BOOK REVIEW of Oceans of Kansas: A Natural History of the Western Interior Sea by Michael J. Everhart

Just as there are seashells on Mt. Everest, there is an exceptional wealth of fossil remains of marine organisms preserved in the chalk of western Kansas. This Cretaceous-aged rock, and the fossils therein, were deposited at a time when a great sea cut northward across the interior of the continent around 85 million years ago, inspiring the provocative title of Everhart's book. The title is true to its subject: documentation of the Cretaceous fossils of western Kansas, their geographic and stratigraphic occurrences, and the inferences that paleontologists can make about how the organisms represented by these fossils may have once lived and interacted with one another.

Layered Clustering Communication Protocol for Wireless Sensor Networks

In this paper, we propose a Layered Clustering Hierarchy (LCH) communication protocol for Wireless Sensor Networks (WSNs). The design of LCH has two goals: scalability and energy-efficiency. In LCH, the sensor nodes are organized as a layered clustering structure. Each layer runs a distributed clustering protocol. By randomizing the rotation of cluster heads in each layer, the energy load is distributed evenly across sensors in the network. Our simulations show that LCH is effective in densely deployed sensor networks. On average, 70% of live sensor nodes are involved directly in the clustering communication hierarchy. Moreover, the simulations also show that the energy load and dead nodes are distributed evenly over the network. As studies prove that the performance of LCH depends mainly on the distributed clustering protocol, the location of cluster heads and cluster size are two critical factors in the design of LCH.