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  • Thumbnail for The last sacrifice : the ritual theory of funerary rites in Vārānasī, India
    The last sacrifice : the ritual theory of funerary rites in Vārānasī, India by Killion, Isabella Maria

    This paper looks at the ritual theory behind the “last sacrifice” funerary rites in Vārānasī, India. The purpose of this investigation is to understand what motivates people to perform the cremation ceremonies and what the implications are for society. There are a number of different elements of the ritual that I stress, including the perspectives on dharma (duty) and mokșa (liberation), the holiness of the Ganga River and Vārānasī, the significance of sacrifice in Hindu tradition, and the intentional steps of ritual that create order in the worldly “chaos.” I examine the attempt to reconcile the gap between what is known and unknown in the world and what can be controlled and what cannot be physically controlled– in this case death. I look at a number of different ritual theorists in an attempt to apply each theory and method to the funerary rites in Vārānasī and in the end offer my own ritual theory that best explains the “last sacrifice.” Through ritual, I argue that those who perform the “last sacrifice” can claim a form of control and self-empowerment. Specifically, I contend that the driving force of the ritual sacrifice is the moment of control, which stems from the attention to detail in ritual, over the looming gap between the living world and what is believed to occur through mokșa.

  • Thumbnail for Evolution of Life History in Three High Elevation Puya (Bromeliaceae)
    Evolution of Life History in Three High Elevation Puya (Bromeliaceae) by Veldhuisen, Leah

    The Andes are known as a hotspot for biodiversity and high species endemism for both plants and animals. Two important tropical, high-elevation ecosystems in the Andes are the puna in Peru, Bolivia and Chile between 7° and 27° South, and the páramo in Colombia, Venezuela and Ecuador between 11° North and 8° South; both are found at elevations above 3500 meters. The genus Puya (Bromeliaceae) is found throughout the puna and the páramo, and is relatively under-studied. Life history of most Puya species is largely unknown, with the notable exception of entirely semelparous Puya raimondii, which flowers once right before dying and does not reproduce clonally. Other species in the genus do reproduce clonally to varying degrees; their life history strategies have not been defined. Decreased cloning ability in Puya may be evolving convergently as in other plant groups endemic to high-elevation, tropical ecosystems. We studied three species of Puya (P. raimondii, P. cryptantha and P. goudotiana) across the two ecosystems in Bolivia and Colombia, and collected data on threshold size at flowering and clonal reproduction. Data were also analyzed in conjunction with life history theory to hypothesize each species’ life history strategy. All three species were found to have a consistent and predictable minimum size at flowering, while P. cryptantha was found to also have a minimum size for clonal reproduction. No such evidence was found for P. goudotiana. Our data supported that P. raimondii is fully semelparous, and indicated that P. goudotiana and P. cryptantha may be semi-semelparous.

  • Thumbnail for CONSPICUOUSNESS OF BAND-WINGED GRASSHOPPERS TO PREDATORS AND CONSPECIFICS (ORTHOPTERA: ACRIDIDAE: OEDIPODINAE)
    CONSPICUOUSNESS OF BAND-WINGED GRASSHOPPERS TO PREDATORS AND CONSPECIFICS (ORTHOPTERA: ACRIDIDAE: OEDIPODINAE) by Salazar, Brae Anne

    In band-winged grasshoppers (subfamily Oedipodinae), the variety of hindwing colors—ranging from blue to red—is both striking and unexplained. Hindwing color can vary both within and between species. However, the functional significance, if any, of this variation is unknown. Notably, the colorful hindwings are revealed only in flight, and remain hidden in stationary individuals. Although experimental evidence is lacking, this flash of color has been proposed to 1) startle potential predators, 2) to signal the quality of a potential mate, and 3) to enhance species recognition. To elucidate their potential function(s), here I measure the spectral and spatial characteristics of the hindwing patterns in 6 different band-winged species. I then model how an avian predator or potential mate might view grasshopper wings at behaviorally relevant distances. These data suggest that there is a rapid change in conspicuousness as a grasshopper moves from rest to flight regardless of the color vision of the receiver. However, there is little within species variation in coloration or wing patterning. My results indicate that while hindwings 1) may function as a protean defense against avian predators, 2) it is unlikely that they serve as a signal of mate quality, although, they 3) may deliver enough information for species recognition. This research helps to elucidate evolutionary relationships leading to the diversification of behavior, visual systems, and coloration within band-winged grasshoppers.

  • Thumbnail for A Nanoscopic Investigation of Pili and Pilus Production in Response to Environmental DNA in Acinetobacter baylyi
    A Nanoscopic Investigation of Pili and Pilus Production in Response to Environmental DNA in Acinetobacter baylyi by Boyd, Caroline Mallory

    Competence is the type of horizontal gene transfer in which a bacterium acquires DNA from the environment and includes this new genetic material in its genome. While this is a common phenomenon in many bacterial species, the mechanism used to ensnare and internalize environmental DNA is unknown. Other studies have shown that type IV pili (T4P), hair-like appendages, are somehow involved in competence but their role is unclear. A highly competent species, Acinetobacter baylyi (ADP1), expresses proteins that comprise the T4P and produce pili on its surface that are morphologically similar to T4P in their diameter and propensity to bundle. To examine the role these pili may play in the process of competence, we exposed ADP1 cells to a variety of environmental DNA concentrations and evaluated pilus production. We expected an increase in abundance or distribution of pili in the presence of more DNA. Pilus production was measured quantitatively by imaging the cells and their pili with atomic force microscopy and semi-automatically tracing the pili. Both the total length of all pili and the number of pili per cell were calculated. Our data demonstrate that ADP1 did not increase pilus production when exposed to more DNA. The cells consistently produced an average of 0.15 +/- 0.05 µm of pili per µm^2 of open mica with a few outliers. Additionally, the Primary pili produced per µm of shoreline was similar across the tested DNA concentrations and minor variations did not follow a trend of increasing Primary pili with increasing DNA concentrations. Slight increases in pilus production were seen at DNA concentrations of 200:1 and 1800:1 DNA molecules:cells and slight decreases seen at 100:1 and 400:1 DNA molecules:cells. Overall, our results do not demonstrate the involvement of pili in the acquisition of environmental DNA as measured by an increase in pilus production when cells were exposed to more DNA. Therefore, more research is needed to elucidate the role of pili in competence.

  • Thumbnail for Repeating earthquakes in the Darfield region, New Zealand
    Repeating earthquakes in the Darfield region, New Zealand by Armstrong, Ryan Scott

    The M 7.1 3 September 2010 Darfield, New Zealand, earthquake ruptured a previously unknown fault system. Fault-slip models (e.g., Beavan et al., 2010; Holden et al., 2011; Eliott et al., 2012) have been calculated using InSAR, GPS, and seismic data. They show that although the rupture initiated on a SW-dipping thrust fault, the majority of fault motion was right-lateral strike slip from the surface to 10 km depth. The InSAR data used in the geodetic model provide the cumulative ground motion due to the Darfield earthquake and some early aftershocks, while the seismic model utilizes waveforms for the mainshock, limiting the solution to slip during the initial rupture. This study utilizes cross correlation methods to identify repeating earthquakes within continuous seismic waveforms from the Canterbury region, New Zealand between September 2010 and January 2011. Repeating events indicate portions of fault segments that are not locked, possibly due to high pore pressure (Bisrat et al. 2012), and thus can indirectly identify locked areas of fault segments. Despite the fact that our method initially recognized 8 groups of potentially repeating earthquakes, a cross correlation check at a second station indicates that none of the identified earthquakes are truly repeating earthquakes. Our method provides negative results, which indicate repeating earthquakes may not be present within the Darfield fault complex, although it remains unclear whether they are truly absent or the methodology is not sufficient to detect them. While our method failed to identify repeating earthquakes, it possibly identified clusters of events with similar focal mechanisms In theory, our study shows a direct relationship between the compactness of a cluster and the similarity of focal mechanisms.

  • Thumbnail for The role of the N6-methyladenosine RNA modification in mediating HOTAIR-protein interactions
    The role of the N6-methyladenosine RNA modification in mediating HOTAIR-protein interactions by Chrupcala, Madeline

    The long noncoding RNA (lncRNA) HOTAIR acts in trans to epigenetically silence a 40-kb region of the HOXD gene cluster during development. In aggressive breast cancer, HOTAIR overexpression promotes metastasis, drug resistance, recurrence, and is a negative prognostic factor. However, the precise molecular mechanisms by which HOTAIR induces the formation of heterochromatin at specific sites in the genome to silence tumor suppressor genes remains widely unknown. To learn more about the molecular role of HOTAIR, we explored whether it was modified by the N6-methyladenosine RNA modification, which is dysregulated in breast cancer and has been proposed to play an essential role in gene repression by mediating lncRNA-protein interactions. Because we mapped m6A to a single nucleotide within the second domain of HOTAIR, we performed a quantitative proteomic analysis to identify additional HOTAIR-protein interactions that may be mediated by the post-transcriptional modification. We found that HOTAIR interacts with the YTH domain-containing protein 1 (YTHDC1), a member of a family of proteins known to recognize m6A residues. To determine the role of m6A in the HOTAIR-YTHDC1 interaction, we performed RNA pulldown assays with purified YTHDC1 and in vitro transcribed wild-type and m6A mutant HOTAIR in the presence or absence of methylation. Our data found that YTHDC1 preferentially interacts with wild-type methylated HOTAIR, suggesting that m6A mediates the HOTAIR-YTHDC1 interaction. However, it is not yet known if the m6A residue of HOTAIR recruits YTHDC1 to promote the transcriptional silencing of important suppressor genes. Thus, future research exploring the role of the m6A-mediated HOTAIR-YTHDC1 interaction in metastatic breast cancer will demonstrate whether a better understanding of the lncRNA can drive the development of breast cancer therapeutics. This is of utmost importance because invasive breast cancer remains a leading cause of death for women worldwide despite recent advancements in diagnosis and treatments.

  • Thumbnail for The Geochronology and Stratigraphy of Comanche National Grasslands, CO
    The Geochronology and Stratigraphy of Comanche National Grasslands, CO by Hager, Alexander Olin

    Little was previously known for certain about the age and depositional history of the strata exposed in Picket Wire Canyon in Comanche National Grasslands, CO, as prior work in developing a comprehensive geochronology and stratigraphy of the area has been minimal. Previous age constraints for the strata have been largely speculative, as the canyon contains the only outcrop of Paleozoic¬–Mesozoic strata within 100 km, and correlating local strata to regional formations is troublesome. Prior chronostratigraphic constraints were based entirely on fossils in Late Triassic and younger strata, but there have not previously been age constraints for strata older than the Late Triassic Chinle Formation. Radiometric U/Pb dating of detrital and volcanic zircon grains, along with carbon and oxygen stable isotope geochemistry, were employed in this study to constrain ages of the strata in Picket Wire Canyon, as well as determine depositional conditions. A 77 m thick eolianite unit disconformably underlies the Chinle Formation and was of unknown age; however, detrital zircons extracted from the base of the unit yielded a youngest grain of 245.5 ± 5.9 Ma, indicating the eolianite is correlative to the Triassic Red Draw Member of Jelm Formation. Additionally, this data suggests the oldest strata in the canyon, those stratigraphically below the eolianite, correlate to the Permian¬–Triassic Lykins Formation. U/Pb dating of volcanic ash in the Ralston Creek Member of the Morrison Formation yields an age of 152.987 ± 0.063 Ma, which is the most precise age for the Morrison Formation known to date. δ13C and δ18O values of Morrison carbonate beds indicate deposition in an arid, hydraulically open lacustrine setting, and are consistent with previous results from other Morrison localities. The Lower Morrison Formation at this locality contains one of the world’s largest continuously mapped dinosaur trackways. These footprints are atypical in that they are preserved in oolite, which due to its granular texture should not theoretically preserve footprints. Thin section analysis of the oolite depicts microbial films both within and surrounding the ooids, along with cementation structures indicative of meteoric vadose diagensis. It is hypothesized that the presence of microbial films and diagenetic cements allowed for the preservation of the footprints by increasing cohesion between grains, thus permitting the imprints to maintain their mold indefinitely.