (10 μ mol/ml blood or lactic acid (5.5 μ mol/ml to heparin blood (N=12 caused significant activation of C3a and C5a compared to control (both p=0.002. Respiratory acidosis activated C3a (p=0.007 and C5a (p=0.003 compared to normocapnic controls. Making blood samples with lactic acidosis hypocapnic resulted in a median pH of 7.37. In this respiratory compensated metabolic acidosis, C3a and C5a were not increased. These experiments show that acidosis itself and not lactate trigger for activation of complement components C3 and C5.

  2. Classification of cyber attacks in South Africa

    CSIR Research Space (South Africa)

    Van Heerden, R

    2016-05-01

    Full Text Available various ATM's throughout South Africa. Two criminals, Motsoane and Masoleng, were arrested in February 2012 and both sentenced to 15 years in jail [36, 37]. 3.10 2013: IOL DDoS Anonymous Africa claimed responsibility for launching a Distributed Denial... of Service (DDoS) attack on the Independent Newspaper web site iol.co.za. The attack was in response to claims that the IOL group supports Zimbabwean president Robert Mugabe. The following taunt was sent to boast about the attack: “IOL bad boys bad boys...

  3. Evading the Boomerang Effect

    DEFF Research Database (Denmark)

    Laursen, Keld; Moreira, Solon; Reichstein, Toke

    2017-01-01

    Technology licensing agreements potentially can create future appropriability problems. Drawing on the appropriability literature, we argue that the inclusion of a grant-back clause in technology licensing agreements is an attempt to balance the gains from and protection of the focal firms’ techn...

  4. Warning Signs of Heart Attack, Stroke and Cardiac Arrest

    Science.gov (United States)

    ... Heart Attack WARNING SIGNS OF HEART ATTACK, STROKE & CARDIAC ARREST HEART ATTACK WARNING SIGNS CHEST DISCOMFORT Most heart ... to the hospital immediately. Learn more about stroke CARDIAC ARREST WARNING SIGNS SUDDEN LOSS OF RESPONSIVENESS No response ...

  5. Evaluation of the membrane attack complex of complement for the detection of a recent myocardial infarction in man

    NARCIS (Netherlands)

    Robert-Offerman, S. R.; Leers, M. P.; van Suylen, R. J.; Nap, M.; Daemen, M. J.; Theunissen, P. H.

    2000-01-01

    The diagnosis of an acute myocardial infarction (MI) can be cumbersome for pathologists. Even with a positive nitroblue tetrazolium (NBT) reaction, haematoxylin and eosin (H&E) evaluation of the myocardial tissue can remain inconclusive. Early signs presumed diagnostic for myocardial infarction,

  6. Detecting Pulsing Denial-of-Service Attacks with Nondeterministic Attack Intervals

    Directory of Open Access Journals (Sweden)

    Xiapu Luo

    2009-01-01

    Full Text Available This paper addresses the important problem of detecting pulsing denial of service (PDoS attacks which send a sequence of attack pulses to reduce TCP throughput. Unlike previous works which focused on a restricted form of attacks, we consider a very broad class of attacks. In particular, our attack model admits any attack interval between two adjacent pulses, whether deterministic or not. It also includes the traditional flooding-based attacks as a limiting case (i.e., zero attack interval. Our main contribution is Vanguard, a new anomaly-based detection scheme for this class of PDoS attacks. The Vanguard detection is based on three traffic anomalies induced by the attacks, and it detects them using a CUSUM algorithm. We have prototyped Vanguard and evaluated it on a testbed. The experiment results show that Vanguard is more effective than the previous methods that are based on other traffic anomalies (after a transformation using wavelet transform, Fourier transform, and autocorrelation and detection algorithms (e.g., dynamic time warping.

  7. Complement regulation and kidney diseases: recent knowledge of the double-edged roles of complement activation in nephrology.

    Science.gov (United States)

    Mizuno, Masashi; Suzuki, Yasuhiro; Ito, Yasuhiko

    2017-03-24

    The complement activation system plays important roles to maintain homeostasis in the host and to fight foreign invaders to protect the host. Therefore, the complement system is considered a core part of innate immunity which also cross-talks to acquired immunity. In the history of nephrology, the complement system is familiar to us, because complement protein or fragment deposition, including C3, C4, C1q, and/or C4d, is routinely estimated by immunohistochemistry to diagnose renal pathologies. The relationships between pathological mechanisms and complement activation have been investigated for renal diseases such as post-infectious glomerulonephritis, lupus nephritis, and primary membranoproliferative glomerulonephritis, which are usually accompanied by hypocomplementemia. However, unregulated complement activation in local areas might be associated with progression of various renal injuries even in the normocomplementemic patient. Recently, attention has focused on dysfunction of complement regulation in various diseases including renal diseases such as atypical hemolytic uremic syndrome and C3 glomerulopathy. Some mechanisms associated with complement activation in these diseases were clarified. In addition, lots of anti-complement agents were developed and some of the agents have become clinically available. Now, anti-complement therapies represent a realistic choice of therapeutic approaches for complement-related diseases. Research on roles of complement activation is proceeding into new stages in the field of nephrology and in other fields involving both basic and clinical research. We herein summarize relationships between the complement activation and regulation systems, their physiological effects and roles in maintenance of homeostasis in the host, and how dysregulation of the complement system triggers disease, especially renal disease.

  8. A vital role for complement in heart disease.

    Science.gov (United States)

    Lappegård, Knut T; Garred, Peter; Jonasson, Lena; Espevik, Terje; Aukrust, Pål; Yndestad, Arne; Mollnes, Tom E; Hovland, Anders

    2014-10-01

    Heart diseases are common and significant contributors to worldwide mortality and morbidity. During recent years complement mediated inflammation has been shown to be an important player in a variety of heart diseases. Despite some negative results from clinical trials using complement inhibitors, emerging evidence points to an association between the complement system and heart diseases. Thus, complement seems to be important in coronary heart disease as well as in heart failure, where several studies underscore the prognostic importance of complement activation. Furthermore, patients with atrial fibrillation often share risk factors both with coronary heart disease and heart failure, and there is some evidence implicating complement activation in atrial fibrillation. Moreover, Chagas heart disease, a protozoal infection, is an important cause of heart failure in Latin America, and the complement system is crucial for the protozoa-host interaction. Thus, complement activation appears to be involved in the pathophysiology of a diverse range of cardiac conditions. Determination of the exact role of complement in the various heart diseases will hopefully help to identify patients that might benefit from therapeutic complement intervention. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. The complement system in systemic lupus erythematosus: an update.

    Science.gov (United States)

    Leffler, Jonatan; Bengtsson, Anders A; Blom, Anna M

    2014-09-01

    The complement system plays a major role in the autoimmune disease, systemic lupus erythematosus (SLE). However, the role of complement in SLE is complex since it may both prevent and exacerbate the disease. In this review, we explore the latest findings in complement-focused research in SLE. C1q deficiency is the strongest genetic risk factor for SLE, although such deficiency is very rare. Various recently discovered genetic associations include mutations in the complement receptors 2 and 3 as well as complement inhibitors, the latter related to earlier onset of nephritis. Further, autoantibodies are a distinct feature of SLE that are produced as the result of an adaptive immune response and how complement can affect that response is also being reviewed. SLE generates numerous disease manifestations involving contributions from complement such as glomerulonephritis and the increased risk of thrombosis. Furthermore, since most of the complement system is present in plasma, complement is very accessible and may be suitable as biomarker for diagnosis or monitoring of disease activity. This review highlights the many roles of complement for SLE pathogenesis and how research has progressed during recent years. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  10. Outdoor Air Pollution, Heart Attack and Stroke

    Science.gov (United States)

    Elevated outdoor ambient air particle pollution triggers heart attacks, strokes, and abnormal heart rhythms and worsens heart failure in individuals at high risk due to underlying medical conditions. Emergency Medical Services in communities are the first responders to these eme...

  11. The role of sleep in migraine attacks

    Directory of Open Access Journals (Sweden)

    Elaine Inamorato

    1993-11-01

    Full Text Available Migraine attacks may be precipitated by sleep deprivation or excessive sleep and sleep is also associated with relief of migraine attacks. In view of this variable relationship we studied the records of 159 consecutive outpatients of our Headache Unit. In 121 records there was reference to sleep involvement, in 55% by a single form and in 45% by more than one form. When only one form was related, relief was most common (70%. 30% of that group of patients had the migraine attack precipitated by sleep, 24% by deprivation and 6% by sleep excess. When the effects of sleep were multiple, these effects were as expected logically in 65%: «in accordance» group (e.g attack precipitated by sleep deprivation and relieved by sleep onset. In a second group, («conflicting» where the involvement was not logical, there were three different combinations of sleep involvement, possibly due to more than one pathophysiological mechanism.

  12. How Is a Heart Attack Treated?

    Science.gov (United States)

    ... heart attack at age 36, it stopped her "dead in her tracks." Jennifer reminds us how heart disease takes too many of our moms, sisters, and friends from us every day. The more we share our stories, the faster ...

  13. How Is a Heart Attack Diagnosed?

    Science.gov (United States)

    ... heart attack at age 36, it stopped her "dead in her tracks." Jennifer reminds us how heart disease takes too many of our moms, sisters, and friends from us every day. The more we share our stories, the faster ...

  14. Transient ischemic attack: definition and natural history.

    Science.gov (United States)

    Caplan, Louis R

    2006-07-01

    The standard definition of a transient ischemic attack--"a cerebral dysfunction of an ischemic nature lasting no longer than 24 hours with a tendency to recur"--was arrived at arbitrarily and is no longer tenable. Experience shows that attacks are much briefer, usually less than an hour, and many are associated with brain infarction. A newer definition, more consonant with the data, is preferred--"transient ischemic attack is a brief episode of neurological dysfunction caused by focal brain or retinal ischemia, with clinical symptoms typically lasting less than an hour, and without evidence of acute infarction." Patients with transient ischemic attacks require urgent evaluation that includes brain and vascular imaging, blood tests, and often cardiac investigations. Treatment will depend on the nature of the causative cervico-cranial vascular, cardiac, and hematologic abnormalities found on investigation.

  15. Diabetes - preventing heart attack and stroke

    Science.gov (United States)

    Diabetes complications - heart; Coronary artery disease - diabetes; CAD - diabetes; Cerebrovascular disease - diabetes ... People with diabetes have a higher chance of having heart attacks and strokes. Smoking and having high blood pressure and high ...

  16. Women's Heart Disease: Heart Attack Symptoms

    Science.gov (United States)

    ... this page please turn JavaScript on. Feature: Women's Heart Disease Heart Attack Symptoms Past Issues / Winter 2014 Table ... NHLBI has uncovered some of the causes of heart diseases and conditions, as well as ways to prevent ...

  17. Marine Attack on Towed Hydrophone Arrays

    National Research Council Canada - National Science Library

    Kalmijn, Ad

    2002-01-01

    The original objective of the SIO Marine Attack project was to identify the electric and magnetic fields causing sharks to inflict serious damage upon the towed hydrophone arrays of US Navy submarines...

  18. Using agility to combat cyber attacks.

    Science.gov (United States)

    Anderson, Kerry

    2017-06-01

    Some incident response practitioners feel that they have been locked in a battle with cyber criminals since the popular adoption of the internet. Initially, organisations made great inroads in preventing and containing cyber attacks. In the last few years, however, cyber criminals have become adept at eluding defence security technologies and rapidly modifying their exploit strategies for financial or political gains. Similar to changes in military combat tactics, cyber criminals utilise distributed attack cells, real-time communications, and rapidly mutating exploits to minimise the potential for detection. Cyber criminals have changed their attack paradigm. This paper describes a new incident response paradigm aimed at combating the new model of cyber attacks with an emphasis on agility to increase the organisation's ability to respond rapidly to these new challenges.

  19. Being active after your heart attack

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000093.htm Being active after your heart attack To use the sharing ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  20. An Attack-Resilient Middleware Architecture for Grid Integration of Distributed Energy Resources

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yifu; Mendis, Gihan J.; He, Youbiao; Wei, Jin; Hodge, Bri-Mathias

    2017-05-04

    In recent years, the increasing penetration of Distributed Energy Resources (DERs) has made an impact on the operation of the electric power systems. In the grid integration of DERs, data acquisition systems and communications infrastructure are crucial technologies to maintain system economic efficiency and reliability. Since most of these generators are relatively small, dedicated communications investments for every generator are capital cost prohibitive. Combining real-time attack-resilient communications middleware with Internet of Things (IoTs) technologies allows for the use of existing infrastructure. In our paper, we propose an intelligent communication middleware that utilizes the Quality of Experience (QoE) metrics to complement the conventional Quality of Service (QoS) evaluation. Furthermore, our middleware employs deep learning techniques to detect and defend against congestion attacks. The simulation results illustrate the efficiency of our proposed communications middleware architecture.

  1. Attack by Pyemotes johnmoseri (Acari: Pyemotidae)

    Science.gov (United States)

    Tulin Askit; Ibrahim Cakmak; John Moser

    2007-01-01

    The Aegean Region of Turkey is one of the largest dried fig producers in the world. A Turkish cultivar sarilop (Ficus carica cv. Calimyrna L.) possesses good qualities for drying process, and has been grown extensively for many years in Turkey. Hypoborus ficus is the most common xylophagous insect attacking fig trees in Aydin (Aks¸it et al. 2003). This pest attacks...

  2. Panic attack history and smoking topography.

    Science.gov (United States)

    Farris, Samantha G; Brown, Lily A; Goodwin, Renee D; Zvolensky, Michael J

    2017-02-01

    Little is known about panic attacks and puffing topography, a behavioral index of the value of smoking reinforcement. This study examined smoking style during the course of smoking of a single cigarette among adult daily smokers with and without a history of panic attacks. Participants (n=124, Mage=43.9, SD=9.7; 44.4% female) were non-treatment seeking daily smokers. Lifetime panic attack history was assessed via diagnostic assessment; 28.2% (n=35) of the sample had a panic attack history. Participants smoked one cigarette during an ad libitum smoking trial. Puff volume, duration, and inter-puff interval were measured using the Clinical Research Support System (CReSS) pocket device. Regression analyses revealed that panic attack status was not associated with significant differences in average puff volume, duration, or inter-puff interval. Multi-level modeling was used to examine puffing trajectories. Puff-level data revealed that there was a significant quadratic time x panic effect for puff volume and duration. Those with a panic attack history demonstrated relatively sustained levels of both puff volume and duration over time, whereas those without a history of panic attacks demonstrated an increase followed by a decrease in volume and duration over time. These effects were not accounted for by the presence of general psychopathology. Smokers with a panic attack history demonstrate more persistent efforts to self-regulate the delivery of nicotine, and thus may be at risk for continued smoking and dependence. Tailored treatment may be needed to address unique vulnerabilities among this group. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Panic Attack History and Smoking Topography

    Science.gov (United States)

    Farris, Samantha G.; Brown, Lily A.; Goodwin, Renee D.; Zvolensky, Michael J.

    2016-01-01

    Background Little is known about panic attacks and puffing topography, a behavioral index of the value of smoking reinforcement. This study examined smoking style during the course of smoking of a single cigarette among adult daily smokers with and without a history of panic attacks. Method Participants (n = 124, Mage = 43.9, SD = 9.7; 44.4% female) were non-treatment seeking daily smokers. Lifetime panic attack history was assessed via diagnostic assessment; 28.2% (n = 35) of the sample had a panic attack history. Participants smoked one cigarette during an ad libitum smoking trial. Puff volume, duration, and inter-puff interval were measured using the Clinical Research Support System (CReSS) pocket device. Results Regression analyses revealed that panic attack status was not associated with significant differences in average puff volume, duration, or inter-puff interval. Multi-level modeling was used to examine puffing trajectories. Puff-level data revealed that there was a significant quadratic time x panic effect for puff volume and duration. Those with a panic attack history demonstrated relatively sustained levels of both puff volume and duration over time, whereas those without a history of panic attacks demonstrated an increase followed by a decrease in volume and duration over time. These effects were not accounted for by the presence of general psychopathology. Discussion Smokers with a panic attack history demonstrate more persistent efforts to self-regulate the delivery of nicotine, and thus may be at risk for continued smoking and dependence. Tailored treatment may be needed to address unique vulnerabilities among this group. PMID:28033542

  4. Cyber Security Audit and Attack Detection Toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Dale

    2012-05-31

    This goal of this project was to develop cyber security audit and attack detection tools for industrial control systems (ICS). Digital Bond developed and released a tool named Bandolier that audits ICS components commonly used in the energy sector against an optimal security configuration. The Portaledge Project developed a capability for the PI Historian, the most widely used Historian in the energy sector, to aggregate security events and detect cyber attacks.

  5. Lone Actor Terrorist Attack Planning and Preparation: A Data-Driven Analysis.

    Science.gov (United States)

    Schuurman, Bart; Bakker, Edwin; Gill, Paul; Bouhana, Noémie

    2017-10-23

    This article provides an in-depth assessment of lone actor terrorists' attack planning and preparation. A codebook of 198 variables related to different aspects of pre-attack behavior is applied to a sample of 55 lone actor terrorists. Data were drawn from open-source materials and complemented where possible with primary sources. Most lone actors are not highly lethal or surreptitious attackers. They are generally poor at maintaining operational security, leak their motivations and capabilities in numerous ways, and generally do so months and even years before an attack. Moreover, the "loneness" thought to define this type of terrorism is generally absent; most lone actors uphold social ties that are crucial to their adoption and maintenance of the motivation and capability to commit terrorist violence. The results offer concrete input for those working to detect and prevent this form of terrorism and argue for a re-evaluation of the "lone actor" concept. © 2017 The Authors. Journal of Forensic Sciences published by Wiley Periodicals, Inc. on behalf of American Academy of Forensic Sciences.

  6. Combined Heuristic Attack Strategy on Complex Networks

    Directory of Open Access Journals (Sweden)

    Marek Šimon

    2017-01-01

    Full Text Available Usually, the existence of a complex network is considered an advantage feature and efforts are made to increase its robustness against an attack. However, there exist also harmful and/or malicious networks, from social ones like spreading hoax, corruption, phishing, extremist ideology, and terrorist support up to computer networks spreading computer viruses or DDoS attack software or even biological networks of carriers or transport centers spreading disease among the population. New attack strategy can be therefore used against malicious networks, as well as in a worst-case scenario test for robustness of a useful network. A common measure of robustness of networks is their disintegration level after removal of a fraction of nodes. This robustness can be calculated as a ratio of the number of nodes of the greatest remaining network component against the number of nodes in the original network. Our paper presents a combination of heuristics optimized for an attack on a complex network to achieve its greatest disintegration. Nodes are deleted sequentially based on a heuristic criterion. Efficiency of classical attack approaches is compared to the proposed approach on Barabási-Albert, scale-free with tunable power-law exponent, and Erdős-Rényi models of complex networks and on real-world networks. Our attack strategy results in a faster disintegration, which is counterbalanced by its slightly increased computational demands.

  7. Activation of the ficolin-lectin pathway during attacks of hereditary angioedema

    DEFF Research Database (Denmark)

    Csuka, Dorottya; Munthe-Fog, Lea; Hein, Estrid

    2014-01-01

    enrolled. We analyzed blood samples drawn during attacks, and obtained 35 samples from the same patients during symptom-free periods. The serum levels of ficolin-2, ficolin-3, MASP-2, ficolin-3/MASP-2 complex, C1-INH, and C4, as well as the extent of ficolin-3-mediated terminal complement complex (FCN3-TCC......) deposition, were measured using ELISA-based methods. RESULTS: Levels of MASP-2 and of the ficolin-3/MASP-2 complex were elevated (P TCC was lower (P TCC...

  8. An oracle-based attack on CAPTCHAs protected against oracle attacks

    OpenAIRE

    Hernández-Castro, Carlos Javier; R-Moreno, María D.; David F. Barrero; Li, Shujun

    2017-01-01

    CAPTCHAs/HIPs are security mechanisms that try to prevent automatic abuse of services. They are susceptible to learning attacks in which attackers can use them as oracles. Kwon and Cha presented recently a novel algorithm that intends to avoid such learning attacks and "detect all bots". They add uncertainties to the grading of challenges, and also use trap images designed to detect bots. The authors suggest that a major IT corporation is studying their proposal for mainstream implementation....

  9. Exploiting Hardware Vulnerabilities to Attack Embedded System Devices: a Survey of Potent Microarchitectural Attacks

    Directory of Open Access Journals (Sweden)

    Apostolos P. Fournaris

    2017-07-01

    Full Text Available Cyber-Physical system devices nowadays constitute a mixture of Information Technology (IT and Operational Technology (OT systems that are meant to operate harmonically under a security critical framework. As security IT countermeasures are gradually been installed in many embedded system nodes, thus securing them from many well-know cyber attacks there is a lurking danger that is still overlooked. Apart from the software vulnerabilities that typical malicious programs use, there are some very interesting hardware vulnerabilities that can be exploited in order to mount devastating software or hardware attacks (typically undetected by software countermeasures capable of fully compromising any embedded system device. Real-time microarchitecture attacks such as the cache side-channel attacks are such case but also the newly discovered Rowhammer fault injection attack that can be mounted even remotely to gain full access to a device DRAM (Dynamic Random Access Memory. Under the light of the above dangers that are focused on the device hardware structure, in this paper, an overview of this attack field is provided including attacks, threat directives and countermeasures. The goal of this paper is not to exhaustively overview attacks and countermeasures but rather to survey the various, possible, existing attack directions and highlight the security risks that they can pose to security critical embedded systems as well as indicate their strength on compromising the Quality of Service (QoS such systems are designed to provide.

  10. Genetic complementation studies of multiple sulfatase deficiency.

    Science.gov (United States)

    Horwitz, A L

    1979-12-01

    Cultured fibroblasts from two individuals with multiple sulfatase deficiency (MSD) were found to have decreased activities of arylsulfatases (aryl-sulfate sulfohydrolase, EC 3.1.6.1) A, B, and C as well as iduronate-sulfate sulfatase, sulfamidase, and N-acetylglucosamine-6-sulfate sulfatase. The activity of N-acetylgalactosamine-6-sulfate sulfatase was decreased in one line but not in the other. Mixtures of MSD cell extracts with extracts from normal cells did not result in inhibition of normal sulfatase activities. Mixtures of MSD cell extracts with extracts of fibroblasts from patients with Hunter or Sanfilippo A syndrome did not activate iduronate-sulfate sulfatase or sulfamidase activity. Heterokaryons formed by fusion of MSD cells with Sanfilippo A fibroblasts demonstrated a partial correction of the enzyme deficiency. In similar manner, MSD-Hunter heterokaryons showed a significant increase in iduronate-sulfate-sulfatase activity. Genetic complementation in heterokaryons of MSD fibroblasts and cells of either Sanfilippo A or Hunter syndrome implies a genetic defect in MSD different from that causing specific sulfatase deficiencies.

  11. Complement: A primer for the coming therapeutic revolution.

    Science.gov (United States)

    Barnum, Scott R

    2017-04-01

    The complement system is an important part of the innate and adaptive immune systems. Originally characterized as a single serum component contributing to the killing of bacteria, we now know that there are close to sixty complement proteins, multiple activation pathways and a wide range of effector functions mediated by complement. The system plays a critical role in host defense against bacteria, viruses, fungi and other pathogens. However, inappropriate complement activation contributes to the pathophysiology of autoimmune diseases and many inflammatory syndromes. Over the last several decades, therapeutic approaches to inhibit complement activation at various steps in the pathways have met with initial success, particularly at the level of the terminal pathway. This success, combined with insight from animal model studies, has lead to an unprecedented effort by biotech and pharmaceutical companies to begin developing complement inhibitors. As a result, complement has been brought for the first time to the attention of pharmacologists, toxicologists, project managers and others in the drug development industry, as well as those in the investment world. The purpose of this primer is to provide a broad overview of complement immunobiology to help those new to complement understand the rationale behind the current therapeutic directions and the investment potential of these new therapeutics. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Complement factor H-related proteins CFHR2 and CFHR5 represent novel ligands for the infection-associated CRASP proteins of Borrelia burgdorferi.

    Directory of Open Access Journals (Sweden)

    Corinna Siegel

    2010-10-01

    Full Text Available One virulence property of Borrelia burgdorferi is its resistance to innate immunity, in particular to complement-mediated killing. Serum-resistant B. burgdorferi express up to five distinct complement regulator-acquiring surface proteins (CRASP which interact with complement regulator factor H (CFH and factor H-like protein 1 (FHL1 or factor H-related protein 1 (CFHR1. In the present study we elucidate the role of the infection-associated CRASP-3 and CRASP-5 protein to serve as ligands for additional complement regulatory proteins as well as for complement resistance of B. burgdorferi.To elucidate whether CRASP-5 and CRASP-3 interact with various human proteins, both borrelial proteins were immobilized on magnetic beads. Following incubation with human serum, bound proteins were eluted and separated by Glycine-SDS-PAGE. In addition to CFH and CFHR1, complement regulators CFHR2 and CFHR5 were identified as novel ligands for both borrelial proteins by employing MALDI-TOF. To further assess the contributions of CRASP-3 and CRASP-5 to complement resistance, a serum-sensitive B. garinii strain G1 which lacks all CFH-binding proteins was used as a valuable model for functional analyses. Both CRASPs expressed on the B. garinii outer surface bound CFH as well as CFHR1 and CFHR2 in ELISA. In contrast, live B. garinii bound CFHR1, CFHR2, and CFHR5 and only miniscute amounts of CFH as demonstrated by serum adsorption assays and FACS analyses. Further functional analysis revealed that upon NHS incubation, CRASP-3 or CRASP-5 expressing borreliae were killed by complement.In the absence of CFH and the presence of CFHR1, CFHR2 and CFHR5, assembly and integration of the membrane attack complex was not efficiently inhibited indicating that CFH in co-operation with CFHR1, CFHR2 and CFHR5 supports complement evasion of B. burgdorferi.

  13. Lectin complement pathway proteins in healthy individuals.

    Science.gov (United States)

    Troldborg, A; Hansen, A; Hansen, S W K; Jensenius, J C; Stengaard-Pedersen, K; Thiel, S

    2017-04-01

    Since the discovery of the lectin pathway of complement activation, numerous clinical cohorts have been examined for one or more proteins, with the intention of uncovering the functions of the proteins or with the aim of discovering new biomarkers or diagnostic tools. To unveil the abnormal, it is pivotal to know the normal. Our aim was to describe the concentrations of the 11 known proteins of the lectin pathway in serum and plasma and to uncover possible gender differences, age and diurnal variations, which must be taken into account for investigation in different cohorts. We examined the concentrations of all lectin pathway proteins mannan-binding lectin (MBL), H-ficolin, L-ficolin, M-ficolin, collectin-K1, collectin-L1, MBL-associated serine protease 2 (MASP-2), MASP-3, MBL-associated protein of 44 kDa (MAp44) and MAp19 in 300 Danish blood donors in serum and ethylenediamine tetraacetic acid (EDTA) plasma in established assays, and we further developed a new assay to measure MASP-1 in the same samples. We found significant differences in concentrations between serum and plasma for all proteins except for MBL and MASP-3. H-ficolin, M-ficolin and MAp19 displayed convincing diurnal variation. H-ficolin, in particular, halved from morning to the middle of the night. There were gender differences for most proteins, whereas age did not seem to influence concentration. The present study underlines the necessity of considering which material to use, correct matching and a trial design that takes the nature of the protein into account in order for the outcome of cohort studies to have significant relevance. © 2016 British Society for Immunology.

  14. Complement-coagulation cross-talk: a potential mediator of the physiological activation of complement by low pH

    Directory of Open Access Journals (Sweden)

    Hany Ibrahim Kenawy

    2015-05-01

    Full Text Available The complement system is a major constituent of the innate immune system. It not only bridges innate and adaptive arms of the immune system but also links the immune system with the coagulation system. Current understanding of the role of complement has extended far beyond fighting of infections, and now encompasses maintenance of homeostasis, tissue regeneration and pathophysiology of multiple diseases. It has been known for many years that complement activation is strongly pH sensitive, but only relatively recently has the physiological significance of this been appreciated. Most complement assays are carried out at the physiological pH 7.4. However, pH in some extracellular compartments, for example renal tubular fluid in parts of the tubule, and extracellular fluid at inflammation loci, is sufficiently acidic to activate complement. The exact molecular mechanism of this activation is still unclear, but possible cross talk between the contact system and complement may exist at low pH with subsequent complement activation. The current article reviews the published data on the effect of pH on the contact system and complement activity, the nature of the pH sensor molecules, and the clinical implications of these effects. Of particular interest is chronic kidney disease (CKD accompanied by metabolic acidosis, in which therapeutic alkalinisation of urine has been shown significantly to reduce tubular complement activation products, an effect which may have important implications for slowing progression of CKD.

  15. The N-linked carbohydrate moiety of male reproductive tract CD52 (mrt-CD52) interferes with the complement system via binding to C1q.

    Science.gov (United States)

    Hardiyanto, Lutfi; Hasegawa, Akiko; Komori, Shinji

    2012-06-01

    Antisperm antibody detected in infertile female patients' sera has been shown to correlate with reduced fertility. The antibody showed strong complement-dependent cytotoxicity as determined by the sperm immobilization test (SIT). CD52 is a human glycosylphosphatidylinositol (GPI)-anchored antigen present in lymphocytes and male reproductive tracts (mrt), including mature sperm and seminal plasma. Recently, purified mrt-CD52 from human seminal plasma has been reported to interfere with the classical complement pathway, but not lectin binding or alternative pathways of the complement system. The purpose of this study is to determine which stage of the classical pathway mrt-CD52 regulates. mrt-CD52 was purified from human seminal plasma or intact sperm membrane. Immunoprecipitation assay was performed with the reaction of mrt-CD52, human complement and mAb H6-3C4. Immunoprecipitate was formed by the carbohydrate moiety of mrt-CD52, but not by the GPI-anchor peptide. The C1q molecule (29 kDa) was detected in the immunoprecipitates by Western blotting analysis probed with anti C1q antibody, indicating that the carbohydrate moiety of mrt-CD52 binds to C1q. Also, the complement-dependent SIT revealed that purified CD52 inhibited sperm immobilization activity by antisperm antibody. These results suggest that mrt-CD52 protects sperm function from complement attack if antisperm antibody is generated in the female reproductive tracts. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. A Game Theoretic Approach to Cyber Attack Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Peng Liu

    2005-11-28

    The area investigated by this project is cyber attack prediction. With a focus on correlation-based prediction, current attack prediction methodologies overlook the strategic nature of cyber attack-defense scenarios. As a result, current cyber attack prediction methodologies are very limited in predicting strategic behaviors of attackers in enforcing nontrivial cyber attacks such as DDoS attacks, and may result in low accuracy in correlation-based predictions. This project develops a game theoretic framework for cyber attack prediction, where an automatic game-theory-based attack prediction method is proposed. Being able to quantitatively predict the likelihood of (sequences of) attack actions, our attack prediction methodology can predict fine-grained strategic behaviors of attackers and may greatly improve the accuracy of correlation-based prediction. To our best knowledge, this project develops the first comprehensive framework for incentive-based modeling and inference of attack intent, objectives, and strategies; and this project develops the first method that can predict fine-grained strategic behaviors of attackers. The significance of this research and the benefit to the public can be demonstrated to certain extent by (a) the severe threat of cyber attacks to the critical infrastructures of the nation, including many infrastructures overseen by the Department of Energy, (b) the importance of cyber security to critical infrastructure protection, and (c) the importance of cyber attack prediction to achieving cyber security.

  17. Power analysis attacks revealing the secrets of smart cards

    CERN Document Server

    Mangard, Stefan; Popp, Thomas

    2008-01-01

    A comprehensive treatment of power analysis attacks and countermeasures. Based on the principle that the only way to defend against power analysis attacks is to understand them, this book explains how power analysis attacks work. It discusses simple and differential power analysis as well as advanced techniques like template attacks.

  18. Transforming Graphical System Models to Graphical Attack Models

    DEFF Research Database (Denmark)

    Ivanova, Marieta Georgieva; Probst, Christian W.; Hansen, Rene Rydhof

    2016-01-01

    approach to transforming graphical system models to graphical attack models in the form of attack trees. Based on an asset in the model, our transformations result in an attack tree that represents attacks by all possible actors in the model, after which the actor in question has obtained the asset....

  19. Fault Analysis Attacks and Its Countermeasure using Elliptic Curve Cryptography

    OpenAIRE

    M. Prabu; R. Shanmugalakshmi

    2010-01-01

    In the last decade, many researchers had published the overall analysis attacks of cryptographic devices against implementation on elliptic curve attacks. Usually such type of information is not sufficient to learn about the individual attacks. Now in this article, we indisputably concentrated on fault analysis attack and its countermeasure.

  20. Modelling Social-Technical Attacks with Timed Automata

    NARCIS (Netherlands)

    David, Nicolas; David, Alexandre; Hansen, René Rydhof; Larsen, K.G.; Legay, Axel; Olesen, Mads Chr.; Probst, Christian W.

    2015-01-01

    Attacks on a system often exploit vulnerabilities that arise from human behaviour or other human activity. Attacks of this type, so-called socio-technical attacks, cover everything from social engineering to insider attacks, and they can have a devastating impact on an unprepared organisation. In

  1. Noncombatants and liability to be attacked in wars

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2013-01-01

    attack," I mean that S has forfeited his or her right not to be attacked by armed forces. Here, "liable" is used in a normative-cum-legal sense, not descriptively as it is when one says "some colors are liable to darken in perpetual shade," and "attack" is used passively, as an equivalent of be attacked...

  2. Modeling attacking of high skills volleyball players

    Directory of Open Access Journals (Sweden)

    Vladimir Gamaliy

    2014-12-01

    Full Text Available Purpose: to determine the model indicators of technical and tactical actions in the attack highly skilled volleyball players. Material and Methods: the study used statistical data of major international competitions: Olympic Games – 2012 World Championships – 2010, World League – 2010–2014 European Championship – 2010–2014. A total of 130 analyzed games. Methods were used: analysis and generalization of scientific and methodological literature, analysis of competitive activity highly skilled volleyball players, teacher observation, modeling technical and tactical actions in attacking highly skilled volleyball players. Results: it was found that the largest volume application of technical and tactical actions in the attack belongs to the group tactics «supple movement», whose indicator is 21,3%. The smallest amount of application belongs to the group tactics «flight level» model whose indicators is 5,4%, the efficiency of 3,4%, respectively. It is found that the power service in the jump from model parameters used in 51,6% of cases, the planning targets – 21,7% and 4,4% planning to reduce. Attacks performed with the back line, on model parameters used in the amount of 20,8% efficiency –13,7%. Conclusions: we prove that the performance of technical and tactical actions in the attack can be used as model in the control system of training and competitive process highly skilled volleyball players

  3. Trace Attack against Biometric Mobile Applications

    Directory of Open Access Journals (Sweden)

    Sanaa Ghouzali

    2016-01-01

    Full Text Available With the exponential increase in the dependence on mobile devices in everyday life, there is a growing concern related to privacy and security issues in the Gulf countries; therefore, it is imperative that security threats should be analyzed in detail. Mobile devices store enormous amounts of personal and financial information, unfortunately without any security. In order to secure mobile devices against different threats, biometrics has been applied and shown to be effective. However, biometric mobile applications are also vulnerable to several types of attacks that can decrease their security. Biometric information itself is considered sensitive data; for example, fingerprints can leave traces in touched objects and facial images can be captured everywhere or accessed by the attacker if the facial image is stored in the mobile device (lost or stolen. Hence, an attacker can easily forge the identity of a legitimate user and access data on a device. In this paper, the effects of a trace attack on the sensitivity of biometric mobile applications are investigated in terms of security and user privacy. Experimental results carried out on facial and fingerprint mobile authentication applications using different databases have shown that these mobile applications are vulnerable to the proposed attack, which poses a serious threat to the overall system security and user privacy.

  4. Panic Attack during Elective Gastrointestinal Endoscopy

    Directory of Open Access Journals (Sweden)

    Charalampos Mitsonis

    2011-01-01

    Full Text Available Background. Esophagogastroduodenoscopy (EGD and colonoscopy (CS can evoke anxiety, embarrassment, and discomfort. These concerns can culminate in panic attacks, which may traumatize patients and significantly decrease their compliance to the procedure. The objective of this study was to evaluate the relationship between preendoscopic anxiety and the possibility of a panic attack during an elective gastrointestinal endoscopy (EGE. Methods. The study population comprised of 79 Greek outpatients. The examination was carried out without the use of conscious sedation. Patients' anxiety levels were assessed before the procedure using the Greek version of the Spielberger State-Trait Anxiety Inventory (STAI-Y. Results. Seventy-nine patients were enrolled: 45 EGD and 34 CS. Females had higher state and trait anxiety levels than males (48.14 ± 7.94 versus 44.17 ± 7.43, <0.05; and 43.68 ± 6.95 versus 39.86 ± 7.46, <0.05. Patients who experienced panic attack had significantly higher levels of both trait and state anxiety, compared to those who were panic-free. There was no significant relationship between panic attacks and sex or type of procedure. Conclusions. Patients who experience panic attacks during endoscopic procedures appear to have significantly higher anxiety levels before the procedure. Administering the STAI questionnaire prior to the endoscopy seems to be a useful screening method for vulnerable patients.

  5. On the anatomy of social engineering attacks : A literature-based dissection of successful attacks

    NARCIS (Netherlands)

    Bullee, Jan-Willem; Montoya, L.; Pieters, Wolter; Junger, Marianne; Hartel, Pieter H.

    2017-01-01

    The aim of this studywas to explore the extent towhich persuasion principles are used in successful social engineering attacks. Seventy-four scenarioswere extracted from 4 books on social engineering (written by social engineers) and analysed. Each scenariowas split into attack steps, containing

  6. Cross-site scripting attacks procedure and Prevention Strategies

    Directory of Open Access Journals (Sweden)

    Wang Xijun

    2016-01-01

    Full Text Available Cross-site scripting attacks and defense has been the site of attack and defense is an important issue, this paper, the definition of cross-site scripting attacks, according to the current understanding of the chaos on the cross-site scripting, analyzes the causes and harm cross-site scripting attacks formation of attacks XXS complete process XSS attacks made a comprehensive analysis, and then for the web program includes Mobility there are cross-site scripting filter laxity given from ordinary users browse the web and web application developers two the defense cross-site scripting attacks effective strategy.

  7. Complement activation in leprosy: a retrospective study shows elevated circulating terminal complement complex in reactional leprosy.

    Science.gov (United States)

    Bahia El Idrissi, N; Hakobyan, S; Ramaglia, V; Geluk, A; Morgan, B Paul; Das, P Kumar; Baas, F

    2016-06-01

    Mycobacterium leprae infection gives rise to the immunologically and histopathologically classified spectrum of leprosy. At present, several tools for the stratification of patients are based on acquired immunity markers. However, the role of innate immunity, particularly the complement system, is largely unexplored. The present retrospective study was undertaken to explore whether the systemic levels of complement activation components and regulators can stratify leprosy patients, particularly in reference to the reactional state of the disease. Serum samples from two cohorts were analysed. The cohort from Bangladesh included multi-bacillary (MB) patients with (n = 12) or without (n = 46) reaction (R) at intake and endemic controls (n = 20). The cohort from Ethiopia included pauci-bacillary (PB) (n = 7) and MB (n = 23) patients without reaction and MB (n = 15) patients with reaction. The results showed that the activation products terminal complement complex (TCC) (P ≤ 0·01), C4d (P ≤ 0·05) and iC3b (P ≤ 0·05) were specifically elevated in Bangladeshi patients with reaction at intake compared to endemic controls. In addition, levels of the regulator clusterin (P ≤ 0·001 without R; P < 0·05 with R) were also elevated in MB patients, irrespective of a reaction. Similar analysis of the Ethiopian cohort confirmed that, irrespective of a reaction, serum TCC levels were increased significantly in patients with reactions compared to patients without reactions (P ≤ 0·05). Our findings suggests that serum TCC levels may prove to be a valuable tool in diagnosing patients at risk of developing reactions. © 2016 British Society for Immunology.

  8. Demand Heterogeneity and the Adoption of Platform Complements

    NARCIS (Netherlands)

    G.J. Rietveld (Joost); J.P. Eggers

    2016-01-01

    textabstractThis paper offers a demand-based theory of how platform maturity affects the adoption of platform complements. We argue that differences between early and late adopters of the platform include willingness to pay for the platform-and-complement bundle, risk preferences, preference for

  9. How antibodies use complement to regulate antibody responses.

    Science.gov (United States)

    Sörman, Anna; Zhang, Lu; Ding, Zhoujie; Heyman, Birgitta

    2014-10-01

    Antibodies, forming immune complexes with their specific antigen, can cause complete suppression or several 100-fold enhancement of the antibody response. Immune complexes containing IgG and IgM may activate complement and in such situations also complement components will be part of the immune complex. Here, we review experimental data on how antibodies via the complement system upregulate specific antibody responses. Current data suggest that murine IgG1, IgG2a, and IgG2b upregulate antibody responses primarily via Fc-receptors and not via complement. In contrast, IgM and IgG3 act via complement and require the presence of complement receptors 1 and 2 (CR1/2) expressed on both B cells and follicular dendritic cells. Complement plays a crucial role for antibody responses not only to antigen complexed to antibodies, but also to antigen administered alone. Lack of C1q, but not of Factor B or MBL, severely impairs antibody responses suggesting involvement of the classical pathway. In spite of this, normal antibody responses are found in mice lacking several activators of the classical pathway (complement activating natural IgM, serum amyloid P component (SAP), specific intracellular adhesion molecule-grabbing non-integrin R1 (SIGN-R1) or C-reactive protein. Possible explanations to these observations will be discussed. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. The role of complement activation in thrombosis and hemolytic anemias.

    Science.gov (United States)

    Chapin, John; Terry, Hunter S; Kleinert, Dorothy; Laurence, Jeffrey

    2016-04-01

    The objective of this study was to describe complement activation in hemostatic and pathologic states of coagulation and in the acquired and congenital hemolytic anemias. We review published and emerging data on the involvement of the classic, alternative and lectin-based complement pathways in coagulation and the hemolytic anemias. The alternative pathway in particular is always "on," at low levels, and is particularly sensitive to hyper-activation in a variety of physiologic and pathologic states including infection, autoimmune disorders, thrombosis and pregnancy, requiring tight control predicated on a variety of soluble and membrane bound regulatory proteins. In acquired hemolytic anemias such as paroxysmal nocturnal hemoglobinuria (PNH) and cold agglutinin disease (CAD), the complement system directly induces red blood cell injury, resulting in intravascular and extravascular hemolysis. In congenital hemolytic anemias such as sickle cell disease and β-thalassemia, the complement system may also contribute to thrombosis and vascular disease. Complement activation may also lead to a storage lesion in red blood cells prior to transfusion. Complement pathways are activated in hemolytic anemias and are closely linked with thrombosis. In acquired disorders such as PNH and possibly CAD, inhibition of the alternative complement pathway improves clinical outcomes and reduces thrombosis risk. Whether complement inhibition has a similar role in congenital hemolytic anemias apart from the atypical hemolytic-uremic (aHUS)-type thrombotic microangiopathies remains to be determined. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Complement evasion by Borrelia burgdorferi: it takes three to tango

    NARCIS (Netherlands)

    de Taeye, Steven W.; Kreuk, Lieselotte; van Dam, Alje P.; Hovius, Joppe W.; Schuijt, Tim J.

    2013-01-01

    The complement system is one of the major innate defense mechanisms Borrelia burgdorferi sensu lato has to overcome to establish an infection of mammalian hosts and to cause Lyme borreliosis in humans. Borrelia prevents complement-mediated killing during host colonization through (i) recruitment of

  12. Inactivation of complement by Loxosceles reclusa spider venom.

    Science.gov (United States)

    Gebel, H M; Finke, J H; Elgert, K D; Cambell, B J; Barrett, J T

    1979-07-01

    Zymosan depletion of serum complement in guinea pigs rendered them highly resistant to lesion by Loxosceles reclusa spider venom. Guinea pigs deficient in C4 of the complement system are as sensitive to the venom as normal guinea pigs. The injection of 35 micrograms of whole recluse venom intradermally into guinea pigs lowered their complement level by 35.7%. Brown recluse spider venom in concentrations as slight as 0.02 micrograms protein/ml can totally inactivate one CH50 of guinea pig complement in vitro. Bee, scorpion, and other spider venoms had no influence on the hemolytic titer of complement. Fractionation of recluse spider venom by Sephadex G-200 filtration separated the complement-inactivating property of the venom into three major regions which could be distinguished on the basis of heat stability as well as size. None was neutralized by antivenom. Polyacrylamide gel electrophoresis of venom resolved the complement inactivators into five fractions. Complement inactivated by whole venom or the Sephadex fractions could be restored to hemolytic activity by supplements of fresh serum but not by heat-inactivated serum, pure C3, pure C5, or C3 and C5 in combination.

  13. Production of complement components by cells of the immune system.

    Science.gov (United States)

    Lubbers, R; van Essen, M F; van Kooten, C; Trouw, L A

    2017-05-01

    The complement system is an important part of the innate immune defence. It contributes not only to local inflammation, removal and killing of pathogens, but it also assists in shaping of the adaptive immune response. Besides a role in inflammation, complement is also involved in physiological processes such as waste disposal and developmental programmes. The complement system comprises several soluble and membrane-bound proteins. The bulk of the soluble proteins is produced mainly by the liver. While several complement proteins are produced by a wide variety of cell types, other complement proteins are produced by only a few related cell types. As these data suggest that local production by specific cell types may have specific functions, more detailed studies have been employed recently analysing the local and even intracellular role of these complement proteins. Here we review the current knowledge about extrahepatic production and/or secretion of complement components. More specifically, we address what is known about complement synthesis by cells of the human immune system. © 2017 British Society for Immunology.

  14. Rat C-reactive protein activates the autologous complement system

    NARCIS (Netherlands)

    Diaz Padilla, Niubel; Bleeker, Wim K.; Lubbers, Yvonne; Rigter, Gemma M. M.; van Mierlo, Gerard J.; Daha, Mohamed R.; Hack, C. Erik

    2003-01-01

    Activation of complement is a biological function of human C-reactive protein (hCRP), whereas rat CRP (rCRP) has been claimed to be unable to activate complement. As important biological functions of proteins are probably conserved among species, we re-evaluated, using various ligands, the

  15. Schur complements of matrices with acyclic bipartite graphs

    DEFF Research Database (Denmark)

    Britz, Thomas Johann; Olesky, D.D.; van den Driessche, P.

    2005-01-01

    Bipartite graphs are used to describe the generalized Schur complements of real matrices having nos quare submatrix with two or more nonzero diagonals. For any matrix A with this property, including any nearly reducible matrix, the sign pattern of each generalized Schur complement is shown...

  16. Rotational Rebound Attacks on Reduced Skein

    DEFF Research Database (Denmark)

    Khovratovich, Dmitry; Nikolić, Ivica; Rechberger, Christian

    2014-01-01

    number of rounds. We also use neutral bits and message modification methods from the practice of collision search in MD5 and SHA-1 hash functions. These methods push the rotational property through more rounds than previous analysis suggested, and eventually establish a distinguishing property......In this paper we combine two powerful methods of symmetric cryptanalysis: rotational cryptanalysis and the rebound attack. Rotational cryptanalysis was designed for the analysis of bit-oriented designs like ARX (Addition-Rotation-XOR) schemes. It has been applied to several hash functions and block...... ciphers, including the new standard SHA-3 (Keccak). The rebound attack is a start-from-the-middle approach for finding differential paths and conforming pairs in byte-oriented designs like Substitution-Permutation networks and AES. We apply our new compositional attack to the reduced version of the hash...

  17. Limb-shaking transient ischemic attack

    Directory of Open Access Journals (Sweden)

    Abhijit Das

    2013-01-01

    Full Text Available Limb shaking Transient Ischemic Attack is a rare manifestation of carotid-occlusive disease. The symptoms usually present with seizure like activity and often misdiagnosed as focal seizures. Only on careful history the important clinical clues-which may help in differentiating from seizure-are revealed: Lack of Jacksonian march or aura; precipitation by maneuvers that lead to carotid compression. We present the case of an elderly gentleman with recurrent limb shaking transient ischemic attacks that was initially diagnosed as a case of epilepsy. His symptoms responded to optimization of blood pressure. The case report highlights the importance of accurate diagnosis as the treatment of the associated carotid artery occlusion may not only abolish the attacks but also reduce the risk of future stroke.

  18. Twisted Polynomials and Forgery Attacks on GCM

    DEFF Research Database (Denmark)

    Abdelraheem, Mohamed Ahmed A. M. A.; Beelen, Peter; Bogdanov, Andrey

    2015-01-01

    nonce misuse resistance, such as POET. The algebraic structure of polynomial hashing has given rise to security concerns: At CRYPTO 2008, Handschuh and Preneel describe key recovery attacks, and at FSE 2013, Procter and Cid provide a comprehensive framework for forgery attacks. Both approaches rely...... heavily on the ability to construct forgery polynomials having disjoint sets of roots, with many roots (“weak keys”) each. Constructing such polynomials beyond naïve approaches is crucial for these attacks, but still an open problem. In this paper, we comprehensively address this issue. We propose to use...... twisted polynomials from Ore rings as forgery polynomials. We show how to construct sparse forgery polynomials with full control over the sets of roots. We also achieve complete and explicit disjoint coverage of the key space by these polynomials. We furthermore leverage this new construction...

  19. Conditional beam splitting attack on quantum key distribution

    OpenAIRE

    Calsamiglia, John; Barnett, Stephen M.; Lütkenhaus, Norbert

    2001-01-01

    We present a novel attack on quantum key distribution based on the idea of adaptive absorption [calsam01]. The conditional beam splitting attack is shown to be much more efficient than the conventional beam spitting attack, achieving a performance similar to the, powerful but currently unfeasible, photon number splitting attack. The implementation of the conditional beam splitting attack, based solely on linear optical elements, is well within reach of current technology.

  20. Discovering Collaborative Cyber Attack Patterns Using Social Network Analysis

    Science.gov (United States)

    Du, Haitao; Yang, Shanchieh Jay

    This paper investigates collaborative cyber attacks based on social network analysis. An Attack Social Graph (ASG) is defined to represent cyber attacks on the Internet. Features are extracted from ASGs to analyze collaborative patterns. We use principle component analysis to reduce the feature space, and hierarchical clustering to group attack sources that exhibit similar behavior. Experiments with real world data illustrate that our framework can effectively reduce from large dataset to clusters of attack sources exhibiting critical collaborative patterns.

  1. Viden: Attacker Identification on In-Vehicle Networks

    OpenAIRE

    Cho, Kyong-Tak; Shin, Kang

    2017-01-01

    Various defense schemes --- which determine the presence of an attack on the in-vehicle network --- have recently been proposed. However, they fail to identify which Electronic Control Unit (ECU) actually mounted the attack. Clearly, pinpointing the attacker ECU is essential for fast/efficient forensic, isolation, security patch, etc. To meet this need, we propose a novel scheme, called Viden (Voltage-based attacker identification), which can identify the attacker ECU by measuring and utilizi...

  2. Physicochemical signatures of nanoparticle-dependent complement activation

    Science.gov (United States)

    Thomas, Dennis G.; Chikkagoudar, Satish; Heredia-Langner, Alejandro; Tardiff, Mark F.; Xu, Zhixiang; Hourcade, Dennis E.; Pham, Christine T. N.; Lanza, Gregory M.; Weinberger, Kilian Q.; Baker, Nathan A.

    2014-01-01

    Nanoparticles are potentially powerful therapeutic tools that have the capacity to target drug payloads and imaging agents. However, some nanoparticles can activate complement, a branch of the innate immune system, and cause adverse side-effects. Recently, we employed an in vitro hemolysis assay to measure the serum complement activity of perfluorocarbon nanoparticles that differed by size, surface charge, and surface chemistry, quantifying the nanoparticle-dependent complement activity using a metric called Residual Hemolytic Activity (RHA). In the present work, we have used a decision tree learning algorithm to derive the rules for estimating nanoparticle-dependent complement response based on the data generated from the hemolytic assay studies. Our results indicate that physicochemical properties of nanoparticles, namely, size, polydispersity index, zeta potential, and mole percentage of the active surface ligand of a nanoparticle, can serve as good descriptors for prediction of nanoparticle-dependent complement activation in the decision tree modeling framework.

  3. [The complement system: a double edge sword in tumor progression].

    Science.gov (United States)

    Daugan, Marie; Noe, Remi; Herman Fridman, Wolf; Sautes-Fridman, Catherine; Roumenina, Lubka T

    2017-10-01

    The complement system is a key component of the innate immunity, playing a role in pathogen elimination and in host homeostasis. The complement system has been considered for long time as an anti-tumoral element. However, recent studies showed a pro-tumoral effect of complement and particularly of the anaphylatoxines C3a and C5a in a large variety of tumor types. Complement proteins act on different levels of tumor progression, affecting the tumor cells, the angiogenesis and the immune microenvironment. The impact of the complement system on tumor progression seems to be cancer type-dependent and this has to be taken into account in the establishment of potential biomarkers and development of therapeutic strategies. © 2017 médecine/sciences – Inserm.

  4. Complement monitoring of Pluronic 127 gel and micelles

    DEFF Research Database (Denmark)

    Hamad, Islam; Hunter, A Christy; Moghimi, Seyed Moien

    2013-01-01

    vascular occlusion. We show that poloxamer gel can trigger the complement system, which is an integral part of innate immunity and its inadvertent activation can induce clinically significant anaphylaxis. Complement activation by the poloxamer gel is through the alternative pathway, but material...... transformations from gel to the solution state further incite complement through calcium-sensitive pathways, where a role for C1q and antibodies has been eliminated. Poloxamer addition to plasma/serum (at levels above its critical micelle concentration, cmc) induced formation of large and diffused structures......, which may have been responsible for triggering complement. Since poloxamer 407 administration has been reported to cause significant changes in plasma cholesterol and triglyceride levels we further examined the role of lipoproteins in poloxamer-mediated complement activation. Our results show...

  5. Proteomic Profiling Analysis Reveals a Link between Experimental Autoimmune Uveitis and Complement Activation in Rats.

    Science.gov (United States)

    Guo, D D; Hu, B; Tang, H Y; Sun, Y Y; Liu, B; Tian, Q M; Bi, H S

    2017-05-01

    Uveitis is an autoimmune disease that usually damages the vision function, leading to poor visual quality in patients. As an autoimmune ocular inflammatory disease, the pathogenesis of uveitis is associated with abnormal expression of some proteins and aberrant regulation of multiple signalling pathways. Nevertheless, the detailed mechanism remains unclear. In this study, we induced an experimental autoimmune uveitis (EAU) model in rats. We determined the levels of C3a and membrane attack complex C5b-9 (soluble C5b-9, sC5b-9) in both plasma and aqueous humour, identified the differentially expressed proteins in plasma by liquid chromatography-tandem mass spectrometry and employed bioinformatics algorithms to analyse differentially expressed proteins in EAU rat plasma. The results demonstrate that there were 168 differentially expressed plasma proteins in EAU rats versus control subjects. The levels of sC5b-9 and C3a were elevated in the plasmas and aqueous humours of EAU rats. Gene ontology enrichment analysis showed that the differentially expressed proteins in EAU rat plasma were mainly involved in metabolic and immune processes. Kyoto encyclopedia of genes and genomes (KEGG) pathway annotation, database for annotation, visualization and integrated discovery (DAVID) and protein-protein interaction analyses revealed that the differentially expressed proteins in EAU rat plasmas were closely associated with complement and coagulation cascades, metabolic pathways, NF-kappa B, PI3K-Akt, Toll-like receptors and autophagy. Overall, the differentially expressed proteins in EAU rat plasmas are mainly involved in the complement and coagulation cascades. The pathogenesis of uveitis closely correlates with complement activation. © 2017 The Foundation for the Scandinavian Journal of Immunology.

  6. Survival of child after lion attack

    OpenAIRE

    Carlos F Dabdoub; Dabdoub, Carlos B.; Chavez, Mario; Molina, Felipe

    2013-01-01

    Background: Injuries to humans caused by attacks from large predators are very rare, especially in the United States, Europe, or Latin America. A few cases were reported on accidents in zoos or animal farms, being very uncommon in children. The purposes of this report include describing the case of a child who sustained an attack by a lion named ?Bang-Bang?, which resulted in injuries to the head, chest, and abdomen, as well as the subsequent neurosurgical treatment and providing a review of ...

  7. Hemolytic plate assay for quantification of active human complement component C3 using methylamine-treated plasma as complement source

    DEFF Research Database (Denmark)

    Ploug, M; Jessen, T E; Welinder, K. G.

    1985-01-01

    A hemolytic plate assay specific for active human complement component C3 is described. The method is well suited for tracing active C3 during preparative purification or for screening of plasma samples. The assay is based on activation of the alternative pathway of complement by unmodified rabbi...

  8. Complement in Non-Antibody-Mediated Kidney Diseases

    Directory of Open Access Journals (Sweden)

    Andrea Angeletti

    2017-07-01

    Full Text Available The complement system is part of the innate immune response that plays important roles in protecting the host from foreign pathogens. The complement components and relative fragment deposition have long been recognized to be strongly involved also in the pathogenesis of autoantibody-related kidney glomerulopathies, leading to direct glomerular injury and recruitment of infiltrating inflammation pathways. More recently, unregulated complement activation has been shown to be associated with progression of non-antibody-mediated kidney diseases, including focal segmental glomerulosclerosis, C3 glomerular disease, thrombotic microangiopathies, or general fibrosis generation in progressive chronic kidney diseases. Some of the specific mechanisms associated with complement activation in these diseases were recently clarified, showing a dominant role of alternative activation pathway. Over the last decade, a growing number of anticomplement agents have been developed, and some of them are being approved for clinical use or already in use. Therefore, anticomplement therapies represent a realistic choice of therapeutic approaches for complement-related diseases. Herein, we review the complement system activation, regulatory mechanisms, their involvement in non-antibody-mediated glomerular diseases, and the recent advances in complement-targeting agents as potential therapeutic strategies.

  9. Cyclosporine Induces Endothelial Cell Release of Complement-Activating Microparticles

    Science.gov (United States)

    Renner, Brandon; Klawitter, Jelena; Goldberg, Ryan; McCullough, James W.; Ferreira, Viviana P.; Cooper, James E.; Christians, Uwe

    2013-01-01

    Defective control of the alternative pathway of complement is an important risk factor for several renal diseases, including atypical hemolytic uremic syndrome. Infections, drugs, pregnancy, and hemodynamic insults can trigger episodes of atypical hemolytic uremic syndrome in susceptible patients. Although the mechanisms linking these clinical events with disease flares are unknown, recent work has revealed that each of these clinical conditions causes cells to release microparticles. We hypothesized that microparticles released from injured endothelial cells promote intrarenal complement activation. Calcineurin inhibitors cause vascular and renal injury and can trigger hemolytic uremic syndrome. Here, we show that endothelial cells exposed to cyclosporine in vitro and in vivo release microparticles that activate the alternative pathway of complement. Cyclosporine-induced microparticles caused injury to bystander endothelial cells and are associated with complement-mediated injury of the kidneys and vasculature in cyclosporine-treated mice. Cyclosporine-induced microparticles did not bind factor H, an alternative pathway regulatory protein present in plasma, explaining their complement-activating phenotype. Finally, we found that in renal transplant patients, the number of endothelial microparticles in plasma increases 2 weeks after starting tacrolimus, and treatment with tacrolimus associated with increased C3 deposition on endothelial microparticles in the plasma of some patients. These results suggest that injury-associated release of endothelial microparticles is an important mechanism by which systemic insults trigger intravascular complement activation and complement-dependent renal diseases. PMID:24092930

  10. Complement in disease: a defence system turning offensive.

    Science.gov (United States)

    Ricklin, Daniel; Reis, Edimara S; Lambris, John D

    2016-07-01

    Although the complement system is primarily perceived as a host defence system, a more versatile, yet potentially more harmful side of this innate immune pathway as an inflammatory mediator also exists. The activities that define the ability of the complement system to control microbial threats and eliminate cellular debris - such as sensing molecular danger patterns, generating immediate effectors, and extensively coordinating with other defence pathways - can quickly turn complement from a defence system to an aggressor that drives immune and inflammatory diseases. These host-offensive actions become more pronounced with age and are exacerbated by a variety of genetic factors and autoimmune responses. Complement can also be activated inappropriately, for example in response to biomaterials or transplants. A wealth of research over the past two decades has led to an increasingly finely tuned understanding of complement activation, identified tipping points between physiological and pathological behaviour, and revealed avenues for therapeutic intervention. This Review summarizes our current view of the key activating, regulatory, and effector mechanisms of the complement system, highlighting important crosstalk connections, and, with an emphasis on kidney disease and transplantation, discusses the involvement of complement in clinical conditions and promising therapeutic approaches.

  11. Intracellular complement - the complosome - in immune cell regulation.

    Science.gov (United States)

    Arbore, Giuseppina; Kemper, Claudia; Kolev, Martin

    2017-09-01

    The complement system was defined over a century ago based on its ability to "complement" the antibody-mediated and cell-mediated immune responses against pathogens. Today our understanding of this ancient part of innate immunity has changed substantially and we know now that complement plays an undisputed pivotal role in the regulation of both innate and adaptive immunity. The complement system consists of over 50 blood-circulating, cell-surface expressed and intracellular proteins. It is key in the recognition and elimination of invading pathogens, also in the removal of self-derived danger such as apoptotic cells, and it supports innate immune responses and the initiation of the general inflammatory reactions. The long prevailing classic view of complement was that of a serum-operative danger sensor and first line of defence system, however, recent experimental and clinical evidences have demonstrated that "local" tissue and surprisingly intracellular complement (the complosome) activation impacts on normal cell physiology. This review will focus on novel aspects of intracellular complement activation and its unexpected roles in basic cell processes such as metabolism. We also discuss what the existence of the complosome potentially means for how the host handles intracellular pathogens such as viruses. Copyright © 2017. Published by Elsevier Ltd.

  12. A Study of Gaps in Attack Analysis

    Science.gov (United States)

    2016-10-12

    Kührer, Thomas Hupperich, Christian Rossow, and Thorsten Holz. Exit from Hell? Re- ducing the Impact of Amplification DDoS Attacks. In Proceedings of...Revisiting Network Protocols for DDoS Abuse. In 21st Annual Network and Distributed System Security Symposium, NDSS 2014, San Diego, California, USA

  13. Using an ontology for network attack planning

    CSIR Research Space (South Africa)

    Van Heerden, R

    2016-09-01

    Full Text Available -1 International Journal of Cyber Warfare and Terrorism, vol. 6(3), 65-78 Using an Ontology for Network Attack Planning Renier van Heerden1,2, Peter Chan2 , Louise Leenen2,3 Jacques Theron4 1 Nelson Mandela Metropolitan University, South Africa 2...

  14. Algebraic Side-Channel Attack on Twofish

    Directory of Open Access Journals (Sweden)

    Chujiao Ma

    2017-05-01

    Full Text Available While algebraic side-channel attack (ASCA has been successful in breaking simple cryptographic algorithms, it has never been done on larger or more complex algorithms such as Twofish. Compared to other algorithms that ASCA has been used on, Twofish is more difficult to attack due to the key-dependent S-boxes as well as the complex key scheduling. In this paper, we propose the first algebraic side-channel attack on Twofish, and examine the importance of side-channel information in getting past the key-dependent S-boxes and the complex key scheduling. The cryptographic algorithm and side-channel information are both expressed as boolean equations and a SAT solver is used to recover the key. While algebraic attack by itself is not sufficient to break the algorithm, with the help of side-channel information such as Hamming weights, we are able to correctly solve for 96 bits of the 128 bits key in under 2 hours with known plaintext/ciphertext.

  15. Cyber Attack! Crime or Act of War?

    Science.gov (United States)

    2011-04-13

    informational, or economic.54 Other legal scholars concur in this interpretation, one using the term ― agressive force‖ in lieu of ―armed force‖ but...distributed whiteboard to determine legal responses to online cyber attacks. Internet Research 16, no. 5, (October 20): 475-490. http

  16. Strengthening Crypto-1 Cipher Against Algebraic Attacks

    Directory of Open Access Journals (Sweden)

    Farah Afianti

    2015-08-01

    Full Text Available In the last few years, several studies addressed the problem of data security in Mifare Classic. One of its weaknesses is the low random number quality. This causes SAT solver attacks to have lower complexity. In order to strengthen Crypto-1 against SAT solver attacks, a modification of the feedback function with better cryptographic properties is proposed. It applies a primitive polynomial companion matrix. SAT solvers cannot directly attack the feedback shift register that uses the modified Boolean feedback function, the register has to be split into smaller groups. Experimental testing showed that the amount of memory and CPU time needed were highest when attacking the modified Crypto-1 using the modified feedback function and the original filter function. In addition, another modified Crypto-1, using the modified feedback function and a modified filter function, had the lowest percentage of revealed variables. It can be concluded that the security strength and performance of the modified Crypto-1 using the modified feedback function and the modified filter function are better than those of the original Crypto-1.

  17. Wrap-Attack Pack: Product Packaging Exercise

    Science.gov (United States)

    Lee, Seung Hwan; Hoffman, K. Douglas

    2016-01-01

    Although many marketing courses discuss traditional concepts pertaining to product strategy, concepts specifically relating to packaging are often glossed over. This exercise, "Wrap-Attack Pack," teaches students about the utilitarian and hedonic design elements of packaging. More specifically, the primary objective is to creatively…

  18. Management of an acute asthma attack.

    Science.gov (United States)

    Barnard, Amanda

    2005-07-01

    Despite a more proactive approach to asthma management, which includes an increased range of drugs, wide dissemination of guidelines, and the use of asthma action plans, an acute severe asthma attack is one of the most common emergencies a general practitioner will encounter. This article discusses the management of an acute asthma attack in the general practice setting. Assessment of severity is vital and can be ascertained quite quickly with a brief history and rapid physical examination. It is important to remember that wheeze is an unreliable indicator of the severity of attack and may be absent in severe asthma. The cornerstones of treatment are oxygen and inhaled beta 2 agonists. Beta 2 agonists can be given continuously in severe life threatening asthma. Early administration of systemic steroids is important. Patients discharged to home after treatment of an asthma attack require close follow up including beta 2 agonists for symptom control, review of medications including a consideration of a short course of oral steroids, a written asthma action plan and detailed advice about what to do in case of deterioration in the next 24 hours. They should be reviewed in 24-48 hours.

  19. Understand Your Risk of Heart Attack

    Science.gov (United States)

    ... other risk factors. Overweight and obese adults with risk factors for cardiovascular disease such as high blood pressure, high cholesterol, ... over 40, or if you have multiple risk factors, work especially closely with ... cardiovascular disease. Heart attack prevention should begin early in ...

  20. Afghanistan: Green-on-Blue Attacks

    Science.gov (United States)

    2013-05-02

    spike-insider-attacks- stress- ramadan - fasting , 24 August 2012 37 Yousafzai, Sami and Moreau, Ron, http://www.thedailybeast.com/newsweek/2012/08/26...Ramazan.” “And so the daily pressures that are on some of these [Afghan] troops, compounded by the sacrifice associated with fasting , the nature of

  1. Survival of child after lion attack

    Science.gov (United States)

    Dabdoub, Carlos F.; Dabdoub, Carlos B.; Chavez, Mario; Molina, Felipe

    2013-01-01

    Background: Injuries to humans caused by attacks from large predators are very rare, especially in the United States, Europe, or Latin America. A few cases were reported on accidents in zoos or animal farms, being very uncommon in children. The purposes of this report include describing the case of a child who sustained an attack by a lion named “Bang-Bang”, which resulted in injuries to the head, chest, and abdomen, as well as the subsequent neurosurgical treatment and providing a review of the literature. Case Description: We report the case of an 8-year-old boy who was attacked by a lion during a circus show. The patient underwent an emergent neurosurgical procedure, including parietal craniectomy, cleaning, and extensive surgical debridement of the wounds. Despite open severe head trauma with brain damage as well as thorax and abdomen trauma, the child survived, with minimal neurological sequelae. Conclusions: Human injury resulting from encounters with nondomesticated animals is increasingly rising throughout the world. This case highlights the potentially violent and aggressive nature of wild mammals held in captivity. Unusual wild animal attacks and the complex injuries that result may pose a challenge to surgeons practicing in resource-limited settings. In this sense, the best treatment in the mentioned case is the prevention of human injuries by these animals. In addition, to attend to these infrequent cases, the authors emphasize the importance of a multidisciplinary approach to achieve the best cosmetic and functional results. PMID:23869277

  2. Shark Attack! Sinking Your Teeth into Anatomy.

    Science.gov (United States)

    House, Herbert

    2002-01-01

    Presents a real life shark attack story and studies arm reattachment surgery to teach human anatomy. Discusses how knowledge of anatomy can be put to use in the real world and how the arm functions. Includes teaching notes and suggestions for classroom management. (YDS)

  3. Attack Classification Schema for Smart City WSNs

    Directory of Open Access Journals (Sweden)

    Victor Garcia-Font

    2017-04-01

    Full Text Available Urban areas around the world are populating their streets with wireless sensor networks (WSNs in order to feed incipient smart city IT systems with metropolitan data. In the future smart cities, WSN technology will have a massive presence in the streets, and the operation of municipal services will be based to a great extent on data gathered with this technology. However, from an information security point of view, WSNs can have failures and can be the target of many different types of attacks. Therefore, this raises concerns about the reliability of this technology in a smart city context. Traditionally, security measures in WSNs have been proposed to protect specific protocols in an environment with total control of a single network. This approach is not valid for smart cities, as multiple external providers deploy a plethora of WSNs with different security requirements. Hence, a new security perspective needs to be adopted to protect WSNs in smart cities. Considering security issues related to the deployment of WSNs as a main data source in smart cities, in this article, we propose an intrusion detection framework and an attack classification schema to assist smart city administrators to delimit the most plausible attacks and to point out the components and providers affected by incidents. We demonstrate the use of the classification schema providing a proof of concept based on a simulated selective forwarding attack affecting a parking and a sound WSN.

  4. Attack Classification Schema for Smart City WSNs.

    Science.gov (United States)

    Garcia-Font, Victor; Garrigues, Carles; Rifà-Pous, Helena

    2017-04-05

    Urban areas around the world are populating their streets with wireless sensor networks (WSNs) in order to feed incipient smart city IT systems with metropolitan data. In the future smart cities, WSN technology will have a massive presence in the streets, and the operation of municipal services will be based to a great extent on data gathered with this technology. However, from an information security point of view, WSNs can have failures and can be the target of many different types of attacks. Therefore, this raises concerns about the reliability of this technology in a smart city context. Traditionally, security measures in WSNs have been proposed to protect specific protocols in an environment with total control of a single network. This approach is not valid for smart cities, as multiple external providers deploy a plethora of WSNs with different security requirements. Hence, a new security perspective needs to be adopted to protect WSNs in smart cities. Considering security issues related to the deployment of WSNs as a main data source in smart cities, in this article, we propose an intrusion detection framework and an attack classification schema to assist smart city administrators to delimit the most plausible attacks and to point out the components and providers affected by incidents. We demonstrate the use of the classification schema providing a proof of concept based on a simulated selective forwarding attack affecting a parking and a sound WSN.

  5. Plant defences against herbivore and insect attack

    Science.gov (United States)

    Plants deploy a number of defences against attack by insects and other herbivores. Direct defence is conferred by plant products and structures that deter or kill the herbivores. Chemical toxins and deterrents vary widely among plant species, and some typical toxins include alkaloids, terpenoids, st...

  6. Rhode Island School Terrorist Attack Preparedness

    Science.gov (United States)

    Dube, Michael W. M.

    2012-01-01

    This study examined the state of safety and terrorist attack preparedness in Rhode Island Schools as determined by Rhode Island school leader perceptions. The study is descriptive in nature as it gathers data to describe a particular event or situation. Using a researcher generated survey based on terrorist preparedness guidelines and suggestions…

  7. Intrusion-Tolerant Replication under Attack

    Science.gov (United States)

    Kirsch, Jonathan

    2010-01-01

    Much of our critical infrastructure is controlled by large software systems whose participants are distributed across the Internet. As our dependence on these critical systems continues to grow, it becomes increasingly important that they meet strict availability and performance requirements, even in the face of malicious attacks, including those…

  8. Association between Terror Attacks and Suicide Attempts

    Science.gov (United States)

    Weizman, Tal; Yagil, Yaron; Schreiber, Shaul

    2009-01-01

    Based on Durkheim's "Control theory," we explored the association between frequency of terror attacks in Israel and the frequency of suicide attempts admitted to the Emergency Room of a major general hospital in Tel-Aviv (1999-2004). Analysis of the six-year study period as a whole revealed no significant correlation between the…

  9. An Adaptive Approach for Defending against DDoS Attacks

    Directory of Open Access Journals (Sweden)

    Muhai Li

    2010-01-01

    Full Text Available In various network attacks, the Distributed Denial-of-Service (DDoS attack is a severe threat. In order to deal with this kind of attack in time, it is necessary to establish a special type of defense system to change strategy dynamically against attacks. In this paper, we introduce an adaptive approach, which is used for defending against DDoS attacks, based on normal traffic analysis. The approach can check DDoS attacks and adaptively adjust its configurations according to the network condition and attack severity. In order to insure the common users to visit the victim server that is being attacked, we provide a nonlinear traffic control formula for the system. Our simulation test indicates that the nonlinear control approach can prevent the malicious attack packets effectively while making legitimate traffic flows arrive at the victim.

  10. Temporal specification and subject reference in Romanian subjunctive complements

    Directory of Open Access Journals (Sweden)

    Maria Aurelia Cotfas

    2009-01-01

    Full Text Available The paper looks at the dependency of Romanian subjunctive complements on the semantic class of the matrix verb. It shows that different types of temporal dependency trigger different identity relations between the null embedded subject and the (subject antecedent in the main clause (cf. Farkas 1984. Volitional verbs are also looked at in terms of the restrictions they impose on the subjunctive complements they subcategorize for. Finally, following Landau’s (1999 classification of infinitive complements in English, Romanian subjunctives are argued to fall into two distinct classses exhibiting different properties in terms of subject reference and temporal dependency.

  11. Recovery of human remains after shark attack.

    Science.gov (United States)

    Byard, Roger W; James, Ross A; Heath, Karen J

    2006-09-01

    Two cases of fatal shark attack are reported where the only tissues recovered were fragments of lung. Case 1: An 18-year-old male who was in the sea behind a boat was observed by friends to be taken by a great white shark (Carcharodon carcharias). The shark dragged him under the water and then, with a second shark, dismembered the body. Witnesses noted a large amount of blood and unrecognizable body parts coming to the surface. The only tissues recovered despite an intensive beach and sea search were 2 fragments of lung. Case 2: A 19-year-old male was attacked by a great white shark while diving. A witness saw the shark swim away with the victim's body in its mouth. Again, despite intensive beach and sea searches, the only tissue recovered was a single piece of lung, along with pieces of wetsuit and diving equipment. These cases indicate that the only tissue to escape being consumed or lost in fatal shark attacks, where there is a significant attack with dismemberment and disruption of the integrity of the body, may be lung. The buoyancy of aerated pulmonary tissue ensures that it rises quickly to the surface, where it may be recovered by searchers soon after the attack. Aeration of the lung would be in keeping with death from trauma rather than from drowning and may be a useful marker in unwitnessed deaths to separate ante- from postmortem injury, using only relatively small amounts of tissues. Early organ recovery enhances the identification of human tissues as the extent of morphologic alterations by putrefactive processes and sea scavengers will have been minimized. DNA testing is also possible on such recovered fragments, enabling confirmation of the identity of the victim.

  12. Entamoeba histolytica and E. dispar trophozoites in the liver of hamsters: in vivo binding of antibodies and complement

    Directory of Open Access Journals (Sweden)

    Gomes Maria A

    2010-03-01

    inoculated with E. dispar. Conclusion Morphological and immunohistochemical results suggest that antibodies and complement are able to bind and destroy some trophozoites in the liver of experimentally infected hamsters, perhaps selecting the more resistant parasites which are responsible by progression of amoebic abscesses. The findings indicate that E. histolytica possesses an enhanced ability in vivo to evade the immune responses compared to E. dispar, although it also causes experimental hepatic lesions.

  13. Value of Plasmatic Membrane Attack Complex as a Marker of Severity in Acute Kidney Injury

    Directory of Open Access Journals (Sweden)

    Eva Rodríguez

    2014-01-01

    Full Text Available The aim of this study was to determine if complement pathway is activated in AKI; for this purpose, we measured, through ELISA sandwich, the terminal lytic fraction of the complement system, called membrane attack complex (C5b-C9, in AKI patients compared with patients with similar clinical conditions but normal renal function. Our data showed that complement system is activated in AKI. Plasmatic MAC concentrations were significantly higher in AKI patients than in those with normal renal function; this difference is maintained independently of the AKI etiology and is proportional to the severity of AKI, measured by ADQI classification. In addition, we found that plasmatic MAC concentrations were significantly higher in patients who did not recover renal function at time of hospitalization discharge, in patients who died during the acute process, and in patients who need renal replacement therapy during hospitalization, but in this last group, the differences did not reach statistical significance. In conclusion, plasmatic MAC concentration seems valuable as a marker of AKI severity.

  14. Value of plasmatic membrane attack complex as a marker of severity in acute kidney injury.

    Science.gov (United States)

    Rodríguez, Eva; Riera, Marta; Barrios, Clara; Pascual, Julio

    2014-01-01

    The aim of this study was to determine if complement pathway is activated in AKI; for this purpose, we measured, through ELISA sandwich, the terminal lytic fraction of the complement system, called membrane attack complex (C5b-C9), in AKI patients compared with patients with similar clinical conditions but normal renal function. Our data showed that complement system is activated in AKI. Plasmatic MAC concentrations were significantly higher in AKI patients than in those with normal renal function; this difference is maintained independently of the AKI etiology and is proportional to the severity of AKI, measured by ADQI classification. In addition, we found that plasmatic MAC concentrations were significantly higher in patients who did not recover renal function at time of hospitalization discharge, in patients who died during the acute process, and in patients who need renal replacement therapy during hospitalization, but in this last group, the differences did not reach statistical significance. In conclusion, plasmatic MAC concentration seems valuable as a marker of AKI severity.

  15. Words Mean Things: The Case for Information System Attack and Control System Attack

    Science.gov (United States)

    2008-10-31

    FINAL 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Words Mean Things: The Case for Information System Attack and Control System...Standard Form 298 (Rev. 8-98) NAVAL WAR COLLEGE Newport, R.I. WORDS MEAN THINGS: THE CASE FOR INFORMATION SYSTEM ATTACK AND... words , the DepSecDef definition acknowledges the existence of a new domain, but strongly implies the accepted definition of CNO is sufficient to

  16. Chosen-name attacks: An overlooked class of type-flaw attacks

    OpenAIRE

    Ceelen, Pieter; Mauw, Sjouke; Radomirovic, Sasa

    2008-01-01

    In the context of Dolev-Yao style analysis of security protocols, we consider the capability of an intruder to dynamically choose and assign names to agents. This capability has been overlooked in all significant protocol verification frameworks based on formal methods. We identify and classify new type-flaw attacks arising from this capability. Several examples of protocols that are vulnerable to this type of attack are given, including Lowe’s modification of KSL. The consequences for automa...

  17. Complement involvement in periodontitis: molecular mechanisms and rational therapeutic approaches

    Science.gov (United States)

    Hajishengallis, George; Maekawa, Tomoki; Abe, Toshiharu; Hajishengallis, Evlambia; Lambris, John D.

    2015-01-01

    The complement system is a network of interacting fluid-phase and cell surface-associated molecules that trigger, amplify, and regulate immune and inflammatory signaling pathways. Dysregulation of this finely balanced network can destabilize host-microbe homeostasis and cause inflammatory tissue damage. Evidence from clinical and animal model-based studies suggests that complement is implicated in the pathogenesis of periodontitis, a polymicrobial community-induced chronic inflammatory disease that destroys the tooth-supporting tissues. This review discusses molecular mechanisms of complement involvement in the dysbiotic transformation of the periodontal microbiome and the resulting destructive inflammation, culminating in loss of periodontal bone support. These mechanistic studies have additionally identified potential therapeutic targets. In this regard, interventional studies in preclinical models have provided proof-of-concept for using complement inhibitors for the treatment of human periodontitis. PMID:26306443

  18. Complement inhibitors to treat IgM-mediated autoimmune hemolysis

    NARCIS (Netherlands)

    Wouters, Diana; Zeerleder, Sacha

    2015-01-01

    Complement activation in autoimmune hemolytic anemia may exacerbate extravascular hemolysis and may occasionally result in intravascular hemolysis. IgM autoantibodies as characteristically found in cold autoantibody autoimmune hemolytic anemia, in cold agglutinin disease but also in a considerable

  19. Complement system activation in ANCA vasculitis : A translational success story?

    NARCIS (Netherlands)

    Kallenberg, Cees G. M.; Heeringa, Peter

    2015-01-01

    The ANCA-associated vasculitides (AAV) are characterized by pauci-immune necrotizing small to medium size vessel vasculitis frequently including necrotizing crescentric glomerulonephritis. Neutrophil activation by ANCA appears a primary pathogenic event. More recently, the complement system has been

  20. The Role of the Complement System in Acute Kidney Injury

    Science.gov (United States)

    McCullough, James W.; Renner, Brandon; Thurman, Joshua M.

    2013-01-01

    Summary Acute kidney injury is a common and severe clinical problem. Patients who develop acute kidney injury are at increased risk of death in spite of supportive measures such as hemodialysis. Research in recent years has revealed that tissue inflammation is central to the pathogenesis of renal injury, even after non-immune insults such as ischemia/reperfusion and toxins. Examination of clinical samples and pre-clinical models demonstrate that activation of the complement system is a critical cause of acute kidney injury. Furthermore, complement activation within the injured kidney is a proximal trigger of many downstream inflammatory events within the renal parenchyma that exacerbate injury to the kidney. Complement activation may also account for the systemic inflammatory events that contribute to remote organ injury and patient mortality. Complement inhibitory drugs have now entered clinical use and may provide an important new therapeutic approach for patients suffering from or at high risk of developing acute kidney injury. PMID:24161039

  1. Complement C4 phenotypes in dementia of the Alzheimer type

    NARCIS (Netherlands)

    Eikelenboom, P.; Goetz, J.; Pronk, J. C.; Hauptmann, G.

    1988-01-01

    Complement C4 phenotype distribution was studied in 64 patients with dementia of the Alzheimer type. In contrast to reported findings we failed to find a significant association between C4B2 gene frequency and Alzheimer's dementia

  2. Complementing T-cell Function: An Inhibitory Role of the Complement System in T-cell-Mediated Antitumor Immunity.

    Science.gov (United States)

    Peng, Weiyi; McKenzie, Jodi A; Hwu, Patrick

    2016-09-01

    New data from Wang and colleagues show that complement C3 suppresses the function of CD8(+) tumor-infiltrating T cells by inhibiting IL10 production, and targeting the complement receptors C3aR and C5aR enhances the antitumor activity of immune checkpoint blockade. Their results not only define a new role of complement receptors as T-cell coinhibitory receptors, but also are useful in the development of novel strategies to improve the effectiveness of cancer immunotherapy. Cancer Discov; 6(9); 953-5. ©2016 AACR.See related article by Wang et al., p. 1022. ©2016 American Association for Cancer Research.

  3. Complement titration by rectilinear attenuance and attempts at its automatization

    Science.gov (United States)

    Satoh, P. S.; Yoshida, T. O.; Fukusima, Y.; Ono, N.; Yoshida, K.; Ito, Y.

    1969-01-01

    Immune haemolysis was determined by rectilinear attenuance at 625 mμ (l = 1.3 mm, 1.25 mm), and the data obtained treated by von Krogh's empirical equation. The C′H50/ml values obtained by the attenuance method had high correlation with those obtained by the conventional photometric method (541 mμ). Automatic complement titration was attempted, as a part of the basic studies on quantitative complement fixation tests. PMID:5386637

  4. Depletion of complement system immunity in patients with myocardial infarction.

    Science.gov (United States)

    Yan, Wenwen; Che, Lin; Jiang, Jinfa; Yang, Fan; Duan, Qianglin; Song, Haoming; Liu, Xiaohong; Shen, Yuqin; Wang, Lemin

    2016-12-01

    The aim of the present study was to evaluate differences in the expression of complement system genes, and serum levels of CH50, C3 and C4 in peripheral blood mononuclear cells from patients with myocardial infarction (AMI), stable angina pectoris (SA) and controls. A total of 100 patients with AMI, 100 with SA and 100 clinical controls were recruited in the present study. In each group, 20 randomly selected individuals were examined using whole human genome microarray analysis to detect the expression of genes of the complement system. The serum levels of CH50, C3 and C4 were measured in all 300 subjects. In the patients with AMI, the expression levels of genes encoding C1qα, C1qβ, C1qγ, C1r, Factor P, C5a (complement component), CR1, integrin αM, integrin αX, integrin β2, C5aR, CRIg (complement receptors) and CD46, CD55 and CD59 (complement regulators) were significantly higher, compared with the respective genes in the SA patients and controls (Pcomplement components or regulators between the SA and control groups. The serum levels of CH50, C3 and C4 were significantly increased in the AMI and SA groups, compared with the controls. In the AMI and SA groups, the complement system was activated. However, the differential mRNA expression of complement components, receptors and regulators in the AMI group suggested the dysfunction of the C5b-9 complex. The depression of complement system immunity in the patients with AMI may be associated with the pathogenesis of AMI.

  5. In Situ complement activation and T-cell immunity in leprosy spectrum: An immunohistological study on leprosy lesional skin.

    Science.gov (United States)

    Bahia El Idrissi, Nawal; Iyer, Anand M; Ramaglia, Valeria; Rosa, Patricia S; Soares, Cleverson T; Baas, Frank; Das, Pranab K

    2017-01-01

    Mycobacterium leprae (M. leprae) infection causes nerve damage and the condition worsens often during and long after treatment. Clearance of bacterial antigens including lipoarabinomannan (LAM) during and after treatment in leprosy patients is slow. We previously demonstrated that M. leprae LAM damages peripheral nerves by in situ generation of the membrane attack complex (MAC). Investigating the role of complement activation in skin lesions of leprosy patients might provide insight into the dynamics of in situ immune reactivity and the destructive pathology of M. leprae. In this study, we analyzed in skin lesions of leprosy patients, whether M. leprae antigen LAM deposition correlates with the deposition of complement activation products MAC and C3d on nerves and cells in the surrounding tissue. Skin biopsies of paucibacillary (n = 7), multibacillary leprosy patients (n = 7), and patients with erythema nodosum leprosum (ENL) (n = 6) or reversal reaction (RR) (n = 4) and controls (n = 5) were analyzed. The percentage of C3d, MAC and LAM deposition was significantly higher in the skin biopsies of multibacillary compared to paucibacillary patients (p = leprosy patients (r = 0.9578, pleprosy patients (p = leprosy patients, suggesting that inflammation driven by complement activation might contribute to nerve damage in the lesions of these patients. This should be regarded as an important factor in M. leprae nerve damage pathology.

  6. The versatile functions of complement C3-derived ligands.

    Science.gov (United States)

    Erdei, Anna; Sándor, Noémi; Mácsik-Valent, Bernadett; Lukácsi, Szilvia; Kremlitzka, Mariann; Bajtay, Zsuzsa

    2016-11-01

    The complement system is a major component of immune defense. Activation of the complement cascade by foreign substances and altered self-structures may lead to the elimination of the activating agent, and during the enzymatic cascade, several biologically active fragments are generated. Most immune regulatory effects of complement are mediated by the activation products of C3, the central component. The indispensable role of C3 in opsonic phagocytosis as well as in the regulation of humoral immune response is known for long, while the involvement of complement in T-cell biology have been revealed in the past few years. In this review, we discuss the immune modulatory functions of C3-derived fragments focusing on their role in processes which have not been summarized so far. The importance of locally synthesized complement will receive special emphasis, as several immunological processes take place in tissues, where hepatocyte-derived complement components might not be available at high concentrations. We also aim to call the attention to important differences between human and mouse systems regarding C3-mediated processes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. The Role of Complement System in Septic Shock

    Directory of Open Access Journals (Sweden)

    Jean Charchaflieh

    2012-01-01

    Full Text Available Septic shock is a critical clinical condition with a high mortality rate. A better understanding of the underlying mechanisms is important to develop effective therapies. Basic and clinical studies suggest that activation of complements in the common cascade, for example, complement component 3 (C3 and C5, is involved in the development of septic shock. The involvement of three upstream complement pathways in septic shock is more complicated. Both the classical and alternative pathways appear to be activated in septic shock, but the alternative pathway may be activated earlier than the classical pathway. Activation of these two pathways is essential to clear endotoxin. Recent investigations have shed light on the role of lectin complement pathway in septic shock. Published reports suggest a protective role of mannose-binding lectin (MBL against sepsis. Our preliminary study of MBL-associated serine protease-2 (MASP-2 in septic shock patients indicated that acute decrease of MASP-2 in the early phase of septic shock might correlate with in-hospital mortality. It is unknown whether excessive activation of these three upstream complement pathways may contribute to the detrimental effects in septic shock. This paper also discusses additional complement-related pathogenic mechanisms and intervention strategies for septic shock.

  8. On the Status of the Complementizer WAA6 in Cantonese

    Directory of Open Access Journals (Sweden)

    Ka-Wai Yeung

    2006-06-01

    Full Text Available Complementizers are generally known as function words that introduce a clausal complement, like that in English, for instance (Radford 1997. In many languages, complementizers are re-analyzed from verba dicendi, or verbs of ‘saying’ (Lord 1976; Frajzyngier 1991; Hopper and Traugott 1993; Lord 1993. This paper argues for the existence of a complementizer re-analyzed from a verb of ‘saying’ in Cantonese by providing a synchronic analysis for waa6. Waa6 has often been assumed to be a lexical verb in serial verb construction because of its following a ‘saying’ predicate or a cognitive predicate. However, this paper argues that waa6 is not always a verb, postulating that waa6 may have different meanings and subcategorizations in different situations, including waa61 meaning ‘say’ [__ (PP CP] or {__PP NP}, the transitive verb waa62 meaning ‘blame/condemn’ [__NP CP], and the complementizer waa63 selecting a clause [__ IP]. This proposal is supported by different tests, such as aspect marking and argument selection, confirming that the complementizer waa63 formally exhibits different properties from that of the verbs waa61 and waa62.

  9. Diverticulitis Diet: Can Certain Foods Trigger an Attack?

    Science.gov (United States)

    ... there trigger foods I should avoid to prevent diverticulitis attacks? Answers from Katherine Zeratsky, R.D., L. ... Actually, no specific foods are known to trigger diverticulitis attacks. And no special diet has been proved ...

  10. Information Warfare: Defining the Legal Response to An Attack

    National Research Council Canada - National Science Library

    Pottorff, James

    1999-01-01

    This paper discusses the difficulty in determining whether an information warfare attack, such as a computer virus, can be treated as an "armed attack" for purposes of national defense under the United Nations charter. As the U.S...

  11. Modelling Social-Technical Attacks with Timed Automata

    DEFF Research Database (Denmark)

    David, Nicolas; David, Alexandre; Hansen, Rene Rydhof

    2015-01-01

    Attacks on a system often exploit vulnerabilities that arise from human behaviour or other human activity. Attacks of this type, so-called socio-technical attacks, cover everything from social engineering to insider attacks, and they can have a devastating impact on an unprepared organisation....... In this paper we develop an approach towards modelling socio-technical systems in general and socio-technical attacks in particular, using timed automata and illustrate its application by a complex case study. Thanks to automated model checking and automata theory, we can automatically generate possible attacks...... in our model and perform analysis and simulation of both model and attack, revealing details about the specific interaction between attacker and victim. Using timed automata also allows for intuitive modelling of systems, in which quantities like time and cost can be easily added and analysed....

  12. Denial of Service Attack Techniques: Analysis, Implementation and Comparison

    Directory of Open Access Journals (Sweden)

    Khaled Elleithy

    2005-02-01

    Full Text Available A denial of service attack (DOS is any type of attack on a networking structure to disable a server from servicing its clients. Attacks range from sending millions of requests to a server in an attempt to slow it down, flooding a server with large packets of invalid data, to sending requests with an invalid or spoofed IP address. In this paper we show the implementation and analysis of three main types of attack: Ping of Death, TCP SYN Flood, and Distributed DOS. The Ping of Death attack will be simulated against a Microsoft Windows 95 computer. The TCP SYN Flood attack will be simulated against a Microsoft Windows 2000 IIS FTP Server. Distributed DOS will be demonstrated by simulating a distribution zombie program that will carry the Ping of Death attack. This paper will demonstrate the potential damage from DOS attacks and analyze the ramifications of the damage.

  13. Aspirin to Prevent a First Heart Attack or Stroke

    Science.gov (United States)

    ... NHLBI on Twitter. Aspirin to Prevent a First Heart Attack or Stroke Also known as aspirin primary prevention. ... if I’m taking aspirin to prevent another heart attack or stroke? The information discussed in Who may ...

  14. Heart Attack Risk Spikes After Respiratory Infection, Study Finds

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_165626.html Heart Attack Risk Spikes After Respiratory Infection, Study Finds Even ... May 16, 2017 (HealthDay News) -- The risk of heart attack increases sharply after a respiratory infection, a new ...

  15. Fatal First-Time Heart Attacks More Common in Blacks

    Science.gov (United States)

    ... gov/news/fullstory_167101.html Fatal First-Time Heart Attacks More Common in Blacks: Study Black men are ... likely than whites to die of a first heart attack, a new analysis suggests. Two out of three ...

  16. Calcium Supplements: A Risk Factor for Heart Attack?

    Science.gov (United States)

    ... factor for heart attack? I've read that calcium supplements may increase the risk of heart attack. ... D. Some doctors think it's possible that taking calcium supplements may increase your risk of a heart ...

  17. Structural Basis for the Function of Complement Component C4 within the Classical and Lectin Pathways of Complement

    DEFF Research Database (Denmark)

    Mortensen, Sofia; Kidmose, Rune Thomas; Petersen, Steen Vang

    2015-01-01

    Complement component C4 is a central protein in the classical and lectin pathways within the complement system. During activation of complement, its major fragment C4b becomes covalently attached to the surface of pathogens and altered self-tissue, where it acts as an opsonin marking the surface...... for removal. Moreover, C4b provides a platform for assembly of the proteolytically active convertases that mediate downstream complement activation by cleavage of C3 and C5. In this article, we present the crystal and solution structures of the 195-kDa C4b. Our results provide the molecular details...... of the rearrangement accompanying C4 cleavage and suggest intramolecular flexibility of C4b. The conformations of C4b and its paralogue C3b are shown to be remarkably conserved, suggesting that the convertases from the classical and alternative pathways are likely to share their overall architecture and mode...

  18. Complement receptor expression and activation of the complement cascade on B lymphocytes from patients with systemic lupus erythematosus (SLE)

    DEFF Research Database (Denmark)

    Marquart, H V; Svendsen, A; Rasmussen, J M

    1995-01-01

    It has previously been reported that the expression of the complement receptors, CR1 on erythrocytes and blood leucocytes and CR2 on B cells, is reduced in patients with SLE, and that the reduced expression of CR1 on erythrocytes is related to disease activity. We have earlier demonstrated...... that normal B cells are capable of activating the alternative pathway (AP) of complement in a CR2-dependent fashion. In this study we have investigated whether disturbances in this activity may be related to the altered phenotype of SLE B cells. Flow cytometry was used to measure expression of complement...... activation by B cells in homologous serum. Finally, we demonstrated an inverse relationship between SLE disease activity index (SLEDAI) and the expression of complement receptor 2 (CR2) on SLE B cells. Thus, determination of CR2 on B cells may emerge as an additional laboratory tool in the assessment of SLE...

  19. Research About Attacks Over Cloud Environment

    Directory of Open Access Journals (Sweden)

    Li Jie

    2017-01-01

    Full Text Available Cloud computing is expected to continue expanding in the next few years and people will start to see some of the following benefits in their real lives. Security of cloud computing environments is the set of control-based technologies and policies absolute to adhere regulatory compliance rules and protect information data applications and infrastructure related with cloud use. In this paper we suggest a model to estimating the cloud computing security and test the services provided to users. The simulator NG-Cloud Next Generation Secure Cloud Storage is used and modified to administer the proposed model. This implementation achieved security functions potential attacks as defined in the proposed model. Finally we also solve some attacks over cloud computing to provide the security and safety of the cloud.

  20. Quantum Communication Attacks on Classical Cryptographic Protocols

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre

    , one can show that the protocol remains secure even under such an attack. However, there are also cases where the honest players are quantum as well, even if the protocol uses classical communication. For instance, this is the case when classical multiparty computation is used as a “subroutine......” in quantum multiparty computation. Furthermore, in the future, players in a protocol may employ quantum computing simply to improve efficiency of their local computation, even if the communication is supposed to be classical. In such cases, it no longer seems clear that a quantum adversary must be limited......In the literature on cryptographic protocols, it has been studied several times what happens if a classical protocol is attacked by a quantum adversary. Usually, this is taken to mean that the adversary runs a quantum algorithm, but communicates classically with the honest players. In several cases...

  1. Two fatal tiger attacks in zoos.

    Science.gov (United States)

    Tantius, Britta; Wittschieber, Daniel; Schmidt, Sven; Rothschild, Markus A; Banaschak, Sibylle

    2016-01-01

    Two captive tiger attacks are presented that took place in Cologne and Münster zoos. Both attacks occurred when the handlers, intent on cleaning the enclosures, entered whilst the tigers accidently retained access to the location, and thus defended their territory against the perceived intruders. Both victims suffered fatal neck injuries from the bites. At Münster, colleagues managed to lure the tiger away from its victim to enable treatment, whilst the Cologne zoo tiger had to be shot in order to allow access to be gained. Whilst it was judged that human error led to the deaths of the experienced zookeepers, the investigation in Münster was closed as no third party was found to be at fault, whereas the Cologne zoo director was initially charged with being negligent. These charges were subsequently dismissed as safety regulations were found to be up to date.

  2. From Fault-tolerance to Attack Tolerance

    Science.gov (United States)

    2011-04-02

    AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Means to build fault - tolerant ...bottlenecks. We also implemented a distributed storage service that uses Byzantine Quo- rum Systems (rather than state machine replication) and employs...From Fault - tolerance to Attack Tolerance AFOSR Grant F9550-06-1-0019 Final Report 1 December 2005 – 30 November 2010 Fred B. Schneider Computer

  3. Collision attack against Tav-128 hash function

    Science.gov (United States)

    Hariyanto, Fajar; Hayat Susanti, Bety

    2017-10-01

    Tav-128 is a hash function which is designed for Radio Frequency Identification (RFID) authentication protocol. Tav-128 is expected to be a cryptographically secure hash function which meets collision resistance properties. In this research, a collision attack is done to prove whether Tav-128 is a collision resistant hash function. The results show that collisions can be obtained in Tav-128 hash function which means in other word, Tav-128 is not a collision resistant hash function.

  4. Fighting Through a Logistics Cyber Attack

    Science.gov (United States)

    2015-06-19

    devices through a Trojan horse program. This method is highly technical; it requires sophisticated hardware, software and a highly skilled hacker...Symantec, a leading manufacturer of anti- virus software and cybersecurity suites published a report on the economic impact of cyber-attacks (Symantec...Prior to the Egyptian’s introduction of the chariot, wars were waged primarily on foot. This horse driven cart added incredible speed on the open

  5. [Acute ischemic proctitis following an epileptic attack

    DEFF Research Database (Denmark)

    Klintmann, C.K.; Hillingso, J.G.; Glenthøj, Andreas

    2008-01-01

    Acute ischemic proctitis is a rare diagnosis mainly because the rectum is supplied by an extensive arterial network. Consequently, in more than 90% of patients with ischemic colitis the rectum is spared. Previously reported cases are related to severe vascular insufficiency of the rectal...... circulation caused by systemic atherosclerosis, usually following aortic or aortoiliac operations. We report one case of acute ischemic proctitis following an epileptic attack Udgivelsesdato: 2008/9/29...

  6. SQL Injection - Database Attack Revolution and Prevention

    OpenAIRE

    Dorai, Ramakanth; Kannan, Vinod

    2011-01-01

    SQL injection came with a bang and caused revolution in database attacking. In recent years, with the explosion in web-based commerce and information systems, databases have been drawing ever closer to the network and it is critical part of network security. This paper is incorporated with our research and firsthand experience in hacking the database by SQL injection. Database is the Storage Brain of a website. A hacked database is the source for Passwords and juicy information like credit ca...

  7. Finding Effective Responses Against Cyber Attacks for Divided Nations

    Science.gov (United States)

    2015-12-01

    Training and Exercise Center CSTIA Central Science and Technology Information Agency DDoS Distributed Denial of Service DNS Domain Name Server DOD...computers in 2004 and Distributed Denial of Service ( DDoS ) attacks in 2009, were attributed to North Korea. North Korea has attacked not only government...President Roh to Lee, North Korea intensified both their criticisms and attacks. In 2009, they conducted extensive DDoS attacks on South Korea and

  8. Randomized, controlled trial of telcagepant over four migraine attacks

    DEFF Research Database (Denmark)

    Ho, Andrew P; Dahlöf, Carl Gh; Silberstein, Stephen D

    2010-01-01

    This study evaluated the calcitonin gene-related peptide (CGRP) receptor antagonist telcagepant (tablet formulation) for treatment of a migraine attack and across four attacks. Adults with migraine were randomized, double-blind, to telcagepant 140 mg, telcagepant 280 mg, or control treatment sequ...... was defined as ≥ 3 successes, and lack of consistent efficacy was defined as ≥ 2 failures, in treatment response. A total of 1677 patients treated ≥ 1 attack and 1263 treated all four attacks....

  9. Cigarette smoke can activate the alternative pathway of complement in vitro by modifying the third component of complement.

    OpenAIRE

    Kew, R R; Ghebrehiwet, B; Janoff, A

    1985-01-01

    Cigarette smoking is associated with significant increases in the number of pulmonary mononuclear phagocytes and neutrophils. A potent chemoattractant for these cells is C5a, a peptide generated during complement (C) activation. We, therefore, investigated the possibility that cigarette smoke could activate the complement system in vitro. Our results show that factor(s) (mol wt less than 1,000) present in an aqueous solution of whole, unfiltered cigarette smoke can deplete the hemolytic capac...

  10. Plaque complement activation and cognitive loss in Alzheimer's disease

    Science.gov (United States)

    Loeffler, David A; Camp, Dianne M; Bennett, David A

    2008-01-01

    Background Complement activation is increased in Alzheimer's disease (AD), but its significance is unclear. The objective of this study was to determine the relationship between complement activation and cognition during the development of AD. Methods iC3b, C9, Bielschowsky, and Gallyas staining was performed on aged normal (n = 17), mild cognitively impaired (n = 12), and AD (n = 17–18) inferior temporal gyrus specimens. Plaques were counted in 10× fields with high numbers of Bielschowsky-stained plaques. One-way ANOVA was used to determine between-group differences for plaque counts and measures of cognitive function, and linear regression was used to evaluate global cognition as a function of Bielschowsky-stained plaques. Terms for iC3b- and C9-stained plaques were then added sequentially as additional predictors in a "mediation analysis" model. Results Complement was detected on plaques in all groups, and on neurofibrillary tangles only in AD specimens. iC3b, C9, and Bielschowsky-stained plaque counts increased 2.5- to 3-fold in AD vs. other groups (all p ≤ 0.01). C9 staining was present on some diffuse plaques, as well as on neuritic plaques. Bielschowsky-stained and complement-stained plaque counts were highly correlated, and were negatively correlated with cognitive measures. When the Bielschowsky plaque count was used as a predictor, its correlations with cognitive measures were statistically significant, but when iC3b and C9 plaque counts were added as additional predictors, these correlations were no longer significant. This loss of significance was attributed to multicollinearity, i.e., high correlations between Bielschowsky-stained and complement-stained plaque counts. Conclusion Both early-stage (iC3b) and late-stage (C9) complement activation occurs on neocortical plaques in subjects across the cognitive spectrum; contrary to previous reports, C9 is present on some diffuse plaques. Because of high correlations between complement-stained and

  11. HIV-1 evades virus-specific IgG2 and IgA responses by targeting systemic and intestinal B cells via long-range intercellular conduits.

    Science.gov (United States)

    Xu, Weifeng; Santini, Paul A; Sullivan, John S; He, Bing; Shan, Meimei; Ball, Susan C; Dyer, Wayne B; Ketas, Thomas J; Chadburn, Amy; Cohen-Gould, Leona; Knowles, Daniel M; Chiu, April; Sanders, Rogier W; Chen, Kang; Cerutti, Andrea

    2009-09-01

    Contact-dependent communication between immune cells generates protection but also facilitates viral spread. Here we found that macrophages formed long-range actin-propelled conduits in response to negative factor (Nef), a human immunodeficiency virus type 1 (HIV-1) protein with immunosuppressive functions. Conduits attenuated immunoglobulin G2 (IgG2) and IgA class switching in systemic and intestinal lymphoid follicles by shuttling Nef from infected macrophages to B cells through a guanine-exchange factor-dependent pathway involving the amino-terminal anchor, central core and carboxy-terminal flexible loop of Nef. By showing stronger virus-specific IgG2 and IgA responses in patients with Nef-deficient virions, our data suggest that HIV-1 exploits intercellular 'highways' as a 'Trojan horse' to deliver Nef to B cells and evade humoral immunity systemically and at mucosal sites of entry.

  12. Fuzzy Expert System for Heart Attack Diagnosis

    Science.gov (United States)

    Hassan, Norlida; Arbaiy, Nureize; Shah, Noor Aziyan Ahmad; Afizah Afif@Afip, Zehan

    2017-08-01

    Heart attack is one of the serious illnesses and reported as the main killer disease. Early prevention is significant to reduce the risk of having the disease. The prevention efforts can be strengthen through awareness and education about risk factor and healthy lifestyle. Therefore the knowledge dissemination is needed to play role in order to distribute and educate public in health care management and disease prevention. Since the knowledge dissemination in medical is important, there is a need to develop a knowledge based system that can emulate human intelligence to assist decision making process. Thereby, this study utilized hybrid artificial intelligence (AI) techniques to develop a Fuzzy Expert System for Diagnosing Heart Attack Disease (HAD). This system integrates fuzzy logic with expert system, which helps the medical practitioner and people to predict the risk and as well as diagnosing heart attack based on given symptom. The development of HAD is expected not only providing expert knowledge but potentially become one of learning resources to help citizens to develop awareness about heart-healthy lifestyle.

  13. Smoking behaviour under intense terrorist attacks.

    Science.gov (United States)

    Keinan-Boker, Lital; Kohn, Robert; Billig, Miriam; Levav, Itzhak

    2011-06-01

    Smoking is one of the varied psychological reactions to stress. This study examined the rate and changes in cigarette smoking among former Gaza and current West Bank Jewish settlers subjected to direct and indirect terrorist attacks during the Al-Aksa Intifada. The relationship with degree of religious observance and emotional distress was explored as well. In this cross-sectional study, the respondents were settlers randomly selected and interviewed by telephone (N = 706). The interview schedule included socio-demographic items, information on direct exposure to terrorist attacks (e.g. threat to life or physical integrity, personal losses, property damage) and on steady and changes in smoking habits, and a scale to measure emotional distress. In contrast with the country population, a larger percentage of settlers who smoked increased the number of cigarettes consumed with exposure to terrorism (10 and 27%, respectively). Respondents who were injured or had their home damaged reported a higher rate of smoking during the preceding year (30 and 20%, respectively). Emotional distress was related to cigarette smoking, but not in the controlled analysis. Religious observance had no effect. Direct or indirect exposure to terrorist attacks had an impact on smoking prevalence rates and on changes in smoking habits. Studies investigating reactions to traumatic events should include a detailed section on smoking while mental health interventions should address the needs of smokers.

  14. STAR Performance with SPEAR (Signal Processing Electronic Attack RFIC)

    Science.gov (United States)

    2017-03-01

    STAR Performance with SPEAR ( Signal Processing Electronic Attack RFIC) Luciano Boglione, Clayton Davis, Joel Goodman, Matthew McKeon, David...Parrett, Sanghoon Shin and Naomi Walker Naval Research Laboratory Washington, DC, 20375 Figure 1: The Signal Processing Electronic Attack RFIC...SPEAR) system. Abstract: The Signal Processing Electronic Attack RFIC (SPEAR) is a simultaneous transmit and receive (STAR) system capable of

  15. Pareto Efficient Solution of Attack-Defence Trees

    NARCIS (Netherlands)

    Aslanyan, Zaruhi; Nielson, Flemming

    Attack-defence trees are a promising approach for representing threat scenarios and possible countermeasures in a concise and intuitive manner. An attack-defence tree describes the interaction between an attacker and a defender, and is evaluated by assigning parameters to the nodes, such as

  16. Quantitative Attack Tree Analysis via Priced Timed Automata

    NARCIS (Netherlands)

    Kumar, Rajesh; Ruijters, Enno Jozef Johannes; Stoelinga, Mariëlle Ida Antoinette; Sankaranarayanan, Sriram; Vicario, Enrico

    The success of a security attack crucially depends on the resources available to an attacker: time, budget, skill level, and risk appetite. Insight in these dependencies and the most vulnerable system parts is key to providing effective counter measures. This paper considers attack trees, one of the

  17. Modeling and Analysis of Information Attack in Computer Networks

    National Research Council Canada - National Science Library

    Pepyne, David

    2003-01-01

    ... (as opposed to physical and other forms of attack) . Information based attacks are attacks that can be carried out from anywhere in the world, while sipping cappuccino at an Internet cafe' or while enjoying the comfort of a living room armchair...

  18. Vulnerability Assessment by Learning Attack Specifications in Graphs

    NARCIS (Netherlands)

    Nunes Leal Franqueira, V.; Lopes, Raul H.C.

    This paper presents an evolutionary approach for learning attack specifications that describe attack scenarios. The objective is to find vulnerabilities in computer networks which minimise the cost of an attack with maximum impact. Although we focus on Insider Threat, the proposed approach applies

  19. Complement activation and interleukin response in major abdominal surgery.

    Science.gov (United States)

    Kvarnström, A L; Sarbinowski, R T; Bengtson, J-P; Jacobsson, L M; Bengtsson, A L

    2012-05-01

    The objective of this study was to evaluate whether major abdominal surgery leads to complement activation and interleukin response and whether the kind of anaesthesia influence complement activation and the release of inflammatory interleukins. The study design was prospective and randomised. Fifty patients undergoing open major colorectal surgery due to cancer disease or inflammatory bowel disease were studied. Twenty-five patients were given total intravenous anaesthesia (TIVA) with propofol and remifentanil, and 25 patients were given inhalational anaesthesia with sevoflurane and fentanyl. To determine complement activation (C3a and SC5b-9) and the release of pro- and anti-inflammatory interleukins (tumour necrosis factor-a (TNF-a)), interleukin-1b (IL-1b), IL-6, IL-8, IL-4 and IL-10), blood samples were drawn preoperatively, 60 minutes after start of surgery, 30 minutes after end of surgery and 24 hours postoperatively. Complement was activated and pro-inflammatory interleukins (IL-6 and IL-8) and anti-inflammatory interleukins (IL-10) were released during major colorectal surgery. There was no significant difference between TIVA and inhalational anaesthesia regarding complement activation and cytokine release. Major colorectal surgery leads to activation of the complement cascade and the release of both pro-inflammatory and anti-inflammatory cytokines. There are no significant differences between total intravenous anaesthesia (TIVA) with propofol and remifentanil and inhalational anaesthesia with sevoflurane and fentanyl regarding complement activation and the release of pro- and anti-inflammatory interleukins. © 2012 The Authors. Scandinavian Journal of Immunology © 2012 Blackwell Publishing Ltd. Scandinavian Journal of Immunology.

  20. Effects of Streptococcus pneumoniae strain background on complement resistance.

    Directory of Open Access Journals (Sweden)

    Catherine Hyams

    Full Text Available BACKGROUND: Immunity to infections caused by Streptococcus pneumoniae is dependent on complement. There are wide variations in sensitivity to complement between S. pneumoniae strains that could affect their ability to cause invasive infections. Although capsular serotype is one important factor causing differences in complement resistance between strains, there is also considerable other genetic variation between S. pneumoniae strains that may affect complement-mediated immunity. We have therefore investigated whether genetically distinct S. pneumoniae strains with the same capsular serotype vary in their sensitivity to complement mediated immunity. METHODOLOGY AND PRINCIPAL FINDINGS: C3b/iC3b deposition and neutrophil association were measured using flow cytometry assays for S. pneumoniae strains with different genetic backgrounds for each of eight capsular serotypes. For some capsular serotypes there was marked variation in C3b/iC3b deposition between different strains that was independent of capsule thickness and correlated closely to susceptibility to neutrophil association. C3b/iC3b deposition results also correlated weakly with the degree of IgG binding to each strain. However, the binding of C1q (the first component of the classical pathway correlated more closely with C3b/iC3b deposition, and large differences remained in complement sensitivity between strains with the same capsular serotype in sera in which IgG had been cleaved with IdeS. CONCLUSIONS: These data demonstrate that bacterial factors independent of the capsule and recognition by IgG have strong effects on the susceptibility of S. pneumoniae to complement, and could therefore potentially account for some of the differences in virulence between strains.