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Sample records for host defence signaling

  1. Post-translational modification of host proteins in pathogen-triggered defence signalling in plants

    NARCIS (Netherlands)

    Stulemeijer, I.J.E.; Joosten, M.H.A.J.

    2008-01-01

    Microbial plant pathogens impose a continuous threat to global food production. Similar to animals, an innate immune system allows plants to recognize pathogens and swiftly activate defence. To activate a rapid response, receptor-mediated pathogen perception and subsequent downstream signalling

  2. Host defence peptides in human burns.

    Science.gov (United States)

    Kaus, Aljoscha; Jacobsen, Frank; Sorkin, Michael; Rittig, Andrea; Voss, Bruno; Daigeler, Adrien; Sudhoff, Holger; Steinau, Hans-Ulrich; Steinstraesser, Lars

    2008-02-01

    The goal of this study was to analyse expression profiles of human epithelial host defence peptides in burned and unburned skin tissue, samples of which were obtained during debridements and snap-frozen in liquid nitrogen. Total RNA was isolated, and cDNA of epithelial host defence peptides and proteins (hCAP-18/LL-37, hBD1-hBD4, dermcidin, S100A7/psoriasin and RNAse7) was quantified by qRT-PCR. In situ hybridisation and immunohistochemical staining localised gene expression of hCAP-18/LL-37, hBD2 and hBD3 in histological sections. Most of the analysed host defence peptides and proteins showed higher mRNA levels in partial-thickness burns than in unburned tissue. In situ hybridisation revealed expression of hCAP-18/LL-37, hBD2 and hBD3 at the surface of burns that was independent of burn depth. However, the finding of higher host defence peptide gene expression rates does not correlate with the incidence of wound infection in burns. We hypothesise that the epithelial innate immune response in burns is complex.

  3. Host Defence to Pulmonary Mycosis

    Directory of Open Access Journals (Sweden)

    Christopher H Mody

    1999-01-01

    Full Text Available OBJECTIVE: To provide a basic understanding of the mechanisms of host defense to pathogenic fungi. This will help physicians understand why some patients are predisposed to fungal infections and update basic scientists on how microbial immunology applies to fungal disease.

  4. A cellular backline: specialization of host membranes for defence.

    Science.gov (United States)

    Faulkner, Christine

    2015-03-01

    In plant-pathogen interactions, the host plasma membrane serves as a defence front for pathogens that invade from the extracellular environment. As such, the lipid bilayer acts as a scaffold that targets and delivers defence responses to the site of attack. During pathogen infection, numerous changes in plasma membrane composition, organization, and structure occur. There is increasing evidence that this facilitates the execution of a variety of responses, highlighting the regulatory role membranes play in cellular responses. Membrane microdomains such as lipid rafts are hypothesized to create signalling platforms for receptor signalling in response to pathogen perception and for callose synthesis. Further, the genesis of pathogen-associated structures such as papillae and the extra-haustorial membrane necessitates polarization of membranes and membrane trafficking pathways. Unlocking the mechanisms by which this occurs will enable greater understanding of how targeted defences, some of which result in resistance, are executed. This review will survey some of the changes that occur in host membranes during pathogen attack and how these are associated with the generation of defence responses. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  5. Long-distance signalling in plant defence.

    Science.gov (United States)

    Heil, Martin; Ton, Jurriaan

    2008-06-01

    Plants use inducible defence mechanisms to fend off harmful organisms. Resistance that is induced in response to local attack is often expressed systemically, that is, in organs that are not yet damaged. In the search for translocated defence signals, biochemical studies follow the physical movement of putative signals, and grafting experiments use mutants that are impaired in the production or perception of these signals. Long-distance signals can directly activate defence or can prime for the stronger and faster induction of defence. Historically, research has focused on the vascular transport of signalling metabolites, but volatiles can play a crucial role as well. We compare the advantages and constraints of vascular and airborne signals for the plant, and discuss how they can act in synergy to achieve optimised resistance in distal plant parts.

  6. IL-1RI (Interleukin-1 Receptor Type I Signalling is Essential for Host Defence and Hemichannel Activity During Acute Central Nervous System Bacterial Infection

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    Juan Xiong

    2012-03-01

    Full Text Available Staphylococcus aureus is a common aetiological agent of bacterial brain abscesses. We have previously established that a considerable IL-1 (interleukin-1 response is elicited immediately following S. aureus infection, where the cytokine can exert pleiotropic effects on glial activation and blood–brain barrier permeability. To assess the combined actions of IL-1α and IL-1β during CNS (central nervous system infection, host defence responses were evaluated in IL-1RI (IL-1 receptor type I KO (knockout animals. IL-1RI KO mice were exquisitely sensitive to intracerebral S. aureus infection, as demonstrated by enhanced mortality rates and bacterial burdens within the first 24 h following pathogen exposure compared with WT (wild-type animals. Loss of IL-1RI signalling also dampened the expression of select cytokines and chemokines, concomitant with significant reductions in neutrophil and macrophage infiltrates into the brain. In addition, the opening of astrocyte hemichannels during acute infection was shown to be dependent on IL-1RI activity. Collectively, these results demonstrate that IL-1RI signalling plays a pivotal role in the genesis of immune responses during the acute stage of brain abscess development through S. aureus containment, inflammatory mediator production, peripheral immune cell recruitment, and regulation of astrocyte hemichannel activity. Taken in the context of previous studies with MyD88 (myeloid differentiation primary response gene 88 and TLR2 (Toll-like receptor 2 KO animals, the current report advances our understanding of MyD88-dependent cascades and implicates IL-1RI signalling as a major antimicrobial effector pathway during acute brain-abscess formation.

  7. Shaping Baltic States Defence Strategy: Host Nation Support

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    Otzulis Valdis

    2017-12-01

    Full Text Available The presence of NATO troops in the Baltic states has increased in the last years due to changing international environment, increased level of potential risks and threats, and necessity to enhance deterrence in the region. As a result of NATO’s Wales and Warsaw summits decisions, Estonia, Latvia, and Lithuania are entitled to host a battalion size battle group. The article aims at investigating how host nation support (HNS can contribute to the national defence and, additionally, to the self-defence capabilities of the Baltic states. The concept of HNS is present in the national defence concepts of all three countries. However, its active application and utilization started in the last two years. The article argues that more intensive incorporation of an HNS system in national defence policies serve the capability development in fields like national military logistics, infrastructure, and civil-military cooperation. Those capabilities can serve as an extension of the national defence.

  8. Post-secretory fate of host defence components in mucus.

    Science.gov (United States)

    Salathe, Matthias; Forteza, Rosanna; Conner, Gregory E

    2002-01-01

    Airway mucus is a complex mixture of secretory products that provide a multifaceted defence against infection. Among many antimicrobial substances, mucus contains a peroxidase identical to milk lactoperoxidase (LPO) that is produced by goblet cells and submucosal glands. Airway secretions contain the substrates for LPO, namely thiocyanate and hydrogen peroxide, at concentrations sufficient for production of the biocidal compound hypothiocyanite, a fact confirmed by us in vitro. In vivo, inhibition of airway LPO in sheep significantly inhibits bacterial clearance, suggesting that the LPO system is a major contributor to host defences. Since secretory products including LPO are believed to be steadily removed by mucociliary clearance, their amount and availability on the surface is thought to be controlled solely by secretion. In contrast to this paradigm, new data suggest that LPO and other substances are retained at the ciliary border of the airway epithelium by binding to surface-associated hyaluronan, thereby providing an apical, fully active enzyme pool. Thus, hyaluronan, secreted from submucosal gland cells, plays a previously unrecognized pivotal role in mucosal host defence by retaining LPO and possibly other substances important for first line host defence at the apical surface 'ready for use' and protected from ciliary clearance.

  9. Leaf Colour as a Signal of Chemical Defence to Insect Herbivores in Wild Cabbage (Brassica oleracea.

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    Jonathan P Green

    Full Text Available Leaf colour has been proposed to signal levels of host defence to insect herbivores, but we lack data on herbivory, leaf colour and levels of defence for wild host populations necessary to test this hypothesis. Such a test requires measurements of leaf spectra as they would be sensed by herbivore visual systems, as well as simultaneous measurements of chemical defences and herbivore responses to leaf colour in natural host-herbivore populations. In a large-scale field survey of wild cabbage (Brassica oleracea populations, we show that variation in leaf colour and brightness, measured according to herbivore spectral sensitivities, predicts both levels of chemical defences (glucosinolates and abundance of specialist lepidopteran (Pieris rapae and hemipteran (Brevicoryne brassicae herbivores. In subsequent experiments, P. rapae larvae achieved faster growth and greater pupal mass when feeding on plants with bluer leaves, which contained lower levels of aliphatic glucosinolates. Glucosinolate-mediated effects on larval performance may thus contribute to the association between P. rapae herbivory and leaf colour observed in the field. However, preference tests found no evidence that adult butterflies selected host plants based on leaf coloration. In the field, B. brassicae abundance varied with leaf brightness but greenhouse experiments were unable to identify any effects of brightness on aphid preference or performance. Our findings suggest that although leaf colour reflects both levels of host defences and herbivore abundance in the field, the ability of herbivores to respond to colour signals may be limited, even in species where performance is correlated with leaf colour.

  10. The vaginal microbiota, host defence and reproductive physiology

    Science.gov (United States)

    Smith, Steven B

    2016-01-01

    Abstract The interaction between the human host and the vaginal microbiota is highly dynamic. Major changes in the vaginal physiology and microbiota over a woman's lifetime are largely shaped by transitional periods such as puberty, menopause and pregnancy, while daily fluctuations in microbial composition observed through culture‐independent studies are more likely to be the results of daily life activities and behaviours. The vaginal microbiota of reproductive‐aged women is largely made up of at least five different community state types. Four of these community state types are dominated by lactic‐acid producing Lactobacillus spp. while the fifth is commonly composed of anaerobes and strict anaerobes and is sometimes associated with vaginal symptoms. The production of lactic acid has been associated with contributing to the overall health of the vagina due to its direct and indirect effects on pathogens and host defence. Some species associated with non‐Lactobacillus vaginal microbiota may trigger immune responses as well as degrade the host mucosa, processes that ultimately increase susceptibility to infections and contribute to negative reproductive outcomes such as infertility and preterm birth. Further studies are needed to better understand the functional underpinnings of how the vaginal microbiota affect host physiology but also how host physiology affects the vaginal microbiota. Understanding this fine‐tuned interaction is key to maintaining women's reproductive health. PMID:27373840

  11. The vaginal microbiota, host defence and reproductive physiology.

    Science.gov (United States)

    Smith, Steven B; Ravel, Jacques

    2017-01-15

    The interaction between the human host and the vaginal microbiota is highly dynamic. Major changes in the vaginal physiology and microbiota over a woman's lifetime are largely shaped by transitional periods such as puberty, menopause and pregnancy, while daily fluctuations in microbial composition observed through culture-independent studies are more likely to be the results of daily life activities and behaviours. The vaginal microbiota of reproductive-aged women is largely made up of at least five different community state types. Four of these community state types are dominated by lactic-acid producing Lactobacillus spp. while the fifth is commonly composed of anaerobes and strict anaerobes and is sometimes associated with vaginal symptoms. The production of lactic acid has been associated with contributing to the overall health of the vagina due to its direct and indirect effects on pathogens and host defence. Some species associated with non-Lactobacillus vaginal microbiota may trigger immune responses as well as degrade the host mucosa, processes that ultimately increase susceptibility to infections and contribute to negative reproductive outcomes such as infertility and preterm birth. Further studies are needed to better understand the functional underpinnings of how the vaginal microbiota affect host physiology but also how host physiology affects the vaginal microbiota. Understanding this fine-tuned interaction is key to maintaining women's reproductive health. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  12. Collective defence portfolios of ant hosts shift with social parasite pressure.

    Science.gov (United States)

    Jongepier, Evelien; Kleeberg, Isabelle; Job, Sylwester; Foitzik, Susanne

    2014-09-22

    Host defences become increasingly costly as parasites breach successive lines of defence. Because selection favours hosts that successfully resist parasitism at the lowest possible cost, escalating coevolutionary arms races are likely to drive host defence portfolios towards ever more expensive strategies. We investigated the interplay between host defence portfolios and social parasite pressure by comparing 17 populations of two Temnothorax ant species. When successful, collective aggression not only prevents parasitation but also spares host colonies the cost of searching for and moving to a new nest site. However, once parasites breach the host's nest defence, host colonies should resort to flight as the more beneficial resistance strategy. We show that under low parasite pressure, host colonies more likely responded to an intruding Protomognathus americanus slavemaker with collective aggression, which prevented the slavemaker from escaping and potentially recruiting nest-mates. However, as parasite pressure increased, ant colonies of both host species became more likely to flee rather than to fight. We conclude that host defence portfolios shift consistently with social parasite pressure, which is in accordance with the degeneration of frontline defences and the evolution of subsequent anti-parasite strategies often invoked in hosts of brood parasites. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  13. Signalling network construction for modelling plant defence response.

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    Dragana Miljkovic

    Full Text Available Plant defence signalling response against various pathogens, including viruses, is a complex phenomenon. In resistant interaction a plant cell perceives the pathogen signal, transduces it within the cell and performs a reprogramming of the cell metabolism leading to the pathogen replication arrest. This work focuses on signalling pathways crucial for the plant defence response, i.e., the salicylic acid, jasmonic acid and ethylene signal transduction pathways, in the Arabidopsis thaliana model plant. The initial signalling network topology was constructed manually by defining the representation formalism, encoding the information from public databases and literature, and composing a pathway diagram. The manually constructed network structure consists of 175 components and 387 reactions. In order to complement the network topology with possibly missing relations, a new approach to automated information extraction from biological literature was developed. This approach, named Bio3graph, allows for automated extraction of biological relations from the literature, resulting in a set of (component1, reaction, component2 triplets and composing a graph structure which can be visualised, compared to the manually constructed topology and examined by the experts. Using a plant defence response vocabulary of components and reaction types, Bio3graph was applied to a set of 9,586 relevant full text articles, resulting in 137 newly detected reactions between the components. Finally, the manually constructed topology and the new reactions were merged to form a network structure consisting of 175 components and 524 reactions. The resulting pathway diagram of plant defence signalling represents a valuable source for further computational modelling and interpretation of omics data. The developed Bio3graph approach, implemented as an executable language processing and graph visualisation workflow, is publically available at http://ropot.ijs.si/bio3graph/and can be

  14. The cytoskeleton in cell-autonomous immunity: structural determinants of host defence

    Science.gov (United States)

    Mostowy, Serge; Shenoy, Avinash R.

    2016-01-01

    Host cells use antimicrobial proteins, pathogen-restrictive compartmentalization and cell death in their defence against intracellular pathogens. Recent work has revealed that four components of the cytoskeleton — actin, microtubules, intermediate filaments and septins, which are well known for their roles in cell division, shape and movement — have important functions in innate immunity and cellular self-defence. Investigations using cellular and animal models have shown that these cytoskeletal proteins are crucial for sensing bacteria and for mobilizing effector mechanisms to eliminate them. In this Review, we highlight the emerging roles of the cytoskeleton as a structural determinant of cell-autonomous host defence. PMID:26292640

  15. Bacteriophages use hypermodified nucleosides to evade host's defence systems

    DEFF Research Database (Denmark)

    Kot, Witold; Olsen, Nikoline S.; Carstens, Alexander Byth

    developed several strategies to evade these defence mechanisms. Ultimately, this led to the oldest and still running arms race - microorganisms vs. their molecular parasites. We here describe a remarkable new strategy used by the recently isolated Escherichia coli phage CAjan belonging to...... to investigate this mechanism in detail we have used several methods including direct plaque sequencing, restriction endonuclease analysis and CRISPR-Cas genome editing. Through generation of specific mutants, we were able to introduce a restriction sensitive phenotype in the CAjan bacteriophage providing new...

  16. Evolution of host innate defence: insights from Caenorhabditis elegans and primitive invertebrates.

    Science.gov (United States)

    Irazoqui, Javier E; Urbach, Jonathan M; Ausubel, Frederick M

    2010-01-01

    The genetically tractable model organism Caenorhabditis elegans was first used to model bacterial virulence in vivo a decade ago. Since then, great strides have been made in identifying the host response pathways that are involved in its defence against infection. Strikingly, C. elegans seems to detect, and respond to, infection without the involvement of its homologue of Toll-like receptors, in contrast to the well-established role for these proteins in innate immunity in mammals. What, therefore, do we know about host defence mechanisms in C. elegans and what can they tell us about innate immunity in higher organisms?

  17. Evolution of host innate defence: insights from C. elegans and primitive invertebrates

    Science.gov (United States)

    Irazoqui, Javier E.; Urbach, Jonathan M.; Ausubel, Frederick M.

    2010-01-01

    Preface The genetically tractable model organism Caenorhabditis elegans was first used to model bacterial virulence in vivo a decade ago. Since then, great strides have been made in the identification of host response pathways that are involved in the defence against infection. Strikingly, C. elegans seems to detect and respond to infection without the involvement of its Toll-like receptor homologue, in contrast to the well-established role for these proteins in innate immunity in mammals. What, therefore, do we know about host defence mechanisms in C. elegans, and what can they tell us about innate immunity in higher organisms? PMID:20029447

  18. In Vitro Activities against Cystic Fibrosis Pathogens of Synthetic Host Defence Propeptides Processed by Neutrophil Elastase.

    LENUS (Irish Health Repository)

    Desgranges, Stephane

    2011-02-22

    The antimicrobial and haemolytic activities of a host defence peptide can be controlled by modification as a propeptide of reduced net charge which can be processed by neutrophil elastase, a serine protease involved in chronic airway inflammation and infections associated with cystic fibrosis.

  19. Mechanisms involved in the evasion of the host defence by Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Kharazmi, A

    1991-01-01

    Pseudomonas aeruginosa, an extracellular opportunistic pathogen, utilizes two major mechanisms to evade the host defence system. One of these mechanisms is the production of a large number of extracellular products, such as proteases, toxins, and lipases. The two proteases, alkaline protease and ...

  20. Pathogenesis and host defence against Mucorales: the role of cytokines and interaction with antifungal drugs.

    Science.gov (United States)

    Roilides, Emmanuel; Antachopoulos, Charalampos; Simitsopoulou, Maria

    2014-12-01

    Innate immune response, including macrophages, neutrophils and dendritic cells and their respective receptors, plays an important role in host defences against Mucorales with differential activity against specific fungal species, while adaptive immunity is not the first line of defence. A number of endogenous and exogenous factors, such as cytokines and growth factors as well as certain antifungal agents have been found that they influence innate immune response to these organisms. Used alone or especially in combination have been shown to exert antifungal effects against Mucorales species. These findings suggest novel ways of adjunctive therapy for patients with invasive mucormycosis. © 2014 Blackwell Verlag GmbH.

  1. A SNARE-protein has opposing functions in penetration resistance and defence signalling pathways

    DEFF Research Database (Denmark)

    Zhang, Ziguo; Feechan, Angela; Pedersen, Carsten

    2007-01-01

    Penetration resistance is often the first line of defence against fungal pathogens. Subsequently induced defences are mediated by the programmed cell death (PCD) reaction pathway and the salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) signalling pathways. We previously demonstrated...

  2. Host ploidy, parasitism and immune defence in a coevolutionary snail-trematode system.

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    Osnas, E E; Lively, C M

    2006-01-01

    We studied the role of host ploidy and parasite exposure on immune defence allocation in a snail-trematode system (Potamopyrgus antipodarum-Microphallus sp.). In the field, haemocyte (the defence cell) concentration was lowest in deep-water habitats where infection is relatively low and highest in shallow-water habitats where infection is common. Because the frequency of asexual triploid snails is positively correlated with depth, we also experimentally studied the role of ploidy by exposing both diploid sexual and triploid asexual snails to Microphallus eggs. We found that triploid snails had lower haemocyte concentrations than did diploids in both parasite-addition and parasite-free treatments. We also found that both triploids and diploids increased their numbers of large granular haemocytes at similar rates after parasite exposure. Because triploid P. antipodarum have been shown to be more resistant to allopatric parasites than diploids, the current results suggest that the increased resistance of triploids is because of intrinsic genetic properties rather than to greater allocation to defence cells. This finding is consistent with recent theory on the advantages of increased ploidy for hosts combating coevolving parasites.

  3. Quorum-Sensing Blockade As A Strategy for Enhancing Host Defences Against Bacterial Pathogens

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Givskov, Michael Christian

    2007-01-01

    Conventional antibiotics target the growth and the basal life processes of bacteria leading to growth arrest and cell death. The selective force that is inherently linked to this mode of action eventually selects out antibiotic-resistant variants. The most obvious alternative to antibiotic...... rise to a new 'drug target rush'. Recently, QS has been shown to be involved in the development of tolerance to various antimicrobial treatments and immune modulation. The regulation of virulence via QS confers a strategic advantage over host defences. Consequently, a drug capable of blocking QS...

  4. Quorum-sensing blockade as a strategy for enhancing host defences against bacterial pathogens

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Givskov, Michael Christian

    2007-01-01

    Conventional antibiotics target the growth and the basal life processes of bacteria leading to growth arrest and cell death. The selective force that is inherently linked to this mode of action eventually selects out antibiotic-resistant variants. The most obvious alternative to antibiotic...... rise to a new 'drug target rush'. Recently, QS has been shown to be involved in the development of tolerance to various antimicrobial treatments and immune modulation. The regulation of virulence via QS confers a strategic advantage over host defences. Consequently, a drug capable of blocking QS...

  5. Combining personal with social information facilitates host defences and explains why cuckoos should be secretive

    Science.gov (United States)

    Thorogood, Rose; Davies, Nicholas B.

    2016-01-01

    Individuals often vary defences in response to local predation or parasitism risk. But how should they assess threat levels when it pays their enemies to hide? For common cuckoo hosts, assessing parasitism risk is challenging: cuckoo eggs are mimetic and adult cuckoos are secretive and resemble hawks. Here, we show that egg rejection by reed warblers depends on combining personal and social information of local risk. We presented model cuckoos or controls at a pair’s own nest (personal information of an intruder) and/or on a neighbouring territory, to which they were attracted by broadcasts of alarm calls (social information). Rejection of an experimental egg was stimulated only when hosts were alerted by both social and personal information of cuckoos. However, pairs that rejected eggs were not more likely to mob a cuckoo. Therefore, while hosts can assess risk from the sight of a cuckoo, a cuckoo cannot gauge if her egg will be accepted from host mobbing. Our results reveal how hosts respond rapidly to local variation in parasitism, and why it pays cuckoos to be secretive, both to avoid alerting their targets and to limit the spread of social information in the local host neighbourhood. PMID:26794435

  6. Plant parasitic nematode effectors target host defence and nuclear functions to establish feeding cells

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    Michaël eQuentin

    2013-03-01

    Full Text Available Plant parasitic nematodes are microscopic worms, the most damaging species of which have adopted a sedentary lifestyle within their hosts. These obligate endoparasites have a biotrophic relationship with plants, in which they induce the differentiation of root cells into hypertrophied, multinucleate feeding cells. Effectors synthesised in the oesophageal glands of the nematode are injected into the plant cells via the syringe-like stylet and play a key role in manipulating the host machinery. The establishment of specialized feeding cells requires these effectors to modulate many aspects of plant cell morphogenesis and physiology, including defence responses. This cell reprogramming requires changes to host nuclear processes. Some proteins encoded by parasitism genes target host nuclei. Several of these proteins were immunolocalised within feeding cell nuclei or shown to interact with host nuclear proteins. Comparative genomics and functional analyses are gradually revealing the roles of nematode effectors. We describe here these effectors and their hypothesised roles in the unique feeding behaviour of these pests.

  7. The Xanthomonas campestris type III effector XopJ targets the host cell proteasome to suppress salicylic-acid mediated plant defence.

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    Suayib Üstün

    Full Text Available The phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria (Xcv requires type III effector proteins (T3Es for virulence. After translocation into the host cell, T3Es are thought to interact with components of host immunity to suppress defence responses. XopJ is a T3E protein from Xcv that interferes with plant immune responses; however, its host cellular target is unknown. Here we show that XopJ interacts with the proteasomal subunit RPT6 in yeast and in planta to inhibit proteasome activity. A C235A mutation within the catalytic triad of XopJ as well as a G2A exchange within the N-terminal myristoylation motif abolishes the ability of XopJ to inhibit the proteasome. Xcv ΔxopJ mutants are impaired in growth and display accelerated symptom development including tissue necrosis on susceptible pepper leaves. Application of the proteasome inhibitor MG132 restored the ability of the Xcv ΔxopJ to attenuate the development of leaf necrosis. The XopJ dependent delay of tissue degeneration correlates with reduced levels of salicylic acid (SA and changes in defence- and senescence-associated gene expression. Necrosis upon infection with Xcv ΔxopJ was greatly reduced in pepper plants with reduced expression of NPR1, a central regulator of SA responses, demonstrating the involvement of SA-signalling in the development of XopJ dependent phenotypes. Our results suggest that XopJ-mediated inhibition of the proteasome interferes with SA-dependent defence response to attenuate onset of necrosis and to alter host transcription. A central role of the proteasome in plant defence is discussed.

  8. Damage-associated responses of the host contribute to defence against cyst nematodes but not root-knot nematodes

    NARCIS (Netherlands)

    Shah, Syed Jehangir; Anjam, Muhammad Shahzad; Mendy, Badou; Anwer, Muhammad Arslan; Habash, Samer S.; Lozano-Torres, Jose L.; Grundler, Florian M.W.; Siddique, Shahid

    2017-01-01

    When nematodes invade and subsequently migrate within plant roots, they generate cell wall fragments (in the form of oligogalacturonides; OGs) that can act as damage-associated molecular patterns and activate host defence responses. However, the molecular mechanisms mediating damage responses in

  9. The gut microbiota plays a protective role in the host defence against pneumococcal pneumonia.

    Science.gov (United States)

    Schuijt, Tim J; Lankelma, Jacqueline M; Scicluna, Brendon P; de Sousa e Melo, Felipe; Roelofs, Joris J T H; de Boer, J Daan; Hoogendijk, Arjan J; de Beer, Regina; de Vos, Alex; Belzer, Clara; de Vos, Willem M; van der Poll, Tom; Wiersinga, W Joost

    2016-04-01

    Pneumonia accounts for more deaths than any other infectious disease worldwide. The intestinal microbiota supports local mucosal immunity and is increasingly recognised as an important modulator of the systemic immune system. The precise role of the gut microbiota in bacterial pneumonia, however, is unknown. Here, we investigate the function of the gut microbiota in the host defence against Streptococcus pneumoniae infections. We depleted the gut microbiota in C57BL/6 mice and subsequently infected them intranasally with S. pneumoniae. We then performed survival and faecal microbiota transplantation (FMT) experiments and measured parameters of inflammation and alveolar macrophage whole-genome responses. We found that the gut microbiota protects the host during pneumococcal pneumonia, as reflected by increased bacterial dissemination, inflammation, organ damage and mortality in microbiota-depleted mice compared with controls. FMT in gut microbiota-depleted mice led to a normalisation of pulmonary bacterial counts and tumour necrosis factor-α and interleukin-10 levels 6 h after pneumococcal infection. Whole-genome mapping of alveolar macrophages showed upregulation of metabolic pathways in the absence of a healthy gut microbiota. This upregulation correlated with an altered cellular responsiveness, reflected by a reduced responsiveness to lipopolysaccharide and lipoteichoic acid. Compared with controls, alveolar macrophages derived from gut microbiota-depleted mice showed a diminished capacity to phagocytose S. pneumoniae. This study identifies the intestinal microbiota as a protective mediator during pneumococcal pneumonia. The gut microbiota enhances primary alveolar macrophage function. Novel therapeutic strategies could exploit the gut-lung axis in bacterial infections. 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/

  10. Host Genetics: Fine-Tuning Innate Signaling

    OpenAIRE

    Fellay, Jacques; Goldstein, David B.

    2007-01-01

    A polymorphism modulating innate immunity signal transduction has recently been shown to influence human susceptibility to many different infections, providing one more indication of the potential of host genetics to reveal physiological pathways and mechanisms that influence resistance to infectious diseases.

  11. Antagonism between salicylic and abscisic acid reflects early host-pathogen conflict and moulds plant defence responses.

    Science.gov (United States)

    de Torres Zabala, Marta; Bennett, Mark H; Truman, William H; Grant, Murray R

    2009-08-01

    The importance of phytohormone balance is increasingly recognized as central to the outcome of plant-pathogen interactions. Recently it has been demonstrated that abscisic acid signalling pathways are utilized by the bacterial phytopathogen Pseudomonas syringae to promote pathogenesis. In this study, we examined the dynamics, inter-relationship and impact of three key acidic phytohormones, salicylic acid, abscisic acid and jasmonic acid, and the bacterial virulence factor, coronatine, during progression of P. syringae infection of Arabidopsis thaliana. We show that levels of SA and ABA, but not JA, appear to play important early roles in determining the outcome of the infection process. SA is required in order to mount a full innate immune responses, while bacterial effectors act rapidly to activate ABA biosynthesis. ABA suppresses inducible innate immune responses by down-regulating SA biosynthesis and SA-mediated defences. Mutant analyses indicated that endogenous ABA levels represent an important reservoir that is necessary for effector suppression of plant-inducible innate defence responses and SA synthesis prior to subsequent pathogen-induced increases in ABA. Enhanced susceptibility due to loss of SA-mediated basal resistance is epistatically dominant over acquired resistance due to ABA deficiency, although ABA also contributes to symptom development. We conclude that pathogen-modulated ABA signalling rapidly antagonizes SA-mediated defences. We predict that hormonal perturbations, either induced or as a result of environmental stress, have a marked impact on pathological outcomes, and we provide a mechanistic basis for understanding priming events in plant defence.

  12. Yersinia virulence factors - a sophisticated arsenal for combating host defences [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Steve Atkinson

    2016-06-01

    Full Text Available The human pathogens Yersinia pseudotuberculosis and Yersinia enterocolitica cause enterocolitis, while Yersinia pestis is responsible for pneumonic, bubonic, and septicaemic plague. All three share an infection strategy that relies on a virulence factor arsenal to enable them to enter, adhere to, and colonise the host while evading host defences to avoid untimely clearance. Their arsenal includes a number of adhesins that allow the invading pathogens to establish a foothold in the host and to adhere to specific tissues later during infection. When the host innate immune system has been activated, all three pathogens produce a structure analogous to a hypodermic needle. In conjunction with the translocon, which forms a pore in the host membrane, the channel that is formed enables the transfer of six ‘effector’ proteins into the host cell cytoplasm. These proteins mimic host cell proteins but are more efficient than their native counterparts at modifying the host cell cytoskeleton, triggering the host cell suicide response. Such a sophisticated arsenal ensures that yersiniae maintain the upper hand despite the best efforts of the host to counteract the infecting pathogen.

  13. Cathelicidin host defence peptide augments clearance of pulmonary Pseudomonas aeruginosa infection by its influence on neutrophil function in vivo.

    Directory of Open Access Journals (Sweden)

    Paula E Beaumont

    Full Text Available Cathelicidins are multifunctional cationic host-defence peptides (CHDP; also known as antimicrobial peptides and an important component of innate host defence against infection. In addition to microbicidal potential, these peptides have properties with the capacity to modulate inflammation and immunity. However, the extent to which such properties play a significant role during infection in vivo has remained unclear. A murine model of acute P. aeruginosa lung infection was utilised, demonstrating cathelicidin-mediated enhancement of bacterial clearance in vivo. The delivery of exogenous synthetic human cathelicidin LL-37 was found to enhance a protective pro-inflammatory response to infection, effectively promoting bacterial clearance from the lung in the absence of direct microbicidal activity, with an enhanced early neutrophil response that required both infection and peptide exposure and was independent of native cathelicidin production. Furthermore, although cathelicidin-deficient mice had an intact early cellular inflammatory response, later phase neutrophil response to infection was absent in these animals, with significantly impaired clearance of P. aeruginosa. These findings demonstrate the importance of the modulatory properties of cathelicidins in pulmonary infection in vivo and highlight a key role for cathelicidins in the induction of protective pulmonary neutrophil responses, specific to the infectious milieu. In additional to their physiological roles, CHDP have been proposed as future antimicrobial therapeutics. Elucidating and utilising the modulatory properties of cathelicidins has the potential to inform the development of synthetic peptide analogues and novel therapeutic approaches based on enhancing innate host defence against infection with or without direct microbicidal targeting of pathogens.

  14. The role of web sharing, species recognition and host-plant defence in interspecific competition between two herbivorous mite species.

    Science.gov (United States)

    Sato, Yukie; Alba, Juan M; Egas, Martijn; Sabelis, Maurice W

    2016-11-01

    When competing with indigenous species, invasive species face a problem, because they typically start with a few colonizers. Evidently, some species succeeded, begging an answer to the question how they invade. Here, we investigate how the invasive spider mite Tetranychus evansi interacts with the indigenous species T. urticae when sharing the solanaceous host plant tomato: do they choose to live together or to avoid each other's colonies? Both species spin protective, silken webs on the leaf surfaces, under which they live in groups of con- and possibly heterospecifics. In Spain, T. evansi invaded the non-crop field where native Tetranychus species including T. urticae dominated. Moreover, T. evansi outcompetes T. urticae when released together on a tomato plant. However, molecular plant studies suggest that T. urticae benefits from the local down-regulation of tomato plant defences by T. evansi, whereas T. evansi suffers from the induction of these defences by T. urticae. Therefore, we hypothesize that T. evansi avoids leaves infested with T. urticae whereas T. urticae prefers leaves infested by T. evansi. Using wild-type tomato and a mutant lacking jasmonate-mediated anti-herbivore defences, we tested the hypothesis and found that T. evansi avoided sharing webs with T. urticae in favour of a web with conspecifics, whereas T. urticae more frequently chose to share webs with T. evansi than with conspecifics. Also, T. evansi shows higher aggregation on a tomato plant than T. urticae, irrespective of whether the mites occur on the plant together or not.

  15. Identification and characterization of novel defence and PCD signalling components in Arabidopsis

    DEFF Research Database (Denmark)

    Xie, Wenjun

    rescued syp121 syp122 ssdx (suppressor of syntaxin-related death) lines were collected. SSD genes are typically required for pathogen defence. In this PhD project, using some of these triple mutant lines, SSD6 and SSD12 were identified to be novel genes by Mutmap and complementation test. SSD6 encode...... a large protein with at least six domains with predicted functions, and mutations in five of these showed that they are important for the lesion mimic phenotype of syp121 syp122. Subcellular localization showed SSD6 to function on the ER. In the project, a split-GFP Gateway vector system was developed...... for topology studies of membrane proteins, and SSD6 was found to be an ER membrane-anchored cytosolic protein. The position of SSD6 in the defence signalling network was studied using syp121 syp122 ssd6 ssdy quadruple mutants, which suggested that SSD6 is not involved in any known signalling pathway. All...

  16. Mycobacterium tuberculosis effectors interfering host apoptosis signaling.

    Science.gov (United States)

    Liu, Minqiang; Li, Wu; Xiang, Xiaohong; Xie, Jianping

    2015-07-01

    Tuberculosis remains a serious human public health concern. The coevolution between its pathogen Mycobacterium tuberculosis and human host complicated the way to prevent and cure TB. Apoptosis plays subtle role in this interaction. The pathogen endeavors to manipulate the apoptosis via diverse effectors targeting key signaling nodes. In this paper, we summarized the effectors pathogen used to subvert the apoptosis, such as LpqH, ESAT-6/CFP-10, LAMs. The interplay between different forms of cell deaths, such as apoptosis, autophagy, necrosis, is also discussed with a focus on the modes of action of effectors, and implications for better TB control.

  17. Crosstalk between autophagy and inflammatory signalling pathways: balancing defence and homeostasis.

    Science.gov (United States)

    Cadwell, Ken

    2016-11-01

    Autophagy has broad functions in immunity, ranging from cell-autonomous defence to coordination of complex multicellular immune responses. The successful resolution of infection and avoidance of autoimmunity necessitates efficient and timely communication between autophagy and pathways that sense the immune environment. The recent literature indicates that a variety of immune mediators induce or repress autophagy. It is also becoming increasingly clear that immune signalling cascades are subject to regulation by autophagy, and that a return to homeostasis following a robust immune response is critically dependent on this pathway. Importantly, examples of non-canonical forms of autophagy in mediating immunity are pervasive. In this article, the progress in elucidating mechanisms of crosstalk between autophagy and inflammatory signalling cascades is reviewed. Improved mechanistic understanding of the autophagy machinery offers hope for treating infectious and inflammatory diseases.

  18. Genome wide expression profiling reveals suppression of host defence responses during colonisation by Neisseria meningitides but not N. lactamica.

    Directory of Open Access Journals (Sweden)

    Hazel En En Wong

    Full Text Available Both Neisseria meningitidis and the closely related bacterium Neisseria lactamica colonise human nasopharyngeal mucosal surface, but only N. meningitidis invades the bloodstream to cause potentially life-threatening meningitis and septicaemia. We have hypothesised that the two neisserial species differentially modulate host respiratory epithelial cell gene expression reflecting their disease potential. Confluent monolayers of 16HBE14 human bronchial epithelial cells were exposed to live and/or dead N. meningitidis (including capsule and pili mutants and N. lactamica, and their transcriptomes were compared using whole genome microarrays. Changes in expression of selected genes were subsequently validated using Q-RT-PCR and ELISAs. Live N. meningitidis and N. lactamica induced genes involved in host energy production processes suggesting that both bacterial species utilise host resources. N. meningitidis infection was associated with down-regulation of host defence genes. N. lactamica, relative to N. meningitidis, initiates up-regulation of proinflammatory genes. Bacterial secreted proteins alone induced some of the changes observed. The results suggest N. meningitidis and N. lactamica differentially regulate host respiratory epithelial cell gene expression through colonisation and/or protein secretion, and that this may contribute to subsequent clinical outcomes associated with these bacteria.

  19. Instar-specific sensitivity of specialist Manduca sexta larvae to induced defences in their host plant Nicotiana attenuata

    NARCIS (Netherlands)

    Van Dam, N.M.; Hermenau, U.; Baldwin, I.T.

    2001-01-01

    1. The time delay associated with the activation of induced defences is thought to be a liability for this type of defence because it allows herbivores to remove biomass before the defence is fully induced. When defences are costly and plants grow with competitors, however, it may be more

  20. Anti-Aspergillus human host defence relies on type 1 T helper (Th1), rather than type 17 T helper (Th17), cellular immunity

    NARCIS (Netherlands)

    L.Y.A. Chai (Louis); F. van de Veerdonk (Frank); R.J. Marijnissen (Renoud); S.C. Cheng (Shih-Chin); A.L. Khoo; M. Hectors (Magda); K. Lagrou (Katrien); A.G. Vonk (Alieke); J. Maertens (Johan); L.A.B. Joosten (Leo); B.J. Kullberg (Bart Jan); M.G. Netea (Mihai)

    2010-01-01

    textabstractSummary Both interferon-γ-producing type 1 T helper (Th1)- and interleukin-17 (IL-17)-producing Th17 cells have been proposed to be involved in anti-fungal host defence. Although invasive aspergillosis is one of the most severe human fungal infections, little is known regarding the

  1. The role of interleukin-1 family members in the host defence against Aspergillus fumigatus.

    Science.gov (United States)

    Gresnigt, Mark S; van de Veerdonk, Frank L

    2014-12-01

    The interleukin (IL)-1 family consists of 11 members, which all play significant roles in regulating inflammatory responses in the host. IL-1α and IL-1β exert potent pro-inflammatory effects and are key players in the recruitment of neutrophils to the site of inflammation. Protective anti-Aspergillus host responses during the early stages of invasive aspergillosis are critically dependent on neutrophil recruitment, and several lines of evidence support that there is an important role for IL-1 in this process. However, IL-1-mediated inflammation needs to be tightly regulated, since uncontrolled inflammation can result in inflammatory pathology and thereby be detrimental for the host. Aspergillus-induced IL-1-mediated inflammation could therefore be amendable for IL-1 blockade under specific circumstances. This review describes the current understanding of the role of IL-1 family members in the host response against Aspergillus fumigatus and highlights the importance of balanced IL-1 responses in aspergillosis.

  2. Damage-associated responses of the host contribute to defence against cyst nematodes but not root-knot nematodes.

    Science.gov (United States)

    Shah, Syed Jehangir; Anjam, Muhammad Shahzad; Mendy, Badou; Anwer, Muhammad Arslan; Habash, Samer S; Lozano-Torres, Jose L; Grundler, Florian M W; Siddique, Shahid

    2017-12-16

    When nematodes invade and subsequently migrate within plant roots, they generate cell wall fragments (in the form of oligogalacturonides; OGs) that can act as damage-associated molecular patterns and activate host defence responses. However, the molecular mechanisms mediating damage responses in plant-nematode interactions remain unexplored. Here, we characterized the role of a group of cell wall receptor proteins in Arabidopsis, designated as polygalacturonase-inhibiting proteins (PGIPs), during infection with the cyst nematode Heterodera schachtii and the root-knot nematode Meloidogyne incognita. PGIPs are encoded by a family of two genes in Arabidopsis, and are involved in the formation of active OG elicitors. Our results show that PGIP gene expression is strongly induced in response to cyst nematode invasion of roots. Analyses of loss-of-function mutants and overexpression lines revealed that PGIP1 expression attenuates infection of host roots by cyst nematodes, but not root-knot nematodes. The PGIP1-mediated attenuation of cyst nematode infection involves the activation of plant camalexin and indole-glucosinolate pathways. These combined results provide new insights into the molecular mechanisms underlying plant damage perception and response pathways during infection by cyst and root-knot nematodes, and establishes the function of PGIP in plant resistance to cyst nematodes. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  3. The Role of Interleukin-1 Family Members in the Host Defence Against Aspergillus fumigatus

    NARCIS (Netherlands)

    Gresnigt, M.S.; Veerdonk, F.L. van de

    2014-01-01

    The interleukin (IL)-1 family consists of 11 members, which all play significant roles in regulating inflammatory responses in the host. IL-1alpha and IL-1beta exert potent pro-inflammatory effects and are key players in the recruitment of neutrophils to the site of inflammation. Protective

  4. A novel Meloidogyne graminicola effector, MgMO237, interacts with multiple host defence-related proteins to manipulate plant basal immunity and promote parasitism.

    Science.gov (United States)

    Chen, Jiansong; Hu, Lili; Sun, Longhua; Lin, Borong; Huang, Kun; Zhuo, Kan; Liao, Jinling

    2018-02-27

    Plant-parasitic nematodes can secrete effector proteins into the host tissue to facilitate their parasitism. In this study, we report a novel effector protein, MgMO237, from Meloidogyne graminicola, which is exclusively expressed within the dorsal oesophageal gland cell and markedly up-regulated in parasitic third-/fourth-stage juveniles of M. graminicola. Transient expression of MgMO237 in protoplasts from rice roots showed that MgMO237 was localized in the cytoplasm and nucleus of the host cells. Rice plants overexpressing MgMO237 showed an increased susceptibility to M. graminicola. In contrast, rice plants expressing RNA interference vectors targeting MgMO237 showed an increased resistance to M. graminicola. In addition, yeast two-hybrid and co-immunoprecipitation assays showed that MgMO237 interacted specifically with three rice endogenous proteins, i.e. 1,3-β-glucan synthase component (OsGSC), cysteine-rich repeat secretory protein 55 (OsCRRSP55) and pathogenesis-related BetvI family protein (OsBetvI), which are all related to host defences. Moreover, MgMO237 can suppress host defence responses, including the expression of host defence-related genes, cell wall callose deposition and the burst of reactive oxygen species. These results demonstrate that the effector MgMO237 probably promotes the parasitism of M. graminicola by interacting with multiple host defence-related proteins and suppressing plant basal immunity in the later parasitic stages of nematodes. © 2018 BSPP AND JOHN WILEY & SONS LTD.

  5. γδ T cells in homeostasis and host defence of epithelial barrier tissues.

    Science.gov (United States)

    Nielsen, Morten M; Witherden, Deborah A; Havran, Wendy L

    2017-12-01

    Epithelial surfaces line the body and provide a crucial interface between the body and the external environment. Tissue-resident epithelial γδ T cells represent a major T cell population in the epithelial tissues and are ideally positioned to carry out barrier surveillance and aid in tissue homeostasis and repair. In this Review, we focus on the intraepithelial γδ T cell compartment of the two largest epithelial tissues in the body - namely, the epidermis and the intestine - and provide a comprehensive overview of the crucial contributions of intraepithelial γδ T cells to tissue integrity and repair, host homeostasis and protection in the context of the symbiotic relationship with the microbiome and during pathogen clearance. Finally, we describe epithelium-specific butyrophilin-like molecules and briefly review their emerging role in selectively shaping and regulating epidermal and intestinal γδ T cell repertoires.

  6. Phospholipase D and phosphatidic acid in plant defence response: from protein–protein and lipid–protein interactions to hormone signalling

    Science.gov (United States)

    Zhao, Jian

    2015-01-01

    Phospholipase Ds (PLDs) and PLD-derived phosphatidic acids (PAs) play vital roles in plant hormonal and environmental responses and various cellular dynamics. Recent studies have further expanded the functions of PLDs and PAs into plant–microbe interaction. The molecular diversities and redundant functions make PLD–PA an important signalling complex regulating lipid metabolism, cytoskeleton dynamics, vesicle trafficking, and hormonal signalling in plant defence through protein–protein and protein–lipid interactions or hormone signalling. Different PLD–PA signalling complexes and their targets have emerged as fast-growing research topics for understanding their numerous but not yet established roles in modifying pathogen perception, signal transduction, and downstream defence responses. Meanwhile, advanced lipidomics tools have allowed researchers to reveal further the mechanisms of PLD–PA signalling complexes in regulating lipid metabolism and signalling, and their impacts on jasmonic acid/oxylipins, salicylic acid, and other hormone signalling pathways that essentially mediate plant defence responses. This review attempts to summarize the progress made in spatial and temporal PLD/PA signalling as well as PLD/PA-mediated modification of plant defence. It presents an in-depth discussion on the functions and potential mechanisms of PLD–PA complexes in regulating actin filament/microtubule cytoskeleton, vesicle trafficking, and hormonal signalling, and in influencing lipid metabolism-derived metabolites as critical signalling components in plant defence responses. The discussion puts PLD–PA in a broader context in order to guide future research. PMID:25680793

  7. BAY 41-2272 activates host defence against local and disseminated Candida albicans infections

    Directory of Open Access Journals (Sweden)

    Paulo Vítor Soeiro-Pereira

    2015-02-01

    Full Text Available In our previous study, we have found that 5-cyclopropyl-2-[1-(2-fluoro-benzyl-1H-pyrazolo[3,4-b]pyridine-3-yl]-pyrimidin-4-ylamine (BAY 41-2272, a guanylate cyclase agonist, activates human monocytes and the THP-1 cell line to produce the superoxide anion, increasing in vitro microbicidal activity, suggesting that this drug can be used to modulate immune functioning in primary immunodeficiency patients. In the present work, we investigated the potential of the in vivo administration of BAY 41-2272 for the treatment of Candida albicans and Staphylococcus aureus infections introduced via intraperitoneal and subcutaneous inoculation. We found that intraperitoneal treatment with BAY 41-2272 markedly increased macrophage-dependent cell influx to the peritoneum in addition to macrophage functions, such as spreading, zymosan particle phagocytosis and nitric oxide and phorbol myristate acetate-stimulated hydrogen peroxide production. Treatment with BAY 41-2272 was highly effective in reducing the death rate due to intraperitoneal inoculation of C. albicans, but not S. aureus. However, we found that in vitro stimulation of peritoneal macrophages with BAY 41-2272 markedly increased microbicidal activities against both pathogens. Our results show that the prevention of death by the treatment of C. albicans-infected mice with BAY 41-2272 might occur primarily by the modulation of the host immune response through macrophage activation.

  8. Dopamine is a key regulator in the signalling pathway underlying predator-induced defences in Daphnia

    Science.gov (United States)

    Weiss, Linda C.; Leese, Florian; Laforsch, Christian; Tollrian, Ralph

    2015-01-01

    The waterflea Daphnia is a model to investigate the genetic basis of phenotypic plasticity resulting from one differentially expressed genome. Daphnia develops adaptive phenotypes (e.g. morphological defences) thwarting predators, based on chemical predator cue perception. To understand the genomic basis of phenotypic plasticity, the description of the precedent cellular and neuronal mechanisms is fundamental. However, key regulators remain unknown. All neuronal and endocrine stimulants were able to modulate but not induce defences, indicating a pathway of interlinked steps. A candidate able to link neuronal with endocrine responses is the multi-functional amine dopamine. We here tested its involvement in trait formation in Daphnia pulex and Daphnia longicephala using an induction assay composed of predator cues combined with dopaminergic and cholinergic stimulants. The mere application of both stimulants was sufficient to induce morphological defences. We determined dopamine localization in cells found in close association with the defensive trait. These cells serve as centres controlling divergent morphologies. As a mitogen and sclerotization agent, we anticipate that dopamine is involved in proliferation and structural formation of morphological defences. Furthermore, dopamine pathways appear to be interconnected with endocrine pathways, and control juvenile hormone and ecdysone levels. In conclusion, dopamine is suggested as a key regulator of phenotypic plasticity. PMID:26423840

  9. A saponin-detoxifying enzyme mediates suppression of plant defences

    Science.gov (United States)

    Bouarab, K.; Melton, R.; Peart, J.; Baulcombe, D.; Osbourn, A.

    2002-08-01

    Plant disease resistance can be conferred by constitutive features such as structural barriers or preformed antimicrobial secondary metabolites. Additional defence mechanisms are activated in response to pathogen attack and include localized cell death (the hypersensitive response). Pathogens use different strategies to counter constitutive and induced plant defences, including degradation of preformed antimicrobial compounds and the production of molecules that suppress induced plant defences. Here we present evidence for a two-component process in which a fungal pathogen subverts the preformed antimicrobial compounds of its host and uses them to interfere with induced defence responses. Antimicrobial saponins are first hydrolysed by a fungal saponin-detoxifying enzyme. The degradation product of this hydrolysis then suppresses induced defence responses by interfering with fundamental signal transduction processes leading to disease resistance.

  10. Phospholipase D and phosphatidic acid in plant defence response: from protein-protein and lipid-protein interactions to hormone signalling.

    Science.gov (United States)

    Zhao, Jian

    2015-04-01

    Phospholipase Ds (PLDs) and PLD-derived phosphatidic acids (PAs) play vital roles in plant hormonal and environmental responses and various cellular dynamics. Recent studies have further expanded the functions of PLDs and PAs into plant-microbe interaction. The molecular diversities and redundant functions make PLD-PA an important signalling complex regulating lipid metabolism, cytoskeleton dynamics, vesicle trafficking, and hormonal signalling in plant defence through protein-protein and protein-lipid interactions or hormone signalling. Different PLD-PA signalling complexes and their targets have emerged as fast-growing research topics for understanding their numerous but not yet established roles in modifying pathogen perception, signal transduction, and downstream defence responses. Meanwhile, advanced lipidomics tools have allowed researchers to reveal further the mechanisms of PLD-PA signalling complexes in regulating lipid metabolism and signalling, and their impacts on jasmonic acid/oxylipins, salicylic acid, and other hormone signalling pathways that essentially mediate plant defence responses. This review attempts to summarize the progress made in spatial and temporal PLD/PA signalling as well as PLD/PA-mediated modification of plant defence. It presents an in-depth discussion on the functions and potential mechanisms of PLD-PA complexes in regulating actin filament/microtubule cytoskeleton, vesicle trafficking, and hormonal signalling, and in influencing lipid metabolism-derived metabolites as critical signalling components in plant defence responses. The discussion puts PLD-PA in a broader context in order to guide future research. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Nest defence in a cuckoo host: great reed warblers risk themselves equally for their own and parasitic chicks

    Czech Academy of Sciences Publication Activity Database

    Honza, Marcel; Procházka, Petr; Šicha, Václav; Požgayová, Milica

    2010-01-01

    Roč. 147, 5-6 (2010), s. 741-756 ISSN 0005-7959 R&D Projects: GA AV ČR IAA600930903; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z60930519 Keywords : brood parasitism * chick discrimination * cuckoo * mobbing * nest defence * nestlingnestling recognition * parental investment Subject RIV: EG - Zoology Impact factor: 1.480, year: 2010

  12. Shifting from priming of salicylic acid- to jasmonic acid-regulated defences by Trichoderma protects tomato against the root knot nematode Meloidogyne incognita

    NARCIS (Netherlands)

    Martínez-Medina, Ainhoa; Fernandez, Ivan; Lok, Gerrit B; Pozo, María J; Pieterse, Corné M J|info:eu-repo/dai/nl/113115113; Van Wees, Saskia C M|info:eu-repo/dai/nl/185445373

    Beneficial root endophytes such as Trichoderma spp. can reduce infections by parasitic nematodes through triggering host defences. Little is currently known about the complex hormone signalling underlying the induction of resistance. In this study, we investigated whether Trichoderma modulates the

  13. PR-39, a porcine host defence peptide, is prominent in mucosa and lymphatic tissue of the respiratory tract in healthy pigs and pigs infected with Actinobacillus pleuropneumoniae.

    Science.gov (United States)

    Hennig-Pauka, Isabel; Koch, Rüdiger; Hoeltig, Doris; Gerlach, Gerald-F; Waldmann, Karl-Heinz; Blecha, Frank; Brauer, Carsten; Gasse, Hagen

    2012-09-28

    Host defence peptides are important components of mammalian innate immunity. We have previously shown that PR-39, a cathelicidin host defence peptide, is an important factor in porcine innate immune mechanisms as a first line of defence after infection with Actinobacillus pleuropneumoniae. PR-39 interacts with bacterial and mammalian cells and is involved in a variety of processes such as killing of bacteria and promotion of wound repair. In bronchoalveolar lavage fluid of infected pigs PR-39 concentrations are elevated during the chronic but not during the acute stage of infection when polymorphonuclear neutrophils (known as the major source of PR-39) are highly increased. Thus it was assumed, that the real impact of PR-39 during infection might not be reflected by its concentration in bronchoalveolar lavage fluid. Using immunohistochemistry this study demonstrates the actual distribution of PR-39 in tissue of the upper and lower respiratory tract of healthy pigs, and of pigs during the acute and chronic stage of experimental infection with Actinobacillus pleuropneumoniae.During the acute stage of infection PR-39 accumulated adjacent to blood vessels and within bronchi. Immune reactions were mainly localized in the cytoplasm of cells with morphological characteristics of polymorphonuclear neutrophils as well as in extracellular fluids. During the chronic stage of infection pigs lacked clinical signs and lung alterations were characterized by reparation and remodelling processes such as tissue sequestration and fibroblastic pleuritis with a high-grade accumulation of small PR-39-positive cells resembling polymorphonuclear neutrophils. In healthy pigs, PR-39 was homogenously expressed in large single cells within the alveoli resembling alveolar macrophages or type 2 pneumocytes. PR-39 was found in all tissue samples of the upper respiratory tract in healthy and diseased pigs. Within the tracheobronchial lymph nodes, PR-39 dominated in the cytoplasm and nuclei of

  14. Staphylococcal Superantigens Spark Host-Mediated Danger Signals

    Directory of Open Access Journals (Sweden)

    Terry eKrakauer

    2016-02-01

    Full Text Available Staphylococcal enterotoxin B (SEB of Staphylococcus aureus, and related superantigenic toxins produced by myriad microbes, are potent stimulators of the immune system causing a variety of human diseases from transient food poisoning to lethal toxic shock. These protein toxins bind directly to specific V regions of T-cell receptors (TCR and major histocompatibility complex (MHC class II on antigen-presenting cells, resulting in hyperactivation of T lymphocytes and monocytes / macrophages. Activated host cells produce excessive amounts of proinflammatory cytokines and chemokines, especially tumor necrosis factor α, interleukin 1 (IL-1, IL-2, interferon γ (IFNγ, and macrophage chemoattractant protein 1 causing clinical symptoms of fever, hypotension, and shock. Because of superantigen-induced T cells skewed towards TH1 helper cells, and the induction of proinflammatory cytokines, superantigens can exacerbate autoimmune diseases. Upon TCR / MHC ligation, pathways induced by superantigens include the mitogen-activated protein kinase cascades and cytokine receptor signaling, resulting in activation of NFκB and the phosphoinositide 3-kinase / mammalian target of rapamycin pathways. Various mouse models exist to study SEB-induced shock including those with potentiating agents, transgenic mice and an SEB-only model. However, therapeutics to treat toxic shock remain elusive as host response genes central to pathogenesis of superantigens have only been identified recently. Gene profiling of a murine model for SEB-induced shock reveals novel molecules upregulated in multiple organs not previously associated with SEB-induced responses. The pivotal genes include intracellular DNA / RNA sensors, apoptosis / DNA damage-related molecules, immunoproteasome components, as well as anti-viral and IFN-stimulated genes. The host-wide induction of these, and other, anti-microbial defense genes provide evidence that SEB elicits danger signals resulting in multi

  15. The structure of lactoferrin-binding protein B from Neisseria meningitidis suggests roles in iron acquisition and neutralization of host defences

    Science.gov (United States)

    Brooks, Cory L.; Arutyunova, Elena; Lemieux, M. Joanne

    2014-01-01

    Pathogens have evolved a range of mechanisms to acquire iron from the host during infection. Several Gram-negative pathogens including members of the genera Neisseria and Moraxella have evolved two-component systems that can extract iron from the host glycoproteins lactoferrin and transferrin. The homologous iron-transport systems consist of a membrane-bound transporter and an accessory lipoprotein. While the mechanism behind iron acquisition from transferrin is well understood, relatively little is known regarding how iron is extracted from lactoferrin. Here, the crystal structure of the N-terminal domain (N-lobe) of the accessory lipoprotein lactoferrin-binding protein B (LbpB) from the pathogen Neisseria meningitidis is reported. The structure is highly homologous to the previously determined structures of the accessory lipoprotein transferrin-binding protein B (TbpB) and LbpB from the bovine pathogen Moraxella bovis. Docking the LbpB structure with lactoferrin reveals extensive binding interactions with the N1 subdomain of lactoferrin. The nature of the interaction precludes apolactoferrin from binding LbpB, ensuring the specificity of iron-loaded lactoferrin. The specificity of LbpB safeguards proper delivery of iron-bound lactoferrin to the transporter lactoferrin-binding protein A (LbpA). The structure also reveals a possible secondary role for LbpB in protecting the bacteria from host defences. Following proteolytic digestion of lactoferrin, a cationic peptide derived from the N-terminus is released. This peptide, called lactoferricin, exhibits potent antimicrobial effects. The docked model of LbpB with lactoferrin reveals that LbpB interacts extensively with the N-terminal lactoferricin region. This may provide a venue for preventing the production of the peptide by proteolysis, or directly sequestering the peptide, protecting the bacteria from the toxic effects of lactoferricin. PMID:25286931

  16. Induction of host defences by Rhizobium during ineffective nodulation of pea (Pisum sativum L.) carrying symbiotically defective mutations sym40 (PsEFD), sym33 (PsIPD3/PsCYCLOPS) and sym42.

    Science.gov (United States)

    Ivanova, Kira A; Tsyganova, Anna V; Brewin, Nicholas J; Tikhonovich, Igor A; Tsyganov, Viktor E

    2015-11-01

    Rhizobia are able to establish a beneficial interaction with legumes by forming a new organ, called the symbiotic root nodule, which is a unique ecological niche for rhizobial nitrogen fixation. Rhizobial infection has many similarities with pathogenic infection and induction of defence responses accompanies both interactions, but defence responses are induced to a lesser extent during rhizobial infection. However, strong defence responses may result from incompatible interactions between legumes and rhizobia due to a mutation in either macro- or microsymbiont. The aim of this research was to analyse different plant defence reactions in response to Rhizobium infection for several pea (Pisum sativum) mutants that result in ineffective symbiosis. Pea mutants were examined by histochemical and immunocytochemical analyses, light, fluorescence and transmission electron microscopy and quantitative real-time PCR gene expression analysis. It was observed that mutations in pea symbiotic genes sym33 (PsIPD3/PsCYCLOPS encoding a transcriptional factor) and sym40 (PsEFD encoding a putative negative regulator of the cytokinin response) led to suberin depositions in ineffective nodules, and in the sym42 there were callose depositions in infection thread (IT) and host cell walls. The increase in deposition of unesterified pectin in IT walls was observed for mutants in the sym33 and sym42; for mutant in the sym42, unesterified pectin was also found around degrading bacteroids. In mutants in the genes sym33 and sym40, an increase in the expression level of a gene encoding peroxidase was observed. In the genes sym40 and sym42, an increase in the expression levels of genes encoding a marker of hypersensitive reaction and PR10 protein was demonstrated. Thus, a range of plant defence responses like suberisation, callose and unesterified pectin deposition as well as activation of defence genes can be triggered by different pea single mutations that cause perception of an otherwise

  17. Airborne signals from Trichoderma fungi stimulate iron uptake responses in roots resulting in priming of jasmonic acid-dependent defences in shoots of Arabidopsis thaliana and Solanum lycopersicum.

    Science.gov (United States)

    Martínez-Medina, Ainhoa; Van Wees, Saskia C M; Pieterse, Corné M J

    2017-11-01

    Root colonization by Trichoderma fungi can trigger induced systemic resistance (ISR). In Arabidopsis, Trichoderma-ISR relies on the transcription factor MYB72, which plays a dual role in the onset of ISR and the activation of Fe uptake responses. Volatile compounds (VCs) from rhizobacteria are important elicitors of MYB72 in Arabidopsis roots. Here, we investigated the mode of action of VCs from Trichoderma fungi in the onset of ISR and Fe uptake responses. VCs from Trichoderma asperellum and Trichoderma harzianum were applied in an in vitro split-plate system with Arabidopsis or tomato seedlings. Locally, Trichoderma-VCs triggered MYB72 expression and molecular, physiological and morphological Fe uptake mechanisms in Arabidopsis roots. In leaves, Trichoderma-VCs primed jasmonic acid-dependent defences, leading to an enhanced resistance against Botrytis cinerea. By using Arabidopsis micrografts of VCs-exposed rootstocks and non-exposed scions, we demonstrated that perception of Trichoderma-VCs by the roots leads to a systemic signal that primes shoots for enhanced defences. Trichoderma-VCs also elicited Fe deficiency responses and shoot immunity in tomato, suggesting that this phenomenon is expressed in different plant species. Our results indicate that Trichoderma-VCs trigger locally a readjustment of Fe homeostasis in roots, which links to systemic elicitation of ISR by priming of jasmonic acid-dependent defences. © 2017 John Wiley & Sons Ltd.

  18. Detection of PR-39, a porcine host defence peptide, in different cell sub-linages in pigs infected with Actinobacillus pleuropneumoniae.

    Science.gov (United States)

    Gabner, S; Egerbacher, M; Gasse, H; Hewicker-Trautwein, M; Höltig, D; Waldmann, K-H; Blecha, F; Saalmüller, A; Hennig-Pauka, I

    2017-10-01

    Innate immunity is critically important for the outcome of infection in many diseases. It was previously shown that cathelicidin PR-39, an important porcine multifunctional host defence peptide, is elevated in bronchoalveolar lavage fluid and respiratory tract tissue after experimental infection with Actinobacillus pleuropneumoniae (A.pp.). To date, neutrophil polymorphonuclear leukocytes (PMNs) are thought to be the only source of PR-39. The aim of this study was to further characterize PR-39⁺ cells and selected immune cell populations in lung tissue during the peracute (7-10 hours), acute (2 days), reconvalescent (7 days) and chronic (21 days) stages of experimental infection with A.pp. serotype 2. In total, six mock-infected control pigs and 12 infected pigs were examined. Using immunofluorescence double-labeling, antibodies against PR-39 were combined with antibodies against CD3 (T-cells), CD79 (B-cells), Iba1 (activated macrophages), TTF-1 (lung epithelial cells expressing surfactant proteins), macrophage/L1 protein and myeloperoxidase (MPO, cells of the myeloid linage). In the peracute and acute phases of infection, total PR-39⁺ cells and myeloid linage cells increased, whereas CD3⁺ cells and TTF-1⁺ cells decreased. Double labeling revealed that most Macrophage/L1 protein+ cells and to a lesser extent MPO⁺ cells co-expressed PR-39. In addition, few bronchial epithelial cells and type 2 alveolar epithelial cells (both identified with TTF-1) produced PR-39. Occasionally, CD3⁺ T cells expressing PR-39 were seen in infected animals. Taken together, this study identifies cell types, other than PMNs, in lungs of A.pp.-infected pigs that are capable of producing PR-39. In addition, these findings provide further insights into the dynamics of different immune cell populations during A.pp.-infection.

  19. Microbiota promote secretory cell determination in the intestinal epithelium by modulating host Notch signaling.

    Science.gov (United States)

    Troll, Joshua V; Hamilton, M Kristina; Abel, Melissa L; Ganz, Julia; Bates, Jennifer M; Stephens, W Zac; Melancon, Ellie; van der Vaart, Michiel; Meijer, Annemarie H; Distel, Martin; Eisen, Judith S; Guillemin, Karen

    2018-02-23

    Resident microbes promote many aspects of host development, although the mechanisms by which microbiota influence host tissues remain unclear. We showed previously that the microbiota is required for allocation of appropriate numbers of secretory cells in the zebrafish intestinal epithelium. Because Notch signaling is crucial for secretory fate determination, we conducted epistasis experiments to establish whether the microbiota modulates host Notch signaling. We also investigated whether innate immune signaling transduces microbiota cues via the Myd88 adaptor protein. We provide the first evidence that microbiota-induced, Myd88-dependent signaling inhibits host Notch signaling in the intestinal epithelium, thereby promoting secretory cell fate determination. These results connect microbiota activity via innate immune signaling to the Notch pathway, which also plays crucial roles in intestinal homeostasis throughout life and when impaired can result in chronic inflammation and cancer. © 2018. Published by The Company of Biologists Ltd.

  20. The wheat NB-LRR gene TaRCR1 is required for host defence response to the necrotrophic fungal pathogen Rhizoctonia cerealis.

    Science.gov (United States)

    Zhu, Xiuliang; Lu, Chungui; Du, Lipu; Ye, Xingguo; Liu, Xin; Coules, Anne; Zhang, Zengyan

    2017-06-01

    The necrotrophic fungus Rhizoctonia cerealis is the major pathogen causing sharp eyespot disease in wheat (Triticum aestivum). Nucleotide-binding leucine-rich repeat (NB-LRR) proteins often mediate plant disease resistance to biotrophic pathogens. Little is known about the role of NB-LRR genes involved in wheat response to R. cerealis. In this study, a wheat NB-LRR gene, named TaRCR1, was identified in response to R. cerealis infection using Artificial Neural Network analysis based on comparative transcriptomics and its defence role was characterized. The transcriptional level of TaRCR1 was enhanced after R. cerealis inoculation and associated with the resistance level of wheat. TaRCR1 was located on wheat chromosome 3BS and encoded an NB-LRR protein that was consisting of a coiled-coil domain, an NB-ARC domain and 13 imperfect leucine-rich repeats. TaRCR1 was localized in both the cytoplasm and the nucleus. Silencing of TaRCR1 impaired wheat resistance to R. cerealis, whereas TaRCR1 overexpression significantly increased the resistance in transgenic wheat. TaRCR1 regulated certain reactive oxygen species (ROS)-scavenging and production, and defence-related genes, and peroxidase activity. Furthermore, H 2 O 2 pretreatment for 12-h elevated expression levels of TaRCR1 and the above defence-related genes, whereas treatment with a peroxidase inhibitor for 12 h reduced the resistance of TaRCR1-overexpressing transgenic plants and expression levels of these defence-related genes. Taken together, TaRCR1 positively contributes to defence response to R. cerealis through maintaining ROS homoeostasis and regulating the expression of defence-related genes. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  1. Nectonema zealandica n. sp. (Nematomorpha: Nectonematoidea) parasitising the purple rock crab Hemigrapsus edwardsi (Brachyura: Decapoda) in New Zealand, with notes on the prevalence of infection and host defence reactions.

    Science.gov (United States)

    Poinar, G; Brockerhoff, A M

    2001-10-01

    A new species of marine hairworm, Nectonema zealandica (Nematomorpha: Nectonematoidea), is described from the purple rock crab Hemigrapsus edwardsi Hilgendorf from the South Island, New Zealand. This is the first record of Nectonema in the South Pacific Ocean and the southernmost locality for the genus. The description is based on juveniles and pre-adults taken from crabs. The new species is characterised by its stomal structure, presence of four cephalic papillae, mesenchyme arranged in eight lobes in pre-adults, insertion of muscle layer increasing body diameter at the septum and translucent anterior chamber. Data on the prevalence of infection over a three-year period, rates of parasitism in relation to host sex and size, and host defence reactions are presented. A list of all reported hosts of nectonematids is included.

  2. Calcium signaling during the plant-plant interaction of parasitic Cuscuta reflexa with its hosts

    NARCIS (Netherlands)

    Albert, M.; Kaiser, B.; Krol, van der A.R.; Kaldenhoff, R.

    2010-01-01

    The plant parasite Cuscuta reflexa induces various responses in compatible and incompatible host plants. The visual reactions of both types of host plants including obvious morphological changes require the recognition of Cuscuta ssp. A consequently initiated signaling cascade is triggered which

  3. Does chemical aposematic (warning) signaling occur between host plants and their potential parasitic plants?

    Science.gov (United States)

    Lev-Yadun, Simcha

    2013-07-01

    Aposematism (warning) signaling is a common defensive mechanism toward predatory or herbivorous animals, i.e., interactions between different trophic levels. I propose that it should be considered at least as a working hypothesis that chemical aposematism operates between certain host plants and their plant predators, parasitic plants, and that although they are also plants, they belong to a higher trophic level. Specific host plant genotypes emit known repelling chemical signals toward parasitic plants, which reduce the level of, slow the directional parasite growth (attack) toward the signaling hosts, or even cause parasitic plants to grow away from them in response to these chemicals. Chemical host aposematism toward parasitic plants may be a common but overlooked defense from parasitic plants.

  4. The Host Plant Metabolite Glucose Is the Precursor of Diffusible Signal Factor (DSF) Family Signals in Xanthomonas campestris

    OpenAIRE

    Deng, Yinyue; Liu, Xiaoling; Wu, Ji'en; Lee, Jasmine; Chen, Shaohua; Cheng, Yingying; Zhang, Chunyan; Zhang, Lian-Hui

    2015-01-01

    Plant pathogen Xanthomonas campestris pv. campestris produces cis-11-methyl-2-dodecenoic acid (diffusible signal factor [DSF]) as a cell-cell communication signal to regulate biofilm dispersal and virulence factor production. Previous studies have demonstrated that DSF biosynthesis is dependent on the presence of RpfF, an enoyl-coenzyme A (CoA) hydratase, but the DSF synthetic mechanism and the influence of the host plant on DSF biosynthesis are still not clear. We show here that exogenous ad...

  5. Physcomitrella patens activates reinforcement of the cell wall, programmed cell death and accumulation of evolutionary conserved defence signals, such as salicylic acid and 12-oxo-phytodienoic acid, but not jasmonic acid, upon Botrytis cinerea infection.

    Science.gov (United States)

    Ponce De León, Inés; Schmelz, Eric A; Gaggero, Carina; Castro, Alexandra; Álvarez, Alfonso; Montesano, Marcos

    2012-10-01

    The moss Physcomitrella patens is an evolutionarily basal model system suitable for the analysis of plant defence responses activated after pathogen assault. Upon infection with the necrotroph Botrytis cinerea, several defence mechanisms are induced in P. patens, including the fortification of the plant cell wall by the incorporation of phenolic compounds and the induced expression of related genes. Botrytis cinerea infection also activates the accumulation of reactive oxygen species and cell death with hallmarks of programmed cell death in moss tissues. Salicylic acid (SA) levels also increase after fungal infection, and treatment with SA enhances transcript accumulation of the defence gene phenylalanine ammonia-lyase (PAL) in P. patens colonies. The expression levels of the genes involved in 12-oxo-phytodienoic acid (OPDA) synthesis, including lipoxygenase (LOX) and allene oxide synthase (AOS), increase in P. patens gametophytes after pathogen assault, together with a rise in free linolenic acid and OPDA concentrations. However, jasmonic acid (JA) could not be detected in healthy or infected tissues of this plant. Our results suggest that, although conserved defence signals, such as SA and OPDA, are synthesized and are probably involved in the defence response of P. patens against B. cinerea infection, JA production appears to be missing. Interestingly, P. patens responds to OPDA and methyl jasmonate by reducing moss colony growth and rhizoid length, suggesting that jasmonate perception is present in mosses. Thus, P. patens can provide clues with regard to the evolution of different defence pathways in plants, including signalling and perception of OPDA and jasmonates in nonflowering and flowering plants. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  6. Mechanisms and ecological consequences of plant defence induction and suppression in herbivore communities.

    Science.gov (United States)

    Kant, M R; Jonckheere, W; Knegt, B; Lemos, F; Liu, J; Schimmel, B C J; Villarroel, C A; Ataide, L M S; Dermauw, W; Glas, J J; Egas, M; Janssen, A; Van Leeuwen, T; Schuurink, R C; Sabelis, M W; Alba, J M

    2015-06-01

    Plants are hotbeds for parasites such as arthropod herbivores, which acquire nutrients and energy from their hosts in order to grow and reproduce. Hence plants are selected to evolve resistance, which in turn selects for herbivores that can cope with this resistance. To preserve their fitness when attacked by herbivores, plants can employ complex strategies that include reallocation of resources and the production of defensive metabolites and structures. Plant defences can be either prefabricated or be produced only upon attack. Those that are ready-made are referred to as constitutive defences. Some constitutive defences are operational at any time while others require activation. Defences produced only when herbivores are present are referred to as induced defences. These can be established via de novo biosynthesis of defensive substances or via modifications of prefabricated substances and consequently these are active only when needed. Inducibility of defence may serve to save energy and to prevent self-intoxication but also implies that there is a delay in these defences becoming operational. Induced defences can be characterized by alterations in plant morphology and molecular chemistry and are associated with a decrease in herbivore performance. These alterations are set in motion by signals generated by herbivores. Finally, a subset of induced metabolites are released into the air as volatiles and function as a beacon for foraging natural enemies searching for prey, and this is referred to as induced indirect defence. The objective of this review is to evaluate (1) which strategies plants have evolved to cope with herbivores and (2) which traits herbivores have evolved that enable them to counter these defences. The primary focus is on the induction and suppression of plant defences and the review outlines how the palette of traits that determine induction/suppression of, and resistance/susceptibility of herbivores to, plant defences can give rise to

  7. Mechanisms and ecological consequences of plant defence induction and suppression in herbivore communities

    Science.gov (United States)

    Kant, M. R.; Jonckheere, W.; Knegt, B.; Lemos, F.; Liu, J.; Schimmel, B. C. J.; Villarroel, C. A.; Ataide, L. M. S.; Dermauw, W.; Glas, J. J.; Egas, M.; Janssen, A.; Van Leeuwen, T.; Schuurink, R. C.; Sabelis, M. W.; Alba, J. M.

    2015-01-01

    Background Plants are hotbeds for parasites such as arthropod herbivores, which acquire nutrients and energy from their hosts in order to grow and reproduce. Hence plants are selected to evolve resistance, which in turn selects for herbivores that can cope with this resistance. To preserve their fitness when attacked by herbivores, plants can employ complex strategies that include reallocation of resources and the production of defensive metabolites and structures. Plant defences can be either prefabricated or be produced only upon attack. Those that are ready-made are referred to as constitutive defences. Some constitutive defences are operational at any time while others require activation. Defences produced only when herbivores are present are referred to as induced defences. These can be established via de novo biosynthesis of defensive substances or via modifications of prefabricated substances and consequently these are active only when needed. Inducibility of defence may serve to save energy and to prevent self-intoxication but also implies that there is a delay in these defences becoming operational. Induced defences can be characterized by alterations in plant morphology and molecular chemistry and are associated with a decrease in herbivore performance. These alterations are set in motion by signals generated by herbivores. Finally, a subset of induced metabolites are released into the air as volatiles and function as a beacon for foraging natural enemies searching for prey, and this is referred to as induced indirect defence. Scope The objective of this review is to evaluate (1) which strategies plants have evolved to cope with herbivores and (2) which traits herbivores have evolved that enable them to counter these defences. The primary focus is on the induction and suppression of plant defences and the review outlines how the palette of traits that determine induction/suppression of, and resistance/susceptibility of herbivores to, plant defences can

  8. SMART DEFENCE AND DEFENCE RESOURCES MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Teodor FRUNZETI

    2012-12-01

    Full Text Available Ever since the Chicago Summit in May 2012. the Euro-Atlantic community has been imprinted, from the security and defence perspective. by me launch of a new initiative known as smart defence, a concept referring to the need to improve the way in which defence spending is made at the Alliance's level. Smart defence also has a corollary at EU's level — i.e., pooling and sharing - the two notions referring. Overall, to the same procedure and implying a crucial need for the two organizations to coordinate their efforts in this. This article approaches the conceptual meaning of smart defence, with special emphasis on its management dimension regarding the defence resources. As a consequence, it is approached in connection with Other similar concepts such as pooling and sharing', Planning, Programming, Budgeting, and Evaluation System (PPBES, and the Connected Force Initiative.

  9. Oxidative defence reactions in sunflower roots induced by methyl-jasmonate and methyl-salicylate and their relation with calcium signalling.

    Science.gov (United States)

    Garrido, Inmaculada; Espinosa, Francisco; Alvarez-Tinaut, M Carmen

    2009-10-01

    Ca(2+) plays a critical role as second messenger in the signal-response coupling of plant defence responses, and methyl-jasmonate and methyl-salicylate are important components of signal transduction cascades activating plant defences. When intact axenic non-induced seedling roots of sunflower were treated with different Ca(2+) concentrations up to 1 mM, there was no significant increase in O(2)(*-) generation or DMAB-MBTH peroxidase (extracellular, ECPOX) activities in the apoplast, probably because these roots had enough Ca(2+) in their exo- and endocellular reservoirs. Both activities were strongly inhibited by the RBOH-NADPH oxidase inhibitor DPI and by the Ca(2+) surrogate antagonist La(3+), but the voltage-dependent Ca(2+) channel blocker verapamil was only inhibitory at concentrations higher than those active on animal L-type Ca(2+) channels. Concentrations >5 mM EGTA (chelating Ca(2+) in the apoplast) and Li(+) (inhibiting PI cycle dependent endogenous Ca(2+) fluxes) also inhibited both activities. W7, inhibitor of binding of Ca-CaM to its target protein, enhanced both activities, but the inactive analogue W5 showed a similar effect. Our data suggest that Ca(2+) from exocellular and, to a lesser extent, from endocellular stores is involved in oxidative activities, and that RBOH-NADPH oxidase is the main system supporting them. Ca(2+) activation of the PM cytosolic side of RBOH-NADPH oxidase is probably the key to Ca(2+) involvement in these processes. Roots induced by MeJA or MeSA showed significant enhancement of both oxidative activities, as corresponding to the oxidative burst evoked by the two phytohormones in the root apoplast. But while ECPOX activity showed a response to the effectors similar to that described above for non-induced roots, O(2)(*-) generation activity in the apoplast of induced roots was insensitive to EGTA, verapamil and Li(+), the inhibitors of exogenous and endogenous Ca(2+) fluxes; only DPI and La(3+) were inhibitory. As

  10. Shifting from priming of salicylic acid- to jasmonic acid-regulated defences by Trichoderma protects tomato against the root knot nematode Meloidogyne incognita.

    Science.gov (United States)

    Martínez-Medina, Ainhoa; Fernandez, Ivan; Lok, Gerrit B; Pozo, María J; Pieterse, Corné M J; Van Wees, Saskia C M

    2017-02-01

    Beneficial root endophytes such as Trichoderma spp. can reduce infections by parasitic nematodes through triggering host defences. Little is currently known about the complex hormone signalling underlying the induction of resistance. In this study, we investigated whether Trichoderma modulates the hormone signalling network in the host to induce resistance to nematodes. We investigated the role and the timing of the jasmonic acid (JA)- and salicylic acid (SA)-regulated defensive pathways in Trichoderma-induced resistance to the root knot nematode Meloidogyne incognita. A split-root system of tomato (Solanum lycopersicum) was used to study local and systemic induced defences by analysing nematode performance, defence gene expression, responsiveness to exogenous hormone application, and dependence on SA and JA signalling of Trichoderma-induced resistance. Root colonization by Trichoderma impeded nematode performance both locally and systemically at multiple stages of the parasitism, that is, invasion, galling and reproduction. First, Trichoderma primed SA-regulated defences, which limited nematode root invasion. Then, Trichoderma enhanced JA-regulated defences, thereby antagonizing the deregulation of JA-dependent immunity by the nematodes, which compromised galling and fecundity. Our results show that Trichoderma primes SA- and JA-dependent defences in roots, and that the priming of responsiveness to these hormones upon nematode attack is plastic and adaptive to the parasitism stage. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  11. Sunyaev–Zel’Dovich Signal from Quasar Hosts: Implications for Detection of Quasar Feedback

    International Nuclear Information System (INIS)

    Chowdhury, Dhruba Dutta; Chatterjee, Suchetana

    2017-01-01

    Several analytic and numerical studies have indicated that the interstellar medium of a quasar host galaxy heated by feedback can contribute to a substantial secondary signal in the cosmic microwave background (CMB) through the thermal Sunyaev–Zel’dovich (SZ) effect. Recently, many groups have tried to detect this signal by cross-correlating CMB maps with quasar catalogs. Using a self-similar model for the gas in the intra-cluster medium and a realistic halo occupation distribution (HOD) prescription for quasars, we estimate the level of SZ signal from gravitational heating of quasar hosts. The bias in the host halo signal estimation due to an unconstrained high mass HOD tail and yet unknown redshift dependence of the quasar HOD restricts us from drawing any robust conclusions at low redshift ( z < 1.5) from our analysis. However, at higher redshifts ( z > 2.5), we find an excess signal in recent observations than what is predicted from our model. The excess signal could be potentially generated from additional heating due to quasar feedback.

  12. Sunyaev–Zel’Dovich Signal from Quasar Hosts: Implications for Detection of Quasar Feedback

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, Dhruba Dutta; Chatterjee, Suchetana, E-mail: dhruba.duttachowdhury@yale.edu [Department of Physics, Presidency University, Kolkata, 700073 (India)

    2017-04-10

    Several analytic and numerical studies have indicated that the interstellar medium of a quasar host galaxy heated by feedback can contribute to a substantial secondary signal in the cosmic microwave background (CMB) through the thermal Sunyaev–Zel’dovich (SZ) effect. Recently, many groups have tried to detect this signal by cross-correlating CMB maps with quasar catalogs. Using a self-similar model for the gas in the intra-cluster medium and a realistic halo occupation distribution (HOD) prescription for quasars, we estimate the level of SZ signal from gravitational heating of quasar hosts. The bias in the host halo signal estimation due to an unconstrained high mass HOD tail and yet unknown redshift dependence of the quasar HOD restricts us from drawing any robust conclusions at low redshift ( z < 1.5) from our analysis. However, at higher redshifts ( z > 2.5), we find an excess signal in recent observations than what is predicted from our model. The excess signal could be potentially generated from additional heating due to quasar feedback.

  13. The trans-generational impact of population density signals on host-parasite interactions.

    Science.gov (United States)

    Michel, Jessica; Ebert, Dieter; Hall, Matthew D

    2016-11-25

    The density of a host population is a key parameter underlying disease transmission, but it also has implications for the expression of disease through its effect on host physiology. In response to higher densities, individuals are predicted to either increase their immune investment in response to the elevated risk of parasitism, or conversely to decrease their immune capacity as a consequence of the stress of a crowded environment. However, an individual's health is shaped by many different factors, including their genetic background, current environmental conditions, and maternal effects. Indeed, population density is often sensed through the presence of info-chemicals in the environment, which may influence a host's interaction with parasites, and also those of its offspring. All of which may alter the expression of disease, and potentially uncouple the presumed link between changes in host density and disease outcomes. In this study, we used the water flea Daphnia magna and its obligate bacterial parasite Pasteuria ramosa, to investigate how signals of high host density impact on host-parasite interactions over two consecutive generations. We found that the chemical signals from crowded treatments induced phenotypic changes in both the parental and offspring generations. In the absence of a pathogen, life-history changes were genotype-specific, but consistent across generations, even when the signal of density was removed. In contrast, the influence of density on infected animals depended on the trait and generation of exposure. When directly exposed to signals of high-density, host genotypes responded differently in how they minimised the severity of disease. Yet, in the subsequent generation, the influence of density was rarely genotype-specific and instead related to ability of the host to minimise the onset of infection. Our findings reveal that population level correlations between host density and infection capture only part of the complex relationship

  14. The host plant metabolite glucose is the precursor of diffusible signal factor (DSF) family signals in Xanthomonas campestris.

    Science.gov (United States)

    Deng, Yinyue; Liu, Xiaoling; Wu, Ji'en; Lee, Jasmine; Chen, Shaohua; Cheng, Yingying; Zhang, Chunyan; Zhang, Lian-Hui

    2015-04-01

    Plant pathogen Xanthomonas campestris pv. campestris produces cis-11-methyl-2-dodecenoic acid (diffusible signal factor [DSF]) as a cell-cell communication signal to regulate biofilm dispersal and virulence factor production. Previous studies have demonstrated that DSF biosynthesis is dependent on the presence of RpfF, an enoyl-coenzyme A (CoA) hydratase, but the DSF synthetic mechanism and the influence of the host plant on DSF biosynthesis are still not clear. We show here that exogenous addition of host plant juice or ethanol extract to the growth medium of X. campestris pv. campestris could significantly boost DSF family signal production. It was subsequently revealed that X. campestris pv. campestris produces not only DSF but also BDSF (cis-2-dodecenoic acid) and another novel DSF family signal, which was designated DSF-II. BDSF was originally identified in Burkholderia cenocepacia to be involved in regulation of motility, biofilm formation, and virulence in B. cenocepacia. Functional analysis suggested that DSF-II plays a role equal to that of DSF in regulation of biofilm dispersion and virulence factor production in X. campestris pv. campestris. Furthermore, chromatographic separation led to identification of glucose as a specific molecule stimulating DSF family signal biosynthesis in X. campestris pv. campestris. (13)C-labeling experiments demonstrated that glucose acts as a substrate to provide a carbon element for DSF biosynthesis. The results of this study indicate that X. campestris pv. campestris could utilize a common metabolite of the host plant to enhance DSF family signal synthesis and therefore promote virulence. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Calcium signaling during the plant-plant interaction of parasitic Cuscuta reflexa with its hosts.

    Science.gov (United States)

    Albert, Markus; Kaiser, Bettina; van der Krol, Sander; Kaldenhoff, Ralf

    2010-09-01

    The plant parasite Cuscuta reflexa induces various responses in compatible and incompatible host plants. The visual reactions of both types of host plants including obvious morphological changes require the recognition of Cuscuta ssp. A consequently initiated signaling cascade is triggered which leads to a tolerance of the infection or, in the case of some incompatible host plants, to resistance. Calcium (Ca(2+)) release is the major second messenger during signal transduction. Therefore, we have studied Ca(2+) spiking in tomato and tobacco during infection with C. reflexa. In our recently published study Ca(2+) signals were monitored as bioluminescence in aequorin-expressing tomato plants after the onset of C. reflexa infestation. Signals at the attachment sites were observed from 30 to 48 h after infection. In an assay with leaf disks of aequorin-expressing tomato which were treated with different C. reflexa plant extracts it turned out that the substance that induced Ca(2+) release in the host plant was closely linked to the parasite's haustoria.

  16. Interleukin-1 signaling is essential for host defense during murine pulmonary tuberculosis

    NARCIS (Netherlands)

    Juffermans, N. P.; Florquin, S.; Camoglio, L.; Verbon, A.; Kolk, A. H.; Speelman, P.; van Deventer, S. J.; van der Poll, T.

    2000-01-01

    Interleukin (IL)-1 signaling is required for the containment of infections with intracellular microorganisms, such as Listeria monocytogenes and Leishmania major. To determine the role of IL-1 in the host response to tuberculosis, we infected IL-1 type I receptor-deficient (IL-1R(-/-)) mice, in

  17. Rewiring cellular metabolism via the AKT/mTOR pathway contributes to host defence against Mycobacterium tuberculosis in human and murine cells

    NARCIS (Netherlands)

    Lachmandas, E.L.; Beigier-Bompadre, M.; Cheng, S.C.; Kumar, V.; Laarhoven, A. van; Wang, X.; Ammerdorffer, A.; Boutens, L.; Jong, D. de; Kanneganti, T.D.; Gresnigt, M.S.; Ottenhoff, T.H.; Joosten, L.A.; Stienstra, R.; Wijmenga, C.; Kaufmann, S.H.; Crevel, R. van; Netea, M.G.

    2016-01-01

    Cells in homeostasis metabolize glucose mainly through the tricarboxylic acid cycle and oxidative phosphorylation, while activated cells switch their basal metabolism to aerobic glycolysis. In this study, we examined whether metabolic reprogramming toward aerobic glycolysis is important for the host

  18. The intrinsically disordered structural platform of the plant defence hub protein RPM1-interacting protein 4 provides insights into its mode of action in the host-pathogen interface and evolution of the nitrate-induced domain protein family.

    Science.gov (United States)

    Sun, Xiaolin; Greenwood, David R; Templeton, Matthew D; Libich, David S; McGhie, Tony K; Xue, Bin; Yoon, Minsoo; Cui, Wei; Kirk, Christopher A; Jones, William T; Uversky, Vladimir N; Rikkerink, Erik H A

    2014-09-01

    Arabidopsis thaliana (At) RPM1-interacting protein 4 (RIN4), targeted by many defence-suppressing bacterial type III effectors and monitored by several resistance proteins, regulates plant immune responses to pathogen-associated molecular patterns and type III effectors. Little is known about the overall protein structure of AtRIN4, especially in its unbound form, and the relevance of structure to its diverse biological functions. AtRIN4 contains two nitrate-induced (NOI) domains and is a member of the NOI family. Using experimental and bioinformatic approaches, we demonstrate that the unbound AtRIN4 is intrinsically disordered under physiological conditions. The intrinsically disordered polypeptide chain of AtRIN4 is interspersed with molecular recognition features (MoRFs) and anchor-identified long-binding regions, potentially allowing it to undergo disorder-to-order transitions upon binding to partner(s). A poly-l-proline II structure, often responsible for protein recognition, is also identified in AtRIN4. By performing bioinformatics analyses on RIN4 homologues from different plant species and the NOI proteins from Arabidopsis, we infer the conservation of intrinsic disorder, MoRFs and long-binding regions of AtRIN4 in other plant species and the NOI family. Intrinsic disorder and MoRFs could provide RIN4 proteins with the binding promiscuity and plasticity required to act as hubs in a pivotal position within plant defence signalling cascades. © 2014 FEBS.

  19. Salicylic acid-independent plant defence pathways

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Loon, L.C. van

    1999-01-01

    Salicylic acid is an important signalling molecule involved in both locally and systemically induced disease resistance responses. Recent advances in our understanding of plant defence signalling have revealed that plants employ a network of signal transduction pathways, some of which are

  20. The acetate switch of an intestinal pathogen disrupts host insulin signaling and lipid metabolism.

    Science.gov (United States)

    Hang, Saiyu; Purdy, Alexandra E; Robins, William P; Wang, Zhipeng; Mandal, Manabendra; Chang, Sarah; Mekalanos, John J; Watnick, Paula I

    2014-11-12

    Vibrio cholerae is lethal to the model host Drosophila melanogaster through mechanisms not solely attributable to cholera toxin. To examine additional virulence determinants, we performed a genetic screen in V. cholerae-infected Drosophila and identified the two-component system CrbRS. CrbRS controls transcriptional activation of acetyl-CoA synthase-1 (ACS-1) and thus regulates the acetate switch, in which bacteria transition from excretion to assimilation of environmental acetate. The resultant loss of intestinal acetate leads to deactivation of host insulin signaling and lipid accumulation in enterocytes, resulting in host lethality. These metabolic effects are not observed upon infection with ΔcrbS or Δacs1 V. cholerae mutants. Additionally, uninfected flies lacking intestinal commensals, which supply short chain fatty acids (SCFAs) such as acetate, also exhibit altered insulin signaling and intestinal steatosis, which is reversed upon acetate supplementation. Thus, acetate consumption by V. cholerae alters host metabolism, and dietary acetate supplementation may ameliorate some sequelae of cholera. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Rhizobial peptidase HrrP cleaves host-encoded signaling peptides and mediates symbiotic compatibility.

    Science.gov (United States)

    Price, Paul A; Tanner, Houston R; Dillon, Brett A; Shabab, Mohammed; Walker, Graham C; Griffitts, Joel S

    2015-12-08

    Legume-rhizobium pairs are often observed that produce symbiotic root nodules but fail to fix nitrogen. Using the Sinorhizobium meliloti and Medicago truncatula symbiotic system, we previously described several naturally occurring accessory plasmids capable of disrupting the late stages of nodule development while enhancing bacterial proliferation within the nodule. We report here that host range restriction peptidase (hrrP), a gene found on one of these plasmids, is capable of conferring both these properties. hrrP encodes an M16A family metallopeptidase whose catalytic activity is required for these symbiotic effects. The ability of hrrP to suppress nitrogen fixation is conditioned upon the genotypes of both the host plant and the hrrP-expressing rhizobial strain, suggesting its involvement in symbiotic communication. Purified HrrP protein is capable of degrading a range of nodule-specific cysteine-rich (NCR) peptides encoded by M. truncatula. NCR peptides are crucial signals used by M. truncatula for inducing and maintaining rhizobial differentiation within nodules, as demonstrated in the accompanying article [Horváth B, et al. (2015) Proc Natl Acad Sci USA, 10.1073/pnas.1500777112]. The expression pattern of hrrP and its effects on rhizobial morphology are consistent with the NCR peptide cleavage model. This work points to a symbiotic dialogue involving a complex ensemble of host-derived signaling peptides and bacterial modifier enzymes capable of adjusting signal strength, sometimes with exploitative outcomes.

  2. Parasitism by Cuscuta pentagona sequentially induces JA and SA defence pathways in tomato.

    Science.gov (United States)

    Runyon, Justin B; Mescher, Mark C; Felton, Gary W; De Moraes, Consuelo M

    2010-02-01

    While plant responses to herbivores and pathogens are well characterized, responses to attack by other plants remain largely unexplored. We measured phytohormones and C(18) fatty acids in tomato attacked by the parasitic plant Cuscuta pentagona, and used transgenic and mutant plants to explore the roles of the defence-related phytohormones salicylic acid (SA) and jasmonic acid (JA). Parasite attachment to 10-day-old tomato plants elicited few biochemical changes, but a second attachment 10 d later elicited a 60-fold increase in JA, a 30-fold increase in SA and a hypersensitive-like response (HLR). Host age also influenced the response: neither Cuscuta seedlings nor established vines elicited a HLR in 10-day-old hosts, but both did in 20-day-old hosts. Parasites grew larger on hosts deficient in SA (NahG) or insensitive to JA [jasmonic acid-insensitive1 (jai1)], suggesting that both phytohormones mediate effective defences. Moreover, amounts of JA peaked 12 h before SA, indicating that defences may be coordinated via sequential induction of these hormones. Parasitism also induced increases in free linolenic and linoleic acids and abscisic acid. These findings provide the first documentation of plant hormonal signalling induced by a parasitic plant and show that tomato responses to C. pentagona display characteristics similar to both herbivore- and pathogen-induced responses.

  3. Fluorescence resonance energy transfer (FRET-based subcellular visualization of pathogen-induced host receptor signaling

    Directory of Open Access Journals (Sweden)

    Zimmermann Timo

    2009-11-01

    Full Text Available Abstract Background Bacteria-triggered signaling events in infected host cells are key elements in shaping the host response to pathogens. Within the eukaryotic cell, signaling complexes are spatially organized. However, the investigation of protein-protein interactions triggered by bacterial infection in the cellular context is technically challenging. Here, we provide a methodological approach to exploit fluorescence resonance energy transfer (FRET to visualize pathogen-initiated signaling events in human cells. Results Live-cell microscopy revealed the transient recruitment of the Src family tyrosine kinase Hck upon bacterial engagement of the receptor carcinoembryonic antigen-related cell adhesion molecule 3 (CEACAM3. In cells expressing a CEACAM3 variant lacking the cytoplasmic domain, the Src homology 2 (SH2 domain of Hck (Hck-SH2 was not recruited, even though bacteria still bound to the receptor. FRET measurements on the basis of whole cell lysates revealed intimate binding between Hck-SH2 (using enhanced yellow fluorescent protein (YPet-Hck-SH2 and the tyrosine-phosphorylated enhanced cyan fluorescent protein-labeled cytoplasmic domain of wild-type CEACAM3 (CEACAM3 WT-CyPet and a flow cytometry-based FRET approach verified this association in intact cells. Using confocal microscopy and acceptor photobleaching, FRET between Hck-SH2 and CEACAM3 was localized to the sites of bacteria-host cell contact. Conclusion These data demonstrate not only the intimate binding of the SH2 domain of Hck to the tyrosine-phosphorylated cytoplasmic domain of CEACAM3 in intact cells, but furthermore, FRET measurements allow the subcellular localization of this process during bacterial infection. FRET-based assays are valuable tools to resolve bacteria-induced protein-protein interactions in the context of the intact host cell.

  4. Uncovering the defence responses of Eucalyptus to pests and pathogens in the genomics age.

    Science.gov (United States)

    Naidoo, Sanushka; Külheim, Carsten; Zwart, Lizahn; Mangwanda, Ronishree; Oates, Caryn N; Visser, Erik A; Wilken, Febé E; Mamni, Thandekile B; Myburg, Alexander A

    2014-09-01

    Long-lived tree species are subject to attack by various pests and pathogens during their lifetime. This problem is exacerbated by climate change, which may increase the host range for pathogens and extend the period of infestation by pests. Plant defences may involve preformed barriers or induced resistance mechanisms based on recognition of the invader, complex signalling cascades, hormone signalling, activation of transcription factors and production of pathogenesis-related (PR) proteins with direct antimicrobial or anti-insect activity. Trees have evolved some unique defence mechanisms compared with well-studied model plants, which are mostly herbaceous annuals. The genome sequence of Eucalyptus grandis W. Hill ex Maiden has recently become available and provides a resource to extend our understanding of defence in large woody perennials. This review synthesizes existing knowledge of defence mechanisms in model plants and tree species and features mechanisms that may be important for defence in Eucalyptus, such as anatomical variants and the role of chemicals and proteins. Based on the E. grandis genome sequence, we have identified putative PR proteins based on sequence identity to the previously described plant PR proteins. Putative orthologues for PR-1, PR-2, PR-4, PR-5, PR-6, PR-7, PR-8, PR-9, PR-10, PR-12, PR-14, PR-15 and PR-17 have been identified and compared with their orthologues in Populus trichocarpa Torr. & A. Gray ex Hook and Arabidopsis thaliana (L.) Heynh. The survey of PR genes in Eucalyptus provides a first step in identifying defence gene targets that may be employed for protection of the species in future. Genomic resources available for Eucalyptus are discussed and approaches for improving resistance in these hardwood trees, earmarked as a bioenergy source in future, are considered. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Pathogenic Leptospires Modulate Protein Expression and Post-translational Modifications in Response to Mammalian Host Signals.

    Science.gov (United States)

    Nally, Jarlath E; Grassmann, Andre A; Planchon, Sébastien; Sergeant, Kjell; Renaut, Jenny; Seshu, Janakiram; McBride, Alan J; Caimano, Melissa J

    2017-01-01

    Pathogenic species of Leptospira cause leptospirosis, a bacterial zoonotic disease with a global distribution affecting over one million people annually. Reservoir hosts of leptospirosis, including rodents, dogs, and cattle, exhibit little to no signs of disease but shed large numbers of organisms in their urine. Transmission occurs when mucosal surfaces or abraded skin come into contact with infected urine or urine-contaminated water or soil. Whilst little is known about how Leptospira adapt to and persist within a reservoir host, in vitro studies suggest that leptospires alter their transcriptomic and proteomic profiles in response to environmental signals encountered during mammalian infection. We applied the dialysis membrane chamber (DMC) peritoneal implant model to compare the whole cell proteome of in vivo derived leptospires with that of leptospires cultivated in vitro at 30°C and 37°C by 2-dimensional difference in-gel electrophoresis (2-D DIGE). Of 1,735 protein spots aligned across 9 2-D DIGE gels, 202 protein spots were differentially expressed ( p 1.25 or expressed proteins were excised for identification by mass spectrometry. Data are available via ProteomeXchange with identifier PXD006995. The greatest differences were detected when DMC-cultivated leptospires were compared with IV30- or IV37-cultivated leptospires, including the increased expression of multiple isoforms of Loa22, a known virulence factor. Unexpectedly, 20 protein isoforms of LipL32 and 7 isoforms of LipL41 were uniformly identified by DIGE as differentially expressed, suggesting that unique post-translational modifications (PTMs) are operative in response to mammalian host conditions. To test this hypothesis, a rat model of persistent renal colonization was used to isolate leptospires directly from the urine of experimentally infected rats. Comparison of urinary derived leptospires to IV30 leptospires by 2-D immunoblotting confirmed that modification of proteins with

  6. Pathogenic Leptospires Modulate Protein Expression and Post-translational Modifications in Response to Mammalian Host Signals

    Directory of Open Access Journals (Sweden)

    Jarlath E. Nally

    2017-08-01

    Full Text Available Pathogenic species of Leptospira cause leptospirosis, a bacterial zoonotic disease with a global distribution affecting over one million people annually. Reservoir hosts of leptospirosis, including rodents, dogs, and cattle, exhibit little to no signs of disease but shed large numbers of organisms in their urine. Transmission occurs when mucosal surfaces or abraded skin come into contact with infected urine or urine-contaminated water or soil. Whilst little is known about how Leptospira adapt to and persist within a reservoir host, in vitro studies suggest that leptospires alter their transcriptomic and proteomic profiles in response to environmental signals encountered during mammalian infection. We applied the dialysis membrane chamber (DMC peritoneal implant model to compare the whole cell proteome of in vivo derived leptospires with that of leptospires cultivated in vitro at 30°C and 37°C by 2-dimensional difference in-gel electrophoresis (2-D DIGE. Of 1,735 protein spots aligned across 9 2-D DIGE gels, 202 protein spots were differentially expressed (p < 0.05, fold change >1.25 or < −1.25 across all three conditions. Differentially expressed proteins were excised for identification by mass spectrometry. Data are available via ProteomeXchange with identifier PXD006995. The greatest differences were detected when DMC-cultivated leptospires were compared with IV30- or IV37-cultivated leptospires, including the increased expression of multiple isoforms of Loa22, a known virulence factor. Unexpectedly, 20 protein isoforms of LipL32 and 7 isoforms of LipL41 were uniformly identified by DIGE as differentially expressed, suggesting that unique post-translational modifications (PTMs are operative in response to mammalian host conditions. To test this hypothesis, a rat model of persistent renal colonization was used to isolate leptospires directly from the urine of experimentally infected rats. Comparison of urinary derived leptospires to IV30

  7. Probiotics: beneficial factors of the defence system.

    Science.gov (United States)

    Antoine, Jean Michel

    2010-08-01

    Probiotics, defined as living micro-organisms that provide a health benefit to the host when ingested in adequate amounts, have been used traditionally as food components to help the body to recover from diarrhoea. They are commonly ingested as part of fermented foods, mostly in fresh fermented dairy products. They can interact with the host through different components of the gut defence systems. There is mounting clinical evidence that some probiotics, but not all, help the defence of the host as demonstrated by either a shorter duration of infections or a decrease in the host's susceptibility to pathogens. Different components of the gut barrier can be involved in the strengthening of the body's defences: the gut microbiota, the gut epithelial barrier and the immune system. Many studies have been conducted in normal free-living subjects or in subjects during common infections like the common cold and show that some probiotic-containing foods can improve the functioning of or strengthen the body's defence. Specific probiotic foods can be included in the usual balanced diet of consumers to help them to better cope with the daily challenges of their environment.

  8. The Battle between Rotavirus and Its Host for Control of the Interferon Signaling Pathway

    Science.gov (United States)

    Arnold, Michelle M.; Sen, Adrish; Greenberg, Harry B.; Patton, John T.

    2013-01-01

    Viral pathogens must overcome innate antiviral responses to replicate successfully in the host organism. Some of the mechanisms viruses use to interfere with antiviral responses in the infected cell include preventing detection of viral components, perturbing the function of transcription factors that initiate antiviral responses, and inhibiting downstream signal transduction. RNA viruses with small genomes and limited coding space often express multifunctional proteins that modulate several aspects of the normal host response to infection. One such virus, rotavirus, is an important pediatric pathogen that causes severe gastroenteritis, leading to ∼450,000 deaths globally each year. In this review, we discuss the nature of the innate antiviral responses triggered by rotavirus infection and the viral mechanisms for inhibiting these responses. PMID:23359266

  9. CD151, a novel host factor of nuclear export signaling in influenza virus infection.

    Science.gov (United States)

    Qiao, Yongkang; Yan, Yan; Tan, Kai Sen; Tan, Sheryl S L; Seet, Ju Ee; Arumugam, Thiruma Valavan; Chow, Vincent T K; Wang, De Yun; Tran, Thai

    2018-05-01

    Despite advances in our understanding of the mechanisms of influenza A virus (IAV) infection, the crucial virus-host interactions during the viral replication cycle still remain incomplete. Tetraspanin CD151 is highly expressed in the human respiratory tract, but its pathological role in IAV infection is unknown. We sought to characterize the functional role and mechanisms of action of CD151 in IAV infection of the upper and lower respiratory tracts with H1N1 and H3N2 strains. We used CD151-null mice in an in vivo model of IAV infection and clinical donor samples of in vitro-differentiated human nasal epithelial cells cultured at air-liquid interface. As compared with wild-type infected mice, CD151-null infected mice exhibited a significant reduction in virus titer and improvement in survival that is associated with pronounced host antiviral response and inflammasome activation together with accelerated lung repair. Interestingly, we show that CD151 complexes newly synthesized viral proteins with host nuclear export proteins and stabilizes microtubule complexes, which are key processes necessary for the polarized trafficking of viral progeny to the host plasma membrane for assembly. Our results provide new mechanistic insights into our understanding of IAV infection. We show that CD151 is a critical novel host factor of nuclear export signaling whereby the IAV nuclear export uses it to complement its own nuclear export proteins (a site not targeted by current therapy), making this regulation unique, and holds promise for the development of novel alternative/complementary strategies to reduce IAV severity. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  10. Cytotoxic Vibrio T3SS1 Rewires Host Gene Expression to Subvert Cell Death Signaling and Activate Cell Survival Networks

    Science.gov (United States)

    De Nisco, Nicole J.; Kanchwala, Mohammed; Li, Peng; Fernandez, Jessie; Xing, Chao; Orth, Kim

    2017-01-01

    Bacterial effectors are potent manipulators of host signaling pathways. The marine bacterium Vibrio parahaemolyticus (V. para), delivers effectors into host cells through two type three secretion systems (T3SS). The ubiquitous T3SS1 is vital for V. para survival in the environment, whereas T3SS2 causes acute gastroenteritis in human hosts. Although the natural host is undefined, T3SS1 effectors attack highly conserved cellular processes and pathways to orchestrate non-apoptotic cell death. Much is known about how T3SS1 effectors function in isolation, but we wanted to understand how their concerted action globally affects host cell signaling. To assess the host response to T3SS1, we compared gene expression changes over time in primary fibroblasts infected with V. para that have a functional T3SS1 (T3SS1+) to those in cells infected with V. para lacking T3SS1 (T3SS1−). Overall, the host transcriptional response to both T3SS1+ and T3SS1− V. para was rapid, robust, and temporally dynamic. T3SS1 re-wired host gene expression by specifically altering the expression of 398 genes. Although T3SS1 effectors target host cells at the posttranslational level to cause cytotoxicity, network analysis indicated that V. para T3SS1 also precipitates a host transcriptional response that initially activates cell survival and represses cell death networks. The increased expression of several key pro-survival transcripts mediated by T3SS1 was dependent on a host signaling pathway that is silenced later in infection by the posttranslational action of T3SS1. Taken together, our analysis reveals a complex interplay between roles of T3SS1 as both a transcriptional and posttranslational manipulator of host cell signaling. PMID:28512145

  11. The role of moulting in parasite defence.

    Science.gov (United States)

    Duneau, David; Ebert, Dieter

    2012-08-07

    Parasitic infections consist of a succession of steps during which hosts and parasites interact in specific manners. At each step, hosts can use diverse defence mechanisms to counteract the parasite's attempts to invade and exploit them. Of these steps, the penetration of parasites into the host is a key step for a successful infection and the epithelium is the first line of host defence. The shedding of this protective layer (moulting) is a crucial feature in the life cycle of several invertebrate and vertebrate taxa, and is generally considered to make hosts vulnerable to parasites and predators. Here, we used the crustacean Daphnia magna to test whether moulting influences the likelihood of infection by the castrating bacterium Pasteuria ramosa. This parasite is known to attach to the host cuticula before penetrating into its body. We found that the likelihood of successful parasite infection is greatly reduced if the host moults within 12 h after parasite exposure. Thus, moulting is beneficial for the host being exposed to this parasite. We further show that exposure to the parasite does not induce hosts to moult earlier. We discuss the implications of our findings for host and parasite evolution and epidemiology.

  12. Trichoderma Biocontrol: Signal Transduction Pathways Involved in Host Sensing and Mycoparasitism

    Directory of Open Access Journals (Sweden)

    Susanne Zeilinger

    2007-01-01

    Full Text Available Fungi of the genus Trichoderma are used as biocontrol agents against several plant pathogenic fungi like Rhizoctonia spp., Pythium spp., Botrytis cinerea and Fusarium spp. which cause both soil-borne and leaf- or flower-borne diseases of agricultural plants. Plant disease control by Trichoderma is based on complex interactions between Trichoderma, the plant pathogen and the plant. Until now, two main components of biocontrol have been identified: direct activity of Trichoderma against the plant pathogen by mycoparasitism and induced systemic resistance in plants. As the mycoparasitic interaction is host-specific and not merely a contact response, it is likely that signals from the host fungus are recognised by Trichoderma and provoke transcription of mycoparasitism-related genes.In the last few years examination of signalling pathways underlying Trichoderma biocontrol started and it was shown that heterotrimeric G-proteins and mitogen-activated protein (MAP kinases affected biocontrol-relevant processes such as the production of hydrolytic enzymes and antifungal metabolites and the formation of infection structures. MAPK signalling was also found to be involved in induction of plant systemic resistance in Trichoderma virens and in the hyperosmotic stress response in Trichoderma harzianum. Analyses of the function of components of the cAMP pathway during Trichoderma biocontrol revealed that mycoparasitism-associated coiling and chitinase production as well as secondary metabolism are affected by the internal cAMP level; in addition, a cross talk between regulation of light responses and the cAMP signalling pathway was found in Trichoderma atroviride.

  13. Diverse opportunities in defence

    Science.gov (United States)

    Brown, Gareth

    2016-08-01

    Working at the UK's defence laboratory gives Gareth Brown the ability to apply his physics and mathematics knowledge to real-world applications - and not necessarily in the ways you might expect. This article is Crown copyright

  14. From Defence To Development

    International Development Research Centre (IDRC) Digital Library (Canada)

    From this perspective, high defence expenditure has been compared to dismantling ...... availability exceed evaporative demand and a state of permanent drought ...... In October 1993, South African authorities seized a container on a plot near ...

  15. Salicylic acid-independent plant defence pathways

    OpenAIRE

    Pieterse, C.M.J.; Loon, L.C. van

    1999-01-01

    Salicylic acid is an important signalling molecule involved in both locally and systemically induced disease resistance responses. Recent advances in our understanding of plant defence signalling have revealed that plants employ a network of signal transduction pathways, some of which are independent of salicylic acid. Evidence is emerging that jasmonic acid and ethylene play key roles in these salicylic acid-independent pathways. Cross-talk between the salicylic acid-dependent and the salicy...

  16. Signaling in Parasitic Nematodes: Physicochemical Communication Between Host and Parasite and Endogenous Molecular Transduction Pathways Governing Worm Development and Survival.

    Science.gov (United States)

    Lok, James B

    2016-12-01

    Signaling or communication between host and parasite may occur over relatively long ranges to enable host finding and acquisition by infective parasitic nematode larvae. Innate behaviors in infective larvae transmitted from the soil that enhance the likelihood of host contact, such as negative geotaxis and hypermotility, are likely mediated by mechanoreception and neuromuscular signaling. Host cues such as vibration of the substratum, elevated temperature, exhaled CO 2 , and other volatile odorants are perceived by mechanosensory and chemosensory neurons of the amphidial complex. Beyond this, the molecular systems that transduce these external cues within the worm are unknown at this time. Overall, the signal transduction mechanisms that regulate switching between dauer and continuous reproductive development in Caenorhabditis elegans , and doubtless other free-living nematodes, have provided a useful framework for testing hypotheses about how the morphogenesis and development of infective parasitic nematode larvae and the lifespan of adult parasites are regulated. In C. elegans , four major signal transduction pathways, G protein-coupled receptor signaling, insulin/insulin-like growth factor signaling, TGFβ-like signaling and steroid-nuclear hormone receptor signaling govern the switch between dauer and continuous development and regulate adult lifespan. Parasitic nematodes appear to have conserved the functions of G-protein-coupled signaling, insulin-like signaling and steroid-nuclear hormone receptor signaling to regulate larval development before and during the infective process. By contrast, TGFβ-like signaling appears to have been adapted for some other function, perhaps modulation of the host immune response. Of the three signal transduction pathways that appear to regulate development in parasitic nematodes, steroid-nuclear hormone signaling is the most straightforward to manipulate with administered small molecules and may form the basis of new

  17. Role of stress-related hormones in plant defence during early infection of the cyst nematode Heterodera schachtii in Arabidopsis

    Science.gov (United States)

    Kammerhofer, Nina; Radakovic, Zoran; Regis, Jully M A; Dobrev, Petre; Vankova, Radomira; Grundler, Florian M W; Siddique, Shahid; Hofmann, Julia; Wieczorek, Krzysztof

    2015-01-01

    Heterodera schachtii, a plant-parasitic cyst nematode, invades host roots and induces a specific syncytial feeding structure, from which it withdraws all required nutrients, causing severe yield losses. The system H. schachtii–Arabidopsis is an excellent research model for investigating plant defence mechanisms. Such responses are suppressed in well-established syncytia, whereas they are induced during early parasitism. However, the mechanisms by which the defence responses are modulated and the role of phytohormones are largely unknown. The aim of this study was to elucidate the role of hormone-based defence responses at the onset of nematode infection. First, concentrations of main phytohormones were quantified and the expression of several hormone-related genes was analysed using quantitative real-time (qRT)-PCR or GeneChip. Further, the effects of individual hormones were evaluated via nematode attraction and infection assays using plants with altered endogenous hormone concentrations. Our results suggest a pivotal and positive role for ethylene during nematode attraction, whereas jasmonic acid triggers early defence responses against H. schachtii. Salicylic acid seems to be a negative regulator during later syncytium and female development. We conclude that nematodes are able to impose specific changes in hormone pools, thus modulating hormone-based defence and signal transduction in strict dependence on their parasitism stage. PMID:25825039

  18. Understanding plant defence responses against herbivore attacks: an essential first step towards the development of sustainable resistance against pests.

    Science.gov (United States)

    Santamaria, M Estrella; Martínez, Manuel; Cambra, Inés; Grbic, Vojislava; Diaz, Isabel

    2013-08-01

    Plant-herbivore relationships are complex interactions encompassing elaborate networks of molecules, signals and strategies used to overcome defences developed by each other. Herbivores use multiple feeding strategies to obtain nutrients from host plants. In turn, plants respond by triggering defence mechanisms to inhibit, block or modify the metabolism of the pest. As part of these defences, herbivore-challenged plants emit volatiles to attract natural enemies and warn neighbouring plants of the imminent threat. In response, herbivores develop a variety of strategies to suppress plant-induced protection. Our understanding of the plant-herbivore interphase is limited, although recent molecular approaches have revealed the participation of a battery of genes, proteins and volatile metabolites in attack-defence processes. This review describes the intricate and dynamic defence systems governing plant-herbivore interactions by examining the diverse strategies plants employ to deny phytophagous arthropods the ability to breach newly developed mechanisms of plant resistance. A cornerstone of this understanding is the use of transgenic tools to unravel the complex networks that control these interactions.

  19. Evolutionary tools for phytosanitary risk analysis: phylogenetic signal as a predictor of host range of plant pests and pathogens.

    Science.gov (United States)

    Gilbert, Gregory S; Magarey, Roger; Suiter, Karl; Webb, Campbell O

    2012-12-01

    Assessing risk from a novel pest or pathogen requires knowing which local plant species are susceptible. Empirical data on the local host range of novel pests are usually lacking, but we know that some pests are more likely to attack closely related plant species than species separated by greater evolutionary distance. We use the Global Pest and Disease Database, an internal database maintained by the United States Department of Agriculture Animal and Plant Health Inspection Service - Plant Protection and Quarantine Division (USDA APHIS-PPQ), to evaluate the strength of the phylogenetic signal in host range for nine major groups of plant pests and pathogens. Eight of nine groups showed significant phylogenetic signal in host range. Additionally, pests and pathogens with more known hosts attacked a phylogenetically broader range of hosts. This suggests that easily obtained data - the number of known hosts and the phylogenetic distance between known hosts and other species of interest - can be used to predict which plant species are likely to be susceptible to a particular pest. This can facilitate rapid assessment of risk from novel pests and pathogens when empirical host range data are not yet available and guide efficient collection of empirical data for risk evaluation.

  20. Evolutionary tools for phytosanitary risk analysis: phylogenetic signal as a predictor of host range of plant pests and pathogens

    Science.gov (United States)

    Gilbert, Gregory S; Magarey, Roger; Suiter, Karl; Webb, Campbell O

    2012-01-01

    Assessing risk from a novel pest or pathogen requires knowing which local plant species are susceptible. Empirical data on the local host range of novel pests are usually lacking, but we know that some pests are more likely to attack closely related plant species than species separated by greater evolutionary distance. We use the Global Pest and Disease Database, an internal database maintained by the United States Department of Agriculture Animal and Plant Health Inspection Service – Plant Protection and Quarantine Division (USDA APHIS-PPQ), to evaluate the strength of the phylogenetic signal in host range for nine major groups of plant pests and pathogens. Eight of nine groups showed significant phylogenetic signal in host range. Additionally, pests and pathogens with more known hosts attacked a phylogenetically broader range of hosts. This suggests that easily obtained data – the number of known hosts and the phylogenetic distance between known hosts and other species of interest – can be used to predict which plant species are likely to be susceptible to a particular pest. This can facilitate rapid assessment of risk from novel pests and pathogens when empirical host range data are not yet available and guide efficient collection of empirical data for risk evaluation. PMID:23346231

  1. Transcriptional Responses in the Hemiparasitic Plant Triphysaria versicolor to Host Plant Signals1[w

    Science.gov (United States)

    Matvienko, Marta; Torres, Manuel J.; Yoder, John I.

    2001-01-01

    Parasitic plants in the Scrophulariaceae use chemicals released by host plant roots to signal developmental processes critical for heterotrophy. Haustoria, parasitic plant structures that attach to and invade host roots, develop on roots of the hemiparasitic plant Triphysaria versicolor within a few hours of exposure to either maize (Zea mays) root exudate or purified haustoria-inducing factors. We prepared a normalized, subtractive cDNA library enriched for transcripts differentially abundant in T. versicolor root tips treated with the allelopathic quinone 2,6-dimethoxybenzoquinone (DMBQ). Northern analyses estimated that about 10% of the cDNAs represent transcripts strongly up-regulated in roots exposed to DMBQ. Northern and reverse northern analyses demonstrated that most DMBQ-responsive messages were similarly up-regulated in T. versicolor roots exposed to maize root exudates. From the cDNA sequences we assembled a unigene set of 137 distinct transcripts and assigned functions by homology comparisons. Many of the proteins encoded by the transcripts are predicted to function in quinone detoxification, whereas others are more likely associated with haustorium development. The identification of genes transcriptionally regulated by haustorium-inducing factors provides a framework for dissecting genetic pathways recruited by parasitic plants during the transition to heterotrophic growth. PMID:11553755

  2. Impact of 4 Lactobacillus plantarum capsular polysaccharide clusters on surface glycan composition and host cell signaling

    Directory of Open Access Journals (Sweden)

    Remus Daniela M

    2012-11-01

    -J produced decreased levels of surface polysaccharides, whereas the molar mass and the composition of polysaccharides was not affected by these cluster mutations. In the quadruple mutant, the amount of surface polysaccharides was strongly reduced. The impact of the cps cluster mutations on toll-like receptor (TLR-mediated human nuclear factor (NF-κB activation in host cells was evaluated using a TLR2 reporter cell line. In comparison to a L. plantarum wild-type derivative, TLR2 activation remained unaffected by the Δcps1A-I and Δcps3A-J mutants but appeared slightly increased after stimulation with the Δcps2A-J and Δcps4A-J mutants, while the Δcps1A-3J and Δcps1A-3J, Δcps4A-J mutants elicited the strongest responses and clearly displayed enhanced TLR2 signaling. Conclusions Our study reveals that modulation of surface glycan characteristics in L. plantarum highlights the role of these molecules in shielding of cell envelope embedded host receptor ligands. Although the apparently complete cps clusters (cps2A-J and cps4A-J contributed individually to this shielding, the removal of all cps clusters led to the strongest signaling enhancement. Our findings provide new insights into cell surface glycan biosynthesis in L. plantarum, which bears relevance in the context of host-cell signaling by probiotic bacteria.

  3. Chemical defences against herbivores

    DEFF Research Database (Denmark)

    Pavia, Henrik; Baumgartner, Finn; Cervin, Gunnar

    2012-01-01

    This chapter focuses on the recent and emerging research involving chemical defences against herbivory in aquatic primary producers. It provides an overview of plant chemical defence theories and highlights recent research on aquatic primary producers addressing a number of aspects...... of these theories, concluding with new chemical approaches to tackle the questions and suggestions for future research directions. It explains that aquatic primary producers are a taxonomically and functionally diverse group of organisms that includes macroalgae, microalgae, and vascular plants. It also states...... that despite the fact that aquatic primary producers constitute a large and diverse group of organisms that vary in their evolutionary histories, selection for chemical defences to resist or reduce grazing are commonplace across the phylogenetic boundaries....

  4. New materials in defence

    International Nuclear Information System (INIS)

    Khan, Sikandar S.; Khan, Shahid A.; Butt, N.M.

    1992-01-01

    National defence is very important and always needs new such materials which have technological and socio-economic development of human society. The types of materials used by a society reflect its level of sophistication. These modern materials are basically the same conventional materials but with a greater knowledge content which include superalloys, modern polymers, engineering ceramics and the advanced composite. The production and use of new materials is playing and important role in the recent development in the defence industry. (A.B.)

  5. Efficient expression of nattokinase in Bacillus licheniformis: host strain construction and signal peptide optimization.

    Science.gov (United States)

    Wei, Xuetuan; Zhou, Yinhua; Chen, Jingbang; Cai, Dongbo; Wang, Dan; Qi, Gaofu; Chen, Shouwen

    2015-02-01

    Nattokinase (NK) possesses the potential for prevention and treatment of thrombus-related diseases. In this study, high-level expression of nattokinase was achieved in Bacillus licheniformis WX-02 via host strain construction and signal peptides optimization. First, ten genes (mpr, vpr, aprX, epr, bpr, wprA, aprE, bprA, hag, amyl) encoding for eight extracellular proteases, a flagellin and an amylase were deleted to obtain B. licheniformis BL10, which showed no extracellular proteases activity in gelatin zymography. Second, the gene fragments of P43 promoter, Svpr, nattokinase and TamyL were combined into pHY300PLK to form the expression vector pP43SNT. In BL10 (pP43SNT), the fermentation activity and product activity per unit of biomass of nattokinase reached 14.33 FU/mL and 2,187.71 FU/g respectively, which increased by 39 and 156 % compared to WX-02 (pP43SNT). Last, Svpr was replaced with SsacC and SbprA, and the maximum fermentation activity (33.83 FU/mL) was achieved using SsacC, which was 229 % higher than that of WX-02 (pP43SNT). The maximum NK fermentation activity in this study reaches the commercial production level of solid state fermentation, and this study provides a promising engineered strain for industrial production of nattokinase, as well as a potential platform host for expression of other target proteins.

  6. TNO and CBRN defence

    NARCIS (Netherlands)

    2015-01-01

    Within the Defence, Safety & Security branch of TNO a dedicated department focuses on Chemical, Biological, Radiological and Nuclear (CBRN) Protection. This is a world class research department consisting of about 50 people and a High Tox laboratory that is the only facility in The Netherlands that

  7. NATO Defence Planning Process. Implications for defence posture

    Directory of Open Access Journals (Sweden)

    Paweł Fleischer

    2015-12-01

    Full Text Available The NATO Defence Planning Process (NDPP is the most important element affecting the Alliance's defence posture. Under the process states commit themselves to provide capabilities and forces required to fulfil NATO missions, defined in the NATO Strategic Concept. The NDPP directly affects national defence plans by harmonizing them with identified security and defence objectives as well by influencing development of the novel national defence capabilities. The emergence of new threats in the NATO environment, demands modifications in the defense planning process and establishing new goals for the Alliance. Enhancement of the NDPP should be priority during the time of unrest.

  8. Unfolding Role of a Danger Molecule Adenosine Signaling in Modulation of Microbial Infection and Host Cell Response

    Directory of Open Access Journals (Sweden)

    Jaden S. Lee

    2018-01-01

    Full Text Available Ectonucleotidases CD39 and CD73, specific nucleotide metabolizing enzymes located on the surface of the host, can convert a pro-inflammatory environment driven by a danger molecule extracellular-ATP to an adenosine-mediated anti-inflammatory milieu. Accordingly, CD39/CD73 signaling has been strongly implicated in modulating the intensity, duration, and composition of purinergic danger signals delivered to host. Recent studies have eluted potential roles for CD39 and CD73 in selective triggering of a variety of host immune cells and molecules in the presence of pathogenic microorganisms or microbial virulence molecules. Growing evidence also suggests that CD39 and CD73 present complimentary, but likely differential, actions against pathogens to shape the course and severity of microbial infection as well as the associated immune response. Similarly, adenosine receptors A2A and A2B have been proposed to be major immunomodulators of adenosine signaling during chronic inflammatory conditions induced by opportunistic pathogens, such as oral colonizer Porphyromonas gingivalis. Therefore, we here review the recent studies that demonstrate how complex network of molecules in the extracellular adenosine signaling machinery and their interactions can reshape immune responses and may also be targeted by opportunistic pathogens to establish successful colonization in human mucosal tissues and modulate the host immune response.

  9. Adaptation to Environmental Stimuli within the Host: Two-Component Signal Transduction Systems of Mycobacterium tuberculosis

    Science.gov (United States)

    Bretl, Daniel J.; Demetriadou, Chrystalla; Zahrt, Thomas C.

    2011-01-01

    Summary: Pathogenic microorganisms encounter a variety of environmental stresses following infection of their respective hosts. Mycobacterium tuberculosis, the etiological agent of tuberculosis, is an unusual bacterial pathogen in that it is able to establish lifelong infections in individuals within granulomatous lesions that are formed following a productive immune response. Adaptation to this highly dynamic environment is thought to be mediated primarily through transcriptional reprogramming initiated in response to recognition of stimuli, including low-oxygen tension, nutrient depletion, reactive oxygen and nitrogen species, altered pH, toxic lipid moieties, cell wall/cell membrane-perturbing agents, and other environmental cues. To survive continued exposure to these potentially adverse factors, M. tuberculosis encodes a variety of regulatory factors, including 11 complete two-component signal transduction systems (TCSSs) and several orphaned response regulators (RRs) and sensor kinases (SKs). This report reviews our current knowledge of the TCSSs present in M. tuberculosis. In particular, we discuss the biochemical and functional characteristics of individual RRs and SKs, the environmental stimuli regulating their activation, the regulons controlled by the various TCSSs, and the known or postulated role(s) of individual TCSSs in the context of M. tuberculosis physiology and/or pathogenesis. PMID:22126994

  10. The coat protein of Alfalfa mosaic virus interacts and interferes with the transcriptional activity of the bHLH transcription factor ILR3 promoting salicylic acid-dependent defence signalling response.

    Science.gov (United States)

    Aparicio, Frederic; Pallás, Vicente

    2017-02-01

    During virus infection, specific viral component-host factor interaction elicits the transcriptional reprogramming of diverse cellular pathways. Alfalfa mosaic virus (AMV) can establish a compatible interaction in tobacco and Arabidopsis hosts. We show that the coat protein (CP) of AMV interacts directly with transcription factor (TF) ILR3 of both species. ILR3 is a basic helix-loop-helix (bHLH) family member of TFs, previously proposed to participate in diverse metabolic pathways. ILR3 has been shown to regulate NEET in Arabidopsis, a critical protein in plant development, senescence, iron metabolism and reactive oxygen species (ROS) homeostasis. We show that the AMV CP-ILR3 interaction causes a fraction of this TF to relocate from the nucleus to the nucleolus. ROS, pathogenesis-related protein 1 (PR1) mRNAs, salicylic acid (SA) and jasmonic acid (JA) contents are increased in healthy Arabidopsis loss-of-function ILR3 mutant (ilr3.2) plants, which implicates ILR3 in the regulation of plant defence responses. In AMV-infected wild-type (wt) plants, NEET expression is reduced slightly, but is induced significantly in ilr3.2 mutant plants. Furthermore, the accumulation of SA and JA is induced in Arabidopsis wt-infected plants. AMV infection in ilr3.2 plants increases JA by over 10-fold, and SA is reduced significantly, indicating an antagonist crosstalk effect. The accumulation levels of viral RNAs are decreased significantly in ilr3.2 mutants, but the virus can still systemically invade the plant. The AMV CP-ILR3 interaction may down-regulate a host factor, NEET, leading to the activation of plant hormone responses to obtain a hormonal equilibrium state, where infection remains at a level that does not affect plant viability. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  11. Inhibition of predator attraction to kairomones by non-host plant volatiles for herbivores: a bypass-trophic signal.

    Directory of Open Access Journals (Sweden)

    Qing-He Zhang

    2010-06-01

    Full Text Available Insect predators and parasitoids exploit attractive chemical signals from lower trophic levels as kairomones to locate their herbivore prey and hosts. We hypothesized that specific chemical cues from prey non-hosts and non-habitats, which are not part of the trophic chain, are also recognized by predators and would inhibit attraction to the host/prey kairomone signals. To test our hypothesis, we studied the olfactory physiology and behavior of a predaceous beetle, Thanasimus formicarius (L. (Coleoptera: Cleridae, in relation to specific angiosperm plant volatiles, which are non-host volatiles (NHV for its conifer-feeding bark beetle prey.Olfactory detection in the clerid was confirmed by gas chromatography coupled to electroantennographic detection (GC-EAD for a subset of NHV components. Among NHV, we identified two strongly antennally active molecules, 3-octanol and 1-octen-3-ol. We tested the potential inhibition of the combination of these two NHV on the walking and flight responses of the clerid to known kairomonal attractants such as synthetic mixtures of bark beetle (Ips spp. aggregation pheromone components (cis-verbenol, ipsdienol, and E-myrcenol combined with conifer (Picea and Pinus spp. monoterpenes (alpha-pinene, terpinolene, and Delta(3-carene. There was a strong inhibitory effect, both in the laboratory (effect size d = -3.2, walking bioassay and in the field (d = -1.0, flight trapping. This is the first report of combining antennal detection (GC-EAD and behavioral responses to identify semiochemical molecules that bypass the trophic system, signaling habitat information rather than food related information.Our results, along with recent reports on hymenopteran parasitoids and coleopteran predators, suggest that some NHV chemicals for herbivores are part of specific behavioral signals for the higher trophic level and not part of a background noise. Such bypass-trophic signals could be of general importance for third trophic level

  12. Defence White Paper 2013

    Science.gov (United States)

    2013-01-01

    nurtured, particularly in Australia’s highly competitive labour market. The Government recognises that Defence’s approach to its people must be... satisfaction , increase attraction and retention, improve cost-effectiveness and support the contemporary Total Force employment model. Defence White...improve job satisfaction and thereby increase attraction and retention in areas of critical skill. Recruiting 10.13 To ensure that we have the high

  13. Opposing roles of Toll-like receptor and cytosolic DNA-STING signaling pathways for Staphylococcus aureus cutaneous host defense.

    Directory of Open Access Journals (Sweden)

    Philip O Scumpia

    2017-07-01

    Full Text Available Successful host defense against pathogens requires innate immune recognition of the correct pathogen associated molecular patterns (PAMPs by pathogen recognition receptors (PRRs to trigger the appropriate gene program tailored to the pathogen. While many PRR pathways contribute to the innate immune response to specific pathogens, the relative importance of each pathway for the complete transcriptional program elicited has not been examined in detail. Herein, we used RNA-sequencing with wildtype and mutant macrophages to delineate the innate immune pathways contributing to the early transcriptional response to Staphylococcus aureus, a ubiquitous microorganism that can activate a wide variety of PRRs. Unexpectedly, two PRR pathways-the Toll-like receptor (TLR and Stimulator of Interferon Gene (STING pathways-were identified as dominant regulators of approximately 95% of the genes that were potently induced within the first four hours of macrophage infection with live S. aureus. TLR signaling predominantly activated a pro-inflammatory program while STING signaling activated an antiviral/type I interferon response with live but not killed S. aureus. This STING response was largely dependent on the cytosolic DNA sensor cyclic guanosine-adenosine synthase (cGAS. Using a cutaneous infection model, we found that the TLR and STING pathways played opposite roles in host defense to S. aureus. TLR signaling was required for host defense, with its absence reducing interleukin (IL-1β production and neutrophil recruitment, resulting in increased bacterial growth. In contrast, absence of STING signaling had the opposite effect, enhancing the ability to restrict the infection. These results provide novel insights into the complex interplay of innate immune signaling pathways triggered by S. aureus and uncover opposing roles of TLR and STING in cutaneous host defense to S. aureus.

  14. Comparing Microbiome Sampling Methods in a Wild Mammal: Fecal and Intestinal Samples Record Different Signals of Host Ecology, Evolution.

    Science.gov (United States)

    Ingala, Melissa R; Simmons, Nancy B; Wultsch, Claudia; Krampis, Konstantinos; Speer, Kelly A; Perkins, Susan L

    2018-01-01

    The gut microbiome is a community of host-associated symbiotic microbes that fulfills multiple key roles in host metabolism, immune function, and tissue development. Given the ability of the microbiome to impact host fitness, there is increasing interest in studying the microbiome of wild animals to better understand these communities in the context of host ecology and evolution. Human microbiome research protocols are well established, but wildlife microbiome research is still a developing field. Currently, there is no standardized set of best practices guiding the collection of microbiome samples from wildlife. Gut microflora are typically sampled either by fecal collection, rectal swabbing, or by destructively sampling the intestinal contents of the host animal. Studies rarely include more than one sampling technique and no comparison of these methods currently exists for a wild mammal. Although some studies have hypothesized that the fecal microbiome is a nested subset of the intestinal microbiome, this hypothesis has not been formally tested. To address these issues, we examined guano (feces) and distal intestinal mucosa from 19 species of free-ranging bats from Lamanai, Belize, using 16S rRNA amplicon sequencing to compare microbial communities across sample types. We found that the diversity and composition of intestine and guano samples differed substantially. In addition, we conclude that signatures of host evolution are retained by studying gut microbiomes based on mucosal tissue samples, but not fecal samples. Conversely, fecal samples retained more signal of host diet than intestinal samples. These results suggest that fecal and intestinal sampling methods are not interchangeable, and that these two microbiotas record different information about the host from which they are isolated.

  15. Comparing Microbiome Sampling Methods in a Wild Mammal: Fecal and Intestinal Samples Record Different Signals of Host Ecology, Evolution

    Directory of Open Access Journals (Sweden)

    Melissa R. Ingala

    2018-05-01

    Full Text Available The gut microbiome is a community of host-associated symbiotic microbes that fulfills multiple key roles in host metabolism, immune function, and tissue development. Given the ability of the microbiome to impact host fitness, there is increasing interest in studying the microbiome of wild animals to better understand these communities in the context of host ecology and evolution. Human microbiome research protocols are well established, but wildlife microbiome research is still a developing field. Currently, there is no standardized set of best practices guiding the collection of microbiome samples from wildlife. Gut microflora are typically sampled either by fecal collection, rectal swabbing, or by destructively sampling the intestinal contents of the host animal. Studies rarely include more than one sampling technique and no comparison of these methods currently exists for a wild mammal. Although some studies have hypothesized that the fecal microbiome is a nested subset of the intestinal microbiome, this hypothesis has not been formally tested. To address these issues, we examined guano (feces and distal intestinal mucosa from 19 species of free-ranging bats from Lamanai, Belize, using 16S rRNA amplicon sequencing to compare microbial communities across sample types. We found that the diversity and composition of intestine and guano samples differed substantially. In addition, we conclude that signatures of host evolution are retained by studying gut microbiomes based on mucosal tissue samples, but not fecal samples. Conversely, fecal samples retained more signal of host diet than intestinal samples. These results suggest that fecal and intestinal sampling methods are not interchangeable, and that these two microbiotas record different information about the host from which they are isolated.

  16. Altruistic defence behaviours in aphids

    Directory of Open Access Journals (Sweden)

    Brodeur Jacques

    2010-01-01

    Full Text Available Abstract Background Altruistic anti-predatory behaviours pose an evolutionary problem because they are costly to the actor and beneficial to the recipients. Altruistic behaviours can evolve through indirect fitness benefits when directed toward kin. The altruistic nature of anti-predatory behaviours is often difficult to establish because the actor can obtain direct fitness benefits, or the behaviour could result from selfish coercion by others, especially in eusocial animals. Non-eusocial parthenogenetically reproducing aphids form colonies of clone-mates, which are ideal to test the altruistic nature of anti-predatory defence behaviours. Many aphids release cornicle secretions when attacked by natural enemies such as parasitoids. These secretions contain an alarm pheromone that alerts neighbours (clone-mates of danger, thereby providing indirect fitness benefits to the actor. However, contact with cornicle secretions also hampers an attacker and could provide direct fitness to the actor. Results We tested the hypothesis that cornicle secretions are altruistic by assessing direct and indirect fitness consequences of smearing cornicle secretions onto an attacker, and by manipulating the number of clone-mates that could benefit from the behaviour. We observed parasitoids, Aphidius rhopalosiphi, foraging singly in patches of the cereal aphid Sitobion avenae of varied patch size (2, 6, and 12 aphids. Aphids that smeared parasitoids did not benefit from a reduced probability of parasitism, or increase the parasitoids' handling time. Smeared parasitoids, however, spent proportionately more time grooming and less time foraging, which resulted in a decreased host-encounter and oviposition rate within the host patch. In addition, individual smearing rate increased with the number of clone-mates in the colony. Conclusions Cornicle secretions of aphids were altruistic against parasitoids, as they provided no direct fitness benefits to secretion

  17. Activation of Host IRE1α-Dependent Signaling Axis Contributes the Intracellular Parasitism of Brucella melitensis

    Directory of Open Access Journals (Sweden)

    Aseem Pandey

    2018-04-01

    Full Text Available Brucella spp. are intracellular vacuolar pathogens that causes brucellosis, a worldwide zoonosis of profound importance. We previously demonstrated that the activity of host unfolded protein response (UPR sensor IRE1α (inositol-requiring enzyme 1 and ER-associated autophagy confer susceptibility to Brucella melitensis and Brucella abortus intracellular replication. However, the mechanism by which host IRE1α regulates the pathogen intracellular lifestyle remains elusive. In this study, by employing a diverse array of molecular approaches, including biochemical analyses, fluorescence microscopy imaging, and infection assays using primary cells derived from Ern1 (encoding IRE1 conditional knockout mice, we address this gap in our understanding by demonstrating that a novel IRE1α to ULK1, an important component for autophagy initiation, signaling axis confers susceptibility to Brucella intracellular parasitism. Importantly, deletion or inactivation of key signaling components along this axis, including IRE1α, BAK/BAX, ASK1, and JNK as well as components of the host autophagy system ULK1, Atg9a, and Beclin 1, resulted in striking disruption of Brucella intracellular trafficking and replication. Host kinases in the IRE1α-ULK1 axis, including IRE1α, ASK1, JNK1, and/or AMPKα as well as ULK1, were also coordinately phosphorylated in an IRE1α-dependent fashion upon the pathogen infection. Taken together, our findings demonstrate that the IRE1α-ULK1 signaling axis is subverted by the bacterium to promote intracellular parasitism, and provide new insight into our understanding of the molecular mechanisms of intracellular lifestyle of Brucella.

  18. A stilbene synthase allele from a Chinese wild grapevine confers resistance to powdery mildew by recruiting salicylic acid signalling for efficient defence.

    Science.gov (United States)

    Jiao, Yuntong; Xu, Weirong; Duan, Dong; Wang, Yuejin; Nick, Peter

    2016-10-01

    Stilbenes are central phytoalexins in Vitis, and induction of the key enzyme stilbene synthase (STS) is pivotal for disease resistance. Here, we address the potential for breeding resistance using an STS allele isolated from Chinese wild grapevine Vitis pseudoreticulata (VpSTS) by comparison with its homologue from Vitis vinifera cv. 'Carigane' (VvSTS). Although the coding regions of both alleles are very similar (>99% identity on the amino acid level), the promoter regions are significantly different. By expression in Arabidopsis as a heterologous system, we show that the allele from the wild Chinese grapevine can confer accumulation of stilbenes and resistance against the powdery mildew Golovinomyces cichoracearum, whereas the allele from the vinifera cultivar cannot. To dissect the upstream signalling driving the activation of this promoter, we used a dual-luciferase reporter system in a grapevine cell culture. We show elevated responsiveness of the promoter from the wild grape to salicylic acid (SA) and to the pathogen-associated molecular pattern (PAMP) flg22, equal induction of both alleles by jasmonic acid (JA), and a lack of response to the cell death-inducing elicitor Harpin. This elevated SA response of the VpSTS promoter depends on calcium influx, oxidative burst by RboH, mitogen-activated protein kinase (MAPK) signalling, and JA synthesis. We integrate the data in the context of a model where the resistance of V. pseudoreticulata is linked to a more efficient recruitment of SA signalling for phytoalexin synthesis. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  19. Identification of plant defence regulators through transcriptional ...

    Indian Academy of Sciences (India)

    2015-02-04

    Feb 4, 2015 ... defence-related genes also supports constitutive activation of defence in cdd1. We screened T-DNA ..... identified through this work as novel plant defence regu- ... to drought stress than untransformed plants (Lee et al. 2012).

  20. Multivalent adhesion molecule 7 clusters act as signaling platform for host cellular GTPase activation and facilitate epithelial barrier dysfunction.

    Directory of Open Access Journals (Sweden)

    Jenson Lim

    2014-09-01

    Full Text Available Vibrio parahaemolyticus is an emerging bacterial pathogen which colonizes the gastrointestinal tract and can cause severe enteritis and bacteraemia. During infection, V. parahaemolyticus primarily attaches to the small intestine, where it causes extensive tissue damage and compromises epithelial barrier integrity. We have previously described that Multivalent Adhesion Molecule (MAM 7 contributes to initial attachment of V. parahaemolyticus to epithelial cells. Here we show that the bacterial adhesin, through multivalent interactions between surface-induced adhesin clusters and phosphatidic acid lipids in the host cell membrane, induces activation of the small GTPase RhoA and actin rearrangements in host cells. In infection studies with V. parahaemolyticus we further demonstrate that adhesin-triggered activation of the ROCK/LIMK signaling axis is sufficient to redistribute tight junction proteins, leading to a loss of epithelial barrier function. Taken together, these findings show an unprecedented mechanism by which an adhesin acts as assembly platform for a host cellular signaling pathway, which ultimately facilitates breaching of the epithelial barrier by a bacterial pathogen.

  1. Operational Analysis on Torpedo Defence

    NARCIS (Netherlands)

    Grootendorst, H.J.; Benders, F.P.A.; Fitski, H.J.; Veldhoven, E.R. van

    2007-01-01

    Since 1998, TNO Defence, Security and Safety has performed operational analysis with the Underwater Warfare Testbed, which provides an environment for evaluation and validation of systems, concepts, and tactics. On top of this testbed the Torpedo Defence System TestBed has been built to simulate

  2. Impact of 4 Lactobacillus plantarum capsular polysaccharide clusters on surface glycan composition and host cell signaling

    NARCIS (Netherlands)

    Remus, D.M.; Kranenburg, van R.; Swam, van I.I.; Taverne, N.; Bongers, R.S.; Wels, M.; Wells, J.; Bron, P.A.; Kleerebezem, M.

    2012-01-01

    Background - Bacterial cell surface-associated polysaccharides are involved in the interactions of bacteria with their environment and play an important role in the communication between pathogenic bacteria and their host organisms. Cell surface polysaccharides of probiotic species are far less well

  3. Pathogenic leptospires modulate protein expression and post-translational modifications in response to mammalian host signals

    Science.gov (United States)

    Pathogenic species of Leptospira cause leptospirosis, a bacterial zoonotic disease with a global distribution affecting over one million people annually. Reservoir hosts of leptospirosis, including rodents, dogs and cattle, exhibit little to no signs of disease but shed large numbers of organisms in...

  4. Inhibition of host extracellular signal-regulated kinase (ERK) activation decreases new world alphavirus multiplication in infected cells

    Energy Technology Data Exchange (ETDEWEB)

    Voss, Kelsey; Amaya, Moushimi [National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA (United States); Mueller, Claudius [Center for Applied Proteomics and Personalized Medicine, George Mason University, 10900 University Boulevard, Manassas, VA (United States); Roberts, Brian [Leidos Health Life Sciences, 5202 Presidents Court, Suite 110, Frederick, MD (United States); Kehn-Hall, Kylene; Bailey, Charles [National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA (United States); Petricoin, Emanuel [Center for Applied Proteomics and Personalized Medicine, George Mason University, 10900 University Boulevard, Manassas, VA (United States); Narayanan, Aarthi, E-mail: anaraya1@gmu.edu [National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA (United States)

    2014-11-15

    New World alphaviruses belonging to the family Togaviridae are classified as emerging infectious agents and Category B select agents. Our study is focused on the role of the host extracellular signal-regulated kinase (ERK) in the infectious process of New World alphaviruses. Infection of human cells by Venezuelan equine encephalitis virus (VEEV) results in the activation of the ERK-signaling cascade. Inhibition of ERK1/2 by the small molecule inhibitor Ag-126 results in inhibition of viral multiplication. Ag-126-mediated inhibition of VEEV was due to potential effects on early and late stages of the infectious process. While expression of viral proteins was down-regulated in Ag-126 treated cells, we did not observe any influence of Ag-126 on the nuclear distribution of capsid. Finally, Ag-126 exerted a broad-spectrum inhibitory effect on New World alphavirus multiplication, thus indicating that the host kinase, ERK, is a broad-spectrum candidate for development of novel therapeutics against New World alphaviruses. - Highlights: • VEEV infection activated multiple components of the ERK signaling cascade. • Inhibition of ERK activation using Ag-126 inhibited VEEV multiplication. • Activation of ERK by Ceramide C6 increased infectious titers of TC-83. • Ag-126 inhibited virulent strains of all New World alphaviruses. • Ag-126 treatment increased percent survival of infected cells.

  5. Inhibition of host extracellular signal-regulated kinase (ERK) activation decreases new world alphavirus multiplication in infected cells

    International Nuclear Information System (INIS)

    Voss, Kelsey; Amaya, Moushimi; Mueller, Claudius; Roberts, Brian; Kehn-Hall, Kylene; Bailey, Charles; Petricoin, Emanuel; Narayanan, Aarthi

    2014-01-01

    New World alphaviruses belonging to the family Togaviridae are classified as emerging infectious agents and Category B select agents. Our study is focused on the role of the host extracellular signal-regulated kinase (ERK) in the infectious process of New World alphaviruses. Infection of human cells by Venezuelan equine encephalitis virus (VEEV) results in the activation of the ERK-signaling cascade. Inhibition of ERK1/2 by the small molecule inhibitor Ag-126 results in inhibition of viral multiplication. Ag-126-mediated inhibition of VEEV was due to potential effects on early and late stages of the infectious process. While expression of viral proteins was down-regulated in Ag-126 treated cells, we did not observe any influence of Ag-126 on the nuclear distribution of capsid. Finally, Ag-126 exerted a broad-spectrum inhibitory effect on New World alphavirus multiplication, thus indicating that the host kinase, ERK, is a broad-spectrum candidate for development of novel therapeutics against New World alphaviruses. - Highlights: • VEEV infection activated multiple components of the ERK signaling cascade. • Inhibition of ERK activation using Ag-126 inhibited VEEV multiplication. • Activation of ERK by Ceramide C6 increased infectious titers of TC-83. • Ag-126 inhibited virulent strains of all New World alphaviruses. • Ag-126 treatment increased percent survival of infected cells

  6. Radiation protection in civil defence

    International Nuclear Information System (INIS)

    Ahlborn, K.

    The brochure contains the information given to the participants of an advanced training course in civil defence, on the subject of radiation protection. The course was held by teachers of Bundesverband fuer den Selbstschutz (BVS). (orig.) [de

  7. Characterization of Arabidopsis Transcriptional Responses to Different Aphid Species Reveals Genes that Contribute to Host Susceptibility and Non-host Resistance

    Science.gov (United States)

    Jaouannet, Maëlle; Morris, Jenny A.; Hedley, Peter E.; Bos, Jorunn I. B.

    2015-01-01

    Aphids are economically important pests that display exceptional variation in host range. The determinants of diverse aphid host ranges are not well understood, but it is likely that molecular interactions are involved. With significant progress being made towards understanding host responses upon aphid attack, the mechanisms underlying non-host resistance remain to be elucidated. Here, we investigated and compared Arabidopsis thaliana host and non-host responses to aphids at the transcriptional level using three different aphid species, Myzus persicae, Myzus cerasi and Rhopalosiphum pisum. Gene expression analyses revealed a high level of overlap in the overall gene expression changes during the host and non-host interactions with regards to the sets of genes differentially expressed and the direction of expression changes. Despite this overlap in transcriptional responses across interactions, there was a stronger repression of genes involved in metabolism and oxidative responses specifically during the host interaction with M. persicae. In addition, we identified a set of genes with opposite gene expression patterns during the host versus non-host interactions. Aphid performance assays on Arabidopsis mutants that were selected based on our transcriptome analyses identified novel genes contributing to host susceptibility, host defences during interactions with M. persicae as well to non-host resistance against R. padi. Understanding how plants respond to aphid species that differ in their ability to infest plant species, and identifying the genes and signaling pathways involved, is essential for the development of novel and durable aphid control in crop plants. PMID:25993686

  8. Probabilistic Flood Defence Assessment Tools

    Directory of Open Access Journals (Sweden)

    Slomp Robert

    2016-01-01

    Full Text Available The WTI2017 project is responsible for the development of flood defence assessment tools for the 3600 km of Dutch primary flood defences, dikes/levees, dunes and hydraulic structures. These tools are necessary, as per January 1st 2017, the new flood risk management policy for the Netherlands will be implemented. Then, the seven decades old design practice (maximum water level methodology of 1958 and two decades old safety standards (and maximum hydraulic load methodology of 1996 will formally be replaced by a more risked based approach for the national policy in flood risk management. The formal flood defence assessment is an important part of this new policy, especially for flood defence managers, since national and regional funding for reinforcement is based on this assessment. This new flood defence policy is based on a maximum allowable probability of flooding. For this, a maximum acceptable individual risk was determined at 1/100 000 per year, this is the probability of life loss of for every protected area in the Netherlands. Safety standards of flood defences were then determined based on this acceptable individual risk. The results were adjusted based on information from cost -benefit analysis, societal risk and large scale societal disruption due to the failure of critical infrastructure e.g. power stations. The resulting riskbased flood defence safety standards range from a 300 to a 100 000 year return period for failure. Two policy studies, WV21 (Safety from floods in the 21st century and VNK-2 (the National Flood Risk in 2010 provided the essential information to determine the new risk based safety standards for flood defences. The WTI2017 project will provide the safety assessment tools based on these new standards and is thus an essential element for the implementation of this policy change. A major issue to be tackled was the development of user-friendly tools, as the new assessment is to be carried out by personnel of the

  9. Defence in depth perspectives

    International Nuclear Information System (INIS)

    Veneau, Tania; Ferrier, Agnes; Barbaud, Jean

    2017-01-01

    The Defence in Depth (DiD) concept was introduced to the field of nuclear safety in the sixties and early seventies. Even though it was not well developed at the beginning, the principles rapidly became close to those currently used. The concept was then composed of 3 levels, and was already associated with operating conditions. These principles have progressed over time and now there are five levels, including progressively situations issued from design extension conditions, to cope with severe accidents and dealing with accident management off-site. Indeed, human and organizational features are considered as a part of the safety provisions at all levels in an integrated approach that is not just related to reactor design. That's the current vision from IAEA, addressed first in INSAG 3 then in INSAG 10, and in the IAEA standards requirements currently addressed by SSR-2/1 superseding NS-R-1). These five levels of DiD are also referred to in other texts including WENRA documents in Europe, but also in the national requirements from different countries. Thus, the application of DiD principle has become a recognized international practice. The 2011 Fukushima Daiichi accidents, even if they raised many questions on nuclear safety issues, confirmed the merits of the DiD concept. Indeed, lessons learned from the accidents have reinforced the use of the DiD concept to ensure adequate safety. The discussions focused more on the implementation of the concept (how it has been or can be used in practice) than the concept itself, and in particular on the following subjects: the notion of level robustness, generally addressed separately from the levels definition, but playing an important role for the efficiency of the concept; the notion of levels independence and the need for strengthening them; the role of diversity to achieve levels independence. However, a prescription of additional diversity and independence across all safety levels could result in inappropriately

  10. In Defence of Pashukanism

    Directory of Open Access Journals (Sweden)

    R Koen

    2011-07-01

    Full Text Available This essay presents an extended defence of the general theory of law formulated by the Bolshevik jurist, Evgeny Pashukanis, and published in his Law and Marxism: A General Theory in 1924. The general theory is a theory of the legal form. Although Pashukanis did not name his theory, it has become known as the commodity form theory of law because of its theorising the legal form as a homologue of the commodity form. However, despite having weighty Marxist and revolutionary Bolshevik credentials, the general theory has been subjected to sustained attack, especially from new left and neo-Marxist circles. This essay identifies and explicates six major objections to Pashukanism from its left critics. These are that the general theory is too abstract to comprehend the reality of legal relations; that it is infused with economic reductionism; that it derives the legal form wrongly from commodity exchange; that it classifies the legal form incorrectly as an attribute of capitalism only; that it lacks the generality required of a general theory of law; and that it is imbricated in the growth of anarchism and Stalinism. Following a brief exegetical exercise, the bulk of the essay is devoted to demonstrating in detail that each of the six objections to the general theory is without merit, and that none makes any serious incursion into its integrity as a theory of the legal form. The central submission of the essay is that the Pashukanist general theory of law is rooted in the first principles of classical Marxism and hence may lay claim legitimately to being the Marxist theory of law.

  11. Signal transduction of Helicobacter pylori during interaction with host cell protein receptors of epithelial and immune cells

    Science.gov (United States)

    Pachathundikandi, Suneesh Kumar; Tegtmeyer, Nicole; Backert, Steffen

    2013-01-01

    Helicobacter pylori infections can induce pathologies ranging from chronic gastritis, peptic ulceration to gastric cancer. Bacterial isolates harbor numerous well-known adhesins, vacuolating cytotoxin VacA, protease HtrA, urease, peptidoglycan, and type IV secretion systems (T4SS). It appears that H. pylori targets more than 40 known host protein receptors on epithelial or immune cells. A series of T4SS components such as CagL, CagI, CagY, and CagA can bind to the integrin α5β1 receptor. Other targeted membrane-based receptors include the integrins αvβ3, αvβ5, and β2 (CD18), RPTP-α/β, GP130, E-cadherin, fibronectin, laminin, CD46, CD74, ICAM1/LFA1, T-cell receptor, Toll-like receptors, and receptor tyrosine kinases EGFR, ErbB2, ErbB3, and c-Met. In addition, H. pylori is able to activate the intracellular receptors NOD1, NOD2, and NLRP3 with important roles in innate immunity. Here we review the interplay of various bacterial factors with host protein receptors. The contribution of these interactions to signal transduction and pathogenesis is discussed. PMID:24280762

  12. Co-ordinate regulation of distinct host cell signalling pathways by multifunctional enteropathogenic Escherichia coli effector molecules.

    Science.gov (United States)

    Kenny, Brendan; Ellis, Sarah; Leard, Alan D; Warawa, Jonathan; Mellor, Harry; Jepson, Mark A

    2002-05-01

    Enteropathogenic Escherichia coli (EPEC) is a major cause of paediatric diarrhoea and a model for the family of attaching and effacing (A/E) pathogens. A/E pathogens encode a type III secretion system to transfer effector proteins into host cells. The EPEC Tir effector protein acts as a receptor for the bacterial surface protein intimin and is involved in the formation of Cdc42-independent, actin-rich pedestal structures beneath the adhered bacteria. In this paper, we demonstrate that EPEC binding to HeLa cells also induces Tir-independent, cytoskeletal rearrangement evidenced by the early, transient formation of filopodia-like structures at sites of infection. Filopodia formation is dependent on expression of the EPEC Map effector molecule - a protein that targets mitochondria and induces their dysfunction. We show that Map-induced filopodia formation is independent of mitochondrial targeting and is abolished by cellular expression of the Cdc42 inhibitory WASP-CRIB domain, demonstrating that Map has at least two distinct functions in host cells. The transient nature of the filopodia is related to an ability of EPEC to downregulate Map-induced cell signalling that, like pedestal formation, was dependent on both Tir and intimin proteins. The ability of Tir to downregulate filopodia was impaired by disrupting a putative GTPase-activating protein (GAP) motif, suggesting that Tir may possess such a function, with its interaction with intimin triggering this activity. Furthermore, we also found that Map-induced cell signalling inhibits pedestal formation, revealing that the cellular effects of Tir and Map must be co-ordinately regulated during infection. Possible implications of the multifunctional nature of EPEC effector molecules in pathogenesis are discussed.

  13. Operational Analysis on Torpedo Defence

    NARCIS (Netherlands)

    Grootendordt, H.J.; Benders, F.P.A.; Fitski, H.J.; Veldhoven, E.R. van

    2008-01-01

    Surface vessels and submarines must be able to defend themselves against a torpedo attack. Self-defence can be approached as a modular concept. The first module involves 'Detection, Classification and Localisation (DCL)'. DCL triggers the second module: the 'evaluator'. This module starts the last

  14. Civil defence information for every home

    International Nuclear Information System (INIS)

    Joutsi, L.

    1995-01-01

    In Finland, the local authorities and the central government are responsible for the general planning of civil defence and for joint protection measures, while individual citizens and corporations are responsible for individual protection measures. In practice, housing companies and employers are required to carry out the statutory preparations needed for civil defence. Preparation for accidents can be improved, for instance, by awareness of correct actions in each situation. The most important individual protection measures are first aid, basic fire extinguishing skills, provision of shelter, and acquisition of a reserve stock of provisions at home. A reserve stock means that there is a sufficient supply of non-perishable foodstuffs, medication and water vessels for a couple of days' needs at home. A warning of imminent danger is usually given by sounding a general alarm signal. Even slight changes in radiation are reported immediately. Shelter should primarily be sought indoors. Instructions may be given on the radio, on TV and by means of loudspeakers. If there is a radiation risk, the thyroid may be protected against radioactive iodine by taking iodine tablets, but they should not be taken until so instructed by the authorities. (2 figs.)

  15. Recombinant Brugia malayi pepsin inhibitor (rBm33) exploits host signaling events to regulate inflammatory responses associated with lymphatic filarial infections.

    Science.gov (United States)

    Sreenivas, Kirthika; Kalyanaraman, Haripriya; Babu, Subash; Narayanan, Rangarajan Badri

    2017-11-01

    Prolonged existence of filarial parasites and their molecules within the host modulate the host immune system to instigate their survival and induce inflammatory responses that contribute to disease progression. Recombinant Brugia malayi pepsin inhibitor (rBm33) modulates the host immune responses by skewing towards Th1 responses characterized by secretion of inflammatory molecules such as TNF-α, IL-6, nitric oxide (NO). Here we also specified the molecular signaling events triggered by rBm33 in peripheral blood mononuclear cells (PBMCs) of filarial endemic normals (EN). rBm33 predominantly enhanced the levels of nitric oxide in cultured PBMCs but did not result in oxidative stress to the host cells. Further, rBm33 treatment of human PBMCs resulted in higher GSH/GSSG levels. MYD88 dependent activation was found to be associated with rBm33 specific inflammatory cytokine production. rBm33 triggered intracellular signaling events also involved JNK activation in host PBMCs. In addition, c-Fos and not NF-κB was identified as the transcription factor regulating the expression of inflammatory cytokines in rBm33 stimulated PBMCs. rBm33 marked its role in filarial pathology by altered levels of growth factors but did not have a significant impact on matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs) activity of host PBMCs. Thus, the study outlines the signaling network of rBm33 induced inflammatory responses within the host immune cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Recent host range expansion of canine distemper virus and variation in its receptor, the signaling lymphocyte activation molecule, in carnivores.

    Science.gov (United States)

    Ohishi, Kazue; Suzuki, Rintaro; Maeda, Taro; Tsuda, Miwako; Abe, Erika; Yoshida, Takao; Endo, Yasuyuki; Okamura, Maki; Nagamine, Takashi; Yamamoto, Hanae; Ueda, Miya; Maruyama, Tadashi

    2014-07-01

    The signaling lymphocyte activation molecule (SLAM) is a receptor for morbilliviruses. To understand the recent host range expansion of canine distemper virus (CDV) in carnivores, we determined the nucleotide sequences of SLAMs of various carnivores and generated three-dimensional homology SLAM models. Thirty-four amino acid residues were found for the candidates binding to CDV on the interface of the carnivore SLAMs. SLAM of the domestic dog (Canis lupus familiaris) were similar to those of other members of the suborder Caniformia, indicating that the animals in this group have similar sensitivity to dog CDV. However, they were different at nine positions from those of felids. Among the nine residues, four of domestic cat (Felis catus) SLAM (72, 76, 82, and 129) and three of lion (Panthera leo persica) SLAM (72, 82, and 129) were associated with charge alterations, suggesting that the felid interfaces have lower affinities to dog CDV. Only the residue at 76 was different between domestic cat and lion SLAM interfaces. The domestic cat SLAM had threonine at 76, whereas the lion SLAM had arginine, a positively charged residue like that of the dog SLAM. The cat SLAM with threonine is likely to have lower affinity to CDV-H and to confer higher resistance against dog CDV. Thus, the four residues (72, 76, 82, and 129) on carnivore SLAMs are important for the determination of affinity and sensitivity with CDV. Additionally, the CDV-H protein of felid strains had a substitution of histidine for tyrosine at 549 of dog CDV-H and may have higher affinity to lion SLAM. Three-dimensional model construction is a new risk assessment method of morbillivirus infectivity. Because the method is applicable to animals that have no information about virus infection, it is especially useful for morbillivirus risk assessment and wildlife conservation.

  17. The Pseudomonas aeruginosa lectin LecA triggers host cell signalling by glycosphingolipid-dependent phosphorylation of the adaptor protein CrkII.

    Science.gov (United States)

    Zheng, Shuangshuang; Eierhoff, Thorsten; Aigal, Sahaja; Brandel, Annette; Thuenauer, Roland; de Bentzmann, Sophie; Imberty, Anne; Römer, Winfried

    2017-07-01

    The human pathogen Pseudomonas aeruginosa induces phosphorylation of the adaptor protein CrkII by activating the non-receptor tyrosine kinase Abl to promote its uptake into host cells. So far, specific factors of P. aeruginosa, which induce Abl/CrkII signalling, are entirely unknown. In this research, we employed human lung epithelial cells H1299, Chinese hamster ovary cells and P. aeruginosa wild type strain PAO1 to study the invasion process of P. aeruginosa into host cells by using microbiological, biochemical and cell biological approaches such as Western Blot, immunofluorescence microscopy and flow cytometry. Here, we demonstrate that the host glycosphingolipid globotriaosylceramide, also termed Gb3, represents a signalling receptor for the P. aeruginosa lectin LecA to induce CrkII phosphorylation at tyrosine 221. Alterations in Gb3 expression and LecA function correlate with CrkII phosphorylation. Interestingly, phosphorylation of CrkII Y221 occurs independently of Abl kinase. We further show that Src family kinases transduce the signal induced by LecA binding to Gb3, leading to Crk Y221 phosphorylation. In summary, we identified LecA as a bacterial factor, which utilizes a so far unrecognized mechanism for phospho-CrkII Y221 induction by binding to the host glycosphingolipid receptor Gb3. The LecA/Gb3 interaction highlights the potential of glycolipids to mediate signalling processes across the plasma membrane and should be further elucidated to gain deeper insights into this non-canonical mechanism of activating host cell processes. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Susceptibility and Immune Defence Mechanisms of Rhynchophorus ferrugineus (Olivier (Coleoptera: Curculionidae against Entomopathogenic Fungal Infections

    Directory of Open Access Journals (Sweden)

    Abid Hussain

    2016-09-01

    Full Text Available Insects infected with entomopathogenic fungi, experience physiological changes that influence their growth and immune defence. The potential of nine isolates of entomopathogenic fungi was evaluated after determining percent germination and relative conidial hydrophobicity. However, nutritional indices were evaluated after immersing eighth-instar Rhynchophorus ferrugineus larvae into each isolate suspension (1 × 107 conidia/mL. The results showed that isolates B6884 and M9374 had 44.51% and 39.02% higher conidial hydrophobicity compared with isolate I03011 (least virulent. The results of nutritional index assays revealed a significant reduction in growth indices after infection with different isolates. Compared with control, B6884 and M9374 greatly decreased larval growth by reducing the efficacy of conversion of ingested food (36%–47% and Efficacy of conversion of digested food (50%–63%. Furthermore, only isolate B6884 induced 100% mortality within 12 days. Compared with control, isolate I03011, possessing the lowest conidial hydrophobicity, only reduced 0.29% of the efficacy of conversion of ingested food (ECI and 0.48% of the efficacy of conversion of digested food (ECD. Similarly, transcriptomic analysis of genes related to the Red palm weevil (RPW immune response, including pathogen recognition receptors (C-type lectin and endo-beta-1,4-glucanse, signal modulator (Serine protease-like protein, signal transductors (Calmodulin-like protein and EF-hand domain containing protein and effectors (C-type lysozyme, Cathepsin L., Defensin-like protein, Serine carboxypeptidase, and Thaumatin-like protein, was significantly increased in larval samples infected with B6884 and M9374. These results suggest that for an isolate to be virulent, conidial hydrophobicity and germination should also be considered during pathogen selection, as these factors could significantly impact host growth and immune defence mechanisms.

  19. The reconfiguration of the SA defence industry in the post-2015-defence review environment: prospects & challenges

    CSIR Research Space (South Africa)

    Khanyile, Moses

    2017-10-01

    Full Text Available IMPLICATIONS • Licence category (FSB) • Credit licence (NCR) • Forex Licence (SARB) Armscor & AMD Initiative: Establishment of the Defence Industry Fund (DIF) WAY FORWARD Finalisation of the Defence Industry Strategy Drafting...

  20. Piloting Snapchat for Finnish Defence Forces

    OpenAIRE

    Immonen, Helena

    2016-01-01

    This thesis is about piloting Snapchat for Finnish Defence Forces. The goals for the thesis are to find out how Snapchat can be used as part of Finnish Defence Forces’ social media communication and strategy. Conscripts are the most important target group for social media communication in the Defence Forces. Young conscripts are the main target group for Snapchat. This thesis is theoretically based on organizational communication, stakeholder communication and social media communicati...

  1. Driving Danish Defence Towards Political Goals

    Science.gov (United States)

    2016-06-10

    discuss the political agreement.90 The Defence Chief of Staff is interviewed in the same paper along the same lines, where he provides an in- depth ...DRIVING DANISH DEFENCE TOWARDS POLITICAL GOALS A thesis presented to the Faculty of the U.S. Army Command and General Staff...4. TITLE AND SUBTITLE Driving Danish Defence Towards Political Goals 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  2. Light exposure at night disrupts host/cancer circadian regulatory dynamics: impact on the Warburg effect, lipid signaling and tumor growth prevention.

    Directory of Open Access Journals (Sweden)

    David E Blask

    Full Text Available The central circadian clock within the suprachiasmatic nucleus (SCN plays an important role in temporally organizing and coordinating many of the processes governing cancer cell proliferation and tumor growth in synchrony with the daily light/dark cycle which may contribute to endogenous cancer prevention. Bioenergetic substrates and molecular intermediates required for building tumor biomass each day are derived from both aerobic glycolysis (Warburg effect and lipid metabolism. Using tissue-isolated human breast cancer xenografts grown in nude rats, we determined that circulating systemic factors in the host and the Warburg effect, linoleic acid uptake/metabolism and growth signaling activities in the tumor are dynamically regulated, coordinated and integrated within circadian time structure over a 24-hour light/dark cycle by SCN-driven nocturnal pineal production of the anticancer hormone melatonin. Dim light at night (LAN-induced melatonin suppression disrupts this circadian-regulated host/cancer balance among several important cancer preventative signaling mechanisms, leading to hyperglycemia and hyperinsulinemia in the host and runaway aerobic glycolysis, lipid signaling and proliferative activity in the tumor.

  3. Host defence against disseminated and invasive candida albicans infections.

    NARCIS (Netherlands)

    Vonk, A.G.

    2004-01-01

    The yeast Candida albicans is the primary etiologic agent of disseminated and invasive candidiasis. The incidence of disseminated and invasive candidiasis has paralleled the use of modern medical procedures that adversely affect the immune system, and highlights the difficulty of treating

  4. Invited Lecture: From Host Defence Peptides to New Antibiotics

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    Antimicrobial peptides hold promise as the next generation of antimicrobial agents. However, the potential is weakened by their susceptibility to proteolytic degradation, poor bioavailabillity , toxicity and high cost. Our research interest is in determining the structure/activity relationships o...... the elucidation of their structure/activity relationships, and our efforts towards developing them into antibiotics....

  5. Cross Border EU Defence Industry Consolidation between Globalization and Europeanization

    DEFF Research Database (Denmark)

    Kluth, Michael Friederich

    as it constitute a rendezvous of traditional market-based efficiency logics and concerns over sovereignty. Moreover, the defence industry has been an institutional island still exhibiting all the national protectionist mechanisms that European integration mostly has done away with in other sectors. The paper...... will depart from these institutional peculiarities drawing on the varieties of capitalism literature. Different patterns in ownership, public-private R&D links and business promotion policies are a key constraint in cross-border mergers. This is compounded by sovereignty concerns hosted by the national...

  6. CSIR eNews: Defence peace safety and security

    CSIR Research Space (South Africa)

    CSIR

    2009-08-01

    Full Text Available , peace, safety and security. CSIR Defence, Peace, Safety and Security provides a national defence S&T capability: supplying knowledge, advice and solutions in defence and matters of national security....

  7. Plant pathology: monitoring a pathogen-targeted host protein.

    Science.gov (United States)

    Ellis, Jeff; Dodds, Peter

    2003-05-13

    A plant protein RIN4 is targeted and modified by bacterial pathogens as part of the disease process. At least two host resistance proteins monitor this pathogen interference and trigger the plant's defence responses.

  8. The Drosophila melanogaster host model

    Science.gov (United States)

    Igboin, Christina O.; Griffen, Ann L.; Leys, Eugene J.

    2012-01-01

    The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed. PMID:22368770

  9. The Drosophila melanogaster host model

    Directory of Open Access Journals (Sweden)

    Christina O. Igboin

    2012-02-01

    Full Text Available The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed.

  10. The Drosophila melanogaster host model.

    Science.gov (United States)

    Igboin, Christina O; Griffen, Ann L; Leys, Eugene J

    2012-01-01

    The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen-host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial-host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis-host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed.

  11. Defence electro-optics: European perspective

    Science.gov (United States)

    Hartikainen, Jari

    2011-11-01

    In 2009 the United States invested in defence R&T 3,6 times and in defence research and development 6,8 times as much as all member states of the European Defence Agency (EDA) combined while the ratio in the total defence expenditure was 2,6 in the US' favour. The European lack of investments in defence research and development has a negative impact on the competitiveness of European defence industry and on the European non-dependence. In addition, the efficiency of investment is reduced due to duplication of work in different member states. The Lisbon Treaty tasks EDA to support defence technology research, and coordinate and plan joint research activities and the study of technical solutions meeting future operational needs. This paper gives an overview how EDA meets the challenge of improving the efficiency of European defence R&T investment with an emphasis on electro-optics and describes shortly the ways that governmental and industrial partners can participate in the EDA cooperation. Examples of joint R&T projects addressing electro-optics are presented.

  12. Defence counsel in international criminal law

    NARCIS (Netherlands)

    Temminck Tuinstra, J.P.W.

    2009-01-01

    The field of international criminal law is relatively new and rapidly developing. This dissertation examines whether international criminal courts enable defence counsel to conduct an effective defence. When the International Criminal Tribunals for the former Yugoslavia and Rwanda (the ad hoc

  13. The South African National Defence Force

    DEFF Research Database (Denmark)

    Mandrup, Thomas

    2009-01-01

    This research paper is an evaluation of The Souch African National Defence Force´s (SANDF) involvement in Peace Support Operations.......This research paper is an evaluation of The Souch African National Defence Force´s (SANDF) involvement in Peace Support Operations....

  14. A Family of Salmonella Type III Secretion Effector Proteins Selectively Targets the NF-κB Signaling Pathway to Preserve Host Homeostasis.

    Science.gov (United States)

    Sun, Hui; Kamanova, Jana; Lara-Tejero, Maria; Galán, Jorge E

    2016-03-01

    Microbial infections usually lead to host innate immune responses and inflammation. These responses most often limit pathogen replication although they can also result in host-tissue damage. The enteropathogenic bacteria Salmonella Typhimurium utilizes a type III secretion system to induce intestinal inflammation by delivering specific effector proteins that stimulate signal transduction pathways resulting in the production of pro-inflammatory cytokines. We show here that a family of related Salmonella Typhimurium effector proteins PipA, GogA and GtgA redundantly target components of the NF-κB signaling pathway to inhibit transcriptional responses leading to inflammation. We show that these effector proteins are proteases that cleave both the RelA (p65) and RelB transcription factors but do not target p100 (NF-κB2) or p105 (NF-κB1). A Salmonella Typhimurium strain lacking these effectors showed increased ability to stimulate NF-κB and increased virulence in an animal model of infection. These results indicate that bacterial pathogens can evolve determinants to preserve host homeostasis and that those determinants can reduce the pathogen's virulence.

  15. Mutational analysis of the N-terminal topogenic signal of watermelon glyoxysomal malate dehydrogenase using the heterologous host Hansenula polymorpha

    NARCIS (Netherlands)

    Gietl, Christine; Faber, Klaas Nico; Klei, Ida J. van der; Veenhuis, Marten

    1994-01-01

    We have studied the significance of the N-terminal presequence of watermelon (Citrullus vulgaris) glyoxysomal malate dehydrogenase [gMDH; (S)-malate:NAD+ oxidoreductase; EC 1.1.1.37] in microbody targeting. The yeast Hansenula polymorpha was used as heterologous host for the in vivo expression of

  16. Epigenetic modulation of host: new insights into immune evasion by ...

    Indian Academy of Sciences (India)

    Viruses have evolved with their hosts, which include all living species. This has been partly responsible for the development of highly advanced immune systems in the hosts. However, viruses too have evolved ways to regulate and evade the host's immune defence. In addition to mutational mechanisms that viruses employ ...

  17. Controlled branched-chain amino acids auxotrophy in Listeria monocytogenes allows isoleucine to serve as a host signal and virulence effector.

    Science.gov (United States)

    Brenner, Moran; Lobel, Lior; Borovok, Ilya; Sigal, Nadejda; Herskovits, Anat A

    2018-03-01

    Listeria monocytogenes (Lm) is a saprophyte and intracellular pathogen. Transition to the pathogenic state relies on sensing of host-derived metabolites, yet it remains unclear how these are recognized and how they mediate virulence gene regulation. We previously found that low availability of isoleucine signals Lm to activate the virulent state. This response is dependent on CodY, a global regulator and isoleucine sensor. Isoleucine-bound CodY represses metabolic pathways including branched-chain amino acids (BCAA) biosynthesis, however under BCAA depletion, as occurs during infection, BCAA biosynthesis is upregulated and isoleucine-unbound CodY activates virulence genes. While isoleucine was revealed as an important input signal, it was not identified how internal levels are controlled during infection. Here we show that Lm regulates BCAA biosynthesis via CodY and via a riboregulator located upstream to the BCAA biosynthesis genes, named Rli60. rli60 is transcribed when BCAA levels drop, forming a ribosome-mediated attenuator that cis-regulates the downstream genes according to BCAA supply. Notably, we found that Rli60 restricts BCAA production, essentially starving Lm, a mechanism that is directly linked to virulence, as it controls the internal isoleucine pool and thereby CodY activity. This controlled BCAA auxotrophy likely evolved to enable isoleucine to serve as a host signal and virulence effector.

  18. Controlled branched-chain amino acids auxotrophy in Listeria monocytogenes allows isoleucine to serve as a host signal and virulence effector.

    Directory of Open Access Journals (Sweden)

    Moran Brenner

    2018-03-01

    Full Text Available Listeria monocytogenes (Lm is a saprophyte and intracellular pathogen. Transition to the pathogenic state relies on sensing of host-derived metabolites, yet it remains unclear how these are recognized and how they mediate virulence gene regulation. We previously found that low availability of isoleucine signals Lm to activate the virulent state. This response is dependent on CodY, a global regulator and isoleucine sensor. Isoleucine-bound CodY represses metabolic pathways including branched-chain amino acids (BCAA biosynthesis, however under BCAA depletion, as occurs during infection, BCAA biosynthesis is upregulated and isoleucine-unbound CodY activates virulence genes. While isoleucine was revealed as an important input signal, it was not identified how internal levels are controlled during infection. Here we show that Lm regulates BCAA biosynthesis via CodY and via a riboregulator located upstream to the BCAA biosynthesis genes, named Rli60. rli60 is transcribed when BCAA levels drop, forming a ribosome-mediated attenuator that cis-regulates the downstream genes according to BCAA supply. Notably, we found that Rli60 restricts BCAA production, essentially starving Lm, a mechanism that is directly linked to virulence, as it controls the internal isoleucine pool and thereby CodY activity. This controlled BCAA auxotrophy likely evolved to enable isoleucine to serve as a host signal and virulence effector.

  19. Recent insights into host-pathogen interaction in white spot syndrome virus infected penaeid shrimp.

    Science.gov (United States)

    Shekhar, M S; Ponniah, A G

    2015-07-01

    Viral disease outbreaks are a major concern impeding the development of the shrimp aquaculture industry. The viral disease due to white spot syndrome virus (WSSV) observed in early 1990s still continues unabated affecting the shrimp farms and cause huge economic loss to the shrimp aquaculture industry. In the absence of effective therapeutics to control WSSV, it is important to understand viral pathogenesis and shrimp response to WSSV at the molecular level. Identification and molecular characterization of WSSV proteins and receptors may facilitate in designing and development of novel therapeutics and antiviral drugs that may inhibit viral replication. Investigations into host-pathogen interactions might give new insights to viral infectivity, tissue tropism and defence mechanism elicited in response to WSSV infection. However, due to the limited information on WSSV gene function and host immune response, the signalling pathways which are associated in shrimp pathogen interaction have also not been elucidated completely. In the present review, the focus is on those shrimp proteins and receptors that are potentially involved in virus infection or in the defence mechanism against WSSV. In addition, the major signalling pathways involved in the innate immune response and the role of apoptosis in host-pathogen interaction is discussed. © 2014 John Wiley & Sons Ltd.

  20. De Nederlandse missile defence capaciteit: Strategisch onmisbaar

    NARCIS (Netherlands)

    Weimar, P.W.L.

    2013-01-01

    Surface based air & missile defence behelst enerzijds de verdediging tegen conventionele luchtdreigingen, zoals vliegtuigen, helikopters en onbemande vliegtuigen (luchtverdediging). Aan de andere kant houdt het de verdediging tegen ballistische raketten en kruisraketten in (raketverdediging). De

  1. A reverse-phase protein microarray-based screen identifies host signaling dynamics upon Burkholderia spp. infection

    Directory of Open Access Journals (Sweden)

    Chih-Yuan eChiang

    2015-07-01

    Full Text Available Burkholderia is a diverse genus of Gram-negative bacteria that cause high mortality rate in humans and cattle. The lack of effective therapeutic treatments poses serious public health threats. Insights toward host-Burkholderia spp. interaction are critical in understanding the pathogenesis of the infection as well as identifying therapeutic targets for drug development. Reverse-phase protein microarray (RPMA technology was previously proven to characterize novel biomarkers and molecular signatures associated with infectious diseases and cancers. In the present study, this technology was utilized to interrogate changes in host protein expression and post-translational phosphorylation events in macrophages infected with a collection of geographically diverse strains of Burkholderia spp. The expression or phosphorylation state of 25 proteins was altered during Burkholderia spp. infections and of which eight proteins were selected for further validation by immunoblotting. Kinetic expression patterns of phosphorylated AMPK-α1, Src, and GSK3β suggested the importance of their roles in regulating Burkholderia spp. mediated innate immune responses. Modulating inflammatory responses by perturbing AMPK-α1, Src, and GSK3β activities may provide novel therapeutic targets for future treatments.

  2. Systems biology of host-mycobiota interactions: dissecting Dectin-1 and Dectin-2 signalling in immune cells with DC-ATLAS.

    Science.gov (United States)

    Rizzetto, Lisa; De Filippo, Carlotta; Rivero, Damariz; Riccadonna, Samantha; Beltrame, Luca; Cavalieri, Duccio

    2013-11-01

    Modelling the networks sustaining the fruitful coexistence between fungi and their mammalian hosts is becoming increasingly important to control emerging fungal pathogens. The C-type lectins Dectin-1 and Dectin-2 are involved in host defense mechanisms against fungal infection driving inflammatory and adaptive immune responses and complement in containing fungal burdens. Recognizing carbohydrate structures in pathogens, their engagement induces maturation of dendritic cells (DCs) into potent immuno-stimulatory cells endowed with the capacity to efficiently prime T cells. Owing to these properties, Dectin-1 and Dectin-2 agonists are currently under investigation as promising adjuvants in vaccination procedures for the treatment of fungal infection. Thus, a detailed understanding of events' cascade specifically triggered in DCs upon engagement is of great interest in translational research. Here, we summarize the current knowledge on Dectin-1 and Dectin-2 signalling in DCs highlighting similarities and differences. Detailed maps are annotated, using the Biological Connection Markup Language (BCML) data model, and stored in DC-ATLAS, a versatile resource for the interpretation of high-throughput data generated perturbing the signalling network of DCs. Copyright © 2013 Elsevier GmbH. All rights reserved.

  3. Heartland virus NSs protein disrupts host defenses by blocking the TBK1 kinase-IRF3 transcription factor interaction and signaling required for interferon induction.

    Science.gov (United States)

    Ning, Yun-Jia; Feng, Kuan; Min, Yuan-Qin; Deng, Fei; Hu, Zhihong; Wang, Hualin

    2017-10-06

    Heartland virus (HRTV) is a pathogenic phlebovirus related to the severe fever with thrombocytopenia syndrome virus (SFTSV), another phlebovirus causing life-threatening disease in humans. Previous findings have suggested that SFTSV can antagonize the host interferon (IFN) system via viral nonstructural protein (NSs)-mediated sequestration of antiviral signaling proteins into NSs-induced inclusion bodies. However, whether and how HRTV counteracts the host innate immunity is unknown. Here, we report that HRTV NSs (HNSs) also antagonizes IFN and cytokine induction and bolsters viral replication, although no noticeable inclusion body formation was observed in HNSs-expressing cells. Furthermore, HNSs inhibited the virus-triggered activation of IFN-β promoter by specifically targeting the IFN-stimulated response element but not the NF-κB response element. Consistently, HNSs blocked the phosphorylation and nuclear translocation of IFN regulatory factor 3 (IRF3, an IFN-stimulated response element-activating transcription factor). Reporter gene assays next showed that HNSs blockades the antiviral signaling mediated by RIG-I-like receptors likely at the level of TANK-binding kinase 1 (TBK1). Indeed, HNSs strongly interacts with TBK1 as indicated by confocal microscopy and pulldown analyses, and we also noted that the scaffold dimerization domain of TBK1 is required for the TBK1-HNSs interaction. Finally, pulldown assays demonstrated that HNSs expression dose-dependently diminishes a TBK1-IRF3 interaction, further explaining the mechanism for HNSs function. Collectively, these data suggest that HNSs, an antagonist of host innate immunity, interacts with TBK1 and thereby hinders the association of TBK1 with its substrate IRF3, thus blocking IRF3 activation and transcriptional induction of the cellular antiviral responses. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. TPL-2-ERK1/2 signaling promotes host resistance against intracellular bacterial infection by negative regulation of type I IFN production.

    Science.gov (United States)

    McNab, Finlay W; Ewbank, John; Rajsbaum, Ricardo; Stavropoulos, Evangelos; Martirosyan, Anna; Redford, Paul S; Wu, Xuemei; Graham, Christine M; Saraiva, Margarida; Tsichlis, Philip; Chaussabel, Damien; Ley, Steven C; O'Garra, Anne

    2013-08-15

    Tuberculosis, caused by Mycobacterium tuberculosis, remains a leading cause of mortality and morbidity worldwide, causing ≈ 1.4 million deaths per year. Key immune components for host protection during tuberculosis include the cytokines IL-12, IL-1, and TNF-α, as well as IFN-γ and CD4(+) Th1 cells. However, immune factors determining whether individuals control infection or progress to active tuberculosis are incompletely understood. Excess amounts of type I IFN have been linked to exacerbated disease during tuberculosis in mouse models and to active disease in patients, suggesting tight regulation of this family of cytokines is critical to host resistance. In addition, the immunosuppressive cytokine IL-10 is known to inhibit the immune response to M. tuberculosis in murine models through the negative regulation of key proinflammatory cytokines and the subsequent Th1 response. We show in this study, using a combination of transcriptomic analysis, genetics, and pharmacological inhibitors, that the TPL-2-ERK1/2 signaling pathway is important in mediating host resistance to tuberculosis through negative regulation of type I IFN production. The TPL-2-ERK1/2 signaling pathway regulated production by macrophages of several cytokines important in the immune response to M. tuberculosis as well as regulating induction of a large number of additional genes, many in a type I IFN-dependent manner. In the absence of TPL-2 in vivo, excess type I IFN promoted IL-10 production and exacerbated disease. These findings describe an important regulatory mechanism for controlling tuberculosis and reveal mechanisms by which type I IFN may promote susceptibility to this important disease.

  5. fundTPL-2 – ERK1/2 Signaling Promotes Host Resistance against Intracellular Bacterial Infection by Negative Regulation of Type I Interferon Production3

    Science.gov (United States)

    McNab, Finlay W.; Ewbank, John; Rajsbaum, Ricardo; Stavropoulos, Evangelos; Martirosyan, Anna; Redford, Paul S.; Wu, Xuemei; Graham, Christine M.; Saraiva, Margarida; Tsichlis, Philip; Chaussabel, Damien; Ley, Steven C.; O’Garra, Anne

    2013-01-01

    Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), remains a leading cause of mortality and morbidity worldwide, causing approximately 1.4 million deaths per year. Key immune components for host protection during tuberculosis include the cytokines IL-12, IL-1 and TNF-α, as well as IFN-γ and CD4+ Th1 cells. However, immune factors determining whether individuals control infection or progress to active tuberculosis are incompletely understood. Excess amounts of type I interferon have been linked to exacerbated disease during tuberculosis in mouse models and to active disease in patients, suggesting tight regulation of this family of cytokines is critical to host resistance. In addition, the immunosuppressive cytokine IL-10 is known to inhibit the immune response to Mtb in murine models through the negative regulation of key pro-inflammatory cytokines and the subsequent Th1 response. We show here, using a combination of transcriptomic analysis, genetics and pharmacological inhibitors that the TPL-2-ERK1/2 signaling pathway is important in mediating host resistance to tuberculosis through negative regulation of type I interferon production. The TPL-2-ERK1/2 signalling pathway regulated production by macrophages of several cytokines important in the immune response to Mtb as well as regulating induction of a large number of additional genes, many in a type I IFN dependent manner. In the absence of TPL-2 in vivo, excess type I interferon promoted IL-10 production and exacerbated disease. These findings describe an important regulatory mechanism for controlling tuberculosis and reveal mechanisms by which type I interferon may promote susceptibility to this important disease. PMID:23842752

  6. Dematerialization in the defence sector

    Energy Technology Data Exchange (ETDEWEB)

    Hedberg, L.; During Aahs, C.; Eriksson, Bjoern; Jungmar, M. [Stockholm Univ. and Swedish Defence Research Agency (FOI) (Sweden). Environmental Strategies Research Group

    2001-07-01

    The goal of dematerialization is to reduce flows of resources from the biosphere and the lithosphere to the technosphere, and to increase the efficiency within the technosphere. Dematerialization can be obtained in many different ways, for example through product design and changed or reduced use of products. Recycling and reuse of material or products are two ways to achieve more efficient use of resources and reduced exploitation of raw material. Substantial amounts of material are stored within the armed forces. An assessment of the total weight of the defence materiel has been made and the result amounts to about 230 000 tons, mainly different metals. The calculation is not complete and excludes for example munitions. The scrapping of the Bofors S-tank is studied as an example of a MIPS-analysis. The MIPS-analysis is a kind of material flow analysis where the weight of all material affected by human activity related to the life-cycle of a product or service utility is estimated. Each tank is assumed to give 20 tons of recycled steel. Recycling will also lead to avoidance of waste rock and slag from extraction, the 'rucksack'. Comparing recycling of an S-tank with landfilling a material flow of roughly 160 tons from the lithosphere to the technosphere is avoided.

  7. European Defence Community: origins of integration in the defence sphere

    Directory of Open Access Journals (Sweden)

    Іван Васильович Яковюк

    2017-12-01

    Full Text Available There is a tendency among non-historians to force «practioners» of the discipline to justify why the study of a particular episode of the past is so important and to articulate the lessons to be learned from the experience. The fate of international constitutions and treaties is particularly prone to demands of this kind. After all, «constitutional borrowing» has long been a common feature of international law and politics. This article will address one such Treaty from the past. But it does not aspire to preserving its historical integrity; rather to awaken interest in it in the first place.          The European Defence Community (EDC was an ambitious initiative in the first years of the 1950s. Leading European countries had different foreign policy agendas towards it. The EDC. could have been a crucial milestone on the long path towards European integration. European Defense Community (EDC, an abortive attempt by western European powers, with United States support, to counterbalance the overwhelming conventional military ascendancy of the Soviet Union in Europe by the formation of a supranational European army and, in the process, to subsume West German forces into a European force, avoiding the tendentious problem of West German rearmament. One can trace the U.S. influence from the very first stages of the EDC. negotiations. Even in the agreement of the EDC., the footprints of U.S. policies can be observed, bringing the NATO Alliance to the forefront. The EDC. is also interrelated with the Marshall Plan, which leads us to think that the EDC. was not solely a European dream as has been widely argued, but rather an instrument of U.S. foreign policy, which could be resorted to as and when needed.          Influenced by the Korean War, the French politician René Pleven evolved a plan that later was put forward by the French foreign minister Robert Schuman at a meeting of the Council of Europe in 1951. Though the weaker

  8. Hosting the first EDRS payload

    Science.gov (United States)

    Poncet, D.; Glynn, S.; Heine, F.

    2017-11-01

    The European Data Relay System (EDRS) will provide optical and microwave data relay services between Low Earth Orbit (LEO) satellites at altitudes up to 2000 km and the ground through geostationary (GEO) satellite nodes. Currently, two such nodes have been procured as part of a Public Private Partnership (PPP) between Astrium (now Airbus Defence and Space) and ESA. The first node (EDRS-A) is a hosted payload embarked upon the Eutelsat 9B satellite and scheduled for launch in early 2015.

  9. The genetic architecture of defence as resistance to and tolerance of bacterial infection in Drosophila melanogaster.

    Science.gov (United States)

    Howick, Virginia M; Lazzaro, Brian P

    2017-03-01

    Defence against pathogenic infection can take two forms: resistance and tolerance. Resistance is the ability of the host to limit a pathogen burden, whereas tolerance is the ability to limit the negative consequences of infection at a given level of infection intensity. Evolutionarily, a tolerance strategy that is independent of resistance could allow the host to avoid mounting a costly immune response and, theoretically, to avoid a co-evolutionary arms race between pathogen virulence and host resistance. Biomedically, understanding the mechanisms of tolerance and how they relate to resistance could potentially yield treatment strategies that focus on health improvement instead of pathogen elimination. To understand the impact of tolerance on host defence and identify genetic variants that determine host tolerance, we defined genetic variation in tolerance as the residual deviation from a binomial regression of fitness under infection against infection intensity. We then performed a genomewide association study to map the genetic basis of variation in resistance to and tolerance of infection by the bacterium Providencia rettgeri. We found a positive genetic correlation between resistance and tolerance, and we demonstrated that the level of resistance is highly predictive of tolerance. We identified 30 loci that predict tolerance, many of which are in genes involved in the regulation of immunity and metabolism. We used RNAi to confirm that a subset of mapped genes have a role in defence, including putative wound repair genes grainy head and debris buster. Our results indicate that tolerance is not an independent strategy from resistance, but that defence arises from a collection of physiological processes intertwined with canonical immunity and resistance. © 2017 John Wiley & Sons Ltd.

  10. Oh sister, where art thou? Spatial population structure and the evolution of an altruistic defence trait.

    Science.gov (United States)

    Pamminger, T; Foitzik, S; Metzler, D; Pennings, P S

    2014-11-01

    The evolution of parasite virulence and host defences is affected by population structure. This effect has been confirmed in studies focusing on large spatial scales, whereas the importance of local structure is not well understood. Slavemaking ants are social parasites that exploit workers of another species to rear their offspring. Enslaved workers of the host species Temnothorax longispinosus have been found to exhibit an effective post-enslavement defence behaviour: enslaved workers were observed killing a large proportion of the parasites' offspring. As enslaved workers do not reproduce, they gain no direct fitness benefit from this 'rebellion' behaviour. However, there may be an indirect benefit: neighbouring host nests that are related to 'rebel' nests can benefit from a reduced raiding pressure, as a result of the reduction in parasite nest size due to the enslaved workers' killing behaviour. We use a simple mathematical model to examine whether the small-scale population structure of the host species could explain the evolution of this potentially altruistic defence trait against slavemaking ants. We find that this is the case if enslaved host workers are related to nearby host nests. In a population genetic study, we confirm that enslaved workers are, indeed, more closely related to host nests within the raiding range of their resident slavemaker nest, than to host nests outside the raiding range. This small-scale population structure seems to be a result of polydomy (e.g. the occupation of several nests in close proximity by a single colony) and could have enabled the evolution of 'rebellion' by kin selection. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  11. Artificial intelligence and finite element modelling for monitoring flood defence structures

    NARCIS (Netherlands)

    Pyayt, A.L.; Mokhov, I.I.; Kozionov, A.; Kusherbaeva, V.; Melnikova, N.B.; Krzhizhanovskaya, V.V.; Meijer, R.J.

    2011-01-01

    We present a hybrid approach to monitoring the stability of flood defence structures equipped with sensors. This approach combines the finite element modelling with the artificial intelligence for real-time signal processing and anomaly detection. This combined method has been developed for the

  12. Cytokinins as key regulators in plant–microbe–insect interactions: connecting plant growth and defence

    NARCIS (Netherlands)

    Giron, D.; Frago, E.; Glevarec, G.; Pieterse, C.M.J.; Dicke, M.

    2013-01-01

    1. Plant hormones play important roles in regulating plant growth and defence by mediating developmental processes and signalling networks involved in plant responses to a wide range of parasitic and mutualistic biotic interactions. 2. Plants are known to rapidly respond to pathogen and herbivore

  13. Jasmonate-deficient plants have reduced direct and indirect defences against herbivores

    NARCIS (Netherlands)

    Thaler, J.S.; Farag, M.A.; Paré, P.W.; Dicke, M.

    2002-01-01

    Plants employ a variety of defence mechanisms, some of which act directly by having a negative effect on herbivores and others that act indirectly by attracting natural enemies of herbivores. In this study we asked if a common jasmonate-signalling pathway links the regulation of direct and indirect

  14. NOD1 contributes to mouse host defense against Helicobacter pylori via induction of type I IFN and activation of the ISGF3 signaling pathway

    Science.gov (United States)

    Watanabe, Tomohiro; Asano, Naoki; Fichtner-Feigl, Stefan; Gorelick, Peter L.; Tsuji, Yoshihisa; Matsumoto, Yuko; Chiba, Tsutomu; Fuss, Ivan J.; Kitani, Atsushi; Strober, Warren

    2010-01-01

    Nucleotide-binding oligomerization domain 1 (NOD1) is an intracellular epithelial cell protein known to play a role in host defense at mucosal surfaces. Here we show that a ligand specific for NOD1, a peptide derived from peptidoglycan, initiates an unexpected signaling pathway in human epithelial cell lines that results in the production of type I IFN. Detailed analysis revealed the components of the signaling pathway. NOD1 binding to its ligand triggered activation of the serine-threonine kinase RICK, which was then able to bind TNF receptor–associated factor 3 (TRAF3). This in turn led to activation of TANK-binding kinase 1 (TBK1) and IκB kinase ε (IKKε) and the subsequent activation of IFN regulatory factor 7 (IRF7). IRF7 induced IFN-β production, which led to activation of a heterotrimeric transcription factor complex known as IFN-stimulated gene factor 3 (ISGF3) and the subsequent production of CXCL10 and additional type I IFN. In vivo studies showed that mice lacking the receptor for IFN-β or subjected to gene silencing of the ISGF3 component Stat1 exhibited decreased CXCL10 responses and increased susceptibility to Helicobacter pylori infection, phenotypes observed in NOD1-deficient mice. These studies thus establish that NOD1 can activate the ISGF3 signaling pathway that is usually associated with protection against viral infection to provide mice with robust type I IFN–mediated protection from H. pylori and possibly other mucosal infections. PMID:20389019

  15. How insects overcome two-component plant chemical defence: plant β-glucosidases as the main target for herbivore adaptation.

    Science.gov (United States)

    Pentzold, Stefan; Zagrobelny, Mika; Rook, Fred; Bak, Søren

    2014-08-01

    Insect herbivory is often restricted by glucosylated plant chemical defence compounds that are activated by plant β-glucosidases to release toxic aglucones upon plant tissue damage. Such two-component plant defences are widespread in the plant kingdom and examples of these classes of compounds are alkaloid, benzoxazinoid, cyanogenic and iridoid glucosides as well as glucosinolates and salicinoids. Conversely, many insects have evolved a diversity of counteradaptations to overcome this type of constitutive chemical defence. Here we discuss that such counter-adaptations occur at different time points, before and during feeding as well as during digestion, and at several levels such as the insects’ feeding behaviour, physiology and metabolism. Insect adaptations frequently circumvent or counteract the activity of the plant β-glucosidases, bioactivating enzymes that are a key element in the plant’s two-component chemical defence. These adaptations include host plant choice, non-disruptive feeding guilds and various physiological adaptations as well as metabolic enzymatic strategies of the insect’s digestive system. Furthermore, insect adaptations often act in combination, may exist in both generalists and specialists, and can act on different classes of defence compounds. We discuss how generalist and specialist insects appear to differ in their ability to use these different types of adaptations: in generalists, adaptations are often inducible, whereas in specialists they are often constitutive. Future studies are suggested to investigate in detail how insect adaptations act in combination to overcome plant chemical defences and to allow ecologically relevant conclusions.

  16. A downy mildew effector attenuates salicylic acid-triggered immunity in Arabidopsis by interacting with the host mediator complex.

    Directory of Open Access Journals (Sweden)

    Marie-Cécile Caillaud

    2013-12-01

    Full Text Available Plants are continually exposed to pathogen attack but usually remain healthy because they can activate defences upon perception of microbes. However, pathogens have evolved to overcome plant immunity by delivering effectors into the plant cell to attenuate defence, resulting in disease. Recent studies suggest that some effectors may manipulate host transcription, but the specific mechanisms by which such effectors promote susceptibility remain unclear. We study the oomycete downy mildew pathogen of Arabidopsis, Hyaloperonospora arabidopsidis (Hpa, and show here that the nuclear-localized effector HaRxL44 interacts with Mediator subunit 19a (MED19a, resulting in the degradation of MED19a in a proteasome-dependent manner. The Mediator complex of ∼25 proteins is broadly conserved in eukaryotes and mediates the interaction between transcriptional regulators and RNA polymerase II. We found MED19a to be a positive regulator of immunity against Hpa. Expression profiling experiments reveal transcriptional changes resembling jasmonic acid/ethylene (JA/ET signalling in the presence of HaRxL44, and also 3 d after infection with Hpa. Elevated JA/ET signalling is associated with a decrease in salicylic acid (SA-triggered immunity (SATI in Arabidopsis plants expressing HaRxL44 and in med19a loss-of-function mutants, whereas SATI is elevated in plants overexpressing MED19a. Using a PR1::GUS reporter, we discovered that Hpa suppresses PR1 expression specifically in cells containing haustoria, into which RxLR effectors are delivered, but not in nonhaustoriated adjacent cells, which show high PR1::GUS expression levels. Thus, HaRxL44 interferes with Mediator function by degrading MED19, shifting the balance of defence transcription from SA-responsive defence to JA/ET-signalling, and enhancing susceptibility to biotrophs by attenuating SA-dependent gene expression.

  17. Defence in depth in nuclear safety

    International Nuclear Information System (INIS)

    Jayakumar, J.S.

    2016-01-01

    Nuclear energy is clean and can prevent global warming and hence it has a lot of importance in the current world. In order for the safe and reliable operation of the NPP, a defence in depth concept has been practised, so that even one level of protection fails the subsequent one will contain the hazardous situation. Various levels, both from consideration of the physical barriers and implementation are described in this paper. Three major accidents happened in nuclear reactors are analysed from the defence in depth concept and shortcomings are discussed. (author)

  18. Inducible indirect defence of plants : from mechanisms to ecological functions

    NARCIS (Netherlands)

    Dicke, M.; Poecke, van R.M.P.; Boer, de J.G.

    2003-01-01

    Inducible defences allow plants to be phenotypically plastic. Inducible indirect defence of plants by attracting carnivorous enemies of herbivorous arthropods can vary with plant species and genotype, with herbivore species or instar and potentially with other environmental conditions. So far,

  19. Impairment of the chemical defence of the beetle, Tenebrio molitor, by metacestodes (cysticeroids) of the tapeworm, Hymenolepis diminuta.

    Science.gov (United States)

    Blankespoor, C L; Pappas, P W; Eisner, T

    1997-07-01

    The defensive glands of beetles, Tenebrio molitor, infected with metacestodes (cysticercoids) of Hymenolepis diminuta are everted less frequently upon stimulation, and contain less toluquinone (methylbenzoquinone) and m-cresol, than glands of uninfected controls. These differences, as shown in predation trials with wild rats, increase the likelihood that both cysticercoids and beetles will be ingested by the tapeworm's definitive host. This is the first documented case of a parasite inhibiting the chemical defence of an intermediate host, and one of only a few reports of parasite-induced manipulation of host biology supported by empirical evidence implicating facilitated parasite transmission between host species.

  20. Civil defence abroad. Pt. 3: The Warsaw Pact countries

    International Nuclear Information System (INIS)

    Schirrmeister, K.G.; Hofmann, H.

    1988-01-01

    Civil defence forms part of the national defence of the G.D.R., and belongs since 1976 to the responsibility of the Defence Ministry. Civil defence service is equal to military service. Civil defence services are organised on a territorial basis and a production-oriented basis: Double concept. Construction of shelters is propagated for 30 years now, maintenance of existing buildings is an obligation since 1965. Principles (triage) of military medical service are applied, and are valid for students and post-graduate medical training. Civil defence training is required in school and industry. Civil defence expenditure is increasing, although there is little acceptance by the population. The issue presents extensive documentation. - Civil defence in the Soviet Union covers services in times of peace and of war. Defence measures are prepared and held up to date in the entire territory. The civil defence service belongs to the responsibility of the Council of Ministers, and the deputy minister of defence is the head of services. The training schedules and principles are laid down by the Central Committee of the Communist Party, the government, and local party organisations and governmental authorities. Civil defence training is a general obligation for all citizens over 8 years of age. The main goal is: Protection of the population as the production force, of the economy, and resources. (orig.) [de

  1. CSIR eNews: Defence peace safety and security

    CSIR Research Space (South Africa)

    CSIR

    2008-12-01

    Full Text Available The CSIR Defence peace safety and security research unit aims to provide a defence evaluation and research institute capability for the Department of Defence. It also serves as the 'in-house' S&T capability of key government departments and agencies...

  2. Civil defence and disaster control services

    International Nuclear Information System (INIS)

    Kolb, P.W.

    1986-01-01

    Today's systems of civil defence and disaster control services are the result of a long process of development, which is outlined for the Federal Republic of Germany. The present organisational and legal systems are explained, together with the institutions concerned. (DG) [de

  3. Defence Output Measures: An Economics Perspective

    Science.gov (United States)

    2011-11-01

    positive or negative impact of defence spending on growth and there is evidence supporting both impacts! The divergent results reflect the need for a...It also protects national interests, including independence and ‘appropriate sovereignty’ (e.g. protecting a nation’s interests in a globalised

  4. The Cooperative Ballistic Missile Defence Game

    NARCIS (Netherlands)

    Evers, L.; Barros, A.I.; Monsuur, H.

    2013-01-01

    The increasing proliferation of ballistic missiles and weapons of mass destruction poses new risks worldwide. For a threatened nation and given the characteristics of this threat a layered ballistic missile defence system strategy appears to be the preferred solution. However, such a strategy

  5. The long road of antimissile defence

    International Nuclear Information System (INIS)

    Gere, Francois

    2001-01-01

    The author proposes a discussion of the elaboration of the National Missile Defence (NMD) by the new US administration in 2001. He first reports the evolution of this concept which resulted in 1999 with the National Missile Defence Act, produced by a commission chaired by Rumsfeld and aimed at the assessment of the threat of ballistic missiles in the world. Before that, in the 1960, the USA already tried to protect themselves by designing two type of missiles: long range interceptors (Nike Zeus), and short range missiles (Sprint). Later, Reagan launched the Strategic Defence Initiative (SDI). By the end of Cold War, the SDI was downgraded into smaller programmes. In a second part, the author discusses some elements of the NMD content: definition of objectives over 20 years, technical and strategic obstacles, definition of Rogue States. In a third part, he proposes an overview of the relationships between antimissile defence and nuclear deterrence, notably through the ABM Treaty, and with problem raised by Arms of Mass Destruction (AMD). In the last part, he comments reactions (mainly opposition) of different countries (Russia, China, European countries and particularly Germany), and proposes some possible true motivations for the creation of the NMD

  6. South Africa's Defence Industrial Participation in Perspective

    African Journals Online (AJOL)

    jvdyk

    2014-03-31

    Mar 31, 2014 ... product and improved the economy through the retention of some ... and maintaining a defence industrial base (DIB) in those countries ... by the Department of Trade and Industry (dti) that focuses primarily ... work share on the purchased equipment (co-production), ..... These upgrades are now an integral.

  7. South Africa's Defence Industrial Participation in Perspective

    African Journals Online (AJOL)

    jvdyk

    2014-03-31

    Mar 31, 2014 ... product and improved the economy through the retention of some 58 000 jobs. ... and maintaining a defence industrial base (DIB) in those countries that have the ... by the Department of Trade and Industry (dti) that focuses primarily on civil industry ... work share on the purchased equipment (co-production), ...

  8. The Immune System and Bodily Defence

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 2. The Immune System and Bodily Defence How Do Parasites and the Immune System Choose their Dances? Vineeta Bal Satyajit Rath. Series Article Volume 2 Issue 2 February 1997 pp 17-24 ...

  9. The Immune System and Bodily Defence

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 6. The Immune System and Bodily Defence How Does the Immune System Organize Itself so as to Connect Target Recognition to Expected Functions? Vineeta Bal Satyajit Rath. Series Article Volume 2 Issue 6 June 1997 pp 25-38 ...

  10. The Immune System and Bodily Defence

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 9. The Immune System and Bodily Defence How Does the Immune System Recognize Everything Under the Sun? Vineeta Bal Satyajit Rath. Series Article Volume 2 Issue 9 September 1997 pp 6-10 ...

  11. Assessment methodology for air defence control systems

    CSIR Research Space (South Africa)

    Oosthuizen, R

    2013-09-01

    Full Text Available In Command and Control, humans have to make sense of the situation to support decision making on the required action. Development of an Air Defence Control system through a Systems Engineering process starts with assessment of existing systems...

  12. Knowing your friends and foes--plant receptor-like kinases as initiators of symbiosis or defence.

    Science.gov (United States)

    Antolín-Llovera, Meritxell; Petutsching, Elena Kristin; Ried, Martina Katharina; Lipka, Volker; Nürnberger, Thorsten; Robatzek, Silke; Parniske, Martin

    2014-12-01

    The decision between defence and symbiosis signalling in plants involves alternative and modular plasma membrane-localized receptor complexes. A critical step in their activation is ligand-induced homo- or hetero-oligomerization of leucine-rich repeat (LRR)- and/or lysin motif (LysM) receptor-like kinases (RLKs). In defence signalling, receptor complexes form upon binding of pathogen-associated molecular patterns (PAMPs), including the bacterial flagellin-derived peptide flg22, or chitin. Similar mechanisms are likely to operate during the perception of microbial symbiont-derived (lipo)-chitooligosaccharides. The structurally related chitin-oligomer ligands chitooctaose and chitotetraose trigger defence and symbiosis signalling, respectively, and their discrimination involves closely related, if not identical, LysM-RLKs. This illustrates the demand for and the challenges imposed on decision mechanisms that ensure appropriate signal initiation. Appropriate signalling critically depends on abundance and localization of RLKs at the cell surface. This is regulated by internalization, which also provides a mechanism for the removal of activated signalling RLKs. Abundance of the malectin-like domain (MLD)-LRR-RLK Symbiosis Receptor-like Kinase (SYMRK) is additionally controlled by cleavage of its modular ectodomain, which generates a truncated and rapidly degraded RLK fragment. This review explores LRR- and LysM-mediated signalling, the involvement of MLD-LRR-RLKs in symbiosis and defence, and the role of endocytosis in RLK function. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  13. Constraints on host choice: why do parasitic birds rarely exploit some common potential hosts?

    Czech Academy of Sciences Publication Activity Database

    Grim, T.; Samaš, P.; Moskát, C.; Kleven, O.; Honza, Marcel; Moksnes, A.; Roskaft, E.; Stokke, B. G.

    2011-01-01

    Roč. 80, č. 3 (2011), s. 508-518 ISSN 0021-8790 R&D Projects: GA AV ČR IAA600930605 Institutional research plan: CEZ:AV0Z60930519 Keywords : antiparasite defence * co-evolution * host selection * interactive effects * parasite avoidance Subject RIV: EG - Zoology Impact factor: 4.937, year: 2011

  14. Public Private Business Models for Defence Acquisition - A Multiple Case Study of Defence Acquisition Projects in the UK

    OpenAIRE

    Ekström, Thomas

    2012-01-01

    Since the ending of the Cold War, the defence sector, particularly the areas of military logistics and defence acquisition, has been undergoing a comprehensive transformation. There are several factors that explain this transformation: changes in defence and security policies for nations and organisations; reductions in defence expenditure; participation in Peace Support Operations; Lessons Learned from these operations, especially in the area of logistics; revolutionary development in the ar...

  15. Identification of bovine leukemia virus tax function associated with host cell transcription, signaling, stress response and immune response pathway by microarray-based gene expression analysis

    Directory of Open Access Journals (Sweden)

    Arainga Mariluz

    2012-03-01

    Full Text Available Abstract Background Bovine leukemia virus (BLV is associated with enzootic bovine leukosis and is closely related to human T-cell leukemia virus type I. The Tax protein of BLV is a transcriptional activator of viral replication and a key contributor to oncogenic potential. We previously identified interesting mutant forms of Tax with elevated (TaxD247G or reduced (TaxS240P transactivation effects on BLV replication and propagation. However, the effects of these mutations on functions other than transcriptional activation are unknown. In this study, to identify genes that play a role in the cascade of signal events regulated by wild-type and mutant Tax proteins, we used a large-scale host cell gene-profiling approach. Results Using a microarray containing approximately 18,400 human mRNA transcripts, we found several alterations after the expression of Tax proteins in genes involved in many cellular functions such as transcription, signal transduction, cell growth, apoptosis, stress response, and immune response, indicating that Tax protein has multiple biological effects on various cellular environments. We also found that TaxD247G strongly regulated more genes involved in transcription, signal transduction, and cell growth functions, contrary to TaxS240P, which regulated fewer genes. In addition, the expression of genes related to stress response significantly increased in the presence of TaxS240P as compared to wild-type Tax and TaxD247G. By contrast, the largest group of downregulated genes was related to immune response, and the majority of these genes belonged to the interferon family. However, no significant difference in the expression level of downregulated genes was observed among the Tax proteins. Finally, the expression of important cellular factors obtained from the human microarray results were validated at the RNA and protein levels by real-time quantitative reverse transcription-polymerase chain reaction and western blotting

  16. Type I Interferons Direct Gammaherpesvirus Host Colonization.

    Directory of Open Access Journals (Sweden)

    Cindy S E Tan

    2016-05-01

    Full Text Available Gamma-herpesviruses colonise lymphocytes. Murid Herpesvirus-4 (MuHV-4 infects B cells via epithelial to myeloid to lymphoid transfer. This indirect route entails exposure to host defences, and type I interferons (IFN-I limit infection while viral evasion promotes it. To understand how IFN-I and its evasion both control infection outcomes, we used Mx1-cre mice to tag floxed viral genomes in IFN-I responding cells. Epithelial-derived MuHV-4 showed low IFN-I exposure, and neither disrupting viral evasion nor blocking IFN-I signalling markedly affected acute viral replication in the lungs. Maximising IFN-I induction with poly(I:C increased virus tagging in lung macrophages, but the tagged virus spread poorly. Lymphoid-derived MuHV-4 showed contrastingly high IFN-I exposure. This occurred mainly in B cells. IFN-I induction increased tagging without reducing viral loads; disrupting viral evasion caused marked attenuation; and blocking IFN-I signalling opened up new lytic spread between macrophages. Thus, the impact of IFN-I on viral replication was strongly cell type-dependent: epithelial infection induced little response; IFN-I largely suppressed macrophage infection; and viral evasion allowed passage through B cells despite IFN-I responses. As a result, IFN-I and its evasion promoted a switch in infection from acutely lytic in myeloid cells to chronically latent in B cells. Murine cytomegalovirus also showed a capacity to pass through IFN-I-responding cells, arguing that this is a core feature of herpesvirus host colonization.

  17. The bile acid deoxycholate elicits defences in Arabidopsis and reduces bacterial infection.

    Science.gov (United States)

    Zarattini, Marco; Launay, Alban; Farjad, Mahsa; Wénès, Estelle; Taconnat, Ludivine; Boutet, Stéphanie; Bernacchia, Giovanni; Fagard, Mathilde

    2017-05-01

    Disease has an effect on crop yields, causing significant losses. As the worldwide demand for agricultural products increases, there is a need to pursue the development of new methods to protect crops from disease. One mechanism of plant protection is through the activation of the plant immune system. By exogenous application, 'plant activator molecules' with elicitor properties can be used to activate the plant immune system. These defence-inducing molecules represent a powerful and often environmentally friendly tool to fight pathogens. We show that the secondary bile acid deoxycholic acid (DCA) induces defence in Arabidopsis and reduces the proliferation of two bacterial phytopathogens: Erwinia amylovora and Pseudomonas syringae pv. tomato. We describe the global defence response triggered by this new plant activator in Arabidopsis at the transcriptional level. Several induced genes were selected for further analysis by quantitative reverse transcription-polymerase chain reaction. We describe the kinetics of their induction and show that abiotic stress, such as moderate drought or nitrogen limitation, does not impede DCA induction of defence. Finally, we investigate the role in the activation of defence by this bile acid of the salicylic acid biosynthesis gene SID2, of the receptor-like kinase family genes WAK1-3 and of the NADPH oxidase-encoding RbohD gene. Altogether, we show that DCA constitutes a promising molecule for plant protection which can induce complementary lines of defence, such as callose deposition, reactive oxygen species accumulation and the jasmonic acid and salicylic acid signalling pathways. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  18. European defence industry consolidation and domestic procurement bias

    DEFF Research Database (Denmark)

    Kluth, Michael Friederich

    2017-01-01

    How have European cross-border defence industrial mergers and acquisitions affected domestic procurement bias among the major EU powers? This article departs from the findings of Andrew Moravcsik more than two decades ago suggesting that major West European states had no ingrained preferences...... for defence industrial autarchy. When cross-national armament projects were derailed, this could be attributed to political efforts of national defence industrial champions favouring purely domestic projects. As former national champions join pan-European defence groups, their preferences are likely modified......-border defence industry consolidation will be analysed. Procurement bias is assessed in two industry segments characterised by pervasive consolidation....

  19. Ecological trade-offs between jasmonic acid-dependent direct and indirect plant defences in tritrophic interactions.

    Science.gov (United States)

    Wei, Jianing; Wang, Lizhong; Zhao, Jiuhai; Li, Chuanyou; Ge, Feng; Kang, Le

    2011-01-01

    Recent studies on plants genetically modified in jasmonic acid (JA) signalling support the hypothesis that the jasmonate family of oxylipins plays an important role in mediating direct and indirect plant defences. However, the interaction of two modes of defence in tritrophic systems is largely unknown. In this study, we examined the preference and performance of a herbivorous leafminer (Liriomyza huidobrensis) and its parasitic wasp (Opius dissitus) on three tomato genotypes: a wild-type (WT) plant, a JA biosynthesis (spr2) mutant, and a JA-overexpression 35S::prosys plant. Their proteinase inhibitor production and volatile emission were used as direct and indirect defence factors to evaluate the responses of leafminers and parasitoids. Here, we show that although spr2 mutant plants are compromised in direct defence against the larval leafminers and in attracting parasitoids, they are less attractive to adult flies compared with WT plants. Moreover, in comparison to other genotypes, the 35S::prosys plant displays greater direct and constitutive indirect defences, but reduced success of parasitism by parasitoids. Taken together, these results suggest that there are distinguished ecological trade-offs between JA-dependent direct and indirect defences in genetically modified plants whose fitness should be assessed in tritrophic systems and under natural conditions. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

  20. Radix isatidis Polysaccharides Inhibit Influenza a Virus and Influenza A Virus-Induced Inflammation via Suppression of Host TLR3 Signaling In Vitro

    Directory of Open Access Journals (Sweden)

    Zhengtu Li

    2017-01-01

    Full Text Available Influenza remains one of the major epidemic diseases worldwide, and rapid virus replication and collateral lung tissue damage caused by excessive pro-inflammatory host immune cell responses lead to high mortality rates. Thus, novel therapeutic agents that control influenza A virus (IAV propagation and attenuate excessive pro-inflammatory responses are needed. Polysaccharide extract from Radix isatidis, a traditional Chinese herbal medicine, exerted potent anti-IAV activity against human seasonal influenza viruses (H1N1 and H3N2 and avian influenza viruses (H6N2 and H9N2 in vitro. The polysaccharides also significantly reduced the expression of pro-inflammatory cytokines (IL-6 and chemokines (IP-10, MIG, and CCL-5 stimulated by A/PR/8/34 (H1N1 at a range of doses (7.5 mg/mL, 15 mg/mL, and 30 mg/mL; however, they were only effective against progeny virus at a high dose. Similar activity was detected against inflammation induced by avian influenza virus H9N2. The polysaccharides strongly inhibited the protein expression of TLR-3 induced by PR8, suggesting that they impair the upregulation of pro-inflammatory factors induced by IAV by inhibiting activation of the TLR-3 signaling pathway. The polysaccharide extract from Radix isatidis root therefore has the potential to be used as an adjunct to antiviral therapy for the treatment of IAV infection.

  1. The European Security and Defence Policy

    DEFF Research Database (Denmark)

    Adler-Nissen, Rebecca

    2009-01-01

    The European Security and Defence Policy (ESDP), which is the operational military and civilian dimension of the Common Foreign and Security Policy (CFSP), is today one of the most dynamic areas of the European Union. However, it is only recently that the EU has acquired explicit military decision....... The Union is thus gradually emerging as an important player on the international scene, with a strategic vision, as well as diplomatic, civilian and military crisis-management instruments that complement the existing economic, commercial, humanitarian and development policies on which the EU has hitherto...... built its reputation as a ‘soft power'. Despite its rapid development, many still regard the EU as weak and ineffi cient when it comes to security and defence policy. Moreover, the EU struggles with internal divisions and has a strained relationship with NATO. Nonetheless, there are good reasons...

  2. The Kassel concept for river flood defence

    Energy Technology Data Exchange (ETDEWEB)

    Toensmann, F. [Kassel Univ. (Germany). Dept. of Hydraulic and Water-Resources Engineering

    2000-07-01

    Following an introduction referring to the history, the regulation of ''interference and compensation'' and the ''sustainable development'' as the foundation of future-oriented flood defence concepts are dealt with. The position of science and technology with respect to the employed planning methods: Models for the determination of spatial and temporal distribution of maximum precipitation, river basin models, methods for water level computation, benefit/cost analysis and environmental assessment are described and evaluated. Thereafter the Kassel Concept for River Flood Defence is presented. The basic principle is a mosaic of de-central, semi-central and central measures with reference to the specific project which are economically eligible and environment-compatible. (orig.)

  3. Immune Defence Factors In Human Milk

    Directory of Open Access Journals (Sweden)

    Kumar Sanjeev

    1985-01-01

    Full Text Available Scientific evidence is accumulating to prove the nutritional, anti-infective, anti-fertility, psychosomal and economic advantages of breast-feeding. A number of studies have shown that breast milk protects against diarrheal, respiratory and other infections. Its value in protecting against allergy has also been established. This article reviews the studies on various immune defence factors present in the human milk. The available scientific knowledge makes a very strong case in favour of promoting breast-feeding.

  4. Radiation Protection and Civil defence Department

    International Nuclear Information System (INIS)

    Gomaa, M.A.; Elshinawy, R.M.K.; Abdelfattah, A.T.

    1991-01-01

    This conference involves subjects of radiation protection, programming of civil defence, on the implementation of 1990 ICRP recommendation, thermoluminescence properties of bone equivalent calcium phosphate ceramics, potassium body burdens in occupational users of egyptian nuclear research centre, transport of radionuclides in fresh water stream, water treatment process for nuclear reactor, research activities related to internal contamination and bioassay and experience and environmental radiation monitoring in inshass. it contains of figures and tables

  5. The Man-in-the-Middle Defence

    Science.gov (United States)

    Anderson, Ross; Bond, Mike

    Eliminating middlemen from security protocols helps less than one would think. EMV electronic payments, for example, can be made fairer by adding an electronic attorney - a middleman which mediates access to a customer’s card. We compare middlemen in crypto protocols and APIs with those in the real world, and show that a man-in-the-middle defence is helpful in many circumstances. We suggest that the middleman has been unfairly demonised.

  6. Neurons of self-defence: neuronal innervation of the exocrine defence glands in stick insects.

    Science.gov (United States)

    Stolz, Konrad; von Bredow, Christoph-Rüdiger; von Bredow, Yvette M; Lakes-Harlan, Reinhard; Trenczek, Tina E; Strauß, Johannes

    2015-01-01

    Stick insects (Phasmatodea) use repellent chemical substances (allomones) for defence which are released from so-called defence glands in the prothorax. These glands differ in size between species, and are under neuronal control from the CNS. The detailed neural innervation and possible differences between species are not studied so far. Using axonal tracing, the neuronal innervation is investigated comparing four species. The aim is to document the complexity of defence gland innervation in peripheral nerves and central motoneurons in stick insects. In the species studied here, the defence gland is innervated by the intersegmental nerve complex (ISN) which is formed by three nerves from the prothoracic (T1) and suboesophageal ganglion (SOG), as well as a distinct suboesophageal nerve (Nervus anterior of the suboesophageal ganglion). In Carausius morosus and Sipyloidea sipylus, axonal tracing confirmed an innervation of the defence glands by this N. anterior SOG as well as N. anterior T1 and N. posterior SOG from the intersegmental nerve complex. In Peruphasma schultei, which has rather large defence glands, only the innervation by the N. anterior SOG was documented by axonal tracing. In the central nervous system of all species, 3-4 neuron types are identified by axonal tracing which send axons in the N. anterior SOG likely innervating the defence gland as well as adjacent muscles. These neurons are mainly suboesophageal neurons with one intersegmental neuron located in the prothoracic ganglion. The neuron types are conserved in the species studied, but the combination of neuron types is not identical. In addition, the central nervous system in S. sipylus contains one suboesophageal and one prothoracic neuron type with axons in the intersegmental nerve complex contacting the defence gland. Axonal tracing shows a very complex innervation pattern of the defence glands of Phasmatodea which contains different neurons in different nerves from two adjacent body segments

  7. Establishment of chronic hepatitis C virus infection: Translational evasion of oxidative defence

    Science.gov (United States)

    Chan, Shiu-Wan

    2014-01-01

    Hepatitis C virus (HCV) causes a clinically important disease affecting 3% of the world population. HCV is a single-stranded, positive-sense RNA virus belonging to the genus Hepacivirus within the Flaviviridae family. The virus establishes a chronic infection in the face of an active host oxidative defence, thus adaptation to oxidative stress is key to virus survival. Being a small RNA virus with a limited genomic capacity, we speculate that HCV deploys a different strategy to evade host oxidative defence. Instead of counteracting oxidative stress, it utilizes oxidative stress to facilitate its own survival. Translation is the first step in the replication of a plus strand RNA virus so it would make sense if the virus can exploit the host oxidative defence in facilitating this very first step. This is particularly true when HCV utilizes an internal ribosome entry site element in translation, which is distinctive from that of cap-dependent translation of the vast majority of cellular genes, thus allowing selective translation of genes under conditions when global protein synthesis is compromised. Indeed, we were the first to show that HCV translation was stimulated by an important pro-oxidant-hydrogen peroxide in hepatocytes, suggesting that HCV is able to adapt to and utilize the host anti-viral response to facilitate its own translation thus allowing the virus to thrive under oxidative stress condition to establish chronicity. Understanding how HCV translation is regulated under oxidative stress condition will advance our knowledge on how HCV establishes chronicity. As chronicity is the initiator step in disease progression this will eventually lead to a better understanding of pathogenicity, which is particularly relevant to the development of anti-virals and improved treatments of HCV patients using anti-oxidants. PMID:24659872

  8. Establishment of chronic hepatitis C virus infection: translational evasion of oxidative defence.

    Science.gov (United States)

    Chan, Shiu-Wan

    2014-03-21

    Hepatitis C virus (HCV) causes a clinically important disease affecting 3% of the world population. HCV is a single-stranded, positive-sense RNA virus belonging to the genus Hepacivirus within the Flaviviridae family. The virus establishes a chronic infection in the face of an active host oxidative defence, thus adaptation to oxidative stress is key to virus survival. Being a small RNA virus with a limited genomic capacity, we speculate that HCV deploys a different strategy to evade host oxidative defence. Instead of counteracting oxidative stress, it utilizes oxidative stress to facilitate its own survival. Translation is the first step in the replication of a plus strand RNA virus so it would make sense if the virus can exploit the host oxidative defence in facilitating this very first step. This is particularly true when HCV utilizes an internal ribosome entry site element in translation, which is distinctive from that of cap-dependent translation of the vast majority of cellular genes, thus allowing selective translation of genes under conditions when global protein synthesis is compromised. Indeed, we were the first to show that HCV translation was stimulated by an important pro-oxidant-hydrogen peroxide in hepatocytes, suggesting that HCV is able to adapt to and utilize the host anti-viral response to facilitate its own translation thus allowing the virus to thrive under oxidative stress condition to establish chronicity. Understanding how HCV translation is regulated under oxidative stress condition will advance our knowledge on how HCV establishes chronicity. As chronicity is the initiator step in disease progression this will eventually lead to a better understanding of pathogenicity, which is particularly relevant to the development of anti-virals and improved treatments of HCV patients using anti-oxidants.

  9. Networks and network analysis for defence and security

    CERN Document Server

    Masys, Anthony J

    2014-01-01

    Networks and Network Analysis for Defence and Security discusses relevant theoretical frameworks and applications of network analysis in support of the defence and security domains. This book details real world applications of network analysis to support defence and security. Shocks to regional, national and global systems stemming from natural hazards, acts of armed violence, terrorism and serious and organized crime have significant defence and security implications. Today, nations face an uncertain and complex security landscape in which threats impact/target the physical, social, economic

  10. Deimatic display in the European swallowtail butterfly as a secondary defence against attacks from great tits.

    Science.gov (United States)

    Olofsson, Martin; Eriksson, Stephan; Jakobsson, Sven; Wiklund, Christer

    2012-01-01

    Many animals reduce the risk of being attacked by a predator through crypsis, masquerade or, alternatively, by advertising unprofitability by means of aposematic signalling. Behavioural attributes in prey employed after discovery, however, signify the importance of also having an effective secondary defence if a predator uncovers, or is immune to, the prey's primary defence. In butterflies, as in most animals, secondary defence generally consists of escape flights. However, some butterfly species have evolved other means of secondary defence such as deimatic displays/startle displays. The European swallowtail, Papilio machaon, employs what appears to be a startle display by exposing its brightly coloured dorsal wing surface upon disturbance and, if the disturbance continues, by intermittently protracting and relaxing its wing muscles generating a jerky motion of the wings. This display appears directed towards predators but whether it is effective in intimidating predators so that they refrain from attacks has never been tested experimentally. In this study we staged encounters between a passerine predator, the great tit, Parus major, and live and dead swallowtail butterflies in a two-choice experiment. Results showed that the dead butterfly was virtually always attacked before the live butterfly, and that it took four times longer before a bird attacked the live butterfly. When the live butterfly was approached by a bird this generally elicited the butterfly's startle display, which usually caused the approaching bird to flee. We also performed a palatability test of the butterflies and results show that the great tits seemed to find them palatable. We conclude that the swallowtail's startle display of conspicuous coloration and jerky movements is an efficient secondary defence against small passerines. We also discuss under what conditions predator-prey systems are likely to aid the evolution of deimatic behaviours in harmless and palatable prey.

  11. Deimatic display in the European swallowtail butterfly as a secondary defence against attacks from great tits.

    Directory of Open Access Journals (Sweden)

    Martin Olofsson

    Full Text Available Many animals reduce the risk of being attacked by a predator through crypsis, masquerade or, alternatively, by advertising unprofitability by means of aposematic signalling. Behavioural attributes in prey employed after discovery, however, signify the importance of also having an effective secondary defence if a predator uncovers, or is immune to, the prey's primary defence. In butterflies, as in most animals, secondary defence generally consists of escape flights. However, some butterfly species have evolved other means of secondary defence such as deimatic displays/startle displays. The European swallowtail, Papilio machaon, employs what appears to be a startle display by exposing its brightly coloured dorsal wing surface upon disturbance and, if the disturbance continues, by intermittently protracting and relaxing its wing muscles generating a jerky motion of the wings. This display appears directed towards predators but whether it is effective in intimidating predators so that they refrain from attacks has never been tested experimentally.In this study we staged encounters between a passerine predator, the great tit, Parus major, and live and dead swallowtail butterflies in a two-choice experiment. Results showed that the dead butterfly was virtually always attacked before the live butterfly, and that it took four times longer before a bird attacked the live butterfly. When the live butterfly was approached by a bird this generally elicited the butterfly's startle display, which usually caused the approaching bird to flee. We also performed a palatability test of the butterflies and results show that the great tits seemed to find them palatable.We conclude that the swallowtail's startle display of conspicuous coloration and jerky movements is an efficient secondary defence against small passerines. We also discuss under what conditions predator-prey systems are likely to aid the evolution of deimatic behaviours in harmless and palatable prey.

  12. Deimatic Display in the European Swallowtail Butterfly as a Secondary Defence against Attacks from Great Tits

    Science.gov (United States)

    Olofsson, Martin; Eriksson, Stephan; Jakobsson, Sven; Wiklund, Christer

    2012-01-01

    Background Many animals reduce the risk of being attacked by a predator through crypsis, masquerade or, alternatively, by advertising unprofitability by means of aposematic signalling. Behavioural attributes in prey employed after discovery, however, signify the importance of also having an effective secondary defence if a predator uncovers, or is immune to, the prey’s primary defence. In butterflies, as in most animals, secondary defence generally consists of escape flights. However, some butterfly species have evolved other means of secondary defence such as deimatic displays/startle displays. The European swallowtail, Papilio machaon, employs what appears to be a startle display by exposing its brightly coloured dorsal wing surface upon disturbance and, if the disturbance continues, by intermittently protracting and relaxing its wing muscles generating a jerky motion of the wings. This display appears directed towards predators but whether it is effective in intimidating predators so that they refrain from attacks has never been tested experimentally. Methodology/Principal Findings In this study we staged encounters between a passerine predator, the great tit, Parus major, and live and dead swallowtail butterflies in a two-choice experiment. Results showed that the dead butterfly was virtually always attacked before the live butterfly, and that it took four times longer before a bird attacked the live butterfly. When the live butterfly was approached by a bird this generally elicited the butterfly’s startle display, which usually caused the approaching bird to flee. We also performed a palatability test of the butterflies and results show that the great tits seemed to find them palatable. Conclusions/Significance We conclude that the swallowtail’s startle display of conspicuous coloration and jerky movements is an efficient secondary defence against small passerines. We also discuss under what conditions predator-prey systems are likely to aid the

  13. Cyclic lipopeptides from Bacillus subtilis activate distinct patterns of defence responses in grapevine.

    Science.gov (United States)

    Farace, Giovanni; Fernandez, Olivier; Jacquens, Lucile; Coutte, François; Krier, François; Jacques, Philippe; Clément, Christophe; Barka, Essaid Ait; Jacquard, Cédric; Dorey, Stéphan

    2015-02-01

    Non-self-recognition of microorganisms partly relies on the perception of microbe-associated molecular patterns (MAMPs) and leads to the activation of an innate immune response. Bacillus subtilis produces three main families of cyclic lipopeptides (LPs), namely surfactins, iturins and fengycins. Although LPs are involved in induced systemic resistance (ISR) activation, little is known about defence responses induced by these molecules and their involvement in local resistance to fungi. Here, we showed that purified surfactin, mycosubtilin (iturin family) and plipastatin (fengycin family) are perceived by grapevine plant cells. Although surfactin and mycosubtilin stimulated grapevine innate immune responses, they differentially activated early signalling pathways and defence gene expression. By contrast, plipastatin perception by grapevine cells only resulted in early signalling activation. Gene expression analysis suggested that mycosubtilin activated salicylic acid (SA) and jasmonic acid (JA) signalling pathways, whereas surfactin mainly induced an SA-regulated response. Although mycosubtilin and plipastatin displayed direct antifungal activity, only surfactin and mycosubtilin treatments resulted in a local long-lasting enhanced tolerance to the necrotrophic fungus Botrytis cinerea in grapevine leaves. Moreover, challenge with specific strains overproducing surfactin and mycosubtilin led to a slightly enhanced stimulation of the defence response compared with the LP-non-producing strain of B. subtilis. Altogether, our results provide the first comprehensive view of the involvement of LPs from B. subtilis in grapevine plant defence and local resistance against the necrotrophic pathogen Bo. cinerea. Moreover, this work is the first to highlight the ability of mycosubtilin to trigger an immune response in plants. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  14. Conversion policy principles of defence factory

    International Nuclear Information System (INIS)

    Fedik, I.I.; Deniskin, V.P.; Stepanov, V.S.

    1997-01-01

    1.Research Production Association 'LUCH' (RPA 'LUCH') have worked at atomic industry for 51 years. Now it is one of the leading scientific production centers of Russia Ministry of Atomic Energy. Not long ago it was a complex of Scientific Research Institute, experimental plant and Obyedenennaya Expedicia at the Semipalatinsk test site (now it is the Institute of Atomic Energy NNC RK). Basic directions of the complex activity are defence tasks. These tasks are to develop structure and technology of producing fuel assemblies for NRE (nuclear rocket engine) reactors. Also the tasks include testing the fuel assemblies at IWG-1, RWD and RA reactors. Also the tasks include structure and technology development, production and testing electric generating channels for nuclear thermal emission converters of nuclear energy into electric one (space board power engineering), power metal optics for powerful lasers, high temperature gas reactors. 2.Main directions of RPA 'LUCH' conversion were determined on the basis of possibilities for developing main achievements in defence technology directions.These directions are high temperature materials and constructions (carbides, refractory metals, measurements, optics, uranium compound, beryllium, molybdenum) 3.At present at RPA 'LUCH' there have been created experimental and industrial productions making temperature sensors for Atomic Electric Power Stations (AEPS). Also these manufactures release commercial products. They produce technological equipment of carbide-silicon for electronic industry as well as parts or X-ray tubes, vermiculite parts for cable driving of AEP stations (high temperature, fireproof ones) of thermal and electrical accumulators. Thus, a scientific-production center is being created. Core of it is a scientific engineers group and development directions, generated from orders of defence department, as well as new foreign technologies (along with investments).The example of the said above can be development of a

  15. Defence and illustration of nuclear deterrence

    International Nuclear Information System (INIS)

    Tertrais, Bruno

    2011-01-01

    After having shown that nuclear deterrence has been efficient since 1945 (nuclear weapons prevented from war, nuclear deterrence contributed to the reduction of risks related to proliferation), the author discusses the amorality and illegality of nuclear deterrence (its ethics can indeed be a matter of discussion, as well as issues like self-defence and international humanitarian law). On another hand, he shows that deterrence costs remain acceptable and that substitutes to nuclear deterrence are not credible. He concludes that deterrence is therefore still useful and legitimate

  16. Peer-to-Peer Enclaves for Improving Network Defence

    Directory of Open Access Journals (Sweden)

    David W. Archer

    2013-07-01

    Full Text Available Information about cyberthreats within networks spreads slowly relative to the speed at which those threats spread. Typical "threat feeds" that are commercially available also disseminate information slowly relative to the propagation speed of attacks, and they often convey irrelevant information about imminent threats. As a result, hosts sharing a network may miss opportunities to improve their defence postures against imminent attack because needed information arrives too late or is lost in irrelevant noise. We envision timely, relevant peer-to-peer sharing of threat information – based on current technologies – as a solution to these problems and as a useful design pattern for defensive cyberwarfare. In our setting, network nodes form communities that we call enclaves, where each node defends itself while sharing information on imminent threats with peers that have similar threat exposure. In this article, we present our vision for this solution. We sketch the architecture of a typical node in such a network and how it might interact with a framework for sharing threat information; we explain why certain defensive countermeasures may work better in our setting; we discuss current tools that could be used as components in our vision; and we describe opportunities for future research and development.

  17. Caterpillar hairs as an anti-parasitoid defence.

    Science.gov (United States)

    Kageyama, Azusa; Sugiura, Shinji

    2016-10-01

    Caterpillar hairs are thought to act as a physical barrier against natural enemies, including parasitoids. However, very few studies have experimentally demonstrated how hairs protect caterpillars from parasitoid oviposition. To clarify the importance of caterpillar hairs as an anti-parasitoid defence, we observed the generalist endoparasitoid Meteorus pulchricornis (Hymenoptera: Braconidae) attacking both smooth and hairy caterpillars under laboratory conditions. A female Meteorus pulchricornis uses its ovipositor to inject venom and lay a single egg inside host larvae. We placed a smooth Spodoptera litura (Lepidoptera: Noctuidae) caterpillar or a hairy Lymantria dispar japonica (Lepidoptera: Erebidae) caterpillar in front of parasitoid females. We observed that 100 % and 84 % of the parasitoids could successfully stab their ovipositors into the smooth larvae of S. litura and first instars of the hairy caterpillar L. dispar japonica, respectively. However, only 24 % of parasitoids could successfully stab their ovipositors into second-instar L. dispar japonica. A higher rate of successful stabs (94 %) by parasitoids was obtained by cutting the hairs of second instar L. dispar japonica much shorter than the parasitoid ovipositor. The results demonstrate that the long, thick hairs of second and later instars of L. dispar japonica function as a physical barrier against parasitoid oviposition.

  18. Limiting immunopathology: Interaction between carotenoids and enzymatic antioxidant defences.

    Science.gov (United States)

    Babin, A; Saciat, C; Teixeira, M; Troussard, J-P; Motreuil, S; Moreau, J; Moret, Y

    2015-04-01

    The release of reactive oxygen and nitrogen species (ROS and RNS) during the inflammatory response generates damages to host tissues, referred to as immunopathology, and is an important factor in ecological immunology. The integrated antioxidant system, comprising endogenous antioxidant enzymes (e.g. superoxide dismutase SOD, and catalase CAT) and dietary antioxidants (e.g. carotenoids), helps to cope with immune-mediated oxidative stress. Crustaceans store large amounts of dietary carotenoids for yet unclear reasons. While being immunostimulants and antioxidants, the interaction of these pigments with antioxidant enzymes remains unclear. Here, we tested the interaction between dietary supplementation with carotenoids and immune challenge on immune defences and the activity of the antioxidant enzymes SOD and CAT, in the amphipod crustacean Gammarus pulex. Dietary supplementation increased the concentrations of circulating carotenoids and haemocytes in the haemolymph, while the immune response induced the consumption of circulating carotenoids and a drop of haemocyte density. Interestingly, supplemented gammarids exhibited down-regulated SOD activity but high CAT activity compared to control ones. Our study reveals specific interactions of dietary carotenoids with endogenous antioxidant enzymes, and further underlines the potential importance of carotenoids in the evolution of immunity and/or of antioxidant mechanisms in crustaceans. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Preconscious defence analysis, memory and structural change.

    Science.gov (United States)

    Ross, John Munder

    2003-02-01

    Beginning with the ways in which the use of the couch lends 'depth to the surface' (Erikson, 1954), I explore the topography of the inter- and intrasubjective psychoanalytic situation and process. I suggest that defences are not by definition unconscious but rather can be observed operating at conscious and preconscious levels, particularly under these conditions. A focus on preconscious disavowal provides a window on what has become unconscious repression. As a result of eliciting and then verbalising the operation of such defences with regard to anxieties in the here-and-now transference, declarative memories of increasingly specific childhood fantasies and events begin to hold sway over unmanageable procedural remnants from the analysand's past. With this may even come the possibility of neuronal regeneration, the more generalisable enhancement of declarative and symbolic functions and the sense of identity with which these are associated. Herein may lie one enduring therapeutic effect of the 'talking cure' - putting feelings into words - as one among a variety of psychotherapeutic modalities.

  20. The dual nature of trehalose in citrus canker disease: a virulence factor for Xanthomonas citri subsp. citri and a trigger for plant defence responses

    KAUST Repository

    Piazza, A.; Zimaro, T.; Garavaglia, B. S.; Ficarra, F. A.; Thomas, L.; Marondedze, C.; Feil, R.; Lunn, J. E.; Gehring, Christoph A; Ottado, J.; Gottig, N.

    2015-01-01

    and proteomic analyses of infected leaves showed that infection with XccΔotsA triggered only weak defence responses in the plant compared with infection with Xcc, and had less impact on the host plant's metabolism than the wild-type strain. These results

  1. 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

  2. Computed Tomography Technology: Development and Applications for Defence

    International Nuclear Information System (INIS)

    Baheti, G. L.; Saxena, Nisheet; Tripathi, D. K.; Songara, K. C.; Meghwal, L. R.; Meena, V. L.

    2008-01-01

    Computed Tomography(CT) has revolutionized the field of Non-Destructive Testing and Evaluation (NDT and E). Tomography for industrial applications warrants design and development of customized solutions catering to specific visualization requirements. Present paper highlights Tomography Technology Solutions implemented at Defence Laboratory, Jodhpur (DLJ). Details on the technological developments carried out and their utilization for various Defence applications has been covered.

  3. Fallout: the defence, industrial and technological benefits of nuclear deterrence

    International Nuclear Information System (INIS)

    Tertrais, Bruno

    2015-01-01

    In the current climate of budgetary restrictions, it is fair to question the weight of military nuclear defence spending. Upon examination, however, nuclear deterrence has numerous military, industrial, and technological benefits. It is, in fact, totally intertwined with the other elements of our defence system. (author)

  4. Methodology to detect gaps in a soccer defence

    DEFF Research Database (Denmark)

    Knudsen, Nikolas Sten; Andersen, Thomas Bull

    2015-01-01

    The purpose of the present study was to create a methodology which can provide information about gaps in an opposing team’s defence. To illustrate the methodology, a defence was tracked during a game in the danish Superliga using ZXY radio tracking and analysed using the methodology. Results show...

  5. Considerations on Defence Thinking in Post-1994 South Africa with ...

    African Journals Online (AJOL)

    ... analyse and discuss the new comprehensive guidelines for defence force design in the Draft Defence Review 2012 and reflects on some of the most important policy implications for the SANDF in this regard – specifically given the demands placed on the SANDF in the field of post-conflict reconstruction and development.

  6. Quantitative Verification and Synthesis of Attack-Defence Scenarios Conference

    NARCIS (Netherlands)

    Aslanyan, Zaruhi; Nielson, Flemming; Parker, David

    Attack-defence trees are a powerful technique for formally evaluating attack-defence scenarios. They represent in an intuitive, graphical way the interaction between an attacker and a defender who compete in order to achieve conflicting objectives. We propose a novel framework for the formal

  7. Infection biology and defence responses in sorghum against Colletotrichum sublineolum

    DEFF Research Database (Denmark)

    Puttalingaiah, Basavaraju; Shetty, Nandini Prasad; Shetty, H. S.

    2009-01-01

    Aims: To investigate the infection biology of Colletotrichum sublineolum (isolate CP2126) and defence responses in leaves of resistant (SC146), intermediately resistant (SC326) and susceptible (BTx623) sorghum genotypes. Methods and Results: Infection biology and defence responses were studied...

  8. Getting prepared for future attack : induction of plant defences by herbivore egg deposition and consequences for the insect community

    NARCIS (Netherlands)

    Pashalidou, F.G.

    2015-01-01

    Plants have evolved intriguing defences against insect herbivores. Compared to constitutive Plants have evolved intriguing defences against insect herbivores. Compared to constitutive defences that are always present, plants can respond with inducible defences when they are attacked. Insect

  9. Impact of antimissile defence on nuclear strategies in Asia

    International Nuclear Information System (INIS)

    Delory, Stephane

    2015-01-01

    As antimissile defence has become a mean to compensate the limitations of nuclear deterrence in Asia, notably within the frame of the US-North Korea relationship, but has also influence on the relationships between countries which do not possess an actual operational antimissile defence like Pakistan and India, the author proposes an assessment of the consequences antimissile defence may have on deterrence logics in Asia. He also notices that various issues must be taken into account: arsenal sizes, the slow rate of ballistic modernisation processes, the weaknesses of C4ISR systems and advanced alarm systems. He recalls the peculiarities of antimissile defence, and then addresses the cases of North Korea, India and Pakistan, and China. For each country, he analyses and discusses the influence of a choice or of the existence of an antimissile defence on the nuclear strategy and doctrine, but also on the posture of other countries like the USA

  10. Ecological mechanisms for the coevolution of mating systems and defence.

    Science.gov (United States)

    Campbell, Stuart A

    2015-02-01

    The diversity of flowering plants is evident in two seemingly unrelated aspects of life history: sexual reproduction, exemplified by the stunning variation in flower form and function, and defence, often in the form of an impressive arsenal of secondary chemistry. Researchers are beginning to appreciate that plant defence and reproduction do not evolve independently, but, instead, may have reciprocal and interactive (coevolutionary) effects on each other. Understanding the mechanisms for mating-defence interactions promises to broaden our understanding of how ecological processes can generate these two rich sources of angiosperm diversity. Here, I review current research on the role of herbivory as a driver of mating system evolution, and the role of mating systems in the evolution of defence strategies. I outline different ecological mechanisms and processes that could generate these coevolutionary patterns, and summarize theoretical and empirical support for each. I provide a conceptual framework for linking plant defence with mating system theory to better integrate these two research fields.

  11. How Human Papillomavirus Replication and Immune Evasion Strategies Take Advantage of the Host DNA Damage Repair Machinery.

    Science.gov (United States)

    Bordignon, Valentina; Di Domenico, Enea Gino; Trento, Elisabetta; D'Agosto, Giovanna; Cavallo, Ilaria; Pontone, Martina; Pimpinelli, Fulvia; Mariani, Luciano; Ensoli, Fabrizio

    2017-12-19

    The DNA damage response (DDR) is a complex signalling network activated when DNA is altered by intrinsic or extrinsic agents. DDR plays important roles in genome stability and cell cycle regulation, as well as in tumour transformation. Viruses have evolved successful life cycle strategies in order to ensure a chronic persistence in the host, virtually avoiding systemic sequelae and death. This process promotes the periodic shedding of large amounts of infectious particles to maintain a virus reservoir in individual hosts, while allowing virus spreading within the community. To achieve such a successful lifestyle, the human papilloma virus (HPV) needs to escape the host defence systems. The key to understanding how this is achieved is in the virus replication process that provides by itself an evasion mechanism by inhibiting and delaying the host immune response against the viral infection. Numerous studies have demonstrated that HPV exploits both the ataxia-telangiectasia mutated (ATM) and ataxia-telangiectasia and rad3-related (ATR) DDR pathways to replicate its genome and maintain a persistent infection by downregulating the innate and cell-mediated immunity. This review outlines how HPV interacts with the ATM- and ATR-dependent DDR machinery during the viral life cycle to create an environment favourable to viral replication, and how the interaction with the signal transducers and activators of transcription (STAT) protein family and the deregulation of the Janus kinase (JAK)-STAT pathways may impact the expression of interferon-inducible genes and the innate immune responses.

  12. THE SMART DEFENCE CONCEPT - A NEW APPROACH OF COMMON DEFENCE WITHIN NATO

    Directory of Open Access Journals (Sweden)

    Liviu IONIȚĂ

    2012-12-01

    Full Text Available The Smart Defence concept was introduced in the NATO policy in a time when the Alliance is confronted with new challenges generated by the global economic crisis, a lack of balance in the participation of the member states in the financing of common operations, threats coming from states that do not adhere to nuclear non-proliferation treaties, as well as the emergence of new state actors at the global level. By implementing the Smart Defence concept, the Alliance intends to adapt its own means of generating critical capabilities in accordance with the pooling and sharing paradigm, implemented with the European Union, an initiative that might lead to stronger cooperation between the two organisms and to a more efficient use of shared capabilities.

  13. How to address patients' defences: a pilot study of the accuracy of defence interpretations and alliance.

    Science.gov (United States)

    Junod, Olivier; de Roten, Yves; Martinez, Elena; Drapeau, Martin; Despland, Jean-Nicolas

    2005-12-01

    This pilot study examined the accuracy of therapist defence interpretations (TAD) in high-alliance patients (N = 7) and low-alliance patients (N = 8). TAD accuracy was assessed in the two subgroups by comparing for each case the patient's most frequent defensive level with the most frequent defensive level addressed by the therapist when making defence interpretations. Results show that in high-alliance patient-therapist dyads, the therapists tend to address accurate or higher (more mature) defensive level than patients most frequent level. On the other hand, the therapists address lower (more immature) defensive level in low-alliance dyads. These results are discussed along with possible ways to better assess TAD accuracy.

  14. Polymeric immunoglobulin receptor-mediated invasion of Streptococcus pneumoniae into host cells requires a coordinate signaling of SRC family of protein-tyrosine kinases, ERK, and c-Jun N-terminal kinase.

    Science.gov (United States)

    Agarwal, Vaibhav; Asmat, Tauseef M; Dierdorf, Nina I; Hauck, Christof R; Hammerschmidt, Sven

    2010-11-12

    Streptococcus pneumoniae are commensals of the human nasopharynx with the capacity to invade mucosal respiratory cells. PspC, a pneumococcal surface protein, interacts with the human polymeric immunoglobulin receptor (pIgR) to promote bacterial adherence to and invasion into epithelial cells. Internalization of pneumococci requires the coordinated action of actin cytoskeleton rearrangements and the retrograde machinery of pIgR. Here, we demonstrate the involvement of Src protein-tyrosine kinases (PTKs), focal adhesion kinase (FAK), extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) but not p38 mitogen-activated protein kinases (MAPK) in pneumococcal invasion via pIgR. Pharmacological inhibitors of PTKs and MAPKs and genetic interference with Src PTK and FAK functions caused a significant reduction of pIgR-mediated pneumococcal invasion but did not influence bacterial adhesion to host cells. Furthermore, pneumococcal ingestion by host cells induces activation of ERK1/2 and JNK. In agreement with activated JNK, its target molecule and DNA-binding protein c-Jun was phosphorylated. We also show that functionally active Src PTK is essential for activation of ERK1/2 upon pneumococcal infections. In conclusion, these data illustrate the importance of a coordinated signaling between Src PTKs, ERK1/2, and JNK during PspC-pIgR-mediated uptake of pneumococci by host epithelial cells.

  15. Raise your defence: a baseline for security

    CERN Multimedia

    Computer Security Team

    2011-01-01

    It is an unfair imbalance: the (computer) security of a system/service is only as strong as the weakest link in the chain of protection. This provides attackers with an incredible advantage: they can choose when to attack, where and with which means. The defence side is permanently under pressure: they must defend at all times all assets against all eventualities. For computer security, this means that every computer system, every account, every web site and every service must be properly protected --- always.   In particular, at CERN, those services visible to the Internet are permanently probed. Web sites and servers are permanently scanned by adversaries for vulnerabilities; attackers repeatedly try to guess user passwords on our remote access gateways like LXPLUS or CERNTS; computing services, e.g. for Grid computing, are analysed again and again by malicious attackers for weaknesses which can be exploited. Thanks to the vigilance of the corresponding system and service experts, these atta...

  16. Assessment of defence in depth for nuclear power plants

    International Nuclear Information System (INIS)

    2005-01-01

    Defence in depth is a comprehensive approach to safety that has been developed by nuclear power experts to ensure with high confidence that the public and the environment are protected from any hazards posed by the use of nuclear power for the generation of electricity. The concepts of defence in depth and safety culture have served the nuclear power industry well as a basic philosophy for the safe design and operation of nuclear power plants. Properly applied, defence in depth ensures that no single human error or equipment failure at one level of defence, nor even a combination of failures at more than one level of defence, propagates to jeopardize defence in depth at the subsequent level or leads to harm to the public or the environment. The importance of the concept of defence in depth is underlined in IAEA Safety Standards, in particular in the requirements set forth in the Safety Standards: Safety of Nuclear Power Plants: Design (NS-R-1) and Safety Assessment and Verification for Nuclear Power Plants (NS-G-1.2). A specific report, Defence in Depth in Nuclear Safety (INSAG-10), describes the objectives, strategy, implementation and future development in the area of defence in depth in nuclear and radiation safety. In the report Basic Safety Principles for Nuclear Power Plants (INSAG-12), defence in depth is recognized as one of the fundamental safety principles that underlie the safety of nuclear power plants. In consonance with those high level publications, this Safety Report provides more specific technical information on the implementation of this concept in the siting, design, construction and operation of nuclear power plants. It describes a method for comprehensive and balanced review of the provisions required for implementing defence in depth in existing plants. This publication is intended to provide guidance primarily for the self-assessment by plant operators of the comprehensiveness and quality of defence in depth provisions. It can be used

  17. Host-bacterial interplay in periodontal disease

    Directory of Open Access Journals (Sweden)

    Rudrakshi Chickanna

    2015-01-01

    Full Text Available A literature search was performed using MEDLINE (PubMed and other electronic basis from 1991 to 2014. Search included books and journals based on the systematic and critical reviews, in vitro and in vivo clinical studies on molecular basis of host microbial interactions. Clearly, an understanding of the host susceptibility factor in addition to microbial factors by elucidating the molecular basis offers opportunity for therapeutic manipulation of advancing periodontal destruction. One of the hallmarks of pathogenesis is the ability of pathogenic organisms to invade surrounding tissues and to evade the host defence. This paper focuses the general overview of molecular mechanisms involved in the microbiota and host response to bacterial inimical behavior in periodontics.

  18. Defence syndromes in lodgepole - whitebark pine ecosystems relate to degree of historical exposure to mountain pine beetles.

    Science.gov (United States)

    Raffa, Kenneth F; Mason, Charles J; Bonello, Pierluigi; Cook, Stephen; Erbilgin, Nadir; Keefover-Ring, Ken; Klutsch, Jennifer G; Villari, Caterina; Townsend, Philip A

    2017-09-01

    Warming climate is allowing tree-killing bark beetles to expand their ranges and access naïve and semi-naïve conifers. Conifers respond to attack using complex mixtures of chemical defences that can impede beetle success, but beetles exploit some compounds for host location and communication. Outcomes of changing relationships will depend on concentrations and compositions of multiple host compounds, which are largely unknown. We analysed constitutive and induced chemistries of Dendroctonus ponderosae's primary historical host, Pinus contorta, and Pinus albicaulis, a high-elevation species whose encounters with this beetle are transitioning from intermittent to continuous. We quantified multiple classes of terpenes, phenolics, carbohydrates and minerals. Pinus contorta had higher constitutive allocation to, and generally stronger inducibility of, compounds that resist these beetle-fungal complexes. Pinus albicaulis contained higher proportions of specific monoterpenes that enhance pheromone communication, and lower induction of pheromone inhibitors. Induced P. contorta increased insecticidal and fungicidal compounds simultaneously, whereas P. albicaulis responses against these agents were inverse. Induced terpene accumulation was accompanied by decreased non-structural carbohydrates, primarily sugars, in P. contorta, but not P. albicaulis, which contained primarily starches. These results show some host species with continuous exposure to bark beetles have more thoroughly integrated defence syndromes than less-continuously exposed host species. © 2017 John Wiley & Sons Ltd.

  19. Specificity in Mesograzer-Induced Defences in Seagrasses.

    Directory of Open Access Journals (Sweden)

    Begoña Martínez-Crego

    Full Text Available Grazing-induced plant defences that reduce palatability to herbivores are widespread in terrestrial plants and seaweeds, but they have not yet been reported in seagrasses. We investigated the ability of two seagrass species to induce defences in response to direct grazing by three associated mesograzers. Specifically, we conducted feeding-assayed induction experiments to examine how mesograzer-specific grazing impact affects seagrass induction of defences within the context of the optimal defence theory. We found that the amphipod Gammarus insensibilis and the isopod Idotea chelipes exerted a low-intensity grazing on older blades of the seagrass Cymodocea nodosa, which reflects a weak grazing impact that may explain the lack of inducible defences. The isopod Synischia hectica exerted the strongest grazing impact on C. nodosa via high-intensity feeding on young blades with a higher fitness value. This isopod grazing induced defences in C. nodosa as indicated by a consistently lower consumption of blades previously grazed for 5, 12 and 16 days. The lower consumption was maintained when offered tissues with no plant structure (agar-reconstituted food, but showing a reduced size of the previous grazing effect. This indicates that structural traits act in combination with chemical traits to reduce seagrass palatability to the isopod. Increase in total phenolics but not in C:N ratio and total nitrogen of grazed C. nodosa suggests chemical defences rather than a modified nutritional quality as primarily induced chemical traits. We detected no induction of defences in Zostera noltei, which showed the ability to replace moderate losses of young biomass to mesograzers via compensatory growth. Our study provides the first experimental evidence of induction of defences against meso-herbivory that reduce further consumption in seagrasses. It also emphasizes the relevance of grazer identity in determining the level of grazing impact triggering resistance and

  20. Thrips advisor: exploiting thrips-induced defences to combat pests on crops.

    Science.gov (United States)

    Steenbergen, Merel; Abd-El-Haliem, Ahmed; Bleeker, Petra; Dicke, Marcel; Escobar-Bravo, Rocio; Cheng, Gang; Haring, Michel A; Kant, Merijn R; Kappers, Iris; Klinkhamer, Peter G L; Leiss, Kirsten A; Legarrea, Saioa; Macel, Mirka; Mouden, Sanae; Pieterse, Corné M J; Sarde, Sandeep J; Schuurink, Robert C; De Vos, Martin; Van Wees, Saskia C M; Broekgaarden, Colette

    2018-04-09

    Plants have developed diverse defence mechanisms to ward off herbivorous pests. However, agriculture still faces estimated crop yield losses ranging from 25% to 40% annually. These losses arise not only because of direct feeding damage, but also because many pests serve as vectors of plant viruses. Herbivorous thrips (Thysanoptera) are important pests of vegetable and ornamental crops worldwide, and encompass virtually all general problems of pests: they are highly polyphagous, hard to control because of their complex lifestyle, and they are vectors of destructive viruses. Currently, control management of thrips mainly relies on the use of chemical pesticides. However, thrips rapidly develop resistance to these pesticides. With the rising demand for more sustainable, safer, and healthier food production systems, we urgently need to pinpoint the gaps in knowledge of plant defences against thrips to enable the future development of novel control methods. In this review, we summarize the current, rather scarce, knowledge of thrips-induced plant responses and the role of phytohormonal signalling and chemical defences in these responses. We describe concrete opportunities for breeding resistance against pests such as thrips as a prototype approach for next-generation resistance breeding.

  1. Plasma membrane order and fluidity are diversely triggered by elicitors of plant defence.

    Science.gov (United States)

    Sandor, Roman; Der, Christophe; Grosjean, Kevin; Anca, Iulia; Noirot, Elodie; Leborgne-Castel, Nathalie; Lochman, Jan; Simon-Plas, Françoise; Gerbeau-Pissot, Patricia

    2016-09-01

    Although plants are exposed to a great number of pathogens, they usually defend themselves by triggering mechanisms able to limit disease development. Alongside signalling events common to most such incompatible interactions, modifications of plasma membrane (PM) physical properties could be new players in the cell transduction cascade. Different pairs of elicitors (cryptogein, oligogalacturonides, and flagellin) and plant cells (tobacco and Arabidopsis) were used to address the issue of possible modifications of plant PM biophysical properties induced by elicitors and their links to other events of the defence signalling cascade. We observed an increase of PM order whatever the elicitor/plant cell pair used, provided that a signalling cascade was induced. Such membrane modification is dependent on the NADPH oxidase-mediated reactive oxygen species production. Moreover, cryptogein, which is the sole elicitor able to trap sterols, is also the only one able to trigger an increase in PM fluidity. The use of cryptogein variants with altered sterol-binding properties confirms the strong correlation between sterol removal from the PM and PM fluidity enhancement. These results propose PM dynamics as a player in early signalling processes triggered by elicitors of plant defence. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  2. The Defence Medical Library Service and military medicine.

    Science.gov (United States)

    Walker, S B

    2005-01-01

    The Defence Medical Library Service (DMLS) supports the clinical practice and career development of military health professionals across the world. Clinical governance and the need for medical knowledge to be evidence-based means the DMLS has a central role to play in support of defence medicine. The DMLS is important for enabling health professionals to make sense of the evidence-based pyramid and the hierarchy of medical knowledge. The Royal Centre for Defence Medicine (RCDM) in Birmingham is recognised as an international centre of excellence. The information, knowledge and research requirements of the RCDM will provide opportunities for the DMLS to support and engage with the academic community.

  3. Reinforcing Defence in Depth: A Practical Systemic Approach

    International Nuclear Information System (INIS)

    Watts, G.; Misak, J.

    2016-01-01

    The concept of defence in depth for ensuring nuclear safety of nuclear installations is often oversimplified and interpreted as a set of physical barriers, whose integrity is ensured by safety provisions in the form of the plant systems implemented independently at various levels of defence. However, the provisions established at each level of defence should in general terms include not only hardware components (active and passive systems), but more comprehensively, also inherent safety characteristics, safety margins, operating procedures and guidelines, quality assurance, safety culture, staff training, and many other organizational measures as parts of management of safety. Many of the above mentioned provisions belong to the category of human and organizational factors. While various hardware components are typically specific for different levels of defence, human and organizational factors may have an impact on several levels of defence. These factors are associated with large uncertainties and can result in latent weaknesses. Their implementation can negatively affect several levels of defence at the same time. The proposed paper will underline the need for a more comprehensive view of the defence in depth concept in order to provide a practical and effective tool for a systemic approach to safety. The paper will consist of two main parts. The first part will introduce a screening method developed by the IAEA as a tool for facilitating the assessment of the comprehensiveness of defence in depth. The method uses screening of safety provisions at five levels of defence to ensure integrity of the physical barriers and achievement of safety objectives at each level of defence. The second part of the paper will focus on human and organizational factors considered as provisions for reliable performance of safety functions. It will explain the significant shift in the demands on the human system between levels 3 and 4 of the defence in depth framework, and will

  4. Metabolic Engineering of Chemical Defence Pathways in Plant Disease Control

    DEFF Research Database (Denmark)

    Rook, Frederik

    2016-01-01

    on each topic. The chapter reviews the some of the scientific and technical challenges in metabolic engineering and the new possibilities emerging from recent technological developments. It concludes by discussing the outlook for bioengineered chemical defences as part of crop protection strategies, also...... with antimicrobial properties for use in crop protection. It presents an overview of the metabolic engineering efforts made in the area of plant chemical defence. For in-depth information on the characteristics of a specific class of chemical defence compounds, the reader is referred to the specialized reviews...

  5. EU Defence Industry Integration between Spillover and High Politics

    DEFF Research Database (Denmark)

    Kluth, Michael Friederich

    on an intergovernmental base. In the past 10 years, however, the defence industries of the major EU powers have instigated a move from cross national collaboration to cross national consolidation. Cross border mergers and acquisitions has been carried out and pressures for regulatory mainstreaming is mounting....... This raises the question: are we witnessing an incursion of spillover mechanisms into the ‘High Politics' domain of the defence industry? What are the drivers eroding the ‘High Politics' character of defence industry integration? Are market forces at play? Does it reflect pressures for institutional...

  6. Pseudomonas Aeruginosa: interactions with organisms in the environment and cells of the immune defence

    DEFF Research Database (Denmark)

    Skindersø, Mette Elena

    2008-01-01

    , which emphasises the urgent need for development of novel strategies that will help us to defeat this pathogen. P. aeruginosa biofilm cells display a multicellular-like coordinated behaviour and control expression of virulence factors, elements involved in biofilm development and immunomodulating...... factors by means of signal molecule mediated communication, known as quorum sensing. This thesis explores a strategy which aims to counteract P. aeruginosa virulence and pathogenicity by impeding its cell-to-cell communication. A treatment regime, which focuses on targeting bacterial communication instead......; two quorum sensing signal molecules; the Pseudomonas Quinolone Signal and N-3-oxododecanoyl L-homoserine lactone exhibit the ability to modulate activities of the immune defence in addition to functioning as quorum sensing mediators. The two signal molecules impair activities of immune cells crucial...

  7. fundTPL-2 – ERK1/2 Signaling Promotes Host Resistance against Intracellular Bacterial Infection by Negative Regulation of Type I Interferon Production3

    OpenAIRE

    McNab, Finlay W.; Ewbank, John; Rajsbaum, Ricardo; Stavropoulos, Evangelos; Martirosyan, Anna; Redford, Paul S.; Wu, Xuemei; Graham, Christine M.; Saraiva, Margarida; Tsichlis, Philip; Chaussabel, Damien; Ley, Steven C.; O’Garra, Anne

    2013-01-01

    Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), remains a leading cause of mortality and morbidity worldwide, causing approximately 1.4 million deaths per year. Key immune components for host protection during tuberculosis include the cytokines IL-12, IL-1 and TNF-α, as well as IFN-γ and CD4+ Th1 cells. However, immune factors determining whether individuals control infection or progress to active tuberculosis are incompletely understood. Excess amounts of type I interferon have bee...

  8. Radiation accidents and defence of population

    International Nuclear Information System (INIS)

    Memmedov, A.M.

    2002-01-01

    ), don't pollute the industry environ and surroundings, don't do real danger of reirradiation and pollution but demand investigation of their origin; accidents as a result when personal and persons from population have gotten a doze of outward irradiation (over PN); accidents as a result when industry or surroundings have been polluted (over PN);.accidents, as a result of outward and inside irradiation of personal, persons from population (over NPP-norms of radiation safety). Volume and character of measures by foregoing radiation accidents and their consequence depend on groups and scale of accident. They include investigation of the accident reasons; realization the radiation control for estimation degree of ionizing radiation pressure to personal and individual persons from population; rendering medical help to victims; definition of surroundings pollution level; equipment, industrial and habitable places; prevention of further influence of ionizing radiation to population and spreading radionuclides in surroundings; elimination of disrepairs and liquidation of radiation accident source. Radiation accident in the nuclear engineering establishments and industry have been divided into accident and proper-crash. At present international organizations have divided a school of crashes and accidents at NPP. According to that scale 3 levels of accidents and 4 levels of crashes have been chosen. The accidents have been qualified: insignificant (1 level), middle difficulty (2 level), serious (3 level), but crashes - within the NPP (4 level), at the risk of surroundings (5 level), difficult (6 level), global (7 level). Character, volume and forms of measures by defence of population in the crashes at NPP depend on both the level of crash and the concrete radiation situation and stage of crash development. Those measures include: notification about crash; rendering medical help to victims, primary measures of personal and population defence (cover, iodine precautions

  9. Interaction between the moss Physcomitrella patens and Phytophthora: a novel pathosystem for live-cell imaging of subcellular defence.

    Science.gov (United States)

    Overdijk, Elysa J R; DE Keijzer, Jeroen; DE Groot, Deborah; Schoina, Charikleia; Bouwmeester, Klaas; Ketelaar, Tijs; Govers, Francine

    2016-08-01

    Live-cell imaging of plant-pathogen interactions is often hampered by the tissue complexity and multicell layered nature of the host. Here, we established a novel pathosystem with the moss Physcomitrella patens as host for Phytophthora. The tip-growing protonema cells of this moss are ideal for visualizing interactions with the pathogen over time using high-resolution microscopy. We tested four Phytophthora species for their ability to infect P. patens and showed that P. sojae and P. palmivora were only rarely capable to infect P. patens. In contrast, P. infestans and P. capsici frequently and successfully penetrated moss protonemal cells, showed intracellular hyphal growth and formed sporangia. Next to these successful invasions, many penetration attempts failed. Here the pathogen was blocked by a barrier of cell wall material deposited in papilla-like structures, a defence response that is common in higher plants. Another common response is the upregulation of defence-related genes upon infection and also in moss we observed this upregulation in tissues infected with Phytophthora. For more advanced analyses of the novel pathosystem we developed a special set-up that allowed live-cell imaging of subcellular defence processes by high-resolution microscopy. With this set-up, we revealed that Phytophthora infection of moss induces repositioning of the nucleus, accumulation of cytoplasm and rearrangement of the actin cytoskeleton, but not of microtubules. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  10. Variation in the effectiveness of biotic defence: the case of an opportunistic ant-plant protection mutualism.

    Science.gov (United States)

    Giusto, Bruno; Anstett, Marie-Charlotte; Dounias, Edmond; McKey, Doyle B

    2001-11-01

    Benefits to plants in facultative ant protection mutualisms are highly variable. This allows examination of the sources of this variation and the mechanisms by which ants protect plants. We studied opportunistic interactions between ants and an extrafloral nectary-bearing vine, Dioscorea praehensilis, during 3 different years. Variation in plant protection among years was striking. Several factors affected the effectiveness of the biotic defence. Stems recently emerged from the underground tuber were self-supporting, contacting no other plants and encountering few foraging ants. Stems then became lianescent, and contact with supporting plants greatly increased ant recruitment. Both species and number of ant workers influenced the effect of ants on the major herbivore, the chrysomelid beetle Lilioceris latipennis. Protective actions included limitation of oviposition (reduction in the number of eggs laid on the plant) and predation, leading to increased larval mortality. The probability of successful predation was strongly dependent on larval size. If temporarily low ant-patrolling activity allows larvae to grow beyond a critical size, their mechanical (thick integument) or chemical (plant-derived compounds in a fecal shield) defences become more effective against ants. Secondary metabolites derived from the host plant thus appear to be important for the anti-predator mechanisms of this beetle, being necessary for its survival and reproduction on a host plant that actively recruits ants as a biotic defence against herbivores.

  11. From Defence to Development: Redirecting Military Resources in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Book cover From Defence to Development: Redirecting Military Resources in ... of the IDRC-funded project "Militarization and the Ecology of Southern Africa." ... Congratulations to the first cohort of Women in Climate Change Science Fellows!

  12. 4th International Conference in Software Engineering for Defence Applications

    CERN Document Server

    Sillitti, Alberto; Succi, Giancarlo; Messina, Angelo

    2016-01-01

    This book presents high-quality original contributions on new software engineering models, approaches, methods, and tools and their evaluation in the context of defence and security applications. In addition, important business and economic aspects are discussed, with a particular focus on cost/benefit analysis, new business models, organizational evolution, and business intelligence systems. The contents are based on presentations delivered at SEDA 2015, the 4th International Conference in Software Engineering for Defence Applications, which was held in Rome, Italy, in May 2015. This conference series represents a targeted response to the growing need for research that reports and debates the practical implications of software engineering within the defence environment and also for software performance evaluation in real settings through controlled experiments as well as case and field studies. The book will appeal to all with an interest in modeling, managing, and implementing defence-related software devel...

  13. suicide prevention and management in the sa national defence force

    African Journals Online (AJOL)

    Rene

    DEFENCE FORCE: A PSYCHOLOGICAL. DISCUSSION ... military, among British veterans of the Falkland war and during the recent Iraq conflict.1 In the United ... Nye reported in her research on Vietnam combat veterans, that posttraumatic ...

  14. The role of thionins in rice defence against root pathogens.

    Science.gov (United States)

    Ji, Hongli; Gheysen, Godelieve; Ullah, Chhana; Verbeek, Ruben; Shang, Chenjing; De Vleesschauwer, David; Höfte, Monica; Kyndt, Tina

    2015-10-01

    Thionins are antimicrobial peptides that are involved in plant defence. Here, we present an in-depth analysis of the role of rice thionin genes in defence responses against two root pathogens: the root-knot nematode Meloidogyne graminicola and the oomycete Pythium graminicola. The expression of rice thionin genes was observed to be differentially regulated by defence-related hormones, whereas all analysed genes were consistently down-regulated in M. graminicola-induced galls, at least until 7 days post-inoculation (dpi). Transgenic lines of Oryza sativa cv. Nipponbare overproducing OsTHI7 revealed decreased susceptibility to M. graminicola infection and P. graminicola colonization. Taken together, these results demonstrate the role of rice thionin genes in defence against two of the most damaging root pathogens attacking rice. © 2015 BSPP AND JOHN WILEY & SONS LTD.

  15. SseK3 Is a Salmonella Effector That Binds TRIM32 and Modulates the Host's NF-κB Signalling Activity.

    Directory of Open Access Journals (Sweden)

    Zhe Yang

    Full Text Available Salmonella Typhimurium employs an array of type III secretion system effectors that facilitate intracellular survival and replication during infection. The Salmonella effector SseK3 was originally identified due to amino acid sequence similarity with NleB; an effector secreted by EPEC/EHEC that possesses N-acetylglucoasmine (GlcNAc transferase activity and modifies death domain containing proteins to block extrinsic apoptosis. In this study, immunoprecipitation of SseK3 defined a novel molecular interaction between SseK3 and the host protein, TRIM32, an E3 ubiquitin ligase. The conserved DxD motif within SseK3, which is essential for the GlcNAc transferase activity of NleB, was required for TRIM32 binding and for the capacity of SseK3 to suppress TNF-stimulated activation of NF-κB pathway. However, we did not detect GlcNAc modification of TRIM32 by SseK3, nor did the SseK3-TRIM32 interaction impact on TRIM32 ubiquitination that is associated with its activation. In addition, lack of sseK3 in Salmonella had no effect on production of the NF-κB dependent cytokine, IL-8, in HeLa cells even though TRIM32 knockdown suppressed TNF-induced NF-κB activity. Ectopically expressed SseK3 partially co-localises with TRIM32 at the trans-Golgi network, but SseK3 is not recruited to Salmonella induced vacuoles or Salmonella induced filaments during Salmonella infection. Our study has identified a novel effector-host protein interaction and suggests that SseK3 may influence NF-κB activity. However, the lack of GlcNAc modification of TRIM32 suggests that SseK3 has further, as yet unidentified, host targets.

  16. The failing firm defence: merger policy and entry

    OpenAIRE

    Mason, Robin; Weeds, Helen

    2003-01-01

    This Paper considers the 'failing firm defence'. Under this principle, found in most antitrust jurisdictions, a merger that would otherwise be blocked due to its adverse effect on competition is permitted when the firm to be acquired is a failing firm, and an alternative, less detrimental merger is unavailable. Competition authorities have shown considerable reluctance to accept the failing firm defence, and it has been successfully used in just a handful of cases. The Paper considers the def...

  17. HumanViCe: Host ceRNA network in virus infected cells in human

    Directory of Open Access Journals (Sweden)

    Suman eGhosal

    2014-07-01

    Full Text Available Host-virus interaction via host cellular components has been an important field of research in recent times. RNA interference mediated by short interfering RNAs and microRNAs (miRNA, is a widespread anti-viral defence strategy. Importantly, viruses also encode their own miRNAs. In recent times miRNAs were identified as key players in host-virus interaction. Furthermore, viruses were shown to exploit the host miRNA networks to suite their own need. The complex cross-talk between host and viral miRNAs and their cellular and viral targets forms the environment for viral pathogenesis. Apart from protein-coding mRNAs, non-coding RNAs may also be targeted by host or viral miRNAs in virus infected cells, and viruses can exploit the host miRNA mediated gene regulatory network via the competing endogenous RNA effect. A recent report showed that viral U-rich non-coding RNAs called HSUR, expressed in primate virus herpesvirus saimiri (HVS infected T cells, were able to bind to three host miRNAs, causing significant alteration in cellular level for one of the miRNAs. We have predicted protein coding and non protein-coding targets for viral and human miRNAs in virus infected cells. We identified viral miRNA targets within host non-coding RNA loci from AGO interacting regions in three different virus infected cells. Gene ontology (GO and pathway enrichment analysis of the genes comprising the ceRNA networks in the virus infected cells revealed enrichment of key cellular signalling pathways related to cell fate decisions and gene transcription, like Notch and Wnt signalling pathways, as well as pathways related to viral entry, replication and virulence. We identified a vast number of non-coding transcripts playing as potential ceRNAs to the immune response associated genes; e.g. APOBEC family genes, in some virus infected cells. All these information are compiled in HumanViCe, a comprehensive database that provides the potential ceRNA networks in virus

  18. China's nuclear arsenal and missile defence

    International Nuclear Information System (INIS)

    Rappai, M.V.

    2002-01-01

    Over the last few years, major focus of the nuclear debate has been turned towards the United States' proposal to erect a National Missile Defence (NMD) shield for itself. Of the existing nuclear weapon powers, China has been the most vociferous critic of this proposal. As and when this shield does become a reality, China will be the first to lose credibility as a deterrent against USA's existing nuclear arsenal. Therefore taking countermeasures against such a proposal is quite natural. China's approach towards non-proliferation mechanisms is steeped in realpolitik and its ability to manoeuvre them in its favour as a P5 and N5 power. Further, the Chinese leadership have been clear about the capabilities and limitations of nuclear weapons and treated them as diplomatic and political tools. The underlying aim is to preserve China's status as a dominant player in the international system while checkmating other possible challengers. Such a pragmatic approach is of far-reaching significance to all nations, especially those that possess nuclear weapons themselves. It will also be in India's long-term strategic interest to assess and take necessary corrective measures in its national security strategy, and make the composition of Indian nuclear strategy meet the desired goal. (author)

  19. Defence in Depth and Ageing Management

    Energy Technology Data Exchange (ETDEWEB)

    Fabbri, S.; Vega, G.; Diluch, A.; Versaci, R., E-mail: versaci@cnea.gov.ar [Comisión Nacional de Energía Atómica, Buenos Aires (Argentina)

    2014-10-15

    Accident prevention is the first safety priority of both designers and operators. It is achieved through the use of reliable structures, components, systems and procedures in a plant operated by personnel who are committed to a strong safety culture. For future nuclear power plants, consideration of multiple failures and severe accidents will be achieved in a more systematic and complete way from the design stage. Defence in depth (DID) consists of a hierarchical deployment of different levels of equipment and procedures in order to maintain the effectiveness of physical barriers placed between radioactive materials and workers, the public or the environment, in normal operation, anticipated operational occurrences and, for some barriers, in accidents at the plant. The primary way of preventing accidents is to achieve a high quality in design, construction and operation of the plant, and thereby to ensure that deviations from normal operation are infrequent. The best way to meet these premises of effectiveness of the barriers and the Systems, Structures and Components (SSCs) is to develop an ageing management programme to prevent potential failures and accidents. In this work we will refer to the ageing management programme for Atucha I and Atucha II power plants and to the Atucha I spent fuel storage. (author)

  20. Transformational Leadership in the Estonian Defence Forces

    Directory of Open Access Journals (Sweden)

    Antek Kasemaa

    2015-06-01

    Full Text Available Purpose – The study is a contribution to the validation of the 15 items and 5 subscales Transformational Leadership Scale (TLS proposed by Rafferty and Griffin (2004. Design/methodology/approach – The sample includes participants from different levels of the Estonian Defence Forces (EDF military hierarchy (N=2570. The structure of the TLS was examined by using exploratory and confirmatory factor analyses. Additionally ANOVA was used to compare the results between different subsamples. Findings – TLS showed satisfactory reliability. Confirmatory factor analyses found TLS as valid five dimensions instrument to measure transformational leadership in the Estonian military context. Different management levels showed different emphases among the dimensions of transformational leadership. Research and practical limitations/implications – TLS will be an important tool to use in transformational leadership research in the Estonian military context and beyond. Additionally, the current research contributes to the development of alternative measurement tools besides the most commonly used MLQ. The limitation of the work will be the rather homogenous sample from the Estonian military, however it will open the door for the subsequent research using different samplings. Originality/value – The current research found TLS to be a reliable and valid instrument, very short and therefore easy to administrate, having the possibility to use it with five dimensional and as one general transformational instrument as well.

  1. Expression profiles of defence related cDNAs in oil palm (Elaeis guineensis Jacq.) inoculated with mycorrhizae and Trichoderma harzianum Rifai T32.

    Science.gov (United States)

    Tan, Yung-Chie; Wong, Mui-Yun; Ho, Chai-Ling

    2015-11-01

    Basal stem rot is one of the major diseases of oil palm (Elaies guineensis Jacq.) caused by pathogenic Ganoderma species. Trichoderma and mycorrhizae were proposed to be able to reduce the disease severity. However, their roles in improving oil palm defence system by possibly inducing defence-related genes in the host are not well characterized. To better understand that, transcript profiles of eleven putative defence-related cDNAs in the roots of oil palm inoculated with Trichoderma harzianum T32 and mycorrhizae at different time points were studied. Transcripts encoding putative Bowman-Birk protease inhibitor (EgBBI2) and defensin (EgDFS) increased more than 2 fold in mycorrhizae-treated roots at 6 weeks post inoculation (wpi) compared to those in controls. Transcripts encoding putative dehydrin (EgDHN), glycine-rich RNA binding protein (EgGRRBP), isoflavone reductase (EgIFR), type 2 ribosome inactivating protein (EgT2RIP), and EgDFS increased in the oil palm roots treated with T. harzianum at 6 and/or 12 wpi compared to those in the controls. Some of these genes were also expressed in oil palm roots treated with Ganoderma boninense. This study provides an insight of some defence-related genes induced by Trichoderma and mycorrhizae, and their roles as potential agents to boost the plant defence system. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  2. EST sequencing and gene expression profiling of defence-related genes from Persea americana infected with Phytophthora cinnamomi

    Directory of Open Access Journals (Sweden)

    Mahomed Waheed

    2011-11-01

    Full Text Available Abstract Background Avocado (Persea americana belongs to the Lauraceae family and is an important commercial fruit crop in over 50 countries. The most serious pathogen affecting avocado production is Phytophthora cinnamomi which causes Phytophthora root rot (PRR. Root pathogens such as P. cinnamomi and their interactions with hosts are poorly understood and despite the importance of both the avocado crop and the effect Phytophthora has on its cultivation, there is a lack of molecular knowledge underpinning our understanding of defence strategies against the pathogen. In order to initiate a better understanding of host-specific defence we have generated EST data using 454 pyrosequencing and profiled nine defence-related genes from Pc-infected avocado roots. Results 2.0 Mb of data was generated consisting of ~10,000 reads on a single lane of the GS FLX platform. Using the Newbler assembler 371 contigs were assembled, of which 367 are novel for Persea americana. Genes were classified according to Gene Ontology terms. In addition to identifying root-specific ESTs we were also able to identify and quantify the expression of nine defence-related genes that were differentially regulated in response to P. cinnamomi. Genes such as metallothionein, thaumatin and the pathogenesis related PsemI, mlo and profilin were found to be differentially regulated. Conclusions This is the first study in elucidating the avocado root transcriptome as well as identifying defence responses of avocado roots to the root pathogen P. cinnamomi. Our data is currently the only EST data that has been generated for avocado rootstocks, and the ESTs identified in this study have already been useful in identifying defence-related genes as well as providing gene information for other studies looking at processes such as ROS regulation as well as hypoxia in avocado roots. Our EST data will aid in the elucidation of the avocado transcriptome and identification of markers for improved

  3. Pattern mimicry of host eggs by the common cuckoo, as seen through a bird's eye.

    Science.gov (United States)

    Stoddard, Mary Caswell; Stevens, Martin

    2010-05-07

    Cuckoo-host interactions provide classical examples of coevolution. Cuckoos place hosts under selection to detect and reject foreign eggs, while host defences result in the evolution of host-egg mimicry in cuckoos. Despite a long history of research, egg pattern mimicry has never been objectively quantified, and so its coevolution with host defences has not been properly assessed. Here, we use digital image analysis and modelling of avian vision to quantify the level of pattern mimicry in eight host species of the common cuckoo Cuculus canorus and their respective cuckoo host-races. We measure a range of pattern attributes, including marking size, diversity in size, contrast, coverage and dispersion. This new technique reveals hitherto unnoticed sophistication in egg pattern mimicry. We show that various features of host egg pattern are mimicked by the eggs of their respective cuckoo host-races, and that cuckoos have evolved better pattern mimicry for host species that exhibit stronger egg rejection. Pattern differs relatively more between eggs of different host species than between their respective cuckoo host-races. We suggest that cuckoos may have more 'average' markings in order to be able to use subsidiary hosts. Our study sheds new light on cuckoo-host coevolution and illustrates a new technique for quantifying animal markings with respect to the relevant animal visual system.

  4. Temporal activation of anti- and pro-apoptotic factors in human gingival fibroblasts infected with the periodontal pathogen, Porphyromonas gingivalis: potential role of bacterial proteases in host signalling

    Directory of Open Access Journals (Sweden)

    Takehara Tadamichi

    2006-03-01

    Full Text Available Abstract Background Porphyromonas gingivalis is the foremost oral pathogen of adult periodontitis in humans. However, the mechanisms of bacterial invasion and the resultant destruction of the gingival tissue remain largely undefined. Results We report host-P. gingivalis interactions in primary human gingival fibroblast (HGF cells. Quantitative immunostaining revealed the need for a high multiplicity of infection for optimal infection. Early in infection (2–12 h, P. gingivalis activated the proinflammatory transcription factor NF-kappa B, partly via the PI3 kinase/AKT pathway. This was accompanied by the induction of cellular anti-apoptotic genes, including Bfl-1, Boo, Bcl-XL, Bcl2, Mcl-1, Bcl-w and Survivin. Late in infection (24–36 h the anti-apoptotic genes largely shut down and the pro-apoptotic genes, including Nip3, Hrk, Bak, Bik, Bok, Bax, Bad, Bim and Moap-1, were activated. Apoptosis was characterized by nuclear DNA degradation and activation of caspases-3, -6, -7 and -9 via the intrinsic mitochondrial pathway. Use of inhibitors revealed an anti-apoptotic function of NF-kappa B and PI3 kinase in P. gingivalis-infected HGF cells. Use of a triple protease mutant P. gingivalis lacking three major gingipains (rgpA rgpB kgp suggested a role of some or all these proteases in myriad aspects of bacteria-gingival interaction. Conclusion The pathology of the gingival fibroblast in P. gingivalis infection is affected by a temporal shift from cellular survival response to apoptosis, regulated by a number of anti- and pro-apoptotic molecules. The gingipain group of proteases affects bacteria-host interactions and may directly promote apoptosis by intracellular proteolytic activation of caspase-3.

  5. Independently recruited oxidases from the glucose-methanol-choline oxidoreductase family enabled chemical defences in leaf beetle larvae (subtribe Chrysomelina) to evolve

    Science.gov (United States)

    Rahfeld, Peter; Kirsch, Roy; Kugel, Susann; Wielsch, Natalie; Stock, Magdalena; Groth, Marco; Boland, Wilhelm; Burse, Antje

    2014-01-01

    Larvae of the leaf beetle subtribe Chrysomelina sensu stricto repel their enemies by displaying glandular secretions that contain defensive compounds. These repellents can be produced either de novo (iridoids) or by using plant-derived precursors (e.g. salicylaldehyde). The autonomous production of iridoids, as in Phaedon cochleariae, is the ancestral chrysomeline chemical defence and predates the evolution of salicylaldehyde-based defence. Both biosynthesis strategies include an oxidative step of an alcohol intermediate. In salicylaldehyde-producing species, this step is catalysed by salicyl alcohol oxidases (SAOs) of the glucose-methanol-choline (GMC) oxidoreductase superfamily, but the enzyme oxidizing the iridoid precursor is unknown. Here, we show by in vitro as well as in vivo experiments that P. cochleariae also uses an oxidase from the GMC superfamily for defensive purposes. However, our phylogenetic analysis of chrysomeline GMC oxidoreductases revealed that the oxidase of the iridoid pathway originated from a GMC clade different from that of the SAOs. Thus, the evolution of a host-independent chemical defence followed by a shift to a host-dependent chemical defence in chrysomeline beetles coincided with the utilization of genes from different GMC subfamilies. These findings illustrate the importance of the GMC multi-gene family for adaptive processes in plant–insect interactions. PMID:24943369

  6. Innate immune defences in the human endometrium

    Directory of Open Access Journals (Sweden)

    Kelly Rodney W

    2003-11-01

    Full Text Available Abstract The human endometrium is an important site of innate immune defence, giving protection against uterine infection. Such protection is critical to successful implantation and pregnancy. Infection is a major cause of preterm birth and can also cause infertility and ectopic pregnancy. Natural anti-microbial peptides are key mediators of the innate immune system. These peptides, between them, have anti-bacterial, anti-fungal and anti-viral activity and are expressed at epithelial surfaces throughout the female genital tract. Two families of natural anti-microbials, the defensins and the whey acidic protein (WAP motif proteins, appear to be prominent in endometrium. The human endometrial epithelium expresses beta-defensins 1–4 and the WAP motif protein, secretory leukocyte protease inhibitor. Each beta-defensin has a different expression profile in relation to the stage of the menstrual cycle, providing potential protection throughout the cycle. Secretory leukocyte protease inhibitor is expressed during the secretory phase of the cycle and has a range of possible roles including anti-protease and anti-microbial activity as well as having effects on epithelial cell growth. The leukocyte populations in the endometrium are also a source of anti-microbial production. Neutrophils are a particularly rich source of alpha-defensins, lactoferrin, lysozyme and the WAP motif protein, elafin. The presence of neutrophils during menstruation will enhance anti-microbial protection at a time when the epithelial barrier is disrupted. Several other anti-microbials including the natural killer cell product, granulysin, are likely to have a role in endometrium. The sequential production of natural anti-microbial peptides by the endometrium throughout the menstrual cycle and at other sites in the female genital tract will offer protection from many pathogens, including those that are sexually transmitted.

  7. Arbuscular Mycorrhizal Fungi and Plant Chemical Defence: Effects of Colonisation on Aboveground and Belowground Metabolomes.

    Science.gov (United States)

    Hill, Elizabeth M; Robinson, Lynne A; Abdul-Sada, Ali; Vanbergen, Adam J; Hodge, Angela; Hartley, Sue E

    2018-02-01

    Arbuscular mycorrhizal fungal (AMF) colonisation of plant roots is one of the most ancient and widespread interactions in ecology, yet the systemic consequences for plant secondary chemistry remain unclear. We performed the first metabolomic investigation into the impact of AMF colonisation by Rhizophagus irregularis on the chemical defences, spanning above- and below-ground tissues, in its host-plant ragwort (Senecio jacobaea). We used a non-targeted metabolomics approach to profile, and where possible identify, compounds induced by AMF colonisation in both roots and shoots. Metabolomics analyses revealed that 33 compounds were significantly increased in the root tissue of AMF colonised plants, including seven blumenols, plant-derived compounds known to be associated with AMF colonisation. One of these was a novel structure conjugated with a malonyl-sugar and uronic acid moiety, hitherto an unreported combination. Such structural modifications of blumenols could be significant for their previously reported functional roles associated with the establishment and maintenance of AM colonisation. Pyrrolizidine alkaloids (PAs), key anti-herbivore defence compounds in ragwort, dominated the metabolomic profiles of root and shoot extracts. Analyses of the metabolomic profiles revealed an increase in four PAs in roots (but not shoots) of AMF colonised plants, with the potential to protect colonised plants from below-ground organisms.

  8. Complexity of the Microglial Activation Pathways that Drive Innate Host Responses During Lethal Alphavirus Encephalitis in Mice

    Directory of Open Access Journals (Sweden)

    Nilufer Esen

    2012-04-01

    Full Text Available Microglia express multiple TLRs (Toll-like receptors and provide important host defence against viruses that invade the CNS (central nervous system. Although prior studies show these cells become activated during experimental alphavirus encephalitis in mice to generate cytokines and chemokines that influence virus replication, tissue inflammation and neuronal survival, the specific PRRs (pattern recognition receptors and signalling intermediates controlling microglial activation in this setting remain unknown. To investigate these questions directly in vivo, mice ablated of specific TLR signalling molecules were challenged with NSV (neuroadapted Sindbis virus and CNS viral titres, inflammatory responses and clinical outcomes followed over time. To approach this problem specifically in microglia, the effects of NSV on primary cells derived from the brains of wild-type and mutant animals were characterized in vitro. From the standpoint of the virus, microglial activation required viral uncoating and an intact viral genome; inactivated virus particles did not elicit measurable microglial responses. At the level of the target cell, NSV triggered multiple PRRs in microglia to produce a broad range of inflammatory mediators via non-overlapping signalling pathways. In vivo, disease survival was surprisingly independent of TLR-driven responses, but still required production of type-I IFN (interferon to control CNS virus replication. Interestingly, the ER (endoplasmic reticulum protein UNC93b1 facilitated host survival independent of its known effects on endosomal TLR signalling. Taken together, these data show that alphaviruses activate microglia via multiple PRRs, highlighting the complexity of the signalling networks by which CNS host responses are elicited by these infections.

  9. Prioritizing plant defence over growth through WRKY regulation facilitates infestation by non-target herbivores

    Science.gov (United States)

    Li, Ran; Zhang, Jin; Li, Jiancai; Zhou, Guoxin; Wang, Qi; Bian, Wenbo; Erb, Matthias; Lou, Yonggen

    2015-01-01

    Plants generally respond to herbivore attack by increasing resistance and decreasing growth. This prioritization is achieved through the regulation of phytohormonal signaling networks. However, it remains unknown how this prioritization affects resistance against non-target herbivores. In this study, we identify WRKY70 as a specific herbivore-induced, mitogen-activated protein kinase-regulated rice transcription factor that physically interacts with W-box motifs and prioritizes defence over growth by positively regulating jasmonic acid (JA) and negatively regulating gibberellin (GA) biosynthesis upon attack by the chewing herbivore Chilo suppressalis. WRKY70-dependent JA biosynthesis is required for proteinase inhibitor activation and resistance against C. suppressalis. In contrast, WRKY70 induction increases plant susceptibility against the rice brown planthopper Nilaparvata lugens. Experiments with GA-deficient rice lines identify WRKY70-dependent GA signaling as the causal factor in N. lugens susceptibility. Our study shows that prioritizing defence over growth leads to a significant resistance trade-off with important implications for the evolution and agricultural exploitation of plant immunity. DOI: http://dx.doi.org/10.7554/eLife.04805.001 PMID:26083713

  10. Pareto Efficient Solutions of Attack-Defence Trees

    DEFF Research Database (Denmark)

    Aslanyan, Zaruhi; Nielson, Flemming

    2015-01-01

    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 proba......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 probability or cost of attacks and defences. In case of multiple parameters most analytical methods optimise one parameter at a time, e.g., minimise cost or maximise probability of an attack. Such methods may lead to sub-optimal solutions when optimising conflicting parameters, e.g., minimising cost while...... maximising probability. In order to tackle this challenge, we devise automated techniques that optimise all parameters at once. Moreover, in the case of conflicting parameters our techniques compute the set of all optimal solutions, defined in terms of Pareto efficiency. The developments are carried out...

  11. Time-dependent reliability analysis of flood defences

    International Nuclear Information System (INIS)

    Buijs, F.A.; Hall, J.W.; Sayers, P.B.; Gelder, P.H.A.J.M. van

    2009-01-01

    This paper describes the underlying theory and a practical process for establishing time-dependent reliability models for components in a realistic and complex flood defence system. Though time-dependent reliability models have been applied frequently in, for example, the offshore, structural safety and nuclear industry, application in the safety-critical field of flood defence has to date been limited. The modelling methodology involves identifying relevant variables and processes, characterisation of those processes in appropriate mathematical terms, numerical implementation, parameter estimation and prediction. A combination of stochastic, hierarchical and parametric processes is employed. The approach is demonstrated for selected deterioration mechanisms in the context of a flood defence system. The paper demonstrates that this structured methodology enables the definition of credible statistical models for time-dependence of flood defences in data scarce situations. In the application of those models one of the main findings is that the time variability in the deterioration process tends to be governed the time-dependence of one or a small number of critical attributes. It is demonstrated how the need for further data collection depends upon the relevance of the time-dependence in the performance of the flood defence system.

  12. Evaluating arguments during instigations of defence motivation and accuracy motivation.

    Science.gov (United States)

    Liu, Cheng-Hong

    2017-05-01

    When people evaluate the strength of an argument, their motivations are likely to influence the evaluation. However, few studies have specifically investigated the influences of motivational factors on argument evaluation. This study examined the effects of defence and accuracy motivations on argument evaluation. According to the compatibility between the advocated positions of arguments and participants' prior beliefs and the objective strength of arguments, participants evaluated four types of arguments: compatible-strong, compatible-weak, incompatible-strong, and incompatible-weak arguments. Experiment 1 revealed that participants possessing a high defence motivation rated compatible-weak arguments as stronger and incompatible-strong ones as weaker than participants possessing a low defence motivation. However, the strength ratings between the high and low defence groups regarding both compatible-strong and incompatible-weak arguments were similar. Experiment 2 revealed that when participants possessed a high accuracy motivation, they rated compatible-weak arguments as weaker and incompatible-strong ones as stronger than when they possessed a low accuracy motivation. However, participants' ratings on both compatible-strong and incompatible-weak arguments were similar when comparing high and low accuracy conditions. The results suggest that defence and accuracy motivations are two major motives influencing argument evaluation. However, they primarily influence the evaluation results for compatible-weak and incompatible-strong arguments, but not for compatible-strong and incompatible-weak arguments. © 2016 The British Psychological Society.

  13. Radiation protection and safety in the Australian Defence Organisation (ADO)

    International Nuclear Information System (INIS)

    Jenks, G.J.; O'Donovan, E.J.B.

    1995-01-01

    Very few organisations have to address such a diverse and complex range of radiation safety matters as the Australian Defence Organisation. The Australian Defence Force and the Department of Defence (its military and civilian branches) have to comply with strict regulations in normal peace time activities. The Surgeon-General, to whom responsibility for policy in radiation protection and safety falls, has established a Defence Radiation Safety Committee, which in turn oversees four specialist subcommittees. Their tasks include recommending policy and doctrine in relation to radiation safety, overseeing the implementation of appropriate regulations, monitoring their compliance. generating the relevant documentation (particularly on procedures to be followed), developing and improving any necessary training courses, and providing sound technical advice whenever and to whomever required. The internal Defence regulations do not permit radiation doses to exceed those limits recommended by the Australian National Health and Medical Research Council and precautions are taken to ensure during normal peace time duties that these levels are not exceeded. At times of national emergency, the Surgeon-General provides guidance and advice to military commanders on the consequences of receiving dose levels that would not be permitted during normal peace time activities. The paper describes the methods adopted to implement such arrangements

  14. A plant EPF-type zinc-finger protein, CaPIF1, involved in defence against pathogens.

    Science.gov (United States)

    Oh, Sang-Keun; Park, Jeong Mee; Joung, Young Hee; Lee, Sanghyeob; Chung, Eunsook; Kim, Soo-Yong; Yu, Seung Hun; Choi, Doil

    2005-05-01

    SUMMARY To understand better the defence responses of plants to pathogen attack, we challenged hot pepper plants with bacterial pathogens and identified transcription factor-encoding genes whose expression patterns were altered during the subsequent hypersensitive response. One of these genes, CaPIF1 (Capsicum annuum Pathogen-Induced Factor 1), was characterized further. This gene encodes a plant-specific EPF-type protein that contains two Cys(2)/His(2) zinc fingers. CaPIF1 expression was rapidly and specifically induced when pepper plants were challenged with bacterial pathogens to which they are resistant. In contrast, challenge with a pathogen to which the plants are susceptible only generated weak CaPIF1 expression. CaPIF1 expression was also strongly induced in pepper leaves by the exogenous application of ethephon, an ethylene-releasing compound, and salicylic acid, whereas methyl jasmonate had only moderate effects. CaPIF1 localized to the nuclei of onion epidermis when expressed as a CaPIF1-smGFP fusion protein. Transgenic tobacco plants over-expressing CaPIF1 driven by the CaMV 35S promoter showed increased resistance to challenge with a tobacco-specific pathogen or non-host bacterial pathogens. These plants also showed constitutive up-regulation of multiple defence-related genes. Moreover, virus-induced silencing of the CaPIF1 orthologue in Nicotiana benthamiana enhanced susceptibility to the same host or non-host bacterial pathogens. These observations provide evidence that an EPF-type Cys(2)/His(2) zinc-finger protein plays a crucial role in the activation of the pathogen defence response in plants.

  15. NK cell receptor/H2-Dk-dependent host resistance to viral infection is quantitatively modulated by H2q inhibitory signals.

    Science.gov (United States)

    Fodil-Cornu, Nassima; Loredo-Osti, J Concepción; Vidal, Silvia M

    2011-04-01

    The cytomegalovirus resistance locus Cmv3 has been linked to an epistatic interaction between two loci: a Natural Killer (NK) cell receptor gene and the major histocompatibility complex class I (MHC-I) locus. To demonstrate the interaction between Cmv3 and H2(k), we generated double congenic mice between MA/My and BALB.K mice and an F(2) cross between FVB/N (H-2(q)) and BALB.K (H2(k)) mice, two strains susceptible to mouse cytomegalovirus (MCMV). Only mice expressing H2(k) in conjunction with Cmv3(MA/My) or Cmv3(FVB) were resistant to MCMV infection. Subsequently, an F(3) cross was carried out between transgenic FVB/H2-D(k) and MHC-I deficient mice in which only the progeny expressing Cmv3(FVB) and a single H2-D(k) class-I molecule completely controlled MCMV viral loads. This phenotype was shown to be NK cell-dependent and associated with subsequent NK cell proliferation. Finally, we demonstrated that a number of H2(q) alleles influence the expression level of H2(q) molecules, but not intrinsic functional properties of NK cells; viral loads, however, were quantitatively proportional to the number of H2(q) alleles. Our results support a model in which H-2(q) molecules convey Ly49-dependent inhibitory signals that interfere with the action of H2-D(k) on NK cell activation against MCMV infection. Thus, the integration of activating and inhibitory signals emanating from various MHC-I/NK cell receptor interactions regulates NK cell-mediated control of viral load.

  16. NK Cell Receptor/H2-Dk–Dependent Host Resistance to Viral Infection Is Quantitatively Modulated by H2 q Inhibitory Signals

    Science.gov (United States)

    Fodil-Cornu, Nassima; Loredo-Osti, J. Concepción; Vidal, Silvia M.

    2011-01-01

    The cytomegalovirus resistance locus Cmv3 has been linked to an epistatic interaction between two loci: a Natural Killer (NK) cell receptor gene and the major histocompatibility complex class I (MHC-I) locus. To demonstrate the interaction between Cmv3 and H2k, we generated double congenic mice between MA/My and BALB.K mice and an F2 cross between FVB/N (H-2q) and BALB.K (H2k) mice, two strains susceptible to mouse cytomegalovirus (MCMV). Only mice expressing H2k in conjunction with Cmv3MA/My or Cmv3FVB were resistant to MCMV infection. Subsequently, an F3 cross was carried out between transgenic FVB/H2-Dk and MHC-I deficient mice in which only the progeny expressing Cmv3FVB and a single H2-Dk class-I molecule completely controlled MCMV viral loads. This phenotype was shown to be NK cell–dependent and associated with subsequent NK cell proliferation. Finally, we demonstrated that a number of H2q alleles influence the expression level of H2q molecules, but not intrinsic functional properties of NK cells; viral loads, however, were quantitatively proportional to the number of H2q alleles. Our results support a model in which H-2q molecules convey Ly49-dependent inhibitory signals that interfere with the action of H2-Dk on NK cell activation against MCMV infection. Thus, the integration of activating and inhibitory signals emanating from various MHC-I/NK cell receptor interactions regulates NK cell–mediated control of viral load. PMID:21533075

  17. Evading plant defence: Infestation of poisonous milkweed fruits (Asclepiadaceae) by the fruit fly Dacus siliqualactis (Diptera: Tephritidae).

    Science.gov (United States)

    Schneider, Michael; Wunder, Cora; Reuss, Esther; Toennes, Stefan W; Mebs, Dietrich

    2017-12-01

    To cope with toxic metabolites plants use for defence, herbivorous insects employ various adaptive strategies. For oviposition, the fruit fly Dacus siliqualactis (Tephritidae) uses milkweed plants of the genus Gomphocarpus (Asclepiadaceae) by circumventing the plant's physical (gluey latex) and chemical (toxic cadenolides) defence. With its long, telescope-like ovipositor, the fly penetrates the exo- and endocarp of the fruit and places the eggs on the unripe seeds located in the centre of the fruit. Whereas most plant parts contain high concentrations of cardenolides such as gomphoside, calotropin/calacatin and gomphogenin, only the seeds exhibit low cardenolide levels. By surmounting physical barriers (fruit membranes, latex), the fly secures a safe environment and a latex-free food source of low toxicity for the developing larvae. One amino acid substitution (Q111V) at the cardenolide binding site of the fly's Na + , K + -ATPase was detected, but the significance of that substitution: reducing cardenolide sensitivity or not, is unclear. However, poisoning of the larvae by low levels of cardenolides is assumed to be prevented by non-resorption and excretion of the polar cardenolides, which cannot passively permeate the midgut membrane. This example of an insect-plant interaction demonstrates that by morphological and behavioural adaptation, a fruit fly manages to overcome even highly effective defence mechanisms of its host plant. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Can Plant Defence Mechanisms Provide New Approaches for the Sustainable Control of the Two-Spotted Spider Mite Tetranychus urticae?

    Directory of Open Access Journals (Sweden)

    Blas Agut

    2018-02-01

    Full Text Available Tetranychus urticae (T. urticae Koch is a cosmopolitan, polyphagous mite which causes economic losses in both agricultural and ornamental plants. Some traits of T. urticae hamper its management, including a short life cycle, arrhenotokous parthenogenesis, its haplodiploid sex determination system, and its extraordinary ability to adapt to different hosts and environmental conditions. Currently, the use of chemical and biological control are the major control methods used against this mite. In recent years, some studies have focused on plant defence mechanisms against herbivores. Various families of plant compounds (such as flavonoids, glucosinolates, or acyl sugars have been shown to behave as acaricides. Plants can be induced upon appropriate stimuli to increase their resistance against spider mites. This knowledge, together with the understanding of mechanisms by which T. urticae detoxifies and adapts to pesticides, may complement the control of this pest. Herein, we describe plant volatile compounds (VOCs with repellent activity, and new findings about defence priming against spider mites, which interfere with the T. urticae performance. The use of VOCs and defence priming can be integrated into current management practices and reduce the damage caused by T. urticae in the field by implementing new, more sustainable crop management tools.

  19. Pertussis Toxin Exploits Host Cell Signaling Pathways Induced by Meningitis-Causing E. coli K1-RS218 and Enhances Adherence of Monocytic THP-1 Cells to Human Cerebral Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Laura Julia Starost

    2016-10-01

    Full Text Available Pertussis toxin (PTx, the major virulence factor of the whooping cough-causing bacterial pathogen Bordetella pertussis, permeabilizes the blood–brain barrier (BBB in vitro and in vivo. Breaking barriers might promote translocation of meningitis-causing bacteria across the BBB, thereby facilitating infection. PTx activates several host cell signaling pathways exploited by the neonatal meningitis-causing Escherichia coli K1-RS218 for invasion and translocation across the BBB. Here, we investigated whether PTx and E. coli K1-RS218 exert similar effects on MAPK p38, NF-κB activation and transcription of downstream targets in human cerebral endothelial TY10 cells using qRT-PCR, Western blotting, and ELISA in combination with specific inhibitors. PTx and E. coli K1-RS218 activate MAPK p38, but only E. coli K1-RS218 activates the NF-κB pathway. mRNA and protein levels of p38 and NF-κB downstream targets including IL-6, IL-8, CxCL-1, CxCL-2 and ICAM-1 were increased. The p38 specific inhibitor SB203590 blocked PTx-enhanced activity, whereas E. coli K1-RS218’s effects were inhibited by the NF-κB inhibitor Bay 11-7082. Further, we found that PTx enhances the adherence of human monocytic THP-1 cells to human cerebral endothelial TY10 cells, thereby contributing to enhanced translocation. These modulations of host cell signaling pathways by PTx and meningitis-causing E. coli support their contributions to pathogen and monocytic THP-1 cells translocation across the BBB.

  20. How insects overcome two-component plant chemical defence

    DEFF Research Database (Denmark)

    Pentzold, Stefan; Zagrobelny, Mika; Rook, Frederik

    2014-01-01

    Insect herbivory is often restricted by glucosylated plant chemical defence compounds that are activated by plant β-glucosidases to release toxic aglucones upon plant tissue damage. Such two-component plant defences are widespread in the plant kingdom and examples of these classes of compounds...... are alkaloid, benzoxazinoid, cyanogenic and iridoid glucosides as well as glucosinolates and salicinoids. Conversely, many insects have evolved a diversity of counteradaptations to overcome this type of constitutive chemical defence. Here we discuss that such counter-adaptations occur at different time points......, before and during feeding as well as during digestion, and at several levels such as the insects’ feeding behaviour, physiology and metabolism. Insect adaptations frequently circumvent or counteract the activity of the plant β-glucosidases, bioactivating enzymes that are a key element in the plant’s two...

  1. Defence in front of challenges related to climate disruption

    International Nuclear Information System (INIS)

    Alex, Bastien

    2015-03-01

    As the Pentagon already noticed a relationship between security and climate change in a report published more than ten years ago, climate change is now considered as a threat multiplier, and is therefore a major stake for industrial, institutional and military actors of defence. The author first describes the relationship between national security and climatic security, how risks related to global warming have also an actual potential of destabilisation. He describes how this issue is increasingly addressed by defence actors, notably with a strategic approach initiated by the USA, a still holding back France, discussions about the impact of operational capabilities, and a trend for a carbon print decrease for the defence sector. In the next part, the author examines whether policies of adaptation to climate change could involve threats, evokes the development of geo-engineering, and briefly outlines that a failed adaptation could increase vulnerability

  2. Nuclear power reactors: reactor safety and military and civil defence

    International Nuclear Information System (INIS)

    Hvinden, T.

    1976-01-01

    The formation of fission products and plutonium in reactors is briefly described, followed by a short general discussion of reactor safety. The interaction of reactor safety and radioactive release considerations with military and civil defence is thereafter discussed. Reactors and other nuclear plants are factors which must be taken into account in the defence of the district around the site, and as potential targets of both conventional and guerilla attacks and sabotage, requiring special defence. The radiological hazards arising from serious damage to a power reactor by conventional weapons are briefly discussed, and the benefits of underground siting evaluated. Finally the author discusses the significance of the IAEA safeguards work as a preventive factor. (JIW)

  3. Grape marc extract acts as elicitor of plant defence responses.

    Science.gov (United States)

    Goupil, Pascale; Benouaret, Razik; Charrier, Olivia; Ter Halle, Alexandra; Richard, Claire; Eyheraguibel, Boris; Thiery, Denis; Ledoigt, Gérard

    2012-07-01

    Plant protection based on novel alternative strategies is a major concern in agriculture to sustain pest management. The marc extract of red grape cultivars reveals plant defence inducer properties. Treatment with grape marc extract efficiently induced hypersensitive reaction-like lesions with cell death evidenced by Evans Blue staining of tobacco leaves. Examination of the infiltration zone and the surrounding areas under UV light revealed the accumulation of autofluorescent compounds. Both leaf infiltration and a foliar spray of the red grape extract on tobacco leaves induced defence gene expression. The PR1 and PR2 target genes were upregulated locally and systemically in tobacco plants following grape marc extract treatment. The grape extract elicited an array of plant defence responses making this natural compound a potential phytosanitary product with a challenging issue and a rather attractive option for sustainable agriculture and environmentally friendly practices.

  4. Accident management-defence in depth in Indian PHWRS

    International Nuclear Information System (INIS)

    Jagannad, V.B.L.; Reddy, V.V.; Hajela, Sameer; Bhatia, C.M.; Nair, Suma

    2015-01-01

    Defence in Depth (DiD) is the established safety principle for the design of Nuclear Power Plants (NPPs). Accident at Fukushima Dai-ichi had highlighted the importance of provisions at Level-4 and 5 of DiD. Post Fukushima accident, on-site measures have been strengthened for Indian Nuclear Power Plants. On procedural front, Accident Management Guidelines have been introduced to handle events more severe than design basis accidents. This paper elaborates enhancement of Defence in Depth provisions for Indian Nuclear Power Plants. (author)

  5. Quantitative Verification and Synthesis of Attack-Defence Scenarios

    DEFF Research Database (Denmark)

    Aslanyan, Zaruhi; Nielson, Flemming; Parker, David

    2016-01-01

    analysis of quantitative properties of complex attack-defence scenarios, using an extension of attack-defence trees which models temporal ordering of actions and allows explicit dependencies in the strategies adopted by attackers and defenders. We adopt a game-theoretic approach, translating attack...... which guarantee or optimise some quantitative property, such as the probability of a successful attack, the expected cost incurred, or some multi-objective trade-off between the two. We implement our approach, building upon the PRISM-games model checker, and apply it to a case study of an RFID goods...

  6. Co-transcriptomic Analysis by RNA Sequencing to Simultaneously Measure Regulated Gene Expression in Host and Bacterial Pathogen

    KAUST Repository

    Ravasi, Timothy; Mavromatis, Charalampos Harris; Bokil, Nilesh J.; Schembri, Mark A.; Sweet, Matthew J.

    2016-01-01

    Intramacrophage pathogens subvert antimicrobial defence pathways using various mechanisms, including the targeting of host TLR-mediated transcriptional responses. Conversely, TLR-inducible host defence mechanisms subject intramacrophage pathogens to stress, thus altering pathogen gene expression programs. Important biological insights can thus be gained through the analysis of gene expression changes in both the host and the pathogen during an infection. Traditionally, research methods have involved the use of qPCR, microarrays and/or RNA sequencing to identify transcriptional changes in either the host or the pathogen. Here we describe the application of RNA sequencing using samples obtained from in vitro infection assays to simultaneously quantify both host and bacterial pathogen gene expression changes, as well as general approaches that can be undertaken to interpret the RNA sequencing data that is generated. These methods can be used to provide insights into host TLR-regulated transcriptional responses to microbial challenge, as well as pathogen subversion mechanisms against such responses.

  7. Co-transcriptomic Analysis by RNA Sequencing to Simultaneously Measure Regulated Gene Expression in Host and Bacterial Pathogen

    KAUST Repository

    Ravasi, Timothy

    2016-01-24

    Intramacrophage pathogens subvert antimicrobial defence pathways using various mechanisms, including the targeting of host TLR-mediated transcriptional responses. Conversely, TLR-inducible host defence mechanisms subject intramacrophage pathogens to stress, thus altering pathogen gene expression programs. Important biological insights can thus be gained through the analysis of gene expression changes in both the host and the pathogen during an infection. Traditionally, research methods have involved the use of qPCR, microarrays and/or RNA sequencing to identify transcriptional changes in either the host or the pathogen. Here we describe the application of RNA sequencing using samples obtained from in vitro infection assays to simultaneously quantify both host and bacterial pathogen gene expression changes, as well as general approaches that can be undertaken to interpret the RNA sequencing data that is generated. These methods can be used to provide insights into host TLR-regulated transcriptional responses to microbial challenge, as well as pathogen subversion mechanisms against such responses.

  8. The influence of space and time on the evolution of altruistic defence: the case of ant slave rebellion.

    Science.gov (United States)

    Metzler, D; Jordan, F; Pamminger, T; Foitzik, S

    2016-05-01

    How can antiparasite defence traits evolve even if they do not directly benefit their carriers? An example of such an indirect defence is rebellion of enslaved Temnothorax longispinosus ant workers against their social parasite Temnothorax americanus, a slavemaking ant. Ant slaves have been observed to kill their oppressors' offspring, a behaviour from which the sterile slaves cannot profit directly. Parasite brood killing could, however, reduce raiding pressure on related host colonies nearby. We analyse with extensive computer simulations for the Temnothorax slavemaker system under what conditions a hypothetical rebel allele could invade a host population, and in particular, how host-parasite dynamics and population structure influence the rebel allele's success. Exploring a wide range of model parameters, we only found a small number of parameter combinations for which kin selection or multilevel selection could allow a slave rebellion allele to spread in the host population. Furthermore, we did not detect any cases in which the reduction of raiding pressure in the close vicinity of the slavemaker nest would substantially contribute to the inclusive fitness of rebels. This suggests that slave rebellion is not costly and perhaps a side-effect of some other beneficial trait. In some of our simulations, however, even a costly rebellion allele could spread in the population. This was possible when host-parasite interactions led to a metapopulation dynamic with frequent local extinctions and recolonizations of demes by the offspring of few immigrants. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  9. T Lymphocyte Immunity in Host Defence against Chlamydia trachomatis and Its Implication for Vaccine Development

    Directory of Open Access Journals (Sweden)

    X Yang

    1998-01-01

    Full Text Available Chlamydia trachomatis is an obligate intracellular bacterial pathogen that causes several significant human infectious diseases, including trachoma, urethritis, cervicitis and salpingitis, and is an important cofactor for transmission of human immunodeficiency virus. Until very recently, over three decades of research effort aimed at developing a C trachomatis vaccine had failed, due mainly to the lack of a precise understanding of the mechanisms for protective immunity. Although most studies concerning protective immunity to C trachomatis have focused on humoral immune responses, recent studies have clearly shown that T helper-1 (Th1-like CD4 T cell-mediated immune responses play the dominant role in protective immunity. These studies suggest a paradigm for chlamydial immunity and pathology based on the concept of heterogeneity (Th1/Th2 in CD4 T cell immune responses. This concept for chlamydial immunity offers a rational template on which to base renewed efforts for development of a chlamydial vaccine that targets the induction of cell-mediated Th1 immune responses.

  10. Sex-specific defence behaviour against brood parasitism in a host with female-only incubation

    Czech Academy of Sciences Publication Activity Database

    Požgayová, Milica; Procházka, Petr; Honza, Marcel

    2009-01-01

    Roč. 81, č. 1 (2009), s. 34-38 ISSN 0376-6357 R&D Projects: GA AV ČR IAA600930605; GA ČR(CZ) GD524/05/H536; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z60930519 Keywords : Aggression * Cuckoo * Egg ejection * Great reed warbler * Nest guarding * Parental roles Subject RIV: EG - Zoology Impact factor: 1.527, year: 2009

  11. γδ T cells in homeostasis and host defence of epithelial barrier tissues

    DEFF Research Database (Denmark)

    Nielsen, Morten M.; Witherden, Deborah A.; Havran, Wendy L.

    2017-01-01

    Epithelial surfaces line the body and provide a crucial interface between the body and the external environment. Tissue-resident epithelial γδ T cells represent a major T cell population in the epithelial tissues and are ideally positioned to carry out barrier surveillance and aid in tissue...... homeostasis and repair. In this Review, we focus on the intraepithelial γδ T cell compartment of the two largest epithelial tissues in the body — namely, the epidermis and the intestine — and provide a comprehensive overview of the crucial contributions of intraepithelial γδ T cells to tissue integrity...

  12. Emerging mosquito-borne viruses: transmission and modulation of host defence

    NARCIS (Netherlands)

    Fros, J.J.

    2015-01-01

    Summary

    Two highly pathogenic arthropod-borne (arbo)viruses, West Nile virus (WNV) and chikungunya virus (CHIKV), recently (re-)emerged in both Europe and the Americas. This resulted in large-scale epidemics of severe encephalitic and arthritogenic human disease,

  13. The gut microbiota plays a protective role in the host defence against pneumococcal pneumonia

    NARCIS (Netherlands)

    Schuijt, Tim J.; Lankelma, Jacqueline M.; Scicluna, Brendon P.; de Sousa E Melo, Felipe; Roelofs, Joris J. T. H.; de Boer, J. Daan; Hoogendijk, Arjan J.; de Beer, Regina; de Vos, Alex; Belzer, Clara; de Vos, Willem M.; van der Poll, Tom; Wiersinga, W. Joost

    2016-01-01

    Pneumonia accounts for more deaths than any other infectious disease worldwide. The intestinal microbiota supports local mucosal immunity and is increasingly recognised as an important modulator of the systemic immune system. The precise role of the gut microbiota in bacterial pneumonia, however, is

  14. The gut microbiota plays a protective role in the host defence against pneumococcal pneumonia

    NARCIS (Netherlands)

    Schuijt, T.J.; Lankelma, J.M.; Scicluna, B.P.; Melo, e F.S.; Roelofs, J.J.; Boer, de J.D.; Hoogendijk, A.J.; Beer, de R.; Vos, de A.; Belzer, C.; Vos, de W.M.; Poll, van der T.; Wiersinga, W.J.

    2016-01-01

    OBJECTIVE: Pneumonia accounts for more deaths than any other infectious disease worldwide. The intestinal microbiota supports local mucosal immunity and is increasingly recognised as an important modulator of the systemic immune system. The precise role of the gut microbiota in bacterial pneumonia,

  15. The role of strategic missile defence in the global architecture de ballistic non proliferation

    International Nuclear Information System (INIS)

    Hautecouverture, Benjamin

    2007-01-01

    Whereas some think that missile defence is a proliferation agent by nature and therefore undermines the already fragile regime of ballistic non proliferation, some others think that missile defence could underpin the non proliferation regime. The author thus discusses these issues and both points of view by commenting the ambiguous discursive relationships between missile defence and arms control, and by highlighting the various roles and missions given to missile defence, notably in treaties (like the ABM treaty) and postures adopted by concerned countries

  16. Escalation of a coevolutionary arms race through host rejection of brood parasitic young.

    Science.gov (United States)

    Langmore, Naomi E; Hunt, Sarah; Kilner, Rebecca M

    2003-03-13

    Cuckoo nestlings that evict all other young from the nest soon after hatching impose a high reproductive cost on their hosts. In defence, hosts have coevolved strategies to prevent brood parasitism. Puzzlingly, they do not extend beyond the egg stage. Thus, hosts adept at recognizing foreign eggs remain vulnerable to exploitation by cuckoo nestlings. Here we show that the breach of host egg defences by cuckoos creates a new stage in the coevolutionary cycle. We found that defences used during the egg-laying period by host superb fairy-wrens (Malurus cyaneus) are easily evaded by the Horsfield's bronze-cuckoo (Chrysococcyx basalis), a specialist fairy-wren brood parasite. However, although hosts never deserted their own broods, they later abandoned 40% of nests containing a lone Horsfield's bronze-cuckoo nestling, and 100% of nests with a lone shining bronze-cuckoo nestling (Chrysococcyx lucidus), an occasional fairy-wren brood parasite. Our experiments demonstrate that host discrimination against evictor-cuckoo nestlings is possible, and suggest that it has selected for the evolution of nestling mimicry in bronze-cuckoos.

  17. Inhibition of tumor vasculogenic mimicry and prolongation of host survival in highly aggressive gallbladder cancers by norcantharidin via blocking the ephrin type a receptor 2/focal adhesion kinase/paxillin signaling pathway.

    Directory of Open Access Journals (Sweden)

    Hui Wang

    Full Text Available Vasculogenic mimicry (VM is a newly-defined tumor microcirculation pattern in highly aggressive malignant tumors. We recently reported tumor growth and VM formation of gallbladder cancers through the contribution of the ephrin type a receptor 2 (EphA2/focal adhesion kinase (FAK/Paxillin signaling pathways. In this study, we further investigated the anti-VM activity of norcantharidin (NCTD as a VM inhibitor for gallbladder cancers and the underlying mechanisms. In vivo and in vitro experiments to determine the effects of NCTD on tumor growth, host survival, VM formation of GBC-SD nude mouse xenografts, and vasculogenic-like networks, malignant phenotypes i.e., proliferation, apoptosis, invasion and migration of GBC-SD cells. Expression of VM signaling-related markers EphA2, FAK and Paxillin in vivo and in vitro were examined by immunofluorescence, western blotting and real-time polymerase chain reaction (RT-PCR, respectively. The results showed that after treatment with NCTD, GBC-SD cells were unable to form VM structures when injecting into nude mouse, growth of the xenograft was inhibited and these observations were confirmed by facts that VM formation by three-dimensional (3-D matrix, proliferation, apoptosis, invasion, migration of GBC-SD cells were affected; and survival time of the xenograft mice was prolonged. Furthermore, expression of EphA2, FAK and Paxillin proteins/mRNAs of the xenografts was downregulated. Thus, we concluded that NCTD has potential anti-VM activity against human gallbladder cancers; one of the underlying mechanisms may be via blocking the EphA2/FAK/Paxillin signaling pathway.

  18. Exploiting Modelling and Simulation in Support of Cyber Defence

    NARCIS (Netherlands)

    Klaver, M.H.A.; Boltjes, B.; Croom-Jonson, S.; Jonat, F.; Çankaya, Y.

    2014-01-01

    The rapidly evolving environment of Cyber threats against the NATO Alliance has necessitated a renewed focus on the development of Cyber Defence policy and capabilities. The NATO Modelling and Simulation Group is looking for ways to leverage Modelling and Simulation experience in research, analysis

  19. CSIR eNews: Defence, peace, safety and security

    CSIR Research Space (South Africa)

    CSIR

    2007-12-01

    Full Text Available At the CSIR, science and technology (S&T) is hard at work for a peaceful, safe and prosperous South Africa. The organisation has developed strong S&T capabilities through its associations with key players in defence, safety and security...

  20. Direct and indirect chemical defence of pine against folivorous insects

    NARCIS (Netherlands)

    Mumm, R.; Hilker, M.

    2006-01-01

    The chemical defence of pine against herbivorous insects has been intensively studied with respect to its effects on the performance and behaviour of the herbivores as well as on the natural enemies of pine herbivores. The huge variety of terpenoid pine components play a major role in mediating

  1. Successive Evolutions of the Defence in Depth Concept

    Energy Technology Data Exchange (ETDEWEB)

    Poulat, B., E-mail: B.Poulat@iaea.org [International Atomic Energy Agency (IAEA), Department of Nuclear Safety and Security, Wagramer Strasse 5, P.O. Box 100, 1400 Vienna (Austria)

    2014-10-15

    Following Fukushima Daiichi accident, the Defence-in-depth concept, which is usually defined as a combination of a number of consecutive and independent levels of protection that would have to fail before harmful effects could be caused, has been confirmed as an essential element to be applied in the design of a nuclear facility to protect people and the environment. However, and although the implementation of the defence in depth concept had been required for long, the Fukushima Daiichi accident and the “stress tests” conducted in different countries have revealed deficiencies in its implementation. Consequently within the review of the IAEA safety requirements requested by Member states, it was important to check whether this concept was appropriately defined in order to be properly understood and fully implemented by vendors and operating organizations. By screening the successive definitions of the defence in depth principle and concept, this paper emphasizes the few issues which have been gradually clarified and enhanced to ensure effectiveness of the defence in depth as expressed from its original statement. (author)

  2. Polymorphism at selected defence gene analogs (DGAs) of Musa ...

    African Journals Online (AJOL)

    One of the major diseases affecting banana is Sigatoka or leaf spot disease that comprises three species, Mycosphaerella fijiensis, Mycosphaerella musicola and Mycosphaerella eumusae. Plants have a large number of defence related genes which trigger a cascade of defense responses that halt the spread of pathogens.

  3. Phytoplankton defence mechanisms: traits and trade-offs

    DEFF Research Database (Denmark)

    Pančić, Marina; Kiørboe, Thomas

    2018-01-01

    mechanisms in phytoplankton are diverse and include physiological (e.g. toxicity, bioluminescence), morphological (e.g. silica shell, colony formation), and behavioural (e.g. escape response) traits. However, the function of many of the proposed defence mechanisms remains elusive, and the costs and benefits...

  4. Alcohol misuse in patients attending a defence force general ...

    African Journals Online (AJOL)

    Results: Of the 658 patients approached, 40 (6%) declined to fill in the questionnaire. 42% of the 618 patients surveyed were ... 38,1% of male apprentices at the technical college and 40,0% of male current defence force members staying on the base scored 8 or more on the AUDIT. In the group scoring less than 8 on the ...

  5. Probabilistic Design of Coastal Flood Defences in Vietnam

    NARCIS (Netherlands)

    Mai Van, C.

    2010-01-01

    This study further develops the method of probabilistic design and to address a knowledge gap in its application regarding safety and reliability, risk assessment and risk evaluation to the fields of flood defences. The thesis discusses: - a generic probabilistic design framework for assessing flood

  6. Developmental Trends of the Defence of Superior Order: Acritical ...

    African Journals Online (AJOL)

    Developmental Trends of the Defence of Superior Order: Acritical Appraisal of the Statute of the International Criminal Court. Eni E Alobo. Abstract. No Abstract. LWATI: A Journal of Contemporary Research, 9(3), 107-125, 2012. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ...

  7. 240 THE RELEVANCE OF THE DEFENCE OF ALIBI IN CRIMINAL ...

    African Journals Online (AJOL)

    Fr. Ikenga

    It is this unique defence that we seek to analyse in this work. ... been guilty'3 According to the Supreme Court in Eke v State4 alibi means ... 3 E. Jowitt, Dictionary of English Law Vol 1 (London, Sweet and Maxwell 1959) pg 156 ... (a) Every person who actually does the act or makes the omission which constitutes the offence ...

  8. Interdepartmental Cooperation in Defence Issues and Strategic Intelligence

    Directory of Open Access Journals (Sweden)

    Nebojsa Nikolic

    2016-05-01

    Full Text Available The motivation for this paper comes from one successfully conducted empirical research about motivation of potential candidates to serve in the active reserve as a kind of military service which is recently introduced in the Serbian Army. The research team was faced with a set of problems related to the deadlines, resources and mandate issues. A solution was found in agile interdepartmental cooperation. Firstly, we started with identification of missing resources and mandates of our research team. Then, we investigated where we could find the missing issues. After that, we established lines for cooperation with other departments in the MoD. The clarity of interdepartmental communication and concretisation of demands and expectations were crucial for success. In the end we realized the full potential of interdepartmental cooperation and started to think about that phenomenon in the wider context of defence and security issues. We found some other examples of interdepartmental cooperation in earlier efforts of the defence sector reform, as well as some results in other armies. The paper presents strengths and opportunities of interdepartmental cooperation through temporary engaged working groups in the specific defence sector environment, as well as potential obstacles. In a wider aspect, interdepartmental cooperation in defence and security issues becomes more and more important because of new security challenges we are facing today.

  9. Currency crises with the threat of an interest rate defence

    NARCIS (Netherlands)

    Daniels, T.R.; Jager, H.; Klaassen, F.

    2011-01-01

    While virtually all currency crisis models recognise that the decision to abandon a peg depends on how tenaciously policy makers defend it, this is seldom modelled explicitly. We add the threat of an interest rate defence to the global game model of Morris and Shin (American Economic Review 88,

  10. Defence in Depth - Applied to the Nuclear System

    Energy Technology Data Exchange (ETDEWEB)

    Weightman, M., E-mail: mike_weightman@hotmail.com

    2014-10-15

    Full text: Normally, the Defence in Depth concept is applied to the technical barriers that provide protection to the public and workers from nuclear accidents. This allows designers, operators and regulators to challenge (along with using other design principles such as independence, redundancy, diversity, single point failure, etc) the technical systems provided to see whether more needs to be done to provide adequate defence in depth to ensure risks are reduced so far as is reasonably practical. Post Fukushima, much thought has gone into reconsidering whether the effectiveness of the defence in depth concept can be enhanced by, for example, rebalancing the attention between prevention and mitigation or enhancing the independence of protective measures such as providing extremely robust standalone emergency cooling capability. This presentation argues that Fukushima teaches us a more fundamental lesson - that the defence in depth concept (along with other design principles') should be applied to the nuclear system to see whether more should be done to enhance the institutional barriers in any particular nuclear system. These barriers are at three main levels: industry, regulators and stakeholders each with sub-barriers. It reinforces the need for industry and regulators to be independent, open and transparent so that the nuclear system can work effectively. Examples are given where the application of the model identifies areas for improvement in existing systems. (author)

  11. Psychiatric, Psychological and “Witchcraft” Defences to Murder in ...

    African Journals Online (AJOL)

    Background: Expert psychiatric testimony may be relevant in certain instances of homicide especially murder. However, the exposure of most psychiatric trainees may be inadequate in relation to the range of psychological defences available to an offender accused of homicide. Aim: To describe the psychiatric and ...

  12. CSIR eNews: Defence peace safety and security

    CSIR Research Space (South Africa)

    CSIR

    2008-03-01

    Full Text Available At the CSIR, science and technology (S&T) is hard at work for a peaceful, safe and prosperous South Africa. The organisation has developed strong S&T capabilities through its associations with key players in defence, safety and security...

  13. "Contributory intent" as a defence limiting delictual liability | Ahmed ...

    African Journals Online (AJOL)

    In terms of delictual liability, the term "fault" generally refers to the defendant's conduct, whereas "contributory fault" refers to the plaintiff's conduct. "Contributory intent" is a form of "contributory fault" and may apply as a defence limiting delictual liability within the ambit of the Apportionment of Damages Act 34 of 1956 ...

  14. The South African Defence Force and Horse Mounted Infantry ...

    African Journals Online (AJOL)

    Jacques

    2003-03-26

    Mar 26, 2003 ... Department of Defence in Pretoria, and oral history interviews with military .... were created almost from scratch and 'refined on the hoof' in the first three ... would culminate in a three or four day, thirty five or forty five kilometre .... organisation of 202 Bn. to be adjusted so as to accommodate horse and dog.

  15. Torpedo and countermeasures modelling in the Torpedo Defence System Testbed

    NARCIS (Netherlands)

    Benders, F.P.A.; Witberg, R.R.; H.J. Grootendorst, H.J.

    2002-01-01

    Several years ago, TNO-FEL started the development of the Torpedo Defence System Testbed (TDSTB) based on the TORpedo SIMulation (TORSIM) model and the Maritime Operations Simulation and Evaluation System (MOSES). MOSES provides the simulation and modelling environment for the evaluation and

  16. Communal range defence in primates as a public goods dilemma.

    Science.gov (United States)

    Willems, Erik P; Arseneau, T Jean M; Schleuning, Xenia; van Schaik, Carel P

    2015-12-05

    Classic socio-ecological theory holds that the occurrence of aggressive range defence is primarily driven by ecological incentives, most notably by the economic defendability of an area or the resources it contains. While this ecological cost-benefit framework has great explanatory power in solitary or pair-living species, comparative work on group-living primates has always found economic defendability to be a necessary, but not sufficient condition to account for the distribution of effective range defence across the taxon. This mismatch between theory and observation has recently been ascribed to a collective action problem among group members in, what is more informatively viewed as, a public goods dilemma: mounting effective defence of a communal range against intrusions by outgroup conspecifics. We here further develop this framework, and report on analyses at three levels of biological organization: across species, across populations within a single lineage and across groups and individuals within a single population. We find that communal range defence in primates very rarely involves collective action sensu stricto and that it is best interpreted as the outcome of opportunistic and strategic individual-level decisions. Whether the public good of a defended communal range is produced by solitary, joint or collective action is thus the outcome of the interplay between the unique characteristics of each individual, local and current socio-ecological conditions, and fundamental life-history traits of the species. © 2015 The Author(s).

  17. On the involvement of host proteins in Cowpea mosaic virus intercellular spread

    NARCIS (Netherlands)

    Hollander, den P.W.

    2014-01-01

    Abstract of thesis Paulus den Hollander entitled “On the involvement of host proteins in Cowpea mosaic virus intercellular spread”.

    Defence: 18th of November 13.30 h

    Abstract

    Intercellular spread of Cowpea mosaic virus (CPMV) occurs via movement

  18. Systemic resistance and lipoxygenase-related defence response induced in tomato by Pseudomonas putida strain BTP1

    Directory of Open Access Journals (Sweden)

    Dommes Jacques

    2008-11-01

    Full Text Available Abstract Background Previous studies showed the ability of Pseudomonas putida strain BTP1 to promote induced systemic resistance (ISR in different host plants. Since ISR is long-lasting and not conducive for development of resistance of the targeted pathogen, this phenomenon can take part of disease control strategies. However, in spite of the numerous examples of ISR induced by PGPR in plants, only a few biochemical studies have associated the protective effect with specific host metabolic changes. Results In this study, we showed the protective effect of this bacterium in tomato against Botrytis cinerea. Following treatment by P. putida BTP1, analyses of acid-hydrolyzed leaf extracts showed an accumulation of antifungal material after pathogen infection. The fungitoxic compounds thus mainly accumulate as conjugates from which active aglycones may be liberated through the activity of hydrolytic enzymes. These results suggest that strain BTP1 can elicit systemic phytoalexin accumulation in tomato as one defence mechanism. On another hand, we have shown that key enzymes of the lipoxygenase pathway are stimulated in plants treated with the bacteria as compared with control plants. Interestingly, this stimulation is observed only after pathogen challenge in agreement with the priming concept almost invariably associated with the ISR phenomenon. Conclusion Through the demonstration of phytoalexin accumulation and LOX pathway stimulation in tomato, this work provides new insights into the diversity of defence mechanisms that are inducible by non-pathogenic bacteria in the context of ISR.

  19. Impaired CXCR1-dependent oxidative defence in active tuberculosis patients.

    Science.gov (United States)

    Alaridah, Nader; Winqvist, Niclas; Håkansson, Gisela; Tenland, Erik; Rönnholm, Anna; Sturegård, Erik; Björkman, Per; Godaly, Gabriela

    2015-12-01

    Much of the pronounced host inflammatory response that occurs in tuberculosis (TB) is related to failed immunity against the invading pathogen. The G-protein coupled receptors CXCR1 and CXCR2 are implicated in important signal transduction pathways in lung inflammatory responses. We investigated the expression and function of these receptors in a simple whole blood model from 24 patients with pulmonary TB and in subjects with latent TB infection (LTBI). Healthy controls were recruited from close contacts to the pulmonary index patients. We found that pulmonary TB patients had significantly increased CXCR1 expression on blood cells compared to LTBI subjects and controls (p microRNA-223 was increased in pulmonary TB patients compared to LTBI (p tuberculosis (Mtb). Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Interpreting the impact of flood forecasts by combining policy analysis studies and flood defence

    Directory of Open Access Journals (Sweden)

    Slomp Robert

    2016-01-01

    Full Text Available Flood forecasting is necessary to save lives and reduce damages. Reducing damages is important to save livelihoods and to reduce the recovery time. Flood alerts should contain expected time of the event, location and extent of the event. A flood alert is not only one message but part of a rehearsed flow of information using multiple canals. First people have to accept the fact that there might be a threat and what the threat is about. People need a reference to understand the situation and be aware of possible measures they can take to assure their own safety and reduce damages. Information to the general public has to be consistent with the information used by emergency services and has to be very clear about consequences and context of possible measures (as shelter in place or preventive evacuation. Emergency services should monitor how the public is responding to adapt their communication en operation during a crisis. Flood warnings and emergency services are often coordinated by different government organisations. This is an extra handicap for having consistent information out on time for people to use. In an information based society, where everyone has twitter, email and a camera, public organisations may have to trust the public more and send out the correct information as it comes in. In the Netherlands Rijkswaterstaat, the National Water Authority and the National Public Works Department, is responsible for or involved in forecasting in case of floods, policy studies on flood risk, policy studies on maintenance, assessment and design of flood defences, elaborating rules and regulations for flood defences, advice on crisis management to the national government and for maintaining the main infrastructure in the Netherlands (high ways and water ways. The Water Management Center in the Netherlands (WMCN has developed a number of models to provide flood forecasts. WMCN is run for and by all managers of flood defences and is hosted by

  1. Multi-modal defences in aphids offer redundant protection and increased costs likely impeding a protective mutualism.

    Science.gov (United States)

    Martinez, Adam J; Doremus, Matthew R; Kraft, Laura J; Kim, Kyungsun L; Oliver, Kerry M

    2018-03-01

    The pea aphid, Acyrthosiphon pisum, maintains extreme variation in resistance to its most common parasitoid wasp enemy, Aphidius ervi, which is sourced from two known mechanisms: protective bacterial symbionts, most commonly Hamiltonella defensa, or endogenously encoded defences. We have recently found that individual aphids may employ each defence individually, occasionally both defences together, or neither. In field populations, Hamiltonella-infected aphids are found at low to moderate frequencies and while less is known about the frequency of resistant genotypes, they show up less often than susceptible genotypes in field collections. To better understand these patterns, we sought to compare the strengths and costs of both types of defence, individually and together, in order to elucidate the selective pressures that maintain multi-modal defence mechanisms or that may favour one over the other. We experimentally infected five aphid genotypes (two lowly and three highly resistant), each with two symbiont strains, Hamiltonella-APSE8 (moderate protection) and Hamiltonella-APSE3 (high protection). This resulted in three sublines per genotype: uninfected, +APSE8 and +APSE3. Each of the 15 total sublines was first subjected to a parasitism assay to determine its resistance phenotype and in a second experiment, a subset was chosen to compare fitness (fecundity and survivorship) in the presence and absence of parasitism. In susceptible aphid genotypes, parasitized sublines infected with Hamiltonella generally showed increased protection with direct fitness benefits, but clear infection costs to fitness in the absence of parasitism. In resistant genotypes, Hamiltonella infection rarely conferred additional protection, often further reduced fecundity and survivorship when enemy challenged, and resulted in constitutive fitness costs in the absence of parasitism. We also identified strong aphid genotype × symbiont-strain interactions, such that the best defensive

  2. Cathelicidin-like helminth defence molecules (HDMs: absence of cytotoxic, anti-microbial and anti-protozoan activities imply a specific adaptation to immune modulation.

    Directory of Open Access Journals (Sweden)

    Karine Thivierge

    Full Text Available Host defence peptides (HDPs are expressed throughout the animal and plant kingdoms. They have multifunctional roles in the defence against infectious agents of mammals, possessing both bactericidal and immune-modulatory activities. We have identified a novel family of molecules secreted by helminth parasites (helminth defence molecules; HDMs that exhibit similar structural and biochemical characteristics to the HDPs. Here, we have analyzed the functional activities of four HDMs derived from Schistosoma mansoni and Fasciola hepatica and compared them to human, mouse, bovine and sheep HDPs. Unlike the mammalian HDPs the helminth-derived HDMs show no antimicrobial activity and are non-cytotoxic to mammalian cells (macrophages and red blood cells. However, both the mammalian- and helminth-derived peptides suppress the activation of macrophages by microbial stimuli and alter the response of B cells to cytokine stimulation. Therefore, we hypothesise that HDMs represent a novel family of HDPs that evolved to regulate the immune responses of their mammalian hosts by retaining potent immune modulatory properties without causing deleterious cytotoxic effects.

  3. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant–plant mutualism

    Science.gov (United States)

    Pringle, Elizabeth G.

    2014-01-01

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant–plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output. PMID:24807259

  4. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant-plant mutualism.

    Science.gov (United States)

    Pringle, Elizabeth G

    2014-06-22

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant-plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output.

  5. Defence Industrial Policies and Their Impact on Acquisition Outcomes: A Comparative Analysis of the United Kingdom and Australia

    Science.gov (United States)

    2012-09-01

    average costs for firms in that industry but nonetheless support a positive (or non- negative ) level of profit. Defence industrial policies & their...prompted by increasing pressure on defence budgets; consolidation of the UK defence industry; “ globalisation ” of UK defence companies & threat of exit

  6. Life-history constraints in grassland plant species: a growth-defence trade-off is the norm

    Science.gov (United States)

    E.M. Lind; E.T. Borer; E.W. Seabloom; P.B. Adler; J.D. Bakker; D.M. Blumenthal; M. Crawley; K.F. Davies; J. Firn; D.S. Gruner; S. Harpole; Y. Hautier; H. Hillebrand; J.M.H. Knops; B.A. Melbourne; B. Mortensen; A.C. Risch; M. Schuetz; C.J. Stevens; P.D. Wragg

    2013-01-01

    Plant growth can be limited by resource acquisition and defence against consumers, leading to contrasting trade-off possibilities. The competition-defence hypothesis posits a trade-off between competitive ability and defence against enemies (e.g. herbivores and pathogens). The growth-defence hypothesis suggests that strong competitors for nutrients are also defended...

  7. Nitric oxide production by Biomphalaria glabrata haemocytes: effects of Schistosoma mansoni ESPs and regulation through the extracellular signal-regulated kinase pathway

    Directory of Open Access Journals (Sweden)

    Kirk Ruth S

    2009-04-01

    Full Text Available Abstract Background Schistosoma mansoni uses Biomphalaria glabrata as an intermediate host during its complex life cycle. In the snail, the parasite initially transforms from a miracidium into a mother sporocyst and during this process excretory-secretory products (ESPs are released. Nitric oxide (NO and its reactive intermediates play an important role in host defence responses against pathogens. This study therefore aimed to determine the effects of S. mansoni ESPs on NO production in defence cells (haemocytes from schistosome-susceptible and schistosome-resistant B. glabrata strains. As S. mansoni ESPs have previously been shown to inhibit extracellular signal-regulated kinase (ERK phosphorylation (activation in haemocytes from susceptible, but not resistant, B. glabrata the regulation of NO output by ERK in these cells was also investigated. Results Haemocytes from resistant snails challenged with S. mansoni ESPs (20 μg/ml over 5 h displayed an increase in NO production that was 3.3 times greater than that observed for unchallenged haemocytes; lower concentrations of ESPs (0.1–10 μg/ml did not significantly increase NO output. In contrast, haemocytes from susceptible snails showed no significant change in NO output following challenge with ESPs at any concentration used (0.1–20 μg/ml. Western blotting revealed that U0126 (1 μM or 10 μM blocked the phosphorylation (activation status of ERK in haemocytes from both snail strains. Inhibition of ERK signalling by U0126 attenuated considerably intracellular NO production in haemocytes from both susceptible and resistant B. glabrata strains, identifying ERK as a key regulator of NO output in these cells. Conclusion S. mansoni ESPs differentially influence intracellular NO levels in susceptible and resistant B. glabrata haemocytes, possibly through modulation of the ERK signalling pathway. Such effects might facilitate survival of S. mansoni in its intermediate host.

  8. AtWRKY22 promotes susceptibility to aphids and modulates salicylic acid and jasmonic acid signalling.

    Science.gov (United States)

    Kloth, Karen J; Wiegers, Gerrie L; Busscher-Lange, Jacqueline; van Haarst, Jan C; Kruijer, Willem; Bouwmeester, Harro J; Dicke, Marcel; Jongsma, Maarten A

    2016-05-01

    Aphids induce many transcriptional perturbations in their host plants, but the signalling cascades responsible and the effects on plant resistance are largely unknown. Through a genome-wide association (GWA) mapping study in Arabidopsis thaliana, we identified WRKY22 as a candidate gene associated with feeding behaviour of the green peach aphid, Myzus persicae The transcription factor WRKY22 is known to be involved in pathogen-triggered immunity, and WRKY22 gene expression has been shown to be induced by aphids. Assessment of aphid population development and feeding behaviour on knockout mutants and overexpression lines showed that WRKY22 increases susceptibility to M. persicae via a mesophyll-located mechanism. mRNA sequencing analysis of aphid-infested wrky22 knockout plants revealed the up-regulation of genes involved in salicylic acid (SA) signalling and down-regulation of genes involved in plant growth and cell-wall loosening. In addition, mechanostimulation of knockout plants by clip cages up-regulated jasmonic acid (JA)-responsive genes, resulting in substantial negative JA-SA crosstalk. Based on this and previous studies, WRKY22 is considered to modulate the interplay between the SA and JA pathways in response to a wide range of biotic and abiotic stimuli. Its induction by aphids and its role in suppressing SA and JA signalling make WRKY22 a potential target for aphids to manipulate host plant defences. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  9. Defence electronics industry profile, 1990-1991

    Science.gov (United States)

    The defense electronics industry profiled in this review comprises an estimated 150 Canadian companies that develop, manufacture, and repair radio and communications equipment, radars for surveillance and navigation, air traffic control systems, acoustic and infrared sensors, computers for navigation and fire control, signal processors and display units, special-purpose electronic components, and systems engineering and associated software. Canadian defense electronics companies generally serve market niches and end users of their products are limited to the military, government agencies, or commercial airlines. Geographically, the industry is concentrated in Ontario and Quebec, where about 91 percent of the industry's production and employment is found. In 1989, the estimated revenue of the industry was $2.36 billion, and exports totalled an estimated $1.4 billion. Strengths and weaknesses of the industry are discussed in terms of such factors as the relatively small size of Canadian companies, the ability of Canadian firms to access research and development opportunities and export markets in the United States, the dependence on foreign-made components, and international competition.

  10. Necessity, private defence and the killing of Mary.

    Science.gov (United States)

    Rogers, J

    2001-07-01

    This article examines the reasons used by the Court of Appeal in Re A (Children) to authorise and justify an operation which would inevitably kill the weaker of a pair of conjoined twins in order to offer the stronger twin a good chance of a long and happy life. The crux of the judgment was that a utilitarian theory of necessity could justify this operation. This article seeks to define the criminal law defences at issue in the case and to argue that utilitarian necessity is such a dangerous doctrine that it should never be employed if there is any other defence which can be made to serve the same purpose--as there was in the present case.

  11. Integration of Renewable Generation in Power System Defence Plans

    DEFF Research Database (Denmark)

    Das, Kaushik

    Increasing levels of penetration of wind power and other renewable generations in European power systems pose challenges to power system security. The power system operators are continuously challenged especially when generations from renewables are high thereby reducing online capacity of conven......Increasing levels of penetration of wind power and other renewable generations in European power systems pose challenges to power system security. The power system operators are continuously challenged especially when generations from renewables are high thereby reducing online capacity......, one of them being the North East area with high share of wind power generation.The aim of this study is to investigate how renewable generations like wind power can contribute to the power system defence plans. This PhD project “Integration of Renewable Generation in Power System Defence Plans...

  12. Nelson Mandela's defence: A psychological capital documentary analysis

    Directory of Open Access Journals (Sweden)

    Rene van Wyk

    2014-11-01

    Full Text Available This qualitative documentary analysis examines Nelson Mandela�s defence statement at the Rivonia Trial, Pretoria Supreme Court, on 20 April 1964. The defence document is analysed through the psychological capital lens, depicting themes that support the constructs of hope, efficacy, resilience and optimism. Psychological capital characteristics played a major role in the initial non-violent policies of negotiation. The inevitable establishment of Umkhonto we Sizwe followed, as a result of the increased restrictions and unwillingness of government to negotiate and collaborate. Mandela showed a determined spirit to unite the country. The discussion gives insight into Mandela�s authentic psychological capital leadership under difficult political and personal circumstances. Some implications are indicated in adopting Mandela�s psychological characteristics for personal reform.

  13. The Morality and Economics of Safety in Defence Procurement

    Science.gov (United States)

    Clement, Tim

    Ministry of Defence policy is to conform as closely as possible to UK health and safety legislation in all its operations. We consider the implications of the law and the guidance provided by the Health and Safety Executive for the arguments we need to make for the safety of defence procurements, and extract four general principles to help in answering the questions that arise when considering the safety of systems with complex behaviour. One of these principles is analysed further to identify how case law and the guidance interpret the requirement for risks to be reduced so far as is reasonably practicable. We then apply the principles to answer some questions that have arisen in our work as Independent Safety Auditors, including the limits to the tolerability of risk to armed forces personnel and civilians in wartime, and the acceptability of the transfer of risk from one group to another when controls on risk are introduced.

  14. Politics, pleasure, violence: Swedish defence propaganda in social media

    OpenAIRE

    Rodrigo Ferrada Stoehrel

    2013-01-01

    In recent years, the Swedish Armed Forces have produced and distributed highly edited video clips on YouTube that show moving images of military activity. Alongside this development, mobile phone apps have emerged as an important channel through which the user can experience and take an interactive part in the staging of contemporary armed conflict. This article examines the way in which the aesthetic and affective experience of Swedish defence and security policy is socially and (media-)cult...

  15. KYPO – A Platform for Cyber Defence Exercises

    OpenAIRE

    Čeleda Pavel; Čegan Jakub; Vykopal Jan; Tovarňák Daniel

    2015-01-01

    Correct and timely responses to cyber attacks are crucial for the effective implementation of cyber defence strategies and policies. The number of threats and ingenuity of attackers is ever growing, as is the need for more advanced detection tools, techniques and skilled cyber security professionals. KYPO – Cyber Exercise & Research Platform is focused on modelling and simulating complex computer systems and networks in a virtualized and separated environment. The platform enables realist...

  16. The Advent of Representative Associations in the Irish Defence Forces

    Science.gov (United States)

    1992-06-05

    year period from 1975 to 1988. The Submission Group had difficulty finding appropriate groups in the Irish labour market against which to compare the...in the Irish Labour market , the average male industrial worker was chosen. In choosing the male industrial worker, it was not suggested that this...Defence Forces to have all young officers attend University College Galway ( UCG ) or a similar third level institute for the purpose of acquiring a

  17. Aerial Refueling For NATO’s Smart Defence Initiative

    Science.gov (United States)

    2012-04-01

    Rome: NATO Defense College, 2012, 148. 40 David A. Brown , "NATO Studying Development of Dedicated Refueling Unit Similar to Early Warning Force...accessed March 1, 2012). Brown , David A. "NATO Studying Development of Dedicated Refueling Unit Similar to Early Warning Force." Aviation Week...Aircraft. Coulsdon, Surrey: IHS Global Limited, 2011. Jennings, Gareth . "Nations Pool for NATO C-17A Fleet." Jane’s Defence Weekly, October 2008

  18. A Primer on Recent Canadian Defence Budgeting Trends and Implications

    Directory of Open Access Journals (Sweden)

    David Perry

    2015-04-01

    Full Text Available Faced with a dangerous world, the federal government has made recapitalizing and updating Canada’s armed forces a priority. Unfortunately, fiscal pressures obliged the government to deviate from its Canada First Defence Strategy, cutting staff and delaying military hardware acquisitions. However, the introduction this year of the Defence Procurement Strategy should allow Ottawa to use improved approaches to buy equipment that would otherwise have been purchased already under the DND’s opaque capital expenditure system. At present, DND capital funds are mostly subject to accrual accounting. Capital costs are charged against the defence budget as annual amortization expenses over equipment lifecycles. While this enables multiple capital projects to go ahead simultaneously, not all of the money covering capital costs is treated this way. Traditional A-Base Vote 5 expenses are still charged to the budget the year the expenditure is made — and the DND consistently underspends the Vote 5 funds available by as much as 28 percent. Since 2007/8, an estimated $6.42 billion wasn’t used as intended. While some of this can be carried forward, there are limits. Leftover funds exceeding them are returned to the Treasury and are thereby lost. It’s up to the DND to make up losses out of future funding. Just as bad, the accrual method doesn’t fully account for inflation, so when schedules slip, project purchasing power diminishes by hundreds of millions of dollars. Ambitious initiatives like the Joint Support Ship and (likely the Canadian Surface Combatant end up taking hits to reflect harsh budgetary realities; the capabilities of Canada’s soldiers suffer. This policy brief draws on research and confidential interviews to highlight the pressing need for reform in Canadian defence procurement.

  19. Can the failing firm defence rule be counterproductive?

    OpenAIRE

    Helder Vasconcelos

    2013-01-01

    The present paper investigates the role of the failing firm defence (FFD) concept in the merger control process within a Cournot setting where (i) endogenous mergers are motivated by prospective efficiency gains and (ii) mergers must be submitted to an antitrust authority that might demand partial divestiture for approval. The findings show that when the FFD concept is one of the tools available for controlling the merger process, firms can strategically embark on a merger that makes other fi...

  20. Chemical defence in chrysomelid eggs and neonate larvae

    OpenAIRE

    Pasteels, Jacques M.; Daloze, D.; Rowell-Rahier, Martine

    2009-01-01

    Eggs and neonate larvae of chrysomelid beetles (sub-tribes Chrysomelina and Phyllodectina) were investigated for the presence of defensive substances. The two isoxazolinone glucosides (compounds 1 and 2), characteristic of the adult defence secretion, were detected in the eggs of all studied species. Compound 2, containing a nitropropionate, is always present in concentrations (above 10-2 M), which are highly deterrent to the ant Myrmica rubra. This compound is not at all or only slightly to...

  1. 2015 Status Report on Major Defence Equipment Procurements

    OpenAIRE

    David Perry

    2015-01-01

    Federal elections may be good for democracy, but the campaigns — particularly the lengthy one recently held in Canada — can be crippling for plans to better arm our military. Just before the election was called, there were public signs of important progress being made in what has long been a frustratingly slow and bureaucratically complex procurement process. But then the campaign left the Department of National Defence and other federal departments unable to secure approvals from either a de...

  2. Mapping a product-service-system delivering defence avionics availability

    OpenAIRE

    Settanni, E.; Thenent, N.; Newnes, L.; Parry, G.; Goh, Y. M.

    2017-01-01

    Long-term support agreements such as availability-based contracts are often associated with the servitization of business models in such sectors as defence aerospace. In practice, there is no unambiguous way of linking availability and service outcomes from an operational perspective; rather, the focus tends to be placed almost exclusively on product-related metrics. To address this gap, this paper outlines a conceptual model of how advanced service outcomes should be delivered under an avail...

  3. Defence and security applications of quantum cascade lasers

    Science.gov (United States)

    Grasso, Robert J.

    2016-09-01

    Quantum Cascade Lasers (QCL) have seen tremendous recent application in the realm of Defence and Security. And, in many instances replacing traditional solid state lasers as the source of choice for Countermeasures, Remote Sensing, In-situ Sensing, Through-Barrier Sensing, and many others. Following their development and demonstration in the early 1990's, QCL's reached some maturity and specific defence and security application prior to 2005; with much initial development fostered by DARPA initiatives in the US, dstl, MoD, and EOARD funding initiatives in the UK, and University level R&D such as those by Prof Manijeh Razeghi at Northwestern University [1], and Prof Ted Masselink at Humboldt University [2]. As QCL's provide direct mid-IR laser output for electrical input, they demonstrate high quantum efficiency compared with diode pumped solid state lasers with optical parametric oscillators (OPOs) to generate mid-Infrared output. One particular advantage of QCL's is their very broad operational bandwidth, extending from the terahertz to the near-infrared spectral regions. Defence and Security areas benefiting from QCL's include: Countermeasures, Remote Sensing, Through-the-Wall Sensing, and Explosive Detection. All information used to construct this paper obtained from open sources.

  4. Transgenerational effects alter plant defence and resistance in nature.

    Science.gov (United States)

    Colicchio, J

    2017-04-01

    Trichomes, or leaf hairs, are epidermal extensions that take a variety of forms and perform many functions in plants, including herbivore defence. In this study, I document genetically determined variation, within-generation plasticity, and a direct role of trichomes in herbivore defence for Mimulus guttatus. After establishing the relationship between trichomes and herbivory, I test for transgenerational effects of wounding on trichome density and herbivore resistance. Patterns of interannual variation in herbivore density and the high cost of plant defence makes plant-herbivore interactions a system in which transgenerational phenotypic plasticity (TPP) is apt to evolve. Here, I demonstrate that parental damage alters offspring trichome density and herbivore resistance in nature. Moreover, this response varies between populations. This is among the first studies to demonstrate that TPP contributes to variation in nature, and also suggests that selection can modify TPP in response to local conditions. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  5. Defence nuclear waste disposal in Russia. International perspective

    International Nuclear Information System (INIS)

    Stenhouse, M.J.; Kirko, V.I.

    1998-01-01

    Significant amounts of liquid and solid radioactive waste have been generated in Russia during the production of nuclear weapons, and there is an urgent need to find suitable ways to manage these wastes in a way that protects both the current population and future generations. This book contains contributions from pure and applied scientists and other representatives from Europe, North America, and Russia, who are, or have been, actively involved in the field of radioactive waste management and disposal. First-hand experience of specific problems associated with defence-related wastes in the USA and the Russian Federation is presented, and current plans are described for the disposal of solid wastes arising from civilian nuclear power production programmes in other countries, including Belgium, Bulgaria, Canada, Germany and the UK. The book provides a good insight into ongoing research at local and national level within Russia, devoted to the safe disposal of defence-related radioactive waste. It also demonstrates how existing expertise and technology from civilian nuclear waste management programmes can be applied to solving the problems created by nuclear defence programmes. Contributions address methods of immobilisation, site selection methodology, site characterisation techniques and data interpretation, the key elements of safety/performance assessments of planned deep (geological) repositories for radioactive waste, and radionuclide transport modelling. Concerns associated with certain specific nuclear waste disposal concepts and repository sites are also presented. refs

  6. Anosognosia as motivated unawareness: the 'defence' hypothesis revisited.

    Science.gov (United States)

    Turnbull, Oliver H; Fotopoulou, Aikaterini; Solms, Mark

    2014-12-01

    Anosognosia for hemiplegia has seen a century of almost continuous research, yet a definitive understanding of its mechanism remains elusive. Essentially, anosognosic patients hold quasi-delusional beliefs about their paralysed limbs, in spite of all the contrary evidence, repeated questioning, and logical argument. We review a range of findings suggesting that emotion and motivation play an important role in anosognosia. We conclude that anosognosia involves (amongst other things) a process of psychological defence. This conclusion stems from a wide variety of clinical and experimental investigations, including data on implicit awareness of deficit, fluctuations in awareness over time, and dramatic effects upon awareness of psychological interventions such as psychotherapy, reframing of the emotional consequences of the paralysis, and first versus third person perspectival manipulations. In addition, we review and refute the (eight) arguments historically raised against the 'defence' hypothesis, including the claim that a defence-based account cannot explain the lateralised nature of the disorder. We argue that damage to a well-established right-lateralised emotion regulation system, with links to psychological processes that appear to underpin allocentric spatial cognition, plays a key role in anosognosia (at least in some patients). We conclude with a discussion of implications for clinical practice. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Defence in depth by 'Leittechnique' systems with graded intelligence

    International Nuclear Information System (INIS)

    Aleite, W.

    1983-01-01

    In the past, only two types of nuclear power plant instrumentation and control systems were in use in the Federal Republic of Germany (FRG): safety systems and operational systems. Present nuclear power plant 'Leittechnique' systems in the FRG have been expanded from this 'black-and-white' status to multiple-grade systems with respect to safety, qualification requirements and intelligence. The extensive experience of the past has encouraged the rule-making committees - representing all parties working in the nuclear field - to differentiate between the protection limitations and condition limitations of the reactor protection system on one hand and the information systems (including the accident monitoring and alarm system) of different safety importance on the other, assuming additional extensive application of non-safety-grade operational Leittechnique systems. These definitions of categories are in accordance with international practice and enable designers to apply 'echelons of defence', composed of equipment of all categories, in accordance with 'defence-in-depth' concepts. They also simplify the introduction of computerized equipment, especially in the lower safety categories. Status, background and reasons of the introduction, as well as typical defence-in-depth modes, of the first running Leittechnique system of this kind (in the Grafenrheinfeld nuclear power plant) and especially their different tasks in disturbance handling are described. The international situation and future developments are briefly characterized. (author)

  8. Microphallids in Gammarus insensibilis Stock, 1966 from a Black Sea lagoon: host response to infection.

    Science.gov (United States)

    Kostadinova, A; Mavrodieva, R S

    2005-09-01

    We examined the patterns of parasite melanization in Gammarus insensibilis using data on microphallids from Pomorie Lagoon (Black Sea) in the light of 3 predictions associated with host survival: (i) hosts invest more in defence in an environment where the likelihood for infection is higher; (ii) multiple immune challenges exhaust host reserves and result in decreased melanization rates in older hosts; (iii) host immune response is directed against the cerebral metacercariae of Microphallus papillorobustus that alter amphipod behaviour and are most detrimental to the host. G. insensibilis was capable of melanizing the metacercariae of all four species of trematodes found to be hosted by the amphipods. The frequency of melanization and mean abundance of melanized metacercariae were substantially higher than those observed in the same amphipod-gammarid system on the French Mediterranean coast. However, the rate of melanization was low and showed a significant decrease with amphipod size. Although the 4 species were differentially melanized, the host response was largely directed against Microphallus hoffmanni and M. subdolum. We suggest that (i) the lower melanization efficiency with age is due to the mode of infection, probably leading to loss of haemolymph and monopolization of the defence resources for wound healing and (ii) in the French system, host response focuses on the most prevalent and abundant species.

  9. Cuckoos versus hosts in insects and birds: adaptations, counter-adaptations and outcomes.

    Science.gov (United States)

    Kilner, Rebecca M; Langmore, Naomi E

    2011-11-01

    Avian parents and social insect colonies are victimized by interspecific brood parasites-cheats that procure costly care for their dependent offspring by leaving them in another species' nursery. Birds and insects defend themselves from attack by brood parasites; their defences in turn select counter-strategies in the parasite, thus setting in motion antagonistic co-evolution between the two parties. Despite their considerable taxonomic disparity, here we show striking parallels in the way that co-evolution between brood parasites and their hosts proceeds in insects and birds. First, we identify five types of co-evolutionary arms race from the empirical literature, which are common to both systems. These are: (a) directional co-evolution of weaponry and armoury; (b) furtiveness in the parasite countered by strategies in the host to expose the parasite; (c) specialist parasites mimicking hosts who escape by diversifying their genetic signatures; (d) generalist parasites mimicking hosts who escape by favouring signatures that force specialization in the parasite; and (e) parasites using crypsis to evade recognition by hosts who then simplify their signatures to make the parasite more detectable. Arms races a and c are well characterized in the theoretical literature on co-evolution, but the other types have received little or no formal theoretical attention. Empirical work suggests that hosts are doomed to lose arms races b and e to the parasite, in the sense that parasites typically evade host defences and successfully parasitize the nest. Nevertheless hosts may win when the co-evolutionary trajectory follows arms race a, c or d. Next, we show that there are four common outcomes of the co-evolutionary arms race for hosts. These are: (1) successful resistance; (2) the evolution of defence portfolios (or multiple lines of resistance); (3) acceptance of the parasite; and (4) tolerance of the parasite. The particular outcome is not determined by the type of preceding

  10. 2015 Status Report on Major Defence Equipment Procurements

    Directory of Open Access Journals (Sweden)

    David Perry

    2015-12-01

    Full Text Available Federal elections may be good for democracy, but the campaigns — particularly the lengthy one recently held in Canada — can be crippling for plans to better arm our military. Just before the election was called, there were public signs of important progress being made in what has long been a frustratingly slow and bureaucratically complex procurement process. But then the campaign left the Department of National Defence and other federal departments unable to secure approvals from either a defence minister or the Treasury Board, until the election ended and the new prime minister appointed the current cabinet. There had already been upheaval prior to that: In the first seven months of 2015, the three senior leaders at the Canadian Forces and the Defence Department (including the minister had been replaced, along with many other people critical to the procurement process. In addition, there had been changes in the Public Works Department and the Defence Procurement Strategy Secretariat. Frustrating and disappointing delays have long been a matter of course in Canada’s defence procurement process. In 2014/15, the number of ministerial or Treasury Board approvals to allow projects to proceed was half of that in 2009/10. Yet the demand for approvals has not abated. In addition to the turnover of key figures involved in the procurement and approval process, delays have come from a number of major steps added to the process, making an already lengthy and complex system even more so. To be sure, these steps were added in the pursuit of improved financial management and project management, with the aim of addressing longstanding problems. But it will take years to see if those objectives have been realized. An irony here is that the budget for military procurement has increased. Between 2004 and 2009, the Defence Department’s procurement budget nearly doubled. But the funding was never matched by the capacity to manage it. In 2003, the Material

  11. A plant natriuretic peptide-like molecule of the pathogen Xanthomonas axonopodis pv. citri causes rapid changes in the proteome of its citrus host

    KAUST Repository

    Garavaglia, Betiana S; Thomas, Ludivine; Zimaro, Tamara; Gottig, Natalia; Daurelio, Lucas D; Ndimba, Bongani; Orellano, Elena G; Ottado, Jorgelina; Gehring, Christoph A

    2010-01-01

    Background: Plant natriuretic peptides (PNPs) belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. The citrus pathogen Xanthomonas axonopodis pv. citri possesses a PNP-like peptide (XacPNP) uniquely present in this bacteria. Previously we observed that the expression of XacPNP is induced upon infection and that lesions produced in leaves infected with a XacPNP deletion mutant were more necrotic and lead to earlier bacterial cell death, suggesting that the plant-like bacterial PNP enables the plant pathogen to modify host responses in order to create conditions favorable to its own survival.Results: Here we measured chlorophyll fluorescence parameters and water potential of citrus leaves infiltrated with recombinant purified XacPNP and demonstrate that the peptide improves the physiological conditions of the tissue. Importantly, the proteomic analysis revealed that these responses are mirrored by rapid changes in the host proteome that include the up-regulation of Rubisco activase, ATP synthase CF1 ? subunit, maturase K, and ?- and ?-tubulin.Conclusions: We demonstrate that XacPNP induces changes in host photosynthesis at the level of protein expression and in photosynthetic efficiency in particular. Our findings suggest that the biotrophic pathogen can use the plant-like hormone to modulate the host cellular environment and in particular host metabolism and that such modulations weaken host defence. 2010 Garavaglia et al; licensee BioMed Central Ltd.

  12. A plant natriuretic peptide-like molecule of the pathogen Xanthomonas axonopodis pv. citri causes rapid changes in the proteome of its citrus host

    Directory of Open Access Journals (Sweden)

    Ottado Jorgelina

    2010-03-01

    Full Text Available Abstract Background Plant natriuretic peptides (PNPs belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. The citrus pathogen Xanthomonas axonopodis pv. citri possesses a PNP-like peptide (XacPNP uniquely present in this bacteria. Previously we observed that the expression of XacPNP is induced upon infection and that lesions produced in leaves infected with a XacPNP deletion mutant were more necrotic and lead to earlier bacterial cell death, suggesting that the plant-like bacterial PNP enables the plant pathogen to modify host responses in order to create conditions favorable to its own survival. Results Here we measured chlorophyll fluorescence parameters and water potential of citrus leaves infiltrated with recombinant purified XacPNP and demonstrate that the peptide improves the physiological conditions of the tissue. Importantly, the proteomic analysis revealed that these responses are mirrored by rapid changes in the host proteome that include the up-regulation of Rubisco activase, ATP synthase CF1 α subunit, maturase K, and α- and β-tubulin. Conclusions We demonstrate that XacPNP induces changes in host photosynthesis at the level of protein expression and in photosynthetic efficiency in particular. Our findings suggest that the biotrophic pathogen can use the plant-like hormone to modulate the host cellular environment and in particular host metabolism and that such modulations weaken host defence.

  13. A plant natriuretic peptide-like molecule of the pathogen Xanthomonas axonopodis pv. citri causes rapid changes in the proteome of its citrus host

    KAUST Repository

    Garavaglia, Betiana S

    2010-03-21

    Background: Plant natriuretic peptides (PNPs) belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. The citrus pathogen Xanthomonas axonopodis pv. citri possesses a PNP-like peptide (XacPNP) uniquely present in this bacteria. Previously we observed that the expression of XacPNP is induced upon infection and that lesions produced in leaves infected with a XacPNP deletion mutant were more necrotic and lead to earlier bacterial cell death, suggesting that the plant-like bacterial PNP enables the plant pathogen to modify host responses in order to create conditions favorable to its own survival.Results: Here we measured chlorophyll fluorescence parameters and water potential of citrus leaves infiltrated with recombinant purified XacPNP and demonstrate that the peptide improves the physiological conditions of the tissue. Importantly, the proteomic analysis revealed that these responses are mirrored by rapid changes in the host proteome that include the up-regulation of Rubisco activase, ATP synthase CF1 ? subunit, maturase K, and ?- and ?-tubulin.Conclusions: We demonstrate that XacPNP induces changes in host photosynthesis at the level of protein expression and in photosynthetic efficiency in particular. Our findings suggest that the biotrophic pathogen can use the plant-like hormone to modulate the host cellular environment and in particular host metabolism and that such modulations weaken host defence. 2010 Garavaglia et al; licensee BioMed Central Ltd.

  14. ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies: an infectious diseases perspective (Intracellular signaling pathways: tyrosine kinase and mTOR inhibitors).

    Science.gov (United States)

    Reinwald, M; Silva, J T; Mueller, N J; Fortún, J; Garzoni, C; de Fijter, J W; Fernández-Ruiz, M; Grossi, P; Aguado, J M

    2018-06-01

    The present review is part of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biologic therapies. To review, from an infectious diseases perspective, the safety profile of therapies targeting different intracellular signaling pathways and to suggest preventive recommendations. Computer-based Medline searches with MeSH terms pertaining to each agent or therapeutic family. Although BCR-ABL tyrosine kinase inhibitors modestly increase the overall risk of infection, dasatinib has been associated with cytomegalovirus and hepatitis B virus reactivation. BRAF/MEK kinase inhibitors do not significantly affect infection susceptibility. The effect of Bruton tyrosine kinase inhibitors (ibrutinib) among patients with B-cell malignancies is difficult to distinguish from that of previous immunosuppression. However, cases of Pneumocystis jirovecii pneumonia (PCP), invasive fungal infection and progressive multifocal leukoencephalopathy have been occasionally reported. Because phosphatidylinositol-3-kinase inhibitors (idelalisib) may predispose to opportunistic infections, anti-Pneumocystis prophylaxis and prevention strategies for cytomegalovirus are recommended. No increased rates of infection have been observed with venetoclax (antiapoptotic protein Bcl-2 inhibitor). Therapy with Janus kinase inhibitors markedly increases the incidence of infection. Pretreatment screening for chronic hepatitis B virus and latent tuberculosis infection must be performed, and anti-Pneumocystis prophylaxis should be considered for patients with additional risk factors. Cancer patients receiving mTOR inhibitors face an increased incidence of overall infection, especially those with additional risk factors (prior therapies or delayed wound healing). Specific preventive approaches are warranted in view of the increased risk of infection associated with some of the

  15. Grapevine fatty acid hydroperoxide lyase generates actin-disrupting volatiles and promotes defence-related cell death

    Science.gov (United States)

    Wang, Hao; Claudel, Patricia; Riemann, Michael; Hause, Bettina; Hugueney, Philippe; Nick, Peter

    2018-01-01

    Abstract Fatty acid hydroperoxides can generate short-chained volatile aldehydes that may participate in plant defence. A grapevine hydroperoxide lyase (VvHPL1) clustering to the CYP74B class was functionally characterized with respect to a role in defence. In grapevine leaves, transcripts of this gene accumulated rapidly to high abundance in response to wounding. Cellular functions of VvHPL1 were investigated upon heterologous expression in tobacco BY-2 cells. A C-terminal green fluorescent protein (GFP) fusion of VvHPL1 was located in plastids. The overexpression lines were found to respond to salinity stress or the bacterial elicitor harpin by increasing cell death. This signal-dependent mortality response was mitigated either by addition of exogenous jasmonic acid or by treatment with diphenyleneiodonium (DPI), an inhibitor of NADPH oxidases. By feeding different substrates to recombinantly expressed enzyme, VvHPL1 could also be functionally classified as true 13-HPL. The cognate products generated by this 13-HPL were cis-3-hexenal and trans-2-hexenal. Using a GFP-tagged actin marker line, one of these isomeric products, cis-3-hexenal, was found specifically to elicit a rapid disintegration of actin filaments. This response was not only observed in the heterologous system (tobacco BY-2), but also in a grapevine cell strain expressing this marker, as well as in leaf discs from an actin marker grape used as a homologous system. These results are discussed in the context of a role for VvHPL1 in a lipoxygenase-dependent signalling pathway triggering cell death-related defence that bifurcates from jasmonate-dependent basal immunity. PMID:29659985

  16. Isolation and characterization of lipid rafts in Emiliania huxleyi: a role for membrane microdomains in host-virus interactions.

    Science.gov (United States)

    Rose, Suzanne L; Fulton, James M; Brown, Christopher M; Natale, Frank; Van Mooy, Benjamin A S; Bidle, Kay D

    2014-04-01

    Coccolithoviruses employ a suite of glycosphingolipids (GSLs) to successfully infect the globally important coccolithophore Emiliania huxleyi. Lipid rafts, chemically distinct membrane lipid microdomains that are enriched in GSLs and are involved in sensing extracellular stimuli and activating signalling cascades through protein-protein interactions, likely play a fundamental role in host-virus interactions. Using combined lipidomics, proteomics and bioinformatics, we isolated and characterized the lipid and protein content of lipid rafts from control E. huxleyi cells and those infected with EhV86, the type strain for Coccolithovirus. Lipid raft-enriched fractions were isolated and purified as buoyant, detergent-resistant membranes (DRMs) in OptiPrep density gradients. Transmission electron microscopy of vesicle morphology, polymerase chain reaction amplification of the EhV major capsid protein gene and immunoreactivity to flotillin antisera served as respective physical, molecular and biochemical markers. Subsequent lipid characterization of DRMs via high performance liquid chromatography-triple quadrapole mass spectrometry revealed four distinct GSL classes. Parallel proteomic analysis confirmed flotillin as a major lipid raft protein, along with a variety of proteins affiliated with host defence, programmed cell death and innate immunity pathways. The detection of an EhV86-encoded C-type lectin-containing protein confirmed that infection occurs at the interface between lipid rafts and cellular stress/death pathways via specific GSLs and raft-associated proteins. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. Aerodynamic Test Facility Requirements for Defence R&D to 2000 and Beyond.

    Science.gov (United States)

    1982-09-01

    Defence Force. Following its review of science and technology, the Australian Science and Technology Council ( ASTEC ) reported I that the present pattern...Organisation (DSTO) within the Department of Defence. Accordingly, ASTEC recommended to the Prime Minister that the Department of Defence be asked to develop...DSTO2 as well as by ASTEC 1 . An additional reason for choosing aerodynamics for early consideration in response to ASTEC’s recommendation is that wind

  18. United Kingdom's defence procurement: a period of smart enlightenment or halting culture

    OpenAIRE

    O Callaghan, D. M.

    2001-01-01

    The aim of this thesis is to map predominant cultures and examine their compatibility with the Smart Procurement Initiative. An initiative that was identified in the Strategic Defence Review to address the limitations of UK's defence procurement process that had previously failed to deliver defence equipment to cost, time and specification. The introduction reviews those factors, which influenced procurement since World War 11. The background to UK's current procurement process...

  19. Rosatom Corporation at the All-Russian civil defence training exercise

    International Nuclear Information System (INIS)

    Glukhikh, E.N.; Glazunov, A.V.; Tyurin, R.L.

    2012-01-01

    The 80th anniversary of civil defence in Russia was marked by the All-Russian civil defence exercise attended by representatives of federal executive authorities, regional and local executive authorities. During the exercise performance of the following activities was verified: introduction of increased preparedness mode for local air-defence emergency-response forces, activities of emergency-response and fire safety commissions, information collection and exchange during implementation of top-priority civil defence measures, etc. The paper describes the activities carried out during the exercise [ru

  20. Was It Really Worth Pain? Refurbishment of Mercedes-Benz Trucks by Botswana Defence Force

    National Research Council Canada - National Science Library

    Rangobana, Samuel A; Alkebaisi, Hussain K

    2005-01-01

    .... Logistics statistics, for refurbished trucks returned to user units, are also gathered from the asset management software database, Mincom Ellipse, in use by the Botswana Defence Force Mechanical...

  1. Costs and benefits of chemical defence in the Red Alga Bonnemaisonia hamifera.

    Directory of Open Access Journals (Sweden)

    Göran M Nylund

    Full Text Available A number of studies have shown that the production of chemical defences is costly in terrestrial vascular plants. However, these studies do not necessarily reflect the costs of defence production in macroalgae, due to structural and functional differences between vascular plants and macroalgae. Using a specific culturing technique, we experimentally manipulated the defence production in the red alga Bonnemaisonia hamifera to examine if the defence is costly in terms of growth. Furthermore, we tested if the defence provides fitness benefits by reducing harmful bacterial colonisation of the alga. Costly defences should provide benefits to the producer in order to be maintained in natural populations, but such benefits through protection against harmful bacterial colonisation have rarely been documented in macroalgae. We found that algae with experimentally impaired defence production, but with an externally controlled epibacterial load, grew significantly better than algae with normal defence production. We also found that undefended algae exposed to a natural epibacterial load experienced a substantial reduction in growth and a 6-fold increase in cell bleaching, compared to controls. Thus, this study provides experimental evidence that chemical defence production in macroalgae is costly, but that the cost is outweighed by fitness benefits provided through protection against harmful bacterial colonisation.

  2. Analogical Arguments in Ethics and Law: A Defence of Deductivism

    Directory of Open Access Journals (Sweden)

    Fábio Perin Shecaira

    2013-09-01

    Full Text Available The paper provides a qualified defence of Bruce Waller’s deductivist schema for a priori analogical arguments in ethics and law. One crucial qualification is that the schema represents analogical arguments as complexes composed of one deductive inference (hence “deductivism” but also of one non-deductive subargument. Another important qualification is that the schema is informed by normative assumptions regarding the conditions that an analogical argument must satisfy in order for it to count as an optimal instance of its kind. Waller’s schema (in qualified form is defended from criticisms formulated by Trudy Govier, Marcello Guarini and Lilian Bermejo-Luque.

  3. Corruption of host seven-transmembrane proteins by pathogenic microbes: a common theme in animals and plants?

    Science.gov (United States)

    Panstruga, Ralph; Schulze-Lefert, Paul

    2003-04-01

    Human diseases like AIDS, malaria, and pneumonia are caused by pathogens that corrupt host chemokine G-protein coupled receptors for molecular docking. Comparatively, little is known about plant host factors that are required for pathogenesis and that may serve as receptors for the entry of pathogenic microbes. Here, we review potential analogies between human chemokine receptors and the plant seven-transmembrane MLO protein, a candidate serving a dual role as docking molecule and defence modulator for the phytopathogenic powdery mildew fungus.

  4. An Indirect Defence Trait Mediated through Egg-Induced Maize Volatiles from Neighbouring Plants.

    Directory of Open Access Journals (Sweden)

    Daniel M Mutyambai

    C. sesamiae parasitic wasps indicated that these parasitoids preferred volatiles from oviposited and neighbouring landrace plants compared to those from the control plants. This effect was absent in the standard commercial hybrid we tested. There was no HIPV induction and no difference in parasitoid attraction in neighbouring and control hybrid maize plants. These results show plant-plant signalling: 'Nyamula' maize plants emitting oviposition-induced volatiles attractive to the herbivore's natural enemies can induce this indirect defence trait in conspecific neighbouring undamaged maize plants. Maize plants growing in a field may thus benefit from this indirect defence through airborne signalling which may enhance the fitness of the volatile-emitting plant by increasing predation pressure on herbivores.

  5. A possible role for polymorphonuclear leucocytes in the defence against recrudescent herpes simplex virus infection in man

    International Nuclear Information System (INIS)

    Russell, A.S.; Miller, C.

    1978-01-01

    A 51 Cr release assay has been used to demonstrate that human polymorphonuclear leucocytes (PMNL) can damage herpes simplex infected target cells sensitized with antiviral antibody. Effective sensitizing antibodies were found in both serum and saliva of all those persons tested who were subject to recurrent cold sores. PMNL were much less effective as killer cells than peripheral blood mononuclear cells, but as they are the predominant inflammatory cell within the HSVl lesion they may be, quantitatively, more important. The cytotoxic effects of both PMNL and mononuclear cells were significantly reduced by prostaglandin El as well as by several drugs that were tested. It is suggested that antibody dependent PMNL-mediated cytotoxicity may play a role in the human host defences against recrudescent herpes simplex infection. (author)

  6. Escherichia coli : host interactions in the pathogenesis of canine pyometra

    OpenAIRE

    Henriques, Sofia Correia Rosa de Barros

    2016-01-01

    Tese de Doutoramento em Ciências Veterinárias na Especialidade de Ciências Biológicas e Biomédicas Canine pyometra develops as a result of a complex interaction of etiological and physiopathological factors, such as the virulence and type of the bacteria and the individual host defence mechanisms. Since Escherichia coli is the most common bacterium isolated from uterus of bitches with pyometra, one main objective of this work was to characterize E. coli virulence potential, and...

  7. Manic Defences in Contemporary Society. The Psychocultural Approach.

    Science.gov (United States)

    Rudan, Dusko; Jakovljevic, Miro; Marcinko, Darko

    2016-12-01

    The article discusses the impact of contemporary culture on the individual's personality. We used the "psychocultural" approach whose key feature is the amalgamation of theories and methods belonging to psychodynamic and psychosocial studies, as well as those used in the field of media and cultural studies. The idea of a potentially therapeutic effect of culture (therapy culture) can already been seen in Freud's and Lacan's texts, and it is often used in critical analyses of contemporary corporate culture, which is more or less developed in some parts of the world. In their criticisms, many contemporary authors emphasize that modern societies have a tendency towards the weakening of basic commitment, or lack thereof, to a social equivalent of Winnicott's concept of environmental provisions as an inalienable democratic right essential for human emotional and mental progress or emotional well-being. The article describes frequent resorting to the so-called manic defences that defensively distort, deny and obscure the awareness that a human being is not the omnipotent source of life, but instead depends on other human beings, and often tries to compensate for loss through various activities. The article describes excessive shopping as an activity that often serves as an attempt to find what was lost, i.e. to fill an emotional void. This solution (resorting to manic defences) is encouraged by contemporary culture, especially through promotional material (e.g. advertising). The main theses of this article are supported by quotations and data from world literature.

  8. Energetic consequences of an inducible morphological defence in crucian carp.

    Science.gov (United States)

    Pettersson, Lars B; Brönmark, Christer

    1999-10-01

    Crucian carp (Carassius carassius) increases in body depth in response to chemical cues from piscivores and the deeper body constitutes a morphological defence against gape-limited piscivores. In the field, deep-bodied individuals suffer a density-dependent cost when competing with shallow-bodied conspecifics. Here, we use hydrodynamic theory and swimming respirometry to investigate the proposed mechanism underlying this effect, high drag caused by the deep-bodied morphology. Our study confirms that drag is higher for deep-bodied crucian carp, both in terms of estimated theoretical drag and power curve steepness. However, deep-bodied fish swimming at the velocity associated with minimum cost of transport, U mc , did not experience higher costs of transport than shallow-bodied fish. Deep-bodied crucian carp had significantly lower standard metabolic rates, i.e. metabolic rates at rest, and also lower U mc , and the resulting costs of transport were similar for the two morphs. Nevertheless, when deep-bodied individuals deviate from U mc , e.g. when increasing foraging effort under competition, their steeper power curves will cause substantial energy costs relative to shallow-bodied conspecifics. Furthermore, there is evidence that reductions in standard metabolic rate incur costs in terms of lower stress tolerance, reduced growth rate, and life history changes. Thus, this work provides links between hydrodynamics, a cost-reducing mechanism, and a density-dependent fitness cost associated with an inducible defence.

  9. How Strong Is Europeanisation, Really? The Danish Defence Administration and the Opt-Out from the European Security and Defence Policy

    DEFF Research Database (Denmark)

    Olsen, Gorm Rye

    2011-01-01

    The article questions how strong Europeanisation is as an explanation of administrative changes in EU member states. Denmark has an opt-out from the European cooperation on defence, and, therefore, its defence administration represents a critical or a less likely case to test the Europeanisation...... thesis. The article shows that in spite of the opt-out, the administrative structures and the policy processes in the Ministry of Foreign Affairs (MFA) have adapted to the common foreign and security policy (CFSP) and the European security and defence policy (ESDP). Surprisingly, the administrative...... structures and the decision-making processes in the Ministry of Defence (MoD) have also adapted to the ESDP. The latter example emphasises the strength of top-down Europeanisation as a possible explanation of domestic administrative changes in member states. It is argued that Europeanisation per se...

  10. Are bacteriophage defence and virulence two sides of the same coin in Campylobacter jejuni?

    NARCIS (Netherlands)

    R.P.L. Louwen (Rogier); P. van Baarlen (Peter)

    2013-01-01

    textabstractThe continuous battle for survival in the environment has led to the development or acquisition of sophisticated defence systems in bacteria. These defence systems have contributed to the survival of the bacterial species in the environment for millions of years. Some systems appear to

  11. A laws of war review of contemporary land-based missile defence ...

    African Journals Online (AJOL)

    Automated precise guided missile defence has been around for some years, and is a modern-day mechanism used frequently since 2011 to defend against rocket attacks penetrating national airspace. Israel's automated Iron Dome Missile Defence System has intercepted over 1 000 rockets during two recent military ...

  12. Civil Defence Commission at the Federal German Ministry of the Interior

    International Nuclear Information System (INIS)

    1987-01-01

    The work of the Civil Defence Commission comprises also interdisciplinary questions of civil defence and disaster relief. The lectures are concerned with the causes and effects of radioactivity, medical practice in the event of disaster, toxicology and pathology, including even psychology in disaster as well as risk management and dosimetry. The subjects chemical accidents and disaster relief are marginally dealt with. (DG) [de

  13. Modelling the effects of a CBRN defence system using a Bayesian Belief Model

    NARCIS (Netherlands)

    Phillipson, F.; Bastings, I.C.L.; Vink, N.

    2015-01-01

    In this paper a Bayes model to quantify the effects of a passive CBRN defence system is presented. The model gives insight in the way of the mutual influence of all the elements of passive CBRN defence, by the use of detailed scenario analysis, sensitivity analysis and root cause analysis. This can

  14. NATO Guide for Judgement-Based Operational Analysis in Defence Decision Making : Client-Oriented Volume

    NARCIS (Netherlands)

    Wijnmalen, D.J.D.; et al

    2012-01-01

    Judgment plays an important role in all Operational Analysis (OA). NATO practitioners have determined that approaches in OA that are based on human judgement are increasingly critical to defence decision making. The purpose of the NATO Guide for Judgement-Based OA in Defence Decision Making is to

  15. NATO Guide for Judgement-Based Operational Analysis in Defence Decision Making : Executive Leaflet

    NARCIS (Netherlands)

    Wijnmalen, D.J.D.; et al

    2012-01-01

    Judgment plays an important role in all Operational Analysis (OA). NATO practitioners have determined that approaches in OA that are based on human judgement are increasingly critical to defence decision making. The purpose of the NATO Guide for Judgement-Based OA in Defence Decision Making is to

  16. Environmental Effects on Constitutive and Inducible Resin Defences of Pinus taeda

    Science.gov (United States)

    Maria L. Lombardero; Matthew P. Ayres; Peter L. Lorio; Jonathan J. Ruel

    2000-01-01

    The ecological literature abounds with studies of environmental effects on plant antiherbivore defences. While various models have been proposed (e.g. plant stress, optimal allocation, growth-differentiation balance), each has met with mixed support. One possible explanation for the mixed results is that constitutive and induced defences are differentialiy affected by...

  17. Computational intelligence methods for the efficient reliability analysis of complex flood defence structures

    NARCIS (Netherlands)

    Kingston, Greer B.; Rajabali Nejad, Mohammadreza; Gouldby, Ben P.; van Gelder, Pieter H.A.J.M.

    2011-01-01

    With the continual rise of sea levels and deterioration of flood defence structures over time, it is no longer appropriate to define a design level of flood protection, but rather, it is necessary to estimate the reliability of flood defences under varying and uncertain conditions. For complex

  18. Between a rock and a hard place: Environmental and engineering considerations when designing coastal defence structures

    NARCIS (Netherlands)

    Firth, L.B.; Thompson, R.C.; Bohn, K.; Abbiati, M.; Airoldi, L.; Bouma, T.J.; Bozzeda, F.; Ceccherelli, V.U.; Colangelo, M.A.; Evans, A.; Ferrario, F.; Hanley, M.E.; Hinz, H.; Hoggart, S.P.G.; Jackson, J.E.; Moore, P.; Morgan, E.H.; Perkol-Finkel, S.; Skov, M.W.; Strain, E.M.; van Belzen, J.; Hawkins, S.J.

    2014-01-01

    Coastal defence structures are proliferating as a result of rising sea levels and stormier seas. With the realisation that most coastal infrastructure cannot be lost or removed, research is required into ways that coastal defence structures can be built to meet engineering requirements, whilst also

  19. the role of the south african national defence force in policing

    African Journals Online (AJOL)

    mosesm

    the history and socioeconomic realities of our society. For ... White Paper on National Defence for the Republic of South Africa of 19962 and ... Reading the 1998 Defence Review,5 it was clearly assumed, without any ... year regarding the crime situation in South Africa. ..... approaches need to be augmented by the SANDF.

  20. Simple growth patterns can create complex trajectories for the ontogeny of constitutive chemical defences in seaweeds.

    Directory of Open Access Journals (Sweden)

    Nicholas A Paul

    Full Text Available All of the theory and most of the data on the ecology and evolution of chemical defences derive from terrestrial plants, which have considerable capacity for internal movement of resources. In contrast, most macroalgae--seaweeds--have no or very limited capacity for resource translocation, meaning that trade-offs between growth and defence, for example, should be localised rather than systemic. This may change the predictions of chemical defence theories for seaweeds. We developed a model that mimicked the simple growth pattern of the red seaweed Asparagopsis armata which is composed of repeating clusters of somatic cells and cells which contain deterrent secondary chemicals (gland cells. To do this we created a distinct growth curve for the somatic cells and another for the gland cells using empirical data. The somatic growth function was linked to the growth function for defence via differential equations modelling, which effectively generated a trade-off between growth and defence as these neighbouring cells develop. By treating growth and defence as separate functions we were also able to model a trade-off in growth of 2-3% under most circumstances. However, we found contrasting evidence for this trade-off in the empirical relationships between growth and defence, depending on the light level under which the alga was cultured. After developing a model that incorporated both branching and cell division rates, we formally demonstrated that positive correlations between growth and defence are predicted in many circumstances and also that allocation costs, if they exist, will be constrained by the intrinsic growth patterns of the seaweed. Growth patterns could therefore explain contrasting evidence for cost of constitutive chemical defence in many studies, highlighting the need to consider the fundamental biology and ontogeny of organisms when assessing the allocation theories for defence.

  1. State Aid as a Defence for Public Authorities?

    DEFF Research Database (Denmark)

    Ølykke, Grith Skovgaard

    2016-01-01

    court’s perception. As the contracts had been declared to be in force by a declaratory judgment that was res judicata, the dispute before the CJEU concerned the national interpretation of the principle of res judicata and its application in a State aid context. The CJEU first turned to the principle......In the annotated judgment a public authority uses the existence of State aid as a defence in a legal action, where its contractual partner aimed to achieve damages and fulfilment of the contracts. The public authority claimed that the contracts were not on market terms, which also was the national...... of consistent interpretation, which it considered could provide various solutions for the national court to draw all the necessary consequences of the possible breach of the duty to notify State aid. In the alternative, the CJEU considered the principle of effectiveness and found that due to the fundamental...

  2. Defence-in-depth concept for the EU-ABWR

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Hiroshi; Fuchs, Steffen; Takada, Toshiaki; Kataoka, Kazuyoshi [Toshiba International Limited (Japan)

    2013-07-01

    The current defence-in-depth (DiD) concept has been established by the Reactor Harmonization Working Group (RHWG) of Western European Nuclear Regulators Association (WENRA). Principally the DiD concept was already part of the very early power reactor designs. However, additional considerations have been done in order to take plant conditions into account which are beyond the original design basis. The most recent advancements have been done based on major lessons learned from the Fukushima Dai-Ichi accident. Especially for new nuclear reactors it has to be demonstrated that DiD aspects have been considered in their design. Currently Toshiba is adapting its Advanced Boiling Water Reactor (ABWR) for the European market, at first in Finland. This presentation aims to describe how the new DiD concept has been applied to achieve the safety goals for a modern reactor type and to ensure a design that can be licensed in Western Europe. (orig.)

  3. Prioritizing Defence Industry Capabilities: Lessons for Canada from Australia

    Directory of Open Access Journals (Sweden)

    J. Craig Stone

    2014-01-01

    Full Text Available A number of Canadian acquisition announcements over the past few years have generated significant debate about a variety of issues like whether or not Canada should have a separate procurement agency, whether or not industrial and regional benefits are appropriate and whether or not Canadian companies should be given preference over international companies. In discussions about improving our procurement process Australia is often used as an example because the nations are generally considered to be similar in size with respect to GDP, population and military. This study examines Australia’s approach to establishing a defence industry policy with a set of Priority Industry Capabilities and how that policy connects with military procurement in order to identify those lessons that might be useful for Canada as it seeks to improve its own procurement process and its relationship with the defence industry. The study looks at some important background information on the Australian experience and then looks more specifically at the most recent articulation of policies in Australia. Although Australia is not without its own challenges, there are a number of lessons that stand out for Canada. This study discusses the lessons for Canada and recommends that government spends the time and effort required to connect a series of related policy documents that provides industry and others with an articulation of what the government of the day intends to do and what their priorities are moving forward. It also recommends a holistic review of the entire procurement process to determine what is working well and what actually needs fixing would be useful.

  4. Interculturalism in the post-multicultural debate: a defence.

    Science.gov (United States)

    Zapata-Barrero, Ricard

    2017-01-01

    The main purpose of this article is to formulate a defence of the emerging intercultural policy paradigm for the benefit of those who are still somewhat reluctant to accept its proper place within the current migration-related diversity policy debate. My defence will take two main lines of argumentation: Firstly, I will state that the increasing intensity of the intercultural policy paradigm must be placed in the present-day post-multicultural period, which recognizes the strengths ​​of the multicultural policy paradigm but also the limits to its process for recognizing differences. The role played by the emerging national civic policy paradigm (a renovated version of assimilation), prioritizing duties before rights, will also be considered crucial to better contextualize interculturalism. Secondly, I will try to identify the main distinctive features of interculturalism, which legitimize its proper place within the diversity debate today. Without rejecting rights-based and duties-based policy approaches, interculturalism places more emphasis on a contacts-based policy approach, aimed at fostering communication and relationships among people from different backgrounds, including national citizens. This approach focuses on common bonds rather than differences. It also views diversity as an advantage and a resource, and centres its policy goals on community cohesion and reframing a common public culture that places diversity within rather than outside the so-called Unity. In reviewing the current literature and the origins of the intercultural policy paradigm, I restate its contribution towards resolving current trends in transnationalism, changing identities, superdiversity and the rise of populist anti-immigrant parties. These are issues the old multicultural project has struggled to deal with, which has provoked the current disillusionment. Lastly, I will propose a research avenue to further consolidate interculturalism as a distinctive and legitimate policy

  5. Ionising radiation safety training in the Australian Defence Organisation (ADO)

    International Nuclear Information System (INIS)

    Jenks, G.J.; O'Donovan, E.J.B.; Wood, W.B.

    1998-01-01

    Training personnel in ionising radiation safety within the Australian Defence Organisation (ADO) requires addressing some unique features of an organisation employing both military and civilian personnel. Activities may include those of a civil nature (such as industrial and medical radiography), specific military requirements (for training and emergency response) and scientific research and development. Some personnel may be assigned to full-time duties associated with radiation. However, most are designated as radiation protection officers as a secondary duty. A further complication is that most military personnel are subjected to postings at regular intervals. The ADO's Directorate of Defence Occupational Health and Safety has established an Ionising Radiation Safety Subcommittee to monitor not only the adequacy of the internal Ionising Radiation Safety Manual but also the training requirements. A Training Course, responding to these requirements, has been developed to emphasize, basic radiation theory and protection, operation of radiation monitors available in the ADO, an understanding of the Ionising Radiation Safety Manual, day-to-day radiation safety in units and establishments, and appropriate responses to radiation accidents and emergencies. In addition, students are briefed on a limited number of peripheral topics and participate in some site visits. Currently, two Courses are held annually, each with about twenty students. Most of the material is presented by ADO personnel with external contractor support. The three Courses held to date have proved successful, both for the students and the ADO generally. To seek national accreditation of the course through the Australian National Training Authority, as a first step, competency standards have been proposed. (authors)

  6. Ionising radiation safety training in the Australian defence organisation (ADO)

    International Nuclear Information System (INIS)

    Jenks, G.J.; O'Donovan, E.J.B.; Wood, W.B.

    1996-01-01

    Full text: Training personnel in ionising radiation safety within the Australian Defence Organisation (ADO) requires addressing some unique features of an organisation employing both military and civilian personnel. Activities may include those of a civil nature (such as industrial and medical radiography), specific military requirements (for training and emergency response) and scientific research and development. Some personnel may be assigned to full-time duties associated with radiation, while others may be designated as radiation protection officers in remote units with few duties to perform in this role. A further complication is that most military personnel are subjected to postings at regular intervals. The ADO's Directorate of Defence Occupational Health and Safety has established an Ionising Radiation Safety Subcommittee to monitor not only the adequacy of the internal Ionising Radiation Safety Manual but also the training requirements. A training course, responding to these requirements, has been developed to emphasise: basic radiation theory and protection; operation of radiation monitors available in the ADO; an understanding of the Safety Manual; day-to-day radiation safety in units and establishments; and appropriate responses to radiation accidents and emergencies. In addition, students are briefed on a limited number of peripheral topics and participate in some site visits. Currently, two Courses are held annually, each with about twenty students. Most of the material is presented by ADO personnel with external contractor support. The three Courses held to date have proved sufficiently successful, both for the students and the ADO generally, to seek national accreditation through the Australian National Training Authority and, as a first step, competency standards have been identified

  7. H(2 enhances arabidopsis salt tolerance by manipulating ZAT10/12-mediated antioxidant defence and controlling sodium exclusion.

    Directory of Open Access Journals (Sweden)

    Yanjie Xie

    Full Text Available BACKGROUND: The metabolism of hydrogen gas (H(2 in bacteria and algae has been extensively studied for the interesting of developing H(2-based fuel. Recently, H(2 is recognized as a therapeutic antioxidant and activates several signalling pathways in clinical trials. However, underlying physiological roles and mechanisms of H(2 in plants as well as its signalling cascade remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this report, histochemical, molecular, immunological and genetic approaches were applied to characterize the participation of H(2 in enhancing Arabidopsis salt tolerance. An increase of endogenous H(2 release was observed 6 hr after exposure to 150 mM NaCl. Arabidopsis pretreated with 50% H(2-saturated liquid medium, mimicking the induction of endogenous H(2 release when subsequently exposed to NaCl, effectively decreased salinity-induced growth inhibition. Further results showed that H(2 pretreatment modulated genes/proteins of zinc-finger transcription factor ZAT10/12 and related antioxidant defence enzymes, thus significantly counteracting the NaCl-induced reactive oxygen species (ROS overproduction and lipid peroxidation. Additionally, H(2 pretreatment maintained ion homeostasis by regulating the antiporters and H(+ pump responsible for Na(+ exclusion (in particular and compartmentation. Genetic evidence suggested that SOS1 and cAPX1 might be the target genes of H(2 signalling. CONCLUSIONS: Overall, our findings indicate that H(2 acts as a novel and cytoprotective regulator in coupling ZAT10/12-mediated antioxidant defence and maintenance of ion homeostasis in the improvement of Arabidopsis salt tolerance.

  8. Macrophages and cytokines in the early defence against herpes simplex virus

    Directory of Open Access Journals (Sweden)

    Ellermann-Eriksen Svend

    2005-08-01

    Full Text Available Abstract Herpes simplex virus (HSV type 1 and 2 are old viruses, with a history of evolution shared with humans. Thus, it is generally well-adapted viruses, infecting many of us without doing much harm, and with the capacity to hide in our neurons for life. In rare situations, however, the primary infection becomes generalized or involves the brain. Normally, the primary HSV infection is asymptomatic, and a crucial element in the early restriction of virus replication and thus avoidance of symptoms from the infection is the concerted action of different arms of the innate immune response. An early and light struggle inhibiting some HSV replication will spare the host from the real war against huge amounts of virus later in infection. As far as such a war will jeopardize the life of the host, it will be in both interests, including the virus, to settle the conflict amicably. Some important weapons of the unspecific defence and the early strikes and beginning battle during the first days of a HSV infection are discussed in this review. Generally, macrophages are orchestrating a multitude of anti-herpetic actions during the first hours of the attack. In a first wave of responses, cytokines, primarily type I interferons (IFN and tumour necrosis factor are produced and exert a direct antiviral effect and activate the macrophages themselves. In the next wave, interleukin (IL-12 together with the above and other cytokines induce production of IFN-γ in mainly NK cells. Many positive feed-back mechanisms and synergistic interactions intensify these systems and give rise to heavy antiviral weapons such as reactive oxygen species and nitric oxide. This results in the generation of an alliance against the viral enemy. However, these heavy weapons have to be controlled to avoid too much harm to the host. By IL-4 and others, these reactions are hampered, but they are still allowed in foci of HSV replication, thus focusing the activity to only relevant sites

  9. IPNV with high and low virulence: host immune responses and viral mutations during infection

    Directory of Open Access Journals (Sweden)

    Skjesol Astrid

    2011-08-01

    . Conclusions Mortality and expression levels of the immune genes were directly related to the rate of viral replication, which was in turn associated with sequences of viral genes. Rapid changes in the viral genome that dramatically reduced virus proliferation might indicate a higher susceptibility to protective mechanism employed by the host. Disease outbreak and mortality depend on a delicate balance between host defence, regulation of signalling cascades and virus genomic properties.

  10. Rapid establishment of a regular distribution of adult tropical Drosophila parasitoids in a multi-patch environment by patch defence behaviour.

    Science.gov (United States)

    de Jong, Peter W; Hemerik, Lia; Gort, Gerrit; van Alphen, Jacques J M

    2011-01-01

    Females of the larval parasitoid of Drosophila, Asobara citri, from sub-Saharan Africa, defend patches with hosts by fighting and chasing conspecific females upon encounter. Females of the closely related, palearctic species Asobara tabida do not defend patches and often search simultaneously in the same patch. The effect of patch defence by A. citri females on their distribution in a multi-patch environment was investigated, and their distributions were compared with those of A. tabida. For both species 20 females were released from two release-points in replicate experiments. Females of A. citri quickly reached a regular distribution across 16 patches, with a small variance/mean ratio per patch. Conversely, A. tabida females initially showed a clumped distribution, and after gradual dispersion, a more Poisson-like distribution across patches resulted (variance/mean ratio was closer to 1 and higher than for A. citri). The dispersion of A. tabida was most probably an effect of exploitation: these parasitoids increasingly made shorter visits to already exploited patches. We briefly discuss hypotheses on the adaptive significance of patch defence behaviour or its absence in the light of differences in the natural history of both parasitoid species, notably the spatial distribution of their hosts.

  11. Abscisic acid deficiency increases defence responses against Myzus persicae in Arabidopsis.

    Science.gov (United States)

    Hillwig, Melissa S; Chiozza, Mariana; Casteel, Clare L; Lau, Siau Ting; Hohenstein, Jessica; Hernández, Enrique; Jander, Georg; MacIntosh, Gustavo C

    2016-02-01

    Comparison of Arabidopsis thaliana (Arabidopsis) gene expression induced by Myzus persicae (green peach aphid) feeding, aphid saliva infiltration and abscisic acid (ABA) treatment showed a significant positive correlation. In particular, ABA-regulated genes are over-represented among genes that are induced by M. persicae saliva infiltration into Arabidopsis leaves. This suggests that the induction of ABA-related gene expression could be an important component of the Arabidopsis-aphid interaction. Consistent with this hypothesis, M. persicae populations induced ABA production in wild-type plants. Furthermore, aphid populations were smaller on Arabidopsis aba1-1 mutants, which cannot synthesize ABA, and showed a significant preference for wild-type plants compared with the mutant. Total free amino acids, which play an important role in aphid nutrition, were not altered in the aba1-1 mutant line, but the levels of isoleucine (Ile) and tryptophan (Trp) were differentially affected by aphids in wild-type and mutant plants. Recently, indole glucosinolates have been shown to promote aphid resistance in Arabidopsis. In this study, 4-methoxyindol-3-ylmethylglucosinolate was more abundant in the aba1-1 mutant than in wild-type Arabidopsis, suggesting that the induction of ABA signals that decrease the accumulation of defence compounds may be beneficial for aphids. © 2015 BSPP AND JOHN WILEY & SONS LTD.

  12. Review of Defence Plans in Europe: Current Status, Strengths and Opportunities

    DEFF Research Database (Denmark)

    De Boeck, Steven; Van Hertem, Dirk; Das, Kaushik

    2016-01-01

    interconnected, a contingency in one area can affect the whole power system and possibly lead to a wide area black out. Therefore adequate defence plans need to be designed and in place to handle these situations. This paper starts with an overview of the terminology used in defence plans. Subsequently...... the current status of defence plans in Europe and the preferred sequence of actions to mitigate contingencies, is given based on a survey conducted among several European TSOs. Furthermore his paper gives an overview of how the ongoing changes with renewables, phasor measurement units (PMUs), power flow...

  13. Discordancy or template-based recognition? Dissecting the cognitive basis of the rejection of foreign eggs in hosts of avian brood parasites

    NARCIS (Netherlands)

    Moskat, Csaba; Ban, Miklos; Szekely, Tamas; Komdeur, Jan; Lucassen, Rim W. G.; van Boheemen, Lotte A.; Hauber, Mark E.

    2010-01-01

    Many avian hosts have evolved antiparasite defence mechanisms, including egg rejection, to reduce the costs of brood parasitism. The two main alternative cognitive mechanisms of egg discrimination are thought to be based on the perceived discordancy of eggs in a clutch or the use of recognition

  14. Acoustic signalling in a small, socially monogamous canid

    DEFF Research Database (Denmark)

    Darden, Safi-Kirstine; Dabelsteen, Torben

    2008-01-01

    Animals that actively defend all or part of their home range for the exclusive use of members of their social group are considered territorial. Defended areas may contain resources such as dens or nests, key foraging sites, or sexual partners that vary in value by season. We investigated territor....... These results suggest that the barking sequence is used in territorial defence and we conclude that at least male swift foxes are territorial in the mating season and they use a long-ranging acoustic signal in territory defence....

  15. Escaping deleterious immune response in their hosts: lessons from trypanosomatids

    Directory of Open Access Journals (Sweden)

    Anne eGeiger

    2016-05-01

    Full Text Available The Trypanosomatidae family includes the genera Trypanosoma and Leishmania, protozoan parasites displaying complex digenetic life cycles requiring a vertebrate host and an insect vector. Trypanosoma brucei gambiense, T. cruzi and Leishmania spp are important human pathogens causing Human African Trypanosomiasis (HAT or Sleeping Sickness, Chagas’ disease, and various clinical forms of Leishmaniasis, respectively. They are transmitted to humans by tsetse flies, triatomine bugs or sandflies and affect millions of people worldwide.In humans, extracellular African trypanosomes (T. brucei evade the hosts’ immune defences, allowing their transmission to the next host, via the tsetse vector. By contrast, T. cruzi and Leishmania sp. have developed a complex intracellular lifestyle, also preventing several mechanisms to circumvent the host’s immune response.This review seeks to set out the immune evasion strategies developed by the different trypanosomatids resulting from parasite-host interactions and, will focus on: clinical and epidemiological importance of diseases; life cycles: parasites-hosts-vectors; innate immunity: key steps for trypanosomatids in invading hosts; deregulation of antigen presenting cells; disruption of efficient specific immunity; and the immune responses used for parasite proliferation.

  16. Mycobacterium tuberculosis Rv3402c enhances mycobacterial survival within macrophages and modulates the host pro-inflammatory cytokines production via NF-kappa B/ERK/p38 signaling.

    Directory of Open Access Journals (Sweden)

    Wu Li

    Full Text Available Intracellular survival plays a central role in the pathogenesis of Mycobacterium tuberculosis, a process which depends on an array of virulence factors to colonize and replicate within the host. The M. tuberculosis iron regulated open reading frame (ORF rv3402c, encoding a conserved hypothetical protein, was shown to be up-regulated upon infection in both human and mice macrophages. To explore the function of this ORF, we heterologously expressed the rv3402c gene in the non-pathogenic fast-growing Mycobacterium smegmatis strain, and demonstrated that Rv3402c, a cell envelope-associated protein, was able to enhance the intracellular survival of recombinant M. smegmatis. Enhanced growth was not found to be the result of an increased resistance to intracellular stresses, as growth of the Rv3402c expressing strain was unaffected by iron depletion, H2O2 exposure, or acidic conditions. Colonization of macrophages by M. smegmatis expressing Rv3402c was associated with substantial cell death and significantly greater amount of TNF-α and IL-1β compared with controls. Rv3402c-induced TNF-α and IL-1β production was found to be mediated by NF-κB, ERK and p38 pathway in macrophages. In summary, our study suggests that Rv3402c delivered in a live M. smegmatis vehicle can modify the cytokines profile of macrophage, promote host cell death and enhance the persistence of mycobacterium within host cells.

  17. Fitness costs of animal medication: antiparasitic plant chemicals reduce fitness of monarch butterfly hosts.

    Science.gov (United States)

    Tao, Leiling; Hoang, Kevin M; Hunter, Mark D; de Roode, Jacobus C

    2016-09-01

    The emerging field of ecological immunology demonstrates that allocation by hosts to immune defence against parasites is constrained by the costs of those defences. However, the costs of non-immunological defences, which are important alternatives to canonical immune systems, are less well characterized. Estimating such costs is essential for our understanding of the ecology and evolution of alternative host defence strategies. Many animals have evolved medication behaviours, whereby they use antiparasitic compounds from their environment to protect themselves or their kin from parasitism. Documenting the costs of medication behaviours is complicated by natural variation in the medicinal components of diets and their covariance with other dietary components, such as macronutrients. In the current study, we explore the costs of the usage of antiparasitic compounds in monarch butterflies (Danaus plexippus), using natural variation in concentrations of antiparasitic compounds among plants. Upon infection by their specialist protozoan parasite Ophryocystis elektroscirrha, monarch butterflies can selectively oviposit on milkweed with high foliar concentrations of cardenolides, secondary chemicals that reduce parasite growth. Here, we show that these antiparasitic cardenolides can also impose significant costs on both uninfected and infected butterflies. Among eight milkweed species that vary substantially in their foliar cardenolide concentration and composition, we observed the opposing effects of cardenolides on monarch fitness traits. While high foliar cardenolide concentrations increased the tolerance of monarch butterflies to infection, they reduced the survival rate of caterpillars to adulthood. Additionally, although non-polar cardenolide compounds decreased the spore load of infected butterflies, they also reduced the life span of uninfected butterflies, resulting in a hump-shaped curve between cardenolide non-polarity and the life span of infected butterflies

  18. Functional analysis of Arabidopsis immune-related MAPKs uncovers a role for MPK3 as negative regulator of inducible defences

    KAUST Repository

    Frei dit Frey, Nicolas

    2014-06-30

    Background Mitogen-activated protein kinases (MAPKs) are key regulators of immune responses in animals and plants. In Arabidopsis, perception of microbe-associated molecular patterns (MAMPs) activates the MAPKs MPK3, MPK4 and MPK6. Increasing information depicts the molecular events activated by MAMPs in plants, but the specific and cooperative contributions of the MAPKs in these signalling events are largely unclear. Results In this work, we analyse the behaviour of MPK3, MPK4 and MPK6 mutants in early and late immune responses triggered by the MAMP flg22 from bacterial flagellin. A genome-wide transcriptome analysis reveals that 36% of the flg22-upregulated genes and 68% of the flg22-downregulated genes are affected in at least one MAPK mutant. So far MPK4 was considered as a negative regulator of immunity, whereas MPK3 and MPK6 were believed to play partially redundant positive functions in defence. Our work reveals that MPK4 is required for the regulation of approximately 50% of flg22-induced genes and we identify a negative role for MPK3 in regulating defence gene expression, flg22-induced salicylic acid accumulation and disease resistance to Pseudomonas syringae. Among the MAPK-dependent genes, 27% of flg22-upregulated genes and 76% of flg22-downregulated genes require two or three MAPKs for their regulation. The flg22-induced MAPK activities are differentially regulated in MPK3 and MPK6 mutants, both in amplitude and duration, revealing a highly interdependent network. Conclusions These data reveal a new set of distinct functions for MPK3, MPK4 and MPK6 and indicate that the plant immune signalling network is choreographed through the interplay of these three interwoven MAPK pathways.

  19. Maritime defence and the South African Navy to the cancellation of ...

    African Journals Online (AJOL)

    The Union of South Africa's declaration of war against Germany on 6. September 1939 ... available only address the history of the British Royal Navy, imperial defence ..... The effect of British naval mastery was also illustrated by the fact that the.

  20. Lepidopteran defence droplets - A composite physical and chemical weapon against potential predators

    DEFF Research Database (Denmark)

    Pentzold, S.; Zagrobelny, Mika; Khakimov, Bekzod

    2016-01-01

    Insects often release noxious substances for their defence. Larvae of Zygaena filipendulae (Lepidoptera) secrete viscous and cyanogenic glucoside-containing droplets, whose effectiveness was associated with their physical and chemical properties. The droplets glued mandibles and legs of potential...

  1. The evolution of plant chemical defence - new roles for hydroxynitrile glucosides in Lotus japonicus

    DEFF Research Database (Denmark)

    Knudsen, Camilla

    Plants are sessile organisms well-known to produce a vast array of chemical compounds of which many are used in chemical defence against herbivores and pathogens. The biosynthesis of these plant chemical defence compounds poses a considerable risk of self-toxicity for the plant itself. Several...... on hydroxynitrile glucoside metabolism in the legume model plant Lotus japonicus. Lotus japonicus produces both cyanogenic and non-cyanogenic hydroxynitrile glucosides as chemical defence compounds. The cyanogenic glucosides linamarin and lotaustralin are stored in the cell vacuole as inactive glycosides and, upon...... function and evolution. Further, it contributes to our understanding of the formation and role of biosynthetic gene clusters in plant chemical defence. The bifurcation in hydroxynitrile glucoside biosynthesis and catabolism observed in Lotus japonicus makes it a very suitable model system to study...

  2. Introducing 'The Diverse Nature of Defence Healthcare' university module for DMS personnel.

    Science.gov (United States)

    Carter, Chris; Blake, L

    2015-12-01

    Over the past 10 years the UK Defence Medical Services has deployed healthcare personnel to a variety of operational areas in support of UK Operations. The unique nature of every operational deployment, in conjunction with the wide variety of roles which healthcare staff undertake, necessitates bespoke educational preparation of the military healthcare force. This paper explores the creation and development of one of the four modules which comprise the BSc (Hons) in Defence Health Care studies, entitled 'The Diverse Nature of Defence Healthcare'. It demonstrates the unique contribution that the Defence School of Healthcare Education makes towards Generation and Preparation of the Force for deployment. 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/

  3. Five Key Changes for the Management of UK Defence - An Agenda for Research?

    National Research Council Canada - National Science Library

    Tatham, Peter; Taylor, Trevor

    2008-01-01

    .... Given the paucity of academic research into the general area of defence management, it is suggested that there is considerable potential for focused application of ideas and concepts from a broad...

  4. Managing the trade-public health linkage in defence of trade ...

    African Journals Online (AJOL)

    Managing the trade-public health linkage in defence of trade liberalisation and ... of United States-measures affecting the production and sale of clove cigarettes. ... Potchefstroom Electronic Law Journal/Potchefstroomse Elektroniese Regsblad.

  5. Development of a single logistic process for the South African National Defence Force

    CSIR Research Space (South Africa)

    Schmitz, Peter MU

    2010-09-01

    Full Text Available The South African National Defence Force (SANDF) contracted the CSIR to investigate and propose methods to improve its logistics and inventory accounting capabilities. The CSIR proposed that a supply chain management approach should be followed...

  6. Host responses in life-history traits and tolerance to virus infection in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Israel Pagán

    2008-08-01

    Full Text Available Knowing how hosts respond to parasite infection is paramount in understanding the effects of parasites on host populations and hence host-parasite co-evolution. Modification of life-history traits in response to parasitism has received less attention than other defence strategies. Life-history theory predicts that parasitised hosts will increase reproductive effort and accelerate reproduction. However, empirical analyses of these predictions are few and mostly limited to animal-parasite systems. We have analysed life-history trait responses in 18 accessions of Arabidopsis thaliana infected at two different developmental stages with three strains of Cucumber mosaic virus (CMV. Accessions were divided into two groups according to allometric relationships; these groups differed also in their tolerance to CMV infection. Life-history trait modification upon virus infection depended on the host genotype and the stage at infection. While all accessions delayed flowering, only the more tolerant allometric group modified resource allocation to increase the production of reproductive structures and progeny, and reduced the length of reproductive period. Our results are in agreement with modifications of life-history traits reported for parasitised animals and with predictions from life-history theory. Thus, we provide empirical support for the general validity of theoretical predictions. In addition, this experimental approach allowed us to quantitatively estimate the genetic determinism of life-history trait plasticity and to evaluate the role of life-history trait modification in defence against parasites, two largely unexplored issues.

  7. Modelling parasite transmission in a grazing system: the importance of host behaviour and immunity.

    Directory of Open Access Journals (Sweden)

    Naomi J Fox

    Full Text Available Parasitic helminths present one of the most pervasive challenges to grazing herbivores. Many macro-parasite transmission models focus on host physiological defence strategies, omitting more complex interactions between hosts and their environments. This work represents the first model that integrates both the behavioural and physiological elements of gastro-intestinal nematode transmission dynamics in a managed grazing system. A spatially explicit, individual-based, stochastic model is developed, that incorporates both the hosts' immunological responses to parasitism, and key grazing behaviours including faecal avoidance. The results demonstrate that grazing behaviour affects both the timing and intensity of parasite outbreaks, through generating spatial heterogeneity in parasite risk and nutritional resources, and changing the timing of exposure to the parasites' free-living stages. The influence of grazing behaviour varies with the host-parasite combination, dependent on the development times of different parasite species and variations in host immune response. Our outputs include the counterintuitive finding that under certain conditions perceived parasite avoidance behaviours (faecal avoidance can increase parasite risk, for certain host-parasite combinations. Through incorporating the two-way interaction between infection dynamics and grazing behaviour, the potential benefits of parasite-induced anorexia are also demonstrated. Hosts with phenotypic plasticity in grazing behaviour, that make grazing decisions dependent on current parasite burden, can reduce infection with minimal loss of intake over the grazing season. This paper explores how both host behaviours and immunity influence macro-parasite transmission in a spatially and temporally heterogeneous environment. The magnitude and timing of parasite outbreaks is influenced by host immunity and behaviour, and the interactions between them; the incorporation of both regulatory processes

  8. The correlated evolution of antipredator defences and brain size in mammals

    OpenAIRE

    Stankowich, Theodore; Romero, Ashly N.

    2017-01-01

    Mammals that possess elaborate antipredator defences such as body armour, spines and quills are usually well protected, intermediate in size, primarily insectivorous and live in simple open environments. The benefits of such defences seem clear and may relax selection on maintaining cognitive abilities that aid in vigilance and predator recognition, and their bearers may accrue extensive production and maintenance costs. Here, in this comparative phylogenetic analysis of measurements of encep...

  9. The Strategic Failure of UK Defence Reform and What Still Needs to Be Done

    Science.gov (United States)

    2016-04-04

    from the previous Labour Government, see HM Government, “Defence Secretary Balances MoD Budget,” https://www.gov.uk/government/news/defence-secretary...conceptualize the different levels of strategy required in a modern environment, inclusive of grand strategy...Learning Under Fire: Military Change in Wartime. Lecture to selected JAWS students , Norfolk, VA, March 2015. HM Government. A Strong Britain in an Age

  10. The Audit of Explosives Storage and Transport Within the Australian Defence Force

    Science.gov (United States)

    1994-08-01

    Headquarters Australian Defence Force Australian Ordnance Council THE AUDIT OF EXPLOSIVES STORAGE AND TRANSPORT WITHIN THE AUSTRALIAN DEFENCE FORCE...control number. 1. REPORT DATE AUG 1994 2. REPORT TYPE 3. DATES COVERED 00-00-1994 to 00-00-1994 4. TITLE AND SUBTITLE The Audit of Explosives...8-98) Prescribed by ANSI Std Z39-18 THE AUDIT OF EXPLOSIVES STORAGE AND TRANSPORT WITHIN THE AUSTRALIAN DFFENCE FORCE - by R.W. Johnson and M.J

  11. Some practical examples of defence in depth analysis for category IV gamma irradiators

    International Nuclear Information System (INIS)

    Rodrigues Junior, Ary de Araujo

    2014-01-01

    The Defence in Depth concept provides a major contribution to the safety philosophy of irradiation facilities. But problems occur when somebody tries to understand or analyse a safety system or develop a new one because there is a lack of practical examples in Safety Series 107 or other IAEA (International Atomic Energy Agency) publications for irradiation facilities. This paper tries to fill this lack of information by providing a series of practical examples and explanations about Defence in Depth concepts. (author)

  12. Antioxidant defences of Norway spruce bark against bark beetles and its associated blue-stain fungus

    Directory of Open Access Journals (Sweden)

    Felicijan Mateja

    2015-12-01

    Full Text Available Bark beetles and their fungal associates are integral parts of forest ecosystems, the European spruce bark beetle (Ips typographus Linnaeus, 1758 and the associated pathogenic blue stain fungus Ceratocystis polonica (SIEM. C. MOREAU, are the most devastating pests regarding Norway spruce [Picea abies (L. H. KARST.]. Bark beetles commonly inhabit weakened and felled trees as well as vital trees. They cause physiological disorders in trees by destroying a phloem and cambium or interrupt the transpiration -ow in the xylem. Conifers have a wide range of effective defence mechanisms that are based on the inner bark anatomy and physiological state of the tree. The basic function of bark defences is to protect the nutrient-and energy-rich phloem, the vital meristematic region of the vascular cambium, and the transpiration -ow in the sapwood. The main area of defence mechanisms is secondary phloem, which is physically and chemically protected by polyphenolic parenchyma (PP cells, sclerenchyma, calcium oxalate crystals and resin ducts. Conifer trunk pest resistance includes constitutive, inducible defences and acquired resistance. Both constitutive and inducible defences may deter beetle invasion, impede fungal growth and close entrance wounds. During a successful attack, systemic acquired resistance (SAR becomes effective and represents a third defence strategy. It gradually develops throughout the plant and provides a systemic change within the whole tree’s metabolism, which is maintained over a longer period of time. The broad range of defence mechanisms that contribute to the activation and utilisation of SAR, includes antioxidants and antioxidant enzymes, which are generally linked to the actions of reactive oxygen species (ROS. The presented review discusses the current knowledge on the antioxidant defence strategies of spruce inner bark against the bark beetle (Ips typographus and associated blue stain fungus (Ceratocystis polonica.

  13. Some practical examples of defence in depth analysis for category IV gamma irradiators

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues Junior, Ary de Araujo, E-mail: aryarj@ig.com.br [Universidade Estadual de Maringa (UEM), Maringa, PR (Brazil). Dept. de Fisica

    2014-07-01

    The Defence in Depth concept provides a major contribution to the safety philosophy of irradiation facilities. But problems occur when somebody tries to understand or analyse a safety system or develop a new one because there is a lack of practical examples in Safety Series 107 or other IAEA (International Atomic Energy Agency) publications for irradiation facilities. This paper tries to fill this lack of information by providing a series of practical examples and explanations about Defence in Depth concepts. (author)

  14. Variation in maternal solitary bee nest defence related to nest state

    OpenAIRE

    Peterson , Jason H.; Hoffmeister , Thomas S.; Roitberg , Bernard D.

    2016-01-01

    International audience; AbstractParental protection of offspring is found in numerous animal species. Protection provides offspring with a greater chance of surviving to be able to reproduce, while at the same time, often posing a cost to the parent. Therefore, the net value of defence for the parent can vary depending on the developmental stage of the offspring and their ability to defend themselves. For example, in commonly studied organisms (e.g. birds), defence level increases over time u...

  15. Politics, pleasure, violence: Swedish defence propaganda in social media

    Directory of Open Access Journals (Sweden)

    Rodrigo Ferrada Stoehrel

    2013-10-01

    Full Text Available In recent years, the Swedish Armed Forces have produced and distributed highly edited video clips on YouTube that show moving images of military activity. Alongside this development, mobile phone apps have emerged as an important channel through which the user can experience and take an interactive part in the staging of contemporary armed conflict. This article examines the way in which the aesthetic and affective experience of Swedish defence and security policy is socially and (media-culturally (co-constructed and how the official representation of Swedish military intervention (reproduces political and economic effects when these activities are distributed through traditional and social media such as YouTube and digital apps. Based on Isabela and Norman Fairclough’s thoughts on political discourse, Michel Foucault’s dialectic idea of power/knowledge, and Sara Ahmed’s concept of the affective, I discuss how the Swedish digital military aesthetic is part of a broader political and economic practice which has consequences beyond the digital, the semiotic and what might at first glance appear to be pure entertainment. 

  16. Politics, pleasure, violence: Swedish defence propaganda in social media

    Directory of Open Access Journals (Sweden)

    Rodrigo Ferrada Stoehrel

    2013-12-01

    Full Text Available In recent years, the Swedish Armed Forces have produced and distributed highly edited video clips on YouTube that show moving images of military activity. Along- side this development, mobile phone apps have emerged as an important channel through which the user can experience and take an interactive part in the staging of contemporary armed conflict. This article examines the way in which the aes- thetic and affective experience of Swedish defence and security policy is socially and (media-culturally (co-constructed and how the official representation of Swedish military intervention (reproduces political and economic effects when these activi- ties are distributed through traditional and social media such as YouTube and digital apps. Based on Isabela and Norman Fairclough’s thoughts on political discourse, Michel Foucault’s dialectic idea of power/knowledge, and Sara Ahmed’s concept of the affective, I discuss how the Swedish digital military aesthetic is part of a broader political and economic practice that has consequences beyond the digital, the semi- otic, and what might at first glance appear to be pure entertainment.

  17. Risk management as a social defence against anxiety

    Directory of Open Access Journals (Sweden)

    Dirk J. Geldenhuys

    2012-03-01

    Research purpose: The aim of the study is to describe how risk management unconsciously influences behaviour when doing business in an African country. Motivation for the study: Operational risk management is a rational management imperative. However, this does not take cognisance of the unconscious role of risk management. A systems-psychodynamic perspective might be particularly relevant if the anxiety implied in risk management is not appropriately contained. Awareness of these dynamics may provide an opportunity for addressing them and allow for a more holistic way of managing risk. Research design, approach and method: The researchers conducted the study as a qualitative case study in an African country. They used purposive sampling and analysed the data using qualitative content analysis. Main findings: Viewing risk management from a systems-psychodynamic perspective allowed the researchers to identify the influence of risk management on the behaviour of people. The emerging hypothesis was that, if businesses do not address the anxiety underlying risk management, managing risk becomes a social defence against the anxiety. Practical/managerial implications: Awareness of the anxiety involved in risk management may assist businesses to manage risk in a more realistic way, making provision for, and even capitalising on, the human element. Contributions/value-add: The article provides a systems-psychodynamic, and hence a more complete, perspective of operational risk management when doing business in an African country.

  18. Diving bradycardia: a mechanism of defence against hypoxic damage.

    Science.gov (United States)

    Alboni, Paolo; Alboni, Marco; Gianfranchi, Lorella

    2011-06-01

    A feature of all air-breathing vertebrates, diving bradycardia is triggered by apnoea and accentuated by immersion of the face or whole body in cold water. Very little is known about the afferents of diving bradycardia, whereas the efferent part of the reflex circuit is constituted by the cardiac vagal fibres. Diving bradycardia is associated with vasoconstriction of selected vascular beds and a reduction in cardiac output. The diving response appears to be more pronounced in mammals than in birds. In humans, the bradycardic response to diving varies greatly from person to person; the reduction in heart rate generally ranges from 15 to 40%, but a small proportion of healthy individuals can develop bradycardia below 20 beats/min. During prolonged dives, bradycardia becomes more pronounced because of activation of the peripheral chemoreceptors by a reduction in the arterial partial pressure of oxygen (O2), responsible for slowing of heart rate. The vasoconstriction is associated with a redistribution of the blood flow, which saves O2 for the O2-sensitive organs, such as the heart and brain. The results of several investigations carried out both in animals and in humans show that the diving response has an O2-conserving effect, both during exercise and at rest, thus lengthening the time to the onset of serious hypoxic damage. The diving response can therefore be regarded as an important defence mechanism for the organism.

  19. Development of 63Ni sources for defence related applications

    International Nuclear Information System (INIS)

    Udhayakumar, J.; Pardeshi, G.S.; Gandhi, Shyamala S.; Dash, A.; Venkatesh, Meera

    2004-01-01

    63 Ni is seen as a good substitute for the conventional sources of ionization used in electron capture detectors in Gas Chromatography applications. It has advantages such as source stability, reasonably long shelf life due to its long half-life and viable for safe and easy handling due to low energy beta emission. At the special request from the Defence Establishments in India for supply of 63 Ni beta source on special dimension of a curved inner copper ring area, the new electro-deposition cell was designed and used for routine preparation and supply of such sources. The paper describes the procedure for fabrication of 63 Ni beta sources by electro-deposition method. Activity up to ∼370 MBq (∼10 mCi) was electrodeposited exclusively on inner curved area of ∼4 sq.cm. Copper annular ring, using Boric acid electrolyte bath solution at a temperature range of 50 deg - 60 deg C with a current density of ∼ 6 ma/sq.cm. For this purpose, a new electro depositing cell was specially designed and used. The paper discusses the details regarding source requirement, source preparation parameters, film thickness and its impact on beta output, source quality control aspects and other applications of the sources. The paper also highlights the demand and supply scenario of such electrodeposited sources, in terms of commercial supply sale value, as an import substitute. (author)

  20. Double checking medicines: defence against error or contributory factor?

    Science.gov (United States)

    Armitage, Gerry

    2008-08-01

    The double checking of medicines in health care is a contestable procedure. It occupies an obvious position in health care practice and is understood to be an effective defence against medication error but the process is variable and the outcomes have not been exposed to testing. This paper presents an appraisal of the process using data from part of a larger study on the contributory factors in medication errors and their reporting. Previous research studies are reviewed; data are analysed from a review of 991 drug error reports and a subsequent series of 40 in-depth interviews with health professionals in an acute hospital in northern England. The incident reports showed that errors occurred despite double checking but that action taken did not appear to investigate the checking process. Most interview participants (34) talked extensively about double checking but believed the process to be inconsistent. Four key categories were apparent: deference to authority, reduction of responsibility, automatic processing and lack of time. Solutions to the problems were also offered, which are discussed with several recommendations. Double checking medicines should be a selective and systematic procedure informed by key principles and encompassing certain behaviours. Psychological research may be instructive in reducing checking errors but the aviation industry may also have a part to play in increasing error wisdom and reducing risk.

  1. Improvement interventions: To what extent are they manifestations of social defences?

    Directory of Open Access Journals (Sweden)

    Jeremias J. de Klerk

    2012-02-01

    Research purpose: The aim is to provide an explanation to the lure behind interventions and to contribute to building a theory on plausible systems psychodynamic drivers and mechanisms of recurrent change interventions. Motivation for the study: This study provides insights into social defences in ways that did not receive much attention previously; specifically how defence mechanisms act as drivers for new change and improvement interventions. Research design, approach and method: A literature study, consisting of a literature review and a phenomenological analysis. The study was conducted from the systems psychodynamic approach. Main findings: Improvement interventions often represent defences that serve to contain anxieties or maintain fantasies. Four specific themes emerged: interventions defend the perception of being in control, they maintain the fantasy that one is busy with worthy actions to overcome challenges, they are defences against boredom or contain anxieties about incompetence, and they maintain the fantasy of being heroic leaders. Practical/managerial implications: The findings can assist leaders to understand their own defences in order to avoid embarking on non-essential interventions. This can free up much time, energy and effort to spend on other priorities, assisting organisations to achieve better results. Contribution/value-add: The study refutes the notion that improvement interventions are always rational coping mechanisms and highlights the role of improvement interventions as defences to reduce anxiety, even though they may contribute little to organisational survival in real terms.

  2. Parental risk management in relation to offspring defence: bad news for kids.

    Science.gov (United States)

    Mahr, Katharina; Riegler, Georg; Hoi, Herbert

    2015-01-07

    Do parents defend their offspring whenever necessary, and do self-sacrificing parents really exist? Studies recognized that parent defence is dynamic, mainly depending on the threat predators pose. In this context, parental risk management should consider the threat to themselves and to their offspring. Consequently, the observed defence should be a composite of both risk components. Surprisingly, no study so far has determined the influence of these two threat components on parental decision rules. In a field experiment, we investigated parental risk taking in relation to the threat posed to themselves and their offspring. To disentangle the two threat components, we examined defence behaviours of parent blue tits Cyanistes caeruleus towards three different predators and during different nestling developmental stages. Nest defence strategies in terms of alarm call intensity and nearest predator approach differed between the three predators. Defence intensity was only partly explained by threat level. Most importantly, parental risk management varied in relation to their own, but not offspring risk. Parent defence investment was independent of nestling risk when parents followed a high-risk strategy. However, parents considered nestling as well as parental risk when following a low-risk strategy. Our findings could have general implications for the economy of risk management and decision-making strategies in living beings, including humans. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  3. The correlated evolution of antipredator defences and brain size in mammals.

    Science.gov (United States)

    Stankowich, Theodore; Romero, Ashly N

    2017-01-11

    Mammals that possess elaborate antipredator defences such as body armour, spines and quills are usually well protected, intermediate in size, primarily insectivorous and live in simple open environments. The benefits of such defences seem clear and may relax selection on maintaining cognitive abilities that aid in vigilance and predator recognition, and their bearers may accrue extensive production and maintenance costs. Here, in this comparative phylogenetic analysis of measurements of encephalization quotient and morphological defence scores of 647 mammal species representing nearly every order, we found that as lineages evolve stronger defences, they suffer a correlated reduction in encephalization. The only exceptions were those that live in trees-a complex three-dimensional world probably requiring greater cognitive abilities. At the proximate level, because brain tissue is extremely energetically expensive to build, mammals may be trading off spending more on elaborate defences and saving by building less powerful brains. At the ultimate level, having greater defences may also reduce the need for advanced cognitive abilities for constant assessment of environmental predation risk, especially in simple open environments. © 2017 The Author(s).

  4. The correlated evolution of antipredator defences and brain size in mammals

    Science.gov (United States)

    Romero, Ashly N.

    2017-01-01

    Mammals that possess elaborate antipredator defences such as body armour, spines and quills are usually well protected, intermediate in size, primarily insectivorous and live in simple open environments. The benefits of such defences seem clear and may relax selection on maintaining cognitive abilities that aid in vigilance and predator recognition, and their bearers may accrue extensive production and maintenance costs. Here, in this comparative phylogenetic analysis of measurements of encephalization quotient and morphological defence scores of 647 mammal species representing nearly every order, we found that as lineages evolve stronger defences, they suffer a correlated reduction in encephalization. The only exceptions were those that live in trees—a complex three-dimensional world probably requiring greater cognitive abilities. At the proximate level, because brain tissue is extremely energetically expensive to build, mammals may be trading off spending more on elaborate defences and saving by building less powerful brains. At the ultimate level, having greater defences may also reduce the need for advanced cognitive abilities for constant assessment of environmental predation risk, especially in simple open environments. PMID:28077771

  5. Fungal-host diversity among mycoheterotrophic plants increases proportionally to their fungal-host overlap.

    Science.gov (United States)

    Gomes, Sofia I F; Merckx, Vincent S F T; Saavedra, Serguei

    2017-05-01

    The vast majority of plants obtain an important proportion of vital resources from soil through mycorrhizal fungi. Generally, this happens in exchange of photosynthetically fixed carbon, but occasionally the interaction is mycoheterotrophic, and plants obtain carbon from mycorrhizal fungi. This process results in an antagonistic interaction between mycoheterotrophic plants and their fungal hosts. Importantly, the fungal-host diversity available for plants is restricted as mycoheterotrophic interactions often involve narrow lineages of fungal hosts. Unfortunately, little is known whether fungal-host diversity may be additionally modulated by plant-plant interactions through shared hosts. Yet, this may have important implications for plant competition and coexistence. Here, we use DNA sequencing data to investigate the interaction patterns between mycoheterotrophic plants and arbuscular mycorrhizal fungi. We find no phylogenetic signal on the number of fungal hosts nor on the fungal hosts shared among mycoheterotrophic plants. However, we observe a potential trend toward increased phylogenetic diversity of fungal hosts among mycoheterotrophic plants with increasing overlap in their fungal hosts. While these patterns remain for groups of plants regardless of location, we do find higher levels of overlap and diversity among plants from the same location. These findings suggest that species coexistence cannot be fully understood without attention to the two sides of ecological interactions.

  6. HOST PLANT UTILIZATION, HOST RANGE OSCILLATIONS AND DIVERSIFICATION IN NYMPHALID BUTTERFLIES: A PHYLOGENETIC INVESTIGATION

    Science.gov (United States)

    Nylin, Sören; Slove, Jessica; Janz, Niklas

    2014-01-01

    It has been suggested that phenotypic plasticity is a major factor in the diversification of life, and that variation in host range in phytophagous insects is a good model for investigating this claim. We explore the use of angiosperm plants as hosts for nymphalid butterflies, and in particular the evidence for past oscillations in host range and how they are linked to host shifts and to diversification. At the level of orders of plants, a relatively simple pattern of host use and host shifts emerges, despite the 100 million years of history of the family Nymphalidae. We review the evidence that these host shifts and the accompanying diversifications were associated with transient polyphagous stages, as suggested by the “oscillation hypothesis.” In addition, we investigate all currently polyphagous nymphalid species and demonstrate that the state of polyphagy is rare, has a weak phylogenetic signal, and a very apical distribution in the phylogeny; we argue that these are signs of its transient nature. We contrast our results with data from the bark beetles Dendroctonus, in which a more specialized host use is instead the apical state. We conclude that plasticity in host use is likely to have contributed to diversification in nymphalid butterflies. PMID:24372598

  7. RIG-I self-oligomerization is either dispensable or very transient for signal transduction.

    Directory of Open Access Journals (Sweden)

    Jade Louber

    Full Text Available Effective host defence against viruses depends on the rapid triggering of innate immunity through the induction of a type I interferon (IFN response. To this end, microbe-associated molecular patterns are detected by dedicated receptors. Among them, the RIG-I-like receptors RIG-I and MDA5 activate IFN gene expression upon sensing viral RNA in the cytoplasm. While MDA5 forms long filaments in vitro upon activation, RIG-I is believed to oligomerize after RNA binding in order to transduce a signal. Here, we show that in vitro binding of synthetic RNA mimicking that of Mononegavirales (Ebola, rabies and measles viruses leader sequences to purified RIG-I does not induce RIG-I oligomerization. Furthermore, in cells devoid of endogenous functional RIG-I-like receptors, after activation of exogenous Flag-RIG-I by a 62-mer-5'ppp-dsRNA or by polyinosinic:polycytidylic acid, a dsRNA analogue, or by measles virus infection, anti-Flag immunoprecipitation and specific elution with Flag peptide indicated a monomeric form of RIG-I. Accordingly, when using the Gaussia Luciferase-Based Protein Complementation Assay (PCA, a more sensitive in cellula assay, no RIG-I oligomerization could be detected upon RNA stimulation. Altogether our data indicate that the need for self-oligomerization of RIG-I for signal transduction is either dispensable or very transient.

  8. Australian DefenceScience. Volume 15, Number 4, Summer

    Science.gov (United States)

    2007-01-01

    marked with a formal dinner held in Melbourne. BAE Systems Australia, having acquired the licence from DSTO to commercialise and market the...undertaken as part of the Cooperative Education for Enterprise Development (CEED) program hosted by UWA. Wearable rechargeable battery system. Australian

  9. Transgenic expression of a functional fragment of harpin protein Hpa1 in wheat induces the phloem-based defence against English grain aphid

    Science.gov (United States)

    Fu, Maoqiang; Xu, Manyu; Zhang, Chunling

    2014-01-01

    The harpin protein Hpa1 has multiple beneficial effects in plants, promoting plant growth and development, increasing crop yield, and inducing resistance to pathogens and insect pests. For these effects, the 10–40 residue fragment (Hpa110–42) isolated from the Hpa1 sequence is 1.3- to 7.5-fold more effective than the full-length protein. Here it is reported that the expression of Hpa110–42 under the direction of an insect-induced promoter induces the phloem-based defence to English grain aphid, a dominant species of wheat aphids. The expression of Hpa110–42 was found to compromise the colonization preference of aphids on the plant and further inhibit aphid reproduction in leaf colonies. In Hpa110–42-expressing wheat lines, moreover, aphid feeding from the phloem was repressed in correlation with the phloem-based defence. This defensive mechanism was shown as enhanced expression of wheat genes encoding phloem lectin proteins (PP2-A1 and PP2-A2) and β-1,3-glucan synthase-like enzymes (GSL2, GSL10, and GSL12). Both PP2-A and β-1,3-glucan formed high molecular mass polymers to block phloem sieve plate pores and therefore impede aphid feeding from the phloem. However, the phloem-based defence was impaired by treating plants with ethylene signalling inhibitors, suggesting the requirement for the ethylene signalling pathway. In addition, if Hpa110–42-expressing plants were subjected to attack by a small number of aphids, they newly acquired agriculturally beneficial characters, such as enhanced vegetative growth and increased tiller numbers and grain output values. These results suggest that the defensive and developmental roles of Hpa110–42 can be integrated into the germplasm of this agriculturally significant crop. PMID:24676030

  10. Transgenic expression of a functional fragment of harpin protein Hpa1 in wheat induces the phloem-based defence against English grain aphid.

    Science.gov (United States)

    Fu, Maoqiang; Xu, Manyu; Zhou, Ting; Wang, Defu; Tian, Shan; Han, Liping; Dong, Hansong; Zhang, Chunling

    2014-04-01

    The harpin protein Hpa1 has multiple beneficial effects in plants, promoting plant growth and development, increasing crop yield, and inducing resistance to pathogens and insect pests. For these effects, the 10-40 residue fragment (Hpa1₁₀₋₄₂) isolated from the Hpa1 sequence is 1.3- to 7.5-fold more effective than the full-length protein. Here it is reported that the expression of Hpa1₁₀₋₄₂ under the direction of an insect-induced promoter induces the phloem-based defence to English grain aphid, a dominant species of wheat aphids. The expression of Hpa1₁₀₋₄₂ was found to compromise the colonization preference of aphids on the plant and further inhibit aphid reproduction in leaf colonies. In Hpa1₁₀₋₄₂-expressing wheat lines, moreover, aphid feeding from the phloem was repressed in correlation with the phloem-based defence. This defensive mechanism was shown as enhanced expression of wheat genes encoding phloem lectin proteins (PP2-A1 and PP2-A2) and β-1,3-glucan synthase-like enzymes (GSL2, GSL10, and GSL12). Both PP2-A and β-1,3-glucan formed high molecular mass polymers to block phloem sieve plate pores and therefore impede aphid feeding from the phloem. However, the phloem-based defence was impaired by treating plants with ethylene signalling inhibitors, suggesting the requirement for the ethylene signalling pathway. In addition, if Hpa1₁₀₋₄₂-expressing plants were subjected to attack by a small number of aphids, they newly acquired agriculturally beneficial characters, such as enhanced vegetative growth and increased tiller numbers and grain output values. These results suggest that the defensive and developmental roles of Hpa1₁₀₋₄₂ can be integrated into the germplasm of this agriculturally significant crop.

  11. Eales′ disease: Oxidant stress and weak antioxidant defence

    Directory of Open Access Journals (Sweden)

    Ramakrishnan S

    2007-01-01

    Full Text Available Eales′ disease (ED is an idiopathic retinal periphlebitis characterized by capillary non-perfusion and neovascularization. In addition to the existing system, a new staging system has been proposed by Saxena et al . Immunological, molecular biological and biochemical studies have indicated the role of human leucocyte antigen, retinal S antigen autoimmunity, Mycobacterium tuberculosis genome, free radical damage and possibly hyperhomocysteinemia in its etiopathogenesis, which appears multifactorial. Oxidant stress has been shown by increase in the levels of thiobarbituric acid reactive substances (lipid oxidation in the vitreous, erythrocytes, platelets, and monocytes. A decrease in vitamins E and C both in active and healed vasculitis, superoxide dismutase, glutathione, and glutathione peroxidase showed a weakened antioxidant defence. Epiretinal membrane from patients of ED who underwent surgery showed, by immunolocalization, presence of carboxy methyl lysine, an advanced glycation end product formed by glycoxidation and is involved in angiogenesis. OH· free radical accumulation in monocytes has been directly shown by electron spin resonance spectrometry. Free radical damage to DNA and of protein was shown by the accumulation of 8 hydroxy 2 deoxyguanosine (in leucocytes and nitrotyrosine (in monocytes, respectively. Nitrosative stress was shown by increased expression of inducible nitric oxide synthase in monocytes in which levels of iron and copper were increased while those of zinc decreased. A novel 88 kDa protein was found in serum and vitreous in inflammatory condition and had antioxidant function. Platelet fluidity was also affected. Oral, methotrexate in low dosage (12.5 mg/week for 12 weeks as well as oral vitamin E (400 IU and C (500 mg daily for 8 weeks are reported to have beneficial effects.

  12. Effectiveness evaluation of flood defence structures in different geomorphological contexts

    Science.gov (United States)

    Morelli, Stefano; Pazzi, Veronica; Fanti, Riccardo

    2017-04-01

    The flood risk in different geomorphological contexts of two less developed countries are investigated in order to evaluate the efficacy of the existing flood defence structures. In particular, a recent floodplain crossed by a wide meandering river and a narrow mountain valley flowed by creek with a torrential regime have been chosen for such analysis in North Albania and central Mexico, respectively. Both areas have been affected by disastrous floods in past years with considerable damages to properties and people. Some safety countermeasures have been performed over time, even if in a non-systematic way. For this reason, the current inclination to flood risk was assessed by means of a freeware software designed to perform one-dimensional (1D) hydraulic modelling for a full network of natural and anthropic channels (HEC-RAS software by Hydrologic Engineering Center River Analysis System). This new analyses take into account: i) the natural morphological variability along the river path, ii) the anthropic interventions on the fluvial dynamics, iii) the landscape appearance after the soil exploitation in the past years, and iv) all the changes induced by an exceeded informal urbanization. The reconstruction of the river and bordering areas geometric data was carried out according to the physical characteristics of the local environment: a bathymetric survey and near-river DGPS acquisitions for the open spaces of the Albanian floodplain, and traditional topographic methods for the highly vegetated Mexican valley. In both cases, the results show that the existing works are, on their own, poorly efficient in containing the predictable floods. Albanians levees seem underdimensioned, while the channelling works are too narrow to contain large amounts of water and solid transport as typical of the Mexican study area. Evidently, a new territorial planning is required in these areas, and some projects are now in place. However, it would be desirable that local authorities

  13. A Defence of Constructionism: Philosophy as Conceptual Engineering

    Directory of Open Access Journals (Sweden)

    Luciano Floridi

    2017-08-01

    Full Text Available The article offers a broad account and a defence of constructionism, both as a metaphilosophical approach and as a philosophical methodology, with some references to the philosophical tradition that has inspired it, the so-called «maker’s knowledge» tradition. The main thesis defended is that Plato’s «user’s knowledge tradition» should be complemented, if not replaced, by a constructionist approach to philosophical problems in general and to knowledge in particular. To put it simply, an epistemic agent knows something when that agent is able to build (reproduce, simulate, model, construct etc. that something and plug the obtained information in the correct network of relations that account for it. Or in even more intuitive terms, an agent qualifies as an epistemic agent not when she is a passive user of some information, but when she is a critical producer of it. Her epistemic expertise increases in relation to the scope and depth of the questions that is able to ask and answer on a particular topic. The maker’s knowledge is knowledge of the ontology of the semantic artefact and this is a fundamental epistemological lesson we can learn from poietic disciplines such as computer science and economics. So constructionism shifts the focus away from the mimetic, passive and declarative knowledge that something is the case, in order to concentrate more on the poietic, interactive and practical knowledge of something being the case, that is, of semantic artefacts. Once applied to the interpretation of philosophy itself, constructionism suggests adding conceptual engineering to conceptual analysis as a fundamental method.

  14. Coagulation factor XI improves host defence during murine pneumonia-derived sepsis independent of factor XII activation

    NARCIS (Netherlands)

    Stroo, Ingrid; Zeerleder, Sacha; Ding, Chao; Luken, Brenda M.; Roelofs, Joris J. T. H.; de Boer, Onno J.; Meijers, Joost C. M.; Castellino, Francis J.; van 't Veer, Cornelis; van der Poll, Tom

    2017-01-01

    Bacterial pneumonia, the most common cause of sepsis, is associated with activation of coagulation. Factor XI (FXI), the key component of the intrinsic pathway, can be activated via factor XII (FXII), part of the contact system, or via thrombin. To determine whether intrinsic coagulation is involved

  15. Characterisation of the legume SERK-NIK gene superfamily including splice variants: Implications for development and defence

    Directory of Open Access Journals (Sweden)

    Rose Ray J

    2011-03-01

    Full Text Available Abstract Background SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK genes are part of the regulation of diverse signalling events in plants. Current evidence shows SERK proteins function both in developmental and defence signalling pathways, which occur in response to both peptide and steroid ligands. SERKs are generally present as small gene families in plants, with five SERK genes in Arabidopsis. Knowledge gained primarily through work on Arabidopsis SERKs indicates that these proteins probably interact with a wide range of other receptor kinases and form a fundamental part of many essential signalling pathways. The SERK1 gene of the model legume, Medicago truncatula functions in somatic and zygotic embryogenesis, and during many phases of plant development, including nodule and lateral root formation. However, other SERK genes in M. truncatula and other legumes are largely unidentified and their functions unknown. Results To aid the understanding of signalling pathways in M. truncatula, we have identified and annotated the SERK genes in this species. Using degenerate PCR and database mining, eight more SERK-like genes have been identified and these have been shown to be expressed. The amplification and sequencing of several different PCR products from one of these genes is consistent with the presence of splice variants. Four of the eight additional genes identified are upregulated in cultured leaf tissue grown on embryogenic medium. The sequence information obtained from M. truncatula was used to identify SERK family genes in the recently sequenced soybean (Glycine max genome. Conclusions A total of nine SERK or SERK-like genes have been identified in M. truncatula and potentially 17 in soybean. Five M. truncatula SERK genes arose from duplication events not evident in soybean and Lotus. The presence of splice variants has not been previously reported in a SERK gene. Upregulation of four newly identified SERK genes (in addition to the

  16. Nuclear Belief Systems and Individual Policy-Makers: Duncan Sandys, Unmanned Weaponry, and the Impossibility of Defence

    OpenAIRE

    Betts, Lewis

    2014-01-01

    This thesis attempts to explore the influence that Duncan Sandys' experiences of the Second World War had on his policy preferences, and policy-making, in relation to British defence policy during his years in government. This is a significant period in British nuclear policy which began with thermonuclear weaponry being placed ostentatiously at the centre of British defence planning in the 1957 Defence White Paper, and ended with the British acquiring the latest American nuclear weapon techn...

  17. Wound-induced proteinase inhibitor in Salix viminalis and its association with defence against insects

    Energy Technology Data Exchange (ETDEWEB)

    Saarikoski, P. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Genetics

    1997-09-01

    For successful traditional breeding, the plant material has to be screened for genetic variation for the desired traits. By screening Salix clones for wound-induced proteinase inhibitor (PI) activity and ethylene evolution, it was possible to identify variation for both characters among the Salix clones tested. However, no correlation was observed with insect and pathogen resistance. Since there was no simple relationship between wound-induced ethylene production, accumulation of PI and pest resistance, a more systematic investigation of Salix PIs was begun. A gene (swin1.1) encoding a 21 kDa trypsin inhibitor with characteristics of Kunitz-type of PI was sequenced. The trypsin inhibitor encoded by the isolated swin1.1 gene was shown to be functional in vitro and exhibit specificity for trypsin. It is therefore likely that this PI is involved in the plant defence in Salix, since many insects have trypsin as their major digestive protease. In further support of this view, in bio-tests with poplar the mortality of the first instar larvae (Lymantria dispar) was significantly increased, both after application of the trypsin inhibitor encoded by swin1.1 directly on poplar leaves and after feeding the larvae with transgenic poplar over-expressing the swin1.1 gene. In Salix, the swin1.1 gene was shown to be induced by mechanical wounding, insect feeding and by treatment with the signalling substances salicylic and jasmonic acid. The locally wound-induced response (mechanical and insect) was greater than the systemic response. Other swin1 gene family members were also differentially expressed after the inductive treatment. 187 refs., 3 figs., 2 tabs.

  18. Hexanoic acid protects tomato plants against Botrytis cinerea by priming defence responses and reducing oxidative stress.

    Science.gov (United States)

    Finiti, Ivan; de la O Leyva, María; Vicedo, Begonya; Gómez-Pastor, Rocío; López-Cruz, Jaime; García-Agustín, Pilar; Real, Maria Dolores; González-Bosch, Carmen

    2014-08-01

    Treatment with the resistance priming inducer hexanoic acid (Hx) protects tomato plants from Botrytis cinerea by activating defence responses. To investigate the molecular mechanisms underlying hexanoic acid-induced resistance (Hx-IR), we compared the expression profiles of three different conditions: Botrytis-infected plants (Inf), Hx-treated plants (Hx) and Hx-treated + infected plants (Hx+Inf). The microarray analysis at 24 h post-inoculation showed that Hx and Hx+Inf plants exhibited the differential expression and priming of many Botrytis-induced genes. Interestingly, we found that the activation by Hx of other genes was not altered by the fungus at this time point. These genes may be considered to be specific targets of the Hx priming effect and may help to elucidate its mechanisms of action. It is noteworthy that, in Hx and Hx+Inf plants, there was up-regulation of proteinase inhibitor genes, DNA-binding factors, enzymes involved in plant hormone signalling and synthesis, and, remarkably, the genes involved in oxidative stress. Given the relevance of the oxidative burst occurring in plant-pathogen interactions, the effect of Hx on this process was studied in depth. We showed by specific staining that reactive oxygen species (ROS) accumulation in Hx+Inf plants was reduced and more restricted around infection sites. In addition, these plants showed higher ratios of reduced to oxidized glutathione and ascorbate, and normal levels of antioxidant activities. The results obtained indicate that Hx protects tomato plants from B. cinerea by regulating and priming Botrytis-specific and non-specific genes, preventing the harmful effects of oxidative stress produced by infection. © 2013 BSPP AND JOHN WILEY & SONS LTD.

  19. Impact of the age of Biomphalaria alexandrina snails on Schistosoma mansoni transmission: modulation of the genetic outcome and the internal defence system of the snail

    Directory of Open Access Journals (Sweden)

    Iman Fathy Abou-El-Naga

    2015-08-01

    Full Text Available Of the approximately 34 identified Biomphalariaspecies,Biomphalaria alexandrinarepresents the intermediate host of Schistosoma mansoniin Egypt. Using parasitological and SOD1 enzyme assay, this study aimed to elucidate the impact of the age of B. alexandrinasnails on their genetic variability and internal defence against S. mansoniinfection. Susceptible and resistant snails were reared individually for self-reproduction; four subgroups of their progeny were used in experiment. The young susceptible subgroup showed the highest infection rate, the shortest pre-patent period, the highest total cercarial production, the highest mortality rate and the lowest SOD1 activity. Among the young and adult susceptible subgroups, 8% and 26% were found to be resistant, indicating the inheritance of resistance alleles from parents. The adult resistant subgroup, however, contained only resistant snails and showed the highest enzyme activity. The complex interaction between snail age, genetic background and internal defence resulted in great variability in compatibility patterns, with the highest significant difference between young susceptible and adult resistant snails. The results demonstrate that resistance alleles function to a greater degree in adults, with higher SOD1 activity and provide potential implications for Biomphalariacontrol. The identification of the most susceptible snail age enables determination of the best timing for applying molluscicides. Moreover, adult resistant snails could be beneficial in biological snail control.

  20. Manipulation of host membranes by bacterial effectors.

    Science.gov (United States)

    Ham, Hyeilin; Sreelatha, Anju; Orth, Kim

    2011-07-18

    Bacterial pathogens interact with host membranes to trigger a wide range of cellular processes during the course of infection. These processes include alterations to the dynamics between the plasma membrane and the actin cytoskeleton, and subversion of the membrane-associated pathways involved in vesicle trafficking. Such changes facilitate the entry and replication of the pathogen, and prevent its phagocytosis and degradation. In this Review, we describe the manipulation of host membranes by numerous bacterial effectors that target phosphoinositide metabolism, GTPase signalling and autophagy.

  1. Crowd-out of defence and health spending: is Israel different from other industrialised nations?

    Science.gov (United States)

    Reeves, Aaron; Stuckler, David

    2013-04-22

    Does high defence spending limit the growth of public health investment? Using comparative data from 31 OECD countries between 1980 and 2010, we find little evidence that defence crowds out public health spending. Whether measured in terms of long-term levels or short-term changes, per capita defence and health spending positively and significantly correlate. To investigate the possibility that countries with high security needs such as Israel exhibit differing patterns, we also compare crowd-out among countries experiencing violent conflicts as well as current high military-spending countries. We observed a greater positive correlation between changes in health and defence spending among conflict-countries (r = 0.65, p military spending countries, Israel's politicians reduced defence spending while increasing health expenditure during its recent recession. These analyses reveal that while Israel's politicians have chronically underinvested in public health, there are modest steps being taken to rectify the country's unique and avoidable crowding out of public health from its high military spending.

  2. Induced defences alter the strength and direction of natural selection on reproductive traits in common milkweed.

    Science.gov (United States)

    Thompson, K A; Cory, K A; Johnson, M T J

    2017-06-01

    Evolutionary biologists have long sought to understand the ecological processes that generate plant reproductive diversity. Recent evidence indicates that constitutive antiherbivore defences can alter natural selection on reproductive traits, but it is unclear whether induced defences will have the same effect and whether reduced foliar damage in defended plants is the cause of this pattern. In a factorial field experiment using common milkweed, Asclepias syriaca L., we induced plant defences using jasmonic acid (JA) and imposed foliar damage using scissors. We found that JA-induced plants experienced selection for more inflorescences that were smaller in size (fewer flowers), whereas control plants only experienced a trend towards selection for larger inflorescences (more flowers); all effects were independent of foliar damage. Our results demonstrate that induced defences can alter both the strength and direction of selection on reproductive traits, and suggest that antiherbivore defences may promote the evolution of plant reproductive diversity. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  3. Defence in Depth: Assessment of Comprehensiveness and Further Strengthening of the Concept

    Energy Technology Data Exchange (ETDEWEB)

    Misak, J., E-mail: Jozef.Misak@ujv.cz

    2014-10-15

    Full text: Defence in depth concept based on multiple levels of protection of the workers, public and the environment against radiation harm is and should remain an essential strategy for ensuring safety of nuclear power plants. This strategy should be comprehensively implemented through all stages of the plant lifetime, from the siting through construction and operation up to decommissioning. First part of the presentation will introduce a screening method developed by the IAEA as a tool facilitating the assessment of the comprehensiveness of defence in depth and will indicate further possibilities for using and updating the approach by taking into account recent lessons learned. Although it is clear that it is not possible for any industrial facility including nuclear power plants to fully eliminate the risk, further strengthening the defence in depth in particular at level 4 dealing with design extension conditions gives very high confidence in prevention and effective mitigation of severe accidents so that they are either practically eliminated or their consequences are limited in area and time. Second part of the presentation will discuss several issues associated with current efforts for strengthening the defence in depth, including the issues of practical elimination, independence and diversity of safety provisions at different levels of defence. (author)

  4. "New Sport" in the street: self-defence, security and space in belle epoque Paris.

    Science.gov (United States)

    Freundschuh, Aaron

    2006-01-01

    Near the turn of the twentieth century, traditional self-defence methods (for example, jiu-jitsu) were revamped into a more accessible and practical set of techniques and tactics for everyday use in urban public space. Framed as a "new sport" with broad public utility, early urban self-defence developed against the backdrop of heightening fears of violent crime and a burgeoning politics of security, as well as tensions provoked by the increasingly common appearance of unchaperoned, middle-class women in public. Self-defence masters pitched their innovations in an inclusive rhetoric, always with separate lessons for men and women and their respective spaces of risk. This article places modern self-defence practices in tension with historical transformations in the urban landscape, arguing that urban self-defence posited a certain subjective relation to the city that tapped simultaneously into the desire for empowerment, fantasies of criminal danger and a law-and-order tone that shaded into urban vigilantism.

  5. Bovine lactoferrin counteracts Toll-like receptor mediated activation signals in antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Patrizia Puddu

    Full Text Available Lactoferrin (LF, a key element in mammalian immune system, plays pivotal roles in host defence against infection and excessive inflammation. Its protective effects range from direct antimicrobial activities against a large panel of microbes, including bacteria, viruses, fungi and parasites, to antinflammatory and anticancer activities. In this study, we show that monocyte-derived dendritic cells (MD-DCs generated in the presence of bovine LF (bLF fail to undergo activation by up-modulating CD83, co-stimulatory and major histocompatibility complex molecules, and cytokine/chemokine secretion. Moreover, these cells are weak activators of T cell proliferation and retain antigen uptake activity. Consistent with an impaired maturation, bLF-MD-DC primed T lymphocytes exhibit a functional unresponsiveness characterized by reduced expression of CD154 and impaired expression of IFN-γ and IL-2. The observed imunosuppressive effects correlate with an increased expression of molecules with negative regulatory functions (i.e. immunoglobulin-like transcript 3 and programmed death ligand 1, indoleamine 2,3-dioxygenase, and suppressor of cytokine signaling-3. Interestingly, bLF-MD-DCs produce IL-6 and exhibit constitutive signal transducer and activator of transcription 3 activation. Conversely, bLF exposure of already differentiated MD-DCs completely fails to induce IL-6, and partially inhibits Toll-like receptor (TLR agonist-induced activation. Cell-specific differences in bLF internalization likely account for the distinct response elicited by bLF in monocytes versus immature DCs, providing a mechanistic base for its multiple effects. These results indicate that bLF exerts a potent anti-inflammatory activity by skewing monocyte differentiation into DCs with impaired capacity to undergo activation and to promote Th1 responses. Overall, these bLF-mediated effects may represent a strategy to block excessive DC activation upon TLR-induced inflammation, adding

  6. Male Rock Sparrow (Petronia petronia) Nest Defence Correlates with Female Ornament Size

    DEFF Research Database (Denmark)

    Griggio, Matteo; Matessi, Giuliano; Pilastro, Andrea

    2003-01-01

    We investigated the relationship between male nest defence and female breast patch size in an alpine population of rock sparrow (Petronia petronia) in northern Italy. We presented a mounted weasel (Mustela nivalis), a common nest predator, to 28 pairs breeding in nest boxes, with 12-13-d-old nest......We investigated the relationship between male nest defence and female breast patch size in an alpine population of rock sparrow (Petronia petronia) in northern Italy. We presented a mounted weasel (Mustela nivalis), a common nest predator, to 28 pairs breeding in nest boxes, with 12-13-d...... defence factor was significantly related only to female breast patch size. We argue that male rock sparrows apparently make parental investment decisions according to their mate's quality, and examine possible alternative hypotheses....

  7. BUILDING HIGH PERFORMANCE STRATEGY OF MILITARY EXPENDITURES: THE UTILITY FUNCTION IN THE MIDDLE OF DEFENCE BUDGETING

    Directory of Open Access Journals (Sweden)

    MARITANA SEDYSHEVA

    2011-01-01

    Full Text Available The present paper proposes tasks and methods which can be used in process of discovering the most expedient variants of the perspective and effective strategy development process of the defence spending in the Republic of Estonia.The author offers a part of strategy model named “Financial Perspective” as one of the improvement tools for the system of planning military expenditures and effective utilization of budgetary funds. The Balanced Scorecard application by using the “utility function” will allow the Estonian Defence Forces to overcome important barriers to strategy implementation by interrelation of military planning and budgeting processes. The Balanced Scorecard might be used as a very strong practical application. It will improve the calculations of long-term perspective plans and the development of the military budgetary policy by taking into account the features of national defence expenses.

  8. A defence in depth approach to safety assessment of existing nuclear power plant

    International Nuclear Information System (INIS)

    Butcher, P.; Holloway, N.J.

    1998-01-01

    The safety assessment of plant built to earlier standards requires an approach to prioritisation of upgrades that is based on sound engineering and safety principles. The principles of defence in depth are universally accepted and can form the basis of a prioritisation scheme for safety issues, and hence for the upgrading required to address them. The described scheme includes criteria for acceptability and issue prioritisation that are based on the number of lines of defence and the consequences of their failure. They are thus equivalent in concept to risk criteria, but are based on deterministic principles. This scheme has been applied successfully to the RBMK plant at Ignalina in Lithuania, for which a Western-style Safety Analysis Report has recently been produced and reviewed by joint Western and Eastern teams. An extended Safety Improvement Programme (SIP2) has been developed and agreed, based on prioritisations from the defence in depth assessment. (author)

  9. Families of returned defence force personnel: a changing landscape of challenges.

    Science.gov (United States)

    Berle, David; Steel, Zachary

    2015-08-01

    This paper aims to identify the key challenges experienced by the families of defence force personnel following deployment. We undertook a selective review of four post-deployment challenges to the families of defence force personnel: (1) changes to relationships; (2) changes to family member roles and responsibilities; (3) adjustment of children and parenting challenges; and (4) anger, family conflict and violence. Emerging issues in the area of post-deployment adjustment are also discussed. Empirical studies of post-deployment family adjustment are lacking. Each of the reviewed challenges can contribute to psychological difficulties and precipitate contact with mental health services. The challenges faced by defence force personnel when returning from deployment arise within a family context. Clinicians should thoroughly assess these factors in families following deployment, but also recognise family strengths and resilience to these challenges. © The Royal Australian and New Zealand College of Psychiatrists 2015.

  10. Can genetically based clines in plant defence explain greater herbivory at higher latitudes?

    Science.gov (United States)

    Anstett, Daniel N; Ahern, Jeffrey R; Glinos, Julia; Nawar, Nabanita; Salminen, Juha-Pekka; Johnson, Marc T J

    2015-12-01

    Greater plant defence is predicted to evolve at lower latitudes in response to increased herbivore pressure. However, recent studies question the generality of this pattern. In this study, we tested for genetically based latitudinal clines in resistance to herbivores and underlying defence traits of Oenothera biennis. We grew plants from 137 populations from across the entire native range of O. biennis. Populations from lower latitudes showed greater resistance to multiple specialist and generalist herbivores. These patterns were associated with an increase in total phenolics at lower latitudes. A significant proportion of the phenolics were driven by the concentrations of two major ellagitannins, which exhibited opposing latitudinal clines. Our analyses suggest that these findings are unlikely to be explained by local adaptation of herbivore populations or genetic variation in phenology. Rather greater herbivory at high latitudes can be explained by latitudinal clines in the evolution of plant defences. © 2015 John Wiley & Sons Ltd/CNRS.

  11. Molecular and Cellular Signaling

    CERN Document Server

    Beckerman, Martin

    2005-01-01

    A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

  12. The octadecanoid signalling pathway in plants mediates a response to ultraviolet radiation

    International Nuclear Information System (INIS)

    Conconi, A.; Smerdon, M.J.; Howe, G.A.; Ryan, C.A.

    1996-01-01

    Many plant genes that respond to environmental and developmental changes are regulated by jasmonic acid, which is derived from linolenic acid via the octadecanoid pathway. Linolenic acid is an important fatty-acid constituent of membranes in most plant species and its intracellular levels increase in response to certain signals. Here we report that irradiation of tomato leaves with ultraviolet light induces the expression of several plant defensive genes that are normally activated through the octadecanoid pathway after wounding. The response to ultraviolet light is blocked by an inhibitor of the octadecanoid pathway and it does not occur in a tomato mutant defective in this pathway. The ultraviolet irradiation maximally induces the defence genes at levels where cyclobutane pyrimidine dimer formation, an indicator of DNA damage, is less than 0.2 dimers per gene. Our evidence indicates that this plant defence response to certain wavelengths of ultraviolet radiation requires the activation of the octadecanoid defence signalling pathway. (author)

  13. Advancing Ruggedness of Nuclear Stations By Expanding Defence In Depth in Critical Areas

    International Nuclear Information System (INIS)

    Koshy, Thomas

    2015-01-01

    than increasing redundancy. There are several events both external and internal that could cause the failure of AC motor driven cooling systems. DC operated steam driven systems and diesel driven cooling systems have avoided several near core melt conditions. Containment Integrity is the last defence for protecting the people and the environment. Diversity in containment cooling is essential for keeping the pressure transients under control. Design provisions to connect potable cooling systems for heat removal and capability to flood the reactor cavity are essential. Recognizing the remote possibility of a severe accident, reliable containment venting (capability to operate with potable energy sources) and filtering could be explored as an option for ensuring an additional layer of protection. These four critical areas need to be viewed as layers in the defence of depth and consequently would require a design that fully removes and common cause failures. Ruggedness of these layers can be achieved only when the process signal sources, power supply and processing of the logic is executed independently. The electrical power system should be re-evaluated for bringing flexibility and adaptability for achieving greater level of safety. (author)

  14. DNA Damage Response and Immune Defence: Links and Mechanisms

    Directory of Open Access Journals (Sweden)

    Björn Schumacher

    2016-08-01

    Full Text Available DNA damage plays a causal role in numerous human pathologies including cancer, premature aging and chronic inflammatory conditions. In response to genotoxic insults, the DNA damage response (DDR orchestrates DNA damage checkpoint activation and facilitates the removal of DNA lesions. The DDR can also arouse the immune system by for example inducing the expression of antimicrobial peptides as well as ligands for receptors found on immune cells. The activation of immune signalling is triggered by different components of the DDR including DNA damage sensors, transducer kinases, and effectors. In this review, we describe recent advances on the understanding of the role of DDR in activating immune signalling. We highlight evidence gained into (i which molecular and cellular pathways of DDR activate immune signalling, (ii how DNA damage drives chronic inflammation, and (iii how chronic inflammation causes DNA damage and pathology in humans.

  15. Growth and Transformation of the South African defence industry: A state owned enterprise perspective

    CSIR Research Space (South Africa)

    Kleynhans, Theo

    2017-10-01

    Full Text Available % localisation • R&D and intellectual property development investment of R550m to R800m annually • 62% of our employees are black and about 30% of our local procurement spend were to black suppliers. • Knowledge-based value added advanced manufacturing A... Confidential Shift In Defence Investments & Smart Layer Add-ons Smart Layer / Add-ons Smart Defence Products + = Critical Focus Area Good Progress On-going SECURE Up- Smarting of Products • Shift in R&D Investments towards Disruptive Technologies...

  16. ENERGY IN THE CONTEXT OF THE PRESENT CHALLENGES TO THE EUROPEAN COMMON SECURITY AND DEFENCE POLICY

    Directory of Open Access Journals (Sweden)

    Gabriel ANDRUSEAC

    2014-10-01

    Full Text Available The Common Security and Defence Policy is a part of the European Union’s Common Foreign and Security Policy (CFSP and establishes the policy framework for the institutional structures and military instruments which have to deal with the security challenges in Europe’s geopolitical neighborhood. The article aims to identify and analyze the role of energy as one of the present challenges to the European Common Security and Defence Policy in the context of the recent events in the world economy.

  17. Design features to achieve defence-in-depth in small and medium sized reactors

    International Nuclear Information System (INIS)

    Kuznetsov, Vladimir

    2009-01-01

    Broader incorporation of inherent and passive safety design features has become a 'trademark' of many advanced reactor concepts, including several evolutionary designs and nearly all innovative small and medium sized design concepts. Ensuring adequate defence-in-depth is important for reactors of smaller output because many of them are being designed to allow more proximity to the user, specifically, when non-electrical energy products are targeted. Based on the activities recently performed by the International Atomic Energy Agency, the paper provides a summary description of the design features used to achieve defence in depth in the eleven representative concepts of small and medium sized reactors. (author)

  18. Interactions between nutritional approaches and defences against microbial diseases in small ruminants.

    Science.gov (United States)

    Caroprese, M; Giannenas, I; Fthenakis, G C

    2015-12-14

    Objective of this review is to discuss the role of small ruminant diet in the defence of these animals against microbial diseases, in relation to different experimental approaches and various stressors acting on animals. The effects of various diets in immune reactions and animal defences are presented. Also, effects in relation to the species studied and the type of stressors acting on animals are discussed. Evidence is provided about the significance of the diet in enhancing immune responses of small ruminants during specific conditions, e.g., around parturition, during lactation, as well as in growing lambs or kids. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Western European Nuclear Regulators’ Association (WENRA) Views on Defence-in-Depth for New Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Reiman, L.; Routamo, T. [STUK, Helsinki (Finland); Féron, F., E-mail: lasse.reiman@stuk.fi [ASN (France)

    2014-10-15

    WENRA published in 2010 a statement on safety objectives for new NPPs. Based on these objectives, WENRA decided to develop common positions, compiled in a booklet (available on www.wenra.org), on selected key safety issues for the design of new NPPs. One position presents WENRA’s Defence-in-Depth approach, describing WENRA’s expectation that multiple failure events and core melt accidents are considered in the original design of new nuclear power plants; another position presents expectations on the independence between different levels of Defence-in-Depth. (author)

  20. NRT/PTR transporters are essential for translocation of glucosinolate defence compounds to seeds

    DEFF Research Database (Denmark)

    Nour-Eldin, Hussam Hassan; Andersen, Tonni Grube; Burow, Meike

    2012-01-01

    glucosinolates in seeds and had more than tenfold over-accumulation in source tissues such as leaves and silique walls, indicating that both plasma membrane-localized transporters are essential for long-distance transport of glucosinolates. We propose that GTR1 and GTR2 control the loading of glucosinolates from......In plants, transport processes are important for the reallocation of defence compounds to protect tissues of high value, as demonstrated in the plant model Arabidopsis, in which the major defence compounds, glucosinolates, are translocated to seeds on maturation. The molecular basis for long...

  1. People's Front in Defence of Land, San Salvador Atenco: A testimony

    OpenAIRE

    Martha Pérez Pineda

    2011-01-01

    Martha Pérez Pineda gives her statement of the Peoples Front in Defence of the Land (The Peoples Front in Defence of Land (Frente del Pueblo en Defensa de la Tierra, FPDT) was formed in 2002, by residents of San Salvador Atenco, to resist their forced displacement by the federal government of Mexico and Estado de Mexico. The government planned to displace them to make way for the new Mexico City Airport. The people of San Salvador Atenco refused and battled, the most common fights were disput...

  2. Manipulation of Host Cholesterol by Obligate Intracellular Bacteria

    Directory of Open Access Journals (Sweden)

    Dhritiman Samanta

    2017-05-01

    Full Text Available Cholesterol is a multifunctional lipid that plays important metabolic and structural roles in the eukaryotic cell. Despite having diverse lifestyles, the obligate intracellular bacterial pathogens Chlamydia, Coxiella, Anaplasma, Ehrlichia, and Rickettsia all target cholesterol during host cell colonization as a potential source of membrane, as well as a means to manipulate host cell signaling and trafficking. To promote host cell entry, these pathogens utilize cholesterol-rich microdomains known as lipid rafts, which serve as organizational and functional platforms for host signaling pathways involved in phagocytosis. Once a pathogen gains entrance to the intracellular space, it can manipulate host cholesterol trafficking pathways to access nutrient-rich vesicles or acquire membrane components for the bacteria or bacteria-containing vacuole. To acquire cholesterol, these pathogens specifically target host cholesterol metabolism, uptake, efflux, and storage. In this review, we examine the strategies obligate intracellular bacterial pathogens employ to manipulate cholesterol during host cell colonization. Understanding how obligate intracellular pathogens target and use host cholesterol provides critical insight into the host-pathogen relationship.

  3. Effects of reflex-based self-defence training on police performance in simulated high-pressure arrest situations

    NARCIS (Netherlands)

    Renden, Peter G.; Savelsbergh, Geert J. P.; Oudejans, Raoul R. D.

    2017-01-01

    We investigated the effects of reflex-based self-defence training on police performance in simulated high-pressure arrest situations. Police officers received this training as well as a regular police arrest and self-defence skills training (control training) in a crossover design. Officers’

  4. An uncertain future: South Africa’s National Defence Force caught between foreign-policy ambitions and domestic development

    DEFF Research Database (Denmark)

    Mandrup, Thomas

    2017-01-01

    In June 2015, the South African Parliament passed the long-awaited defence review (DR2015). The aim of the review was to stop the decline of the South African National Defence Force (SANDF) and to create an economical and sustainable force structure capable of continuing to fulfil its constitutio...

  5. The association between self-image and defence mechanisms in a group of adolescent patients receiving psychiatric treatment.

    Science.gov (United States)

    Treger, Bartosz; Matusiak, Feliks; Pilecki, Maciej; Rogoż, Monika

    2015-01-01

    The aim of the study was to explore the relationship between various areas of self-image and defence mechanisms in adolescents. The study included a division into groups according to whether or not they were receiving psychiatric treatment. Data were obtained from two groups: a clinical group (30 persons), consisting of adolescent patients of the Adolescent Inpatient Ward of the Child and Adolescent Psychiatry Clinic and a control group (40 persons), adolescents attending upper secondary school. The Defence Style Questionnaire DSQ-40 and the Offer Self Image Questionnaire were used in the study. Results showed no differences, in the maturity levels of the defence mechanisms, between the two groups. Subjects from the clinical group had a significantly lower self-image of themselves than subjects from the control group.. In both groups, the use of mature defence mechanisms was accompanied by a positive self-image, while the use of less mature defence mechanisms was associated with a lower self-image. Comparison of the groups revealed different relationships between the aspects of self-image and used defence mechanisms, in particular the mechanism of projection. Number of significant correlations was greater in the clinical group. In the context of lower self-image, the study revealed the importance of such defence mechanisms as projection, acting out, somatization or schizoid fantasies. The obtained results seem to confirm a hypothesis that the assessment of the maturity of defence mechanisms in the period of adolescence is less clear and clinically useful.

  6. Host age modulates within-host parasite competition.

    Science.gov (United States)

    Izhar, Rony; Routtu, Jarkko; Ben-Ami, Frida

    2015-05-01

    In many host populations, one of the most striking differences among hosts is their age. While parasite prevalence differences in relation to host age are well known, little is known on how host age impacts ecological and evolutionary dynamics of diseases. Using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa, we examined how host age at exposure influences within-host parasite competition and virulence. We found that multiply-exposed hosts were more susceptible to infection and suffered higher mortality than singly-exposed hosts. Hosts oldest at exposure were least often infected and vice versa. Furthermore, we found that in young multiply-exposed hosts competition was weak, allowing coexistence and transmission of both parasite clones, whereas in older multiply-exposed hosts competitive exclusion was observed. Thus, age-dependent parasite exposure and host demography (age structure) could together play an important role in mediating parasite evolution. At the individual level, our results demonstrate a previously unnoticed interaction of the host's immune system with host age, suggesting that the specificity of immune function changes as hosts mature. Therefore, evolutionary models of parasite virulence might benefit from incorporating age-dependent epidemiological parameters. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  7. The Capsicum annuum class IV chitinase ChitIV interacts with receptor-like cytoplasmic protein kinase PIK1 to accelerate PIK1-triggered cell death and defence responses

    Science.gov (United States)

    Kim, Dae Sung; Kim, Nak Hyun; Hwang, Byung Kook

    2015-01-01

    The pepper receptor-like cytoplasmic protein kinase, CaPIK1, which mediates signalling of plant cell death and defence responses was previously identified. Here, the identification of a class IV chitinase, CaChitIV, from pepper plants (Capsicum annuum), which interacts with CaPIK1 and promotes CaPIK1-triggered cell death and defence responses, is reported. CaChitIV contains a signal peptide, chitin-binding domain, and glycol hydrolase domain. CaChitIV expression was up-regulated by Xanthomonas campestris pv. vesicatoria (Xcv) infection. Notably, avirulent Xcv infection rapidly induced CaChitIV expression in pepper leaves. Bimolecular fluorescence complementation and co-immunoprecipitation revealed that CaPIK1 interacts with CaChitIV in planta, and that the CaPIK1–CaChitIV complex is localized mainly in the cytoplasm and plasma membrane. CaChitIV is also localized in the endoplasmic reticulum. Transient co-expression of CaChitIV with CaPIK1 enhanced CaPIK1-triggered cell death response and reactive oxygen species (ROS) and nitric oxide (NO) bursts. Co-silencing of both CaChitIV and CaPIK1 in pepper plants conferred enhanced susceptibility to Xcv infection, which was accompanied by a reduced induction of cell death response, ROS and NO bursts, and defence response genes. Ectopic expression of CaPIK1 in Arabidopsis enhanced basal resistance to Hyaloperonospora arabidopsidis infection. Together, the results suggest that CaChitIV positively regulates CaPIK1-triggered cell death and defence responses through its interaction with CaPIK1. PMID:25694549

  8. Modelling joint air defence doctrinal issues with a LinkZA-based integration of two C2 simulators – a case study

    CSIR Research Space (South Africa)

    Nel, JJ

    2007-07-01

    Full Text Available This paper describes the integration between two command and control simulators in order to clarify doctrinal issues surrounding Joint Air Defence using as example the uncertainty of roles and responsibilities between the Air Defence Cell...

  9. Enforcing host cell polarity: an apicomplexan parasite strategy towards dissemination.

    Science.gov (United States)

    Baumgartner, Martin

    2011-08-01

    The propagation of apicomplexan parasites through transmitting vectors is dependent on effective dissemination of parasites inside the mammalian host. Intracellular Toxoplasma and Theileria parasites face the challenge that their spread inside the host depends in part on the motile capacities of their host cells. In response, these parasites influence the efficiency of dissemination by altering adhesive and/or motile properties of their host cells. Theileria parasites do so by targeting signalling pathways that control host cell actin dynamics. The resulting enforced polar host cell morphology facilitates motility and invasiveness, by establishing focal adhesion and invasion structures at the leading edge of the infected cell. This parasite strategy highlights mechanisms of motility regulation that are also likely relevant for immune or cancer cell motility. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Transcriptional profile and differential fitness in a specialist milkweed insect across host plants varying in toxicity.

    Science.gov (United States)

    Birnbaum, Stephanie S L; Rinker, David C; Gerardo, Nicole M; Abbot, Patrick

    2017-12-01

    Interactions between plants and herbivorous insects have been models for theories of specialization and co-evolution for over a century. Phytochemicals govern many aspects of these interactions and have fostered the evolution of adaptations by insects to tolerate or even specialize on plant defensive chemistry. While genomic approaches are providing new insights into the genes and mechanisms insect specialists employ to tolerate plant secondary metabolites, open questions remain about the evolution and conservation of insect counterdefences, how insects respond to the diversity defences mounted by their host plants, and the costs and benefits of resistance and tolerance to plant defences in natural ecological communities. Using a milkweed-specialist aphid (Aphis nerii) model, we test the effects of host plant species with increased toxicity, likely driven primarily by increased secondary metabolites, on aphid life history traits and whole-body gene expression. We show that more toxic plant species have a negative effect on aphid development and lifetime fecundity. When feeding on more toxic host plants with higher levels of secondary metabolites, aphids regulate a narrow, targeted set of genes, including those involved in canonical detoxification processes (e.g., cytochrome P450s, hydrolases, UDP-glucuronosyltransferases and ABC transporters). These results indicate that A. nerii marshal a variety of metabolic detoxification mechanisms to circumvent milkweed toxicity and facilitate host plant specialization, yet, despite these detoxification mechanisms, aphids experience reduced fitness when feeding on more toxic host plants. Disentangling how specialist insects respond to challenging host plants is a pivotal step in understanding the evolution of specialized diet breadths. © 2017 John Wiley & Sons Ltd.

  11. Creatine-induced activation of antioxidative defence in myotube cultures revealed by explorative NMR-based metabonomics and proteomics

    Directory of Open Access Journals (Sweden)

    Nielsen Niels

    2010-02-01

    Full Text Available Abstract Background Creatine is a key intermediate in energy metabolism and supplementation of creatine has been used for increasing muscle mass, strength and endurance. Creatine supplementation has also been reported to trigger the skeletal muscle expression of insulin like growth factor I, to increase the fat-free mass and improve cognition in elderly, and more explorative approaches like transcriptomics has revealed additional information. The aim of the present study was to reveal additional insight into the biochemical effects of creatine supplementation at the protein and metabolite level by integrating the explorative techniques, proteomics and NMR metabonomics, in a systems biology approach. Methods Differentiated mouse myotube cultures (C2C12 were exposed to 5 mM creatine monohydrate (CMH for 24 hours. For proteomics studies, lysed myotubes were analyzed in single 2-DGE gels where the first dimension of protein separation was pI 5-8 and second dimension was a 12.5% Criterion gel. Differentially expressed protein spots of significance were excised from the gel, desalted and identified by peptide mass fingerprinting using MALDI-TOF MS. For NMR metabonomic studies, chloroform/methanol extractions of the myotubes were subjected to one-dimensional 1H NMR spectroscopy and the intracellular oxidative status of myotubes was assessed by intracellular DCFH2 oxidation after 24 h pre-incubation with CMH. Results The identified differentially expressed proteins included vimentin, malate dehydrogenase, peroxiredoxin, thioredoxin dependent peroxide reductase, and 75 kDa and 78 kDa glucose regulated protein precursors. After CMH exposure, up-regulated proteomic spots correlated positively with the NMR signals from creatine, while down-regulated proteomic spots were negatively correlated with these NMR signals. The identified differentially regulated proteins were related to energy metabolism, glucose regulated stress, cellular structure and the

  12. Beneficial and Harmful Interactions of Antibiotics with Microbial Pathogens and the Host Innate Immune System

    Directory of Open Access Journals (Sweden)

    Ronald Anderson

    2010-05-01

    Full Text Available In general antibiotics interact cooperatively with host defences, weakening and decreasing the virulence of microbial pathogens, thereby increasing vulnerability to phagocytosis and eradication by the intrinsic antimicrobial systems of the host. Antibiotics, however, also interact with host defences by several other mechanisms, some harmful, others beneficial. Harmful activities include exacerbation of potentially damaging inflammatory responses, a property of cell-wall targeted agents, which promotes the release of pro-inflammatory microbial cytotoxins and cell-wall components. On the other hand, inhibitors of bacterial protein synthesis, especially macrolides, possess beneficial anti-inflammatory/cytoprotective activities, which result from interference with the production of microbial virulence factors/cytotoxins. In addition to these pathogen-directed, anti-inflammatory activities, some classes of antimicrobial agent possess secondary anti-inflammatory properties, unrelated to their conventional antimicrobial activities, which target cells of the innate immune system, particularly neutrophils. This is a relatively uncommon, potentially beneficial property of antibiotics, which has been described for macrolides, imidazole anti-mycotics, fluoroquinolones, and tetracyclines. Although of largely unproven significance in the clinical setting, increasing awareness of the pro-inflammatory and anti-inflammatory properties of antibiotics may contribute to a more discerning and effective use of these agents.

  13. Novel host restriction factors implicated in HIV-1 replication.

    Science.gov (United States)

    Ghimire, Dibya; Rai, Madhu; Gaur, Ritu

    2018-04-01

    Human immunodeficiency virus-1 (HIV-1) is known to interact with multiple host cellular proteins during its replication in the target cell. While many of these host cellular proteins facilitate viral replication, a number of them are reported to inhibit HIV-1 replication at various stages of its life cycle. These host cellular proteins, which are known as restriction factors, constitute an integral part of the host's first line of defence against the viral pathogen. Since the discovery of apolipoprotein B mRNA-editing enzyme 3G (APOBEC3G) as an HIV-1 restriction factor, several human proteins have been identified that exhibit anti-HIV-1 restriction. While each restriction factor employs a distinct mechanism of inhibition, the HIV-1 virus has equally evolved complex counter strategies to neutralize their inhibitory effect. APOBEC3G, tetherin, sterile alpha motif and histidine-aspartate domain 1 (SAMHD1), and trim-5α are some of the best known HIV-1 restriction factors that have been studied in great detail. Recently, six novel restriction factors were discovered that exhibit significant antiviral activity: endoplasmic reticulum α1,2-mannosidase I (ERManI), translocator protein (TSPO), guanylate-binding protein 5 (GBP5), serine incorporator (SERINC3/5) and zinc-finger antiviral protein (ZAP). The focus of this review is to discuss the antiviral mechanism of action of these six restriction factors and provide insights into the probable counter-evasion strategies employed by the HIV-1 virus. The recent discovery of new restriction factors substantiates the complex host-pathogen interactions occurring during HIV-1 pathogenesis and makes it imperative that further investigations are conducted to elucidate the molecular basis of HIV-1 replication.

  14. Host phylogeny determines viral persistence and replication in novel hosts.

    Directory of Open Access Journals (Sweden)

    Ben Longdon

    2011-09-01

    Full Text Available Pathogens switching to new hosts can result in the emergence of new infectious diseases, and determining which species are likely to be sources of such host shifts is essential to understanding disease threats to both humans and wildlife. However, the factors that determine whether a pathogen can infect a novel host are poorly understood. We have examined the ability of three host-specific RNA-viruses (Drosophila sigma viruses from the family Rhabdoviridae to persist and replicate in 51 different species of Drosophilidae. Using a novel analytical approach we found that the host phylogeny could explain most of the variation in viral replication and persistence between different host species. This effect is partly driven by viruses reaching a higher titre in those novel hosts most closely related to the original host. However, there is also a strong effect of host phylogeny that is independent of the distance from the original host, with viral titres being similar in groups of related hosts. Most of this effect could be explained by variation in general susceptibility to all three sigma viruses, as there is a strong phylogenetic correlation in the titres of the three viruses. These results suggest that the source of new emerging diseases may often be predictable from the host phylogeny, but that the effect may be more complex than simply causing most host shifts to occur between closely related hosts.

  15. Host Phylogeny Determines Viral Persistence and Replication in Novel Hosts

    Science.gov (United States)

    Longdon, Ben; Hadfield, Jarrod D.; Webster, Claire L.

    2011-01-01

    Pathogens switching to new hosts can result in the emergence of new infectious diseases, and determining which species are likely to be sources of such host shifts is essential to understanding disease threats to both humans and wildlife. However, the factors that determine whether a pathogen can infect a novel host are poorly understood. We have examined the ability of three host-specific RNA-viruses (Drosophila sigma viruses from the family Rhabdoviridae) to persist and replicate in 51 different species of Drosophilidae. Using a novel analytical approach we found that the host phylogeny could explain most of the variation in viral replication and persistence between different host species. This effect is partly driven by viruses reaching a higher titre in those novel hosts most closely related to the original host. However, there is also a strong effect of host phylogeny that is independent of the distance from the original host, with viral titres being similar in groups of related hosts. Most of this effect could be explained by variation in general susceptibility to all three sigma viruses, as there is a strong phylogenetic correlation in the titres of the three viruses. These results suggest that the source of new emerging diseases may often be predictable from the host phylogeny, but that the effect may be more complex than simply causing most host shifts to occur between closely related hosts. PMID:21966271

  16. union defence forces : statistics of the wounded and prisoners of war ...

    African Journals Online (AJOL)

    UNION DEFENCE FORCES : STATISTICS OF THE. WOUNDED AND PRISONERS OF WAR DURING. THE SECOND WORLD WAR 1939-1945. Compiled by Captain J.E. Loraine-Grews. In 1943, after active service as ROMS of Die Middellandse Regiment in the Western Desert during which he escaped capture at Tobruk ...

  17. Jamali lauds PAEC contribution to scientific development defence needs of country

    CERN Multimedia

    2003-01-01

    "The Prime Minister Mir Zafarullah Khan Jamali has appreciated role of Pakistan Atomic Energy Council (PAEC) for its contribution to the scientific development and defence needs of the country. He directed that all resources and energy be devoted to the development of human resource and infrastructure for socio-economic uplift of the nation" (1 page).

  18. Christina Isajiw. Negotiating Human Rights: In Defence of Dissidents during the Soviet Era. A Memoir.

    Directory of Open Access Journals (Sweden)

    Barbara Martin

    2015-09-01

    Full Text Available Christina Isajiw. Negotiating Human Rights: In Defence of Dissidents during the Soviet Era. A Memoir. Edmonton and Toronto: Canadian Institute of Ukrainian Studies Press, 2014. xxx, 407 pp. Foreword by Bohdan Nahaylo. Introduction. Illustrations. Appendices on separate CD-Rom. Index. Paper.

  19. On combining coastal defence and aquaculture: opportunities in the Southwest Delta of the Netherlands

    NARCIS (Netherlands)

    Sluis, van C.J.; Ysebaert, T.

    2012-01-01

    In reaction to an extreme flooding event in 1953 in the south-western part of the Netherlands, the Dutch shortened and strengthened their estuarine coastline with dams, dikes and land reclamation. In retrospect, the construction of these large scale artificial coastal defence structures and the

  20. Drought-induced trans-generational tradeoff between stress tolerance and defence: consequences for range limits?

    Science.gov (United States)

    Alsdurf, Jacob D; Ripley, Tayler J; Matzner, Steven L; Siemens, David H

    2013-01-01

    Areas just across species range boundaries are often stressful, but even with ample genetic variation within and among range-margin populations, adaptation towards stress tolerance across range boundaries often does not occur. Adaptive trans-generational plasticity should allow organisms to circumvent these problems for temporary range expansion; however, range boundaries often persist. To investigate this dilemma, we drought stressed a parent generation of Boechera stricta (A.Gray) A. Löve & D. Löve, a perennial wild relative of Arabidopsis, representing genetic variation within and among several low-elevation range margin populations. Boechera stricta is restricted to higher, moister elevations in temperate regions where generalist herbivores are often less common. Previous reports indicate a negative genetic correlation (genetic tradeoff) between chemical defence allocation and abiotic stress tolerance that may prevent the simultaneous evolution of defence and drought tolerance that would be needed for range expansion. In growth chamber experiments, the genetic tradeoff became undetectable among offspring sib-families whose parents had been drought treated, suggesting that the stress-induced trans-generational plasticity may circumvent the genetic tradeoff and thus enable range expansion. However, the trans-generational effects also included a conflict between plastic responses (environmental tradeoff); offspring whose parents were drought treated were more drought tolerant, but had lower levels of glucosinolate toxins that function in defence against generalist herbivores. We suggest that either the genetic or environmental tradeoff between defence allocation and stress tolerance has the potential to contribute to range limit development in upland mustards.

  1. Trade-off among different anti-herbivore defence strategies along an altitudinal gradient

    Czech Academy of Sciences Publication Activity Database

    Dostálek, T.; Rokaya, Maan Bahadur; Maršík, P.; Rezek, J.; Skuhrovec, J.; Pavela, R.; Münzbergová, Z.

    2016-01-01

    Roč. 8, Jul 11 (2016), č. článku plw026. ISSN 2041-2851 Institutional support: RVO:67179843 Keywords : Climate change * Lamiaceae * VOCs * defence strategies * elevation * greenhouse experiment * insect herbivory * plant–animal interactions Subject RIV: EH - Ecology, Behaviour Impact factor: 2.238, year: 2016

  2. The Australian Defence Force Mental Health Prevalence and Wellbeing Study: design and methods.

    NARCIS (Netherlands)

    Hooff, M.V.; McFarlane, A.C.; Davies, C.E.; Searle, A.K.; Fairweather-Schmidt, A.K.; Verhagen, A.F.; Benassi, H.; Hodson, S.E.

    2014-01-01

    BACKGROUND: The Australian Defence Force (ADF) Mental Health Prevalence and Wellbeing Study (MHPWS) is the first study of mental disorder prevalence in an entire military population. OBJECTIVE: The MHPWS aims to establish mental disorder prevalence, refine current ADF mental health screening

  3. The Party Politics of Legislative-Executive Relations in Security and Defence Policy

    NARCIS (Netherlands)

    Wagner, W.M.; Herranz-Surralles, A.; Kaarbo, J.; Ostermann, F.

    2017-01-01

    The move from territorial defence to ‘wars of choice’ has influenced the domestic politics of military interventions. This paper examines the extent to which both the substance and the procedure of military interventions are contested among political parties. Regarding the substance, our analysis of

  4. Defence responses of arabidopsis thaliana to infection by pseudomonas syringae are regulated by the circadian clock

    KAUST Repository

    Bhardwaj, Vaibhav; Meier, Stuart; Petersen, Lindsay N.; Ingle, Robert A.; Roden, Laura C.

    2011-01-01

    of Arabidopsis defence-related genes showed both diurnal- and circadian-regulation, including genes involved in the perception of the PAMP flagellin which exhibit a peak in expression in the morning. Accordingly, we observed that PAMP-triggered callose deposition

  5. Protect and Survive: "Whiteness" and the Middle-Class Family in Civil Defence Pedagogies

    Science.gov (United States)

    Preston, John

    2008-01-01

    "Civil defence pedagogies" normalise continuous emergency through educational channels such as school, community and adult education. Using critical whiteness studies, and critiques of white supremacy from critical race theory, as a conceptual base, the protection of whiteness, and particularly the white middle-class family, is considered to be…

  6. The defence architecture of the superficial cells of the oral mucosa

    NARCIS (Netherlands)

    Asikainen, P.; Ruotsalainen, T.J.; Mikkonen, J.J.W.; Koistinen, A.; ten Bruggenkate, C.M.; Kullaa, A.M.

    2012-01-01

    The oral epithelium together with the saliva and its components forms a complex structure which is the first line of defence in the oral cavity. The surface of superficial cells of the oral epithelium contains ridge-like folds, microplicae (MPL), which are typical of the surfaces of areas covered

  7. Application of Defence of Insanity in Nigerian Courts: The Missing Link

    African Journals Online (AJOL)

    Aim: This paper is aimed at appraising the import of forensic psychology to the legal trials of mentally ill people. Method: Nigeria laws are replete with Criminal Codes and Criminal Procedure Acts but there are numerous failed cases of insanity defences in Nigeria. The research technique of content analysis of insanity ...

  8. Parasitism by Cuscuta pentagona sequentially induces JA and SA defence pathways in tomato

    Science.gov (United States)

    Justin B. Runyon; Mark C. Mescher; Gary W. Felton; Consuelo M. De Moraes

    2010-01-01

    While plant responses to herbivores and pathogens are well characterized, responses to attack by other plants remain largely unexplored. We measured phytohormones and C18 fatty acids in tomato attacked by the parasitic plant Cuscuta pentagona, and used transgenic and mutant plants to explore the roles of the defence-related phytohormones salicylic...

  9. Anticipatory action in self-defence: essence and limits under international law

    NARCIS (Netherlands)

    Tibori Szabó, K.

    2011-01-01

    The legality of preemptive strikes is one of the most controversial questions of contemporary international law. At the core of this controversy stands the temporal dimension of self-defence: when and for how long can a state defend itself against an armed attack? Can it resort to armed force before

  10. Ebola expert says building up health systems is best defence | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2018-05-22

    May 22, 2018 ... Ebola expert says building up health systems is best defence ... community of public health experts to control viral epidemics in several countries. ... says the problem of infectious diseases has grown in the past 30 years, but ...

  11. An Analysis of SE and MBSE Concepts to Support Defence Capability Acquisition

    Science.gov (United States)

    2014-09-01

    Architecture Review Meeting ATM Automatic Teller Machine AUSDAF Australian Defence Architecture Framework (also known as DAF) BOK Body of Knowledge BPMN ...behaviour trees, • business process modelling notation ( BPMN ™), • flowcharts, • IDEFx™ family of diagrams, and • Architecture Description...model diagraming of the ilk of BPMN , UML and SysML33 is heavily rules- 32 Architecture

  12. Fitness consequences of indirect plant defence in the annual weed, Sinapis arvensis

    NARCIS (Netherlands)

    Gols, R.; Wagenaar, R.; Poelman, E.H.; Kruidhof, H.M.; van Loon, J.J.A.; Harvey, J.A.

    2015-01-01

    Plant traits that enhance the attraction of the natural enemies of their herbivores have been postulated to function as an 'indirect defence'. An important underlying assumption is that this enhanced attraction results in increased plant fitness due to reduced herbivory. This assumption has been

  13. The state and the defence committees in the Ghanaian revolution, 1981-1984

    NARCIS (Netherlands)

    Konings, P.J.J.; Hesseling, G.S.C.M.; Binsbergen, van W.M.J.; Reyntjens, F.

    1986-01-01

    In an attempt to overcome some of the shortcomings of the theory of the postcolonial state, this study analyses the relationship between the 'revolutionary' leadership in Ghana and the 'revolutionary' mass organizations established by the new regime, the Defence Committees. The contradictions

  14. Did fleshy fruit pulp evolve as a defence against seed loss rather ...

    Indian Academy of Sciences (India)

    dispersers. Most seed dispersal studies are ecological and examine the role of fruit pulp in promoting seed dispersal. ... Introduction. Endozoochory, the interaction between fleshy-fruited plants ... adaptations for seed defence may have led to the evolution ..... Eriksson O and Bremer B 1992 Pollination systems, dispersal.

  15. Trade-off among different anti-herbivore defence strategies along an altitudinal gradient

    Czech Academy of Sciences Publication Activity Database

    Dostálek, Tomáš; Rokaya, Maan Bahadur; Maršík, Petr; Rezek, Jan; Skuhrovec, J.; Pavela, R.; Münzbergová, Zuzana

    2016-01-01

    Roč. 8, Jul 11 (2016), č. článku plw026. ISSN 2041-2851 R&D Projects: GA ČR GP13-10850P Institutional support: RVO:67985939 ; RVO:61389030 Keywords : climate change * plant–animal interactions * defence strategies Subject RIV: EF - Botanics; EF - Botanics (UEB-Q) Impact factor: 2.238, year: 2016

  16. Interactive effects of above- and belowground herbivory and plant competition on plant growth and defence

    NARCIS (Netherlands)

    Jing, Y.; Raaijmakers, C.; Kostenko, O.; Kos, M.; Mulder, P.P.J.; Bezemer, T.M.

    2015-01-01

    Competition and herbivory are two major factors that can influence plant growth and plant defence. Although these two factors are often studied separately, they do not operate independently. We examined how aboveground herbivory by beet armyworm larvae (Spodoptera exigua) and belowground herbivory

  17. Comparing Presidents and Their Actions "To Provide for the Common Defence"

    Science.gov (United States)

    O'Brien, Joe; Hood, Jack

    2009-01-01

    As noted by Onosko, the nature of the social studies curriculum typically results in superficial and disconnected coverage of the content with few opportunities for in-depth investigation and discussion of that content. Engaging students in a comparative study of U.S. Presidents and actions they took "to provide for the common defence"…

  18. Implementation of defence in depth for next generation light water reactors

    International Nuclear Information System (INIS)

    1997-12-01

    The publication of this IAEA technical document represents the conclusion of a task, initiated in 1995, devoted to defence in depth in future reactors. It focuses mainly on the next generation of LWRs, although many general considerations may also apply to other types of reactors

  19. Lipids in host-pathogen interactions: pathogens exploit the complexity of the host cell lipidome.

    Science.gov (United States)

    van der Meer-Janssen, Ynske P M; van Galen, Josse; Batenburg, Joseph J; Helms, J Bernd

    2010-01-01

    Lipids were long believed to have a structural role in biomembranes and a role in energy storage utilizing cellular lipid droplets and plasma lipoproteins. Research over the last decades has identified an additional role of lipids in cellular signaling, membrane microdomain organization and dynamics, and membrane trafficking. These properties make lipids an attractive target for pathogens to modulate host cell processes in order to allow their survival and replication. In this review we will summarize the often ingenious strategies of pathogens to modify the lipid homeostasis of host cells, allowing them to divert cellular processes. To this end pathogens take full advantage of the complexity of the lipidome. The examples are categorized in generalized and emerging principles describing the involvement of lipids in host-pathogen interactions. Several pathogens are described that simultaneously induce multiple changes in the host cell signaling and trafficking mechanisms. Elucidation of these pathogen-induced changes may have important implications for drug development. The emergence of high-throughput lipidomic techniques will allow the description of changes of the host cell lipidome at the level of individual molecular lipid species and the identification of lipid biomarkers.

  20. Perception of low red:far-red ratio compromises both salicylic acid- and jasmonic acid-dependent pathogen defences in Arabidopsis.

    Science.gov (United States)

    de Wit, Mieke; Spoel, Steven H; Sanchez-Perez, Gabino F; Gommers, Charlotte M M; Pieterse, Corné M J; Voesenek, Laurentius A C J; Pierik, Ronald

    2013-07-01

    In dense stands of plants, such as agricultural monocultures, plants are exposed simultaneously to competition for light and other stresses such as pathogen infection. Here, we show that both salicylic acid (SA)-dependent and jasmonic acid (JA)-dependent disease resistance is inhibited by a simultaneously reduced red:far-red light ratio (R:FR), the early warning signal for plant competition. Conversely, SA- and JA-dependent induced defences did not affect shade-avoidance responses to low R:FR. Reduced pathogen resistance by low R:FR was accompanied by a strong reduction in the regulation of JA- and SA-responsive genes. The severe inhibition of SA-responsive transcription in low R:FR appeared to be brought about by the repression of SA-inducible kinases. Phosphorylation of the SA-responsive transcription co-activator NPR1, which is required for full induction of SA-responsive transcription, was indeed reduced and may thus play a role in the suppression of SA-mediated defences by low R:FR-mediated phytochrome inactivation. Our results indicate that foraging for light through the shade-avoidance response is prioritised over plant immune responses when plants are simultaneously challenged with competition and pathogen attack. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.