Animal Rips Apart Own Skin Before Meals

Tiny freshwater animals known as hydra must rip open their mouth skin in order to eat, and now new research shows how they manage to do this.

The unusual process involves changes to the hydra’s mouth skin cells that allow the creature to stretch and split apart these cells in a dramatic deformation. The findings are published in the latest issue of the Biophysical Journal.

“The fact that the cells are able to stretch to accommodate the mouth opening, which is sometimes wider than the body, was really astounding,” senior author Eva-Marie Collins said in a press release. “When you watch the shapes of the cells, it looks like even the cell nuclei are deformed.”

Collins, who is a biophysicist at the University of California, San Diego, and her team genetically engineered hydra so that the animals’ two layers of tissues would light up, revealing how their mouths and bodies work on a cellular level.

Hydra measure less than one half an inch long. They look like a column with a ring of tentacles at the end. In the wild, the other end adheres to a rock or some other kind of surface, keeping the hydra in place while it waits for unsuspecting prey to swim by.

When a potential victim, such as a small shrimp, brushes against the hydra’s tentacles, the predator shoots out poisoned barbs to sting and paralyze its prey. Once the hydra contracts its tentacles, a special group of cells splits apart to display the black interior of its mouth, and the hydra sucks the prey in.

When the meal is digested, the hydra rips open its mouth to spit out any leftover materials. It then seals it back up into a continuous sheet of tissue, and waits for the next shrimp or other victim to swim by.

In the below video, a hydra in a lab eats a small crustacean, showing what the hunting and feasting look like from farther away:

The lit tissues of the genetically engineered hydra showed that the animal’s cells change their shape, rather than move around, when the mouth opens.

“We can try to understand what look like very complicated processes in the living animal with relatively simple physics,” Collins said.

She and her team next determined that once triggered, radially oriented fibers in the hydra’s tissue contract to stretch the cells apart, similar to how muscles in the iris contract to open our pupils. When the researchers added magnesium chloride to act as a muscle relaxant, the hydras couldn’t open their mouths at all.

Read more at Discovery News

Shakespeare's Curse-Protected Grave Gets Radar Scan

Documentary filmmakers have radar scanned William Shakespeare’s grave this year as Britain celebrates the 400th anniversary of the Bard’s death, Channel 4 said and the Daily Telegraph reported Monday.

The grave in the Holy Trinity Church in Shakespeare’s birthplace of Stratford upon Avon is a place of pilgrimage for fans and has an inscription on it with a curse against anyone planning to tamper with it.

“Bleste be the man that spares these stones, And curst be he that moves my bones,” the inscription reads.

The survey could help researchers learn more about Shakespeare’s life and family, helping to detect unmarked or previously unknown graves and items buried within the coffins, the Telegraph reported.

“We can confirm a scan has been completed. The results of the scan will be revealed as part of a Channel 4 documentary later in the spring,” a spokesman for the church was quoted as saying.

A Channel 4 spokeswoman confirmed the report to AFP.

Shakespeare’s wife Anne Hathaway and daughter Suzanna as well as other members of his extended family are buried in graves around his own.

The pre-eminent British writer, who lived between 1564 and 1616, is believed to have written around 38 plays — although the precise authorship of some works has been disputed — and 154 sonnets.

Britain is marking the anniversary of his death on April 23 with a series of performances and academic workshops as well as a planned candlelit vigil in the Holy Trinity Church itself on the day.

From Discovery News

Mars Mission Buzzes Weird Moon Phobos

This eerie portrait of Mars' moon Phobos in ultraviolet light was snapped by the NASA orbiter MAVEN as their orbits crossed paths.

Phobos is the nearer and stranger of Mars' two moons — in the 1950s and 1960s, some scientists thought that its unusual orbit, spiraling inward, suggested that it might be a hollow, artificial body. The little moon has long, shallow grooves along its sides, likely caused by the pull of Mars, and it moves about 6.6 feet (2 meters) closer to the Red Planet every hundred years, NASA officials have said.

In fact, Phobos is the closest moon to its planet in the solar system, circling Mars at just 3,700 miles (6,000 kilometers) above its surface. It's so close that it orbits within the sphere of Mars' thin atmosphere — the blue pixels that form the new portrait's background are the ultraviolet light scattered from hydrogen gas in Mars' extended upper atmosphere. The orange comes from  longer ultraviolet wavelengths of sunlight reflected from the moon's surface.

NASA's MAVEN (short for Mars Atmosphere and Volatile Evolution) mission snapped the shot with its Imaging Ultraviolet Spectrograph in December 2015 as its orbit crossed paths with Phobos', and researchers are hoping MAVEN's measurements will help determine what the moon is made of, where it came from and whether it has organic molecules on its surface. (A previous measurement, by the Mars Express spacecraft, found evidence of such organic molecules.)

"The images will allow MAVEN scientists to better assess the composition of this enigmatic object, whose origin is unknown," NASA officials said in a statement.

Original article on Space.com. Copyright 2016 SPACE.com, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

From Discovery News

Rare 2500-Year-Old Woman's Seal Found

A rare 2,500-year-old seal bearing the name of an "exceptional" woman has been discovered in Jerusalem, the Israeli Antiquities Authority (IAA) announced on Monday.

Found in a large ancient building in the City of David, in the Jerusalem Walls National Park, the seal dates back to the era of the First Temple, which, according to the Hebrew Bible, was constructed by King Solomon in the 10th century B.C. and then destroyed 400 years later.

"Finding seals that bear names from the time of the First Temple is hardly a commonplace occurrence, and finding a seal that belonged to a woman is an even rarer phenomenon," excavation directors Doron Ben-Ami, Yana Tchekhanovets and Salome Cohen, said in a statement.

The seal, made of semi-precious stone, bears the mirror-writing of "to Elihana bat Gael" carved in ancient Hebrew letters. It means "Elihana daughter of Gael."

Such seals were used for signing documents, and were frequently inlaid as part of a ring that was worn by the owner.

"In antiquity they designated the identity, genealogy and status of the owner of the seal," the archaeologists said.

The name Elihana does not appear in the Bible, and there is no other information regarding the identity of the woman, but the fact that she owned a seal shows her high social status.

"She was exceptional compared to other women of the First Temple period: she had legal status which allowed her to conduct business and possess property," the archaeologists said.

Hagai Misgav, from the Hebrew University of Jerusalem's Institute of Archaeology, noted that most of the women's seal that are known today bear the name of the father rather than that of the husband.

"Here, as in other cases, this might indicate the relatively elevated status of Elihana, which depended on her original family, and not on her husband's family," Misgav said.

"It seems that Elihana maintained her right to property and financial independence even after her marriage and therefore her father's name was retained; however, we do not have sufficient information about the law in Judah during this period," he added.

Legal and financial independence for women was a rare thing in those times.

According to the Book of Proverbs, an ideal wife was responsible for providing for the needs of her household when her husband was engaged in public and legal affairs at the city gate.

"She seeks wool and flax, and works with willing hands … Her husband is known in the gates, when he sits among the elders of the land," it stated.

Read more at Discovery News

Plans Afoot to Clone Extinct Siberian Cave Lion

The Siberian Times reports that South Korean cloning scientist Hwang Woo-Suk plans to clone an extinct Siberian cave lion, using tissue samples from one of a pair of the animals found preserved in permafrost last year.

The two prehistoric big cats were infants when they died, their remains estimated to be some 12,000 years old, found in a cave in Yakutia, a part of Siberia also called the Sakha Republic.

Woo-Suk, already pursuing the resurrection of a woolly mammoth, got his samples after a dispute over tissue sample size was settled via compromise between the Korean and Siberian scientists.

Siberian cave lions (Panthera leo spelaea) would have looked roughly like modern lions. They lived during the Pleistocene and were distributed throughout Europe, Asia and northwestern North America, before going extinct about 10,000 years ago.

It’s likely they preyed on animals such as bison, young or injured mammoths, deer, and horses.

The lion cubs were estimated to be only a couple of weeks old. While the circumstances surrounding their deaths is not certain, Albert Protopopov, head of the mammoth fauna studies department of the Yakutian Academy of Sciences, told the Times he surmises the cubs were placed in the cave by their mother for protection, but then a landslide sealed the area, trapping the young animals inside.

From Discovery News

100 Tombs Found Near Biblical Bethlehem

An ancient necropolis that once held more than 100 tombs from as far back as 4,000 years ago has been discovered near the Palestinian town of Bethlehem in the West Bank.

The burial ground was discovered in spring 2013 during the construction of an industrial park. In 2014 a team from the Ministry of Tourism and Antiquities of Palestine excavated some of the tombs, and in 2015 a joint Italian-Palestinian team surveyed the necropolis and created a plan for future exploration. The archaeologists found that the necropolis covered 3 hectares (more than 7 acres) and originally contained more than 100 tombs in use between roughly 2200 B.C. and 650 B.C.

Located on the side of a hill, the archaeological site — now called Khalet al-Jam’a — was likely a burial ground for a nearby settlement whose location is unknown.

The site’s “long-lasting utilization, over a millennium and a half or more, and the large number of tombs, suggest that Khalet al-Jam’a was the necropolis of a major settlement in the area, possibly a town,” Lorenzo Nigro, professor at Sapienza University of Rome, wrote in an article published recently in the journal Vicino Oriente.

Nigro said that finds from the necropolis indicate that the settlement was a wealthy place, with access to trade routes. Ancient texts refer to a “Beth-Lehem” that flourished in the area.

“Typical pieces of the burial sets are finely executed carinated bowls, small shouldered jars/bowls with everted rim, one-spouted lamps, huge and well-refined Canaanite jars with two or four handles, as well as bronze daggers and spearheads,” Nigro wrote.

Ancient finds

Though the necropolis has been partly destroyed by looting and construction, the archaeologists were able to identify at least 30 tombs. “The necropolis of Khalet al-Jam’a is mainly characterized by shaft tombs with single or multiple rock-cut chambers,” the team wrote in another paper published in Vicino Oriente, noting that the builders enlarged and renovated natural cavities on the hillside.

In one tomb, the remains of a man, woman and child were found buried with two bronze daggers and a variety of ceramics, including twin vases attached together. Archaeologists found that the tomb dated to the Middle Bronze Age, more than 3,500 years ago.

Another tomb at Khalet al-Jam’a contained a nearly complete male skeleton buried with a ceramic lamp that had four sides folded into spouts. Archaeologists said this particular tomb may date to an earlier point in the Bronze Age more than 4,000 years ago.

Another intriguing tomb contained two Egyptian-like amulets, known as scarabs, which were mounted on rings made of bronze or gold. It’s possible that, rather than being imported from Egypt, the scarabs were made locally.

The scarabs date to the 13th dynasty of Egypt (1802 B.C. to 1640 B.C.), Nigro said. One of the scarabs contains a series of circular decorations, while the other has swirling designs and what appears to be hieroglyphic writing. Two of the hieroglyphic symbols are written within an oval circle known as a cartouche. The Egyptians often wrote royal names in cartouches, and archaeologists are studying the scarabs for these types of details.

Egyptian scarabs have been found at many other sites in the eastern Mediterranean. Ancient records say the Egyptians were very active in the region, trading for goods and, at times, conquering territory.

Read more at Discovery News

Earth's Fiery Depths Filled with Brimstone

Earth’s inner core is a metallic mix of iron and light elements such as sulfur, hydrogen and silicon, a new study finds.

This isn’t the first time scientists have proposed that Earth’s fiery depths are filled with brimstone, another name for sulfur. That’s because the inner core is less dense than it would be if the solid metal ball were pure iron. However, the new research further confirms the idea with tests of pure iron at the extreme temperatures and pressures found in the inner core.

Researchers at Tohoku University in Sendai, Japan, mimicked the inner core in a laboratory equipped with a laser-heated diamond anvil cell. A small crumb of pure iron was squeezed between two diamond-tipped anvils to create high pressure and blasted with laser beams to boost the temperature. The experiment reached 163 gigapascals (about 1.6 million times the pressure at sea level) and about 5,000 degrees Fahrenheit (3,000 kelvins, or about 2,700 degrees Celsius).

During the experiment, the team measured how fast sound waves traveled through iron at these conditions. If the Earth’s inner core was pure iron, then the speed of sound waves traveling through the core should be similar to the experimental results.

But instead, the researchers discovered the velocity of sound waves through Earth’s actual core is lower than if it were made only of iron. The data and observations match more closely if 5 to 10 percent of the core’s weight is a mix of sulfur, hydrogen and silicon, the researchers reported in the journal Science Advances.

“This result helps us constrain the candidate elements in the core,” said lead study author Tatsuya Sakamaki, of Tohoku University. “We already know that the Earth’s core contains some amount of light elements because the density of the core is smaller than that of iron. In this study, we newly show that the velocity of the core is also smaller than that of iron,” Sakamaki told Live Science in an email interview.

Read more at Discovery News

Mercury's Carbon-Rich Crust is Surprisingly Ancient

Before its planned crash into Mercury last year, NASA’s MESSENGER spacecraft gave scientists a parting gift.

In its final orbits, MESSENGER not only confirmed that Mercury’s dark hue is due to carbon, but also revealed that the carbon wasn’t deposited by impacting comets, as some researchers suspected.

Instead, scientists now believe they are seeing remnants of the planet’s primordial crust, which likely formed when a global ocean of super-heated magma cooled, allowing minerals to solidify.

Computer simulations and experiments show that most of these crystallized minerals would sink -- with one key exception. Graphite, the studies show, would float.

Scientists used an instrument on MESSENGER called a neutron spectrometer to make low-altitude measurements of the darkest regions on the planet’s surface, which were suspected of having the most low-reflectance material (LRM.)

“The measurements showed enhanced fluxes of thermal neutrons over three areas of LRM, so only graphite as the darkening agent fits both the spectral reflectance observations and the neutron measurements,” MESSENGER’s lead scientist Sean Solomon, with Columbia University, wrote in an email to Discovery News.

Scientists also were able to match the carbon-rich material with large impact craters, evidence that the material stemmed from deep within Mercury’s crust and was exposed after an impacting body gouged out a crater.

“Because LRM deposits on Mercury are all associated with material excavated from depth by large impact craters, they must come from the mid to lower crust,” Solomon said.

Scientists estimate the ancient crust was about .62 mile, or 1 kilometer, thick.

The crust of present-day Mercury has been bashed by impacts, covered with lava, melted and otherwise disturbed.

“The processes … would dilute any primordial crust,” physicist Patrick Peplowski, with Johns Hopkins University Applied Physics Lab, and colleagues write in a paper published this week in Nature Geoscience.

Read more at Discovery News

DNA 'scrunching' occurs as RNA polymerase selects a position to begin synthesizing RNA

A research collaboration that combines novel "big-data" informatics tools with expertise in basic biology has uncovered details of an essential process in life: how a crucial enzyme locates the site on DNA where it begins to direct the synthesis of RNA.

A research collaboration that combines novel "big-data" informatics tools with expertise in basic biology has uncovered details of an essential process in life: how a crucial enzyme locates the site on DNA where it begins to direct the synthesis of RNA. This finding may aid in the discovery of new antimicrobial medicines, and the powerful technological approaches developed for this research may shed light on other essential cellular processes.

A bioinformatics group from The Children's Hospital of Philadelphia collaborated with researchers from Rutgers University on the study, which appeared online today in Science.

"The algorithms we developed enable us to tackle many questions across diverse areas of DNA and RNA biology," said study co-author Deanne M. Taylor, Ph.D., Director of Bioinformatics in the Department of Biomedical and Health Informatics at The Children's Hospital of Philadelphia (CHOP). "Understanding these fundamental processes may help in developing antimicrobial treatments to fight bacterial disease."

Taylor collaborated on the study with biochemist Bryce Nickels, Ph.D., and chemist Richard Ebright, Ph.D., both from Rutgers, the State University of New Jersey.

The research focuses on transcription--how cells read genetic information stored in DNA by first synthesizing a copy of that genetic information as RNA. The enzyme RNA polymerase is the molecular machine that carries out transcription. In the current study, the CHOP/Rutgers team determined how RNA polymerase locates the site on DNA where it starts transcription.

In particular, working in bacteria, the CHOP/Rutgers team showed that after RNA polymerase binds to DNA and partly unwinds the two strands of the DNA helix, it then continues unwinding those two strands, pulling the unwound DNA strands into itself until it engages the transcription start site (TSS). The researchers call this process--unwinding DNA and pulling strands into itself--"DNA scrunching." Nickels points out, "Scientists have known for more than three decades that transcription start sites vary, but did not previously know the mechanism."

To detect DNA scrunching during TSS selection, the researchers developed powerful new experimental approaches, called MASTER and MASTER-XL. The CHOP/Rutgers team first described MASTER (for "massively systematic transcript end readout") in a December 2015 paper in Molecular Cell.

MASTER-XL combines the MASTER technology with crosslinking--introducing artificial amino acids at specific sites on proteins to crosslink to sites in DNA. Using high-throughput algorithms, the study team was able to precisely and rapidly pinpoint those crosslinking sites in a million different DNA sequences, each carrying a distinct TSS region. In each sequence, the team identified the TSS as well as front (leading edge) and rear (trailing edge) positions where RNA polymerase attached to DNA.

Yuanchao Zhang, a graduate student working with Taylor's bioinformatics group at CHOP, developed the big-data algorithms with Taylor to analyze the sequencing data output from MASTER and MASTER-XL experiments. "Our algorithms rapidly process many millions of DNA and RNA sequence reads," said Taylor.

The rapid sequencing, plus advanced biochemical and chemical methods underlying the crosslinking, provided a key finding on how DNA scrunching occurs during transcription. As the position of the TSS changes, the position of RNA polymerase's leading edge changes in lock step, but the enzyme's trailing edge remains in the same position. This causes the DNA to scrunch: it remains fastened to RNA polymerase at its trailing edge, but RNA polymerase unwinds the adjacent DNA and pulls the unwound DNA into itself until it locates a new TSS.

"The crucial feature of our approach," explained Ebright, "is the combination of protein-DNA crosslinking with next-generation-sequencing of DNA. This enables us to perform crosslinking studies with a million different DNA sequences in the same amount of time that we previously would have needed to perform crosslinking studies with one DNA sequence." He added, "The million-fold increase in throughput allows biological problems to be solved that couldn't be solved before."

Read more at Science Daily

Cosmochemists find evidence for unstable heavy element at solar system formation

The Allende carbonaceous meteorite is peppered with inclusions that have a ceramic-like chemistry (red for calcium, blue for aluminum, green for magnesium in the false color image below; field of view is 0.5 millimeters, approximately one-hundredth of an inch). When they formed, these inclusions incorporated the short-lived nuclide curium-247 (with a half life of 15 million years), traces of which have been detected in research conducted at the University of Chicago as a significant excess in uranium-235, its decay product. Curium-247 came from nucleosynthesis in stars that lived and died before the solar system was born.

University of Chicago scientists have discovered evidence in a meteorite that a rare element, curium, was present during the formation of the solar system. This finding ends a 35-year-old debate on the possible presence of curium in the early solar system, and plays a crucial role in reassessing models of stellar evolution and synthesis of elements in stars. Details of the discovery appear in the March 4 edition of Science Advances.

"Curium is an elusive element. It is one of the heaviest-known elements, yet it does not occur naturally because all of its isotopes are radioactive and decay rapidly on a geological time scale," said the study's lead author, François Tissot, UChicago PhD'15, now a W.O. Crosby Postdoctoral Fellow at the Massachusetts Institute of Technology.

And yet Tissot and his co-authors, UChicago's Nicolas Dauphas and Lawrence Grossman, have found evidence of curium in an unusual ceramic inclusion they called "Curious Marie," taken from a carbonaceous meteorite. Curium became incorporated into the inclusion when it condensed from the gaseous cloud that formed the sun early in the history of the solar system.

Curious Marie and curium are both named after Marie Curie, whose pioneering work laid the foundation of the theory of radioactivity. Curium was only discovered in 1944, by Glenn Seaborg and his collaborators at the University of California, Berkeley, who, by bombarding atoms of plutonium with alpha particles (atoms of helium) synthesized a new, very radioactive element.

To chemically, and unambiguously, identify this new element, Seaborg and his collaborators studied the energy of the particles emitted during its decay at the Metallurgical Laboratory at UChicago (which later became Argonne National Laboratory). The isotope they had synthesized was the very unstable curium-242, which decays in a half-life of 162 days.

On Earth today, curium exists only when manufactured in laboratories or as a byproduct of nuclear explosions. Curium could have been present, however, early in the history of the solar system, as a product of massive star explosions that happened before the solar system was born.

"The possible presence of curium in the early solar system has long been exciting to cosmochemists, because they can often use radioactive elements as chronometers to date the relative ages of meteorites and planets," said study co-author Nicolas Dauphas, UChicago's Louis Block Professor in Geophysical Sciences.

Indeed, the longest-lived isotope of curium (247Cm) decays over time into an isotope of uranium (235U). Therefore, a mineral or a rock formed early in the solar system, when 247Cm existed, would have incorporated more 247Cm than a similar mineral or rock that formed later, after 247Cm had decayed. If scientists were to analyze these two hypothetical minerals today, they would find that the older mineral contains more 235U (the decay product of 247Cm) than the younger mineral.

"The idea is simple enough, yet, for nearly 35 years, scientists have argued about the presence of 247Cm in the early solar system," Tissot said.

Early studies in the 1980s found large excesses of 235U in any meteoritic inclusions they analyzed, and concluded that curium was very abundant when the solar system formed. More refined experiments conducted by James Chen and UChicago alumnus Gerald Wasserburg, SB'51, SM'52, PhD'54, at the California Institute of Technology showed that these early results were spurious, and that if curium was present in the early solar system, its abundance was so low that state-of-the-art instrumentation would be unable to detect it.

Scientists had to wait until a new, higher-performance mass spectrometer was developed to successfully identify, in 2010, tiny excesses of 235U that could be the smoking gun for the presence of 247Cm in the early solar system.

"That was an important step forward but the problem is, those excesses were so small that other processes could have produced them," Tissot noted.

Models predict that curium, if present, was in low abundance in the early solar system. Therefore, the excess 235U produced by the decay of 247Cm cannot be seen in minerals or inclusions that contain large or even average amounts of natural uranium. One of the challenges was thus to find a mineral or inclusion likely to have incorporated a lot of curium but containing little uranium.

With the help of study co-author Lawrence Grossman, UChicago professor emeritus in geophysical sciences, the team was able to identify and target a specific kind of meteoritic inclusion rich in calcium and aluminum. These CAIs (calcium, aluminum-rich inclusions) are known to have a low abundance of uranium and likely to have high curium abundance. One of these inclusions--Curious Marie-- contained an extremely low amount of uranium,

"It is in this very sample that we were able to resolve an unprecedented excess of 235U," Tissot said. "All natural samples have a similar isotopic composition of uranium, but the uranium in Curious Marie has six percent more 235U, a finding that can only be explained by live 247Cm in the early solar system."

Thanks to this sample, the research team was able to calculate the amount of curium present in the early solar system and to compare it to the amount of other heavy radioactive elements such as iodine-129 and plutonium-244. They found that all these isotopes could have been produced together by a single process in stars.

Read more at Science Daily