1,397 research outputs found

    Conceptual design of single turbofan engine powered light aircraft

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    The conceptual design of a four place single turbofan engine powered light aircraft was accomplished utilizing contemporary light aircraft conventional design techniques as a means of evaluating the NASA-Ames General Aviation Synthesis Program (GASP) as a preliminary design tool. In certain areas, disagreement or exclusion were found to exist between the results of the conventional design and GASP processes. Detail discussion of these points along with the associated contemporary design methodology are presented

    Foodmaster and three stories

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    Graduation date: 2004The purpose of this thesis was to create a sustained piece of fiction that both\ud represented my growth as a writer throughout my time at Oregon State University, and\ud wove together a mixture of imagination, language, and creativity. My hope was to write\ud a novella that incorporated and drew from themes including work, community, and\ud family relationships, and also was an exploration in the very structure and form of literary\ud fiction.\ud After completing the novella, I found that similar themes continued to appear\ud within my fiction during my ongoing growth as a writer. What I ended up with was a\ud novella and collection of related stories that reflected the influences of my advisor Tracy\ud Daugherty and his tutelage, the courses that I took at this university and my\ud undergraduate university, and my own personal history.\ud This thesis was written over a two-year period, during which drafts of this novella\ud and stories were written and rewritten. Each story and chapter was submitted to a writing\ud workshop, read and edited by my major and minor advisor, and carefully reworked and\ud redrafted after much scrutiny and attention.\ud During the course of writing this thesis, many things influenced me, the most\ud prominent being the world of fiction that existed all around me. I was influenced by\ud fiction that I was reading in my course work, such as Donald Barthelme and Philip Roth,\ud but writers that I had grown up with, like Edgar Allen Poe and Ray Bradbury also\ud influenced me. Beyond the world of published fiction, I found not only influence, but\ud also more importantly inspiration from the work and criticism of the writers and students\ud within the Creative Writing Program here at Oregon State University.\ud The end result of these two years of work, study, writing, and criticism was a\ud piece of fiction that I am proud of, and plan to publish. This collection of fiction\ud represents not only a sustained study on the craft of creative writing, but also serves an\ud exploration of my own voice and style, and an awakening of my identity as a fiction\ud writer

    Efficacy of cyclosporin A in psoriasis: a summary of the United States’ experience

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    Since its discovery in 1972, cyclosporin A (CyA) has been widely used in the experimental treatment of multiple inflammatory diseases considered to be of immune-mediated aetiology. In dermatology, oral CyA is most effective in the treatment of psoriasis and has been used successfully for plaque-type, pustular and erythrodermic forms of the disease. While dosages ranging from 1 to 14 mg/kg/day have been used, a starting dose of 4 mg/kg/day gives a rapid response with few side-effects. Nephrotoxicity remains the greatest concern in long-term use of the drug. Although intralesional CyA has proven effective in psoriasis, topical preparations have not. It is hoped that future research will provide effective topical formulations of CyA which are efficacious without the risks inherent in systemic administration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72330/1/j.1365-2133.1990.tb02878.x.pd

    Methylene Blue as an Inhibitor of Superoxide Generation by Xanthene Oxidase: A Potential New Drug for the Attenuation of Ischemia/Reperfusion Injury

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    Tissue oxidases, especially xanthine oxidase, have been proposed as primary sources of toxic oxygen radicals in many experimental models of disease states. Among these, ischemia-reperfusion injury may be of the greatest clinical interest. In this paper we propose the use of methylene blue as a means of suppressing the production of superoxide radicals, O2, by acting as an alternative electron acceptor for xanthine oxidase. Previous work has indicated that methylene blue accepts electrons from xanthine oxidase at the iron-sulfur center. Initial experiments in our laboratory demonstrated that (1) pairs of electrons from each enzymatic oxidation are transferred to methylene blue, (2) the reduction of methylene blue can be achieved by model iron-sulfur centers, similar to the iron-sulfur center of xanthine oxidase, (3) reduced methylene blue auto-oxidizes to produce H2O2 directly, rather than O2, and (4) methylene blue is effective at non-toxic levels (2-5 mg/kg) in preventing free radical damage to liver and kidney tissues in an in vitro model of ischemia and reoxygenation. Accordingly, we propose that methylene blue may represent a new class of antioxidant drugs that competitively inhibit reduction of molecular oxygen to superoxide by acting as alternative electron acceptors for tissue oxidases. We have termed these agents “parasitic” electron acceptors

    Theory and Application of Dissociative Electron Capture in Molecular Identification

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    The coupling of an electron monochromator (EM) to a mass spectrometer (MS) has created a new analytical technique, EM-MS, for the investigation of electrophilic compounds. This method provides a powerful tool for molecular identification of compounds contained in complex matrices, such as environmental samples. EM-MS expands the application and selectivity of traditional MS through the inclusion of a new dimension in the space of molecular characteristics--the electron resonance energy spectrum. However, before this tool can realize its full potential, it will be necessary to create a library of resonance energy scans from standards of the molecules for which EM-MS offers a practical means of detection. Here, an approach supplementing direct measurement with chemical inference and quantum scattering theory is presented to demonstrate the feasibility of directly calculating resonance energy spectra. This approach makes use of the symmetry of the transition-matrix element of the captured electron to discriminate between the spectra of isomers. As a way of validating this approach, the resonance values for twenty-five nitrated aromatic compounds were measured along with their relative abundance. Subsequently, the spectra for the isomers of nitrotoluene were shown to be consistent with the symmetry-based model. The initial success of this treatment suggests that it might be possible to predict negative ion resonances and thus create a library of EM-MS standards.Comment: 18 pages, 7 figure

    Unbiased Comparative Evaluation of Ranking Functions

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    Eliciting relevance judgments for ranking evaluation is labor-intensive and costly, motivating careful selection of which documents to judge. Unlike traditional approaches that make this selection deterministically, probabilistic sampling has shown intriguing promise since it enables the design of estimators that are provably unbiased even when reusing data with missing judgments. In this paper, we first unify and extend these sampling approaches by viewing the evaluation problem as a Monte Carlo estimation task that applies to a large number of common IR metrics. Drawing on the theoretical clarity that this view offers, we tackle three practical evaluation scenarios: comparing two systems, comparing kk systems against a baseline, and ranking kk systems. For each scenario, we derive an estimator and a variance-optimizing sampling distribution while retaining the strengths of sampling-based evaluation, including unbiasedness, reusability despite missing data, and ease of use in practice. In addition to the theoretical contribution, we empirically evaluate our methods against previously used sampling heuristics and find that they generally cut the number of required relevance judgments at least in half.Comment: Under review; 10 page

    Which smoking cessation interventions work best?

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    Nicotine replacement therapy (NRT), bupropion, nortriptyline, clonidine, and varenicline are all effective, although insufficient evidence exists to recommend one intervention over another (SOR: A, systematic reviews). Effective nonpharmacologic interventions include brief physician advice and more intensive counseling, such as proactive telephone counseling, group and individual counseling, and use of quit lines (SOR: A, systematic reviews)

    How mutations in tRNA distant from the anticodon affect the fidelity of decoding

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    The ribosome converts genetic information into protein by selecting aminoacyl tRNAs whose anticodons base-pair to an mRNA codon. Mutations in the tRNA body can perturb this process and affect fidelity. The Hirsh suppressor is a well-studied tRNA^(Trp) harboring a G24A mutation that allows readthrough of UGA stop codons. Here we present crystal structures of the 70S ribosome complexed with EF-Tu and aminoacyl tRNA (native tRNA^(Trp), G24A tRNA^(Trp) or the miscoding A9C tRNA^(Trp)) bound to cognate UGG or near-cognate UGA codons, determined at 3.2-Ă… resolution. The A9C and G24A mutations lead to miscoding by facilitating the distortion of tRNA required for decoding. A9C accomplishes this by increasing tRNA flexibility, whereas G24A allows the formation of an additional hydrogen bond that stabilizes the distortion. Our results also suggest that each native tRNA will adopt a unique conformation when delivered to the ribosome that allows accurate decoding

    Double-blind, placebo-controlled study to evaluate the efficacy of fish oil and low-dose UVB in the treatment of psoriasis

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    Since eicosanoids have been implicated in the pathogenesis of psoriasis, less potent eicosanoid mediators derived from fish oil might improve psoriasis. Using a double-blind, randomized, parallel design, 18 patients with stable, plaque psoriasis received capsules of either fish oil or identical-appearing placebo olive oil for 15 weeks, with concomitant sub-erythemal UVB in weeks 3 to 11. At the conclusion of phototherapy, and 4 weeks later, patients in the fish oil group had a greater decrease in the total body surface area of psoriasis and more improvement compared to patients in the olive oil group. The improvement in the fish oil group was statistically significantly greater for all parameters compared to the change in the olive oil group. The apparent safety and general health-promoting features of fish oil could provide an ideal adjunctive therapy for psoriasis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73035/1/j.1365-2133.1989.tb01378.x.pd
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