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Eco-Resonance At The Arctic's Edge: Unraveling Microbial Methane Mysteries And Quantifying Collaborative Research Challenges, Tamara Sade Marcus

Doctoral Dissertations

Lakes in northern latitudes, especially those formed in peatlands, play a critical role in global carbon cycling. They store a substantial amount of organic carbon (OC) in their sediments but remain a poorly understood component of the carbon cycle. Despite their significance, CH₄ emissions from lakes were once considered negligible in climate models. However, recent studies highlight their substantial contribution, prompting the need for their inclusion in climate models, yet uncertainties persist around the CH₄ contributions from these systems.

This dissertation delves into the microbial controls on CH₄ emissions from arctic lake sediments, focusing on Stordalen Mire in northern Sweden, …

Differential Roles Of Replication Protein A Large Subunit Paralogs In Dna Damage Repair, Ian Mills

Doctoral Dissertations

DNA damage is a constant threat for all organisms. The most severe form of DNA damage is a double-strand break (DSB) that can have disastrous consequences to the cell including genome truncation and programmed cell death. As such, organisms have multiple complex pathways dedicated to repairing DSBs. These repair pathways begin with a signaling cascade that results in the resecting of the ends of the break to create 3’ OH overhangs which are immediately bound by a single-stranded binding protein called Replication Protein A (RPA). This is followed by the cell either undergoing programmed cell death or utilizing non-homologous end …

Plasma Membrane Remodeling And Biochemical Mechanisms Underpinning Bacterial Persistence In Fractured Subsurface Shale, Chika Jude Ugwuodo

Doctoral Dissertations

During hydraulic fracturing, a water-based fluid containing proppants and several chemical additives is injected under high pressure into a ~2 km deep wellbore, to extend fractures in the underlying rock. This process introduces a host of microorganisms into the reservoir, some of which survive, persist for long periods of time and cause several problems including production of H2S, a corrosive toxicant and biofilm formation which clogs rock fractures. Over time, the bacterial genus Halanaerobium dominates the microbial community composition in many geologically distinct fractured formations. Our understanding of shale reservoir microbial dynamics remains limited despite extensive studies in the past …

The Splintered Man: Masculine Responses To Feminism In 20th Century Fiction, Jess Flarity

Doctoral Dissertations

Splintered masculinity is a pattern of behaviors where men engage with the rhetoric of feminism and gender equality for their own benefit rather than as an authentic commitment to advancing women’s rights. This dissertation tracks the emergence of the “splintered man,” or s-man, from 1915 to 1982 in mainstream literary fiction along with science fiction to demonstrate how this identity crosses cultural and socioeconomic barriers to uphold principles related to hegemonic masculinity. Three kinds of s-men emerged within Modernism: the anti-human s-man, the self-aggrandizing s-man, and the confused/conflicted s-man, each with different traits regarding their goals in engaging with feminism. …

Leveraging Genome Evolution To Address Questions Of Biological Function, Hannah Pare

Doctoral Dissertations

Advances in sequencing technology have facilitated a surge in the production of genome data for diverse animal species. Researchers are presented with the opportunity to create comprehensive phylogenomic datasets, which have previously not been feasible. Unfortunately, extracting biologically relevant information from such a large amount of data is time consuming and computationally expensive, often limiting the scope and possibility of such analyses. My Ph.D. research aims to establish a methodological framework for investigating questions of biological function using comparative genomic and phylogenetic methods. Using two different metazoan genomic datasets we demonstrate the wide-ranging applicability of this framework by addressing research …

Evaluating The Role Of Dissolved Organic Phosphorus Uptake By Phytoplankton, Caroline Anderson

Master's Theses and Capstones

Phytoplankton form the basis of the marine ecosystem and require phosphorus (P) for growth. Typically, phytoplankton utilize inorganic phosphate (PO43-) as it is the more biologically available form of P. Many regions across the global ocean have been found to exhibit vanishingly low concentrations of PO43- including the subtropical North Atlantic and North Pacific. Dissolved organic phosphorus (DOP) has been shown to serve as an alternative P source when PO43- concentrations are low. However, the concentration of PO43- which leads to significant phytoplankton DOP uptake has not been widely established. In this work, both experimental and field DOP data were …

Characterizing The Influence Of Depth And Glacial Drift On Microbial Community Diversity And Potential Carbon-Cycling Enzyme Activity In Permafrost Soils, Dana Victoria Bakke

Master's Theses and Capstones

Microbial communities in permafrost soils play an important role in breaking down organic matter and cycling nutrients. Despite difficult environmental conditions including below-freezing temperatures, yearly freeze-thaw cycles, and short growing seasons, these microbial communities remain active year-round. To better understand the microbial community diversity and potential activity across environmental gradients in northern Alaska, I sequenced the microbial community and measured the potential enzyme activity of three carbon-cycling enzymes at 5-centimeter increments in 60-centimeter soil cores spanning active layer and permafrost at three moist acidic tundra sites located on landscapes with different glacial histories in northern Alaska. I found that microbial …

Annual And Seasonal Variability In Tundra Vole (Microtus Oeconomus) Diet, Mary Kathleen Lisi

Master's Theses and Capstones

Within arctic ecosystems, small mammals (voles and lemmings) influence plantcommunity composition, soil nutrient availability, and carbon cycling through foraging and the deposition of waste. Yet, little is known about rodent diet specifically and how it may vary annually and seasonally. Here, we characterize the composition and stability in tundra vole (Microtus oeconomus) diet in northern Alaska using stable isotope analysis of fecal and hair samples collected over a seven-year period. Results from Bayesian stable isotope mixing models from both fecal and hair sample data show that tundra voles in northern Alaska predominately feed on rhizomatous sedges, Eriophorum vaginatum and Carex …

Investigating The Relationship Between Sediment Methane Production And Ebullition In Sub-Arctic Lakes, Josibel Pardo

Master's Theses and Capstones

Arctic and subarctic ecosystems are experiencing accelerated warming compared to other regions. Increasing arctic lake sediment and water temperatures stimulate the formation and emission of methane (CH4). Methane is a potent greenhouse gas that can contribute to a global warming feedback loop, in which temperatures rise due to increasing greenhouse gas emissions, which in return further increases those emissions. Methane emitted from lakes is primarily emitted through ebullition (bubbling). Various environmental characteristics have an impact on CH4 cycling in aquatic environments, such as temperature, water depth, organic matter, and nutrient availability. Sediment CH4 production is also an important driver of …

Stable Isotopic Signatures From Methane Bubbles, Lake Sediments, And Plants: A Latitudinal Study Of Lake Sediment Methane And Organic Carbon, Theresa Reynolds

Master's Theses and Capstones

Stable isotopes of carbon can be measured in gases (methane (CH4) and carbon dioxide (CO2)) and in organic carbon material like sediments and plants. The stable carbon isotopic ratios in methane (δ13C-CH4) are used in atmospheric inversion models to determine ground sources and calculate the magnitude of emissions. δ13C-CH4 from natural ecosystems is influenced not only by microbial production and oxidation processes but also by the precursor organic matter’s isotopic ratios (plants and dissolved inorganic carbon (DIC)). Lakes account for 9-24% of global methane emissions and emissions are expected to increase with climate change and warming temperatures. The δ13C-CH4 signatures …

The Microbial Diversity In The Spruce Hole Aquifer Associated With Artificial Recharge Practices, Rafaela Paes De Souza Barbosa

Master's Theses and Capstones

Aquifer Storage and Recovery (ASR) Systems are utilized globally for underground water storage and subsequent retrieval, serving as a key water management strategy. In Durham, NH, an ASR system was established in the Spruce Hole formation to address various water supply needs, including meeting future demand, reducing treatment costs, and providing backup supply options. This system replenishes the aquifer using water from the Lamprey River. Given the importance of microbial communities in groundwater quality, understanding their composition is crucial. This study explores the microbial diversity in the Spruce Hole aquifer, comparing it to the surface water used for recharge and …

Assessing The Resistance And Resilience Of Recreationally Important Fish Species To Extreme Events In Coastal Texas, Ana Cecilia Silverio

Master's Theses and Capstones

Climate change is predicted to increase the frequency and severity of extreme weather events. In turn, these extreme events may affect coastal resources such as fisheries. Extreme events not only have ecological effects but also economic and cultural impacts as human communities throughout the world depend on coastal resources for their livelihoods. In this thesis, I used long-term fisheries independent data to discern how different coastal Texas recreational fish species (Red Drum, Spotted Seatrout, Black Drum, and Southern Flounder) were affected by Hurricane Harvey in 2017 and a freeze event in 2021. I found variation in the post-storm response (percent …

Reconstructing Paleo-Sulfate Methane Transition Zones In The Japan Trench, Camille Rachel Sullivan

Master's Theses and Capstones

In deep marine subduction zone settings, the movement of sediment pore fluids, as well as sediment transport and deposition, are likely to occur during earthquake ruptures and leave evidence in the sedimentary record. This seismic activity could influence the depth of the sulfate methane transition zone (SMTZ), a moving diagenetic front that produces sulfide and carbonate minerals through time. One method for the reconstruction of paleo-SMTZ positions in marine sediments is the measurement of downcore bulk sulfur isotopic compositions. Sulfide produced by organoclastic sulfate reduction (OSR) is less enriched in δ34S while sulfide produced by anaerobic oxidation of methane (AOM) …

A Novel ‘Adjacent Mycorrhizal Symbiosis’ In Invasive Garlic Mustard, Joshua A. Trombley

Master's Theses and Capstones

Invasion of temperate forests by Alliaria petiolata (garlic mustard) may be affected by interactions with arbuscular mycorrhizal fungi (AMF). Although AMF are generally mutualists of land plants, they suppress the growth of close relatives of garlic mustard1–3. Garlic mustard produces indolic glucosinolates, a class of organic compounds known to suppress AMF4,5 and which may protect the plant from AMF antagonism. We would therefore expect a negative interaction between these organisms. Contrary to this expectation, we show that AMF inoculation promotes garlic mustard growth, and this effect is influenced by investments in plant defense. AMF inoculation and subsequent colonization increased plant …

The Influence Of Lake Productivity On Methane Production And Ebullition From Temperate And Arctic Lake Sediments, Megan Wimsatt

Master's Theses and Capstones

Northern freshwater lakes (> 40°N) are an increasingly recognized major contributor of methane (CH4), a potent greenhouse gas, to the atmosphere. Climate warming and eutrophication acceleration threaten to increase CH4 emissions from these lake ecosystems, particularly in littoral (shallow lake edge) zones where ebullition (bubbling) is often a dominant flux pathway. Few studies have investigated the impacts of lake productivity on limnological CH4 cycling for a range of trophic classes and provided a comparison between different latitudes. Here, we analyzed chlorophyll α (chlα; proxy for lake productivity), other water quality parameters, sediment CH4 production rates, and ebullition rates at nine …

Fate Of Per- And Polyfluoroalkyl Substances In A Wastewater Treatment Facility Using A Novel Membrane Bioreactor, Lindsay Ann Guertin

Master's Theses and Capstones

Per- and polyfluoroalkyl substances (PFAS) are a broad class of chemicals known for their environmental persistence and unique thermal and chemical stability which has led them to be used in a variety of products including paper, carpets, clothes, cosmetics, food packaging, kitchen ware, chrome plating, and aqueous film forming foams (AFFFs). Their resistance to biochemical degradation has led regulators to be interested in reducing PFAS loads to the environment and sources that humans are exposed to (e.g. drinking water). Recent studies have shown that concentrations of some terminal PFAS increase after secondary (biological) wastewater treatment indicating that precursor compounds are …

Characterizing Modality And Cognitive Effects In Implicit-Statistical Learning: Theoretical Implications For Language Learning In Adults, Katelyn Lerner

Master's Theses and Capstones

This study examined the presence of modality and cognitive effects within implicit statistical learning (ISL) to characterize how it operates within the context of language learning. The first research aim looked to investigate differences in ISL performance as it relates to modality, specifically auditory versus visual formats. Additionally, the relationship between cognitive measures and ISL task performance was investigated to characterize potential interactions between learning and cognition. In this study healthy adults between the ages of 18-35 were administered auditory and visual ISL experimental tasks. Participants were familiarized with a target grammar pattern in an exposure phase. After the exposure …

Suspended Ion Exchange For Extensive, Low-Energy And N2o-Emission-Free Removal Of Nitrogen In Municipal Purification, Bailey Jones

Master's Theses and Capstones

In recent years, high concentrations of anthropogenic ammonia have been measured in surface and groundwaters in Europe which can devastate ecosystems due to eutrophication. Sources of this excess ammonia are fertilizers used in the agricultural industry and municipal wastewater discharge. Stricter regulations limiting the amount of ammonia a wastewater treatment plant (WWTP) can discharge may be enacted soon to prevent ammonia’s negative effects. A major issue facing WWTPs in the Netherlands is that conventional biological treatment processes used by these facilities are not able to meet the proposed ammonia discharge regulations. These facilities must soon turn to chemical solutions and …

Unh Participatory Science Working Group Community And Citizen Science Roundtable Report, Alyson L. Eberhardt

UNH Cooperative Extension

No abstract provided.

Faculty Spotlight: Anna O’Brien, Sarah Schaier

UNH Today Archive

No abstract provided.

Can Listeners Differentiate Varieties Using Prosodic Information? Lect Identification In A Persona-Matching Task, Nicole Holliday, Rachel Steindel Burdin, Paul Reed

Faculty Publications

Sociolinguists and lay people have long been interested in the mechanisms by which dialect and speaker identification occur. The current study aims to test whether realizational differences found in production studies are salient factors in identification of different lects, as well as to examine differences between groups in identification. In this study, listeners were instructed to match clips containing H* and L+H* pitch accents with specific personae who represented speakers of five lects of interest (African American English, Jewish English, Appalachian English, Southern English, and Midwestern English). Listeners from different groups (Appalachian, African American, Jewish, and those who were not …

Can Listeners Differentiate Varieties Using Prosodic Information? Lect Identification In A Persona-Matching Task, Nicole Holliday, Rachel Steindel Burdin, Paul Reed

Faculty Publications

Sociolinguists and lay people have long been interested in the mechanisms by which dialect and speaker identification occur. The current study aims to test whether realizational differences found in production studies are salient factors in identification of different lects, as well as to examine differences between groups in identification. In this study, listeners were instructed to match clips containing H* and L+H* pitch accents with specific personae who represented speakers of five lects of interest (African American English, Jewish English, Appalachian English, Southern English, and Midwestern English). Listeners from different groups (Appalachian, African American, Jewish, and those who were not …

Management Of Aphids On Winter High Tunnel Crops, Samantha A. Willden, Allison Zablah, Anna Wallingford, Laura L. Ingwell

Faculty Publications

High tunnels offer several benefits to specialty crop growers including crop protection and season extension. Although crops are actively grown in high tunnels during the winter, few management recommendations exist for winter pests that are actively feeding and reproducing in this protected environment. This study evaluated the efficacy of three commercially available predators used for the augmentative biological control of aphids, Adalia bipunctata, Orius insidiosus, and Chrysoperla carnea, in combination with OMRI-approved pesticides labeled for aphids on spinach and strawberry. Pesticides included PyGanic (pyrethrin), Neemix (azadirachtin), and Sil-MATRIX (Potassium silicate). Laboratory and field experiments indicate high survival of biocontrol agents …

Management Of Aphids On Winter High Tunnel Crops, Samantha A. Willden, Allison Zablah, Anna Wallingford, Laura L. Ingwell

Faculty Publications

High tunnels offer several benefits to specialty crop growers including crop protection and season extension. Although crops are actively grown in high tunnels during the winter, few management recommendations exist for winter pests that are actively feeding and reproducing in this protected environment. This study evaluated the efficacy of three commercially available predators used for the augmentative biological control of aphids, Adalia bipunctata, Orius insidiosus, and Chrysoperla carnea, in combination with OMRI-approved pesticides labeled for aphids on spinach and strawberry. Pesticides included PyGanic (pyrethrin), Neemix (azadirachtin), and Sil-MATRIX (Potassium silicate). Laboratory and field experiments indicate high survival of biocontrol agents …

Five Graduate Students, Alumni Receive Nsf Graduate Research Fellowships, Sarah Schaier, Hayley Barnhard, Beth Potier

UNH Today Archive

No abstract provided.

Simple Guide To Starting A Research Group, Patricia Condon, Julie Simpson, Jessica A. Bolker, William C. Clyde, Summer B. Cook, Eleanor M. Jaffee, Jennifer Miksis-Olds, Cari A. Moorhead, Christopher Neefus, Cesar J. Rebellon, Nathan A. Schwadron, Michael J. Simmons, R. Scott Smith, John E. Sparrow, Sharon Tarleton, May-Win Thein, Anita R. Tucker, Karen T. Van Gundy, James Wible

Integrity in Research and Scholarship

Conducting cutting-edge research and scholarship becomes more complicated with each passing year; forming a collaborative research group offers a way to navigate this increasing complexity. Yet many individuals whose work might benefit from the formation of a collaborative team may feel overwhelmed by the prospect of attempting to build and maintain a research group. We propose this simple guide for starting and maintaining such an enterprise.

This version (V2, 2024) updates the original version (V1, 2019) with two new topics, expanded content, and additional resources.

Listening To Moose Tracks, Maeve Gifford

UNH Today Archive

No abstract provided.

Colsa's Grandy Earns Professional Achievement Award From Soil Ecology Society, Jeremy Gasowski

UNH Today Archive

No abstract provided.

Researchers Crowdsource Public Videos To Identify Distinct Moose Sounds In Natural Environments, Robbin Ray

Media Relations

No abstract provided.

Unh’S Easton White Named To Un’S World Ocean Assessment Working Group, Nicholas Gosling

UNH Today Archive

No abstract provided.