Sample LASURI Abstracts

  • This is but a small sample of the research completed by students participating in LASURI.


Beatrice Go (Mentor: Dr. Don Morrison)

Genome Editing by Natural Transformation in Streptococcus pneumoniae

Streptococcus pneumoniae is a human pathogen able to acquire and integrate exogenous DNA via genetic transformation. The proteins associated with this process are produced in a short period called competence. When competence is induced by any of several environmental signals, two competence regulons containing >30 genes are activated and expressed. Upon internalization of exogenous DNA, dsDNA is split into single-stranded fragments (ssDNA). The ssDNA is protected and processed by other competence regulon proteins before integration into the host chromosome. Among these proteins is the dedicated recombinase loader DprA, an integral protein binding ssDNA and promoting the activation of RecA, the ubiquitous recombinase. RecA, the focus of this project, is a necessary enzyme that controls genome maintenance and aids in homologous recombination. When competence occurs, RecA assimilates the donor linear ssDNA into the host chromosome by seeking homologous marker sequences and promoting displacement of resident strands. Measuring transformation efficiency to determinee the optimal length and concentration of linear donor DNA for provoking gene replacement has applications for targeted gene modification. A Ser127Leu substitution in the DNA Gyrase B of S. pneumoniae is known to confer novobiocin resistance. DNA flanking and containing this mutation was amplified by polymerase chain reaction for use in various novobiocin transformation experiments. We found that viable transformant yield increased linearly in proportion to DNA concentration below 100 ng/ml and reached half-maximal yield by 100 ng/ml. The size of donor DNA also strongly affected transformant level below 3 kilobasepairs; above 4 kb, the transformant count leveled off, though 300 ng/ml of 6-kb donor DNA provided the maximal yield. Future extensions of this research will attempt to determine exactly how many of the several genes copies carried in a competent cell are replaced during a single competence cycle. This research was supported by funds from LASURI and the NSF.


Nanci Alanis Alcantara (Mentor: Dr. Kristine Molina)

How Do Different Stressors Relate to Body Mass Index among U.S. and Foreign-Born Latinas?

 

AlanisAlcantara 2014-15Latinas experience a disproportionately higher prevalence of obesity than their non-Latina white counterparts, with a prevalence of 45% compared to 35% for all females. Latinas also face a number of stressors that put them at greater risk of obesity. However, we do not know which stressors are associated with obesity for Latinas, and whether they matter differently by nativity status (U.S. vs. foreign-born). We investigated whether stressors were independently associated with body mass index among Latinas, and whether these associations were moderated by nativity status. We conducted a series of weighted linear regression analyses using the Latino female subsample (N = 1,427) of the National Latino and Asian American Study.  We included self-reported measures of everyday discrimination, family burden and cultural conflict, neighborhood safety, and psychological distress as our independent variables. Our outcome measure was self-reposted BMI, using the standard formula: weight in kilograms (kg)/height in meters squared (m2). Weighted multivariable analyses showed after controlling for sociodemographic factors, only everyday discrimination was associated with higher levels of BMI among Latinas (B = .08, SE = .03, p < .05). Moreover, this association was moderated by nativity status (B =  -.20, SE = .07, p <.05), such that the adverse effects of discrimination on BMI were stronger for U.S. born Latinas. Our findings have implications for responding to group-specific needs related to the role of discrimination and its association with increased risk of higher BMI levels, and for the development of tailored prevention efforts for reducing obesity among Latinas, one of the largest growing segments of our population.



Clare Gorman (Mentor: Dr. Stacy Fifer)

Translation: An Avenue to Broaden Global Perspective

For my LASURI project, I worked on translating a Congolese play from French into English. This play is called  Année Blanche pour Kalemba, and is written by Pierre Mumbere Mujomba. While translating, we came across problems expressing the societal implications of specific words, phrases, and ideas. These difficulties, however, helped me formulate my own idea of translation. From this experience, I’ve learned that the term “translation” involves more than just equating words from the original language of a text into another language; it also involves fitting a language’s understanding of words into the psychological and societal norms of the culture of the translated language. Dr. Fifer and I would split the play by scene; we would pick how to split particular scenes at the beginning of the week, and meet and discuss our work at the end of the week. We did this until    we had a rough draft completed. Then, we sent out this draft to readers to see if they understood anything, and if anyone had comments or suggestions.  In March, we had the fortune of working with Mujomba himself, which allowed us to gain insight as to how to go about editing our drafts.  With luck, we will publish our translation and have it read or performed in Chicago.



Ariunaa Bayanjargal  (Mentor: Dr. Robert Paul Malchow)

Changes in Volume and Surface Area in Isolated Retinal Müller Cells After Treatment with ATP

 

10478538_725304574201371_5471446798064759285_n.jpgGlial cells are key cellular elements in the nervous system. Outnumbering the nerve cells by approximately 10:1, these cells are believed to be important in maintaining normal levels of extracurricular ions and in maintaining overall levels of osmolarity of the extracellular fluids. In the vertebrate retina, Müller cells (radial glial cells extending from the base of the retina to the beginnings of the outer segments of the photoreceptors) are believed to be crucial in these processes. Recent work in the Malchow lab has shown that isolated glial cells respond to changes in levels of fluid osmolarity by altering their length and shape. A similar alteration in the morphology of these cells occurs upon application of the extracellular neurotransmitter ATP. The purpose of the present study was to develop an appropriate method to quantify these alterations in cell shape, and to attempt to understand the underlying molecular mechanisms leading to these shape changes. Optical slices through isolated individual cells were obtained using a confocal microscope to examine and quantify changes in cell shape and structure. Image processing and morphometric measurements were performed with ImageJ program. Pre and post volume and surface area in micrometers were calculated. The obtained data suggested a definite change in the shape and morphology of glial cells after ATP treatment and decreased quantities of volume and surface area confirming a significant effect of ATP solution on Müller cells. The current study and its results add a complementary perspective to studies already underway to examine other aspects of glial cell functioning. 




Victoria Gavaghan (Mentor: Dr. Thomas Park)

Naked Mole Rats: Survivors of Extreme Hypoxic Conditions

The naked mole rat is an extraordinary species that is studied as a model organism because it seems to thrive in a challenging environment of chronically low oxygen levels and chronically high carbon dioxide levels. Naked mole rats are unusual because they combine a challenging subterranean existence with extreme sociality, living in large social groups of up to 300 individuals, which depletes oxygen in their burrows. This research analyzed aspects of survivability, pulmonary edema, and cyclical behavior in the naked mole rate under levels of low oxygen (5%) and levels of high carbon dioxide (80%). These tests were subsequently performed on mice as a control. It was found that naked mole rats are much more resilient compared to mice under conditions of low oxygen, as well as, high carbon dioxide. In comparison to mice, which perish at an average of 18 minutes in low oxygen levels, naked mole rats survive the complete duration of a 5-hour exposure.  Also, naked mole rats show no signs of pulmonary edema whereas mice develop significant levels of pulmonary edema under the same conditions. This tolerance is consistent with what is known about the subterranean environment of the naked mole rat, where oxygen is periodically depleted in portions of their burrows. Although resilient under extreme conditions, there was no significance found for a circadian clock that triggers activity in naked mole rats when exposed to extreme conditions. In conclusion, one consequence of low oxygen exposure is edema as seen in high altitude sickness. Indeed the mice showed significant levels of pulmonary edema whereas the naked mole rats did not. The next step in this research is to look for the adaptations that enable the naked mole rat to survive conditions that are lethal to other mammals. Knowledge of these adaptations could provide therapeutic targets for illnesses such as high altitude sickness and traumatic oxygen deprivation as seen in heart attack and stroke. 



Kevin Chung (Mentor: Dr. Leslie Fung)

Triclosan Resistance in I192F-F203S Mutant FtFabI

KevinChung2014-15Francisella tularensisis a pathogenic gram negative bacterium that is highly contagious and lethal (Oyston, 2008). One of the few antibiotics that treat Francisella tularensis infection is triclosan, which inhibits the enzyme FabI. FabI is necessary for fatty acid biosynthesis, and thus for the survival of the bacteria. This research project provides understanding of how triclosan binds FtFabI, and how mutations in FtFabI affect their interactions.

A triclosan resistant mutation found in E. coli was introduced into a Francisella tularensis plasmid by site-directed mutagenesis to mutate two active site amino acid residues (I192F and F203S), which both are involved in triclosan binding (Xu et al.,2008). E. coli cells containing the mutant FtFabI plasmid or the wild-type FtFabI plasmid are grown. Recombinant proteins, tagged with (His)6, were extracted and purified from the cells using nickel affinity column chromatography. Polyacrylamide gel electrophoresis showed the wild type FabI protein to be of 95% purity and the mutant protein to be of 85% purity. The absorbance of NADH was then measured, using the Victor3 V plate reader to measure the specific activity of the wild type and mutant proteins. The I192F-F203S mutant FtFabI exhibit little triclosan effect on its enzyme activities. However, the activity for the mutant is significantly reduced.



Matthew Beifuss (Mentor: Dr. Stephen Engelmann)

Herbert Spencer, Use-Inheritance, and the End of Liberalism

This paper explores the political-theoretical implications of the transition from Lamarckian to neo-Darwinist evolutionary paradigms at the end of the nineteenth century, particularly in imagining a post-imperial world order. Building on the work of David Weinstein and Robert Richards, we examine shifts in the voluminous oeuvre of “our great philosopher, Herbert Spencer” (Darwin, Descent of Man), especially in dialogue with J.S. Mill, Darwin, and August Weismann. Spencer's attempt to give liberal utilitarianism a naturalist basis was deeply reliant on Lamarckian use-inheritance, and the political conclusions he drew from it were anti-imperialist, but in the context of a thoroughly imperial “civilizational” cosmopolitanism and globalism. At least in Europe, Spencer's failure to adapt his sociology and political theory to the emerging modern synthesis doomed it to a creeping irrelevance, and ceded the scientific high ground to the racial nationalism of theorists like Rudolf Kjellen. Our point of departure is a close reading of the fascinating “Progress, Its Law and Its Cause” (1857), and we close with some reflections on the possible political implications of post-genomic critiques of neo-Darwinism in our neo-liberal context.



Diya Majumdar (Mentor: Dr. Chris Whelan)

A Seedy Tale: Do Grasses and Forbs Invest Differently in Seed Chemical Defenses?

DiyaMajumdar 2014-15Plant secondary metabolites (PSMs), found almost universally throughout the plant kingdom, function in myriad ways, including defense against enemies, attraction of pollinators, communication between plants, and protection against various abiotic stressors. Extensive research has examined how PSMs mediate interactions between plants and herbivores and plant and frugivores. In contrast, little research has investigated their potential role in defense against granivores. A number of investigators have hypothesized that grasses tend to be less chemically defended than forbs and invest more heavily in physical digestibility reducers, such as silica. To investigate the validity of this statement, we screened for six classes of PSMs in seeds of 16 native grass and 16 native forb species field collected or purchased from a native plant nursery. Standard phytochemical tests were employed to determine the presence or absence of the following PSMs: alkaloids, phenolic acids, tannins, saponins, flavanoids, and terpenes. Our findings are not consistent with the hypothesis that grasses are less chemically defended than forbs.  Of the seven grasses and five forbs screened to date, grasses appear to contain as many classes of PSMs as forbs, with the possible exception of saponins. In fact, among the various PSMs screened, saponins appear to be the most underrepresented amongst both grasses and forbs. Our results, contrary to the original hypothesis, suggest that not only are PSMs common in seeds of grasses, they may play a previously unsuspected role in shaping patterns of seed selection amongst granivores.



Nathan Rogers (Mentor: Dr. Ryan Martin)

Bayesian estimation in autoregressive models using reversible jump Markov chain Monte Carlo

In most real applications, there is uncertainty about the statistical model to be considered.  In this paper, we consider a particular class of autoregressive time series models where the order of the model---which determines the dimension of parameter---is uncertain.  A common approach for model selection is to balance model fit with model complexity using, say, an AIC criterion.  However, such an approach provides no meaningful measure of uncertainty about the selected model.  A Bayesian approach, on the other hand, which treats the model and model parameters as random variables, can directly accommodate model uncertainty.  The challenge is that the Bayesian posterior distribution is supported on a union of spaces of different dimensions, which makes computation difficult.  We consider a reversible jump Markov chain Monte Carlo method for sampling from the posterior, and apply this method to provide a Bayesian analysis of simulated and real data. 



John Ryan
(Mentor: Dr. Anna Roosevelt)

Talking Across Lines: An Oral Historian in Indian Country

My research explores the unique and understudied story of contemporary, intertribal, American Indian communities, especially as they exist in urban areas following the relocation legislation of the forties and fifties. The study draws on eight months of experience as a volunteer and investigator at Chicago's American Indian Center. I argue that the complex social mosaic represented by communities like the AIC in Chicago's Uptown neighborhood stands in stark contrast to particular essentialist, romanticized, unschooled, or prejudiced veins of mainstream or even academic history. Underpinning these multifaceted communities is a type of synchretic social potential which informs much of the resilience of contemporary American Indian culture. Responding to the pressures of relocation, Indian communities like Chicago's proved adaptable. Spaces like the AIC formed the ideal home for cross-cultural and cross-generational discourse. In such spaces the often matrilineal or matrilocal traditions of particular cultures were preserved to various degrees, the result frequently being high status positions for women within the community. Also, the AIC community has historically recognized and celebrated its multi-racial character creating an additional layer to the intersectional investigation it encouraged. I believe that my research on Northside Chicago's contemporary Indian Community will productively complicate dimensions of both Urban and American Indian Studies, hopefully drawing them into dialogue. Additionally, it will bolster studies of diasporic peoples within urban spaces, providing meaningful spaces for future compartive study. Lastly, I would like to the thank the American Indian Center, Professor Anna Roosevelt, and the source of my grant funding, UIC's college of Liberal Arts and Sciences LASURI program. Without such support this project would not have been possible. 



Allyson Urista (Mentor: Dr. Kelly Quinn)

Femininity in Military Culture

Women have increasingly taken significant roles in the military over the last 70 years. Women currently make up 15.16% of all the active duty United States Armed Forces, as opposed to 2% in 1950 (DMDC, 2014; Walker, 2012). This dramatic increase has created steady influence in U.S. military culture, particularly since the initiation of the Global War on Terror (Walker, 2012).  Despite this increase, there is still a dichotomy of gender expectations within the military (Williams, 2005).  Previous research in this area is thin, though it offers a modest start through the exploration of feminine perspectives within a predominantly masculine culture.  For instance, dimensions of femininity have been explored, such as the relationship of femininity to leadership (Walker, 2012) and the transformation of perceptions of femininity upon entry into a collegiate ROTC program (Silva, 2008). These limited perspectives however do not address the true meaning of owning femininity in military culture.  This study provides additional insight into how military culture and femininity intersect by examining data gathered through 20 unstructured interviews with women who are currently members of the US military.  Major themes and concepts related to the display and constraints of feminine identity will lead to a greater understanding of female roles in military culture and the ways in which women utilize their femininity to define themselves as competent leaders and service members.



Matthew Perlman
(Mentor: Dr. Kevin Tucker)

Towards a computation of the limit of the F-signature of the E7 singularity

 

MatthewPerlman 2014-15The roots of a set of polynomial equations correspond to geometric objects called algebraic varieties, the fundamental objects of study in algebraic geometry. I study singularities of these varieties, which are points where the variety fails to be smooth. The F-signature function is a characteristic p invariant of these singularities designed to encode information related to the Hilbert-Kunz multiplicity and the F-signature, two invariants that measure singularities. In all known cases, the F-signature function of a polynomial limits to a piece-wise polynomial as p goes to infinity. However, this behavior is not well-understood and this function is notoriously difficult to compute. For example, it is not known whether the F-signature of the polynomial f=x3+xy3 limits to a piece-wise polynomial. In this paper, I will introduce algebraic varieties and the F-signature function, and then I will discuss this example, which I have computed for my capstone project.

 


 

Erica Nahin (Mentor: Dr. Evelyn Behar)

The Effects of Verbal and Imaginal Worry on Memory for Panic Symptoms

Previous research has shown that in order to successfully extinguish a fear response, there must be complete emotional processing as evidenced by activation of the memory structure and incorporation of corrective information (Foa & Kozak, 1986).  Other studies have also shown that the verbal-linguistic quality of worry, as opposed to the imagery based quality, may be responsible for an inhibition of somatic response and therefore an inability for emotional processing to take place (Behar & Borkovec, in press; Vrana, Cuthbert, & Lang, 1986).  The purpose of the present study was to determine the effects of verbal-linguistic versus imagery-based worrisome thinking on participants’ memory for panic symptoms during a subsequent panic-induction procedure. Data for this study come from Behar and Borkovec’s (in press) original publication and utilize the one-week memory task, which was not presented in the original paper.  Participants were asked to engage in relaxation, worry imaginally, or worry verbal-linguistically prior to three repeated interoceptive exposure tasks.  Between the three conditions, participants’ ratings on their subjective distress, panic symptom severity, and cognitive symptom severity during the exposure procedure were compared with their recall and recognition ratings one week later. The primary hypothesis of this study was that relative to verbal-linguistic mentation, imagery-based mentation will be associated with improved memory for panic symptoms one week after induction of these symptoms. It was also hypothesized that relative to thought-based mentation, imagery-based mentation will be associated with greater sensitivity, specificity, and discriminability index (DI) scores. The results of the study did not support either of the hypotheses. 


Rhiday Pandya (Mentor: Dr. Eric Leshikar)

Adaptive Memory: A Test of the Future Simulation Hypothesis

Memory is typically theorized as a system built to remember what you have experienced in the past. However, a view that has gained significant attention more recently holds that memory is a system that allows you to draw upon your past experiences to make predictions about what might occur in the future. Due to this adaptive nature of memory, it would be expected that whether or not your prediction is accurate should be reflected in memory. That is, inconsistent predictions should be remembered very well because they allow you to make more accurate judgments in the future, while consistent predictions might not be remembered as well because they do not help as much in making better judgments in the future. This idea has not been investigated in prior studies. The present study was designed to address this gap in the literature. We examined whether or not people are more likely to remember inconsistent predictions over consistent predictions. In this study, participants learned the personality characteristics of 16 different individuals. Using this information, they made predictions about which behaviors those individuals might perform. Participants were then presented with the behaviors that the individuals actually performed, which were either consistent or inconsistent with their personality characteristics. Lastly, the participants underwent a free recall task and a recognition task to test their memory for the performed behaviors. The findings of this study indicate that inconsistent predictions are remembered better than consistent predictions, in line with the hypothesis.


Laura Cuevas (Mentor: Dr. Michael Ragozzino)

Adenosine 2A Receptor Agonist Treatment Alleviates a Cognitive Flexibility Deficit and Stereotyped Behavior in a Mouse Model of Autism

Autism spectrum disorder (ASD) is defined by social-communication deficits along with restricted interests (behavioral inflexibility) and repetitive behaviors (RRBs). Research indicates that RRBs in ASD may be due to under activation of the cortico-striatal circuitry. Under activation of the “indirect pathway” has been associated with increased RRB expression. The BTBR T+ Itpr3tf/J (BTBR) mouse, like ASD individuals, exhibits impairments in probabilistic reversal learning. Treatment with the adenosine 2A agonist CGS21680 is believed to facilitate activation of the indirect cortico-striatal pathway. The current study tested whether facilitation of the indirect pathway through stimulation of adenosine 2A receptors attenuates probabilistic reversal learning (behavioral inflexibility) and repetitive grooming behavior (repetitive behaviors) in BTBR and B6 mice, a typically used comparison strain. Mice were tested in spatial discrimination tasks using an 80/20 probabilistic reinforcement procedures, acquisition and reversal learning. Mice learned to obtain reinforcement from the “correct” spatial location (reinforced on 80% of trials) compared with the “incorrect” spatial location (reinforced on 20% of trials). Prior to the reversal learning phase, mice received a systemic injection of 0.01 mg/kg of CGS21680 or vehicle. As observed previously, vehicle-treated BTBR mice required significantly more trials to criterion than B6 mice during probabilistic reversal learning (p < 0.05). CGS21680 treatment in BTBR mice significantly reduced the trials to criterion in reversal learning compared to that of vehicle-treated BTBR mice (p < 0.05) and to a level that was comparable to B6 vehicle-treated mice (p > 0.05).  In BTBR mice, CGS21680 treatment improved reversal learning by significantly reducing regressive errors compared to vehicle treatment (p < 0.05). CGS21680 treatment also significantly reduced repetitive grooming in BTBR mice compared to vehicle treatment (p < 0.05). Thus, treatment with an adenosine 2A receptor agonist may reduce RRBs in ASD and serve as a novel treatment in ASD.


Kiran Malhotra (Mentor: Dr. Pauline Maki)

Childhood emotional neglect, but not physical neglect, is associated with alterations in the stress response system in midlife women

KiranMalhotra 2014-15Childhood trauma is associated with alterations in the hypothalamic-pituitary-adrenal (HPA) axis. In women specifically, these alterations increase the risk for depression and anxiety disorders later in life. We examined HPA axis responsivity during the Trier Social Stress Test (TSST), a well-validated laboratory psychosocial stressor involving public speaking, in midlife women with and without a history of severe childhood neglect. We hypothesized that a history of childhood trauma would be associated with a dampened cortisol response to the TSST. Forty perimenopausal and early postmenopausal women (Mean age =50.32) community volunteers completed the TSST and a control procedure. Psychiatric interviews were conducted to screen out women with current mood or anxiety disorders. Salivary cortisol levels and self-reported anxiety (State-Trait Anxiety Scale) were measured across the experimental and control tasks. To assess physical and emotional abuse and neglect, women completed the Childhood Trauma Questionnaire. Group differences in stress responsivity were examined with a series of generalized estimating equations (GEE). A high proportion of volunteers - 70% - reported severe emotional and/or physical neglect. As expected, cortisol levels and self-reported anxiety and stress increased during the TSST compared to the control condition (p’s < 0.01).  Severe childhood emotional neglect, but not physical neglect, was associated with alterations in HPA axis function. Specifically, women with severe childhood emotional neglect had higher baseline cortisol levels than women without severe emotional neglect (p<0.05). Both groups demonstrated similar cortisol and subjective stress responses to the TSST. Similar to individuals with major depressive disorder, midlife women with severe childhood emotional neglect show elevated baseline cortisol levels despite being free of a current mood disorder. This adverse shift in the HPA axis is specific to early emotional neglect in women.




Blessing Obioma (Mentor: Dr. Amy Bailey)

Psychology of Poverty

 

BlessingObioma 2014-15The majority of studies on the relationship between corruption and poverty focus on the effect of corruption on poverty. This study, however, intends to explore the relationship between perception of corruption, trust and individual poverty levels in Nigeria. I will utilize data from Afrobarometer Round 4: The Quality of Democracy and Governance in Nigeria, 2008 (ICPSR 34009), a sample of 2324 Nigerian citizens, to evaluate whether trust and perceptions of corruption in government and public officer are associated with poverty. I predict that those confronted with economic hardship or will be more likely to perceive officials as more corrupt than individuals that are in better economic conditions. Since corruption and trust are related, I also predict that individuals in more difficult economic situations will be less trusting of officials than those in better living standards. Results from a linear regression reveal a statistically significant relationship between perception of corruption and poverty such that individuals in poor economic situations perceive government officials as more corrupt than those in better living condition. However, no statistically significant relationship was found between trust and poverty.








Tyler Crump (Mentor: Dr. Brian Kay)

Cloning, Synthesis and Characterization of Fibronectin Type III (FN3) Monomers that bind to Pak1

Sandwich Enzyme Linked Immunosorbent Assay (ELISA) one of the most common diagnostic methods used today. This assay uses a pair of binding reagents (usually antibodies) to detect the presence of biomarkers within a human sample. Inherently, this technique requires two binding reagents that recognize different epitopes on the same target protein. Unfortunately, the current approach to isolating such proteins is epitope mapping. This method is both laborious and costly:  it requires one to purchase or produce multiple affinity reagents, and to determine if each pair-wise combination binds non-competitively to the target. MegaSTAR (Megaprimer shuffling for Tandem Affinity Reagents) is a method that utilizes phage-display to isolate such pairs by performing affinity selection with millions of tandem constructs (ie. two binding domains linked together). In a previous study, MegaSTAR was used to link two fibronectin type III molecules that likely bind to different epitopes on the same target (A9, C12). Phage ELISA revealed that heterodimers (C12-A9, A9-C12) gave a higher signal in ELISA when compared to homodimers (C12-C12, A9-A9) and monomers (A9, C12). The goal of this project is to purify soluble forms of the monomers, and compare their usefulness in ELISA and pull-down with already-purified heterodimer.  Essentially, the comparison of such reagents can be applied to real-world applications in which increased affinity and specificity to a molecular target is advantageous, due to its ability to attach to target molecules in a more efficient manner. Ultimately, the objective of this research is to isolate such proteins. 



Brad Wilson
(Mentor: Dr. Jennifer Wiley)

Stuck On Stereotypes: The Relationship of Working Memory to Fixation Under Stereotype Threat

Individuals who identify with oppressed groups have been shown to suffer stereotype-confirming performance deficits when made aware of stereotypes against them, a phenomenon referred to as stereotype threat. Research has shown that stereotype threat lead to mental fixation on the Luchins water jug task (Carr & Steele, 2009). In this mathematical task, a complex solution is necessary for the first few problems, but later problems may be solved with either the same complex solution or a simpler solution. Individuals under stereotype threat who exhibit mental fixation continued to use the complicated solution on later problems. In other research with the Luchins water jug task, fixation has been shown to vary as a function of working memory capacity (WMC), with high WMC individuals exhibiting more fixation. However, this difference was not observed under performance pressure (Beilock & DeCaro, 2007). The current experiment tested whether the effects of stereotype threat on fixation also vary as a function of WMC with the stereotype of women being bad at math. Female subjects completed the running span and backwards digit span tasks to measure WMC and the Luchins water jug task to measure fixation. High WMC subjects were more likely to be fixated in the control condition, but this difference was not observed in the stereotype threat condition, similar to performance pressure.  




Briana Certa (Mentor: Dr. Aixa Alfonso)

Is the abnormal behavior of hlh-3 mutant males dependent on the protein ODR-10?

Certa2014-2015ODR-10 is a membrane receptor necessary for detection of a chemical found on the nematode food, diacetyl (1). Factors such as genetic sex, developmental stage, and feeding state have been found to regulate odr-10 expression (2). Normal (wild type), well fed, adult  males do not express this protein in the AWA cell and are not attracted to food whereas normal, well fed, adult hermaphrodites have the receptor in the AWA cell and are attracted to food (2).  Surprisingly adult, well fed, hlh-3 mutant males (re)express the ODR-10 protein in their AWA cell (Marquez and Alfonso, unpublished), and behave more like hermaphrodites; they appear to be attracted to food (this work). HLH-3 is a transcription factor necessary for the terminal differentiation of neurons required for sex-specific behaviors (3). Our hypothesis is that this abnormal behavior in the hlh-3 mutant males is a direct result of expressing the ODR-10 protein in their AWA neurons.



Mohammed Mirza (Mentor: Dr. Kay Gonzalez-Vilbazo)

Connectivity Effects on Sluicing in English-Hindi/Urdu Code-Switching

Sluicing is an elliptical construction, as shown below, in which the embedded clause of an indirect interrogative is not pronounced, and only the wh-phrase (and sometimes a preposition) is pronounced (Merchant 2006). John hit someone, but I don’t know who. The sentence above can be compared to its equivalent non-sluiced counterpart. John hit someone, but I don’t know who John hit.

Merchant 2001 argues that only semantic conditions constrain sluicing, in the form of a double entailment condition. Several accounts have challenged this theory, positing instead a hybrid condition where some syntactic identity is required (e.g. Chung 2006). Along these studies, González & Ramos (2011) use Spanish/German code-switching data to provide further evidence of a morphosyntactic constraint in sluicing. The present study follows on this line of research by looking at sluicing constructions on a pair of typologically different languages: English-Hindi/Urdu. We test whether bilingual speakers accept constructions where the argument structure differs between the antecedent clause, given in one language, and the embedded clause, in the other language. The stimuli was presented aurally, and participants rated them using a 1-7 Likert scale. An example of the critical stimuli is given below:

Alex was proud of someone, lekin     mujjhe             nahiiN pat-aa             kaun.
Alex was proud of someone, but        1SG.DAT          not       know-PFV        who-NOM
‘Alex was proud of someone, but I don’t know who.’

Per our findings, the monolingual control data results are not in line with the literature on Urdu. Participants accepted SOV, OSV and OVS word orders (i.e. both wh-movement and wh- in-situ) in embedded questions and bare nominative wh-phrases (i.e. “kaun”) in case mismatches in sluicing. This could suggest significant differences between the bilingual Urdu speakers who participated in this study and the communities reported in the literature. The code-switching results are conflicting and not in line with the inferences derived from González-Vilbazo and Ramos (2012). Some of the data might suggest a repair effect by sluicing (Merchant 2001), especially when the antecedent is in English. As such, the study does not corroborate with previous works on code-switching, although the nominative wh-phrase remnant (“kaun”) could possibly suggest a cleft sluicing structure (Vicente 2008).




Anam Chhatriwala (Mentor: George Papadontonakis)

When Good Cells Go Bad: the Role of p53

p53 plays a vital role in cell cycle growth phase arrest and DNA repair. Growth arrest prevents progression of the cell cycle at the G1 checkpoint as the p53 protein recognizes DNA damage. It then activates DNA repair proteins in an attempt to resolve the issue and consequently the cell is not allowed to enter the next phase of the cell cycle until the DNA is completely repaired. When the p53 protein is mutated, it cannot sufficiently carry out its functions. More than half of all tumors contain a mutation in p53, making it the most targeted source of mutations leading to cancer proliferation. There are six “hot spot” amino acid residues in p53 where mutations leading to cancer are the most frequent. These residues are 175, 248, 245, 249, 273, and 282. Employing bioinformatics algorithms we report that guanine is the most frequently mutated nitrogenous base, followed by cytosine while adenine and thymine are mutated at relatively low frequencies. Arginine is the most frequently mutated amino acid, followed by cysteine. No particular amino acid was found as being the most common to substitute in a missense type mutation; however a group of a few amino acids (cysteine, glutamine, and histidine) tend to substitute at high frequencies relative to other amino acids.  Our investigation shows that each cancer had different amino acids as the highest frequency mutated, for lung cancer it is glutamine, for gastric cancer it is STOP codon and tryptophan, for colon cancer it is serine and cysteine, for ovarian cancer it is cysteine and tyrosine, for prostate cancer it is histidine and cysteine, and for breast cancer it is histidine and serine.



Erin Kohnke (Mentor: Dr. Kara Morgan-Short)

Brain-Based Language Processing Signals Over Time: A Study of the Retest Reliability of the N400 and P600 Event-Related Potential Components

In language research, electroencephalography (EEG) has become an increasingly popular tool for understanding the neural processes underlying language behavior.  Using EEG, it is possible to identify certain event-related potentials (ERPs) that are associated with particular language processing events, such as the N400 component (a negative-going wave maximal around 400 ms post-stimulus onset), thought to be linked to semantic processing, and the P600 component (positive-going waveform, maximal around 600 ms post-stimulus onset), often associated with syntactic processing.  Although non-linguistic ERP effects have been found to be moderately reliable over time (Hammerer et. al, 2013; Cassidy, Robertson & O’Connell, 2012; Weinberg & Hajcak, 2011; Gasper, Rousselet & Pernet, 2011), little is known regarding the test-retest reliability of language-related components such as the N400 and P600.  The present experiment seeks to analyze the reliability of these two ERP components in native-language processing.  EEG data were recorded from monolingual English-speaking participants as they completed a grammaticality judgment task in their native language at two points in time, separated by approximately 4.5 months, in order to determine whether processing signatures would be similar or different over time.  Analyses revealed that the N400 and P600 ERP components were largely reliable across the two testing sessions.  These findings support the assumption that the N400 and P600 components are reliable over time in the absence of language development.  These results have important implications for previous and future studies that investigate longitudinal change and stability in language processing signatures.