The most-studied mass extinction in Earth history happened 65 million years ago and is widely thought to have wiped out the dinosaurs. New University of Washington research indicates that a separate extinction came shortly before that, triggered by volcanic eruptions that warmed the planet and killed life on the ocean floor.
The well-known second event is believed to have been triggered by an asteroid at least 6 miles in diameter slamming into Mexico’s Yucatán Peninsula. But new evidence shows that by the time of the asteroid impact, life on the seafloor – mostly species of clams and snails – was already perishing because of the effects of huge volcanic eruptions on the Deccan Plateau in what is now India. (more…)
UD researchers show how beneficial soil bacteria can boost plant immunity
With the help of beneficial bacteria, plants can slam the door when disease pathogens come knocking, University of Delaware researchers have discovered.
A scientific team under the leadership of Harsh Bais, assistant professor of plant and soil sciences in UD’s College of Agriculture and Natural Resources, found that when pathogens attempt to invade a plant through the tiny open pores in its leaves, a surprising ally comes to the rescue. Soil bacteria at the plant’s roots signal the leaf pores to close, thwarting infection. (more…)
Scientists are setting sail on August 25 to study ocean acidification in the Arctic and what this means for the future survival of marine and terrestrial organisms.
The Arctic Ocean is one of the most vulnerable places on the planet for acidification, yet it is the least-explored ocean. Acidification can disturb the balance of marine life in the world’s oceans, and consequently affect humans and animals that rely on those food resources.
Ocean acidification is particularly harmful to organisms such as corals, oysters, crabs, shrimp and plankton, as well as those up and down the food chain. Higher acidity decreases an organism’s calcification rate, meaning they lose their ability to build shells or skeletons. (more…)
A third of Earth’s organisms live in rocks and sediments, but their lives have been a mystery
By some estimates, a third of Earth’s organisms live in our planet’s rocks and sediments, yet their lives are almost a complete mystery.
This week, the work of microbiologist James Holden of the University of Massachusetts-Amherst and colleagues shines a light into this dark world.
In the journal Proceedings of the National Academy of Sciences (PNAS), they report the first detailed data on methane-exhaling microbes that live deep in the cracks of hot undersea volcanoes. (more…)
UCLA life scientists, working with colleagues in China, have discovered a new method to quickly assess plants’ drought tolerance. The method works for many diverse species growing around the world. The research, published in the journal Methods in Ecology and Evolution, may revolutionize the ability to survey plant species for their ability to withstand drought, said senior author Lawren Sack, a UCLA professor of ecology and evolutionary biology.
“This method can be applied rapidly and reliably for diverse species across ecosystems worldwide,” he said of the federally funded research by the National Science Foundation.(more…)
Ocean eddies help jump-start plankton blooms that spread across hundreds of square miles
On this July 4th week, U.S. beachgoers are thronging their way to seaside resorts and parks to celebrate with holiday fireworks. But across the horizon and miles out to sea toward the north, the Atlantic Ocean’s own spring and summer ritual unfolds. It entails the blooming of countless microscopic plants, or phytoplankton.
In what’s known as the North Atlantic Bloom, an immense number of phytoplankton burst into existence, first “greening,” then “whitening” the sea as one or more species take the place of others.
What turns on this huge bloom, what starts these ocean fireworks? Is it the Sun’s warmth? (more…)
Berkeley Lab scientists develop new method for evaluating short-lived pollutants.
New research from Lawrence Berkeley National Laboratory (Berkeley Lab) has found that levels of methane—a potent greenhouse gas emitted from many man-made sources, such as coal mines, landfills and livestock ranches—are at least one-and-a-half times higher in California than previously estimated.
Working with scientists from the National Oceanic and Atmospheric Administration (NOAA) Berkeley Lab scientists Marc L. Fischer and Seongeun Jeong combined highly accurate methane measurements from a tower with model predictions of expected methane signals to revise estimated methane emissions from central California. They found that annually averaged methane emissions in California were 1.5 to 1.8 times greater than previous estimates, depending on the spatial distribution of the methane emissions. (more…)
Berkeley Lab and SLAC Researchers Study Key Protein Complex Crucial to Photosynthesis
Future prospects for clean, green, renewable energy may hinge upon our ability to mimic and improve upon photosynthesis – the process by which green plants, algae and some bacteria convert solar energy into electrochemical energy. An artificial version of photosynthesis, for example, could use sunlight to produce liquid fuels from nothing more than carbon dioxide and water. First, however, scientists need a better understanding of how a large complex of proteins, called photosystem II, is able to split water molecules into oxygen, electrons and hydrogen ions (protons). A new road to reaching this understanding has now been opened by an international team of researchers, led by scientists at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and SLAC National Accelerator Laboratory.
Using ultrafast, intensely bright pulses of X-rays from SLAC’s Linac Coherent Light Source (LCLS), the research team produced the first ever images at room temperature of microcrystals of the photosystem II complex. Previous imaging studies, using X-rays generated via synchrotron radiation sources, required cryogenic freezing, which alters the samples. Also, to catalyze its reactions, photosystem II relies upon an enzyme that contains a manganese-calcium cluster that is highly sensitive to radiation. With the high-intensity femtosecond X-ray pulses of the LCLS, the research team was able to record intact images of these clusters before the radiation destroyed them. (more…)
