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Abstract. The chemical composition of the graphitic black carbon (GBC) fraction of marine organic matter was explored in several marine and freshwater sedimentary environments along the west coast of North America and the Pacific Ocean. Analysis by carbon x-ray absorption near edge structure (C-XANES) spectroscopy and scanning transmission x-ray microscopy (STXM) show the GBC-fraction of Stillaguamish River surface sediments to be dominated by more highly-ordered and impure forms of graphite, together forming about 80% of the GBC, with a smaller percent of an aliphatic carbon component. Eel River Margin surface sediments had very little highly-ordered graphite, and were instead dominated by amorphous carbon and to a lesser extent, impure graphite.However, the GBC of surface sediments from the Washington State Slope and the Mexico Margin were composed almost solely of amorphous carbon. Pre-anthropogenic, highly-oxidized deep-sea sediments from the open Equatorial Pacific Ocean contained over half their GBC in different forms of graphite as well as highly-aliphatic carbon, low aromatic/highly-acidic aliphatic carbon, low aromatic/highly aliphatic carbon, and amorphous forms of carbon. Our results clearly show the impact of graphite and amorphous C phases in the BC fraction in modern riverine sediments and nearby marine shelf deposits. The pre-anthropogenic Equatorial Pacific GBC fraction is remarkable in the existence of highly-ordered graphite.2

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Assessment of student learning in anatomy and physiology is an important aspect of science curriculum in undergraduate and graduate education. The use of computer models for anatomic instruction and physiology exercises is increasingly popular for a variety of reasons (logistical, cost, convenience, etc). There remains legitimate concern, and debate, about the effectiveness of this modality as evidenced by learning outcomes. This study continues previous work where we have examined student experiences objectively (student performance), and subjectively (student assessment) comparing virtual and traditional dissection modalities of education. Student evaluation records and exam performance records were recorded over a nine semester period. These were divided into two groups: group 1 participated in primarily traditional methodology (cadaver dissection, physiology lab exercises) and group 2 participated in primarily virtual lab exercises. The mean class test scores in group 1 was 74.7%, and group 2 was 78.8%. The average student evaluation scores were 2.92/3.00 in group 1, and 2.98/3.00 in group 2. By the Student "t" test on the binomial distribution, student performance was statistically different among the two groups when measured objectively, or assessed subjectively. These results suggest that use of computerized models and exercises is as effective as traditional use of cadavers in the undergraduate setting, when measured by student achievement of learning outcomes, and student's subjective perception of the experience.