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This research employs pepsin-containing membranes to digest proteins online after a capillary electrophoresis (CE) separation and prior to tandem mass spectrometry. Proteolysis after the separation allows the peptides from a given protein to enter the mass spectrometer in a single plug. Thus, migration time can serve as an additional criterion for confirming the identification of a peptide. The membrane resides in a sheath-flow electrospray ionization (ESI) source to enable digestion immediately before spray into the mass spectrometer, thus limiting separation of the digested peptides. Using the same membrane, digestion occurred reproducibly during 20 consecutive CE analyses performed over a 10 h period. Additionally, after separating a mixture of six unreduced proteins with CE, online digestion facilitated protein identification with at least 2 identifiable peptides for all the proteins. Sequence coverages were >75% for myoglobin and carbonic anhydrase II but much lower for proteins containing disulfide bonds. Development of methods for efficient separation of reduced proteins or identification of cross-linked peptides should enhance sequence coverages for proteins with disulfide bonds. Migration times for the peptides identified from a specific protein differed by <∼30 s, which allows for rejection of some spurious peptide identifications. 

The objective of this research is to evaluate the effects of cropping choices on land, water use for irrigation, and greenhouse gas emissions after introducing canola (Brassica napus L.) cultivation for the production of 60 million gallons of biodiesel per year. Characterization of regional farm-level cropping patterns and agronomic inputs and economic data are used to model the adoption of canola in place of the diverse incumbent cropping patterns in four regions of California: Northern and Southern San Joaquin Valleys, Sacramento Valley, and Southern California, using the Bioenergy Crop Adoption Model. The life cycle assessment approach is then used to assess environmental impacts due to cultivation of canola in place of the incumbent cropping patterns in terms of: (1) land use; (2) life-cycle greenhouse gas emissions due to direct land use change (kg CO2e ac-1); (3) greenhouse gas emissions due to irrigation water (kg CO2e ac-1); and (4) life-cycle greenhouse gas emissions expressed in grams of carbon dioxide equivalent per megajoule of biodiesel. Preliminary results show the adoption price of the canola with a yield of 1.5 U.S. tons per acre is estimated to be $481 per ton of canola in 2012 dollars at which point a total of 508,400 acres appear in canola cultivation. This land area (508, 400 acres) is equivalent to approximately 89 million gallons of biodiesel from canola per year given the assumptions stated in this study. Consequentially, crops that are less profitable are replaced with canola and greenhouse gas emissions due to irrigation water are reduced while maintaining a diversified percentage of the incumbent cropping patterns, as well as canola cultivation. 

The objective of this research is to evaluate the effects of cropping choices on land, water use for irrigation, and greenhouse gas emissions after introducing canola (Brassica napus L.) cultivation for the production of 60 million gallons of biodiesel per year. Characterization of regional farm-level cropping patterns and agronomic inputs and economic data are used to model the adoption of canola in place of the diverse incumbent cropping patterns in four regions of California: Northern and Southern San Joaquin Valleys, Sacramento Valley, and Southern California, using the Bioenergy Crop Adoption Model. The life cycle assessment approach is then used to assess environmental impacts due to cultivation of canola in place of the incumbent cropping patterns in terms of: (1) land use; (2) life-cycle greenhouse gas emissions due to direct land use change (kg CO2e ac-1); (3) greenhouse gas emissions due to irrigation water (kg CO2e ac-1); and (4) life-cycle greenhouse gas emissions expressed in grams of carbon dioxide equivalent per megajoule of biodiesel. Preliminary results show the adoption price of the canola with a yield of 1.5 U.S. tons per acre is estimated to be $481 per ton of canola in 2012 dollars at which point a total of 508,400 acres appear in canola cultivation. This land area (508, 400 acres) is equivalent to approximately 89 million gallons of biodiesel from canola per year given the assumptions stated in this study. Consequentially, crops that are less profitable are replaced with canola and greenhouse gas emissions due to irrigation water are reduced while maintaining a diversified percentage of the incumbent cropping patterns, as well as canola cultivation.