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Rochlin C.,Southern California Gas Company | Hite R.,CA
Electricity Journal

As electric generation becomes cleaner and greener, the emissions reduction benefit directly related to combined heat and power systems has come into question. Separate analyses dealing with increased efficiencies in double benchmark standards, falling grid GHG intensity, or increases in a renewable portfolio standard all point to significant reductions in CHP's ability to reduce GHG emissions. © 2015 Elsevier Inc. Source

Bhatia R.,CA | Seto E.,University of California at Berkeley
Environmental Impact Assessment Review

Health Impact Assessment (HIA) considers multiple effects on health of policies, programs, plans and projects and thus requires the use of diverse analytic tools and sources of evidence. Quantitative estimation has desirable properties for the purpose of HIA but adequate tools for quantification exist currently for a limited number of health impacts and decision settings; furthermore, quantitative estimation generates thorny questions about the precision of estimates and the validity of methodological assumptions. In the United States, HIA has only recently emerged as an independent practice apart from integrated EIA, and this article aims to synthesize the experience with quantitative health effects estimation within that practice. We use examples identified through a scan of available identified instances of quantitative estimation in the U.S. practice experience to illustrate methods applied in different policy settings along with their strengths and limitations. We then discuss opportunity areas and practical considerations for the use of quantitative estimation in HIA. © 2010 Elsevier Inc. Source

Raghupathy S.,Sociometrics Corporation | Hahn-Smith S.,CA
International Quarterly of Community Health Education

The Youth Risk Behavior Survey (YRBS) is frequently used by states and local school districts for monitoring and assessing health risk behaviors among middle and high school youth in the United States. This study assessed the reliability of the High School YRBS questions when the survey is administered as a web-based survey. A test-retest reliability study was conducted on a sample of high school students in grades 9-12. Students self-administered an online version of the high school YRBS at two different time periods. Kappa scores were computed for all items in order to measure reliability. Items measured prevalence estimates of behaviors related to unintentional injuries and violence, tobacco use, alcohol and other drug use, and sexual behaviors. The mean kappa reliability score was similar to scores obtained in prior reliability studies of the YRBS when administered as paper surveys; 87% of the 69 selected items from the 79-item paper survey used had kappa scores that indicated moderate or substantial reliability. Findings indicate the reliability of the online High School YRBS when administered to students online and its potential as an alternative to paper survey © 2012, Baywood Publishing Co., Inc. Source

Teutsch S.M.,CA | Fielding J.E.,University of California at Los Angeles
Health Affairs

Comparative effectiveness research to date has focused primarily on the diagnosis and treatment of diseases and injuries in individuals. Yet the greatest drivers of people's overall health are found in their social and physical environments. We recommend that the comparative effectiveness research agenda focus on the public health issues responsible for the greatest overall illness and death levels, such as programs to increase high school graduation rates, which are strongly associated with improvements in long-term illness and death rates. In so doing, the agenda should spotlight efforts to address widely recognized social and environmental determinants of health, such as improving access to early childhood development programs and education, as well as interventions aimed at affecting climate change and addressing behavioral risk factors such as smoking. We also urge federal health agencies to invest in further development of methods to compare public health interventions and to use those methods to conduct the studies. © 2011 by Project HOPE - The People-to-People Health Foundation, Inc. Source

Sleep N.H.,CA | Bird D.K.,Stanford University | Pope E.C.,Stanford University
Philosophical Transactions of the Royal Society B: Biological Sciences

Submarine hydrothermal vents above serpentinite produce chemical potential gradients of aqueous and ionic hydrogen, thus providing a very attractive venue for the origin of life. This environment was most favourable before Earth's massive CO 2 atmosphere was subducted into the mantle, which occurred tens to approximately 100 Myr after the moon-forming impact; thermophile to clement conditions persisted for several million years while atmospheric pCO 2 dropped from approximately 25 bar to below 1 bar. The ocean was weakly acid (pH ~ 6), and a large pH gradient existed for nascent life with pH 9-11 fluids venting from serpentinite on the seafloor. Total CO 2 in water was significant so the vent environment was not carbon limited. Biologically important phosphate and Fe(II) were somewhat soluble during this period, which occurred well before the earliest record of preserved surface rocks approximately 3.8 billion years ago (Ga) when photosynthetic life teemed on the Earth and the oceanic pH was the modern value of approximately 8. Serpentinite existed by 3.9 Ga, but older rocks that might retain evidence of its presence have not been found. Earth's sequesters extensive evidence of Archaean and younger subducted biological material, but has yet to be exploited for the Hadean record. © 2011 The Royal Society. Source

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