Physical Sciences and Mathematics Commons^™

The Oxidation State Of Hawaiian Magmas, Michael Vollinger

Masters Theses

In order to estimate the oxygen fugacity of Hawaiian lavas I have measured the ferric/ferrous ratios of samples from the 1984 eruption of Mauna Loa volcano and from the ongoing (1983-2017) Puu Oo eruption of Kilauea volcano. Fifteen samples were studied from the 21 day Mauna Loa eruption and 86 samples, erupted between 1983 and 2004, of the 34 year long Kilauea eruption. Both studies show that, in order to obtain reliable estimates of oxygen fugacity when, where, and how basaltic lava is sampled is of critical importance. Water-quenched lavas and spatter sampled at, or near vents, are less oxidized …

Exploring Long-Term Fault Evolution In Obliquely Loaded Systems Using Tabletop Experiments And Digital Image Correlation Techniques, Kevin Toeneboehn

Masters Theses

This thesis focuses on the use of scaled physical experiments to better understand the development and long-term evolution of fault systems that are otherwise impossible to observe directly. The document is divided into three chapters. The first chapter documents the implementation of an inexpensive stereo vision method for acquiring high resolution three-dimensional strain data for table-top experiments. The second chapter applies the stereo vision method to a tectonic problem—the development of slip partitioning in obliquely loaded crustal systems. Slip partitioned fault systems accommodate oblique convergence with different slip rake on two or more faults and are well documented in the …

How The E. Coli Hsp70 Molecular Chaperone, Dnak, Binds A Client Protein, Joseph Tilitsky

Masters Theses

Protein folding is essential for all cellular life. While some proteins are able to reach their folded state reliably using nothing but their amino acid sequence, a great number of essential proteins are unable to do so without the aid of molecular chaperones. One family of molecular chaperone, the Hsp70 family, is found in virtually all cell types and across all domains of life. Certain to the function of Hsp70s are how they bind their client proteins. Substantial effort has been expended to study how Hsp70s work on model peptides as a substrate mimic, but relatively little work has been …

Non-Equispaced Fast Fourier Transforms In Turbulence Simulation, Aditya M. Kulkarni

Masters Theses

Fourier pseudo-spectral method on equispaced grid is one of the approaches in turbulence simulation, to compute derivative of discrete data, using fast Fourier Transform (FFT) and gives low dispersion and dissipation errors. In many turbulent flows the dynamically important scales of motion are concentrated in certain regions which requires a coarser grid for higher accuracy. A coarser grid in other regions minimizes the memory requirement. This requires the use of Non-equispaced Fast Fourier Transform (NFFT) to compute the Fourier transform, by solving a system of linear equations.

To achieve similar accuracy, the NFFT needs to return more Fourier coefficients than …

Juvenile River Herring In Freshwater Lakes: Sampling Approaches For Evaluating Growth And Survival, Matthew T. Devine

Masters Theses

River herring, collectively alewives (Alosa pseudoharengus) and blueback herring (A. aestivalis), have experienced substantial population declines over the past five decades due in large part to overfishing, combined with other sources of mortality, and disrupted access to critical freshwater spawning habitats. Anadromous river herring populations are currently assessed by counting adults in rivers during upstream spawning migrations, but no field-based assessment methods exist for estimating juvenile densities in freshwater nursery habitats. Counts of 4-year-old migrating adults are variable and prevent understanding about how mortality acts on different life stages prior to returning to spawn (e.g., juveniles …

Influence Of Biomimetic Chelating Packaging On Natural Antimicrobial Efficacy, Paul Castrale

Masters Theses

The iron chelating molecule, ethylenediaminetetraacetic acid (EDTA) is used in food applications for the preservation of oxidation prone ingredients. Research has suggested that EDTA is also capable of enhancing the antimicrobial effectiveness of various compounds including naturally-derived antimicrobials. With consumer demand for cleaner food labels, there remains an opportunity to introduce new chelating technology to replace synthetically-derived EDTA. Through photographting and chemical conversion, hydroxamic acid ligands were covalently bound to polypropylene films resulting in polypropylene-graft-poly(hydroxamic acid) (PP-g-PHA). The resulting films demonstrated an ability to chelate 64 nmol/cm² from an iron saturated environment or 163 nmol/cm …

Modelling Bird Migration With Motus Data And Bayesian State-Space Models, Justin Baldwin

Masters Theses

Bird migration is a poorly-known yet important phenomenon, as understanding movement patterns of birds can inform conservation strategies and public health policy for animal-borne diseases. Recent advances in wildlife tracking technology, in particular the Motus system, have allowed researchers to track even small flying birds and insects with radio transmitters that weigh fractions of a gram. This system relies on a community-based distributed sensor network that detects tagged animals as they move through the detection nodes on journeys that range from small local movements to intercontinental migrations. The quantity of data generated by the Motus system is unprecedented, is on …

Multiple Testing Correction With Repeated Correlated Outcomes: Applications To Epigenetics, Katie Leap

Masters Theses

Epigenetic changes (specifically DNA methylation) have been associated with adverse health outcomes; however, unlike genetic markers that are fixed over the lifetime of an individual, methylation can change. Given that there are a large number of methylation sites, measuring them repeatedly introduces multiple testing problems beyond those that exist in a static genetic context. Using simulations of epigenetic data, we considered different methods of controlling the false discovery rate. We considered several underlying associations between an exposure and methylation over time.

We found that testing each site with a linear mixed effects model and then controlling the false discovery rate …

Petrogenesis And Concentric Zonation Of The Belchertown Intrusive Complex, West-Central Massachusetts, Karen June Van Wagner

Masters Theses

The Belchertown Intrusive Complex is a ~164 km2 Devonian pluton that intruded Paleozoic metasedimentary and metavolcanic rocks in west-central Massachusetts. Intrusion of the pluton was synchronous with Acadian deformation (Ashwal, 1974). The complex is concentrically zoned, with a core of orthopyroxene-biotite monzodiorite, a middle zone of clinopyroxene-hornblende-biotite granodiorite, and an outermost zone of hornblende-biotite granodiorite. Zoning from a more to less hydrous mineral suite from the outside to the inside of the pluton led Ashwal (1974) to suggest that metamorphic hydration most strongly affected the outermost zones of the complex. Basaltic inclusions occur most commonly near the edges of …

A Combined Historical And Sedimentological Reconstruction Of Extratropical Cyclone Derived Coastal Flooding In Boston, Ma, Zachary D. Stromer

Masters Theses

Many flood risk assessments are based on instrumental records less than a century in length. Sedimentary and historical archives provide the opportunity to extend flood records by several centuries to millennia. In doing so these longer flood records provide opportunities for improving upon current flood risk assessment and gaining additional insight on the various climatic and geomorphic processes that drive changes in flood frequency. Such a reconstruction has not been attempted previously for Boston, MA where extratropical cyclones (ETC) are currently the dominant mechanism of coastal flooding. Here, we present both a historical reconstruction of extreme storm tides to affect …

Microtransplantation Of Rat Brain Neurolemma Into Xenopus Laevis Oocytes To Study The Effect Of Environmental Toxicants On Endogenous Voltage-Sensitive Ion Channels, Edwin Murenzi

Masters Theses

Microtransplantation of mammalian neurolemma into Xenopus laevis oocytes has been used to study ion channels in terms of their structure and function in the central nervous system. Use of microtransplanted neurolemma is advantageous in that tissue can be obtained from various sources, ion channels and receptors are present in their native configuration and they can be used to evaluate numerous channelpathies caused by environmental toxicants. Here we show that Xenopus oocytes injected with fragments of rat brain neurolemma successfully express functional native ion channels that are assembled in their own plasma membrane. Using a high throughput two electrode voltage clamp …

Botswana’S Elephant-Back Safari Industry – Stress-Response In Working African Elephants And Analysis Of Their Post-Release Movements, Tanya Lama

Masters Theses

Understanding how African elephants (Loxodonta africana) respond to human interactions in ecotourism operations is critical to safeguarding animal and human welfare and sustaining wildlife ecotourism activities. We investigated the stress response of elephants to a variety of tourist activities over a 15-month period at Abu Camp in northern Botswana. We compared fecal glucocorticoid metabolite (FGM) concentrations across three elephant groups, including: eight elephants in an elephant-tourism operation (Abu herd), three elephants previously reintroduced back into the wild from the Abu herd, and wild elephants. There were no differences in FGM concentrations between the three groups of elephants. The highest observed …

Explorations Into Machine Learning Techniques For Precipitation Nowcasting, Aditya Nagarajan

Masters Theses

Recent advances in cloud-based big-data technologies now makes data driven solutions feasible for increasing numbers of scientific computing applications. One such data driven solution approach is machine learning where patterns in large data sets are brought to the surface by finding complex mathematical relationships within the data. Nowcasting or short-term prediction of rainfall in a given region is an important problem in meteorology. In this thesis we explore the nowcasting problem through a data driven approach by formulating it as a machine learning problem.

State-of-the-art nowcasting systems today are based on numerical models which describe the physical processes leading to …

Achieving Perfect Location Privacy In Wireless Devices Using Anonymization, Zarrin Montazeri

Masters Theses

The popularity of mobile devices and location-based services (LBS) have created great concerns regarding the location privacy of the users of such devices and services. Anonymization is a common technique that is often being used to protect the location privacy of LBS users. This technique assigns a random pseudonym to each user and these pseudonyms can change over time. Here, we provide a general information theoretic definition for perfect location privacy and prove that perfect location privacy is achievable for mobile devices when using the anonymization technique appropriately. First, we assume that the user’s current location is independent from her …

Volatiles In Subglacially Erupted Basaltic Glasses And Their Use In Reconstructing Paleo-Ice Thicknesses, Carver Lee

Masters Theses

Volatile concentrations in basaltic tuyas, edifices that form during a subglacial eruption and remain once the ice sheet has retreated, have been used to calculate the thickness of the overlying ice sheet at the onset of the eruption (Tuffen, 2010). However, subglacial eruptions are complex events and this technique does not always provide a clear answer (Schopka et al., 2006; Edwards et al., 2009). The purpose of this research is to evaluate this technique and investigate constraints on the quality of data collected by attempting to calculate the minimum ice thickness under which Hlöðufell, a tuya in south-central Iceland, erupted. …

Time Domain Sar Processing With Gpus For Airborne Platforms, Dustin Lagoy

Masters Theses

A time-domain backprojection processor for airborne synthetic aperture radar (SAR) has been developed at the University of Massachusetts’ Microwave Remote Sensing Lab (MIRSL). The aim of this work is to produce a SAR processor capable of addressing the motion compensation issues faced by frequency-domain processing algorithms, in order to create well focused SAR imagery suitable for interferometry. The time-domain backprojection algorithm inherently compensates for non-linear platform motion, dependent on the availability of accurate measurements of the motion. The implementation must manage the relatively high computational burden of the backprojection algorithm, which is done using modern graphics processing units (GPUs), programmed …