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 …

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 …

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 …

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 …

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 …

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, …

Adult-Use Cannabis And State Research Agencies An Exploratory Study And Development Of A Harm-Reduction Course, Abigail Wiegand

Electronic Theses and Dissertations

The increasing demand of adult-use cannabis is outpacing the regulatory stride of the states that legalize recreational marijuana. This work is the product of two studies that focus on those states’ agencies that closely work with their constituents. They include those who are invested or reliant on cannabis businesses and those who consume cannabis for medical or recreational purposes. State agencies and resources are funded by those same constituents’ taxes, for which they have the responsibility to protect the public’s best interests as the industry grows. Chapter 2 describes an inquiry on what information and support is shared with adult-use …

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 …

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 …

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) …

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 …

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 …

Adaptation Strategies For Wild Blueberry Growers In A Changing Climate: Mulching Effects On Crop Productivity And Fertility Effects On Blueberry Gall Midge, Rebecca Gumbrewicz

Electronic Theses and Dissertations

Wild blueberry (Vaccinium angustifolium Aiton.) cropping systems are considered resilient to environmental changes due to ecological and genetic diversity within each field. However, wild blueberries can be sensitive to weather fluctuations that cause extreme temperature or moisture regimes. Climate change in Maine is represented by increasing rates of warming temperatures, more intense precipitation events, and more frequent atmospheric “blocking” patterns. Warming temperatures result in the northward expansion of pest ranges and altered growing seasons. More extreme rainfall events lead to damaged plantings and soil erosion. Atmospheric blocking leads to an increased likelihood of heat waves and drought. Two experiments were …

Forest Disturbance And Occupancy Patterns Of Carnivores: Results Of A Large-Scale Field Study In Maine, Usa, Bryn E. Evans

Electronic Theses and Dissertations

Understanding trends in the abundance and distribution of carnivores is important at global, regional and local scales due to their ecological role, their aesthetic and economic value, and the numerous threats to their populations. Carnivores in Maine range from the American black bear (Ursus americanus), to numerous native mesocarnivore species, such as American marten (Martes americana), fisher (Pekania pennanti), coyote (Canis latrans), red fox (Vulpes vulpes), bobcat (Lynx rufus), Canada lynx (Lynx canadensis) and to two small weasel species (Mustela erminea and Neogale frenata). …

Gradient Generating Microfluidic Coculture System For Disease Modeling And Neural Development, Phaneendra Chennampally

Electronic Theses and Dissertations

Cellular microenvironment or cell niche plays an important role in developmental biology and disease pathophysiology. Physical or chemical signals in microenvironment drive the cellular activity. These signaling molecules are generated from the surrounding cells/tissues as part of intercellular communication; a fundamental property of a cell. Dynamic profile of these signaling molecules in the microenvironment plays a pivotal role in transfer of molecular information from cell to cell in disease proliferation or fate determination. Recapitulating these signaling cues in an in vitro study is difficult to achieve using standard cell culture techniques. However microfluidic systems are capable of addressing these issues, …

Whole Genome Sequencing Reveals Genes And Pathways Associated With Anthrax Survivorship In Plains Zebra, Carly Dickson

Electronic Theses and Dissertations

Pathogens are significant selective forces on natural populations, and therefore genes and gene regulators involved with combatting infections experience some of the strongest selection pressures in the vertebrate genome. Studies in humans have used high-throughput next generation sequencing to identify genes associated with infectious diseases, however, these studies have been limited in wildlife systems despite their potential to improve public health, agricultural production, and wildlife conservation. Anthrax is a globally distributed disease caused by the virulent bacterial pathogen Bacillus anthracis, which has significant effects on morbidity and mortality in humans, livestock, and wildlife populations. In this study, we utilize whole …

American Woodcock (Scolopax Minor) Migration Ecology In Eastern North America, Alexander Fish

Electronic Theses and Dissertations

Across temperate regions of North America, migrating animals must contend with seasonally influenced thermal extremes, changing food abundance, and stochastic weather events. Migrating individuals must locate suitable areas, termed stopover locations, to rest and rebuild energy reserves needed to continue migration (Rodewald and Brittingham 2004, Taylor et al. 2011). The American Woodcock (Scolopax minor; woodcock hereinafter) is a migratory forest bird that has experienced long-term population declines (Seamans and Rau 2019). We created the Eastern Woodcock Migration Research Cooperative, including 34 provincial, federal, state, and non-governmental partners, with the goal of describing the migration ecology of woodcock in the eastern …

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 …

Krüppel-Like Factor 9 Is A Feed-Forward Regulator Of Glucocorticoid Signaling, Ian Gans

Electronic Theses and Dissertations

Epidemiological studies show that children of chronically stressed mothers are at higher risk for adverse health outcomes throughout life, but the pathological mechanisms underlying this increased risk remain poorly understood. Using zebrafish as a model system, the Coffman Lab at the MDI Biological Laboratory showed in 2016 that larvae exposed to chronically elevated levels of the glucocorticoid (GC) stress hormone cortisol exhibit elevated pro-inflammatory gene expression. Further, the Coffman Lab showed that immune gene response to injury or infection was blunted in adult fish raised from cortisol treated larvae, presenting a novel paradigm for the investigation of disease mechanisms involving …

Cellulose Nanofibril Coated Bio-Based Composites For Food Serving Applications, Rakibul Hossain

Electronic Theses and Dissertations

Cellulose nanofibrils (CNFs) and lignin-containing cellulose nanofibrils (LCNFs) have excellent binding properties with lignocellulosic materials such as wood particles, cellulose fibers, and other particles. They also have excellent oil and grease barrier properties. A novel application by utilizing the binder and barrier properties of CNF and LCNF has been proposed. In this study, multi-layer oil-resistant food serving containers were made using cellulose nanofibril coated wood flour composites. Composites were made with different formulations by using LCNF from old corrugated containers (OCC) at different fines content and CNF at 20, 30, and 40% binder content combined with wood particles. LCNF and …

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 …

Experimental Warming Effects On Growth, Yield, And Biotic Pressure Of Wild Blueberries In Maine, Yu-Ying Chen

Electronic Theses and Dissertations

As the global temperature rises, a need exists for understanding the potential impacts of warming on the wild blueberry industry in Maine. Warming can change the physiology, growth, and pest pressure of crops, and also accelerates the evapotranspiration rate, resulting in decreased soil moisture. The objectives of this study were: (1) To characterize the response of phenological, morphological, and physiological traits of the wild blueberries to warming; (2) To quantify the impacts of different temperature levels on yield and berry quality; (3) To determine the abiotic and biotic factors that may influence yield, such as winter damages, freezing temperatures, the …

Eastern Wild Turkey Population Ecology Across Land Use Gradients In Maine, Matthew Gonnerman

Electronic Theses and Dissertations

Wild turkeys are a wide-ranging species with considerable cultural and economic significance. As they can exist across a variety of ecosystems, understanding how land use affects population vital rates can be a crucial component of informed population management. This is even more important for turkey populations in Maine, where harsh winters can have negative impacts on survival and reproduction.

I used a combination of banding and tracking data to better understand the relationship between turkey population ecology at their northern range limit and the diverse landscape gradient they occupy in Maine. I produced wildlife management district specific estimates of turkey …

Functional Diversity In Blueberries And Their Responses To Extreme Drought, Pratima Pahadi

Electronic Theses and Dissertations

Climate change is expected to lead to novel climate conditions with an increase in frequency and severity of drought across many places around the globe including the north-eastern (NE) United States. Therefore, experimental studies that test the impacts of changing environmental conditions over long time scales or experimental studies that mimic these conditions are crucial to understand the potential impact on crops in this region. Wild lowbush blueberries and highbush blueberries are two important crops in NE USA. In this study, the leaf functional, structural, nutrient traits across genotypes of wild blueberries (Vaccinium angustifolium and V. myrtilloides) at …

Development Of A Novel Haptic Feedback System For Gait Training Applications, Mohsen Alizadeh Noghani

Electronic Theses and Dissertations

Until recently, study and correction of motor or gait functions required costly sensors and measurement setups (e.g., optical motion capture systems) which were only available in laboratories or clinical environments. However, due to (1) the growing availability and affordability of inertial measurement units (IMUs) with high accuracy, and (2) progress in wireless, high bandwidth, and energy-efficient networking technologies such as Bluetooth Low Energy (BLE), it is now possible to measure and provide feedback in real-time for biomechanical parameters outside of those specialized settings. To enable gait training without an expert who can provide verbal feedback, augmented feedback, which is divided …