Life Sciences Commons^™

Peripheral And Central Mechanisms Of Temporal Pattern Recognition, Christa Ann Baker

Arts & Sciences Electronic Theses and Dissertations

Encoding information into the timing patterns of action potentials, or spikes, is a strategy used broadly in neural circuits. This type of coding scheme requires downstream neurons to be sensitive to the temporal patterns of presynaptic inputs. Indeed, neurons with temporal filtering properties have been found in a wide range of sensory pathways. However, how such response properties arise was previously not well understood. The goal of my dissertation research has been to elucidate how temporal filtering by single neurons contributes to the behavioral ability to recognize timing patterns in communication signals.

I have addressed this question using mormyrid weakly …

Evolutionary Developmental Leaf Morphology Of The Plant Family Araceae, Claudia Liliana Henriquez

Arts & Sciences Electronic Theses and Dissertations

Studying the evolutionary developmental morphology of leaves using next-generation phylogenetics, a candidate gene approach and comparative developmental studies in the plant family Araceae is the overarching theme of the dissertation.

The plant family Araceae is an ancient lineage from the Early Cretaceous and belongs to the monocotyledons. Members of Araceae display striking variation in leaf development; such variation contradicts traditional models of monocot leaf development. Additionally, dissected leaves, which are rare in monocots, seem to have evolved independently multiple times in Araceae by various developmental mechanisms.

Despite extensive efforts to elucidate the evolutionary history of Araceae, phylogenetic ambiguity in the …

The U1a/U2b"/Snf Family Of Rna Binding Proteins: Evolution Of Rna Binding Specificity And Contributions Of Heterotropic Linkage To Snrnp Protein Partitioning, Sandra Gisela Williams

Arts & Sciences Electronic Theses and Dissertations

The U1A/U2B"/SNF is a family of RNA binding proteins that is a highly conserved throughout eukaryotes. These proteins are found in the U1 and/or U2 splicing snRNPs (small nuclear ribonucleoprotein particles). In humans, U1A and U2B" specifically bind to the U1 and U2 snRNAs, respectively. The Drosophila genome codes for SNF, an essential protein that localizes to both the U1 and U2 snRNP. While a specific splicing functions for these proteins have not been determined, their conserved snRNP localization suggests an important splicing-related function.

The difference in protein number and partitioning between Drosophila and humans suggested that these proteins may …

Characterizing The Fitness Landscapes Of Gut Symbionts In Defined Community And Diet Contexts, Meng Wu

Arts & Sciences Electronic Theses and Dissertations

A species' niche is the description of all the environmental conditions required to permit a population of that species to persist, including the effects of the population on those conditions. This definition includes the species' resource requirements, as well as stress tolerances and interactions with other species acting as competitors, predators, parasites, and mutualists. The human gut microbiota serves as a microbial `metabolic organ' tasked in part with the biotransformation of many components of our diet. Relatively little is known about the factors that allow members of the human gut microbiota to persist in a habitat that experiences marked changes …

The Genetic Architecture And Evolution Of Brain Cortical Folding In A Pedigreed Primate Population, Elizabeth Grace Atkinson

Arts & Sciences Electronic Theses and Dissertations

Elevated neurological faculty, related to the dramatic increase in brain volume, is a hallmark of the primates. Cognitive capacity, the processing power and speed of the brain, is directly related to the number of neurons in the cerebral cortex and the connectivity network underlying information processing in the brain. Increased cortical folding (gyrification) allows for more neurons to be contained within the volume of the braincase and the arrangement of folds and ridges across the cerebral cortex is an indication of the underlying neural network connecting regions. The goal of this dissertation is to develop a better understanding of the …