In the desert Southwest, predation and monsoon thunderstorms are determinants of aquatic invertebrate communities. Recent research has focused on the potential of non-native species, like bullfrogs (Rana catesbeiana), to change communities into which they are introduced. Bullfrogs were introduced into Arizona in the mid-1900s and have established widespread populations that predate on and compete with native fauna. In an effort to control bullfrog populations, state and federal agencies have focused on the eradication of bullfrogs in Southeast Arizona – a biodiversity hotspot with many endemic species. Although the effects of bullfrogs on vertebrate species are documented, how and whether bullfrogs alter aquatic invertebrate communities remains uncertain. We examined how the effects of bullfrogs compare to the seasonal effects of the monsoon in influencing invertebrate communities. The objectives of this study were to 1) examine and quantify the effects of bullfrogs on aquatic invertebrate communities by comparing ponds with and without bullfrogs; 2) determine the effect of monsoonal seasonality by sampling invertebrate communities during the early- and late-monsoon, and 3) observe the interaction of bullfrogs and monsoonal seasonality to explore the relative importance of these two factors in shaping aquatic invertebrate communities. We hypothesized a lower invertebrate abundance and richness in ponds with bullfrogs. We expected to see taxonomic differences in community composition based on body size, dispersal ability, habitat use, feeding group, and defense. We anticipated smaller invertebrates and a higher number of defended invertebrates in ponds with bullfrogs. Finally, we expected that the relative abundance of high dispersing insects would increase in late monsoon samples. Preliminary analyses suggest that invertebrate abundance and richness is negatively related to the number of bullfrogs present at a pond. By studying the effects of bullfrogs on aquatic invertebrate communities, we can begin to understand and quantify the impact of this heavily managed non-native predator.

Malaria is a parasitic infection due to Protozoa Plasmodium. This is a severe global disease with 250 million annual cases leading to 1-2 million deaths. The most virulent, P. falciparum, is responsible for severe clinical malaria and death. An array of anti-malarial treatments exist today, however parasites evolve continuously to develop resistance even to the newest frontline anti-malarial drugs. Previous studies in the Rathod laboratory have demonstrated that drug resistance can be generated in the lab and that some drugs can be utilized to characterize Accelerated Resistance to Multiple Drugs (ARMD) parasites, such as the laboratory strain Dd2, and non-ARMD parasites, such as the laboratory strain HB3. In the current study, we are using a cyclopropyl carboxamide (GSK 2645947) to select for resistant parasites. Cyclopropyl carboxamides are a chemically novel class of antimalarial agents identified recently and they prevent the growth of P. falciparum in the early trophozoite stages of the erythrocytic Plasmodium cycle. This project focuses on determining the conditions for the development of resistance against GSK 2645947 with Dd2 and HB3 by conducting a series of selection experiments utilizing different concentrations of GSK 2645947 and starting parasites populations. Unlike previous conditions which indicate that the Dd2 strain acquires resistance at a significantly higher frequency than the HB3 stain; the data from this study suggests that both Dd2 and HB3 strains respond similarly to GSK 2645947. Through this study, we can further understand the behavior of resistant P. falciparum parasites. 

This project seeks to better understand climate change corollary to the migration of the Intertropical Convergence Zone (ITCZ) in the tropical Pacific from the Little Ice Age (~AD 1400-1850) to the present using hydrogen isotopes as a proxy for climate change. During this time, the ITCZ is hypothesized to have reached its most southern location, the consequences of which were evident on a global scale. However, more research is needed to further investigate this hypothesis. Specifically, this study examines hydrogen isotope ratios of the source specific lipids Taraxerol and Dinosterol from Lake Escondido, Isabela Island, Galapagos. Lipids were solvent-extracted from sections of the cores, separated through silica gel columns, and the ratio of Deuterium and Hydrogen (δD) of specific lipids was quantified using a Gas Chromatograph-Isotope Ratio Mass Spectrometer. The combined fluxes of both terrestrially and aquatically sourced δD ratios over time provide a proxy for climate change through the present. Due to the widespread effects of the ITCZ on global hydrology, understanding its movement, and what triggers migration, can provide insight into future climate scenarios.

When looked at in chronological order, it is impossible to deny that the work of Francisco Goya (1746-1828) underwent a major shift in style, palette, medium and content in the middle of his life. Past scholars have pointed out that there are multiple reasons for this shift, including Goya's increased involvement in the turbulent politics of eighteenth century Spain and his fascincation with the aging process that only increased with his own age. Another frequently cited cause is the onset of deafness that the artist suffered after a near fatal illness in 1792 at the age of forty six. The relationship between his deafness and his new found forms of expression has been explored by scholars in a variety of fields. In my research on the topic, I have gathered information from otology and neuroscience periodicals and placed them alongside art history and biographical information, blurring the line between the art and science of Goya. Along with these unusual sources, I will be taking a different approach in terms of my visual analysis of Goya's work. Most scholars resort to analyzing his most famous paintings to point out the differences between his early and late style, such as his royal portraits and "Saturn Devouring his Children" (1819-1823). I have decided to use three of his seven known self-portraits instead: "Self Portrait 1" (1773), the frontispiece for "Los Caprichos" (1798), and "Self-Portrait with Dr. Arrietta" (1820). I chose to examine these self-portraits because Goya created them at three pivotal points in his life and they reflect the artist's self-image at the time. Goya was very self-aware of his position in the universe and his extraordinary knack for creating truthful depictions allow his self-portraits to freeze him in time for us to dissect hundreds of years later.

Ai WeiWei, a contemporary Chinese artist and self-described "dissident," is the first to admit that political activism forms the basis of his aesthetic. In an artist’s statement, from a recent exhibition at the Hirshhorn Museum in Washington, DC, Ai plainly stated: “I’ve always believed it is essential for contemporary artists to question established assumptions and challenge beliefs.” The majority of Ai’s installations at the Hirshhorn function as a platform for his renegade agenda, and his piece He Xie is no exception. The striking collection of ceramic river crabs, in various shades of red and brown, is invested with manifest symbolism. However, a deeper investigation of the work reveals a latent significance, not readily gleaned from a limited investigation of its formal elements. In order to adequately engage with Ai’s work, one must look beyond the surface and trace the installation back to its historical origins and cultural conditions. To draw out his strategic use of symbolism, I analyze Ai’s installation according to German art historian Erwin Panofsky's iconographical approach. Panofsky begins with the simplest translation of visual forms and works his way toward a more nuanced historical and culturally relevant perspective. In short, Panofsky’s three-pronged methodological approach allows me to demonstrate the complexity of Ai’s He Xie. In this presentation, I discuss the conceptual stimulus behind Ai's sprawling display of porcelain delicacies, exploring its political significance and identifying a larger metaphysical trend in the artist's career.

Among the library of plays known as “classics” within Japanese theatre, few compare in longevity, versatility, and uniqueness to Kanadehon Chushingura. This work weaves the tale of 47 loyal retainers enacting revenge on behalf of their deceased leader by murdering the man responsible for his death. The play draws on themes of loyalty, trust, and righteousness. First debuted in 1748, this story has been adapted hundreds of times into multiple artistic mediums, including kabuki and bunraku theater, woodblock prints, and film. However, unlike most literary classics of the Western World, Chushingura’s compelling plot was drawn directly from current events. Through the examination of primary and secondary sources, as well as through close reading of Kanadehon Chushingura, I have traced the transition of Chushingura from fact to folktale. This research begins with the actual bloody events that inspired the story. I later explore the event’s changes and adaptations for the purpose of both suiting its consumption by the merchant class in Edo period Japan, and to evade censorship by the shoganate government. My research concludes by following Chushingura into its role within contemporary entertainment. I hope to accurately chronicle the metamorphosis from historical event to contemporary folktale and thus invite others to examine the origins of what they may consider familiar. Doing so will result in a more accurate catalog of our cultural origins for both current and future generations.

In the urban centers of Senegal, graffiti artists work to deconstruct the memories of the former French colonial apparatus by refurbishing public spaces with new and sacred meaning.  These artists belong to the Muridiyya Sufi tariqa, an order of Islamic mystics, and the basis of their art is reimagining the only known photograph of the order's enigmatic founder, Cheikh Bamba.  This photograph, taken by French authorities while Bamba was under house arrest in 1913, has been used as the matrix image for subsequent representations of the Cheikh.  This paper will explore the efforts of those contemporary Murid artists who adorn the city walls of Senegal with Bamba's likeness, relating their endeavors to the writings of social critic Walter Benjamin and cultural theorist Stuart Hall.  For the Muridiyya, images of Bamba function as transmitters of his baraka, his divine blessings.  As a receptacle of this baraka, public space is transformed in a process that I will compare to the Muridiyya's appropriation of land controlled by the French during the tariqa's formative years: members of the order, the Murids, had initially emigrated into certain areas based upon the proximity to Bamba, and his presence invested the space with new meaning.  The settled land became part of the larger Daar-al-Murid, or the House of the Muridiyya, considered sacred and conceptually separate from other spaces in which Bamba's baraka could not be felt.  Around this space, a communal identity for the Muridiyya was formed, an identity culturally and religiously autonomic.  Drawing on the theoretical bases of Benjamin and Hall, concerning respectively the dissemination of images and the circulation of culture, this research will examine the development of a distinct visual culture, highlighting how imagery can reshape and invest public space with new meaning.

 Transition-metal ions promote a wide range of vital enzymatic biological and chemical processes involving dioxygen (O₂), including photosynthetic H₂O splitting, biosynthesis of neurotransmitters, and DNA replication and repair. These are some of the most fundamental processes of life, and yet they are also some of the most poorly understood. A complete grasp of how these processes function at the chemical level is therefore of critical importance to our development of technology that improves our lives and the world around us. For example, understanding how to efficiently oxidize H₂O to O₂ is essential to the development of renewable solar fuels and fuel cells. The challenge for research lies in that these transition-metal containing enzymes are inherently difficult to probe by traditional spectroscopy methods because of their structural complexity. The difficulty in characterizing these species and their reactions, coupled with their importance in the natural world, has made them a subject of intense research across all scientific disciplines. The Kovacs research group studies the structure and reactivity of these transition-metal containing enzymes, or metalloenzymes. Our research method involves modeling a metal ion’s local environment with a ligand scaffold and implementing changes to these so-called biomimetic models that may elucidate how reactivity corresponds with various structural and electronic modifications. Spectroscopy is more diagnostic in these simpler models because the complex proteins that obscure the active site in the actual enzyme are not incorporated into the model. By comparing similarities in reactivity between the biomimetic model and the actual enzyme, we may help elucidate properties and chemistry of the enzyme itself. Preliminary work has been undertaken with a novel series of thiolate ligated, coordinatively unsaturated Co(II) complexes; the reactivity of these complexes with O₂ and O₂^- is currently being probed.

Over the past decade, measurements of hydrogen isotopes of lipid biomarkers, in particular leaf waxes, have been used to reconstruct past climate change. This method is appealing because lipids are well preserved in sediment and their hydrogen isotope ratio is primarily controlled by the hydrogen isotope ratio of their source water, which itself is controlled by factors such as precipitation amount and temperature. However, it has been shown that the isotopic difference between source water and lipids is distinctive among different plant species. In particular, it has been shown that salinity strongly affects the hydrogen isotope ratio of lipids produced by mangroves, but the mechanism that controls this relationship is unknown. Plants, including mangroves, take in water mainly from surrounding source water, but the deuterium to hydrogen ratio within the plant may be impacted by differences in transpiration rate, photosynthetic rate and respiratory water production. The photosynthetic rate (mol CO2 m-2s-1), internal carbon, (μmol CO2/ mol air) and conductance (mol H2O m-2s-1) of three species of mangrove, Rhizophora apiculata, Avicennia germinans, and Xylocarpus granatum, were measured at six different salinities from 5 to 30 ppt. The date, time, and leaf number were also recorded as additional measurements. Determining whether salinity, time of day and/or differences among species affects photosynthetic rate, internal carbon, and conductance is important in comparing the biosynthetic pathways of the three species of mangroves. It will allow us to investigate the cause of increased deuterium discrimination in mangroves at high salinity.

Seabird distribution and abundance can be used as indicators of the health of the coastal ecosystem. In the Gulf of Alaska over the last four decades there has been growing evidence of climate change and ocean acidification. The largest oil spill in the United States, the Exxon Valdez, occurred here. We used data from the Coastal Observation and Seabird Survey Team (COASST), a citizen science, beached bird survey program with 14 years of surveys from beaches in the Pacific Northwest, and eight years of data from Alaska. We seek to compare U.S. Fish and Wildlife Service (USFWS) data from historical surveys in the Gulf of Alaska (1970-1989), to the current beached bird data collected through the COASST program (2005-present). Historic data include monthly surveys of sites from the Kenai Peninsula to Yakutat Bay, and one offshore island, Middleton (n>250 surveys). Current COASST data cover this same range, include additional surveys from Kodiak Island, but exclude Middleton (n>1200 surveys). These data will be analyzed to examine the differences in monthly encounter rate (carcasses/km) averaged over this region, cumulative species diversity, and oiling rate (percent of recorded carcasses that are oiled). This comparison will provide insight into possible changes in the encounter rate index in the Gulf of Alaska over the past 40 years.

The fact that hydrogen isotope deuterium/protium (D/H) ratios in algal lipids co-vary with their surrounding water D/H ratios is well established. Paleoclimatologists have taken advantage of this relationship in their compound-specific D/H analyses, but little is known about the individual environmental parameters, such as temperature, salinity, light levels, and nutrient concentrations that influence D/H fractionation, or the state of unequal isotope composition. Laboratory experiments conducted with batch cultured green algae, Eudorina unicocca and Volvox aureus, grown at temperatures of 15°C and 25°C suggest that there is increased fractionation with increased temperature. The work presented here aims to elucidate the magnitude of D/H fractionation in a natural population of algae where temperature is the primary environmental variable. To test this relationship, surface water was sampled from Lake Washington once a month for one year, with a surface temperature range from ~8°C in February to ~24°C in August. Phytoplankton were filtered from the water and lipids are extracted and analyzed by gas-chromatography isotope ratio mass spectrometry (GC-IRMS) to determine the extent of D/H fractionation. We found that there was a positive correlation between temperature and D/H fractionation, in which fractionation increased with increasing temperature. The results from this research, as well as the results of similar experiments with other environmental parameters, will give paleoclimatologists accurate modern-day calibrations to apply to the analysis of lipids extracted from sediment cores in order to reveal climatic variations for the past.