1,252 research outputs found

    Laminar-flow flight experiments

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    The flight testing conducted over the past 10 years in the NASA laminar-flow control (LFC) will be reviewed. The LFC program was directed towards the most challenging technology application, the high supersonic speed transport. To place these recent experiences in perspective, earlier important flight tests will first be reviewed to recall the lessons learned at that time

    Testing the impact of an educational intervention designed to promote ocular health among people with age-related macular degeneration

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    Research has shown that individuals affected by age-related macular degeneration (AMD) do not always consume foods or supplements known to be beneficial for ocular health. This study tested the effectiveness of an educational intervention designed to promote healthy eating and nutritional supplementation in this group. A total of 100 individuals with AMD completed baseline measures of several variables: confidence that diet affects AMD, motivation to engage in health-protective behaviours, knowledge about which nutrients are beneficial, and intake of kale, spinach, and eggs. Participants were allocated to either intervention or control conditions. Intervention participants received a leaflet and prompt card that contained advice regarding dietary modification and supplementation. Control participants received a leaflet created by the Royal College of Optometrists. A follow-up questionnaire, measuring the same variables assessed at baseline, was administered 2 weeks later. At follow-up, significant condition × time interactions were found for confidence that diet affects AMD (F(1, 92) = 4.54, p < .05), motivation to talk to an eye professional about supplementation (F(1, 92) = 4.53, p = .036), motivation to eat eggs (F(1, 92) = 12.67, p = .001), and egg intake (F(1, 92) = 11.97, p = .001). In each case, intervention participants scored higher than control participants. Receiving an educational intervention increased participants’ confidence that diet affects AMD, motivation to engage in health-protective behaviours, and egg intake. This intervention could be easily incorporated into current clinical practice delivered by either optometrists or ophthalmologists

    Macular pigment optical density is related to blood glutathione levels in healthy individuals

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    Purpose. To assess the relationship between macular pigment optical density (MPOD) and blood markers for antioxidant defense in otherwise healthy volunteers. Methods. Forty-seven healthy volunteers were subjected to blood analysis to detect the level of circulating glutathione in its reduced (GSH) and oxidized (GSSG) forms. The level of MPOD was measured using heterochromatic flicker photometry. Systemic blood pressure (BP) parameters, heart rate (HR), body mass index (BMI), and plasma levels of total, HDL, and LDL cholesterol and triglycerides (TGs) were also determined. Results. A simple correlation model revealed that the level of MPOD correlated significantly and positively with both GSH (P 0.05). Age, sex, systemic BP parameters, HR, BMI, and plasma levels of cholesterol and TGs did not have any influence on either MPOD or glutathione levels (all P > 0.05). In addition, a forward stepwise multiple regression analysis showed MPOD to have a significantly and independent correlation with GSH levels (ß = 0.63; P < 0.001). Conclusions. In otherwise healthy older individuals, there is a positive correlation between local and systemic antioxidant defense mechanisms

    Primordial Nucleosynthesis with CMB Inputs: Probing the Early Universe and Light Element Astrophysics

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    Cosmic microwave background (CMB) determinations of the baryon-to-photon ratio ηΩbaryonh2\eta \propto \Omega_{\rm baryon} h^2 will remove the last free parameter from (standard) big bang nucleosynthesis (BBN) calculations. This will make BBN a much sharper probe of early universe physics, for example, greatly refining the BBN measurement of the effective number of light neutrino species, Nν,effN_{\nu,eff}. We show how the CMB can improve this limit, given current light element data. Moreover, it will become possible to constrain Nν,effN_{\nu,eff} independent of \he4, by using other elements, notably deuterium; this will allow for sharper limits and tests of systematics. For example, a 3% measurement of η\eta, together with a 10% (3%) measurement of primordial D/H, can measure Nν,effN_{\nu,eff} to a 95% confidence level of \sigma_{95%}(N_\nu) = 1.8 (1.0) if η6.0×1010\eta \sim 6.0\times 10^{-10}. If instead, one adopts the standard model value Nν,eff=3N_{\nu,eff}=3, then one can use η\eta (and its uncertainty) from the CMB to make accurate predictions for the primordial abundances. These determinations can in turn become key inputs in the nucleosynthesis history (chemical evolution) of galaxies thereby placing constraints on such models.Comment: 17 pages, 13 figures, plain LaTe

    Necessary fictions: indigenous claims and the humanity of rights

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    Indigenous right insistently challenges the surpassing arrogations of sovereign right. In so doing, it affirms dimensions of being-together denied or stunted in sovereign modes of political formation. This force of Indigenous right is amplified here through legal and literary instantiations. These, in turn, uncover the continuously created and fictional quality of rights, revealing them to be necessary fictions
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