Life Sciences Commons^™

Soil Organic Carbon In Maine, Its Responses To Biochar Addition, And Climate Change, Xue Bai

Electronic Theses and Dissertations

Soil organic carbon (SOC), as one of the largest C pools in terrestrial ecosystems, plays a key role in governing soil ecosystem processes and climate regulation. Climate change concerns have resulted in a rapidly growing interest in understanding the potential for natural climate solutions (NCS) that include enhancing SOC sequestration and reduce net atmospheric greenhouse gas (GHG) emissions. This research focused on addressing information needs about SOC in Maine, specifically in evaluating available soil databases to accurately quantify SOC density and concentration, and study the response of selected representative Maine soils to biochar amendments under a changing climate.

Maine SOC …

Effects Of A Novel Dsrna-Based Insecticide On The Colorado Potato Beetle, Samuel J. Pallis

Electronic Theses and Dissertations

The Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) is one of the most destructive pests of the cultivated potato, Solanum tuberosum. Colorado potato beetles have been devastating potato crops for the past 150 years and have expanded their range during that time, becoming a globally distributed agricultural pest. Potato beetles are well-suited to agricultural environments and have evolved some degree of resistance to virtually all chemical insecticides. As such, the development of novel control methods to both control potato beetle populations and manage the evolution of insecticide resistance are in constant demand

The knockdown of gene functioning through ribonucleic acid …

Determining Effects Of Management Practices On Potato Early Dying And Soil Microbiome And Assessing Risk Of Fungicide Resistance In Verticillium Dahliae, Kedi Li

Electronic Theses and Dissertations

Potato early dying (PED) is a yield-constraining soilborne disease of potato, caused by Verticillium spp. with V. dahliae being the predominant causal agent. Since the pathogen inhabits soil for long periods, PED management aims to reduce the population of V. dahliae in soil. Benzovindiflupyr and azoxystrobin are effective chemicals and frequently used in the control of V. dahliae. In this study, field trials were conducted at Aroostook Farm, Presque Isle, ME in 2019 and 2020. Chemical and biological products have been studied for PED control, and fungicide resistance was also examined. To evaluate fungicide resistance, benzovindiflupyr was characterized on …

Economics And Operational Decision Constraints Of Small-Diameter Tree Harvesting, Libin Thaikkattil Louis

Electronic Theses and Dissertations

Sustainably managed forests are crucial in balancing trade-off between various ecosystem functions and optimum product utilization. Improving the utilization of these renewable resources through diversified forest wood products faces various socio-economic, ecological, and cultural challenges. A major challenge faced by forest managers in the Northeastern United States is overstocked stands dominated by small-diameter trees (SDT). Major woody portion of the harvested residues is constituted by SDT and are typically of low value. Data from the national inventory indicates a high number of SDT in Northeastern forests such that the average size of all trees in the region is less than …

Real-Time Monitoring Of Cell Death Progress Using Capacitance Spectroscopy, Suyang Wu

Electronic Theses and Dissertations

Biologics, including the monoclonal antibody (mAb), has experienced rapid development in the last decade. However, the price of biologics is often prohibitively high because of the low process efficiency. Delaying the inevitable cell death improves the productivity of upstream bioprocessing, whose success relies on monitoring the cell death onset that indicates the timing for preventive actions.

This study proposes to develop a real-time monitoring model that quantifies the dying cell percentage in lab-scale bioreactors using capacitance spectroscopy. The capacitance spectroscopy contains cell death-related information due to various physical properties changes during the cell death process, e.g., cytoplasmic conductivity change. The …

Understanding Snow Leopard (Panthera Uncia) Population Structure, Diet, And Human-Wildlife Dimensions Using Noninvasive Genetic Approaches, Charlotte Hacker

Electronic Theses and Dissertations

Snow leopards (Panthera uncia) are a large cat endemic to the mountains of Central Asia. Despite their status as a flagship species, there are numerous knowledge gaps surrounding their population status, dietary ecology, and relationship with humans. Such knowledge gaps are prohibitive for effective conservation action for the species. Snow leopards are threatened by habitat loss, decreased prey availability, retaliatory killings, and large-scale negative impacts associated with climate change. In order to help bridge these gaps, noninvasive genetic methodologies were deployed in this work across several disciplines. Population genetic metrics were garnered at local, regional, and range-wide scales, …

Analysis Of Spore Shape Determination In Streptomyces, Ning Sun

Electronic Theses and Dissertations

Streptomycetes are Gram-positive, soil-dwelling bacteria that possess a complex life cycle with the alternation of vegetative mycelium, aerial mycelium, and spores. Streptomyces. coelicolor spore maturation is a complex process that involves spore shape metamorphosis from cylindrical pre-spores into ellipsoid spores, but the details of this process have remained enigmatic. Previously, our lab identified a novel gene ssdA that might play a role in spore shape determination using a transposon-based insertion mutagenesis in S. coelicolor. In this study, I isolated a S. coelicolor ssdA-null mutant that showed increased colony hydrophobicity and misshapen spores in sizes and shapes, confirming the …

Cgrp-Driven Lateralization Of Pain Modulation By The Central Amygdala, Heather Allen

Electronic Theses and Dissertations

The central amygdala (CeA) is a bilateral, mid limbic brain region involved in the processing of pain and emotion. Interestingly, the left and right CeA are functionally lateralized in the context of bladder pain, with the left and right CeA having opposing effects on bladder pain-like behavior. However, the specific mechanisms driving these divergent functions are unknown. Nociceptive signals from the bladder are relayed to the CeA via projection neurons in the parabrachial nucleus (PBN) that express high levels of calcitonin gene-related peptide (CGRP). In these studies, we investigated the influence of PBN CGRP signaling in the left and right …

Retroviral Infection Dynamics In Maine's Wild Turkeys, Stephanie A. Shea

Electronic Theses and Dissertations

Widespread wild turkey reintroductions in the late 1900s have led to increases in population density and geographic distribution across North America. This rapid population expansion has put them into proximity with closely-related wild and domestic avian species, increasing the risks of pathogen transmission. Lymphoproliferative disease virus (LPDV) is an avian oncogenic retrovirus detected in wild turkeys in 2009, and previously known to infect domestic turkeys. Following its initial detection, surveys reported variable LPDV prevalence across eastern North America with most wild turkeys being asymptomatic, however diagnostic cases revealed 10% mortality of LPDV-infected individuals. Given its recent detection, little is known …

Food Safety And Functionality Assessment Of Kombucha Systems Through Bacillus Cereus Spore And Probiotic Inoculations, Alexandria L. Bromley

Electronic Theses and Dissertations

Kombucha is a SCOBY-fermented tea beverage known for its taste, sensorial qualities, and high endogenous microbial load. In recent years, kombucha has become a popular functional food with a compound annual growth rate of 25% from 2015 to 2020 in American kombucha sales alone, and sales are predicted to keep increasing significantly over the next decade. However, kombucha is lacking in scientific research, and there is still much to be explored regarding its safety and native probiotic content. This research looked into the various routes of contamination of several kombucha systems as well as the feasibility of the producing a …

Utilization Of Secondary Processing Mill Residues In Maine To Produce Raw Materials For Manufacturing Wood-Plastic Composites (Wpcs), Geeta Pokhrel

Electronic Theses and Dissertations

The overall objective of this study was to explore the potential of utilizing secondary processing mill residues generated in Maine (1.6 million tons annually) in Wood-Plastic Composites (WPCs). Attributable to the huge shipping costs for transporting wood flour over long distances, wood pellets are explored as alternative feedstock for WPCs manufacturing. The mill residues from four species based on their abundance and potential applicability for utilization in WPCs manufacturing were used to make the two different feedstocks. The properties of the wood flour and pellets were studied along with the comparison of the properties of polypropylene-based WPCs using both of …

Seasonal Flammability Comparisons Of Native And Exotic Plants In The Post Oak Savannah, Blackland Prairie, And Pineywoods Ecoregions Of Texas, Michael Tiller

Electronic Theses and Dissertations

East Texas’ diverse landscape can present year-round wildfire seasons that can be influenced by seasonal and regional differences in climate and physiography. Greater insight into the fundamental thermal behavior of wildland fuels can aid in fire behavior prediction and development of fire-resistant plant lists. This study focused on estimating seasonal and regional flammability characteristics of five evergreen species: yaupon (Ilex vomitoria), Chinese privet (Ligustrum sinense), greenbrier (Smilax spp.), eastern red cedar (Juniperus virginiana), and escarpment live oak (Quercus fusiformis); and two deciduous species: Chinese tallow (Triadica sebifera) and southern …

Computationally Modeling Dynamic Biological Systems, Katherine Jarvis

Electronic Theses and Dissertations

Modeling biological systems furthers our understanding of dynamic relationships and helps us make predictions of the unknown properties of the system. The simple interplay between individual species in a dynamic environment over time can be modeled by equation-based modeling or agent- based modeling (ABM). Equation based modeling describes the change in species quantity using ordinary differential equations (ODE) and is dependent on the quantity of other species in the system as well as a predetermined rates of change. Unfortunately, this method of modeling does not model each individual agent in each species over time so individual dynamics are assumed to …

Consumer Characteristics, Acceptance And Knowledge Of, And Preferences For Kombucha, Matthew Walker

Electronic Theses and Dissertations

Consumer interest in fermented and functional foods, including kombucha, continues to grow at exponential rates. However, there is limited research on consumer demographics, preferences, beliefs, and behaviors related to kombucha consumption. The purpose of this study was to identify the characteristics of current kombucha consumers, better understand their preferences and buying habits, and identify groups that could be likely kombucha consumers in the future. These preferences and identifying factors were determined via an online consumer survey. The online survey was launched in February 2021. A total of 2,149 participants met the inclusion criteria of living in the United States, being …

Role Of Meibum And Tear Phospholipids In The Evaporative Water Loss Associated With Dry Eye., Samiyyah M. Sledge

Electronic Theses and Dissertations

It is generally believed that the tear film lipid surface film inhibits the rate of evaporation (Revap) of the underlying tear aqueous. It is also generally believed that changes in the composition of the tear film lipid layer is responsible for an increase in Revap in patients with dry eye. Both of these ideas have never been proven. The purpose of the current studies was to test these ideas. Revap was measured in vitro gravimetrically. Lipid spreading was measured using Raman spectroscopy and microscopy. The influence of the following surface films on the Revap of the sub phase of physiologically …

Assessing Plant And Lichen Diversity Using Reflectance Spectra, Lance Stasinski

Electronic Theses and Dissertations

Biodiversity is changing and it is imperative that we continually assess it in order to preserve ecological services that we rely on. Spectral platforms are increasingly being used to assess biodiversity due to the fact that light reflected from an organism’s surface carries much of information about that organism. Despite the promise spectroscopy shows, two gaps in our knowledge remain. First, we do not know how well reflectance spectra can be used to estimate fine-scale diversity – intraspecific genetic and phenotypic diversity – that is fundamental to ecological and evolutionary processes. Second, spectral libraries, used to construct models to estimate …

Investigation Of Mitochondrial Inheritance In The Smut Fungus Sporisorium Reilianum., Hector Eduardo Mendoza

Electronic Theses and Dissertations

An important goal in evolutionary biology is to address the origin of Earth’s immense biodiversity through the evolution of complex sexual reproduction mechanisms in eukaryotes. Inheritance of mitochondria during sexual reproduction has received special attention in recent years, as these organelles cannot be synthesized de novo and must be transmitted from parent to offspring. The importance of these organelles far exceeds its common function as the energy-producing “powerhouse” of the cell, as it has been found to also be involved in fundamental processes like apoptosis, aging and metabolic homeostasis. Thus, appropriate inheritance of mitochondria is essential for growth and development …

Q-Griffithsin Interactions And Utility For The Prevention And Treatment Of Mucosal Infections., Henry Nabeta

Electronic Theses and Dissertations

Griffithsin (GRFT) is a carbohydrate binding agent (lectin) that was originally identified in the red alga Griffithsia sp. Q-Griffithsin (Q-GRFT) is an oxidation stable analog of GRFT. GRFT has demonstrated inhibitory activity against HIV-1, Coronaviruses, Hepatitis C, influenza and Ebola viruses. The broad-spectrum activity suggests the potential utility of this lectin in a wide range of viral infections. However, the lectin’s activity in mucosal infections has not been extensively studied. Using in vitro, ex vivo and in vivo assays, we have demonstrated that Q-GRFT maintains the ability to bind glycosylated ligands following incubation in murine, macaque and human rectal …

Visualizing Anhydrobiosis: Liquid-Liquid Phase Separation, Membraneless Organelles, And Cellular Reorganization., Clinton J. Belott

Electronic Theses and Dissertations

Water is an integral and necessary component of life. It is then, exceedingly remarkable that some species are capable of surviving virtually complete water loss for extended periods of time. Several decades of intense research into anhydrobiosis, or life without water, have given significant insights into the molecular mechanisms governing this phenomenon. Anhydrobiosis-related intrinsically disordered (ARID) proteins have been demonstrated to be critically important for desiccation tolerance in many anhydrobiotic species and exhibit a considerably wide range of protective properties that include membrane stabilization, reinforcing bioglass formation, and protein stabilization. This dissertation begins with cellular dielectrophoresis suggesting that two ARID …

Natural Regeneration Dynamics And Survival Influenced By Abiotic And Biotic Factors In A Bottomland Hardwood Forest, Lydia J. Voth Rurup

Electronic Theses and Dissertations

Riparian ecosystems are vital to the landscape, providing critical services including water filtration and purification, flood and erosion control, carbon sequestration, biodiversity support, and aesthetic value. Bottomland hardwood forests, however, are threatened by invasive species, land loss/conversion, inconsistent or absence of harvesting disturbances, and altered hydrological patterns, leading to reduced success of desired, native species. This research assessed regeneration dynamics and one-year survival in a seasonally-flooded bottomland hardwood forest at Boggy Slough Conservation Area in East Texas to identify abiotic and biotic factors important for successful establishment of native regeneration. Areas sampled included two that were previously treated with herbicide …

Effects Of Varying Warmup Stimuli On Running Economy, Connor Bigenho

Electronic Theses and Dissertations

Purpose: The purpose of this study was to determine the effects of two potentiating warm-up stimuli (weighted-vest strides and plyometrics) on running economy (RE) over short (5-10 minutes) and longer durations (30+ minutes) of exercise in trained distance runners. Methods: Five recreationally trained male runners were recruited to participate in this study. Each trial consisted of a 10-min self-paced warm-up on the treadmill followed by baseline RE test and baseline leg-stiffness. This was immediately followed by one of two intervention warmup protocols. The protocols consisted of either a series of plyometric movements, 6 x 10-sec strides with a …

Assessing Freezing Effect On Kiwifruit Cultivars And Mapping Suitable Areas For Growing The Crop In Eastern Texas, Lais De Oliveira Machado

Electronic Theses and Dissertations

Kiwifruit is a perennial vine originating from China where it has been grown for centuries. In the United States, green kiwifruit (Actinidia deliciosa) is primarily produced commercially in California. They are fuzzy, green fleshed and well known in the marketplace. Kiwifruit plants require low to moderate soil pH, adequate winter chilling and adequate precipitation to guarantee plant development and good fructification. Actinidia chinesis or golden kiwifruit are smooth skinned, feature golden flesh and are a more recent introduction into the global market. Kiwifruit crops have attributes that favor production in east Texas, including low pest problems, current long …

Evaluation Of The Effectiveness Of Ventless Trap Survey In Capturing Sublegal American Lobster Abundance In The Inshore Gulf Of Maine, Shiyue Zhao

Electronic Theses and Dissertations

The stock assessment of American lobster (Homarus americanus) plays an important role in managing the fishery in the Gulf of Maine (GOM). Various fishery-dependent and fishery-independent data are required in the stock assessment to estimate key fisheries parameters that define the population dynamics of American lobster. In the 2015 benchmark stock assessment, ventless trap survey (VTS) data were included for the first time to provide information about the sublegal lobster (carapace length < 83 mm) dynamics. However, the effectiveness of VTS data in monitoring sublegal lobsters has not been evaluated and we have little information on whether the VTS sampling design can capture sublegal lobster dynamics. The primary goal of this thesis research was to evaluate and determine whether the data collected from the Maine VTS provide robust estimation of design-based sublegal lobsters abundance index in the inshore GOM. To achieve this goal, I (1) estimated and evaluated variations in catch rates derived, respectively, from the first, second, and third ventless trap per site; 2) predicted sublegal lobster population at a high spatial resolution using generalized additive models (GAMs); (3) sampled the simulated sublegal lobster population following the sampling protocol used in the VTS program to derive a simulated VTS abundance index; and 4) compared the simulated VTS abundance index with the

predicted population abundance index in the simulated sublegal lobster population. The spatial scale of the study was defined by the National Marine Fisheries Service (NMFS) statistical areas in …

The Intersection Of Extracellular Signaling And Stress Pathways, Sari Mayhue

Electronic Theses and Dissertations

Cell growth is reliant on the flawless orchestration of cellular signaling and is crucial to evade cancer metastasis. It is important to understand key elements of cellular processes like gene regulation and stress signaling and how they contribute to oncogenesis. Cancer cells prove exceptionally adaptive as they effectively evade cellular stress, thus encouraging a tumor hospitable environment and subsequently cancer metastasis. Protein-folding and cellular homeostasis are essential functions of the endoplasmic reticulum (ER). An overabundance of protein accumulation within the ER jeopardizes cellular homeostasis causing stress. Under ER stress, these functions fail to maintain cellular stability resulting in the activation …

Health-Related Quality Of Life (Hrqol) In Sexual Minority (Sm) College Undergraduate Students, Leigh Neptune

Electronic Theses and Dissertations

It is well documented that disparities exist in health-related quality of life (HRQOL) among sexual minority (SM) youth and adults compared to their heterosexual peers, and among college undergraduate students compared to all young adults. Yet, no studies have been conducted to date examining HRQOL, diet quality, or weight dissatisfaction at the intersection of SM and college undergraduate student status. In 2020, a cross-sectional convenience sample of college undergraduate students (N=690) from the University of Maine and Rutgers University completed an online survey consisting of items assessing demographic variables, HRQOL, diet quality, and weight dissatisfaction. Of this sample, 23.9% (n=165) …

Evaluating The Foraging Ecology And Energetics Of Atlantic Bluefin Tuna (Thunnus Thynnus) In The Gulf Of Maine, Samantha Nadeau

Electronic Theses and Dissertations

Atlantic bluefin tuna (Thunnus thynnus, ABFT) have been a commercially and recreationally valuable species in the Gulf of Maine (GOM) since the early 1950s. Over the past few decades, abundance, spatial distribution, and physical condition of ABFT have shifted, possibly as a result of trophic changes including the composition, distribution, and/or condition of available prey. Historically, ABFT forage has most commonly consisted of Atlantic herring (Clupea harengus), Atlantic mackerel (Scomber scombrus), squids (Cephalopoda), bluefish (Pomatomus saltatrix), and sand lance (Ammodytes spp.). The current stock assessment for Atlantic herring, the dominant prey item for ABFT, suggests a reduction in spawning stock …

Biotic Interactions At Species’ Range Limits In A Changing Climate, Isaac Shepard

Electronic Theses and Dissertations

As the global climate changes, many species are shifting their geographic ranges, often towards the poles or upslope in elevation. The ubiquity of these observation has renewed discussions about the mechanisms that determine species’ range margins. Leading hypotheses state abiotic variables should be the most important factor for setting range limits in environmentally stressful habitats. However, I propose an alternative hypothesis that biotic interactions may still be critically important for setting range limits, even in abiotically stressful habitats. Using a model system of ponds in the Rocky Mountains of Colorado, I developed several field experiments to empirically test the role …

Cumulative Effects Of Habitat Change: American Marten Habitat Selection And 30 Years Of Forest Harvesting In Maine, Tyler Woollard

Electronic Theses and Dissertations

Wildlife habitat conservation in landscapes where human activities cause chronic habitat disturbance is contingent upon developing land management strategies that minimize the effects of future habitat changes on wildlife populations. Long term studies can provide unique opportunities to understand how species respond to progressive habitat change, and such an understanding can reveal ways in which the often conflicting objectives of wildlife habitat conservation and human land use can be reconciled. Characterizing how animals respond behaviorally to habitat conditions may be a useful tool for identifying potential negative effects of disturbance before such effects impact rates of species occurrence, population demography, …

Use Of The New England Aquarium To Evaluate Environmental Dna Metabarcoding Of Gulf Of Maine Vertebrates And Invertebrates, Samantha Silverbrand

Electronic Theses and Dissertations

Environmental DNA (eDNA) metabarcoding is a tool that has been used to characterize biodiversity in a range of diverse systems. However, blind application of eDNA metabarcoding primer sets to new regions and species pools can result in poor taxon coverage and unaccounted detection biases. For the Maine-eDNA EPSCoR program, one of the main focuses is to understand and characterize community assemblages in the Gulf of Maine (GoM) using eDNA to further inform conservation, monitoring, and sustainability. In this study, I selected a subset of the best performing vertebrate and invertebrate metabarcoding assys to test against GoM species present in the …

The Impact Of Diet Quality On Health-Related Quality Of Life In College Students, Kayla Parsons

Electronic Theses and Dissertations

Objective The objective of this research was to explore the influence of diet quality on health-related quality of life among college undergraduate students. Methods A cross-sectional convenience sample of college students completed an online survey consisting of the Center for Disease Control’s Health Related Quality of Life (HRQOL) modules, shortened Perceived Stress Scale, sleep questionnaire, and the National Cancer Institute’s Fruit and Vegetable Screener. Body mass index (BMI) was calculated using self-reported height and weight. Independent t-test were used to compare HRQOL between students who consumed above/below average fruit and vegetable intake. Two multiple regression analyses were used to determine …