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Understanding the Role of Serine 26 Phosphorylation Changes in Peroxidemediated Trafficking of System x\u3csub\u3ec\u3c/sub\u3e\u3csup\u3e-\u3c/sup\u3e to the Cell Membrane
Get PDFComposed of xCT and 4F2HC, System xc- is involved in importing cystine and exporting glutamate from the cell. xCT is directly involved in cystine-glutamate transport, and 4F2hc is responsible for stabilizing and moving xCT onto the cell membrane. Previous studies found that phosphorylating serine 26 (S26) on xCT inhibits xCT activity by moving system xc- off the cell membrane into lysosomes to be degraded (Figure 1). A previous study by the Chase lab showed that treating COS7 cells with hydrogen peroxide (H2O2) led to significantly higher amounts of xCT on the cell membrane. The objective of our research is to determine if a change in S26 phosphorylation on xCT plays a role in peroxide-mediated System xc- movement to the cell membrane. To explore the effects of H2O2 on S26 phosphorylation, we use two xCT mutants: S26A and S26D. S26A is an xCT mutant where S26 is replaced with alanine, mimicking a non-phosphorylated serine. S26D is an xCT mutant where S26 is replaced with aspartate, mimicking a phosphorylated serine. We treated half the S26A and S26D groups with H2O2 for 10 minutes, and used immunocytochemistry and biotinylation to compare the amount of membrane-bound xCT for the control and H2O2-treatment groups. Statistically significant results of a two-way ANOVA of a Western Blot biotinylation procedure showed that a higher proportion of membrane-bound xCT occurred in cells with the S26A mutation and cells treated with H2O2. Immunocytochemistry analysis results were not consistent with these findings, and the proportion of membrane-bound xCT was the highest in S26A mutant cells that were not treated with H2O2, and this group was statistically significantly higher than the rest of the groups. Unexpectedly, the control treatment S26D mutant cells had a higher proportion of membrane-bound xCT than the S26A mutant cells treated with H2O2. Ultimately, this work aims to understand the specific way that S26 phosphorylation regulates in system xc-
The Synthesis and Electropolymerization of Porphyrin-substituted Ethylenedioxythiophene (EDOT) Monomers
Get PDFTwo electroactive monomers were synthesized for use in forming redox-active films on electrodes. Such electroactive films are useful as redox mediating coatings in the functionalization of electrodes for sensor applications. Tetraphenylporphyrins were coupled to 3,4-ethylenedioxythiophene (EDOT) using different connector lengths and then metallated with iron to form monomers capable of electropolymerization. Hydroxymethyl EDOT was tosylated and then reacted with 4-hydroxybenzaldehyde in a Williamson ether synthesis to give an EDOT-functionalized aldehyde. This aldehyde was condensed with pyrrole under acidic conditions to form a novel EDOT-substituted porphyrin. The second porphyrin monomer was prepared similarly with a four carbon chain connector inserted between the EDOT and the benzaldehyde moieties. Both monomers were metallated with FeCl2. The properties of these porphyrin-EDOT monomers are currently being explored through electropolymerization using cyclic voltammetry and through electrochemical characterization of the resulting films to explore their use in electrode functionalization
The Effect of Visual Dominance on Word Learning in Infants and Adults
Get PDFLearning new words is critical in infancy, and continues to play a role in learning throughout the lifespan. In infancy, it often involves discerning the link between an object and its name. However, when an object\u27s name is heard, many objects could be present, making it difficult to determine which object goes with the name. Yu and Smith (2012) documented one factor that may aid early word learning: infants hold objects close to their faces, making those objects appear larger ( visual dominance ). They found correlational evidence that successful name learning was associated with visual dominance. We adapted a method used for studying object-name learning in both infants and adults, and tested experimentally whether visual dominance aids linking a heard name with the correct object. We exposed infants and adults to 12 objects (3 per trial for 80 trials), but only four object names (1 per trial; see Figure 1). Participants within each condition either heard the targets\u27 names (Naming) or not (Non-Naming Control) (Figure 1a). We examined whether having the named objects ( targets ) be larger (Dominant Condition) would aid linking the targets with their names, compared to a condition where objects were equally sized (Equal Condition). We hypothesize that dominant objects will draw participants\u27 eyes to the target and sustain them, facilitating linkages between names and the correct referents. After training, we tested which object participants looked at (Figure 1b) and pointed to (Figure 1c) when asked, where is the [novel name] . Preliminary data indicates that visual dominance may have a small or non-significant effect on adult word learning (Figure 2). Future analyses will examine the effect of dominance on infant learning. These results will help us determine whether visual dominance is critical in word learning or if other factors such as holding objects may aid learning
Render unto Hitler: Examining the Inconsistency between Mormon Beliefs and Mormon Policies in the Nazi Era
Get PDFAmid the Nazi persecution of various Christian sects, Heber J. Grant, the president and living prophet of the Church of Jesus Christ of Latter-Day Saints (LDS), declared to his congregation in Salt Lake City that Mormons in Germany were able to gather freely. The LDS Church has a long history of displaying its pro-Jewish beliefs, which should have made them natural enemies of the Third Reich. Yet, the Latter-Day Saints leadership, through a logical and carefully fostered survival strategy, offered legitimation to the Nazi state for the sake of self-preservation. From incorporating anti-Semitic references in LDS publications to excommunicating a young Church member who was beheaded by the Nazis for a protest, Church leaders constantly attempted to buddy up to Hitler\u27s regime. Moreover, their collaboration did not grow out of ignorance of Nazi atrocities; in fact, it was in light of them that LDS leaders surrendered their deeply held Zionist beliefs for self-preservation. Through both public and private communications, Church leaders repeatedly demonstrated their awareness of Jewish suffering in Germany. This project examines the inconsistency between Mormon beliefs and Mormon policies in the Nazi era and argues that faith must lead to discernment and moral courage, even in the face of some of the most challenging circumstances in history. Unfortunately, despite their faith clearly pointing them against the Nazi regime, the Latter-Day Saints rendered unto Hitler, thereby contradicting their own professed beliefs
Fishing for Answers: Studying Hypoxia\u27s Effects on the Zebrafish Olfactory Epithelium
Get PDFHypoxia, i.e. low oxygen, is a physiologically damaging condition found in many health conditions such as ischemic stroke, sleep apnea, asthma, etc. Additionally, decreased dissolved oxygen levels in aquatic environments occur as a result of climate change. Zebrafish offer an excellent model to study hypoxia due to extensive neuroplasticity and injury-induced cell proliferation, which allows them to recover lost function in the central nervous system (CNS). We have shown that olfaction (i.e., the ability to smell), decreases in response to hypoxic exposure in adult zebrafish. Thus, it is important to study the structural abnormalities underlying this loss of smell. Olfactory sensory neurons (OSN) in the olfactory epithelium (OE) detect and transmit odorant information to the olfactory bulb (OB) which discriminates odorants and relays the information further to the brain. We hypothesized that hypoxia is associated with a loss of smell due to abnormalities in the olfactory epithelium, specifically in the form of damage to OSNs and mucus production. To do this, we exposed adult zebrafish to acute hypoxia (0.6-0.8 mg/mL dissolved oxygen) for 15 minutes. OSN activity was analyzed through immunohistochemistry using c-Fos, a marker of neural activity, following exposure to the odorants, cadaverine and food essence, and compared between conditions. Additionally, to assess whether the loss of olfactory function was due to dysfunction in mucus production, we utilized Alcian Blue stainings of the OE to visualize the mucus layer and the presence of mucus-producing Bowman Glands. We predicted that hypoxic conditions would show a decreased activity of OSNs in the following odorant exposure. Additionally, because the mucus layer has been shown to thin in response to hypoxia, we predict that there will be more Bowman Glands to counteract the mucus reduction. This work provides insights into hypoxia’s impact on olfaction, specifically olfactory morphology and function
Role of Intermolecular Interactions between Nanoparticle Capping Ligands and Hydrogel Surfaces During Sliding
Get PDFModern treatments for osteoarthritis increasingly involve the use of nanoparticles as drugdelivery systems, but there is little known about the influence of nanoparticle chemical composition and surface chemistry between nanoparticles and soft materials in sliding contact. This work implements cartilage-mimicking polyacrylamide (PAM) hydrogels as a well-studied, fundamental platform. In situ (in a fluid environment) macroscale friction tests as a function of shear rate were conducted with a rheometer with a tribology adapter, controlling for contact pressure. Comparing different nanoparticle compositions, citrate capped metal (gold) nanoparticles exhibited a 50% increase in friction relative to water. With no difference in solution viscosity, this difference is likely driven by hydrogen bonding between the citrate ligands and PAM surface. In contrast, carbon based nanoparticles (nanodiamonds) with no capping ligands exhibited a 50% decrease in friction relative to water. Here, a higher solution viscosity for the nanodiamonds is likely dictating the sliding mechanism. Additional tests exploring gold nanoparticles with controlled capping ligands further support the impact of intermolecular interactions between nanoparticle capping ligands and the PAM surface in controlling sliding mechanisms. Post-sliding characterization of the PAM with confocal Raman microscopy surfaces indicate no damage to the hydrogel, and the presence of uncapped nanoparticle aggregates. Next steps will focus on the extent to which nanoparticles might be embedded within the PAM surface as a result of sliding
No Butts About It: The Heavy Metal Impact of Cigarette Litter
Get PDFCigarettes are the most common litter globally. Following smoking, the filter is left with carcinogenic compounds, tar and metals. All of which are highly toxic for wildlife, affecting reproduction, behavior and mortality rate in animals. The heavy metals that are left within the filter also have potential to leach from the cigarettes and enter the groundwater system. As these heavy metals enter the system, it leads to adverse effects on the environment and can cause detrimental health effects in humans, such as cell damage, induced carcinogenic processes and loss of cellular functions. Much research that exists currently only focuses on the content of cigarettes. Little research has been done on the degradation and leaching of its contents into the environment. For our experiment, we analyzed which heavy metals are present in cigarette butts. The concentration of each was also analyzed and quantified. The goal of our research was to determine the concentrations of heavy metals that can leach into a watershed from improperly discarded cigarette filters. We found lab rainwater simulated cigarettes and roadside cigarettes had the highest concentrations of metals. With Iron being the highest concentration followed by Magnesium, Zinc and several other metals. Utilizing the concentrations determined by the MARS 6 digester, we calculated a conservative estimate of each metal. Iron, our highest concentration, releases approximately 1297μg of Iron into the environment every day. Each metal was quantified and the annual flux of cigarettes for a 300m roadside collection in Holland, Michigan was calculated
What’s My Social Distance? Measuring Individual Differences in Personal Space
Get PDFPersonal space is a concept that was brought into public awareness during the COVID-19 pandemic, when safety precautions were put in place to inhibit natural tendencies to stand particular distances apart. Although a number of variables influence preferred distances (Hayduk, 1983), researchers have yet to evaluate the extent to which people naturally vary in their preferences. This study was designed to investigate preferred personal space during social interactions employing the social relations model (Kenny, 1994). This model proposes that social behavior is explained by three sources of variance: the actor (the tendency to act the same way to all people), the partner (the tendency for all people to act the same way to certain people), and the relationship (the tendency for individuals to act uniquely with certain other individuals). Our analysis seeks to test the relative influence of these three sources of variance on preferred personal distances.
Groups of up to six people participated in a round robin design, in which they took turns interacting with every other group member. After informed consent was acquired, one participant stood at one end of a large room. The other participants then took turns walking down the room to where the single participant was standing to answer a chosen, introductory question. The researchers then recorded the distance between the two participants. Each participant did this three times before a new individual was then moved to the end of the room. After all rounds were over, participants completed a survey designed to assess their familiarity with and impressions of the other participants, using a variation of the Big 5 personality traits. Finally, height and arm span measurements were taken.
We expect the upcoming results to help us to better understand what factors most strongly influence the distances people create and maintain with others
What Makes a Host Unique? A Prototype Analysis
Get PDFThe concept of hospitality has been in human culture for thousands of years. However, despite its historical significance, hosting has mostly been overlooked in scientific studies. Although a scale for measuring hospitality was recently developed (Meagher et. a, 2022), it draws from philosophical and theological accounts of hospitality. The current study instead investigates the associations held by the general population regarding the concept of a good host, relative to a good visitor and a good person. Following the procedure used by Samuelson et. al (2014), two studies investigate what attributes are most prototypical of a good host.
In Study 1, 300 participants were recruited through an online panel, and were randomly assigned to one of three conditions: good host, good visitor, or good person. In each, participants were asked to write down the characteristics and attributes of a good [host/visitor/person]? and to generate ten words. After collapsing synonymous responses, we found a larger overlap between host and visitor as compared to host and person. This highlights the importance of place (i.e., home) in determining these social roles\u27 central qualities.
In Study 2, a new sample of participants rated the terms generated from the first study on their prototypicality, using a Likert scale. The prompt given: how characteristic is each term of a good [host/visitor/person], ranging from almost never to almost always. We used a paired samples t-test to investigate the conceptual overlap between these social roles, seeing if unique terms were rated as more or less prototypical than overlapping terms.
Taken together, these two studies will provide a better understanding of the overlap between the concepts of a good host, a good visitor and a good person, thereby helping to reveal which characteristics are most prototypical of the role of a good host
The Anchor: March 2023
Get PDFThe Anchor began in 1887 and was first issued weekly in 1914. Covering national and campus news alike, Hope College’s student-run newspaper has grown over the years to encompass over two-dozen editors, reporters, and staff. For much of The Anchor\u27s history, the latest issue was distributed across campus each Wednesday throughout the academic school year (with few exceptions). In recent years The Anchor moved to monthly print issues and a more frequently updated website. The Anchor is now published in print twice per academic semester. Occasionally, the volume and/or issue numbering is irregular