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Mechanisms Of Nutrient Limitation And Nutrient Acquisition In Managed And Unmanaged Forest Ecosystems, Matthew A. Vadeboncoeur

Doctoral Dissertations

Understanding the interactions between global change, human and natural disturbances, and other factors on biogeochemical processes in forests is necessary to ensure the sustainability of forest management. Here I report the results of several investigations into nutrient acquisition processes in the forests of New Hampshire. I begin with a meta-analysis of fertilization studies showing that phosphorus (P) and calcium (Ca) as well as nitrogen (N) may limit primary production in deciduous forests of the region. Because these limiting nutrients are all removed from the ecosystem when trees are harvested, I compared nutrient budgets under a range of harvesting scenarios with …

Development Of Unsaturated Flow Functions For Low Impact Development Stormwater Management Systems Filter Media And Flow Routines For Hydrological Modeling Of Permeable Pavement Systems, Iulia Aurelia Barbu

Doctoral Dissertations

Low Impact Development - Stormwater Management (LID-SWM) systems are relatively new technologies that were developed in order to meet the water quality criteria imposed by the Clean Water Act. LID-SWM is also used to replicate the natural hydrology of developed sites. However, the hydrological benefits of LID systems cannot be accurately predicted with the existing simulation models. Currently used software packages represent LID systems as storage units and do not specifically represent water routing through the systems' hydraulically restrictive sublayers. Since the LID's functionality at system level is not fully understood, the relationships of design variables and the systems' hydrological …

Intermittent Swim Stress Effects On Anxiety Behavior, Timothy A. Warner

Doctoral Dissertations

Millions of Americans are suffering from depression each year, leading to a significant number of individuals who seek treatment for their ailment. However, fewer than 50 percent of depressed individuals fully recover using current methods. The comorbidity between depression and anxiety could be a contributing factor in the lower rates of recovery. The demonstrated correlation between anxiety and depression has led to the term "anxious depression," which is associated with difficulty in coping, a poorer rate of recovery, and more severe symptoms of depression. The purpose of this dissertation was to expand on an existing animal model of depression (intermittent …

Writing Assessment's "Debilitating Inheritance": Behaviorism's Dismissal Of Experience, Maja Joiwind Wilson

Doctoral Dissertations

In this project, I examine the legacy of behaviorism's dismissal of experience on contemporary writing assessment theory and practice within the field of composition studies. I use an archival study of John B. Watson's letters to Robert Mearns Yerkes to establish behaviorism's systematic denial of experience and its related constructs: mind, consciousness, thought, emotions, purpose, and meaning. I trace this denial through the efficiency movement's effects on education and educational measurement in the early 20th century and the establishment of the behaviorist infrastructure of assessment---an infrastructure that contributed; paradoxically, to the early focus in composition studies on experience. I analyze …

A Longitudinal Analysis Of The Effect Of Disability Type And Emotional/Behavior Problems On Different Forms Of Maltreatment Across Childhood, Jennifer A. Vanderminden

Doctoral Dissertations

Children are among the most vulnerable people in our population, especially those with disabilities, emotional and behavioral problems (EBP), and those who experience maltreatment. This dissertation increases our understanding of the complex relationships between disability, internalizing symptoms (IS), externalizing symptoms (ES), and maltreatment across developmental stages. Previous literature suggests that children with disabilities (CWD) are at a heightened risk for maltreatment (Spencer, Devereux, Wallace, Sundrum, Shenoy, Bacchus, and Logan 2005 ; Sullivan and Knutson 2000). Yet, recently the Fourth National Incidence Study of Child Abuse and Neglect (NIS-4) has challenged the notion that CWD are at increased risk, showing that …

Investigating Priming, Inhibition, And Individual Differences In Visual Attention, Jennifer Lechak

Doctoral Dissertations

While much has been explored within the attentional control literature, questions still exist as to how attentional processing is modulated, and how different types of visual search paradigms can elucidate the underlying mechanisms involved in successful visual search. Throughout this dissertation, I will focus on the multifaceted aspects that come with the study of visual attention. After discussing visual attention I explore priming of pop out along two different dimensions. Specifically, using a rapid serial visual presentation design, I demonstrate that temporal and spatial priming interact along a similar mechanism. This result adds to the priming literature by demonstrating simultaneous …

Developing Competence: A Qualitative Inquiry Of College Student Leadership In University Outdoor Orientation Programs, J David Starbuck

Doctoral Dissertations

Forty-nine formal research studies have been conducted on participants of college outdoor orientation programs. Although many variables have been examined for the incoming students, only one study has focused on the impact on the student leaders.

The goal of this study was to understand how student leaders in outdoor orientation programs understand the impact of their leadership experience, and what aspects of the leadership role fostered value or personal significance. The study also investigated whether there were any notable differences between leadership experiences in faith-based versus non-faith-based programs. Data was collected from 36 first-time student leaders from 4 programs using …

What Do Students Do In Self-Formed Mathematics Study Groups?, Gillian E. Galle

Doctoral Dissertations

An implicit assumption of many university classes is that students will spend a large amount of time outside the classroom refining their understanding of the material to develop mastery of the concepts. This is especially true in first year mathematics courses at the undergraduate level. However, little is known about what students do to fulfill this didactical contract with their instructors. The currently available research relies primarily on self-reported data from the students collected through questionnaires or interviews. This study sought to start describing what students do while studying mathematics in a self-created group outside of the classroom setting through …

Impressions Of College Intructors: Stability And Change In Student Ratings, Kari L. Dudley

Doctoral Dissertations

Although the topic of stability and change in classroom impressions research is not new, there remain unanswered questions about what impressions are stable, when they are likely to change, and for whom they are likely to change over the course of a semester. My research will begin to answer those questions.

My research took place in four college classroom studies and assessed students' impressions of their instructor's teaching effectiveness and personal qualities 1) after the first day of class, 2) before and following at least one exam, and 3) at the end of the semester. My results supported previous findings …

Peer Mediation In Massachusetts Public Middle & High Schools: Perceptions Of Educators, Eve I. Noss

Doctoral Dissertations

While many studies related to school violence and its prevention have focused on the perceptions of elementary students and counselors, there is a dearth of research studies that focus on the perceptions of administrators and teachers. This study examines Massachusetts public middle and high school principals, assistant principals, and teachers (n=135), from 30 schools, perceptions of their peer mediation program's impact on student conflicts. Comparisons between administrators and between levels of schools were conducted to provide a finer grain for the analysis.

Methodology: The method of data collection is a mixed, hybrid methodology of 41 quantitative (closed-end) and quasi-quantitative (open-ended) …

Approaches To Modeling Pathogen And Natural Organic Matter Removals In Slow-Rate Biofilters, Jeffrey Dale Senders

Doctoral Dissertations

There are limited expressions capable of estimating removals in one of the world's oldest and most sustainable water treatment systems: slow-rate biofilters. This research addresses the problem by deriving semi-empirical models that predict pathogen and natural organic matter removals within these natural and engineered sand filters. The more complex pathogen model, or phenomenological colloidal filtration theory (pCFT), applies the 1937 Iwasaki solution to New England pilot scale E. coli observations. The derived pCFT was then calibrated through a series of experimental bench scale phases. Further pCFT validation came by way of a seamless application to multiple microorganisms. Viruses (MS2 as …

Mechanisms Of Nutrient Limitation And Nutrient Acquisition In Managed And Unmanaged Forest Ecosystems, Matthew A. Vadeboncoeur

Doctoral Dissertations

Understanding the interactions between global change, human and natural disturbances, and other factors on biogeochemical processes in forests is necessary to ensure the sustainability of forest management. Here I report the results of several investigations into nutrient acquisition processes in the forests of New Hampshire. I begin with a meta-analysis of fertilization studies showing that phosphorus (P) and calcium (Ca) as well as nitrogen (N) may limit primary production in deciduous forests of the region. Because these limiting nutrients are all removed from the ecosystem when trees are harvested, I compared nutrient budgets under a range of harvesting scenarios with …

Identification And Stoichiometric Analysis Of The Monosomal Translational Complex, Xin Wang

Doctoral Dissertations

The identification of the components involved in translational complexes has relied primarily on in vitro studies. Determining which proteins associate together in these complexes, under what conditions they do so, and how the composition of the complexes change under different conditions have became the key issues of in vivo studies. After a one-step affinity purification, using a novel technique of analytical ultracentrifugation with a fluorescence detection system (AU-FDS) I have identified a 77S monosomal translational complex in the yeast Saccharomyces cerevisiae. Major components of the 77S complex include the 80S ribosome, mRNA, and components of the closed-loop structure, eIF4E, eIF4G1/eIF4G2 …

"An Ill-Judged Piece Of Business": The Failure Of Slave Trade Suppression In A Slaveholding Republic, Sarah A. Batterson

Doctoral Dissertations

This dissertation examines the U.S. suppression of the slave trade from the ratification of the Constitution in 1789 to the onset of the Civil War in 1861. Instead of studying the slave trade in isolation, this dissertation evaluates U.S. slave trade policy within the context of the development of federal power during the early republic and antebellum period. This work assesses the disconnect between the harsh laws against the slave trade and the United States' ineffectiveness at suppressing the trade, especially since, at its founding, U.S. involvement in the African slave trade seemed to have a looming expiration date.

By …

Characterization Of Low-Temperature Properties Of Plant-Produced Rap Mixtures In The Northeast, Marcelo S. Medeiros Junior.

Doctoral Dissertations

The dissertation outlined herein results from a Federal Highway Administration sponsored project intended to investigate the impacts of high percentages of RAP material in the performance of pavements under cold climate conditions. It is comprised of two main sections that were incorporated into the body of this dissertation as Part I and Part II. In Part I a reduced testing framework for analysis of HMA mixes was proposed to replace the IDT creep compliance and strength testing by dynamic modulus and fatigue tests performed on an AMPT device. A continuum damage model that incorporates the nonlinear constitutive behavior of the …

Molecular Self-Assembly Of Functionalized Pentacenes And Fullerenes On Metal Surfaces By Stm And Dft Investigations, Jun Wang

Doctoral Dissertations

Enormous efforts have been made in seeking alternative pathways to more effectively use solar energy. Organic solar cells, composed essentially of carbon-based organic molecular materials, have attracted considerable scientific and industrial attentions because of their economic and environmental benefits. It is advantageous to have the comprehension of the molecular structures and interfacial morphologies for these active molecular materials on substrates in the nanoscale regime.

Controlling the heterostructures of the molecular donor and acceptor materials is essential to overcoming the efficiency bottleneck in organic photovoltaics. Molecular self-assembly on patterned substrates provides a bottom-up approach to create well-controlled molecular heterojunctions and a …

Planning Under Time Pressure, Ethan Burns

Doctoral Dissertations

Heuristic search is a technique used pervasively in artificial intelligence and automated planning. Often an agent is given a task that it would like to solve as quickly as possible. It must allocate its time between planning the actions to achieve the task and actually executing them. We call this problem planning under time pressure. Most popular heuristic search algorithms are ill-suited for this setting, as they either search a lot to find short plans or search a little and find long plans. The thesis of this dissertation is: when under time pressure, an automated agent should explicitly attempt to …

Interactions Of Shiga-Like Toxin-2 (Stx-2) From Escherichia Coli O157:H7 And The Bcl-2 Family Of Proteins During Host Cell Programmed Cell Death, Lia K. Jeffrey

Doctoral Dissertations

Stx-2 is a major contributor to the pathogenesis of Escherichia coli 0157:H7. Prior reports suggest that Stx-2 increases necrosis and apoptosis of a variety of host cells including those of endothelial origin as well as immune cells such as neutrophils (156). However, the role Stx-2 plays in delayed apoptosis of neutrophils is not fully understood given that previous studies have shown conflicting results (118, 51). The process of apoptosis is mediated by the Bcl-2 protein family (2, 46, 226). The purpose of this research was to define the molecular mechanisms of Stx-2 and Bcl-2 protein family interactions. These studies examined …

Pulsating Aurora: Source Region & Morphology, Allison Jaynes

Doctoral Dissertations

Pulsating aurora, a common phenomenon in the polar night sky, offers a unique opportunity to study the precipitating particle populations responsible for this subtle yet fascinating display of lights. The conjecture that the source of these electrons originates near the equator, made decades ago, has now been confirmed using in-situ measurements. In this thesis, we present these results that compare the frequencies of equatorial electron flux pulsations and pulsating aurora luminosity fluctuations at the ionospheric footprint. We use simultaneous satellite-based data from GOES 13 and ground-based data from the THEMIS allsky imager array to show that there is a direct …

Characterization Of The Expression Profile Of Polyamine Biosynthetic Genes (Spermidine Synthase) And Polyamine Metabolic Regulation In Arabidopsis, Lin Shao

Doctoral Dissertations

Polyamines are ubiquitously distributed cationic compounds, which play important roles in numerous cellular functions in plants. This study was aimed at elaborating the regulation of polyamine biosynthetic gene expression and polyamine metabolism. The organ/tissue specific expression patterns of two genes encoding the polyamine biosynthetic enzyme spermidine synthase ( AtSPDS1 and AtSPDS2) were studied in Arabidopsis at different developmental stages using promoter::reporter approach. The two homologues showed similar ubiquitous expression with subtle differences being observed in certain tissues (e.g. root, siliques, and embryos). Neither transgenic manipulation by over-expression of AtSPDSI alone nor its concomitant expression with genes encoding other biosynthetic enzymes …

Engineering Lipases And Solvents For Trans/-Esterification Of Used Vegetable Oils, Michael Dore Gagnon

Doctoral Dissertations

Diminishing petroleum reserves and increasing environmental awareness has led to an urgent need to develop alternative fuels, such as biodiesel. However, the conventional method to produce biodiesel uses environmentally harmful chemical catalysts. A relatively new development in the production of biodiesel is through enzymatic trans/- esterification with a lipase catalyst. Despite several advantages, there are a few technical and economical obstacles that limit this process: (1) immiscibility of the hydrophilic methanol and hydrophobic triglyceride which results in the formation of an interface leading to mass transfer resistance, (2) insufficient availability of large quantities of inexpensive lipase suitable for catalysis, and …

Aspects Of Holography In Lorentz-Violating Gravity, Jishnu Bhattacharyya

Doctoral Dissertations

The study of black hole thermodynamics has provided deep insights into the nature of quantum gravity. In particular, it is almost universally accepted nowadays that 'quantum gravity is holographic', so that the maximum amount of information allowed in a given region of spacetime is proportional to the area of the boundary rather than the volume of the region. This is against the conventional notion of extensivity of information (entropy), but in accord with Bekenstein's proposal on the proportionality of black hole entropy to its event horizon area. Due to the very definition of black holes, however, conventional black hole thermodynamics …

Characterization Of The Prokaryotic Community Associated With The Giant Barrel Sponge, Xestospongia Muta Across The Caribbean, Cara L. Fiore

Doctoral Dissertations

Sponges have long been known to be ecologically important members of the benthic fauna on coral reefs. Recently, it has been shown that sponges, and their symbiotic microbes, are also important contributors to the nitrogen biogeochemistry of coral reefs. Here, I investigate the ecology and physiology of the microbial community associated the ecologically dominant sponge, Xestospongia muta. A natural experiment was conducted with X. muta form three different locations (Florida Keys, USA; Lee Stocking Island, Bahamas, and Little Cayman, Cayman Islands) to compare nitrogen cycling and prokaryotic community composition. The dissolved inorganic nitrogen (DIN) fluxes of sponges were studied using …

Bacterial Biodegradation Of Soluble Crude Oil Hydrocarbons And The Influence Of Protists In Simulated Arctic Seawater And Sea Ice, Heather Ballestero

Doctoral Dissertations

With expected increases in vessel traffic, drilling, and exploration for petroleum and natural gas, the potential for an Arctic oil spill is heightened, yet knowledge of contaminant fate and behavior is limited in this environment. With challenging conditions in the Arctic and limited equipment caches, response will be extremely difficult. In freezing conditions, oil may become encapsulated in ice. Understanding biodegradation potential in this environment can dictate response options for spills that occur in Arctic marine waters. The influence of protists on bacterial biodegradation of water accommodated fractions (WAF) of petroleum hydrocarbons is unknown, yet important because it could enhance …

A Personal And Collaborative Journey Of Change: Lessons Learned About Leadership, Mentoring And Motivation From An Educational Community's Work With Donald Graves, Barbara Plummer Jasinski

Doctoral Dissertations

Change is often expected as the logical outcome of large scale investments in professional development, yet research studies (e.g., Tyack & Cuban, 1995; Lipson, Mosenthal & Woodside-Jiron, 2000; Schraw & Olafson, 2002) note wide variations in instructional practice despite such efforts. This qualitative inquiry was designed to understand factors that support or undermine teacher learning and to examine how change in instructional practices took hold for members of one school community exposed to radically different thinking about the teaching of writing. The participants were teachers and an administrator who collaborated with Donald Graves in Atkinson, New Hampshire during his groundbreaking …

Everyday Food Practices Among Three Low-Income Groups: Rural, Homeless, And Refugee, Amy L. Redman

Doctoral Dissertations

Lower-income groups are more susceptible to diet-related diseases like obesity, diabetes, and heart disease (CDC, 2010). They are also more likely to need food and nutritional assistance (USDA, 2011). Yet very little is known about the day-to-day food practices of these individuals and families. Many times those who are relatively adjacent in terms of income are assumed to have similarities in food consumption (Hupkens, Knibbe, & Drop, 2000); however, this has not been empirically examined. The main objectives of this research are to 1) gain an exploratory in-depth understanding of the everyday food practices of individuals in three low-income groups: …

Currency Risk And Imperfect Knowledge: Cointegrated Var Analyses With Survey Data, Josh R. Stillwagon

Doctoral Dissertations

Much progress has been made in understanding excess returns in the foreign exchange market through the use of survey data on traders' exchange rate forecasts. On the whole, this literature, which is reviewed in chapter 1, has found that excess returns derive from both violations of the rational expectations hypothesis (non white-noise forecast errors) as well as a time-varying risk premium. What this literature has not done however is to determine whether any of the existing models of the risk premium can account for the time-varying risk premium found in survey data. The second and third chapters use the Cointegrated …

Extreme Value Theory: Applications To Estimation Of Stochastic Traffic Capacity And Statistical Downscaling Of Precipitation Extremes, Eric Matthew Laflamme

Doctoral Dissertations

This work explores two applications of extreme value analysis. First, we apply EV techniques to traffic stream data to develop an accurate distribution of capacity. Data were collected by the NHDOT along Interstate I93, and two adjacent locations in Salem, NH were examined. Daily flow maxima were used to estimate capacity, and data not associated with daily breakdown were deemed censored values. Under this definition, capacity values are approximated by the generalized extreme value (GEV) distribution for block maxima. To address small sample sizes and the presence of censoring, a Bayesian framework using semi-informative priors was implemented. A simple cross …

"I Am A Scientist": How Setting Conditions That Enhance Focused Concentration Positively Relate To Student Motivation And Achievement Outcomes In Inquiry-Based Science, Robin B. Ellwood

Doctoral Dissertations

This research investigated how student social interactions within two approaches to an inquiry-based science curriculum could be related to student motivation and achievement outcomes. This qualitative case study consisted of two cases, Off-Campus and On-Campus, and used ethnographic techniques of participant observation. Research participants included eight eighth grade girls, aged thirteen to fourteen years old. Data sources included formal and informal participant interviews, participant journal reflections, curriculum artifacts including quizzes, worksheets, and student-generated research posters, digital video and audio recordings, photographs, and researcher field notes. Data were transcribed verbatim and coded, then collapsed into emergent themes using NVIVO 9. The …

Examining Social Climate And Youth Social Goals On Extended Wilderness Courses: A Path Toward Improving Participant Experiences, Benjamin J. Mirkin

Doctoral Dissertations

This dissertation examined participants' expectations of the social climate on extended wilderness courses, how students' actually experienced the social climate during their course, and how these expectations, perceptions and the influence of environmental characteristics, impacted their goals for peer interactions. Pre and posttest surveys were used to assess students' expectations and perceptions of their experience and multi level modeling was used to better understand the relationship of social climate to peer interaction. The research was undertaken to improve the practical and theoretical understanding of organizations' and leaders' ability to facilitate a social climate that promotes adaptive forms of social motivation. …