The voice in the wilderness

Historical series, 16. Sermon preached on the second Sunday at the Christ Lutheran Church, Vancouver, British Columbia, Advent 2003. Lk 3:1-6

Church conflict: from contention to collaboration

Title: Church conflict: from contention to collaboration. Author: Everist, Norma Cook Church conflict 158 p. Publisher: Nashville : Abingdon Pr, 2004

Honour for shame

Historical series, 7. Sermon delivered at Christ Lutheran Church, Vancouver, 7 N 2004 (All Saints Sunday). Luke 6: 17-26

Barge Transport of Illinois River Sediment from Peoria to Chicago

A barge load of sediment excavated by clamshell from Lower Peoria Lake was shipped to Chicago, Ill. It was loaded onto trucks with a large excavator and placed at a conservation area and the Paxton I landfill reclamation site (Figures 1 and 2). The material handled well and maintained its consistency in the barge and after placing. It readily dumped from the trucks and formed piles about 2.5 feet high. The demonstration showed that this material can be transported and handled with conventional equipment and placed on fields without the necessity of using engineered containment structures

Order Invariance on Decomposable Structures

Order-invariant formulas access an ordering on a structure's universe, but the model relation is independent of the used ordering. Order invariance is frequently used for logic-based approaches in computer science. Order-invariant formulas capture unordered problems of complexity classes and they model the independence of the answer to a database query from low-level aspects of databases. We study the expressive power of order-invariant monadic second-order (MSO) and first-order (FO) logic on restricted classes of structures that admit certain forms of tree decompositions (not necessarily of bounded width). While order-invariant MSO is more expressive than MSO and, even, CMSO (MSO with modulo-counting predicates), we show that order-invariant MSO and CMSO are equally expressive on graphs of bounded tree width and on planar graphs. This extends an earlier result for trees due to Courcelle. Moreover, we show that all properties definable in order-invariant FO are also definable in MSO on these classes. These results are applications of a theorem that shows how to lift up definability results for order-invariant logics from the bags of a graph's tree decomposition to the graph itself.Comment: Accepted for LICS 201

Are Wild Bee Pollinator Populations Declining?

How climate change may affect insect pollinator populations in the Midwest.Environmental Change Institute UIUCAgroecology and Sustainable Agriculture Program UIUCunpublishednot peer reviewe