Envelope stress responses

Wecke T, Znhlke D, Mader U, Jordan S, Voigt B, Pelzer S, Labischinski H, Homuth G, Hecker M, Mascher T. (2009) Daptomycin versns frinlimicin B In-depth profihng of Bacillus subtilis cell envelope stress responses. Antimicrob Agents Chemother 53 1619-1623. 

Klein, G., Lindner, B., Brabetz, W., Brade, H., Raina, S. Escherichia coli K-12 suppressor-free mutants lacking early glycosyltransferases and late acyltransferases minimal lipopolysaccharide structure and induction of envelope stress response. J Biol Chem 284 (2009) 15369-15389. 

In conclusion, it should be noted that PolyPs are polyfunctional compounds. Their most important functions are as follows phosphate and energy reservation, sequestration and storage of cations, formation of membrane channels, participation in phosphate transport, involvement in cell-envelope formation and function, gene activity control, regulation of enzyme activities, and, as a result, an important role in stress response and stationary-phase adaptation. 

Typically, beams or columns with low axial compression exhibit predominantly tensile yielding. Therefore, the monotonic curve provides a reasonable envelope to the cyclic response in the tension range, while compressive behavior deviates. In columns with high compression stress levels and high confinement ratios, reinforcing bars may be subject to strain reversals of almost equal magnitude. In that case the stress level for a given strain may substantially exceed the stress indicated by the monotonic behavior (Priestley et al. 1996). 

In general, experimental results on beam-column joints without transverse steel shear reinforcement emphasize a strictly degrading behavior caused, on one hand, by the shear behavior of the joint panels and, on the other hand, by the bond-slip behavior of longitudinal reinforcements anchored in it see Fig. 10. Experimental research on the seismic performance of the beam-column joints (Walker 2001 Alire 2002 Pantelides et al. 2002) has revealed that the joint shear stress-strain response, typically, has a degrading envelope and a highly pinched hysteresis. Moreover, the common practice of terminating the beam s bottom reinforcement within the joints makes the bottom reinforcement prone to pullout under a seismic excitation. Insufficient beam bottom bar anchorage precludes the formation of bond stresses necessary to develop the yield stress in the beam s bottom reinforcement. 

This is a curious result, as it indicates that a nonlinear property can be calculated from linear data, but it has been found to describe accurately the response of polymeric liquids at sufficiently low shear rates. The low-shear-rate limiting behavior indicated by the above equations, which involves monotone increasing functions, is always shown in plots of nonlinear data the nonlinear responses involve overshoots in the material functions, but should always start out at short times, when the strain is still small, by following the low-shear-rate, LVE curve. Then, as the shear rate increases, the nonlinear data fall below the linear envelopes at shorter and shorter times [44,45]. These features can be seen in Fig. 10.9, which shows the data of Menezes and Graessley [46] for shear and first normal stress difference in start-up of simple shear. The dashed lines are calculated from the linear spectrum using Eqs.4.8 and 10.49. As expected, the... 

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