480 research outputs found

    Postsynaptic α1-Adrenergic vasoconstriction is impaired in young patients with vasovagal syncope and is corrected by nitric oxide synthase inhibition

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    BACKGROUND: Syncope is a sudden transient loss of consciousness and postural tone with spontaneous recovery; the most common form is vasovagal syncope (VVS). During VVS, gravitational pooling excessively reduces central blood volume and cardiac output. In VVS, as in hemorrhage, impaired adrenergic vasoconstriction and venoconstriction result in hypotension. We hypothesized that impaired adrenergic responsiveness because of excess nitric oxide can be reversed by reducing nitric oxide. METHODS AND RESULTS: We recorded cardiopulmonary dynamics in supine syncope patients and healthy volunteers (aged 15-27 years) challenged with a dose-response using the α1-agonist phenylephrine (PE), with and without the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine, monoacetate salt (L-NMMA). Systolic and diastolic pressures among control and VVS were the same, although they increased after L-NMMA and saline+PE (volume and pressor control for L-NMMA). Heart rate was significantly reduced by L-NMMA (P<0.05) for control and VVS compared with baseline, but there was no significant difference in heart rate between L-NMMA and saline+PE. Cardiac output and splanchnic blood flow were reduced by L-NMMA for control and VVS (P<0.05) compared with baseline, while total peripheral resistance increased (P<0.05). PE dose-response for splanchnic flow and resistance were blunted for VVS compared with control after saline+PE, but enhanced after L-NMMA (P<0.001). Postsynaptic α1-adrenergic vasoconstrictive impairment was greatest in the splanchnic vasculature, and splanchnic blood flow was unaffected by PE. Forearm and calf α1-adrenergic vasoconstriction were unimpaired in VVS and unaffected by L-NMMA. CONCLUSIONS: Impaired postsynaptic α1-adrenergic vasoconstriction in young adults with VVS can be corrected by nitric oxide synthase inhibition, demonstrated with our use of L-NMMA

    Effects of text messaging in addition to emails on physical activity among university and college employees in the UK

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    Objectives To test the effects of adding text messages to weekly email communications on recipients’ total physical activity (leisure-time; workplace; domestic and garden; and active transportation) in employees of universities and colleges in the UK. Methods A randomised trial with two study groups (email only or email plus text messaging for 12 weeks) was implemented at five workplaces. Data were collected at baseline, immediately after, and four weeks after the intervention. Intervention effects on physical activity were evaluated using latent growth modelling. Results Total physical activity decreased over time in both groups but the decrease was non-significant. The only significant difference between groups was found for workplace physical activity, with the group receiving emails and text messages having a linear decrease of 2.81 Metabolic Equivalent h/week (β = −0.31, p = 0.035) compared to the email only group. Conclusions Sending employees two additional text messages resulted in less physical activity. Further investigation is needed to understand whether text messaging may play a beneficial role in promoting physical activity in workplace settings

    MAMS: High resolution atmospheric moisture/surface properties

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    Multispectral Atmospheric Mapping Sensor (MAMS) data collected from a number of U2/ER2 aircraft flights were used to investigate atmospheric and surface (land) components of the hydrologic cycle. Algorithms were developed to retrieve surface and atmospheric geophysical parameters which describe the variability of atmospheric moisture, its role in cloud and storm development, and the influence of surface moisture and heat sources on convective activity. Techniques derived with MAMS data are being applied to existing satellite measurements to show their applicability to regional and large process studies and their impact on operational forecasting

    Low adherence of Swiss children to national dietary guidelines.

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    INTRODUCTION: Dietary guidelines aim to inform people of the types of foods and quantities they should consume each day or week to promote and maintain health. The aim of this study was to describe children's dietary behaviors in terms of adherence to the Swiss Society for Nutrition (SSN) dietary guidelines and possible determinants. METHODS: A cross-sectional study was conducted in September 2010 with 568 children aged 6-12 years old living in Ticino Switzerland. Food intake was collected using 7-day food logs. Adherence with the dietary guidelines from the SSN was assessed according to age group. RESULTS: With the exception of fish and cereal/potato intake (adherence rates of 68.5% and 47.9%, respectively), adherence to SSN guidelines was low: 26.9% for meat; 22.7% for eggs; 10.4% for fruit; 9.5% for sweets, snacks &amp; soft drinks; 3.5% for milk &amp; dairy, and 0% for vegetables. Multivariate analysis showed no consistent association between the child or their parent's socio-demographic characteristics and adherence to SSN guidelines. Girls had a higher likelihood of adhering with fruit and meat guidelines: multivariate adjusted odds ratio (95% confidence interval) 1.98 (1.10-3.56) and 1.80 (1.08-2.99), respectively. Children aged 10 to 12 had a lower likelihood of adhering with cereals and potatoes 0.48 (0.29-0.78), and a higher likelihood of adhering with the guideline for eggs 1.78 (1.00-3.15). CONCLUSION: Dietary intake of Ticinese children shows poor adherence with SSN guidelines. Given the lack of specific socio-demographic factors associated with adherence, population-wide interventions to improve dietary intake are necessary

    Is it better at home with my family? The effects of people and place on children's eating behavior.

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    The people and places children eat with can influence food consumption. This study investigates the people and places Swiss school-aged children ate with over a 7-day period and analyses the effects of eating at home with family on food consumption. Children completed a 7-day food diary documenting the foods they consumed, the people with whom they ate, and the place where they ate. Analyses were conducted for all meals and included 9911 meal occasions. Most meals (80.5%) were consumed at home with family. Generalized estimating equations were used to model the effects of the home-family dyad on the child's chance of consuming a certain food while controlling for age, gender and BMI of the child, education, nationality and BMI of the parent. Compared to eating in other dyads (e.g. school-peers or restaurant-family), eating in the home-family dyad was associated with higher consumption of vegetables (+66% and +142% at weekday lunch and dinner and +180% and +67% at weekend lunch and dinner), lower consumption of sweets (-45% and -49% at weekday lunch and dinner; -43% and -49% at weekend lunch and dinner), and fewer soft drinks (-37% and -61% at weekday lunch and dinner; -66% and -78% at weekend lunch and dinner). This study shows the positive influence of eating at home with the family on food consumption in a sample of Swiss children. Interventions and policies that encourage children and parents to eat together at home could serve as effective prevention against a poor diet

    Orbit Selection for the Proposed Lynx Observatory Mission

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    The Advanced Concepts Office design team performed several analyses and trades in support of orbit selection for the proposed Lynx mission, an x-ray observatory being submitted to the Astro2020 Decadal Survey. Though the descriptions in this Technical Memorandum (TM) focus on the Lynx mission, the approach and process for selecting the final orbit is applicable to a variety of proposed science and exploration missions. To select the best orbit for the Lynx science, mission designers assembled a team of subsystem and discipline experts, in addition to mission analysts, to evaluate several candidate orbits. These discipline experts included members of the science and instrument team, power and avionics, thermal, propulsion, and environments. The goal was to clearly show the benefits and weaknesses of each orbit in the trade space and provide sound justification for the final selection. Discipline experts conducted trades and evaluated the results using a variety of methods including engineering judgement, rough estimates, and detailed calculations, and rolled the results into a final grade using a weighted grading method. The orbit options could then be ranked. The principal investigator (PI) for the mission, along with the science team, was given the task of final orbit selection. The result of the trades indicated that a halo orbit about the second Sun-Earth Lagrange point (SE-L2), similar to the planned orbit for the James Webb Space Telescope (JWST), was the best choice for the Lynx mission. Details of how the team arrived at this selection are below
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