928 resultados para Osmotic Tolerance


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Previous studies have demonstrated that the initial hypoalgesic effect of spinal manipulative therapy was not antagonized by naloxone and did not exhibit tolerance with repeated applications. The implication is that endogenous opioid mechanisms of pain relief are probably not at play in spinal manipulative therapy. The role of endogenous opioid peptides in manipulation of the peripheral joints has not been investigated. The aim of this study was to evaluate whether the initial hypoalgesic effect of a peripheral manipulative technique (mobilization-with-movement treatment for the elbow) demonstrated a tolerance to repeated applications (ie, reduction in magnitude of effect over repeated applications). Twenty-four participants with unilateral chronic lateral epicondylalgia participated in the study. A repeated measures study was conducted to examine the effect of repeated applications of the mobilization-with-movement treatment for the elbow on 6 separate treatment occasions at least 2 days apart. Pain-free grip strength and pressure pain threshold were chosen as the pain-related outcome measures. Changes in the percent maximum possible effect scores of measures of hypoalgesia were evaluated across the 6 treatment sessions by using linear trend analysis. The results showed no significant difference for the hypoalgesic effect of the treatment technique between sessions (P >.05). This peripheral manipulative therapy treatment technique appeared to have a similar effect profile to previously studied spinal manipulative therapy techniques, thereby contributing to the body of knowledge that indicates that manipulative therapy most likely induces a predominant non-opioid form of analgesia.

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CD40 is a key signaling pathway for the function of B cells, monocytes, and dendritic cells in the immune system, and plays an important role in inflammatory pathways of nonhemopoietic cells. The NFkappaB family of transcription factors is a critical mediator in inflammation. NFkappaB is involved both in the regulation of CD40 expression and in cell signaling after CD40 ligation. This positive feedback loop linking NFkappaB and CD40 plays an important role in the control of the adaptive immune response, with fundamental implications for immunity and tolerance in vivo.

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Aluminium (At) tolerance in plants may be conferred by reduced binding of Al in the cell wall through low root cation exchange capacity (CEC) or by organic acid exudation. Root CEC is related to the degree of esterification (DE) of pectin in the cell wall, and pectin hydrolysis plays a role in cell expansion. Therefore, it was hypothesised that Al-tolerant plants with a low root CEC maintain pectin hydrolysis in the presence of Al, allowing cell expansion to continue. Irrespective of the DE, binding of Al to pectin reduced the enzymatic hydrolysis of Al-pectin gels by polygalacturonase (E.C. 3.2.1.15). Pectin gels with calcium (Ca) were slightly hydrolysed by polygalacturonase. It was concluded, therefore, that Al tolerance conferred by low root CEC is not mediated by the ability to maintain pectin hydrolysis. Citrate and malate, but not acetate, effectively dissolved Al-pectate gel and led to hydrolysis of the dissolved pectin by polygalacturonase. The organic acids did not dissolve Ca-pectate, nor did they increase pectin hydrolysis by polygalacturonase. It was concluded that exudation of some organic acids can remove Al bound to pectin and this could alleviate toxicity, constituting a tolerance mechanism. (C) 2003 Editions scientitiques et medicales Elsevier SAS. All rights reserved.

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Abstract: There is a need for heat tolerant wheat cultivars adapted to the expansion of cultivation areas in warmer regions due to the high demand of this cereal for human consumption. The objective of this study was to evaluate the effect of high temperatures on grain yield and yield components of wheat and characterize heat tolerant wheat genotypes at different development stages. The genotypes were evaluated in the field with and without heat stress. High temperatures reduced the number of spikelets per spike (21%), number of grains per spike (39%), number of grains per spikelet (23%), 1000-grain weight (27%) and grain yield (79%). Cultivars MGS 1 Aliança, Embrapa 42, IAC 24-Tucuruí and IAC 364-Tucuruí III are the most tolerant to heat stress between the stages double ridge and terminal spikelet; MGS 1 Aliança, BRS 264, IAC 24-Tucuruí, IAC 364-Tucuruí III and VI 98053, between meiosis and anthesis; and BRS 254, IAC-24-Tucuruí, IAC-364-Tucuruí III and VI 98053, between anthesis and physiological maturity. High temperatures reduce grain yield and yield components. The number of grains per spike is the most reduced component under heat stress. The genotypes differed in tolerance to heat stress in different developmental stages.

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Predators and Tourism Increase Intolerance? A. Treves and J. Bruskotter Perspective in Ecology "Tolerance for Predatory Wildlife" (2 May, 344: 476) suggest that intolerance for predators do not fit into the conventional view of perceived threats for livelihoods but instead by complex social factors. Although the above perspective focuses in jaguars, wolves, lions and bears, the same reasoning is perfectly applied to other economical contexts and different human-wildlife interactions. Nature tourism is a growing industry attracting a significant number of people to exotic places to see wildlife and, of course, many predators are on the main "menu". [...].

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YAP4, a member of the yeast activator protein (YAP) gene family, is induced in response to osmotic shock in the yeast Saccharomyces cerevisiae. The null mutant displays mild and moderate growth sensitivity at 0.4 M and 0.8 M NaCl respectively, a fact that led us to analyse YAP4 mRNA levels in the hog1 (high osmolarity glycerol) mutant. The data obtained show a complete abolition of YAP4 gene expression in this mutant, placing YAP4 under the HOG response pathway. YAP4 overexpression not only suppresses the osmosensitivity phenotype of the yap4 mutant but also relieves that of the hog1 mutant. Induction, under the conditions tested so far, requires the presence of the transcription factor Msn2p, but not of Msn4p, as YAP4 mRNA levels are depleted by at least 75% in the msn2 mutant. This result was further substantiated by the fact that full YAP4 induction requires the two more proximal stress response elements. Furthermore we find that GCY1, encoding a putative glycerol dehydrogenase, GPP2, encoding a NAD-dependent glycerol-3-phosphate phosphatase, and DCS2, a homologue to a decapping enzyme, have decreased mRNA levels in the yap4 -deleted strain. Our data point to a possible, as yet not entirely understood, role of the YAP4 in osmotic stress response.

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This paper presents an architecture (Multi-μ) being implemented to study and develop software based fault tolerant mechanisms for Real-Time Systems, using the Ada language (Ada 95) and Commercial Off-The-Shelf (COTS) components. Several issues regarding fault tolerance are presented and mechanisms to achieve fault tolerance by software active replication in Ada 95 are discussed. The Multi-μ architecture, based on a specifically proposed Fault Tolerance Manager (FTManager), is then described. Finally, some considerations are made about the work being done and essential future developments.

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Erythrocyte osmotic fragility (EOF) was carried out in nineteen dogs naturally infected by Leptospira interrogans serovar icterohaemorrhagiae/copenhagi. A decreased EOF was observed, suggesting a modification of erythrocyte components secondary to disturbances that occur during canine leptospirosis, such as renal damage and hepatic disease.

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Dissertation presented to obtain a Doctoral degree in Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa.

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It is imperative to accept that failures can and will occur, even in meticulously designed distributed systems, and design proper measures to counter those failures. Passive replication minimises resource consumption by only activating redundant replicas in case of failures, as typically providing and applying state updates is less resource demanding than requesting execution. However, most existing solutions for passive fault tolerance are usually designed and configured at design time, explicitly and statically identifying the most critical components and their number of replicas, lacking the needed flexibility to handle the runtime dynamics of distributed component-based embedded systems. This paper proposes a cost-effective adaptive fault tolerance solution with a significant lower overhead compared to a strict active redundancy-based approach, achieving a high error coverage with the minimum amount of redundancy. The activation of passive replicas is coordinated through a feedback-based coordination model that reduces the complexity of the needed interactions among components until a new collective global service solution is determined, improving the overall maintainability and robustness of the system.

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Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Didáctica do Inglês,

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The osmotic threshold for vasopressin release was studied in normal patients (n = 7) and in patients with the chronic form of Chagas'disease (n = 11). Positive correlation between osmotic threshold and plasma cortisol concentration was obtained for the Controls (y1 = 273,30 + 0,75x i; r = 0,78;P < 0,05), suggesting a modulating effect of cortisol on vasopressin release. The lack of correlation between the two parameters for the chronic chagasic patients was interpreted, on the basis of the general denervation associated with Chagas ' disease, to be the result of neuronal destruction in hypothalamic and/or extrahypothalamic centers related to the secretory control of vasopressin.