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Excerpt from huffingtonpost.com An army of huge carnivorous "terror birds" -- some as big as 10 feet tall -- ruled South America for tens of millions of years before going extinct some 2.5 million years ago.Now, with the discovery of a new species of terror bird called Llallawavis scagliai, paleontologists are gaining fresh insight into this fearsome family of top predators.More than 90 percent of the bird's fossilized skeleton was unearthed in northeastern Argentina in 2010, making it the most complete terror bird specimen ever found. “It’s rare to find such a complete fossil of anything, let alone a bird,” Dr. Lawrence Witmer, an Ohio University paleontologist who wasn’t involved in the new research, told Science magazine. “This is a very exciting find.”
Skeleton of Llallawavis scagliai on display at the Lorenzo Scaglia Municipal Museum of Natural Sciences in Mar del Plata, Argentina. Preserved skeleton of Llallawavis scagliai. Bones colored in gray were missing in the specimen. Scale bar equals 0.1 m.Llallawavis likely lived around 3.5 million years ago, near the end of terror birds' reign, according to the researchers. It stood about four feet tall and weighed about 40 pounds.“The discovery of this species reveals that terror birds were more diverse in the Pliocene than previously thought," Dr. Federico Degrange, a researcher at the Center for Research in Earth Sciences in Argentina and the leader of the team that identified the new species, said in a written statement. "It will allow us to review the hypothesis about the decline and extinction of this fascinating group of birds.” CT scans of the bird's inner ear structures indicated that its hearing was tuned for low-pitched sounds, and that it likely produced these kinds of ostrich-like sounds too."Low-frequency sounds are great for long-[distance] communication, or if you're a predator, for sensing the movements of prey animals," Witmer told Live Science.The researchers hope further analyses will yield insights into the bird's vision and other senses.An article describing the findings was published online March 20 in the Journal of Vertebrate Paleontology.
University of Maryland computer scientist Yiannis Aloimonos (center) is developing robotic systems able to visually recognize objects and generate new behavior based on those observations. DARPA is funding this research through its Mathematics of Sensing, Exploitation and Execution (MSEE) program. (University of Maryland Photo)
January 29, 2015
DARPA program advances robots’ ability to sense visual information and turn it into action
Robots can learn to recognize objects and patterns fairly well, but to interpret and be able to act on visual input is much more difficult. Researchers at the University of Maryland, funded by DARPA’s Mathematics of Sensing, Exploitation and Execution (MSEE) program, recently developed a system that enabled robots to process visual data from a series of “how to” cooking videos on YouTube. Based on what was shown on a video, robots were able to recognize, grab and manipulate the correct kitchen utensil or object and perform the demonstrated task with high accuracy—without additional human input or programming. “The MSEE program initially focused on sensing, which involves perception and understanding of what’s happening in a visual scene, not simply recognizing and identifying objects,” said Reza Ghanadan, program manager in DARPA’s Defense Sciences Offices. “We’ve now taken the next step to execution, where a robot processes visual cues through a manipulation action-grammar module and translates them into actions.”Another significant advance to come out of the research is the robots’ ability to accumulate and share knowledge with others. Current sensor systems typically view the world anew in each moment, without the ability to apply prior knowledge.“This system allows robots to continuously build on previous learning—such as types of objects and grasps associated with them—which could have a huge impact on teaching and training,” Ghanadan said. “Instead of the long and expensive process of programming code to teach robots to do tasks, this research opens the potential for robots to learn much faster, at much lower cost and, to the extent they are authorized to do so, share that knowledge with other robots. This learning-based approach is a significant step towards developing technologies that could have benefits in areas such as military repair and logistics.”The DARPA-funded researchers presented their work today at the 29th meeting of the Association for the Advancement of Artificial Intelligence. The University of Maryland paper is available here: http://ow.ly/I30im
Excerpt fromnews.wustl.eduBy Jim Dryden
|The eye can detect light at wavelengths in the visual spectrum. Other wavelengths, such as infrared and ultraviolet, are supposed to be invisible to the human eye, but Washington University scientists have found that under certain conditions, it’s possible for us to see otherwise invisible infrared light. Image: Sara Dickherber|
Any science textbook will tell you we can’t see infrared light. Like X-rays and radio waves, infrared light waves are outside the visual spectrum. But an international team of researchers co-led by scientists at Washington University School of Medicine in St. Louis has found that under certain conditions, the retina can sense infrared light after all. Using cells from the retinas of mice and people, and powerful lasers that emit pulses of infrared light, the researchers found that when laser light pulses rapidly, light-sensing cells in the retina sometimes get a double hit of infrared energy. When that happens, the eye is able to detect light that falls outside the visible spectrum. The findings are published Dec. 1 in the Proceedings of the National Academy of Sciences (PNAS) Online Early Edition. The research was initiated after scientists on the research team reported seeing occasional flashes of green light while working with an infrared laser. Unlike the laser pointers used in lecture halls or as toys, the powerful infrared laser the scientists worked with emits light waves thought to be invisible to the human eye.
“They were able to see the laser light, which was outside of the normal visible range, and we really wanted to figure out how they were able to sense light that was supposed to be invisible,” said Frans Vinberg, PhD, one of the study’s lead authors and a postdoctoral research associate in the Department of Ophthalmology and Visual Sciences at Washington University. Vinberg, Kefalov and their colleagues examined the scientific literature and revisited reports of people seeing infrared light. They repeated previous experiments in which infrared light had been seen, and they analyzed such light from several lasers to see what they could learn about how and why it sometimes is visible.“We experimented with laser pulses of different durations that delivered the same total number of photons, and we found that the shorter the pulse, the more likely it was a person could see it,” Vinberg explained. “Although the length of time between pulses was so short that it couldn’t be noticed by the naked eye, the existence of those pulses was very important in allowing people to see this invisible light.”
“The visible spectrum includes waves of light that are 400-720 nanometers long,” explained Kefalov, an associate professor of ophthalmology and visual sciences. “But if a pigment molecule in the retina is hit in rapid succession by a pair of photons that are 1,000 nanometers long, those light particles will deliver the same amount of energy as a single hit from a 500-nanometer photon, which is well within the visible spectrum. That’s how we are able to see it.”
Kefalov’s team developed this adapter that allowed scientists to analyze retinal cells and photopigment molecules as they were exposed to infrared light. The device already is commercially available and in use at several vision research centers around the world.
Frans Vinberg, PhD (left), and Vladimir J. Kefalov, PhD, sit in front of a tool they developed that allows them to detect light responses from retinal cells and photopigment molecules.