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Full-Text Articles in Life Sciences

Assessing Morphological Deformities In Cetaceans: Definition Of Patterns And Quantification With A Case Study (Madeira Island, Ne Atlantic), Erich Dietterle Dec 2017

Assessing Morphological Deformities In Cetaceans: Definition Of Patterns And Quantification With A Case Study (Madeira Island, Ne Atlantic), Erich Dietterle

Masters Theses

Documenting deformities in cetaceans can lead to understandings in the health of the populations, but also the state of ocean and human health in an area. Deformities like skin lesions can lead to information about local pollution levels or possible diseases, while physical impacts can give insight into vessel traffic or fishing gear entanglement information. Cetaceans encounter threats like vessel strikes and fishing gear entanglements worldwide, but less obvious activities like whale watching or pollution can also have impacts. Studies have been conducted worldwide and around the Madeira Archipelago to document deformities, but there are various descriptions for what is ...


Phosphorus Retention In West Michigan Two-Stage Agricultural Ditches, Emily Kindervater Dec 2017

Phosphorus Retention In West Michigan Two-Stage Agricultural Ditches, Emily Kindervater

Masters Theses

Input of excess nutrients into a water body can negatively impact ecological structure and function, as well as the economic vitality of surrounding communities, by contributing to eutrophication. For example, phosphorus (P) and sediment inputs from agricultural drainage have facilitated the development of hypereutrophic conditions in Lake Macatawa, a drowned river mouth lake located in Holland, Michigan. Two-stage ditches, an agricultural best management practice (BMP), are used in some areas of the Midwest to reduce N export downstream via denitrification. This BMP simulates a mini-floodplain by replacing a traditional, trapezoidal ditch with a channel that has excavated benches on each ...


Stressing Out: Dynamics Of Chromatin Insulator Body Formation In Eukaryotes Under Osmotic Stress, Shannon Marie Garland Dec 2017

Stressing Out: Dynamics Of Chromatin Insulator Body Formation In Eukaryotes Under Osmotic Stress, Shannon Marie Garland

Masters Theses

Higher order genome organization and the role it plays in governing cell dynamics and protein expression has become a widely studied field. Chromatin insulators are important to this organization in their ability to form long range contacts between distant regions on the genome. During times of osmotic stress, insulator proteins leave their binding sites on the DNA to form insulator bodies in the nucleus. This phenomenon relieves the DNA of its structure and is rapidly reversible. Using a variety of immunofluorescent staining methods, this work looked to further characterize this process while attempting to identify molecular mechanisms that mediate chromatin ...


Reproduction And Bioconfinement Of Mir156 Transgenic Switchgrass (Panicum Virgatum L.), Chelsea Renai Johnson Dec 2017

Reproduction And Bioconfinement Of Mir156 Transgenic Switchgrass (Panicum Virgatum L.), Chelsea Renai Johnson

Masters Theses

Genetic engineering of switchgrass (Panicum virgatum L.), an emerging cellulosic bioenergy feedstock, has been performed to alter cell walls for improved biofuel conversion. However, gene flow from transgenic switchgrass presents regulatory issues that may prevent commercialization of the genetically engineered crop in the eastern United States. Depending on its expression level, microRNA156 (miR156) can reduce, delay or eliminate flowering, which may be useful to mitigate transgene flow. However, flowering transition is dependent upon both environmental and genetic cues. In this study of transgenic switchgrass, two low (T14 and T35) and two medium (T27 and T37) miR156 overexpressing ‘Alamo’ lines and ...


Coping With Drought In Beef Cattle Production: Innovation Through Optimal Warm-Season Forage Systems, Katelynn Elizabeth Zechiel Dec 2017

Coping With Drought In Beef Cattle Production: Innovation Through Optimal Warm-Season Forage Systems, Katelynn Elizabeth Zechiel

Masters Theses

Drought conditions have had detrimental effects on beef cattle production in the southeastern states where forages are the primary source of feed for livestock. Many southeastern states lie within the fescue-belt, where tall fescue is the predominant livestock forage. Tall fescue is a cool-season (CS) grass that thrives in the cooler temperatures of spring and fall, becoming semi-dormant during peak summer temperatures and again in winter. Conversely, warm-season (WS) forage species increase in production during the summer months and exhibit drought tolerant qualities, making them a viable summer forage option to complement tall fescue for beef cattle producers. The primary ...


Bat Population Status And Roost Selection Of Tri-Colored Bats In The Great Smoky Mountains National Park In The Era Of White-Nose Syndrome, Grace Marie Carpenter Dec 2017

Bat Population Status And Roost Selection Of Tri-Colored Bats In The Great Smoky Mountains National Park In The Era Of White-Nose Syndrome, Grace Marie Carpenter

Masters Theses

The ongoing spread of white-nose syndrome is causing devastating declines range-wide for certain North American bat species. Baseline population data that would help mangers monitor bat populations in the face of WNS is lacking. Likewise, knowledge of summer roosts, a limiting resource for tri-colored bats (Perimyotis subflavus), a species threatened by WNS, is lacking in the southern portion of their range. In our study, we investigated the effect that WNS has had on a population of tricolored bats in the Great Smoky Mountains National Park, TN-NC. We also characterized summer roosts for the species at the microhabitat and landscape levels ...


Surveillance Of Ticks Parasitizing Tennessee Beef Cattle And Investigations Into The Microbial Communities Of Cattle Associated And Questing Amblyomma Maculatum, David Paul Theuret Dec 2017

Surveillance Of Ticks Parasitizing Tennessee Beef Cattle And Investigations Into The Microbial Communities Of Cattle Associated And Questing Amblyomma Maculatum, David Paul Theuret

Masters Theses

Despite the risks that ticks and tick-borne disease pose to the beef cattle industry, many Tennessee producers are unaware of the dangers they represent. This mindset could facilitate the invasion and establishment of exotic ticks and pathogens that would devastate the cattle industry. Current control practices rely on chemical methods, which are not effective long-term; therefore, investigations into creating an integrated approach to control would create more sustainable methods. This study aims to address this through two objectives: The first is to determine the species composition, seasonal prevalence, geographic distribution and diversity of ticks on Tennessee cattle. The second is ...


Aspects Of The Physiological And Behavioral Defense Adaptations Of The Mountain Madtom (Noturus Eleutherus), Meredith Leigh Hayes Dec 2017

Aspects Of The Physiological And Behavioral Defense Adaptations Of The Mountain Madtom (Noturus Eleutherus), Meredith Leigh Hayes

Masters Theses

Madtoms (Noturus spp.) are a highly endemic clade of miniature catfishes that faces widespread imperilment. Little is known about the ecology of these secretive fishes, and understanding the behavioral and physiological adaptations madtoms have evolved to resist pathogens and competitors is necessary for conservation.

Madtoms nest under cover and provide extensive paternal care. Attempts to rear eggs in captivity result in high mortality rates from infection, leading to questions about how wild nests resist disease. In many fishes, males produce antimicrobial substances that confer protection to eggs. To determine if guardian males deter disease in nests, Mountain Madtoms (Noturus eleutherus ...


Identification Of Deletions In The Hdc Gene Of Drosophila Melanogaster Generated Through Transposon-Excision Mutagenesis, Gregory A. Wesseling Aug 2017

Identification Of Deletions In The Hdc Gene Of Drosophila Melanogaster Generated Through Transposon-Excision Mutagenesis, Gregory A. Wesseling

Masters Theses

Histamine is a biogenic amine that functions as a neurotransmitter in a number of vertebrate and invertebrate systems and is synthesized from its precursor histidine by the enzyme histidine decarboxylase (HDC). In Drosophila, histamine has been shown to have function in photoreceptors, mechanoreceptor cells, as well as centrally located neurons. Mutations of the Hdc gene, such as HdcJK910, exhibit defects in histamine synthesis and display altered behaviors such as blindness, inability to groom, impaired thermal tolerance, and altered sleep rhythms. However, all Hdc mutants obtained thus far demonstrate some transcriptional activity.

In order to remove Hdc expression completely, part ...


Yellow Perch Genetic Stock Structure In Eastern Lake Michigan: What Is The Importance Of Drowned River Mouth Lakes?, Gregory M. Chorak Aug 2017

Yellow Perch Genetic Stock Structure In Eastern Lake Michigan: What Is The Importance Of Drowned River Mouth Lakes?, Gregory M. Chorak

Masters Theses

Habitat heterogeneity has the possibility of structuring populations. Even in connected landscapes, there can be cryptic structuring of populations that coincides with landscape features that limit gene flow or select for different phenotypes within a species. Yellow perch (Perca flavescens) is an economically and ecologically prominent fish in the Laurentian Great Lakes. In the Lake Michigan basin, yellow perch reside in nearshore Lake Michigan, including drowned river mouths (DRMs, lake-like habitats that link tributaries to Lake Michigan). The goal of this study was to understand whether yellow perch populations are structured in eastern Lake Michigan by the connected DRM lake ...


Polychlorinated Biphenyl Concentrations In Fish From Lake Michigan Tributaries And A Preliminary Risk Assessment Concerning Their Consumption By Sport And Tribal Fishermen, Amanda K. Potter Aug 2017

Polychlorinated Biphenyl Concentrations In Fish From Lake Michigan Tributaries And A Preliminary Risk Assessment Concerning Their Consumption By Sport And Tribal Fishermen, Amanda K. Potter

Masters Theses

Human and environmental health continues to be threatened by persistent organic pollutants in the Great Lakes ecosystem. Polycholorinated biphenyls (PCBs) are considered one of the most toxic contaminants in the Great Lakes due to their recalcitrance, bioaccumulation, lipid solubility, and adverse health effects.

The three main questions examined in this research were: 1) Do PCB concentrations vary between largemouth bass (Micropterus salmoides), northern pike (Esox Lucius), smallmouth bass (Micropterus dolomieu), and walleye (Sander vitreus) in west Michigan tributaries of Lake Michigan; 2) Do PCB concentrations vary on a watershed level among Manistee Lake, Muskegon Lake, Pentwater Lake, Tippy Pond, and ...


Nest-Site Selection And Neonate Survival Of Eastern Box Turtles (Terrapene Carolina Carolina) In Michigan’S Northern Lower Peninsula, Joseph T. Altobelli Aug 2017

Nest-Site Selection And Neonate Survival Of Eastern Box Turtles (Terrapene Carolina Carolina) In Michigan’S Northern Lower Peninsula, Joseph T. Altobelli

Masters Theses

Turtles (Order Testudines) are experiencing global declines largely due to anthropogenic influences such as habitat fragmentation, illegal collection and sales, and the threat of global climate change. Removal of individuals from the adult age-classes means there is now a greater need to understand the survival of neonate and juvenile turtle age-classes. In this study I examined a population of eastern box turtles (Terrapene carolina carolina) at the northern limit of their range in Michigan’s lower peninsula. The objectives of my thesis were 1. to determine the microhabitat factors that influence nestsite selection by female box turtles and how selected ...


Wild Turkey Resource Use On Food-Subsidized Landscapes And The Relationship Between Nesting Chronology And Gobbling Activity, Aaron David Griffith Aug 2017

Wild Turkey Resource Use On Food-Subsidized Landscapes And The Relationship Between Nesting Chronology And Gobbling Activity, Aaron David Griffith

Masters Theses

Across the Southeast, heightened concern exists that wild turkey (Meleagris gallopavo) productivity and populations are declining, but the underlying reasons are largely unknown. Further concern stems from declining turkey harvest in several southeastern states. I answered questions germane to formulating turkey harvest regulations, specifically related to supplemental feeding and the correlation of gobbling timing with nest incubation and the timing of the hunting season. I examined turkey resource use in the Red Hills region of northern Florida and southern Georgia, where supplemental feeding for northern bobwhite (Colinus virginianus) is common. This supplements food availability and may alter resource use of ...


Effect Of Ultrasonication On The Physicochemical Properties Of Sorghum Kafirin And Evaluation Of Its Anti-Inflammatory Properties In Vitro, Andrew Cullen Sullivan Aug 2017

Effect Of Ultrasonication On The Physicochemical Properties Of Sorghum Kafirin And Evaluation Of Its Anti-Inflammatory Properties In Vitro, Andrew Cullen Sullivan

Masters Theses

Sorghum is one of the hardiest, most drought resistent cereal grains known to exist, providing the bulk of nutritional content for many semi-arid regions and developing countries throughout Africa and southwestern Asia. It contains dense nutritional value, but due to inhibition factors within the grain, much of these nutrients are indigestible. Access to these nutrients, which have shown to contain high contents of bioactive molecules linked to the decrease of prevalence of chronic disease, must then be facilitated before consumption. In sorghum, these molecules could include complex carbohydrates, proteins and polyphenols. The overall objective of this study was to determine ...


Stable Isotopes, Phylogenetics, And Experimental Data Indicate A Unique Nutritional Mode For Rickenella Fibula, A Bryophyte-Associate In The Hymenochaetales, Hailee Brynn Korotkin Aug 2017

Stable Isotopes, Phylogenetics, And Experimental Data Indicate A Unique Nutritional Mode For Rickenella Fibula, A Bryophyte-Associate In The Hymenochaetales, Hailee Brynn Korotkin

Masters Theses

Fungal-bryophyte interactions have been documented in all lineages of bryophytes, however, many of these relationships are poorly understood. The fungus Rickenella fibula is a known associate of various mosses, but results from previous studies have not yielded conclusive evidence of its relationship to mosses or its trophic mode. The Rickenella clade exhibits a wide variety of nutritional modes, including other bryophyte-associated fungi. Here, I combine a broad range of methods, using phylogenetics, stable isotope analyses, PCR assays, in vitro experiments, and genomics to determine the nutritional mode of R. fibula. First, phylogenetic analysis of a supermatrix of 28S rRNA, 18S ...


Effect Of Different Cover Crop Species On Crop Production And Soil Health, Mingwei Chu Aug 2017

Effect Of Different Cover Crop Species On Crop Production And Soil Health, Mingwei Chu

Masters Theses

Integration of cover crops (CCs) can provide several benefits to row crop production systems. Comprehensive studies to understand the effectiveness of a mixture of CCs versus single or double species CCs are limited. In this study, we evaluated the effect of single and double species CCs, and the soil health mix (SHM, a combination of five species recommended by the United States Department of Agriculture) on soil quality attributes and crop production in western Tennessee. The results showed an increase in soybean yield after 3-years of SHM treatment, which corresponded with significantly higher soil moisture content and soil inorganic nitrogen ...


Application Of The Actigraph Gt9x Imu For The Assessment Of Turning During Walking And Running, Robert Thomas Marcotte Aug 2017

Application Of The Actigraph Gt9x Imu For The Assessment Of Turning During Walking And Running, Robert Thomas Marcotte

Masters Theses

PURPOSE: The purpose of this study was to examine the use of the ActiGraph GT9X gyroscope and magnetometer for turn detection and quantifying turn degree during walking and running. METHODS: Participants (N=17) completed pivot trials, treadmill walking and running (3 to 6 mph) and different degrees of turns (i.e. 45°, 90°, 135°, and 180°) during over-ground walking and running. Pivot and walking and running activities were completed for 1-minute and 6-minutes per trial, respectively. Turn frequency was constant (10 turns/minute) across all overground walking and running trials. ActiGraph GT9X devices were placed on the left and right ...


The Impact Of Genetic And Environmental Factors On Phytonutrient Concentrations Within Leafy Specialty Crops In Controlled Environments, Rosalie M. Metallo Aug 2017

The Impact Of Genetic And Environmental Factors On Phytonutrient Concentrations Within Leafy Specialty Crops In Controlled Environments, Rosalie M. Metallo

Masters Theses

Specialty leafy greens are excellent sources of antioxidants, vitamins, and minerals. Many of these metabolites are influenced by microclimate environmental conditions and genotype. The objective of this thesis was to measure the impacts of abiotic factors on plant growth and development along with nutritional content of specialty leafy greens in controlled environments. Chapter one looks at changes in biomass and nutritional content of different microgreen cultivars grown in a greenhouse over four growing seasons. Chapter two looks at the influence of light-emitting diode (LED) treatments on the growth and nutritional content of hydroponically grown kale. The morphology and nutritional content ...


Secondary Data Analysis: Associations Between Breastfeeding Intention And Accurate Body Size Estimation Among A Female, First-Time College Student Population., Katherine Dabney Powell Aug 2017

Secondary Data Analysis: Associations Between Breastfeeding Intention And Accurate Body Size Estimation Among A Female, First-Time College Student Population., Katherine Dabney Powell

Masters Theses

Background: Intentions towards feeding a future child may develop prior to conception. The Theory of Planned Behavior suggests that internal and external factors contribute to behavioral intentions. Among pre- and post-natal populations, negative body image has been identified as a potential barrier to breastfeeding intention. Though negative body image is of concern among young adult females, little is known about how this may relate to future breastfeeding intentions.

Research Objective: To explore possible relationships between intention to breastfeed, accuracy of body size estimation (BSE), and body size satisfaction (BSS) among a sample of freshman undergraduate females, and to identify other ...


Analyzing The Utilization And Trade Of Distillers’ Dried Grains With Solubles, Maria Celeste De Matteis Aug 2017

Analyzing The Utilization And Trade Of Distillers’ Dried Grains With Solubles, Maria Celeste De Matteis

Masters Theses

The production and consumption of distillers’ dried grains with solubles (DDGS), a coproduct of corn-based ethanol, has rapidly grown over the last decade in the United States (U.S.) and lately in other countries that prompt biofuel production, such as Argentina. DDGS has a more concentrated nutritional value relative to traditional feed grains and can be used in feed rations to meet the energy and protein requirements. In the first study, I evaluated the factors that determine the exports of U.S. DDGS, while the second study focused on the effects of the inclusion of DDGS in the feed rations ...


Genetic Analysis Of Distinct Clades Of Plethodon Cinereus At A Secondary Contact Zone In Northeast Ohio, Brian Waldron Jul 2017

Genetic Analysis Of Distinct Clades Of Plethodon Cinereus At A Secondary Contact Zone In Northeast Ohio, Brian Waldron

Masters Theses

Contact zones between species, subspecies, or incipient lineages offer important insights into the processes that maintain reproductive isolation. Plethodon cinereus, a highly abundant and wide-ranging terrestrial salamander found in the northeast United States and southeast Canada, provides an excellent model system for studying secondary contact zones. Using mtDNA, six distinct clades have been identified across the range of P. cinereus. Populations of two such clades, the Ohio (OH) clade, which dispersed through central Ohio following receding glaciers of the last glacial maximum, and the Pennsylvania (PA) clade, which dispersed through Pennsylvania and then west through northern Ohio, can be found ...


Foliar Mineral Accumulation Patterns Of Gypsophiles And Their Relatives From The Usa And Spain, Clare Muller Jul 2017

Foliar Mineral Accumulation Patterns Of Gypsophiles And Their Relatives From The Usa And Spain, Clare Muller

Masters Theses

Gypsum endemism in plants (gypsophily) is common on gypsum outcrops worldwide, but little is known about the functional ecology of Chihuahuan Desert gypsophiles. We investigated whether leaf chemistry of gypsophile lineages from the northern Chihuahuan Desert are similar to leaves of related non-endemic (gypsovag) species relative to their soil chemistry. We expected widely-distributed gypsophiles, hypothesized to be older lineages on gypsum, would have distinct leaf chemistry from narrowly-distributed, relatively younger lineages endemic to gypsum and gypsovags, reflecting adaptation to gypsum. We collected leaves from 23 gypsophiles and related non-endemic taxa growing on non-gypsum soils. Soils and leaves were analyzed for ...


The Influence Of Matrix Contrast On Species Richness In Fragmented Landscapes, Ian Reider Jul 2017

The Influence Of Matrix Contrast On Species Richness In Fragmented Landscapes, Ian Reider

Masters Theses

Habitat destruction is the leading threat to biodiversity worldwide, causing once continuous landscapes to become fragmented and isolated and harming the persistence of biodiversity. Our goal was to determine how species richness in fragmented forest landscapes is influenced by the vegetation density of the surrounding matrix. We gathered existing studies of fragmented landscapes with Species Area Relationship (SAR) data and analyzed the landscape vegetation in each study site using satellite imagery in ArcGIS. We investigated to see how contrast between vegetation density in matrix versus forested habitat areas correlated to the strength of the SAR for the 45 study landscapes ...


Effective Population Size, Demography, And Viability Of Eastern Massasaugas (Sistrurus Catenatus) In Southwest Michigan, Danielle R. Bradke May 2017

Effective Population Size, Demography, And Viability Of Eastern Massasaugas (Sistrurus Catenatus) In Southwest Michigan, Danielle R. Bradke

Masters Theses

As humans increasingly exploit natural areas, wildlife populations face a growing number of threats that often result in population decline and isolation. Small, isolated populations are vulnerable to extirpation due to both genetic and demographic factors. Yet, low detectability of many imperiled species often precludes the collection of population-level data important for assessing population viability and implementing successful conservation. The eastern massasauga (Sistrurus catenatus) is a cryptic pitviper that has been extirpated throughout much of its historic range due to agricultural conversion of wetland habitat and other synergistic threats. Consequently, this species is federally listed as threatened in both the ...


The Antimicrobial And Biofilm Disruption Activity Of Novel Amphiphiles, Elizabeth A. Rogers May 2017

The Antimicrobial And Biofilm Disruption Activity Of Novel Amphiphiles, Elizabeth A. Rogers

Masters Theses

Antibiotic resistant infections are responsible for approximately 23,000 deaths every year in the United States alone. The formation of bacterial biofilms makes resistant bacteria difficult to eliminate completely using chemical treatment. Therefore, novel antimicrobial compounds such as amphiphiles are essential to slow or stop the spread of resistant bacteria. Several novel series of amphiphiles were synthesized, and discrete aspects of their chemical structure were altered to investigate the relationship between structure and antibacterial activity. Minimum inhibitory concentration (MIC) assays were used to measure antibacterial activity against two Gram-negative and five Gram-positive bacteria, and the most effective compounds were tested ...


The Effects Of Coffee Ingestion On The Acute Testosterone Response To Exercise, Taylor Landry May 2017

The Effects Of Coffee Ingestion On The Acute Testosterone Response To Exercise, Taylor Landry

Masters Theses

Abstract

This study investigated the effects of coffee ingestion (COF) on serum testosterone responses to exercise in recreationally weight-trained males. Subjects ingested either 12 ounces of 6mg/kg caffeinated coffee (COF), decaffeinated coffee (DEC), or water (PLA) one hour prior to exercise in a randomized, within-subject, crossover design. The exercise session consisted of 21 minutes of high intensity interval cycling (alternating intensities corresponding to two minutes at power outputs associated with 2.0 mmol/L lactate and 4.0 mmol/L lactate) followed by resistance exercise (7 exercises, 3 sets of 10 repetitions, 65% 1RM, 1-minute rest periods). Subjects also ...


The Effects Of Caffeine Ingestion On The Hemostatic Response To Simulated Firefighting Activities, Sierra D. Wassell May 2017

The Effects Of Caffeine Ingestion On The Hemostatic Response To Simulated Firefighting Activities, Sierra D. Wassell

Masters Theses

Sudden cardiac events are the leading cause of death among firefighters, and it is acknowledged that most ischemic events are due to an occlusive thrombus formation. In addition, due to the demanding job requirements and shift work, firefighters commonly overuse caffeine. The purpose of this study was to examine the potential effects of caffeine on the hemostatic response to simulated firefighting activity. Twelve healthy male firefighters (age, 31.3 ± 5.4 yrs; weight, 94.2 ± 13.1 kg; BMI, 28.7 ± 2.9 kg·m-2) participated in this study, wearing full personal protective equipment (PPE) and self-contained breathing apparatus ...


Mouth Exposure To Carbohydrate Prior To Exercise Possibly Impairs The Efficacy Of Carbohydrate Mouth Rinsing During Exercise, Kevin Decker May 2017

Mouth Exposure To Carbohydrate Prior To Exercise Possibly Impairs The Efficacy Of Carbohydrate Mouth Rinsing During Exercise, Kevin Decker

Masters Theses

Decker K. P., M. J. Saunders, N. D. Luden, C. J. Womack, and N. J. Hladick. Mouth Exposure to Carbohydrate Prior to Exercise Possibly Impairs the Efficacy of Carbohydrate Mouth Rinsing during Exercise. Purpose: Carbohydrate mouth-rinsing (CHO-MR) during intense endurance exercise has been associated with improved cycling performance, due to neurological influences. However, prior studies have reported the efficacy of CHO-MR is attenuated following a pre-exercise meal. To determine if this outcome is related to desensitization of CHO receptors (rather than metabolic effects following digestion), this study will investigate whether CHO-MR prior to exercise influences cycling performance when CHO-MR is ...


The Effect Of Calcium In Artificial Substrates For Oyster Restoration: Implications For The Mitigation Of Oyster Population Decline, Jessie Mandirola May 2017

The Effect Of Calcium In Artificial Substrates For Oyster Restoration: Implications For The Mitigation Of Oyster Population Decline, Jessie Mandirola

Masters Theses

Oyster populations in the Chesapeake Bay have declined by 99% over the past 150 years due to overharvesting, disease, ocean acidification, and poor water quality. Restoration efforts are needed to reestablish native oyster populations. Current restoration efforts utilize natural oyster shells but these methods are expensive and unsustainable. Therefore, restoration is starting to use artificial substrates instead. Concrete has been successfully used in previous research; spat will attach and oysters will grow. However, there is a lack of knowledge about how the composition of concrete effects oyster larval recruitment. We tested concrete made with limestone sand (“special concrete”) to increase ...


Female Color Variation And Male Harassment In The Polymorphic Damselfly Megalagrion Calliphya, Phoebe Cook May 2017

Female Color Variation And Male Harassment In The Polymorphic Damselfly Megalagrion Calliphya, Phoebe Cook

Masters Theses

Female dimorphism is commonly hypothesized to be a result of adaptations to male harassment. I tested whether polymorphic female coloration in the Hawaiian damselfly Megalagrion calliphya is under selection from male sexual harassment via two possible forms of negative frequency-dependent selection: the male mimicry and the learned mate recognition hypotheses. I measured male behavior toward tethered females at mating sites under naturally occurring conditions and found no evidence for either hypothesis. Harassment rates did not significantly differ between female morphs. One measure of morph frequency did predict harassment of all individuals, but this relationship was driven by a single population ...