- 50-Million-Year-Old Insect Trove Found in Indian Amber
- Pet Frogs Transmit Salmonella
- Cooling Lava Flow Spotted on Venus
Posted: 25 Oct 2010 01:08 PM PDT
A collection of amber deposits unearthed in northwest India has opened a spectacular window into insect life some 50 million years ago.
At that time, what's now the Asian subcontinent had just crashed into mainland Asia — about 100 million years after breaking off the coast of east Africa. During its long isolated float, life on that giant island had time to evolve into strange new forms.
That's what's researchers expected, anyway, but not what they found in the amber, described October 26 in the Proceedings of the National Academy of Sciences.
Instead, the insects resemble what's seen in amber deposits from continental landmasses of the time. (Amber is the geological name for fossilized tree resin, which often preserves insects that get stuck in it.) The findings suggest an unexpected transfer of insects, perhaps across chains of volcanic islands.
Although the new amber didn't yield bizarre new species, it's still loaded with fossil treasures. More than 700 insect species representing 55 families of insects have been identified inside. Among them are ancient bees, termites and ants — highly social insects that form some of the world's most complex societies.
In the years to come, scientists will compare these ancient specimens to modern forms and develop a deeper understanding of how these creatures have evolved. Until they do, the bugs are plenty amazing to look at.
Images: Courtesy of David Grimaldi, American Museum of Natural History.
Citation: "Biogeographic and Evolutionary Implications of a Diverse Paleobiota in Amber from the Early Eocene of India," by Jes Rust, Hukam Singh, Rajendra S. Ran, Tom McCann, Lacham Singh, Ken Anderson, Nivedita Sarkar, Paul C. Nascimbene, Frauke Stebner, Jennifer C. Thomas, Monica Solórzano Kraemer, Christopher J. Williams, Michael S. Engel, Ashok Sahni and David Grimaldi. Proceedings of the National Academy of Sciences, Vol. 107 No. 43, October 26, 2010.
Posted: 25 Oct 2010 11:47 AM PDT
VANCOUVER, British Columbia — Buying your tyke a pet frog might carry a downside that extends well beyond the "ick" factor, a new study finds. Pet African dwarf frogs harboring salmonella have sickened at least 113 people, most of them children, researchers from the Centers for Disease Control and Prevention report.
"This is the first multistate outbreak of salmonella associated with frogs," says Shauna Mettee, a public health nurse at the CDC in Atlanta who presented the findings October 22 in Vancouver, Canada, at a meeting of the Infectious Diseases Society of America.
CDC investigators became curious when doctors began reporting a spate of cases of the typhimurium subspecies of salmonella in 2009. Between April 2009 and March 2010, Mettee and her colleagues identified 113 cases of this infection, three-fourths occurring in children under age 10. The median age of the patients was 5. A sampling of 54 of these patients showed that about one-third needed hospitalization. Symptoms ranged from cramping to severe and even bloody diarrhea. There were no fatalities.
Bacteria transmission took many forms. For example, one woman cleaned a frog aquarium in the kitchen sink and subsequently bathed a 3-week-old infant in it, Mettee says.
The researchers traced the infected frogs to a single breeding facility that houses 800,000 to 1 million African dwarf frogs and sells them. Health authorities are now working with the facility's owner to implement cleanup procedures designed to limit salmonella among the animals.
The facility hasn't been shut down or even identified publicly, Mettee says, because "we have no regulatory authority … regarding the sale of frogs."
But that doesn't stop health officials from weighing in on the topic. "Children should avoid all contact with frogs and keep them out of the home," Mettee says.
James Hughes, an infectious-disease physician at Emory University School of Medicine in Atlanta and incoming president of IDSA, says these findings "should remind us of the importance of good hand hygiene in the kitchen and other areas of the house, especially if there are reptiles or amphibians in the household."
Amphibians and reptiles can carry salmonella bacteria without appearing sick, says Patricia Griffin, a physician and chief of the enteric diseases epidemiology branch at CDC. She notes that pet turtles, which were popular in the 1970s, were found to expose people to salmonella. Small turtles have since been banned as pets, but some street sales continue, Mettee says.
Since March 31, an additional 57 cases of the salmonella subspecies have been reported. Mettee and her colleagues are now checking whether these cases also trace to frogs from the same breeding facility.
Image: Flickr/Kelli Gaskill
Posted: 25 Oct 2010 07:45 AM PDT
Beneath its dreary shroud of clouds, Venus could be positively hopping: Planetary geologists have spotted a lava flow they say is just decades old. If confirmed, it would be the youngest evidence for volcanism on Venus.
"The flow we studied seems to be very young — it is still warm inside," says Nataliya Bondarenko, a planetary scientist at the University of California, Santa Cruz. She and her colleagues describe their findings in an upcoming issue of Geophysical Research Letters.
Researchers have long thought that Venus must be geologically active, since more than 1,000 volcanoes dot its surface. But scientists have struggled to gather definitive evidence that the planet is active today, like Earth, and not long dead, like Mars.
The new study builds on recent work suggesting that Venusian volcanoes are indeed a thing of the present.
Bondarenko's team analyzed microwave data collected by NASA's Magellan mission, which orbited Venus in the early 1990s. Microwave radiation indicates heat coming from the planet, such as a lava flow in the process of cooling.
In the Bereghinia Planitia region in Venus' northern hemisphere, the team found a flow that appeared up to 85 degrees Celsius hotter than expected. Had the flow been more than a century old, Bondarenko says, it would have cooled down enough that Magellan wouldn't have spotted any excess heat.
The flow must have been at least 15 years old when detected by Magellan, she says, because the Pioneer Venus orbiter photographed it in 1978.
But there's little other evidence supporting Bereghinia Planitia as recently volcanically active, says Suzanne Smrekar, a planetary geologist at the Jet Propulsion Laboratory in Pasadena, California.
In April, Smrekar and colleagues published a paper in Science describing lava flows from three regions in Venus' southern hemisphere. All three were places known to be hot spots of geological activity, similar to Hawaii. Using data from the European Space Agency's Venus Express mission, currently orbiting the second planet, Smrekar's team found several flows that looked fresh. The flows' unweathered appearance, compared with the surrounding landscape, suggests that they formed no more than 2.5 million years ago and probably in the past 250,000 years, the team concluded.
Because the Venus Express data come only from the southern hemisphere, they can't say anything about whether Bereghinia Planitia is also active, Smrekar says. But any claim of a decades-old flow in the north "sort of falls into the 'extraordinary claims require extraordinary proof' category," she says.
For their part, Bondarenko and her colleagues want to expand their research to look for other fresh flows on Venus.
Image: As seen in microwave wavelengths, a lava flow in Venus' northern hemisphere shows hot spots (red) up to 85 degrees Celsius warmer than expected. The flow could be just decades old and still cooling down, a new study suggests. Nataliya Bondarenko et al/GRL
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