Recursos de colección

The KnowledgeBank at OSU (74.597 recursos)

Knowledge Bank contains collections of presentations, publications and reports related to Ohio State University.

27th Hayes Graduate Research Forum (March, 2013)

Mostrando recursos 1 - 20 de 31

  1. Diketopiperazine and oxazolone structures: an investigation of the influence of the third residue on b2 structure in QAXIG and NAXIG analogues

    Morrison, Lindsay
    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...

  2. Catalysis of the Oxygen Reduction Reaction on Bimetallic PtCu Nanostructures

    Coleman, Eric
    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...

  3. Beverage Intake of U.S. Children by Weight Status

    Watowicz, Rosanna
    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...

  4. Ethnicity specific microbial signatures in the oral microbiome

    Mason, Matthew R.
    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...

  5. Vaporizing foil welding: A new tool for collision welding

    Hansen, Steven
    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...

  6. NF-kB Activation in Microglia Induces Motor Neuron Death in Amyotrophic lateral sclerosis

    Frakes, Ashley
    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...

  7. Rapid Hydrothermal Synthesis of Faujasitic Zeolites

    Severance, Michael
    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.

  8. Designing, Validating and Piloting a Genomics and Bioinformatics Assessment

    Campbell, Chad
    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...

  9. The Impact of Borderline Personality Disorder Symptoms on Self-Reported Invalidation and Learning Task Performance

    Stigen, Ciara
    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...

  10. 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.

    Barry, Andrew
    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...

  11. "I'm hoping for a miracle" and "I am too": Hopes Expressed Between Victims and Offenders Following Detention for Domestic Violence

    Carotta, Christin
    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...

  12. Analysis and comparison of vacant land resources for urban food production

    Kerrick, Benjamin
    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...

  13. An acoustic investigation of postaspirated stops in Seville Spanish

    Horn, Meagan
    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...

  14. Stress-induced recruitment of peripheral macrophages to the brain promotes anxiety-like behavior

    Wohleb, Eric
    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...

  15. Polarization Doped Nanowire Devices as an Alternative to Impurity Doping

    Carnevale, Santino
    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...

  16. Black Ballerinas in U.S. Popular Culture

    Fobbs, Joyelle
    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...

  17. Factors of Emotion and Affect in Designing Interactive Virtual Characters

    Maicher, Kellen
    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.

  18. On The Origin of Super-Hot Electrons in Laser-Plasma Interactions

    Krygier, Andrew
    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).

  19. Internalization and dissemination of human norovirus GII.4 and animal caliciviruses in hydroponically grown Romaine lettuce

    DiCaprio, Erin
    Fresh produce is a major vehicle for the transmission of human norovirus (NoV) because it is easily contaminated during both pre- and post-harvest stages however, the ecology of human NoV in fresh produce is poorly understood. In this study, we determined whether human NoV and its surrogates can be internalized via roots and disseminated to edible portions of the plant. The roots of Romaine lettuce growing in hydroponic feed water were inoculated with 1×106RNA copies/ml of human NoV GII.4 strain or 1-2×106PFU/mL of animal caliciviruses (Tulane virus, TV; and murine norovirus, MNV-1), and plants were allowed to grow for 2...

  20. Development of a Nanoscale DNA Based Force Transducer

    Hudoba, Michael W.
    Biological cells navigate their environment by means of local forces that push and pull on the cell substrate. These traction forces are generated internally and transmitted to the external substrate via attachment points called focal adhesions. Traction forces mediated by single membrane protein complexes are on the order of 10’s of piconewtons (pN); however, current technologies to measure these forces are limited to ~100-1000 pN resolution and are restricted to non-physiological 2D environments. The goal of this research is to develop a nanoscale sensor-based approach to measure traction force fields at resolutions down to the 1-10’s of pN scale in...

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