Nov 21, 2014
Since 2001, for two weeks at a stretch, every year or two, a team of researchers from Johns Hopkins University dug in an open-pit coal mine in India, northeast of Mumbai. The site was bountiful, to say the least, yielding a vast collection of bones.
Among those bones were in excess of 200 fossils from a previously little-documented animal called Cambaytherium thewissi. The bones were dated to about 54.5 million years old.
What was so special about a couple of hundred really old bones in a mine in India? The researchers consider them the closest thing yet seen to a common ancestor of Perissodactyla-- the group to which modern horses, tapirs, and rhinos belong.
"Many of Cambaytherium’s features, like the teeth, the number of sacral vertebrae, and the bones of the hands and feet, are intermediate between Perissodactyla and more primitive animals," said lead researcher Ken Rose, Ph.D., a professor of functional anatomy and evolution at the Johns Hopkins University School of Medicine, in a release.
Paleontologists already have a fairly long view of Perissodactyla -- fossils from the group have been described as far back as about 56 million years ago, at the beginning of the Eocene. But the group's earlier evolution remained a mystery. While the Cambaytherium bones are a bit younger than the oldest of those already known fossils, the Johns Hopkins team says Cambaytherium provides a window into what a common ancestor of all Perissodactyla would have looked like (see photo above for a depiction).
In addition to opening a wider window onto the ancestry of modern rhinos and horses, the scientists say the Cambaytherium thewissi fossils also represent the first evidence to support the notion that several groups of mammals from the early Eocene might have evolved on the Indian subcontinent while it was still isolated at sea and had not yet smashed into Asia. That idea was first posed in a 1990 paper by David Krause and Mary Maas, of Stony Brook University.
Read more at Discovery News
The research, conducted at the Wellcome Trust Sanger Institute, reveals the genetic secrets of the elusive parasite with origins in the Far East. It’s a tapeworm known as Spirometra erinaceieuropaei that no human would want as a guest.
The worm causes sparganosis, meaning inflammation of the body’s tissues in response to the parasite. When this occurs in the brain, it can result in seizures, memory loss and headaches. Thankfully the UK man lived to tell the tale and is now doing well.
“We did not expect to see an infection of this kind in the UK, but global travel means that unfamiliar parasites do sometimes appear,” co-author Effrossyni Gkrania-Klotsas from the Department of Infectious Disease at Addenbrooke’s NHS Trust said in a press release.
It is thought that people may become infected with the worm by accidentally consuming tiny infected crustaceans from lakes, eating raw meat from reptiles and amphibians, or by using a raw frog poultice, which is a Chinese remedy to calm sore eyes.
Before the nearly ½-inch-long parasite was diagnosed in the man and successfully removed by surgery, it had traveled 2 inches from the right side of the man’s brain to the left. It’s little wonder that the victim reported suffering from headaches. The tapeworm was reserved for the later genome sequencing.
Fortunately for the patient, the gene’s DNA sequence revealed that the parasite was the more benign of two known sparganosis-causing worm species. The researchers, however, were shocked by the size of the tapeworm’s genome.
Spirometra erinaceieuropaei’s genome turned out to be 1.26Gb long, making it 10 times larger than other tapeworm genomes and one-third the size of the human genome. The medical experts suspect that some of this comes from an increase in the number of genes that may help the parasite to break up proteins and invade its host, coupled with the fact that the genome is much more repetitive than other tapeworm genomes.
The tapeworm was also found to possess a large selection of molecular motors for moving proteins around its cells, which could underpin the large changes in body shape and environmental adaptions that the worm undergoes during its complicated lifecycle.
Read more at Discovery News
The letter, typed on Einstein's personal stationary, is dated June 10, 1939, and was sent from the scientist's residence on Mercer Street in Princeton, New Jersey, to Isidore Zelniker, a Jewish hat merchant in midtown Manhattan.
The historical document is expected to fetch at least $10,000, according to Nate D. Sanders Inc., the auction house handling the sale. Bids for the online auction will close today (Nov. 20) at 5 p.m. PT (8 p.m. ET).
At the time the letter was written, Einsteinhad been living in Princeton for six years, and was serving as a professor of theoretical physics at the Institute for Advanced Study. Previously, Einstein lived in several European countries, including Italy and Switzerland, but he moved to the U.S. in 1933 from Berlin — the same city where Adolf Hitler had recently been elected chancellor.
Considering Einstein was born to Jewish parents in Ulm, Germany, the timing of his departure was no coincidence. After escaping the horrors of the Nazi regime with his family, Einstein never stopped advocating for those he referred to as his "Jewish brethren" in Europe.
When he wasn't revolutionizing the world of physics, Einstein worked to help Jewish refugees escape the Nazis and tried to persuade political leaders in the United States and Europe to take action to help the Jewish population. He wrote countless letters thanking those who were involved in the effort to help imperiled Jews. The letter now up for auction is just one example.
The document reads:
''My dear Mr. Zelniker: May I offer my sincere congratulations to you on the splendid work you have undertaken on behalf of the refugees during Dedication Week. The power of resistance which has enabled the Jewish people to survive for thousands of years has been based to a large extent on traditions of mutual helpfulness. In these years of affliction our readiness to help one another is being put to an especially severe test. May we stand this test as well as did our fathers before us. We have no other means of self-defense than our solidarity and our knowledge that the cause for which we are suffering is a momentous and sacred cause. It must be a source of deep gratification to you to be making so important a contribution toward rescuing our persecuted fellow-Jews from their calamitous peril and leading them toward a better future.''
In 1939, when Einstein wrote this letter, Europe was in turmoil. Hitler was just months away from invading Poland — an action that would result in the United Kingdom's official declaration of war. But the Nazis' persecution of minority groups had been ongoing since Hitler's rise to power in 1933, according to the Jewish Virtual Library.
Read more at Discovery News
The study analyzed information from more than 138,000 U.S. adults between 2009 and 2011.
Nearly 1 in 3adults was an excessive drinker, usually because they engaged in binge drinking on multiple occasions. Excessive drinking is defined as either binge drinking — consuming four or more drinks on an occasion for women, five or more drinks on occasion for men — or consuming eight or more drinks per week for women, and 15 or more per week for men. Any alcohol use by people under 21 or pregnant women is also considered excessive drinking.
However, only about 10 percent of excessive drinkers are alcohol dependent, meaning they have a craving for alcohol, they continue to use alcohol despite repeated problems with drinking, and they have an inability to control their alcohol consumption.
Even among people who reported binge drinking 10 or more times per month, more than two-thirds did not meet criteria for alcohol dependence, the researchers said.
Overall, about 1 in 30 (3 percent) of adults are alcohol dependent, the report found.
Binge drinking was most common among people with annual family incomes of more than $75,000, while alcohol dependence was most common among people with incomes less than $25,000, the report said.
Drinking too much alcohol is responsible for 88,000 deaths yearly in the U.S., costing $223.5 billion in 2006, the report said.
"Although alcohol dependence is an important public health problem, these findings suggest that most excessive drinkers are unlikely to need addiction treatment," the researchers wrote in the Nov. 20 issue of the journal Preventing Chronic Disease.
Read more at Discovery News
|It’s a bird, it’s a plane, it’s…neither. It’s actually the colugo, a gliding mammal with no sense of decency.|
Really, the problem had more to do with mammals like us not being cut out for flight. Well, except for bats. There are, though, critters like sugar gliders and flying squirrels, which can pull off some pretty solid glides. But compared to the adorable and little-known colugo, they got nothin’. This is the most accomplished mammalian glider of all—on account of being essentially a giant flap of skin—capable of soaring an incredible 200 feet from tree to tree. Its expansive membrane, known as a patagium, stretches from its face to the tips of its digits all the way back to its tail, so “geometrically, it has the greatest surface area that you can have between those limbs without actually evolving an entire wing like bats did,” said conservation biologist Jan Janecka of Duquesne University.
|With undeniable cuteness and way too much skin, the colugo is an aesthetic conundrum, like adorable old people.|
Colugos are such adept gliders that mothers have no problem bringing their babies along for the ride. And they’ll do so for quite some time, for their young are born highly underdeveloped. They’re not as helpless as, say, marsupial young ‘uns, which enjoy the comfort of their mother’s pouch, but certainly not as developed as most mammals.
|The colugo’s unique comb-shaped teeth, which may help in feeding or grooming, but only when it’s not a skeleton though.|
Unfortunately, beyond watching mothers sail around with their babies, we don’t know much at all about the colugo’s social life. And efforts to keep them in captivity have largely been for naught. Remember that these are creatures used to gliding up to 200 feet, and good luck finding that kind of space in a zoo. “Basically their enclosures weren’t large enough to allow them to glide long distances,” said Janecka. “And because they couldn’t glide, they couldn’t keep their patagium well maintained and dry enough.” They developed infections on their skin, perhaps from a fungus, and died.
Ironically enough, it’s too much space in the wild that’s threatening some colugo populations. Deforestation can strand species in islands of trees, but even if loggers just thin out spots in the forest, it’s big trouble for the colugo. They’re the most accomplished mammalian glider on Earth, sure, but if there’s too much space between trees, the colugo runs the risk of sinking right to the ground. And as you can see below in the video from National Geographic (they strapped a camera to a colugo—enough said), the creature’s extra skin makes it all but worthless when anywhere but the canopy. It’s an easy target in a habitat packed with predators.
Because colugos tend to live in isolated habitats and because they insist on emerging only at night, much of what we know about them comes from anecdotal evidence. Case in point: colugo doo-doo. It … moves.
“I’ve seen some videos of fecal material that they’ve dropped where there’s so many worms it’s actually moving,” said Janecka. “It’s squirming around.” The colugo digestive tract, it seems, has a really, really high parasite load. “And that whole dynamic, whether it happened to be in a population that has a lot of parasites or it’s something that’s more normal for the colugos that they’ve learned to deal with, that’s one of those unknown questions at this point.”
What is abundantly clear is that the colugo has a very long digestive tract, which makes sense for a creature that eats trees. That stuff takes a whole lot of time to digest. But such long guts could also be acting as a sort of mansions for parasitic worms, which have lots of room to make themselves comfortable. Until someone starts studying colugo turds at length, though, we’ll have to leave this one a mystery.
Read more at Wired Science
Nov 20, 2014
The strange glow worms, which are thought to be the larval stage of an as-yet-unidentified species of beetle, may use their phosphorescence to lure unsuspecting flies and ants into their waiting, open jaws.
Ants or termites will "fly right into their jaws, and then they'll just clamp shut and that's their meal," said Aaron Pomerantz, an entomologist who works with a rainforest expedition company at the Refugio Amazonas near the Tambopata Research Center in Peru, where the glowing larvae were discovered.
In tests, the glow worms readily devoured stick insects and termites, Pomerantz said. Their style of attack seems similar to that of the enormous, man-eating worms in the 1990 campy movie "Tremors," albeit at a much smaller scale, he said.
"They're underground, and they burst from the earth," Pomerantz told Live Science.
Nature photographer Jeff Cremer found the tiny pinpricks of light glowing in a wall of earth when he was working at a lodge in the Peruvian jungle. On closer inspection, Cremer discovered several dozen of these tiny insects, which measured about 0.5 inches (1.2 centimeters), shining green in the night.
Cremer brought them to the attention of entomologists who work at the rainforest nature lodge, who had never seen anything similar in the region.
The team determined that the worms were the larvae of an unknown species of click beetle. These beetles, which belong to the family Elateridae, use a fast popping or "clicking" motion to escape predators, Pomerantz said. Adults may feed on flowers and nectar, but the larvae are probably predatory.
There are more than 10,000 species of click beetles, including about 200 that are bioluminescent, meaning that they give off light. These strange little creatures may potentially be cousins of Brazilian fire beetles and could belong to the group of bugs called Pyrophorini, Pomerantz said.
Brazilian fire beetles burrow into termite mounds, creating ethereal, glowing towers at night, Pomerantz said. Though it's not exactly clear how the newly discovered insects produce light, similar creatures use a class of molecules known as luciferins to give off their ghostly yellow glow. Pyrophorini typically maintain a constant glow through the night, and may even shine brighter when a predator touches them.
Bioluminescent animals usually glow to either lure in prey or to warn predators that they contain noxious chemicals. But the glowing also occasionally serves other purposes. For instance, fireflies' blinking is essentially a come-hither signal for potential mates, Pomerantz said.
Read more at Discovery News
Dubbed by the Greek media “a small underwater Pompeii,” the structures lay at a depth of just 6 feet on the northeastern coast of Delos.
“In the past these ruins were identified as port facilities,” the culture ministry said.
But a new investigation by the National Hellenic Research Foundation and the Ephorate of Undersea Archaeology, led to different conclusions. Rather than a dock, a pottery workshop and other buildings once stood at the site.
Archaeologists found 16 terracotta pots and remains of a kiln embedded in the sea floor.
“Similar workshops have been found in Pompeii and Herculaneum,” the ministry said.
Large stones were found lined in front of the workshop remains. According to the archaeologists, they were probably part of the settlement’s waterfront.
Possibly related to commercial and crafting activities, the settlement somehow collapsed. The man-made ruins have remained hidden on the sea bed ever since.
Underwater archaeologists identified several structures, including fallen colonnades and the remains of walls which once extended along the shoreline.
The findings add new intriguing details to one of Greece’s most important archaeological sites.
Located in the center of the Cyclades archipelago near the island of Mykonos, Delos is where, according to Greek myth, the sun god Apollo was born.
As the site of the Apollo cult and one of the main centers of the Aegean slave trade (as many as 10,000 slaves were said to be sold in a single day) Delos flourished for 700 years, from the 8th until the 1st centuries B.C.
For much of antiquity people were not allowed to die or give birth on the sacred island, which nonetheless became a thriving commercial port, especially under the Romans in the 3rd and 2nd century BC.
Decline came as the troops of Mithridates VI of Pontus attacked the island in 88 BC, slaughtering 20,000 inhabitants.
Read more at Discovery News
But what they found left them puzzled: a strange, asymmetrical pattern of highly charged hydrogen atoms moving quickly away from the star.
With the help of a new three-dimensional computer model, they now have an explanation. The model, which takes into account all known interactions between stellar winds and planetary atmospheres, indicates that the mysterious hydrogen flow is a telltale sign of the planet being bathed in stellar winds from its parent star that reached 249 mile-per-second during the transit.
The model also shows that the planet’s magnetic field was about 10 percent as powerful as Jupiter’s at the time.
The new model, reported in this week’s Science, is expected to become a useful tool for assessing how planets beyond the solar system are interacting with their host stars.
From Discovery News
They say that using X-rays is faster than existing radio wave communications, can carry more information and won’t be blocked when spacecraft enter a planet’s thick atmosphere.
“While we are using X-ray navigation to guide us to Pluto, we might also use X-ray communication to talk back to Earth,” said Keith Gendreau, principal investigator at NASA’s Goddard Space Flight Center in Greenbelt, Md.
The concept of X-ray navigation will be tested during a NASA mission called NICER/SEXTANT that is set to launch in August 2016. The spacecraft will study the insides of neutron stars, which produce X-rays, and test equipment that could be used for x-ray navigation.
Gendreau and other scientists have been thinking for several decades about using pulsars, which also emit beams of X-rays, as outer space lighthouses to help spacecraft tell where they are. Instead of just using a single radio source from Earth to tell their position and location, a future mission would tap into a hypothetical map of pulsars, each of which sends out its own identifiable frequency.
Existing “star charts will tell your spacecraft orientation, but it won’t tell you in three dimensions,” Gendreau said. “With radio waves, you get precise range information between your spacecraft and the Earth, but that’s only one direction in the sky. Pulsars are distributed all over the galaxy. They are more or less uniform in the sky.”
Other engineering teams have also been working on pulsar navigation using X-rays, but so far haven’t convinced NASA or other space agencies to fully implement the idea yet. Werner Becker, an astrophysicist at the Max Planck Institute in Germany, has been simulating pulsar navigation in his laboratory and published a study last year about using pulsar navigation to allow spacecraft to navigate autonomously.
“This technology of pulsar navigation is so simple,” Becker said. “You just need a demonstrator mission.”
Becker is so excited about pulsar navigation that he’s putting on a conference in Germany next year to further explore the idea.
Other experts say that X-ray navigation, or XNAV, just needs a little push to get it going, according to Dan Jablonski, communications engineer at Johns Hopkins University’s Applied Physics Laboratory.
“Things are constantly being adapted from one mission to another and they find their way to the communications market pretty quickly,” Jablonski said. “Everybody watches everybody else’s projects with great interest. When it works they take it and run with it.”
NASA’s Gendreau also believes he can communicate and send scientific data back to Earth in almost real-time using X-rays. In a crowded second floor lab in Goddard’s Building 34, Gendreau has set up a small experiment that uses a small X-ray source to transmit digital music from his iPhone across a workbench to a nearby speaker.
“We’ve developed the core technology, we just now just need to refining existing encoding techniques and maybe going beyond,” Gendreau said.
Read more at Discovery News
Nov 19, 2014
If the findings in house mice translate to threatened species, it means captive-bred animals may not be as effective at increasing the genetic diversity of wild populations as originally expected, the researchers say.
Their findings are published today in the Royal Society journal Biology Letters.
Millions of dollars are spent each year on breeding threatened species in captivity for release into the wild, says team member Dr Michael Magrath, a senior scientist at Zoos Victoria.
In some cases, he says, the aim is to increase the genetic diversity of existing populations, but the success of such programs is variable.
The strategy relies on captive-bred animals interbreeding with wild animals but there is much evidence that captivity affects the behaviour of animals.
Magrath and colleagues wondered whether periods of captivity could affect an animal's preference for a mate.
The researchers kept house mice in captivity for three generations before releasing them into a larger "semi-naturalistic" enclosure with mice freshly caught from the wild.
After 20 weeks they took genetic samples of the offspring that resulted to find out which mice had mated together.
They discovered the vast majority of mice mated with their own kind.
"Only 17 per cent of offspring were produced from mixed-source pairings," says Magrath.
Magrath says the mate preferences found in the study could have implications for the success of captive breeding programs.
"If you are starting a new population and there is no existing wild population then it is not an issue because the animals you are introducing are all from captivity," he says.
But, says Magrath, if the aim is to introduce captive animals to increase genetic diversity of an existing wild population there may be a problem -- at least in the short term.
"They may pair with each other and this will reduce integration of their genetic material into the wild population," he says.
Magrath says if a batch of introduced captive-bred males failed to mate with wild females conservation programs could fail.
Alternatively, a batch of introduced males and females may breed with each other and form a sub-population.
But this sub-population may be at a disadvantage because failing to mix with the wild animals means they may not inherit or learn crucial 'streetwise' behaviours like predator awareness.
Magrath, who is involved in captive breeding programs for the eastern barred bandicoot, Leadbeater's possom and Tasmanian devil, among others, says the next step is to monitor programs to see if mate choice is affecting their success.
If it is, he says, then it would be good to find out what causes this behaviour.
One explanation is that animals may stick to breeding with their own kind because other animals have a different smell due to the diet and environment they had when they were reared, says Magrath.
Read more at Discovery News