Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 171

Full-Text Articles in Life Sciences

An Examination Of Tern Diet In A Changing Gulf Of Maine, Keenan Yakola Oct 2019

An Examination Of Tern Diet In A Changing Gulf Of Maine, Keenan Yakola

Masters Theses

The Gulf of Maine is a dynamic ecosystem with rapidly warming sea surface temperatures (SSTs), therefore it is vital to understand how species interactions vary over time and space. In chapter two, I quantify and compare dietary differences among four tern species, across seven islands in the region, over a 32-year period. Multivariate statistical analyses were employed to discern spatial and temporal differences in foraging ecology. Findings suggest there are significant differences between species and islands; however, only three prey species comprise the majority of chick diet for all terns and islands. The reliance on only a few prey items ...


Investigating The Role Of Lbh During Early Embryonic Development In Xenopus Laevis, Emma Weir Oct 2019

Investigating The Role Of Lbh During Early Embryonic Development In Xenopus Laevis, Emma Weir

Masters Theses

LBH is a highly conserved protein whose role during vertebrate development is relatively under-studied. In collaboration with the Albertson lab, our lab has previously shown that it is necessary for cranial neural crest cell migration in the zebrafish and in Xenopus laevis. The molecular mechanisms through which it acts are not well understood.

In Xenopus, LBH is a maternally deposited protein. As such, studying its role in early development has not been feasible through the morpholino-mediated knockdown techniques that prevent translation of target genes. Recently, a technique for degrading endogenous proteins was developed, called Trim-Away. This was developed in mammalian ...


The Effects Of Acidosis On Calcium Dependent Binding Of A Single Crossbridge, Matthew Unger Oct 2019

The Effects Of Acidosis On Calcium Dependent Binding Of A Single Crossbridge, Matthew Unger

Masters Theses

Intracellular acidosis is a putative agent of skeletal muscle fatigue, in part, because acidosis depresses the calcium (Ca2+) sensitivity and force production of muscle (18, 50). However, the molecular mechanisms behind this depression in Ca2+ sensitivity and force production are unknown. This gap in knowledge poses a significant challenge in generating a complete understanding of the fatigue process. To close this gap, the ability of myosin to bind to a single actin filament was measured under acidic conditions, in a laser trap assay, with and without regulatory proteins. Decreasing pH from 7.4 to 6.5 reduced the ...


Arboriculture Safety Around The World, Jamie Lim Oct 2019

Arboriculture Safety Around The World, Jamie Lim

Masters Theses

Arboricultural work is inherently dangerous, with more serious injuries and fatalities than most other professions. Safety standards exist in some jurisdictions, but it is unclear how many standards exist, how they compare to one another, and whether (and how many) jurisdictions share standards. To establish a baseline understanding of these issues, my objectives were to (i) develop a database of existing standards, (ii) identify the most frequently occurring safety topics and (iii) describe similarities and differences in safety topics among standards from different countries. I worked with a variety of contacts and traditional university library resources to identify, obtain, analyze ...


The Efficacy Of Atp Monitoring Devices At Measuring Organic Matter On Postharvest Surfaces, Kristin Lane Oct 2019

The Efficacy Of Atp Monitoring Devices At Measuring Organic Matter On Postharvest Surfaces, Kristin Lane

Masters Theses

The Food Safety Modernization Act (FSMA), specifically the Produce Safety Rule (PSR), requires growers to clean and sanitize food-contact surfaces to protect against produce contamination. The ATP monitoring device is a potential sanitation tool to monitor the efficacy of an on-farm cleaning and sanitation program that could help growers meet regulatory expectations mandated by PSR. The ATP device uses bioluminescence to detect all ATP (found in bacteria and produce matter cells) from a swabbed surface. Little work has been done to test the efficacy of these tools under postharvest conditions. The present study evaluated ATP measurement for postharvest surface cleanliness ...


Patterns Of Morphological Plasticity In Metriaclima Zebra And Danio Rerio Suggest Differently Canalized Phenotypes Due To Form-Function Relationships, Dylan Jockel Oct 2019

Patterns Of Morphological Plasticity In Metriaclima Zebra And Danio Rerio Suggest Differently Canalized Phenotypes Due To Form-Function Relationships, Dylan Jockel

Masters Theses

In order to ascertain the degree of compatibility in developmental restructuring and behavioral plasticity between two fish species frequently made subject of laboratory research (Metriaclima zebra & Danio rerio), alternative trophic niche exposure experiments utilizing novel three-prong feeding treatments were conducted to obtain morphometric data, which demonstrated both species do bear some degree of plasticity. The results are somewhat complicated by differences in locality of detectable restructuring, which may be due to disparity in the form-function relationship for each species’ lineage. Each is notable in the manner of respective species’ jaw protrusion, as it is driven by anterior kinethmoid rotation in ...


Optical Meets Mechanical: Use Of Luminescence Spectroscopy To Assess Ageing In Biodegradable Films, Louis Colaruotolo Oct 2019

Optical Meets Mechanical: Use Of Luminescence Spectroscopy To Assess Ageing In Biodegradable Films, Louis Colaruotolo

Masters Theses

With the growing concern of the accumulation of plastic-based food packaging waste, the search for bio-based biodegradable packages is on the rise. These materials differ from their petro-based counterparts in their degradation rates, which are much higher in the former. Not only do bio-based biodegradable materials degrade faster during post-usage processes but also they age faster during usage and storage, which affects their performance and functionality. The application of noninvasive testing methods with the capability to report on the matrix’s state could assist in the development of a more ubiquitous way to assess ageing in food packaging, particularly in ...


Tropomyosin-Based Effects Of Acidosis On Thin-Filament Regulation During Muscle Fatigue, Brent Scott Jul 2019

Tropomyosin-Based Effects Of Acidosis On Thin-Filament Regulation During Muscle Fatigue, Brent Scott

Masters Theses

Skeletal muscle fatigue is defined as a loss in the force/velocity generating capacity of a muscle. A portion of the loss in function is attributable to effects of acidosis (i.e. low pH) on the regulatory proteins, troponin and tropomyosin (Tm), which regulate the binding of myosin and actin in a calcium (Ca++) dependent manner. However, the relative role of troponin and Tm on myosin-actin function during acidosis is not clear, nor are the mechanisms underlying these effects. PURPOSE: To determine the role of Tm in the acidosis-induced depression of muscle function using isolated muscle proteins in an in ...


Changes In Color Guidance Over The Course Of A Complex Visual Search, Ryan Papargiris Jul 2019

Changes In Color Guidance Over The Course Of A Complex Visual Search, Ryan Papargiris

Masters Theses

When searching for an object, we store a mental representation of the target, which guides our search through the use of attention. The effectiveness of this search guidance varies depending on the task and the relationship between target and distractors. With a better understanding of how search guidance changes over time within a trial, we can better compare the differences between experimental conditions. Eye tracking data from a variety of search tasks were analyzed to determine how color guidance varied over the course of the trial. Color guidance for a given fixation was evaluated based on the distance in color ...


Development And Cross-Validation Of A Cadence-Based Metabolic Equation For Walking, Christopher C. Moore Jul 2019

Ecological Considerations And Application Of Urban Tree Selection In Massachusetts, Ashley Mcelhinney Jul 2019

Ecological Considerations And Application Of Urban Tree Selection In Massachusetts, Ashley Mcelhinney

Masters Theses

Trees provide countless environmental, economic, and societal benefits to the urban environment, and may become increasingly important to maintaining environmental quality and human well-being in the face of increasing urbanization and climate change. However, trees in these urban areas are rapidly diminishing across the United States. Much of this loss can be prevented with proper planning and management, focused on selecting tree species that are both well-suited to the area’s growing conditions and able to survive the many stress factors in an urban setting. Choosing which tree species to plant in Massachusetts is especially challenging considering the lack of ...


The Efficacy Of Nanoemulsion-Based Delivery Systems To Improve Vitamin D3 Bioaccessibility And Bioavailability, Alagu Selvi Kadappan Jul 2019

The Efficacy Of Nanoemulsion-Based Delivery Systems To Improve Vitamin D3 Bioaccessibility And Bioavailability, Alagu Selvi Kadappan

Masters Theses

Vitamin D deficiency is an epidemic issue in all age groups in Western countries and that affects both skeletal and non-skeletal functions. Even with the wide application of food fortification, vitamin D deficiency tends to increase continuously. Being hydrophobic in nature, vitamin D has poor solubility; thereby it negatively affects its absorption and bioavailability when compared to other hydrophilic dietary compounds. The need to develop a novel strategy is of greater importance to enhance its bioavailability and thereby improving vitamin D level in the body.

In this study, lipid-based delivery of oil-in-water nanoemulsion (diameter < 200nm) was utilized to improve the bioaccessibility and oral bioavailability of vitamin D3. First, we examined the in ...


Photosynthesizing The Workplace: A Study In Healthy And Holistic Production Spaces, Kaeli Howard Jul 2019

Photosynthesizing The Workplace: A Study In Healthy And Holistic Production Spaces, Kaeli Howard

Masters Theses

Throughout time nature has been a prescribed healer of stress on the human condition. Its vital integration into our daily lives has been proven by scientific evidence. The majority of Americans spend approximately 1/3 of their life working, whatever that job may entail. Therefore, it makes sense that the environments that we spend so much of our life in for work at extremely important to our physical and mental health, however, current workplace models are not acknowledging that. Redefining the workplace to integrate nature would start to change work life in this country and how work itself is viewed ...


One Year Change In Cognitive Function In Male And Female Common Marmosets (Callithrix Jacchus), Brianna Healey Jul 2019

One Year Change In Cognitive Function In Male And Female Common Marmosets (Callithrix Jacchus), Brianna Healey

Masters Theses

Long term cognitive studies in humans and nonhuman primates such as macaques are difficult because of their long lifespan. The common marmoset (Callithrix jacchus) is a non-human primate who shares with humans many features characteristic of primates, including a complex brain and cognitive function. They also have a short lifespan (~10 years) that makes them a great model in studies of cognitive aging. This study focuses on the rate of decline in cognitive function in male and female marmosets based on performance on reversal learning tasks over 2 years of testing.

We found that marmosets improved their overall performance from ...


Mechanisms And Mitigation Of Skeletal Muscle Fatigue In Single Fibers From Older Adults, Aurora Foster Jul 2019

Mechanisms And Mitigation Of Skeletal Muscle Fatigue In Single Fibers From Older Adults, Aurora Foster

Masters Theses

Skeletal muscle fatigue is the contraction-induced decline in whole muscle force or power, and can be greater in older versus young adults. Fatigue primarily results from increased metabolism elevating phosphate (Pi) and hydrogen (H+), which alters myosin-actin interactions; however, which steps of the myosin-actin cross-bridge cycle are changed and their reversibility are unclear. PURPOSE: This study sought to: 1) Examine the effects of elevated Pi and H+ on molecular and cellular function, and 2) Test the ability of deoxyadenosine triphosphate (dATP), an alternative energy to adenosine triphosphate (ATP), to reverse the contractile changes induced with high Pi ...


Garlic Mustard (Alliaria Petiolata) Management Effectiveness And Plant Community Response, Erin Coates-Connor Jul 2019

Garlic Mustard (Alliaria Petiolata) Management Effectiveness And Plant Community Response, Erin Coates-Connor

Masters Theses

The control and eradication of the invasive biennial herb garlic mustard (Alliaria petiolata) and the restoration of invaded forest habitats present important linked challenges to land managers in North America. Removing garlic mustard by hand and by glyphosate herbicide application have both been used as eradication strategies with mixed results. Each method has advantages and disadvantages, but they are rarely compared for effectiveness and community impact across multiple years of management. Some previous studies have shown improvements in species diversity and plant community composition following management, while others have found no differences. To better understand both garlic mustard population and ...


Sex, Motivation, And Reversal Learning In The Common Marmoset (Callithrix Jacchus), Alyssa Carlotto Jul 2019

Sex, Motivation, And Reversal Learning In The Common Marmoset (Callithrix Jacchus), Alyssa Carlotto

Masters Theses

This study examined the relationships between motivation and cognitive performance in male and female common marmosets (Callithrix jacchus). This question was driven by prior data from the Lacreuse lab showing a robust female impairment in reversal learning, as assessed by the number of trials needed to acquire a reversal following a simple discrimination between two stimuli. This thesis tested the hypothesis that the female impairment in reversal learning was mediated by deficits in motivation. Two sets of measures were used to test this hypothesis. I evaluated physical effort via testing on the progressive ratio (PR), a test that requires animals ...


Studies On The Interaction And Organization Of Bacterial Proteins On Membranes, Mariana Brena Jul 2019

Studies On The Interaction And Organization Of Bacterial Proteins On Membranes, Mariana Brena

Masters Theses

Bacteria have developed various means of secreting proteins that can enter the host cell membrane. In this work I focus on two systems: cholesterol-dependent cytolysins and Type III Secretion.

Cholesterol is a molecule that is critical for physiological processes and cell membrane function. Not only can improper regulation lead to disease, but also the role cholesterol plays in cell function indicates it is an important molecule to understand. In response to this need, probes have been developed that detect cholesterol molecules in membranes. However, it has been recently shown that there is a need for probes that only respond to ...


Ecological And Economic Implications Of Establishing Quercus Spp. In The Urban Environment, Tierney Bocsi Jul 2019

Ecological And Economic Implications Of Establishing Quercus Spp. In The Urban Environment, Tierney Bocsi

Masters Theses

As urban greening efforts continue, it is important to assess whether decisions to intensify street tree planting are meeting intended goals of improving urban canopy cover and increasing ecosystem services. Benefits of the urban forest take many forms, from ecological and economic to social and cultural, and are frequently cited in support of street tree planting. However, it is unknown to what extent factors such as species or nursery production method affect the ability of trees to successfully establish and provide ecosystem services in the urban environment. Using a system of oak trees planted along roads in South Amherst, Massachusetts ...


Urban Biodiversity Experience And Exposure: Intervention And Inequality At The Local And Global Scale, Evan Kuras Mar 2019

Urban Biodiversity Experience And Exposure: Intervention And Inequality At The Local And Global Scale, Evan Kuras

Masters Theses

As cities expand globally, researchers must clarify how human activities and institutions shape biodiversity and conversely, how ecological processes shape human outcomes. Two features of contemporary cities motivate this thesis. First, urban residents, and especially children, are spending less time in nature and consequently, miss out on healthy and formative experiences with biodiversity. Second, residents with the least access to biodiversity tend to be those with the lowest socioeconomic status (SES). Together, these patterns convey a multi-layered environmental injustice: not only might urbanites become increasingly estranged from biodiversity, disinterested from its conservation, and disconnected from its benefits, but these outcomes ...


Apple Disease Forecasting Models: When Climate Changes The Rules, Elizabeth W. Garofalo Mar 2019

Apple Disease Forecasting Models: When Climate Changes The Rules, Elizabeth W. Garofalo

Masters Theses

With a changing global climate, plant pathologists must understand the impact aberrant weather events may have on the development of plant diseases. Fungal plant infections are largely dependent on temperature and precipitation, climate parameters that are predicted to change more in this century. Venturia inaequalis causes apple scab, one of the most destructive apple diseases of temperate growing regions. Temperature and precipitation drive apple scab infections and forecast models, which guide growers in efficient, effective fungicide applications. In some recent years in the Northeast, these models have failed to accurately predict when ascospores of this fungus are available to cause ...


Visual Attention In Jumping Spiders, Margaret Bruce Mar 2019

Visual Attention In Jumping Spiders, Margaret Bruce

Masters Theses

The different ways that animals extract and analyze visual information from their environment is of interest to sensory ecologists. Jumping spiders, well-known for visually guided mating and hunting behavior, are an interesting model for the study of visual attention because they quickly and efficiently integrate information from eight eyes with a small brain. Stimuli in front of the spider are examined by two functionally and morphologically distinct pairs of forward-facing eyes. The principal eyes discern fine details and have small retinas and thus a small visual field. However, their position at the back of moveable tubes within the cephalothorax expands ...


Influence Of Shipping Container Upon Temperature, Relative Humidity, And Bacterial Growth On Broccoli, Nicholas Berus Mar 2019

Influence Of Shipping Container Upon Temperature, Relative Humidity, And Bacterial Growth On Broccoli, Nicholas Berus

Masters Theses

Temperature and relative humidity of produce throughout the cold chain can greatly affect the quality and safety of the food product. Different packaging systems or containers can provide better cooling environments for food products that could decrease temperature abuse and ultimately safety risks. In this study we compiled temperature and relative humidity profiles of broccoli packed in different shipping containers throughout the produce supply chain. The shipping containers looked at were the wax corrugated box, reusable plastic containers (RPC), and Eco Pack Green Box with and without a lid. Large differences were seen in the temperature profiles of each package ...


Evaluating The Toxicity And Formation Of Halobenzoquinones In Point-Of-Use Chlorinated Drinking Water, Stephanie Hung Oct 2018

Evaluating The Toxicity And Formation Of Halobenzoquinones In Point-Of-Use Chlorinated Drinking Water, Stephanie Hung

Masters Theses

Chlorine has effectively reduced the prevalence of waterborne diseases, however there are secondary consequences to this public health advancement. Disinfection byproducts (DBPs) are chemicals formed when chlorine reacts with natural organic matter (NOM) in water. A new class of DBPs, halobenzoquinones (HBQs), has recently been identified and data suggests it could be potentially carcinogenic and up to 1000 times more toxic than some regulated DBPs. So far, in vitro studies have assessed HBQ toxicity without taking into account its transformation in cell media into potentially less toxic compounds. This study evaluated the toxic effects of one HBQ, 2,6-DCBQ, and ...


Use Of Alamarblue As An Indicator Of Microbial Growth In Turbid Solutions For Antimicrobial Evaluation, Precious Henshaw Oct 2018

Use Of Alamarblue As An Indicator Of Microbial Growth In Turbid Solutions For Antimicrobial Evaluation, Precious Henshaw

Masters Theses

The use of antibiotics in animal feed is a large cause of concern due to bacterial resistance, which occurs when bacteria change after exposure to antibiotics and become less affected by the drug. Consequently, the desire to find a replacement for these antibiotics has garnered interest in both farmers and consumers. The ideal substance would display antimicrobial activity without promoting bacterial resistance and would still function as a growth promoter in animals. One antimicrobial that fits this criterion is carvacrol, a compound found in oregano extract. Carvacrol exhibits antimicrobial activity in a number of bacteria, including E.coli O157:H7 ...


Influences Of Antroquinonol And 4-Acetylantroquinonol B On Inflammatory Tumorigenesis In The Mcf-7 Breast Cancer Cell Line With Or Without Tnf-Α Stimulation, Ting-Chun Lin Oct 2018

Influences Of Antroquinonol And 4-Acetylantroquinonol B On Inflammatory Tumorigenesis In The Mcf-7 Breast Cancer Cell Line With Or Without Tnf-Α Stimulation, Ting-Chun Lin

Masters Theses

Breast cancer (BC) is one of the most common cancers among women worldwide that ~25% of new cancer cases diagnosed every year would be BC; moreover, ~15% of cancer deaths per year caused by BC makes it the leading cause of cancer death among women worldwide. To date, though the cause of a large proportion of BC are still unclear, recent studies have revealed that a supportive breast tissue microenvironment is critical for the development and progression of BC, especially the communication with immune cells within breast tissue. Therefore, breast inflammatory microenvironment is currently received a substantial attention in the ...


Understanding The Thermal Stability And Environmental Sensitivity Of Phycocyanin Using Spectroscopic And Modelling Tools, Cally Toong Oct 2018

Understanding The Thermal Stability And Environmental Sensitivity Of Phycocyanin Using Spectroscopic And Modelling Tools, Cally Toong

Masters Theses

Phycocyanin (PC), a pigment-protein conjugate from Arthrospira platensis, is increasingly used in foods as a natural alternative to artificial blue dyes. Although PC has been classified as a color additive exempt from certification by the Food and Drug Administration, its limited stability has hindered its widespread application in food products. The objectives of this study were: a) to evaluate the photophysical properties of PC and their sensitivity to temperature, viscosity, and water activity, b) to monitor PC’s thermal degradation based on changes in the optical properties of its intrinsic fluorophores, namely its chromophores and aromatic amino acids, and c ...


Application And Evaluation Of Lighthouse Technology For Precision Motion Capture, Soumitra Sitole Oct 2018

Application And Evaluation Of Lighthouse Technology For Precision Motion Capture, Soumitra Sitole

Masters Theses

This thesis presents the development towards a system that can capture and quantify motion for applications in biomechanical and medical fields demanding precision motion tracking using the lighthouse technology. Commercially known as SteamVR tracking, the lighthouse technology is a motion tracking system developed for virtual reality applications that makes use of patterned infrared light sources to highlight trackers (objects embedded with photodiodes) to obtain their pose or spatial position and orientation. Current motion capture systems such as the camera-based motion capture are expensive and not readily available outside of research labs. This thesis provides a case for low-cost motion capture ...


Development And Application Of A Sers Needle For One-Step Multi-Phase Analysis, Haoxin Chen Oct 2018

Development And Application Of A Sers Needle For One-Step Multi-Phase Analysis, Haoxin Chen

Masters Theses

Surface-enhanced Raman spectroscopy (SERS) is an emerging and sensitive technique in food analysis providing advantages of rapid detection, simple sample preparation and on-site detection capability over GC and LC methods. Most SERS applications focus on detecting trace amount of analyte in liquid as an alternative approach to HPLC. Herein, we invented an innovative SERS-active needle which is composed with an injection needle and a gold-nanoparticles coated fiber inside the injection needle. The gold nanoparticles-coated fiber was fabricated by reducing gold (III) on a chemically etched stainless wire. The SERS needle can be used to insert into the headspace and liquid ...


Modulation Of The Redox Environment During Sensitive Developmental Periods Impairs Pancreatic Organogenesis In The Zebrafish (Danio Rerio), Haydee Jacobs Oct 2018

Modulation Of The Redox Environment During Sensitive Developmental Periods Impairs Pancreatic Organogenesis In The Zebrafish (Danio Rerio), Haydee Jacobs

Masters Theses

The developing pancreas has been identified as a potentially sensitive target for oxidative damage caused by environmental toxicant exposure in the developing zebrafish, Danio rerio. The objectives of this study were to 1) investigate the effects of exposure to a common pro-oxidizing toxicant, Mono(2-ethylhexyl) phthalate (MEHP), on pancreatic development, and 2) elucidate redox-sensitive temporal windows of pancreatic organogenesis in the zebrafish. We also investigated the involvement of Nrf2 (Nfe2l2), a transcription factor involved in the oxidative stress response, in toxicant-mediated pancreatic toxicity. In aim one, zebrafish embryos were exposed to 0 or 200 µg/L MEHP beginning at 3 ...