Shape selection in Landsat time series: a tool for monitoring forest dynamics.

We present a new methodology for fitting nonparametric shape-restricted regression splines to time series of Landsat imagery for the purpose of modeling, mapping, and monitoring annual forest disturbance dynamics over nearly three decades. For each pixel and spectral band or index of choice in temporal Landsat data, our method delivers a smoothed rendition of the trajectory constrained to behave in an ecologically sensible manner, reflecting one of seven possible 'shapes'. It also provides parameters summarizing the patterns of each change including year of onset, duration, magnitude, and pre- and postchange rates of growth or recovery.

A critical pathway for patients with acute chest pain and low risk for short-term adverse cardiac events: role of outpatient stress testing.

Study Objective: We evaluate the safety and feasibility of a critical care pathway protocol in which patients with acute chest pain who are low risk for coronary artery disease and short-term adverse cardiac outcomes receive outpatient stress testing within 72 hours of an emergency department (ED) visit.

Methods: We performed an observational study of an ED-based chest pain critical pathway in an urban, community hospital in 979 consecutive patients. Patients enrolled in the protocol were observed in the ED before receiving 72-hour outpatient stress testing.

Prevalence and degree of childhood and adolescent overweight in rural, urban, and suburban Georgia.

The prevalence and severity of child and adolescent overweight (OW) in the United States have been documented, but little is known regarding the prevalence of OW and "Extent of Overweight" (EOW) in individual states or specific regions within states. The aim of this study was to determine the prevalence of OW and EOW in school-aged youths from 4 regions of Georgia. A 2-stage cluster sampling procedure was performed in 2002, with participation of 4th-, 8th- and 11th-grade students (N = 3114).

Directed walk designs for dose-response problems with competing failure modes.

We examine adaptive allocation designs for the problem of determining the optimal therapeutic dose for subjects in early-phase clinical trials. A subject can fail due to lack of efficacy or due to a toxic reaction. Successful subjects will have both a positive response and no toxic side effects.