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Marsupial And Monotreme Enamel Structure, K. S. Lester, A. Boyde, C. Gilkeson, M. Archer

Scanning Microscopy

We present some recent developments in our understanding of two basic questions: the origin, extent, nature and course of marsupial enamel tubules; and the characterisation of monotreme enamel, more particularly, the prismatic nature of platypus enamel.

Methods used included SEM of methacrylate casts of marsupial enamel tubules, worn and cut surfaces of whole marsupial teeth, developing and erupted platypus teeth, and a well-developed molar of the newly discovered Miocene ornithorhynchid Obdurodon sp., and tandem scanning reflected light microscopy of intact marsupial teeth.

We conclude that there are significant species differences with respect to prism shape, row formation and tubule disposition …

Agenda: External Development Affecting The National Parks: Preserving "The Best Idea We Ever Had", University Of Colorado Boulder. Natural Resources Law Center

External Development Affecting the National Parks: Preserving "The Best Idea We Ever Had" (September 14-16)

Conference organizers and/or faculty included University of Colorado School of Law professors Lawrence J. MacDonnell and Daniel Magraw.

The conference will be held at the Aspen Lodge, adjacent to Rocky Mountain National Park near Estes Park, Colorado.

It was Wallace Stegner who called the national parks "the best idea we ever had." The continuing increases in usage attest to their popularity. National parks are created to preserve areas of special scenic and cultural value for enjoyment and use. Managing the parks in a manner that protects the important values and purposes for which they were created presents important and difficult …

Otoconia As Test Masses In Biological Accelerometers: What Can We Learn About Their Formation From Evolutionary Studies And From Work In Microgravity?, Muriel D. Ross, Kathleen M. Donovan

Scanning Electron Microscopy

This paper reviews previous findings and introduces new material about otolith end organs that help us to understand their functioning and development. In particular, we consider the end organs as biological accelerometers. The otoconia are dealt with as test masses whose substructure and evolutionary trend toward calcite may prove significant in understanding formation requirements. Space-flight helps illuminate the influence of gravity, while right-left asymmetry is suggested by study of certain rat strains.

The Role Of Plant Hormones In Grass Tiller Development, Marit Snow

Undergraduate Honors Capstone Projects

Two bunchgrass species commonly found in the Intermountain West, Agropyron spicatum and A. desertorum, are morphologically similar but respond to defoliation very differently. A. desertorum produces more daughter tillers and is more hardy than A. spicatum. Hormones were applied to experimental plants to observe changes in tillering rates, growth rates, and response of plants to the stress of exogenous hormone application. Gibberellic acid treatments were related to increased tiller height in both species, but also a decrease in daughter tiller production in A. desertorum and an increase in senescence in A. spicatum. Kinetin increased senescence in A. desertorum. Auxin showed …