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Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Positron Emission Tomography In Oncology And Environmental Science, Samantha Delaney Jun 2024

Positron Emission Tomography In Oncology And Environmental Science, Samantha Delaney

Dissertations, Theses, and Capstone Projects

The last half century has played witness to the onset of molecular imaging for the clinical assessment of physiological targets. While several medical imaging modalities allow for the visualization of the functional and anatomical properties of humans and living systems, few offer accurate quantitation and the ability to detect biochemical processes with low-administered drug mass doses. This limits how physicians and scientists may diagnose and treat medical issues, such as cancer, disease, and foreign agents.

A promising alternative to extant invasive procedures and suboptimal imaging modalities to assess the nature of a biological environment is the use of positron emission …


Phase Equilibria And Heat Capacities For Tetraarylphosphonium-Based Ionic Liquids, Allan Wilson May 2024

Phase Equilibria And Heat Capacities For Tetraarylphosphonium-Based Ionic Liquids, Allan Wilson

Honors Theses

Climate change is one of the most pressing issues facing humanity in the 21st century. A major contributing factor to this problem is the continued use of fossil-fuel based sources of energy. Concentrated solar power (CST) with thermal energy storage (TES) provides a potential opportunity to support this transition away from fossil fuels but suffers from high costs and extended downtimes. Current heat transfer fluids used in these processes often consist of a mixture of alkali metal nitrates with melting points above 200°C. For CST and TES to be viable, a thermally stable, low melting fluid is needed. Ionic liquids …


Assessing Nordihydroguaiaretic Acid Properties And Its Potential Therapeutic Effect For Glioblastoma, Jose Arturo Guerrero May 2024

Assessing Nordihydroguaiaretic Acid Properties And Its Potential Therapeutic Effect For Glioblastoma, Jose Arturo Guerrero

Open Access Theses & Dissertations

This study employs a combination of theoretical and experimental analysis to spectroscopically investigate the biomechanistic structure relationship and therapeutic effects of the Nordihydroguaiaretic Acid (NDGA) chemical derived from the Larrea Tridentata plant. These relationships are crucial for understanding NDGA's efficacy in disease prevention, treatment, and potential toxicological effects. While the medicinal and antiviral properties of the NDGA have been studied extensively, there remains a gap in optically identifying and reporting its structural changes. The current research successfully reveals evident trends in NDGA's vibrational signatures, particularly highlighting the absence of the Raman feature at 780 〖cm〗^(-1) as indicative of a fully …


Exploring Cation Exchange: Unveiling Its Significance In Biochar And Bioenergetics Applications, Gyanendra Kharel Apr 2024

Exploring Cation Exchange: Unveiling Its Significance In Biochar And Bioenergetics Applications, Gyanendra Kharel

Chemistry & Biochemistry Theses & Dissertations

Cation exchange, a cornerstone of soil chemistry and nutrient cycling, is a fundamental chemical process that occurs in soils, sediments, membranes, and other solid materials. It involves the interchange of positively charged ions, or cations, between a solid matrix and a surrounding solution. This process is crucial in various natural and engineered systems, leading to a range of applications across different fields.

This dissertation presents an extensive investigation into the applications of cation exchange in the fields of biochar and bioenergetics, encompassing three distinct aims. The first aim concentrates on the surface oxygenation of biochar through ozonization, aiming to achieve …


Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia Dec 2023

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …


Integration Of Algae And Biomass Processes To Synthesize Renewable Bioproducts For The Circular Economy, Jessica Martin Nov 2023

Integration Of Algae And Biomass Processes To Synthesize Renewable Bioproducts For The Circular Economy, Jessica Martin

USF Tampa Graduate Theses and Dissertations

Rapid population growth and global industrialization have substantially heightened the demand for fossil-based fuels and products in various sectors of the global economy, including energy production, transportation fuels, and as raw materials for petrochemicals. The intense consumption of fossil fuels has caused immense environmental impacts, especially pertaining to carbon dioxide emissions. Shifting to renewable feedstocks (raw materials) is expected to reduce these emissions by lowering the carbon footprint of fuels and products compared to traditional fossil-derived alternatives. This transition aligns with the goal of creating a sustainable and circular economy, emphasizing efficient resource use, and reducing waste generation through recycling …


Du Undergraduate Showcase: Research, Scholarship, And Creative Works, Caitlyn Aldersea, Justin Bravo, Sam Allen, Anna Block, Connor Block, Emma Buechler, Maria De Los Angeles Bustillos, Arianna Carlson, William Christensen, Olivia Kachulis, Noah Craver, Kate Dillon, Muskan Fatima, Angel Fernandes, Emma Finch, Colleen Cassidy, Amy Fishman, Andrea Francis, Stacia Fritz, Simran Gill, Emma Gries, Rylie Hansen, Shannon Powers, Jacqueline Martinez, Zachary Harker, Ashley Hasty, Mykaela Tanino-Springsteen, Kathleen Hopps, Adelaide Kerenick, Colin Kleckner, Ci Koehring, Elijah Kruger, Braden Krumholz, Maddie Leake, Lyneé Alves, Seraphina Loukas, Yatzari Lozano Vazquez, Haley Maki, Emily Martinez, Sierra Mckinney, Mykaela Tanino-Springsteen, Audrey Mitchell, Kipling Newman, Audrey Ng, Megan Lucyshyn, Andrew Nguyen, Stevie Ostman, Casandra Pearson, Alexandra Penney, Julia Gielczynski, Tyler Ball, Anna Rini, Christina Rorres, Simon Ruland, Helayna Schafer, Emma Sellers, Sarah Schuller, Claire Shaver, Kevin Summers, Isabella Shaw, Madison Sinar, Claudia Pena, Apshara Siwakoti, Carter Sorensen, Madi Sousa, Anna Sparling, Alexandra Revier, Brandon Thierry, Dylan Tyree, Maggie Williams, Lauren Wols May 2023

Du Undergraduate Showcase: Research, Scholarship, And Creative Works, Caitlyn Aldersea, Justin Bravo, Sam Allen, Anna Block, Connor Block, Emma Buechler, Maria De Los Angeles Bustillos, Arianna Carlson, William Christensen, Olivia Kachulis, Noah Craver, Kate Dillon, Muskan Fatima, Angel Fernandes, Emma Finch, Colleen Cassidy, Amy Fishman, Andrea Francis, Stacia Fritz, Simran Gill, Emma Gries, Rylie Hansen, Shannon Powers, Jacqueline Martinez, Zachary Harker, Ashley Hasty, Mykaela Tanino-Springsteen, Kathleen Hopps, Adelaide Kerenick, Colin Kleckner, Ci Koehring, Elijah Kruger, Braden Krumholz, Maddie Leake, Lyneé Alves, Seraphina Loukas, Yatzari Lozano Vazquez, Haley Maki, Emily Martinez, Sierra Mckinney, Mykaela Tanino-Springsteen, Audrey Mitchell, Kipling Newman, Audrey Ng, Megan Lucyshyn, Andrew Nguyen, Stevie Ostman, Casandra Pearson, Alexandra Penney, Julia Gielczynski, Tyler Ball, Anna Rini, Christina Rorres, Simon Ruland, Helayna Schafer, Emma Sellers, Sarah Schuller, Claire Shaver, Kevin Summers, Isabella Shaw, Madison Sinar, Claudia Pena, Apshara Siwakoti, Carter Sorensen, Madi Sousa, Anna Sparling, Alexandra Revier, Brandon Thierry, Dylan Tyree, Maggie Williams, Lauren Wols

DU Undergraduate Research Journal Archive

DU Undergraduate Showcase: Research, Scholarship, and Creative Works


Determination Of Cadmium Uptake In Crassostrea Virginica Shell Under Controlled Conditions, Joseph John Pavelites Ii May 2023

Determination Of Cadmium Uptake In Crassostrea Virginica Shell Under Controlled Conditions, Joseph John Pavelites Ii

<strong> Theses and Dissertations </strong>

The objective of this thesis was to meet growing demand for the development of environmental biomonitors that protect ecosystems and public health. To do this, I determined the potential of oyster shell as a bioindicator of cadmium (Cd) in the environment by determining the mode of Cd uptake and relationships between Cd concentrations in the environment, shell, and soft tissues of juvenile eastern oysters (Crassostrea virginica Gmelin). I performed a review of the literature on the ability of oyster shell to retain metal contaminants and the factors that could affect this process (Chapter 2). I then reared C. virginica …


Development Opportunities And Technical Challenges Of Industrialization For Hydrogen Production From Bio-Ethanol Reforming, Xue Han, Hong He, Guojun Yue, Hailong Lin, Jinsong Liu, Bin Yu Jan 2023

Development Opportunities And Technical Challenges Of Industrialization For Hydrogen Production From Bio-Ethanol Reforming, Xue Han, Hong He, Guojun Yue, Hailong Lin, Jinsong Liu, Bin Yu

Bulletin of Chinese Academy of Sciences (Chinese Version)

Bio-ethanol reforming for hydrogen production, using renewable raw materials and adopting mature and efficient chemical processes, is an important source of green hydrogen supply to achieve the goals of carbon peaking and carbon neutrality. Bio-ethanol is a widely used substitute for fossil fuels. With the continuous progress of cellulosic ethanol technology in recent years, bio-ethanol will gradually break through the constraints of starch-based raw material supply. Based on the industrialization achievements of hydrogen production and bio-ethanol, bio-ethanol reforming can realize a rapid linkage with the existing hydrogen energy industry. However, the existence of a carbon-carbon signal bond in ethanol poses …


Dual Ionic Liquid-Functionalized Cellulosic Materials: Thermal, Mechanical And Conductive Properties, Elizabeth Mcgrew, Kevin M. Miller Phd Jan 2023

Dual Ionic Liquid-Functionalized Cellulosic Materials: Thermal, Mechanical And Conductive Properties, Elizabeth Mcgrew, Kevin M. Miller Phd

Posters-at-the-Capitol

Cellulose, an inexpensive and renewable biomacromolecule, represents an intriguing synthetic foundation for new materials with task-specific properties. Here, we wish to report a synthetic route for functionalizing cellulose with a side chain containing two ionic liquid functional groups using azide-alkyne ‘click’ cyclization strategy, followed by quaternization of the two resulting heterocycles (1,2,3-triazole and imidazole). Through this functionalization strategy, the resulting cellulosic materials exhibited significant softening, with several glass transition (Tg) values observed below room temperature, indicating the amorphous nature of the materials, with the Tg dependent on both the length of the side chain and the …


Protein Extraction And Purification By Differential Solubilization, Barry J. Ryan, Gemma K. Kinsella, Gary T. Henehan Jan 2023

Protein Extraction And Purification By Differential Solubilization, Barry J. Ryan, Gemma K. Kinsella, Gary T. Henehan

Books/Book Chapters/ Proceedings

The preparation of purified soluble proteins for biochemical studies is essential and the solubility of a protein of interest in various media is central to this process. Selectively altering the solubility of a protein is a rapid and economical step in protein purification and is based on exploiting the inherent physicochemical properties of a polypeptide. Precipitation of proteins, released from cells upon lysis, is often used to concentrate a protein of interest before further purification steps (e.g., ion exchange chromatography, size exclusion chromatography etc).

Recombinant proteins may be expressed in host cells as insoluble inclusion bodies due to various influences …


Food Waste Storage Gaseous Emissions Detection And Quantification Using Infrared Spectroscopy, Ryley A. Burton-Tauzer Jan 2023

Food Waste Storage Gaseous Emissions Detection And Quantification Using Infrared Spectroscopy, Ryley A. Burton-Tauzer

Cal Poly Humboldt theses and projects

A growing interest in sustainable waste management and the implementation of new policies have prompted a shift towards alternative resource recovery methods for organic waste, including food waste. To effectively assess alternative food waste treatment scenarios, it is important to evaluate the life cycle impacts associated with each scenario. The storage phase of food waste, encompassing its accumulation in kitchens, and storage in bins for collection and transportation, has been overlooked as a source of greenhouse gases in previous studies. This investigation aimed to identify the greenhouse gases emitted during the initial five-day period of low-oxygen storage. An open dynamic …


Next-Generation Sequencing Shows Increasing Temperatures Affect Stream Fungal Communities, Regan Hodgson Dec 2022

Next-Generation Sequencing Shows Increasing Temperatures Affect Stream Fungal Communities, Regan Hodgson

Electronic Theses and Dissertations

Under climate change predictions, surface air temperature is expected to continue to rise and will likely affect functioning of stream ecosystems and microbial communities. Aquatic hyphomycetes are key fungal decomposers of plant litter in headwater streams controlling carbon, energy, and nutrient flows to higher trophic levels. This project addressed the effects of temperature on stream fungal communities in two recently conducted experiments (microcosm and streamside channel studies) using Illumina sequencing. The objectives were to determine (1) if temperature affects community structure of stream fungi based on relative abundances of ITS2 rDNA sequences, (2) if the effects of temperature on aquatic …


Wrack Lines Volume 22, Number 2, Fall-Winter 2022-2023, Nancy C. Balcom, Juliana Barrett, Judy Benson, Ben Crnic, Sto Len Dec 2022

Wrack Lines Volume 22, Number 2, Fall-Winter 2022-2023, Nancy C. Balcom, Juliana Barrett, Judy Benson, Ben Crnic, Sto Len

Wrack Lines

With the theme, "Looking Ahead: People and Projects Shaping the Future," the Fall-Winter 2022-2023 leads with the first in what will be a series of articles about offshore wind development impacting Connecticut. That is followed by the inspiring story of how a dying forest was replanted for climate resilience. Next, a profile of longtime marine educator Tim Visel tells about his lasting impact on Connecticut schools and students. Lastly, the complex challenge of dealing with Contaminants of Emerging Concern is examined, with descriptions of how Sea Grant is involved and the particularly troublesome group of substances called PFAS.


Nanotechnology-Based Approaches To Mitigate Environmental Pollutants -- Induced Neurological Disorders, Jyoti Ahlawat May 2022

Nanotechnology-Based Approaches To Mitigate Environmental Pollutants -- Induced Neurological Disorders, Jyoti Ahlawat

Open Access Theses & Dissertations

Neurodegenerative diseases such as Parkinson's disease (PD), Alzheimerâ??s Disease (AD) and Huntingtonâ??s Disease (HD) have no cure despite intensive research efforts geared towards therapeutics development. In the USA, patients with PD and AD alone cost the nation ~ $200 billion annually in patient care and lost productivity. Therefore, there remains an urgent and unmet need to develop novel drugs and drug carriers with the potential to slow down, halt and ideally reverse the course of neurodegenerative disorders. The dissertation focuses on developing approaches towards targeting PD using multifactorial mechanisms including the targeting of protein aggregation and oxidative stress. This is …


Floating Treatment Wetlands For Brackish Waters: Plant Selection And Nutrient Uptake Potential., Andrea Landaverde May 2022

Floating Treatment Wetlands For Brackish Waters: Plant Selection And Nutrient Uptake Potential., Andrea Landaverde

All Theses

Brackish water bodies in coastal regions provide critical ecosystem services that support human and environmental health. Anthropogenic activities such as agricultural and industrial activities, construction, urban settlements, and tourism contribute to increased inputs of nitrogen (N) and phosphorus (P) in brackish coastal ecosystems. Excess nutrients can lead to impaired water quality and affect marine organisms. Floating treatment wetlands (FTWs) are a vegetated-base technology used to remove contaminants from water column, that has been mainly studied and applied in freshwater systems. Application of FTWs in brackish systems requires further investigation, as high salinity in brackish waters could result in toxicity to …


Evaluating Alternative Ebullition Models For Predicting Peatland Methane Emission And Its Pathways Via Data–Model Fusion, Shuang Ma, Lifen Jiang, Rachel M. Wilson, Jeff P. Chanton, Scott Bridgham, Shuli Niu, Colleen M. Iversen, Avni Malhotra, Jiang Jiang, Xingjie Lu, Yuanyuan Huang, Jason Keller, Xiaofeng Xu, Daniel M. Ricciuto, Paul J. Hanson, Yiqi Luo Apr 2022

Evaluating Alternative Ebullition Models For Predicting Peatland Methane Emission And Its Pathways Via Data–Model Fusion, Shuang Ma, Lifen Jiang, Rachel M. Wilson, Jeff P. Chanton, Scott Bridgham, Shuli Niu, Colleen M. Iversen, Avni Malhotra, Jiang Jiang, Xingjie Lu, Yuanyuan Huang, Jason Keller, Xiaofeng Xu, Daniel M. Ricciuto, Paul J. Hanson, Yiqi Luo

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding the dynamics of peatland methane (CH4) emissions and quantifying sources of uncertainty in estimating peatland CH4 emissions are critical for mitigating climate change. The relative contributions of CH4 emission pathways through ebullition, plant-mediated transport, and diffusion, together with their different transport rates and vulnerability to oxidation, determine the quantity of CH4 to be oxidized before leaving the soil. Notwithstanding their importance, the relative contributions of the emission pathways are highly uncertain. In particular, the ebullition process is more uncertain and can lead to large uncertainties in modeled CH4 emissions. To improve model simulations of CH4 emission and its pathways, …


Honey As A Biomonitor For Air Pollutant Deposition In The Eastern United States Using Ion Chromatography And Scanning Electron Microscopy, Cole Cochran Apr 2022

Honey As A Biomonitor For Air Pollutant Deposition In The Eastern United States Using Ion Chromatography And Scanning Electron Microscopy, Cole Cochran

Undergraduate Honors Theses

Anthropogenic activities generate metal, acid, and particulate air pollutants which negatively impact human and ecological health. In the United States, power plant, industrial, and vehicle emissions are leading causes of air pollution, however, the measurement of air pollution at high-resolution spatial regimes remains a challenge. Honey has emerged as a powerful biomonitoring tool to effectively quantify contaminants without the need for a large array of monitoring instruments. I hypothesized that honey could be used to effectively measure and map modern air pollutant spatiotemporal relationships over the Eastern U.S. Using ion chromatography with sulfate as an indicator for air pollution and …


Review Of The Effects Of Asphalt Fume Emission (Vocs And Pahs) In Vitro, In Vivo And Human Studies, Omran Taqi, Nastassja Lewinski, Elham Fini, Eran Rozewski, Judith Klein-Seetharaman Jan 2022

Review Of The Effects Of Asphalt Fume Emission (Vocs And Pahs) In Vitro, In Vivo And Human Studies, Omran Taqi, Nastassja Lewinski, Elham Fini, Eran Rozewski, Judith Klein-Seetharaman

Undergraduate Research Posters

Review of the effects of Asphalt fume emission (VOCs and PAHs) in vitro, in vivo and human studies

Omran Taqi, Nastassja Lewinski1

1) Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA

Background

Asphalt is abundantly available around human operations including road paving and roofing sites. However, their emissions and fumes (specifically volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs)) have been found to have adverse effects on health. Asphalt fumes are a class 2A carcinogen and exposure can increase the risk of lung cancer, asthma, headache, fatigue, and other cardiovascular diseases.

Methods

We used …


Influence Of Physical Variability Of Highly Weathered Sedimentary Rock On Nitrate In Area 3 Of The Enigma Field Research Site At Y-12, Erin Kelly Dec 2021

Influence Of Physical Variability Of Highly Weathered Sedimentary Rock On Nitrate In Area 3 Of The Enigma Field Research Site At Y-12, Erin Kelly

Masters Theses

Uranium processing and waste storage in unlined waste ponds leached contaminants into the groundwater at Y-12, Oak Ridge, Tennessee, from the 1950s to 1980s. Groundwater wells near the S-3 ponds have had the highest nitrate concentrations of groundwater anywhere in the world (>10,000 mg/L). For reference, the maximum contaminant level for nitrate in drinking water set by the U.S. Environmental Protection Agency is 10 mg/L. Since 2012, the ENIGMA (Ecosystems and Networks Integrated with Genes and Molecular Assemblies) group has been characterizing, monitoring, and conducting field experiments to understand the interactions between contaminants, microbes, and the subsurface. The goals …


Computational Simulation Of The Lung Doses Of Air-Borne Fine And Ultrafine Particles Inhaled By Humans At Industrial Workplaces, Mohammed Ali Nov 2021

Computational Simulation Of The Lung Doses Of Air-Borne Fine And Ultrafine Particles Inhaled By Humans At Industrial Workplaces, Mohammed Ali

Technology Faculty Publications and Presentations

This study correlates computational predictions with in-vivo experimental results of inhaled fine and ultrafine particulate matters (PMs) transport, dissemination, and deposition in the human respiratory airways. Epidemiological studies suggest that workplace exposure of anthropogenic pollutant PMs as a risk factor for increased susceptibility to acute broncho-pulmonary infections. However, investigations on detailed human inhalation and PM transport processes are restrictive from time, cost, and ethical perspectives. To overcome this problem, computational simulation of particle deposition based on the Multiple Path Particle Dosimetry (MPPD) model was employed. Here, the physical, mechanical, and electrical properties of PMs of carbon black and nanoparticles from …


Pacific Black Duck Ecology And Habitat Assessment In Aunu'u, American Samoa, And Their Relationship To Other Mallard-Like Ducks Of Oceania, Greater Indonesia, And The Philippines, Marissa Kaminski Aug 2021

Pacific Black Duck Ecology And Habitat Assessment In Aunu'u, American Samoa, And Their Relationship To Other Mallard-Like Ducks Of Oceania, Greater Indonesia, And The Philippines, Marissa Kaminski

Open Access Theses & Dissertations

Determining a species’ ecological needs, assessing the quality of their habitat, and determining genetic differentiation and connectivity among populations is essential to their conservation. My dissertation focuses on obtaining such a holistic view for a population of Pacific Black Ducks recently established on the Island of Aunu’u, American Samoa. Specifically, I present the first evaluation of the ecology and habitat of a recently established population of Pacific Black Ducks on the Island of Aunu’u, American Samoa, in Chapter 1, while I assess the genetic connectivity and relationship of this population to other Mallard-like ducks found in Greater Indonesia, Oceania, and …


Polycyclic Aromatic Hydrocarbons And The Microbiomes Of Two Benthic Species, Samantha Ells Aug 2021

Polycyclic Aromatic Hydrocarbons And The Microbiomes Of Two Benthic Species, Samantha Ells

Master's Theses

The presence of oil has been shown to affect the microbiomes of the water column, sediments, and organisms, both by altering the diversity and the composition of those microbial communities. If the microbiome is altered it may no longer provide benefits to its host organism, impacting its ability to survive. Thus, it is important to understand the effects of large-scale contamination events including the Deepwater Horizon oil spill. This study set out to examine the effects of oil exposure on the microbiome of two benthic species, southern flounder (Paralichthys lethostigma) and eastern oysters (Crassostrea virginica) to further understand the effects …


Selection And Demography Drive Range-Wide Patterns Of Mhc Variation In Mule Deer (Odocoileus Hemionus), Rachel M. Cook Aug 2021

Selection And Demography Drive Range-Wide Patterns Of Mhc Variation In Mule Deer (Odocoileus Hemionus), Rachel M. Cook

Theses and Dissertations

Variation at functional genes involved in immune response is of increasing concern as wildlife diseases continue to emerge and threaten populations. The amount of standing genetic variation in a population is directly associated with its potential for rapid adaptation to novel environments. For genes in the major histocompatibility complex (MHC), which are crucial in activating the immune response and which have extremely high levels of polymorphism, the genetic variation has been shown to be influenced by both parasite-mediated selection and historical population demography. To better understand the relative roles of parasite-mediated selection and demography on MHC evolution in large populations, …


Improvement Of Biochar Through Ozonization And Biosafety Of Genetically Engineered Cyanobacteria, Oumar Sacko Jul 2021

Improvement Of Biochar Through Ozonization And Biosafety Of Genetically Engineered Cyanobacteria, Oumar Sacko

Chemistry & Biochemistry Theses & Dissertations

Through the innovative technique of biochar post-production surface oxygenation by ozonization, we were able to improve certain properties of biochar. In project one, the incubation of an insoluble phosphate rock material (hydroxyapatite) with the wet ozonized pine 400 biochar and its filtrate resulted in a solubilization of 80 times more phosphate from hydroxyapatite (569.0 mg/L ± 6.4) compared to the pure water-hydroxyapatite control (7.2 mg/L ± 0.3). The ozonized biochar may provide a new possible way to unlock the phosphorus from insoluble phosphate mineral phases. The cation exchange capacity (CEC) is a key property of biochar when used as a …


Salicylic Acid Response To Simulated Herbivory In Geographically Distinct T. Heterophylla And H. Discolor Populations, Amy E. Castle May 2021

Salicylic Acid Response To Simulated Herbivory In Geographically Distinct T. Heterophylla And H. Discolor Populations, Amy E. Castle

Honors Projects

It is commonly known that plants may produce salicylic acid as a chemical defense response to wounding, although the phenomenon has usually been observed with regard to insect herbivory. Stem and leaf tissue of two species, Tsuga heterophylla and Holodiscus discolor, which are often eaten by deer, were extracted in methanol and analyzed by HPLC to quantify salicylic acid concentration in experimentally wounded or control samples. No salicylic acid response was detectable in T. heterophylla, suggesting it is a less useful candidate species for future study. Some but not all H. discolorsamples had a measurable salicylic acid …


The Effects Of Endocrine Disrupting Chemicals On Plants, Christian Mathew Pridemore Jan 2021

The Effects Of Endocrine Disrupting Chemicals On Plants, Christian Mathew Pridemore

Theses, Dissertations and Capstones

Endocrine disrupting chemicals (EDCs) are a diverse group of chemicals which can have a detrimental effect on human health, affecting any physiological body system sensitive to hormonal changes. Human exposure to EDCs is inevitable due to their prevalence in modern living; EDCs are integral compounds found in everyday items with which humans interact and ingest. These, along with other indirect avenues leading to EDC exposure, pose a threat to both human health and to the health of wildlife and agricultural environments. Studies on the effects of EDCs on plants can be substantially informative and necessary for progress towards solving the …


The Quantitative Assessment Of Pond Scum: An Examination Of The Biogeochemistry Of Phosphorus Cycling In The Belgrade Lakes, Abbey M. Sykes Jan 2021

The Quantitative Assessment Of Pond Scum: An Examination Of The Biogeochemistry Of Phosphorus Cycling In The Belgrade Lakes, Abbey M. Sykes

Honors Theses

The internal recycling phosphorus in freshwater lake bottom sediments represents a significant source of hypolimnetic phosphorus (P) release for many of Maine’s lakes. In summer months, Maine lakes often thermally stratify and the lake hypolimnion develops anoxia, leading to a reduction in redox potential at the sediment-water interface. These reducing conditions facilitate the reductive dissolution of ferric iron, and, since phosphorus is often present in freshwater lake sediments as solid FeOOH-PO4 complexes, results in release of soluble phosphorus into the water column. Our current study presents field and laboratory data from sediment fractionation extractions designed to quantify concentrations of …


Not Too Hot, Not Too Cold, But Moderately Variable: The Influence Of Environmental Variability On Coral Thermal Tolerance, Courtney Nicole Klepac Dec 2020

Not Too Hot, Not Too Cold, But Moderately Variable: The Influence Of Environmental Variability On Coral Thermal Tolerance, Courtney Nicole Klepac

Biological Sciences Theses & Dissertations

Anthropogenic climate change is causing an increase in the frequency and severity of marine heat waves, resulting in declining health of coral reef ecosystems worldwide. Coral bleaching events – the breakdown in symbiosis between the coral host and their intracellular photosynthetic algae – are increasingly common in recent years and contribute to widespread losses in coral cover. However, bleaching and heat stress responses vary across spatial scales both within and among coral species. Coral populations native to highly variable environments can have greater bleaching resistance than corals from more stable habitats and corals transplanted into these variable reef sites can …


Algal Biomarkers As A Proxy For Pco2: Constraints From Late Quaternary Sapropels In The Eastern Mediterranean, Caitlyn R. Witkowski, Marcel T.J. Van Der Meer, Brian Blais, Jaap S. Sinninghe Damsté, Stefan Schouten Sep 2020

Algal Biomarkers As A Proxy For Pco2: Constraints From Late Quaternary Sapropels In The Eastern Mediterranean, Caitlyn R. Witkowski, Marcel T.J. Van Der Meer, Brian Blais, Jaap S. Sinninghe Damsté, Stefan Schouten

Science and Technology Department Faculty Journal Articles

Records of carbon dioxide concentrations (partial pressure expressed as pCO2) over Earth’s history provide trends that are critical to understand our changing world. To better constrain pCO2 estimations, here we test organic pCO2 proxies against the direct measurements of pCO2 recorded in ice cores. Based on the concept of stable carbon isotopic fractionation due to photosynthetic CO2 fixation (Ɛp), we use the stable carbon isotopic composition (δ13C) of the recently proposed biomarker phytol (from all photoautotrophs), as well as the conventionally used alkenone biomarkers (from specific species) for comparison, to reconstruct pCO2 over several Quaternary …