The Moderate-resolution Imaging Spectroradiometer (MODIS) instrument on board the Terra satellite offers an unprecedented combination of daily spatial coverage, spatial resolution, and spectral characteristics. These capabilities make MODIS ideal to observe a variety of rapid events: active fires, floods, smoke transport, dust storms, severe storms, iceberg calving, and volcanic eruptions. A new processing system has been developed at NASA's Goddard Space Flight Center to provide a rapid response to those events, with initial emphasis on active fire detection and 250-m resolution imagery. MODIS data of most of the Earth's land surface is processed within a few hours of data acquisition. Collaboration between NASA, the University of Maryland and the USDA Forest Service has been developed to provide fire information derived from MODIS to the fire managers. Active fire locations in the conterminous United States are produced by the MODIS Rapid Response System and communicated to the Forest Service within a few minutes of production. These active fire locations are used to generate regional fire maps, updated daily and provided to the fire managers to help them allocate adequate resources to firefighters. Active fire locations are also distributed to the Global Observation of Forest Cover (GOFC) user community through a Web interface integrating MODIS active fire locations and geographic information system datasets.

A method for assessing the preserved stem-loops of RNA secondary structures is presented. Frequently recurring helical stems in a set of secondary structures resulting from the simulated folding process of a given RNA are assessed and consensus structural motifs can then be selected to construct a secondary structure of the RNA. Alternatively, it can be applied to a series of 'optimal' and 'suboptimal' secondary structures computed using the dynamic program developed by Williams and Tinoco. To demonstrate the power and the usefulness of the program we give examples of this procedure.

A fixed-point alignment analysis technique is presented which is designed to locate common sequence motifs in collections of proteins or nucleic acids. Initially a program aligns a collection of sequences by a common sequence pattern or known biological feature. The common pattern or feature (fixed-point) may be a user-specified sequence string or a known sequence position like mRNA start site, which may be taken directly from the annotated feature table of GenBank. Once all alignment markers are located, the sequences are scanned for occurrences of given oligomers within a specified span both upstream and downstream of the fixed-point. The occurrences may then be plotted as a function of the position relative to the fixed-point, displayed as an actual sequence alignment or selectively summarized via various program options. Applications of the technique are discussed.