179 research outputs found

    The radial velocity search for extrasolar planets

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    Researchers are measuring small changes in the line-of-sight velocities of stars to detect the oscillating reflex acceleration induced by large planets. The intention is to observe enough stars for a long enough time to be able to make a statement of the probability of planets in a certain range of masses even if no planetary perturbations are detected. To make these measurements of Doppler shift with the required sensitivity, a new instrument was specifically designed, built and tested for this campaign of ground-based planet detection. The instrument is an optical spectrometer for which wavelengths are first calibrated by transmission through a tunable Fabry-Perot etalon interferometer. The intrinsic stability of the etalon and an image-scrambling fiber optic light feed provide great sensitivity to line-of-sight accelerations and immunity to systematic errors

    Use of Emerging Tobacco Products in the United States

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    This paper provides the first nationally representative estimates for use of four emerging products. Addressing the issue of land-line substitution with cell phones, we used a mixed-mode survey to obtain two representative samples of US adults. Of 3,240 eligible respondents contacted, 74% completed surveys. In the weighted analysis, 13.6% have tried at least one emerging tobacco product; 5.1% snus; 8.8% waterpipe; 0.6% dissolvable tobacco products; 1.8% electronic nicotine delivery systems (ENDS) products. Daily smokers (25.1%) and nondaily smokers (34.9%) were the most likely to have tried at least one of these products, compared to former smokers (17.2%) and never smokers (7.7%), P<.001. 18.2% of young adults 18–24 and 12.8% of those >24 have tried one of these products, P<.01. In multivariable analysis, current daily (5.5, 4.3–7.6), nondaily (6.1, 4.0–9.3), and former smoking status (2.7, 2.1–3.6) remained significant, as did young adults (2.2, 1.6–3.0); males (3.5, 2.8–4.5); higher educational attainment; some college (2.7, 1.7–4.2); college degree (2.0, 1.3–3.3). Use of these products raises concerns about nonsmokers being at risk for nicotine dependence and current smokers maintaining their dependence. Greater awareness of emerging tobacco product prevalence and the high risk demographic user groups might inform efforts to determine appropriate public health policy and regulatory action

    A Single Geostationary Satellite for Mobile Terrestrial Transmitter Tracking

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    This paper will describe the Energetics Satellite Locating Service (ESLS) which is a unique, patented, proprietary satellite based geolocation system. This system called SAT/TRAC for Satellite Tracking, Ranging and Communications may be used to quickly determine the present location within 50 feet of any person, vehicle or object that is equipped with a ESLS low power transmitter. This technology represents a novel approach to radio tracking. The single point location system uses a single satellite with a 165 foot inflatable antenna

    Commercial lending distance and historically underserved areas

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    We study recent changes in the geographic distances between small businesses and their bank lenders, using a large random sample of loans guaranteed by the Small Business Administration. Consistent with extant research, we find that small borrower-lender distances generally increased between 1984 and 2001, with a rapid acceleration in distance beginning in the late-1990s. We also document a new phenomenon: a fundamental reordering of borrower-lender distance by the borrowers' neighborhood income and race characteristics. Historically, borrower-lender distance tended to be shorter than average for historically underserved (for example, low-income and minority) areas, but by 2000 borrowers in these areas tended to be farther away from their lenders on average. This structural change is coincident in time with the adoption of credit scoring models that rely on automated lending processes and quantitative information, and we find indirect evidence consistent with this link. Our findings suggest that there has been increased entry into local markets for small business loans and this should help allay fears that movement toward automated lending processes will reduce small businesses' access to credit in already underserved markets.

    Airborne radar ground clutter return

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    Call number: LD2668 .T4 1964 M16Master of Scienc

    What Aspect of Dependence Does the Fagerström Test for Nicotine Dependence Measure?

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    Although the Fagerström Test for Nicotine Dependence (FTND) and the Heaviness of Smoking Index (HSI) are widely used, there is a uncertainty regarding what is measured by these scales. We examined associations between these instruments and items assessing different aspects of dependence. Adult current smokers ( , mean age 33.3 years, 61.9% female) completed a web-based survey comprised of items related to demographics and smoking behavior plus (1) the FTND and HSI; (2) the Autonomy over Tobacco Scale (AUTOS) with subscales measuring Withdrawal, Psychological Dependence, and Cue-Induced Cravings; (3) 6 questions tapping smokers’ wanting, craving, or needing experiences in response to withdrawal and the latency to each experience during abstinence; (4) 3 items concerning how smokers prepare to cope with periods of abstinence. In regression analyses the Withdrawal subscale of the AUTOS was the strongest predictor of FTND and HSI scores, followed by taking precautions not to run out of cigarettes or smoking extra to prepare for abstinence. The FTND and its six items, including the HSI, consistently showed the strongest correlations with withdrawal, suggesting that the behaviors described by the items of the FTND are primarily indicative of a difficulty maintaining abstinence because of withdrawal symptoms

    Viable Influenza A Virus in Airborne Particles Expelled During Coughs Versus Exhalations

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    Background To prepare for a possible influenza pandemic, a better understanding of the potential for the airborne transmission of influenza from person to person is needed. Objectives The objective of this study was to directly compare the generation of aerosol particles containing viable influenza virus during coughs and exhalations. Methods Sixty-one adult volunteer outpatients with influenza-like symptoms were asked to cough and exhale three times into a spirometer. Aerosol particles produced during coughing and exhalation were collected into liquid media using aerosol samplers.The samples were tested for the presence of viable influenza virus using a viral replication assay (VRA). Results Fifty-three test subjects tested positive for influenza A virus. Of these, 28 (53%) produced aerosol particles containing viable influenza A virus during coughing, and 22 (42%) produced aerosols with viable virus during exhalation. Thirteen subjects had both cough aerosol and exhalation aerosol samples that contained viable virus, 15 had positive cough aerosol samples but negative exhalation samples, and 9 had positive exhalation samples but negative cough samples. Conclusions Viable influenza A virus was detected more often in cough aerosol particles than in exhalation aerosol particles, but the difference was not large. Because individuals breathe much more often than they cough, these results suggest that breathing may generate more airborne infectious material than coughing over time. However, both respiratory activities could be important in airborne influenza transmission. Our results are also consistent with the theory that much of the aerosol containing viable influenza originates deep in the lung

    Data Assimilation Enhancements to Air Force Weathers Land Information System

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    The United States Air Force (USAF) has a proud and storied tradition of enabling significant advancements in the area of characterizing and modeling land state information. 557th Weather Wing (557 WW; DoDs Executive Agent for Land Information) provides routine geospatial intelligence information to warfighters, planners, and decision makers at all echelons and services of the U.S. military, government and intelligence community. 557 WW and its predecessors have been home to the DoDs only operational regional and global land data analysis systems since January 1958. As a trusted partner since 2005, Air Force Weather (AFW) has relied on the Hydrological Sciences Laboratory at NASA/GSFC to lead the interagency scientific collaboration known as the Land Information System (LIS). LIS is an advanced software framework for high performance land surface modeling and data assimilation of geospatial intelligence (GEOINT) information

    DHA supplementation during pregnancy does not reduce BMI or body fat mass in children: follow-up of the DHA to Optimize Mother Infant Outcome randomized controlled trial

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    First published March 30, 2016The omega-3 (n-3) long-chain polyunsaturated fatty acid (LCPUFA) docosahexaenoic acid (DHA) has proven effective at reducing fat storage in animal studies. However, a systematic review of human trials showed a lack of quality data to support or refute this hypothesis.We sought to determine whether maternal DHA supplementation during the second half of pregnancy results in a lower body mass index (BMI) and percentage of body fat in children.We conducted a follow-up at 3 and 5 y of age of children who were born to mothers enrolled in the DOMInO (DHA to Optimize Mother Infant Outcome) double-blind, randomized controlled trial, in which women with a singleton pregnancy were provided with DHA-rich fish-oil capsules (800 mg DHA/d) or vegetable-oil capsules (control group) in the second half of pregnancy. Primary outcomes were the BMIzscore and percentage of body fat at 3 and 5 y of age. Potential interactions between prenatal DHA and the peroxisome proliferator-activated receptor-γ (PPARγ) genotype as a measure of the genetic predisposition to obesity were investigated.A total of 1614 children were eligible for the follow-up. Parent or caregiver consent was obtained for 1531 children (95%), and these children were included in the analysis. BMIzscores and percentages of body fat of children in the DHA group did not differ from those of children in the control group at either 3 y of age [BMIzscore adjusted mean difference: 0.03 (95% CI: -0.07, 0.13;P= 0.61); percentage of body fat adjusted mean difference: -0.26 (95% CI: -0.99, 0.46;P= 0.47)] or 5 y of age [BMIzscore adjusted mean difference: 0.02 (95% CI: -0.08, 0.12;P= 0.66); percentage of body fat adjusted mean difference: 0.11 (95% CI: -0.60, 0.82;P= 0.75)]. No treatment effects were modified by thePPARγgenotype of the child.Independent of a genetic predisposition to obesity, maternal intake of DHA-rich fish oil during the second half of pregnancy does not affect the growth or body composition of children at 3 or 5 y of age. This trial was registered atwww.anzctr.org.auas ACTRN1260500056906 and ACTRN12611001127998.Beverly S Muhlhausler, Lisa N Yelland, Robyn McDermott, Linda Tapsell, Andrew McPhee, Robert A Gibson, and Maria Makride
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