Elevated levels of carbon dioxide predicted by models of climate change can drive increased production of fungal spores, including some associated with allergies and asthma, according to a new study in Environmental Health Perspectives.
Researchers have programmed an autonomous molecular "robot" made out of DNA to start, move, turn, and stop while following a DNA track.
The development could ultimately lead to molecular systems that might one day be used for medical therapeutic devices and molecular-scale reconfigurable robots---robots made of many simple units that can reposition or even rebuild themselves to accomplish different tasks.
Results of the research have been published in Nature.
The traditional view of a robot is that it is "a machine that senses its environment, makes a decision, and then does something---it acts," said Erik Winfree, associate professor of computer science, computation and neural systems, and bioengineering at Caltech.
A team of Yale paleontologists have discovered a rich array of exceptionally preserved fossils of marine animals in Morocco that lived during the the early part of the Ordovician, between 480 million and 472 million years ago.
The specimens are the oldest yet discovered soft-bodied fossils from a period marked by intense biodiversification. The findings, which appear in Nature, greatly expand scientists' understanding of the sea creatures and ecosystems that existed at a crucial point in evolutionary history, when most of the animal life on the planet was found in the oceans.
Judging by recent polls, you would think that the environment is not much of a concern to Americans. And You would also be wrong, say researchers from Standford University. When pollsters ask Americans to name the most important problem facing the country, the environment is rarely mentioned. But these results change drastically if pollsters replace "country" with "world" in the question, the researchers say.
"For years, the wording used in traditional surveys has systematically underestimated the priority that the public has placed on global warming and the environment," said Jon Krosnick, a professor of communication and of political science at Stanford. "To fully understand public concern about these issues, traditional surveys should be asking a different question."
To avoid of the health risks associated with traditional cigarettes, attempts have been made to develop cigarettes that contain no tobacco and no nicotine. But a team of researchers writing in Cell Cycle has found that the supposedly safe cigarettes may be more carcinogenic because they actually induce more extensive DNA damage than tobacco products.
Using laser scanning cytometry (LSC) technology to measure DNA damage response to the smoke from commercially available tobacco- and nicotine-free cigarettes, the research team expected to find the alternative products were less hazardous than regular tobacco cigarettes.
By analyzing tiny variations in the isotopic composition of silver in meteorites and Earth rocks, scientists are putting together a timetable of how our planet was assembled 4.5 billion years ago. The new study, published in Science, indicates that water and other key volatiles may have been present in at least some of Earth's original building blocks, rather than acquired later from comets, as some scientists have suggested.
Compared to the Solar System as a whole, Earth is depleted in volatile elements, such as hydrogen, carbon, and nitrogen, which likely never condensed on planets formed in the inner, hotter, part of the Solar System. Earth is also depleted in moderately volatile elements, such as silver.