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Stresses Related (stress + relate)
Selected AbstractsCase study on eye abnormalities in tank-reared hybrid walleyes (Sander vitreus×S. canadensis)AQUACULTURE RESEARCH, Issue 5 2006Mary Ann Garcia-Abiado Abstract Hybrid walleye is important for recreational fisheries and is a potential aquaculture species in the north central region of the United States. Stress related to intensive culture conditions has been documented to cause eye lesions in fish. Finfish eyes do not have eyelids, hence the cornea is permanently exposed to mechanical damage and toxic substances. We documented various disorders of the eye in juvenile hybrid walleyes reared in a flow-through tank system. Abnormalities include exophthalmia, enophthalmia, unilateral loss of globe and bilateral loss of globe. These lesions negatively affected body weight, specific growth rate and condition factor of hybrid walleyes reared in tanks. [source] Two-dimensional gel electrophoresis-based proteomic analysis of the Medicago truncatula,rust (Uromyces striatus) interactionANNALS OF APPLIED BIOLOGY, Issue 2 2010M.Á. Castillejo A two-dimensional gel electrophoresis (2-DE) based proteomic approach has been used to study the Medicago truncatula,Uromyces striatus interaction. The 2-DE leaf protein profile of three M. truncatula genotypes displaying different phenotypes (susceptible and showing prehaustorial and posthaustorial resistance) in both noninoculated and inoculated plants have been compared. Multivariate statistical analysis identified 63 differential protein spots under the experimental conditions (genotypes/treatments). Variable spots were subjected to tandem mass spectrometry (MS, matrix-assisted laser desorption ionisation time of flight, MALDI-TOF/TOF) analysis to identify their possible functions. A total of 27 proteins were identified using a combination of peptide mass fingerprinting (PMF) and MSMS fragmentation. Most of these observed changes correspond to enzymes involved in photosynthesis, energy metabolic pathways and stress related, whose pattern expression was different in relation to susceptibility/resistance of the genotypes studied. Results obtained in this work suggest that differences observed could be related to efficiency in energy utilisation and the induction of proteins involved in defence mechanism operating during early stages of infection. [source] Spondylolysis in a pre-contact San Francisco Bay population: behavioural and anatomical sex differencesINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2009E. Weiss Abstract Spondylolysis refers to a separation of the spinal body from the arch. Researchers have documented that these fractures occur due to stresses related to activities involving the lower limb and back. Spondylolysis in sacral and lumbar vertebrae of 146 (66 males, 66 females, 14 indeterminates) California Amerinds were examined to determine whether sex differences were present. Sacral anatomy (i.e. sacralisation and lumbarisation, sacral base angles, and superior facet morphology) was analysed in relation to spondylolysis and sex, to explore whether sex differences could be better explained through activity patterns or anatomical variation. Spondylolysis afflicted 24 individuals (16.4%). Males had more than twice the rate of spondylolysis than did females (26% and 11%, respectively). Activity patterns, such as thrusting and throwing shafted obsidian points, could explain the sex differences. Males were most frequently buried with obsidian point artefacts, whereas females were buried with mortar and pestles. For sacral anatomy, only males had lumbarisation, and all other anatomical variation had no significant sex differences. Lumbarisation related to spondylolysis in males. In this study, sacral anatomical variation could not fully account for sex differences in spondylolysis; activity patterns provided a better explanation. Nonetheless, anatomical variation may predispose males to spondylolysis, or spondylolysis may affect sacral anatomy. Copyright © 2008 John Wiley & Sons, Ltd. [source] Theoretical and experimental studies of anisotropic shrinkage in injection moldings of semicrystalline polymersPOLYMER ENGINEERING & SCIENCE, Issue 6 2006Keehae Kwon A novel approach to predict anisotropic shrinkage of semicrystalline polymers in injection moldings was proposed using flow-induced crystallization, frozen-in molecular orientation, elastic recovery, and PVT equation of state. The anisotropic thermal expansion and compressibility affected by the frozen-in orientation function and the elastic recovery that was not frozen during moldings were introduced to obtain the in-plane anisotropic shrinkages. The frozen-in orientation function was calculated from amorphous and crystalline contributions. The amorphous contribution was based on the frozen-in and intrinsic amorphous birefringence, whereas the crystalline contribution was based on the crystalline orientation function, which was determined from the elastic recovery and intrinsic crystalline birefringence. To model the elastic recovery and frozen-in stresses related to birefringence during molding process, a nonlinear viscoelastic constitutive equation was used with temperature- and crystallinity-dependent viscosity and relaxation time. Occurrence of the flow-induced crystallization was introduced through the elevation of melting temperature affected by entropy production during flow of the viscoelastic melt. Kinetics of the crystallization was modeled using Nakamura and Hoffman-Lauritzen equations with the rate constant affected by the elevated melting temperature. Numerous injection molding runs on polypropylene of various molecular weights were carried out by varying the packing time, flow rate, melt temperature, and mold temperature. The anisotropic shrinkage of the moldings was measured. Comparison of the experimental and simulated results indicated a good predictive capability of the proposed approach. POLYM. ENG. SCI., 46:712,728, 2006. © 2006 Society of Plastics Engineers [source] | ||||||||||