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Full-Text Articles in Life Sciences

Assessing The Mechanisms And Implications Of Altered Carbon Cycling In Arctic And Boreal Lakes, Rachel Fowler May 2019

Assessing The Mechanisms And Implications Of Altered Carbon Cycling In Arctic And Boreal Lakes, Rachel Fowler

Electronic Theses and Dissertations

Dissolved organic carbon (DOC) is an important component of lake ecology, as it contributes to light attenuation and carbon cycling. In recent years, DOC declined in a suite of lakes in Greenland. I performed experiments to test potential mechanisms of DOC loss. The tested mechanisms did not reduce DOC concentration, but DOC composition was affected. I also paired water quality data with meteorological observations to evaluate effects of climate drivers on lake variables. The lake variables were temporally coherent and associated with patterns of mean annual precipitation.

In the northeastern U.S., recovery from acidification and climate change have contributed ...


Blacklegged Tick (Ixodes Scapularis) Distribution In Maine, Usa, As Related To Climate Change, White-Tailed Deer, And The Landscape, Susan P. Elias May 2019

Blacklegged Tick (Ixodes Scapularis) Distribution In Maine, Usa, As Related To Climate Change, White-Tailed Deer, And The Landscape, Susan P. Elias

Electronic Theses and Dissertations

Lyme disease is caused by the bacterial spirochete Borrelia burgdorferi, which is transmitted through the bite of an infected blacklegged (deer) tick (Ixodes scapularis). Geographic invasion of I. scapularis in North America has been attributed to causes including 20th century reforestation and suburbanization, burgeoning populations of the white-tailed deer (Odocoileus virginianus) which is the primary reproductive host of I. scapularis, tick-associated non-native plant invasions, and climate change. Maine, USA, is a high Lyme disease incidence state, with a history of increasing I. scapularis abundance and northward range expansion. This thesis addresses the question: “To what extent has the range expansion ...


Muscle Degeneration In A Zebrafish Model Of Lysosomal Related Myopathy, Elizabeth Coffey May 2019

Muscle Degeneration In A Zebrafish Model Of Lysosomal Related Myopathy, Elizabeth Coffey

Electronic Theses and Dissertations

Muscle development and homeostasis are critical for normal muscle function. A key aspect of muscle physiology during development, growth and homeostasis is modulation of protein turnover. Protein turnover is the balance between synthesis and degradation of muscle proteins. The rate of protein degradation is the major factor underlying overall muscle growth during development. Protein degradation mainly takes place in the lysosome. The efficiency of lysosomal protein degradation depends upon lysosomal pH, which is generated and maintained by proton pumps. Despite the importance of protein degradation in muscle growth during development, the impact of dysregulated lysosomal pH on muscle development, growth ...


Living On The Edge: Thermophysiology Of The Southern Flying Squirrel At Its Northern Range Margin, Vanessa R. Hensley May 2019

Living On The Edge: Thermophysiology Of The Southern Flying Squirrel At Its Northern Range Margin, Vanessa R. Hensley

Electronic Theses and Dissertations

Climate change has the potential to upset entire ecological systems, making predictive models of the utmost importance. The incorporation of physiological parameters into predictive models not only bolsters their accuracy but also provides a mechanistic explanation for ecological changes already observed and those yet to come. North American flying squirrels, for example, have already experienced dramatic range shifts northward over recent decades, with climate change being the suspected driver. While other studies have focused on warming winter temperatures, I explored the hypothesis that rising summer temperatures were driving the observed range shifts. Unable to find a reliable population of the ...


Productivity, Costs, And Best Management Practices For Major Timber Harvesting Frameworks In Maine, Harikrishnan Soman May 2019

Productivity, Costs, And Best Management Practices For Major Timber Harvesting Frameworks In Maine, Harikrishnan Soman

Electronic Theses and Dissertations

Though the timber harvesting industry in Maine ranges over two centuries, the state has more forest cover than a century ago. Currently, some of the crucial challenges faced by the forest management industry in Maine and elsewhere in the northeastern US are increasing costs of forest operations, diminishing monetary returns and falling markets.

The major goal of this study was to evaluate the production economics of timber harvesting frameworks under different silvicultural prescriptions common to the region. For which, two field studies were conducted at two different locations in Maine, US. The first field study (Study I) was conducted in ...


Innovative Resources In Small Ruminant Health, Sarah Paluso May 2019

Innovative Resources In Small Ruminant Health, Sarah Paluso

Electronic Theses and Dissertations

Caseous lymphadenitis (CL) is a chronic bacterial infection caused by Corynebacterium pseudotuberculosis (C. pseudoTB) that affects small ruminants. This disease has a worldwide prevalence and results in significant economic losses to the sheep and goat industries. Antibiotics have had limited success in treating CL, due to the difficulty of penetrating the dry, thick-walled abscesses that characterize this disease. Essential oils are complex bioactive compounds that have been increasingly explored as sources of antimicrobial activity. Due to the nature of these oils, tissue and wood penetration may be possible, enabling topical and environmental treatment (e.g.; disinfectants of farm surfaces, such ...


Characterization Of Ethanol-Related Phenotypic Differences Between C57bl/6j And C57bl/6nj Substrains: Role Of Cyfip2?, Matthew C. Hartmann May 2019

Characterization Of Ethanol-Related Phenotypic Differences Between C57bl/6j And C57bl/6nj Substrains: Role Of Cyfip2?, Matthew C. Hartmann

Electronic Theses and Dissertations

The C57BL/6 (B6) mouse is the most commonly used inbred strain in biomedical research, and has served as the basis for various large-scale genetic and genomic projects. Although the parental substrain, C57BL/6J (B6J), originated at The Jackson Laboratory, isolated breeding colonies are now maintained at numerous sites. This separation has resulted in genetic drift that has led to the emergence of phenotypic differences among these colonies. For instance, B6J mice display higher levels of voluntary ethanol consumption and increased locomotor responses to psychostimulants, relative to C57BL/6N mice (B6N). Initial progress has been made in elucidating the genetic ...


Safety Assessment Of Hydroponic Closed System, Adwoa S. Dankwa May 2019

Safety Assessment Of Hydroponic Closed System, Adwoa S. Dankwa

Electronic Theses and Dissertations

The hydroponic system is an increasing sector for horticultural production. It is used mostly for fruit and vegetable production. Lettuce (Lactuca sativa) is one of the most cultivated types of produce in the hydroponic system. It runs on nutrient solution and in some cases substrates. Water serves as the backbone for hydroponic production, mainly utilized for nutrient solution preparation. Substrates are sometimes added to provide support for plants root systems. Selection of substrate depends on the type of crop and the availability of the substrate. A good substrate should be able to balance the oxygen - water ratio around the root ...


Ecological And Economic Implications Of Increased Storm Frequency And Severity For Boreal Lakes, Kathryn Warner May 2019

Ecological And Economic Implications Of Increased Storm Frequency And Severity For Boreal Lakes, Kathryn Warner

Electronic Theses and Dissertations

In boreal regions, increased precipitation events have been linked to increased concentrations of dissolved organic carbon (DOC), however less is known about the extent and implications of these events on lakes. We assessed the effects of precipitation events on six drinking water lakes in Maine, USA to better understand how DOC concentration and quality change in response to precipitation events. Our results revealed three types of responses: (1) an initial spike in DOC concentrations and quality metrics; (2) a sustained increase in DOC concentrations and quality metrics and; (3) no change during all sampling periods. Lake residence time was a ...


Submist As An Effective Method For The Rooting Of Herbaceous And Woody Ornamental Plants By Stem Cuttings, Olivia Sanchez May 2019

Submist As An Effective Method For The Rooting Of Herbaceous And Woody Ornamental Plants By Stem Cuttings, Olivia Sanchez

Electronic Theses and Dissertations

The primary method of vegetative propagation by stem cutting is to insert leafy cuttings into a solid soilless media and place the cuttings in an environment that provides moist, humid conditions to the foliage through fog or overhead intermittent mist. These systems reduce water loss through transpiration by reducing leaf temperature and provide moisture to the rooting media. However, excess water, both on the media and on the leaves can result in an increase incident of diseases. To alleviate some of these issues, research has found stem cuttings can be rooted in sub-mist systems that apply water solely to the ...


The Effects Of European Fire Ants On Blacklegged Ticks In Acadia National Park, Lucy Guarnieri Apr 2019

The Effects Of European Fire Ants On Blacklegged Ticks In Acadia National Park, Lucy Guarnieri

Honors College

The blacklegged tick (Ixodes scapularis) and the European fire ant (Myrmica rubra) are notable invasive pests in Maine, especially across coastal and southern regions. I. scapularis is the primary vector of the bacterium Borrelia burgdorferi, which is the causative agent of Lyme disease, and Maine currently has one of the highest Lyme disease incidence rates in the U.S. Ticks have many natural predators, including ants. This study investigates the effects of M. rubra on I. scapularis abundance and pathogen infection prevalence in Acadia National Park (ANP). I collected ticks by drag-sampling at eight ant-infested sites and eight control sites ...


The Effect Of Embryonic Arsenic Exposure On The Sensorimotor Behavior Of Zebrafish (Danio Rerio), Laura Paye Apr 2019

The Effect Of Embryonic Arsenic Exposure On The Sensorimotor Behavior Of Zebrafish (Danio Rerio), Laura Paye

Honors College

The goal of this study is to determine the effect of arsenic exposure on vision in zebrafish (Danio rerio). The optic system of D. rerio is ideal for examining visual defects. Their eyes are similar to eyes of humans and can therefore be useful models in studies of human eye disease. Their optic system functions similarly to humans, so it is beneficial to observe how zebrafish are affected by contaminants in the environment. Arsenic is ubiquitous in groundwater, due to its natural presence in bed rock, but is elevated by human activities. In order to see any immediate effects on ...


The Most Critical Resource: How Climate Change Fuels The Crisis In Syria And The Implications For The World At Large, Edward Medeiros Apr 2019

The Most Critical Resource: How Climate Change Fuels The Crisis In Syria And The Implications For The World At Large, Edward Medeiros

Honors College

The Syrian crisis, both domestic and international in scope, may well be the defining geopolitical challenge of the generation. Climate change may be the single greatest challenge to face humanity in the entirety of our species’ life history. The dramatic effects of climate change can be seen in the origins of the Syrian crisis when one looks to humanity’s single most critical resource: water. We take the word critical to have two meanings in this context: first, that water is essential to human survival and second that water is a resource in critical condition. Syria’s water crisis pre-dates ...


The Impact Of New Nih Requirements On The Preclinical Research Sex Disparity --- A Meta-Analysis, Nicole Mcgrath Apr 2019

The Impact Of New Nih Requirements On The Preclinical Research Sex Disparity --- A Meta-Analysis, Nicole Mcgrath

Honors College

Historically, women as subjects have been underrepresented in clinical research. Due to this problem, legislation was enacted by Congress in 1993 to require inclusion of women in NIH funded clinical trials. Female animals are also underrepresented in preclinical research and need to be included to ensure safe and effective drugs. Studies exclude female mammals under the assumption that the estrus cycle contributes to variability (Beery, 2011). This notion has been contradicted by several studies (Prendergast, 2014; Becker, 2016). New requirements of NIH funded researchers to consider sex as a basic biological variable were announced in 2014 (Clayton, 2014). As of ...


Influence Of Environmental Conditions And Call Playback On Detection Of Eastern Forest Owls During Standardized Surveys, Kyle Lima Apr 2019

Influence Of Environmental Conditions And Call Playback On Detection Of Eastern Forest Owls During Standardized Surveys, Kyle Lima

Honors College

Owls provide ecosystem services and play crucial roles in the environment making them important to monitor and study. However, standardized methods for most species do not exist, and we lack understanding of the effects of many environmental variables and playbacks on detection probability of owls. We performed a multispecies occupancy analysis on owl monitoring data collected from 2004 – 2013 across the state of Maine, to examine the effects of environmental variables, conspecific and heterospecific playback on detection, and general survey protocols for three forest owls: Northern Saw-whet Owl (Aegolius acadicus), Barred Owl (Strix varia), and Great Horned Owl (Bubo virginianus ...


Trials And Tribulations Of Modern Day Childbirth: A Literature Analysis Of Factors Contributing To The Recent Decline In Vaginal Birth After Cesarean Delivery, Camilla Horton Apr 2019

Trials And Tribulations Of Modern Day Childbirth: A Literature Analysis Of Factors Contributing To The Recent Decline In Vaginal Birth After Cesarean Delivery, Camilla Horton

Honors College

C-sections are an extremely common procedure in modern day America, and while there are serious indications for cesarean delivery including complications for mother and baby, there are likely far more cesareans performed each year than medically necessary. This A comprehensive literature analysis was compared to individual data collection from the Center for Disease Control and Prevention’s National Vital Statistics System. Both the analysis of the literature and the individual data collection confirmed that cesarean deliveries in the US have increased to from less than 10% in the 1970s, to over 30% in the years following 2005. Vaginal birth after ...


Determining Key Residues Of The Lyt-R Domain In The Streptococcal Cpsa Protein, Mohammad Hashmi Apr 2019

Determining Key Residues Of The Lyt-R Domain In The Streptococcal Cpsa Protein, Mohammad Hashmi

Honors College

Streptococcus agalactiae or Group B Streptococcus (GBS), is a Gram-positive commensal bacterium that is harmless in healthy adults, yet causes systemic diseases in neonates, the elderly, and immunocompromised individuals. Neonates are at risk of GBS infection in utero or during delivery due to the colonization of the organism in the vaginal canal of between 15-30% of adult females. GBS can cause severe neonatal sepsis and meningitis, as well as chorioamnionitis, which can cause premature birth and stillbirth. GBS infection is greatly facilitated by the presence of a bacterial capsule; a protective, polysaccharide matrix surrounding the cell that plays a key ...


Mmp13 Inhibition Does Not Rescue Gmppb-Deficient Skeletal Muscle In Zebrafish, Sean Driscoll Apr 2019

Mmp13 Inhibition Does Not Rescue Gmppb-Deficient Skeletal Muscle In Zebrafish, Sean Driscoll

Honors College

The dystroglycan protein is one of many that attach skeletal muscle fibers to the basement membrane at the myotendinous junction. In the alpha-subunit of the dystroglycan molecule, there are sugar chains that help with the adhesion of the molecule to the basement membrane. A mutation in any gene that codes for an enzyme that adds these sugar chains can result in a form of congenital muscle disease called secondary dystroglycanopathy. One of the genes that codes for an enzyme that adds sugar chains is GMPPB and a mutation in this gene results in GMPPB-associated dystroglycanopathy. Using zebrafish as a model ...


A Qualitative Study Of The Perceived Risks Of The Impacts Of Moose-Winter Tick Interactions On Human Health, Maine Economy, And Maine Culture, Asha Dimatteo-Lepape Apr 2019

A Qualitative Study Of The Perceived Risks Of The Impacts Of Moose-Winter Tick Interactions On Human Health, Maine Economy, And Maine Culture, Asha Dimatteo-Lepape

Honors College

In order to answer the question of how people perceive the interactions between winter ticks and moose, and the impacts that these interactions may have on culture, economy, and recreational practices in Maine, interviews were conducted with participants from four stakeholder groups: hunters, outfitters, Wabanaki citizens, and wildlife managers. By using a case study methodology, I was able to explore moose health risk perceptions as described by participants from the four stakeholder groups, and the likely impacts on recreation behavior, livelihoods and economic viability, cultural maintenance, and wildlife management. In this study, multiple data generation techniques (i.e., semi-structured interviews ...


Do Different Methods Of Communication Impact Undergraduate Student's Knowledge, Attitudes, & Beliefs Towards White-Nose Syndrome In Little Brown Bats, Kiley Davan Apr 2019

Do Different Methods Of Communication Impact Undergraduate Student's Knowledge, Attitudes, & Beliefs Towards White-Nose Syndrome In Little Brown Bats, Kiley Davan

Honors College

White-nose syndrome (WNS) is a deadly fungal disease that has killed millions of hibernating bats since its introduction to North America in 2006. The little brown bat (Myotis lucifugus), once widespread across the US, has been the most severely impacted with some colonies experiencing a 99% decline. Scientists believe changing people’s behavior is the key to bat conservation as the fungus is spread primarily by humans transferring the fungus between bat colonies. Outreach is a common method used to affect behavioral change in people, but not all outreach methods are equally effective. The purpose of this study was to ...


Assessing The Effectiveness Of Attractants To Increase Detection Probabilities In Northeastern Mammals, Michael Buyaskas Apr 2019

Assessing The Effectiveness Of Attractants To Increase Detection Probabilities In Northeastern Mammals, Michael Buyaskas

Honors College

A primary problem with camera trapping in wildlife occupancy studies is the failure to detect an animal when it is present at the site. My objective was to determine the optimal attractant setup for maximizing detection probabilities of northeast mammalian communities. I carried out an camera trapping project in northern Maine, USA from August to November 2018, and tested 3 distinct attractant setup. Sampling stations consisted of four camera units, and each sampling unit constituted either a treatment or a control: 1) bait + lure (treatment), 2) bait only (treatment), 3) lure only (treatment), and 4) camera only (control). Data analysis ...


The Potential Roles Of Melanopsin Signaling In Mediating The Effects Of Environmental Light On Voluntary Ethanol Intake In Mice, Rachel Brooks Apr 2019

The Potential Roles Of Melanopsin Signaling In Mediating The Effects Of Environmental Light On Voluntary Ethanol Intake In Mice, Rachel Brooks

Honors College

Intrinsically photosensitive retinal ganglion cells (ipRGCs) comprise a small subset of photoreceptors found in the eye containing the newly discovered photopigment, melanopsin. ipRGCs project directly to the hypothalamic suprachiasmatic nucleus (SCN), the central “pacemaker” underlying the generation and entrainment of circadian rhythms. Photic stimuli detected by ipRGCs are transmitted to the SCN via the retinohypothalamic tract (RHT), mediating the entrainment of the SCN pacemaker. In addition to circadian entrainment, these pathways may also contribute to seasonal changes seen in both animals and humans, such as seasonal breeding cycles in animals and seasonal affective disorder in humans. Our lab has recently ...


Personality In Small Mammals: From Home Range To Microhabitat Selection, Kara Aiken Apr 2019

Personality In Small Mammals: From Home Range To Microhabitat Selection, Kara Aiken

Honors College

Consistent variation in behavior among individuals of the same species is referred to as animal personality. Personality has been found in a wide variety of species across all taxa, including numerous small mammal species. Animal personality has the potential to affect the life history characteristics of individuals within a population. Particularly, personality may affect the way in which an individual interacts with its environment, be this through home range or microhabitat selection. To further understand how personality affects home range and microhabitat selection in small mammals, we conducted a field study in the Penobscot Experimental Forest, Maine (USA). Three small ...


Distribution Of Shell-Boring Polychaetes At Shellfish Aquaculture Sites Along The Northeast Coast Of The Us, Samantha Silverbrand Apr 2019

Distribution Of Shell-Boring Polychaetes At Shellfish Aquaculture Sites Along The Northeast Coast Of The Us, Samantha Silverbrand

Honors College

Coastal shellfish aquaculture has expanded substantially in recent years in Maine and New England as traditional wild fishery stocks have declined. As shellfish aquaculture has expanded, producers have become more concerned about marine worm pests (i.e., polychaetes) that infest cultured bivalves. In particular, worms from the genus Polydora (also known as “polydorids”) burrow into oyster and scallop shells where they feed and deposit mud. Bivalves cover over the muddy burrows creating blisters that can decrease their market value and hinder growth. Farmers and researchers have identified methods to control infestations of P. websteri, one common species of shell-boring worm ...


Uncoupling Protein 1 In Bornean Treeshrews, Emily Gagne Apr 2019

Uncoupling Protein 1 In Bornean Treeshrews, Emily Gagne

Honors College

Many thermoregulatory functions of mammals are related to the fact that they are endotherms. There are several morphological and physiological adaptations that mammals have developed over time to allow them to maintain internal heat, even in cold climates. Many mammals use UCP1, a protein that facilities non-shivering thermogenesis, to generate heat. Recent work has shown that despite UCP1’s importance for non-shivering thermogenesis, inactivating mutations have occurred in at least 8 of 18 placental orders (Gaudry et al. 2017). My study focused on three species of Bornean treeshrews: Tupaia tana, Tupaia montana, and Tupaia minor (Order: Scandentia), and aimed to ...


Determining The Key Residues For Capsule Production In The Gbs Cpsa Protein, Anna Struba Apr 2019

Determining The Key Residues For Capsule Production In The Gbs Cpsa Protein, Anna Struba

Honors College

Streptococcus agalactiae (GBS) is a common bacterium found commensally in the vaginal mucosa of healthy adults. GBS also causes severe infection in neonates, often leading to meningitis, which can cause lifelong health consequences including impaired hearing and seizures. Infection of newborns mainly arises from a colonized mother, either before birth through ascending infection or during labor. Ascending infection, where the bacteria travel to the fetus from the vaginal mucosa, is especially concerning as it can lead to loss of pregnancy or premature birth. The most common method of neonatal GBS disease prevention is antibiotic prophylaxis during delivery, though this method ...


Construction Of A Cpsa Double Mutant To Determine The Function Of The Lyt-R Domain, Klarissa Klier Apr 2019

Construction Of A Cpsa Double Mutant To Determine The Function Of The Lyt-R Domain, Klarissa Klier

Honors College

Streptococcus agalactiae, otherwise known as Group B Streptococcus (GBS), is a zoonotic, Gram-positive, commensal and invasive bacteria which is the leading cause of neonatal bacterial infections. These bacterial infections include sepsis, meningitis, pneumonia, and bacteremia. In neonates, GBS is most commonly transferred to the child in utero or during birth when the child aspirates amniotic or vaginal fluids. GBS can also infect the child through the bloodstream while in utero, causing premature births or still births. Children who survive the initial infection develop severe morbidities which include mental retardation, cerebral palsy, and seizures. GBS can also affect immunocompromised adults, leading ...


The Effect Of Elevation On Factors Influencing Adult Body Size Of Asynarchus Nigirculus, Mykayla Hagaman Apr 2019

The Effect Of Elevation On Factors Influencing Adult Body Size Of Asynarchus Nigirculus, Mykayla Hagaman

Honors College

Across the range of a species realized niche, individuals can face a range of environmental factors that change as you move from the central range towards the edge. These changes in environmental factors can have a significant impact on the fitness of an individual. In insects, one way to determine this impact is to study the difference in adult body size across the span of the species range. In western Colorado, caddisflies are the biomass dominant detritivores in alpine pond ecosystems. Caddisflies are fundamental in providing nutrients to the ecosystem because of the nutrients that they recycle as detritivores. Understanding ...


Functional Analysis Of Amino Acid Changes In The Metal Binding Pocket Of The Lyt-R Domain Of The Cpsa Protein, Sydney Green Apr 2019

Functional Analysis Of Amino Acid Changes In The Metal Binding Pocket Of The Lyt-R Domain Of The Cpsa Protein, Sydney Green

Honors College

The Center for Disease Control approximates that one out of every four women carries Group B Streptococcus (GBS) bacteria. GBS can be passed to the neonate from the pregnant mother during vaginal delivery or in utero by the ascending route1. Some notable diseases that are caused by GBS are sepsis, meningitis, pneumonia, certain skin infections, and types of bone and joint infections2. One of the most important virulence factors for GBS is capsule, which has sialic acid residues attached to the polysaccharide chains helping to prevent the host immune system from being triggered when the pathogen is present ...


Building A Better Understanding Of Equine Anatomy Through Integrated Learning, Emily Gorney Apr 2019

Building A Better Understanding Of Equine Anatomy Through Integrated Learning, Emily Gorney

Honors College

Most people tend to have horses as their first contact with livestock animals. They are usually more common to see or interact with than cows, sheep, or other farm animals. This makes them a good starting animal for students learning about livestock, as well as the fact that they can be used for show, for work, or as a pet, making the equine industry a big one. While models have been used to teach students in topics such as architecture, cycles, and human muscles, little published research was found on the topic of having students build models of equine anatomy ...