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1
Burrells, C. "Studies on ovine pulmonary defence mechanisms." Thesis, Edinburgh Napier University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355318.
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Ravenscroft, Harriet. "Defence mechanisms of dental pulp stem cells." Thesis, Queen's University Belfast, 2018. https://pure.qub.ac.uk/portal/en/theses/defence-mechanisms-of-dental-pulp-stem-cells(0e1880c7-13b4-4072-86c6-4b52a05d5175).html.
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O'Donovan, Lisa Anne. "Mechanisms of defence against tannins by Streptococcus caprinus /." Title page, contents and abstract only, 1999. http://web4.library.adelaide.edu.au/theses/09NP/09anpo26.pdf.
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Stanley, P. "Host defence mechanisms of the upper respiratory tract." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47263.
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Crampton, Bridget Genevieve. "Elucidation of defence response mechanisms in pearl millet." Thesis, Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-10132008-143627.
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Joshi, Nimisha. "Bactericidal mechanisms of nanoparticles and microbial defence strategies." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/12223.
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Manufactured nanoparticles can be toxic to living organisms. This work aims to study the interaction of nanoparticles with bacteria as a model organism. The first objective was, to determine the mechanistic pathways of nanotoxicity with an emphasis on ions and oxidative stress as two key contributors and the second objective, was to investigate what mechanisms bacteria have developed as a strategy to protect themselves against nanotoxicity. The thesis further explores the role of environmental variables such as water chemistry, organic matter and other microorganisms, all of which can potentially change speciation of nanoparticles through their transformation into less toxic species. KEIO deletion mutants lacking genes encoding proteins which mediate resistance to oxidative stress and ionic toxicity were screened and found to be sensitive to both ionic silver and silver nanoparticles. A bioreporter to detect silver ions was constructed. This was found not to be induced by silver nanoparticles, yet showed reduced viability; this observation also indicates that besides ionic silver there are other toxicity pathways. E. coli strains capable of mediating resistance to oxidative stress by overexpression of certain proteins and bio reporters that could detect oxidative stress were constructed. The biosensor cells provide some but not too significant signals. Overexpression of proteins like superoxide dismutase and catalase reduces cell growth, hence, cell viability assays do not provide a realistic measure of protective impact, and thus this strategy is not suited to detect the nature of nanotoxicity. The protective role of extracellular polymeric substances (EPS) was studied by developing an engineered strain of E. coli that overproduces the EPS colanic acid, and use of mutant strains of Sinorhizobium meliloti, a free-living N2 fixing bacterium. Nanoparticle exposure studies reveal that overproduction of EPS mitigates silver nanotoxicity. EPS encapsulates the cells and leads to aggregation of nanoparticles, as shown by microscopy and dynamic light scattering. Furthermore, addition of xanthan, an EPS analogue also produces a similar effect. Lastly, x-ray absorption spectroscopy (XAS) of microcosms amended with silver and zinc oxide nanoparticles show rapid transformation of nanoparticles into corresponding oxides and sulphides. The microcosms show a significant presence of dissimilatory sulphate reducing bacteria (DSRB), and display only marginal change in bacterial community composition on exposure to nanoparticles. These findings suggest that nanomaterials will undergo changes in speciation dependent on the sediment chemistry and the metabolic activities of bacteria in the environment. This process will influence the impact of nanoparticles and the outcomes could be quite different from controlled in vitro exposure studies.
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Hsieh, Ji-Fan (Sarah). "Molecular and Chemical Mechanisms of Defence against Myrtle Rust in Australian Myrtaceae." Phd thesis, Canberra, ACT : The Australian National University, 2018. http://hdl.handle.net/1885/143530.
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Increased human disturbance to forest ecosystems has exacerbated
the spread of fungal pathogens to non-native environments. Rust
pathogens (Pucciniales) can spread long distances by human
activity and wind dispersal, and can cause severe disease
outbreaks in cereal crops and in forest trees. The exotic fungus
Austropuccinia psidii (myrtle rust) arrived in Australia in 2010
and most species of native Myrtaceae including Eucalyptus and
Melaleuca are susceptible to infection to various degrees. Plants
infected by A. psidii can suffer from crown loss and eventual
mortality, which can be detrimental to ecosystems as well as to
many rural industries that produce essential oils and flavourings
from species of Myrtaceae. Within-species variation in resistance
to A. psidii has been discovered in many native species. However,
the molecular and chemical mechanisms of resistance to A. psidii
infection in these species are largely unknown. Finding the
molecular and chemical basis of resistance against A. psidii is
therefore an essential part of ensuring that future plantations
and re-afforestation programs are resistant to this pathogen.
This thesis therefore aims to elucidate the molecular and
chemical mechanisms of resistance to A. psidii in Myrtaceae in
Australia, with the goal of obtaining a comprehensive view of
potential mechanisms involved in defence to identify candidate
genes that may be implemented into resistance breeding. After
first screening multiple species of Myrtaceae, I selected
Melaleuca alternifolia (tea tree) and M. quinquenervia (broadleaf
paperbark) for detailed molecular study because they showed
varying disease symptoms from resistance to susceptibility among
individuals, and were economically and ecologically important and
amenable to molecular studies. I used a variety of experimental
approaches, including RNA-Seq, qRT-PCR, GC-MS, and functional
characterisation through heterologous gene expression in E. coli
to apply an integrated analysis that examined both molecular and
chemical aspects of plant defence. I constructed the
transcriptomes of M. alternifolia and M. quinquenervia de novo
and investigated differential gene expressions between resistant
and susceptible plants. I showed that resistant M. alternifolia
and M. quinquenervia over-express genes which may be contribute
to defence against to A. psidii infection, and have found and
functionally characterised new terpene synthase genes that showed
induction in response to infection by A. psidii in M.
quinquenervia.
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Ormrod, Douglas James. "Modulation of non-specific cellular defence mechanisms by cyclosporin A." Thesis, University of Auckland, 1990. http://hdl.handle.net/2292/3195.
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The immune response modifier Cyclosporin A (CsA) is widely used in the management of organ graft rejection and in the treatment of inflammatory disorders. CsA is a potent suppressor of T-lymphocyte function and it’s biological effects have been defined almost exclusively in these terms. However, recent studies in which the agent was shown to exacerbate a T-lymphocyte independent, experimentally induced bacterial infection of the kidney (pyelonephritis), indicated that CsA had effects on host defence mechanisms other than T-lymphocytes. The present study, using animal models, was undertaken to identify the host defence component modified by CsA. Neutrophils are a key component in the early response to infection and the administration of CsA resulted in an increase in the number of these cells in the circulation. When the effect of CsA on the in vitro metabolic activity of neutrophils and their ability to kill microorganisms was investigated, no changes were observed, but the in vivo ability of neutrophils to emigrate from the vasculature to a sterile inflammatory foci was markedly impaired. A model of localised subcutaneous infection was used to determine the effect of this CsA-associated suppression of neutrophil emigration on the ability of the host to mount a response to an infectious challenge. In CsA treated animals, neutrophil accumulation in E. coli infected, subcutaneously implanted sponges was initially suppressed, allowing bacterial numbers to increase rapidly. By 48 hours this powerful bacterial stimulus overrode the suppressive effects of CsA and led to a substantial increase in the size of the neutrophilic infiltrate. This finding of an initially reduced inflammatory response, followed by an increase in the influx of inflammatory cells, provided a possible explanation for the earlier observation that CsA promoted infection and tissue damage in experimental pyelonephritis. The relationship between the effect of CsA on neutrophil emigration and the pathogenesis of experimental pyelonephritis was therefore investigated. When CsA was administered to animals prior to inducing pyelonephritis, the neutrophilic infiltrate was markedly suppressed in the early stages. As predicted, this led to a logarithmic increase in bacterial numbers, the infiltration of large numbers of neutrophils and, ultimately, an exacerbation of tissue damage. Further studies, examining the effects of CsA on neutrophil-mediated inflammatory mechanisms, identified impaired neutrophil-to-endothelial cell adhesion as the most likely explanation for the observed defect in host defences. The integrated nature of cellular defence mechanisms in infectious disease is highlighted by these investigations. when microorganisms invade tissue, even though the number and function of circulating leucocytes may be normal their effective participation in the host response to infection depends on the ability to emigrate from the blood vessels to the site of infection. In summary, the discovery of additional properties of CsA provide an explanation for the patterns of infectious disease in patients treated with CsA, in whom infection with extracellular pathogens is common. It also seems likely that the ability of CsA to suppress neutrophil emigration may contribute to the effectiveness of the agent in the management of inflammatory diseases, such as rheumatoid arthritis, uveitis and psoriasis.
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Pipe, R. K. "Haemocytes of the mussel Mytilus edulis : aspects of defence mechanisms." Thesis, Swansea University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638536.
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The blood cells of the common blue mussel Mytilus edulis have been characterized using a range of criteria including, electron microscopy, lectin-affinity and enzyme localization. Three distinct sub-populations of haemocyte have been identified; these can be characterized on the basis of ultrastructural morphology as small agranular cells, granular cells containing small granules and granular cells containing large granules. Lectin-binding studies have shown the small granules of the granular cells to be positive for Helix pomatia lectin (HPA) indicating the presence of N-acetyl-α-galactosaminyl residues within the granules. The larger granules were not positive for HPA but did bind wheat-germ agglutinin (WGA) which has an affinity for N-acetyl-β-glucosaminyl residues and N-acetyl-β-D-glucosamine oligomers. Furthermore the WGA-positive granules demonstrated a differential pattern of binding according to granule size, so that peripheral labelling was observed for granules of around 0.5 μm diameter whereas labelling occurred throughout the matrix for granules over 1 μm diameter. The lectin binding studies also demonstrated binding of both HPA and WGA as well as Tetragonolobus purpureas lectin( TPA) to the plasma membrane of a number of haemocytes; however the results did not demonstrate any correlation between surface lectin binding and cell type, as defined by the ultrastructural morphology. A range of hydrolytic enzymes was localized in association with the large granules of the granular cells, these included arylsulphatase, β-glucuronidase, elastase, lysozyme and cathepsin B, indicating that these granules constitute a form of lysosome. The small granules contained protease enzymes and in particular cathepsin G antibodies showed a high affinity for these granules.
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Adams, Nicolette. "Investigation of defence mechanisms against Botrytis cinerea in Arabidopsis thaliana." Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/4235.
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Includes bibliographical references (leaves 63-86).Disease resistance in plants has been extensively studied for the past century with many new and exciting results being discovered each year. A plant utilises both preformed and induced defence responses to resist pathogen attack but researchers have focused on dissecting the induced defence response pathway. The complex signal transduction pathway underlying the establishment of resistance to a wide range of pathogen attack is currently being dissected using Arabidopsis thaliana as a model organism. Arabidopsis mutants displaying altered disease resistance response to pathogen infections can help us to get a beUer understanding of the genetiC and molecular basis of the disease resistance pathway. Extensive research has shown that accumulation of 3 signalling molecules are vitally important for establishing a resistance response, as aberrant signalling or accumulation of salicylic acid , ethylene or jasmonic acid `leads to an altered resistance response. Researchers continue to isolate and characterise defence-related mutants to piece together the intricate puzzle of defence-signalling components. A dominant Arabidopsis mutant, constitutive induced resistance 3 (cir3), had been isolated from an ethylmethane sulfonate (EMS) mutagenised transgenic line expressing luciferase under the control of the PR-1 promoter (PR-1
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Lee, Min-Hi. "Induction and regulation of antiviral defence mechanisms through intracytoplasmic sensors." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2009. http://dx.doi.org/10.18452/15950.
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Das Wechselspiel zwischen Viren und ihren Wirtszellen beginnt meist an pattern recognition-Rezeptoren (PRRs), die für die Erkennung unterschiedlichster Pathogene anhand bestimmter Strukturen, sogenannten pathogen-associated molecular patterns (PAMPs), zuständig sind. Nach Detektion lösen die PRRs über verschiedene Signalkaskaden eine antivirale Antwort aus, die zur Expression antiviraler Gene führt. RIG-I und MDA5 sind zytoplasmatisch lokalisierte PRRs und erkennen RNA-Strukturen, die insbesondere während der viralen Replikation und Transkription verfügbar sind. Hantaviren sind humanpathogene RNA-Viren mit einem einzelsträngigen, segmentierten Genom. Die Konsequenzen hantaviraler Infektionen auf molekularer Ebene wurden bereits detailliert untersucht, aber die Mechanismen, die zur Induktion der Immunantwort führen, wie auch mögliche Immunevasionsstrategien, die wahrscheinlich in Zusammenhang mit der Pathogenität des jeweiligen Hantavirusstamms variieren, konnten bisher nicht identifiziert werden. Da Hantaviren im Cytoplasma ihrer Wirtszellen replizieren, stellen RIG-I und MDA5 potentielle Detektoren dar. In dieser Doktorarbeit wird die Bedeutung von RIG-I und MDA5 für die Erkennung von Hantavirus-Infektionen untersucht. Wachstumskinetiken zeigten, daß RIG-I die Replikation von pathogenen wie auch apathogenen Hantaviren beeinträchtigt. Außerdem konnte die RNA hantaviraler Nukleocapsid- (N-) ORFs als eine virale Komponente identifiziert werden, die Typ I Interferon über RIG-I induziert. Das Ausmaß der Interferon-Aktivierung korrelierte hierbei tendenziell mit dem Virulenzgrad der Virusstämme und war für die nicht-pathogenen Hantaviren nicht nachweisbar. Unterschiede in der Aktivierungsstärke können anhand vorläufiger Daten wahrscheinlich auf noch nicht identifizierte Motive zurückgeführt werden, die am 3’-Ende der N ORFs liegen. Im Gegensatz dazu wurde keine Interferon-Aktivierung durch hantavirale Komponenten über MDA5 festgestellt.Host-virus interaction is usually initated by pattern recognition receptors (PRRs) which are responsible for the recognition of various pathogens based on so-called pathogen-associated molecular patterns (PAMPs). Upon detection, PRRs trigger an antiviral immune response through different signalling cascades that lead to the expression of antiviral genes including interferon genes. RIG-I and MDA5 are cytoplasmically localised PRRs and recognise RNA patterns that are particularly available during viral replication and transcription. Hantaviruses are RNA viruses with single-stranded segmented genomes. The consequences of hantaviral infections have been analysed in detail, but the mechanisms that lead to the induction of the innate immune response as well as immune evasion strategies depending on the pathogenicity of the respective hantavirus strains have not been identified yet. Since hantaviruses replicate in the cytoplasm of their host cells, RIG-I and MDA5 represent potential PRRs for hantaviral detection. This thesis investigates the impact of RIG-I and MDA5 on recognition of hantaviral infections. Growth kinetics show that RIG-I impairs the replication of pathogenic as well as non-pathogenic hantaviruses. Furthermore, the RNA of hantaviral nucleocapsid protein (N) ORF could be identified as a viral component responsible for the induction of RIG-I signalling. It is shown that the degree of interferon promotor activation correlates with the virulence of the hantavirus strain from which the N ORF was derived. Based on preliminary data, differences in activation strength may be attributed to not yet identified motifs at the 3’ end of the ORF. In contrast, no interferon activation through MDA5 could be observed.
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Jordan, Nicholas David. "Partial purification and characterisation of a wheat N-acetyl-#beta#-D-hexosaminidase and its role in defensive lignin deposition." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240956.
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Vallance, Lisa. "Aspects of defence : discourse of veterans, research regarding current UK forces and veterans and working around defence mechanisms." Thesis, City University London, 2012. http://openaccess.city.ac.uk/3022/.
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Veterans seeking psychological input for mental health issues, following service with the UK Armed Forces, report difficulties in relating to mental health practitioners, often causing them to disengage with therapy. A wealth of quantitative research including epidemiology studies and outcome reports is available for this client group as well as best practice of treating mental health issues including combat-related post-traumatic stress disorder. More qualitative studies are being produced, both for this client group and their associated mental health issues. However, there appears to be a paucity of qualitative literature regarding the language of veterans and it is this, especially in terms of improving the psychologists’ understanding of this client group, which has inspired this research. Nine veterans were interviewed using a semi-structured schedule and the data was transcribed and analysed using discourse analysis. Nineteen repertoires are described within five groups: Professional/Objective; Personal/Subjective; Exclusive: Mind-Body Connection: and Refutation. In addition, one discourse superstructure – Defence – is identified. Synthesis of the repertoires and superstructure takes place in relation to: military culture; masculinity; Ehlers and Clarks 2000 cognitive model of PTSD and DSM IV symptom criteria; and, neuro-psychology of memory and Brewin, Dalgleish and Joseph’s 1996 Dual Representation Theory of PTSD. In addition, applications of the repertoires for counselling are suggested.
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Tang, M. "Elicitor-induced defence response and signal mechanisms in Medicago sativa L." Thesis, Swansea University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.639158.
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In this study, the responses and signal mechanisms were explored with a model system, concerning the interactions between lucerne suspension cells (Medicago sativa L., cv. Kabul) and elicitor either from avirulent (V2) or virulent (V1) isolate of Verticillium, alboatrum. V2 elicitor induced a two-phase of H2O2 accumulation in the cell cultures. Activation of defence expression led to an increase in PAL activity, phytoalexin accumulation and deposition of phenolic polymers. However, activities of antioxidant enzymes, such as catalase, peroxidases, glucanase, glutathione reductase, did not show obvious increase within 24 h after treatment with the elicitor. Glutathione S-transferase activity increased after 1st oxidative burst. V1 elicitor induced similar defence responses as V2 did, but a stronger response was observed when the same concentration of elicitor was used, confirming that Kabul is a resistance cultivar to V. albo-atrum. Ca2+ influx is necessary for oxidative burst, PAL activity and phytoalexin accumulation. Either blocking Ca2+ channel by La3+ or reduction of extracellular Ca2+ amount by EGTA, had an important inhibition on oxidative burst, PAL activity and phytoalexin accumulation. Intracellular Ca2+ also played a role in downstream signalling. Intracellular Ca2+ inhibitors. TBM-8 and Ruthenium red, strongly inhibited the PAL activity and phytoalexin accumulation. Oxidative burst has a relation with defence expression. An NADPH oxidase inhibitor, diphenyleneiodonium (DPI), which inhibited oxidative burst effectively, also inhibited PAL activity and phytoalexin accumulation. However, DCN, an inhibitor of peroxidase, also inhibited and oxidative burst, PAL activity and phytoalexin accumulated in micromolar range. Oxidative burst with superoxide-origin is related to defence activation. The H2O2 itself did not stimulate an activation of PAL activity. Addition of superoxide dismutase (SOD) stimulated an increase in H2O2 accumulation. Microsomal membranes are capable of superoxide synthesis when NADPH/NADH was used as electron donor, which was DPI-sensitive. This enzyme activity increased after treatment of the cell cultures with elicitor.
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Wilkinson, J. R. "The role of mitochondria in defence mechanisms of human endothelial cells." Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/147918/.
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Introduction: Mitochondria are considered to be the powerhouse of the cell being the primary generators of ATP, they also have numerous other important functions including; being the main generator of reactive oxygen species (ROS) and a central role in apoptosis. As the main intracellular source of ROS, many people believe that mitochondria play a significant role in ageing. Senescence is associated with ageing and has been associated with atherosclerotic vascular disease. The concept of human cells lacking functional mitochondria (Rho 0 cells) is not new and was first described by Attardi et al in 1989. However, most of this work has been done on immortalised cell lines. Aims: To see if it is possible to generate and characterise Rho 0 human endothelial cells. To use these cells as a tool to investigate the mechanisms by which they respond to stress and whether differences in ROS production and/or antioxidant defences account for any differences observed. Methods: Human Umbilical Vein Endothelial Cells (HUVEC) were grown in media supplemented with glucose and uridine in the presence of low dose ethidium bromide. Rho 0 status of the cells was confirmed by auxotrophy for uridine, quantitative PCR for mitochondrial-encoded gene expression and western blots for mitochondrial-encoded proteins. Results: The Rho 0 status of the cells was confirmed by; auxotrophy for uridine (Rho 0 cells die in medium lacking uridine), absence of mitochondrial-encoded genes (subunit-1 of complex IV and subunit-6 of subunit V) and lack of expression of the mitochondrial-encoded protein subunit-1 of complex IV. Rho 0 cells are resistant to both stress-induced senescence and apoptosis. They produce less ROS and have upregulated antioxidant defences. Conclusions: It is possible to grow Rho 0 HUVEC. These cells are a useful tool for studying the role of mitochondria in senescence and apoptosis in the cardiovascular system.
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VAEZI, ANZEHA ZAHRA. "Host defence peptides: mechanisms of membrane perturbation and target cell selectivity." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2015. http://hdl.handle.net/2108/201991.
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Host defence peptides (HDPs) are effector molecules of the innate immune system. They show broad activity against bacteria and cancer cells, usually by perturbing the permeability of cell membranes, leading to the death of pathogens by collapse of transmembrane electrochemical gradients and loss of important metabolites and cellular components. Due to this mechanism of action, development of resistance is unlikely. For this reason, HDPs are excellent candidates as a new class of therapeutics to address the problem of drugresistance pathogens. Pore formation in the pathogen membranes requires a significant accumulation of peptide molecules on the cell surface. Therefore, it is conceivable that other effects, in addition to permeabilization, might take place. In this thesis, the effects on membrane dynamics of four peptides (magainin, melittin, LAH4 and killer-FLIP) were analysed. In all cases, a peptide-induced reduction in lipid mobility and lateral diffusion was observed. These effects appeared to be independent of peptide electrostatic charge. A significant hindering of lipid dynamics might lead to inhibition of the function of membrane proteins, contributing to the bactericidal activity of the peptides. Cell selectivity of HDPs is due to the different composition of pathogen and host membranes, and particularly to the negatively charged lipids present in the membranes of bacteria and cancer cells. As a consequence, the cationic charge of most HDPs is an essential determinant of selectivity. However, it is not sufficient: extensive structure-activity relationship studies with a number of HDPs have revealed that a delicate balance between net charge, amphipathicity, hydrophobicity, and structural propensity is critically important to ensure antimicrobial potency and target cell selectivity. An immediate consequence of HDP amphipathicity is the tendency of several of these peptides to aggregate in water. In this thesis, the role of this phenomenon in cell-selectivity has been investigated, focusing on the cationic peptide killer-FLIP, which is strongly selective for cancer cells. We observed that this property is linked to the formation of aggregates. Notwithstanding the cationic charge, the monomeric peptide has a significant affinity towards all membrane compositions, because the water-exposed apolar residues provide a hydrophobic driving force for binding and insertion into neutral membranes of normal cells. By contrast, in the aggregates the hydrophobic sidechains are buried, thus reducing the affinity towards neutral membranes. At the same time, the aggregates still tend to associate to the anionic membranes of cancer cells, driven by electrostatic attraction. Overall, these findings provide a better understanding of the structural determinants of the membrane-perturbing activity and selectivity of HDPs, which is essential for the development of novel HDP-inspired drugs to effectively fight resistant infections and cancer, with minimum toxicity to eukaryotic cells.
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Shackleton, Kyle. "Novel aspects of nest defence in stingless bees." Thesis, University of Sussex, 2018. http://sro.sussex.ac.uk/id/eprint/76550/.
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Defence against predators is fundamental to increasing an organism's fitness. My thesis explores this central theme in behavioural ecology using stingless bees as study organisms. The thesis contains a general introduction (Chapter 1), three data chapters (2-4) and a final discussion (5). Chapter 2 is a comparative study of aggression in nest defence among stingless bee species, and describes a new form of nest defence, suicidal biting, which is most prevalent in the genus Trigona. Chapter 3 describes a remarkable behaviour in Partamona helleri, which crashes head-first when entering its nest. An experiment suggests that this behaviour helps to avoid predation at the nest entrance. Chapter 4 studies nest defence in the hovering guards of Tetragonisca angustula, and demonstrates that through coordinated vigilance, a group level behaviour rarely observed in animals, the ability of the group to detect predators is enhanced.
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Jansson, Marianne. "HIV-1 variability in relation to host defence mechanisms and disease outcome /." Stockholm, 1998. http://diss.kib.ki.se/search/diss.se.cfm?19980608jans.
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Crumlish, Margaret. "A study on the innate defence mechanisms in farmed tropical Rana spp." Thesis, University of Stirling, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321973.
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Zhang, Shaoli. "Molecular aspects of pancreatic islet cell defence mechanisms in Type I diabetes." Thesis, University of Southampton, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240906.
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Nedoboy, Polina. "Myeloperoxidase-derived oxidants: their Intracellular targets, defence mechanisms and role in disease." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/9910.
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Myeloperoxidase, a heme enzyme secreted by activated phagocytes at sites of inflammation, catalyses the oxidation of Cl- and SCN- to HOCl and HOSCN, which play an essential role in innate immunity. The misregulated production of these oxidants can be detrimental to the host. Thiocyanate is a preferred substrate of MPO, and higher SCN- levels are present in the plasma of smokers, suggesting that HOSCN formation may contribute to the enhanced risk of atherosclerosis (and other diseases) in smokers. The studies described in this thesis used both plasma samples, and the murine macrophage-like J774A.1 cells to investigate the role of HOSCN. Elevated levels of plasma SCN- positively correlated with thiol oxidation under conditions mimicking an inflammatory episode. Higher levels of plasma SCN-, in combination with low levels of MPO, correlated with lower rates of 12-year all-cause mortality, thus suggesting a protective role of SCN- under certain conditions. Cell-based experiments examined the effects of HOSCN and HOCl on NADPH-dependent antioxidant enzymes and GSH/S-glutathionylation. These studies demonstrated the inhibition of TrxR activity, oxidation and hyperoxidation of Prxs, and GSH loss following HOSCN treatment, whilst HOCl caused a significant decrease in GPx activity. This suggests the presence of intracellular defence mechanisms for different MPO-derived oxidants.
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Fortin, Jutta Emma. "Mechanisms of defence and emotional control in nineteenth-century literature of the fantastic." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619519.
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Zhang, Yan. "Investigation of the mechanisms by which the Arabidopsis RPS4 activates avrRps4-dependent defence." Thesis, University of East Anglia, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410243.
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West, Christopher. "The effect on phytophagous insects of variations in defence mechanisms within a plant." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670399.
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Miklis, Marco. "A high-throughput procedure for the identification of genes contributing to plant defence mechanisms." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=974329037.
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Garcia-Garbi, Natalio. "Interaction of immunostimulants and stress on innate defence mechanisms of rainbow trout, Oncorhynchus mykiss." Thesis, University of Stirling, 1998. http://hdl.handle.net/1893/26672.
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This study investigated the use of non-specific immunostimulants to alleviate stress-mediated suppression of defence mechanisms and subsequent susceptibility to bacterial pathogens in rainbow trout (Oncorhynchus mykiss). One yeast (1-3),)1-6)-β-glucan and a bacterial peptidoglycan were selected as immunostimulants from a panel of test substances on the basis of enhanced intracellular superoxide generation by kidney macrophages stimulated in vitro. Kidney macrophage effector activity was not affected after 1, 2, 3 or 4 weeks of in-feed treatment with 0.05% or 5% of glucan or peptidoglycan. However, production of bactericidal superoxide by inflammatory peritoneal macrophages did increase significantly after four weeks of oral treatment with 0.05% peptidoglycan. Although a single confinement of fish (93% reduction of water volume for five minutes) caused a physiological stress response, as indicated by hyperglycaemia in plasma, kidney and inflammatory macrophage activities were only affected after six daily confinements. Phagocytosis, intracellular superoxide production and killing of Aeromonas salmonicida in vitro by kidney macrophages were significantly reduced. Conversely, production of extracellular superoxide, which may be associated with damage to self, was enhanced. Peritoneal macrophages displayed a similar but less marked respiratory burst response after repeated confinement. Some of the alterations in macrophage function caused by daily confinement were prevented by feeding 0.05% peptidoglycan four weeks before the first confinement. The increase in kidney macrophage extracellular superoxide production caused by repeated confinement was significantly alleviated by in-feed peptidoglycan. Similarly, the decrease in intracellular production by peritoneal macrophages caused by repeated confinement was prevented by in-feed treatment with peptidoglycan. Neither peptidoglycan nor repetitive confinement had any effect on complement lytic activity. These results indicate that dietary peptidoglycan was able to reduce, by regulating macrophage function, the impact of stress on certain bactericidal defences and potential damage to self. However, there was no significant difference in the persistence of viable A. salmonicida in the spleen or blood of infected fish in any of the experimental treatments.
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Wilson, Kirsty. "Modelling the airway epithelium in vitro as a tool for understanding pulmonary innate defence mechanisms." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/13496/.
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The airway epithelium forms a continuous barrier from the nose to the alveoli and serves a variety of functions. Multiple functionally distinct cell types are involved in these processes. The innate defence functions require a patent airway epithelium, with infections often associated with epithelial defects and phenotypic alterations that are themselves associated with multiple lung diseases. Non-typeable Haemophilus influenzae (NTHi) and respiratory syncytial virus (RSV) are frequently identified in the airways in a range of respiratory diseases These pathogens often trigger exacerbations and worsening symptoms that often result in hospitalisation. This is particularly true in paediatric populations. Although mortality for NTHi and RSV infections alone are themselves low it remains unclear what role these infections play in mortality rates in complex chronic respiratory infections. These studies aimed to establish NTHi and RSV infections within airway epithelium models, and use them as tools to study pulmonary innate defence mechanisms in order to understand the role of these infections in respiratory disease. In vitro airway models were established using lung derived cell lines, undifferentiated primary human bronchial epithelial (uHBE) cells and air-liquid interface (ALI) differentiated uHBE cell cultures. Following establishment of differentiation we validated ALI cultures using a number of markers, including for the putative innate defence PLUNC family proteins, gel-forming mucins and tubulin. These markers are representative of different epithelial cell types within the cultures. Cultures were infected with NTHi or RSV for periods of time ranging from 1 hour to 7 days with a view to establishing chronic infections and allowing biofilm formation. Monolayer cultures showed an enhanced susceptibility to both infections. Cytokine array profiling showed enhanced pro-inflammatory cytokine profiles in response to NTHi and RSV infections in ALI cells resulting in an ability to manage infections compared to monolayer cultures. Expression analysis indicated that both infections altered the transcription of a number of pro-inflammatory genes. Neutrophil products and trypsin were shown to degrade PLUNC proteins in ALI cell secretions. NTHi also appeared to cause degradation of PLUNC proteins suggesting that infection may impair the innate defence shield of the airway epithelium. Our data showed that differential ALI cultures of human airway cells are a useful model for the study of respiratory pathogens.
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Ndiweni, Nomathemba. "The effects of vitamin E and selenium on defence mechanisms of the bovine mammary gland." Thesis, University of Bristol, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363290.
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Trindade, Maria Margarida Silva. "Mecanismo de defesa e resistência das plantas a agentes patogénicos." Master's thesis, Universidade de Évora, 2021. http://hdl.handle.net/10174/29296.
Full textAbstract:
As plantas são constantemente ameaçadas por diversos microrganismos
patogénicos que prejudicam o seu crescimento e reprodução. Com isto, desenvolveram
eficientes mecanismos de defesa físicos e químicos que podem ser inatos ou induzidos.
Dependendo do tipo de interação com o patogénio, as plantas empregam estratégias
de defesa distintas e específicas para a patogénese, através de um sistema imunológico
multicamada, caracterizado por duas linhas de defesa: uma primeira, extracelular, que
pode desencadear respostas de largo espetro (PTI) e uma segunda, intracelular, em que
ocorre o reconhecimento muito específico do agente patogénico (ETI). Adicionalmente,
embora não tenham um sistema imunológico, podem criar resistência induzida, que se
caracteriza pela sinalização sistémica da resposta de defesa do local de infeção para as
partes distantes do mesmo, estabelecendo uma capacidade defensiva melhorada.
Compreender os mecanismos de defesa das plantas é fundamental para que se
possam obter plantas mais tolerantes ou mimetizar e induzir estes mecanismos; ABSTRACT: Plants defence and resistance mechanisms against pathogens
Plants are constantly threatened by several pathogenic microorganisms that harm
their growth and reproduction. With this, they developed efficient mechanisms of
physical and chemical defence that can be innate or induced. Depending on the type of
interaction with the pathogen, plants employ distinct and specific defence strategies for
the pathogenesis, through a multi-layered immune system, which is characterized by
two lines of defence: a first, extracellular, which can trigger wide-spectrum responses
(PTI) and a second one, with intracellular origin, in which the very specific recognition of
the pathogenic agent occurs (ETI). Additionally, although lacking an immune system,
they can create induced resistance, which is characterized by the systemic signalling of
the defence response from the infection site to the distant parts of it, establishing an
improved defensive capacity.
Understanding the defence mechanisms of plants is essential to obtain more
tolerant plants or to mimic and induce those mechanisms.
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Johansson, Anna. "Verticillium longisporum, infection, host range, prevalence and plant defence responses /." Uppsala : Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/10157752.pdf.
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Kinnunen, H. (Heli). "Surface structure, wax and methanol-extractable compounds in Scots pine and Norway spruce needles enhanced UV-B." Doctoral thesis, University of Oulu, 1999. http://urn.fi/urn:isbn:9514252799.
Full textAbstract:
Abstract
Increased amounts of epicuticular waxes and UV-absorbing compounds, such as flavonoids, and smaller leaf/needle surface area are plant defence mechanisms against UV-B radiation. The response of the needle epicuticular waxes of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies Karst.) seedlings to increased UV-B were investigated in short-term and long-term greenhouse experiments. In a more realistic long-term field experiment with mature Scots pines, the methanol-extractable UV-absorbing compounds were also analysed.
Some significant changes were observed in the wax tube distribution (WTD, %) and the amount of waxes in Norway spruce seedlings in the short-term Belgian greenhouse experiment (UV-BBE 0, 11.3 and 22.6 kJ m-2 d-1), but no changes were detected in Scots pine seedlings. No changes in waxes were observed in the long-term Finnish greenhouse experiment (UV-BBE 0, 2.2–6.6 and 5.6–16.8 kJ m-2 d-1), where both the Norway spruce and the Scots pine seedlings seemed to respond by having smaller needle surface areas. A field experiment (UV-BBE 0.5–2.4 kJ m-2 d-1 and 0.7–5.1 kJ m-2 d-1) with mature Scots pines revealed no significant changes in WTD during the three growing seasons or the amount of waxes during the third growing season.
In the long-term field experiment the amount of UV-absorbing compounds varied significantly between seasons and/or needle age classes. Elevated amounts of these compounds were already observed in the three-day-old needles and also in the oldest (c + 2) needles when the waxes were still undeveloped or already somewhateroded. No significant differences in the amount of UV-absorbing compounds were observed between the treatments during the first and second growing seasons. During the third growing season, needles of all ages contained significantly or slightly less UV-absorbing compounds in supplemental UV-B than in the ambient treatment, possibly due to cumulative effects of UV-B in already inhibited pigment synthesis. This suggests that these defence mechanisms are not efficient enough to prevent the UV-B-induced damage in the long term.
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Santén, Kristina. "Pathogenesis-related proteins in barley : localization and accumulation patterns in response to infection by Bipolaris sorokiniana /." Alnarp : Dept. of Plant Protection Biology, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/200786.pdf.
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Hagberg, Malin. "Immune cell responses to the cattle lungworm, Dictyocaulus viviparus /." Uppsala : Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, 2008. http://epsilon.slu.se/200837.pdf.
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Hu, Songhua. "Immunomodulatory and adjuvant effects of ginseng extracts : with emphasis on defence mechanisms of the bovine udder /." Uppsala : Dept. of Obstetrics and Gynaecology, Swedish Univ. of Agricultural Sciences ([Institutionen för obstetrik och gynekologi], Sveriges lantbruksuniv.), 2002. http://epsilon.slu.se/avh/2002/91-576-6380-7.pdf.
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Persson, Mattias. "Cell death and defence gene responses in plant-fungal interactions /." Uppsala : Dept. of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, 2008. http://epsilon.slu.se/200851.pdf.
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Staal, Jens. "Genes and mechanisms in Arabidopsis innate immunity against Leptosphaeria maculans /." Uppsala : Dept. of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200669.pdf.
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Di, Maggio Paula. "Dietary lipids and inflammation : chylomicron remnants suppress pro-inflammatory pathways and activate antioxidant defence mechanisms in human macrophages." Thesis, Royal Veterinary College (University of London), 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618287.
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Kaliff, Maria. "Genes, hormones and signalling pathways implicated in plant defence to Leptosphaeria maculans /." Uppsala : Dept. of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/2007119.pdf.
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Sanmartín, Martínez Neus. "Deciphering mechanisms underlying Mycorrhizal Induced Resistance in tomato plants." Doctoral thesis, Universitat Jaume I, 2021. http://dx.doi.org/10.6035/14104.2021.722450.
Full textAbstract:
En esta tesis doctoral he tratado de descifrar algunos de los mecanismos tras la Resistencia Inducida por Micorrizas (MIR).
Las plantas micorrizadas son más sensibles y perciben más rápido un futuro estrés. Esto está acompañado por un reordenamiento metabolómico y una aumentada deposición de callosa dirigida por cambios proteicos tras el establecimiento de la simbiosis. Estas modificaciones pueden ser los mecanismos claves en la MIR frente a Botrytis cinerea. Además, cambios puntuales en los volátiles en plantas micorrizadas también pueden contribuir a la mayor resistencia frente al patógeno al mostrar propiedades antifúngicas.In this doctoral thesis I have tried to decipher some mechanisms behind Mycorrhiza-Induced Resistance (MIR). Mycorrhizal plants become more sensitive and perceive earlier the upcoming stress. This is accompanied by a plant metabolic rearrangement and enhanced callose accumulation directed by protein changes after symbiosis establishment. These modifications can be key components of defence priming behind MIR against Botrytis cinerea. Furthermore, the changes in specific VOCs released by mycorrhizal plants likely contribute to the enhanced resistance since they show antifungal properties.
Programa de Doctorat en Ciències
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Saleh, Nadeh S., and n/a. "Characterisation of the immune response in otitis media." University of Canberra. Applied Science, 2002. http://erl.canberra.edu.au./public/adt-AUC20061107.163007.
Full textAbstract:
Acute otitis media is the most common illness diagnosed during early childhood that
can cause significant morbidity (Brook, 1994) and sometimes can cause irreversible
sequelae such as a hearing defect and subsequent learning difficulties (Klein, 1994). The
aims of the research presented here were to study some aspects of the middle ear
defence mechanisms in both immune and non-immune rats following experimental
otitis media (OM) with two pathogens nontypeable Haemophilus influenzae (NTHi) and
Moraxella catarrhalis (M. catarrhalis). This study also aimed at developing a suitable
technique for preparing immunohistochemical staining of middle ear sections (chapter
2).
A previous study has shown that a regime where rats received an IPP immunisation
combined with an IT boost was effective in enhancing clearance of a middle ear
infection with the same strain of NTHi and also in the presence of a concomitant viral
infection (Moore et al, 2001). Results of this study have shown that for NTHi infection
a distinct cellular influx to the middle ear in the immune rats was accompanied by an
enhanced bacterial clearance compared to the non-immunised rats (chapter 3). This
cellular influx was responsible for the remarkable reduction in the bacterial number.
The sharp decline in PMNs numbers in the NTHi immunised rats that followed
complete bacterial clearance at 72h post infection (Table 3.1) indicate a more
effectively controlled down regulation of this cell infiltrate than the non-immunised rats.
For M. catarrhalis infection, there was no difference in cell infiltrate between immune
and non-immune rats, but enhanced clearance of the bacteria were observed for the
immune animals.
The histopathological changes in the middle ear mucosa of rats with experimentally
induced infection were studied to provide a better understanding about the distribution
of the inflammatory cells and changes in the mucosa during the first 24h post challenge
with NTHi and M. catarrhalis (Chapter 4). These changes have not been previously
studied for the two pathogens at 24h post challenge in rats. Induced infections with the
two pathogens were found to produce similar histopathological changes but more
inflammatory infiltration was observed within the infected mucosa with NTHi than that
seen with M. catarrhalis. The infections were characterized by increased thickness of
the middle ear mucosa, Eustachian tube mucosa, periosteum and tympanic membrane.
There was also an increase in the number and size of small blood vessels at all sites, and
these small blood vessels seem to be the source of the inflammatory infiltration into the
middle ear mucosa and middle ear cavity during the infection. These findings provided
an essential background to the immunohistochemical study.
The effect of mucosal immunisation on the distribution of CD4+T cells and CD8+T
cells has not been investigated previously. Results of the present study (Chapter 5) show
the pattern of distribution of these cells during the first 48h post infection with NTHi in
the rat. The number of CD4+and CD8+T cells peaked at 24h post infection in the nonimmunised
animal and were highest at 48h post-infection in the immunised rats. The
difference in response in the immunised rats may represent regulation of the
inflammatory response by the immune system. The inflammatory response regulation is
indicated by the difference in cellular influx into the immune rats and the response in
the immune rats that corresponds to enhanced bacterial clearance prior to a decrease in
numbers of inflammatory cells once the bacteria was no longer detected (Chapter 3).
This resolution of the inflammatory mass would reduce the opportunity for continued
damage to local tissue. These changes are also supported by the reduction in the
thickness of the middle ear mucosa of the immunised rats especially at 24h and 48h
post-infection (Chapter 5).
This study has shown that there are distinct differences in the rate of bacterial clearance
and cellular changes in the middle ear mucosa and tympanic bulla in immunised rats
during a middle ear infection. Future studies are still required to gain a better
understanding of differences in the inflammatory response for both pathogens, NTHi
and M. catarrhalis.
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Hoviatdoost, Pejman. "Understanding mechanisms of change of Intensive Short Term Dynamic Psychotherapy." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/232623/1/Pejman_Hoviatdoost_Thesis.pdf.
Full textAbstract:
This program of research is the first to systematically evaluate a key process in Intensive Short Term Dynamic Psychotherapy (ISTDP). The study developed a new methodology for identifying unlocking and the findings suggest that "unlocking" and "defense restructuring" may represent mechanisms of change in ISTDP case studies. A series of case studies revealed the nuances of "unlocking" and "defense restructuring" in a clinical setting. The findings of this research increase the overall understanding of mechanisms of change in ISTDP, contributing to the current body of scientific research in the area of psychotherapy process and outcome research.
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Khorramdelazad, Mahsa. "Investigation of genetic and molecular mechanisms of lentil (Lens culinaris) cv. ILL7537 during early defence responses to Ascochyta lentis." Thesis, Griffith University, 2019. http://hdl.handle.net/10072/389670.
Full textAbstract:
Lentil (Lens culinaris) is a valuable and popular cool season legume worldwide. The lens shaped seed legume is a rich source of protein (up to 35%), complex carbohydrates, vitamin A and B, and potassium and iron and is high in fibre and low in sodium and fat. Therefore, lentil is a staple food in no- and low-meat diets especially in North Africa, the Middle East, the Indian subcontinent and parts of the Americas. Due to the high demand for lentil globally, its annual production has increased from 0.85 to 5.03 Mt within the last five decades. Australia is the fourth largest producer in the world with an annual export value of $185 million AUD. However, lentil global production and yield quality is greatly affected by the devastating fungal disease “Ascochyta blight” (AB).
Ascochyta lentis (Vassilievsky) is a necrotrophic fungus that causes AB, affecting all above-ground parts of the plant resulting in up to 70% yield loss and marketability reduction annually. The fungus is endemic to lentil growing regions globally and is the top biotic constraint to lentil production in Australia. A range of studies have been conducted on A. lentis to clarify the epidemiology, diagnostics, lifecycle, survival, chemical susceptibility as well as pathogenic variation and physiology of the host-pathogen interaction. The knowledge on A. lentis pathogenicity together with identification of genetic and molecular mechanisms of lentil defence in the naturally resistant lentil genotypes would lead to the most economic, environmentally friendly and effective method of disease management.
This study identified the genetic and molecular aspects of defence to A. lentis by identifying novel defence related genes and molecular pathways, their functions and locations on lentils chromosomes as well as some linked SNPs to the candidate genes. The identified genes, SNPs and QTLs identified may be used as genetic tools for the selection of A. lentis resistance within ILL7537 in future pre-breeding efforts.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Langer, Melissa Natalie [Verfasser]. "Interactions of host defence peptides with innate immune cells : unravelling molecular mechanisms of immune modulation and bacterial killing / Melissa Natalie Langer." Hannover : Stiftung Tierärztliche Hochschule Hannover, 2018. http://d-nb.info/118040288X/34.
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Börner, Michaela. "Real and illusory reports of posttraumatic growth and their correlation with well-being : an empirical examination with special focus on defence mechanisms." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/38528/.
Full textAbstract:
Reports of posttraumatic growth can sometimes be illusory. Several researchers have argued that reports of posttraumatic growth may incorporate two separate phenomena, namely real posttraumatic growth and illusory posttraumatic growth. However, it is not often made explicit which kinds of illusions indicate illusory posttraumatic growth. An explicit conceptualisation of illusory posttraumatic growth is, however, necessary in order to investigate the research questions within this thesis, namely (a) whether reports of posttraumatic growth are correlated with illusions and (b) whether real posttraumatic growth and illusory posttraumatic growth differ in their correlation with well-being. Within the thesis, it was, therefore, primarily suggested that defensiveness could be responsible for illusory posttraumatic growth. The assumption was that high levels of maladaptive defensiveness may be used when distress cannot be endured. Internal and external experiences could then be pushed away. This case could potentially indicate illusory posttraumatic growth. In contrast, people who use low levels of maladaptive defences or high levels of mature defences may be able to endure the distress following a trauma or adversity. Internal and external experiences may be processed and accommodated. This case could potentially indicate real posttraumatic growth. The assumptions about illusions were tested within the thesis. It was investigated which kind of illusions could be adaptive psychological operations and which illusions could be maladaptive psychological operations. The results supported the assumptions within this thesis concerning adaptive versus maladaptive illusions. Within three studies, self-reported posttraumatic growth was significantly correlated with a neurotic defence style. It was concluded that this correlation could indicate that sometimes reports of posttraumatic growth are not real. However, other interpretations were also discussed. Four studies investigated whether real posttraumatic growth and illusory posttraumatic growth differ in their correlation with well-being. Within chapter 5, real posttraumatic growth, indicated by low levels of a neurotic or an immature defence style, was correlated positively with negative change following adversity (non significant). In contrast, illusory posttraumatic growth, indicated by high levels of a neurotic or an immature defence style, was not correlated with negative change following adversity. Although the difference between illusory posttraumatic growth and real posttraumatic growth concerning negative change following adversity had a meaningful effect size, it was not significant. Within chapter 7.3, real posttraumatic growth, indicated by extremely low levels of neurotic defensiveness, was correlated significantly with posttraumatic stress. In contrast, illusory posttraumatic growth, indicated by extremely high levels of neurotic defensiveness, was not correlated with posttraumatic stress. The difference between real posttraumatic growth and illusory posttraumatic growth was significant. Within chapter 8, real posttraumatic growth (high levels of mature defensiveness) was correlated with decreases in hedonic well-being measured by positive and negative affect. In contrast, illusory posttraumatic growth (low levels of mature defensiveness) was correlated with increased levels of hedonic well-being. The difference between real posttraumatic growth and illusory posttraumatic growth was significant. In total, reports of posttraumatic growth may, in fact, sometimes be correlated with defensiveness. However, real posttraumatic growth and illusory posttraumatic growth do only slightly differ concerning their correlation with well-being.
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Almeida, Maria Filipa Martins de. "A culpa escondida: uma leitura analítica da culpabilidade em filhos de idosos institucionalizados." Master's thesis, Universidade de Évora, 2018. http://hdl.handle.net/10174/23107.
Full textAbstract:
O presente estudo propõe-se analisar a existência da culpabilidade, em filhos, com pai ou mãe institucionalizados, assim como o uso de mecanismos de defesa para gerir essa culpabilidade. Para o efeito, foram selecionados 10 participantes (6 mulheres e 4 homens), com idades entre 50 e 70 anos. A análise das entrevistas semiestruturadas foi realizada com recurso ao método fenomenológico, o que permitiu encontrar dez constituintes essenciais: (1) Desresponsabilização da decisão de institucionalizar; (2) Racionalização e generalização; (3) Idealização das instituições e desidealização da casa familiar; (4) Sentimentos dos filhos; (5) Perceção, pelos filhos, dos sentimentos dos pais; (6) Pagamento como alívio; (7) Institucionalização como último recurso; (8) Visitas e contactos como alívio da culpabilidade; (9) Saídas temporárias da instituição (10) O peso do passado no relacionamento com os pais. A generalidade dos filhos revelou sentimentos de culpabilidade, devido à institucionalização dos pais, usando vários mecanismos inconscientes, como defesas; Abstract:
The Hidden Guilt
An analytical view of the guilt felt by adult children
of institutionalized elderly
The present study aims at analysing the existence of guilt in children, who have an institutionalized father or mother, as well as the defence mechanisms used by them to deal with this guilt. For this purpose, 10 participants were selected (6 women and 4 men), aged from 50 to 70 years. The analysis of the semi-structured interviews was carried out using the phenomenological method, which allowed us to find ten essential constituents.: (1) Non-responsibility for the decision of institutionalization; (2) Rationalization and generalization; (3) Idealisation of the institutions and devaluation of the family home; (4) Children’s feelings; (5) Children’s perceptions about their parents’ feelings; (6) Payment as a relief; (7) Institutionalization as last option; (8) Visits and contacts as guilt relief; (9) Temporary departures from the institution (10) The weight of the past in the relationship with parents. Most children revealed feelings of guilt, due to the institutionalization of parents, using various unconscious mechanisms, such as defences.
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COLONE, ALESSIA. "Role of CpG ODNs in human macrophages before and after infection with Mycobacterium tuberculosis and their effects in cellular and molecular defence mechanisms." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2010. http://hdl.handle.net/2108/1265.
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Oligodeoxynucleotides, containing unmethylated CpG dinucleotides within specific sequence contexts in bacterial or viral DNA, are detected as a danger signal by the vertebrate immune system. CpG motifs are sequences with a potent antymycobacterial activity and we tested a panel of eight synthetic CpG ODNs for their capacity to reduce Mycobacterium tuberculosis growth analyzing their effects in vitro in human macrophages. CpG2 ODN is able significantly to reduce pathogen growth while CpG3 ODN determines an enhancement in replication than control macrophages. In term of molecular and cellular mechanisms of defence in the host-pathogen interaction we found a specificity of CpG ODN sequence in intracellular pH decrease but not in Reactive Oxygen Species production, both influenced by CpG. Moreover we analyzed environment of macrophages, stimulated with these two CpG ODNs, before and after infection showing a correlation between mycobacterial growth and IFN- transcription following 1 hour of CpG treatment, and a down-regulation in IFN-mRNA upon pathogen contact. Finally we described a pathway of cytokines, among them SerpinE1 never associated before in M. tuberculosis infection involved in macrophages migration. In conclusion CpG ODNs could be used as vaccine adjuvants confirming their capacities
to improve protection against M. tuberculosis involving mechanisms of defence.
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Chang, Christine Chi-Chen. "Mechanisms and genes controlling the signalling network for biotic and abiotic stress defences in Arabidopsis thaliana (L.) Heyhn : Functional cross-talk between photo-produced reactive oxygen species, photosynthesis and plant disease defence responses." Doctoral thesis, Stockholm : Department of Botany, Stockholm University, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-418.
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Hämäläinen, Jaana. "Molecular mapping of potyvirus resistance genes in diploid potatoes /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5703-3.pdf.
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Ekman, Johanna. "Alarmsignaler hos terrestra sniglar : Påverkar en attackerad artfrände försvarsbeteendet?" Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-84251.
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Försvarsmekanismer är vanligt förekommande svar på predation och aggression bland djur. Till exempel uppvisar många terrestra sniglar en högre aktivitet och förändrat rörelsemönster när de identifierar kemiska signaler från predatorer. I denna studie undersökte jag hur kemiska signaler från en attackerad artfrände påverkade försvarsbeteenden hos trädgårdssnigel (Arion distinctus), där pantersnigel (Limax maximus) representerade aggressor. Ett laboratorieexperiment utfördes med fyra behandlingar (totalt 48 replikat): med slemspår av en trädgårdssnigel, med spår av en pantersnigel, med spår av båda arter tillsammans, samt utan spår. Jag förutspådde att spår av en attackerad artfrände (det vill säga spår från båda arter tillsammans) skulle medföra högre aktivitet och undvikande beteende hos trädgårdssnigeln, samt att båda arter under förberedelsen för behandlingarna skulle uppvisa en högre aktivitet vid närvaro av den andra arten än ensamma. Resultaten visade ingen signifikant effekt av behandling på trädgårdssniglarnas aktivitet eller rörelsemönster, eller på någon av arternas aktivitet vid närvaro av varandra. Eftersom sniglars försvarsbeteenden är kostsamma, är det möjligt att pantersnigeln inte utgjorde ett tillräckligt stort hot för att det skulle vara fördelaktigt för trädgårdssnigeln att utföra dessa beteenden.Defence mechanisms are a common response to predation and aggression in animals. For example, many terrestrial slugs exhibit a higher activity and change their movement patterns when identifying chemical signals from predators. In this study, I examined how chemical signals from an attacked conspecific affected the defence mechanisms of the common garden slug (Arion distinctus), where the leopard slug (Limax maximus) represented the aggressor. A laboratory experiment was conducted with four treatments (48 replicas in total): with mucus trails from a common garden slug, with trails from a leopard slug, with trails from both species together, and without trails. I predicted that trails from an attacked conspecific (i.e. trails from both species together) would result in increased activity and an avoiding behaviour in the common garden slug, and that both species during the preparation for the treatments would exhibit an increased activity in presence with the other species than alone. The results showed no significant effect of treatment on the common garden slug’s activity or movement pattern, or on both species’ presence of each other. Because slugs’ defence mechanisms are costly, it is possible that the leopard slug did not pose a threat big enough to be beneficial for the common garden slug to execute these behaviours.
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Terhoeven, Niklas [Verfasser], Jörg [Gutachter] Schultz, Rainer [Gutachter] Hedrich, and Dirk [Gutachter] Becker. "Genomics of carnivorous Droseraceae and Transcriptomics of Tobacco pollination as case studies for neofunctionalisation of plant defence mechanisms / Niklas Terhoeven ; Gutachter: Jörg Schultz, Rainer Hedrich, Dirk Becker." Würzburg : Universität Würzburg, 2020. http://d-nb.info/1220227978/34.
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