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Full-Text Articles in Physical Sciences and Mathematics

Reproductive Life History And Signal Evolution In A Multi-Species Assemblage Of Electric Fish, Joseph Waddell Jan 2017

Reproductive Life History And Signal Evolution In A Multi-Species Assemblage Of Electric Fish, Joseph Waddell

Electronic Theses and Dissertations

Animals that co-occur in sympatry with multiple closely-related species use reproductive mate attraction signals not only to assess the quality of a potential conspecific mate (sexual selection), but also to discriminate conspecifics from heterospecifics (species recognition). However, the extent to which sexual selection and species recognition may interact, or even conflict, is poorly known. Neotropical electric fish offer unrivaled opportunities for understanding this problem. They generate simple, stereotyped mate attraction signals that are easy to record and quantify, and that are well-understood from the neurobiological perspective. Additionally, they live in electrically-crowded environments, where multiple congeners live and reproduce in close …


The Role Of The Y-Chromosome In The Evolution Of Autosomally Coded Traits, Ian Kutch Jan 2017

The Role Of The Y-Chromosome In The Evolution Of Autosomally Coded Traits, Ian Kutch

Electronic Theses and Dissertations

Recent work indicates that the Y-chromosome of the fruit fly Drosophila melanogaster can influence gene regulation on the autosomes and X chromosome. This newly discovered function of the Y has the potential to dramatically shape the regulatory evolution of numerous genes that reside throughout the genome; even for genes that code for both male and female traits. Given that the mechanism underlying the Y-linked influence on gene expression in D. melanogaster appears to exist in other independently evolved heterogametic sex chromosomes, the evolutionary implications of Y-linked regulatory variation (YRV) deserves to be explored. These implications include the potential for Y-chromosomes …


Using Low-Coherence Interferometry To Monitor Cell Invasion In An In-Vitro Model System, Behnaz Davoudi Nasab Jan 2017

Using Low-Coherence Interferometry To Monitor Cell Invasion In An In-Vitro Model System, Behnaz Davoudi Nasab

Honors Undergraduate Theses

In an optically random system, such as naturally occurring and man-made media, light undergoes pronounced multiple scattering. This phenomenon has shown a remarkable potential in characterizing complex materials. In this regime, scattering occurs from each individual center of the scattering and independent scattering events lead to multiple light scattering. This phenomenon is often described as a random walk of photons and can be modeled in terms of a diffusion equation based on the radiative transfer theory. In this thesis, we used optical path-length spectroscopy (OPS), which is an experimental method to obtain the path-length probability density of the propagating light …


Micro-Spectroscopy Of Bio-Assemblies At The Single Cell Level, Jeslin Kera Jan 2017

Micro-Spectroscopy Of Bio-Assemblies At The Single Cell Level, Jeslin Kera

Honors Undergraduate Theses

In this thesis, we investigate biological molecules on a micron scale in the ultraviolet spectral region through the non-destructive confocal absorption microscopy. The setup involves a combination of confocal microscope with a UV light excitation beam to measure the optical absorption spectra with spatial resolution of 1.4 μm in the lateral and 3.6 μm in the axial direction. Confocal absorption microscopy has the benefits of requiring no labels and only low light intensity for excitation while providing a strong signal from the contrast generated by the attenuation of propagating light due to absorption. This enables spatially resolved measurements of single …