Student evaluations of teaching (SETs) are a tool commonly employed at universities for assessing faculty members’ teaching performance and even eligibility for promotions. Survey items often ask students to make judgments about the professor’s knowledgeability, teaching style, and class difficulty. Fair and consistent review of SETs is critical for faculty members as they seek to improve their teaching skills and gain professional recognition. The present study investigates the novel question of how judgments of completed SETs are made. Undergraduate students (n = 160) and faculty participants were shown and asked to make judgments about a fictional SET. The four conditions varied in whether the fictional professor being evaluated was rated lower or higher than average, and whether or not the professor gave in-class quizzes. Follow-up questions had participants evaluate why they made certain judgments about the professor. This research helps explicate the factors that contribute to faculty members’ interpretations of and students’ responses on SETs.

In nature, it is adaptive for an animal to learn to make different responses to different stimuli (e.g., climb some trees to obtain ripe fruit but forage near the base of others). In the laboratory, learning to make different responses (e.g., lever pressing vs. chain pulling) is facilitated by different outcomes (e.g., food vs. water) for each response. The current research aimed to extend this differential outcomes effect in rats with a visual discrimination procedure. Rats were reinforced for pressing a lever on the left side (left lever) of operant box in the presence of one visual stimulus (e.g., a flashing light) and for pressing the right lever in the presence of another visual stimulus (e.g., a solid light). In the experimental group, the rats received a different outcome for each correct response (flashing light -> left lever -> sugar water; solid light -> right lever -> chocolate pellets). In the control group, the rats received only one of the outcomes (e.g., sugar water) for both responses. The data will be discussed in terms of support for the differential outcomes effect. Examining the effects of a differential outcomes procedure in a variety of tasks will help to better understand the conditions under which this effect can facilitate learning.

Few studies have directly evaluated the assumption that equivalence-based instruction establishes stimulus classes with greater efficiency than direct instruction of all possible stimulus relations within each class. Therefore, this study evaluated the efficiency of EBI protocol compared to direct instruction (DI), using fifteen visual abstract stimuli (A1 through E3). Forty-eight undergraduate students were assigned to one of four groups: The EBI-DI group received EBI in Phase 1 and DI in Phase 2, and vice versa for DI-EBI group. EBI-EBI and DI-DI group received EBI and DI in both phases, respectively. In Phase 1,EBI-first groups received training on AB and BC relations and DI-first groups received training with all possible relations. After achieving mastery criterion, the ABC test included all possible trial types. In Phase 2, all groups received training to (a) add a fourth stimulus (D), and (b) add a fifth stimulus (E) to the class. No statistically significant difference was found between EBI and DI-first groups in the number of trials, reaction time during test and overall trials to achieve criteria and the performance in ABC test. There was an interaction between the first training condition (EBI vs. DI) and the second training condition (EBI vs. DI) on percentage accuracy in the first ABCD test, but not in ABCDE test.

This study explored the extent to which nostalgia proneness (a sentimental longing for the past) is associated with attitudes towards intimate partner violence (IPV). Research has found that individuals who report more conflict in their romantic relationships also report being more nostalgic for their own and for their relationships’ past. If nostalgia is related to more conflict in relationships, then it may also be related to greater acceptance of IPV. In this study, a sample of 142 participants completed measures of self-relevant nostalgia, relationship-relevant nostalgia, and attitudes toward IPV (using it and enduring it), and relationship outcomes (e.g., optimism, satisfaction, commitment). Results showed positive correlations between nostalgia (self-oriented and relationship-centered) and self-use of IPV (both using it and enduring it). These preliminary results suggest that a sentimental longing for the past is associated with endorsement of IPV use, however, other unexplored personality variables such as attachment style may moderate these associations. Future work should explore these findings in experimental and longitudinal designs.

Investigating how people regulate their learning is important because study decisions can impact actual learning. Compared to younger adults, older adults often show age-related deficits in memory. This deficit may be because older adults are less effective at regulating their learning. One factor that can influence memory is the valence of information. Prior research has established that older and younger adults are more likely to recall emotional information compared to neutral information and also predict that emotional information will be better remembered relative to neutral information (e.g., Tauber & Dunlosky, 2012). It is unclear how both age groups regulate their learning of emotional and neutral information. Investigating this issue, older and younger adults studied words that were positive (e.g., circus), negative (e.g., snake), or neutral (e.g., fork). Participants regulated their learning by self-pacing their study (Experiment 1) or by selecting half of the words to restudy (Experiment 2). After studying each word, participants predicted the likelihood of remembering it on a scale of 0% (will not remember) to 100% (will remember). Finally, participants took a free-recall test. Consistent with prior research, both age groups demonstrated higher predicted and actual memory for emotional information relative to neutral. Importantly, both age groups’ self-paced study times did not differ for emotional and neutral information. In contrast, both age groups restudied neutral words more frequently than emotional words. Thus, when participants were forced to strategize their learning, both age groups made good study decisions, prioritizing neutral information at the expense of emotional information.

For my SERC grant proposal, I studied the effect of auricular vagus nerve stimulation (aVNS) on learning in adults with dyslexia. The vagus nerve is a cranial nerve that, when stimulated, initiates the release of two neurotransmitters (NT’s) that are important in learning and memory (norepinephrine and acetylcholine). When a stimulus is presented at the same time as vagus nerve stimulation, this increases neural plasticity for the paired item. We have already tested this approach on typically-developing adults using the auricular branch of the vagus nerve, which runs through the ear and can be stimulated non-invasively. During this intervention, timed bursts of electrical stimulation were delivered while the participant learned novel letter-to-sound correspondences for Hebrew letters with the goal of increasing recall and automaticity. We have already found significant improvements in letter recognition, reading speed, and nonword decoding in typically-reading participants receiving stimulation compared to those in control groups. Our ultimate goal is to help children with dyslexia read more fluently. In the first step towards this goal, we enrolled a group of adult participants with dyslexia who received 10 days of Hebrew orthography training paired with aVNS. Participants were evaluated at four timepoints to monitor learning and compare progress with other groups: at day 1, halfway through training, at the end of training, and 3 weeks after training ended. We measured letter recognition, letter-to-sound fluency, and decoding at each time point. We will present our preliminary findings at SRS and discuss future directions.

Early life stress has shown to be related to an increased preference for smaller, more quickly acquired rewards over larger, delayed rewards—or an inability to delay gratification—a fundamental component of impulsivity. Beyond this, impulsivity is also characterized by difficulty concentrating and exercising self-control and has been found to significantly impact learning and memory. Specifically, in children, higher impulsivity is associated with greater learning difficulties, such as with reading. Previous research has also shown that adults with higher levels of inflammation portray higher impulsivity. The current study aims to investigate the relationship between impulsivity, inflammation, and childhood environmental conditions within children between the ages of 3-17. Saliva samples were collected from 248 children visiting the Fort Worth Museum of Science and History in order to measure current levels of proinflammatory cytokines, which indicate immune activation. Children then participated in a series of tasks that measured their ability to concentrate, learn to inhibit their responses, and delay gratification, while background and demographic information was collected from their parents. Results will reveal whether children growing up in stressful environments also have higher levels of inflammation and impulsivity.

Attitude Representation Theory (Lord & Lepper, 1999) asserts that individuals evaluate attitudes based on a subset of associations. As this subset of associations varies, attitudes can vary as well. Previous research demonstrated that people can mistake self-generated information for provided information, through source monitoring errors (Johnson, Hashtroudi, & Lindsay, 1993), after extrapolating beyond the information given (Lu, 2015). We sought to apply ART and cognitive tasks (e.g., extrapolation, embellishment, and validity) by having participants judge the actions of fictitious groups. Although these groups are fictitious, they allude to current political viewpoints. We tested the effects of extrapolation (thinking about additional attributes of a target group; Experiment 1), embellishment (convincing a friend not to join the target group; Experiment 2), and biased assimilation (testing truth and validity of sources; Experiment 3) on polarization of moral judgments. Compared to a control group, embellishment polarized negative attitudes toward the group. The current set of studies could shed some insight about how people view issues, self-radicalize judgments, and understand thoughts of lone-wolf terrorists.

There are many benefits for children to receive music education. Research shows that note reading and music playing skills are positively correlated with cognitive development, motor proficiency, and self-esteem (Bilhartz, Bruhn, & Olson, 1999; Costa-Giomi, 2004; Schellenberg, 2004). The purpose of this study was to evaluate the use of equivalence-based instruction (EBI) to teach elements of music to children who have no music background in the age range of 4-7 years. The children first learned to relate the name of a note (e.g. “quarter”, “half”) to the length of the note as well as a picture of the note. They were also taught to name the lengths and names of sequences of notes (e.g. “quarter, quarter, half”). In the second part of this study, the children learned letter names of notes (e.g., “A”), keyboard placement, and what finger (e.g. thumb) goes with each letter name and piano key. Finally, we tested for emergent relations from part one and part two. Date collection in progress, but we predict to see emergence of relations between what was taught in part one and what was taught in part two. For example, when told “play this sequence on A,” participants will be able to use the correct finger on the correct piano key to play the notes in the sequence at the correct lengths.

Will work for alcohol! Reward value of alcohol in rats.
Joanna B. Thompson and Mauricio R. Papini

Abstract

The misuse of alcohol is a prevalent problem in the United States, contributing to an array of public health, social, and economic issues. It is estimated that over 16 million Americans each year receive a diagnosis of an alcohol use disorder (AUD) which contributes to an economic burden upwards of $249 billion (NIAAA, 2017). Previous research has shown that alcohol has rewarding properties which motivate organisms to engage in voluntary, oral consumption (Jupp et al., 2011). Although studies have provided evidence for decreased alcohol consumption in rodents, no studies to date have examined high concentration alcohol (upwards of 60%). We used a mixed Pavlovian-instrumental paradigm to train rats to self-administer solutions of 0, 2, 10, and 66% alcohol. Once oral self-administration was established, rats were switched to a progressive-ratio schedule of reinforcement where a greater response effort was required to gain access to each of the alcohol solutions. Solution presentation was switched between rats each day. Higher levels of behavioral responding to an empty sipper to gain access to the alcohol solution was indicative of the reward value of that particular solution. Rats exhibited similar breakpoints for each alcohol solution, though expended less effort for 0% (water). Future directions will involve antagonizing the orexin-1 receptor, which has demonstrated to decrease alcohol consumption (Anderson et al., 2014). A non-peptide selective orexin-1 receptor antagonist, SB-334867, will be administered prior to sessions of progressive-ratio alcohol self-administration to determine the effective dose (0, 1, 5, or 10 mg/kg) at decreasing self-administration of alcohol. These findings are relevant for developing an animal model of alcohol intoxication aimed at a potential clinical drug therapy for alcohol abuse.

Anderson, R., Becker, H., Adams, B., Jesudason, C., & Rrick-Kehn, L. (2014). Orexin-1 and orexin-2 receptor antagonists reduce alcohol self-administration in high-drinking rodent models. Frontiers in Neuroscience, 8, 33.
Jupp, B., Krivdic, B., Krstew, E., & Lawrence, A.J. (2011). The orexin-1 receptor antagonist SB-334867 dissociates the motivational properties of alcohol and sucrose in rats. Brain Research, 1291(1), 54-59.
National Institute on Alcohol Abuse and Alcoholism. (2017). Alcohol use disorder. Retrieved February 2019 from https://www.niaaa.nih.gov/alcohol-health/overview-alcohol-consumption/alcohol-use-disorders

Since the 1920s, it has been recognized that nonhuman animals are capable of forming expectations about rewards and exhibit emotional responses when those expectations are violated—when obtained rewards have lower value than expected rewards. Our lab utilizes a rodent model for coping with unexpected reward loss with a specific interest in furthering our understanding of the underlying neural correlates. Frustration effects in rats are commonly and reliably produced using the consummatory successive negative contrast (cSNC) procedure, where rats are given access to a highly preferred 32% sucrose solution followed by an unexpected downshifted to 4% sucrose. Such surprising nonreward leads to a suppression of behavior compared to a control group that always received the less-preferred, 4% sucrose solution. Studies involving neurological manipulation indicate that permanent lesion or reversible deactivation of the central amygdala (CeA) and the basolateral amygdala (BLA) eliminate the cSNC effect. While these studies are important for identifying key structures, they provide little information about the underlying circuitry. The present research examined the role of the neural pathway between the BLA and CeA in the cSNC task using a chemogenetic approach known as Designer Receptor Exclusively Activated by Designer Drugs (DREADDs). Inhibitory DREADDs are intracranially infused into the key structures and later activated by intraperitoneal injections of clozapine N-oxide (CNO). Both groups of rats received unilateral inactivation of the BLA and CeA. The experimental (contralateral) group has one functioning area in each hemisphere, a procedure that disrupts communication between the two areas. The control (ipsilateral) group has one hemisphere disrupted while the other is left intact. Preliminary results indicate a disconnecting the BLA-CeA pathway reduces the cSNC effect in contralateral rats compared to ipsilateral rats. The BLA-CeA pathway is necessary to respond to surprising nonreward. These results add to the hypothesized model of circuity underlying unexpected reward loss in mammals. Because the amygdala circuitry is highly conserved across species, these results inform us about the neural circuitry engaged by similar instances of frustrative nonreward in the human brain.

According to Terror Management Theory, religious people are motivated to cling to their religious beliefs when reminded of their death. Quest motivated religious people, however, value doubt in their beliefs and are uncertain about the validity of their religion. The purpose of the present work was to examine medical decision making among individuals who actively question their religious beliefs when death concerns are salient. Specifically, we found that individuals who are quest motivated reject traditional faith healing in favor of more scientific medical practices. These effects were exacerbated by death awareness. These findings support previous research suggesting that quest individuals are motivated to embrace their religious doubts in when faced with existential concerns.

The Texas horned lizard (Phrynosoma cornutum) is considered a threatened species in Texas and Oklahoma, due to substantial range declines over the past several decades. Horned lizards are believed to be highly vulnerable to habitat alterations, due to extreme specialization on ants, particularly harvester ants (Pogonomyrmex spp.). I analyzed diets of Texas horned lizards from two small towns by identifying exoskeletons of prey items found in fecal pellets. I assessed dietary specialization by comparing diet to prey availability, based on pitfall traps and abundance of harvester ant colonies. My results found strong spatio-temporal variation with respect to prey abundance and consumption. Harvester termites (Tenuirostritermes cinereus) and big-headed ants (Pheidole spp.) accounted for over 70% of all prey consumed. Average consumption of big-headed ants was comparable to their abundance in pitfall traps, but consumption of harvester termites was much higher than their pitfall trap abundance. Consumption of harvester ants is strongly correlated with the number of harvester ant colonies within study sites and horned lizard home ranges. Dietary diversity and richness were positively related to the area of dense vegetation in sites and lizard home ranges. These results suggest horned lizards in these towns adjust diet in relation to prey availability, which is considered a characteristic of generalist predators. The superior nutritional value of harvester termites relative to similarly sized ants could explain the apparent lack of size-based prey preference in these horned lizard populations.

Exposure to contaminants during development has the potential to cause adverse biological alterations that can persist through depuration periods and into adulthood. This study examined the effects of chemically induced, early-life-stage thyroid disruption on endpoints associated with thyroidal and reproductive function in the fathead minnow (Pimephales promelas). Fish were exposed to propylthiouracil (PTU) from 1 to 43 days post hatch (dph) to induce hypothyroidism. At the end of exposure, length and weight were measured and samples were taken for gene expression analysis. The remaining fish were transferred to un-dosed water and raised to maturity and, at 164 dph, a 21-day breeding assay was performed. At the end of exposure, fish exposed to PTU had significantly reduced length and weight indicating successful thyroid disruption. There were also significant differences in expression of several genes involved in the thyroidal and reproductive signaling systems. After maturation, there were no significant differences in any morphological variables. During the 21-day breeding assay, fish from the PTU exposure group had significantly reduced overall fecundity relative to controls. Based on data collected so far, it appears that this reduction in fecundity is due to either ovarian dysfunction or alterations in reproductive behavior. The results show that early-life-stage hypothyroidism can affect reproductive function later in life even after thyroid related endpoints have returned to control levels.

Hepatitis C Virus is estimated to infect 3% of the world’s population and is transmitted by contaminated blood. HCV can be asymptomatic or lead to cirrhosis of the liver, liver cancer or hepatocellular carcinoma. Understanding the virus life cycle and the viral proteins generated by HCV will help generate new mechanisms of inhibition of the virus. HCV produces 10 viral proteins when it infects hepatocytes that increase the reproduction ability of the virus. The anti-viral response of the body uses transcription factors such as ATF-2, NFKB, and IRF-3 that translocated into the nucleus and bind to the interferon gene that produces interferon to alert the body of a viral infection. HCV viral protein NS3/4A acts as protease to cleave the polycistronic strand of viral proteins made by HCV and is known to inhibit IRF-3 movement into the nucleus to inhibit the production of interferon. HCV viral protein NS5A is known to inhibit the movement of transcription factor NFKB into the nucleus, thus inhibiting the anti-viral response. We are interested to see if NS3/4A inhibits the anti-viral response by blocking the movement of both transcription factors IRF-3 and NFKB into the nucleus.

Psychological stress afflicts a considerable portion of the world’s population, and is linked, as both a risk factor and potential contributor, to dementia-related brain dysfunction in diseases such as Alzheimer’s disease (AD). The brain dysfunction in AD is marked by an increase in Amyloid-beta, the protein responsible for plaque deposition in the brain. The present study aimed to explore alterations in the production of amyloid-beta in response to stress and inflammation. Specifically, we were interested in social isolation stress- and inflammation-induced differences in cognition and amyloid-beta production in male and female mice. Mice were subjected to acute social isolation (6 days) and chronic isolation (28 days) or control group housing. Results revealed that exposure to both acute and social isolation can lead to an exacerbated inflammatory response to lipopolysaccharide (LPS). Subsequently, we examined if the stressors altered amyloid-beta production following the same inflammatory stimulus. Animals received LPS or saline injections once per day for seven consecutive days after the completion of either stress protocol or group housing. The contextual fear conditioning paradigm (CFC) was utilized to assess cognition. Brain tissue extractions were performed to quantify amyloid-beta protein levels. It is hypothesized that isolated animals will demonstrate cognitive deficits in CFC as well as increased brain amyloid-beta following LPS injections.

Mercury (Hg) is a toxic heavy metal that has contaminated all aquatic food webs and can pose a health risk to aquatic predators. Piscivorous birds are apex predators in aquatic systems that are exposed to mercury through the consumption of Hg-contaminated fish. Although there is extensive data on Hg concentrations in fish, the data on Hg concentrations in birds is relatively limited. I used a previously published relationship between Hg concentrations in piscivorous bird blood and Hg concentrations in prey fish to estimated Mg concentrations in the blood of four species of piscivorous wading birds in the south central U.S. [Little Blue Herons (Egretta caerulea), Green Herons (Butorides verescens), Great Egrets (Ardea albus) and Great Blue Herons (Ardea herodias)] from the concentration of Hg found in bluegill (Lepomis macrochirus). Estimated Hg concentrations in bird blood increased with the size of prey fish consumed and was lowest for Little Blue Herons and Green Herons, intermediate for Great Egrets and highest for Great Blue Herons. Estimated Hg concentrations in bird blood was greatest in ecoregions where conifer-adjusted mercury deposition was highest. Mercury risk to bird health varied with bird species and increased with Hg deposition. Little Blue Herons, Green Herons, Great Egrets and Great Blue Herons were at some level of risk in 14, 36, 86 and 100% of ecoregions, respectively. The threat of Hg to the health of piscivorous wading birds may not be unique to south central U.S. and may extend throughout the southeastern United States due to high Hg deposition and extensive forest coverage.

Hydrilla verticillata is an invasive aquatic weed in the United States (U.S.) that has recently
developed resistance to the herbicide fluridone. In this study, we utilized genome walking and
quantitative real-time PCR to investigate the phytoene desaturase (PDS) gene copy number of
hydrilla samples with different ploidy levels. We asked 1) if copy number simply corresponds to the
ploidy level, and 2) if there is increased PDS copy number in resistant populations due to gene
duplication. Using qPCR and microsatellite loci to compare PDS copy number between diploid,
triploid and tetraploid samples, we found that diploid hydrilla from Africa showed higher PDS copy
number than triploid populations from the U.S. The results also indicated that there was no
significant difference in PDS gene copy numbers between the fluridone-resistant and -susceptible
triploid populations. Our study suggests that PDS amplification may not be a mechanism
responsible for fluridone resistance in hydrilla.

Methylmercury (MeHg) is a toxic environmental contaminant found in all waterbodies on Earth. Aquatic emergent insects, such as mosquitoes and midges, can transfer MeHg from waterbodies to terrestrial ecosystems. Terrestrial shoreline spiders consume aquatic emergent insects and become contaminated with MeHg. Methylmercury-contaminated spiders can pose a risk to songbirds that consume terrestrial spiders. Because shoreline spiders have MeHg concentrations that reflect MeHg contamination of nearby aquatic ecosystems and are an important source of MeHg to songbirds, they have been proposed as a biosentinel species that can be used to estimate MeHg contamination of waterbodies. In this study, I used long-jawed orb weavers (Tetragnatha sp.) as a biosentinel species to examine MeHg contamination along the Clear Fork and the West Fork of the Trinity River, Fort Worth, Texas. The objectives of this study were to: 1) evaluate MeHg contamination in long-jawed orb weavers from two forks of the Trinity River, and 2) determine if the concentrations of MeHg in the spiders pose a risk to songbirds that feed on spiders. I collected 101 and 105 spiders along the Clear Fork and the West Fork, respectively. I used a Direct Mercury Analyzer to determine the total Hg concentration of the long-jawed orb weavers. Because MeHg is the primary species of mercury in spider tissues, I used total Hg as a proxy for MeHg. All spiders were contaminated with MeHg, with spiders along the Clear Fork having significantly higher MeHg concentrations than spiders along the West Fork. Methylmercury in spiders increased with spider size along the Clear Fork. Concentrations of MeHg in spiders along the Clear Fork and the West Fork were high enough to pose a risk to the physiology of nestling songbirds that feed on spiders.

Understanding bacterial virulence is important because it provides insight into the molecular basis behind bacterial infections. With the decreased efficacy of antibiotics due to the development of drug resistance, this knowledge could be used to identify specific targets for new pharmacological targets thereby strengthening our arsenal against these pathogens. Currently, our main mechanism by which to evaluate in vivo virulence is the mouse model (Mus musculus). While this model is effective, there are substantial ethical and resource constraints associated with vertebrate use. In order to provide alternative in vivo testing models, this study investigated the invertebrate wax worm larvae, G. mellonella, as an in vivo infection model for B. anthracis. To validate the ability of G. mellonella to discern attenuated bacterial strains, previously identified virulence mutants were constructed and assessed. This model proved capable of distinguishing between virulent and avirulent strains. Next, we tested whether G. mellonella could identify novel virulence mutants. A small collection of transposon mutants was screened for deficits in reactive oxygen species (ROS) survival and iron acquisition using in vitro screens. This yielded 10 attenuated mutants. These mutants were then assessed in G. mellonella and 2 were found to have an in vivo phenotype. These results demonstrate the potential effectiveness of G. mellonella as a future infection model and could increase the efficiency in the identification of novel bacterial virulence mutants.

Dreissena polymorpha, zebra mussels, are an invasive species of freshwater bivalves that have recently spread into bodies of water across North America via the Great Lakes. Zebra mussels are mainly spread throughout the United States by their free-swimming larvae called veligers that are moved from waterbody to waterbody by human boat traffic, attributing to the success of their invasive spread. Once an adult zebra mussel population is established, they proliferate quickly and cause many problems to the ecosystem by their efficient filter feeding abilities. They also cause damage to boating and water treatment equipment by tightly attaching to many hard surfaces. Zebra mussels have recently entered many Texas waterways, indicating that they have possibly adapted to conditions outside of originally expected for a cold water species that are not representative of the Great Lakes region. The focus of this study was to look at various environmental factors which may affect zebra mussel survival and reproduction including temperature and the effects of a copper-based molluscicide, EarthTec QZ, as a potential mechanism of control. Zebra mussel survival and reproductive success were examined in various experiments to gain an overall understanding of the effects at all zebra mussel life stages.

Methylmercury (MeHg) is an aquatic contaminant that can be transferred to terrestrial predators by emergent aquatic insects such as odonates (damselflies and dragonflies). We observed the effects of time on odonate-mediated MeHg flux (calculated as emergent odonate biomass MeHg concentration) in 20 experimental ponds and the potential risk to nestling red-winged blackbirds (Agelaius phoeniceus) posed by consuming MeHg-contaminated odonates. Emergent odonates were collected weekly from ponds containing four emergent traps per pond over an 9-mo period (February–October 2017). The MeHg flux from damselflies, aeshnid dragonflies, and libellulid dragonflies began in March and peaked in May, June, and July, respectively, and then declined throughout the rest of the summer. Nesting of red-winged blackbirds overlapped with peak odonate emergence and odonate-mediated MeHg flux. Because their diet can be dominated by damselflies and dragonflies, we tested the hypothesis that MeHg-contaminated odonates may pose a health risk to nestling red-winged blackbirds. Concentrations of MeHg in odonates exceeded wildlife values (the minimum odonate MeHg concentrations causing physiologically significant doses in consumers) for nestlings, suggesting that MeHg-contaminated odonates can pose a health risk to nestling red-winged blackbird.

Alzheimer’s Disease (AD) is a neurodegenerative disease that is characterized by deficits in learning and memory. AD pathology is associated with neuronal death through the accumulation of amyloid beta (Aβ) plaques in the synapses. Our lab has previously demonstrated that Lipopolysaccharide (LPS), a component of gram-negative bacteria, induces an inflammatory response that increases Aβ found in the brain. Dendritic spines are projections on dendrites that may or may not be synapsing with an axon. Previous research indicates that there is a correlation between the number of properly functioning synapses and the number of dendritic spines. In this study, LPS was administered to induce inflammation, stimulating Aβ production. We then quantified dendritic spine density in order to compare dendritic spine density in the hippocampus of both LPS- and saline-treated groups. Contrary to our hypothesis, we saw a non-significant increase in dendritic spine density following LPS treatment, when compared to saline controls.

There has been mounting concern from both scientists and the public regarding the presence and biological effects of emerging contaminants (ECs) in the environment. ECs can be defined as contaminants that are not currently subject to routine monitoring programs or regulatory standards, but that have the potential to cause adverse environmental or human health effects. These pollutants are being found in increasing levels in aquatic environments, and as such, the possible health impacts of these contaminants have become a growing focus of scientific research. Some classes of ECs, especially those that disrupt neurological development or thyroid hormone levels, have the potential to alter the growth, development, and function of the eyes. For many organisms, eyesight is crucial to survival as it allows them to avoid danger, obtain food, and perform many other important activities. However, reliable methods for testing the effects of ECs on vision are scarce, so the full impact of many ECs remains unknown. As such, this project aimed to determine dependable ways to measure visual development and function in the fathead minnow, a small fish frequently used to screen for chemical toxicity and adverse effects. We found that the feeding assay was a straightforward and promising option for measuring vision because it estimated the average prey capture ability of a group in a relatively short amount of time. We also found that the optomotor assay, while compelling, presented no significant differences between groups for the variables tested. However, there were practical differences observed throughout the trials, indicating that although the assay is complex, further testing and development could transform it into a reliable source of data.

Zebra and Quagga mussels are aquatic and highly invasive freshwater bivalve molluscs native to Eurasia. They have spread at an exponential rate into bodies of water throughout the country by means of our interconnected waterway. Prior analysis of their distribution has determined a consistent global pattern in which a population of zebra mussels initially invades a body of water and subsequently, a population of quagga mussels is established in the same region. Despite differential habitat preferences, both species have been found to live and reproduce in the same location. Since both species exhibit broadcast spawning as a reproductive mechanism, the potential for hybridization exists; this potential was analyzed via evaluating the initial fertilization and early embryonic cleavage stages required for production of viable hybrid offspring. A series of hybridization crosses were performed and compared against a control. Fertilization events observed and analyzed included motility and chemotaxis, the acrosome reaction, sperm binding and entry into the egg cytoplasm, and finally cleavage and early development. Inability to produce viable offspring suggests a hybridization-block has been established between the two species at the level of fertilization or early development.