Digital Commons Network^™

The Importance Of The Multicomponent Display In Sexual Selection Of Black Morph Girardinus Metallicus (Pisces: Poeciliidae), Erin M. Wojan

Master's Theses

Multicomponent displays are composed of traits, such as coloration, structural ornaments, and behavior, that become integrated and signal information to conspecifics. Estimation of multicomponent displays in fishes often involves measurement of color traits. Fish color measurements are often obtained following immobilization via chemical anesthesia; however, the anesthetics may alter the resulting measurements, for example by darkening the skin. Girardinus metallicus, a poeciliid fish endemic to Cuba, has a multicomponent courtship and aggressive display. Black morph males exhibit black ventral coloration including the gonopodium (copulatory organ) and yellow in the non-black areas of their bodies. I investigated the effects of …

Effect Of Oxygen-Limiting Tidal Conditions On Muscle Metabolism And Structure In The Giant Acorn Barnacle, Balanus Nubilus, Katie O. Grady

Master's Theses

Crustacean muscle fibers are some of the largest cells in the animal kingdom, with fiber diameters in the giant acorn barnacle (Balanus nubilus) exceeding 3 mm. Sessile animals with extreme muscle sizes and that live in the hypoxia-inducing intertidal zone – like B. nubilus – represent ideal models for probing the effects of oxygen limitation on muscle cells. We investigated changes in metabolism and structure of B. nubilus muscle in response to: normoxic immersion, anoxic immersion, or air emersion, for acute (6h) or chronic (6h exposures twice daily for 2wks) time periods. Following exposure, we immediately measured hemolymph …

The Water Table And Soil Moisture Response Following The Removal Of Conifers From An Encroached Meadow, Thomas W. Sanford

Master's Theses

Montane meadows play a key role in the physical and biologic processes of coniferous forests in the western United States. However, due to climate change, over grazing, and fire suppression, conifer encroachment into meadows has accelerated. In some western regions, nearly half of all meadow habitat has been loss due to conifer encroachment. To combat this issue, encroaching conifers can be removed in an attempt to increase meadow habitat and function. While multiple studies have assessed changes in soil structure and vegetation composition, few studies directly investigate changes in hydrology following meadow conifer removal projects. The goal of this study …

Stakeholder Engagement In Marine Protected Area Network Planning In Southern California: Understanding Fishing, Government, And Environmental Perspectives, Nicole Catalano

Master's Theses

This study focuses on the MPA network planning process associated with California’s Marine Life Protection Act (MLPA) in southern California, occurring between 2008-2009. This case study demonstrates the ongoing complexity of MPA planning efforts in balancing social and science goals and reinforces the view that public participation alone may not be sufficient in achieving the type of stakeholder support needed for successful MPA implementation. Using a qualitative approach, this research draws upon the field of public participation to examine the efficacy of the planning process from the perspectives of fishing, government, and environmental stakeholders. Findings reveal significant differences in perceptions …

Psychopathology And Creativity Among Creative And Non-Creative Professions, Victor Kwan

Master's Theses

The mad genius debate has been a topic that has been discussed in both popular culture and academic discourse. The current study sought to replicate previous findings that linked psychopathology to creativity. A total of 165 biographies of eminent professionals (artists, scientists, athletes) were rated on 19 mental disorders using a three point scale of not present (0), probable (1), and present (2) for potential symptoms. Athletes served as an eminent but not creative comparison group in order to discern whether fame, independent of creativity, was associated with psychopathology. Comparison of proportion analyses were conducted to identify differences of proportion …

Experiments With And Implementation Of A Context Sensitive Text Summarizer, Charles Joseph Bocage

Master's Theses

Automatic text summarization is the ability to obtain key ideas from a text passage using as few words as possible. With the increase in data on the web, manual summarization of web pages has become unfeasible, and the need for automatic text summarization has become ever greater. This project explored and implemented various parts of the automatic text summarization process for an open source search engine, Yioop. These parts included stemming, text segmentation, term frequency weighting, automatic sentence compression, and content management system detection.

In addition, experiments were conducted on different pre-existing Yioop summarizers. These results served as a baseline …

Trapped In Endoderm-1 Reveals A Novel Role For Fruitless In Drosophila Melanogaster Courtship, Peter Luu

Master's Theses

Understanding how genes can direct behaviors has been a prevailing goal of neuroscience. Courtship in D. melanogaster is a complex yet stereotyped array of behaviors established by sex-specific genetic pathways mediated by sensory inputs by the nervous system. However, much remains to be discovered about the neurobiological and molecular mechanisms that regulate this complex set of behaviors. We have identified a group of cells expressing Trapped in endoderm 1 (Tre1) in which male Fruitless proteins are required to reduce the speed of courtship initiation. Tre1 encodes a G-protein-coupled receptor required for establishment of cell polarity and cell migration and has …

Cux2-Positive Radial Glial Cells Generate Diverse Subtypes Of Neocortical Projection Neurons And Macroglia, Ton Dan Nguyen

Master's Theses

The mammalian neocortex is 6-layered structure that develops in an “inside-out” manner, with cells of the deep layers (Layers 5-6) born first. Cells of the superficial outer layers (Layers 2-4) are generated subsequently and must migrate past older born cells to their final laminar position. Pioneering transplant studies suggested a progressive lineage restriction model, which posits that early neural stem cells (or radial glial cells, RGCs) are multipotent and sequentially generate different types of cortical neurons based on birthdate. Recently published work from Franco et al. (2012) argues against this paradigm, and proposes the existence of a subclass of neural …

Wilderness State Park Volunteers: A Qualitative Case Study Of Meaning And Sustainability, Christina A. Peterson

Master's Theses

In an increasingly urbanized world, parks, open space and wilderness areas are vitally important to human well-being. California State Parks provide people with the ability to connect with nature and engage in outdoor recreation. Moreover, these parks protect natural and cultural resources and preserve biodiversity. California State Parks are underfunded and rely on volunteers to support essential park services. The Wilderness State Park Uniformed Volunteer Program provides essential recreation, resource protection, and biodiversity services. In order to determine the elements of the volunteering experience that contribute to a strong sense of volunteer identity and meaning, a qualitative case study was …

Localization And Investigation Of Secondary Metabolite Producing Styela Clava-Associated Streptomyces Bacteria, James Demayo

Master's Theses

Natural products and natural product derivatives comprise some of the most successful drugs to date. Many natural products derive from the secondary metabolite profiles of high GC content actinomycete bacteria of the genus Streptomyces, which are sometimes associated with eukaryotic hosts. Identification of biosynthetic gene sequences for natural product secondary metabolites in Streptomyces can assist in isolation of the identified natural product. Moreover, the biosynthetic pathways of drug-like secondary metabolites derived from Streptomyces bacteria often provide insight into the available metabolites that can be produced. As a result, identification of bacteria capable of producing antibacterial products, including Streptomyces, …

A Replication-Inducible Recombinant Vaccinia Virus System To Conditionally Transcribe The Entire Human Rhinovirus C Genome, Zhixin Jing

Master's Theses

No abstract provided.

Assessing The Impact Of Breastfeeding Cessation On The Reported Incidence Of Diarrhea In Infants Between The Ages Of 7 To 12 Months: A Secondary Data Analysis, Ana Francisca Diallo

Master's Theses

Background: Diarrheal diseases remain a major cause of childhood morbidity in the United States. Optimal breastfeeding has been identified as one of the most effective measure to prevent diarrheal diseases in childhood.

Purpose: To evaluate the impact of breastfeeding duration during the first 6 months on the incidence of diarrhea in infants between 7 and 12 months in the United States.

Method: A secondary data analysis was performed using mothers and infants participating in the Infant Feeding Practices Study II (2005-2007).

Results: Compared to those who breastfed for 6 months or more, infants who discontinued breastfeeding between 0 …

Computational Design Of Ceramic Bone Scaffolds Fabricated Via Direct Ink Writing, Jeffrey Roberge

Master's Theses

Bone scaffold porosity and stiffness play a critical role in the success of critical-size bone defect rehabilitation. In this work, we present a computational procedure to design ceramic bone scaffolds to provide adequate mechanical support and foster bone healing. The scaffolds considered in our study consist of a lattice of curved rods fabricated via direct ink writing. We develop cellular solids models of the scaffold's effective elastic constants as functions of its geometric parameters, up to some unknown coefficients. To determine numeric values for these coefficients, we execute a computational design of experiments whereby effective elastic properties are obtained using …

Eye Tracking Food Cues In Subjects Who Are Overweight/Obese, Weight Loss Maintainers, And Normal Weight, Carrie A. Petro

Master's Theses

Adult obesity is associated with increased morbidity and mortality. Increasing success in weight loss maintenance will decrease the prevalence of overweight and obesity, and therefore help control the adverse health effects of excess weight. Much is known about the behavioral characteristics of successful long-term weight loss maintenance, but less is known about the cognitive processes behind weight loss maintenance. The purposes of this study were to (1) identify differences in visual attention to high-energy dense foods between individuals who are normal weight, weight loss maintainers, and overweight/obese in a high-risk (food-buffet) situation; (2) to evaluate differences in food choices from …

Physically Effective Fiber Threshold, Apparent Digestibility, And Novel Fecal Microbiome Identification Of The Leopard Tortoise (Stigmochelys Pardalis), Breanna Paige Modica

Master's Theses

Particle size distribution of diet, feces, and change from diet to feces, as well as apparent digestibility (aDig, %) of selected nutrients, and novel fecal microbiome identification of mature female leopard tortoises (Stigmochelys pardalis, n = 16) fed exclusively one of three, nutritionally complete, pelleted diets were evaluated in a blind, complete randomized design study. Two diets included insoluble fiber (powdered cellulose) consisting of either 2.0 mm or 0.2 mm length. Insoluble fiber provides nutritional and physical benefits to both the animal host and the microorganisms that inhabit the gastrointestinal tract. Insoluble fiber length was used as a …

Analysis Of Machine Learning Classifier Performance In Adding Custom Gestures To The Leap Motion, Eric Yun

Master's Theses

The use of supervised machine learning to extend the capabilities and overall viability of motion sensing input devices has been an increasingly popular avenue of research since the release of the Leap Motion in 2013. The device's optical sensors are capable of recognizing and tracking key features of a user's hands and fingers, which can be obtained and manipulated through a robust API. This makes statistical classification ideal for tackling the otherwise laborious and error prone nature of adding new programmer-defined gestures to the set of recognized gestures.

Although a handful of studies have explored the effectiveness of machine learning …

Experimentation Of Mode I And Mode Ii Fracture Of Uni-Directional Composites And Finite Element Analysis Of Mode I Fracture Using Cohesive Contact, Joseph Daniel Garrett

Master's Theses

As the use of fiber-reinforced composites has increased over the decades, so has the need to understand the complexity of their failure mechanisms as engineers seek to improve the damage tolerance of composite laminated structures. One of the most prevalent and limiting mode of failure within composite laminates is delamination, since it not only reduces a structures stiffness and strength, but can be very difficult to detect without the use of special non-destructive equipment. Industry testing organizations have utilized several fracture tests in order to characterize the fracture toughness of composite materials under different loading conditions. For this research, ASTM …

Examining Valve Shape Variation In The Freshwater Diatom Genus Eunotia Over Time And Space, Jordan M. Bishop

Master's Theses

A geometric morphometrics landmark analysis was used to investigate evolutionary shape change of Eunotia, a cosmopolitan freshwater diatom genus. Modern records from temperate and tropical habitats were compared with fossils originating from a locality in the Northwest Territories of Canada. The Giraffe Pipe sediment core from a middle Eocene tropical lake contains abundant siliceous remains of diatoms and other taxa, including Eunotia, making these the oldest known representatives of the genus. The purpose of this study was to investigate the shape of Eunotia when comparing modern tropical specimens to analogous fossil specimens. Over 600 specimens were examined in total, …

Gender In 17th Century Southern New England, Megan K. Willison

Master's Theses

This thesis, written in the form of two broadly related articles, aims to address questions related to topics of gender, identity, cultural change and continuity, and the materiality of social institutions. Each article investigates how artifacts, as physical objects unintentionally or purposefully discarded, represent and reflect human behavior, societal ideologies, and cultural infrastructures. Using primary sources, archaeological evidence, and linguistic data, each article proposes that certain artifact classes are representative of larger societal ideals and cultural mores, such as gender systems and ways of defining one's gender identity. The first article studies these topics through the analysis of funerary remains …

The Receptacular Nectar Tubes Of Pelargonium (Geraniaceae): A Study Of Development, Length Variation, And Histology, Timothy Tsai

Master's Theses

The nectaries of Pelargonium are unusual in the Geraniaceae in that the flowers only have one deep dorsal tube as opposed to five shallow canals. The genus is also known for having great length variation in nectar tubes, variation that has been suggested to play an important role in the diversification of this genus. Interpretations of Pelargonium nectaries contradict each other as some describe the nectar tube as an adnate sepal spur while others describe it as an hypanthial tube as a result of an elongate receptacle. In addition, the developmental basis of differing nectar tube lengths is unknown.

SEM …

Ecological Risks And Benefits From The Novel Crop Camelina Sativa (L.) Crantz (Camelina), Richard C. Rizzitello

Master's Theses

It is important to fully understand the ecological implications of introducing new crop species and genetic traits because of potential hazards such as changes in native plant populations or the establishment of aggressive weeds. Conversely, the introduction of new crops and traits could provide ecological benefits such as providing pollen and nectar forage for pollinators. Camelina sativa (camelina or false flax) is an oilseed crop that is being genetically engineered (GE) for the production of biofuel, bioplastics, and dietary supplements for humans and animals. Relatively little scientific information exists about camelina cultivation, reproductive biology, and ecology. The primary research goals …

Association Of The Dietary Inflammatory Index With Metabolic Syndrome In The National Health And Nutrition Examination Survey (2001-2006), Genevieve C. Caron

Master's Theses

Metabolic syndrome currently affects one third of adults in the U.S. and has been associated with a variety of chronic diseases that pose a burden to the nation. ^1,2 In the nationally representative NHANES dataset (2001-2006), dietary inflammatory index scores were found to significantly predict metabolic syndrome outcome among individuals above the age of 50 (OR=1.088; 95% CI=1.014-1.167; p=0.0184). Individuals older than 50 years of age who consume diets very high inflammatory properties were found to be 2.14 times more likely to have metabolic syndrome than those who consume a diet with very low inflammatory properties. This study supports the …

Characterizing Headwater Stream Hydrology And Nitrogen Export During Storms Across A Gradient Of Watershed Development, Jason Sauer

Master's Theses

Nitrogen (N) is a critical element for aquatic ecosystem function that can degrade water quality and cause eutrophication if in excess of natural levels. Anthropogenic nonpoint sources contribute more than 90% of total N added to major watersheds in the U.S, in excess of natural levels, and they are increasing with land development. Storms mobilize N from anthropogenic sources and generate periods of high N export to aquatic ecosystems. In this thesis, I explore how a gradient of watershed development affects the volume-weighted load, composition, and timing of N exported from first-order streams in New England during storms. I find …

The Driver Of The Carbon Isotope Minima During The Last Deglaciation: A Weakened Biological Pump Or Enhanced Southern Ocean Circulation?, Melissa C. Cote

Master's Theses

The cause of the initial rise in atmospheric CO₂ during the last deglaciation remains unknown. Coincident with the rising atmospheric CO₂, the δ¹³C of atmospheric CO₂ decreased by ~0.3‰ during Heinrich Stadial 1 (HS1: 14.5-17.5 kyr BP), which requires the input of carbon from an isotopically light reservoir. The light carbon signal in the atmosphere occurred concurrently with the carbon isotope minimum, or a decrease in surface ocean δ¹³C of ~0.5‰, suggesting the two phenomena are related. The leading hypotheses explaining the δ¹³C minimum are (1) enhanced ventilation of ^{13 …}

Perceived Self-Efficacy And Financial Incentives: Factors Affecting Health Behavior And Body Weight In Individuals With Overweight And Obesity, Julia Ann Simon

Master's Theses

No abstract provided.

Qm/Mm Calculations Of Spectral Tuning In Squid Rhodopsin, Jennifer Pardus

Master's Theses

This study utilized a QM/MM methodology to model and explore the protein structure and active site of invertebrate squid rhodopsin, and employed time dependent density functional theory (td-dft) calculations to further investigate the excited states of this protein. The high-resolution (2.5 Å) X-ray crystal structure of squid rhodopsin (species Todarodes pacificus) was the first Gq-coupled Guanine Protein Coupled Receptor (GPCR) structure to be determined. The availability of this novel x-ray structure data, in conjunction with computational tools, provided the opportunity to study the relationship between certain structural attributes of squid rhodopsin in the vicinity of the photoreactive center, and the …

The Mediterranean Diet And Cardiovascular Disease: A Multilevel Meta-Analysis, Julia E. Shook

Master's Theses

No abstract provided.

A Physiologically Motivated Approach To The Classification Of Natural Sounds Using High Order Sound Statistics, Brian B. Bishop

Master's Theses

The ability of humans and animals to classify sounds into behaviorally relevant categories is an ongoing field of study in auditory neuroscience and psychophysics. We employed a physiologically motivated signal processing scheme to extract time-varying statistics from a large database of real sounds. Our hypothesis is that two sound statistics, intensity and contrast, will be sufficient to classify broad categories of sounds using a naïve Bayesian classifier. We seek to evaluate this hypothesis, determine to what extent these two time-varying statistics can be used to classify sounds and to evaluate the limitations of the technique. The sounds themselves were organized …

Hydrologic Characteristics Of Summer Stream Temperatures In Little Creek And Scotts Creek At The Swanton Pacific Ranch, Justin M. Louen

Master's Theses

Stream temperature impacts have resulted in increased restrictions on land management such as timber harvest and have created considerable uncertainty for future planning and management of redwood forestlands. Challenges remain in the assessment of downstream cumulative effects given the complexity of stream temperature dynamics. The goal of this research is to identify the risk of downstream temperature heating based on the summer low flow residence times, stream morphological characteristics, stream water storage, and heat budget exchanges. Stream temperature, hydrologic, climatic, and channel morphological data were collected on two, approximately 800 m stream reaches on Little Creek and Scotts Creek located …

The Organization Of Technology In The Pine Hills Of Mississippi, Ronald W. Wise Jr.

Master's Theses

This thesis details the use of experimental flintknapping to better understand stone tool production and the organization of technology among Woodland period hunter-gatherers within the Pine Hills region of Mississippi. The Pine Hills region is characterized archaeologically by the presence of numerous sites consisting of flake scatters and little other material remains. Local tool stone resources consist of high grade chert in the form of small river cobbles, which restricts potential tool forms available to users.

Research for this project focused on the statistical analysis of debitage created during the experimental replication of stone tools using local chert cobbles. Special …