Rhinovirus is the most prevalent virus in humans and is often the cause of the common cold. Modeling the dynamics of rhinovirus can allow us to observe important aspects of the virus including the general growth of the virus, the remaining target cells, the number of cells in the eclipse phase, and the number of infected cells. Following that, we can attempt to estimate parameters such as how much virus an infected cell produces or how long it takes an infected cell to start producing virus. We can use a method called Markov Chain Monte Carlo (MCMC) to try and gain more accurate estimates of those parameter based off observed data. Modeling rhinovirus will give us deeper insight into the workings of rhinovirus and allow us to try better and more accurate models of the virus.
Non-invasive temperature sensing is necessary for the analysis of biological processes occurring in the human body including cellular enzyme activity, protein expression, and ion regulation. Considering that a variety of such biological processes occur at the microscopic scale, a mechanism allowing for the detection of the temperature changes in microscopic environments is desired. Although several such techniques have been developed involving nanomaterials, there is still a need in deterministic non-invasive biocompatible approach allowing for temperature measurements both outside the cells and in the intracellular compartments. Here we develop a novel approach utilizing graphene quantum dots (GQDs) as agents for such detection. Because of their small 2-5 nm size, non-invasive optical sensitivity to temperature change and high biocompatibility, GQDs enable biologically safe sub-cellular resolution imaging. Both bottom-up synthesized nitrogen-doped graphene quantum dots and quantum dots produced from reduced graphene oxide via top-down approach in this work exhibit temperature-induced fluorescence variations used as sensing mechanism. Distinctive quenching of quantum dot fluorescence by up to 19.8 % is observed, in a temperature range from 25℃ to 49℃, in aqueous solution, while the intensity is restored to the original values as the temperature decreases back to 25℃. A similar trend is observed in vitro in HeLa cells as the cellular temperature is increased from 25℃ to 41℃. Our findings suggest that the temperature-dependent fluorescence quenching of bottom-up and top-down-synthesized graphene quantum dots can serve as non-invasive reversible deterministic mechanism for temperature sensing in microscopic sub-cellular biological environments.
Star clusters are key age-dateable tracers of the chemical history of the Milky Way. Star clusters can provide significant constraints on galaxy chemical evolution models. The large discrepancies between different small studies limit the accuracy of these constraints, so a large uniform study is needed. To create a large uniform sample, we observed stars in 63 clusters with the same telescope. We then determined the chemical makeup of these stars using a machine learning tool called The Cannon. Using this sample, we examine the change in chemical abundance over the radius of our galaxy.
Nano- and microcrystalline ZnO is a low-cost material, employed in many applications due to its optoelectronic, structural and chemical properties as well as a great variety of synthesis methods. Among these applications, antibacterial action of ZnO is a budding field of interdisciplinary research. Despite numerous studies of this antibacterial action, the physical and chemical mechanisms behind it are still largely not understood. In particular, the influence of the crystal surface morphology and surface-surface interactions between the bacteria and ZnO are largely unknown. Hexagonal (wurtzite) ZnO crystals terminate with three different types of crystallographic surfaces: charged polar hexagonal (Zn or O), electrically neutral nonpolar rectangular and partially polar pyramidal slanted. In our studies we employ a hydrothermal growth procedure to synthesize nanocrystals and microcrystals of ZnO with tunable morphology to investigate the influence of surface types on interactions with bacteria as well as surface charge dynamics. To quantify the antibacterial action we employ minimum inhibitory concentration (MIC) assays of staphylococcus aureus with hydrothermally-grown ZnO microcrystals. Scanning electron microscopy (SEM) is used to characterize the morphology of the as-grown ZnO specimens as well as the organization of these particles after their interactions with bacteria. To characterize electronic structure and dominant charge transport mechanisms at ZnO surfaces we performed photovoltage (SPV) experiments. Our results confirm that antibacterial action is a result of ZnO surface interactions with extracellular material, whereas internalization of ZnO particles (happening in the case of nanoscale ZnO) is not necessary for inhibition. We also report that the electronic transitions at the surface of the ZnO particles are consistent the theoretically predicted electronic structure of ZnO, with the spectral signatures of surface states which could be the source of the antimicrobial action.
Author(s): John Reeks Physics & Astronomy Pavan Ahluwalia Physics & Astronomy Edward Bormashenko Physics & Astronomy Luc Le Physics & Astronomy Logan Simon Physics & Astronomy
Advisor(s): Yuri Strzhemechny Physics & Astronomy
Reportedly, hydrophobic surfaces of polysulfone (PSu) thin films become hydrophilic following exposure to UV radiation and it can affect PSu novel applications in microfluidics and biophysics. Fundamental mechanisms behind this effect remain unknown. To elucidate them, in our work we study surface charge transport employing surface photovoltage (SPV) on thin PSu polysulfone films spin-cast on silicon substrates. Since exposure of PSu even to an ambient UV light could affect the surface properties we ran SPV spectroscopy as well as SPV transient experiments on both as-received samples fabricated in darkness and UV-irradiated films of varying and controllable thicknesses. We report on the comparison of the SPV response in the as-deposited and UV-irradiated polysulfone samples.
Modern astronomical catalogs consist of up to billions of stars and measure various properties of these objects. There have been recent data releases from two of these surveys, GAIA which measures positions and distances, and APOGEE which measures radial velocities and stellar physical properties. By combining these datasets we have the full 6D phase space information for each star and can compute orbital characteristics and kinematics properties. APOGEE targeted specific stellar populations in our Milky Way and determined some of their physical properties. By cross matching with GAIA, we are able to fully describe the orbits of these populations and look for potential new members that have the same physical and kinematic properties but are not located in the immediate vicinity. We will present kinematic properties of the full cross matched dataset as well as information on the targeted stellar populations of the Milky Way.
Metal nanoparticles on a substrate have gained significant attention in recent years as novel systems for new generations of catalysts. Among other metals, iron attracts constant attention due to its low cost. Iron possess either the body-centered cubic (bcc) or the face-centered cubic (fcc) structure. Up to 917 °C, iron exists in its α-form (α-Fe) with the thermodynamically bcc lattice. At 917 °C, α-Fe transforms into the fcc lattice, and this allotrope is termed as γ-iron (γ-Fe) (austenite) with diamagnetic properties. According to the iron-carbon phase diagram, γ-Fe can incorporate up to 2.03% carbon. Lowering the temperature below 917 °C, carbon atoms diffuse out of the structure, and γ-Fe turns back to α-Fe. Up to now, γ-Fe could not be stabilized without such impurities as Mn, Cr, Ni at room temperature. We have obtained of iron nanoparticles with the face-centered cubic structure with diameters of up to 200 nm without impurities on the substrate of graphene oxide by thermal annealing in an inert gas. In our work we show that phases formation of iron depends on the temperature of annealing. At the annealing temperature from 300 ºC through 600 ºC only iron oxides are formed. We established the unexpected formation of the γ-phase already at 700°C by X-Ray diffraction and Mössbauer spectroscopy. These methods clearly identify the stability of the γ-phase at room temperature. The rather low transition temperature of α-Fe to γ-Fe already starting at 700 °C suggests that the mechanism for the transformation is different from that observed for bulk iron. The maximum γ-iron nanoparticles content on the substrate of graphene oxide was fixed at an annealing temperature of 950 °C.
Author(s): Daniel Alvarez Torres Psychology Margarette Alvarado Psychology Cheyenne Elliott Psychology Ian Hanson Psychology Kenneth Leising Psychology Cokie Nerz Psychology
Advisor(s): Kenneth Leising Psychology
Habituation occurs when responding to a stimulus decreases with repeated exposure. This decrease can be seen in an array of behaviors, including wheel running. In this experiment, rats ran in four different contexts (i.e., running wheels with different backgrounds/scents) for 30 minutes every day. One group ran in the same context daily while the other alternated between contexts. Rats running in different contexts should habituate less and run more consistently and at a higher rate. By increasing our understanding of the influence of habituation on exercise, results will have important implications for those wanting to maintain interest in an exercise routine.
Abstract SRS: Effects of Cross-Situational Generalization on Memory and Attitude Polarization Toward Social Groups
Serena Avitia, Akua Jonah, & Kaleigh Decker
When people generalize about others, they go beyond the information they are given and infer a level of cross-situational consistency that may polarize their attitudes. The current study investigates how cross-situational generalizations about a group’s traits can affect subsequent attitudes and memory. We predicted that participants who generalized about a fictitious groups behavior across various settings will rate the likelihood of cross-situational trait consistency as significantly higher than the scale mid-point, and report more negative attitudes toward the group than participants who reviewed the initial information they were given. Generalizers will also write paragraphs that more depict group members as displaying the original traits in general rather than only in the given situations, mistakenly recall and recognize some of the situations they rated as part of the initial information, and mistakenly report that their reported attitudes (after they generalized) were the same as their impressions immediately after reading the initial information. The predicted results will increase our understanding of the processes by which attitudes toward an entire group can polarize without any additional information.
(Presentation is private)
Past research suggests that conditions of scarcity increase the intensity of female same-sex competition. As such, cues to resource scarcity (vs. abundance) might lead women to perceive greater competitive tendencies in their same- (vs. opposite-) sex peers. This prediction was examined across three studies. Across all studies, the opposite pattern of results emerged. Study 1 demonstrated that women perceived higher levels of competitive interactions to occur amongst female (as compared to male and mixed-sex) target groups in environments where resources were abundant. In Study 2, women who perceived resources to be widely available evaluated same-sex others as more competitive than opposite-sex others. Finally, Study 3 provided evidence that women who are led to believe that resources are abundant reported expecting more competitive behavior from their same- (vs. opposite-) sex peers. These results suggest that resource abundance might foster greater competition among women, which has implications for women’s workplace and interpersonal relationships.
(Presentation is private)
Previous research in our lab has found that extrapolating from known to unknown attributes about a group can cause individuals to adopt more extreme attitudes (i.e., become self-radicalized) toward the group. This has been found to be particularly true when people extrapolate from known to unknown attributes about people who agree and disagree with them about a social issue. The current experiment aimed to extend our understanding of these processes by determining whether extrapolating about people who agree and disagree with the extrapolator about a social issue would also report greater self-radicalization toward the social issue in general. Our results revealed that participants who initially opposed kneeling during the national anthem reported more negative attitudes toward kneeling during the national anthem after extrapolating than did participants in the control condition. Conversely, participants who initially favored kneeling during the anthem reported more positive post-manipulation attitudes after extrapolating than did participants in the control condition. These results extend the understanding by which attitudes can become more extreme in the absence of new information.
In this exploratory, mixed methods project, we seek to understand how implementation of Trust-Based Relational Intervention (TBRI), a trauma-informed, evidence-based model of caregiving developed by TCU faculty, has shaped systems of care for vulnerable children and youth. The current study reports on the first year of implementation across nine child welfare organizations participating in a county-wide mental health collaborative. Data included monthly implementation process interviews conducted with representative staff of each agency [TBRI Implementation Strategy Use; n = 9 agencies], as well as survey data from a subset of agencies [TCU Survey of Organizational Functioning (SOF); n = 4 agencies]. The data sample reveals overall increases for TBRI strategy use during the first year of implementation. In addition, organizational functioning scores that were above the baseline mean of the sample yielded increased scores in strategy use. Future research suggests further analyzing the complexities of TBRI implementation across the large-scale collaborative.
Hope Connection 2.0 is a therapeutic camp developed by the Karyn Purvis Institute of Child Development (KPICD) that utilizes Trust-Based Relational Intervention® (TBRI®), a trauma-informed and attachment-based intervention, to meet the needs of adoptive families. To examine its effectiveness in meeting these needs, data from child and parent measures are collected from participating families during a one-year time period. The current study specifically examines the effectiveness of this intervention in decreasing aggression in adopted children and decreasing relational frustration between the parent and adopted children from pre- to post-camp. The results of this study indicate that both aggression and relational frustration significantly decreased after families participated in the intervention. Additionally, results suggest a significant positive correlation between aggression and relational frustration, suggesting the more a child exhibits aggression, the more relational frustration the parent(s) feels. Results of this study indicate the effectiveness of Hope Connection 2.0 in reducing aggression and frustration in adoptive families, demonstrating the potential benefit of this post-adoption intervention in meeting the needs of adoptive families.
Institutional care can negatively impact a child's development, leading to developmental delays and emotional and behavioral problems. These issues can be treated through an attachment-based, trauma-informed intervention, such as Trust-Based Relational Intervention (TBRI). The government of Rwanda learned about the effects of institutional care and TBRI and aimed to improve its orphan care. In order to do this, they found families for every orphan and provided TBRI training for caregivers who adopted these children. In the current study, we conducted semi-structured interviews with 10 volunteers who helped train and support these caregivers. A phenomenological approach was used to analyze the interviews. Results revealed five main themes: Rwandans took ownership of the need to care for orphans; they recognized the children's need for connection; they valued the role of family in a child's life; the utilized the power of community in making TBRI use successful; and the volunteers acted as mediators in the adoptive families. This study is the first to examine TBRI use internationally, and the results demonstrate the usefulness of Rwanda's model of orphan care with TBRI implementation that could be replicable in other settings.
Few studies have directly evaluated the assumption that equivalence-based instruction (EBI) establishes stimulus classes with greater efficiency than complete instruction (CI) of all possible stimulus relations within each class. The present study was identical to a previous study that failed to support this assumption, except that in the present study, mastery assessment was designed to favor the EBI condition over the CI condition. Forty-eight undergraduate students were assigned to one of four groups that received instruction on arbitrary stimulus relations. The EBI-CI group received EBI in Phase 1 and CI in Phase 2, and vice versa for the CI-EBI group. The EBI-EBI and CI-CI group received EBI and CI in both phases, respectively. In Phase 1, EBI-first groups received training on AB and BC relations and CI-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, using either EBI or CI. EBI took significantly fewer trials to complete than CI in both phases, but EBI in Phase 1 did not facilitate EBI in Phase 2. The results suggest the EBI arrangement used in this study may be more efficient than CI only because it permits faster learning assessment.
In academic environments, the ability to comprehend written text is critical for successful learning. In spite of the importance of this skill, few programs exist for improving comprehension, especially for typically-developing readers. Previous research demonstrated that cervical vagus nerve stimulation (cVNS) is a safe and effective method for driving neural plasticity. However, an invasive and expensive procedure is not practical for a reading intervention. Recent research has demonstrated that the auricular branch of the vagus nerve can be accessed non-invasively through transcutaneous auricular vagus nerve stimulation (taVNS) at the outer ear (Frangos, Ellrich, & Komisaruk, 2015). Recent work in our lab provides evidence that taVNS paired with training can improve novel letter-sound learning (Thakkar et al., under review). Thus, we hypothesized that pairing taVNS with reading would aid reading comprehension in typically-developing young adults. We recruited typically-developing young adult readers and verified reading ability using standard assessments. Eligible participants were randomly assigned to receive either active or sham stimulation to the posterior tragus of the left ear while reading passages and subsequently answering standard comprehension questions from the GORT-5 (Wiederholt & Bryant, 2012). Participants were scored on time spent reading, errors in reading, and comprehension. While data collection is ongoing, pilot data suggest a benefit of active stimulation on comprehension, as compared to those receiving sham stimulation. Implications of this work may suggest using taVNS as a novel intervention for reading comprehension, but further studies should extend the methods in a sample of struggling readers.
The purpose of the study was to compare the effects of three instructional conditions on emergent relations between visual stimuli. Participants were 75 college students who were randomly assigned to three groups. Participants in the standard group were trained to relate the visual stimuli they saw to text labels, referred to as tact training, prior to learning to relate pairs of text labels, referred to as intraverbal training. Participants in the reverse group received the intraverbal training before the tact training. The instructed visualization group received the same training sequence as the standard group but were given explicit instructions to visualize the images they learned during intraverbal training. The match-to-sample (MTS) testing format was used to evaluate the emergent relations between the visual stimuli. We predicted that the instructed visualization group would complete the MTS task faster and with higher accuracy than other groups because of their histories of visualizing the stimulus relations during the intraverbal training session. The results showed that the instructed visualization group had non-significantly faster reaction times during the MTS test compared to the standard and reverse groups but performed significantly more accurately (p< .001).
Title: Dyadic transfer of romantic nostalgia
Authors: Jordan Stables, Krissy Le, Julie A. Swets, & Cathy Cox
Problem: Nostalgia, a sentimental longing for the past, is associated with greater psychological outcomes, with recent work showing how nostalgia for the past of one’s romantic relationship may have benefits for the self (e.g., Mallory, Spencer, Kimmes, & Pollitt, 2018; Sedikides & Wildschut, 2018). Specifically, individuals who are more nostalgic are likely to claim higher satisfaction in their romantic partnerships. However, it is not yet known whether sharing these nostalgic thoughts can benefit the other partner and the relationship. The goal of the current study is to reveal that sharing relationship-oriented nostalgia will result in beneficial well-being effects that are comparable to those created by individual nostalgia.
Method: We recruited 146 romantic couples from a local university to participate. One member of each romantic relationship was randomly assigned either to write about a nostalgic experience they shared with their partner (relationship nostalgia), a personally nostalgic experience, or a control topic. Then they answered a variety of relationship questionnaires measuring relationship outcomes (e.g., relational self-esteem, optimism). At a later date, their partner (who was blind to their partner’s involvement in the study) read their written narrative and provided their own written response to what they read. Finally they responded to the same relationship measures. Additionally, Pennebaker, Booth, Boyd, and Francis’ (2017) Linguistic Inquiry and Word Count (LIWC) was used to content analyze the nostalgic essays based on affect, sociality, time perspective, and other pertinent themes.
Results: Analyses of variance were conducted to analyze the links between essay condition, nostalgia, and well-being outcomes. First, we found that the more nostalgic the writing partner was, the more nostalgic the reading partner was. Then using LIWC, we found that the relationship nostalgia essays were generally longer, more authentic, and included more first-person plural pronouns (e.g., we, us; demonstrating a stronger sense of interdependence in the essays). It was also found that reading a relationship-centered nostalgic narrative had a significantly positive effect on the readers’ positive mood, when compared to personally nostalgic experiences or control writings. These results also varied as a function of attachment avoidance and anxiety, which is consistent with past research (Abeyta, Routledge, Roylance, Wildschut, & Sedikides, 2015; Juhl, Sand, & Routledge, 2012).
Conclusions: This study has important implications for the analysis of shared nostalgic memories. We reveal that there are clear and immediate benefits for romantic relationships of engaging in and communicating shared nostalgia. This research also is foundational for exploring correlational and causal connections between shared romantic nostalgic reverie and its individual and relationship outcomes. Specifically, future work should explore additional mediating and moderating effects of the advantages of a shared sentiment for the past, as well as the duration of these positive effects.
Children who are adopted often experience early-life trauma, resulting in dysregulation and trauma-related emotional and behavioral problems. When these children are brought into adoptive homes, these trauma-related symptoms could negatively affect the attachment relationship by adversely impacting the parent’s perspective on the parent-child relationship. The current study examined the relationship between trauma symptoms in children who were adopted and the quality of the parent-child relationship within these families. Participants included adoptive families who were participating in a therapeutic camp intervention. The data analyzed was baseline data from a larger study prior to any intervention being done. Trauma symptoms of the adopted child, including anxiety, depression, anger, and post-traumatic stress arousal, were significantly correlated with parenting communication, confidence, and frustration. Specifically, the more trauma symptoms an adopted child exhibited, the poorer the quality of the parent-child relationship. Understanding this relationship and the bidirectional effects of trauma on adopted children and adoptive parents could result in better therapeutic interventions for families with adopted children, leading to better outcomes for both adopted children and adoptive parents.
Dyslexia is a prevalent developmental disorder characterized by unexpected reading difficulty in children and adults with otherwise normal IQ and intelligence. Dyslexia is a heterogeneous disorder and a variety of deficits are observed in the population, with auditory perception and rapid stimulus processing occurring most frequently. Genetic variants are likely related to this heterogeneity. One such gene that has been reliably linked to dyslexia is the neural migration gene DCDC2. Suppression of this gene in a rat model dramatically impairs speech-sound discrimination ability from a stream of rapidly-presented auditory stimuli (Centanni et al., 2016), suggesting a potential role for this gene in rapid stimulus processing deficits in humans and supporting a prior study linking this gene to reading speed (Neef et al., 2017). One potential casualty of processing speed impairments is the ability to process unpredictable stimuli. In the current study, we designed a rapid speech sound discrimination and prediction task to evaluate whether the rapid speech sound impairment previously linked with Dcdc2 also causes deficits on a prediction task. If increased presentation rate impairs the ability to process unpredictable stimuli, then the addition of a stable predictor sound should improve performance. To test this hypothesis, homozygous Dcdc2-knockout, heterozygous, and wild type rats were trained to respond to a target sound /dad/ in a stream of rapidly presented distractors in the presence or absence of a predictor sound /bad/, which occurred reliably prior to the target in 40% of trials. In wild type rats, the results indicate the presence of a predictor enhances response to the target /dad/ at low speeds, but as the stimulus presentation rate increased the rats began responding to the predictor /bad/ rather than the target. I will present these findings as well as pilot data from rats with Dcdc2 knockout to investigate the role of this gene on the response to a stable predictor.
A recent study (Petursdottir & Oliveira, accepted pending revision) found that when comparing equivalence-based instruction (EBI) to a complete instruction (CI) control condition using concurrent training and equal mastery criteria, EBI did not inherently produce faster or better learning than CI. However, this study included only a single EBI training structure. The purpose of the present experiment was to (a) evaluate the efficiency of linear series (LS) and one-to-many (OTM) EBI protocols relative to CI, and (b) to assess transfer of function following the three arrangements. Sixty undergraduate students were assigned to one of three groups (CI, EBI-OTM and EBI-LS), all of which received training to establish three 4-member stimulus classes. In the class establishment phase (ABCD training), the CI and EI groups were presented with 36 and 9 types of trials, respectively. After achieving mastery criterion, the ABCD test included all possible trial types, with no feedback. After achieving criterion on the ABCD test, all participants proceeded to transfer of function phase, in which they were taught to execute different motor responses to one stimulus in each class, and then tested with the remaining stimuli in each class. Results suggest the OTM protocol, but not the LS protocol, was more efficient than CI. The three groups performed equally well on the transfer-of-function test.
Language learning in adulthood is often important for personal or vocational reasons, but learning a second language after the sensitive period ends is time-consuming and retention is difficult. Research has suggested that cervical vagus nerve stimulation (cVNS) can help to improve cognitive function (Sjogren et, al. 2002) and working memory in patients (Sun et al., 2017). Transcutaneous auricular vagus nerve stimulation (taVNS), a less invasive method, activates similar brain structures as cVNS (Yakunina, Kim, & Nam, 2016). Recently, our lab demonstrated that taVNS paired with training improved letter-sound learning in typically-developing young adults (Thakkar et al., under review). The current study was designed to evaluate this approach in language learning. During a training session, they were exposed to 30 words in Palau, their English translations, and a picture that corresponded to the word while receiving either active or sham stimulation to the outer left ear. Each stimulus was repeated 10 times. At the end of training, a free-recall test was given where participants saw a trained word and provided the English translation. After one week, participants completed the same free-recall test of English translations to evaluate retention of the 30 trained words. While data collection is still in progress, we are seeing trends in the hypothesized direction such that those receiving active stimulation recall more words after training and at retention than those receiving sham stimulation.
Adopted children often have trauma–related emotional and behavioral problems, such as depression, anger, and anxiety, and these problems can continue to exist after adoption. Post-adoption, the adoptive family’s impact on these problems is not well understood. The current study examines the relationship between adopted children’s trauma symptoms and family communication – a construct that is associated with child social-emotional adjustment in traditional, biological families. Data was collected from adoptive families who were recruited to participate in a therapeutic family intervention. The results revealed a significant negative correlation between family communication and trauma-related emotional and behavioral problems in adopted children; specifically, the healthier the family communicated, the less problems the adopted child exhibited. Further, we wanted to determine if a similar relationship was found between biological children’s emotional problems in adoptive families and family communication. The results revealed a similar relationship: the healthier the family communicated, the less emotional problems the biological children experienced. The results of this study indicate that family communication may be a significant factor when considering the severity of adopted children’s trauma-related emotional and behavioral problems post-adoption.
As the threat of antimicrobial-resistant infections continues to rise, the need for novel antibiotics grows. Targeting virulence factors in bacterial pathogens is one potential strategy for antibiotic development because inhibiting virulence would decrease the ability of the pathogen to evade the host immune response. This strategy may decrease the development of resistance since the treatment is not directly bactericidal and there is less selective pressure put on the bacteria population. Our goal is to discover new virulence genes in Bacillus anthracis that could potentially be a therapeutic target. Specifically, we are interested in finding genes that allow B. anthracis to acquire iron from the host. For bacterial pathogens, iron is critical for growth and often a limiting nutrient in the host. It has been linked with proper functioning of electron transfer proteins and superoxide dismutase enzymes. In B. anthracis infection, iron is acquired from host hemoglobin through a hemolytic pathway, but the complete mechanism of this is unknown. Approximately 1000 transposon mutants of B. anthracis were screened for the inability to acquire iron from hemoglobin, and five were deficient in acquiring iron from hemoglobin in in vitro assays. Of those five mutant strains, only one (9F12) also exhibited an in vivo phenotype using the wax worm model of infection. The gene disrupted in the 9F12 transposon mutant is the dUTPase/aminopeptidase gene. Our aim in this study is to confirm that the disruption of the dUTPase gene leads to the inability to acquire iron from hemoglobin in B. anthracis. Using targeted mutagenesis, we created an insertional mutant strain to disrupt the dUTPase gene and we are currently testing it, along with WT and 9F12, for the ability to grow in iron-limited conditions with or without hemoglobin. Confirmation of this phenotype will demonstrate that the dUTPASE/aminopeptidase gene is important for iron acquisition from hemoglobin and will support further studies to understand the role of this gene in the virulence of B. anthracis.
Aquatic parameters such as increased temperatures and dissolved oxygen levels is critical in determining the survival and ability to thrive of trout species, including the Bonneville cutthroat trout. Bonneville cutthroat trout (Oncorhynchus clarkia Utah), a subspecies of Yellowstone cutthroat trout, originated in the Bonneville Basin and is native to many river basins in Utah, Wyoming, Idaho, and Nevada(Duff 1996). East Canyon Creek is a headwater tributary in the Weber River Basin of northern Utah, and a stream where Bonneville cutthroat trout are native. However, due to the introduction of nonnative trout and multiple causes of habitat quality decline, they no longer occur in the stream. Over the summer of 2018, I participated in data collection which assessed the habitat qualities of East Canyon Creek. This data includes temperature, aquatic, and riparian qualities. Data on the corresponding summer for dissolved oxygen is available as well. When compared to Colorado’s Coldwater Criteria, it appears that the temperatures of East Canyon Creek exceeded the acute (22.1°C) and chronic (17.0°C) upper thermal thresholds for cutthroat trout(Todd et al 2008). When compared to the acute (5.0 mg/L) and chronic (6.0 mg/L) dissolved oxygen minimum concentrations(Null et al 2017), East Canyon Creek’s concentrations appear to have dropped below the identified concentrations. The objective of this paper is to statistically analyze the temperature and dissolved oxygen data on East Canyon Creek from 2018, and determine if a restoration project of Bonneville cutthroat trout in East Canyon Creek would be successful. Through the data analysis, we have found that water temperatures during the summer months have significantly exceeded both acute and chronic upper survival limits, and that dissolved oxygen concentrations are significantly lower than the minimum chronic survival level, indicating that East Canyon Creek is not yet suitable for a successful reintroduction of Bonneville cutthroat trout.