Mar 19, 2016
The researchers show for the first time that the fungus Neurospora crassa can transform manganese into a mineral composite with favorable electrochemical properties.
"We have made electrochemically active materials using a fungal manganese biomineralization process," says Geoffrey Gadd of the University of Dundee in Scotland. "The electrochemical properties of the carbonized fungal biomass-mineral composite were tested in a supercapacitor and a lithium-ion battery, and it [the composite] was found to have excellent electrochemical properties. This system therefore suggests a novel biotechnological method for the preparation of sustainable electrochemical materials."
Gadd and his colleagues have long studied the ability of fungi to transform metals and minerals in useful and surprising ways. In earlier studies, the researchers showed that fungi could stabilize toxic lead and uranium, for example. That led the researchers to wonder whether fungi could offer a useful alternative strategy for the preparation of novel electrochemical materials too.
"We had the idea that the decomposition of such biomineralized carbonates into oxides might provide a novel source of metal oxides that have significant electrochemical properties," Gadd says.
In fact, there have been many efforts to improve lithium-ion battery or supercapacitor performance using alternative electrode materials such as carbon nanotubes and other manganese oxides. But few had considered a role for fungi in the manufacturing process.
In the new study, Gadd and his colleagues incubated N. crassa in media amended with urea and manganese chloride (MnCl2) and watched what happened. The researchers found that the long branching fungal filaments (or hyphae) became biomineralized and/or enveloped by minerals in various formations. After heat treatment, they were left with a mixture of carbonized biomass and manganese oxides. Further study of those structures show that they have ideal electrochemical properties for use in supercapacitors or lithium-ion batteries.
"We were surprised that the prepared biomass-Mn oxide composite performed so well," Gadd says. In comparison to other reported manganese oxides in lithium-ion batteries, the carbonized fungal biomass-mineral composite "showed an excellent cycling stability and more than 90% capacity was retained after 200 cycles," he says.
Read more at Discovery News
One of the biggest and most complex magnets in history is being manufactured at the ASG facilities, Italy. This gigantic "D" shaped coil will be form part of the system that will confine ITER's super-hot plasma which is expected to reach 150 million ˚C. Basically, an impressive magnetic shield will entrap the hot gas and keep it away from the walls of the vessel of the world's biggest fusion machine.
F4E is responsible for the supply of 10 out of the 18 TF coils that ITER will need to operate. Witnessing the first TF coil taking shape is a turning point for the project and the 600 people having contributed to this milestone from at least 26 companies. This is the result of various contracts starting in 2008 when F4E started its collaboration with several suppliers for the production of Europe's TF conductor, which reached a length of 20 km.
Iberdrola, ASG and Elytt Energy, have used parts of this conductor to manufacture Europe's first TF coil. Winding, sandblasting and heat treatment have been some of the main steps taken in order to fit the conductor into stainless steel plates, known as radial plates, manufactured by CNIM and SIMIC. Piece by piece the conductor had to be lifted, wrapped, insulated and placed back in the grooves of the plates before it got covered. Then, the structure containing the conductor has been laser welded and wrapped with insulating material, before going through impregnation.
To create the inner-core of the TF coil, a pack of seven of these structures had to be stacked, electrically jointed, wrapped, insulated and impregnated. Pipes through which cold liquid helium will circulate inside the magnet to help it reach a superconducting state and instruments to measure its performance have also been added. Each of these packs, known as a winding pack in the ITER jargon, is 14 m high, 9 m wide and 1 m thick. Its weight is approximately 110 tonnes which compares to that of a Boeing 747!
For Alessandro Bonito-Oliva, F4E's Manager for Magnets, and his team, this has been an accomplishment of significant importance. "Thanks to our determination to meet the tight planning for magnets and the excellent collaboration between F4E and its suppliers we are heading towards Europe's first TF coil, which also happens to be a first for ITER. Seeing a magnet of such complexity taking shape suggests that we can deliver some of the most technically challenging systems of ITER. Sharing expertise and good communication between F4E, ITER International Organization and Japan's Domestic Agency for ITER have been fundamentally important for the achievement of this milestone and will continue to be as production is still ongoing.
Read more at Science Daily
Mar 18, 2016
NASA's New Horizons mission continues to download information gathered from Pluto and its moon Charon during its historic flyby on 14 July, 2015. As this data arrives on Earth, scientists process and study it. In the first of five papers in this package, Jeffrey Moore et al. offer some of the first descriptions of the wide array of geological features on Pluto and Charon. They report evidence of tectonics, glacial flow, transport of large water-ice blocks, and broad mounds on Pluto -- possibly a result of cryovolcanoes.
Data on the variability of terrain suggests the dwarf planet has been frequently resurfaced by processes like erosion, pointing to active geomorphic processes within the last few hundred million years. Such processes have not been active so recently on Charon; divided into a rugged north and a smooth south, the moon is marked with older craters and troughs, contrasting with Pluto.
In a second study, Will Grundy et al. analyze the colors and chemical compositions of the icy surfaces of Pluto and Charon. The volatile ices, including water ice and solid nitrogen, that dominate Pluto's surface are distributed in a complicated way, they report, a result of geomorphic processes acting on the surface over different seasonal and geological timescales. Broad expanses of reddish-brown molecules called tholins accumulated in some parts of Pluto, the study suggests. In a third study, G. Gladstone et al. investigate the atmosphere of Pluto, which is colder and more compact than expected and hosts numerous extensive layers of haze.
In a fourth study, Harold Weaver et al. examine the small moons Styx, Nix, Kerberos, and Hydra, which are irregularly shaped, fast rotating and have bright surfaces. Finally, Fran Bagenal et al. report how Pluto modifies its space environment, including interactions with the solar wind and a lack of dust in the system. Taken together, these results from the flyby of Pluto pave the way for scientists' better understanding of processes of planetary evolution.
From Science Daily
In a study recently published in the journal Zoology in the Middle East, scientists from the United States and Israel report sightings of striped hyenas roaming amid packs of grey wolves in the Negev desert.
Neither hyenas nor wolves usually behave very well in their dealings with other carnivores. Hyenas will fight, usurp kills from, and make life miserable for animals from lions to leopards to cheetahs. Wolves, for their part, will make meals out of coyotes and dogs.
The study’s co-authors -- University of Tennessee, Knoxville researcher Vladimir Dinets and Israeli zoologist Beniamin Eligulashvili -- think the two species traveling together may be an example of animals bending their own rules and instincts a bit, in the name of survival in an extreme, arid landscape.
“Animal behavior is often more flexible than described in textbooks,” said Dinets in a statement. “When necessary, animals can abandon their usual strategies and learn something completely new and unexpected. It’s a very useful skill for people, too.”
Why would working together help the two species?
The researchers suspect the predatory animals are willing to put up with each other because each gets something out of the deal. Wolves can take down large prey themselves, while hyenas are super sniffers that can smell and find, from miles away, dead animals worth eating.
Hyenas, the scientists note, are also adept at ferreting food out of human refuse -- digging up buried garbage and opening cans and large boxes.
Read more at Discovery News
Recent analysis of the Latin Bible, which was published in 1535 by Henry VIII’s printer, has revealed fascinating English annotations made during the 16th-century Reformation. The Reformation was a period of immense upheaval in England, which saw the Church of England break away from the authority of the Catholic Church in Rome.
Housed in the library of Lambeth Palace, which is the official London residence of the Archbishop of Canterbury, the Bible is one of just seven surviving copies.
“We know virtually nothing about this unique Bible – whose preface was written by Henry himself – outside of the surviving copies,” said Eyal Poleg, a historian at Queen Mary University of London, in a press release.
Close inspection revealed that heavy paper had been pasted over blank parts of the Bible. “The challenge was how to uncover the annotations without damaging the book,” explained Poleg.
The historian brought in Graham Davis, a specialist in 3D x-ray imaging at the university’s School of Dentistry. The experts took two images in long exposure. For one image, a light sheet slid beneath the pages was turned on, for another, it was turned off.
The first image revealed all the annotations, scrambled with the printed text, while the second picture showed only the printed text. Davis wrote a piece of software to “subtract” the second image from the first, revealing a clear picture of the annotations, which are written in English.
“The annotations are copied from the famous ‘Great Bible’ of Thomas Cromwell, seen as the epitome of the English Reformation,” explained the university, in its press release. “Written between 1539 and 1549, they were covered and disguised with thick paper in 1600.”
Poleg said that the annotations support the idea that the Reformation was a gradual process. “Until recently, it was widely assumed that the Reformation caused a complete break, a Rubicon moment when people stopped being Catholics and accepted Protestantism, rejected saints, and replaced Latin with English,” he explained. “This Bible is a unique witness to a time when the conservative Latin and the reformist English were used together, showing that the Reformation was a slow, complex, and gradual process.”
Poleg’s research also uncovered a handwritten transaction between two men on the back page of the book. The transaction states that James Elys Cutpurse of London promised to pay William Cheffyn of Calais 20 shillings, or would go to the notorious Marshalsea prison. Subsequent research conducted by Poleg revealed that Cutpurse was hanged in July 1152.
Read more at Discovery News
The research team, led by Dr. Saad B. Omer, reviewed published reports of measles outbreaks in the United States since 2000 — the year the disease was eliminated from the population — as well as all outbreaks of whooping cough (pertussis) since 1997, when that disease was at its lowest point. The goal was to evaluate the association between vaccination and the epidemiology of these diseases, both of which are preventable.
The authors analyzed a study of national measles data reported to the CDC from 1985 through 1992, which found “unvaccinated children who had a vaccine exemption were 35 times more likely to contract measles compared with vaccinated children. The epidemic curve of measles determined that the resurgence started a year earlier among children with exemptions compared with vaccinated children.”
In much of the world people are unvaccinated for the simple reason that vaccines are unavailable or cost too much money. That was not the case in the United States. In fact most of those who contracted measles were offered free or inexpensive vaccines, but they (or their parents) refused them despite having no medical reason to do so. Although vaccine prices have risen in recent years, insurance companies have been required under the Affordable Care Act to completely cover childhood vaccinations since 2011.
Reasons the researchers found for vaccine refusal included personal belief exemptions; specific cultural norms (for example in Amish communities); and religious exemptions. Less often a vaccine could not be provided because of medical or logistical reasons, including that the patient was sick at the time the medication was to be given, or the patient could not physically make it to his or her appointment.
Some parents refuse to have their children vaccinated because of false health concerns raised by anti-vaccination activists such as actress Jenny McCarthy, who in turn based their concerns largely on a since-retracted study by Dr. Andrew Wakefield which seemed to show a link between vaccines and the onset of autism in young children.
Read more at Discovery News
Mar 17, 2016
Antiquities Minister Mamdouh al-Damaty told a press conference that analysis of radar scans carried out by Japanese specialist Hirokatsu Watanabu revealed two hidden spaces on the north and eastern walls of the 3,300-year-old tomb.
"Furthermore, based on the GPR data, curves that might indicate doors were also detected above the cavities, which can be seen as an entrance to those cavities," al-Damaty said.
The metal and organic material possibly revealed by the scans strongly suggest to the presence of a another burial, boostering a claim by Nicholas Reeves, a British Egyptologist at the University of Arizona.
In July 2015 Reeves published a paper arguing that high-resolution images of the tomb’s walls show “distinct linear traces” pointing to the presence of two still unexplored chambers.
“It does look from the radar evidence as if the tomb of Tutankhamun is a corridor tomb and it continues beyond the decorated burial chamber,” Reeves said at a press conference last November.
According to Reeves, one hidden chamber would contain the remains, and possibly the intact grave goods, of queen Nefertiti, wife of the “heretic” monotheistic pharaoh Akhenaten, Tutankhamun’s father.
Reeves speculated that the tomb of King Tut was not ready when he died unexpectedly at 19 in 1323 B.C., after having ruled a short reign of nine to 10 years. Consequently, he was buried in a rush in what was originally the tomb of Nefertiti, who had died 10 years earlier.
According to al-Damaty, the hidden chambers could contain the tomb of a member of King Tut’s family. However, he did not speculate on Nefertiti.
Read more at Discovery News
Results from new scientific experiments may explain why and the development of a new image-processing filter could help potential tetrachromats develop their unique talent.
Several years ago, artist Concetta Antico became known as the “woman with rainbow vision” after University of Washington researcher Jay Neitz discovered that she was a tetrachromat. Women like Antico with the genetic mutation have four color receptors in their eyes instead of three, meaning they can perceive more colors.
The mutation isn’t all that rare, but a tetrachromat who reliably demonstrates this enhanced vision is exceptional, BBC Future reported. Antico has described seeing multiple colors where others don’t: in green leaves, in a bunch of tomatoes, in a tiny pebble. She applies this ability to vivid oil paintings that often feature flowers, birds, and landscapes.
“The intense colors are speaking to me all the time,” she told the BBC.
Recently a team of scientists set up experiments with Antico to evaluate her color perception against others. Kimberly Jameson from the Institute for Mathematical Behavioral Sciences at UC Irvine led the research, which entailed testing participants’ sensitivity to different luminescence levels, the BBC reported.
Test subjects included an artist without tetrachromacy as well as another tetrachromat who is not an artist. Jameson and her team discovered that Antico was indeed more sensitive than the other subjects — even the other person with the mutation. They concluded this likely stemmed from her artistic training.
Jameson and her team used the results to develop an image-processing filter that isolated the parts of an image where Antico saw enhanced colors. While such a filter can’t help folks who only have three color perceptors, the researchers think it could help potential tetrachromats in developing unique artistry.
Read more at Discovery News
This means that Melanesians — people native to Vanuatu, the Solomon Islands, Fiji, Papua New Guinea, New Caledonia, West Papua and the Maluku Islands — have the highest degree of archaic human ancestry ever documented. Neanderthals and Denisovans went extinct several thousand years ago, so the family roots of Melanesians go incredibly deep.
The discovery, reported in the journal Science, adds to the growing body of evidence that all humans alive today are basically hybrids.
“I think there is no such thing as a purebred modern human,” senior author Joshua Akey of the University of Washington’s Department of Genome Science told Discovery News. “All of our genomes are a mosaic of different ancestries, and admixture is a recurring theme throughout human evolutionary history.”
For the study, Akey and his team analyzed the genomes of 1,523 individuals from around the world, including 35 Melanesians. They confirmed prior findings that all non-African people inherited roughly 1.5 to 4 percent of their genomes from Neanderthals. Melanesians, however, were the only population that also had significant Denisovan ancestry.
Such seemingly small percentages are misleading, because the researchers also found strong evidence that recurrent natural selection against archaic DNA sequences happened as the various human groups interbred. As a result, today’s Neanderthal and Denisovan heritage percentages likely don’t reflect the true amount of interbreeding that took place.
As Akey said, “Our data suggests matings with archaic individuals may be more prevalent than currently thought.”
The regions of the modern human genome that appear particularly depleted of archaic sequences are those that play a role in speech and language development, suggesting that these skills could have set modern humans apart from Neanderthals and Denisovans.
Anne Stone, a professor and director of the Center for Bioarchaeological Research at Arizona State University, points out that regions of our genome that are less likely to contain archaic DNA are those areas that “encode important adaptations for modern humans, i.e. what makes us modern human, while those that contain more archaic DNA may represent regions where archaic adaptations were advantageous.”
Based on earlier research, such advantages might have included changes to immunity, hair and skin to better match the needs of out-of-Africa environments.
Akey and his team also mapped out the genetic flow of the Neanderthal and Denisovan sequences and found that Neanderthal gene flow (admixture) with modern human DNA occurred at least three distinct times in modern human history. The researchers only found evidence for one such admixture event with Denisovans.
Anthropologists are not entirely sure where and how the fateful matings between modern humans migrating out of Africa and Neanderthals and Denisovans took place. Akey, however, said that he and his colleagues “can order the times of distinct admixture events, including admixture that occurred in all non-African populations shortly after the out-of-Africa dispersal; another pulse of admixture that occurred in the ancestors of Europeans and East Asians after they diverged from Melanesians; and a third pulse of admixture with the ancestors of present day East Asians after they diverged from Europeans.”
He suspects that modern humans mated with Denisovans in Southeast Asia before some of those individuals traveled to Melanesia.
Read more at Discovery News
“Together, these nine stars outshine the sun by a factor of 30 million,” notes the European Space Agency in a press release about the discovery, which is published in the Monthly Notices of the Royal Astronomical Society.
The most massive star in the universe, known as R136a1, is more than 250 times bigger than the sun.
An international team of scientists discovered the nine bigwigs by combining Hubble Wide Field Camera 3 pictures with high-resolution ultraviolet imagery collected by Hubble’s Space Telescope Imaging Spectrograph, or STIS instrument.
The discovery is expected to fuel debate about how such massive stars come to exist.
“There have been suggestions that these monsters result from the merger of less extreme stars in close binary systems. From what we know about the frequency of massive mergers, this scenario can’t account for all the really massive stars that we see in R136,” University of Sheffield astronomer Saida Caballero-Nieves said in a statement.
STIS data also showed that the giant stars are losing mass rapidly, ejecting the equivalent mass of Earth every month.
From Discovery News
The evidence is all over Pluto’s face, which was observed close-up for the first time by NASA’s New Horizons spacecraft on July 14, 2015.
With most of the high-resolution images from the flyby now back on Earth, scientists say Pluto’s mountains, glacial flows, rotated ice blocks, volcano-like mounds and other features rival the geology found on much larger, warmer planets like Mars.
The physical and chemical conditions on Pluto, located about 40 times farther away from the sun than Earth, have played out in unusual and largely unforeseen ways. Highly volatile cryogenic ices, such as nitrogen, carbon monoxide, methane, vaporize into Pluto’s hazy and surprisingly compact atmosphere. Internal heating, fueled by the natural decay of radioactive elements in Pluto’s rocks and other sources, likely keeps an ocean of ammonia-rich water liquid beneath the dwarf planet’s frozen surface.
“We now have half a dozen worlds, like (Saturn’s moon) Enceladus, (Jupiter’s moons) Europa and Ganymede, and now Pluto, that seem to have oceans in their interiors,” New Horizons’ lead scientist Alan Stern, with the Southwest Research Institute told Discovery News.
“It’s interesting that only Earth wears its ocean on the outside,” he said. “From the surface, we don’t see them. Who know that oceans would turn out to be fairly common?”
As far as the prospect for life on Pluto, Stern said, “Anytime you have liquid water, the astrobiologists get interested in that place. That’s as far as I’m willing to go.”
For Earth-like life to exist, a planet would need water, an energy source, the right chemical elements and time, added planetary scientist William McKinnon, with Washington University in St. Louis.
“All we can say is that we think that Pluto has an ocean and we think that this ocean has survived to the present day. It’s the kind of ocean that is deep inside the interior of Pluto, in total darkness. But, it would lie between a floating water ice shell and the rocky interior, so it would be in contact with rock. There would be a modest amount of heat leaking out. You certainly couldn’t rule it out, but anything about life on Pluto is simply speculation,” McKinnon told Discovery News.
Read more at Discovery News
Mar 16, 2016
The Siberian Times reports that the extinct Pleistocene canid species was found close to evidence of human activity, causing researchers to suspect it may have been a pet.
The thawed creature had to have thousands of years of mud and dirt washed away before an autopsy could be performed by Moscow's Geological Institute:
“We will be able to say more precisely after it is extracted,” Moscow researcher Pavel Nikolsky told the Times. “For now we can see it on MRI scans. Of course, it has dried out somewhat, but the parencephalon, cerebellum and pituitary gland are visible. We can say that this is the first time we have obtained the brain of a Pleistocene canid.”
In an interesting sub-plot to the find, there is already talk of cloning the pleistocene pet.
Present for the autopsy was South Korean scientist Hwang Woo-Suk, who was collecting samples for a potential cloning of the puppy. Woo-Suk is known for his ambition to clone woolly mammoths and, recently, an extinct cave lion. He’s also building an animal cloning facility in China and has held a dog-cloning competition in the United Kingdom.
Read more at Discovery News
That is a fresh twist on a long-running mystery over the origins of these 28 hominins from Sima de Los Huesos in northern Spain. Initially, researchers in 2013 showed that their maternally inherited mitochondrial DNA was distantly related to Denisovans, extinct relatives of Neanderthals in Asia who lived in Siberia and apparently elsewhere in Asia.
But the finding stirred up quite a debate, since the skeletal remains carry Neanderthal-derived features.
Now, researchers of the Max Planck Institute for Evolutionary Anthropology managed to sequence nuclear DNA from fossils from the cave.
|To put a human face on our ancestors, scientists from the Senckenberg Research Institute used sophisticated methods to form 27 model heads based on tiny bone fragments, teeth and skulls collected from across the globe.|
“The recovery of a small part of the nuclear genome from the Sima de los Huesos hominins is not just the result of our continuous efforts in pushing for more sensitive sample isolation and genome sequencing technologies”, Meyer adds. “This work would have been much more difficult without the special care that was taken during excavation.”
The researchers credited the breakthrough with advances in analyzing DNA.
“We have hoped for many years that advances in molecular analysis techniques would one day aid our investigation of this unique assembly of fossils,” Juan-Luis Arsuaga of the Complutense University in Madrid, Spain, who has led the excavations at Sima de los Huesos for three decades. “We have thus removed some of the specimens with clean instruments and left them embedded in clay to minimize alterations of the material that might take place after excavation.”
Read more at Discovery News
However, it’s not Dawn that has found the latest clue as to what these bright patches could be; it was a powerful observatory on Earth that noticed very slight changes as Ceres’ surface is gently heated by the sun.
The bright spots in question are mainly clustered inside a large crater called Occator. Now that Dawn is in its lowest mapping orbit around the small world nestled in the Main Asteroid Belt (between the orbits of Mars and Jupiter), zipping across the cratered landscape at an altitude of only 240 miles, it has captured wonderfully detailed observations of the crater’s floor. The bright feature is actually a cluster of bright spots with diffuse, almost powder-like material surrounding the brightest patches.
The leading theory, so far, is that it’s an icy material such as water ice, but some kind of mineral deposit is also a possibility. Now, with the help of the HARPS spectrograph attached to the ESO 3.6-meter telescope at La Silla, Chile, it seems the ice theory has just become a whole lot stronger.
“As soon as the Dawn spacecraft revealed the mysterious bright spots on the surface of Ceres, I immediately thought of the possible measurable effects from Earth,” said Paolo Molaro, at the INAF–Trieste Astronomical Observatory and lead author of a study published in the journal Monthly Notices of the Royal Astronomical Society. “As Ceres rotates the spots approach the Earth and then recede again, which affects the spectrum of the reflected sunlight arriving at Earth.”
As Ceres rotates every 9 hours, HARPS is so sensitive that it can detect the very slight Doppler shift in spectrum frequency as the bright spots rotate toward and away Earth, but during observations for 2 nights in July and August 2015, more changes not related to Ceres’ spin were detected.
“The result was a surprise,” said co-author Antonino Lanza, also from the INAF–Catania Astrophysical Observatory. “We did find the expected changes to the spectrum from the rotation of Ceres, but with considerable other variations from night to night.”
Read more at Discovery News
Studying a supermassive black hole some 3.5 billion light-years away is no easy feat, but this isn’t a regular object: it’s a quasar that shows quasi-periodic brightening events every 12 years or so — a fact that has helped astronomers reveal its extreme nature.
Quasars are extremely bright accretion disks in galactic cores driven by copious quantities of matter falling into the central supermassive black hole. The vast majority of galaxies are thought to contain supermassive black holes, though modern galaxies have calmed down and quasars no longer shine. But it’s a different story for galaxies that are billions of light-years away.
The object at the center of the strange quasar called OJ287 “weighs in” at 18 billion solar masses and is one of the biggest supermassive (or ultramassive?) black holes in the known universe. Interestingly, it is also one of the most well-studied quasars as it is located very close to the apparent path of the sun’s motion across the sky as seen from Earth — a region where historic searches for asteroids and comets are regularly carried out. Therefore, astronomers have over 100 years of serendipitous brightness data for OJ287, allowing them to predict when the next flaring event would be.
On closer inspection of the flaring events that occurred in recent decades, astronomers realized that rather than a single brightening event occurring every 12 years, the brightening is actually a double peak, providing a clue as to what might be causing it.
Mauri Valtonen of University of Turku, Finland, and his international team used several optical telescopes around the world in conjunction with NASA’s SWIFT X-ray space telescope to realize that these 12-year double-brightening events are triggered by a smaller black hole in orbit around OJ287. Valtonen is the lead author of the study published in the Astrophysical Journal.
The massive black hole possesses a very hot accretion disk, a key component of a quasar. The material accumulates in the disk and gets pulled into the black hole, feeding it. Along the way, the disk material is heated and emits powerful electromagnetic radiation. OJ287′s smaller black hole partner, which itself is still 100 solar masses (still a huge black hole!) has a highly elongated orbit, swinging close to the more massive black hole every 12 years. During closest approach, the smaller black hole “splashes” into OJ287′s accretion disk once during the incoming swing and once more as it swings around the black hole’s far side, creating 2 distinct flaring events, as this diagram demonstrates:
With this binary black hole model in mind, the researchers were able to predict when the latest event was due to occur. The last brightening happened on Nov. 18, 2015, only a few days before Valtonen’s prediction, confirming his team’s binary black hole model. But through these observations, the supermassive black hole’s spin could also be calculated and it’s fast. The team’s observations show that it is spinning at a third of the speed of light.
Interestingly, from the historical data of OJ287, the team was also able to calculate how much energy is being lost from the system via gravitational waves. Of course, gravitational waves are currently a very hot topic, having been directly detected for the first time by the US-based Laser Interferometer Gravitational-wave Observatory (LIGO) and announced last month. That LIGO detection was the signature produced by 2 orbiting and merging black holes, a discovery that not only confirmed one of Einstein’s final predictions of general relativity, but also directly confirmed the existence of 2 black holes merging as one.
Read more at Discovery News
Mar 15, 2016
Lying in Omani waters, the wreck site was identified as possibly belonging to the ship Esmeralda. It is the oldest shipwreck from Europe’s age of exploration ever to be found, Oman’s Ministry of Heritage and Culture said on Tuesday.
The wreck was first discovered in 1998, on the 500th anniversary of Vasco da Gama’s epic discovery of the direct sea route to India, after an extensive search in the Portuguese archives.
David Mearns, of the recovery company Bluewater Recoveries Ltd, identified the wreck site off the coast of the remote Al Hallaniyah Island, some 28 miles from mainland Oman.
“The bay where the site is located was almost a perfect geographical match for where the ship wrecked, according to the descriptions of the chroniclers,” Mearns said.
The site wasn't explored until 2013 when a two-year excavation, led by Mearns in partnership with Oman’s Ministry of Heritage and Culture, took place in the island’s waters.
No hull timbers or large ship structures were found on the seabed, but archaeologists recovered more than 2,800 artifacts that helped in the identification of the wreck site.
Along with another ship, São Pedro, Esmeralda was the leading vessel of a five-ship squadron left behind by Da Gama when he returned from India to Lisbon in 1503.
The vessels were commanded by da Gama’s maternal uncles, Vicente and Brás Sodré, respectively. They were supposed to patrol the waters off the southwest Indian coast and protect the newly established Portuguese factories. Instead, they sailed to the Gulf of Aden between the Arabian Peninsula and Africa, where they looted Arab ships, sparing no lives and burning every ship after their plunder.
In May 1503, the squadron was anchored at Al Hallaniyah island. Local fishermen warned the Portuguese that a dangerous storm was approaching. Confidant that their iron anchors were strong enough, the Sodré brothers ignored the warning, while the smaller vessels of the fleet moved to a safe location on the other side of the island.
When the winds came, the São Pedro and the Esmeralda were torn from their moorings and smashed against the rocky shoreline.
“While most men on the São Pedro survived by scrambling across the fallen mast and rigging on to land, it was reported that everyone from the Esmeralda, including the squadron commander Vicente Sodré, perished in the deeper waters of the bay,” Mearns wrote in the International Journal of Nautical Archaeology.
Among the key artifacts recovered from the wreck site are a copper-alloy disc marked with the Portuguese royal coat of arms, a bronze bell carrying the inscription “498″ that suggests the ship was built in 1498, gold coins minted in Lisbon between 1495 and 1501, and an extraordinarily rare silver coin, called the Indio, commissioned in 1499 specifically for trade with India.
“The extreme rarity of the silver Indio, as only the second known specimen in the world, and the fact it was used specifically for Portuguese trade in India, is by itself a strong indicator of the ship’s nationality,” Mearns wrote.
He noted there is a clear geographical correlation between the site and the historical record of the loss of the ships commanded by the Sodré brothers.
Read more at Discovery News
The dust grains — also known as presolar grains, since they're older than Earth's sun — were likely spewed out by stars that blew up hundreds of millions of years before Earth's solar system formed. And in a new analysis of data collected from these tiny particles, researchers have come closer to pinpointing the type of stellar blast that produced the dust, 5 billion years ago.
To trace the origins of the stardust's subatomic "fingerprints," scientists built computer models simulating the explosive conditions that could have produced them, to test whether the dust grains' point of origin might have been an exploding white dwarf star in a double-star system.
This study adds to decades of analysis devoted to puzzling out the age and origins of these presolar grains, according to study co-author Christopher Wrede.
Wrede, an assistant professor of physics at Michigan State University, told Live Science in an email that researchers look at the grains' isotopes — variations of an element that have different numbers of neutrons. About a dozen grains held a great deal of the isotope silicon-30, which has been linked to a certain type of stellar explosion called a classical nova.
Classical novas — stellar eruptions that happen in a binary, or paired, star system — are different from supernovas, Wrede said, in that they are a type of explosion that can happen over and over again. The smaller star in a pair, a white dwarf, steals fuel from its larger neighbor, heating up its own surface and eventually blasting dust and gas into space.
"After a classical nova, the white dwarf can continue to siphon fuel from the companion and ignite again," Wrede said. "In a supernova, the entire star explodes, so it can only happen once."
When Earth's solar system was forming, collisions heated and mixed the building blocks of dust and gas, cooking them uniformly so that they shared many of the same isotopes. Grains with unusual isotopes — like silicon-30, which is rare on Earth — stand out, Wrede explained. "This tells us that they must have been produced prior to the formation of the solar system," dating back around 5 billion years, Wrede said.
Read more at Discovery News
The success of the project, outlined in the journal Evolution, brings scientists a step closer to creating “Dino-Chicken,” a chicken fully reverted to one of its dinosaur ancestors. That isn’t what this research team is after, though.
“The experiments are focused on single traits, to test specific hypotheses,” senior author Alexander Vargas of the University of Chile’s Department of Biology explained in a press release.
The scientists wanted to explore how the drumstick, or lower leg bone, of modern birds evolved. In extinct dinosaurs, the comparable bone — called the fibula — is tube shaped and reaches all the way down to the ankle.
In the evolution from dinosaurs to birds, the fibula lost its lower end and no longer connects to the ankle. It’s also is shorter than the other bone in the lower leg, the tibia.
Several decades ago, scientists noted that bird embryos develope a tubular, dinosaur-resembling fibula. Only as the embryo continues to grow does this leg bone become shorter than the tibia and acquire its adult drumstick shape.
Vargas and his team suspected that if they inhibited a single bird bone maturation gene, called Indian Hedgehog (IHH), they would wind up with modern birds essentially sporting dinosaur legs. They did just that in chickens and, sure enough, managed to create birds that had the leg bones of a dinosaur. Just like dinos, the fibula in the lab-grown chickens connected to the ankle.
You can see what those bone changes looked like in the figures published in the paper.
The experiment suggests that over time, the fibula lost its lower end, which likely allowed for the evolution of tibias that are much longer. The latter bears much of the body’s weight and plays an essential role in movement and locomotion.
The study is not the first time that lead author Joâo Botelho and his colleagues have caused chickens to de-evolve an ancestral dinosaur feature. Previously, they managed to undo the evolution of the perching toe of today’s birds. This resulted in a non-twisted, non-opposed toe, as seen in the remains of extinct dinosaurs.
Yet another research team, based at Yale, also altered gene expression in chickens. This resulted in chickens with a dinosaur-like snout.
Read more at Discovery News
The remains also could contain the holy grail of all dinosaur fossils: DNA.
"Yes, it's possible," Lindsay Zanno told Discovery News, referring to genetic material that may be present in this as well as similar dinosaur finds. "We have some evidence that fragments of DNA may be preserved in dinosaur fossils, but this remains to be tested further."
What has been confirmed so far is that the T. rex, which was found in Montana and dates to 68 million years ago, retained medullary bone that reveals the individual was pregnant. Medullary bone is only present in female living dinosaurs, i.e. birds, just before and during egg laying. It's this type of bone that could retain preserved DNA.
Zanno is an assistant research professor of biological sciences at North Carolina State University, where she is also head of the North Carolina Museum of Natural Sciences' Paleontology Research Lab and is curator of paleontology. She explained that medullary bone lines the marrow cavity of the long bones of birds.
"It's a special tissue that is built up as easily mobilized calcium storage just before egg laying," she said. "The outcome is that birds do not have to pull calcium from the main part of their bones in order to shell eggs, weakening their bones the way crocodiles do."
Crocodiles, she said, are the closest living relatives of dinosaurs.
"Medullary bone is thus present just before and during egg laying, but is entirely gone after the female has finished laying eggs," she said.
Early on, Mary Schweitzer suspected that medullary bone was present in the tyrannosaur remains, and was able to confirm her suspicions after she, Zanno and their team conducted a chemical analysis of the T. rex's femur.
The material, found to be consistent with known medullary tissues from ostriches and chickens, contained karatan sulfate, a substance not present in any other bone types.
"This analysis allows us to determine the gender of this fossil, and gives us a window into the evolution of egg laying in modern birds," Schweitzer said.
"The discovery of medullary bone is just one more piece of evidence that blurs the line between birds and other theropod (carnivorous two-legged) dinosaurs like T. rex," she said.
The research is published in Nature Scientific Reports.
In a prior study, Sarah Werning of the University of California and Berkeley and her colleagues found medullary bone in the carnivorous dinosaur Allosaurus as well as in the plant-eating dino Tenontosaurus. The discoveries happened somewhat by chance, as she and the other researchers were studying dinosaur growth rates when they realized three of the dinosaurs were pregnant females.
She said, "We were lucky to find these female fossils. Medullary bone is only around for three to four weeks in females who are reproductively mature, so you'd have to cut up a lot of dinosaur bones to have a good chance of finding this."
Schweitzer agrees, and said that the femur her team studied was already broken when she received it. Echoing Werning, she acknowledged that most paleontologists would not want to cut open, or demineralize, their fossils in order to search for the rare medullary bone.
Read more at Discovery News
The horse-sized dinosaur fills gaps in the fossil record of T. rex evolution, helping to solve many mysteries about the enormous carnivore that was at the top of the terrestrial food chain before it went extinct as the Age of Dinosaurs came to a close about 65 million years ago.
We now know that, long before T. rex emerged, "tyrannosaurs were already hardwired with the sensory arsenal of a top predator before they got to be super giants," project leader Steve Brusatte of the University of Edinburgh's School of GeoSciences told Discovery News.
The findings are published in the journal Proceedings of the National Academy of Sciences.
Co-authors Alexander Averianov and Hans-Dieter Sues found the remains of the new tyrannosaur while conducting expeditions in the remote deserts of Uzbekistan, Central Asia. They named the tyrannosaur Timurlengia euotica after a central Asian warlord, Timur, and also with a word meaning "well eared." The word refers to the new dinosaur's incredible sense of hearing.
Brusatte explained that the 90-million-year-old dino had a very long spiral cavity of the inner ear (cochlea), which allowed it to hear low frequency sounds that would have been undetected by other dinosaurs.
On top of this super sensory hearing, "Timurlengia was a nimble pursuit hunter with slender, blade-like teeth suitable for slicing through meat," Sues said, adding that "it probably preyed on the various large plant-eaters, especially early duck-billed dinosaurs, which shared its world."
The fast-running, long-legged Timurlengia was just a fraction of the size of T. rex, which could grow to be 40 feet long, 20 feet tall and weighed as much as 9 tons. The dichotomy in size strongly suggests that during the final 20 million years of the Cretaceous, tyrannosaurs evolved enormous bodies in a relatively short period of time.
As for why, Brusatte said "it is interesting that there was a mass extinction event about 94 million years ago, seemingly caused by extensive volcanism leading to global warming."
He suspects that the extinction of prior top carnivores left a void for "tyrannosaurs (to) opportunistically take over the apex predator role," but he said more fossils from the middle Cretaceous would be needed to test the theory.
The ancestors of T. rex migrated out of that region, such that T. rex later dominated western North America. Carr agrees that Timurlengia helps to fill many gaps in the fossil record separating the earliest, most primitive tyrannosaurs from the giant, advanced species like T. rex.
Lindsay Zanno, head of the North Carolina Museum of Natural Sciences' Paleontology Research Lab and curator of paleontology, said about Timurlengia and other earlier, smaller tyrannosaurs, "We know these guys were understudies for other dinosaurian mega-predators on northern landmasses for some time before seizing the opportunity to be the starring act."
Read more at Discovery News
Mar 13, 2016
Darwin's Theory of Evolution introduced the concept of 'survival of the fittest'. At each generation the 'fittest' individuals are selected and this is a major force shaping the biological world we see today. Selection can explain why a cheetah runs fast -- cheetah's that run fast catch the food to feed their cubs. Those that don't run fast get less food, and fewer cubs survive. Over time evolution selects against cheetahs that cannot run fast enough. But, how fast is fast enough, and big does the difference have to be before selection is effective? This question was asked by two researchers at Uppsala University, graduate student Gerrit Brandis and Professor Diarmaid Hughes.
Brandis and Hughes used Salmonella (a bacterium that causes infections in humans and animals) to measure the power of selection to choose the fittest individuals. Salmonella is similar to animals like cheetahs in the sense that it competes for food and is under intense selection to use that food to grow as fast or faster than any other individuals in the same environment. Evolution selects for the fittest variants.
To grow, bacteria, like all living organisms, must translate their genetic code into amino acids that are joined together to make proteins. The speed of translation determines how fast Salmonella can grow. Translation is one of the most ancient processes in biology and has been under selection for billions of years on earth.
The genetic code has 'redundancy', meaning that there are several different 'codons' that can be translated into any one amino acid. For some amino acids up to 6 different codons can be used. Brandis and Hughes asked whether it mattered which particular codons were used to make EF-Tu, one of the most important proteins in Salmonella.
Brandis and Hughes changed many different codons and showed that changing even a single codon in the gene for this protein into any one of the alternative 'synonymous' codons reduced the 'fitness' of Salmonella. The codons that are actually used by Salmonella are the very best, and any change reduces the fitness of the bacteria.
Brandis and Hughes quantified the fitness cost of changing codons in this gene. On average, changing a single codon reduced the fitness of the bacteria, by 0.01 procent per generation. This tiny change in fitness is big enough for evolution to select the 'fittest' DNA sequence and causes what is called 'codon usage bias' -- the widespread use of particular codons to make highly expressed proteins. Codon usage bias is found in nearly all fast-growing organisms, including bacteria and yeasts that cause infections in humans. Evolution has shaped their translation machinery so that they can grow as rapidly and efficiently as possible -- not necessarily good for us, but good for the survival of bacteria and yeast.
Read more at Science Daily
Our human ancestors, who looked like a cross between apes and modern humans, had access to food, water and shady shelter at a site in Olduvai Gorge, Tanzania. They even had lots of stone tools with sharp edges, said Gail M. Ashley, a professor in the Rutgers Department of Earth and Planetary Sciences in the School of Arts and Sciences.
But "it was tough living," she said. "It was a very stressful life because they were in continual competition with carnivores for their food."
During years of work, Ashley and other researchers carefully reconstructed an early human landscape on a fine scale, using plant and other evidence collected at the sprawling site. Their pioneering work was published recently in the Proceedings of the National Academy of Sciences.
The landscape reconstruction will help paleoanthropologists develop ideas and models on what early humans were like, how they lived, how they got their food (especially protein), what they ate and drank and their behavior, Ashley said.
Famous paleoanthropologist Mary Leakey discovered the site in 1959 and uncovered thousands of animal bones and stone tools. Through exhaustive excavations in the last decade, Ashley, other scientists and students collected numerous soil samples and studied them via carbon isotope analysis.
The landscape, it turned out, had a freshwater spring, wetlands and woodland as well as grasslands.
"We were able to map out what the plants were on the landscape with respect to where the humans and their stone tools were found," Ashley said. "That's never been done before. Mapping was done by analyzing the soils in one geological bed, and in that bed there were bones of two different hominin species."
The two species of hominins, or early humans, are Paranthropus boisei -- robust and pretty small-brained -- and Homo habilis, a lighter-boned species. Homo habilis had a bigger brain and was more in sync with our human evolutionary tree, according to Ashley.
Both species were about 4.5 to 5.5 feet tall, and their lifespan was likely about 30 to 40 years.
Through their research, the scientists learned that the shady woodland had palm and acacia trees. They don't think the hominins camped there. But based on the high concentration of bones, the primates probably obtained carcasses elsewhere and ate the meat in the woods for safety, Ashley said.
In a surprising twist, a layer of volcanic ash covered the site's surface, nicely preserving the bones and organic matter, said Ashley, who has conducted research in the area since 1994.
"Think about it as a Pompeii-like event where you had a volcanic eruption," she said, noting that a volcano is about 10 miles from the site. The eruption "spewed out a lot of ash that completely blanketed the landscape."
On the site, scientists found thousands of bones from animals such as giraffes, elephants and wildebeests, swift runners in the antelope family. The hominins may have killed the animals for their meat or scavenged leftover meat. Competing carnivores included lions, leopards and hyenas, which also posed a threat to hominin safety, according to Ashley.
Paleoanthropologists "have started to have some ideas about whether hominins were actively hunting animals for meat sources or whether they were perhaps scavenging leftover meat sources that had been killed by say a lion or a hyena," she said.
"The subject of eating meat is an important question defining current research on hominins," she said. "We know that the increase in the size of the brain, just the evolution of humans, is probably tied to more protein."
The hominins' food also may have included wetland ferns for protein and crustaceans, snails and slugs.
Read more at Science Daily