566 research outputs found
Identifying Very Metal-Rich Stars with Low-Resolution Spectra: Finding Planet-Search Targets
We present empirical calibrations that estimate stellar metallicity,
effective temperature and surface gravity as a function of Lick/IDS indices.
These calibrations have been derived from a training set of 261 stars for which
(1) high-precision measurements of [Fe/H], T_eff and log g have been made using
spectral-synthesis analysis of HIRES spectra, and (2) Lick indices have also
been measured. Our [Fe/H] calibration, which has precision 0.07 dex, has
identified a number of bright (V < 9) metal-rich stars which are now being
screened for hot Jupiter-type planets. Using the Yonsei-Yale stellar models, we
show that the calibrations provide distance estimates accurate to 20% for
nearby stars.
This paper outlines the second tier of the screening of planet-search targets
by the N2K Consortium, a project designed to identify the stars most likely to
harbor extrasolar planets. Discoveries by the N2K Consortium include the
transiting hot Saturn HD 149026 b (Sato et al. 2005, astro-ph/0507009) and HD
88133 b (Fischer et al. 2005). See Ammons et al. (2005, In Press) for a
description of the first tier of N2K metallicity screening, calibrations using
broadband photometry.Comment: Accepted for publication in the Astrophysical Journa
A new species of hippopotamine (Cetartiodactyla, Hippopotamidae) from the late Miocene Baynunah Formation, Abu Dhabi, United Arab Emirates
The discovery of new hippopotamid material from the late Miocene Baynunah Formation (Abu Dhabi, United Arab
Emirates) has prompted the revision of the existing material of this as yet unnamed fossil taxon. The Baynunah hippopotamid
appears to be distinct from all other contemporary and later species in having a relatively more elongate symphysis, a feature
similar to the earlier (and more primitive) Kenyapotamus. Yet, the Baynunah hippopotamid presents a dentition typical of the
Hippopotaminae. It is therefore a distinct species attributed to the later subfamily, described and named in this contribution. This
species provides further evidence for a ca. 8 Ma evolutionary event (termed âHippopotamine Eventâ) that initiated the spread and
ecological significance of the Hippopotaminae into wet habitats across Africa and Eurasia. The morphological affinities of the new
species from Abu Dhabi suggest that the Arabian Peninsula was not a dispersal route from Africa toward southern Asia for the
Hippopotamidae at ca. 7.5 Ma to 6.5 Ma
Impact of physical and biological processes on temporal variations of the ocean carbon sink in the mid-latitude North Atlantic (2002â2016)
The ocean is currently a significant net sink for anthropogenically remobilised CO2, taking up around 24% of global emissions. Numerical models predict a diversity of responses of the ocean carbon sink to increased atmospheric concentrations in a warmer world. Here, we tested the hypothesis that increased atmospheric forcing is causing a change in the ocean carbon sink using a high frequency observational dataset derived from underway pCO2 (carbon dioxide partial pressure) instruments on ships of opportunity (SOO) and a fixed-point mooring between 2002 and 2016. We calculated an average carbon flux of 0.013 Pg yrâ1 into the ocean at the Porcupine Abyssal Plain (PAP) site, consistent with past estimates. In spite of the increase in atmospheric pCO2, monthly average seawater pCO2 did not show a statistically significant increasing trend, but a higher annual variability, likely due to the decreasing buffer capacity of the system. The increasing led to an increasing trend in the estimated CO2 flux into the ocean of 0.19 ± 0.03 mmol mâ2 dayâ1 per year across the entire 15 year time series, making the study area a stronger carbon sink. Seawater pCO2 variability is mostly influenced by temperature, alkalinity and dissolved inorganic carbon (DIC) changes, with 77% of the annual seawater pCO2 changes explained by these terms. DIC is in turn influenced by gas exchange and biological production. In an average year, the DIC drawdown by biological production, as determined from nitrate uptake, was higher than the DIC increase due to atmospheric CO2 dissolution into the surface ocean. This effect was enhanced in years with high nutrient input or shallow mixed layers. Using the rate of change of DIC and nitrate, we observed Redfieldian carbon consumption during the spring bloom at a C:N ratio of 6.2 ± 1.6. A comparison between SOO and PAP sustained observatory data revealed a strong agreement for pCO2 and DIC. This work demonstrates that the study area has continued to absorb atmospheric CO2 in recent years with this sink enhancing over time. Furthermore, the change in pCO2 per unit nitrate became larger as surface buffer capacity changed
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Racial/ethnic disparities in health-related quality of life and health status across pre-, early-, and mid-adolescence: a prospective cohort study.
PURPOSE:To examine (1) racial/ethnic disparities in health-related quality of life (HRQOL) and overall health status among Black, Latino, and White youth during adolescence; (2) whether socioeconomic status (SES) and family contextual variables influence disparities; and (3) whether disparities are consistent from pre- to early- to mid-adolescence. METHODS:A population sample of 4823 Black (1755), Latino (1812), and White (1256) youth in three US metropolitan areas was prospectively assessed in a longitudinal survey conducted on three occasions, in 5th, 7th, and 10th grades, when youth reported their HRQOL using the PedsQLâą short-form Total, Physical and Psychosocial scales and youth and parents separately reported on youth's overall health status. Parents reported their education and household income to index SES, family structure, and use of English at home. RESULTS:Based on analysis conducted separately at each grade, marked racial/ethnic disparities were observed across all measures of HRQOL and health status, favoring White and disfavoring Black, and especially Latino youth. More strongly present in 5th and 7th grade, HRQOL disparities decreased by 10th grade. Most disparities between White and Black youth disappeared when adjusting for SES. However, even after adjusting for SES, family structure, and English use, overall health status disparities disfavoring Latino youth remained across all three assessments. CONCLUSIONS:Racial/ethnic disparities in adolescent HRQOL and health are substantial. These disparities appear consistent from pre- to early-adolescence but diminish for HRQOL by mid-adolescence. As disparities appear influenced by SES and other family contextual variables differently in different racial/ethnic groups, efforts to reduce health disparities in youth should address culturally specific conditions impinging on health
Sexual Minorities in England Have Poorer Health and Worse Health Care Experiences: A National Survey
ABSTRACT BACKGROUND The health and healthcare of sexual minorities have recently been identified as priorities for health research and policy. OBJECTIVE To compare the health and healthcare experiences of sexual minorities with heterosexual people of the same gender, adjusting for age, race/ethnicity, and socioeconomic status. DESIGN Multivariate analyses of observational data from the 2009/2010 English General Practice Patient Survey. PARTICIPANTS The survey was mailed to 5.56 million randomly sampled adults registered with a National Health Service general practice (representing 99 % of Englandâs adult population). In all, 2,169,718 people responded (39 % response rate), including 27,497 people who described themselves as gay, lesbian, or bisexual. MAIN MEASURES Two measures of health status (fair/poor overall self-rated health and self-reported presence of a longstanding psychological condition) and four measures of poor patient experiences (no trust or confidence in the doctor, poor/very poor doctor communication, poor/very poor nurse communication, fairly/very dissatisfied with care overall). KEY RESULTS Sexual minorities were two to three times more likely to report having a longstanding psychological or emotional problem than heterosexual counterparts (age-adjusted for 5.2 % heterosexual, 10.9 % gay, 15.0 % bisexual for men; 6.0 % heterosexual, 12.3 % lesbian and 18.8 % bisexual for women; p < 0.001 for each). Sexual minorities were also more likely to report fair/poor health (adjusted 19.6 % heterosexual, 21.8 % gay, 26.4 % bisexual for men; 20.5 % heterosexual, 24.9 % lesbian and 31.6 % bisexual for women; p < 0.001 for each). Adjusted for sociodemographic characteristics and health status, sexual minorities were about one and one-half times more likely than heterosexual people to report unfavorable experiences with each of four aspects of primary care. Little of the overall disparity reflected concentration of sexual minorities in low-performing practices. CONCLUSIONS Sexual minorities suffer both poorer health and worse healthcare experiences. Efforts should be made to recognize the needs and improve the experiences of sexual minorities. Examining patient experience disparities by sexual orientation can inform such efforts. Electronic supplementary material The online version of this article (doi:10.1007/s11606-014-2905-y) contains supplementary material, which is available to authorized users
Evaluation of Talking Parents, Healthy Teens, a new worksite based parenting programme to promote parent-adolescent communication about sexual health: randomised controlled trial
Objective To evaluate a worksite based parenting programmeâTalking Parents, Healthy Teensâdesigned to help parents learn to address sexual health with their adolescent children
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Increasing the Availability and Consumption of Drinking Water in Middle Schools: A Pilot Study
Introduction: Although several studies suggest that drinking water may help prevent obesity, no US studies have examined the effect of school drinking water provision and promotion on student beverage intake. We assessed the acceptability, feasibility, and outcomes of a school-based intervention to improve drinking water consumption among adolescents. Methods: The 5-week program, conducted in a Los Angeles middle school in 2008, consisted of providing cold, filtered drinking water in cafeterias; distributing reusable water bottles to students and staff; conducting school promotional activities; and providing education. Self-reported consumption of water, nondiet soda, sports drinks, and 100% fruit juice was assessed by conducting surveys among students (n = 876), preintervention and at 1 week and 2 months postintervention, from the intervention school and the comparison school. Daily water (in gallons) distributed in the cafeteria during the intervention was recorded. Results: After adjusting for sociodemographic characteristics and baseline intake of water at school, the odds of drinking water at school were higher for students at the intervention school than students at the comparison school. Students from the intervention school had higher adjusted odds of drinking water from fountains and from reusable water bottles at school than students from the comparison school. Intervention effects for other beverages were not significant. Conclusion: Provision of filtered, chilled drinking water in school cafeterias coupled with promotion and education is associated with increased consumption of drinking water at school. A randomized controlled trial is necessary to assess the intervention's influence on students' consumption of water and sugar-sweetened beverages, as well as obesity-related outcomes
Racial and Ethnic Health Disparities among Fifth-Graders in Three Cities
http://dx.doi.org/10.1056/NEJMsa111435
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