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University of Massachusetts Amherst

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Full-Text Articles in Life Sciences

The Genomic Dynamics Of Fermented Food Microbes, Katherine Chacón-Vargas Apr 2023

The Genomic Dynamics Of Fermented Food Microbes, Katherine Chacón-Vargas

Doctoral Dissertations

Along with the agriculture and domestication revolution, humans have utilized bacteria, yeasts, and molds for millennia in the production of traditionally fermented foods and beverages. Fermentation is a very ancient practice of high relevance nowadays since it contributes with a great variety of foods worldwide. Microbial fermentation allows metabolic transformation of the raw food materials leading to biochemical changes that played a key role in food preservation, health benefits, nutrition, flavors, and texture, among others. Food fermentation practices could diverge from traditional artisanal spontaneous fermentation to industrialize methods with specialized microbial starters and although fermented environments tend to be very …


The Relative Effects Of Functional Diversity And Structural Complexity On Carbon Dynamics In Late-Successional, Northeastern Mixed Hardwood Forests, Samantha Myers Apr 2023

The Relative Effects Of Functional Diversity And Structural Complexity On Carbon Dynamics In Late-Successional, Northeastern Mixed Hardwood Forests, Samantha Myers

Masters Theses

Late-successional forests provide a unique opportunity to explore adaptive management approaches that mitigate atmospheric carbon dioxide levels through carbon storage while also enhancing ecological resilience to novel climate and disturbances. Typical benchmarks for adaptive forest management include species diversity and structural complexity, which are widely considered to increase ecosystem stability and productivity. However, the role of functional trait diversity (e.g., variation in leaf and stem traits) in driving forest productivity and ecosystem resilience remains underexplored. We leveraged existing continuous forest inventory (CFI) data and collected local functional trait observations from CFI plots within late-successional forests in western Massachusetts to explore …


Evaluation Of Acoustic Telemetry Array Performance And Fine- Scale And Broad-Scale Spatial Movement Patterns For Coral Reef Species In Culebra, Puerto Rico, Roxann Cormier Apr 2023

Evaluation Of Acoustic Telemetry Array Performance And Fine- Scale And Broad-Scale Spatial Movement Patterns For Coral Reef Species In Culebra, Puerto Rico, Roxann Cormier

Masters Theses

Acoustic telemetry is an important tool when studying the spatial ecology of marine animals. First, it is important to identify the challenges of using this tool in shallow tropical marine environments before tracking marine animals. One significant issue that can influence the effectiveness of acoustic telemetry is the efficiency or detectability of acoustic signals by receivers. Understanding factors influencing detection efficiency of acoustic tags is especially important for fine-scale positioning systems (such as the VEMCO positioning system, VPS) that use detections in an overlapping receiver network to calculate geographic positions of tagged fish. I modelled the efficiency of an acoustic …


Inverse Probability Weighting In Survival Analysis And Network Analysis, Yukun Lu Feb 2023

Inverse Probability Weighting In Survival Analysis And Network Analysis, Yukun Lu

Doctoral Dissertations

Inverse probability weighting is a popular technique to accommodate selection bias due to non-random sampling and missing data. In the first chapter, we develop an inverse probability weighted estimator and an augmented inverse probability weighted estimator of regression coefficients for a linear model with randomly censored covariates, when the censoring mechanism may be dependent on the outcome. We investigate the asymptotic properties of both estimators and evaluate their finite sample performance through extensive simulation studies. We apply the proposed methods to an Alzheimer’s disease study. In the second chapter, we present an application of network analysis in a study of …


Human Milk: From Covid-19 Immunity To Breast Cancer Risk Assessment, Vignesh Narayanaswamy Feb 2023

Human Milk: From Covid-19 Immunity To Breast Cancer Risk Assessment, Vignesh Narayanaswamy

Doctoral Dissertations

Breastmilk is a complex biological fluid containing macromolecules including lipids, oligosaccharides, proteins as well as several types of cells. Several studies have reported in detail of these components. My focus is studying the protein component of breastmilk, specifically antibodies, cytokines, and other secreted factors in the setting of different pathogenicity in women. Studies have demonstrated that the levels of numerous cytokines as well as the levels of pathogen-specific antibodies are altered in milk upon either maternal or infant infections. Additionally, there are reports that the levels of certain inflammatory markers are altered in milk among women with breast cancer or …


Characterizing The Roles Of The Variable Linker And Hub Domains In Camkii Activation, Noelle Dziedzic Feb 2023

Characterizing The Roles Of The Variable Linker And Hub Domains In Camkii Activation, Noelle Dziedzic

Doctoral Dissertations

Learning and memory formation at the cellular level involves decoding complex electrochemical signals between nerve cells, or neurons. Understanding these processes at the molecular level requires a comprehensive study of calcium-sensitive proteins that serve as signal mediators within cells. More specifically, the protein calcium/calmodulin-dependent protein kinase II (CaMKII) is a key regulator of downstream cellular signaling events in the brain, playing an important role in long term memory formation. CaMKII is encoded in humans on four different genes: alpha, beta, gamma and delta. For added complexity, each of these gene products can be alternatively spliced and translated into multiple protein …


Habitat Use And Individual-Based Modeling Of Bald Eagles In Maine Near Current And Potential Wind Energy Facilities, Blake Massey Jan 2023

Habitat Use And Individual-Based Modeling Of Bald Eagles In Maine Near Current And Potential Wind Energy Facilities, Blake Massey

Doctoral Dissertations

Wind energy facilitates have expanded significantly in the United States over the last few decades due to technological advancements, regulatory incentives, and policies aimed at increasing renewable energy production, but poorly sited turbines may have adverse effects on local and migratory birds, bats, and other wildlife and their habitats. In the northeastern United States, Maine has become the leader in wind energy but also has the greatest density of Bald Eagles in the region. As wind energy production continues to be developed across the state and in coastal waters, research is needed to analyze and assess potential risks, including displacement, …


Comparison Of The Humoral Immune Response Following Both Bacterial Challenge And Rnai Of Major Factors On Proliferation Of Bartonella Quintana In The Human Louse, Jake Zina Oct 2022

Comparison Of The Humoral Immune Response Following Both Bacterial Challenge And Rnai Of Major Factors On Proliferation Of Bartonella Quintana In The Human Louse, Jake Zina

Masters Theses

Human body lice, Pediculus humanus humanus, and head lice, Pediculus humanus capitis, have been hematophagous ectoparasites of humans for thousands of years. Despite being ecotypes, only body lice are known to transmit bacterial diseases to humans, and it appears that lower humoral and cellular immune responses allow body lice to possess a higher vector competence. We previously observed that the transcription level of the defensin 1 gene was up-regulated only in head lice following oral challenge of Bartonella quintana, a causative agent of trench fever, and also that body lice excreted more viable B. quintana in their …


Changes In Gene Expression From Long-Term Warming Revealed Using Metatranscriptome Mapping To Fac-Sorted Bacteria, Christopher A. Colvin Oct 2022

Changes In Gene Expression From Long-Term Warming Revealed Using Metatranscriptome Mapping To Fac-Sorted Bacteria, Christopher A. Colvin

Masters Theses

Soil microbiomes play pivotal roles to the health of the environment by maintaining metabolic cycles. One question is how will climate change affect soil bacteria over time and what could the repercussions be. To answer these questions, the Harvard Forest Long-Term Warming Experiment was established to mimic predicted climate change by warming plots of land 5℃ above ambient conditions. In 2017, 14 soil core samples were collected from Barre Woods warming experiment to mark 15 years since the establishment of the soil warming in that location. These samples underwent traditional metatranscriptomics to generate an mRNA library as well as a …


The Mouse Mammary Gland: A Tool To Evaluate The Environmental Chemical Butyl Benzyl Phthalate, And Approaches To Improve Regulatory Testing, Jessica Daum Oct 2022

The Mouse Mammary Gland: A Tool To Evaluate The Environmental Chemical Butyl Benzyl Phthalate, And Approaches To Improve Regulatory Testing, Jessica Daum

Masters Theses

In the first part of this thesis, we utilize the mouse model to evaluate the environmental chemical Butyl Benzyl Phthalate. Due to lack of research on female exposure to BBP, this thesis focuses on quantifying the effects of gestational exposure on the female mammary gland Here male and female parental mice were exposed before mating and through pregnancy and lactation to one of three doses of BBP or the control via oral ingestion. After weaning, offspring were sacrificed at puberty or early adulthood and evaluated for altered mammary gland morphology or hormonal receptor expression. Results indicate a persistent statistically significant …


Characterization Of The Poly (Adp-Ribose) Polymerase Family In The Fusarium Oxysporum Species Complex, Daniel Norment Oct 2022

Characterization Of The Poly (Adp-Ribose) Polymerase Family In The Fusarium Oxysporum Species Complex, Daniel Norment

Masters Theses

Fusarium oxysporum is a filamentous fungus that is known to invade over a hundred different hosts and poses a major threat to the economy and food supply world-wide. Poly (Adenosine diphosphate-Ribose) Polymerase (PARP) is a family of regulatory proteins that affect change in the cell through transfer of ADP-Ribose moieties onto target molecules. The most well-studied PARP protein is the human PARP1, a PARylating nuclear protein that serves as our model PARP protein. F. oxysporum was found to contain a large expansion of PARP catalytic-domain-containing proteins compared to other filamentous fungi. We utilized in silico multiple sequence alignments and domain …


Assessing Warm-Season Annual Grasses To Increase Forage Inventory, Andrea Marroquin Oct 2022

Assessing Warm-Season Annual Grasses To Increase Forage Inventory, Andrea Marroquin

Masters Theses

Summers are expected to continue to increase in heat/dryness in the Northeast, causing issues pertaining to forage production during the summer to worsen. Many pastures grow cool season grasses, even during the summer. These grasses enter a dormant period and slowdown in production during the months of July and August, leading to what is referred to as “summer slump”. Some farms grow corn silage during the summer, and while corn silage is a valuable crop, its cultivation often does not support soil biology. This research addresses solutions for both summer slump foraging and more sustainable silage. Summer annuals grow more …


Evaluation Of Semiochemicals For Attractiveness To Multiple Tortricid (Lepidoptera) Pests In Apple Orchards, Ajay P. Giri Oct 2022

Evaluation Of Semiochemicals For Attractiveness To Multiple Tortricid (Lepidoptera) Pests In Apple Orchards, Ajay P. Giri

Masters Theses

Tortricid moths (Lepidoptera) are known for their outstanding olfaction capabilities that allow them to detect, process, and respond to chemical information emitted by host or non-host plants. Such an ability to filter out odors from the complex mixture to locate their host has allowed researchers and integrated pest management (IPM) practitioners to develop and implement semiochemically-based pest control strategies. The major goal of this study was to evaluate, under field conditions, the response of male and female oriental fruit moth (OFM), codling moth (CM), redbanded leafroller (RBLR) and three lined leafroller (TLLR) to experimental kairomone lures in commercial apple orchards …


Chemosensory Receptors In Berghia Stephanieae: Bioinformatics And Localization, Kelsi L. Watkins Oct 2022

Chemosensory Receptors In Berghia Stephanieae: Bioinformatics And Localization, Kelsi L. Watkins

Masters Theses

Chemosensation is achieved through the binding of chemical signals to chemoreceptor proteins embedded in the membranes of sensory neurons. The molecular identity of these receptors, as well as the downstream processing of chemosensory signals, has been well studied in arthropods and vertebrates. However, very little is known about molluscan chemosensation. The identity of chemoreceptor proteins in the nudibranch mollusc Berghia stephanieae are unknown. Data from other protostome and molluscan studies suggest Berghia may use ionotropic receptors for some forms of chemoreception. This study used a bioinformatics approach to identify potential chemosensory ionotropic receptors in the transcriptome of Berghia. A …


Incorporating Excess Post-Exercise Oxygen Consumption Into Accelerometer Energy Expenditure Estimation Algorithms, Nicholas Remillard Oct 2022

Incorporating Excess Post-Exercise Oxygen Consumption Into Accelerometer Energy Expenditure Estimation Algorithms, Nicholas Remillard

Masters Theses

Accelerometers are objective monitors of physical activity (PA) that can be used to estimate energy expenditure (EE). Most accelerometer EE estimation equations are based on steady-state data and do not consider excess post-exercise oxygen consumption (EPOC) after exercise. PURPOSE: To quantify the error in accelerometer EE estimates due to EPOC after varying durations of high-intensity treadmill running. METHODS: Nine young, healthy, recreationally active males participated in three study visits. Visit 1 included a treadmill VO2 peak test to determine the treadmill speed correlating to 80% VO2 peak for visits 2 and 3. Visit 2 included a seated 20-min …


Applications Of Statistical Physics To Ecology: Ising Models And Two-Cycle Coupled Oscillators, Vahini Reddy Nareddy Oct 2022

Applications Of Statistical Physics To Ecology: Ising Models And Two-Cycle Coupled Oscillators, Vahini Reddy Nareddy

Doctoral Dissertations

Many ecological systems exhibit noisy period-2 oscillations and, when they are spatially extended, they undergo phase transition from synchrony to incoherence in the Ising universality class. Period-2 cycles have two possible phases of oscillations and can be represented as two states in the bistable systems. Understanding the dynamics of ecological systems by representing their oscillations as bistable states and developing dynamical models using the tools from statistical physics to predict their future states is the focus of this thesis. As the ecological oscillators with two-cycle behavior undergo phase transitions in the Ising universality class, many features of synchrony and equilibrium …


Exposure To Endocrine Disrupting Chemicals And The Effects On Inflammation And Mammary Tumor Progression, Stephanie Morin Oct 2022

Exposure To Endocrine Disrupting Chemicals And The Effects On Inflammation And Mammary Tumor Progression, Stephanie Morin

Doctoral Dissertations

The vast majority of breast cancers, ~70%, are not directly related to an inherited genetic mutation. Environmental factors play a dominant role in the etiology of most breast cancers. There is a subset of chemicals that are able to affect the homeostasis of hormones called endocrine disrupting chemicals (EDCs). Many of these chemicals are pervasive and persistent making the chances for lifetime exposure more prevalent. While many of these chemicals have been deemed safe, a subset of them have come under review to reassess their safety. As estrogen is critical for breast development and can act as a mitogen in …


Root Growth Dynamics In Response To Moderate Temperatures, Maura J. Zimmermann Oct 2022

Root Growth Dynamics In Response To Moderate Temperatures, Maura J. Zimmermann

Doctoral Dissertations

Temperature can impact growth in plants though both physical and biological means. Plants physically respond to temperature by scaling their enzyme reaction rate to temperature, such as seen in the redox reactions of photosynthesis. Biologically, a plant can respond to temperature more specifically, such as adjusting its flowering time. Recently, the Baskin lab discovered that cell division in the root of the model plant Arabidopsis thaliana is temperature acclimated (Yang et al., 2017). Between the non-extreme temperatures of 15 and 25˚C cell division and growth zone length are constant. While the rate of cell division increases with temperature, the number …


The Sos Response In Escherichia Coli K12: An Exploration Of Mutations In Lexa And Reca Using Fluorescence Microscopy, Steven Van Alstine Oct 2022

The Sos Response In Escherichia Coli K12: An Exploration Of Mutations In Lexa And Reca Using Fluorescence Microscopy, Steven Van Alstine

Doctoral Dissertations

Faithful replication of the genome is paramount for maintaining the fitness of an organism. Therefore, life has evolved inducible mechanisms to be able to repair damaged DNA and maintain evolutionary fitness. The SOS response is a highly conserved DNA damage inducible response that is tightly regulated. Multiple factors contribute to the ability of the cell to perform proper DNA repair and induction of the SOS response including the amount of RecA, mutations in RecA that affect competition for DNA, and other proteins that interact with the RecA filament. The complex relationship between RecA and LexA is the subject of this …


Chemical Biology Approaches For Tracking And Manipulation Of Macrophage Phenotypes, Javier A. Mas Rosario Oct 2022

Chemical Biology Approaches For Tracking And Manipulation Of Macrophage Phenotypes, Javier A. Mas Rosario

Doctoral Dissertations

Macrophages are white blood cells of the innate immune system that have the ability to change phenotypically depending on the stimuli present in their surroundings through a process commonly referred to as polarization. Macrophage phenotypes broadly range from pro-inflammatory, anti-tumor (M1) to immune-suppressing (M2). Of particular interest to this work, breast cancer progression and metastasis rely on the presence of M2-like tumor-associated macrophages (TAMs). While many studies have shown the involvement of macrophages in tumor progression and metastasis, there remains a need to further explore these interactions and the polarization process, including tracking of macrophage subtypes. Toward this end, I …


Frontiers In The Self-Assembly Of Charged Macromolecules, Khatcher O. Margossian Oct 2022

Frontiers In The Self-Assembly Of Charged Macromolecules, Khatcher O. Margossian

Doctoral Dissertations

The self-assembly of charged macromolecules forms the basis of all life on earth. From the synthesis and replication of nucleic acids, to the association of DNA to chromatin, to the targeting of RNA to various cellular compartments, to the astonishingly consistent folding of proteins, all life depends on the physics of the organization and dynamics of charged polymers. In this dissertation, I address several of the newest challenges in the assembly of these types of materials. First, I describe the exciting new physics of the complexation between polyzwitterions and polyelectrolytes. These materials open new questions and possibilities within the context …


Principles Of Aaa+ Proteases, Samar Mahmoud Oct 2022

Principles Of Aaa+ Proteases, Samar Mahmoud

Doctoral Dissertations

ATPases associated with diverse cellular activities (AAA+) proteases in bacteria help maintain protein homeostasis by degrading misfolded and regulatory proteins. While a handful of protein targets for these proteases have been identified in Caulobacter crescentus and other organisms, more research is needed to elucidate mechanisms that govern substrate specificity. In the second chapter of this thesis, I will elaborate on how AAA+ substrate specificity is less rigid than previous work has suggested and how limiting ATP or mutations can alter substrate preferences of the ClpXP protease. In the third chapter, I will highlight our efforts to use a quantitative proteomics …


Intracellular Delivery Of Therapeutic Biomolecules Through Versatile Polymer Nanotechnology, David C. Luther Oct 2022

Intracellular Delivery Of Therapeutic Biomolecules Through Versatile Polymer Nanotechnology, David C. Luther

Doctoral Dissertations

Advancing pharmaceutical technology has made it possible to treat diseases once considered ‘undruggable.’ Access to these new pharmaceutical targets is possible thanks to the advent of protein and nucleic acid therapeutics. Responses to the COVID-19 pandemic, as well as cutting-edge treatments for cancer and multiple sclerosis have centered on these biologic therapies, promising even greater value in the future. However, their utility is limited at a cellular level by inability to cross the plasma membrane. Nanocarrier technologies encapsulate therapeutics and facilitate uptake into the cell but are often trapped and degraded in endosomes. Arginine-functionalized gold nanoparticles (Arg-NPs) provide efficient, direct …


Investigation Of Kinase Conformational Dynamics And Analytes Detection With Protein Nanopore, Fanjun Li Oct 2022

Investigation Of Kinase Conformational Dynamics And Analytes Detection With Protein Nanopore, Fanjun Li

Doctoral Dissertations

Protein nanopores are pore-forming proteins which have been developed as single-molecule biosensors. Due to the high sensitivity, selectivity, label-free and real-time detection methodology, protein nanopores have been used for a wide variety of applications. In this dissertation, we use ClyA nanopore to investigate kinase conformational dynamics and develop a kinase/nanopore system for the specific detection of kinase allosteric inhibitors. Besides, we engineer OmpG nanopore to be a sensor for nucleic acid detection. Protein kinases play essential roles in cellular regulation by catalyzing the phosphorylation of target proteins and are promising drug targets. The conformational dynamics are critical for kinase functions. …


Flexible Phenotypes, Energetics, And Whole-Animal Performance Of Migratory Songbirds, Michael Griego Oct 2022

Flexible Phenotypes, Energetics, And Whole-Animal Performance Of Migratory Songbirds, Michael Griego

Doctoral Dissertations

Animal life has evolved innumerable strategies to adapt to a great range of environmental conditions present on earth. The physiology of free-living animals has thus been shaped to allow for maximal performance under challenging conditions and has given rise to traits that enable animals to overcome daunting ecological pressures. Few life history stages in the animal kingdom rival the intensity of annual avian migration: the extreme metabolic requirements of long-distance flight coupled with navigating vast and hostile ecological barriers results in enormously high mortality for young birds. It is therefore the main focus of this thesis to identify physiological traits …


Biomedical Applications Of Protein Films And Polymeric Nanomaterials, Sanjana Gopalakrishnan Oct 2022

Biomedical Applications Of Protein Films And Polymeric Nanomaterials, Sanjana Gopalakrishnan

Doctoral Dissertations

Biomaterials are widely applied for the diagnosis and treatment of numerous diseases. In addition to fulfilling specific biological functions, biomaterials must also be non-toxic, biocompatible, and sterilizable to be regarded as safe-for-use. Polymers are excellent candidates for fabricating functional biomaterials due to their wide availability and varied properties and may be natural or synthetic. Polymer precursors are fabricated into coatings, foams, scaffolds, gels, composites, and nanomaterials for several biomedical applications. This dissertation focuses on two types of polymeric biomaterials – protein-based materials and synthetic polymeric nanoparticles. Proteins are biopolymers that naturally occur with a variety of structural and functional properties. …


Constraints Of The Imagination: How Phenotypes Are Shaped Through Genetics, The Environment, And Development, Michelle Gilbert Oct 2022

Constraints Of The Imagination: How Phenotypes Are Shaped Through Genetics, The Environment, And Development, Michelle Gilbert

Doctoral Dissertations

Phenotypic constraints are ubiquitous throughout nature, being found throughout all stages of life and at multiple different biological levels including cellular, genetic, environmental, behavioral, evolutionary, and developmental. These constraints have shaped, not only the natural world, but the way that we perceive what is possible, or impossible, an observation made clear by François Jacob in his 1977 paper “Evolution and Tinkering”. This is reflected in the literature, repeatedly, by the regular occurrence of densely packed visualization of phenotypic space that seemingly always have large areas that go unoccupied. Despite constrained regions of space being observable across countless taxa, identifying the …


Analysis Of Food Colorants Using Raman Spectroscopy, Haochen Dai Oct 2022

Analysis Of Food Colorants Using Raman Spectroscopy, Haochen Dai

Doctoral Dissertations

Color is one of the most important quality attributes that affect consumers' selection of food. The increasing demand of consumers for natural colorants over artificial ones has placed challenges in both product development and regulatory practices. However, current analytical solutions for food colorants are mostly limited to a sophisticated laboratory setting with tedious sample preparation procedures. Herein, this research focuses on the analytical developments toward cost-effective determination of colorant adulteration and stability analysis. The main technique explored is Raman spectroscopy, which measures the inelastic light scattering and allows one to obtain unique molecular fingerprints for specific molecules. Compared with chromatographic …


Novel Approaches For Preventing Lipid Oxidation In Emulsion-Based Food Systems, Mitchell D. Culler Oct 2022

Novel Approaches For Preventing Lipid Oxidation In Emulsion-Based Food Systems, Mitchell D. Culler

Doctoral Dissertations

Consumer interest in “clean” labels has continued to be a key driver of consumer behavior and purchasing habits over the past decade. Food manufacturers are therefore eager to replace synthetic antioxidants such as ethylenediaminetetraacetic acid (EDTA) with natural alternatives, however alternative chelators that will bind iron at low pH remain elusive. Coupled with the current oil shortages and supply chain challenges that have arisen recently, there is an urgent need for innovative solutions to increase the oxidative stability of edible oils. One available strategy is diluting oils high in unsaturated fatty acids into more stable, more saturated oils, thus delaying …


Ecology And Phytochemistry Of The Non-Native Plant Thlaspi Arvense (Brassicaceae) In Subalpine Meadows Of Colorado, Usa, Elsa Cousins Oct 2022

Ecology And Phytochemistry Of The Non-Native Plant Thlaspi Arvense (Brassicaceae) In Subalpine Meadows Of Colorado, Usa, Elsa Cousins

Doctoral Dissertations

Climate change is altering ecosystems at multiple scales. Globally, warming temperatures and increasing irregularity of precipitation will have large scale impacts on species distribution and success. Locally, understanding species response to fine scale microhabitat variation can provide key insights into population adaptation. Non-native plants represent an opportunity to investigate population level response and adaptation to relatively novel combinations of biotic and abiotic environments. Subalpine meadows are at the intersection of biotic and abiotic change, as large-scale climatic shifts alter water and temperature regimes and species range shifts become increasingly common and larger in scale. This dissertation addresses these questions of …