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Full-Text Articles in Life Sciences

Functionalized Electrospun Nanofibers For Food Science Applications, Minhui Dai Jul 2016

Functionalized Electrospun Nanofibers For Food Science Applications, Minhui Dai

Doctoral Dissertations

This work is separated into two individual parts. The first part demonstrates the ability to electrospin reagents into water-soluble nanofibers resulting in a stable on-chip enzyme and a microphage storage format.

1a) Polyvinylpyrrolidone (PVP) nanofibers were spun incorporating the enzyme horseradish peroxidase (HRP). Scanning electron microscopy of the spun nanofibers was used to confirm the non-woven structure with an average diameter of 155±34 nm. The HRP containing fibers were tested for a change in activity following electrospinning and during storage. A colorimetric assay was used to characterize the activity of HRP reacting with the nanofiber mats in a microtiter ...


Inhibition Of Dna Methylation In Acquired Tamoxifen-Resistant Breast Cancer: Cell Line Model And Clinical Implications, Stephanie Zimmers Jul 2016

Inhibition Of Dna Methylation In Acquired Tamoxifen-Resistant Breast Cancer: Cell Line Model And Clinical Implications, Stephanie Zimmers

Doctoral Dissertations

One out of every eight American women will develop invasive breast cancer throughout their lifetime. Approximately 70% of breast cancers are estrogen receptor alpha (ER)-positive and can therefore be treated with an anti-estrogen such as tamoxifen. Although tamoxifen treatment has been successful at reducing breast cancer death rates, nearly one-third of women treated with tamoxifen for 5 years will have disease recurrence. Therefore, it is imperative that researchers investigate the mechanisms involved in developing acquired tamoxifen resistance and identify biomarkers that are predictive of acquired resistance.

DNA methylation is known to play a role in the development of breast ...


Spider Brain Morphology & Behavior, Skye M. Long Jul 2016

Spider Brain Morphology & Behavior, Skye M. Long

Doctoral Dissertations

Spiders are ideal model animals for experimental and comparative studies of behavior, learning and perception. They display many complex behaviors, such as the multimodal mating dances of lycosid spiders, the stealthy hunting strategies of the jumping spider Portia sp., to the labile sociality of theridiids. Spiders also demonstrate a wide range of cognitive capabilities. Spiders perceive their environment using multiple sensory modalities including: chemosensory organs; lyriform and slit-sense organs and specialized hairs that detect vibration and air movement; and up to eight eyes that vary in function, some able to detect polarization and a broad spectrum of light, including ultraviolet ...


Alternative Methods For The Treatment Of Chemo-Resistant Cancers, Kaitlyn Wong Jul 2016

Alternative Methods For The Treatment Of Chemo-Resistant Cancers, Kaitlyn Wong

Doctoral Dissertations

Great strides have been made in cancer therapy in the past century, yet it remains one of the leading causes of death in the United States today. This work aimed to shed light on novel methods to treat a variety of aggressive and often chemo-resistant cancers both in vitro and in vivo.

The first aim of this work was to evaluate the therapeutic efficacy of poly(methacryloyloxyethyl phosphorylcholine) (polyMPC) prodrugs compared to standard chemotherapeutic agents. Conjugation of polyMPC to drugs such as doxorubicin (Dox) can result in its improved solubility, prolonged half-life and therapeutic efficacy. PolyMPC and polyMPC-Dox (at a ...


Macronutrients And The Risk Of Premenstrual Syndrome, Serena C. Houghton Jul 2016

Macronutrients And The Risk Of Premenstrual Syndrome, Serena C. Houghton

Doctoral Dissertations

Premenstrual syndrome (PMS) affects 8-20% of reproductive-aged women, impacting work, family, and social interactions. Limitations in available PMS treatments, including side effects and limited medication efficacy, indicate the need for improved prevention. Modifiable risk factors for prevention of PMS include dietary factors. Several micronutrients have been identified as risk factors, but there has been little evaluation of macronutrients. Thus, the research aim was to examine prospectively whether macronutrient consumption was associated with PMS development among a subset of women enrolled in the Nurses’ Health Study II cohort.

Chapter 1 evaluates the association of fat intake and PMS risk. Among 3 ...


Morphological And Material Effects In Van Der Waals Interactions, Jaime C. Hopkins Jul 2016

Morphological And Material Effects In Van Der Waals Interactions, Jaime C. Hopkins

Doctoral Dissertations

Van der Waals (vdW) interactions influence a variety of mesoscale phenomena, such as surface adhesion, friction, and colloid stability, and play increasingly important roles as science seeks to design systems on increasingly smaller length scales. Using the full Lifshitz continuum formulation, this thesis investigates the effects of system materials, shapes, and configurations and presents open-source software to accurately calculate vdW interactions.

In the Lifshitz formulation, the microscopic composition of a material is represented by its bulk dielectric response. Small changes in a dielectric response can result in substantial variations in the strength of vdW interactions. However, the relationship between these ...


Novel Advancements For Improving Sprout Safety, Kyle S. Landry Jul 2016

Novel Advancements For Improving Sprout Safety, Kyle S. Landry

Doctoral Dissertations

All varieties of bean sprouts (mung bean, alfalfa, broccoli, and radish) are classified as a “super-food” and are common staples for health conscious consumers. Along with the proposed health benefits, there is also an inherent risk of foodborne illness. When sprouts are cooked, there is little risk of illness. The purpose of this dissertation was to explore novel techniques to minimize or prevent the incidence of foodborne illness associated with the consumption of sprouts. Three areas were investigated: 1) the use of a biocontrol organism, 2) the use of a novel spontaneous carvacrol nanoemulsion, and 3) the influence of the ...


The Role Of The Formin Protein Family In Membrane Dynamics, Petrus Adrianus Cornelis Van Gisbergen Jul 2016

The Role Of The Formin Protein Family In Membrane Dynamics, Petrus Adrianus Cornelis Van Gisbergen

Doctoral Dissertations

Using molecular genetics, and high end imaging techniques, I assessed the function of the formin protein family in the moss Physcomitrella patens. Formins are proteins that can nucleate and elongate actin filaments. P. patens has 9 formins, divided over three classes. I found that a class II formin (For2A) is essential for polarized growth and specifically binds to the phosphoinositide PI(3,5)P2. Additionally, I show that this formin polymerizes actin filaments in vivo. I demonstrated that binding PI(3,5)P2 is essential for formin function.

My work also shows that one of the class I ...


The Meat-Farming Ants: Predatory Mutualism Between Melissotarsus Ants (Hymenoptera: Formicidae) And Armored Scale Insects (Hemiptera: Diaspididae), Scott A. Schneider Jul 2016

The Meat-Farming Ants: Predatory Mutualism Between Melissotarsus Ants (Hymenoptera: Formicidae) And Armored Scale Insects (Hemiptera: Diaspididae), Scott A. Schneider

Doctoral Dissertations

Ant agricultural mutualisms are common, well studied, and receive attention from scientific and public spheres due to shared similarities with human agriculture (i.e. ant/fungus ‘crop farming’ and ant/insect ‘dairy farming’). They also serve as important model systems for studying many facets of mutualism. This study reveals that the repertoire of ant agriculture may also include ‘meat farming’. Predatory mutualisms occur between Melissotarsus ants and various species of armored scale insects. This dissertation employs a multi-disciplinary approach to investigate the evolutionary history and nature of ant/diaspidid mutualisms. Chapter 1 reviews the current state of knowledge regarding species ...


Synthesis And Applications Of Non-Migratory Metal Chelating Active Packaging, Maxine J. Roman Jul 2016

Synthesis And Applications Of Non-Migratory Metal Chelating Active Packaging, Maxine J. Roman

Doctoral Dissertations

Many packaged foods use synthetic chelators (e.g. ethylenediaminetetraacetic acid, EDTA) to inhibit metal promoted oxidation and/or microbial growth that may cause food spoilage. Consumer demand for foods without synthetic additives has prompted growing interest in alternative preservation methods. Our research group has previously developed non-migratory metal chelating active packaging materials by surface immobilization of polymeric chelators and demonstrated their ability to inhibit lipid oxidation in model food emulsions. The work presented in this dissertation investigates the synthesis, performance stability, and practical application of metal chelating surface modifications to optimize design of non-migratory metal chelating active packaging materials.

Metal ...


Enzyme Stabilization In Hierarchical Biocatalytic Food Packaging And Processing Materials, Dana Erin Wong Jul 2016

Enzyme Stabilization In Hierarchical Biocatalytic Food Packaging And Processing Materials, Dana Erin Wong

Doctoral Dissertations

The partnership of biocatalysts and solid support materials provides many opportunities for bioactive packaging and bioprocessing aids beneficial to the agricultural and food industries. Biocatalysis, or reactions modulated by enzymes, allows bioactive materials to assist in bringing a substrate to product. Enzymes are proteins which catalyze reactions by lowering the activation energy required to drive the production of a desired product. Enzymes are commonly utilized in food processing as catalysts with specificity in order to enhance product quality through the production of beneficial food components, and to break down undesirable components that may be harmful or may decrease product quality ...


Chemically Mediated Interactions Between Hosts, Parasitic Plants And Insect Herbivores, Muvari C. Tjiurutue Jul 2016

Chemically Mediated Interactions Between Hosts, Parasitic Plants And Insect Herbivores, Muvari C. Tjiurutue

Doctoral Dissertations

Species interactions, by changing phenotypic traits, can alter the outcome of subsequent interactions. Plant-mediated responses to herbivores have been extensively studied, but little is known about plant-mediated responses involving parasitic plants within a broader community context that also includes herbivores. Because parasitic plants are important components of many ecosystems and can shape community structure, it is important to understand how host-mediated interactions influence parasite preference and success. The goal of this thesis is to examine interactions between hosts, parasitic plants and herbivores mediated by chemical traits. We first examined the effects of dodder (Cuscuta sp.) parasitism on induced defenses in ...


Feasibility Of A Combined Physical Activity And Sleep Education Intervention For Girls Living In A Low Socioeconomic Status Urban Community, Cory J. Greever Jul 2016

Feasibility Of A Combined Physical Activity And Sleep Education Intervention For Girls Living In A Low Socioeconomic Status Urban Community, Cory J. Greever

Doctoral Dissertations

Declining sleep duration and poor sleep quality is a public health epidemic disproportionately effecting elementary age girls living in low socioeconomic status urban communities. The Girls Dancing and Sleeping for Health (Girls DASH) program was designed to test the feasibility, acceptability, and efficacy of a combined physical activity and sleep education program in this population. In combination with baseline data from a previously conducted intervention in elementary age urban girls living in a low SES community in Springfield, MA, results from a cross-sectional analysis indicated that greater screen time was positively associated with parental reports of child’s sleep quality ...


Photolysis Of Triazenylbenzoic Acids For Click Chemistry, Adam Gann Jul 2016

Photolysis Of Triazenylbenzoic Acids For Click Chemistry, Adam Gann

Doctoral Dissertations

Copper catalyzed cycloaddition of terminal alkynes and azides has revolutionized the field of bioconjugate chemistry. Unfortunately, typical copper catalysts are known to disrupt relevant biological systems, so it has become necessary to develop new, copper-free methods that are less cytotoxic. particular interest are "click" probes which can be activated with an outside light source, giving the user spatial and temporal control over the system being investigated. We have developed a method in which an aryl diazonium salt is rapidly generated using photolysis of the triazene functional group, and subsequently coupled with an electron rich aromatic nucleophile to yield an azobenzene ...


Bioengineered Platforms To Study Carcinoma Cell Response To Drug Treatment, Thuy V. Nguyen Jul 2016

Bioengineered Platforms To Study Carcinoma Cell Response To Drug Treatment, Thuy V. Nguyen

Doctoral Dissertations

The tumor extracellular matrix (ECM) plays an important role in facilitating tumor growth and mediating tumor cells' resistance to drugs. However, during drug development, potential chemotherapeutics are screened in plastic plates, which lack relevant ECM physicochemical cues. In order to improve drug development process, this dissertation includes the development of relevant 2D and 3D biomaterial systems that can be used to study carcinoma cell response to drug treatment.

A novel poly(ethylene glycol)-phosphorylcholine (PEG-PC) high-throughput biomaterial platform was developed to study how the ECM mechanochemical properties affect cancer cells' response to drug. The PEG-PC biomaterial is optically transparent, has ...


Spatial Ecology Of Great Barracuda (Sphyraena Barracuda) Around Buck Island Reef National Monument, St. Croix, U.S.V.I., Sarah L. Becker Jul 2016

Spatial Ecology Of Great Barracuda (Sphyraena Barracuda) Around Buck Island Reef National Monument, St. Croix, U.S.V.I., Sarah L. Becker

Masters Theses

Marine protected areas (MPAs) are increasing in popularity as a tool to manage fish stocks through conservation of entire habitats and fish assemblages. Quantifying the habitat use, site fidelity, and movement patterns of marine species is vital to this method of marine spatial planning. The success of these protected areas requires that sufficient habitat is guarded against fishing pressure. For large animals, which often have correspondingly large home range areas, protecting an entire home range can be logistically challenging. For MPAs to successfully protect large top predator species, it is important to understand what areas of a home range are ...


Conversion Of Cellulose To Ethanol By The Biofuels Microbe Clostridium Phytofermentans: Quantification Of Growth And Role Of An Rnf-Complex In Energy Conservation, Jesús G. Alvelo-Maurosa Jul 2016

Conversion Of Cellulose To Ethanol By The Biofuels Microbe Clostridium Phytofermentans: Quantification Of Growth And Role Of An Rnf-Complex In Energy Conservation, Jesús G. Alvelo-Maurosa

Doctoral Dissertations

The anaerobic mesophilic bacterium Clostridium phytofermentans grows and ferments multiple plant-based substrates into ethanol as the main product of fermentation. The capacity of C. phytofermentans to convert plant biomass into ethanol, propanol, and short-chain fatty acids is strongly attractive for industry. Specific physiological capabilities of C. phytofermentans allow the microbe to generate high amounts of ethanol compared to acetate. However, little is known about membrane energetics in C. phytofermentans, or its role in energy conservation and production of high levels of ethanol during fermentation of plant biomass substrates.

In the first research project presented in this dissertation, we examined C ...


Trophic Relationships Among Caribou Calf Predators In Newfoundland, Chris Zieminski Jul 2016

Trophic Relationships Among Caribou Calf Predators In Newfoundland, Chris Zieminski

Masters Theses

Using specially trained scat detection dogs we located fecal samples from black bear (Ursus americanus) and coyote (Canis latrans) throughout three study areas in Newfoundland, Canada, to describe these predators diet. Our sampling efforts were designed around seasons which were important to woodland caribou (Rangifer tarandus caribou) calving and resource use. We identified hairs microscopically to prey species and grouped other remains to facilitate our analysis. Bear exhibited an omnivorous diet throughout the study areas, ecological seasons and inside and outside the caribou calving grounds while coyote were limited to caribou, moose and snowshoe hare.


Curcumin And Its Oxidative Degradation Products: Their Comparative Effects On Inflammation, Julia Zhu Jul 2016

Curcumin And Its Oxidative Degradation Products: Their Comparative Effects On Inflammation, Julia Zhu

Masters Theses

The anti-inflammatory agent curcumin degrades rapidly, leading to speculations that curcumin’s reported effects stem from its degradation products. Curcumin can degrade via hydrolysis, and more recently it was discovered that curcumin can degrade via oxidation at physiological pH. Additionally, bicyclopentadione is the major degradation product from this oxidation reaction. Evidence from the literature suggests that curcumin degrades primarily through oxidation. However, the biology of the oxidation products is not well characterized, and there is debate on whether oxidation intermediates or curcumin itself is more biologically active. To further elucidate the biology of the oxidation products, their effects on inflammation ...


Enzymatic Digestion Improved Bacteria Separation From Leafy Green Vegetables, Danhui Wang Jul 2016

Enzymatic Digestion Improved Bacteria Separation From Leafy Green Vegetables, Danhui Wang

Masters Theses

An effective and rapid method for the separation of bacteria from food matrix remains a bottleneck for rapid bacteria detection for food safety. Bacteria can strongly attach to the food surface or internalize within the matrix which makes their isolation extremely difficult. Traditional methods of separating bacteria from foods routinely involve stomaching, blending and shaking, however these methods may not be efficient at removing all the bacteria from complex matrices. Here, we investigate the benefits of using enzyme digestion followed by immunomagnetic separation to isolate Salmonella from spinach and lettuce. Enzymatic digestion using pectinase and cellulase was able to break ...


Dynamics Of Microtubule Networks With Antiparallel Crosslinkers, Kasimira T. Stanhope Jul 2016

Dynamics Of Microtubule Networks With Antiparallel Crosslinkers, Kasimira T. Stanhope

Masters Theses

Microtubules are the most rigid element of the cytoskeleton. They are responsible for the structure of cells and make up the tracks for intracellular cargo transport. Interactions between microtubules, motor proteins, and microtubule-associated proteins drive important mechanisms in the cell, such as cell division, cell motility, cell homeostasis, and cell signaling. I seek to understand how such complex, energy-consuming non-equilibrium biological networks self-organize by studying in vitro microtubules bundled by microtubule-associated protein 65 (MAP65), in kinesin-1 gliding assays. I found that large networks can break into smaller, cell-like networks that can mimic types of cell motility. Dynamics of these networks ...


Primate Aesthetics, Chelsea L. Sams Jul 2016

Primate Aesthetics, Chelsea L. Sams

Masters Theses

A cultural, historical, and scientific survey of the phenomena of primate pictorial behavior, presented in a series of interconnected vignettes. What do primates find visually appealing? What is their motivation when creating images? What are the implications for art and for science? By drawing explicit and implicit connections between science, art, case studies, research, and personal narrative, I attempt to weave together what we know, and what we may never be able to know about this complex field.


Understory Plant Community Structure In Forests Invaded By Garlic Mustard (Alliaria Petiolata), Jason Aylward Jul 2016

Understory Plant Community Structure In Forests Invaded By Garlic Mustard (Alliaria Petiolata), Jason Aylward

Masters Theses

ABSTRACT

UNDERSTORY PLANT COMMUNITY STRUCTURE IN FORESTS INVADED BY GARLIC MUSTARD (ALLIARIA PETIOLATA)

MAY 2016

JASON ALLEN AYLWARD, B.S., PAUL SMITH’S COLLEGE

M.S. UNIVERSITY OF MASSACHUSETTS AMHERST

Directed by: Professor Kristina Stinson

Plant invasions represent a significant threat to the structure and function of natural ecosystems. Garlic mustard (Alliaria petiolata) has been identified as a threat to native communities mostly through small-scale studies and focused experiments. In this in situ observational study I examined the effects of garlic mustard invasion on species composition across multiple sites by comparing plant diversity and composition in invaded and adjacent non-invaded ...


Influence Of Hierarchical Interfacial Assembly On Lipase Stability And Performance In Deep Eutectic Solvent, Stephanie M. Andler Jul 2016

Influence Of Hierarchical Interfacial Assembly On Lipase Stability And Performance In Deep Eutectic Solvent, Stephanie M. Andler

Masters Theses

Hierarchical systems that integrate nano- and macroscale structural elements can offer enhanced stability over traditional immobilization methods. Microparticles were synthesized using interfacial assembly of lipase with (CLMP-N) and without (CLMP) nanoparticles into a crosslinked polymeric core, to determine the impact of the highly ordered system on lipase stability in extreme environments. Kinetic analysis revealed the macrostructure significantly increases the turnover rate (kcat) following immobilization. The macrostructure also stabilized lipase at neutral and basic pH values, while the nanoparticles influenced stability under acidic pH conditions. A greener solvent, choline chloride and urea, was applied to produce sugar ester surfactants. Microparticles ...


Modeling Historical And Future Range Of Variability Scenarios In The Yuba River Watershed, Tahoe National Forest, California, Maritza Mallek Jul 2016

Modeling Historical And Future Range Of Variability Scenarios In The Yuba River Watershed, Tahoe National Forest, California, Maritza Mallek

Masters Theses

In California's northern Sierra Nevada mountains, the fire-dependent processes of forest ecosystems have been interrupted and altered by human land use and fire suppression. U.S. Forest Service policy directs land managers to plan for a future that includes multiple use and the restoration of resilient ecosystems. Planning decisions are to be informed by an analysis of the range of variability of ecological processes at multiple scales. Current climate trends in the northern Sierra are of increasing temperatures, increased precipitation, and earlier snowmelt, as well as changes to the frequency and duration of drought. These climate changes have and ...


An In Vivo Study Of Cortical Dynein Dynamics And Its Contribution To Microtubule Sliding In The Midzone, Heather M. Jordan Jul 2016

An In Vivo Study Of Cortical Dynein Dynamics And Its Contribution To Microtubule Sliding In The Midzone, Heather M. Jordan

Masters Theses

In LLC-Pk1 cells, and most cultured mammalian cells, cell division is highly regulated to achieve equal sized daughter cells. During this process, duplicated centrosomes separate and establish a bipolar array called the mitotic spindle. The mitotic spindle is responsible for aligning the chromosomes at the metaphase plate, and separating sister chromatids during anaphase. Spindle positioning and elongation are thought to be driven by the interaction between dynamic astral microtubules and cortical dynein. Extensive research has revealed that dynein is anchored to the cortex via the highly conserved NuMA/LGN/Gαi ternary complex in metaphase and the additional PIP/PIP2/NuMA ...


Mechanisms Of Slowed Foot Tap Speed In Older Adults, Erica L. Hartman Jul 2016

Mechanisms Of Slowed Foot Tap Speed In Older Adults, Erica L. Hartman

Masters Theses

Rapid repetitive tapping, like the Foot Tap Test (FTT), slows with age, but the underlying mechanisms are unknown. Purpose: 1. Test the hypotheses that greater performance variability, increased muscle coactivation, and slowed muscle contractile speeds are related to lower foot tap count (FTC) in older adults; 2. Examine the relationship between FTC and physical function in older adults, using the advanced SPPB-A. Methods: 18 (25.0±3.1years, 9F, mean±SD), and 28 (73.4±4.9, 14F) adults were recruited; the later were divided into Higher (HFO) and Lower (LFO) Functioning based on SPPB-A score. Participants performed 10s of ...


Fruit And Vegetable Intake, Attitudes, And Beliefs Of Multicultural Middle School Students In Central Massachusetts, Emily M. Harrington Jul 2016

Fruit And Vegetable Intake, Attitudes, And Beliefs Of Multicultural Middle School Students In Central Massachusetts, Emily M. Harrington

Masters Theses

High fruit and vegetable (FV) intake is associated with healthy weights and decreased risk of chronic disease. Yet, adolescent FV intakes fall below national recommendations. Few studies involve racial/ethnic minority adolescents in formative research, despite their increased risk of poor FV intake. Consequently, the purpose of this study was to describe the type and frequency of FV intake of urban multicultural young adolescents, and to examine their attitudes and beliefs towards increased consumption of FV. A convenience sample (n=79) of racially diverse (e.g., 31% Hispanic/Latino, 27.4% Black/African American) grade seven students, participated in our ...


Evaluating A Novel Photochemical Tool For Labeling And Tracking Live, Endogenous Calcium-Permeable Ampars, Rosamund Elizabeth Combs-Bachmann Jul 2016

Evaluating A Novel Photochemical Tool For Labeling And Tracking Live, Endogenous Calcium-Permeable Ampars, Rosamund Elizabeth Combs-Bachmann

Masters Theses

The purpose of this research is to advance development of a photochemical tool designed to probe the role of ionotropic glutamate receptor signaling in neurodegenerative processes, and to delve more deeply into the biological processes underlying the role of these receptors in signaling and memory formation. This ligand-targeted nanoprobe was designed and developed in our lab to label endogenous calcium-permeable AMPARs (CP-AMPARs) in live cells with minimal disruption to native receptor activity. Nanoprobe is designed to use naphthyl acetyl spermine (NASPM) as a photocleavable ligand to target and covalently label native CP-AMPARs with a non-perturbing, fluorescent marker that then allows ...


Echerichia Coli Biofilm Formation In Musca Domestica Crops, Lufan Wang Mar 2016

Echerichia Coli Biofilm Formation In Musca Domestica Crops, Lufan Wang

Masters Theses

The house fly, Musca domestica can transmit human pathogens including Escherichia coli O157:H7 through regurgitation of ingested bacteria from the crop which is a foregut organ of house fly and stores the excess ingested nutrients. Interactions between the ingested bacteria and the crop have a direct influence on bacteria persistence, survival and ultimately fly vector competence. In this research, in situ crop vessel assay was developed to investigate bacterial growth within fly crops up to 48 hours post-ingestion. Flies were fasted for 12 h prior to feeding E. coli O157:H7 pEGFP and then fed bacteria with ...