Characterization of vascular cavity coatings and microscopic tube-shaped structures from Upper Cretaceous dinosaur bone: evidence of a bacterial origin for dinosaur blood vessels""

Recent claims of blood vessels extracted from dinosaur fossils challenge classical views of soft-tissue preservation. Alternatively, these structures may represent postdepositional,diagenetic biofilms that grew on vascular cavity surfaces within the fossil. Similar red, hollow, tube-shaped structures were recovered from well-preserved and poorly-preserved (abraded, desiccated, exposed) Upper Cretaceous dinosaur fossils in this study. Integration of light microscopy, scanning electron microscopy, and energy dispersive x-ray spectroscopy was used to compare these vessel structures to the fossils from which they are derived. Vessel structures are typically 100-400 μm long, 0.5-1.5 μm thick, 10-40 μm in diameter and take on a wide range of straight, curved, andbranching morphologies. Interior surfaces vary from smooth to globular and typically contain spheres, rods, and fibrous structures (< 2 μm in diameter) incorporated into the surface. Exterior surfaces exhibit 2-μm-tall converging ridges, spaced 1-3 μm apart, that are sub-parallel to the long axis of the vessel structure. Fossil vascular cavities are typically coated with a smooth or grainy orange layer that shows a wide range of textures including smooth, globular, rough, ropy, and combinations thereof. Coatings tend to overlay secondary mineral crystals and framboids, confirming they are not primary structures of the fossil. For some cavity coatings, the surface that had been in contact with the bone exhibits a ridged texture, similar to that of vessel structures, having formed as a mold of the intravascular bone surface. Thus, vessel structures are interpreted as intact cavity coatings isolated after the fossil is demineralized. The presence of framboids and structures consistent in size and shape with bacteria cells, the abundance of iron in cavity coatings, and the growth of biofilms directly from the fossil that resemble respective cavity coatings support the hypothesis that vessel structures result from ironconsuming bacteria that form biofilms on the intravascular bone surfaces of fossil dinosaur bone. This also accounts for microstructures resembling osteocytes as some fossil lacunae are filled with the same iron oxide that comprises vessel structures andcoatings. Results of this study show that systematic, high-resolution SEM analyses of vertebrate fossils can provide improved insight on microtaphonomic processes, including the role of bacteria in diagenesis. These results conflict with earlier claims of dinosaurblood vessels and osteocytes.

Dads, Daughters, And Disney: The Historical Trajectory Of Fairy Tale Fathers And Daughters

In my thesis I use a historical approach to close readings of fairy tale texts and movies to study the evolution of fathers, daughters, and marriage within three landmark tales: ¿Cinderella,¿ ¿Sleeping Beauty,¿ and ¿Snow White.¿ Using the works of Giambattista Basile, Charles Perrault, Jacob and Wilhelm Grimm, and Walt Disney and his cohort of animators, I trace the historical trajectory of these three elements, analyzing both the ways they change and develop as history progresses as well as the ways they remain consistent. Through close and comparative readings of primary sources and films, I demonstrate the power structures and familial dynamics evident through the interactions of fathers and daughters. Specifically, I show that through the weakness and ineptitude of fairy tale fathers, fairy tale daughters are able to gain power, authority, and autonomy by using magic and marriage to navigate patriarchal systems. The work I have done is important because it explores how each tale is a product of the story before it and thus that in order for these tales to continue to survive the test of time, we must not only recognize the validity of the academic merit of the Disney stories, but also remember them and others as we forge new paths in the stories we use to teach both children and parents. Specifically, this work is important because it explores the historical trend evident in the evolving relationships between fathers and daughters. This relationship ultimately it reveals the deep underlying need for family within all of us.