3,837 research outputs found

    Focus drive mechanism for the IUE scientific instrument

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    A compact, lightweight mechanism was developed for in-orbit adjustment of the position of the secondary mirror (focusing) of the International Ultraviolet Explored telescope. This device is a linear drive with small (.0004 in.) and highly repeatable step increments. Extremely close tolerances are also held in tilt and decentering. The unique mechanization is described with attention to the design details that contribute to positional accuracy. Lubrication, materials, thermal considerations, sealing, detenting against launch loads, and other features peculiar to flight hardware are discussed. The methods employed for mounting the low expansion quartz mirror with minimum distortion are also given

    Psychometric Analysis of a 9-Item M-Hooked-On Nicotine Checklist for Vaping Among College Students

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    Background: Adolescent participation in electronic vapor products (EVP) is on the rise and with it many new health concerns present themselves. EVP use tripled among high school and middle school students from 2013-2014 and has continued to grow. Previous nicotine related studies have shown that the earlier the age of initiation to nicotine, the higher likelihood to develop a nicotine dependence. Methods: Using the “Hooked on Nicotine Checklist” (HONC) current rates of nicotine dependence among college students at a southwest Missouri university was assessed. One hundred and fifty-six students were recruited from a KIN 210 class as a convenience sample. Data was obtained by administering an online survey that was given during the KIN 210 class. Analysis: Scores were classified as signs of diminishing autonomy (HONC 1-4) or full autonomy (HONC 0) for each question. Psychometric analyses were run to determine the reliability and validity of the 9-item m-HONC. Descriptive statistics were used to determine the frequency of nicotine dependency, strength of dependency, and the loss of autonomy. Results: The 9-item m-HONC reported excellent internal consistency with Cronbach’s α = .953, an exploratory factor analysis was also run to confirm the unidimensional nature of the scale

    759-2 Use of Artificial Neural Networks within Deterministic Logic for Computer ECG Diagnosis of Myocardial Infarction

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    The study was aimed at assessing the effect of incorporating neural networks (NN) inside an existing deterministic computer ECG analysis program in order to enhance the diagnosis of myocardial infarction. Separate neural networks were trained for inferior and anterior myocardial infarction using 200 normals, 100 IMI. 80 AMI and 42 left ventricular hypertrophy cases, all clinically validated. All the networks had a single output to discriminate between MI and non-MI. A variable number of inputs to the networks was used consisting of QRS±ST-T measurements. Separate test sets including 200 normals. 42 LVH, 101 AMI and 80 IMI cases were then utilised to find the best performing neural networks for IMI and AMI. The best neural network for each of IMI and AMI was then selected and inserted into the existing Glasgow Program (GP) for ECG analysis together with some modifications (M) to the diagnostic logic. The modified and original GP were then assessed using a completely new test set composed of 74 AMI, 52 IMI, 60 LVH and 230 normals.ResultsAMI SeIMI SeNSpLSpOSpGP76%69%100%93%99%GP+NN+M78%88%100%85%97%Se=sensitivity, Sp=specificity, N=normal. L=LVH, Oa=overallConclusionsThis first report of neural networks for the diagnosis of myocardial infarction embedded within a deterministic logic program has shown that (1) the technique significantly improves the diagnosis of inferior though not anterior MI; (2) the evaluation of specificity using only normals is misleading; (3) the technique can usefully be adopted selectively to enhance diagnostic ECG programs in future

    Research Notes : Genetic linkage analysis

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    The Rj2 gene (Caldwell, 1966), which conditions ineffective nodulation wtth strains of the cl and 122 serogroup of Rhizobium japonicum (Kirchner) Buhanan, and the Rj4 gene (Vest and Caldwell, 1972), conditioning an inef-fective nodulation response with rhizobial strain 61 of the Beltsville Culture Collection R. japonicum, were tested for linkage association with the gene L1 (black pod). The rj1 gene (Williams and Lynch, 1954), conditon-. ing a non-nodulating response with a broad spectrum of strains of R. Japonicum, was tested for linkage with the gene fr (roots nonfluorescent in UV light) and L1 (black pod). The gene y9 (chlorophyll defective) was tested for possible linkage with the genes ln (narrow leaf), and P1 (glabrous). The P1 gene was also tested for linkage with the gene fr

    Research notes: Genetic analysis of factors controlling nodulation response in soybeans

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    Two of the genes controlling nodulation response in soybeans were tested for linkage associations with genes controlling pubescence color (T) and flower color (W1 ), chlorophyll deficiency (y9 ) and absence of pubescence (P). The rj1 gene (W1lliams and Lynch, 1954) in homozygous recessive condition results in a non-nodulating phenotype with a broad spectrum of Rhizobium japonicum strains. The dominant gene, Rj4 (Vest and Caldwell, 1972) conditions an ineffective nodulation response when inoculated specifically with R. japonicum strain 61 of the Beltsville Culture Collection
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