Category: science

Mammals Go Nocturnal in Bid to Avoid Humans

By Julia Jacobs

Humans, it turns out, can annoy more than just one another. In fact, some animal populations are escaping their Homo sapiens cohabitants by sleeping more during the day, a new study finds.

Mammals across the globe are becoming increasingly nocturnal to avoid humans’ expanding presence, according to the study, published Thursday in Science magazine. The findings show that humans’ presence alone can cause animals across continents — including coyotes, elephants and tigers — to alter their sleep schedules.

“We’re just beginning to scratch the surface on how these behavioral changes are affecting entire ecosystems,” said Kaitlyn Gaynor, an ecologist and graduate student in environmental science at the University of California, Berkeley, who led the study.

Previous research has found that mammals went from being noctural to being active during both day and night about 65.8 million years ago, roughly 200,000 years after most dinosaurs went extinct. “Species for millions of years have been adapting to diurnal activity, but now we’re driving them back into the night and may be driving natural selection,” Ms. Gaynor said in an interview.

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Weird Low-Light Bacteria Could Potentially Thrive on Mars

By Sarah Lewin

An international team of scientists has found that a strange type of bacteria can turn light into fuel in incredibly dim environments.

Similar bacteria could someday help humans colonize Mars and expand our search for life on other planets, researchers said in a statement released with the new work.

Organisms called cyanobacteria absorb sunlight to create energy, releasing oxygen in the process. But until now, researchers thought these bacteria could absorb only specific, higher-energy wavelengths of light. The new work reveals that at least one species of cyanobacteria, called Chroococcidiopsis thermalis—which lives in some of the world’s most extreme environments—can absorb redder (less energetic) wavelengths of light, thus allowing it to thrive in dark conditions, such as deep underwater in hot springs.

“This work redefines the minimum energy needed in light to drive photosynthesis,” Jennifer Morton, a researcher at Australian National University (ANU) and a co-author of the new work, said in the statement. “This type of photosynthesis may well be happening in your garden, under a rock.” (In fact, a related species has even been found living inside rocks in the desert.)

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Giant Black Hole Swallows a Star and Belches Out a Superfast Particle Jet

By Lee Billings

Marshaling a decade’s worth of data from telescopes around the world, scientists have captured new details of a gargantuan black hole feasting on a hapless star, watching as the black hole consumed its prey and burped out a jet of material moving at a significant fraction of the speed of light. The results are published in the June 14 edition of Science, and could help researchers better understand how black holes grow and influence their galactic surroundings.

“Never before have we been able to directly observe the formation and evolution of a jet from one of these events,” says study co-author Miguel Pérez-Torres of the Institute of Astrophysics of Andalusia in Spain.

The discovery’s first inklings emerged in January 2005, when a team led by astronomer Seppo Mattila of the University of Turku in Finland detected a brilliant pointlike source of infrared light from within Arp 299, a pair of merging galaxies some 150 million light-years from Earth. That July another team led by Pérez-Torres reanalyzing previously gathered data confirmed a bright source of radio waves from the same location.

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A Huge Dust Storm on Mars Is Threatening NASA’s Opportunity Rover

By Niraj Chokshi

A vast dust storm blanketing about a quarter of the surface of Mars has threatened NASA’s Opportunity rover, plunging the solar-powered vehicle into what the space agency has described as a “dark, perpetual night.”

With its primary energy source obscured, the rover, which sits in the Perseverance Valley of Mars near the center of the storm, appears to have automatically entered a power-saving mode in which it will remain until the sun re-emerges, agency officials said.

“We’re concerned, but we’re hopeful that the storm will clear and the rover will begin to communicate with us,” John Callas, the Opportunity project manager, told reporters on a Wednesday conference call with other NASA officials.

Opportunity is at historically low energy levels. The rover weathered another serious storm in 2007, but the current storm is much worse, having intensified more rapidly and more completely blocking out the sun, NASA said.

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These Are the Most Ancient Frogs Ever Found Preserved in Amber

By George Dvorsky

The extraordinary discovery of four small frogs preserved in amber is providing the earliest evidence of these now-prolific amphibians living in tropical rainforests.

New research published today Scientific Reports shows that frogs—an animal that first emerged some 200 million years ago—were occupying soggy forested regions at least 100 million years ago. This discovery is a big deal because fossils of forest amphibians are rare, and because scientists haven’t been sure when frogs first started to venture into tropical habitats.

“Frogs are common animals to encounter in the wet tropical forests of today, and easily more than a third of the nearly 7,000 species of frogs live in these wet forests,” David C. Blackburn, a co-author of the new study and the associate curator of amphibians and reptiles at the Florida Museum of Natural History, told Gizmodo. “But being small and living in a tropical forest also means that your likelihood of ending up in the fossil record is pretty low.”

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The Battle Behind the Periodic Table’s Latest Additions

By Edwin Cartlidge

The mood at Bäckaskog Castle in southern Sweden should have been upbeat when chemists and physicists gathered there for a symposium in May 2016. The meeting, sponsored by the Nobel Foundation, offered researchers a chance to take stock of global efforts to probe the limits of nuclear science, and to celebrate four new elements that they had added to the periodic table a few months earlier. The names of the elements were due to be announced within days, a huge honour for the researchers and countries responsible for the discoveries.

Although many at the meeting were thrilled with how their field was developing — and the headlines it was generating — a significant number were worried. They feared that there were flaws in the process of assessing claims about new elements, and were concerned that reviews of the recent discoveries had fallen short. Some felt there was not enough evidence to justify enshrining the most controversial elements, numbers 115 and 117. The scientific integrity of the periodic table was at stake.

Towards the end of the meeting, one scientist asked for a show of hands on whether or not they should announce the elements’ names as planned. The question exposed the depth of concern among the crowd. Most researchers voted to delay the announcement, says Walter Loveland, a nuclear chemist at Oregon State University in Corvallis. And that triggered a remarkable reaction from some of the Russian scientists who had led efforts that resulted in three of the elements. “They just stomped their feet and walked out,” says Loveland. “I’ve never seen that in a scientific meeting.”

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Once climate change skeptic, new NASA chief Bridenstine wants Earth science to remain key agency mission

By Ledyard King

WASHINGTON — Newly installed NASA Administrator James Bridenstine said the agency will — and should — continue to monitor the Earth’s carbon dioxide emissions that contribute to global warming, marking another break from many of the conservative lawmakers with whom he once served.

Two weeks after telling a Senate panel he now believes human activity is the primary source of climate change, the former GOP congressman from Oklahoma told a group of reporters Wednesday that NASA must continue its work on Earth science missions.

“NASA can lead when it comes to studying the Earth and studying the climate. That’s what we have been doing and that’s what we intend to keep doing,” he said. “And there’s no agency on the face of the planet that has the credibility to study and understand so that policy makers can make good decisions than NASA.”

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Africa’s majestic baobab trees are mysteriously dying

By Sarah Wild

Africa’s iconic baobab trees are dying, and scientists don’t know why. In a study intended to examine why the trees are so long-living, researchers made the unexpected finding that many of the oldest and largest of the trees have died in the past decade or so.

The African baobab tree (Adansonia digitata L.) is the oldest living flowering plant, or angiosperm, and is found in the continent’s tropical regions. Individual trees — which can contain up to 500 cubic metres of wood — can live for more than 2,000 years. Their wide trunks often have hollow cavities, and their high branches resemble roots sticking up into the air.

The researchers — who published their findings1 in Nature Plants on 11 June — set out to use a newly developed radiocarbon-dating technique to study the age and architecture of the species. Usual tree-ring dating methods are not suitable for baobabs, because their trunks do not necessarily grow annual rings.

The trees’ ages were previously attributed to their size, and in local folklore, baobabs are often described as being old, says study author Adrian Patrut, a radiochemist at Babeş-Bolyai University in Romania.

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Yes, There Are Bacteria on Your Kitchen Towel. No, They Won’t Make You Sick

By Rachael Rettner

Your kitchen towel may harbor a number of different bacteria, a new study finds. But does that mean your towel can actually make you sick?

Although the new finding may sound gross, it doesn’t mean you should ditch your kitchen towel; experts said the bacteria found on the towels in this study aren’t particularly concerning when it comes to foodborne illnesses.

For the study, the researchers gathered 100 kitchen towels from families. The scientists took samples from the towels — which had been used, without being washed, for one month — and cultured, or grew, these samples in lab dishes. The study found that 49 percent of the towels tested positive for bacteria and that the amount of bacteria was higher for towels used by large families or families with children, compared with towels used by smaller families or families without children.

In addition, towels used for multiple purposes — including wiping utensils, drying hands and wiping surfaces — grew more bacteria than towels used for a single purpose, the researchers found. And damp towels grew more bacteria than dry towels, according to the study, which was presented Saturday (June 9) at the American Society for Microbiology meeting in Atlanta.

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The artist who walked on the Moon: Alan Bean

By Richard Taylor

In November 1969, when I was six years old, my father pointed to the Moon and told me that a man was walking on it. I looked up at the silver sphere and wondered what he was doing up there in that remote, crater-riddled land. I later learned that his name was Alan Bean, and that he was the fourth of only 12 humans so far to walk on another world. Even in that select group, he was unique: he was the only one to record what he saw on canvas and in paint. In May, he died at the age of 86.

As my interest in space travel grew, I read about the trajectory that led Bean to his Apollo 12 Moon landing. Earning an aeronautical-engineering degree from the University of Texas at Austin in 1955, he soon achieved his childhood dream of becoming a Navy test pilot. His instructor was Pete Conrad, later a fellow member of the Apollo 12 mission and Moon-walker, who became his closest friend. Inspired by the “sights, sounds and smells of high performance flying machines”, as Bean put it, they hatched their plan to ride the biggest flying machine of them all.

Standing 110 metres tall, the Saturn V remains the most powerful rocket ever flown. Four months before the Apollo 12 launch, one of these behemoths had carried Neil Armstrong and his crew to the first Moon landing. But whereas Armstrong took off on a sweltering summer’s day, Bean, Conrad and fellow astronaut Richard Gordon sat on their rocket engulfed by a winter thunderstorm. Thirty-six seconds into their launch, the unthinkable happened. The Saturn V was struck by lightning — twice. “I looked up at the display that had all of the caution lights and there were more on than I’d ever seen in my life,” Bean recalled. Seconds away from aborting the mission, he managed to reboot the affected systems. The astronauts’ nervous laughter could be heard all the way to orbit.

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