Digital Commons Network^™

The Future Of Maine's Forests Under Alternative Socioeconomic, Climate And Conservation Pathways, Jianheng Zhao

Electronic Theses and Dissertations

Maine is a historically important timber supply region in North America and understanding the potential change in forestlands and their product industries affected by climate change and various socio-economic conditions can better improve the forest healthy and sustain a sustainable product industry. A statistical harvest choice model for the state of Maine was developed in chapter 1. It was estimated using a multinomial logit model of two products, under varying management intensities, and ownership classifications across varying market conditions. Results indicate that stumpage prices have a significant effect on forest landowners' harvest decisions and that the expansion of conservation land …

High Fidelity Computational Modeling And Analysis Of Voice Production, Weili Jiang

Electronic Theses and Dissertations

This research aims to improve the fundamental understanding of the multiphysics nature of voice production, particularly, the dynamic couplings among glottal flow, vocal fold vibration and airway acoustics through high-fidelity computational modeling and simulations. Built upon in-house numerical solvers, including an immersed-boundary-method based incompressible flow solver, a finite element method based solid mechanics solver and a hydrodynamic/aerodynamic splitting method based acoustics solver, a fully coupled, continuum mechanics based fluid-structure-acoustics interaction model was developed to simulate the flow-induced vocal fold vibrations and sound production in birds and mammals. Extensive validations of the model were conducted by comparing to excised syringeal and …

The Effect That Testing Has On Nondeclarative Memory, David Smith

Electronic Theses and Dissertations

Testing has been shown to improve long-term memory retention by decreasing the amount of material forgotten, a phenomenon known as the testing effect. This positive impact of testing has been shown using direct tests of memory that require declarative memory, things like memorizing word-pairs and single-word lists. This dissertation is the first research to investigate how testing impacts nondeclarative memory using three experiments. The first and second experiment utilize the word fragment completion task to measure the effect that testing has on words learned via methodology thought to recruit either declarative or nondeclarative memory. The third experiment utilizes a probabilistic …

Evaluating Lignosulfonates Potential As Legume Hay And Silage Preservatives, Angela Yenny Leon-Tinoco

Electronic Theses and Dissertations

The aim was to screen and optimize low-cost lignosulfonates (LST) as legume silage and hay preservatives to decrease losses of DM and nutritive value due to spoilage. In experiment 1, we evaluated the effects of untreated silage (0%), sodium lignosulfonate (NaL) and magnesium lignosulfonate (MgL) applied independently at 0.5, 1, and 1.5 (% w/w, fresh basis) and INO (Pediococcus pentosaceus and Lactobacillus plantarum; 5 and 4 log cfu/fresh alfalfa g, on high moisture alfalfa (Medicago sativa L.) silage nutrient preservation. Data were analyzed as a randomized complete block design (RCBD; 5 blocks) and linear and quadratic polynomial contrasts were used …

The Maine Teacher Resilience Study: Using Sem To Create A Teacher Costs To Caring Resilience Model, Sherry Pineau Brown

Electronic Theses and Dissertations

For decades, researchers have understood the deleterious emotional and psychological effects that can result from working with individuals who have experienced trauma and adverse childhood experiences (ACEs) including vicarious traumatization, compassion fatigue, secondary traumatic stress (STS), burnout, and an intent to leave the profession (Figley, 1995; McCann & Pearlman, 1990; Stamm, 1999). Figley (1995) deemed such effects as an almost inevitable “cost to caring” (p.1) for those who have experienced adversity. Teachers, however, have been largely left out of the discussion surrounding such effects. The purpose of this quantitative study is two-fold. First, the purpose is to understand the extent …

Evaluating Tlb (Translation Lookaside Buffer) Performance Overhead For Nvm (Non-Volatile Memory) Hybrid System, Xiang Guo

Electronic Theses and Dissertations

As the non-volatile memory (NVM) technology offers near-DRAM performance and near-disk capacity, NVM has emerged as a new storage class. Conventional file systems, designed for hard disk drives or solid-state drives, need to be re-examined or even re-designed for NVM storage. For example, new file systems such as NOVA, HMFS, HMVFS and Ext4-DAX, have been developed and implemented to fully leverage NVM’s characteristics, such as fast fine-grained access. This thesis research uses a variety of I/O workloads to evaluate the performance overhead of the TLB (translation lookaside buffer) in various file systems on emulated NVM storage systems, in which NVM …

Sustainable Production Of Feed For Recirculating Aquaculture Using Black Solider Flies And Microalgae, Patrick Erbland

Electronic Theses and Dissertations

The demand for high-quality, nutritious food continues to increase as human populations grow. As wild fisheries are depleted, aquaculture production is growing to meet the demand for seafood. Sustainable alternatives to wild caught fish meal are increasingly valued for aquaculture feed production. Microalgae and insect larvae are both valuable sources of fatty acids in aquaculture feed. Black soldier fly larvae, Hermetia illucens (L.) are used to convert organic waste streams into insect-based animal feeds. We tested their ability to retain alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) from feeding substrates, which has important implications for their use …

Fostering Coastal Destination Resilience In Maine: Understanding Climate Change Risks And Behaviors, Lydia Horne

Electronic Theses and Dissertations

Tourism is an increasingly important global industry. Coastal and nature-based tourism destinations are especially vulnerable to climate change. Trends in visitation are expected to shift under changing climate conditions, influencing tourist travel behaviors related to destination selection, timing of visits, and activity participation. Tourism suppliers’ adaptation and mitigation behaviors have the potential to alleviate negative shifts in visitation and respond to negative climate change impacts, while also enabling suppliers to take advantage of emerging opportunities. The purpose of this dissertation is to understand how tourism stakeholders, including tourism suppliers (i.e., business owners, managers) and consumers (i.e., visitors), perceive their risk …

Use Of Gis To Find Optimum Locations For Anaerobic Digestion Or Composting Facilities In Maine, Usha Humagain

Electronic Theses and Dissertations

As per US EPA, in 2017, 41 million tons of food waste was generated, but only 6.3% was diverted from landfills (US EPA, 2020). When landfilled or incinerated, organic waste (food waste, sludge, manure, agricultural waste) causes environmental pollution through greenhouse gas emissions, land, water, and air pollution. In contrast, if we compost or digest organic waste, we can generate soil additives and a mixture of methane and carbon dioxide gas to produce electricity or energy. Both digestion and composting reduce greenhouse gas emissions, improve the land through additives, and boost the economy. Many countries are adopting anaerobic digestion and …

Holistic Monitoring Of Maine Sea Lice (Lepeoptheirus Salmonis, Kroyer, 1837) Sensitivities To Therapies: Developing A Novel Assay To Examine Lice Behavior, Kathryn Liberman

Electronic Theses and Dissertations

Sea lice (Lepeoptheirus salmonis) present significant economic and animal welfare challenges to salmon aquaculture globally. Chemical delousing agents are used in many countries, with each nation eventually reporting sea lice developing reduced sensitivities to treatments. While some countries have in place sea lice sensitivity monitoring programs, that is not the case in Maine, USA. Although chemical delousing agents are not currently used in Maine, they have been used in the past and are currently used in neighboring Canadian salmon farms. Different bay management areas (BMAs) were sampled during different seasons to determine if there is a seasonal or spatial component …

Optical Signatures Of Plankton In The Open Ocean: From Individual Cells To Global Patterns, Nils Haentjens

Electronic Theses and Dissertations

Marine plankton ecosystems play a major role on Earth, having implications for the global carbon cycle and the food-web structures. Ocean color satellites and networks of autonomous platforms equipped with optical sensors are the primary tools used to study phytoplankton dynamics. They provide long term records while offering a synoptic view of our oceans, enabling to study impact of climate variability on planktonic ecosystems. Interpretation of these observations rely heavily on optical theory and how light propagating through the water is affected by particles who absorb and scatter light (e.g. phytoplankton, sediments). However, the complexity of the optical properties of …

An Experimental Investigation Of Alternative Wave Attenuation Mechanisms For A Modular Breakwater, Richard Perry

Electronic Theses and Dissertations

Global warming and sea level rise threaten to render traditional coastal protection structures as less effective. Floating breakwaters offer the advantages of adapting to rising sea level, allowing important material transport to occur, and being able to deploy and adapt to varying environmental conditions (seabed, depth, etc.). Traditional floating breakwaters typically consist of reflective concrete structures that are limited semi-sheltered locations. This research aimed to construct floating breakwaters out of lightweight materials with a smaller footprint while utilizing alternative attenuation mechanisms. Three breakwaters consisting of a box, beach, and pipe designs were constructed at 1:40 scale and tested in a …

Modeling Of Non-Newtonian Fluid Flow In A Porous Medium, Hamza Azzam

Electronic Theses and Dissertations

Flows of Newtonian and non-Newtonian fluids in porous media are of considerable interest in several diverse areas, including petroleum engineering, chemical engineering, and composite materials manufacturing. In the first part of this thesis, one-dimensional linear and radial isothermal infiltration models for a non-Newtonian fluid flow in a porous solid preform are presented. The objective is to investigate the effects of the flow behavior index, preform porosity and the inlet boundary condition (which is either a known applied pressure or a fluid flux factor) on the infiltration front, pore pressure distribution, and fluid content variation. In the second part of the …

Development, Design, And Utilization Of A Reflective Based Photoplethysmography Sensor, Madeline Mazjanis

Electronic Theses and Dissertations

Plethysmography refers to the dynamic measurement of biological tissue volumes that, for example, may change due to fluctuations in blood volume. Photoplethysmography (PPG) makes use of the attenuation of light penetrating into vascular tissues to determine these changes in blood volume. Modern PPG is an optical technique involving low cost photosensors and light emitting diodes (LED), and is capable of measuring multiple biological vitals simultaneously. For example, in addition to heart rate determination, PPG devices can be used as pulse oximeters, capable of calculating the blood oxygen saturation (SpO2) through a series of simple optical calculations performed on either reflectance …

Design And Fabrication Of A 3-Dimensional Capacitive-Based Force Sensor, Md Shafiqur Rahman

Electronic Theses and Dissertations

The detection of abnormal gait patterns is imperative for early diagnoses and treatment of serious health issues such as loss of mobility and balance, risk of falls, cardiovascular disease, etc. Human gait analysis is the tool used to detect abnormal gait patterns. Gait analysis also can help to understand the cause of gait abnormalities and to make a treatment plan for individual patients. Ground reaction forces (GRFs) at the foot during walking or running are essential for kinetic analysis of the human gait. However, there are no wearable systems that can directly measure three-directional (3D) forces during daily walking. Currently, …

Wildlife Rehabilitation Datasets As An Underutilized Resource To Understand Avian Threats, Mortality, And Mitigation Opportunities, Michelle M. Duffy

Electronic Theses and Dissertations

Wildlife rehabilitation centers collect large datasets that focus on medical care, yet they also collect information more broadly relevant to wildlife conservation. The goal of this study was to demonstrate the potential for these datasets to be used in conservation science to better understand avian threats, mortality, and mitigation opportunities. We quantified the causes of bird admissions to rehabilitation centers within the Northeast and Midwest United States, the mortality rates during rehabilitation by admission cause, and the proportion of anthropogenic-caused admissions. Additionally, we related human population and development metrics to the number of bird admissions to better understand geographic bias …

Examining The Function Of Protein Acyltransferase Via The Dhhc Domain Of The Paz5 Protein In The Organism Dictyostelium Discoideum, George M. Stuart-Ranchev

Electronic Theses and Dissertations

Protein S-palmitoylation plays a crucial role in many biological systems. S-palmitoylation involves the post-translational attachment of palmitate to a cysteine residue through a reversible thioester linkage. S-Palmitoylation is used to modify both integral and membrane proteins, many of which are involved in intracellular trafficking, membrane localization, and signal transduction pathways. Intracellular palmitoylation is mediated by a family of protein acyltransferases (PATs). PAT mutations are associated with neurological diseases and cancer progression. Proteins in the PAT family are defined by the presence of a 51-amino acid cysteine-rich domain (CRD), which contains a highly conserved aspartate-histidine-histidine-cysteine (DHHC) motif. The …

An Intramolecular Method For The Formation Of Glycosidic Bonds, Sudeera Nadeeshani Kamburugamuwa Kamburugamuwe Loku Acharige

Electronic Theses and Dissertations

The improved understanding of carbohydrate functions in biological systems has increased the demand for well-characterized and pure carbohydrates in biomedical research. Chemical synthesis is the most feasible method to satisfy the scientific demand despite the inherent challenges of the glycosylation reaction. Therefore, it is essential to investigate novel methods for the formation of glycosidic bonds. In this work, an intramolecular method was developed using a thio-methylene-silyl linker to tether a glycosyl donor and acceptor. The glycosylation conditions resulted in the formation of both anomeric isomers with a preference for the inversion pathway, which is inconsistent with an entirely intermolecular glycosylation …

Reaction Kinetics And Mechanism Investigations Of Renewable Chemicals Production From Biomass, Hussein Talib Abdulrazzaq

Electronic Theses and Dissertations

The development of the technologies and the improved processes for the production of high value bio-based chemicals is one of the most important challenges at the present time. This new movement is not only important from an environmental perspective, but also it is a profitable approach to provide affordable and efficient processes. Therefore, the chemical catalytic upgrading processes over various homogenous and heterogeneous catalysis could be an outstanding modification to upgrade biomass-derived platform molecule to high value applications. In this dissertation, we highlight our recent progress in developing new chemistries and processes for upgrading biomass-derived molecules and address the challenges …

Pyramiding Approaches For Potato Disease Resistance Breeding, Kristen M. Brown-Donovan

Electronic Theses and Dissertations

This study establishes the start of late blight genetic profiles for varieties and clones used as potato breeding material across the United States,and a Mendelian use of marker-assisted selection is employed to estimate allele dosage.

Potato is the fourth most important staple crop worldwide, with both high nutritional and economic values. Breeders seek improvements for many traits related to yield, dry matter, and surface and internal defects. Resistances to several diseases are also desired traits that breeders try to incorporate into their programs. The advent of DNA-based genetic technologies help breeding programs facilitate faster selection, including the use of marker-assisted …

Understanding Biomass Upgrading Through Hydrogenolysis Reactions: Kinetics And Mechanism, Jalal Tavana

Electronic Theses and Dissertations

This dissertation involves several hydrogenolysis reactions but is mainly focused on hydrodechlorination (HDC) of chlorobenzene (PhCl) and hydrodeoxygenation (HDO) of 2-furancarboxylic acid (FCA). Hydrodechlorination of PhCl has been the subject of research for some time. Here, we used a Pd/C catalyst to study this reaction though rigorous kinetics and mechanistic analyses in a CSTR reactor. The H₂/D₂ kinetic isotope effect (KIE) experiment revealed that H₂ is not involved in a rate controlling step. The kinetics data are in agreement with similar systems reported before and follow a first-order dependence on chlorobenzene, half order for hydrogen and …

Evaluating The Current Weed Community In Wild Blueberry Fields And Ipm Strategies For Spreading Dogbane (Apocynum Androsaemifolium), Anthony G. Ayers

Electronic Theses and Dissertations

Lowbush blueberry (Vaccinium angustifolium) is Maine’s third largest crop (USDA 2020 a). From 2017 – 2019 the three seasons yield average was 27,200 tons were harvested from 19,500 acres for a value of $22,468,000 (USDA 2020 c). Lowbush blueberries are managed on a two-year cycle. Every other year, lowbush blueberry fields are pruned to the ground either through the use of a tractor mounted flail mower or a prescribed burn (Yarborough 2009). Pruning is a necessary part of managing lowbush blueberries as the second-year growth produces the highest yield but steadily declines in subsequent years (Drummond et al. …

Microsite Requirements For Successful Regeneration In Lowland Northern White-Cedar (Thuja Occidentalis) Forests, Jeanette Allogio

Electronic Theses and Dissertations

Declines in stands of northern white-cedar (Thuja occidentalis L., hereafter cedar) have been observed as both shifts in species composition and reductions in cedar densities, particularly those stands in lowland sites (Curtis 1946, Boulfroy 2012). While several factors inhibiting cedar regeneration have been identified, a thorough understanding of the conditions that best promote regeneration is lacking. Our objectives for the first chapter were to characterize the site conditions associated with successful regeneration in lowland cedar stands and to describe how spatial patterns of various cedar size classes relate to site preference and to regeneration dynamics. These objectives were achieved …

Live Cell Super-Resolution Microscopy Quanitifies An Interaction Between Influenza Hemagglutinin And Phosphatidylinositol 4,5-Bisphosphate, Jaqulin N. Wallace

Electronic Theses and Dissertations

Influenza virus, colloquially known as the flu, is an acute respiratory disease that infects several millions of individuals each year in the U.S. and kills tens of thousands of those infected. Yearly viral vaccines are widely available, however, due to the virus’s high mutation rate, their efficacy varies greatly. Due to the variability in vaccine efficiency against seasonal influenza, and the potential for even more pathogenic versions of influenza to emerge at any time, there is a high demand for a universal treatment option.

Influenza virus hijacks a variety of host cell components in order to replicate. The glycoprotein hemagglutinin …

Integrating Local Ecology And Human Dimensions To Understand A Tidally Dynamic Ecosystem In Downeast Maine, Gabriella Marafino

Electronic Theses and Dissertations

Coastal community resilience requires connecting people with useful information that reflects their needs and interests and empowers them to make informed marine resource decisions. In this thesis, I explore how to effectively integrate disparate data from different disciplines and sources to make information more useful and usable at federal, state, tribal, and local levels in order to support more holistic and integrated management. To accomplish this, I draw on different types of knowledge and approaches, including Western science, local ecological knowledge, traditional ecological knowledge, and citizen science, to incorporate the social perspective and community values for holistic marine resource management. …

Adsorptive Surface Modification Of Cellulose Nanocrystals To Stabilize Nutraceuticals Loaded Lipid Carriers For Food Application, Avinash S. Patel

Electronic Theses and Dissertations

Lipid carriers such as emulsions and liposomes have been widely studied as carriers for different nutraceuticals. However, lipid carriers' physicochemical instability results in the leakage of loaded nutraceuticals and the low solubility into the digestion medium, thus reducing the bioaccessibility. Cellulose nanocrystals (CNC) are nano-sized cellulose derivatives obtained after hydrolysis of cellulosic matrices that possess potential applications in functional foods and nutraceuticals. However, hydrophilicity, anionic surface potential, and poor re-dispersibility limit CNC’s applications. The primary objectives of this research were 1) to modify CNC via adsorbing polyethylene glycol (PEG) to stabilize liposomes and to study its physiochemical stability at different …

Monarch Butterfly (Danaus Plexippus) Roost Site-Selection And Viability East Of The Appalachian Mountains, Brandon Boxler

Electronic Theses and Dissertations

The Monarch butterfly is a flagship species and pollinator whose populations have declined by approximately 85% in the last two decades. Their largest population overwinters in Mexico, then disperses across the eastern United States and Canada during April to August. Between September-December, the butterflies return south using two migratory flyways, one spanning the central United States and another following the Atlantic coast. They fly during the day and at night roost in large groups. Roosting habitat is essential to the continuation of the Monarchs’ migration, however, threats such as anthropogenic habitat disturbance and climate change potentially endanger sustainability of these …

Potato Yield Response To Different Rates Of Phosphorus Fertilization In Northern Maine - Usa, Ahmed A. Algburi

Electronic Theses and Dissertations

Potato (Solanum tuberosum L.) is a major vegetable crop worldwide, including the United States of America. No other crops could equal potato in its production of food in terms of energy and value per unite area. Because potato is a high-value vegetable, farmers apply phosphorus fertilization at high rates despite high soil phosphorus availability. Phosphorus is the most critical major soil nutrient limiting potato growth after nitrogen and potassium. Six rates of P fertilization (0 – 280 kg P ha−1) were applied at twelve different sites across Northern Maine, United States of America. In the present study, soil pH was …

The Design And Validation Of A Uav Propeller Intended For Extremely Low Reynolds Number Environments, Benjamin Hebert

Electronic Theses and Dissertations

Mars exploration and UAV development have both advanced significantly over the past century, and are now being considered in tandem. Currently needed are UAV propellers that can operate in the Martian atmosphere. Flow will be in the range of Re < 20,000, creating extreme conditions not typically examined. A Blade Element Momentum Theory (BEMT) algorithm is developed using a variety of corrections designed specifically for low Reynolds number and rotational flows. Due to both the simplicity of the basic BEMT formulation, corrections are easy to put in place and often necessary to achieve accurate estimates. Aerodynamic coefficients are determined from XFOIL code, and have questionable accuracy in this regime. To account for this, a correction model is developed by comparing XFOIL results to experimental results of airfoils at low Re. This is all tested against a previous low Re propeller experiment. The results of this comparison are used to adjust the values in the correction, to produce more accurate results for theoretical design.

From here, a design philosophy for the propeller is developed using established methods and previous experimental data. High thrust is prioritized, with efficiency being a secondary concern. A hard mach limit of 0.7 is set to avoid major drag penalties, limiting the usable ranges of RPM and radius. Airfoil designs are then examined, based on previous designs, theoretical intuition, and …

Approximating Fol Ontologies Using Owl2, Robert W. Powell

Electronic Theses and Dissertations

With the amount of data collected everyday ever expanding, techniques which allow com- puters to semantically understand data are growing in importance. Ontologies are a tool to describe the relationships connecting data so that computers can correctly interpret and combine data from many sources. An ontology about water needs to describe what the term "river" may refer to: An arbitrary river or one usable for navigation; a single tributary or an entire river network; the riverbed or the water itself? Well-designed ontologies can be shared, reused, and extended across multiple applications and facilitate betters integration of different data collections.

Common …