Curse Tablets Found in 2,400-Year-Old Grave

Five lead tablets that cursed tavern keepers some 2,400 years ago have been discovered in a young woman’s grave in Athens, Greece.

Four of the tablets were engraved with curses that invoked the names of “chthonic” (underworld) gods, asking them to target four different husband-and-wife tavern keepers in Athens. The fifth tablet was blank and likely had a spell or incantation recited orally, the words spoken over it.

All five tablets were pierced with an iron nail, folded and deposited in the grave. The grave would have provided the tablets a path to such gods, who would then do the curses’ biddings, according to ancient beliefs.

One of the curses targeted husband-and-wife tavern keepers named Demetrios and Phanagora. The curse targeting them reads in part (translated from Greek):

“Cast your hate upon Phanagora and Demetrios and their tavern and their property and their possessions. I will bind my enemy Demetrios, and Phanagora, in blood and in ashes, with all the dead…”

“I will bind you in such a bind, Demetrios, as strong as is possible, and I will smite down a kynotos on tongue.”

The word kynotos literally means “dog’s ear,” an ancient gambling term that “was the name for the lowest possible throw of dice,” Jessica Lamont, an instructor at John Hopkins University in Baltimore who recently completed a doctorate in classics, wrote in an article published recently in the journal Zeitschrift für Papyrologie und Epigraphik. The “physical act of hammering a nail into the lead tablet would have ritually echoed this wished-for sentiment,” Lamont wrote.

“By striking Demetrios’ tongue with this condemningly unlucky roll, the curse reveals that local taverns were not just sociable watering holes, but venues ripe for gambling and other unsavory activities in Classical Athens,” Lamont wrote.

A woman’s grave

The grave where the five curse tablets were found was excavated in 2003 by archaeologists with Greece’s Ephorate for Prehistoric and Classical Antiquities. The grave was located northeast of the Piraeus, the port of Athens. Details of the burial have not yet been published, but Lamont said that excavation reports indicate that it contained the cremated remains of a young woman. Lamont has been studying the curse tablets at the Piraeus Museum, where they are now kept.

“The way that curse tablets work is that they’re meant to be deposited in an underground location,” such as a grave or well, Lamont told Live Science. “It’s thought that these subterranean places provided a conduit through which the curses could have reached the underworld,” and its chthonic gods would then do the curse’s biddings, Lamont said.

The woman buried in the grave might have had nothing to do with the curses or tavern keeping, Lamont said. Perhaps she died at the time when someone wanted to cast these curses on others in the same community, Lamont said.

Read more at Discovery News

Ancient Burials Revealed at Mysterious Plain of Jars

Archaeologists have uncovered ancient human remains and various burial practices at the mysterious Plain of Jars in Laos, Australian researchers said Monday, as scientists attempt to unravel the puzzle of the stone vessels.

The Plain of Jars in Laos’ central Xieng Khouang province is scattered with thousands of stone jars and scientists have long been perplexed by their original use.

“This will be the first major effort since the 1930s to attempt to understand the purpose of the jars and who created them,” Dougald O’Reilly from the Australian National University’s school of archaeology said in a statement.

He said excavations uncovered three types of burials at the site. In one practice, bones were buried in pits with a large limestone block placed over them, while other bones were found buried in ceramic vessels, separate from the jars.

The researchers also found for the first time an instance of a body being placed in a grave.

O’Reilly said while the jars were empty now, it is possible they were once used to hold bodies until the flesh had completely decomposed so the bones could then be buried.

“We don’t have any evidence for cremation which is something that has been suggested in the past,” said O’Reilly, adding that it was also unclear where those buried had lived.

Despite the finds, he said the original purpose of the jars remains unknown.

“The stone jars remain a mystery as to what they were used for,” O’Reilly said.

Only a few simple objects, such as a handful of glass beads, have been found with the human remains at the burial sites, which are thought to date from about 500 or 600 BC to 550 AD.

Read more at Discovery News

Pig Heart Kept Beating in Baboon for Years

One day, cardiac patients may enjoy a new lease on life with pig hearts beating in their chests, said researchers reporting a major advance Tuesday in cross-species organ transplantation.

Given the dire shortage of organ donors, the use of animal hearts, lungs or livers to save human lives has long been a holy grail of medical science.

But organ rejection has stood stubbornly in the way.

On Tuesday, scientists from the United States and Germany said they had succeeded in keeping transplanted pig hearts alive in baboons, primate cousins of humans, for a record 2.5 years.

Their method uses a combination of gene modification and targeted immune-suppressing drugs.

“It is very significant because it brings us one step closer to using these organs in humans,” said study co-author Muhammad Mohiuddin of the National Heart, Lung and Blood Institute in Maryland.

“Xenotransplants — organ transplants between different species — could potentially save thousands of lives each year that are lost due to a shortage of human organs for transplantation,” he told AFP by email.

In experiments with five baboons, the hearts survived for up to 945 days, breaking previous records held by the same group of researchers.

The hearts did not replace those of the monkeys, but were connected to the circulatory system via two large blood vessels in the baboon abdomen.

The transplanted heart beat like a normal heart, but the baboon’s own heart continued the function of pumping blood — a known method in studying organ rejection.

Donor organs are often rejected by a recipient’s immune system, which can recognise it as foreign, and thus a threat.

In this trial, the donor organs came from pigs which had been genetically modified to have high tolerance to immune response, basically making them invisible to the recipient’s natural defence system.

The scientists also added a human genetic signature to the pigs that help prevent blood clotting.

The recipient baboons were given a drug that suppresses immune response.

- Safe for humans? -

Scientists have been experiment with the transplantation of primate kidneys, hearts and livers into humans since the 1960s. None survived beyond a few months.

Given their genetic proximity to humans, primates were initially thought to be the best donor candidates. But there is no large source of captive-bred apes — which take long to grow and mature, and some like chimpanzees are endangered.

Their genetic closeness also poses a higher danger of inter-species disease transmission, as well as ethical questions.

Pigs have since emerged as better donors. Their hearts are anatomically similar to ours, they pose less of a disease transmission risk, they grow up fast and are already widely farmed.

In these xenotransplant trials, baboons serve as human models.

Read more at Discovery News

Ancient Animal Carried Its Young Like Tethered Kites

A tiny arthropod from 430 million years ago dubbed “The Kite Runner” had a novel way of hauling around its young: It stashed them in individual capsules tethered to its body, like so many kites at the ends of pieces of string.

That’s what a team of researchers from the United States and the United Kingdom found when they studied the fossil of an ancient arthropod named Aquilonifer spinosus, a creature not even half of an inch long that would have made its living on the sea floor alongside the sponges, snails, worms and other aquatic neighbors of its day.

The researchers described the many-tethered parent as having no eyes, its head covered by a shield-like apparatus.

Thanks to virtual reconstruction techniques, the scientists were able to determine that 10 juveniles were tethered to the fossil, in varying stages of development.

The pouches -- or “kites,” to continue the analogy -- holding the juveniles were attached to the adult by thin, flexible threads. The pouches themselves looked like “flattened lemons,” the scientists said.

“Modern crustaceans employ a variety of strategies to protect their eggs and embryos from predators: attaching them to the limbs, holding them under the carapace, or enclosing them within a special pouch until they are old enough to be released,” said the study’s lead author Derek Briggs, of Yale University, in a statement. “But this example is unique.”

Briggs and his colleagues from Oxford, the University of Leicester, and Imperial College London, ruled out any chance the juveniles were instead parasites attached to a convenient host, noting that their method of attachment would not have been very good for stealing nutrients.

Read more at Discovery News

Medieval Whip Used by Self-Flagellating Monks Found

British archaeologists have solved the mystery over some ancient pieces of woven copper-alloy wires that were unearthed at a Medieval monastery.

Found in 2014 at Rufford Abbey, Nottinghamshire, the braided-together length of copper wire, turned to be part of a whip or cat-o-nine-tail used by monks for self-flagellation.

According to Nottinghamshire County Council, the true meaning of the 14th century wire was realized after comparing it with a similar metal scourge found at another British monastery.

“This is a fascinating discovery which helps us to build a picture of what life could have been like for the monks living in the Abbey during the dark days of the Black Death and its aftermath,” Councillor John Knight, committee chairman for culture, said in a statement.

The Black Death plague ravaged the country between 1348 and 1350, causing the decline of Rufford Abbey which lost much of its income from the wool industry. Because of the Abbey's dire financial situation, various kings excused the Abbey from paying taxes during this time.

The whip is one of only four uncovered in the country. It would have been used in this period by the Cistercian monks in an attempt to ward off the Black Death, or as an act of penance to take the population’s sins upon themselves.

The monks lived in austerity — they would rise at 4.30 a.m. to take part in church services and then labor in the fields for long hours.

Despite the use of the self-flagellating whip, historical records reveal that some Rufford monks strayed from the monastic vows. They include Brother William, arrested for the murder of Brother Robert in 1280, and two monks who were charged with the £200 ($285) robbery of Thomas De Holme.

Read more at Discovery News

Great Barrier Reef Bleaching 'Worst in Its History'

Australia’s Great Barrier Reef corals are in trouble.

The northern part of the world’s largest coral reef ecosystem is experiencing “the worst mass bleaching event in its history,” according to a statement released in late March by the Australian Research Council.

Documented by the National Coral Bleaching Taskforce (NCBT) in aerial surveys, observations of more than 500 coral reefs spanning 2,485 miles (4,000 kilometers) showed that the majority of reefs were undergoing extensive and severe bleaching.

“Almost without exception, every reef we flew across showed consistently high levels of bleaching, from the reef slope right up onto the top of the reef,” said Terry Hughes of the NCBT, calling the surveys “the saddest research trip of my life.”

Bleaching happens when corals are exposed to stresses such as warmer-than-average waters for prolonged periods of time. The corals respond to the stress by expelling the algae that provide them with their color, which makes the corals look like they’ve been bleached white. Bleaching can be fatal for corals if the stress is too intense, or if it continues for too long and the algae are unable to recolonize them.

Ecosystem at risk

Australia’s Great Barrier Reef (GBR) covers 134,364 square miles (348,000 square kilometers), making it larger than the U.K., Switzerland and the Netherlands combined, according to the Great Barrier Reef Marine Park Authority. Recognized as a World Heritage Area in 1981, the reef contains 400 types of coral and hosts 1,500 types of fish and 4,000 mollusk species, as well as other marine life such as large green turtles and dugongs (“sea cows”).

The GBR experienced bleaching events in 1998 and in 2002, but the current mass bleaching is much more severe, experts are saying. Rebecca Albright, a marine biologist with the Carnegie Institution for Science in Washington, D.C., has studied the GBR since 2011. Albright told Live Science that 95 percent of the GBR’s northern reefs are currently showing signs of extreme bleaching, compared with 18 percent that experienced bleaching in 2002.

Even the more robust corals are affected, Albright said, another sign that this event is particularly serious. She cautioned that it’s still too early to assess the long-term impacts of bleaching on the corals, though estimates of coral mortality anticipate losses of about 50 percent.

Two factors are responsible for stressing the corals, Albright said: climate change, which is driving ocean temperatures upward, and a strong El Niño  — a cyclical climate event associated with warmer-than-average sea surface temperatures in the tropical Pacific. And with El Niño conditions expected to extend through 2016, that doesn’t bode well for the corals’ recovery.

“Corals are sensitive to not only the anomaly in temperature — how high it goes — but also the duration of that exposure,” Albright told Live Science. “This kind of perfect storm of all these factors coming together makes this a catastrophic scenario right now.” [Images: Colorful Corals of the Deep Barrier Reef]

A global event

But what’s happening to the GBR is only part of the picture. A global bleaching event prolonged by El Niño is currently underway — “the longest coral die-off on record,” according to a statement released by the National Oceanic and Atmospheric Administration (NOAA) on Feb. 23.

Mark Eakin, coordinator of the NOAA Coral Reef Watch program, told Live Science that the event, which began in 2014 in the Pacific, could linger through 2017.

“We consider it a global bleaching event if it’s widespread in all three of the major ocean basins — Indian, Atlantic and Pacific,” he said. Eakin described current reports of bleaching that extend over half of the Southern Hemisphere, with severe bleaching in New Caledonia, Fiji and southern Indonesia, as well as in the GBR.

Even fast-growing corals take decades to develop, so damaged reefs will need time before they’re restored to their former level of health, Eakin said.

And recovery time may be in short supply. Global bleaching events have been expanding their reach and increasing in severity since the first event was documented in 1998, Eakin told Live Science.

“We’re seeing prolonged high temperatures that cause bleaching coming back repeatedly. We’re seeing areas that have seen high temperatures for two to three years in a row. There’s no time for corals to recover,” he said.

The 1998 global bleaching event was associated with a strong El Niño — the strongest on record — but as ocean temperatures rise, even a mild El Niño can trigger a devastating effect on the world’s corals. And the global bleaching event that’s underway right now began in 2014, before the current El Niño was active, Eakin said.

Read more at Discovery News

350-Year-Old Pendulum Clock Mystery Solved

The 350-year-old mystery of why pendulum clocks hanging from the same wall can influence each other and synchronize over time may hold even more secrets than previously thought, researchers say.

Solving this mystery could shed light on puzzling aspects of a variety of synchronized behaviors, such as how brain cells work together, the scientists added.

In 1665, the inventor of the pendulum clock, Dutch physicist Christiaan Huygens, was lying in bed sick, watching two of his clocks, when he noticed something odd: No matter how the pendulums on these clocks started, they ended up swinging in exactly the opposite direction from each other within about a half-hour.

For centuries, the cause of this effect was unknown. Solving the puzzle could help shed light on the mysterious phenomenon of synchronization, scientists say.

“The synchronization phenomenon is one of the most pervasive drives in nature,” said study lead author Jonatan Peña Ramirez, a dynamicist at the Center for Scientific Research and Higher Education in Ensenada, Mexico. “For example, consider a couple dancing to the rhythm of music, or violinists in an orchestra playing in unison, or a school of fish gracefully swimming.”

In a separate study published last year in the journal Scientific Reports, scientists suggested that the explanation for this phenomenon involved sound pulses traveling from clock to clock — for instance, through the wall on which the machines hang. However, Peña and his colleagues now suggest that Huygens’ original explanation for this mystery could be the correct one.

The researchers experimented with two complex pendulum clocks known as monumental clocks.”To the best of our knowledge, this is the first time that Huygens’ experiment is reproduced using real monumental pendulum clocks,” Peña told Live Science. “Previous studies have used scaled-down versions of pendulum clocks, or commercial and generic clocks.”

The scientists placed both clocks on the same wooden table. As they expected, the motion of the clock pendulums synchronized over time.

However, unlike the clocks in Huygens’ experiment, the clocks did not swing in opposite directions. Rather, they unexpectedly moved in exactly the same direction. Moreover, while the clocks stayed in sync, they became slower and more inaccurate over time, the scientists said.

To explain these findings, the researchers developed a mathematical model of the clocks, taking into account the flexible nature of the wooden support that both machines rested on. The model suggested that the clocks could make the wooden board vibrate.

The researchers found that the support connecting the clocks (in this case, the wooden table) could serve as a kind of communication channel between the clocks, which they could use to exchange energy. The rigidity, thickness and mass of this support can influence the way in which the clocks synchronize and how inaccurate they become, the researchers said.

Long ago, Huygens suggested that the synchronous behavior of the clocks he observed might be caused by “the imperceptible vibrations of the beam on which they are hanging,” Peña said. Huygens “was so brilliant that he gave the correct explanation for his discovery without using a single equation.”

These findings suggest that much remains unknown about how coupled pendulum clocks behave, Peña said. “There still are hidden secrets to be revealed, and consequently, further studies of this system are necessary in order to unveil more details about the complex yet intriguing synchronization phenomenon,” Peña said.

A better understanding of synchronization could have technological and biological implications. For instance, consider two rotors mounted on an elastic support. “A familiar example of this kind of devices is a washing machine,” Peña said. Under certain conditions, the rotors may synchronize to rotate in the same direction, or in opposite directions, he said.

The synchronization of these rotors in opposite directions is highly desirable, because this will reduce or even eliminate the vibrations of the washing machine while its rotors are operating, Peña said. However, synchronization of these rotors in the same direction is not desired at all, because strong vibrations can result, with harmful and undesirable effects, he explained.

Read more at Discovery News

Black Hole Jets Hotter Than Expected

New observations of a jet-emitting black hole show astonishing temperatures inside the jets of 10 trillion degrees Kelvin — a toasty 18 trillion degrees Fahrenheit. This new measurement shows that quasars can blow far past the theoretical temperature limit of 100 billion degrees Kelvin (179 billion degrees Fahrenheit), which has scientists puzzled.

“This result is very challenging to explain with our current understanding of how relativistic jets of quasars radiate,” said lead author Yuri Kovalev of the Moscow’s Lebedev Physical Institute in a statement.

Observations of quasar 3C 273 were done with the Russian Skeptr-R satellite working in concert with three ground observatories as part of the larger RadioAstron mission. Quasars are supermassive black holes that emit intense jets of radiation.

Previously, it was believed there was a limit to the temperature because the electrons inside the jet would produce X-rays and gamma rays, interact with each other and cool down.

Astronomers hailed the finding as a triumph for interferometry, which occurs when multiple telescopes are linked together to get fine resolution of a distant object. The four observatories working together can get better resolution than the Hubble Space Telescope (although Hubble does not observe in X-rays or gamma rays).

The team also had a secondary find, which was that 3C 273 had previously unknown visible distortions to its substructure as seen from Earth, caused by peering through the interstellar medium in our own Milky Way. The distortion was only spotted because of the resolution of RadioAstron, researchers said in a statement.

The results were published in The Astrophysical Journal.

From Discovery News

Heat and light get larger at the nanoscale

This is a schematic of two beams at different temperatures exchanging heat using light. In the situation when the beams are far from each other (left), heat transfer resulting from thermal radiation is small. When the beams are brought very close from each other (right) heat transfer becomes almost 100 times larger than predicted by conventional thermal radiation laws.

In a new study recently published in Nature Nanotechnology, researchers from Columbia Engineering, Cornell, and Stanford have demonstrated heat transfer can be made 100 times stronger than has been predicted, simply by bringing two objects extremely close--at nanoscale distances--without touching. Led by Columbia Engineering's Michal Lipson and Stanford Engineering's Shanhui Fan, the team used custom-made ultra-high precision micro-mechanical displacement controllers to achieve heat transfer using light at the largest magnitude reported to date between two parallel objects.

"At separations as small as 40 nanometers, we achieved almost a 100-fold enhancement of heat transfer compared to classical predictions," says Lipson, Eugene Higgins Professor of Electrical Engineering and professor of applied physics. "This is very exciting as it means that light could now become a dominant heat transfer channel between objects that usually exchange heat mostly through conduction or convection. And, while other teams have demonstrated heat transfer using light at the nanoscale before, we are the first to reach performances that could be used for energy applications, such as directly converting heat to electricity using photovoltaic cells."

All objects in our environment exchange heat with their surroundings using light. This includes the light coming at us from the sun, the glowing red color of the heating element inside our toaster ovens, or the "night vision" cameras that enable image recording even in complete darkness. But heat exchange using light is usually very weak compared to what can be achieved by conduction (i.e., by simply putting two objects in contact with each other) or by convection (i.e., using hot air). Radiative heat transfer at nanoscale distances, while theorized, has been especially challenging to achieve because of the difficulty of maintaining large thermal gradients over nanometer-scale distances while avoiding other heat transfer mechanisms like conduction.

Lipson's team was able to bring objects at different temperatures very close to each other--at distances smaller than 100 nanometers, or 1/1000th of the diameter of a strand of human hair. They were able to demonstrate near-field radiative heat transfer between parallel SiC (silicon carbide) nanobeams in the deep sub-wavelength regime. They used a high-precision micro-electromechanical system (MEMS) to control the distance between the beams and exploited the mechanical stability of nanobeams under high tensile stress to minimize thermal buckling effects, thus keeping control of the nanometer-scale separation even at large thermal gradients.

Using this approach, the team was able to bring two parallel objects at different temperatures to distances as small as 42 nm without touching. In this case they observed that the heat transfer between the objects was close to 100 times stronger that what is predicted by conventional thermal radiation laws (i.e. "blackbody radiation"). They were able to repeat this experiment for temperature differences as high as 260oC (500oF) between the two objects. Such high temperature difference is especially important for energy conversion applications since, in these cases, the conversion efficiency is always proportional to the thermal difference between the hot and the cold objects involved.

"An important implication of our work is that thermal radiation can now be used as a dominant heat transfer mechanism between objects at different temperatures," explains Raphael St-Gelais, the study's lead author and postdoctoral fellow working with Lipson at Columbia Engineering. "This means that we can control heat flow with a lot of the same techniques we have for manipulating light. This is a big deal since there are a lot of interesting things we can do with light, such as converting it to electricity using photovoltaic cells."

St-Gelais and Linxiao Zhu, who co-authored the study and is a PhD candidate in Fan's group at Stanford, note that the team's approach can be scaled up to a larger effective area by simply arraying several nanobeams--on top of a photovoltaic cell, for example--and by individually controlling their out-of-plane displacement using MEMS actuators. The researchers are now looking at applying their same approach for ultra-high-precision displacement control, this time with an actual photovoltaic cell to generate electricity directly from heat.

Read more at Science Daily

Mile-high Mars mounds built by wind and climate change

This images shows sediment-filled craters on Mars (top) in different stages of erosion compared with results of a crater model in a wind tunnel experiment (bottom). Warm colors reflect high elevation, and cool colors low elevation.

New research has found that wind carved massive mounds of more than a mile high on Mars over billions of years. Their location helps pin down when water on the Red Planet dried up during a global climate change event.

The research was published in the journal Geophysical Research Letters, a journal of the American Geophysical Union, on March 31.

The findings show the importance of wind in shaping the Martian landscape, a force that, on Earth, is overpowered by other processes, said lead author Mackenzie Day, a graduate student at The University of Texas at Austin Jackson School of Geosciences.

"On Mars there are no plate-tectonics, and there's no liquid water, so you don't have anything to overprint that signature and over billions of years you get these mounds, which speaks to how much geomorphic change you can really instigate with just wind," Day said. "Wind could never do this on Earth because water acts so much faster, and tectonics act so much faster."

Day conducted the research with Jackson School researchers Gary Kocurek and David Mohrig of the Department of Geological Sciences and University of Texas at Dallas researcher William Anderson.

First spotted during NASA's Viking program in the 1970s, the mounds are at the bottom of craters. Recent analysis by the Mars rover Curiosity of Mount Sharp, a mound over three miles high inside Gale Crater, has revealed that the thickest ones are made of sedimentary rock, with bottoms made of sediments carried by water that used to flow into the crater and tops made of sediments deposited by wind. However, how the mounds formed inside craters that were once full of sediments was an open question.

"There's been a theory out there that these mounds formed from billions of years of wind erosion, but no one had ever tested that before," Day said. "So the cool thing about our paper is we figured out the dynamics of how wind could actually do that."

To test whether wind could create a mound, the researchers built a miniature crater 30 centimeters wide and 4 centimeters deep, filled it with damp sand, and placed it in a wind tunnel. They tracked the elevation and the distribution of sand in the crater until all of it had blown away. The model's sediment was eroded into forms similar to those observed in Martian craters, forming a crescent-shaped moat that deepened and widened around the edges of the crater. Eventually all that was left of the sediment was a mound -- which, in time, also eroded away.

"We went from a filled crater layer cake to this mounded shape that we see today," Day said.

To understand the wind dynamics, researchers also built a computer model that simulated how the wind flowed through the crater at different stages of erosion.

The mounds' structure helps link their formation to climate change on Mars, Kocurek said, with the bottom being built during a wet time, and the top built and mound shaped in a dry time.

"This sequence signals the change from a dominance of depositional processes by water during a wetter time, to wind reworking of these water-laid sediments with the onset of aridity, followed by wind erosion once these sediment supplies have been exhausted," he said. "Overall, we are seeing the complete remaking of the sedimentary cycle on Mars to the one that characterizes the planet today."

Read more at Science Daily