The provocative lumbar facet joint

Low back pain is the most common pain symptom experienced by American adults and is the second most common reason for primary care physician visits. There are many structures in the lumbar spine that can serve as pain generators and often the etiology of low back pain is multifactorial. However, the facet joint has been increasingly recognized as an important cause of low back pain. Facet joint pain can be diagnosed with local anesthetic blocks of the medial branches or of the facet joints themselves. Subsequent radiofrequency lesioning of the medial branches can provide more long-term pain relief. Despite some of the pitfalls associated with facet joint blocks, they have been shown to be valid, safe, and reliable as a diagnostic tool. Medial branch denervation has shown some promise for the sustained control of lumbar facet joint-mediated pain, but at this time, there is insufficient evidence that it is a wholly efficacious treatment option. Developing a universal algorithm for evaluating facet joint-mediated pain and standard procedural techniques may facilitate the performance of larger outcome studies. This review article provides an overview of the anatomy, pathophysiology, diagnosis, and treatment of facet joint-mediated pain

Dart: Distributed automated regression testing for large-scale network applications

This paper presents DART, a framework for distributed automated regression testing of large-scale network applications. DART provides programmers writing distributed applications with a set of primitives for writing distributed tests and a runtime that executes distributed tests in a fast and efficient manner over a network of nodes. It provides a programming environment, scripted execution of multi-node commands, fault injection, and performance anomaly injection. We have implemented a prototype implementation of DART that implements a useful subset of the DART architecture and is targeted at the Emulab network emulation environment. Our prototype is functional, fast, and is currently being used to test the correctness, robustness, and performance of PIER, a distributed relational query processor.

Information and Control in Gray-Box Systems

In modern systems, developers are often unable to modify the underlying operating system. To build services in such an environment, we advocate the use of gray-box techniques. When treatin