Jan 21, 2017

Ants find their way even when going backwards

Cataglyphis velox ant.
An international team including researchers at the university of Edinburgh and Antoine Wystrach of the Research Centre on Animal Cognition (CNRS/Université Toulouse III -- Paul Sabatier) has shown that ants can get their bearings whatever the orientation of their body. Their brains may be smaller than the head of a pin, but ants are excellent navigators that use celestial and terrestrial cues to memorize their paths. To do so, they use several regions of the brain simultaneously, proving once again that the brain of insects is more complex than thought. The researchers' findings were published in Current Biology on January 19, 2017.

Until now, ethological research suggested that ants memorized the scenery perceived along their route as it is projected on their multifaceted retinas -- thus using a body-centered, or egocentric, frame of reference. By this hypothesis, to recognize memorized surroundings and follow a path formerly traveled, ants would need to orient their bodies in the same way each time. But they sometimes need to walk backwards as well, and this doesn't prevent them from finding their way back to their nest. Could it be that ants can recognize a route when facing the opposite direction? Are they able to create a visual model of their environment that is independent of their body orientation?

To answer these questions, the researchers studied Cataglyphis velox, an Andalusian desert ant known for its solo navigation ability. First they let the insects familiarize themselves with a route that included a 90° turn. After a day of training, ants that received a cookie crumb light enough to carry while walking forward handled the turn without the slightest difficulty. However, those given large cookie crumbs had to move backward, and unlike the others, they maintained their bearing instead of turning.

They also exhibited unexpected behavior: After walking backward a bit, they would occasionally drop their crumb, turn around, observe the scenery while pointing their bodies in the right direction, return to the crumb, and resume towing it backward -- but this time in the correct direction. For these ants, body alignment thus seems necessary for recognition of scenery perceived by their retinas, but they are then able to memorize the new bearing and follow it backward. This behavior also shows that they can recall the existence of the dropped cookie crumb, and its location, in order to return to it after updating their bearing. These observations imply that at least 3 kinds of memory are working in unison: the visual memory of the route, the memory of the new direction to follow, and the memory of the crumb to retrieve.

Through another experiment using a mirror to reflect the sun1, the team demonstrated that the ants used celestial cues to maintain their bearing while walking backwards. Furthermore, ants were able to move in straight paths, whether walking forward, backward, or sideways. Once a bearing is memorized, they stay on it no matter how their bodies are oriented. Together these observations suggest that ants register direction using an external -- or allocentric -- frame of reference.

Read more at Science Daily

Study of round worm that returns to life after freezing

Antarctic nematode worms photographed under the microscope.
The first molecular study of an organism able to survive intracellular freezing (freezing within its cells) is published this week by British Antarctic Survey (BAS), in collaboration with researchers from the University of Otago, New Zealand. The paper represents a milestone in scientists' understanding of an extraordinary adaptation.

The tiny Antarctic nematode, more commonly known as a round worm, (Panagrolaimus sp. DAW1) was cultured from a coastal Antarctic penguin rookery at McMurdo Sound, and is the best-documented organism able to survive the disruptions brought about by total freezing. The nematode is also able to undergo a form of freeze avoidance by eliminating all of its water content, called cryoprotective dehydration. However, it is the ability to survive intracellular freezing which makes this organism really stand out.

Exploring gene expression patterns, the researchers were able to show how molecularly active the nematodes are while in a frozen state, highlighting certain key genes enabling them to endure such an extreme physical state.

This is the first study of its kind, shedding light on a possibly rare adaptation, which could lead to new applications.

From Science Daily

Astronomers Prepare to Search for Alien Life at Nearby 'Habitable' Exoplanet

As we continue the hunt for habitable worlds beyond our solar system, we're finding more and more candidates closer to home. There's even a small rocky exoplanet within the so-called "habitable zone" at Proxima Centauri, the dinky red dwarf star right next door. But there's more, and astronomers are beginning to identify which of these strange new worlds we could soon get a good look at with the next generation of advanced telescopes on Earth and in space.

One tantalizing potentially habitable exoplanet orbits the star Wolf 1061, only 14 light-years away — a distance that is practically on our galactic doorstep. Known to host three exoplanets, the Wolf 1061 system is interesting as it could be a target for NASA's James Webb Space Telescope (JWST) that is scheduled to launch in 2018. Sitting at the sun-Earth L2 point — an island of gravitational calm nearly one million miles away in Earth's shadow — the infrared JWST could be used to detect atmospheric components in worlds that could, hypothetically, support life. Other exoplanet-hunting projects are being launched, such as the Transiting Exoplanet Survey Satellite (TESS), the CHaracterising ExOPlanet Satellite (CHEOPS), and the PLAnetary Transits and Oscillations of stars (PLATO) mission, that will greatly benefit from this advanced research to characterize the habitable potential of distant worlds.

Nestled in the habitable zones of stars, exoplanets (like the one in Wolf 1061) are thought to be neither too hot or too cold for liquid water to persist on their surfaces. On Earth, where there's liquid water, there's life, and if there's water on these worlds, there could be life there too. That's the basic logic, but there are many other factors at play that determine whether a planet can indeed support life. So if we can properly characterize exoplanetary atmospheres, we might, some day, be able to detect the chemicals that may reveal information about any "biomarkers" that may be present — chemicals that reveal the presence of biological processes. As Wolf 1061 hosts a small rocky exoplanet (called Wolf 1061c) within its habitable zone, it is one of the closest exoplanetary locations where we could uncover this biological evidence.

"The Wolf 1061 system is important because it is so close and that gives other opportunities to do follow-up studies to see if it does indeed have life," said Stephen Kane, an astronomer at San Francisco State University and lead author of new research to be published in the Astrophysical Journal.

Working with researchers at Tennessee State University and in Geneva, Switzerland, Kane's team took precise measurements of the Wolf 1061 system to calculate the extent of its habitable zone, stellar activity and planetary orbits. Interestingly, Wolf 1061c has a chaotic orbit that is heavily influenced by the gravity of the other planets in the system, causing it to lurch sometimes closer to the star and at other times further away. It also occupies the inside edge of the star's habitable zone, which poses a quandary for its true habitable potential.

Venus, for example, lies within the inside edge of the sun's habitable zone, yet Venus is anything but "habitable" — despite being approximately Earth-sized. The toxic and thick Venusian atmosphere is the consequence of a runaway greenhouse effect where too much energy has been trapped by the atmosphere, causing it to heat up to lead-boiling temperatures. Though it may have once been a more temperate world, any water that once existed on its surface has been broken down into its component hydrogen and oxygen atoms. The only regions of Venus that are remotely "Earth-like" are high up in Venus' atmosphere — leading to speculative ideas that floating lifeforms may be present, or that humans may one day inhabit Venus in "cloud cities" that float high above the crushing lower atmospheric pressures.

Read more at Discovery News

Jan 20, 2017

Too much sitting, too little exercise may accelerate biological aging

As a cell ages, its telomeres naturally shorten and fray, but health and lifestyle factors, such as obesity and smoking, may accelerate that process. Shortened telomeres are associated with cardiovascular disease, diabetes and major cancers.
Researchers at University of California San Diego School of Medicine report that elderly women who sit for more than 10 hours a day with low physical activity have cells that are biologically older by eight years compared to women who are less sedentary.

The study, publishing online January 18 in the American Journal of Epidemiology, found elderly women with less than 40 minutes of moderate-to-vigorous physical activity per day and who remain sedentary for more than 10 hours per day have shorter telomeres -- tiny caps found on the ends of DNA strands, like the plastic tips of shoelaces, that protect chromosomes from deterioration and progressively shorten with age.

As a cell ages, its telomeres naturally shorten and fray, but health and lifestyle factors, such as obesity and smoking, may accelerate that process. Shortened telomeres are associated with cardiovascular disease, diabetes and major cancers.

"Our study found cells age faster with a sedentary lifestyle. Chronological age doesn't always match biological age," said Aladdin Shadyab, PhD, lead author of the study with the Department of Family Medicine and Public Health at UC San Diego School of Medicine.

Shadyab and his research team believe they are the first to objectively measure how the combination of sedentary time and exercise can impact the aging biomarker.

Nearly 1,500 women, ages 64 to 95, participated in the study. The women are part of the larger Women's Health Initiative (WHI), a national, longitudinal study investigating the determinants of chronic diseases in postmenopausal women. The participants completed questionnaires and wore an accelerometer on their right hip for seven consecutive days during waking and sleeping hours to track their movements.

"We found that women who sat longer did not have shorter telomere length if they exercised for at least 30 minutes a day, the national recommended guideline," said Shadyab. "Discussions about the benefits of exercise should start when we are young, and physical activity should continue to be part of our daily lives as we get older, even at 80 years old."

Read more at Science Daily

The Brains of Women and Men Are More Alike Than You May Think

We all know the cliches: Men are from Mars, women are from Venus. Women are quicker to cry. Men don't show their emotions.

But research that looked at differences in the brain — specifically in the brain's emotion center — suggests that may all be bunk.

"That belief that there's a male-type brain and female-type brain is just not true," said Lise Eliot, an associate professor of neuroscience at the Chicago Medical School of Rosalind Franklin University of Medicine and Science. "It's not true for the amygdala. It is turning out to be not true for the hippocampus, for the corpus callosum, for left-right dominance. There's just not an attribute of the brain that reliably marks it as male or female."

Eliot, whose 2009 book "Pink Brain, Blue Brain" explained how gender stereotypes are reinforced on young brains, led recent research that analyzed 6,726 MRIs taken from 58 separate studies. Her team scrutinized the brain scans of men and women, and measured the volume of the amygdala in each subject. Previous research using animal models and MRIs had suggested that the amygdala may be larger in males than in females.

The amygdala (of which there are two in the brain) is known as the center for emotion, social behavior, aggression and sexual drive. If men's amygdalae are, in fact, larger, it could be evidence of one way that men and women are wired differently.

The researchers did find that amygdala volumes were in fact about 10 percent larger in male brains. But, Eliot says that corresponds to men's larger body size, including the 10-12 percent overall larger volume of men's brains.

"The difference in amygdala volume is just in proportion to their size difference — it's 10-12 percent larger, which makes sense because men are 10 to 12 percent larger than women," Eliot said. "But if you control for individual head size, there's no difference."

The Franklin University team's finding, which was published in the journal NeuroImage, is the latest in a series of studies that have looked for differences in male and female brains — and found none.

Eliot's team found in a 2015 study that there is no discernible difference in the size of men's and women's hippocampus. The hippocampus plays a key role in the consolidation of learning from short-term memory to long-term memory and in spatial navigation.

A 1997 study from the University of Alberta analyzed scans from 49 studies published since 1980 and found no significant sex difference in the size or shape of the brain's corpus callosum. This bundle of nerves is the part of the mind that allows communication between the two hemispheres of the brain.

Then there is the common belief that people are either "right-brained" or "left-brained," and that women tend to be more right-brained and associated with creativity rather than the calculating, analytical characteristics commonly linked with the left brain. That notion, too, has been challenged.

A 2014 University of Utah Health Sciences study asserted that there is no evidence within brain imaging that indicates some people are right-brained or left-brained.

"It's absolutely true that some brain functions occur in one or the other side of the brain. Language tends to be on the left, attention more on the right," Jeff Anderson, the study's lead author, said at the time. "But people don't tend to have a stronger left- or right-sided brain network. It seems to be determined more connection by connection."

One of the most comprehensive surveys looked at several areas of the brain and analyzed the volume of gray matter and white matter in the brains of more than 1,400 individuals. The researchers from Tel Aviv University in Israel concluded in the 2015 research that all of our brains seem to share a patchwork of forms that crossed gender lines.

Finally, one might wonder if hormones are at play in the brain, leading men and women to think differently.

Again, Eliot says, the research just doesn't show it.

"The studies that have tried to find effects of estrogen and testosterone on thinking skills or emotional skills have been very sketchy," she remarked. "About the only thing we know for sure is that testosterone increases sex drive in both sexes. Other than that, estrogen and testosterone, it's the same thing — they appear to have no effect on any cognitive skills."

Read more at Discovery News

Seals Use Their Whiskers to Detect the Breathing of Hidden Prey

The whiskers on a harbor seal are more than just a touch of added cuteness - they're hunting tools that help it detect the smallest perturbations of water made by its favorite food hiding on the seafloor.

That's what researchers from the University of Rostock (UR) found when they tested the animals for the ability, in research just published in the Journal of Experimental Biology.

The prey at the root of the experiment, flatfish, a favorite food of harbor seals, are camouflage experts that can hide in plain sight or burrow under the sand on the seafloor. Trouble is (for the fish), the seals find them anyway, even when the fish are sitting stock still.

Scientists were already aware that seals will track prey - even over long distances - by honing in on the currents fish make when they swim. But, according to the researchers, the new study answered a question that had bedeviled marine scientists: How do the seals find stationary, hiding fish?

For the study, the researchers used a special training tank, with a platform through which air currents – calibrated to simulate a flounder "breathing" - were pumped.

Then, trained seals from UR's marine science center were given eye masks and tested for their ability to locate the fake-flounder (in real life masters of hiding in plain sight) breathing. The seals did just that. With or without the blindfolds, the scientists found, they were able to locate the currents and move their snouts over the openings from which the currents were created – just as they would be able to locate the breathing of flounder camouflaged on the seafloor.

This seal has learned to wear an eye mask and headphones for behavioral studies.
When their whiskers were covered, though, as New Scientist noted, the seals weren't able to locate the currents.

It's all thanks to the whiskers. Study co-author Wolf Hanke has spent a fair amount of research time on them, discovering, in 2011 that seals can use them to "see" shapes echoed in water ripples, as Live Science reported.

Now, a new ability can be ascribed to them.

"Seals feel these water movements with their beard hair, even when the seal moves forward at velocities of one meter per second, and when further wind and wave currents are present," the scientists explained in a press release.

Read more at Discovery News

Massive Burial Ground Unearthed at Medieval Monastery in Sudan

Four cemeteries, from which at least 123 individuals have been excavated so far, have been unearthed near the remains of a medieval Christian monastery in Sudan. A few of the burials contained individuals buried in unusual ways.

The cemeteries and remains, which have been excavated over the past two years, are located at a monastery called al-Ghazali near the Nile River. The people who were buried there lived about 1,000 years ago, during a time when a series of Christian kingdoms flourished in the area, according to Robert Stark, a doctoral student at McMaster University in Hamilton, Ontario, who presented the findings this month in Toronto at the joint annual meeting of the Archaeological Institute of America and the Society for Classical Studies.

The discoveries include well-preserved burial shrouds that in a few instances still cover the skulls of the deceased, Stark said. The archaeologists also found tombstones with engravings of prayers that were written in Greek or Coptic (an Egyptian language that uses the Greek alphabet). In one cemetery, some people were buried in mysterious ways: For example, two individuals were found with post-mortem cut marks incised in their bones.

Stark is part of an archaeological expedition of the Polish Centre of Mediterranean Archaeology, at the University of Warsaw, which is excavating al-Ghazali.

Massive burial ground

An archaeologist named Peter Shinnie first excavated the cemeteries at al-Ghazali in the 1950s, Stark said. While Shinnie believed al-Ghazali held more than 1,000 burials, he uncovered just a few during the course of his fieldwork. The Polish Centre of Mediterranean Archaeology is the first organization to conduct large-scale excavations at al-Ghazali's cemeteries, he added.

An overhead view of cemetery two, which is located beside the Christian monastery, at al-Ghazali in Sudan.
One of the cemeteries consists almost entirely of adult males and was probably used by the monks from the monastery, Stark said. Two cemeteries contain a wider mix of individuals and appear to have been used by people who lived in nearby settlements. The fourth cemetery was discovered recently by archaeologists and contains only 15 burials — and some of those have features that are unusual.

In all four of the cemeteries the remains of stone structures were found on the surface, above the burials, Stark said, adding that some of these structures have the remains of tombstones.

The writing on the tombstones tended to follow a particular format. "To make it simple. The writing on tombstones can be divided into two parts," Artur Obluski, the director of the excavations at al-Ghazali, told Live Science in an email.

The first part consisted of prayers, which included "a prayer for the soul of the deceased, a prayer to the Providence of God, the God himself often described as merciful," Obluski said. These prayers ask "that the soul will be taken care of and can rest on the bosom of Abraham, Isaac and Jacob or in the world of the Living."

The second part of the tombstone engravings "contains some individual information of the deceased: his name, age at the time of death, sometimes titles he bore during his life time — so-called cursus honorum — and professions he performed," said Obluski.

Read more at Discovery News

Jan 19, 2017

Lost Dark Age Kingdom Uncovered in Scotland

Archaeologists may have finally found the lost kingdom of Rheged, the most elusive of all the sixth century kingdoms of Dark Age Britain.

The mysterious kingdom was pre-eminent in northern Britain in the sixth century, but faded into obscurity after it was deliberately destroyed in the beginning of the following century.

Historians had speculated that the kingdom was headquartered in Cumbria, a county in north west England, but no evidence of it was ever found. Then digs carried in 2012 at Trusty's Hill, which overlooks the Fleet valley in Galloway in south-west Scotland, revealed clues of the presence of a royal stronghold.

"Our excavation revealed all the hallmarks of an early medieval royal site," Ronan Toolis at GUARD Archaeology in Glasgow, told Seeker.

The discovery is detailed in a new book, "The Lost Dark Age Kingdom of Rheged," which is being released Saturday.

Toolis and co-author Christopher Bowles found that in the decades around 600 A.D. the summit of the hill was fortified with a timber-laced stone rampart. They also recovered remains of supplementary defenses and enclosures along the lower-lying slopes, revealing that Trusty's Hill was fortified.

"This is a type of fort that has been recognized in Scotland as a form of high status secular settlement of the early medieval period," Toolis said. "The evidence makes a compelling case for Galloway being the core of the kingdom of Rheged."

Anglo-saxon style bronze jewellery. Originally gilded and silvered and made of leaded brass, it was probably brought to the site as loot.
Little is known about Rheged. Fragments of early medieval historical records and medieval poetry indicate the kingdom was particularly powerful under the warrior king Urien, whose prowess was celebrated by his court-bard Taliesin.

Toolis and Bowles discovered that anyone approaching the summit of the hill passed through a symbolic entrance way defined by Pictish carvings on one side and a large rock-cut basin on the other. The Picts were a tribal group of people who lived in what is today eastern and northern Scotland during the Late Iron Age and Early Medieval periods.

"It was a rite of passage where early medieval kings were perhaps anointed and ceremonies performed," Toolis said.

He noted the entrance way bears a close resemblance to one found some 180 miles north at Dunadd hillfort, the royal center for the kings of Dalriada in what is now Argyll and Bute. There, an entrance way with Pictish carving and a rock-cut basin was also found.

The king's hall may have stood at the highest part of Trusty's Hill on the west side. On the slightly lower area on the eastern side, the archaeologists found a workshop that produced metalwork of gold, silver, bronze and iron.

The team also unearthed e-ware, a type of pottery imported from continental Europe, which indicates the royal household was part of a trade network that linked western Britain with Ireland and continental Europe.

Other activities at Rheged included the spinning of wool, preparation of leather and feasting.

A laser scan image of the carved Pictish symbols.
"The household's wealth relied on their control of farming, animal husbandry and the management of local natural resources — minerals and timber — from an estate probably spanning the wider landscape of the Fleet valley and estuary," Christopher Bowles, Scottish borders council archaeologist, said.

"Control was maintained by bonding the people of this land and the districts beyond to the royal household, by gifts, promises of protection and the bounties of raiding and warfare," he added.

Analysis of the Pictish stone carvings revealed the symbols cannot be deciphered.

"The literal meaning of the symbols at Trusty's Hill will probably never be known. There is no Pictish Rosetta Stone," Toolis said.

Read more at Discovery News

A Desert Antelope That Was Extinct in the Wild Is Making a Comeback

The scimitar-horned oryx, an animal once hunted to extinction in the wild, is continuing a return to its native North Africa, thanks to a reintroduction program now in its second release phase.

This week, a group of 23 of the antelopes will be released to a nature preserve in the African nation of Chad, New Scientist reports. It's the second such batch of re-introductees, with 25 oryx having been released successfully to the preserve in August 2016.

The scimitar-horned oryx was hunted nearly wiped out by hunters seeking its distinctive horns. Habitat loss and persistent drought conditions also contributed to its near demise.

However, the animal never completely disappeared, thanks to worldwide zoo breeding programs. The August 2016 group of oryx were delivered from Abu Dhabi to the Ouadi Rimé-Ouadi Achim Game Reserve in Chad, which is also the settling site for the new group of 23 animals.

When the first transplanted oryx arrived in Chad in 2016, it was the first time in three decades that the species had been in the country. The creatures were outfitted with GPS collars to keep an eye on their movements and allow scientists to get an idea how they were behaving, as they acclimated to their new home. Here's some Smithsonian footage of one of them being released:

The chances for the newly placed animals look good, as the first reintroduction appears to have been a success.

"So far, the animals look exceptionally healthy," Jared Stabach, of the Smithsonian's National Zoo and Conservation Biology Institute (SCBI), told New Scientist. "They seem to be adapting to the environment really well."

Ultimately, the idea is to establish within five years a population of about 500 scimitar-horned oryx that can hold their own in nature, according to the SCBI.

The initial groups are being watched by rangers, and wildlife specialists will also be working with local communities to help ward off the chance the animals will be hunted again. Things seem good on that score, so far, as well. "There's a lot of excitement in the local community about this animal being returned. They want to protect it," Stabach told New Scientist.

Read more at Discovery News

Cassini Gets Up Close and Personal With Saturn's 'Wavemaker' Moon Daphnis

Cassini's daring ring-skimming orbits of Saturn are already paying off, producing some beautiful and awe-inspiring views that have, until now, been too far away to see. But now, as this almost surreal observation of Saturn's tiny moon Daphnis shows, we're finally getting a really good look at the small-scale processes that are at work in Saturn's rings.

Orbiting the Saturnian system since 2004, NASA's Cassini mission has enriched us incredible views of the seemingly flat ring plane. Beyond the robotic probe's camera resolution, however, are the ripples and waves that are inevitably caused by the gravities of small moons embedded in the many ring gaps. In one 26-mile-wide gap, called the Keeler Gap, a 5-mile-wide moon roams and it has a pretty dramatic effect on the tiny particles at the gap's borders.

The oblique viewing angle is a little misleading; we're not looking directly down on the ring plane, we're actually looking at the moon from the side. The waves in the foreground are therefore rippling up and down as the moon goes about its orbit. The ring gap also looks more narrow than its 26-mile width, an optical effect known as foreshortening. Cassini was 17,000 miles from the moon when this image was captured on Jan. 16.

Previously, in 2009, Cassini was able to spot these waves in Saturn's rings, albeit from afar, when the ringed gas giant was passing through its equinox. At this time, the ring plane was parallel to the direction of sunlight, allowing any vertical structures in the rings to cast a long shadow:

Cassini's view of Daphnis and the waves it creates in 2009 when the spacecraft was 414,000 miles from the moon
Viewing Daphnis so close means that previously unseen details pop into view. Of particular note is the narrow ridge that seems to run around the moon's equator and the smooth layer that covers its surface — traits shared by other ring moons Atlas and Pan. These features are likely a build-up of ring particles that have collided with the moon and accumulated during its orbits. Also, small craters are evident, proving that even the smallest of moons are not immune from impacts.

Read more at Discovery News

Iceman Ötzi's Last Meal Was 'Stone Age Bacon'

Ötzi the famous "iceman" mummy of the Alps appears to have enjoyed a fine slice or two of Stone Age bacon before he was killed by an arrow some 5,300 years ago.

His last meal was most likely dried goat meat, according to scientists who recently managed to dissect the contents of Ötzi's stomach.

"We've analysed the meat's nanostructure and it looks like he ate very fatty, dried meat, most likely bacon," German mummy expert Albert Zink said at a talk in Vienna late Wednesday.

More specifically, the tasty snack is thought to have come from a wild goat in South Tyrol, the northern Italian region where Ötzi roamed around and where his remains were found in September 1991.

Mummified in ice, he was discovered by two German hikers in the Ötzal Alps, 3,210 meters (10,500 feet) above sea level.

Scientists have used hi-tech, non-invasive diagnostics and genomic sequencing to penetrate his mysterious past.

These efforts have determined Ötzi died around the age of 45, was about 1.60 meters (five foot, three inches) tall and weighed 50 kilos (110 pounds).

He suffered a violent death, with an arrow severing a major blood vessel between the rib cage and the left shoulder blade, as well as a laceration on the hand.

As part of their latest discoveries, Zink's team also found that Ötzi had an ulcer-inducing bacteria and may have suffered from stomach aches.

But for all his parasites, worn ligaments and bad teeth, he was in "pretty good shape," Zink wrote in the journal Science earlier this month.

From Discovery News

Extreme Astronomy Unlocks Cosmic Secrets From the South Pole

Imagine doing astronomy where grease won't stay greasy, where it's nighttime all day during the winter, and where nighttime temperatures fall to -100 Fahrenheit. Well, there's a hardy group of astronomers that enthusiastically do that, year-in, year-out, at Antarctica's South Pole Telescope.

The South Pole is a harsh environment, but it's excellent for astronomy due to its dry atmosphere (water vapor interferes with observations). Researchers at the Harvard Smithsonian Center for Astrophysics are even considering building a telescope at a site called Dome A, about 1,000 miles from the pole and a long trek from habitation.

What is it really like to work down there for up to a year, which is the typical over-winter stay of Antarctic personnel? According to University of Toronto experimental cosmologist Keith Vanderlinde, who spent 11 months there over the winter, it attracts a certain type of person who doesn't necessarily need the company of other people to work well. His group vacillated between being super-social in shared quarters, and choosing to retreat individually to their own quarters. He also saw people "going toasty" (this Antarctic slang for changed behavior comes from bread turning into toast) as they grappled with months of isolation away from families.

"People who didn't work outside at all, they got toasty very quickly. You develop a short fuse," Vanderlinde told Seeker. "People develop a 1,000-mile stare and stare at the wall for an hour and not do anything."

Vanderlinde came to the National Science Foundation-funded South Pole Telescope in 2008 after his Ph.D., when the facility was just in its second year of operations. It was a half-hour trek from the living quarters to the telescope, where Vanderlinde and a colleague checked in to make sure the telescope was staying healthy. Overall the work went well, except for occasional mechanical issues. He recalled, for example, one time when the power went out on a Sunday night, which required a long warm-up procedure that Monday to get the telescope up and running again.

The South Pole Telescope during Antarctic night
The conditions are harsh, but Vanderlinde says the science is worth it. The telescope is mapping out the cosmic microwave background (CMB), which is the leftover energy from when the universe was first expanding. It can best be seen in microwave wavelengths. As the CMB shines through galaxy clusters, Vanderlinde says, some light scatters off hot electrons and can show up as an excess of energy.

"By looking at these little shadows, you can figure out where all of the largest structures in the universe are," he said. Over time and with observations from the South Pole Telescope's first camera, he said, scientists can also learn how galaxy clusters grew in different eras of the universe, and how dark energy — the ill-understood force that is causing the universe's expansion to accelerate — works.

The second-generation camera on the South Pole Telescope measures the intensity of the light and polarization, or how light is oriented related to the direction where it came from. As the CMB is lensed through galaxies and other structures, scientists can measure how large clumps of matter form over time, which in turn tells them how gravity works. Oddly, he said, tiny particles called neutrinos significantly impact how structure forms in the universe, and how gravity pulls gas and dust together into clusters and galaxies. So by looking at the big scale, scientists can better constrain how massive neutrinos are.

Read more at Discovery News

Jan 18, 2017

Lazy Ants Make Colonies More Productive

Ants, at a glance, have an understandable reputation for industry. But it turns out they're not all obsessed with work: Some ants are lazier than others, a new study finds, and that's actually a good thing for the colony.

Researchers from the Missouri University of Science and Technology studied ants in motion and at rest. At issue was a question of energy expenditure in a colony. Scientists knew that larger ant colonies expended less energy than smaller ones, per capita, but they did not know why. Until now.

"In this work, we found that this is because in large colonies, there are relatively more 'lazy workers,' who don't move around, and therefore don't consume energy," explained the study's lead researcher, Chen Hou, in a statement.

As ant group sizes grew, so, in a regular pattern, did the number of inactive members, the scientists found. In groups of 30 ants, 60 percent of ants were not moving around, while in 300-ant groups 80 percent of the critters were doing their best to do nothing.

What's more, the 300-ant group used only half the energy, per capita, of that expended by the 30-ant group.

By not consuming energy, the researchers said, the layabout ants saved resources for the colony overall, which made it a more productive foraging unit.

Efficient, coordinated foraging activity seems to be how the ants can be more productive gathering resources while expending less energy to do so.

"Maximizing resource acquisition would require most individuals to be highly active, but would also result in high energy expenditure and long average foraging time," Hou explained. "In contrast, minimizing time and energy expenditure would require most individuals to be inactive, but would also result in low resource acquisition. Thus, we postulate that ant colonies balance these two optimization rules by the coordination of the forager's interaction," said Hou.

The researchers used an automated vision analysis computer program and algorithm to track ant motion over long periods of time – on the order of two hours at a stretch. Previous studies, they said, only analyzed ant motion in one-minute intervals and thus may have missed out on true depictions of ant behavior and energy use.

When the scientists studied the ant motion videos, they found some interesting nuggets about the insects. For one thing, they move at highly variable speeds – from 0.2 centimeters per second to 1.4 centimeters per second. For another, they got a clearer picture of individual ants' energy expenditure when working vs. resting.

"We found that walking ants consume five times more energy than resting ants," said Hou. "This means that, energy-wise, one walking ant is equivalent to five resting ants. Thus, if a group has 20 percent active members, this group would consume 180 percent more energy than a similar sized group with all inactive members."

Read more at Discovery News

The Mystery of African Desert 'Fairy Circles' Might Have Just Been Solved

If you fly over the Namibian desert, on the west coast of southern Africa, you will see one of nature's great mysteries. Vast expanses of the landscape are pocked with circles of bare patches of earth. These strange patterns — two to 35 meters wide — stretch for miles and, until now, no one was sure why.

On Wednesday, a team of scientists from universities around the globe with expertise that ranges from plant biology to termite physiology and behavior to data gathering and analysis and modeling — brought together by a National Science Foundation grant — published a theory in Nature that finally explains, and can predict mathematically, this mystery.

This study may also offer insights into familiar phenomena worldwide. Organized vegetation patterns are widespread in nature. But, even after debunking theories involving aliens and fairies, scientists have long disputed what causes them. Some believe they are created by plants engaged in a feedback loop caused by competition for limited resources. Others suggest that the patterns are caused by the subterranean activities of termites, ants or rodents. Neither explanation completely answers why the patters are geometric and worldwide.

But according to the research of this multidisciplinary team, the answer is a bit of both: The plants and animals engaged are in an ecosystem dance — expansion, competition, die off, rebirth — that results in a repeating pattern of death and renewal.

"We developed a general framework that can be used to understand many of the regular vegetation patterns around the globe as the result of the interaction between fauna and vegetation," explains Juan Bonachela, an assistant professor at the University of Strathclyde. "You can adapt our framework to the specifics of other patterns by changing details about the territorial animal and vegetation that are interacting and the environmental conditions."

Previously neither the plant nor animal scientists could reliably predict these patterns.

"But by applying a multidisciplinary approach to the problem — combining ground and satellite data, computational models, and statistical analyses," Bonachela said, "we found that only by including the dynamics of both termites and vegetation and their interaction can we replicate all the main properties reported for Fairy Circles, including the fact that they are born and die, their timing, and the properties of the vegetation between fairy circles."

This settles a debate that has raged among scientists for many years.

"Each side tried to explain the phenomenon according to what, for them, were the most reasonable scientific arguments," says Bonachela. Neither was wrong — or completely right. "The fact that their arguments are to some extent included in our comprehensive explanation tells you that the mechanisms they identified indeed are important for the emergence of fairy circles. But those mechanisms are not mutually exclusive, and considering the dynamics of their interaction at multiple scales provides the most complete description of the ecosystem."

Read more at Discovery News

The Survival of Primates Is in Doubt

A future without primates outside of humans seems unthinkable, but an extensive review of ape, monkey, tarsier, lemur and loris populations finds that 60 percent of all primates are now threatened with extinction, and about 75 percent are declining in numbers.

The review, the most comprehensive of its kind to date and published in Science Advances, paints a dire future for our closest biological relatives. Their only hope hangs on global conservation becoming an immediate priority, the international team of authors says.

"It is possible that some primates will go extinct in our lifetimes if we don't increase our efforts dramatically," Russell Mittermeier, a primatologist who is the president of Conservation International, told Seeker from a Madagascar airport.

Madagascar is one of just four countries—with Brazil, Indonesia and the Democratic Republic of Congo being the other three—that host two-thirds of all species of primates. Mittermeier, who is also the chair of the IUCN/SSC Primate Specialist Group, explained that "primates are largely tropical rainforest animals," and these countries have such habitat, although these once-lush landscapes are shrinking across the planet.

A species of monkey might have already gone extinct during your lifetime: Miss Waldron's red colobus monkey. It was reportedly last seen in 1978.

Paul Garber, who co-led the new study with Alejandro Estrada, said, "Several species of lemurs, monkeys and apes—such as the ring-tailed lemur, Udzunga red colobus monkey, Yunnan snub-nosed monkey, white-headed langur and Grauer's gorilla—are down to a population of a few thousand individuals."

Garber added, "In the case of the Hainan gibbon, a species of ape in China, there are fewer than 30 animals left."

Forest converted to soy fields in Brazil.
Contrast those low numbers with the current estimated population of humans on the planet, around 7.4 billion. Our actions are behind all of the factors that currently threaten primate populations. The IUCN has found that agriculture, logging and wood harvesting, livestock farming and ranching, as well as direct loss due to hunting and trapping pose the primary threats. Still other threats include habitat loss due to road and rail construction, oil and gas drilling and mining, pollution and climate change.

Reducing the impact of such threats would require addressing issues concerning local poverty and population growth, Garber said.

"Building economies based on the preservation of forests and their primate inhabitants, and broadening educational opportunities for women would begin to address some of the greatest threats to these animals."

Those proposed solutions, however, will need substantial time to implement, and primates are running out of time. Given their low populations, most are "in the eleventh hour," Garber said.

Mittermeier agrees that the drivers of primate destruction clearly must be addressed, "but if that is all we do, the primates will be gone before we have the impact desired."

He continued, "We need very specific targeted approaches to primate conservation, focusing on the highest priority regions, ensuring that protected areas work where they already exist and creating new ones where they don't, and carrying out targeted efforts for the most endangered."

Yunnan snub-nosed monkey (Rhinopithecus bieti) in China.
He and his colleagues point out that non-human primates offer critical insights into our own evolution, biology and behavior. They are key to rainforest ecosystems, with their decline impacting other animal populations as well as plants. In the wild, they also benefit local economies, given the growth of ecotourism in recent years. Mittermeier is even hoping that "primate-watching" will become as, or more, popular than bird-watching, "to get more people out into the forest and to get more excited about helping to conserve."

Madagascar, with its 111 species and subspecies of primates—94 percent of which are endangered—offers particularly rewarding ecotourism opportunities. Mittermeier explained that the country has been isolated from the rest of the world for at least 90 million years, so primates evolved there to fill many different ecological niches.

Read more at Discovery News

Earth Sets Heat Record in 2016 for Third Year in a Row

Earth in 2016 was the hottest year it's been in 137 years of record keeping. And it was the third year in a row to take the number one slot, a mark of how much the world has warmed over the last century because of human activities, U.S. government scientists announced Wednesday.

Last year is a "data point at the end of many data points that indicates" long-term warming, Deke Arndt, chief of the monitoring branch of the National Centers for Environmental Information, said.

While the record was expected, the joint announcement by NASA and the National Oceanic and Atmospheric Administration came in the midst of Senate confirmation hearings for President-elect Trump's cabinet nominees, several of whom have expressed doubts about established climate science, as has Trump himself.

Many climate scientists, policy experts and environmentalists are concerned about the potential for the incoming administration to limit funding for climate science and roll back both national and international progress toward limiting the greenhouse gases that are warming the planet.

According to NOAA data, the global average temperature for 2016 was 1.69°F (0.94°C) above the 20th century average and 0.07°F (0.04°C) above the previous record set last year.

In NASA's records, 2016 was 1.8°F (0.99°C) above the 1951-1980 average.

Each agency has slightly different methods of processing the data and different baseline periods they use for comparison, as do other groups around the world that monitor global temperatures, leading to slightly different year-to-year numbers.

But despite these differences, all of these records "are capturing the same long-term signal. It's a pretty unmistakable signal," Arndt said. Or as he likes to put it: "They're singing the same song, even if they're hitting different notes along the way."

Several spots around the globe had record heat for 2016, including Alaska and a swath of the eastern U.S. The contiguous U.S. had its second hottest year on record, according to NOAA, but with the remarkable warmth experienced by Alaska factored in, 2016 would be the hottest for the country as a whole.

The first eight months of the year were all record hot globally; in NOAA's data, they were part of an unprecedented streak of 16 record hot months in a row.

Of the 17 hottest years on record, 16 have occurred in the 21st century (the exception being the strong El Niño year of 1998).

While El Niño played a role in bumping up global temperatures during 2015 and 2016, the bulk of the warmth was due to the excess heat trapped by greenhouse gases emitted by humans over the past century, particularly carbon dioxide.

In 2016, CO2 concentrations also permanently passed the 400 parts per million mark for the first time in human history; during preindustrial times, that concentration was 280 ppm.

As example of how greenhouse gases have affected global temperatures, 2016 was almost 0.5°F (0.9°C) warmer than 1998, both years that experienced comparably strong El Niños. Even 2014, before the most recent El Niño emerged, was warmer than 1998.

Nearly 120 nations, including the U.S., have ratified the 2015 Paris climate agreement and committed to keeping the worst impacts of warming from materializing by reducing greenhouse gas emissions. The agreement cites a goal of keeping global temperature rise "well below" 2°C (3.6°F) above preindustrial levels by the end of this century, with a limit of 1.5°C as a more aggressive goal.

To show how close the world already is to surpassing those limits, Climate Central has been reanalyzing the global temperature data by averaging the NASA and NOAA numbers and comparing them to a baseline closer to preindustrial times. That analysis shows that 2016 was 1.2°C (2.16°F) above the average from 1881-1910.

"We have clearly passed 1 degree above preindustrial temperatures," and likely won't go below it without a major volcanic eruption (which tends to cool global temperatures), Gavin Schmidt, director of NASA's Goddard Institute for Space Studies, said.

Read more at Discovery News

Merging Galaxies Have a Violent Black Hole Particle Accelerator at Their Core

Astronomers have discovered an immense surge of energy coming from a cosmic particle accelerator located about 2 billion light years from Earth. It's powered by interactions between a supermassive black hole and the colliding galaxy clusters Abell 3411 and Abell 3412.

Using several telescopes, researchers have traced extremely energetic particles back to a giant black hole shooting out matter, and this material is then caught up in the galaxy merger, flinging the particles away with even more power. The research team compared the process to launching a rocket into low-Earth orbit and then sending that rocket out of the solar system with another rocket blast.

"We have seen each of these spectacular phenomena separately in many places," study leader Reinout van Weeren, a fellow at the Harvard-Smithsonian Center for Astrophysics (CfA), said in a statement. "This is the first time, however, that we['ve] seen them clearly linked together in the same system."

Researchers now know that a supermassive black hole in one of the galaxy clusters created a magnetic funnel, which generates powerful electromagnetic fields. The fields then accelerate the gas away from the black hole into a jet.

Inside the jet, the particles are pushed again when they hit shock waves coming from gas-cloud collisions within the two merging galaxy clusters. The "doubly accelerated" particles shine in radio wavelengths, which have been long observed (but not understood) in Abell 3411 and Abell 3412.

"These particles are among the most energetic particles observed in the universe, thanks to the double injection of energy," co-author Felipe Andrade-Santos, a postdoctoral research fellow at CfA, said in the same statement. The research team said that more examples of these particles should be found in future deep-space studies, using radio and X-ray wavelengths.

The results were presented at the American Astronomical Society meeting in Grapevine, Texas, Thursday (Jan. 5) and will be published in the inaugural issue of the journal Nature Astronomy. Observations were performed using the orbiting Chandra X-ray Telescope, the Giant Metrewave Radio Telescope (GMRT) in India, the National Science Foundation's Karl G. Jansky Very Large Array in New Mexico and several other telescopes.

From Discovery News

Jan 17, 2017

Neanderthal's Eye for Bling Revealed by Unique Rock Stashed in Cave

Around 130,000 years ago, a Neanderthal in what is now Croatia eyed a pretty striped chunk of limestone and picked it up. He (or she) then carried it to a favorite cave for just one reason, according to researchers who just discovered the rock: the Neanderthal thought it looked really cool.

The discovery, reported in the journal Comptes Rendus Palevol, provides some of the earliest known evidence that early humans collected rocks. It also adds to the growing body of evidence that Neanderthals appreciated beauty and had a sense of curiosity as well as symbolic-like capacities normally associated with modern humans.

"Neanderthals are generally considered to be dull-witted and savage, compared to modern Homo sapiens," co-author David Frayer told Seeker. "As more and more evidence is being accumulated, their sophistication is being better appreciated. Our work on this rock is just another little piece of evidence that they were not the clods many assume they were."

Frayer, a professor emeritus of anthropology from the University of Kansas, lead author Davorka Radovčić of the Croatian Natural History Museum in Zagreb and their team analyzed the rock, which was found at a site called Krapina. The object is roughly five inches long, four inches high and about a half-inch thick. Made of brown limestone, the rock features natural dark striations and a reddish hue on its corners. When wet, the stripes and redness become even more pronounced.

Both sides of a limestone rock collected by a Neanderthal 130,000 years ago. The arrows point to an area where the striation-causing inclusions are especially large.
Frayer says that if he or his colleagues had come upon the rock as the Neanderthal did, "we would have likely taken it home with us. It is unique in the collection of 1000-plus tools in its brown color and the black inclusions … It was never flaked and was not used as a tool. We think it was collected as a curiosity, just as someone might pick up a piece of petrified wood in the California desert."

The scientists think that the rock was either picked up just over a mile north of Krapina, where there are known outcroppings of this type of stone, or the Kraponica stream could have transported it closer to the cave site.

Social animals aside from humans are also known to collect interesting objects just because they like the look of them. Male bowerbirds, for example, collect pretty stones and other natural bling to attract females. Crows and ravens have been observed grabbing unique stones and staring at them for lengthy periods, but the jury is still out on what they are actually doing with the rocks.

Neanderthals weren't only interested in rocks, either. Prior research found that these early humans from Europe and Asia also collected interesting-looking teeth, shells and bird feathers, which they modified to wear as jewelry.

Read more at Discovery News

In a First, Shark Switches from Sexual to Asexual Reproduction

A zebra shark named Leonie has done something never before documented in a shark species: After having produced pups the old-fashioned way, she switched to asexual reproduction, hatching eggs without the help of a mate.

Scientists with Australia's University of Queensland (UQ) observed the change at the Reef HQ Aquarium and have documented it in a new study in the journal Scientific Reports.

While other sharks have reproduced without a mate, in a process called parthenogenesis, in which embryos develop without fertilization, the researchers there say Leonie is the first shark documented to have once produced offspring via mating and then jumped to doing so without a mate.

Up until 2013, Leonie had been documented breeding pups successfully with a mate. However, the duo had to be separated to solve space issues during a slow-down of the breeding program at the aquarium, CNN reported.

Leonie had no intervening males in her life, during the next three mating seasons, but in summer 2016 the news came that she had hatched three eggs anyway.

Now, genetic analysis of the 2016 hatching has ruled out other factors and confirmed that Leonie indeed had a parthenogenic birth, making her "switch" from sexual to asexual reproduction a shark first.

"We thought she could be storing sperm, but when we tested the pups and the possible parent sharks using DNA fingerprinting we found they only had cells from Leonie," explained the study's lead researcher Christine Dudgeon, in a statement.

So-called "virgin births" are not new to sharks. "It's much like a chicken: They lay eggs whether they are fertilized or not, if the conditions are good," Dudgeon told CNN. They happen in other animals too, such as snakes, insects, lizards, and other types of fish.

Dudgeon and her colleagues think Leonie simply adapted to her circumstances, once she'd lost her mate.

Next, the UQ scientists plan to study Leonie's pups - all female, as the shark could only pass on her own genetic information - to see if they will be able to reproduce with a partner.

"You lose genetic diversity with generations of asexual reproduction, so we'll be seeing if these offspring can mate sexually themselves," added Dudgeon.

Read more at Discovery News

Pendant Found at Nazi Death Camp Possibly Linked to Anne Frank

Archaeologists excavating one of the most infamous Nazi death camps have uncovered a mysterious connection to Anne Frank in the shape of a unique pendant.

Found in Sobibór, one of the main Nazi extermination camps in German-occupied Poland, the triangular pendant appears to be identical to one known to have belonged to the Holocaust diarist.

It bears the Hebrew words "Mazel Tov" (Congratulations), the date 3.7.1929 and the word Frankfurt on one side. On the reverse side, it features the Hebrew letter hei, used to symbolize God's name, as well as three Stars of David.

"The only difference is that this pendant features a date of birth different to that of Anne Frank, who was born on June 12, 1929," Yoram Haimi, an archaeologist at the Israel Antiquities Authority (IAA), said.

Separated by just three weeks, both the owner of the pendant and Frank were born in Frankfurt.

After searching a database of Holocaust victims, researchers at Yad Vashem, the World Holocaust Remembrance Center, came to the conclusion that the necklace belonged to a girl by the name of Karoline Cohn. Indeed, the girl was the only recorded individual born on July 3, 1929, in Frankfurt.

"She was on board a transport that departed in November 1941 from Frankfurt am Main to Minsk ghetto, " Joel Zissenwein, director of the deportations database project at Yad Vashem, said.

Historians have found no other pendants like those owned by Karoline and Anne, who was murdered in early 1945 at the Bergen-Belsen concentration in Germany, when she was 15 years old.

They believe the girls are likely related and are now looking for relatives who may be able to shed light on any possible connection.

It is not known if Cohn survived the harsh conditions in the Minsk ghetto, however her pendant reached Sobibór sometime between November 1941 and September 1943, when the ghetto was liquidated and the 2,000 Jewish prisoners interned there were deported to the death camp in eastern Poland.

Haimi, along with Polish archaeologist Wojciech Mazurek and Dutch colleague Ivar Schute, found the pendant and other personal items, such as a woman's watch and a metal prayer charm, in the remains of a building where prisoners spent the last minutes of their lives.

It was there that "victims undressed and their heads shaved before being sent into the gas chambers," IAA said in a statement.

The building was located on the "Pathway to Heaven," the path on which a naked mass of people was forced to walk before entering the gas chambers.

Researchers believe the pendant belonging to the teenager Karoline Cohn slipped through floorboards and remained buried in the ground for over 70 years.

Sobibór was built in 1942 for the sole purpose of efficiently murdering Jews from German-occupied eastern Poland and occupied parts of the Soviet Union.

Non-Jewish prisoners of war as well as Jews from Czechoslovakia, Austria, Holland, Belgium and France were also put to death there.

The victims, overall an estimated 250,000 people, died within hours of arriving there.

The gas chambers were linked up to the exhaust systems of large diesel engines which produced carbon monoxide. It often took up to 30 minutes to die.

Some prisoners were spared immediate death and were retained to do labor, including helping in the gas chamber operations, as well as burying and cremating thousands of corpses.

The death camp was evacuated and destroyed on the orders of the SS chief Heinrich Himmler in October 1943, after an uprising by inmates.

Read more at Discovery News

A Giant Gravity Wave Has Been Found in Venus' Clouds

Venus is wrapped in thick clouds of sulfuric acid that swirl around the planet at 225 mph, but not everything in the atmosphere is moving.

On Dec. 7, 2015, during its very first orbit around Venus, Japan's Akatsuki spacecraft discovered a mammoth, bow-shaped structure in the upper atmosphere that remained oddly fixed over a mountainous region known as the western highlands of Aphrodite.

The structure, which stretched for 6,200 miles across the sky, remained fixed in place until Dec. 11. Five days later, when Akatsuki's longwave infrared camera was next available to make observations, the bright region was gone.

"We believe it is generated by a gravity wave," physicist Makoto Taguchi, with Rikkyo University in Tokyo, wrote in an email to Seeker. "We examined every possibility, such as a thermal tide or an instrumental error, but all of them except for a gravity wave were excluded."

Like on Earth, gravity waves on Venus could be triggered by disturbances in stable layers of the atmosphere, such as the flow of wind over a mountain range. The effect is similar to ripples that are caused by dropping a stone into a pool of water.

Gravity waves are not to be confused with the recently detected cosmological phenomenon known as gravitational waves, which are caused by the bending of space and time due to extremely massive objects, such as colliding black holes.

Taguchi and colleagues, writing in this week's Nature Geoscience, said they believe Venus' mountains caused a gravity wave to form in the lower atmosphere. The bow-shaped structure, which was hotter than surrounding atmosphere, then rose up to an altitude of about 40 miles.

Computer models show a gravity wave on Venus could propagate to such an enormous size and altitude, but more work is needed to understand the planet's near-surface conditions, the scientists said.

"We suggest that winds in the deep atmosphere may be spatially or temporally more variable than previously thought," the paper said.

Additional observations with Akatsuki, which is expected to remain operational until mid-2018, are underway.

From Discovery News

Eugene Cernan, Last Man to Walk on the Moon, Has Died at 82

US astronaut Eugene Cernan, the last man to set foot on the moon, died Monday at age 82, NASA and his family announced.

Cernan was the spacecraft commander of Apollo 17 — his third space flight and the last scheduled US manned mission to the moon — in December 1972.

"We are saddened by the loss of retired NASA astronaut Gene Cernan, the last man to walk on the moon," the US space agency said on Twitter.

According to a family statement released by NASA, Cernan, a retired naval officer, died following ongoing health issues.

"It is with very deep sadness that we share the loss of our beloved husband and father," the family said.

"Our family is heartbroken, of course, and we truly appreciate everyone's thoughts and prayers. Gene, as he was known by so many, was a loving husband, father, grandfather, brother and friend," the statement added.

"Even at the age of 82, Gene was passionate about sharing his desire to see the continued human exploration of space and encouraged our nation's leaders and young people to not let him remain the last man to walk on the moon."

'Ad Astra'

The space community quickly took to Twitter to pay tribute to Cernan and honor his legacy.

"Saddened by the loss of pioneer, fellow naval aviator, astronaut and friend Gene Cernan #RIP #lastmanonthemoon," said retired American astronaut Scott Kelly.

"Ad Astra, Gene," tweeted NASA's Kennedy Space Center, using a Latin phrase meaning "to the stars."

"We mourn the loss of our friend Gene Cernan, the Last Man on the Moon and a hero for the ages," said the Smithsonian National Air and Space Museum. "Godspeed the Commander of Apollo 17."

On what would be the last manned mission to the lunar surface, Cernan's second to the moon, the crew captured the iconic image of a full view of the planet Earth dubbed "Blue Marble."

"Everything's three dimension when you look back at the Earth in all its splendor, in all its glory, multicolors of the blues of the oceans and whites of the snow and the clouds," the astronaut said of his final mission, in a 2007 interview with NASA.

The footprints Cernan left on the moon's surface remain visible more than four decades later.

"I'd just like to record that America's challenge of today has forged man's destiny of tomorrow," he said as he left the moon for the final time.

'Bold ambitions'

Born in Chicago in 1934, Cernan received a degree in electrical engineering from Indiana's Purdue University in 1956.

He went on to earn a master's degree in aeronautical engineering from the US Naval Postgraduate School in California.

Cernan was one of a class of 14 astronauts chosen to join NASA in 1963, and went on to serve on both Gemini and Apollo missions.

He has spent 566 hours and 15 minutes in space — logging more than 73 hours on the moon's surface.

Cernan retired from the Navy and NASA in 1976. He later entered the private business sector and provided television commentary during early space shuttle flights.

"The Last Man on the Moon" — a documentary about his life — was released in 2016.

Read more at Discovery News

Jan 16, 2017

Seeing the quantum future, literally

Trapped Ytterbium ions were used as one of the most advanced laboratory quantum systems for this study. Professor Biercuk's research laboratories are now located in the Sydney Nanoscience Hub, after six years as a visiting scientist at the National Measurement Institute.
Scientists at the University of Sydney have demonstrated the ability to "see" the future of quantum systems, and used that knowledge to preempt their demise, in a major achievement that could help bring the strange and powerful world of quantum technology closer to reality.

The applications of quantum-enabled technologies are compelling and already demonstrating significant impacts -- especially in the realm of sensing and metrology. And the potential to build exceptionally powerful quantum computers using quantum bits, or qubits, is driving investment from the world's largest companies.

However a significant obstacle to building reliable quantum technologies has been the randomisation of quantum systems by their environments, or decoherence, which effectively destroys the useful quantum character.

The physicists have taken a technical quantum leap in addressing this, using techniques from big data to predict how quantum systems will change and then preventing the system's breakdown from occurring.

The research is published today in Nature Communications.

"Much the way the individual components in mobile phones will eventually fail, so too do quantum systems," said the paper's senior author Professor Michael J. Biercuk.

"But in quantum technology the lifetime is generally measured in fractions of a second, rather than years."

Professor Biercuk, from the University of Sydney's School of Physics and a chief investigator at the Australian Research Council's Centre for Engineered Quantum Systems, said his group had demonstrated it was possible to suppress decoherence in a preventive manner. The key was to develop a technique to predict how the system would disintegrate.

Professor Biercuk highlighted the challenges of making predictions in a quantum world: "Humans routinely employ predictive techniques in our daily experience; for instance, when we play tennis we predict where the ball will end up based on observations of the airborne ball," he said.

"This works because the rules that govern how the ball will move, like gravity, are regular and known. But what if the rules changed randomly while the ball was on its way to you? In that case it's next to impossible to predict the future behavior of that ball.

"And yet this situation is exactly what we had to deal with because the disintegration of quantum systems is random. Moreover, in the quantum realm observation erases quantumness, so our team needed to be able to guess how and when the system would randomly break.

"We effectively needed to swing at the randomly moving tennis ball while blindfolded."

The team turned to machine learning for help in keeping their quantum systems -- qubits realised in trapped atoms -- from breaking.

What might look like random behavior actually contained enough information for a computer program to guess how the system would change in the future. It could then predict the future without direct observation, which would otherwise erase the system's useful characteristics.

The predictions were remarkably accurate, allowing the team to use their guesses preemptively to compensate for the anticipated changes.

Doing this in real time allowed the team to prevent the disintegration of the quantum character, extending the useful lifetime of the qubits.

"We know that building real quantum technologies will require major advances in our ability to control and stabilise qubits -- to make them useful in applications," Professor Biercuk said.

Read more at Science Daily

First humans arrived in North America a lot earlier than believed

This horse mandible from Cave 2 shows a number of cut marks on the lingual surface. They indicate that the animal's tongue was cut out with a stone tool.
The timing of the first entry of humans into North America across the Bering Strait has now been set back 10,000 years.

This has been demonstrated beyond a shadow of a doubt by Ariane Burke, a professor in Université de Montréal's Department of Anthropology, and her doctoral student Lauriane Bourgeon, with the contribution of Dr. Thomas Higham, Deputy Director of Oxford University's Radiocarbon Accelerator Unit.

The earliest settlement date of North America, until now estimated at 14,000 years Before Present (BP) according to the earliest dated archaeological sites, is now estimated at 24,000 BP, at the height of the last ice age or Last Glacial Maximum.

The researchers made their discovery using artifacts from the Bluefish Caves, located on the banks of the Bluefish River in northern Yukon near the Alaska border. The site was excavated by archaeologist Jacques Cinq-Mars between 1977 and 1987. Based on radiocarbon dating of animal bones, the researcher made the bold hypothesis that human settlement in the region dated as far back as 30,000 BP.

In the absence of other sites of similar age, Cinq-Mars' hypothesis remained highly controversial in the scientific community. Moreover, there was no evidence that the presence of horse, mammoth, bison and caribou bones in the Bluefish Caves was due to human activity.

To set the record straight, Bourgeon examined the approximate 36,000 bone fragments culled from the site and preserved at the Canadian Museum of History in Gatineau -- an enormous undertaking that took her two years to complete. Comprehensive analysis of certain pieces at UdeM's Ecomorphology and Paleoanthropology Laboratory revealed undeniable traces of human activity in 15 bones. Around 20 other fragments also showed probable traces of the same type of activity.

"Series of straight, V-shaped lines on the surface of the bones were made by stone tools used to skin animals," said Burke. "These are indisputable cut-marks created by humans."

Bourgeon submitted the bones to further radiocarbon dating. The oldest fragment, a horse mandible showing the marks of a stone tool apparently used to remove the tongue, was radiocarbon-dated at 19,650 years, which is equivalent to between 23,000 and 24,000 cal BP (calibrated years Before Present).

"Our discovery confirms previous analyses and demonstrates that this is the earliest known site of human settlement in Canada," said Burke. It shows that Eastern Beringia was inhabited during the last ice age."

Beringia is a vast region stretching from the Mackenzie River in the Northwest Territories to the Lena River in Russia. According to Burke, studies in population genetics have shown that a group of a few thousand individuals lived in isolation from the rest of the world in Beringia 15,000 to 24,000 years ago.

"Our discovery confirms the 'Beringian standstill [or genetic isolation] hypothesis,'" she said, "Genetic isolation would have corresponded to geographical isolation. During the Last Glacial Maximum, Beringia was isolated from the rest of North America by glaciers and steppes too inhospitable for human occupation to the West. It was potentially a place of refuge."

The Beringians of Bluefish Caves were therefore among the ancestors of people who, at the end of the last ice age, colonized the entire continent along the coast to South America.

Read more at Science Daily

How to be winner in the game of evolution

Jellyfish, polyps and the like belong to a phylum called Cnidaria, one of about 30 major groups that make up the animal kingdom.
A new study by University of Arizona biologists helps explain why different groups of animals differ dramatically in their number of species, and how this is related to differences in their body forms and ways of life.

For millennia, humans have marveled at the seemingly boundless variety and diversity of animals inhabiting the Earth. So far, biologists have described and catalogued about 1.5 million animal species, a number that many think might be eclipsed by the number of species still awaiting discovery.

All animal species are divided among roughly 30 phyla, but these phyla differ dramatically in how many species they contain, from a single species to more than 1.2 million in the case of insects and their kin. Animals have incredible variation in their body shapes and ways of life, including the plant-like, immobile marine sponges that lack heads, eyes, limbs and complex organs, parasitic worms that live inside other organisms (e.g. nematodes, platyhelminths), and phyla with eyes, skeletons, limbs and complex organs that dominate the land in terms of species numbers (arthropods) and body size (chordates).

Amidst this dazzling array of life forms, one question has remained as elusive as it is obvious: why is it that some groups on the evolutionary tree of animals have branched into a dizzying thicket of species while others split into a mere handful and called it a day?

From the beginnings of their discipline, biologists have tried to find and understand the patterns underlying species diversity. In other words, what is the recipe that allows a phylum to diversify into many species, or, in the words of evolutionary biologists, to be "successful?" A fundamental but unresolved problem is whether the basic biology of these phyla is related to their species numbers. For example, does having a head, limbs, and eyes allow some groups to be more successful and thus have greater species numbers?

In the new study, Tereza Jezkova and John Wiens, both in the University of Arizona's Department of Ecology and Evolutionary Biology, have helped resolve this problem. They assembled a database of 18 traits, including traits related to anatomy, reproduction, and ecology. They then tested how each trait was related to the number of species in each phylum, and to how quickly species in each phylum multiplied over time (diversification). The results are published in the journal American Naturalist.

Jezkova and Wiens found that just three traits explained most variation in diversification and species numbers among phyla: the most successful phyla have a skeleton (either internal or external), live on land (instead of in the ocean), and parasitize other organisms. Other traits, including those that might seem more dramatic, had surprisingly little impact on diversification and species numbers: evolutionary accomplishments such as having a head, limbs, and complex organ systems for circulation and digestion don't seem to be primary accessories in the evolutionary "dress for success."

"Parasitism isn't correlated with any of the other traits, so it seems to have a strong effect on its own," said Wiens.

He explained that when a host species splits into two species, it takes its parasite population(s) with it.

"You can have a number of parasite species living inside the same host," he said, "for example, there could be ten species of nematodes in one host species, and if that host species splits into two, there are 20 species of nematodes. So that really multiplies the diversity."

The researchers used a statistical method called multiple regression analysis to tease out whether a trait such as parasitic lifestyle is a likely driver of species diversification.

"We tested all these unique traits individually," Wiens explained, "for example, having a head, having eyes, where the species in a phylum tend to live, whether they reproduce sexually or asexually, whether they undergo metamorphosis or not; and from that we picked six traits that each had a strong effect on their own. We then fed those six traits into a multiple regression model. And then we asked, 'what combination of traits explains the most variation without including any unnecessary variables?' -- and from that we could reduce it down to three key variables."

The authors point out that the analysis does not make any assumptions about the fossil record, which is not a true reflection of past biodiversity as it does not reveal most soft-bodied animals or traits like a parasitic lifestyle.

"We wanted to know what explains the pattern of diversity in the species we see today," said Wiens. "Who are the winners, and who are the losers?"

Marine biodiversity is in jeopardy from human activities such as acidification from carbon emissions, posing an existential threat to many marine animals, Wiens said.

Read more at Science Daily

Martin Luther King, Jr.'s Legacy Remembered

Forty-eight years after his death, Martin Luther King, Jr. still stands as one of the most symbolic, most loved and most tragic of figures of the Civil Rights Movement.

This year, the home where the civil rights leader was born in some 88 years ago, will reopen after being closed since August for repairs. The modest Atlanta, Ga. home at at 450 Auburn Ave. N.E., was originally built in 1895. The historic site typically draws up to 20,000 visitors on Martin Luther King, Jr. Day, which caused some wear and tear. After repairs to the first floor of the house, where King lived until age 12, it will open again to the public in time for the MLK holiday.

Across the country, Americans are honoring King through rallies, services and days of service. Here, in honor of Martin Luther King, Jr. Day, take a look back at his life and some of his greatest accomplishments.

Son of a Preacher Man

King was born Jan. 15, 1929, in Atlanta, Ga., to Rev. Martin Luther King, Sr. and Alberta Williams King.

He studied theology, eventually earning a Ph.D. and following in his father's footsteps, becoming a preacher. Eventually, the two Rev. Kings would co-pastor Ebenezer Baptist Church in Atlanta until the younger King's death in 1968.

In the photo below, Martin Luther King, Jr. looks on as his father delivers a sermon.

A Family of Kings

King married Coretta Scott on June 18, 1953. The couple would go on to have four children. After his death, the King family, led by Coretta, took on his mission of promoting racial equality.

Peaceful Protest

In this photo from June 1963, King leads a march of mourners in a funeral procession for fellow civil rights leader Medgar Evers.

Known for his marches and peaceful protests, King was still arrested 30 times, according to the King Center.

A Fitting Farewell
King delivered his "I Have a Dream" speech to a crowd of civil rights activists gathered at the Lincoln Memorial on Aug. 28, 1963.

The moment and the phrase, "I have a dream..." have gone down in history as the pinnacle moment of his career.

Peace Prize

Famous for his non-violent protests, King was awarded the Nobel Peace Prize in 1964. At age 35, he was the youngest man, the second American and the third black man to be so honored, according to the King Center.

Voting Rights

In this photo, dated Aug. 5, 1965, King meets with President Lyndon B. Johnson and other civil rights leaders.

The following day, President Johnson signed the 1965 Voting Rights Act, outlawing discriminatory voting practices.

A Fitting Farewell

King was shot and killed while standing on the balcony of the Lorraine Motel in Memphis, Tenn., on April 4, 1968.

Thousands of mourners, including the Rev. Jesse Jackson (pictured at right) attended the funeral.

A Lasting Legacy

Mourners at King's funeral procession show their support for the iconic figure.

Only four days after his death, the first legislation providing for a Martin Luther King, Jr. federal holiday was filed. It would take until June 7, 1999 for all 50 states to recognize the holiday, according to the King Center. The third Monday of January is now officially Martin Luther King, Jr. Day across the country.

From Discovery News