OTHER SIGHTS: Reflections on the Movement

These days—when tourists run from one memorial to the next, checking them off a sightseeing list, displaying appropriate grief—one has to ask: What is the purpose of the memorial? What is its effect when the historical events it memorializes lie beyond personal memory? Does the memorial serve to make history present and alive or does it seal off the past? What if "history" is still the present? How can we make the experience of reviewing history fresh and powerful both intellectually and emotionally, and in a way that might have lasting effect? How can we turn the viewer into a participant and—the ultimate ambition of memorializing projects—effect change within that person? OTHER SIGHTS began as a conversation between myself and Karen Bermann, my faculty adviser, on these issues.     

N-methyl-D-aspartate induces neurogranin/RC3 oxidation in rat brain slices

Neurogranin/RC3 (Ng), a postsynaptic neuronal protein kinase C (PKC) substrate, binds calmodulin (CaM) at low level of Ca2+. In vitro, rat brain Ng can be oxidized by nitric oxide (NO) donors and by oxidants to form an intramolecular disulfide bond with resulting downward mobility shift on nonreducing SDS-polyacrylamide gel electrophoresis. The oxidized Ng, as compared with the reduced form, is a poorer substrate of PKC but like the PKC-phosphorylated Ng has a lower affinity for CaM than the reduced form. To investigate the physiological relevance of Ng oxidation, we tested the effects of neurotransmitter, N-methyl-D-aspartate (NMDA), NO donors, and other oxidants such as hydrogen peroxide and oxidized glutathione on the oxidation of this protein in rat brain slices. Western blot analysis showed that the NMDA-induced oxidation of Ng was rapid and transient, it reached maximum within 3-5 min and declined to base line in 30 min. The response was dose-dependent (EC50 approximately 100 microM) and could be blocked by NMDA-receptor antagonist 2-amino-5-phosphonovaleric acid and by NO synthase inhibitor NG-nitro-L-arginine methyl ester and NG-monomethyl-L-arginine. Ng was oxidized by NO donors, sodium nitroprusside, S-nitroso-N-acetylpenicillamine, and S-nitrosoglutathione, and H2O2 at concentrations less than 0.5 mM. Oxidation of Ng in brain slices induced by sodium nitroprusside could be reversed by dithiothreitol, ascorbic acid, or reduced glutathione. Reversible oxidation and reduction of Ng were also observed in rat brain extracts, in which oxidation was enhanced by Ca2+ and the oxidized Ng could be reduced by NADPH or reduced glutathione. These results suggest that redox of Ng is involved in the NMDA-mediated signaling pathway and that there are enzymes catalyzing the oxidation and reduction of Ng in the brain. We speculate that the redox state of Ng, similar to the state of phosphorylation of this protein, may regulate the level of CaM, which in turn modulates the activities of CaM-dependent enzymes in the neurons.     

LacZ and OMP are co-expressed during ontogeny and regeneration in olfactory receptor neurons of OMP promoter-lacZ transgenic mice

The ontogeny and cellular specificity of expression of beta-galactosidase activity and olfactory marker protein (OMP) are compared in olfactory tissue of the H-OMP-lacZ-3 line of transgenic mice. In this line the expression of lacZ is driven by a 0.3 kb fragment of the rat OMP promoter. During fetal development, lacZ expression is detectable in olfactory receptor neurons (ORNs) shortly after the initial appearance of endogenous OMP. The beta-galactosidase marker was observed only in mature olfactory receptor neurons where it co-localized with endogenous OMP. It was absent from immature neurons that express the growth associated phosphoprotein B50/GAP43. Lesion of the peripheral olfactory pathway by intranasal irrigation with Triton X-100 eliminated expression of both OMP and lacZ in the olfactory neuroepithelium. Subsequent regeneration of the full complement of olfactory receptor neurons was associated with co-expression of both OMP and beta-galactosidase activity. Neither OMP nor beta-galactosidase activity was induced in any other cell type of the regenerating olfactory mucosa. Thus, as little as 0.3 kb of the OMP promoter has the ability to target lacZ expression to olfactory receptor neurons in a temporally and spatially defined manner. We discuss the potential utility of this transgenic line for future studies of the olfactory system.     

A KNOWLEDGE-BASED SYSTEM FOR COURSE SCHEDULING

Abstract

A knowledge-based scheduling system has been developed for the domain of university class scheduling. The problem addressed is how to schedule courses during the various time periods throughout the day. The class schedule must satisfy a variety of appropriate constraints. The system, written in Prolog, resolves conflicting assignments through backtracking. The inefficiency of Prolog's backtracking feature, with respect to this application, is partly circumvented by the use of a dynamic circular array. The system is now being used to help schedule industrial engineering classes at the Pennsylvania State University.     

The Design and Implementation of a Cooperative Design-view Environment for Interactive Partitioning Applications

This paper presents a cooperative design-view environment for interactive partitioning applications. This environment provides the user with a comprehensive viewing facility that describes the potentially complex relationships between various design objects. Using this environment, the user is able to evaluate and analyse design results visually throughout the entire partitioning process. We have developed a graphical user interface (GUI) environment for the InterPar system which supports mixed automatic and manual partitioning for multiple-field programmable gate array (FPGA) designs. The preliminary experiments have shown that the use of InterPar may lead to a new direction for the exploration of new partitioning approaches based on the circuit-structure analysis.