8,757 research outputs found
A survey of thermodynamic properties of the compounds of the element CHNOPS Progress report, 1 Mar. - 30 Jun. 1968
Thermodynamic property data tables for CHNOPS compounds and heats of combustion and formation for organic compounds of biological interes
Feeding interventions for growth and development in infants with cleft lip, cleft palate or cleft lip and palate.
BACKGROUND: Cleft lip and cleft palate are common birth defects, affecting about one baby of every 700 born. Feeding these babies is an immediate concern and there is evidence of delay in growth of children with a cleft as compared to those without clefting. In an effort to combat reduced weight for height, a variety of advice and devices are recommended to aid feeding of babies with clefts. OBJECTIVES: This review aims to assess the effects of these feeding interventions in babies with cleft lip and/or palate on growth, development and parental satisfaction. SEARCH STRATEGY: The following electronic databases were searched: the Cochrane Oral Health Group Trials Register (to 27 October 2010), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 4), MEDLINE via OVID (1950 to 27 October 2010), EMBASE via OVID (1980 to 27 October 2010), PsycINFO via OVID (1950 to 27 October 2010) and CINAHL via EBSCO (1980 to 27 October 2010). Attempts were made to identify both unpublished and ongoing studies. There was no restriction with regard to language of publication. SELECTION CRITERIA: Studies were included if they were randomised controlled trials (RCTs) of feeding interventions for babies born with cleft lip, cleft palate or cleft lip and palate up to the age of 6 months (from term). DATA COLLECTION AND ANALYSIS: Studies were assessed for relevance independently and in duplicate. All studies meeting the inclusion criteria were data extracted and assessed for validity independently by each member of the review team. Authors were contacted for clarification or missing information whenever possible. MAIN RESULTS: Five RCTs with a total of 292 babies, were included in the review. Comparisons made within the RCTs were squeezable versus rigid feeding bottles (two studies), breastfeeding versus spoon-feeding (one study) and maxillary plate versus no plate (two studies). No statistically significant differences were shown for any of the primary outcomes when comparing bottle types, although squeezable bottles were less likely to require modification. No difference was shown for infants fitted with a maxillary plate compared to no plate. However, there was some evidence of an effect on weight at 6 weeks post-surgery in favour of breastfeeding when compared to spoon-feeding (mean difference 0.47; 95% confidence interval 0.20 to 0.74). AUTHORS' CONCLUSIONS: Squeezable bottles appear easier to use than rigid feeding bottles for babies born with clefts of the lip and/or palate, however, there is no evidence of a difference in growth outcomes between the bottle types. There is weak evidence that breastfeeding is better than spoon-feeding following surgery for cleft. There was no evidence to suggest that maxillary plates assist growth in babies with clefts of the palate. No evidence was found to assess the use of any types of maternal advice and/or support for these babies
Global Health and Economic Impacts of Future Ozone Pollution
Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/).We assess the human health and economic impacts of projected 2000-2050 changes in ozone pollution using the MIT Emissions Prediction and Policy Analysis-Health Effects (EPPA-HE) model, in combination with results from the GEOS-Chem global tropospheric chemistry model that simulated climate and chemistry effects of IPCC SRES emissions. We use EPPA to assess the human health damages (including acute mortality and morbidity outcomes) caused by ozone pollution and quantify their economic impacts in sixteen world regions. We compare the costs of ozone pollution under scenarios with 2000 and 2050 ozone precursor and greenhouse gas emissions (SRES A1B scenario). We estimate that health costs due to global ozone pollution above pre-industrial levels by 2050 will be ) and that acute mortalities will exceed 2 million. We find that previous methodologies underestimate costs of air pollution by more than a third because they do not take into account the long-term, compounding effects of health costs. The economic effects of emissions changes far exceed the influence of climate alone.United States Department of Energy, Office of
Science (BER) grants DE-FG02-94ER61937 and DE-FG02-93ER61677, the United States
Environmental Protection Agency grant EPA-XA-83344601-0, and the industrial and foundation
sponsors of the MIT Joint Program on the Science and Policy of Global Change
Combining a New Vehicle Fuel Economy Standard with a Cap-and-Trade Policy: Energy and Economic Impact in the United States
http://globalchange.mit.edu/research/publications/2271The United States has adopted fuel economy standards that require increases in the on-road efficiency of new passenger vehicles, with the goal of reducing petroleum use, as well as (more recently) greenhouse gas (GHG) emissions. Understanding the cost and effectiveness of this policy, alone and in combination with economy-wide policies that constrain GHG emissions, is essential to inform coordinated design of future climate and energy policy. In this work we use a computable general equilibrium model, the MIT Emissions Prediction and Policy Analysis (EPPA) model, to investigate the effect of combining a fuel economy standard with an economy-wide GHG emissions constraint in the United States. First, a fuel economy standard is shown to be at least five to fourteen times less cost effective than a price instrument (fuel tax) when targeting an identical reduction in cumulative gasoline use. Second, when combined with a cap-and-trade (CAT) policy, the fuel economy standard increases the cost of meeting the GHG emissions constraint by forcing expensive reductions in passenger vehicle gasoline use, displacing more cost-effective abatement opportunities. Third, the impact of adding a fuel economy standard to the CAT policy depends on the availability and cost of abatement opportunities in transport—if advanced biofuels provide a cost-competitive, low carbon alternative to gasoline, the fuel economy standard does not bind and the use of low carbon fuels in passenger vehicles makes a significantly larger contribution to GHG emissions abatement relative to the case when biofuels are not available. This analysis underscores the potentially large costs of a fuel economy standard relative to alternative policies aimed at reducing petroleum use and GHG emissions. It also demonstrates the importance of jointly considering the effects of multiple policies aimed at reducing petroleum use and GHG emissions, and the associated economic costs
The Revenue Implications of a Carbon Tax
A primary reason for implementing a carbon or greenhouse gas tax is to reduce emissions, but in recent years there has been increased interest in a carbon tax’s revenue potential. This revenue could be used for federal deficit reduction, to help finance tax reform, support new spending priorities such as infrastructure spending, offset the burden of the tax on households, or other purposes. With an environmental goal to reduce emissions to very low levels, programs that become dependent on the revenue may come up short when and if carbon revenue begins to decline. To date, the revenue potential of a carbon tax has not been studied in detail. This study focuses on how much carbon tax revenue can be collected and whether there is a carbon “Laffer Curve” relationship, with a point where revenue begins to decline. We employ the MIT U.S. Regional Energy Policy (USREP) model, a dynamic computable general equilibrium model for the U.S. economy, for the numerical investigation of this question. We consider scenarios with different carbon prices and emissions reductions goals to explore how they may affect whether and at what tax rate revenues peak. We find that a sufficiently high tax rate would induce a revenue peak between now and 2050. For the scenarios we study, however, we find that carbon tax revenue is a dependable source of revenue to finance federal fiscal initiatives over a thirty-year period at the minimum. We also explore how the cost of low-carbon technology and existing energy policies interact with tax rates and revenues. Our results indicate that lower costs of abatement technology make emissions more responsive to the tax rate, and removing regulations on renewables and personal transportation results in more carbon tax revenues. Our results also show that either lowering technology costs or removing existing policies would reduce the welfare cost of a carbon policy with specific reduction goals, with a larger offsetting gain from eliminating distortions associated with existing policies
Whatever happened to the progenitors of supernovae 2008cn, 2009kr and 2009md?
We present new late-time, high-resolution observations of the sites of supernovae (SNe) 2008cn, 2009kr and 2009md, acquired with the Hubble Space Telescope. In all instances, significant flux from the SNe is still recovered at late times. We show that the previous identification of the progenitor of SN 2008cn was actually a blend of two sources, whose locations are resolved in these new observations. We suggest that the progenitor of SN 2008cn was actually a red supergiant with Minit < 16 M⊙. In the late-time observations of SN 2009kr, we find that the pre-explosion source (previously thought to be a yellow supergiant) is most probably a small compact cluster with mass ∼6000 M⊙. In late-time F814W observations of the site of SN 2009md, we find a single point source with identical brightness to the pre-explosion source, suggesting some caution in assuming that the pre-explosion source was the progenitor
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