DLD is a highly common yet underdiagnosed neurodevelopmental disorder which impacts receptive and/or expressive language and cannot be attributed to another etiology such as hearing loss or lack of early language exposure. There is a lack of research into the brain differences that characterize DLD, especially in adult populations. The purpose of this project was to explore whether there are brain differences that underlie reading ability in adults with DLD. I specifically focused on the white-matter integrity of reading-related tracts using diffusion magnetic resource imaging (MRI). Participants included a group of adults identified as having DLD, as well as a group of typically developed adults. To measure reading ability, we used the Test of Integrated Language & Literacy Skills (TILLS) and focused on the Nonword Reading and Reading Comprehension subtests. For brain analysis, I first used data-driven hypothesis-free analysis of white matter across the whole brain with tract-based spatial statistics (TBSS). Next, I used probabilistic tractography to evaluate white-matter microstructure in tracts in the dorsal language stream, and in particular, the bilateral SLF. I hypothesized that lower reading scores would be associated with white-matter tract differences in the bilateral SLF. This research matters because reading ability is something that impacts all aspects of modern life, including learning, navigating directions in the world, and succeeding in the workplace. Adults with DLD are often undiagnosed in childhood, and this can carry lifelong social, emotional, and career effects. It is essential to understand whether brain differences underlie DLD and reading, particularly in adulthood, in order to better understand how to ultimately understand, support, and treat this disorder.

Cleft palate is a prevalant congenital anomaly in the United States, often creating differences in speech and communicative efficacy among affected children. When acquiring speech with a cleft palate, children use compensatory misarticulations to help force air through the mouth instead of the nasal passages. When the cleft is surgically repaired, children continue to use these marticulations. In my undergraduate research, I helped develop a study to assess these misarticulations. Our question was whether the velopharyngeal port (the opening between the oral and nasal passages) was open or closed during these compensatory articulations following palatal repair. I determined a list of words to have children repeat in order to elicit these misarticulations. The data used to answer our research question are novel -- vocal tract MRI (vtMRI). These data show the whole vocal tract moving while a participant is in a standard MRI scanner, reading aloud or repeating phrases. I am thus able to tell for each speaker and for each type of misarticulation, whether the velopharyngeal port is open or closed during misarticulations. This research presents some of the first quantitative data indicating whether misarticulations following palatal repair are habitual or structural in nature, and may indicate pathways for speech therapy to address the misarticulations. 

Oxygen deficient zones (ODZs) are large, naturally-occurring regions of the world's oceans where dissolved oxygen concentrations drop to low levels—less than 10 nM. These regions are important to the biogeochemical cycling of carbon, nitrogen, methane, and sulfur and are expected to expand as ocean temperatures rise due to anthropogenic climate change. Located above and below the anoxic ODZ core are oxyclines where dissolved oxygen concentrations change rapidly with depth. The deep oxycline extends into the deep ocean supporting an understudied microbial community adapted to these low-oxygen conditions. In this study, I examine a metagenomic library previously generated from a water sample collected at 1000 meters on the RR1804 POMZ cruise to determine both the diversity and genetic potential of microbes in the deep oxycline. I found that three groups of prokaryotes dominate in the deep oxycline: the cosmopolitan alphaproteobacteria, Pelagibacter ubique (20%); the uncultured candidate phylum SAR324 (16%); and archaea of the phylum Thaumarchaea (12%). I generated metagenome-assembled genomes (MAGs) from this sample to determine the genetic potential of this microbial assemblage. By examining these MAGs, I expect to find genes encoding for processes such as low-oxygen stress responses, alternate terminal electron acceptors, and carbon-fixation pathways. By better understanding the contributions of the deep oxycline microbial community to biogeochemical cycles, we can more accurately predict how nutrients will be consumed and regenerated in ODZs as they expand.