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Exploring How Middle School Students' Epistemologies In Practice Change Across Time With Varying Content Areas And Knowledge Product Contexts, Mackenzie Evan English

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Recently, the National Research Council developed A Framework for K-12 Science Education (NRC, 2012), to support a new vision of science education. The Framework (2012) focuses on three integrated dimensions--disciplinary core ideas, crosscutting concepts, and scientific and engineering practices which is different than traditional ways of learning science. I focused on students' engagement in scientific practices, attention to epistemological practices (EIP) that guide students' construction, evaluation and revision of knowledge products. I examined how students EIP's changed over time and across contexts with respect to different knowledge product types (models and explanations). I present data from 103, 6th grade students …

Assortative Fertilization In The Elegans-Group Of Caenorhabditis, Sara Rose Seibert

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Assortative fertilization refers to the species-specific interactions between sperm and oocytes that affect the success of fertilization. One type of interaction is chemotaxis of sperm to oocytes. In Caenorhabditis elegans, amoeboid sperm must crawl along the uterine lining towards the spermathecae in response to oocyte-derived prostaglandin signals for fertilization. This chemotactic signaling system likely operates in other species of the Elegans-Group of Caenorhabditis as sperm of C. briggsae and C. remanei do localize to the C. elegans spermathecae. In this project the impacts of species-specific chemotaxis on fertilization and female fecundity were assessed. To accomplish this, the localization of …

Opiliones Biodiversity In Cusuco National Park, Honduras, Brittany N. Damron

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Biodiversity in the tropics is especially diverse and describing species found in the tropics is important. Opiliones species richness is higher in the tropics than the temperate zone, with diversity highest in low latitudes. This study aims to catalog the Opiliones community in Cusuco National Park, Honduras, while estimating species richness and describing their abundance, distribution and community structure. Fifty hours of sampling at 6 sites yielded 18 morphospecies and 264 individual Opiliones were collected. This study added one new described species to the Opiliones fauna of Honduras, and fourteen morphospecies may represent new species. An estimated 43 to 112 …

Co-Evolution Of Mitochondrial And Nuclear Genomes In Caenorhabditis , Emily Elaine Hill

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Nuclear and mitochondrial genomes have co-adapted through evolution. Interactions between these genomes are required for mitochondrial functions. My goal was to determine how divergence of these interactions affected mitochondrial function and organismal fitness. The impact of divergence between Caenorhabditis briggsae populations and between C. briggsae and its sister species, C. nigoni was assessed. To accomplish this, four sets of hybrid lines were constructed. Each hybrid line possessed the nuclear genome of one parental strain and mitochondria from another parental strain. Two sets of hybrid lines were constructed from strains derived from different C. briggsae populations. The other two were constructed …

Direct And Indirect Effects Of White-Tailed Deer (Odocoileus Virginianus) Herbivory On Beetle And Spider Assemblages In Northern Wisconsin, Elizabeth J. Sancomb

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White-tailed deer directly impact vegetation structure and species composition through selective foraging, and indirectly impact other species by altering habitat, food-web interactions, and microclimate. I examined the direct effects of deer exclusion on vegetation communities, and indirect effects on beetle, spider, and web-building spider (WBS) assemblages. Forb and woody plant percent cover were higher in exclosures, while graminoid cover was higher in controls. There were no differences in beetle and spider assemblages between browsed and protected areas. The absence of differences could be attributed to legacy effects, or alternatively high vagility of individuals. WBS assemblages were more abundant and diverse …

Binding And Entry Mechanisms Of Adenovirus In Polarized Epithelial Cells, Trisha Lynn Brockman

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Adenovirus's primary receptor, the Coxsackievirus and adenovirus receptor (CAR), has two transmembrane isoforms with differential localization within polarized epithelial cells (CAREx7 (basolateral), CAREx8 (apical)). I hypothesized that each isoform of CAR is degraded at different rates and is regulated by Src-family kinases. Increasing or decreasing the concentration of CAR is predicted to directly alter adenoviral entry. To test this hypothesis, inducible Madin Darby Canine Kidney (MDCK) cell lines either expressing CAREx7, CAREx8, or mCherry, under a doxycycline-inducible promoter were used in pulse-chase structured experiments to calculate the half-lives of these proteins. Alternatively, a polarized model lung epithelium (CaLu-3) treated with …

Effects Of Rev Protein On Microtubule Arrays In Living Cells, Nayana M. Nikumbh

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The HIV protein Rev regulates the expression of essential viral proteins during the course of infection by a mechanism that is well understood. It promotes nuclear export of viral transcripts, normally retained in the nucleus owing to the presence of introns, by interacting with host cell transport factors. However, over-expression of Rev in cells leads to defects in cell cycle progression, specifically slowing growth and impairing progression through mitosis (43). While it is possible that Rev may be altering the proteins in transport pathways, cell cycle defects may be attributed to Rev's interactions with other proteins.

In vitro experiments show …