Digital Commons Network^™

Climatic And Biotic Interactions In Terrestrial Systems During Ancient Warm Periods, Sarah Johnson Widlansky

Doctoral Dissertations

This work focuses on two terrestrial sedimentary records in the western United States that record the ancient greenhouse interval of the early Paleogene (~ 55 million years ago). The Paleogene, and past warm periods in general, offer a means of understanding potential biotic and environmental response to future warming scenarios. Part One of this dissertation establishes a new stable isotope climate record from the Bighorn Basin of Wyoming that is tied to an extensive fossil mammal assemblage (Chapter 1). This new stable isotope record captures carbon isotope excursions (CIEs) associated with the early Eocene hyperthermals ETM2, H2, and potentially I1 …

Heat Transport By Baroclinic Acoustic Streaming, Jacques Abdul Massih

Doctoral Dissertations

Acoustic streaming refers to time-averaged flows generated by time-periodic sound waves. In classic“Rayleigh streaming”, the mean flow is generated by the interaction of a standing acoustic wave with a solid boundary (e.g., a channel wall). Applications of acoustic streaming include inducing fluid mixing in microfluidic medical devices, improving the efficiency of chemical reactions, and enhancing heat transfer. Recently, Chini et al. [J. Fluid Mech., Vol. 744 (2014)] and Michel & Chini [J. Fluid Mech., Vol. 858 (2019)] demonstrated that strong acoustic streaming flows can be generated in gases subjected to an imposed cross-channel temperature gradient. In contrast with Rayleigh streaming, …

Penalized Regression Splines-Based Tests For Comparing Two Time Series With Unequal Lengths, Mirajul Islam

Doctoral Dissertations

The Spline-based modeling has been an established tool for parametric and nonparametricregression modeling because of its continuous progress on theoretical and computational fronts over the last three decades. This thesis explores the idea of penalized spline modeling and goodness of fit testing in the context of time series testing in the frequency domain approach. The comparison of different time series is an important topic in statistical data analysis and has various applications in scientific research. One approach to identifying similarities or dissimilarities between two stationary processes is to compare the spectral densities of both time series. This thesis examines whether …

Efficient Data-Driven Robust Policies For Reinforcement Learning, Bahram Behzadian

Doctoral Dissertations

Applying the reinforcement learning methodology to domains that involve risky decisions like medicine or robotics requires high confidence in the performance of a policy before its deployment. Markov Decision Processes (MDPs) have served as a well-established model in reinforcement learning (RL). An MDP model assumes that the exact transitional probabilities and rewards are available. However, in most cases, these parameters are unknown and are typically estimated from data, which are inherently prone to errors. Consequently, due to such statistical errors, the resulting computed policy's actual performance is often different from the designer's expectation. In this context, practitioners can either be …

Recombination Drives Genomic Divergence And Cooperation Across Bacterial Populations, Isaiah Paolo Atienza Lee

Doctoral Dissertations

Genetic recombination is a major driving evolutionary force across the Tree of Life, but it plays a special role in bacteria. In the absence of sexual reproduction, bacteria rely on horizontal transmission to recombine their genetic material. Horizontally transferred genes can spread rapidly across a population, greatly expanding the niches available to bacteria. We are only beginning to understand the degree to which recombination varies between and even within bacterial taxa. In the first part of this dissertation (Chapter 1 and Chapter 2), I investigate how patterns of recombination influence bacterial diversity. In Chapter 1, I studied the pan-genome of …

Sociocultural Dimensions Of Environmental Stewardship In New Hampshire: Implications For Adult Environmental Education, Ian Patrick Hanley

Doctoral Dissertations

The overarching aim of this dissertation is to expand evidence and theory of adult identity processes in the context of environmental stewardship, as well as to provide knowledge and recommendations to environmental stewardship and environmental education professionals. The intent is to better understand variation in how adult environmental stewards report on and value their own engagement with both sociocultural and natural systems. This line of inquiry stems from the fundamental claim that environmental stewardship activity is not singularly based on environmental content knowledge but is also related to forms of cultural and social engagement. By recognizing these dual aspects of …

Notes From The Underground: An Exploration Of Burying Beetle Thermal Ecology, Sound Production And Reception, And Brain Morphology., Michelle Ward

Doctoral Dissertations

In a climatically and structurally changing world, it is important to understand how different thermal and social environments influence the behavior and physiology of the pillars of terrestrial ecosystems: insects. In this dissertation, I explored how insects, specifically Nicrophorus beetles, respond to biotic and abiotic challenges. Through this research, I addressed 1) how daily fluctuations in temperature influence Nicrophorus americanus reproductive success, 2) the context in which breeding pairs use stridulation during carcass burial, and subsequently how inhibition of stridulation influences reproductive success, 3) if the clypeal membrane on Nicrophorus beetles has the physiological properties of a tympanum, and if …

Compound, Elemental, And Isotopic Perspectives On Mercury Mobilization During Thaw In A Discontinuous Permafrost Zone, Maria F. Fahnestock

Doctoral Dissertations

Arctic ecosystems are a major global sink for both carbon (C) and mercury (Hg), both of which are influenced by anthropogenic activities. The accelerated climate-change-induced warming documented in the Arctic has led to permafrost thaw resulting in landscape evolution from hydrological, vegetation and microbial shifts. All of these resulting changes have the potential to influence how Hg, a toxic contaminant, is mobilized and re-cycled in this ecosystem. In this body of work, I investigate patterns of Hg speciation, elemental abundances, and stable isotopes across the thaw gradient in a permafrost peatland and interconnected freshwater lakes in Abisko, Sweden to assess …

Query-Specific Subtopic Clustering In Response To Broad Queries, Sumanta Kashyapi

Doctoral Dissertations

Information Retrieval (IR) refers to obtaining valuable and relevant information from various sources in response to a specific information need. For the textual domain, the most common form of information sources is a collection of textual documents or text corpus. Depending on the scope of the information need, also referred to as the query, the relevant information can span a wide range of topical themes. Hence, the relevant information may often be scattered through multiple documents in the corpus, and each satisfies the information need to varying degrees. Traditional IR systems present the relevant set of documents in the form …

Interventions Towards Sustainable Watershed Management As Demonstrated By Hydrologic Simulation, Shan Zuidema

Doctoral Dissertations

Increasing population, changing climate, and on-going legacies of environmental mismanagement motivate our need for deeper understanding of the process and limits of adaptation towards sustainable management of water resources. Movements towards open-science and transdisciplinary research have enabled deeper assessments of the co-evolution of human society and changing landscapes. Policies and decisions enabling environmental restoration or sustainable resource use have been actively pursued for decades. The social barriers that prevent adaptations to succeed are deep and entrenched, but equally important are the physical barriers. Successful adaptations in water resource management need to explicitly consider the joint interactions of intervention magnitude, or …

Pretreatment Optimization For Ceramic Microfiltration With Ozonation And Coagulation For The Reuse Of Wastewater Effluent, Nicola Elardo

Master's Theses and Capstones

Ceramic microfiltration (CMF) is a promising alternative to traditional polymeric microfiltration and its chemical resistance makes it particularly attractive for sustainable water reuse applications. This research investigated the ability of ozonation and coagulation as pretreatments to improve the performance of ceramic microfiltration using HHNK’s WWTP in Wervershoof, The Netherlands. With a CMF pilot plant design flow of 200 L/h, critical flux tests were completed using ozonation individually and with coagulation sequentially to evaluate the ceramic membrane filtration performance. Results showed that with an ozone residual before the ceramic membrane, the performance increased significantly compared to no pretreatment and without an …

Fungal Fruiting And Dispersal Following Timber Harvest, Benjamin William Borgmann-Winter

Master's Theses and Capstones

Forest-dwelling fungi are critical to ecosystem function in their roles as decomposers and nutrient cyclers, food sources, pathogens, and mycorrhizal symbionts. In northern New England, a region with a substantial timber industry, the degree to which fungal communities are resilient to timber harvest, as well as their ability to recolonize post-disturbance, may impact ecosystem function and forest regeneration. In this thesis, we investigate the impacts of (1) timber harvest on fungal fruiting, an important element of fungal reproduction, and (2) the dispersal mechanisms by which fungi may re-colonize harvested areas. In Chapter 1, we investigate the impact of timber harvest …

Cognitive Correlates Of Storytelling In Severe Tbi, Serena Mae Jaskolka

Master's Theses and Capstones

Introduction: Difficulties with narrative discourse, executive functions, declarative memory, and pragmatic function are pervasive in adults with TBI. As narrative discourse (e.g., storytelling) plays a significant role in social contexts, these difficulties have broad reaching impacts on everyday interactions. Existing research in adults with TBI does not address cognitive correlates of story length, completeness, or elaboration within a story grammar framework, which is a structure for organizing the content of stories. A better understanding of these relationships will allow for more effective evaluation and treatment for this population. Methods: Transcripts from Cinderella stories of 48 participants with severe TBI were …

Analysis Of Turbulence In The Near-Shore Marine Atmospheric Surface Layer Using Sonic Anemometer Data, Alberto Javier Bodoque Garcia

Master's Theses and Capstones

This thesis investigates turbulence in the marine atmospheric boundary layer (MABL), above,the wave boundary layer (WBL). To conduct this research, wind velocity and temperature data was collected by a sonic anemometer located onWood, Island, NH, mounted to a tower 4 meters above the ground. To study turbulence in the MABL, variables such as Reynolds stress and friction velocity were calculated for different days in August 2019. Friction velocity was calculated following three different approaches: the first approach employs the eddy covariance method, the second employs a tilt correction to the eddy covariance method, and the third uses the Reynolds stress …

Whether They Return: Modeling Outdoor Recreation Behaviors, Decision-Making, And Intention-To-Return In Congressionally Designated Wilderness, Alexander Robert Caraynoff

Master's Theses and Capstones

Visitation to parks and protected areas (PPAs) has become increasingly widespread in the United States. This increased visitation is especially concerning within congressionally designated wilderness areas where federal agencies are dually tasked with preserving wilderness character while simultaneously providing high-quality outdoor recreation experiences. This study investigated the influence of social, situational, and ecological factors on outdoor recreation visitor behaviors and decision-making within the Lye Brook Wilderness (LBW) area in Vermont, USA. An on-site intercept survey (n=576) was employed to collect data from LBW visitors in the summer of 2021. Multi-variate statistics (e.g., binary logistic regression, structural equation modeling) indicate visitor …

Crystal Plasticity Modeling For Predicting Load Reversals In Dual Phase Steels And Aluminium Alloys: Applications To Predicting Springback Behavior, Sowmya Daroju

Master's Theses and Capstones

Numerical modeling of sheet metal forming is of growing interest for industry and academia. Metal forming operations often involve non-monotonic deformation paths with frequent unloading. This research explores the use of elasto-plastic self-consistent (EPSC) modeling in predicting the monotonic and load reversal deformation of aluminum alloys, and dual-phase steels. The EPSC model considers anisotropic elasticity, dislocation density-hardening, and intra granular slip system-level backstress fields in addition to accounting for inter granular stress fields; the detailed contribution of this helps in properly predicting the phenomena such as unloading non-linearity, the Bauschinger effect (BE), and changes in hardening rates during reversals. In …

Rna-Seq Analysis Of Transgenic Arabidopsis Thaliana With Conferred Overproduction Of Putrescene By A Mouse Ornithine Decarboxylase Gene, Eric English

Master's Theses and Capstones

Polyamines are a class of low molecular weight, nitrogenous bases that participate in many important functions in plants, from germination to senescence and many steps in between. These molecules have been shown to play key roles in various abiotic and biotic stress responses which makes their biosynthetic pathway a focal point for engineering plants to better adapt to rapidly changing local environments and global climate change. Previous work with plants capable of producing high polyamine titers shows that they have superior stress responses as compared to their wild type counterparts. This study investigated what broader impacts a genetic manipulations to …

Gli3 And P300: Modulating Inflammatory Cytokine Production In Monocytes, Storm Devin Gardner

Master's Theses and Capstones

GLI3 is an important protein traditionally found in the Sonic Hedgehog pathway. It is involved in numerous events that take place during embryogenesis such as the differentiation and patterning of cells in the body. Monocytes are important innate immune cells which infiltrate the site of inflammation when a pathogen invades our body. Gli3 has also been shown to be upregulated in monocytes following pathogen stimulation, suggesting Gli3 could have an important role in mediating the release of inflammatory signals known as cytokines. The histone acetylase protein p300 traditionally acetylates histones to epigenetically modify them to allow DNA unwinding and subsequently …

Larval Assessment And Infection Etiology Of Cultivated And Wild Eastern Oysters, Crassostrea Virginica, Of Great Bay Estuary, Nh, Alyssa Stasse

Master's Theses and Capstones

Eastern oyster, Crassostrea virginica, populations have been declining steadily over the past several decades across the North American east coast. Great Bay Estuary (GBE), located in New Hampshire, is experiencing this loss and restoration efforts have been put into effect. This work addresses restoration needs by characterizing abundances of settled spat and two early stages of C. virginica, D-hinge and veliger, in GBE from June 2020 through November 2020. Abundances are compared based on the collection site and the physicochemical data recorded on each sampling date. It was found that there were no differences in larval abundance at different sites …

The Impact Of Hurricanes On The Acoustic Detection Of Cetaceans, Aditi Tripathy

Master's Theses and Capstones

Passive acoustic monitoring (PAM) is valuable for understanding the presence, behavior, distribution, and population density of marine mammals. While long-term variability of ambient sound is typically evaluated, the impact of short-term variability due to episodic events has not been assessed until now. Hurricanes Dorian (Category 5; 2019), Florence (Category 4; 2018), and Humberto (Category 3; 2019) impacted the soundscape as observed from the passive acoustic data at the Atlantic Deepwater Ecosystem Observatory Network (ADEON) locations in the US Mid- and South Atlantic Outer Continental Shelf. Hurricanes are increasingly prevalent in the North Atlantic and increase the ambient sound level at …

Uv Sulfite Advanced Reduction Process For Pfos Transformation In Wastewater Treatment, Cassidy Rae Yates

Master's Theses and Capstones

Most nutrients and contaminants within municipal wastewaters are removed through physical, chemical, and biological treatment methods. Per- and polyfluoroalkyl substances (PFAS) are a class of contaminants of emerging concern (CECs) that are concentrated in wastewater treatment facilities (WWTFs) from municipal, industrial, and commercial sources in communities. PFAS are poorly removed in conventional municipal wastewater treatment because these facilities are generally not designed for treatment of low-level CECs. Some PFAS leave WWTFs through aqueous effluent, while others partition to solids and are handled in sludges due to properties based on the degree of fluorination, chain length, and headgroup. As the last …

Plasticity Characterization By Deriving Non-Linear Displacements For In-Plane Biaxial Cruciform Testing, Jordan Michaela Hoffman

Master's Theses and Capstones

In-plane biaxial testing using a cruciform type specimen is a useful experimental method to characterize the elasto-plastic material behavior under non-uniaxial conditions. Different stress states can be imposed to the specimen simply by varying loading ratios along two orthogonal axes. Experiments can be performed using one experimental setup and one specimen geometry. Among different control options for loading, the displacement control in each arm is a stable and consistent option to keep the static deformation rate. However, a non-linear relationship exists between the control parameter e.g., displacement, and derived quantities, e.g., stress and strain. Therefore, it is a challenge to …

Bridging The Gap Between Retrieval And Summarization, Connor Lennox

Master's Theses and Capstones

Information Retrieval is, at its core, a field focused on providing information to users to fulfill an information need. One of the most common use cases of Information Retrieval is document-level retrieval, which seeks to provide a collection of documents to the user that addresses their needs. In contrast to this, single document retrieval seeks to instead provide the user with a single document comprised of all required information. We seek to extend single document retrieval to single document generation, in which we use multiple source documents to create a new document which directly addresses the information need.

Methods For Determining The Refractive Index Structure Parameter In The Marine Atmospheric Boundary Layer, Daniel Joseph Laughlin

Master's Theses and Capstones

An experimental study of the marine atmospheric boundary layer effects on the index of refraction was conducted off the coast of Portsmouth, NH between Battery Farnsworth and Wood Island. This study aimed to compare measured changes in the refractive index structure parameter (Cn2) to estimates using time series data of single point atmospheric variables, including temperature, pressure, and wind velocity. A scintillometer transmitter and receiver located at Battery Farnsworth and Wood Island, respectively, provided direct measurements of Cn2. Data from a weather tower containing a sonic anemometer was used to estimate Cn2.

Three methods of analysis to estimate Cn2 from …

Analysis Of Acoustic Scattering Layers In And Around Petermann Fjord, Northwest Greenland, Erin Heffron

Master's Theses and Capstones

In 2015 a major international collaborative expedition took place focused on understanding the processes associated with the recent rapid decline of the Greenland Ice Sheet (GIS) and the impact that this decline could have on global sea-level rise. The Petermann Expedition collected a broad range of data designed to characterize the Petermann Glacier system, a marine-terminating glacier with a floating ice tongue that has undergone dramatic changes in the last decade. During the expedition, sonars were used to map the seafloor and the water column, generating a continuous dataset over 30 days. The water column mapping revealed extensive acoustic scattering …

Characterization And Knockdown Of Tata-Binding Protein 1 In Toxoplasma Gondii, Malorie R. Nitz

Master's Theses and Capstones

Toxoplasma gondii is a single celled eukaryotic parasite that causes the disease toxoplasmosis, which infects approximately thirty to fifty percent of the world’s population. Current treatments for toxoplasmosis are lacking and immunocompromised individuals are at risk of a reactivation of acute infection. Tight control of transcription initiation is critical for maintaining proper infection for the parasite. TATA-binding proteins (TBPs) are critical transcription factors for recognizing and binding to the TATA-box and other motifs in eukaryotes to recruit the transcription preinitiation complex. Toxoplasma contains two TBPs, TgTBP1 and TgTBP2, but TATA-boxes or other conserved motifs have not yet been identified in …

Error Detection And Correction During Object Naming In Individuals With Aphasia, Anne O'Donnell

Master's Theses and Capstones

Aphasia is a neurogenic communication disorder that occurs following a left hemisphere stroke and commonly co-occurs with apraxia of speech (AOS). Individuals with aphasia typically make errors in their lexical retrieval and have difficulties detecting and correcting them. While there is ample research in how errors occur, few researchers go as far as to look at error detection and subsequent correction in this population. Given this need for research, we took a pre-existing data set of 23 individuals with aphasia grouped for presence of AOS (nine with comorbid AOS) and coded their spoken responses on the Object Naming subtest of …

Public Monuments In Changing Societies And Political Orders, Jake Connolly

Comm-entary

No abstract provided.

Comm-Entary, Spring 2021 - Full Issue

Comm-entary

No abstract provided.

Textures For Coding Bathymetric Data Quality Sectors On Electronic Navigational Chart Displays: Design And Evaluation, Christos Kastrisios, Colin Ware

Center for Coastal and Ocean Mapping

The Zones of Confidence (ZOC) is a composite data quality indicator used in Electronic Navigational Charts. Accident reports show that failing to account for chart data quality can result in maritime accidents and loss of life. ZOC overlays are intended to help mariners in identifying potential seafloor hazards and in plotting routes safe for the vessel, but a major concern with the ZOC concept has been the utilized symbology with glyphs consisting of stars. Due to its recognized deficiencies, star-symbology has been rejected for use with the successor of ZOC, the Quality of Bathymetric Data (QoBD). This work presents a …