Apr 28, 2016

Half the World's Farmed Fish May Be Hard of Hearing

An ear bone deformity has left an estimated half of the world’s farmed fish with hearing loss, according to research just published in the journal Scientific Reports.

Hearing is critical for a fish’s balance as well as its hearing. If something in the farming process is causing the deformity, the study’s authors say, there may be animal welfare issues to address.

Also, the deformity could help explain the underperformance of some fish conservation programs, which breed fish in captivity so they can be released into the wild.

Thanks to a malformed chemical structure, the deformed ear bones end up being bigger, lighter and more brittle than they should be. This impacts proper hearing in the animal.

The prevalence of the deformity – 10 times more likely in farmed fish than wild, regardless of species — was uncovered by researchers from the University of Melbourne, who chose to study Atlantic salmon farms from the world’s top salmon producers: Canada, Chile, Norway, Scotland and Australia.

Shown are the left and right ear bones of a juvenile farmed salmon. The left one is normal, and the right one is deformed. The deformed ear bone is larger and more opaque.
“The deformity occurs at an early age, most often when fish are in a hatchery, but its effects on hearing become increasingly more severe as the fish age,” explained the study’s lead author Tormey Reimer in a statement, adding that the deformity can cost a fish up to 50 percent of its hearing.

The scientists compared ear structures in both farmed and wild salmon from the top-producing countries and also used a mathematical model to predict what the fish would be able to hear based upon their ear structures.

The researchers found that no matter which country’s fish they studied the ear bone deformity was much higher in the farmed fish versus wild.

“We estimate that roughly half of these fish have the earbone deformity and thus have compromised hearing,” said Reimer. “We don’t yet know exactly how this hearing loss affects their performance in farms.”

"However," she added, "producing farmed animals with deformities contravenes two of the 'Five Freedoms' that form the basis of legislation to ensure the welfare of farmed animals in many countries."

“We now need to work out what is the root cause, to help the global salmon industry produce fish with acceptable welfare standards,” Reimer said.

Read more at Discovery News

Snoring Lizards Reveal Sleep Predates Dinosaurs

Owners of pet lizards for years have anecdotally reported that their reptilian friends snore, appear to dream, and seem to enjoy snoozing just as we do, and now new research finds that reptiles do indeed experience the same sleep states of mammals and birds.

Before, it was thought that only birds, humans and other mammals went through rapid eye movement sleep (REM) and slow-wave sleep (SWS) as they snoozed, but the new findings, published in the journal Science, suggest that these sleep patterns evolved in the common ancestor of all such animals more than 300 million years ago.

By extension, it is then likely that today’s reptiles dream, and that many long-extinct animals such as dinosaurs did so as well.

“Dreaming, like sleep, consciousness, language, pain etc. are all concepts or phenomena that were first experienced and described in a self-referential manner by humans, assigned a word and implicitly considered as uniquely human,” senior author Gilles Laurent, director of the Max Planck Institute for Brain Research, told Discovery News.

“But if you think as a biologist about these phenomena, accept that most of them probably did not drop from the sky onto the first human being, but rather result from some slow evolutionary process, then we can start thinking about dreams as patterns of neuronal activity in the brain during sleep that are at least partly built up from past experience,” he added. “If you are ready to accept that bits of neuronal playback in certain brain areas during sleep can be called dreams, then I’ll bet that lizards dream.”

Scientists for decades tried to detect sleep patterns in reptiles by placing electrodes on the surface of the animals’ brains, similar to doing an EEG. Laurent and his team took this a step further, by implanting probes right into the brains of five bearded dragons (lizards). As a result, the researchers were better able to record the sleep patterns and to match them to eye movements.

Humans go through four or five 60 to 90 minute SWS-REM cycles on average every night, but the lizards experienced about 350 80-second cycles. Rest is unaffected, Laurent said, as the two sleep cycles run together, just as they do in humans. The individual is basically unaware that all of this brain wave change is happening.

“Among mammals, there tends to be some relationship between animal size and length of sleep cycle,” he said. “It is not absolute, but is statistically true. For example, the human sleep cycle is about 60–90 minutes, while it is 30 minutes for cats and 15 minutes for rats.”

Even insects and arachnids like spiders sleep, but it is unclear if they experience REM and SWS sleep patterns. Some animals rest, but do not technically sleep.

Laurent explained, “Multicellular animals without brains, such as sponges and jellyfish…most likely do not express ‘brain sleep’ both by definition since they lack a brain and because REM and SWS require certain neural circuits that, as far as we know, they lack.”

Even for these creatures, prior amounts of rest, temperature shifts and other environmental factors seem to affect rest, which in multicellular animals without brains probably is expressed through their circadian rhythms, otherwise known as their internal “body clocks.”

As for now-extinct dinosaurs, Laurent said that “it seems likely they expressed REM and SWS.” They therefore probably dreamed and consolidated their memories as they slept in a way that was at least somewhat similar to how we and many other animals do so today.

Thanos Siapas, a professor of computation and neural systems at Caltech, told Discovery News that the new study “is a truly groundbreaking paper that sheds new light into how the architecture of sleep evolved. The data and analysis are very compelling and suggest an ancient origin of the two alternating stages of sleep.”

Read more at Discovery News

Kennewick Man to Receive Native American Burial

Kennewick Man, one of the oldest and best-preserved skeletons ever found in North America, is related to modern Native American tribes, the U.S. Army Corps of Engineers said Wednesday, possibly closing a debate that lasted 20 years.

The corps, which owns and has custody of the remains, said the 8,500-year-old bones are now covered by the Native American Graves Protection and Repatriation Act, opening the process to return Kennewick Man to tribes for Native American burial.

The decision was based upon review and analysis of new information, in particular a DNA study and skeletal analyses published last year in the journal Nature.

Researchers from the University of Copenhagen and Stanford University School of Medicine used the latest in DNA isolation and sequencing techniques to analyze the genetic material in a bone sample.

They concluded that, although it is impossible to assign Kennewick Man to a particular tribe, he is closely related to members of the Confederated Tribes of the Colville Reservation in Washington.

The results challenged a 2014 study that assumed, based on anatomical data, that Kennewick Man was more related to indigenous Japanese or Polynesian peoples than to Native Americans.

Earlier this month scientists from the University of Chicago, independently validated the genetic study published in Nature.

“We concur with the findings of the original paper that the sample is genetically closer to modern Native Americans than to any other population worldwide,” John Novembre, David Witonsky, and Anna Di Rienzo of Chicago University wrote.

The validated DNA and skeletal analyses prompted Army Brig. Gen. Scott Spellmon, commander of the corps’ Northwestern Division to put to an end a decade-long debate over the skeleton’s origins.

“I find that there is substantial evidence to determine that Kennewick Man is related to modern Native Americans from the United States,” Spellmon ruled.

The skeletal remains were discovered in 1996 along the shores of the Columbia River in Washington state. The finding prompted a legal, spiritual and scientific dispute between scientists, who wanted to study the bones, and Native Americans, who claimed Kennewick Man as an ancestor and called him the Ancient One.

The court battle began with a lawsuit filed against the U.S. Army Corps of Engineers by eight scientists seeking access to study the bones.

In February 2004, a three-judge panel of the 9th U.S. Circuit Court of Appeals ruled in favor of the anthropologists, concluding that “a significant relationship of the tribal claimants with Kennewick Man” could not be proved.

Reburial requests were halted to allow further investigation into the skeleton’s origins.

Legally the property of the U.S. Army Corps of Engineers, as they were found on land under its custody, the remains of Kennewick Man are locked away at the Burke Museum at the University of Washington, where they were deposited in 1998.

“At present, there has been no decision to transfer the remains,” Spellmon said.

Read more at Discovery News

One of Titan's Strange Seas is Pure Methane

A new study of eight years of radar data collected by the Saturn-orbiting Cassini spacecraft shows that the planet’s largest moon, Titan — the only other body in the solar system besides Earth where liquids pool on the surface — has a sea of pure methane.

Before Cassini, scientists had expected Titan’s seas to be dominated by ethane, since sunlight breaks apart methane and converts it into the more complex ethane hydrocarbon.

Instead, Alice Le Gall, a Cassini scientist at France’s LATMOS research laboratory, and colleagues discovered that Ligeia Mare, Titan’s second-largest sea, is almost pure methane.

Scientists suspect that methane rain may be regularly filling the sea, or that ethane is locked in the sea’s crust, or flowing into the adjacent sea, according to a press release about the study, which was published in the March 11 issue of Journal of Geophysical Research Planets.

The findings are based on radar observations made by Cassini between 2007 and 2015. Those measurements of heat given off by Ligeia Mare were combined with results of a 2013 experiment that bounced radar waves off the seafloor, which allowed scientists to estimate the sea’s depth.

Ligeia Mare, which turns out to be as deep as 525 feet, also likely sports a layer of organic-rich sludge on its floor, the scientists said.

“It’s a marvelous feat of exploration that we’re doing extraterrestrial oceanography on an alien moon,” Cassini scientist Steve Wall, with NASA’s Jet Propulsion Laboratory in Pasadena, Calif., noted in the press release.

Cassini, which has been studying the Saturn system for almost 12 years, has revealed that almost 2 percent of Titan’s 620,000 square miles of real estate are covered in liquid.

The moon has three large seas, all located in the northern polar region, that are surrounded by small lakes. So far, just one large lake has been found in Titan’s southern hemisphere.

From Discovery News

Mysterious 'Haloes' on Pluto Puzzle Scientists

The discovery of strange halo-like craters on Pluto has raised a new mystery about how the odd scars formed on the icy world.

Pluto’s “halo” craters are clearly visible in a new image from NASA’s New Horizons spacecraft, which made the first-ever flyby of the dwarf planet in July 2015. In the image, a black-and-white view reveals dozens of ringed craters (NASA describes these formations as “haloed”) strewn across the dark landscape of Vega Terra, a region in the far western reaches of the hemisphere photographed by New Horizons during its flyby. The craters have bright walls and rims, making them stand out from their darker surroundings.

While the haloed craters are eye-catching, what has really stumped scientists is what these features are made of.

A glimpse at the craters provided by New Horizons’ Ralph/Linear Etalon Imaging Spectral Array revealed a surprising connection between the bright halo features and the distribution of methane ice, NASA officials explained in an image description. This methane ice around the craters shows up as a deep purple in an inset view included in the new image. The crater floors and in-between regions, meanwhile, are colored blue to indicate water ice.

“Exactly why the bright methane ice settles on these crater rims and walls is a mystery; also puzzling is why this same effect doesn’t occur broadly across Pluto,” NASA officials wrote in the image description.

So that’s yet another mystery for scientists to ponder as the images and data continue to beam back to Earth from New Horizon’s Pluto flyby on July 14, 2015. Mission scientists have said the probe’s data download should be complete by October or November.

NASA’s New Horizons spacecraft launched in 2006 and is currently headed out into the Kuiper Belt, a region of icy bodies beyond the orbit of Neptune. Last week, mission scientists submitted a proposal for an extended mission that, if approved, would send the probe by the Kuiper Belt object 2014 MU69 on Jan. 1, 2019.

From Discovery News

Apr 27, 2016

Hyena Ate Early Human 500,000 Years Ago

About 500,000 years ago, a hyena ate a human literally down to the bone, according to a new paper that describes the gory find.

The chewed up human thighbone adds to the growing body of evidence that humans were frequently both predators and prey before their numbers increased and weapons improved. The discovery is reported in the journal PLOS ONE.

Project leader Camille Daujeard and colleagues analyzed the ancient gnawed human bone, which was unearthed in a cave named “Grotte √† Hominid√©s,” located near Casablanca, Morocco.

“This bone represents the first evidence of consumption of human remains by carnivores in the cave,” the authors wrote. They added that the “chewed femur indicates that humans were a (food) resource for carnivores, underlying their close relationships during the Middle Pleistocene in Atlantic Morocco.”

The relationships appear to have been too close, with Daujeard and colleagues sharing that there was “competition for resources as well as for living spaces.”

The researchers suspect that a hyena ate the human, based on both the many tooth marks left on the thighbone and the way in which the individual was eaten. Once the hungry hyena finished with the flesh, it crushed the bone ends and ate the deceased’s marrow.

The human was probably a member of the species Homo rhodesiensis, since other remains of this early human have been found elsewhere at the site. Such individuals looked a lot like we do today.

The researchers wrote that, at the time, the early humans “hunted in groups and relied on new effective weapons; these two improvements allowed them to slaughter larger gregarious prey and to handle encounters with dangerous competitors. Still, this was a period of stiff competition between large carnivores and hominins…” The authors added that both groups “shared the same landscapes and competed for resources and natural shelter.”

It remains unclear if the hyena killed the human, or if the toothy mammal came upon an already dead individual and consumed the remains. Both scenarios are possible, according to the researchers.

Bones for many other species were found at and around the site, revealing that gazelles, antelopes, bears, leopards, porcupines, wildebeest, baboons, zebras, rhinos and many other animals were in the ecosystem with humans, who likely hunted most, if not all, of them.

“Coprolites (fossilized clumps of poo) are numerous,” according to the researchers, providing further evidence of the animals’ presence.

We will probably never know the true extent of the killing that went on back in the day: both humans hunting multiple species, and animals killing early humans.

Read more at Discovery News

Face of Neanderthal 'Altamura Man' Recreated

The calcite-encrusted face of a Neanderthal who lived around 150,000 years ago has come alive as researchers reconstructed a hyper-realistic model of his face and body.

The fossilized complete skeleton, known as the Altamura Man, is the most ancient Neanderthal from which portions of genetic material DNA have been extracted.

Discovered in 1993 in the karstic cave of Lamalunga, near the town of Altamura in Puglia, the skeleton has been shown in a life-size model complete with hair, beard and moustache.

Featuring a short and stocky body, the Altamura Man had a jutting brow, an elongated cranium and a very big nose.

“To me he looks beautiful,” David Caramelli, associate professor of anthropology at the University of Florence, told Discovery News.

The Altamura Man rested undisturbed in the cave until a group of speleologists spotted a 26-foot-deep well. Inside was a tunnel that opened into a large cavity, with other tunnels branching out from it. One of them, about 200 feet long, led to another cave, rich with stalagmites. There, encrusted in a corner, looking like a large piece of coral, was a skeleton lying on its back.

Researchers assume the unfortunate hominid fell in a well and remained trapped there, dying of starvation or from lack of water intake. The skeleton was then covered with droplets of limestone that helped preserve it for millennia.

Last year, Caramelli, Giorgio Manzi, professor of paleoanthropology and human ecology at Rome’s Sapienza University, and colleagues were able to extract DNA from the articular portion of the right scapula.

The analysis confirmed the Altamura Man was a Neanderthal, the species that inhabited Europe between 200,000 and 40,000 years ago.

The researchers estimated the hominid lived approximately 150,000 years ago, in the late-Middle to early-Late Pleistocene — an ancient phase in the existence of Neanderthals.

To create the hyper-realistic model, Manzi and Caramelli used photogrammetry and laser scanning of the encrusted skeleton combined with data from the DNA analysis.

Read more at Discovery News

Pyramid Interior Revealed Using Cosmic Rays

The internal structure of an ancient Egyptian pyramid was revealed for the first time using cosmic particles, a team of international researchers reports.

The innovative technology was applied to the Bent Pyramid, a 4,500-year-old monument so named because of its sloping upper half.

According to the researchers, who presented their results in Cairo on Tuesday to Khaled El-Enany, minister of Antiquities and the former minister Mamdouh El-Damaty, the outcome was “excellent” as it showed the inside of the monument as with an X-ray.

The technology relies on muons, cosmic particles that permanently and naturally rain on Earth, which are able to penetrate any material very deeply.

This is the first of four pyramids to be investigated within the ScanPyramids, a project carried out by a team from Cairo University’s Faculty of Engineering and the Paris-based non-profit organization Heritage, Innovation and Preservation under the authority of the Egyptian Ministry of Antiquities. The others are the Great Pyramid, Khafre or Chephren at Giza, and the Red pyramid at Dahshur.

Scheduled to last a year, the project uses a mix of innovative technologies such as infrared thermography, muon radiography, and 3-D reconstruction to better understand the monument and possibly identify the presence of unknown internal structures and cavities.

Located at the royal necropolis of Dahshur, about 25 miles south of Cairo, the Bent pyramid was built under the Old Kingdom Pharaoh Sneferu (about  2600 BC). It's the first with a smooth face, after generations of stepped pyramids.

The monument has two entrances, one on the north side and one on the west side. These entries open on two corridors leading to two burial chambers arranged one above the other.

It was speculated that pharaoh Sneferu rests inside the pyramid in an undiscovered burial chamber, but the innovative technology ruled out the hypothesis. The scanning did not detect any additional chamber of the size of the upper chamber or beyond in the field of view covered by the muography.

“Nevertheless, this is indeed a scientific breakthrough as it validates the muography principle applied to Egyptian pyramids. It paves the way to new investigations,” said Mehdi Tayoubi, co-director of the ScanPyramids mission with Hany Helal, professor at Cairo University’s Faculty of Engineering and former minister of research and higher education.

The results come four months after a team led by specialist Kunihiro Morishima, from the Institute for Advanced Research of Nagoya University, Japan, installed (as explained in this video) 40 muon detector plates inside the lower chamber of the Bent pyramid.

Covering a surface of about 10 square feet in the pyramid’s lower chamber, the plates contained two emulsion films that are sensitive to muons that continually shower the Earth’s surface.

They come from the upper layers of Earth’s atmosphere, where they're created from collisions between cosmic rays and the nuclei of atoms in the atmosphere.

“Just like X-rays pass through our bodies allowing us to visualize our skeleton, these elementary particles, weighing around 200 times more than electrons, can very easily pass through any structure, even large and thick rocks, such as mountains,” Tayoubi said.

The plate detectors allow researchers to discern void areas -- these are places where muons cross without problem -- from denser areas where some muons are absorbed or deflected.

Morishima’s team retrieved the detector plates from the Bent pyramid in January 2016 after 40 days of exposure. This is the maximal lifetime of chemical emulsions within the temperature and humidity conditions inside that pyramid.

The films were then developed in a dedicated lab installed at the Grand Egyptian Museum (GEM), and shipped to Nagoya University for analysis.

“From these plates, more than 10 millions of muon tracks were analyzed. We count the muons and according to their angular distribution we are able to reconstruct an image,” Tayoubi said.

“For the first time ever, the internal structure of a pyramid was revealed with muon particles. The images obtained clearly show the second chamber of the pyramid located roughly 60 feet above the lower one in which emulsions plates were installed,” he added.

Tayoubi stressed that each step in the project is important.

“We learn a lot from the reality of the field. We improve the knowledge of the monuments but we also improve the technologies progressively. We are not in a hurry,” he said.

Tayoubi admitted that the available statistics from the 40 days of exposure is not yet sufficient to precisely reveal the known corridors or unknown voids smaller than those in the upper chamber.

However, the researchers made simulations by randomly placing, within the field of view, a hypothetic chamber of size similar or larger than the upper one.

“Compared with the results obtained, these simulations could validate the fact there is no additional chamber of this size in the surroundings,” professor Morishima said.

Strong of their results, the researchers will now apply the muography to other Old Kingdom pyramids.

Read more at Discovery News

Explore Mariana Trench with Live Video Feed

Here’s an odd fact about the National Oceanic and Atmospheric Administration’s Okeanos Explorer, the nation’s only federally funded ship assigned to explore the world’s oceans: Most of the scientists who participate in its missions remain onshore.

That’s because the ship is wired with video cameras and broadband Internet to enable telepresence, in which observers on land can watch live images from the ocean floor from the comfort of their own desks.

Now, NOAA is providing you with a chance to see some of the same amazing sights that the scientists view. From now until July 10, as the Okeanos Explorer probes some largely unexplored areas in and around the Mariana Trench Marine National Monument and the Northern Marianas Islands in the Pacific, you’ll be able to watch a live video feed.

The ship is equipped with two robotic remotely operated vehicles (ROVs), which descend into the depths. Here’s a map that tracks the ship’s location in real time.

Located in the Mariana Archipelago east of the Philippines, the national monument protects about 95,000 square miles of ocean waters and floor. The Mariana Trench itself is the deepest place on the planet, farther down than the summit of Mount Everest is above sea level.

One portion of the monument, an arc of undersea mud volcanoes and thermal vents, supports exotic life forms that exist in some of the harshest conditions imaginable on the planet — highly acidic and boiling-hot water.

One of its features, the Champagne vent, produces almost pure carbon dioxide, one of only two such known sites in the world.

Another of the monument’s curiosities is the Daikoku submarine volcano, which has the planet’s only pool of liquid molten sulfur. The other such known pool is on Io, a moon of the planet Jupiter. For more information, check out this primer from the U.S. Fish and Wildlife Service.

From Discovery News

Lake Beneath Antarctic Ice Could Hold Hidden Life

British scientists believe they may have discovered a large lake beneath the ice of the Antarctic continent, one that may harbor life that has lain undisturbed for millennia. They believe the lake, which measures approximately 87 by 12 miles, is connected to a canyon system that in total is roughly 680 miles in extent. The scientists first published their finding in the journal Geology and expanded upon them this month at the European Geosciences Meeting in Vienna.

Their conclusions are based on discerning faint grooves in the ice after closely examining satellite imagery of the area, in a region of the froze continent known as Princess Elizabeth Land.

“We’ve seen these strange, linear channels on the surface, and are inferring these are above massive, 1000-kilometer-long channels, and there’s a relatively large subglacial lake there too,” Martin Siegert of Imperial College London, a member of the research team, told New Scientist.

Siegert further stated that researchers from China and the US have flown over the region and gathered ice penetrating radar data, which they hope will confirm the presence of the under-ice features.

“We’re meeting in May to look at the data,” he said. “It will be a very good test of our hypothesis about the lake and channels.”

Although big, the putative lake would not be the largest discovered under the frozen ice cap of the Antarctic. That honor belongs to Lake Vostok, which measures 160 by 30 miles — which would make it the sixth-largest in the United States, more than twice as large as Utah’s Great Salt Lake and bested only by the Great Lakes.

In 2012, Russian scientists drilled a borehole into Lake Vostok, which has been covered by ice for 15 million years and lies more than two and a quarter miles below the surface, and claimed to have found evidence of unusual life. However, their findings were met with skepticism and controversy because the water samples were contaminated with fluid used to help the drilling process; last year, having corrected their technique, they began to drill for a second time.

An American team that drilled into Lake Whillans — a sliver of water just 7 feet deep, which is half a mile below the surface of the Ross Ice Shelf — in 2013 was able to avoid such contamination issues by deploying a series of sterilization measures. To their astonishment, they found microbial life in a density comparable to that in many of the world’s deep oceans, and a complex community of bacteria and archaea at least 4,000 species strong.

Read more at Discovery News