Interpretations of and options in dual-rate predictive control

The main purpose of this paper is to give insight into dual rate predictive control. First it gives an overview of common techniques deployed in the design of predictive control and then discusses how these have been modified for use on dual-rate systems. It is also shown how the approaches vary with differing model availability and the repercussions this can have on the control design. The key contribution is then to expose common pitfalls for the control designer and suggest some simple remedies. Some discussion is also given to robustness analysis and the relationship with the respective sample rates.     

A cruciform-dumbbell model for inverted dimer formation mediated by inverted repeats

Small inverted repeats (small palindromes) on plasmids have been shown to mediate a recombinational rearrangement event in Escherichia coli leading to the formation of inverted dimers (giant palindromes). This recombinational rearrangement event is efficient and independent of RecA and RecBCD. In this report, we propose a cruciform-dumbbell model to explain the inverted dimer formation mediated by inverted repeats. In this model, the inverted repeats promote the formation of a DNA cruciform which is processed by an endonuclease into a linear DNA with two hairpin loops at its ends. Upon DNA replication, this linear dumbbell-like DNA is then converted to the inverted dimer. In support of this model, linear dumbbell DNA molecules with unidirectional origin of DNA replication (ColE1 ori ) have been constructed and shown to transform E.coli efficiently resulting in the formation of the inverted dimer. The ability of linear dumbbell DNA to transform E.coli suggests that the terminal loops may be important in bypassing the requirement of DNA supercoiling for initiation of replication of the ColE1 ori.     

Expression of fibronectin splicing variants in organ transplantation: a differential pattern between rat cardiac allografts and isografts

Allograft rejection is associated with infiltration of inflammatory cells and deposition of extracellular matrix proteins. The extent to which diversity in the extracellular matrix regulates inflammatory cell function in transplants remains unclear. One group of extracellular matrix proteins, termed fibronectins (FNs), exhibits inherent diversity as a consequence of alternative splicing in three segments: EIIIA, EIIIB, or V. Although the EIIIA segment has documented functions in mesenchymal cell differentiation, neither this segment nor the EIIIB segment have been tested for effects specific to leukocyte functions. By contrast, the V region can include the CS-1 segment to which leukocytes may adhere through alpha 4 beta 1 integrins. In this study, we demonstrate that EIIIA+, EIIIB+, and V+ FN variants are synthesized, primarily by macrophages in distinct temporal and spatial patterns in two rat cardiac transplant models: either with antigenic challenge, allografts, or without challenge, isografts. The ratio of EIIIA inclusion into FN increases by day 1 in allografts and isografts and remains high until allografts are rejected (approximately 7 days) but falls to normal levels in tolerated isografts (day 6). EIIIB+ FN ratios in allografts peak later than do EIIIA+ FNs (day 4). EIIIB+ FN ratios remain relatively low in isografts. Interestingly, EIIIA+ and EIIIB+ FNs are deposited prominently in the myocardium of rejecting allografts in close association with infiltrating leukocytes, and FN expression and deposition are prominent at sites of infarction. By contrast, these FNs are largely restricted to the epicardium and to a lesser degree in the immediately adjacent myocardium in isografts. CS-1+ FNs increase in allografts and isografts at 3 hours after transplantation but are particularly prominent in allografts 1 to 3 days before rejection. Our data suggest that FN splicing variants have a differential role in the effector functions of leukocytes in allografts and isografts and provide a foundation for testing their function on leukocytes and a rationale for FN-based therapeutics to modulate allograft rejection in transplant recipients.     

Ganglioside GM1 attenuates scopolamine-induced amnesia in rats and mice

We evaluated ethanol- and HCl-induced mucosal damages in developing rats. The degree of damage induced by ethanol and HCl was greatest in 1-week-old rats and decreased significantly with age until 4 weeks; thereafter it increased again. To evaluate the effect of weaning on the maturational changes in mucosal defense, we compared ethanol-induced mucosal damage among three groups of newborn rats: (1) receiving milk only; (2) receiving only rat chow from 14 days of age, and (3) having free access to milk and chow. There were no significant differences at 18 and 21 days of age. The mucus thickness increased with age until 8 weeks and was not affected by weaning. In conclusion, developmental changes occur in gastric mucosal protection in rats. Weaning does not have a significant effect on these changes.