Andrew Crowell

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Solvent precipitation is commonly used to purify protein samples, as seen with the removal of sodium dodecyl sulfate through acetone precipitation. However, in its current practice, protein loss is believed to be an inevitable consequence of acetone precipitation. We herein provide an in depth characterization of protein recovery through acetone(More)
General trees are usually displayed as planar straight-line grid drawings which provide an easily understandable structure to the viewer. Current general tree drawing algorithms have one common problem: their drawings on high degree trees produce many small angles, which makes it difficult to distinguish edges. The algorithm we propose in this paper allows(More)
For bottom-up MS, the digestion step is critical and is typically performed with trypsin. Solvent-assisted digestion in 80% acetonitrile has previously been shown to improve protein sequence coverage at shorter digestion times. This has been attributed to enhanced enzyme digestion efficiency in this solvent. However, our results demonstrate that tryptic(More)
The analysis of large sums of data can be extremely difficult to perform if the data is not presented graphically. As a result, many graphing techniques have been developed, such as scatter plots, histograms. Generally, the main purpose of graphically displaying data is to do one of two things: First, to find the general average of where most of the data(More)
RATIONALE The identification of trace constituents in biological and environmental samples is frequently based on the fragmentation patterns resulting from the collision-induced dissociation (CID) of gas-phase ions. Credible mechanistic characterization of fragmentation processes, including rearrangements, is required to make reliable assignments for(More)
UNLABELLED Protein precipitation with organic solvent is an effective means of depleting contaminants such as sodium dodecyl sulfate (SDS), while maintaining high analyte recovery. Here, we report the use of a disposable two-stage spin cartridge to facilitate isolation of the precipitated protein, with subsequent enzyme digestion and peptide cleanup in the(More)
RATIONALE Fluorinated surfactants are being explored as mass spectrometry (MS)-friendly alternatives to sodium dodecyl sulfate (SDS) for proteome analysis. Previous work demonstrates perfluorooctanoic acid (PFOA) to be compatible with electrospray ionization (ESI)-MS. The high volatility of PFOA provides an intrinsic approach to potentially eliminate the(More)
The quality of a graph drawing algorithm is often measured by its edge crossings, angular resolution, aspect ratio, and node labeling. Algorithms for drawing trees in general are segregated from algorithms for drawing graphs. In this paper we present a graph visualization system that uses a novel interconnection between a tree drawing algorithm and graph(More)
A new graphic visualization tool, Trajectory Galaxy Visualization (TrajGalaxyViz) has been developed that significantly enhances analysts' ability to determine the accuracy of flight trajectory predictions, i.e. the anticipated route of an aircraft. The partnership between the Federal Aviation Administration's Conflict Probe Assessment Team (CPAT) and the(More)