Fossil bones housed at a Los Angeles museum belong to the smallest dinosaur discovered in North America, scientists said Tuesday.
The newly identified creature weighed less than two pounds and stood a little over 2 feet tall, said Luis Chiappe, director of the Dinosaur Institute of the Natural History Museum of Los Angeles County where the fossil bones are stored.
The dinosaur "would have looked like a roadrunner on steroids," Chiappe said.
It likely ate plants and hunted bugs during the late Jurassic period, about 150 million years ago. It was so tiny and fast that it probably darted between the legs of larger dinosaurs, researchers said.
Bones of four individuals - including skull, arm and leg fragments - were discovered three decades ago in Fruita in western Colorado and kept at the museum.
Science & Technology
© Stuart Starrs
Site of the Pacopampa temple.
Site of the Pacopampa temple.
On the highest terrace of the San Pedro mountain in what is today Chota in Cajamarca, the birth of a girl began what was to be a new episode of the Formative Period some 3000 years ago. Born in the archaeological complex that we now call San Pedro de Pacopampa, the healthy baby girl would be raised to one day lead her people.
Could the Large Hadron Collider be sabotaging itself from the future, as some physicists say
Explosions, scientists arrested for alleged terrorism, mysterious breakdowns - recently Cern's Large Hadron Collider (LHC) has begun to look like the world's most ill-fated experiment.
Is it really nothing more than bad luck or is there something weirder at work? Such speculation generally belongs to the lunatic fringe, but serious scientists have begun to suggest that the frequency of Cern's accidents and problems is far more than a coincidence.
Explosions, scientists arrested for alleged terrorism, mysterious breakdowns - recently Cern's Large Hadron Collider (LHC) has begun to look like the world's most ill-fated experiment.
Is it really nothing more than bad luck or is there something weirder at work? Such speculation generally belongs to the lunatic fringe, but serious scientists have begun to suggest that the frequency of Cern's accidents and problems is far more than a coincidence.
Scientists have discovered a series of caves on Mars that might provide shelter to future explorers and may hold evidence of life, the U.S. Geological Survey said.
The caves were probably formed when lava cooled and solidified on top of channels created during ancient volcanic eruptions, making tunnels, said a statement today from the USGS.
The formations may hold evidence of microbial life that would have been destroyed or buried on the surface of the planet, said Glen Cushing, a USGS physicist who made the discovery.
"There's even been speculation that lava tubes could be sealed and pressured to create a habitat for long term use," said Cushing in a telephone interview from Portland, Oregon. "That's in the pretty far distant future, but it's seems like a fairly reasonable prospect once we do get to that level."
NASA is currently planning to return humans to the moon by 2020 as a step toward an eventual manned mission to Mars.
Cushing, 39, discovered the caves by studying images of grooves on the planet's surface, some longer than 100 kilometers (62 miles), with depressions he said are skylight entrances into the tunnels.
The caves were probably formed when lava cooled and solidified on top of channels created during ancient volcanic eruptions, making tunnels, said a statement today from the USGS.
The formations may hold evidence of microbial life that would have been destroyed or buried on the surface of the planet, said Glen Cushing, a USGS physicist who made the discovery.
"There's even been speculation that lava tubes could be sealed and pressured to create a habitat for long term use," said Cushing in a telephone interview from Portland, Oregon. "That's in the pretty far distant future, but it's seems like a fairly reasonable prospect once we do get to that level."
NASA is currently planning to return humans to the moon by 2020 as a step toward an eventual manned mission to Mars.
Cushing, 39, discovered the caves by studying images of grooves on the planet's surface, some longer than 100 kilometers (62 miles), with depressions he said are skylight entrances into the tunnels.
© Chiara Bellini
"About 20 seconds later, a second object appeared." That was a US military weather satellite (DMSP F-18), which the Centaur booster had helped launch earlier in the evening from Vandenberg, Air Force Base in California. "And then," the Bellinis continue, "a big circular halo followed the two across the sky." The halo, shown here in a movie recorded by Jonas Förste of Jakobstad, Finland, was probably an expanding puff of gas emitted during an earlier firing of the Centaur.
This remarkable show surprised observers in almost every country of Europe. Browse the links below for more sightings.
It was the oddest of scenes: A neurosurgeon delicately threaded a scope up the neck and into the skull of a disembodied, 4,000-year-old mummified head. Sweating with concentration, another doctor clamped a molar and began to rock it gently back and forth.
Three hours later, the nerve-wracking operation yielded a tooth, a time capsule holding precious DNA, which might reveal the identity of the ancient Egyptian head.
The surgical team - doctors from Massachusetts General Hospital and curators and conservation specialists from the Museum of Fine Arts - was assembled recently in an attempt to solve this longstanding ancient art mystery.
The question arose after the 1915 excavation of a tomb in a necropolis 186 miles south of Cairo. Robbers had disturbed the tomb, which belonged to Governor and Lady Djehutynakht, who ruled the district of Hermopolis in about 2000 BC. They left behind a torso, scattered mummy wrappings, fine examples of Egyptian art, objects for the afterlife, and the head.
Three hours later, the nerve-wracking operation yielded a tooth, a time capsule holding precious DNA, which might reveal the identity of the ancient Egyptian head.
The surgical team - doctors from Massachusetts General Hospital and curators and conservation specialists from the Museum of Fine Arts - was assembled recently in an attempt to solve this longstanding ancient art mystery.
The question arose after the 1915 excavation of a tomb in a necropolis 186 miles south of Cairo. Robbers had disturbed the tomb, which belonged to Governor and Lady Djehutynakht, who ruled the district of Hermopolis in about 2000 BC. They left behind a torso, scattered mummy wrappings, fine examples of Egyptian art, objects for the afterlife, and the head.
© Jefferson Teng
"I woke up early in the morning to observe the shower through my bedroom window," says Teng. "This one was quite bright considering the light pollution in Shanghai."
Forecasters expect the shower to peak on Wednesday, Oct. 21st, with dozens of meteors per hour. The best time to look is during the dark hours before sunrise. For best results, get away from city lights, but as Teng discovered, country darkness is not absolutely necessary.
The brain never sits idle. Whether we are awake or asleep, watch TV or close our eyes, waves of spontaneous nerve signals wash through our brains. Researchers at the Salk Institute for Biological Studies studying visual attention have discovered a novel mechanism that explains how incoming sensory signals make themselves heard amidst the constant background rumblings so they can be reliably processed and passed on.
"We live with the illusion that our visual system processes all the information that is available in the visual scene in a single glimpse," says John H. Reynolds, Ph.D., an associate professor in the Systems Neurobiology Laboratory at the Salk Institute and senior author of the current study. "In reality, there is far too much detail in a typical scene for the visual system to take it in all at once. So our perception of the world around us is in a sense pieced together from what we pay attention to."
Researchers had known for some time that paying attention to visual details increases the firing rate of neurons tuned for attended stimulus. Until now, it was assumed that these attention-dependent increases in neural activity were the primary cause of the improvement in perceptual discrimination that we experience when we focus a sensory stimulus.
"We live with the illusion that our visual system processes all the information that is available in the visual scene in a single glimpse," says John H. Reynolds, Ph.D., an associate professor in the Systems Neurobiology Laboratory at the Salk Institute and senior author of the current study. "In reality, there is far too much detail in a typical scene for the visual system to take it in all at once. So our perception of the world around us is in a sense pieced together from what we pay attention to."
Researchers had known for some time that paying attention to visual details increases the firing rate of neurons tuned for attended stimulus. Until now, it was assumed that these attention-dependent increases in neural activity were the primary cause of the improvement in perceptual discrimination that we experience when we focus a sensory stimulus.
© iStockphoto
New research finds an area of the drosophila brain that can trick hungry flies into acting full.
New research finds an area of the drosophila brain that can trick hungry flies into acting full.
Two decades ago, the discovery of neuropeptide Y (NPY), a peptide in the mammalian brain involved in food-seeking behavior, sparked a search for a weight-loss remedy that could interfere with its activity. Eventually the promise of other drug targets, along with the possible side effects of targeting NPY, put a damper on the effort - until now. New findings about the action of this appetite-promoting peptide could bring NPY back to the front burner.
A study released this week in Cell reports on fruit fly neural circuitry that is affected by the drosophila equivalent of NPY - dNPF. The latter peptide disrupts a group of neurons that would normally put the brakes on tapping memory to search for food. Instead, dNPF allows neurons to release signals that prompt flies to hunt for a meal. By blocking the effect that dNPF has on neurons that interact with drosophila's memory center, the researchers found they could halt the flies' feeding frenzy, and trick them into thinking they were full, even though they had not eaten. The fact that NPY in mammals has similar appetite-inducing activity as its drosophila analogue suggests that it might also govern an as-yet unknown network in the human brain that regulates our desire to seek sustenance.
"We know quite a lot about the memory system for olfactory memory in the fruit flies. That gave us some hope that we would be able to find a site of integration between [hunger] state and...memory," says Scott Waddell, an associate professor of neurobiology at the University of Massachusetts Medical School in Worcester, and supervisor of the new research.
Peter Mitchell was an eccentric figure. For much of his career he worked in his own lab in a restored manor house in Cornwall in the UK, his research funded in part by a herd of dairy cows. His ideas about the most basic process of life - how it gets energy - seemed ridiculous to his fellow biologists.
"I remember thinking to myself that I would bet anything that [it] didn't work that way," biochemist Leslie Orgel wrote of his meeting with Mitchell half a century ago. "Not since Darwin and Wallace has biology come up with an idea as counter-intuitive as those of, say, Einstein, Heisenberg and Schrödinger."
"I remember thinking to myself that I would bet anything that [it] didn't work that way," biochemist Leslie Orgel wrote of his meeting with Mitchell half a century ago. "Not since Darwin and Wallace has biology come up with an idea as counter-intuitive as those of, say, Einstein, Heisenberg and Schrödinger."
