Mindy Weisberger is a senior writer for Live Science covering general science topics, especially those relating to brains, bodies, and behaviors in humans and other animals — living and extinct. Mindy studied filmmaking at Columbia University; her videos about dinosaurs, biodiversity, human origins, evolution, and astrophysics appear in the American Museum of Natural History, on YouTube, and in museums and science centers worldwide. Follow Mindy on Twitter.
In a step forward for robotics design, humanoid robot DURUS uses heel-to-toe walking.
Credit: Christian Hubicki / Georgia Tech
A bipedal robot can now put its best foot forward, stepping with a heel-toe motion that copies human locomotion more closely than flat-footed robot walkers can.
By rocking its "feet" forward from the heel and pushing off at the toe, the DURUS robot closely imitates the walking motion of people, making it more energy-efficient and better at navigating uneven terrain, according to Christian Hubicki, a postdoctoral fellow in robotics at the Georgia Institute of Technology and one of the researchers who helped DURUS find its footing.
Enhanced walking capabilities could help robots navigate environments that people move around in, and could improve the performance of bots created for disaster response, Hubicki told Live Science. [Robots on the Run! 5 Bots That Can Really Move]
The humanoid robot DURUS was designed collaboratively by the research nonprofit SRI International and Georgia Tech's Advanced Mechanical Bipedal Experimental Robotics (AMBER) Lab. An earlier DURUS design was modified to accommodate the new manner of walking, enabled by a novel mathematical algorithm that adjusts the robot's momentum and balance, one step at a time.
Well-heeled
Robots that walk on two legs typically have "feet" that are large and flat, to provide a more stable platform, Hubicki told Live Science.
Heel-to-toe walking makes DURUS more energy-efficient and more stable than flat-footed walkers.
Credit: Christian Hubicki / Georgia Tech
"Bigger feet mean a bigger polygon of support, and the harder it is to fall," Hubicki said.
The algorithms that dictate a robot's forward momentum typically keep those big feet flat on the ground when pushing off, to minimize the risk that the bot will tip over.
"As soon as you lean on an edge, you're like a pendulum — on a pivot point that can fall forward or backward," Hubicki said.
But while a flat-footed walker might perform well on a treadmill, uneven terrain in the real world that doesn't accommodate a flat foot could confound the algorithm and stop a robot in its tracks.
Enter the AMBER Lab researchers, who designed a new algorithm that works to keep a robot upright and moving forward even if only parts of the foot are engaged. Hubicki and his colleagues tested DURUS using a modified foot with an arch; every step began with the heel making contact — the "heel strike," according to Hubicki — and then rolling to the ball of the foot to push off from the ground. Springs installed by the robot's ankles act like tendons, storing the heel strike's energy to be released later, as lift.
On July 12, AMBER Lab posted a video of a confidently striding DURUS on YouTube. DURUS' new feet are about the same size as human feet — about half as long as the feet on the original model. And to emphasize the similarity, the team laced them into a pair of sneakers.
"We wanted to show that our algorithms could make it walk with human-size feet," Hubicki said. "What better way to do that than [by] putting shoes on it?"
The algorithm may even have applications beyond robotics, Hubicki added, suggesting that it could be used to improve the design of prosthetics and exoskeletons to help people who use assistance to get around.
FBI officials have scanned the irises of nearly 460,000 people in a pilot program that may soon replace fingerprints. While iris-scanning technology has been around for more than 25 years, it's just now getting to where it's fast, easy and relatively bug-free.
"It's a powerful biometric," said Patrick Grother, a computer scientist at the National Institute of Standards and Technology in Gaithersburg, Md., who has been developing algorithms and software for iris scanning. "It's fast to process, it has discriminative power -- my iris doesn't look like your iris, and it has reasonable permanence."
Iris scanning has replaced retinal scans, a method that has been pretty much abandoned since it turned out to be uncomfortable for people to endure, Grother explained. Iris scan technology was featured recently in the AMC mini-series " The Night Manager," based on a John LeCarre spy novel. The lead character used an iris scan camera on his smartphone to access his Swiss bank account (just before a big truck blew up).
Grother says that kind of quick reading ability isn't far away, and several banks are looking at using it. Windows' Lumia Nokia and Fujitsu both have iris scanners to unlock their phones, (similar to the iPhone fingerprint pad) but it's not ready to authenticate other sorts of apps or accounts.
Iris scanning cameras can be hand-held or attached to a wall. They are effective from three to six feet away from the subject's eyes. Soldiers in Iraq have been using them to authenticate Iraqi civilians who are authorized to work inside U.S. military facilities.
The iris is a part of the eye outside of the pupil that is made of collagen in a three-dimensional arrangement. This pattern can be imaged with light at certain wavelengths.
"It's like taking picture of sand dunes from space," he said. "It's a 3-D object."
The FBI's Iris Pilot program is being deployed by law enforcement officials in California, Texas and Missouri during the booking process. The U.S. Border Patrol and Department of Defense are also using iris scans, according to Stephen Fischer, an FBI spokesman.
The next step is collecting iris scans from photographs of people's eyes.
"Iris images enrolled in the FBI Iris Pilot are primarily captured during the booking process in a controlled setting with a camera designed to capture the iris image," Fischer said in an email to DNews. "These cameras capture the iris image in near-infrared light. Research is currently being conducted on the extraction of iris images from high-resolution photographs."
People with brown eyes have more pigment than those with blue eyes, said Grother. That makes it tougher to capture iris information from photographs of brown-eyed folks.
Of course, anyone who blinks, squints or scrunches up their eyes will make it difficult for law enforcement to get a good scan.
Grother and other experts now are developing software to recognize iris patterns from several different camera angles, making it easier to use a hand-held device or smartphone.
As a senior writer for Live Science, Laura Geggel covers general science, including the environment and amazing animals. She has written for The New York Times, Scholastic, Popular Science and Spectrum, a site covering autism research. Laura grew up in Seattle and studied English literature and psychology at Washington University in St. Louis before completing her graduate degree in science writing at NYU. When not writing, you'll find Laura playing Ultimate Frisbee. Follow Laura on Google+.
Silkworms have been genetically engineered to produce spider silk, which could lead to bullet-resistant clothing one day.
Credit: Kraig Biocraft Laboratories
Genetically modified silkworms that spin special fibers, known as "Dragon Silk," could soon be used to protect soldiers in the U.S. Army, its manufacturer, Kraig Biocraft Laboratories, announced this week.
The U.S. Army recently awarded the Michigan-based company a contract to test its silk products, Kraig Biocraft Laboratories announced on Tuesday (July 12). Researchers at the lab will collect the modified silk and give it to another company. That company will weave it into fabric and then give it to the U.S. Army for testing, the company said.
"Dragon Silk scores very highly in tensile strength and elasticity," which makes is one of the toughest fibers known to man, Jon Rice, the chief operations officer at Kraig Biocraft Laboratories, said in a statement. [7 Technologies That Transformed Warfare]
Despite its mythical name, Dragon Silk is actually the work of genetic engineers. It's widely known, at least in the materials industry, that spider silk has exceptional strength, resilience and flexibility, Rice told Live Science.
A typical silk cocoon (left) next to a genetically altered one (right), under ultraviolet light.
Credit: Copyright Kraig Biocraft Laboratories
"Spider silk is five to 10 times stronger than conventional silkworm silk," Rice said. "It's also, in some cases, as much as twice as elastic. It's even tougher than Kevlar."
However, it isn't possible to set up a one-stop shop for spider silk. Spiders aren't amenable to producing silk in concentrated colonies, largely because many are cannibalistic, he said. So, engineers found DNA within several spiders that is responsible for making silk-related proteins, and inserted it into silkworms.
In 2011, a study published in the journal Proceedings of the National Academy of Sciences described the technique, explaining how the researchers removed the silkworms' silk-making proteins and replaced them with the spiders' proteins to create super silkworms — that is, silkworms that can spin composite spider silk.
A silkworm has a lifecycle that's similar to any caterpillar's that turns into a moth. Silkworms spin cocoons when they're about 30 to 35 days old, just when they're ready to metamorphose into moths, Rice said. Most of these cocoons are collected by Kraig Biocraft Laboratories, and the company then makes them into silk. But some silkworms are able to reproduce and pass down their newly acquired silky trait to their offspring, Rice said.
Genetically altered silkworm moths standing on top of cocoons.
Credit: Copyright Kraig Biocraft Laboratories
The modified silk is about 1,000 times more cost effective than its competitors, Rice added. Modified silk made from complex fermentation processes costs about $30,000 to $40,000 a kilogram (2.2 lbs.), while the lab's silk costs less than $300 for the same amount, Rice said.
If Dragon Silk performs well in the U.S. Army tests, which include ballistic-impact trials, Kraig Biocraft Laboratories could receive a nearly $1 million contract with the military to produce more of the fabric, the company said in the statement.
Still, Rice doesn't want to limit Dragon Silk to military uses. He plans to expand the company's products into the realm of other protective clothing, as well as athletic wear, he said.
Stephanie interned as a science writer at Stanford University Medical School, and also interned at ScienceNow magazine and the Santa Cruz Sentinel. She has a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science writing from the University of California, Santa Cruz.
On June 26, 2016, NASA's Terra satellite snapped this image of gravity waves off the coast of Africa.
Credit: NASA Earth Observatory image by Jesse Allen
Interlacing waves of clouds decorate the sky above the coast of Angola in a new satellite image.
The image, taken June 26 by an instrument on NASA's Terra satellite, highlights the atmospheric patterns off the coast of West Africa. The clouds are called gravity waves, which form as gravity and buoyancy try to balance each other out. (Gravity waves are different than gravitational waves, which are ripples in space-time.)
According to NASA's Earth Observatory, the culprit here is dry, cool air moving out of the nighttime Namib desert and over the ocean. This cool air pushes the humid and warm ocean air up (there's the buoyancy part of the equation). As the moisture rises and condenses to form clouds, gravity pushes it back down, where it hits the rising column of dry air and gets hoisted up again. (A similar push-and-pull occurs at the ocean's surface because of the interactions of wind and gravity.)
Gravity twists these clouds into a wave-like shape.
Credit: NASA Earth Observatory image by Jesse Allen
The ripple-like clouds seen in this image represent the peaks of the gravity waves, where the moisture in the air condenses. The clear skies between the peaks are the troughs of the gravity waves.
On the day the Moderate Resolution Imaging Spectroradiometer on the Terra satellite captured this image, winds were creating gravity waves in all different directions, Bastiaan van Diedenhoven, who researches ice-containing clouds at NASA's Goddard Space Flight Center, told the Earth Observatory. The result was a complicated pattern of crisscrossing clouds curving across at least 620 miles (1,000 kilometers). These patterns are often seen off Angola and Namibia in the morning and early afternoon, van Diedenhoven told the Earth Observatory, and tend to be pushed out to sea as the day goes on.
Gravity waves may be important for commercial air travel. A study presented in 2012 at the annual meeting of the American Geophysical Union found that gravity waves can break against an aircraft just as ocean waves break against a beach, causing turbulence in otherwise clear skies.
Stephanie interned as a science writer at Stanford University Medical School, and also interned at ScienceNow magazine and the Santa Cruz Sentinel. She has a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science writing from the University of California, Santa Cruz
Colli Albani, a volcanic complex outside Rome, was thought to be extinct, that is, until it showed signs of activity.
Credit: Fabio Florindo
A volcano outside Rome, long thought extinct, is rumbling to life. But don't panic: The volcano isn't likely to blow its top for at least another 1,000 years.
Colli Albani is a volcanic complex of hills located 19 miles (30 kilometers) from the center of Rome. There are no historical records of eruptions from Colli Albani, so it was long thought to be extinct, according to the American Geophysical Union (AGU). Now, researchers have reported in the journal Geophysical Research Letters that Colli Albani just doesn't erupt that often. In fact, it enters an eruptive phase every 31,000 years or so.
A team of researchers, led by volcanologist Fabrizio Marra of the National Institute of Geophysics and Volcanology in Rome, used ground-based observations of rising land, earthquake swarms and steam vents alongside satellite data to track Colli Albani's recent activity. An analysis of rocks from the volcano revealed a history of past eruptions, the most recent of which occurred 36,000 years ago. [The 11 Biggest Volcanic Eruptions in History]
Now, the ground underneath the volcano is inflating, rising at a maximum of about 0.08 inches (2 millimeters) per year in areas where steam vents are emerging, Marra and his colleagues reported. During the past 200,000 years, the area has risen by about 164 feet (50 meters) in elevation, they found. This suggests that magma is entering fractures beneath the volcano, they said.
The reason for the change has to do with the subsurface geology of Colli Albani, Marra told the AGU. Until about 2,000 years ago, the surrounding land held together a fracture under the volcano, preventing magma from bubbling to the surface. More recently, however, the subsurface stresses have changed so that the rock on one side of the fracture is moving and sliding against the rock on the other side, according to the AGU.
So far, these changes have manifested in a swarm of earthquakes around Rome that lasted from 1991 to 1995. Another sign was a small fumarole, or steam vent, that appeared in a road near Rome's Fiumicino airport in 2013.
Given its 31,000-year cycle, Colli Albani is arguably overdue for an eruption, but the volcano won't unexpectedly blow its top, Marra told the AGU. It likely won't build up enough pressure for an explosive eruption for at least 1,000 years. Even then, Romans can expect plenty of warning, Marra said, as an explosive eruption would be preceded by initial stages of moderate volcanic activity.
Owen Jarus writes about archaeology and all things about humans' past for Live Science. Owen has a bachelor of arts degree from the University of Toronto and a journalism degree from Ryerson University. He enjoys reading about new research and is always looking for a new historical tale.
One of the skeletons found in the possible Philistine cemetery in Ashkelon, Israel, had a juglet stuck to its skull.
Credit: Copyright Tsafrir Abayov/Leon Levy Expedition
A 3,000-year-old graveyard with the bones of about 200 individuals discovered in Ashkelon, Israel, is being hailed as the first (and only) Philistine cemetery ever found.
If valid, the finding would reveal more about a mysterious people known as the Philistines. Archaeological evidence suggests that the Philistines came from the Aegean Sea region, along with other groups of people, during the 12th century B.C, at a time when cities and civilizations in Greece and the Middle East were collapsing.
According to the Hebrew Bible the Philistines fought a series of battles against the Israelis. The conflict between the Philistine giant Goliath and Israel's King David (who was armed only with a slingshot) is the most famous encounter. Little is known about the burial practices of this culture, archaeologists said.
However, experts not affiliated with the excavations are not yet convinced of the claim, saying that the identity of the people buried at the Ashkelon cemetery is not clear-cut and the finding itself has not been published in a peer-reviewed scientific journal. Further muddying the waters, other burials found in known Philistine cities, though never confirmed, also have dibs on the title of "first-discovered Philistine cemetery." [See Photos of the Possible Philistine Cemetery and Artifacts]
Archaeologists are waiting to see what the scientific publication of the Ashkelon cemetery will show. "Though the Ashkelon Philistine cemetery received much media attention, the full professional archaeological picture still awaits further clarification," said Shlomo Bunimovitz, an archaeology professor at Tel Aviv University in Israel.
Here, a skull found in a 3,000-year-old cemetery in Ashkelon, Israel, that may be the first Philistine cemetery known.
Credit: Copyright Tsafrir Abayov/Leon Levy Expedition
The excavators acknowledge that other burials identified as Philistine have been found before, but say that their finds will show that most of the past discoveries were incorrectly identified as "Philistine."
"Ninety-nine percent of the chapters and articles written about Philistine burial customs should be revised or ignored now that we have the first and only Philistine cemetery, found just outside the city walls of Tel Ashkelon, one of the five primary cities of the Philistines," expedition co-director Lawrence Stager, a professor at Harvard University in Massachusetts, said in the press release announcing the find.
Are these Philistine people?
Radiocarbon dating and analysis of the cemetery's pots indicate that the cemetery was in use between the late 11th century B.C. and the early eighth century B.C., said Daniel Master, a professor at Wheaton College in Illinois and a co-director of the excavations at Ashkelon.
"We have a high degree of confidence that Ashkelon was a major Philistine city in this period because of a convergence of earlier and later texts from Egypt, the Hebrew Bible, Assyria and Babylon," Master said. He also noted that the burial styles seen at the cemetery appear different than those of other groups who lived in the region, such as the Canaanites.
Amihai Mazar, an archaeology professor at the Hebrew University of Jerusalem, said he believes the answer is more complicated. Previous archaeological studies indicate that the Philistines arrived in Israel from the Aegean Sea region during the 12th century B.C., he told Live Science in an interview.
By the 10th century B.C., the Philistines were intermixing with the local Canaanite population and adopting local traditions as well as Canaanite artifacts and practices, Mazar said.
He said that while you "can call [the cemetery] Philistine," there may be differences between how people were buried in this 3,000-year-old cemetery and how they would have been buried 3,200 years ago, when the Philistines were newcomers to the region.
Images of the cemetery published in media outlets show numerous Phoenician pots and a structure with Phoenician architectural elements, Mazar said, adding that these features suggest that some of the people buried in the cemetery could be Phoenician merchants rather than Philistines.
Master agreed that not all the people buried in the cemetery were Philistine. "No one can be sure of the affiliation of every person in any ancient cemetery," he said.
Additionally, the people buried in the cemetery may not have thought of themselves as being Philistine and may have identified themselves more on the city they lived in or on their religious practices, said Raz Kletter, a professor of theology at the University of Helsinki in Finland.
Kletter doesn't dispute that the people buried at Ashkelon used a series of artifacts that modern-day archaeologists identify as belonging to the Philistines. However, that doesn't mean the people buried there thought of themselves as Philistine, he said.
"We do not know how they [the Philistines] viewed themselves, having few written sources that are mostly from outside Philistia," Kletter said. "People living in Iron Age Philistia could identify themselves by city or religion, and not necessarily by an ethnic group."
Is it the first Philistine cemetery ever discovered?
Neither Mazar nor Kletter agree with the assertion that the cemetery found at Ashkelon is the only known Philistine cemetery.
Kletter has been excavating an ancient city in Israel called Yavneh, which he says also contains artifacts that can be identified as "Philistine." Additionally, he and his colleagues found a cemetery there, which they described in the journal Atiqot in 2015. That cemetery also dates to a time when ancient texts say that Yavneh was a Philistine city. "I believe the people buried there [in Yavneh's cemetery] were Philistines," Kletter said.
Other sites with burials that could be considered "Philistine" have also been previously discovered both Kletter and Mazar said.
For instance, a Philistine cemetery at Azor, a site located near modern-day Tel Aviv, was excavated in the 1950s by the late archaeologist Moshe Dothan said Mazar. Additionally, some archaeologists consider burials dug up in southern Israel by British archaaeologist Sir Flinders Petrie a century ago to be Philistine, Mazar added.
"Ashkelon is not a 'first,' but it is certainly an important find," Kletter said.
Identifying a burial as that of a Philistine is difficult because archaeologists have to use ancient records of the areas that the Philistines ruled and try to confirm, using the artifacts they find, that the people in a cemetery are Philistine and not from other groups. These findings are published in scientific journals and can be the subject of debates that can go on for many years.
January 2015, Vol.181:73–81, doi:10.1016/j.biocon.2014.10.035
Title
Assessing the importance of multiple threats to an endangered globose cactus in Mexico: Cattle grazing, looting and climate change
Author
Carlos Martorell a,,
Delfín M. Montañana a
Carolina Ureta b,
María C. Mandujano c,
aDepartamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México, D.F., Mexico
bDepartamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México, D.F., Mexico
cInstituto de Ecología, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México, D.F., Mexico
Received 29 January 2014. Revised 15 October 2014. Accepted 21 October 2014. Available online 28 November 2014.
Abstract
Cacti are a priority for conservation because their slow recovery rates and high habitat specificity make their populations particularly susceptible to looters who raid their populations, anthropogenic disturbance and climate change (CC). Identifying the most damaging threat is critical to the direction and efficiency of conservation efforts. We analyzed the impacts of looting, disturbance and CC on the geographically rare globose cactusCoryphantha werdermanniiin Coahuila, Northern Mexico. We collected evidence on looting and estimated the impacts of seed and adult plant extraction through demographic models. We compared 10 sites differing in disturbance intensity and analyzed the effect on plant density, size structure and reproduction. The potential distribution ofC.werdermanniiunder current conditions and future CC was assessed through ecological niche modeling. We found that looting is mostly confined to seeds, which have little impact on population growth and therefore not responsible for population decline. As in many globose cacti, the density ofC.werdermanniipopulations increased with disturbance, likely because cattle grazing increases recruitment rates. Contrastingly, even the most optimistic CC scenarios suggest a 90% reduction in the potential distribution area by 2050, indicating thatC.werdermanniiis an endangered species most threatened by CC. We suggest that relocation programs and the maintenance of livestock levels appropriate for this species (moderate-high) may effectively counteract or delay the effects of CC. Our results suggest that current efforts are devoted to relatively minor threats, while CC is neglected, and highlight the importance of formal assessments of multiple threats.
