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The roll dynamics of a 5-kg, 1.3 -m high sounding rocket are analysed in a vertical wind tunnel. Significant turbulence in the tunnel makes the system identification of the effective inertia, damping, and asymmetry with respect to roll challenging. A novel method is developed, which decouples the disturbance from the rocket frame's intrinsic roll dynamics and allows accurate prediction of roll rate and angle. The parameter identification method is integral-based, and treats wind disturbances as equivalent to a movement in the actuator fins. The method is robust, requires minimal computation, and gave realistic disturbance distributions reflecting the randomness of the turbulent wind flow. Two models, one with constant damping and one with fin angle-dependant damping were considered. The mean absolute roll rate of the rocket frame observed in experiments was 16.4°/s and both models predicted the roll rate with a mean absolute error less than 0.10°/s with a standard deviation less than 0.08°/s. The roll angle (measured by an encoder), was tracked by the model with a mean absolute error less than 0.20° and a standard deviation less than 0.15°. These results prove the concept of this minimal modelling approach which will be extended to varying wind speed, and pitch, and yaw dynamics in the future. [ABSTRACT FROM AUTHOR]

Fundus autofluorescence (FAF) imaging takes advantage of the fluorescent properties of some molecules, especially lipofuscin. FAF derives mainly from retinal pigment epithelium (RPE) and Bruch's membrane. Using confocal scanning laser ophthalmoscope (cSLO) we have previously shown that FAF associated with pigmented choroidal lesions can be attributed to mainly lipofuscin (orange pigment) within the RPE. Other causes of FAF include hyperpigmentation, drusen, or fibrous metaplasia probably because they also cause lipofuscin accumulation in the overlying RPE. There is a total or partial correlation between FAF and the foci of lipofuscin and hyperpigmentation in about 90% of the cases. The FAF patterns of choroidal melanocytic lesions were classified as patchy or diffuse. The patchy pattern was defined as the presence of distinct areas of increased FAF between areas of normal autofluorescence. The diffuse pattern was characterized by the presence of increased FAF with indistinct borders over a larger part (>50%) of the tumour in the absence of such intervening areas. Choroidal melanomas presented with either a diffuse or patchy pattern, whereas choroidal naevi demonstrated only the patchy pattern. Diffuse FAF pattern was more often associated with larger choroidal melanomas as well as with early venous and late hyperfluorescence on fluorescein angiography. Limitations of these observations depend on the field of depth of cSLO; thus, FAF from other planes could not be detected. Increased retinal thickness, intraretinal oedema, or presence of subretinal fluid may also affect the FAF signal.Eye (2009) 23, 497–503; doi:10.1038/eye.2008.244; published online 1 August 2008 [ABSTRACT FROM AUTHOR]

Background: Self-reported food preferences and frequencies of food consumption have served as proxy measures of the current diet in consumer research and in nutritional epidemiology studies, respectively. Objective: The objective was to determine whether food preferences and food-frequency scores are associated variables that are predictive of nutrient intakes. Design: College-age women (n = 87) completed a 98-item food-frequency questionnaire and rated preferences for many of the same foods on a 9-point category scale. Estimated intakes of fat, fiber, and vitamin C were obtained by using 3-d food records. Results: For virtually all item pairs tested, food preferences and reported frequencies of consumption of the same foods were significantly correlated with each other. The median Pearson correlation coefficient was 0.40 (range: -0.04 to 0.62). Correlations improved when foods were aggregated into factor-based food groups. The slope of the relation between food preferences and frequency of consumption varied with food category. Both food preferences and food frequencies predicted dietary outcomes. Fat consumption was predicted equally well by either approach in a multiple regression model. Intakes of fiber and vitamin C were better predicted by food-frequency scores than by stated preferences for vegetables and fruit. Conclusions: Reported frequencies of food consumption, the core of the food-frequency approach, were associated with food likes and dislikes. Food preferences were a predictor of dietary intakes and may provide an alternative to the food-frequency approach for dietary intake assessment. Copyright 1999 American Society for Clinical Nutrition [ABSTRACT FROM AUTHOR]

BACKGROUND--Some patients with angina pectoris and normal coronary arteriograms have reduced coronary flow reserve and abnormal endothelium dependent vasodilator responses. Endothelin-1 (ET-1), a potent vasoconstrictor, is an important modulator of microvascular function and may also have algogenic properties. METHOD--Plasma ET-1 was measured in peripheral venous blood in 40 patients (30 women) (mean (SD) age 56 (8) years) with angina and normal coronary arteriograms and 21 normal controls (17 women) (mean (SD) age 53 (7) years). Patients with systemic hypertension, left ventricular hypertrophy, or coronary spasm were excluded. Plasma ET-1 was measured using radioimmunoassay. RESULTS--Thirty five patients had > or = 1 mm ST segment depression during exercise. Left bundle branch block was present in four patients at rest and in one during exercise. Mean (SD) (range) concentration of ET-1 (pg/ml) was higher in patients than in controls (3.84 (1.25) (1.97-7.42) v 2.88 (0.71) (1.57-4.48) P < 0.0001). In patients with "high" (> control mean (one SD)) ET-1 concentrations (n = 23), the time to onset of chest pain during exercise was significantly shorter (6.21 (3.9) v 9.03 (3.9) min; p = 0.01) than in patients with "low" ET-1 concentrations. Of the five patients with left bundle branch block, four had plasma ET-1 concentration > 4.0 pg/ml. CONCLUSION--Plasma endothelin is raised in patients with angina and normal coronary arteriograms and is consistent with the demonstration of endothelial dysfunction in such patients. The association between "high" plasma ET-1 and an earlier onset of chest pain during exercise suggests that endothelin may also have a role in the genesis of chest pain in patients with normal coronary arteries. [ABSTRACT FROM PUBLISHER]