An extended southern subtropical plume of CO meanders > 15,000 km around the world, gradually spreading around ̃20 S. This southern pollution plume is most noticeable in the burning season, southern spring; a similar subtropical plume appears in the northern spring. We use tracer maps to guide the use of trajectories to trace observations of the plume to their origins. The MM5 mesoscale model provides highresolution, near-global synoptic reconstructions of the weather. Two situations are analyzed: NASA's airborne Pacific Exploratory Mission-Tropics A (PEM-Tropics A) period, September-October 1996 and the PEM-Tropics B period, March-April 1999. Similar features are noted for a much earlier mission in 1977, which apparently captured the first, but never-recognized, samples of the global pollution of the Southern Hemisphere. For PEM-Tropics A, near-source pieces of the plume are clearly seen in the Total Ozone Mapping Spectrometer (TOMS) absorbing aerosol product and are well simulated. Downwind, the aircraft sampling of several strands deriving from a single plume seems representative and well simulated. A general mechanism of the plume emerges: The southern plume arises in surface accumulation regions in Africa and South America. Thunderstorm-scale venting of pollutants usually lofts the plume; however, synoptic-scale lifting can produce intense outbreaks. The plume flows eastward in the subtropical jet region as a single coherent but articulated current until it is increasingly filamented by storms in the Pacific. A similar northern subtropical plume is described for the PEM-Tropics B period. The 100-km model resolution we used seemed to capture much of the variability. However, the model somewhat under predicted the highest values. Copyright 2002 by the American Geophysical Union.

This dissertation will focus on detecting analytes in aqueous solution that chemically react with or bind to functional groups near the opening of synthetic ion channels derived from gramicidin A (gA). Detection is achieved when a measurable change in the conductance of ions across the ion channel is produced after the analyte interacts with the channel. Ion channel sensors have great potential for achieving ultrasensitive detection since a single chemical modification near the lumen of the channel can lead to detectable changes in channel conductance. The dissertation will specifically focus on: (1) the development of design parameters to improve sensing with gA-based nanosensors; (2) the demonstration of sensing analytes in aqueous solution by manipulating the charge of a chemical group near the pore of gA (charge-based sensing); (3) the chemistry for producing reactive building blocks of gA for developing robust and diverse gA -based nanosensors; (4) the detection of enzyme activity using our charge-based sensing approach to achieve picomolar limits of detection; and (5) the small structural changes that can be introduced to the peptide near the lumen of the channel to control conductance

Escape to the Void is an interactive fiction game that has you play as a scientist trying to escape from a crashing space station. You must make tough decisions if you are to escape from this tragedy alive. The game's purpose is to explore a persons moral character by having the player choose between being selfish or selfless. The game also shows that our actions have unforeseen consequences.

Author biographies for Special Issue