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Defensive Responses (defensive + response)
Selected AbstractsFeeding by Hessian fly [Mayetiola destructor (Say)] larvae does not induce plant indirect defencesECOLOGICAL ENTOMOLOGY, Issue 2 2007JOHN F. TOOKER Abstract 1.,Recent research has addressed the function of herbivore-induced plant volatiles in attracting natural enemies of feeding herbivores. While many types of insect herbivory appear to elicit volatile responses, those triggered by gall insects have received little attention. Previous work indicates that at least one gall insect species induces changes in host-plant volatiles, but no other studies appear to have addressed whether gall insects trigger plant indirect defences. 2.,The volatile responses of wheat to feeding by larvae of the Hessian fly Mayetiola destructor (Say) (Diptera: Cecidomyiidae) were studied to further explore indirect responses of plants to feeding by gall insects. This specialist gall midge species did not elicit a detectable volatile response from wheat plants, whereas a generalist caterpillar triggered volatile release. Moreover, Hessian fly feeding altered volatile responses to subsequent caterpillar herbivory. 3.,These results suggest that Hessian fly larvae exert a degree of control over the defensive responses of their host plants and offer insight into plant-gall insect interactions. Also, the failure of Hessian fly larvae to elicit an indirect defensive response from their host plants may help explain why natural enemies, which often rely on induced volatile cues, fail to inflict significant mortality on M. destructor populations in the field. [source] ORIGINAL RESEARCH,PAIN: Vaginismus and Dyspareunia: Automatic vs.THE JOURNAL OF SEXUAL MEDICINE, Issue 6 2010Deliberate Disgust Responsivity ABSTRACT Introduction., The difficulty of penetration experienced in vaginismus and dyspareunia may at least partly be due to a disgust-induced defensive response. Aims., To examine if sex stimuli specifically elicit: (i) automatic disgust-related memory associations; (ii) physiological disgust responsivity; and/or (iii) deliberate expression of disgust/threat. Methods., Two single target Implicit Association Task (st-IAT) and electromyography (EMG) were conducted on three groups: vaginismus (N = 24), dyspareunia (N = 24), and control (N = 31) group. Main Outcome Measures., st-IAT, to index their initial disgust-related associations and facial EMG for the m. levator labii and m. corrugator supercilii regions. Results., Both clinical groups showed enhanced automatic sex-disgust associations. As a unique physiological expression of disgust, the levator activity was specifically enhanced for the vaginismus group, when exposed to a women-friendly SEX video clip. Also at the deliberate level, specifically the vaginismus group showed enhanced subjective disgust toward SEX pictures and the SEX clip, along with higher threat responses. Conclusions., Supporting the view that disgust is involved in vaginismus and dyspareunia, for both, clinical groups' sex stimuli automatically elicited associations with disgust. Particularly for the vaginismus group, these initial disgust associations persisted during subsequent validation processes and were also evident at the level of facial expression and self-report data. Findings are consistent with the notion that uncontrollable activated associations are involved in eliciting defensive reactions at the prospect of penetration seen in both conditions. Whereas deliberate attitudes, usually linked with the desire for having intercourse, possibly generate the distinction (e.g., severity) between these two conditions. Borg C, de Jong PJ, and Schultz WW. Vaginismus and dyspareunia: Automatic vs. deliberate disgust responsivity. J Sex Med 2010;7:2149,2157. [source] Expression, purification, crystallization and preliminary X-ray analysis of the N-terminal domain of GNBP3 from Drosophila melanogasterACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2009Yumiko Mishima Gram-negative bacteria-binding protein 3 (GNBP3) is a pattern-recognition receptor which contributes to the defensive response against fungal infection in Drosophila. The protein consists of an N-terminal domain, which is considered to recognize ,-glucans from the fungal cell wall, and a C-terminal domain, which is homologous to bacterial glucanases but devoid of activity. The N-terminal domain of GNBP3 (GNBP3-Nter) was successfully purified after expression in Drosophila S2 cells. Diffraction-quality crystals were produced by the hanging-drop vapour-diffusion method using PEG 2000 and PEG 8000 as precipitants. Preliminary X-ray diffraction analysis revealed that the GNBP3-Nter crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 134.79, b = 30.55, c = 51.73,Å, , = 107.4°, and diffracted to 1.7,Å using synchrotron radiation. The asymmetric unit is expected to contain two copies of GNBP3-Nter. Heavy-atom derivative data were collected and a samarium derivative showed one high-occupancy site per molecule. [source] Feeding by Hessian fly [Mayetiola destructor (Say)] larvae does not induce plant indirect defencesECOLOGICAL ENTOMOLOGY, Issue 2 2007JOHN F. TOOKER Abstract 1.,Recent research has addressed the function of herbivore-induced plant volatiles in attracting natural enemies of feeding herbivores. While many types of insect herbivory appear to elicit volatile responses, those triggered by gall insects have received little attention. Previous work indicates that at least one gall insect species induces changes in host-plant volatiles, but no other studies appear to have addressed whether gall insects trigger plant indirect defences. 2.,The volatile responses of wheat to feeding by larvae of the Hessian fly Mayetiola destructor (Say) (Diptera: Cecidomyiidae) were studied to further explore indirect responses of plants to feeding by gall insects. This specialist gall midge species did not elicit a detectable volatile response from wheat plants, whereas a generalist caterpillar triggered volatile release. Moreover, Hessian fly feeding altered volatile responses to subsequent caterpillar herbivory. 3.,These results suggest that Hessian fly larvae exert a degree of control over the defensive responses of their host plants and offer insight into plant-gall insect interactions. Also, the failure of Hessian fly larvae to elicit an indirect defensive response from their host plants may help explain why natural enemies, which often rely on induced volatile cues, fail to inflict significant mortality on M. destructor populations in the field. [source] Enemy Recognition of Reed Warblers (Acrocephalus scirpaceus): Threats and Reproductive Value Act Independently in Nest Defence ModulationETHOLOGY, Issue 6 2010Daniela Campobello Organisms should respond more aggressively towards species perceived as a danger to their offspring, but intensity of defence may be gauged by the value of current offspring weighed against the value of future reproductive opportunities. We tested whether defensive responses of nesting reed warblers (Acrocephalus scirpaceus) are the result of an interaction effect between the type of stimulus confronted and the value of the warbler's nesting attempt. We quantified the ability of reed warblers to discriminate among brood parasites, nestling predators and non-threatening species at different stages of the breeding cycle. We also determined whether variables that influence the value of offspring, such as time of season, size and age of clutch or brood, and time of day and number of visits to the nest, explain variation in the intensity of defence recorded during the egg and nestling stages. Responses to the three stimuli differed significantly, as reed warblers consistently directed their mobbing calls and attacks towards parasites, whereas they were less conspicuous when confronted with models of predators. Reed warblers modulated their responses towards each stimulus in accordance with the threat each posed at a specific nesting stage, whereas they were not affected by other variables relative to their reproductive potential. The churr call, however, was uttered independently of the stimulus, as it was triggered by the mere presence of nestlings in the nest. [source] Distinct contributions of the amygdala and hippocampus to fear expressionEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2009Yogita Chudasama Abstract The present study attempted to distinguish the independent contributions of the amygdala and hippocampus to fear expression. Rhesus monkeys (Macaca mulatta) with bilateral excitotoxic amygdala lesions (n = 4), bilateral excitotoxic hippocampal lesions (n = 8) and unoperated controls (n = 9) were allowed to reach over a neutral junk object or fear-provoking stimulus (i.e., a rubber snake or a jumping rubber spider) to retrieve a food reward. Monkeys were exposed to each stimulus for 30 s. On each trial we recorded the monkey's latency to retrieve the food reward and scored their whole-body reactions to the object. Confirming previous work we found that, relative to controls, both operated groups showed shorter food-retrieval latencies and exhibited fewer defensive and more approach behaviors when exposed to the fear-provoking stimuli. However, only monkeys with amygdala lesions showed an abnormal, excessive visual interest in the snake and spider. By contrast, monkeys with hippocampal lesions displayed behaviors that were unrelated to the presence of the fear stimuli, thereby indicating a lack of interest in, and emotional reactivity towards, the snake and spider. These data show that the hippocampus and amygdala contribute independently to the overall expression of defensive responses. [source] Transcriptional profiling of a mice plague model: insights into interaction between Yersinia pestis and its hostJOURNAL OF BASIC MICROBIOLOGY, Issue 1 2009Haihong Liu Abstract Despite the importance of pneumonic plague caused by Yersinia pestis, a few is known about the interaction between Y. pestis and its host at the molecular level during the pneumonic plague development. In this study, we employed an intranasally challenged plague model in mice for investigating the kinetics of the disease progression by transcriptional profiling of Y. pestis and mice using qRT-PCR and microarray, respectively. The increasing transcription of important virulence genes of Y. pestis and of mice genes involving in immune and inflammatory defensive responses, and responses to stimuli, presents an overview of interaction between Y. pestis and mice during development of pneumonic plague. The early and persisting up-regulation of caf 1, psa A and lcr V in vivo indicated their role in resisting the host innate immune responses. The up-regulation of fur, ybt A and hms H in vivo reflected the ability of Y. pestis for acquiring iron. The transcription regulators, including pho P, oxy R and omp R, were up-regulated during plague development, suggesting their roles in interaction between Y. pestis and mice. Many genes encoding cytokines, such as IL2, IL-1B, CXCL2, CXCL5, CCL20, CD14 and TNFRSF13B, were up-regulated during the infection, confirming the report that they are important mediators to activate host responses to invading pathogens. The up-regulation of some genes encoding important virulent factors of Y. pestis and expression alterations of some genes encoding cytokines in the host reflect the interaction between the pathogen and the host, which will help us better understand plague pathogenesis. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Blockade of NMDA receptors and nitric oxide synthesis in the dorsolateral periaqueductal gray attenuates behavioral and cellular responses of rats exposed to a live predatorJOURNAL OF NEUROSCIENCE RESEARCH, Issue 11 2009Daniele Cristina Aguiar Abstract Innate fear stimulus induces activation of neurons containing the neuronal nitric oxide synthase enzyme (nNOS) in defensive-related brain regions such as the dorsolateral periaqueductal gray (dlPAG). Intra-dlPAG administration of nitric oxide synthase (NOS) inhibitors and glutamate antagonists induce anxiolytic-like responses. We investigated the involvement of nitric oxide (NO) and glutamate neurotransmission in defensive reactions modulated by dlPAG. We tested if intra-dlPAG injections of the selective nNOS inhibitor, N-propyl- L -arginine (NP), or the glutamate antagonist, AP7 (2-amino-7-phosphonoheptanoic acid), would attenuate behavioral responses and cellular activation induced by predator exposure (cat). Fos-like immunoreactivity (FLI) was used as a marker of neuronal functional activation, whereas nNOS immunohistochemistry was used to identify NOS neurons. Cat exposure induced fear responses and an increase of FLI in the dlPAG and dorsal premammillary nucleus (PMd). NP and AP7 attenuated the cat-induced behavioral responses. Whereas NP tended to attenuate FLI in the dlPAG, AP7 induced a significant reduction in cellular activation of this region. The latter drug, however, increased FLI and double-labeled cells in the PMd. Cellular activation of this region was significantly correlated with time spent near the cat (r = 0.7597 and 0.6057 for FLI and double-labeled cells). These results suggest that glutamate/NO-mediated neurotransmission in the dlPAG plays an important role in responses elicit by predator exposure. Blocking these neurotransmitter systems in this brain area impairs defensive responses. The longer time spent near the predator that follows AP7 effect could lead to an increased cellular activation of the PMd, a more rostral brain area that has also been related to defensive responses. © 2009 Wiley-Liss, Inc. [source] An anxious profession in an age of fearJOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 4 2006R. LAKEMAN dipcpnsg bn ba hons pgdip (psychotherapy) fanzcmhn mhn (credentialed) This paper proposes that some practices and trends in mental health care may be considered as defensive responses to collective anxiety and fear. On a larger scale similar dynamics occur around fear of terrorism. Collectively and individually we are pulled by the defensive forces and dynamics associated with anxiety. This can in part explain the polarization that occurs around issues of definition and response to mental illness. Fear and anxiety push services towards simplistic viewpoints and futile practices. The capacity to view things from the perspective of others, embracing explanatory and therapeutic pluralism and adopting a humble attitude, may be helpful in enabling anxiety to be channelled productively. [source] Gall insects can avoid and alter indirect plant defensesNEW PHYTOLOGIST, Issue 3 2008John F. Tooker Summary ,,Parasitic species can dramatically alter host traits. Some of these parasite-induced changes can be considered adaptive manipulations that benefit the parasites. Gall-inducing insects are parasites well known for their ability to alter host-plant morphology and physiology, including the distribution of plant defensive compounds. Here it was investigated whether gall-inducing species alter indirect plant defenses, involving the release of volatile compounds that are attractive to foraging natural enemies. ,,Using field and factorial laboratory experiments, volatile production by goldenrod (Solidago altissima) plants was examined in response to attack by two gall-inducing species, the tephritid fly Eurosta solidaginis and the gelechiid moth Gnorimoschema gallaesolidaginis, as well as the meadow spittlebug, Philaenus spumarius, and the generalist caterpillar Heliothis virescens. ,,Heliothis virescens elicited strong indirect defensive responses from S. altissima, but the gall-inducing species and spittlebugs did not. More significantly, infestation by E. solidaginis appeared to suppress volatile responses to subsequent attack by the generalist caterpillar. ,,The extensive control that E. solidaginis apparently exerts over host-plant defense responses may reduce the predation risk for the gall inducer and the subsequent herbivore, and could influence community-level dynamics, including the distribution of herbivorous insect species associated with S. altissima parasitized by E. solidaginis. [source] Conversations with a Polish populist: Tracing hidden histories of globalization, class, and dispossession in postsocialism (and beyond)AMERICAN ETHNOLOGIST, Issue 2 2009DON KALB ABSTRACT Building on the work of Jonathan Friedman and of Andre Gingrich and Marcus Banks, I explain the rise of populist, neonationalist sensibilities in Poland as a set of defensive responses by working-class people to the silences imposed by liberal rule. I trace in detail a sequence of all-around dispossessions experienced by Polish working-class sodalities since 1989, when activists with substantial legitimacy among organized workers had claimed de facto and de jure control over assets crucial for working-class reproduction. "Democratization" and "markets" were shrewd legal ways by which the new liberal capitalist state reappropriated and recentralized those assets from local constituencies. Meanwhile, the reputation of workers, whose fights with the party-state had been essential for regaining national sovereignty and establishing parliamentary democracy, was systematically annihilated in the public sphere by discourses of "internal orientalism."[postsocialism, dispossession, class, neonationalism, populism, neoliberalism, globalization, privatization, Europe] [source] Consequences of sequential attack for resistance to herbivores when plants have specific induced responsesOIKOS, Issue 8 2007D. V. Viswanathan Plants in nature are attacked sequentially by herbivores, and theory predicts that herbivore-specific responses allow plants to tailor their defenses. We present a novel field test of this hypothesis, and find that specific responses of Solanum dulcamara lead to season-long consequences for two naturally colonizing herbivores, irrespective of the second herbivore to attack plants. This result indicates that responses induced by the initial herbivore made plants less responsive to subsequent attack. We show that initial herbivory by flea beetles and tortoise beetles induce distinct plant chemical responses. Initial herbivory by flea beetles lowered the occurrence of conspecifics and tortoise beetles relative to controls. Conversely, initial herbivory by tortoise beetles did not influence future herbivory. Remarkably, the experimentally imposed second herbivore to feed on plants did not modify consequences (induced resistance or lack thereof) of the first attacker. Induction of plant chemical responses was consistent with these ecological effects; i.e. the second herbivore did not modify the plant's initial induced response. Thus, canalization of the plant resistance phenotype may constrain defensive responses in a rapidly changing environment. [source] Spatial association of photosynthesis and chemical defense in Arabidopsis thaliana following herbivory by Trichoplusia niPHYSIOLOGIA PLANTARUM, Issue 2 2009Jennie Tang Because they share common precursors and require significant amounts of energy, photosynthesis and defense against herbivores and pathogens may be inversely related. This relationship was examined in Arabidopsis thaliana exposed to herbivory by Trichoplusia ni neonates. The spatial pattern of photosynthesis was compared statistically with that of induction of the defense-related cinnamate-4-hydroxylase (C4H) gene across individual leaves exposed to herbivory in transgenic plants harboring a C4H:GUS gene fusion. In portions of the leaf where C4H:GUS expression was upregulated, photosynthesis was depressed, while non-photochemical quenching was increased, suggesting a trade-off between these two processes. However, photosynthetic damage spread further into surrounding areas than the induction of C4H:GUS expression. Photosynthetic depression was observed up to 1 mm from the edges of holes, whereas C4H:GUS induction typically was limited to about 0.5 mm or less from edges. Other mechanisms may be responsible for the spread of photosynthetic damage beyond where C4H-related defense was induced. Alternatively, C4H induction may reflect a subset of defensive responses more limited in their spatial distribution than the downregulation of photosynthesis. The suppression of photosynthesis in remaining leaf tissue represents a ,hidden cost' of herbivore damage. [source] Interspecific variation in the defensive responses of ant mutualists to plant volatilesBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2008EMILIO M. BRUNA In ant,plant mutualist systems, ants patrol their host plants and search for herbivores. Such patrolling can be inefficient, however, because herbivore activity is spatio-temporally unpredictable. It has been proposed that rapid and efficient systems of communication between ants and plants, such as volatile compounds released following herbivory, both elicit defensive responses and direct workers to sites of herbivore activity. We performed bioassays in which we challenged colonies of two Amazonian plant-ants, Azteca sp. and Pheidole minutula, with extracts of leaf tissue from (1) their respective host-plant species (Tococa bullifera and Maieta guianensis, both Melastomataceae), (2) sympatric ant-plants from the Melastomataceae, and (3) two sympatric but non-myrmecophytic Melastomataceae. We found that ants of both species responded dramatically to host-plant extracts, and that these responses are greater than those to sympatric myrmecophytes. Azteca sp. also responded to non-myrmecophytes with an intensity similar to that of sympatric ant-plants. By contrast, the response of P. minutula to any non-myrmecophytic extracts was limited. These differences may be driven in part by interspecific differences in nesting behaviour; although P. minutula only nests in host plants, Azteca sp. will establish carton satellite nests on nearby plants. We hypothesize that Azteca sp. must therefore recognize and defend a wider array of species than P. minutula. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 94, 241,249. [source] | ||||||||||||||||||||||