Digital Commons Network^™

Physiology Of Cold Acclimation And Deacclimation Responses Of Cool-Season Grasses: Carbon And Hormone Metabolism, Xian Guan

Masters Theses

Winter injury of cool-season turfgrasses in northern climates is a significant issue, leading to losses in turf cover and subsequent increased inputs for recovery. Despite the different potential causes for winter injury, the overall level of plant freezing tolerance has been shown to account for a majority of the variation in winter survival of grasses. Freezing tolerance is achieved through cold acclimation, based on a series of physiological and biochemical changes that increase cell stability at freezing temperatures. Winter injury can result from insufficient cold acclimation, or rapid cold deacclimation triggered by temperature fluctuations or freeze-thaw cycles. Previous research has …

Attention Modulates Erp Indices Of The Precedence Effect, Benjamin H. Zobel

Masters Theses

When presented with two identical sounds from different locations separated by a short onset asynchrony, listeners report hearing a single source at the location of the lead sound, a phenomenon called the precedence effect (Wallach et al., 1949; Haas, 1951). When the onset asynchrony is above echo threshold, listeners report hearing the lead and lag sounds as separate sources with distinct locations. Event-related potential (ERP) studies have shown that perception of separate sound sources is accompanied by an object-related negativity (ORN) 100-250 ms after onset and a late posterior positivity (LP) 300-500 ms after onset (Sanders et al., 2008; Sanders …

Properties Of Potential Substrates Of A Cyanobacterial Small Heat Shock Protein, Yichen Zhang

Masters Theses

Most proteins must fold into native three-dimensional structures to be functional. But, newly synthesized proteins are at high risk of misfolding and aggregating in the cell. Stress, disease or mutations can also cause protein aggregation. A cyanobacterial small heat shock protein, Hsp16.6, can act as a chaperone to prevent irreversible protein aggregation during heat stress. This thesis is focused on the properties of proteins that were associated with Hsp16.6 during heat stress, and which therefore may be “substrates” of Hsp16.6. Bioinformatics were used to determine if Hsp16.6 preferentially binds to proteins with certain properties, and biochemical studies were performed to …

Expression And Purification Of Human Lysosomal Β-Galactosidase From Pichia Pastoris, Sarah E. Tarullo

Masters Theses

Lysosomal storage diseases are genetically inherited diseases caused by the dysfunction of lysosomal enzymes. In a normal cell, lysosomal enzymes cleave specific macromolecules as they are transported to the lysosome. However, in diseased cells, these lysosomal enzymes are either absent or malfunctioning, causing macromolecular substrates to accumulate, becoming toxic to the cell. Over fifty lysosomal storage diseases have been identified, collectively occurring in one out of 7,700 live births. We investigated the lysosomal enzyme β-galactosidase (β-gal). In order to study the biochemistry and enzymology of this protein a robust expression system was needed. The GLB1 gene has been inserted into …

Age-Related Changes In Sleep-Dependent Consolidation Of Visuo-Spatial Memory, Akshata Sonni

Masters Theses

Healthy aging is associated with a reduction in slow-wave sleep (SWS), crucial for declarative memory consolidation in young adults; consequently, previously observed benefits of sleep on declarative learning in older adults could reflect a passive role of sleep in protecting memories from waking interference, rather than an active, stabilizing effect. To dissociate the passive and active roles of sleep, a visuo-spatial task was administered; memory was probed after a 12 hr interval consisting of either daytime wake or overnight sleep and post-wake/post-sleep stability of the memories was tested following task-related interference. Ninety five older adults (mean=65.43 yrs; SD=7.6 yrs) and …

Intuitive Eating, Attitudes To Food, And Body Size: A Comparison Between Nutrition Majors And Non-Majors, Katelyn Russell

Masters Theses

Dietitians are expected to deliver sound and scientifically objective advice to the general public, yet their personal beliefs and behaviors could influence delivery of nutrition care. Increased understanding of the personal attitudes and behaviors of dietitians concerning eating behavior and body image could help improve dietetic practice. Traditional nutrition education emphasizes cognitive eating, i.e., monitoring energy intake and comparing macronutrient intakes to the current acceptable ranges. Intuitive eating, however, promotes the release of cognitive eating in favor of greater attention to physiologic cues, or “body wisdom”. We hypothesized that nutrition students in a traditional curriculum would report eating less intuitively …

Volatile Profiles And Resistance To Herbivory In Eastern Hemlock, Elizabeth A. Mckenzie

Masters Theses

Eastern hemlock hosts the hemlock woolly adelgid, an introduced sap-feeding insect that causes rapid deterioration of the host. Like most conifers, eastern hemlock produces a variety of constitutive and induced defenses, primarily terpenoids. To explore the relationship of terpenoid defenses with adelgid infestations, we artificially infested hemlocks at a forest site and a plantation site, and compared their terpenoid concentrations to those in control trees. Infested trees showed lower terpenoid concentrations than control trees, suggesting that eastern hemlock not only fails to induce production of terpenoids in response to adelgid infestation, but becomes less able to produce carbon-based defenses due …

Assessing Wild Canid Distribution Using Camera Traps In The Pioneer Valley Of Western Massachusetts, Eric G. Leflore

Masters Theses

With the ever-increasing human population, more people reside in urban areas than ever before; this is having marked effects on the landscape and in turn, wildlife. This study uses automatically triggered wildlife cameras to assess the distribution of three carnivore species (coyotes, Canis latrans; red foxes, Vulpes vulpes; and gray foxes, Urocyon cinereoargenteus) around the Pioneer Valley of Massachusetts in relation to a gradient of human development. Cameras were placed at 141 locations within the 320-km² study area over the course of three field seasons (3,052 trap nights). Relative abundances for fourteen other species and site …

Effect Of Spring And Winter Temperatures On Winter Moth (Geometridae: Lepidoptera) Larval Eclosion In New England, Emily L. Hibbard

Masters Theses

Field and laboratory experiments were conducted to elucidate various factors influencing the temperature-dependent larval eclosion of winter moth, Operophtera brumata L, in New England. We found no difference in duration of the embryonic stage of eggs reared from larvae collected in Massachusetts (MA) and on Vancouver Island, British Columbia (BC), where winter temperatures are rarely below freezing. The number of growing degree days (GDD) required for larval eclosion declined with the number of days chilled in the laboratory and number of days below freezing in the field, confirming the findings of previous studies. Thus, eggs hatched with fewer GDD, when …

Increased Body Weight In Adulthood Following A Peripubertal Stressor And Proposed Mechanism For Effects Of Increased Adiposity On Estrogen-Dependent Behaviors, Christina F. Gagliardi

Masters Theses

Exposure to certain stressors during a sensitive period around puberty can lead to enduring effects on an animal’s response to estradiol. In estradiol-influenced behaviors, such as sexual receptivity, hippocampal-dependent learning and memory, depression-like behavior, and anxiety-like behaviors, exposure to a peripubertal stressor such as shipping stress or an injection of lipopolysaccharide (LPS) can eliminate or even reverse the normal response to estradiol. In addition to regulating these behaviors, estradiol play a role in the regulation of body weight. While some of the previous studies touched on short-term effects on body weight, no systemic long-term study of the effects of a …

Modification Of Gold Nanoparticles For Sers Application In Emulsion And Lipid Systems, Michael J. Driver

Masters Theses

Gold nanoparticles produced using the Turkevich method were able to have their hydrophobicity modified using octanethiol in a novel method for SERS application. Both amphiliphic GNPs and hydrophobic GNPs were produced and differentiated by Raman signals. The amphiliphic GNPs were able to enhance the SERS signals of the protein emulsifier in the emulsion in situ and the hydrophobic GNPs were able to enhance the SERS signals from canola oil. Further purification of the hydrophobic GNPs proved to have higher enhancement and sensitivity, but still poor consistency which is typical of SERS. Monitoring lipid oxidation using Raman and SERS using alternative …

Sequence Analysis Of Maize Yellow Stripe3 Candidate Genes, Dennis B. Depaolo

Masters Theses

The work presented here focuses on the molecular mechanism of phytosiderophore secretion in graminaceous plants. In maize, yellow stripe3 (ys3) is a mutant that is deficient in its ability to secrete iron-chelating compounds of the mugineic acid family known as phytosiderophores. Phytosiderophores are specific to grasses and are used for the acquisition of iron. Genetic linkage mapping of the ys3 locus lead to a region of interest on chromosome 3 defined by marker UMC1773. The sequence of eleven candidate genes (GRMZM2G390345, GRMZM2G390374, GRMZM2G342821, GRMZM5G800764, GRMZM2G502560, GRMZM5G849435, GRMZM2G105766, GRMZM5G876835, GRMZM2G036976, GRMZM2G502563, miR167g) revealed several small deletions …

The Effects Of Suburbanization On Nest Ectoparasites And Nest Defense Behavior In The Wood Thrush, Evan N. Dalton

Masters Theses

The Wood Thrush (Hylocichla mustelina) is declining throughout its range, yet is capable of persisting in both contiguous forests and small forest patches surrounded by human suburban development. Thus, it is an ideal species for gaining insight into the effects of suburbanization on migrant songbirds. I investigated two aspects of Wood Thrush nesting ecology: nest ectoparasites and nest defense behavior in order to determine if suburbanization influences either aspect. Nests from suburban forests had fewer haematophagous mites, though the abundance of haematophagous blowfly larvae did not differ between suburban and contiguous forests. There was no relationship between the …

Spatio-Temporal Factors Affecting Human-Black Bear Interactions In Great Smoky Mountains National Park, Nathan Buckhout

Masters Theses

Wildlife managers use models to aid in predicting high risk areas for human and black bear (Ursus americanus) interactions (HBI). These tools help managers implement management strategies to minimize HBI. Over 3,000 incidents of HBI were compiled from management reports at Great Smoky Mountains National Park (GSMNP) during 1998-2011, a park with 9-10.2 million visitors per year and a black bear population of about 1,600 bears.

We used data from bear management reports along with annual visitor use, mast and bear abundance data to develop a series of generalized linear models to assess the spatial and temporal factors …

Were Neandertal Humeri Adapted For Spear Thrusting Or Throwing? A Finite Element Study, Michael Anthony Berthaume

Masters Theses

An ongoing debate concerning Neandertal ecology is whether or not they utilized long range weaponry. The anteroposteriorly expanded cross-section of Neandertal humeri have led some to argue they thrusted their weapons, while the rounder cross-section of Late Upper Paleolithic modern human humeri suggests they threw their weapons. We test the hypothesis that Neandertal humeri were built to resist strains engendered by thrusting rather than throwing using finite element models of one Neandertal, one Early Upper Paleolithic (EUP) human and three recent human humeri, representing a range of cross-sectional shapes and sizes. Electromyography and kinematic data and articulated skeletons were used …

The Role Of Sleep Timing On Diet Quality And Physical Activity Among College-Aged Women Participating In The University Of Massachusetts Vitamin D Status Study, Deniz Azarmanesh

Masters Theses

Overweight and obesity are risk factors for various chronic diseases. Sleep has been associated with overweight and obesity. One potential mechanism by which sleep may lead to overweight and obesity is through positive energy balance (i.e. energy intake exceeding expenditure). There are few studies examining the impact of sleep timing (onset and wake time) on diet and exercise. In a cross sectional study, we examined associations between sleep timing and diet quality, and in separate models, between sleep timing and meeting the 2008 Physical Activity Guidelines for Americans among the participants of the UMass Vitamin D Status Study. A total …

Designing A Pore-Forming Toxin Cytolysin A (Clya) Specific To Target Cancer Cells, Alzira Rocheteau Avelino

Masters Theses

Cytolysin A (ClyA) is a member of a class of proteins called pore-forming toxins (PFTs). ClyA is secreted by Gram-negative bacteria, and it attacks a number of mammalian cells by inserting into and forming channels within the cell membrane (Oscarsson J et al., 1999). It has been suggested that ClyA binds to cholesterol (Oscarsson J et al., 1999) and thus can insert into the membranes of many different cell types of eukaryotic origin. In our studies we propose to engineer a ClyA protein that can only attack a small subset of cell types. We propose to engineer ClyA that can …

Influence Of Physical States (Crystalized Versus Solubilized) Of Bioactive Components And Oil Composition On Bioaccessibility And Bioavailability, Ziyuan Xia

Masters Theses

Three systems were compared in the first case study: (1). pre-dissolved β-carotene nanoemulsion (d< 200nm); (2). corn oil emulsion (d< 200nm) with β-carotene crystals being added before digestion; (3). phosphate buffer saline with β-carotene being added before digestion. Oil-in-water nanoemulsions were formed by high-pressure homogenization using Tween 20 as emulsifier and corn oil as carrier oil and then they were subjected to a simulated mouth, stomach and small intestine digestion. The rate and extent of free fatty acid production in small intestine decreased in the order (2)>(1)>(3); whereas the β-carotene bioaccessibility decreased in the order (1)>>(2)>(3). In system (3), even without any fat content, there is still noticeable consumption of NaOH, which is due to the ester bonds existing in the non-ionic surfactant (Tween 20). In the second case study, we developed two comparing groups by differentiating their oil concentration (20%, 4% respectively). The bioaccessibility of the high fat group is only half of the low fat group due to the insufficient digestion of fat in the …

The Role Of The Novel Lupus Antigen, Acheron, In Moderating Life And Death Decisions, Ankur Sheel

Masters Theses

Programmed cell death (PCD) is a major regulatory mechanism employed during development and homeostasis. The term PCD was coined to describe the death of the intersegmental muscles (ISMs) of moths at the end of metamorphosis. The timing of ISM death in the Tobacco Hawkmoth, Manduca sexta, is regulated by a fall in the titer of the steroid molting hormone 20-hydroxyecdysone (20E) late on day 17of pupal-adult development. This triggers the release of the peptide hormone, Eclosion Hormone (EH), which mediates its effects via the secondary messenger cGMP. It has been previously demonstrated that ISM death requires de novo gene expression. …

The Combined Effects Of Genistein And Daidzein On Adipocyte Differentiation, Oumou Habybat Kone

Masters Theses

Dietary soy isoflavones have been shown to ameliorate insulin resistance and Type 2 diabetes. However, many in vitro studies used supra-physiological concentrations of individual isoflavones that make it difficult to interpret the results as potential mechanisms in vivo. Since the insulin-sensitizing effects of thiazolidinediones, anti-diabetic drugs, have been shown to be mediated through activation of peroxisome proliferators-activated receptor gamma (PPARγ), the key transcription factor for adipocyte differentiation, we examined the effects of the two main soy isoflavones genistein and daidzein either as individual compound or combined on adipocyte differentiation and PPARγ expression, as well as whether the Wnt/β-catenin signaling …

Kinetic Asymmetries During Submaximal And Maximal Speed Running, Devon H. Frayne

Masters Theses

An important issue for sports scientists, coaches and athletes is an understanding of the factors within a running stride that can enhance or limit maximal running speed. Previous research has identified many sprint-related parameters as potential kinetic limiters of maximal Center of Mass velocity (Chapman and Caldwell, 1983b; Weyand et al., 2001). Bilateral asymmetry is present for many of these parameters during running; however the degree to which such asymmetries change as running speed increases is unknown. It was hypothesized that asymmetries in key sprinting parameters would be larger at maximal speed than all other tested speeds. Kinematics and kinetics …

Rapid Method Of Processing Sperm For Nucleic Acid Extraction In Clinical Research, Matthew K. De Gannes

Masters Theses

Background: Sperm contain highly compact nuclei, inhibiting DNA extraction using traditional techniques. Current methods extracting sperm DNA involve lengthy lysis and no means of stabilizing DNA, hindering clinical research.

Objective: We sought to optimize an efficient method of extracting high quality human sperm DNA.

Methods: Sperm from three volunteers were isolated using PureCeption. We tested 1) proteinase K with DNA/RNA Shield, 2) DTT and TCEP as reducing agents, 3) QIAshredder homogenization, and 4) stability of sperm DNA fresh (baseline) or after 4 weeks of storage at 4^OC in DNA/RNA Shield using modified Quick-gDNA MiniPrep. DNA was PCR amplified …