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Stress Situations (stress + situation)
Selected AbstractsThe nature of tobacco resistance against Botrytis cinerea depends on the infection structures of the pathogenENVIRONMENTAL MICROBIOLOGY, Issue 1 2010Mohamed El Oirdi Summary To protect themselves, plants have evolved an armoury of defences in response to pathogens and other stress situations. These include the production of pathogenesis-related (PR) proteins and the accumulation of antimicrobial molecules such as phytoalexins. Here we report that resistance of tobacco to Botrytis cinerea is cultivar specific. Nicotiana tabacum cv. Petit Havana but not N. tabacum cv. Xanthi or cv. samsun is resistant to B. cinerea. This resistance is correlated with the accumulation of the phytoalexin scopoletin and PR proteins. We also show that this resistance depends on the type of B. cinerea stage. Nicotiana tabacum cv. Petit Havana is more resistant to spores than to mycelium of B. cinerea. This reduced resistance of N. tabacum cv. Petit Havana to the mycelium compared with spores is correlated with the suppression of PR proteins accumulation and the capacity of the mycelium, not the spores, to metabolize scopoletin. These data present an important advance in understanding the strategies used by B. cinerea to establish its disease on tobacco plants. [source] Fluctuating asymmetry and developmental instability in evolutionary biology: past, present and futureJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2006S. V. DONGEN Abstract The role of developmental instability (DI), as measured by fluctuating asymmetry (FA), in evolutionary biology has been the focus of a wealth of research for more than half a century. In spite of this long period and many published papers, our current state of knowledge reviewed here only allows us to conclude that patterns are heterogeneous and that very little is known about the underlying causes of this heterogeneity. In addition, the statistical properties of FA as a measure of DI are only poorly grasped because of a general lack of understanding of the underlying mechanisms that drive DI. If we want to avoid that this area of research becomes abandoned, more efforts should be made to understand the observed heterogeneity, and attempts should be made to develop a unifying statistical protocol. More specifically, and perhaps most importantly, it is argued here that more attention should be paid to the usefulness of FA as a measure of DI since many factors might blur this relationship. Furthermore, the genetic architecture, associations with fitness and the importance of compensatory growth should be investigated under a variety of stress situations. In addition, more focus should be directed to the underlying mechanisms of DI as well as how these processes map to the observable phenotype. These insights could yield more efficient statistical models and a unified approach to the analysis of patterns in FA and DI. The study of both DI and canalization is indispensable to obtain better insights in their possible common origin, especially because both have been suggested to play a role in both micro- and macro-evolutionary processes. [source] Adipokinetic hormone (Pyrap-AKH) enhances the effect of a pyrethroid insecticide against the firebug Pyrrhocoris apterusPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 4 2010Dalibor Kodrík Abstract BACKGROUND: Adipokinetic hormones (AKHs) are insect neuropetides controlling stress situations including those elicited by insecticide treatment. The effect of Pyrap-AKH on the mortality of the firebug Pyrrhocoris apterus (L.) treated with the insecticide permethrin (Ambush 25 EC) was studied. RESULTS: Coinjection of 50 ng permethrin with 80 pmol Pyrap-AKH induced a significant 2.3-fold increase in bug mortality compared with the insecticide alone. The results were confirmed by topical coapplication of both agents (400 ng and 80 pmol respectively). Injections of 50 and 100 ng permethrin elicited a significant increase in the AKH level in CNS and the haemolymph. The results indicate an involvement of AKH in stress response to permethrin. The enhanced effect of insecticide by AKH treatments probably results from the stimulatory role in bug metabolism: carbon dioxide production was increased 3.5- and 2.5-fold respectively 1 and 3 h after permethrin treatment, and 4.3- and 3.4-fold after the permethrin plus AKH cotreatment, compared with the control. CONCLUSION: The elevation of metabolism could intensify the permethrin action by its faster penetration into tissues and by stimulation of biochemically active cells, and could be a reason for enhanced action of permethrin after its cotreatment with Pyrap-AKH. Copyright © 2009 Society of Chemical Industry [source] Role of gp130-mediated signalling pathways in the heart and its impact on potential therapeutic aspectsBRITISH JOURNAL OF PHARMACOLOGY, Issue S1 2008P Fischer IL-6-type cytokines bind to plasma membrane receptor complexes containing the common signal transducing receptor chain gp130 that is ubiquitously expressed in most tissues including the heart. The two major signalling cascades activated by the gp130 receptor, SHP2/ERK and STAT pathways, have been demonstrated to play important roles in cardiac development, hypertrophy, protection and remodelling in response to physiological and pathophysiological stimuli. Experimental data, both in vivo and in vitro, imply beneficial effects of gp130 signalling on cardiomyocytes in terms of growth and survival. In contrast, it has been reported that elevated serum levels of IL-6 cytokines and gp130 proteins are strong prognostic markers for morbidity and mortality in patients with heart failure or after myocardial infarction. Moreover, it has been shown that the local gp130 receptor system is altered in failing human hearts. In the present review, we summarize the basic principles of gp130 signalling, which requires simultaneous activation of STAT and ERK pathways under the tight control of positive and negative intracellular signalling modulators to provide a balanced biological outcome. Furthermore, we highlight the key role of the gp130 receptor and its major downstream effectors in the heart in terms of development and regeneration and in response to various physiological and pathophysiological stress situations. Finally, we comment on tissue-specific diversity and challenges in targeted pharmacological interference with components of the gp130 receptor system. British Journal of Pharmacology (2008) 153, S414,S427; doi:10.1038/bjp.2008.1; published online 4 February 2008 [source] Stress Response of Escherichia coliCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 3 2006H.J. Chung ABSTRACT:,Escherichia coli encounter numerous different stresses during their growth, survival, and infection. These stresses are relevant to survival in foods and food processing environments. E. coli and other bacteria respond to stress conditions by activating small or large groups of genes under the control of common regulator proteins. Stress conditions result in the accumulation of these regulator proteins and subsequent transcription of many genes allows cells to cope with specific stress situations, conferring stress tolerance and survival. In addition, induced stress tolerance of cells is attributed to enhanced virulence and enhanced tolerance to other stresses (cross-protection). In this review, regulation of stress and the stress tolerance response of E. coli to heat, acid, starvation, and cold stresses that are commonly used in food preservation and food production will be addressed. The effect of different stress on survival, adaptation, and cross-protection of E. coli studied using laboratory media, and real foods will be briefly summarized. Finally, the relationship of stress response and subsequent virulence and cross-protection will also be discussed. [source] Societal Safety: Concept, Borders and DilemmasJOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 2 2007Odd Einar Olsen In most industrialized countries, the end of the Cold War marked a change in focus from preparedness for war to an increasing focus on civil society's own vulnerability and safety. To meet new threats and changing risks, there is also a need for new analytical concepts. Societal safety is a concept developed in Norway during the last decade. It could be defined as: ,The society's ability to maintain critical social functions, to protect the life and health of the citizens and to meet the citizens' basic requirements in a variety of stress situations'. It aims to be a systematic approach for understanding, mitigating and responding to social problems such as extraordinary stresses and losses, interferences in complex and mutual dependent systems, or lack of trust in vital social institutions. Future threats to society are not limited to specific sectors or areas, but stem from complex interactions amongst economic, technological, social and cultural factors. Thus, the main challenges to improve societal safety will be the ability to coordinate, organize and assign clear roles to different actors at the international, national and local levels. Societal safety has interfaces with other safety-related areas such as national security, sustainable development, human security and incident management (handling of isolated accidents, common illness and ordinary criminal acts). Societal safety is, however, a sensitive political issue containing dilemmas and value choices that are hardly possible to perceive or solve as pure scientific problems. [source] | ||||||||||