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University of Massachusetts Amherst

2020

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Articles 31 - 60 of 125

Full-Text Articles in Life Sciences

Fear, Parental Behavior, And Community Structure In Residential Lands, Aaron M. Grade Sep 2020

Fear, Parental Behavior, And Community Structure In Residential Lands, Aaron M. Grade

Doctoral Dissertations

In an urbanizing world, residential lands present an opportunity for conservation of biodiversity right in our backyards. Informed conservation necessitates a mechanistic understanding of how development influences animal populations and communities. Birds nesting in residential lands are less productive in urban yards than rural yards. Urban yards also have higher densities of potential predators, but lower per capita predation, indicating that direct predation is not entirely responsible for lack of productivity. I suggest that fear effects, also known as non-lethal effects, could be a mechanism by which predators exert indirect influence on bird parental behavior and nestling condition in urban …


The Comparison Of Functional And Physical Properties Of Commercial Pulse Proteins To Soy Protein, Kai Kai Ma Sep 2020

The Comparison Of Functional And Physical Properties Of Commercial Pulse Proteins To Soy Protein, Kai Kai Ma

Masters Theses

There has been growing interest in the utilization of plant-derived proteins as functional ingredients in many food and beverage applications because they are perceived as being more sustainable, healthy, and ethical than animal-derived proteins by many consumers. Traditionally, soy proteins have been the most widely employed plant protein in the food industry. However, a number of alternative plant-based protein sources have recently become available, with pulse proteins being one of the most popular. In this study, the physicochemical properties and functional attributes of various commercially available pulse protein isolates were compared with those of soy protein isolate to evaluate their …


Anti-Inflammatory Effect Of Red Seaweed Extracts, Yingying Yang Sep 2020

Anti-Inflammatory Effect Of Red Seaweed Extracts, Yingying Yang

Masters Theses

Red seaweeds are reported to represent the largest group of algae, with more species accounted for than the combination of brown and green seaweeds. Due to the high amount of polysaccharides in red seaweeds, they are mainly utilized for commercial agar and carrageenan production in industry. However, increasing studies indicate other valuable compounds such as lipids and polyphenols could be potential utilized for multiple human needs (e.g., drug development) (1, 2). With increasing studies demonstrating the potential health benefits of seaweed components, two red seaweed species commonly consumed in Asia, hong qı´ lı´n c a`i (HQL), Eucheuma sp and zhe` …


2020 Pesticide Safety August 20: 2020 Pathology Review, Sai Sree Uppala Aug 2020

2020 Pesticide Safety August 20: 2020 Pathology Review, Sai Sree Uppala

Cranberry Station Extension meetings

No abstract provided.


2020 Pesticide Safety August 20: Insect Review, Anne Averill Aug 2020

2020 Pesticide Safety August 20: Insect Review, Anne Averill

Cranberry Station Extension meetings

No abstract provided.


2020 Pesticide Safety August 20: Newest Insects Of The Day (Scale,Golden Casebearer), Martha Sylvia Aug 2020

2020 Pesticide Safety August 20: Newest Insects Of The Day (Scale,Golden Casebearer), Martha Sylvia

Cranberry Station Extension meetings

No abstract provided.


2020 Pesticide Safety August 20: Fumigants, Slns, Roundup, Japanese Knotweed, And Kerb Update, Hilary A. Sandler Aug 2020

2020 Pesticide Safety August 20: Fumigants, Slns, Roundup, Japanese Knotweed, And Kerb Update, Hilary A. Sandler

Cranberry Station Extension meetings

No abstract provided.


2020 Pesticide Safety August 18: Wps, Safety And Pesticide Restrictions In 2020, Martha Sylvia Aug 2020

2020 Pesticide Safety August 18: Wps, Safety And Pesticide Restrictions In 2020, Martha Sylvia

Cranberry Station Extension meetings

No abstract provided.


2020 Pesticide Safety August 18: Compare Your Pesticide Usage?, Martha Sylvia Aug 2020

2020 Pesticide Safety August 18: Compare Your Pesticide Usage?, Martha Sylvia

Cranberry Station Extension meetings

No abstract provided.


2020 Pesticide Safety August 18: Ipm For Tick Management, Blake Dinius Aug 2020

2020 Pesticide Safety August 18: Ipm For Tick Management, Blake Dinius

Cranberry Station Extension meetings

No abstract provided.


2020 Pesticide Safety August 18: Zeus, Callisto And Clethodim, Katherine Ghantous Aug 2020

2020 Pesticide Safety August 18: Zeus, Callisto And Clethodim, Katherine Ghantous

Cranberry Station Extension meetings

No abstract provided.


2020 Pesticide Safety August 18: Chemigation Review, John Mason Aug 2020

2020 Pesticide Safety August 18: Chemigation Review, John Mason

Cranberry Station Extension meetings

No abstract provided.


Interacting Effects Of Climate And Biotic Factors On Mesocarnivore Distribution And Snowshoe Hare Demography Along The Boreal-Temperate Ecotone, Alexej P. Siren Jul 2020

Interacting Effects Of Climate And Biotic Factors On Mesocarnivore Distribution And Snowshoe Hare Demography Along The Boreal-Temperate Ecotone, Alexej P. Siren

Doctoral Dissertations

The motivation of my dissertation research was to understand the influence of climate and biotic factors on range limits with a focus on winter-adapted species, including the Canada lynx (Lynx canadensis), American marten (Martes americana), and snowshoe hare (Lepus americanus). I investigated range dynamics along the boreal-temperate ecotone of the northeastern US. Through an integrative literature review, I developed a theoretical framework building from existing thinking on range limits and ecological theory. I used this theory for my second chapter to evaluate direct and indirect causes of carnivore range limits in the northeastern US, …


Depolymerizable And Dissipative Chemical Systems: Role In Material Synthesis And Applications, Vikash Kumar Jul 2020

Depolymerizable And Dissipative Chemical Systems: Role In Material Synthesis And Applications, Vikash Kumar

Doctoral Dissertations

Biomimetic systems which can show a functional response when treated with external stimuli are advantageous in applications such as self-healing, drug delivery, diagnostic and sensing. Depolymerizable and dissipative chemical systems are ideal tools to synthesize biomimetic systems that mimic nature. While there is abundance of synthetic chemistry tools to design depolymerizable systems, there is a lack of synthetic and formulation methodologies for developing useful materials from them. Majority of this thesis is directed towards narrowing that gap in knowledge, by utilizing depolymerizable systems to synthesize useful materials such as hydrogel and polyelectrolyte complexes for applications including self-healing, drug delivery and …


Origin Of Gene Specificity In The Nitrogen-Fixing Symbiosis, Christina Marie Stonoha-Arther Jul 2020

Origin Of Gene Specificity In The Nitrogen-Fixing Symbiosis, Christina Marie Stonoha-Arther

Doctoral Dissertations

Many legumes form a symbiosis with nitrogen-fixing bacteria found in the soil. This relationship is beneficial to both the plant and the bacteria; the plant receives nitrogen that is otherwise limited, and the bacteria receive fixed carbon. Upon sensing the bacteria, the plant forms a new organ (the nodule) where the bacteria are housed within the cells. Many genes are required for the proper formation and function of nodules; this dissertation is broadly focused on how genes required for nitrogen-fixing symbiosis are co-opted from other cellular processes and how they are specialized for symbiosis. Protein trafficking from the plant to …


Dissecting Regulatory Mechanisms Of Quorum Sensing Pathways In Bacillus Subtilis, Patrick Hill Jul 2020

Dissecting Regulatory Mechanisms Of Quorum Sensing Pathways In Bacillus Subtilis, Patrick Hill

Doctoral Dissertations

Living organisms generally share a small number of characteristics, among which include maintaining homeostasis, growth, and responding to changing environments. Wherever we find life, we typically observe this life performing these tasks. Likely no environment is truly barren, so organisms must be able to continue living in crowded conditions. Humans use their senses to determine the quality of their local environment. Individuals use languages, written, spoken and digital to communicate these findings to their neighbors. Bacteria have evolved complex systems to sense these conditions, and to trigger appropriate developmental programs to help them survive, grow, and respond in changing environments. …


Physiology Of A Basal Vertebrate, The Sea Lamprey (Petromyzon Marinus): Osmoregulation And Corticosteroid Action, Ciaran A. S. Shaughnessy Jul 2020

Physiology Of A Basal Vertebrate, The Sea Lamprey (Petromyzon Marinus): Osmoregulation And Corticosteroid Action, Ciaran A. S. Shaughnessy

Doctoral Dissertations

Lamprey represent the most basal living example of a vertebrate animal which regulates its internal fluid and ion homeostasis. This phylogenetic position among vertebrates makes lamprey an important model organism for understanding the basal state, and thus the evolution, of physiological systems such as the mechanisms of osmo- and ionoregulation and the endocrine factors controlling them. Sea lamprey (Petromyzon marinus) are an anadromous fish, migrating from freshwater (FW) to seawater (SW) as juveniles, then returning back upstream as mature adults to spawn. Surviving this transition from a solute-poor FW environment to a solute-concentrated SW environment requires many changes …


Hedgehog Signaling (Hh/Gli) Regulates Neurogenesis In The Zebrafish Hypothalamus, Ira Male Jul 2020

Hedgehog Signaling (Hh/Gli) Regulates Neurogenesis In The Zebrafish Hypothalamus, Ira Male

Doctoral Dissertations

The hypothalamus is the central regulator of a diverse homeostatic processes that are essential for the survival of the animal. Recently, the hypothalamus has been shown to be a neurogenic zone in many animal species including mice, zebrafish, sheep and potentially even humans with hypothalamic neurogenesis implicated in energy metabolism, stress, anxiety and reproduction. However, the identification of the cellular components and the signaling mechanisms regulating hypothalamic neurogenesis are only beginning to be elucidated. My dissertation research elucidates the role of Hh signaling in regulating hypothalamic neurogenesis throughout life. The first chapter of the dissertation offers a survey into the …


How Do Adult Songbirds Learn New Sounds? Using Neuromodulators To Probe The Function Of The Auditory Association Cortex, Matheus Macedo-Lima Jul 2020

How Do Adult Songbirds Learn New Sounds? Using Neuromodulators To Probe The Function Of The Auditory Association Cortex, Matheus Macedo-Lima

Doctoral Dissertations

The ability to associate sounds and outcomes is vital in the life history of many species. Animals constantly assess the soundscape for cues associated with threats, competitors, allies, mates or prey, and experience is crucial for those associations. For vocal learning species such as humans and songbirds, learning sounds (i.e. perception and association learning) is also the first step in the process of vocal learning. Auditory learning is thought to depend on high-order cortical brain structures, where sounds and meaning are bound. In songbirds, the caudomedial nidopallium (NCM) is part of the auditory association cortex and is known to be …


Structure Function Analysis Of Mitochondrial Dna Polymerase Ic Reveals Multiple Roles In Kinetoplast Maintenance, Jonathan Miller Jul 2020

Structure Function Analysis Of Mitochondrial Dna Polymerase Ic Reveals Multiple Roles In Kinetoplast Maintenance, Jonathan Miller

Doctoral Dissertations

Kinetoplastid organisms including medically relevant species like Trypanosoma brucei, Trypanosoma cruzi, and Leishmania are distinguished by their single flagellum and unique mitochondrial DNA called kDNA, among other features. While there is heterogeneity in copy number and sequence classes among different species, kDNA is most often found as a network of thousands of DNA molecules catenated together. This unique biological property of disease-causing organisms has been a subject of study as a potential drug target since it is essential for parasite survival. Trypanosoma brucei is the causative agent of African Sleeping Sickness in humans and related diseases in other mammals and …


Accessory Genes Contribute To Rewiring The Transcriptional Network In Fusarium Oxysporum, He Yang Jul 2020

Accessory Genes Contribute To Rewiring The Transcriptional Network In Fusarium Oxysporum, He Yang

Doctoral Dissertations

The presence of accessory chromosomes is one of the most fascinating features in the genomes of Fusarium oxysporum (Fo) species complex that includes both plant and animal pathogens. In plant-pathogenic Fo strains, these accessory chromosomes govern host-specific pathogenicity through unique sets of virulence factors, including secreted effectors and plant cell wall degrading enzymes, while the identity of such factors are largely unknown in human infecting strains. This dissertation is composed of three projects that focused on studying the gene composition and transcriptional regulation of human-pathogenic Fo strains. The first project deciphered the genome of the clinical Fo strain, …


Design And Fabrication Of Colloidal Delivery Systems To Encapsulate And Protect Curcumin: An Important Hydrophobic Nutraceutical, Mahesh Kharat Jul 2020

Design And Fabrication Of Colloidal Delivery Systems To Encapsulate And Protect Curcumin: An Important Hydrophobic Nutraceutical, Mahesh Kharat

Doctoral Dissertations

Curcumin is a polyphenolic compound found in Turmeric (Curcuma longa) rhizome that has excellent biological benefits such as antioxidant, anti-inflammatory, and anti-cancer properties to name a few. However, its incorporation in food and pharmaceuticals is difficult due to low water solubility and chemical instability. This study focuses on developing colloidal delivery systems for efficient encapsulation and increased protection of curcumin for maximizing the proposed health benefits of curcumin. It was found that the physical and chemical stability of pure curcumin is impacted by pH, storage temperature, and molecular environment both in aqueous solutions and in oil-in-water emulsions. Pure …


Elucidating Mechanisms Of Metastasis With Implantable Biomaterial Niches, Ryan Adam Carpenter Jul 2020

Elucidating Mechanisms Of Metastasis With Implantable Biomaterial Niches, Ryan Adam Carpenter

Doctoral Dissertations

Metastasis is the leading cause of cancer related deaths, yet it remains the most poorly understood aspect of tumor biology. This can be attributed to the lack of relevant experimental models that can recapitulate the complex and lengthy progression of metastatic relapse observed in patients. Mouse models have been widely used to study cancer, however they are critically limited to study metastasis. Most models generate aggressive metastases in the lung without the use of unique cell lines or specialized injection techniques. This limits the ability to study disseminated tumor cells (DTCs) in other relevant metastasis prone tissues. Prolonged observation of …


Redox Signaling In The Zebrafish Embryo And Implications For Endocrine Pancreas Morphogenesis, Archit Rastogi Jul 2020

Redox Signaling In The Zebrafish Embryo And Implications For Endocrine Pancreas Morphogenesis, Archit Rastogi

Doctoral Dissertations

The glutathione (GSH) system evolved to combat oxygen toxicity in nearly all living organisms, and serves as the predominant cellular redox buffer in vertebrates. This dissertation explores the roles of GSH during embryogenesis using the zebrafish (Danio rerio). The first agnostic in vivo characterization of GSH utilization in the embryo revealed strict spatiotemporal GSH profiles in developing organ systems. Interruption of these GSH profiles by exogenous xenobiotics led to organ specific adverse developmental outcomes; pancreatic β-cells were found to be especially susceptible and developed atypical morphologies following redox active xenobiotic exposures. Pancreatic β-cells lacked expression of Nrf2a (Nuclear …


Improved Molecular Diagnostics For Soil-Transmitted Helminths, Nils Pilotte Jul 2020

Improved Molecular Diagnostics For Soil-Transmitted Helminths, Nils Pilotte

Doctoral Dissertations

Current World Health Organization recommendations for the diagnosis of soil-transmitted helminths (STH) rely on antiquated microscopy-based techniques that lack both diagnostic sensitivity and specificity. While sufficient for providing rough estimates of infection frequency and intensity within high prevalence settings, these techniques lack the capacity to effectively estimate infection levels following successful intervention efforts, as worm burdens decline and community prevalences decrease. Furthermore, an expanding body of evidence is suggesting that microscopy-based misdiagnosis of infection is likely a larger concern then previously believed. As such, with an increase in programmatic support for transmission interruption and an escalating belief in the possibility …


Structural Analysis Of Protein Therapeutics Using Covalent Labeling – Mass Spectrometry, Patanachai Limpikirati Jul 2020

Structural Analysis Of Protein Therapeutics Using Covalent Labeling – Mass Spectrometry, Patanachai Limpikirati

Doctoral Dissertations

Using mass spectrometry (MS) to obtain information about a higher order structure of protein requires that a protein’s structural properties are encoded into the mass of that protein. Covalent labeling (CL) with reagents that can irreversibly modify solvent accessible amino acid side chains is an effective way to encode structural information into the mass of a protein, as this information can be read-out in a straightforward manner using standard MS-based proteomics techniques. The differential reactivity of proteins under two or more conditions can be used to distinguish protein topologies, conformations, and/or binding sites. CL-MS methods have been effectively used for …


Involvement Of Calcium-Dependent Protein Kinases And Phosphatases In Sperm Capacitation-Associated Events, Bidur Paudel Jul 2020

Involvement Of Calcium-Dependent Protein Kinases And Phosphatases In Sperm Capacitation-Associated Events, Bidur Paudel

Doctoral Dissertations

ABSTRACT To acquire fertilizing ability, mammalian sperm undergo a series of biochemical and physiological changes collectively known as capacitation1,2. At the molecular level, capacitation is associated with a fast bicarbonate (HCO3-)-dependent activation of a unique type of soluble adenyl cyclase (sAC) and a consequent increase in cyclic AMP (cAMP) levels and PKA activation3. Activation of a cAMP/PKA pathway results in the phosphorylation of PKA substrates, which in turn initiates activation of several signaling cascades ultimately leading to an increase in phosphorylation on tyrosine residues (P-Tyr) of sperm axonemal proteins4,5. Increase in …


Lmea, A Conserved Cell-Envelope Protein In Mycobacteria, Is Important For Antibiotic Resistance And Cell Envelope Permeability, Sarah Hassan Osman Jul 2020

Lmea, A Conserved Cell-Envelope Protein In Mycobacteria, Is Important For Antibiotic Resistance And Cell Envelope Permeability, Sarah Hassan Osman

Masters Theses

The cell envelope of mycobacteria is critical for the survival and virulence of pathogenic species during infection, and its biosynthesis has been a proven drug target. Therefore, finding new targets in the biosynthetic pathway of cell envelope components is of great interest. Mycobacterium smegmatis is a model organism for the study of the devastating pathogen Mycobacterium tuberculosis. Previously, lipomannan elongation factor A (LmeA) has been identified as a cell envelope protein that is critical for the control of mannan chain length of lipomannan (LM) and lipoarabinomannan (LAM), lipoglycan components of the cell envelope. The deletion mutant, ∆lmeA, accumulates abnormal LM/LAM …


Development Of Headspace Analysis Of Living And Postharvest Fresh Produce Using Surface-Enhanced Raman Spectroscopy (Sers), Xinyi Du Jul 2020

Development Of Headspace Analysis Of Living And Postharvest Fresh Produce Using Surface-Enhanced Raman Spectroscopy (Sers), Xinyi Du

Masters Theses

The increasing market demand for fresh produce promotes a keen interest in developing a rapid, sensitive and reliable method for monitoring plant health and determining the shelf-life of postharvest produce. The objective of this study is to explore the capability of Surface-enhanced Raman spectroscopy (SERS) in these applications. SERS integrates Raman spectroscopy which measures molecular vibrations and nanotechnology which enhances the weak Raman signals. Herein, we developed two SERS methods based on a surface detection approach using nanoparticles solution and a headspace detection approach using gold nanoparticles (AuNPs) fibers, to detect biochemical changes during postharvest storage of arugula leaves. Compared …


Autonomous Recording Units As An Alternative Method For Monitoring Songbirds, Lindsay Clough Jul 2020

Autonomous Recording Units As An Alternative Method For Monitoring Songbirds, Lindsay Clough

Masters Theses

There is an increasing interest in the use of autonomous recording units as an alternative survey method to point count surveys conducted by human observers; however, questions remain about whether or not these recording units perform similarly to point count surveys and produce valid, comparable results. The use of individual listeners to transcribe the acoustic data collected by autonomous recording units is a common method for the analysis of recorded acoustic data, but potential variability among transcribers raises questions about the standardization of listening protocols to decrease inconsistencies in transcription results.

Autonomous recording units have been used to monitor birds …