Life Sciences Commons^™

Encapsulation Of Probiotic Microorganisms In Food-Grade Hydrogel Microbeads For Improving Long-Term Storage And Oral Delivery, Timothy W. Yeung

Masters Theses

Probiotics die over time during processing, storage and digestion, resulting in reduced health benefits to the consumer. Microencapsulation of microorganisms is an effective way to improve probiotic viability by restricting cell exposure to extreme conditions through the gastrointestinal tract until release in the colon. In this work, appearance and survival of encapsulated probiotic species from two genera was explored. Lactococcus lactis and Bifidobacterium longum were suspended in calcium alginate microbeads by spraying droplets of alginate-probiotic mixture into calcium chloride solution. This produced uniformly shaped transparent microbeads with high encapsulation yield. Encapsulating Lactococcus lactis extended viability during dry room temperature storage. …

Investigate The Interactions Between Silver Nanoparticles And Spinach Leaf By Surface Enhanced Raman Spectroscopic Mapping, Zhiyun Zhang

Masters Theses

Owing to their increasing application and potential toxicity, engineered nanoparticles (ENPs) have been considered as a potential agricultural contaminant that may pose unknown risk to human beings. However, many techniques require invasive and complicated sample preparation procedures to detect and characterize engineered nanomaterials in complex matrices. In the first part of this thesis, we present a non-destructive and label-free approach based on surface enhanced Raman spectroscopic (SERS) mapping technique to qualitatively detect and characterize gold nanoparticles (AuNPs), on and in spinach leaves in situ. We were able to detect the clearly enhanced signals from AuNPs at 15 to 125 nm …

Modifications Of Myofilament Structure And Function During Global Myocardial Ischemia, Mike K. Woodward

Masters Theses

Cardiac arrest is a prevalent condition with a poor prognosis, attributable in part to persistent myocardial dysfunction following resuscitation. The molecular basis of this dysfunction remains unclear. We induced cardiac arrest in a porcine model of acute sudden death and assessed the impact of ischemia and reperfusion on the molecular function of isolated cardiac contractile proteins. Cardiac arrest was electrically induced, left untreated for 12 min, and followed by a resuscitation protocol. With successful resuscitations, the heart was reperfused for 2 h (IR2) and the muscle harvested. In failed resuscitations, tissue samples were taken following the failed efforts (IDNR). Actin …

Utilizing Nutritive Sweeteners To Control Lipid Oxidation In Low Moisture Baked Goods, Samantha Vieira

Masters Theses

In this study, we determined the effect of nutritive sweeteners at 0 to 0.50 moles/kg on lipid oxidation in a model cookie system. Confocal microscopy using Bodipy 493 as a fat soluble dye showed that the fat formed a continuous phase surrounding the starch granules regardless of sugar type. The impact of glucose concentration on lipid oxidation was monitored by lipid hydroperoxides and headspace hexanal during storage at 55°C. Low concentrations of glucose (0.09) were strong inhibitors. At equal molar concentrations, reducing sugars (glucose and fructose) inhibited lipid oxidation, greater than a two months increase in lag phase compared to …

Probiotics As A Treatment For Increased Nighttime Activity In Rhesus Macaques (Macaca Mulatta) Displaying Self-Injurious Behavior, Lauren L. Stanwicks

Masters Theses

Self-injurious behavior (SIB) is a behavioral pathology seen in a small percentage of humans and non-human primates. In one previous study, macaques with SIB had more sleep disruption than controls, but observations were limited. Two studies were conducted: a baseline study to investigate nighttime activity in rhesus macaques (Macaca mulatta) displaying SIB and controls, and a probiotic study to assess probiotic Bifidobacterium infantis 35624 for high nighttime activity. Subjects were 13 rhesus macaques, 5 with SIB (3 females; 1 SIB). Videocapture of Nighttime Activity (VNRA) was developed to record in complete darkness. IR-receptive webcams were connected to a …

Trypanosoma Brucei Mitochondrial Dna Polib Cell Cycle Localization And Effect On Polic When Polib Is Depleted, Sylvia L. Rivera

Masters Theses

Trypanosoma brucei is the causative agent of Human African Trypanosomiasis (HAT), also known as African sleeping sickness. T. brucei is unique in several ways that distinguish this organism from other eukaryotes. One of the unique features of T. brucei is the organism’s mitochondrial DNA, which is organized in a complex structure called kinetoplast DNA (kDNA). Since kDNA is unique to the kinetoplastids, kDNA may serve as a good drug target against T. brucei. Previews studies have shown that kDNA has 4 different family A mitochondrial DNA polymerases. Three of these mitochondrial DNA polymerases (POLIB, POLIC, and POLID) are essential …

Characterizing The Inhibition Of Katanin Using Tubulin Carboxy-Terminal Tail Constructs, Corey E. Reed

Masters Theses

Understanding how the cellular cytoskeleton is maintained and regulated is important to elucidate the functions of many structures such as the mitotic spindle, cilia and flagella. Katanin p60, microtubule-severing enzymes from the ATPase associated with cellular activities (AAA+) family, has previously been shown in our lab to be inhibited by free tubulin as well as α- and β-tubulin carboxy-terminal tail (CTT) constructs. Here we investigate the inhibition ability of several different tubulin CTT sequences. We quantify the effect of the addition of these constructs on the severing and binding activity of katanin. We find that some constructs inhibit katanin better …

Ecological Consequences Of Lost Anadromous Forage Fish In Freshwater Ecosystems, Steven R. Mattocks

Masters Theses

Beginning in the early 1600s, dam construction in New England obstructed anadromous fish access to spawning grounds during migration. As a result, anadromous forage fish populations have declined, which has impacted freshwater, marine, and terrestrial ecosystems. To determine the impacts of dams on anadromous forage fish and freshwater ecosystems, I used historical and current data to estimate population changes in alewives (Alosa pseudoharengus) from 1600-1900. A significant reduction in spawning habitat occurred in New England as a result of 1,642 dams constructed between 1600 and 1900, resulting in 14.8% and 16.6% lake and stream habitat remaining by 1900, …

River Herring Conservation In Freshwater: Investigating Fish Reproductive Success And The Educational Value Of Citizen Monitoring Programs, Meghna Marjadi

Masters Theses

Over the last century anadromous alewife (Alosa psuedoharengus) and blueback herring (Alosa aestivalis), collectively called river herring, suffered drastic declines throughout their range from Newfoundland (Canada) to North Carolina (USA). A 2011 petition to include river herring in the Endangered Species Act (ESA) was rejected, partly due to inadequate information towards identifying coast-wide population status. Additionally, knowledge gaps were identified with basic ecology of the river herring life cycle in freshwater, including species reproductive strategies. In Chapter 2, I investigated how body size, spawning arrival time, and sex influence river herring reproductive success. I collaborated with …

Distribution Of Enterotoxigenic Clostridium Perfringens Spores In U.S. Retail Spices, Chi-An Lee

Masters Theses

246 samples of bulk and packaged spices from retail stores in the western, southeastern, southern, midwestern, and northeastern areas of the U.S. were examined for the presence of Clostridium -perfringens. Isolates were checked for the presence of the lecithinase gene (cpa) and enterotoxin genes (cpe) by PCR. Enterotoxin formation during sporulation was investigated using the Oxoid Toxin Detection Kit. Forty-three confirmed isolates (from 17% of total samples) were cpa-positive. Of those, 27 were cpe-positive. Together, levels of C. perfringens spores ranged from 3.6-2400/gm. The amount of enterotoxin in cell extracts ranged from …

A Genetic Analysis Of Cichlid Scale Morphology, Kenta C. Kawasaki

Masters Theses

Epidermal appendages are found on every vertebrate this world has to offer. In fish, these are commonly represented by scales. While we have a solid grasp of how scales develop, little is known about the underlying genetic mechanisms behind these phenotypic changes. Using two species of African cichlids (Labeotropheus fuelleborni and Tropheops “red cheek”) with varying scale phenotypes, we sought to examine their F2 hybrid offspring and statistically link the responsible genetic elements to their respective parental phenotypes through Quantitative Loci Trait (QTL) analysis.

Scales were removed from six different locations across the midline of each individual. Then, numerous …

The Role Of Micrornas In Regulating The Translatability And Stability Of Target Messenger Rnas During The Atrophy And Programmed Cell Death Of The Intersegmental Muscles Of The Tobacco Hawkmoth Manduca Sexta., Elizabeth Chan

Masters Theses

A variety of diseases lead to the atrophy and/or death of skeletal muscle. To better understand the molecular mechanisms that mediate these processes, I have taken advantage of the intersegmental muscles (ISMs) of the tobacco hawkmoth Manduca sexta, which undergo sequential programs of atrophy and programmed cell death at the end of metamorphosis. ISM death is mediated by changes in gene expression and numerous cell-death associated transcripts have been identified. MicroRNAs (miRs) are small (~22 nucleotide) non-coding RNAs that bind to sequences in messenger RNAs (mRNAs) and either cause translational arrest or mRNA degradation. To test the hypothesis that …

Investigating The Balance Between Estrogen Receptor Mediated Cell Proliferation And Genomic Surveillance, Margarita Brown

Masters Theses

Breast cancer is a leading cause of cancer in women and the second leading cause of cancer death. Lifetime exposure to estrogen contributes to this risk but high dose estrogen has been used to induce apoptosis as treatment for breast cancer. These opposing tumorigenic and anti-tumorigenic effects of estrogen may be regulated differently by the two Estrogen Receptors (ER), Estrogen Receptor alpha (ERα) and Estrogen Receptor beta (ERβ). Although the receptors share a 96% homology in their DNA binding domain, they are unique in the ligand-binding domain with 53% amino acid homology. Previous studies have shown that ERα drives cell …

Factors Affecting Habitat Quality For Wintering Wood Thrushes In A Coffee Growing Region In Honduras, Brett A. Bailey

Masters Theses

Amongst the diversity of taxa that occur in the Neotropics, 200 migratory bird species that breed in temperate North America can be found. Many of these populations have seen significant declines since the 1960s. The Wood Thrush, Hylocichla mustelina, is one such species. Shade coffee and other agroforestry practices show potential for benefiting migratory species, but the quality of coffee habitat and optimal habitat characteristics for Wood Thrushes remain unknown.

I surveyed a spatially complex, agricultural landscape in Honduras outside the recognized winter range of the Wood Thrush and radio-tagged 46 individuals within rustic coffee farms during the winters …

Iron Signaling In Arabidopsis Thaliana, Celina Abundis

Masters Theses

Iron is among the essential micronutrients for all living organisms and is a cofactor for many cellular redox reactions. Although iron is a highly abundant metal element found in the earth’s crust, it is also a limiting factor in plant development when it is present as insoluble ferric oxides. Plants have evolved two strategies to acquire soluble iron referred to as Strategy I and Strategy II. Our lab has focused on the Arabidopsis thaliana double mutant ysl1ysl3. The mutants display a chlorotic phenotype and are unable to correctly respond to iron deficiency.

Grafting is a common method for joining …

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 …

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 …

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 were …

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

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

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

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 …

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 (k_cat) 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 …

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 continue to …

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, or 4.1G/R/NuMA, pathways during …

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 rapid tapping (FTT) while seated. A MATLAB …

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 study comprised of a self-administered survey …

Chemical Stability Of Curcumin: Structure And Activity Relationship (Sar) Study, Zheyuan Du

Masters Theses

Over the past decades, numerous studies have shown that curcumin has potent biological activities. As a potential chemopreventing agent, curcumin was demonstrated to exert anti-cancer effects in both in vitro and in vivo studies. However, low bioavailability of curcumin limited human clinical trials and its application to be formulated as therapeutics. In this thesis, we will summarize the anti-cancer effects of curcumin in animal studies and clinical trials. In addition, an SAR study will be introduced to elucidate the mechanism of curcumin degradation at physiological pH. We synthesized various curcumin analogues and compared their stability in phosphate buffer using HPLC …

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

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 red …