In 2005, an astrophysicist came out with a new picture of the chemical composition of the sun. His calculations showed that the abundances of carbon, nitrogen, oxygen, and neon in the star—the most plentiful elements in it besides hydrogen and helium—were about half as high as researchers had previously worked out. The new values solved a puzzle, because the previous calculations had always made the sun’s chemistry seem oddly out of sync with that of its galactic environment. But when researchers plugged the new abundances into models of the solar interior, the resulting predictions about the sun’s temperature profile no longer matched observations. The mismatch led to a debate over which of the two was right: the new abundances or the models. Five years later, the question has not been resolved.

DOI:  http://dx.doi.org/10.1126/science.329.5996.1144

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Yet the composite Human Development Index, a widely used metric that incorporates measures of literacy, life expectancy, and income, has improved markedly since the mid-1970s in both rich and poor nations. The index correlates strongly with other measures of prosperousness. Some measures of personal security buck the upward trend, but the overall improvement in well-being cannot, it seems, be denied. Does this paradox mean that concern about ecosystem services is overblown?Raudsepp-Hearne and her coauthors first examine the notion that the traditional measures of well-being are flawed—that average well-being is in fact declining despite the numbers suggesting otherwise. But they reject that idea.They then examine three other ideas, derived from different academic traditions, that might reconcile improving human well-being with decreasing ecosystem services. The selection, as Raudsepp-Hearne and her coauthors acknowledge, does not exhaust the possibilities, but it encompasses some plausible ones. One idea is that food production (which has increased) is more important for human well-being than are other ecosystem services, another is that technology and innovation have decoupled human well-being from ecosystem degradation, and the third is that there is a time lag after ecosystem service degradation before human well-being is affected. The interested reader should consult the article to learn how the authors judge these hypotheses: All find some support, though with important qualifications.

DOI:  http://dx.doi.org/10.1525/bio.2010.60.8.1

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In this article description of various technology applications for passive and active utilization of solar radiation is presented, as well as some results of short-term and long-term experiments, including evaluation of 1-year operation of the greenhouse from the energy and interior temperature viewpoints. A comparison of the calculated energy flows in the greenhouse to real measured values, for verification of the installed model is also involved.

doi:10.1016/j.solener.2010.07.004

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Results: The probable daily intake (PDI) of MeHg for an adult population based on 60 kg body weight (bw
was considerably higher in Wanshan than in the other three locations. With an average
PDI of 0.096 µg/kg bw/day (range, 0.015–0.45 µg/kg bw/day), approximately 34% of the inhabitants in Wanshan exceeded the reference dose of 0.1 µg/kg bw/day established by the U.S. Environmental Protection Agency. The PDI of MeHg for residents in the three other locations were all well below 0.1 µg/kg bw/day (averages from 0.017 to 0.023 µg/kg bw/day, with a maximum of 0.095 µg/kg bw/day). In all four areas, rice consumption accounted for 94–96% of the PDI of MeHg.Conclusion: We found that rice consumption is by far the most important MeHg exposure route; however, most of the residents (except those in Hg-mining areas) have low PDIs of MeHg.

doi: http://dx.doi.org/10.1289/ehp.1001915

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1. Methylmercury in Marine Ecosystems—From Sources to Seafood Consumers
2. Water-stingy Agriculture Reduces Arsenic In Rice Markedly

In an effort to process wet algal biomass directly, eliminate organic solvent use during lipid extraction, and recover nutrients (e.g., N, P, and glycerol) for reuse, we developed a catalyst-free, two-step technique for algal biodiesel production. In the first step, wet algal biomass (ca. 80% moisture) reacts in subcritical water to hydrolyze intracellular lipids, conglomerate cells into an easily filterable solid that retains the lipids, and produce a sterile, nutrient-rich aqueous phase. In the second step, the wet fatty acid-rich solids undergo supercritical in situ transesterification (SC-IST/E) with ethanol to produce biodiesel in the form of fatty acid ethyl esters (FAEEs). Chlorella vulgaris grown sequentially under photo- and heterotrophic conditions served as the lipid-rich feedstock (53.3% lipids as FAEE). The feedstock and process solids were characterized for lipid components using highly automated microscale extraction and derivatization procedures and high-temperature gas chromatography. Hydrolysis was examined at 250 °C for 15 to 60 min; solids recovered by filtering contained 77−90% of the lipid originally present in the algal biomass, mainly in the form of fatty acids. The effects of reaction time (60 or 120 min), temperature (275 or 325 °C), and ethanol loading (approximately 2−8 w/w EtOH/solids) were examined on the yield and composition of biodiesel produced from the SC-IST/E of the hydrolysis solids. Longer time, higher temperature, and greater ethanol loading tended to increase crude biodiesel and FAEE yields, which ranged from about 56−100% and 34−66%, respectively, on the basis of lipid in the hydrolysis solids. Isomerization and decomposition of unsaturated FAEEs was quantified, and its effect on fuel yield is discussed.

DOI:  http://dx.doi.org/10.1021/ef1008314

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1. Direct Transformation of Fungal Biomass from Submerged Cultures into Biodiesel
2. Production potential of Chlorella zofingienesis as a feedstock for biodiesel

Coastal ecosystems rely upon oyster reefs to filter water, provide protection from storms, and build habitat for other species. From a chemistry perspective, few details are available to illustrate how these shellfish construct such extensive reef systems. Experiments presented here show that oysters generate a biomineralized adhesive material for aggregating into large communities. This cement is an organic−inorganic hybrid and differs from the surrounding shells by displaying an alternate CaCO3 crystal form, a cross-linked organic matrix, and an elevated protein content. Emerging themes and unique aspects are both revealed when comparing oyster cement to the adhesives of other marine organisms. The presence of cross-linked proteins provides an analogy to mussel and barnacle adhesives whereas the high inorganic content is exclusive to oysters. With a description of oyster cement in hand we gain strategies for developing synthetic composite materials as well as a better understanding of the components needed for healthy coastal environments.

DOI:  http://dx.doi.org/10.1021/ja104996y

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