Properties of optimal survivable paths in a graph

AbstractWe introduce the concept of a survivable path in an undirected graph G. A survivable path between a pair of vertices in G is a pair of edge-disjoint paths consisting of a working path and a redundant protection path. Protection paths share edges in such a manner as to provide guaranteed recovery upon the failure of any single edge. Survivable paths play an important role in the design of survivable communication networks. We demonstrate several results on the properties of the optimal set of survivable paths

Alpha-ring independent assembly of the 20S proteasome

Archaeal proteasomes share many features with their eukaryotic counterparts and serve as important models for assembly. Proteasomes are also found in certain bacterial lineages yet their assembly mechanism is thought to be fundamentally different. Here we investigate α-ring formation using recombinant proteasomes from the archaeon Methanococcus maripaludis. Through an engineered disulfide cross-linking strategy, we demonstrate that double α-rings are structurally analogous to half-proteasomes and can form independently of single α-rings. More importantly, via targeted mutagenesis, we show that single α-rings are not required for the efficient assembly of 20S proteasomes. Our data support updating the currently held "α-ring first" view of assembly, initially proposed in studies of archaeal proteasomes, and present a way to reconcile the seemingly separate bacterial assembly mechanism with the rest of the proteasome realm. We suggest that a common assembly network underpins the absolutely conserved architecture of proteasomes across all domains of life

EVALUATION OF A FINANCIAL DECISION SUPPORT SYSTEM IN BUSINESS EDUCATION: AN EXPERIMENTAL STUDY

This study explores the use of computers in business education and its impact on the performance of students. A controlled experimental study has been carried out to determine the differences in performance of students in a computer assisted mstruction (CAI) group with that of a control group. It investigates the relationship between performance and various student-specific characteristics such as aptitude, attitude, sex, domain experience, domain expertise, and system experience. The relationships b between attitude towards CAI, fulfillment of expectations, and satisfaction with the system and course have also been explored. The results indicate that CAI has favorable effects on students\u27 performance and that personal attributes have relatively less important roles to play