27th Hayes Graduate Research Forum (March, 2013)

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Arts
1st place: Maicher, Kellen
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2nd place: Barry, Andrew
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3rd place: Fobbs, Joyelle
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Biological Sciences
1st place: Wojton, Jeffrey
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2nd place: Watowicz, Rosanna
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Business
1st place: Easwar, Karthikeya
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2nd place: Wynter, Matthew
3rd place: Polin, Beth
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Education and Human Ecology
1st place: Carotta, Christin
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2nd place: Beggrow, Elizabeth
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3rd place: Campbell, Chad
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Engineering
1st place: Hudoba, Mikael
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2nd place: Carnevale, Santino
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3rd place: Thompson, Julie
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FAES
1st place: Dicaprio, Erin
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2nd place: Wang, Wenfei
3rd place: Huang, En
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Humanities
1st place: Dean, Austin
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2nd place: Phillips, Chelsea
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3rd place: Horn, Meagan
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Math and Physical Sciences
1st place: Morrison, Lindsay
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2nd place: Severance, Michael
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3rd place: Krygier, Andrew
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Professional Biological Sciences
1st place: Frakes, Ashley
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2nd place: Burns, Erin
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3rd place: Mason, Matthew
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Social and Behavioral Sciences
1st place: Conklin, Laren
2nd place: Wohleb, Eric
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3rd place: Lee, Jayeon
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Poster Division: Arts, Humanities, and Social Sciences
1st place: Kerrick, Ben
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2nd place: Stigen, Ciara
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3rd place: Hubbell, Zachariah

Poster Division: Biological Sciences
1st place: Lee, Priscilla
2nd place: Shah, Nirav
3rd place: Hansen, Christopher
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Poster Division: Engineering, Math, and Physical Sciences
1st place: Coleman, Eric
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2nd place: Hansen, Steven
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3rd place: Short, Aaron



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Recent Submissions

Now showing 1 - 20 of 31
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    Diketopiperazine and oxazolone structures: an investigation of the influence of the third residue on b2 structure in QAXIG and NAXIG analogues
    (2013-03) Morrison, Lindsay; Wysocki, Vicki
    Variables impacting the formation of b2 ions along the "diketopiperazine" pathway are explored using IRMPD action spectroscopy and gas-phase hydrogen-deuterium exchange for a series of QAXIG and NAXIG pentapeptide analogues. The b2 ion is a unique fragment in peptide fragmentation because it can be one of two main isobaric structures, the diketopiperazine or the oxazolone. The formation of these has been thought to be largely governed by the identity of the first two residues at the N-terminus of the peptide. We show here that a basic residue is not required for the formation of the diketopiperazine structure, as the amide side chain of a glutamine or asparagine residue is implicated in the formation of this structure. Furthermore, the length of the peptide and identity of the third residue of the peptide is shown for the first time to influence the diketopiperazine:oxazolone ratio.
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    Rapid Hydrothermal Synthesis of Faujasitic Zeolites
    (2013-03) Severance, Michael; Dutta, Prabir; Gustafson, Terry
    In this paper, we propose modifications to a typical hydrothermal synthesis of zeolite which leads to very rapid crystallization. Water is gradually removed from the reaction mixture leading to a highly concentrated, extensively nucleated supersaturated gel, with the water added back slowly to this gel, crystallization of high-quality zeolite takes place rapidly.
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    Catalysis of the Oxygen Reduction Reaction on Bimetallic PtCu Nanostructures
    (2013-03) Coleman, Eric; Co, Anne
    We describe the design and synthesis of Pt-Cu electrocatalysts with well-defined, tunable morphology and composition. Electron microscopy and Brunauer-Emmett-Teller (BET) surface analysis indicate our catalysts have extremely high porosity, which acts to maximize mass transport, increase active surface area, and minimize the overall precious metal content. Production of these catalysts is quite facile and begins with synthesis of a porous Cu substrate, formed by etching Al from a Cu-Al alloy. The porous Cu substrate is then coated with a Pt layer via galvanic replacement with K2PtCl4. Growth of the Pt layer is manipulated by time, temperature, concentration of K2PtCl4, and convection rate during galvanic replacement. Data from inductively coupled plasma-mass spectrometry (ICP-MS) and energy dispersive X-ray spectroscopy (EDX) confirm multiple Pt loadings have been achieved via the galvanic replacement process. The Pt layer was found to enhance the oxygen reduction activity 30%-75% relative to the current state-of-the-art Pt/C catalyst and act as a barrier towards corrosion of the Cu understructure. The high ORR activity obtained indicates that high catalytic activity could potentially be achieved from fine-tuning this technique for other bimetallic Pt-based catalysts.
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    Beverage Intake of U.S. Children by Weight Status
    (2013-03) Watowicz, Rosanna; Taylor, Christopher
    Sugar-sweetened beverages have been implicated in the childhood obesity epidemic, however few studies have examined sugar-sweetened beverages in context with other beverage intake and by weight status. We used 1999-2010 NHANES 24-hour recall data from children aged 2-18 to calculate total grams, calories, and grams of added sugar consumed per beverage by weight status. We also examined the percent consumers of each beverage by weight category. Differences were found in total sugar-sweetened beverage intake, as well as soda and low-calorie beverage intake. Soda reduction remains an appropriate intervention, as it accounted for more than half of the sugar-sweetened beverage intake and consumption was clinically significant across all weight categories.
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    Ethnicity specific microbial signatures in the oral microbiome
    (2013-03) Mason, Matthew R.; Kumar, Purnima S.
    Personalized medicine is based on the paradigm that definitions of health and disease vary significantly among individuals. Successful treatment of caries and periodontitis requires re-establishing healthy oral biofilms, and current treatment protocols assume that the composition of health-compatible biofilms is similar among all individuals. However, It has been established that susceptibility to these diseases varies among ethnicities suggesting that oral microbial communities differ between ethnicities. Therefore, we investigated if ethnicity contributes to the variations in the composition of health-compatible oral biofilms. Saliva, supragingival and subgingival plaque samples were collected from 192 adults of Caucasian, African-American, Hispanic, and Chinese ethnicities. All subjects reported no systemic disease, pregnancy, and recent or prophylactic antibiotic use. Terminal restriction fragment length polymorphism (t-RFLP) and 16s pyrotag sequencing were used for community and bacterial level characterizations. Microbial profiles were compared between ethnicities using Non-metric Multidimensional scaling and ANOVA. Random Forest Machine Learning Classifier was used to examine the efficacy of oral microbial signatures as predictors of ethnicity. Only subgingival microbial communities demonstrated significant clustering of t-RFLP patterns based on ethnicity. Although eight species were detected in all 100 individuals, microbial profiles that were unique to each ethnicity were identified. Further, African Americans demonstrated a significantly lower diversity and equitability when compared to the other ethnicities. The subgingival microbial fingerprint was capable of identifying an individual’s ethnicity with 62% accuracy, 58% sensitivity and 86% specificity. The fingerprint was best able to identify African Americans with a 100% sensitivity and 74% specificity. The work presented here provides evidence for the existence of ethnicity-specific subgingival microbiomes that are characterized by differing bacterial lineages and varying diversities. Understanding that the microbial profiles of healthy subgingival biofilms are unique to different ethnicities will drive the development of personalized therapeutics and treatment plans. This research was supported by the Ohio State College of Dentistry CTOC T32 DE 0143220 training grant.
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    Vaporizing foil welding: A new tool for collision welding
    (2013-03) Hansen, Steven; Daehn, Glenn
    A new method for implementing collision welding at a laboratory scale has been developed. The pressure that drives the flyer plate toward the target is created by electrically driven rapid vaporization of a thin metallic conductor, rather than by chemical explosives or magnetic forces. Dissimilar welding couples of copper-titanium, copper-steel, aluminum-copper, aluminum-magnesium and titanium-steel have been successfully created with the same set of input parameters (foil driver geometry, input energy and standoff distance). Instrumented peel tests, lap shear tests, and optical and scanning electron microscopy reveal a broad spectrum of strengths and interface microstructures. For example, copper-titanium and copper-steel welds are strong and display wavy interfaces characteristic of collision welds, with little intermetallics or void formation. The other combinations have brittle interfaces with intermetallics and defects with the collision welding parameters used presently. The ideal impact angle for copper-titanium, with the currently used input energy, was identified to be 20°. Peak velocities of up to 560 m/s were observed for titanium flyer sheets. This work introduces the new technique; further research will be done on geometrical, material, and electrical parameters of the process.
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    Analysis and comparison of vacant land resources for urban food production
    (2013-03) Kerrick, Benjamin; Hoy, Casey
    Urban growth in the 20th and 21st centuries has had, and will continue to have, two direct effects on urban food systems: greater urban populations require more food, and expanding urban footprints diminish agricultural production areas around cities. Increasing globalization, consolidation, and industrialization of the food supply have been concurrent with this urban growth, leading to a profound physical and psychological distance between urban dwellers and the sources of their food. As concerns about climate change, sustainability, and food insecurity have come to the forefront of conversations about our food system, scholars, practitioners, and policymakers have explored the extent to which cities might feed themselves. Urban agriculture can expand food access in cities, engage urban dwellers in food production, and provide a beneficial use for unused urban lots. Idle or vacant land, both publicly and privately owned, represents an important resource for urban gardeners and farmers, and potentially for their rural counterparts as well. Applying the concept of usufruct, or productively using another's unused land, could increase agricultural use of both privately and publicly owned land resources. However, little is understood about how these land resources vary according to degree of urbanization, or the degree to which they might provide land access and food relative to the needs of the local population. This research aims to gain a better understanding of how vacant land resources vary according to ownership and urbanization. Over one hundred "walking distance"-defined study sites (300-meter radius) were randomly selected in seven central Ohio counties comprising and surrounding the city of Columbus; these study sites represented a range of classified urbanization values. Within each study site, GIS-based classification was used to identify publicly and privately owned vacant land that is suitable for vegetable production, based on soil quality, slope, water access, and solar exposure. These vacant land resources were compared among urban categories and between public and private ownership. No appreciable differences were found between publicly and privately owned land in terms of parcel size, perimeter-area ratio, or quality; however, privately owned land was more prevalent, and when present, was likely to occur in greater quantities. Idle vacant land is rarest in the least urban settings, where it is likely to already be in production, and most prevalent in low- or mid-density urban contexts, whereas parcel size was found to decrease as urbanization increased. The findings of this research demonstrate that privately owned land is a significantly more prevalent land resource for urban food production than public land, suggesting that policy instruments which facilitate or incentivize usufruct agreements between private owners and urban farmers would be effective in increasing urban agriculture. The land suitability index used in this research shows that soil quality is the most significant obstacle to enabling food production in more urban areas.
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    NF-kB Activation in Microglia Induces Motor Neuron Death in Amyotrophic lateral sclerosis
    (2013-03) Frakes, Ashley; Kaspar, Brian
    ALS is a fatal neurodegenerative disease that affects motor neurons (MNs) resulting in severe muscle atrophy and paralysis. Despite the fact that about 5,600 people are diagnosed with ALS in the US each year, there is no cure. One of the most striking pathological hallmarks observed in patients and rodent models of ALS is neuroinflammation, characterized by activation of microglia, the resident immune cells of the central nervous system. Genetic approaches to globally eliminate single inflammatory genes in ALS mouse models have largely failed, highlighting the complexity of this inflammatory process. Nuclear Factor-kappa B (NF-κB) regulates many pro-inflammatory mediators found in areas of MN death in ALS, and this pathway is activated in the spinal cords of ALS patients. Therefore, the purpose of this study is to determine the role of NF-κB, a master regulator of inflammation, in ALS. By immunoblot and immunohistochemical analyses, we determined NF-kB activation increases with disease progression in ALS mice and occurs predominantly in microglia. To determine the role of NF-kB activation in microglial-mediated MN death, we utilized an in vitro co-culture model in which 61% of MNs die when co-cultured with ALS microglia after 72 hours. NF-kB inhibition in ALS microglia fully rescued MNs from microglial-mediated death in vitro. Remarkably, conditional inhibition of NF-kB in microglia in vivo extends survival in the ALS mice by delaying disease progression by 51%, one of the longest extensions reported in this severe model. NF-kB inhibition in microglia leads to marked reduction in prototypic inflammatory markers such as CD68, CD86 and iNOS, suggesting that NF-kB regulates microglial conversion to a pro-inflammatory, neurotoxic state in ALS. Furthermore, we show that constitutive activation of NF-kB selectively in microglia in wild-type mice promoted a similar microglial activation state observed in ALS mice. Strikingly, microglia isolated from these constitutively active NF-kB mice rapidly induced 48% MN death in vitro. These data provide a cellular and molecular mechanism by which microglia induce MN death in ALS and suggest a novel therapeutic target to modulate microglial activation and slow the progression of ALS and other neurodegenerative diseases by which microglial activation plays a role.
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    "I'm hoping for a miracle" and "I am too": Hopes Expressed Between Victims and Offenders Following Detention for Domestic Violence
    (2013-03) Carotta, Christin; Bonomi, Amy
    We used a phenomenological qualitative approach to examine hopes expressed between domestic violence victims and offenders during the especially fragile time immediately following the offender's detention. Audio-recorded telephone conversations of 17 couples were analyzed (up to 120 minutes of conversational data for each couple), using a lexical definition of hope as the starting point. Data analysis began with the generation of narrative summaries, followed by the thematic identification and coding of expressed hopes within each relationship. Several hopes were expressed consistently by victims and offenders. The most consistent hope was the desire for love to be known and reciprocated. These hopes were complicated, however, by real or imagined threats to the fidelity of their relationship and concerns about the ability to overcome relational conflict. In addressing these concerns, partners expressed hope for explanations of truth about controversial behavior, change in future behavior, and personal exoneration from blame. Emotionally-charged discussions, regarding relationship turmoil, occasionally entailed victims and offenders expressing a desire to end the relationship. Vacillations in the desire to maintain the relationship, however, were temporal in nature, with couples returning to expressions of love, a desire for sympathy or help, and hope for the offender's release. These findings advance an understanding of the dynamics of violent couples and the complex emotional experience following a severe violent event. As a collective process, even when heated discussions about ending the relationship and disagreements about change or blame occurred, couples commonly still returned to expressions of love, and hope for the offender's release.
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    The Impact of Borderline Personality Disorder Symptoms on Self-Reported Invalidation and Learning Task Performance
    (2013-03) Stigen, Ciara; Cheavens, Jennifer
    Invalidation has been defined as the perception that one’s thoughts, emotions, or behaviors are inappropriate, inaccurate, or misunderstood by others. Invalidating responses have been shown to increase emotional arousal (Shenk, 2007) and impair cognitive ability (Fruzzetti, 2005). Invalidation may be particularly problematic for individuals with Borderline Personality Disorder (BPD) and related features, due to increased emotional sensitivity and reactivity (Domes, Schulze, & Herpertz, 2009) and negative interpersonal biases (Barnow et al., 2009). We experimentally assessed the impact of validating and invalidating experiences on learning task performance. Undergraduate participants (N = 66) first completed the borderline features scale of the Personality Assessment Inventory (PAI-BOR; Morey, 1991) and a self-report measure of invalidation. They were then randomized to receive 4 minutes of either validating or invalidating feedback while recalling a time they were angry; finally, cognitive flexibility was assessed using a card-sorting task. We predicted that 1) Higher BPD features would predict greater self-reported invalidation, and 2) BPD features would moderate the relationship between feedback condition and learning task performance, such that higher BPD features would be associated with poorer performance. We found that as BPD features increased, invalidation also increased; however, this main effect was in the context of a significant interaction effect, such that highest self-reported invalidation occurred at high levels of BPD symptoms in the invalidation condition. Furthermore, higher BPD features were associated with committing a greater number of errors on the learning task when invalidated. Thus, invalidation may be particularly problematic in terms of learning for those with heightened BPD features; future research should examine the impact of invalidation within the context of psychotherapy, to inform practitioners and guide clinical practice.
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    Encapsulation, Color Stability, and Distribution of Anthocyanins from Purple Corn (Zea mays L.), Blueberry (Vaccinium sp.), and Red Radish (Raphanus sativus) in a Cold-Setting Pectin-Alginate Gel.
    (2013-03) Barry, Andrew; Giusti, Monica
    Anthocyanins are a broad class of water soluble pigments found in a wide array of plants. They are responsible for a variety of the attractive colors found in fruits including red, purple, orange, and blue. There use as a natural alternative to synthetic colorants has been investigated extensively in the past several years as consumers have been asking for greater choice in the marketplace. Their limited stability in food applications several limits their widespread adoption. Meanwhile, other research has been focused on the potential health promoting benefits of eating a diet high in anthocyanins. The objective of this work was to encapsulate an anthocyanin rich extract in a novel system that uses pectin and alginate as the encapsulating material in hopes to increase stability. It was then necessary to investigate not only the color stability of the particles, but also the anthocyanin stability and profile as well. A variety of anthocyanin sources was chosen to represent a cross section of the structural differences that exist: blueberry (5 of the 6 common anthocyanidins all with a single, varying sugar moiety), purple corn (3 monoglycosylated anthocyanins and their malonated counterparts), and red radish (pelargonidin derivatives with 3 glycosylations and aromatic acids). All three anthocyanins sources were successfully encapsulated using the technique described later. The stability of the particles was monitored by increasing color of the solutions the particles were stored in, the color of the particles themselves, and the total monomeric anthocyanin content of both. The purple corn particles performed the best in regards to color leaching into the solution. The solution color indices for the experimental and control were more different than for the other anthocyanin sources tested. This performance carried over when measuring the color of the gels directly. The purple corn loaded gels were statistically darker and had greater color intensity than the empty control gels. The red radish loaded gels performed the worst for every measurement that was taken. The interesting difference was noted in the amount of anthocyanin recovered from each gel. The amount of anthocyanin leached into the solutions was not different among the sources. Another interesting note was that the anthocyanin profile of the various extracts did not change significantly during the storage study, meaning that preferential leaching or retention in the gel was not noted. The pectin-alginate system was able to encapsulate various anthocyanin rich extracts, with the purple corn performing the best of those tested, with the blueberry performing similarly. Since these anthocyanins are relatively small compared to others, it is theorized that molecule size is not the main factor contributing to pigment retention. It is possible that other anthocyanin sources will work just as well.
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    Designing, Validating and Piloting a Genomics and Bioinformatics Assessment
    (2013-03) Campbell, Chad; Nehm, Ross
    Over the past decade, hundreds of studies have introduced genomics and bioinformatics (GB) curricula and laboratory activities at the undergraduate level. While these publications have facilitated the teaching and learning of cutting-edge content, one key aspect of evidence-based practice has been left behind: the development of assessment tools capable of generating valid and reliable inferences about student learning. Content validity is a core facet of construct validity, and must be used to guide instrument and item development. Based on previous work which reported on the correspondence of content validity evidence gathered from independent sources, our current work details: (1) the process of item development using this evidence and (2) the results from a pilot administration of the assessment. By including only the subtopics that were shown to have robust support across our content validity sources, 22 GB subtopics were established for inclusion in our assessment. An expert panel subsequently developed, evaluated, and revised two multiple-choice items to align with each subtopic, producing a final item pool of 44 items. These items were piloted with student samples of varying content exposure levels. We report on Classical Test Theory (CTT) and Rasch analyses of individual items and overall instrument quality.
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    Black Ballerinas in U.S. Popular Culture
    (2013-03) Fobbs, Joyelle; Miller, Bebe; White Dixon, Melanye
    The ballet world has not been a stranger to bias; in fact, the difficulties that a black ballerina already faces in finding a place in a ballet company demonstrate this bias. In order to tackle the issues of beauty and bias, the successful black ballerina has utilized both her performance abilities in ballet and her involvement in popular culture. A recent example is Misty Copeland, who has been featured as a collaborator with the legendary pop star Prince and was later promoted to soloist ranking at American Ballet Theatre in New York City. Similarly, Aesha Ash was a ballerina who performed as a dance double in the movie, Center Stage, for the actress Zoë Saldana, and danced in the corps de ballet for the New York City Ballet (NYCB). Dancers like Copeland and Ash have experienced more opportunities in ballet following their work in the field of entertainment. Unfortunately, many are missing from historical dance texts, though their contributions to dance and popular culture are obviously noteworthy. This presentation ultimately draws from published articles, archival work, film, and oral history, to historicize the black ballerina and her strategies used to overcome commonly held notions of beauty and technical competence in ballet.
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    An acoustic investigation of postaspirated stops in Seville Spanish
    (2013-03) Horn, Meagan; Campos-Astorkiza, Rebeka
    The purpose of this investigation has been to analyze the phonetic mechanisms behind an innovative sound change currently occurring in Seville, Spain. The aspiration of the consonant /s/ in syllable final position to a breathy [h] is a common process in many Spanish dialects. However in Sevillian Spanish, when followed by the voiceless occlusive /t/, the aspiration of the /s/ is being realized as postaspiration resulting in the affricate [ts]. This change of production from [st] > [ts] has become a distinctive dialectal feature of the region and is not documented in any other Spanish consonant system. This study involves the analysis of recorded speech of 26 native Spanish speakers from Seville, Spain evenly distributed within the sociolinguistic categories of age, gender and educational level. In order to investigate the impact of the following voiceless consonant on the postaspiration of /s/, each participant was recorded while reading a list of sentences that included the consonant clusters, [sp], [st] and [sk] in three distinct phonetic environments: word internally, over word boundaries and in the presence of stressed and unstressed vowels. The speech analysis software Wavesurfer was then used in order to determine the degree of aspiration after each occlusive /p, t, k/ in the different phonetic contexts. This measurement, known as Voice Onset Time (VOT), is the duration of aspiration in milliseconds after the explosion of air from the occlusion and the beginning of the following vowel. Also included in the measurements of each token were the length of the preceding vowel, the duration of preaspiration and the duration of the closure of each voiceless occlusive. A four part statistical analysis was performed to determine the existence of statistically significant relationships between postaspiration and the different social and linguistic variables. The results show that the phenomenon is linguistically motivated, as no social factors were selected as significant predictors when speaker was integrated as a random effect into the statistical models. First, when postaspiration of the following occlusive was analyzed as a categorical dependent factor, either present or absent, it was found that the place of articulation of the following occlusive is the only reliable predictor. More specifically, both dental and velar stops predicted significantly higher rates of longer postaspiration than their bilabial counterpart. Second, when postaspiration was analyzed as a continuous dependent factor, the duration of postaspiration could be statistically predicted only by the linguistic factors. As found by this study, significantly longer postaspiration durations were predicted when the consonant cluster consisted of a dental or velar occlusive in a word internal boundary with a preceding stress pattern. Third, the effect of the phonetic realization of the sibilant as a part of the target cluster was analyzed. The possible phonetic productions were categorized as either a fully realized sibilant [s] or one of two types of reduced variants, either the aspirate [h] or the phonetic zero [Ø]. It was found that, across social and linguistic environments, the two reduced variants patterned similarly and predicted significantly longer durations of postaspiration than that of the fully realized sibilant. Finally, a series of correlation analyses show that significant negative correlation relationships exist between the duration of the postaspiration and the surrounding segments. A combination of these findings is shown to provide strong evidence that this postaspiration phenomenon is a result of coarticulatory compensation. Thus, the results from this study are interpreted via the theoretical model of Articulatory Phonology. Through the use of this framework, it is shown that when the individual articulatory gestures associated for each sound are placed onto a spatiotemporal spectrum, intergestural timing is capable of capturing the wide variety of pre and postaspiration productions found in the study. Additionally, the model allows for the prediction of possible future outcomes for this particular phenomenon. Finally, the research presented here contributes to a better understanding of the phonetic inventory of Spain Spanish by providing statistical analyses of linguistic data and an understanding of the intergestural configurations resulting in these postaspirated productions. Furthermore, it is shown that, contrary to past studies, this particular phenomenon is being driven by linguistic forces instead of social factors. This provides insight into the importance of investigating and understanding possible underlying phonetic mechanisms when interpreting the development of innovative productions in different dialects of Spanish around the world.
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    Polarization Doped Nanowire Devices as an Alternative to Impurity Doping
    (2013-03) Carnevale, Santino; Myers, Roberto
    It is difficult to control electrical conductivity in wide band gap semiconductors using impurity doping because of large ionization energies in these materials. Polarization-induced doping in compositionally graded heterostructures is a possible alternative to impurity doping in certain wide band gap materials. Here we present compositionally graded AlGaN nanowires grown on Si(111) substrates by plasma-assisted molecular beam epitaxy that utilize polarization-induced doping to form p-n junctions. GaN quantum wells are inserted into the nanowires to create polarization-induced nanowire light emitting diodes (PINLEDs) that emit ultraviolet light. Variable temperature electrical measurements show that dopants in the structure are ionized by polarization-induced charge and therefore do not freeze-out at cryogenic temperatures. Furthermore, electroluminescence measurements show that polarization-induced charge alone (i.e. with no intentionally added dopants) can be used to form working LEDs.
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    Stress-induced recruitment of peripheral macrophages to the brain promotes anxiety-like behavior
    (2013-03) Wohleb, Eric; Sheridan, John
    Social stress is associated with altered immunity and higher incidence of anxiety-related disorders. Repeated social defeat (RSD) is a murine stressor that primes peripheral myeloid cells, activates microglia, and induces anxiety-like behavior. Here we show that RSD-induced anxiety-like behavior corresponded with an exposure-dependent increase in circulating monocytes (CD11b+/Ly6Chi) and brain macrophages (CD11b+/CD45hi). Moreover, RSD-induced anxiety-like behavior corresponded with brain region-dependent cytokine and chemokine responses involved with myeloid cell recruitment. Next, LysM-GFP+ and GFP+ BM-chimeric mice were used to determine the neuroanatomical distribution of peripheral myeloid cells recruited to the brain during RSD. LysM-GFP+ mice showed that RSD increased recruitment of GFP+ macrophages to the brain and increased their presence within the perivascular space (PVS). In addition, RSD promoted recruitment of GFP+ macrophages into the PVS and parenchyma of the prefrontal cortex, amygdala, and hippocampus of GFP+ BM-chimeric mice. Last, mice deficient in chemokine receptors associated with monocyte trafficking, chemokine receptor-2 (CCR2KO) or fractalkine receptor (CX3CR1KO), failed to recruit macrophages to the brain and did not develop anxiety-like behavior following RSD. These findings indicate that monocyte recruitment to the brain in response to social stress represents a novel cellular mechanism that contributes to the development of stress-induced anxiety.
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    Factors of Emotion and Affect in Designing Interactive Virtual Characters
    (2013-03) Maicher, Kellen; Price, Alan
    This paper represents a review of literature concerning factors of affective interactive virtual character design. Affect and it's related concepts are defined followed by a detail of work being conducted in relevant areas such as design, animation, robotics. The intent of this review as to inform the author on overlapping concepts in fields related to affective design in order to apply these concepts interactive character development.
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    On The Origin of Super-Hot Electrons in Laser-Plasma Interactions
    (2013-03) Krygier, Andrew; Freeman, Richard
    Particle-in-call modeling is used to identify the acceleration mechanism responsible for the observed generation of super-hot electrons in ultra-intense laser-plasma interactions with solid targets with pre-formed plasma. Several features of direct laser acceleration (DLA) are identified that drive the generation of super-hot electrons. The electrons that become super-hot are primarily injected by a looping mechanism named loop-injected direct acceleration (LIDA).
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    Students’ Use of Alternative Scientific Causal Models in Explanations about Evolutionary Change: Selective vs. Stochastic Reasoning
    (Evolution Education and Outreach, 2013-03) Beggrow, Elizabeth; Haury, David
    Non-adaptive, stochastic evolutionary causes, such as genetic drift, comprise an important element of biologists’ explanatory models of evolutionary change, and yet science education research has focused almost exclusively on student ideas and misconceptions about natural selection. After instruction that includes stochastic causal factors (such as genetic drift), how do students construct evolutionary explanations? We used clinical interviews, open- response and multiple-choice instruments to investigate undergraduate students’ non-adaptive reasoning (NAR) patterns. After instruction, we found NAR to be very uncommon in students’ explanatory models of evolutionary change in both written assessments and clinical interviews. However, when NAR was used by students, it was conceptualized in an expert-like way; that is, non-adaptive and stochastic factors were modeled as alternatives to selection. Interestingly, non- adaptive reasoning was not found to be associated with greater understanding of natural selection in interviews or written assessments, or with fewer misconceptions of natural selection. Thus, NAR appears to be a distinct facet of evolutionary thinking. Greater attention to NAR in biology education is needed given how uncommonly students use it to explain evolutionary change.
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    Elevated MMP-9 in the Thoracic and Lumbar Cord Impedes Activity Dependent Plasticity and Recovery Early after SCI in Mice
    (2013-03) Hansen, Christopher; Basso, D Michele
    PURPOSE: Spinal cord injury (SCI) disrupts sensory and motor systems resulting in permanent functional deficits. The inability to walk is the most noticeable and debilitating impairment. New advances in activity-based neurorehabilitation has improved recoveryin the clinic, but complete recovery remains elusive.. To further optimize recovery, activity-based therapy like treadmill training should be combined with therapeutics to increase neural plasticity. To date, local cell death and inflammation at the injury site have been important factors in the extent of locomotor recovery after SCI. One explanation for persistent locomotor deficits is that this type of pathology extends beyond the primary injury site distally into the regions of the cord responsible for organizing locomotion. Indeed, we previously found pronounced microglial activation and pro-inflammatory cytokine production in the lumbar cord but the role of remote inflammation on locomotor recovery remains unknown. Here, we explore the role of one of the earliest inflammatory signals, matrix-metalloproteinase-9 (MMP-9), as a regulator of plasticity and locomotor recovery. MMP-9 promotes inflammation by increasing permeability of the blood vessels in the spinal cord, facilitating immune cell access and activating pro-inflammatory cytokines. Primary outcomes for permeability, cell trafficking and cytokine production were collected in the lumbar cord in SCI groups with and without treadmill training. RESEARCH METHOD: Using a mouse SCI model that replicates human pathology, we produced moderate/severe contusions at midthoracic levels (T9) and analyzed the remote lumbar cord. To identify novel mechanisms of remote neuroinflammation, we used ELISA, gel and in situ zymography to measure MMPs and pro-inflammatory cytokines in C57BL/6 (WT) mice. We used immunohistochemistry to describe remote microglia phenotype and anatomy. To prove that early inflammation impedes locomotor plasticity, we examined recovery after SCI in WT and MMP-9 KO mice with or without treadmill (TM) training delivered in acute (2d) or chronic (35d) phases of recovery. FINDINGS: Pro-gelatinase MMP-3 increased significantly at 24 hrs in L4/5 (423.9% Naïve) whileMMP-9 and TNFα protein increased at 7d (511.9% and 197% Naïve, respectively) and 42d. MMP-2 remained at baseline in KO and WT mice in the lumbar enlargement. Reactivity was observed in lumbar endothelia as active MMP-9 localized to vasculature. Microglia displayed an activated phenotype within 24h through 7d in L1-L5 gray matter. TM training delivered in the presence or absence of MMP-9 had differential effects. Neither TM training alone nor MMP-9 depletion alone promoted recovery. In WT mice with SCI, TM training failed to induce locomotor recovery compared to untrained groups and paralysis persisted. However, acute TM training in MMP-9 KO mice resulted in robust recovery. Independent walking was evident in early trained KO mice by 7d (p<.01) and improvements were retained 4 wks after training ended (p<.05). IMPLICATIONS: Midthoracic SCI produces acute pathology at- and distant to the injury site that prevents plasticity and recovery in locomotor networks. Early markers of cellular inflammation included resident microglial activation and reactivity in lumbar endothelia. MMP-9 activity persisted around lumbar vasculature during the first week of SCI alongside increased pro-inflammatory cytokine production within centers for locomotion. Robust locomotor recovery occurred only when MMP-9 deletion was combined with acute TM training. We show for the first time, that locomotor recovery after SCI depends on at-level and remote inflammation. It is likely that neurorehabilitation will be most effective when delivered early but only in a low inflammatory environment.