World’s Oldest Sea Turtle Was 6 Feet Long, Fossil Shows

Paleontologists have described what is now believed to be the world's oldest sea turtle specimen, beating the previous record holder by 25 million years. The 120-million-year-old creature, dubbed Desmatochelys padillai sp., measures nearly 2 meters (6.5 feet) long.

In 2007, the "almost completely preserved skeleton" was discovered next to four skulls and two shells in central Colombia by hobby paleontologists. Researchers have dated the fossils back to the Cretaceous period based on the turtles' physical characteristics and the sediment in which the fossils were discovered.

That the turtle dates back to the Cretaceous period is significant: It was at some point during that period that turtles split into land and sea dwellers. A "sparse" fossil record, however, prevents paleontologists from determining exactly when the split occurred.

"This lends a special importance to every fossil discovery that can contribute to clarifying the phylogeny of the sea turtles," turtle expert Dr. Edwin Cadena explains in a news release.

Cadena and his colleagues have classified Desmatochelys padillai sp. in the Chelonioidea group, making it an ancestor of the modern hawksbill and green sea turtles.

From Discovery News

Hidden Blue Paint Found in Ancient Mummy Portraits

A stash of 1,900-year-old Egyptian mummy paintings that sat mostly undisturbed for 100 years is helping researchers understand how ancient artists used a fashionable pigment called Egyptian blue.

Researchers previously thought that ancient painters reserved Egyptian blue for eminent occasions because, as the first man-made blue pigment, it took effort to make it. But in an analysis of 15 paintings, scientists found five contained the pigment.

Intriguingly, the blue pigment was used for preliminary sketches and color modulation, meaning it was hidden beneath other colors used later during the painting process.

“This defies our expectations for how Egyptian blue would be used,” study co-author Marc Walton, a research associate professor of materials science and engineering at Northwestern University in Illinois and an expert on the color blue, said in a statement. “The discovery changes our understanding of how this particular pigment was used by artists in the second century A.D. I suspect we will start to find unusual uses of this colorant in a lot of different works of art, such as wall paintings and sculpture.”

Researchers uncovered the paintings in 1899 and 1900 during excavations at the archaeological site of Tebtunis (modern-day Umm el-Breigat), located about 92 miles (148 kilometers) southwest of Cairo.

Today, the paintings are housed at the University of California, Berkeley, and comprise one of the largest groupings of Roman Egyptian mummy portraits and paintings to survive intact since their excavation, the researchers wrote in the study. The research was published online Aug. 14 in the journal Applied Physics A.

Based on the artistic style, researchers dated all of the portraits to the second century, when Roman Egyptians painted portraits of the dead on wood panels, and tied this artwork to the deceased’s face during mummification.

During that time, Roman-period painters tried to emulate Greek painters, who were considered masters of the art world. Before the Greek era, painters used the lapis-inspired Egyptian blue throughout the Mediterranean, including on frescoes, temples, pottery and Egyptian funerary masks. But the Greeks tended to avoid blue pigments, instead relying almost exclusively on yellow, white, black and red.

“When you look at the Tebtunis portraits we studied, that’s all you see, those four colors,” Walton said. “But when we started doing our analysis, all of a sudden we started to see strange occurrences of this blue pigment, which luminesces. We concluded that although the painters were trying hard not to show they were using this color, they were definitely using blue.”

Pigment scrutiny

In the study, the researchers studied 11 mummy portraits and four painting fragments from Tebtunis. The investigators examined the artwork with a routine battery of tools, such as X-ray fluorescence (a method that bombards material with high-energy X-rays and examines the type of fluorescent X-rays emitted), X-ray diffraction (a technique that identifies crystalline material) and a scanning electron microscope (an instrument that gives a magnified view of paint particles).

The analyses showed that four portraits and one panel had unusual amounts of Egyptian blue, the researchers found.

“Our findings confirm the distinction between the visual and physical natures of artifacts — expect the unexpected when you begin to analyze an artwork,” said study co-author Jane Williams, a conservator at Phoebe A. Hearst Museum of Anthropology at UC Berkeley. “We see how these artists manipulated a small palette of pigments, including this unusual use of Egyptian blue, to create a much broader spectrum of hues.”

Read more at Discovery News

Grandmothers Drove Evolution of Monogamy

Women not only have grandmothers to thank for our long lives, it turns out they helped men evolve into monogamous mates, a new study suggests.

The finding, published today in the Proceedings of the National Academy of Science , builds on previous research around the evolution of grandmothering.

The ‘grandmother hypothesis’ was proposed by Professor Kristen Hawkes — co-author on this latest study — and colleagues in 1997 based on their observations in the 1980s of the Hazda hunter-gatherer people in Tanzania.

They noted that older women of the tribe spent their days collecting foods for their grandchildren. Except for humans, all other primates and mammals collect their own food after weaning.

Hawkes, from the Department of Anthropology at the University of Utah, proposed that when grandmothers helped feed their grandchildren after weaning, their daughters could produce more children at shorter intervals.

They then used computer modelling to show that by allowing their daughters to have more children, those ancestral females who lived long enough to become grandmothers passed their longevity genes to more descendants, who had longer adult lifespans as a result.

The team’s computer simulations showed from a start point of just 1 per cent of women living to grandmother age within 24,000-60,000 years about 43 per cent of adult women are grandmothers — a figure consistent with today’s hunter-gatherer populations.

For the latest study, Hawkes and her team again used computer modelling to examine how the evolution of grandmothering impacted on male to female interaction.

For the study they compared simulations of male to female sex ratios of great apes — no grandmothering — with modern-day human hunter-gatherer populations.

They found that over a million years, the ratio of available males to females ready to conceive doubled when ‘grandmothering’ was present, averaging about 111 males for every female.

Co-author Dr Peter Kim, at the University of Sydney, says the increase in human life span meant while older women became infertile after menopause, older men still remained able to reproduce.

Over time this created an imbalance in the sex ratio of fertile adults increasing competition among men for the still-fertile females, says Kim.

Increased competition led to reduced success in finding a mate, making it more important to find a mate and guard them.

Read more at Discovery News

NASA's Europa Mission May Land on Ocean-Harboring Moon

NASA’s upcoming mission to Europa may actually touch down on the potentially life-harboring Jupiter moon.

While the main thrust of the Europa mission, which NASA aims to launch by the mid-2020s, involves characterizing the icy satellite from afar during dozens of flybys, the space agency is considering sending a small probe down to the surface as well.

“We are actively pursuing the possibility of a lander,” Robert Pappalardo, Europa project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, said last week during a panel discussion at the American Institute of Aeronautics and Astronautics’ Space 2015 conference in Pasadena. (JPL manages the Europa mission.)

“NASA has asked us to investigate: What would it take? How much would it cost? Could we put a small surface package on Europa with this mission?” Pappalardo added.

NASA has also asked the European Space Agency if it would be interested in contributing a lander, ice-penetrating impactor or other piggyback probe to the roughly $2 billion Europa mission, Spaceflight Now reported in April.

Solar system’s best bet for alien life?

The 1,900-mile-wide (3,100 kilometers) Europa is covered by an ice shell perhaps 50 miles (80 km) thick, but underneath this crust is thought to lie a huge ocean of liquid water 12 miles (20 km) deep or so.

At least five other moons in the solar system — the Jovian satellites Ganymede and Callisto, Saturn’s Enceladus and Titan and the Neptune moon Triton — are believed to harbor such subsurface seas, Kevin Hand, deputy chief scientist at JPL’s Solar System Exploration Directorate, said during the same panel discussion at Space 2015.

But only the oceans of Enceladus and Europa are likely in contact with the rocky mantle, a scenario that makes all sorts of interesting chemical reactions possible, he added. (The other moons’ oceans are probably sandwiched between layers of ice.)

So Europa and Enceladus are the top two destinations on many astrobiologists’ mission wish lists. Hand gives the Jovian moon a slight edge, though.

Researchers know enough about Europa to surmise that its ocean has existed since the dawn of the solar system 4.5 billion years ago, giving putative lifeforms plenty of time to evolve, Hand explained.  Modeling work about the 310-mile-wide (500 km) Enceladus is less mature, so it’s unclear how long the Saturn satellite has harbored its sea.

“When it comes to habitability, we’d like to have the knowledge that the potentially habitable environment has been there for a significant duration,” Hand said.

But enthusiasm about a possible Enceladus mission is high as well, especially because the Saturn moon’s powerful geysers offer a way to sample its ocean from afar. Indeed, NASA is considering a potential mission called Enceladus Life Finder (ELF) that would do just that.

The Europa flyby mission

While ELF remains a concept at this point — it’s competing with about two dozen other proposals to become the next mission in NASA’s low-cost Discovery Program — the Europa project is officially on the space agency’s books.

The as-yet-unnamed Europa mission could launch as early as 2022. After reaching Jupiter orbit, the robotic probe will perform 45 flybys of Europa over the course of 2.5 years or so.

During these flybys, the spacecraft will scrutinize Europa using nine different science instruments, including high-resolution cameras, a heat detector and ice-penetrating radar. The mission’s observations should teach scientists a great deal about the moon’s surface composition, the nature of its underground ocean and its ability to support life as we know it, NASA officials have said. (Actively hunting for signs of life is not part of the current plan.)

Read more at Discovery News

Climate change could leave Pacific Northwest amphibians high and dry

Far above the wildfires raging in Washington's forests, a less noticeable consequence of this dry year is taking place in mountain ponds. The minimal snowpack and long summer drought that have left the Pacific Northwest lowlands parched also affect the region's amphibians due to loss of mountain pond habitat.

According to a new paper published Sept. 2 in the open-access journal PLOS ONE, this summer's severe conditions may be the new normal within just a few decades.

"This year is an analog for the 2070s in terms of the conditions of the ponds in response to climate," said Se-Yeun Lee, research scientist at University of Washington's Climate Impacts Group and one of the lead authors of the study.

Current conditions provide a preview of how that will play out.

"We've seen that the lack of winter snowpack and high summer temperatures have resulted in massive breeding failures and the death of some adult frogs," said co-author Wendy Palen, an associate professor at Canada's Simon Fraser University who has for many years studied mountain amphibians in the Pacific Northwest. "More years like 2015 do not bode well for the frogs."

Mountain ponds are oases in the otherwise harsh alpine environment. Brilliant green patches amid the rocks and heather, the ponds are breeding grounds for Cascades frogs, toads, newts and several other salamanders, and watering holes for species ranging from shrews to mountain lions. They are also the cafeterias of the alpine for birds, snakes and mammals that feed on the invertebrates and amphibians that breed in high-altitude ponds.

The authors developed a new model that forecasts changes to four different types of these ecosystems: ephemeral, intermediate, perennial and permanent wetlands. Results showed that climate-induced reductions in snowpack, increased evaporation rates, longer summer droughts and other factors will likely lead to the loss or rapid drying of many of these small but ecologically important wetlands.

According to the study, more than half of the intermediate wetlands are projected to convert to fast-drying ephemeral wetlands by the year 2080. These most vulnerable ponds are the same ones that now provide the best habitat for frogs and salamanders.

At risk are unique species such as the Cascades frog, which is currently being evaluated for listing under the Endangered Species Act. Found only at high elevations in Washington, Oregon and California, Cascades frogs can live for more than 20 years and can survive under tens of feet of snow. During the mating season, just after ponds thaw, the males make chuckling sounds to attract females.

"They are the natural jesters of the alpine, incredibly tough but incredibly funny and charismatic," said Maureen Ryan, the other lead author, a former UW postdoctoral researcher who is now a senior scientist with Conservation Science Partners.

The team adapted methods developed for forecasting the effects of climate change on mountain streams. Wetlands usually receive little attention since they are smaller and often out of sight. Yet despite their hidden nature, ponds and wetlands are globally important ecosystems that help store water and carbon, filter pollution, convert nutrients and provide food and habitat to a huge range of migratory and resident species. Their sheer numbers -- in the tens of thousands across the Pacific Northwest mountain ranges -- make them ecologically significant.

Read more at Science Daily

A humanoid robot to liaise between space station crews

A team of French researchers from the Institut cellule souche et cerveau (Inserm/Université Claude Bernard Lyon 1), led by CNRS senior researcher Peter Ford Dominey, has developed "an autobiographical memory" 1 for the robot Nao, which enables it to pass on knowledge learnt from humans to other, less knowledgable humans. This technological progress could notably be used for operations on the International Space Station, where the robot, which is the only permanent member, would liaise between the different crews that change every six months in order to pass on information. These results will be presented at the 24th International Symposium on Robot and Human Interactive Communication, on September 3, 2015 in Kobe, Japan.

Human culture stems from knowledge acquired through society's shared experience. Cultural transmission enables new members of society to quickly learn from this accumulated experience. In order for a robot to understand cooperative behavior, which is necessary for the cultural transmission of knowledge, researchers developed a system whereby a human agent can teach the Nao humanoid new actions through physical demonstration (by putting the robot's members in the correct position), visual imitation (through the Kinect system), or voice command. These individual actions are then combined into procedures and stored in the robot's autobiographical memory developed by researchers, thus enabling the robot to reproduce them for other human agents if needed.

Researchers set up this autobiographical memory system to meet the challenge of cooperation between humans and robots, which is becoming more and more of a reality in the field of space operations, with the humanoid Robonaut 2 2 now permanently flying aboard the International Space Station.

To test their system, the scientists imagined a scenario that could occur on the International Space Station. The transmission of information on board is essential, since crews change every six months. In this scenario, an electronic card is damaged. Nao plays the role of the scientist's assistant by following his directions, bringing or holding parts of the card during repair. If this same failure happens again, the memory of this event will enable the robot to use a video system to show the repair that was made to a new member of the crew. It could also respond to questions regarding the previous event, while helping with the new repair. If a slightly different failure takes place, the robot could share its expertise on failures of this type, while recording the steps needed to resolve this new problem and then transferring them to the scientists in the next crew.

These results demonstrate the feasibility of this system, and show that such humanoid robots represent a potential solution for the accumulation and transfer of knowledge. Researchers are now hoping to test their Nao robot in the real conditions of space operations, with zero gravity. They would also like to develop another area of application, assisting the elderly, with the robot this time playing the role of a personal memory aid.

Read more at Science Daily

Mathematical 'Gingko trees' reveal mutations in single cells that characterize diseases

Seemingly similar cells often have significantly different genomes. This is often true of cancer cells, for example, which may differ one from another even within a small tumor sample, as genetic mutations within the cells spread in staccato-like bursts. Detailed knowledge of these mutations, called copy number variations, in individual cells can point to specific treatment regimens.

The problem is that current techniques for acquiring this knowledge are difficult and produce unreliable results. Today, scientists at Cold Spring Harbor Laboratory (CSHL) publish a new interactive analysis program called Gingko that reduces the uncertainty of single-cell analysis and provides a simple way to visualize patterns in copy number mutations across populations of cells.

The open-source software, which is freely available online, will improve scientists' ability to study this important type of genetic anomaly and could help clinicians better target medications based on cells' specific mutation profiles. The software is described online today in Nature Methods.

Mutations come in many forms. For example, in the most common type of mutation, variations may exist among individual people--or cells--at a single position in a DNA sequence. Another common mutation is a copy number variation (CNV), in which large chunks of DNA are either deleted from or added to the genome. When there are too many or too few copies of a given gene or genes, due to CNVs, disease can occur. Such mutations have been linked not only with cancer but a host of other illnesses, including autism and schizophrenia.

Researchers can learn a lot by analyzing CNVs in bulk samples--from a tumor biopsy, for example--but they can learn more by investigating CNVs in individual cells. "You may think that every cell in a tumor would be the same, but that's actually not the case," says CSHL Associate Professor Michael Schatz.

"We're realizing that there can be a lot of changes inside even a single tumor," says Schatz. "If you're going to treat cancer, you need to diagnose exactly what subclass of cancer you have." Simultaneously employing different drugs to target different cancer subclasses could prevent remission, scientists have proposed.

One powerful single-cell analytic technique for exploring CNV is whole genome sequencing. The challenge is that, before sequencing can be done, the cell's DNA has to be amplified many times over. This process is rife with errors, with some arbitrary chunks of DNA being amplified more than others. In addition, because many labs use their own software to examine CNVs, there is little consistency in how researchers analyze their results.

To address these two challenges, Schatz and his colleagues created Gingko. The interactive, web-based program automatically processes sequence data, maps the sequences to a reference genome, and creates CNV profiles for every cell that can then be viewed with a user-friendly graphical interface. In addition, Gingko constructs phylogenetic trees based on the profiles, allowing cells with similar copy number mutations to be grouped together.

Importantly, Gingko, which Schatz and his colleagues validated by reproducing the findings of five major single-cell studies, also analyzes patterns in the sequence reads in order to recognize, and greatly reduce, amplification errors.

Read more at Science Daily

Nanoparticles: Small but unique

Scientists at Chalmers University of Technology have developed a new way to study nanoparticles one at a time, and have discovered that individual particles that may seem identical in fact can have very different properties. The results, which may prove to be important when developing new materials or applications such as hydrogen sensors for fuel cell cars, will be published in Nature Materials.

"We were able to show that you gain deeper insights into the physics of how nanomaterials interact with molecules in their environment by looking at the individual nanoparticle as opposed to looking at many of them at the same time, which is what is usually done," says Associate Professor Christoph Langhammer, who led the project.

By applying a new experimental approach called plasmonic nanospectroscopy, the group studied hydrogen absorption into single palladium nanoparticles. They found that particles with exactly the same shape and size may exhibit differences as great as 40 millibars in the pressure at which hydrogen is absorbed. The development of sensors that can detect hydrogen leaks in fuel cell powered cars is one example of where this new understanding could become valuable in the future.

"One main challenge when working on hydrogen sensors is to design materials whose response to hydrogen is as linear and reversible as possible. In that way, the gained fundamental understanding of the reasons underlying the differences between seemingly identical individual particles and how this makes the response irreversible in a certain hydrogen concentration range can be helpful," says Christoph Langhammer.

Others have looked at single nanoparticles one at a time, but the new approach introduced by the Chalmers team uses visible light with low intensity to study the particles. This means that the method is non-invasive and does not disturb the system it is investigating by, for example, heating it up.

"When studying individual nanoparticles you have to send some kind of probe to ask the particle 'what are you doing?'. This usually means focusing a beam of high-energy electrons or photons or a mechanical probe onto a very tiny volume. You then quickly get very high energy densities, which might perturb the process you want to look at. This effect is minimized in our new approach, which is also compatible with ambient conditions, meaning that we can study nanoparticles one at a time in as close to a realistic environment as possible," says Christoph Langhammer.

Even though they have now reached the level where their results are ready to be published, Christoph Langhammer believes they have just scratched the surface of what their discovery and developed experimental methodology will lead to in relation to further research. He hopes that they have helped to establish a new experimental paradigm, where looking at nanoparticles individually will become standard in the scientific world.

Read more at Science Daily

ATLAS and CMS experiments shed light on Higgs properties

Three years after the announcement of the discovery of a new particle, the so-called Higgs boson, the ATLAS and CMS Collaborations present for the first time combined measurements of many of its properties, at the third annual Large Hadron Collider Physics Conference (LHCP 2015). By combining their analyses of the data collected in 2011 and 2012, ATLAS and CMS draw the sharpest picture yet of this novel boson. The new results provide in particular the best precision on its production and decay and on how it interacts with other particles. All of the measured properties are in agreement with the predictions of the Standard Model and will become the reference for new analyses in the coming months, enabling the search for new physics phenomena. This follows the best measurement of the mass of the Higgs boson, published in May 2015 after a combined analysis by the two collaborations.

"The Higgs boson is a fantastic new tool to test the Standard Model of particle physics and study the Brout-Englert-Higgs mechanism that gives mass to elementary particles," said CERN1 Director General Rolf Heuer. "There is much benefit in combining the results of large experiments to reach the high precision needed for the next breakthrough in our field. By doing so, we achieve what for a single experiment, would have meant running for at least 2 more years."

There are different ways to produce a Higgs boson, and different ways for a Higgs boson to decay to other particles. For example, according to the Standard Model, the theory that describes best forces and particles, when a Higgs boson is produced, it should decay immediately in about 58% of cases into a bottom quark and a bottom antiquark. By combining their results, ATLAS and CMS determined with the best precision to date the rates of the most common decays.

Such precision measurements of decay rates are crucially important as they are directly linked to the strength of the interaction of the Higgs particle with other elementary particles, as well as to their masses. Therefore, the study of its decays is essential in determining the nature of the discovered boson. Any deviation in the measured rates compared to those predicted by the Standard Model would bring into question the Brout-Englert-Higgs mechanism and possibly open the door to new physics beyond the Standard Model.

"This is a big step forward, both for the mechanics of the combinations and in our measurement precision, " said ATLAS Spokesperson Dave Charlton. "As an example, from the combined results the decay of the Higgs boson to tau particles is now observed with more than 5 sigma significance, which was not possible from CMS or ATLAS alone."

"Combining results from two large experiments was a real challenge as such analysis involves over 4200 parameters that represent systematic uncertainties," said CMS Spokesperson Tiziano Camporesi. "With such a result and the flow of new data at the new energy level at the LHC, we are in a good position to look at the Higgs boson from every possible angle."

Read more at Science Daily

Predator Numbers Don't Always Increase with Prey

Scientists said this week they have uncovered what seems to be an unusual law of nature that keeps big predator numbers low across vast spaces of the Earth and its oceans.

Even when there are plenty of prey around for larger creatures like lions to eat, the number of lions in an area does not increase, said the findings in the journal Science.

The same pattern holds just as true for big animals as it does for tiny sea creatures like zooplankton, which eat phytoplankton.

"Where prey are abundant, there are not proportionally more predators," said the study, which analyzed data going back 50 years on plants and animals across 2,260 ecosystems in 1,512 distinct locations worldwide, including grasslands, lakes, forests and oceans.

Rather than predators rising in number to match the available prey, predator populations are limited by the rate at which prey reproduce.

And in crowded settings, prey reproduced less than they did in settings where there were fewer prey around, suggesting that competition for resources may be working to limit prey offspring.

"Until now, the assumption has been that when there is a lot more prey, you'd expect correspondingly more predators," said study author Ian Hatton, a doctoral student at McGill University.

"But as we looked at the numbers, we discovered instead, that in the lushest ecosystems, no matter where they are in the world, the ratio of predators to their prey is greatly reduced," Hatton said.

"This is because with greater crowding, prey species have fewer offspring for every individual. In effect, the prey's rates of reproduction are limited, which limits the abundance of predators."

Co-author Kevin McCann, of Guelph University's department of integrated biology, said researchers were "astonished" by what they viewed as an "amazing pattern."

The relative amounts of predator and prey biomass in diverse ecosystems could be "remarkably well-predicted by a simple mathematical function called a power scaling law," said McCann.

This "power law" shows there are always fewer top predators than expected in resource-rich ecosystems than in resource-poor ecosystems.

Read more at Discovery News