Digital Commons Network^™

Halotolerant Biodegradation And Detoxification Of Synthetic Dyes By Marine-Derived Penicillium Oxalicum M6a: Metabolite Profiling And Ecotoxicity Assessment, Ugochukwu Okechukwu Ozojiofor, Mohammed Sani Abdulsalami, Nkechi Eucharia Egbe, Ahmed Ali Haroun, Yakubu Magaji

Applied Environmental Research

The complex aromatic structures of synthetic dyes in contaminated water bodies make them difficult to degrade, posing a serious environmental challenge and representing a significant emerging pollutant that warrants urgent intervention. This study evaluated the biodegradation and detoxification potential of a halotolerant, marine-derived fungal strain, Penicillium oxalicum M6A, isolated from the Nigerian coastline, against Indigo carmine (IC) and Remazol Brilliant Blue R (RBBR). The effects of pH, temperature, salinity, and dye concentration on degradation efficiency, alongside enzymatic activity, were assessed. FTIR and GC‒MS analyses were employed to identify degradation products and predict metabolic pathways, whereas toxicity was evaluated in three …

Blue Carbon Stock Assessment Of The Mangrove Swamp Forest Reserve In Baganga, Davao Oriental, Philippines, Renz Morales Lanaban, Yves Paul M. Montero, Hilario L. Wong, Jr., Marnie Grace I. Sonico

Applied Environmental Research

Mangrove ecosystems are vital carbon sinks, yet they are threatened by anthropogenic pressures and natural disturbances, causing significant carbon stock losses. Given the limited data for Baganga, Davao Oriental, this study quantified the aboveground biomass (AGB) and blue carbon stock in the Lucod mangrove swamp forest reserve. We identified mangrove species, measured AGB and carbon content via allometric equations, and compared storage among species. The results indicated that the mangrove forest AGB was within typical ranges for tropical wet regions and the Asia-Pacific region, but its overall carbon content did not reach highly productive ecosystem levels. Nonparametric analysis revealed significant …

Spatial Distribution And Potential Ecological Risk Of Microplastics In Surface Sediments Of The Inner Gulf Of Thailand, Sarayut Suanluang, Pathompong Vibhatabandhu, Sarawut Srithongouthai

Applied Environmental Research

The global surge in plastic usage during the COVID–19 pandemic raised concerns about increased microplastic (MP) contamination in aquatic environments. This study assessed the abundance, characteristics, and ecological risk of MPs in surface sediments of the inner Gulf of Thailand during the post–COVID–19 period (April 2021). The sediment samples were analyzed via density separation, stereomicroscopic examination, and polymer identification via micro–FTIR. The mean MP abundance was 196.07 ± 85.60 pieces kg-1, with concentrations ranging from 73.08 to 351.19 pieces kg-1. PTFE and PP were the dominant polymer types, comprising 50% and 32% of all the MPs, respectively. Fibers (34%) and …

Health Risk Assessment Of Copper Exposure Through Hand-To-Mouth Activities In The Lithium-Ion Battery Manufacturing Industry, Adisorn Phungkum, Worawat Meevasana, Khanidtha Marungrueang

Applied Environmental Research

This study aims to evaluate the occupational exposure levels of copper (Cu) among workers in a battery manufacturing facility by analyzing the Cu concentrations on hand surfaces at three distinct time periods: before work (BW), before lunch (BL), and after work (AW). A total of 30 workers involved in 13 different workstations or tasks—such as battery cell preparation, spot welding, soldering, and labeling—were included in the study to reflect diverse exposure scenarios. Surface wipe sampling was conducted according to NIOSH Method 9102, and the Cu concentrations were quantified via inductively coupled plasma‒mass spectrometry (ICP‒MS). Additionally, the hazard quotient (HQ) was …

Spatial Estimation Of Trophic State For Reservoir Using Ground Monitoring And Remote Sensing Data, Thong Nguyen Hoang, Van Tran Thi

Applied Environmental Research

Nutrient pollution, also known as eutrophication, is a severe environmental problem that leads to harmful algal blooms in water bodies and affects water supplies for human use. This study aims to determine the trophic state of the reservoir based on the trophic state index (TSI) calculated from ground monitoring data of Secchi depth (SD), total phosphorus (TP), and chlorophyll-a (Chl-a) obtained from 35 points in 2 survey periods during the late rainy season to early dry season 2012–2013 and May 2023. In addition, we combined remote sensing data to spatially estimate the eutrophication situation across the reservoir through correlation analysis …

Efficient Oxidation Of Methylene Blue Via Catalytic Activation Of Peroxymonosulfate Via An Engineered Δ-Feooh/Pili Nutshell Biochar Composite, Lorenz Borromeo

Applied Environmental Research

This study introduces a novel composite catalyst formed by anchoring delta iron oxyhydroxide (δ-FeOOH) onto pyrolyzed Pili nutshell biochar via a room-temperature coprecipitation technique, marking the first application of Pili nutshell waste in advanced oxidation processes for wastewater treatment. This innovative methodology enhances catalyst dispersion and stability, facilitating the activation of peroxymonosulfate (PMS) to generate reactive sulfate radicals (SO4•–) for the degradation of methylene blue (MB), a thiazine dye commonly used in the medical field and the dye industry. Different techniques have been used to characterize synthesized composites in terms of their morphology, elemental composition, surface functional groups, and crystalline …

Assessment Of The Carbon Stock Of Trees In Selected Urban Green Spaces Of Davao City, Philippines, Daiseree Cuabo, Yves P.M. Montero, Daryl S. Salas, John P.M. Viernes

Applied Environmental Research

The combined impacts of deforestation, tree cover loss, and urbanization in urban and suburban areas significantly reduce the capacity of natural carbon sinks to sequester and store carbon. Hence, this study assessed the aboveground biomass (AGB) and carbon stock of trees in the selected green spaces of Davao City. A purposive sampling technique was employed in placing quadrats, with data collected from 27 plots categorized by size. AGB was estimated via an allometric equation, and aboveground carbon (AGC) was derived from the AGB values. A total of 358 individual trees from 25 species, 24 genera, and 13 families were documented. …

Spatial And Temporal Trends In Surface Water Quality And Pollution Sources In Ben Tre, Vietnam: A Principal Component Analysis/Factor Analysis-Based Approach, Nguyen Xuan Tong, Luu Tang Phuc Khang

Applied Environmental Research

Surface water quality is vital for maintaining ecological health and supporting sustainable development, particularly in the Mekong Delta, Vietnam, where water is heavily utilized. However, rapid urbanization and economic activities have led to water pollution. This study assessed the spatial and temporal variations in surface water quality in Ben Tre Province from January 2022 to December 2023 using 384 samples collected across dry and rainy seasons and two zones (headwater streams and cities). The water quality index (WQI) was calculated on the basis of 15 parameters, and principal component analysis/factor analysis was applied to identify pollution sources. Five key factors …

Leveraging Epigenomics And Transcriptomics To Develop High-Dimensional Biomarkers Of Neuroinflammation, Steven C. Pike

Dartmouth College Ph.D Dissertations

Neuroinflammation is a critical physiological phenomenon implicated in most neurological disorders, either as a cause or a consequence of pathology. Our understanding of neuroinflammation is limited by the inability to directly profile the cells of interest. Thus, developing biomarkers of neuroinflammation is clinically urgent as we know neuroinflammation correlates with patient outcomes and treatment success. The recent advances in “omics” technologies, particularly epigenomics and transcriptomics, provides the opportunity for high-dimensional profiling of biospecimens for potential biomarkers. Within this dissertation, I demonstrate that biomarkers obtained from “omics” platforms can detect neuroimmunological phenomena in clinical and preclinical settings. In chapter one, DNA …

It’S Time To Stop Calling People "Stakeholders", Bethann Garramon Merkle, Evelyn Valdez-Ward, Priya Shukla, Skylar R. Bayer

Human–Wildlife Interactions

Although the term “stakeholder” has been widely used in science communication, recent expansion in the discourse around the negative connotations of the term necessitate that scientists and practitioners cease using the term. We discuss why this shift is necessary, how it affects our own praxis, and suggest resources for working through more respectful and just language. Looking to the science communication literature can help recalibrate terminology in positive ways.

Evaluating Lethal Coyote Management In The Chicago Metropolitan Area Using A Conflict Recurrence Metric, Jeffrey T. Schultz, Scott Beckerman, Robert Erickson, Danielle Montgomery, Stewart W. Breck

Human–Wildlife Interactions

Human–coyote (Canis latrans) conflict in urban environments is prevalent in cities throughout the United States. Urban areas commonly use nonlethal techniques to mitigate coyote-caused conflicts but will also incorporate selective removal of individual coyotes when conflicts persist. However, little research has evaluated these management strategies. This study analyzed coyote removal efforts conducted in the Chicago Metropolitan Area from 2010 to 2020. To evaluate the management actions, we used “time without incidence”—the time elapsing from an initial conflict until either a subsequent conflict occurred in the same area, or when the data collection period ended—as an index of effectiveness. …

Monograph Available: Urban Coyotes As A Source Of Conflict With Humans: An Evaluation Of Common Management Practices

Human–Wildlife Interactions

This is an announcement about the published monograph titled "Urban Coyotes as a Source of Conflict with Humans: An Evaluation of Common Management Practices." This publication, part of the HWI Monograph Series, is online and open access.

Relative Seat Height Effects On Knee Joint Kinematics In Older Adults, Sadie N. Zimmerman

Research Papers

No abstract provided.

The Design And Synthesis Of New Materials Using Nucleophilic Aromatic Substitution Reactions, Lavneet Kaur, Kenneth E. Maly

Theses and Dissertations (Comprehensive)

Abstract The overall objective of this research was to synthesize and study the structure-property relationships of novel polycyclic aromatic compounds capable of producing open crystalline networks based on π-stacking interactions in solid state. In this work, we describe a method of producing polycyclic aromatic compounds bearing electron-rich and electron-poor rings in order to promote cofacial π-stacking in the solid state. These compounds were synthesized from easily accessible molecules using nucleophilic aromatic substitution and copper-catalyzed aryl amination. The scope of phenoxazines bearing N-aryl substituents was explored for the synthesis of various polycyclic aromatic compounds. Interesting characteristics such as luminescence and predictable …

Coupling Remote Sensing And Modelling To Monitor The Spatial Distribution And Trends Of Surface Temperature And Ice Thickness On Sub-Arctic Lakes, Gifty Attiah

Theses and Dissertations (Comprehensive)

Lake surface temperature (LST), lake ice thickness (LIT), and lake ice phenology (LIP) play significant roles in the diverse regional processes of freshwater in cold regions. They offer direct indications of regional weather and climate conditions, and their interactions with the atmosphere impact climate processes. Furthermore, lake ice is valuable to northern communities, such as those in the Northwest Territories (NWT). Ice roads, including the longest ice road in the NWT, spanning over 80 lakes, are constructed during winter to haul goods to and from industrial establishments (e.g., mines) and for travel within and between communities. A significant challenge to …

The Impacts Of Permafrost Thaw Slumps On Arctic Stream Ecology, Maria Dolan

Theses and Dissertations (Comprehensive)

Climate change is intensifying permafrost thaw across terrain of the circumpolar Arctic. Increased temperatures and rainfall at northern latitudes have resulted in the expansion of thermokarst features such as retrogressive thaw slumps, which make previously frozen debris available for transport into nearby river systems. In the Peel Plateau, Northwest Territories, the mobilization of these materials exposes rivers to a large quantity of sediment and solutes that may act as a chronic, press disturbance, potentially altering stream food webs. Here, I examine if: 1) thaw slumps have driven changes to the physical and biological properties of slump impacted streams since an …

“People [Are] Not Dying Because Officers Aren't Following Their Training. ‘It's Because They Are.”: The Construction Of Police De-Escalation Of Individuals In Mental Health Crises In Canadian Media, Renée Haddock

Theses and Dissertations (Comprehensive)

Police are often assumed to be the "de facto" response to people in mental health crises. Contact between police and Canadians with mental illness and in crisis is routine and on the rise (Livingston, 2016). Police responses to these incidences have been criticized after several, highly publicized and tragic encounters between police and people in mental health crisis and the overrepresentation of people of colour in these instances. Media outlets determine which stories are prioritized, how they are framed, and which information to include or omit (Fawzi, 2018). Notably, public knowledge of police activities greatly impacts community perceptions of police …

Investigating The Thermal Stratification Patterns Of A Shallow Polymictic Boreal Shield Lake And The Effectiveness Of Models In Predicting Shallow Lake Thermal Profiles, Matthew Roberts

Theses and Dissertations (Comprehensive)

Thermal stratification is a core process of lakes which plays a critical role in shaping the ecological dynamics of lakes, influencing major processes like nutrient cycling and oxygen availability. For shallow polymictic lakes, thermal stratification patterns present some unique differences due to the complex and variable nature of these lakes. In this thesis, I examined thermal stratification in a shallow polymictic lake in northwestern Ontario during the ice-free season of 2019 to investigate the frequency, duration, and driving factors of thermal stratification. The lake underwent 146 separate stratification events, with a median duration of 2 hours per event, with a …

Lactate's Role In Appetite Suppression, Seth Mccarthy

Theses and Dissertations (Comprehensive)

Once considered metabolic waste produced during exercise, lactate is now known to have diverse roles in biology. Muscle-derived lactate can travel through the bloodstream and be taken up by other tissues and i) oxidized, ii) converted to glucose via gluconeogenesis, or iii) bind to its receptor to trigger molecular signaling cascades. Lactate has been described as a “myokine” capable of inter-organ crosstalk and compelling evidence demonstrates lactate’s role as a signalling molecule in pathways related to the regulation of appetite. The purpose of this dissertation was to further elucidate lactate’s role in appetite regulation using series of studies aimed at …

Reversible Degradation Of Peptidoglycan By Lytic Transglycosylases, Aaron Devereaux

Theses and Dissertations (Comprehensive)

Antimicrobial resistance continues to be a burden on the global healthcare system with an estimated cost of billions of dollars and millions of deaths each year. Recently, there has been little to no development on new antibiotics to treat bacterial infection, and any that are developed become resisted to within a few years. Both Gram-positive and Gram-negative bacteria contain a mesh-like layer called peptidoglycan (PG) that surrounds their cells providing strength, cell shape, and protection from their environments. This layer is a polymer of N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) connected via a b-1,4-glycosidic bond, with each strand being cross-linked …

“It Is Tiny And It Is Everything”: Exploring The Effects Of Arts-Integrated Gardening On Experiences Of Ecological Grief Through Autoethnographic Research, Christina Kingsbury

Theses and Dissertations (Comprehensive)

This study explores how arts-integrated gardening affects experiences of ecological grief through autoethnography and draws on my personal experiences as a survivor of environmentally linked cancer and artist working with gardens through social practice. My research builds on two areas of emergent scholarship—investigations of ecological grief and gardens as sites for social work practice—to explore how social work may address ecological grief through arts-integrated gardening. I use a quilting autoethnography as a method of inquiry to foreground my subjective knowledge and analyze it through intersectional feminist, disability and decolonizing theories. By incorporating narrative analysis and arts-based inquiry—writing in place, poetic …

Exploring Mating Patterns: The Interplay Of Genes, Environment, And Their Evolutionary Outcomes, Sanduni Talagala

Theses and Dissertations (Comprehensive)

There is great variation in the reproductive tactics exhibited both between and within different species, which is reflected in how individuals engage in mate assessment, mate choice and offspring production. It is therefore important to understand general mating patterns of populations, the factors that influence these mating patterns, and the consequences they carry, in order to get a more holistic understanding of mating systems. This doctoral research represents a multi-pronged investigation of the factors shaping mating patterns and their consequences, how environmental factors influence mating patterns, and how both genotypes and the environment interact to influence mate choice decisions and …

Evaluation Of The Dnazyme Gr5 For The Determination Of Lead Speciation In Natural Waters, Gaganprit Gill

Theses and Dissertations (Comprehensive)

This thesis explores the development and application of a DNAzyme-based biosensor designed to detect labile metal species in environmental samples. Real time and on-site monitoring of labile metal fractions would make a valuable contribution to environmental management, as these fractions are the most bioavailable and pose significant toxicity risks to aquatic organisms. Conventional methods for detecting labile metals, while effective, are often burdened by high costs, complexity, and lengthy processing times, making them less ideal for rapid and widespread environmental assessments.

The first manuscript of this thesis (chapter 2) establishes the fundamental capabilities of the Pb²⁺-specific DNAzyme GR5 …

Quantifying Ecological Processes Predicting Barren-Ground Caribou (Ɂetthën; Rangifer Tarandus Groenlandicus) Occurrence Across A Heterogenous Northern Indigenous Protected And Conserved Area., Eric Jolin

Theses and Dissertations (Comprehensive)

Northern ecosystems are experiencing a period of rapid and unprecedented change, with implications for species distributions, mammal community dynamics, and habitat associations. Understanding the ecological processes that shape species distributions is crucial for developing effective conservation strategies that can adapt to such change. This study examines drivers of barren-ground caribou occurrence, a species of cultural and ecological significance, across Thaıdene Nëné Indigenous Protected Area, an ecologically intact landscape of high habitat heterogeneity straddling the treeline of the Northwest Territories. I use spatial and temporal variation in caribou detections generated by camera traps to test the relative importance of apparent competition, …

Npr1 As A Temperature-Sensitive Regulator Of Pipecolic Acid-Mediated Plant Systemic Immunity, Spencer Tout

Theses and Dissertations (Comprehensive)

Healthy plant development requires balancing both abiotic (e.g. climate) and biotic (e.g. pathogen) challenges, which intercept important signaling pathways in plants. For example, climate change-associated elevated temperature can negatively modulate various aspects of plant immunity, including the production of central immune signals salicylic acid (SA) and N-hydroxypipecolic acid (NHP). Since SA and NHP signaling both require the master immune co-activator protein NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1), it is important to investigate NPR1 as a potentially temperature-regulated molecular hub. Although the NPR1 gene is not transcriptionally downregulated at elevated temperatures (28° C vs. 23° C), little is known about …

Influence Of Temperature On Tfm Tolerance In Lake Sturgeon, Emily Bouffard

Theses and Dissertations (Comprehensive)

The lampricide, 3-trifluoromethyl-4-nitrophenol (TFM), has been used to successfully control invasive sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes for over 50 years. TFM’s effectiveness is due to the relatively low capacity of sea lamprey to detoxify TFM. Water temperature has been shown to increase TFM tolerance in larval sea lamprey. However, the effects of temperature on TFM sensitivity in non-target species such as the endangered lake sturgeon (Acipenser fulvescens) are poorly understood, particularly during their early life stages. To determine how temperature affected TFM sensitivity, age 1-year-plus (1+) lake sturgeon acclimated to 8, 16, …

Grief On The Margins: The Death Of A Family Member To Substance Use, Adair Shaw

Theses and Dissertations (Comprehensive)

Despite Canada's high death rates from substance use, there is limited research on the sociopsychological impact on families, who often face stigma and disenfranchised grief. This study explores how family members make meaning of a substance-related death. Through qualitative inquiry, eleven family members were interviewed on their experience of grief from substance death. The imprint of losing a family member to mental illness and substance use is fraught with intergenerational grief, ambiguity, prolonged mental-emotional distress, and relationship challenges. Substance death was also associated with stigma, social withdrawal, and shame for many participants. However, grievers reconstructed the socially prescribed negative perceptions …

Impact Of Membrane Lipid Composition On The Structure And Function Of Uncoupling Proteins 1 And 2 From Arabidopsis Thaliana (Atucp1 And Atucp2), Elizabeth Silva

Theses and Dissertations (Comprehensive)

A proton gradient across the inner mitochondrial membrane (IMM) is required for the synthesis of adenosine triphosphate (ATP) via ATP synthase. In other words, generation of the proton gradient is coupled to the synthesis of ATP. Interestingly, uncoupling proteins (UCPs), also located in the IMM, dissipate the proton gradient, meaning that the gradient is not efficiently used for the production of ATP.¹ The mechanism of proton transport activity of UCPs has been hypothesized and widely debated for the past 20 years to also reduce oxidative stress by reducing the production of reactive oxygen species (ROS).² The majority of …

Lichen It: Optimizing Post-Fire Caribou Lichen Transplantation And Assessment, Elise Brown-Dussault

Theses and Dissertations (Comprehensive)

Caribou lichen species are common in mid- to late-seral boreal forests, serving as an important winter diet staple for boreal woodland caribou. However, as climate change causes boreal wildfires to increase in size, severity, and frequency, available tracts of mature forest are decreasing, diminishing the extent of mature caribou lichen stands. Caribou lichens reproduce vegetatively, so bigger and more severe fires could exacerbate their dispersal limitations, potentially extending the timeline for caribou lichen stand recovery beyond 80 years. Trials have shown that “transplanting” caribou lichen fragments into disturbed areas can lead to the establishment of caribou lichen mats; as such, …

Timing Of Migration And Seasonal Movements Of Arctic Grayling (Thymallus Arcticus) In Relation To Water Temperature In The Kakisa River And Upper Mackenzie River, Nwt: Results From An Acoustic Telemetry Study., Levi Snook

Theses and Dissertations (Comprehensive)

Arctic grayling (Thymallus arcticus) are a cold-water salmonid that inhabit waterbodies throughout the circumpolar regions of the northern hemisphere. In the last decade, Ka'a'gee Tu First Nation members as well as local sport fishers, have observed lower catches of Arctic grayling during their annual spawning run in the Kakisa River, NWT. Many potential causes of this decline have been hypothesized including climate change and over harvesting. Outside of the general annual spawning activity in the headwaters of the Kakisa River, the ecology of the population, including post-spawn habitat use and migratory patterns, remained understudied. To address these knowledge gaps, acoustic …