From time to time I will summarize new science research from recently published, or about-to-be published papers. Usually, notice of the research comes in the form of press releases from universities that are made available to the media. Although the Arizona Daily Star sometimes prints science stories, their selection of stories seems to be confined to reprints of AP articles. So here are some of the stories I didn’t see in the Star.
Most Egyptian pottery is undecorated, but during the New Kingdom, the period when Egypt was at the zenith of its power, a variety of pottery was elegantly decorated in a distinctive pale blue.
Most blue comes from copper, but “Copper-based pigments must be applied in thick layers and were added after firing, so they tended to flake off when an object was handled. Instead of copper, the colorant used on most of the blue painted pottery is cobalt, which was fired onto the pots.” Where did the cobalt mineral come from? “Generic Geologist” Jennifer Smith finds the source. See: http://news.wustl.edu/news/Pages/20426.aspx
A recent advance by Arizona State University researchers in developing nanowires could lead to more efficient photovoltaic cells for generating energy from sunlight, and to better light-emitting diodes (LEDs) that could replace less energy-efficient incandescent light bulbs.
Karl A. Gschneidner Jr., a senior metallurgist at the U.S. Department of Energy’s Ames Laboratory, today cautioned members of a Congressional panel that “rare-earth research in the USA on mineral extraction, rare-earth separation, processing of the oxides into metallic alloys and other useful forms, substitution, and recycling is virtually zero.” Rare-earth elements are critical components in the great majority of America’s high-tech commercial and military products. Yet the United States and other nations have ceded much of this alloying knowledge to China.
The melting of glaciers is well documented, but when looking at the rate at which they have been retreating, a team of international researchers steps back and says not so fast. Previous studies have largely overestimated mass loss from Alaskan glaciers over the past 40-plus years, according to Erik Schiefer, a Northern Arizona University geographer who coauthored a paper in the February issue of Nature Geoscience that recalculates glacier melt in Alaska. http://www4.nau.edu/insidenau/releases/2010/glacier.html
Researchers evaluate climate fluctuations from 115,000 years ago
At the end of the last interglacial epoch, around 115,000 years ago, there were significant climate fluctuations. In Central and Eastern Europe, the slow transition from the Eemian Interglacial to the Weichselian Glacial was marked by a growing instability in vegetation trends with possibly at least two warming events. This is the finding of German and Russian climate researchers who have evaluated geochemical and pollen analyses of lake sediments in Saxony-Anhalt, Brandenburg and Russia. Writing in Quaternary International, scientists from the Helmholtz Centre for Environmental Research (UFZ), the Saxon Academy of Sciences (SAW) in Leipzig and the Russian Academy of Sciences say that a short warming event at the very end of the last interglacial period marked the final transition to the ice age.
Fossil corals, up to half a million years old, are providing fresh hope that coral reefs may be able to withstand the huge stresses imposed on them by today’s human activity.
Reef ecosystems were able to persist through massive environmental changes imposed by sharply falling sea levels during previous ice ages, an international scientific team has found. This provides new hope for their capacity to endure the increasing human impacts forecast for the 21st century. http://www.coralcoe.org.au/news_stories/lowsea.html
Challenges evidence that global warming was the cause
Scientists broadly agree that global warming may threaten the survival of many plant and animal species; but global warming did not kill the Monteverde golden toad, an often cited example of climate-triggered extinction, says a new study. The toad vanished from Costa Rica’s Pacific coastal-mountain cloud forest in the late 1980s, the apparent victim of a pathogen outbreak that has wiped out dozens of other amphibians in the Americas. Many researchers have linked outbreaks of the deadly chytrid fungus to climate change, but the new study asserts that the weather patterns, at Monteverde at least, were not out of the ordinary.
The role that climate change played in the toad’s demise has been fiercely debated in recent years. The new paper, in the March 1 issue of the Proceedings of the National Academy of Sciences, is the latest to weigh in. In the study, researchers used old-growth trees from the Monteverde Cloud Forest Reserve to reconstruct moisture levels in that region over the last century. They expected to see global warming manifested in the form of a long-term warming or drying trend, but instead discovered that the forest’s dry spells closely tracked El Niño, the periodic and natural warming of waters off South America that brings drought to some places and added rainfall and snow to others. http://www.eurekalert.org/pub_releases/2010-03/teia-ena030110.php