Liver transplantation is a widely performed treatment for patients with end stage liver disease. Each day, the liver transplant waiting list grows longer due to a shortage of acceptable organs. Hepatic steatosis in donor livers is an increasing problem that contributes to discarding otherwise-transplantable livers. Numerous studies and surgeries have shown that high fat content in livers correlates with poor graft function and lower patient survival. Longer waiting lists are causing transplant centers to consider moderately steatotic livers as a part of extended donor criteria. However, a method is needed to objectively quantify fat content in livers in order to select suitable organs. Many studies over the past 30 years have characterized a correlation between fat content of livers and acoustic properties such as sound speed and attenuation. This research seeks to employ an acoustic caliper device to acquire acoustic measurements that can be used to quickly, accurately, and noninvasively evaluate the fat in transplant donor livers. Sound speed and attenuation were measured by transmitting short pulses of ultrasound at frequencies from 1-10 MHz through excised pig and cow livers. Liver thicknesses were measured with a dial caliper to permit sound speed estimates, and reference measurements were taken in water to calculate the additional attenuation created by the presence of the liver. In addition, a thermocouple was used to take precise temperature measurements in liver and water, since sound speed varies with temperature. Although fat content was not quantified, sound speed and attenuation did correlate with the presence of visually observable fat. However, significant variabilities between measurements were also found with regard to the preparation of the liver samples and tissue inhomogeneities. This work has led to ideas for an improved acoustic caliper device and for testing lipid emulsions as tissue phantoms for evaluating measurement capabilities.

Building a reference library of life on earth is an enormous task of paramount importance given the current threatened state of species across the planet. Collecting DNA barcodes - essentially genetic fingerprints - for every species on the planet has been proposed as a means of rapid species identification. In 2004, the Barcode of Life Database (BOLD) was initiated and is compiling DNA barcodes for every species using a small fraction of the genome called the, "CO1" gene. Unfortunately, the universal primers used to sequence the CO1 gene have a low success rate at producing DNA sequences for amphibians, and a relatively high error rate for species identification. My research investigates the success and accuracy of new amphibian-specific CO1 primers in comparison to an alternative DNA barcode, 16s rRNA, which is widely used in amphibian systematics and taxonomy, but is presently not accepted by the DNA barcoding community. I analyze and compare both CO1 and 16s genes for their utility as DNA barcodes by building phylogenetic trees using maximum likelihood and Bayesian inference to quantify their species identification accuracy. In collaboration with the UW Burke Museum of Natural History and Culture, I sequenced DNA for 162 frogs (representing 22 species) collected from the rainforest in Southern Ghana. The sub-Saharan rainforests of West Africa host a high number of endemic amphibian species. However, increasing habitat threat are heavily impacting species in these forest, and an estimated one third of amphibians are considered threatened. All DNA sequences obtained for this study are being submitted to the BOLD and GenBank databases and are linked to voucher specimens at the UW Burke Museum, which will inform future biodiversity studies, assist monitoring, and aid conservation efforts.

Immigrant farmworkers have been an integral part of Eastern Washington communities for decades. Their health and well-being are essential for the health of our communities. But for many farmworkers, health care access is unavailable or limited by a lack of insurance, health providers, discrimination, and social marginalization, making it difficult to assess their health status and burden of disease. A lack of basic information about farmworker health complicates the decision-making of state and local officials, physicians, and other advocates dedicated to improving farmworker health. In partnership with the Migrant Clinicians Network and the Pacific Northwest University of Health Sciences, I used community-based research techniques to design a farmworker public health study which could provide the necessary data to inform policies to improve farmworker health. Our survey research was designed to assess the serious injuries, diseases and causes of death among farmworkers and their families.

Hybrid organic/inorganic composites of conjugated polymers with quantum dots are of interest due to their potential for low-cost, solution processable solar cells and photodetectors. We use photoinduced absorption (PIA) spectroscopy to study charge generation in hybrid bulk heterojunction blends of the conjugated polymers with PbS quantum dots. We have previously shown that selective excitation of the quantum dots leads to formation of positively charged polarons on the conjugated polymer. By computing the relative yields of long-lived holes following photoexcitation of both the polymer and quantum dot phases, we estimate that more long-lived polarons are produced per absorbed photon by the polymer phase than the quantum dot phase. In this study, we aim to determine whether the formation of long-lived charge carriers due to quantum dot photoexciation is wavelength-dependent by investigating the polaron yield resulting from selective PbS excitation at varying energies in the near infrared. These results will give insight into the process of hole transfer from photoexcited quantum dots to the organic host polymer.

Solar technology is a potential way to help meet the growing demand for clean, renewable energy. Hybrid composites of inorganic quantum dots, with organic semiconducting polymers offer a potential means of producing low-cost, solution-processable photovoltaics. The synthesis of quantum dots typically involves the use of large surfactant molecules to facilitate particle growth and solubility. These native ligands act as electrical insulators that impede charge transport in photovoltaic devices. Therefore, it is necessary to exchange these large ligands with small molecules to achieve efficient charge carrier photogeneration and transport. In this research, we examine bulk heterojunction blends of low band gap PbS quantum dots with the conjugated polymer poly((4,8-bis(octyloxy)benzo(1,2-b:4,5-b')dithiophene-2,6-diyl)(2-((dodecyloxy)carbonyl)thieno(3,4-b)thiophenediyl)) (PTB1) treated with different ligands including cetyltrimethlammonium bromide (CTAB), tetrabutylammonium thiocyanate (TBAT), and 3-mercaptopropionic acid (MPA). We aim to elucidate how these different ligands influence the photovoltaic performance of PbS/PTB1blends by studying the differences in long-lived charge generation and recombination kinetics associated with the quantum dot ligand treatments using transient photovoltage (TPV) and photoinduced absorption (PIA) spectroscopy, respectively. We will also determine whether different ligand treatments influence film morphology using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We hope to gain a better understanding of how quantum dot ligand treatments may be used to optimize the performance of hybrid photovoltaics.

Lucha libre, or Mexican Free Wrestling, is both sport and entertainment with strong connections to the history of Mexican cultural production. Employing ethnography, historical research, and media documentation, that includes a film and an interactive art exhibition, my research produced a complex examination of the mind, soul and body of a gendered and transnational identity formation within lucha libre. My earlier ethnographic study of Lucha Libre Volcánica, a local school and performance group, found that male and female performers use physical embodiment and characterization to achieve a fluid gender boundary. Now my focus centers on a specifically female gendered standpoint and the cultural implications on women’s roles in US and Mexican society as a result of the sport’s transnational migration. Ethnographic research of Princesa Quetzal in Ciudad Victoria, Mexico, Las Poubelles in Los Angeles and La Avispa in Seattle illustrates how their involvement in lucha libre parallels a metaphorical struggle of “la lucha” (the fight) for three possibilities – visibility, empowerment, and a new identity or transnational cultural hybrid. Framing their performances within the historical context of post-revolutionary Mexico and the migratory movement of Mexican culture to Los Angeles and Seattle sheds light on how the perfect climate was created for the development of both lucha libre and female empowerment as evidenced in studies of cultural production by Heather Levi, Jose Muñoz, Laura Gutierrez, Eric Zolov, and Laura Pérez. It will not only open your eyes to the experience of being a female wrestler within a masculine world but also emphasize the important implications beyond the wrestling ring into the social fabric we all share.

A recent discovery in reproductive endocrinology, the kisspeptin system has been found to play a pivotal role in the regulation of the brain-pituitary-gonadal axis. Kisspeptin signaling in the brain is vital to the onset of puberty, control and regulation of sex steroid production, and regulation of fertility and reproductive function in mammals. However, the importance of the kisspeptin system in other vertebrates, such as fish, is not as clear. The goal of the current study was to clone the kisspeptin genes (kiss1, kiss2, and the receptor kiss1ra) for the first time in the marine teleost Anoplopoma fimbria (sablefish), and explore their potential roles in gonadal development. Previously, expression of the kiss2 gene was demonstrated in the gonads of sablefish. Partial kiss mRNA sequences were obtained by PCR and rapid amplification of cDNA ends (RACE) cloning techniques. Semi-quantitative PCR assays developed for each gene allowed us to measure kiss1, kiss2 and kiss1ra mRNA levels in a variety of adult tissues. We found the highest abundance of these mRNAs in the gonads, brain, and pituitary. In particular, kiss2 mRNA was abundant in the ovary and appeared to be the most highly expressed of the kiss genes. We are currently analyzing the expression of the kiss genes in gonads of fish undergoing sexual differentiation. Preliminary data suggest that there is sexually dimorphic expression of all three genes early in life. The ultimate goal of this project is to determine if gonadal kiss gene expression plays an important role in sexual differentiation and/or gametogenesis in fish.

Commercial fish stock populations can be linked to the health of forage fish populations. The Pacific sand lance, Ammodytes hexapterus, is an essential link between zooplankton and higher trophic levels such as birds, marine mammals, and fishes. Understanding the behavior and habitat of Pacific sand lance is key to ensuring the long-term sustainability of sand lance populations. Sand lance spend most of their time either schooling in the water column or buried beneath the substrate. We performed paired preference trials during daylight hours to compare burrowing tendencies between sediment sizes. Sediments were collected on San Juan Island and sorted using a RoTap sediment analyzer. The grain sizes chosen for the trial were medium sand (0.25 – 0.5 mm), coarse sand (0.5 – 1.0 mm), very coarse sand (1.0 – 2.0 mm), and very fine gravel (2.0 – 4.0 mm). The study was conducted on sub adults (8.5-11.5cm total length) to account for any ontogenetic variability in burrowing behavior. We found that sand lance could burrow into all of the provided substrates, but they prefer coarse sand. Observations have shown that Pacific sand lance spend the majority of the night buried under the sediment. We also conducted nocturnal preference experiments during night time hours (2300 – 0300). At night, A. hexapterus displayed no preference between coarse sand and very coarse sand, but did prefer coarse sand over medium sand. At night, when visual clues are eliminated, the preference for substrate type is relaxed. However, preference is also being evaluated by other sensory systems as there is still a notable distinction in the proportion of buried sand lance between substrates.