'Plants grew on land about 475 mn yrs ago'
BALTIMORE: Scientists have found the best evidence yet that plants appeared on land about 475 million years ago, 50 million years earlier than fossils had established before.
While spores dating back about 475 million years had already been found, it had not been proven whether they came from land or aquatic plants.
In the new study, the spores were found with the spore sac that produced them, indicating they came from a land-based plant, said study author Charles Wellman of the University of Sheffield in England.
The oldest fossils of land plants themselves are about 425 million years old and the age discrepancy between the oldest spores and the oldest fossils has puzzled scientists, Wellman said.
"Now, we've actually got the spores in the plants," said Wellman, whose paper appears in Thursday's issue of the journal Nature.
"I've found the spores lots of times, but I've never found the actual plants that produce the spores." The spores are similar to those from a moss-like plant liverwort.
The spores and plant matter were discovered by sieving through core samples drilled in the search for oil, in this case a 4,950-foot deep core drilled in northern Oman. Wellman's group dissolved the rock in a type of acid that does not destroy organic matter, and then strained the acid.
Cloud-seeding yields rains in Hindupur
HYDERABAD: Lepakshi, Hindupur and adjoining areas received rains after cloud-seeding operations were carried out in Hindupur on Wednesday night.
Officials have been directed to build a database of rainfall and study the correlation between the cloudseeding and rainfall.
Immediately upon his return from Israel on Thursday, Naidu reviewed the situation with regard to cloudseeding.
He was informed that on Wednesday night cloud-seeding was carried out in some areas in Hindupur and there were reports of rain in Lepakshi and Hindupur and some other places.
Naidu reviewed the water supply position in the Krishna delta and directed the irrigation department to work out requirement of water to irrigate paddy fields.
He reviewed the release of water in Warangal district under Sriramsagar project to save 2.5 lakh acres of irrigated dry crop. He gave directions for crops to be given at least two wettings at the earliest.
Coal-eating bacteria aid methane recovery
SCIENTISTS AT the U.S Department of Energy's Brookhaven National Laboratory are exploring the use of bacteria to increase the recovery of methane, a clean natural gas, from coal beds, and to decontaminate water produced during the methane-recovery process.
Methane gas burns without releasing sulphur contaminants. But the process of recovering methane, which is often trapped within porous, unrecovered or waste coal, produces large amounts of water contaminated with salts, organic compounds, metals, and naturally occurring radioactive elements. "Our idea is to use specially developed bacteria to remove the contaminants from the wastewater, and also help to release the trapped methane," says a Brookhaven National laboratory press release.
The chemist Mow Lin and his team have developed several strains of bacteria that can use coal as a nutrient and adsorb or degrade contaminants.
They started with natural strains already adapted to extreme conditions, such as the presence of metals or high salinity, then gradually altered the nutrient mix and contaminant levels and selected the most hardy bugs.
In lab tests, various strains of these microbes have been shown to absorb contaminant metals, degrade dissolved organics, and break down coal in a way that would release trapped methane. Use of such microbe mixtures in the field could improve the efficiency and lower the associated clean-up costs of coal-bed methane recovery, Lin says.