Aug 2, 2014

Experimental Ebola Serum Likely Treating Sick Americans

An American doctor working in West Africa and another health care worker, also American, who contracted Ebola there have both received experimental treatments for the deadly viral disease, according to news reports.

Nancy Writebol, a worker with the charity Samaritan's Purse, received an experimental serum, and Dr. Kent Brantly, from the same charity, received a blood transfusion from a patient who recovered from Ebola, according to NBC News. One or both of the health care workers are also being flown to an isolation unit in an American hospital for treatment, according to news reports.

Though there are conflicting reports, and no one is saying exactly what the experimental serum is, its likely that both of the reported methods contained antibodies to the Ebola virus, said Dr. William Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt University Medical Center in Nashville, Tenn. Delivering antibodies to a patient could slow the virus's replication, and give the immune system time to recover.

"There is a long tradition of using immune serum as treatment," Schaffner told Live Science. "You give the person antibodies, and you would hope that those antibodies would then bind the viruses and interfere with their multiplication."

No current treatments

This Ebola outbreak is the largest in history and has so far claimed 729 lives in Sierra Leone, Guinea and Liberia. Doctors without Borders has said that the crisis is "out of control." Sierra Leone has declared a national emergency, closed all of its schools and is quarantining disease hot spots.

There are no treatments or vaccines available for Ebola, though several are in the pipeline. A study in Nature this year reported that one drug improved survival in monkeys who were exposed to a closely related virus, called Marburg virus. Public Health Canada is testing another antibody-based treatment and the company Tekmira Pharmaceuticals has developed an experimental drug that uses a process called RNA interference to block the virus' replication, Forbes reported.

Antibody methods

As for the American health-care workers, one possibility is that Writebol was given a concentrated form of antibodies to the virus from someone who survived, Schaffner said. To make such a treatment, researchers would have to separate and concentrate the antibodies from a survivor's blood.

If Writebol did receive such an immune serum, it would almost certainly have to have been created at the site of the outbreak and have come from someone infected with the same strain of Ebola that she has, said Thomas Geisbert, a virologist at the University of Texas Medical Branch in Galveston, who has helped develop potential Ebola drugs. There are several species of Ebola virus; the current outbreak is caused by one called the Zaire species.

Brantly is reportedly receiving a transfusion of whole blood from a 14-year-old patient who survived the disease.

In an Ebola infection, the virus first disables some of the immune system's frontline cells and then replicates almost unchecked. It then bursts out of cells throughout the body and damages them, eventually causing multi-organ failure.

Both experimental treatments, if they work, would need to lower the viral load by binding to the virus and preventing it from replicating, which would give the immune system enough time to regenerate its cells and fight the disease, Geisbert said.

However, such treatments likely have limitations. In the last stages of the disease, in a process known as a cytokine storm, the immune system goes haywire and inflammatory molecules called cytokines attack the body's own tissue.

At that point, "if you're 24 to 72 hours from death and you've got a full blown case of Ebola hemorrhagic fever, there's probably nothing on the planet that's going to save you," Geisbert told Live Science.

Will it work?

It's not clear that using antibodies from recovering patients would work. In a 1995 outbreak, eight patients were given serum from recovering patients and only one died, according to a 1999 study in the Journal of Infectious Diseases. However, those patients may have been given the drug when they were already on the road to recovery, Geisbert said.

When Geisbert and his colleagues tested a treatment made from human antibodies in monkeys injected with Ebola, the antibodies failed to protect rhesus macaques from infection and death, according to a 2007 study in PLOS Pathogens.

However, a cocktail of engineered Ebola antibodies called MB-003 developed by Mapp Biopharmaceuticals seemed to protect monkeys exposed to the virus, a 2013 study in Science reported. In animal models, some of the newer antibody treatments seem to be more effective at combating the disease, perhaps because they are more targeted, Geisbert said.

Measuring effects

In the current outbreak, about 40 percent of victims have survived even without treatments, making it hard to gauge any treatment's effectiveness, Geisbert said.

Read more at Discovery News

How Ebola Rumor and Folklore Go Viral

The latest Ebola outbreak in West Africa has killed more than 700 people and continues to concern doctors around the world. U.S. officials yesterday issued warnings to travelers about visiting Guinea, Liberia and Sierra Leone, noting that the outbreak is getting worse.

While doctors and epidemiologists fight to contain the outbreak and treat patients, they are battling something almost as difficult to fight as the Ebola virus itself: rumor, folklore and myths about the disease.

In some cases doctors have been physically kept away from treating those most in need. According to an article in the New York Times:
“Workers and officials, blamed by panicked populations for spreading the virus, have been threatened with knives, stones and machetes, their vehicles sometimes surrounded by hostile mobs. Log barriers across narrow dirt roads block medical teams from reaching villages where the virus is suspected. Sick and dead villagers, cut off from help, are infecting others.”

Foreign — and especially Western — doctors are often particularly distrusted as potentially harboring dark motives under the guise of medical help. In some cases doctors have been accused of intentionally infecting victims with Ebola for sinister purposes, such as testing experimental drugs on unsuspecting victims.

These rumors have many roots, including xenophobia and a general distrust of doctors. For many, the beliefs make perfect sense. Patients around the world avoid going to doctors out of fear of what they might find out, preferring not to know if something is wrong. Others avoid hospitals because, they say, that’s where many people get sicker than before they went in. To be fair, there’s some truth to that — many otherwise healthy people have died after being infected with MRSA and other deadly bacteria while in hospitals.

The rumors are not just preventing doctors from treating patients and spreading the disease — they are also offering false claims of cures. In Nigeria, for example, public officials have grown concerned about rumors that shamen and witch doctors have cured Ebola victims: “Commissioner for Information and Strategy Aderemi Ibirogba specifically advised the citizenry to be wary of the activities of alleged fraudsters who were reportedly making spurious claims about their ability to provide cure for the deadly virus,” according to a statement. Other rumors claim that Ebola can be spread through casual contact (it can’t) or that home remedies or even magic can cure it.

Rumor of Disease

The stories and myths circulating about Ebola are not new, in fact they have appeared for many decades in reference to other diseases. Jon Lee, author of “An Epidemic of Rumors: How Stories Shape Our Perception of Disease” has studied the folklore (including rumors, legends and conspiracy theories) behind various diseases among both the affected groups and the news media.

He notes:
“The nature of the disease itself is almost of secondary consideration when it comes to narrative: regardless of which outbreak is making headlines — whether it’s AIDS or SARS or H1N1 — the basic stories are the same. Narratives are recirculated from one outbreak to the next, modified not in their themes but in the specific details necessary to link the narratives to the current situation.”

These rumors and myths are not started maliciously. They’re not part of a widespread attempt to spread the disease or harm outsiders. Instead they emerge from people trying to make sense of the death that’s going on around them, and a misunderstanding of science. Standard Western medical procedures designed to stop the spread of the virus — something as simple as strangers sealing a deceased victim’s body in plastic and taking it away to be examined or buried in isolation – conflict with traditional customs and practices.

Read more at Discovery News

Aug 1, 2014

Companion planets can increase old worlds' chance at life

Having a companion in old age is good for people -- and, it turns out, might extend the chance for life on certain Earth-sized planets in the cosmos as well.

Planets cool as they age. Over time their molten cores solidify and inner heat-generating activity dwindles, becoming less able to keep the world habitable by regulating carbon dioxide to prevent runaway heating or cooling.

But astronomers at the University of Washington and the University of Arizona have found that for certain planets about the size of our own, the gravitational pull of an outer companion planet could generate enough heat -- through a process called tidal heating -- to effectively prevent that internal cooling, and extend the inner world's chance at hosting life.

UW astronomer Rory Barnes is second author of a paper published in the July issue of the Monthly Notices of the Royal Astronomical Society. The lead authors are graduate student Christa Van Laerhoven and planetary scientist Richard Greenberg at the University of Arizona.

Tidal heating results from the gravitational push and pull of the outer companion planet on its closer-in neighbor, Barnes said. The effect happens locally, so to speak, on Jupiter's moons Io and Europa. The researchers showed that this phenomenon can take place on exoplanets -- those outside the solar system -- as well.

Using computer models, the researchers found the effect can occur on older Earth-sized planets in noncircular orbits in the habitable zone of low-mass stars, or those less than one-quarter the mass of the Sun. The habitable zone is that swath of space around a star just right to allow an orbiting rocky planet to sustain liquid water on its surface, thus giving life a chance.

"When the planet is closer to the star, the gravitational field is stronger and the planet is deformed into an American football shape. When farther from the star, the field is weaker and the planet relaxes into a more spherical shape," Barnes said. "This constant flexing causes layers inside the planet to rub against each other, producing frictional heating."

The outer planet is necessary, Barnes added, to keep the potentially habitable planet's orbit noncircular. When a planet's orbit is circular, the gravitational pull from its host star is constant, so its shape never changes, and there is no tidal heating.

And so, the researchers conclude, any discoveries of Earth-sized planets in the habitable zone of old, small stars should be followed by searches for outer companion planets that might improve the inner world's chance at hosting life.

The combined effect of the ancient planet's own tectonics and tidal heating generated by the outer companion, Barnes said, might allow such planets to host some of the longest-lived surface habitats in the universe.

Read more at Science Daily

Moving Ebola Patients to U.S. Involves Extreme Isolation

When the first American Ebola patients arrive back home in the next few days, they probably won't be greeted with banners or TV cameras. Their route from Atlanta's Hartsfield Airport to the Emory University Medical Hospital will be a closely guarded secret to keep them from getting stuck in traffic or alerting the public.

Two humanitarian aid workers, Kent Brantly of Texas and Nancy Whitebol of North Carolina, were stricken by the disease while working in Liberia. They're being flown back in a private jet. It's not clear which of them will be taken to Emory, according to a hospital statement.

Emory has a special isolation unit, one of four in the country, to treat patients with serious infectious diseases. It is physically separated from other patient areas and is run in conjunction with the U.S. Centers for Disease Control and Prevention in Atlanta, the hospital said.

From the hospital in Monrovia, to the Liberian airport and then during the 12-hour flight across the Atlantic, the patients will be in special chambers the whole time, according to Andrew Pekosz, associate professor of molecular microbiology and immunology at Johns Hopkins University who has worked on highly-contagious infectious diseases.

"This is not something being put together at the last minute," Pekosz said. "The CDC has been planning and putting protocol and facilities and equipment for exactly this kind of event for many years. There is a well-worked-out system from any part of the world where a patient can be identified, prepared and transported and delivered to the containment facility."

Here's how the medical team will protect themselves and others from the Ebola virus raging inside the patients:

- Clothes: Health-care workers wear impermeable polyvinyl chlorine (PVC) coveralls, a separate hood, vinyl boots and three pairs of gloves. A special high-efficiency particulate air (HEPA) filtered respirator powered by a rechargeable battery supplies air for breathing and cooling. Those filters remove particles down to .03 micrometers, including viruses like Ebola, according to CDC protocols.

- Stretcher: The patients will be placed inside the Vickers aircraft transport isolator (VATI), designed for prolonged patient transportation and in-flight care. It uses negative air pressure and filters that exchange the air five times per hour. Medical workers will administer to the patients through special gloves built into the sides of the transparent chamber.

- Patient care: Since air travel is stressful and involves the effects of altitude and confinement, only patients that are expected to survive the flight would be moved. Doctors and nurses have to be watching for signs of respiratory failure and the presence of gas inside the body that could pose a problem at high altitude.

- Stopping the virus: Since there's no cure for Ebola, the most that doctors can do is try and help the body's own immune system fight it. They will also be trying to keep vital organs, like the liver and kidneys, functioning against the blood-borne virus, as well as removing excess fluid building up in the body, according to Pekosz.

- Hospital trip: Once the plane lands, there's another transfer to a special ambulance with a tent-like structure covering the patient. The route will be kept quiet to minimize traffic and publicity. At the hospital, workers deploy a well-rehearsed plan that details where the ambulance is supposed to pull up. The patient is put into a containment center and is not allowed to leave. Staff members have to go through a two-phase decontamination procedure for all of their clothing, while chemical sprays used to kill the virus must also go to a separate system instead of the normal hospital sewer pipe.

- Staying alive: The infection can last from several days to several weeks. "What the doctors are trying to do is minimize the damage and get the organs through the infection and stay alive," Pekosz said. "Clearly it can be done at Emory, but it cannot be done on the ground in Africa."

In Africa, officials from the CDC and the U.S. Army Medical Research Institute of Infectious Diseases are working overtime to control the spread of the disease and perhaps develop a treatment. USAMRIID virologist Randal Schoepp has been in Monrovia for the past two weeks using a molecular genetic test to identify patients who have contracted the disease. Schoepp said the rate of new infections is rising in Liberia, Guinea and Sierra Leone.

The World Health Organization said Friday that the outbreak has killed 729 people and infected another 1,200. However, Schoepp said that could be an underestimate.

"We are only seeing the tip of the iceberg," Schoepp said during a teleconference from Monrovia. "To really control the outbreak, you need contact tracing, contacts with confirmed Ebola patients that could be then followed for the possibility of them being infected. We don't have a good system here set up for that. I believe we are only seeing a small portion of the actual cases out there. It's putting a tremendous stress on the medical system."

Schoepp said drivers are afraid to bring back medical samples to scientists like him working in a specialized laboratory.

"In Sierra Leone and Liberia, we are seeing an increase in samples and positive samples," Schoepp said. "That indicates that we are still on an increasing slope and haven't reached the peak yet."

Read more at Discovery News

Mystery Galactic Gamma-ray 'Bubbles' Defy Explanation

In 2010, astronomers announced the discovery of two vast — and very mysterious — bubbles of gamma-ray emissions towering above and below our galaxy’s disk. Four years on, after oodles of analysis, the source of these bubbles is as mysterious as ever.

The scale of these gamma-ray structures is truly mind-blowing. Apparently originating directly from the galactic core, the two lobes extend tens of thousands of light-years into intergalactic space. They both generate gamma-ray radiation at an astonishing luminosity, “like two 30,000-light-year-tall incandescent bulbs screwed into the center of the galaxy,” according to a Stanford University news release.

The discovery was made by NASA’s Fermi Gamma-Ray Observatory that orbits the Earth away from our planet’s gamma-ray absorbing atmosphere. Without Fermi, we wouldn’t have even been aware of these giant structures.

Since their discovery by Fermi’s Large Area Telescope (LAT), it was assumed that an ancient eruption by the Milky Way’s supermassive black hole may have energized galactic matter, inflating these two energetic bubbles. But since astronomers have been studying the nature of these features, their origin is as foggy as ever.

After subtraction of extragalactic gamma-ray sources, the bubbles have very clearly defined edges and, closest to the galactic plane, are associated with microwave emissions. However, the microwave emissions appear to fade away — the gamma-ray emissions glow uniformly throughout. This is a peculiar and vexing problem for astronomers.

“Since the Fermi bubbles have no known counterparts in other wavelengths in areas high above the galactic plane, all we have to go on for clues are the gamma rays themselves,” said postdoctoral researcher Anna Franckowiak of the Kavli Institute for Particle Astrophysics and Cosmology.

A few models have been put forward, but none fully explain the shape, scope or luminosity of these gamma-ray factories. Could the bubbles be expanding from black hole jets? Or could it be that a cluster of young massive stars formed and exploded at the same time, producing the huge bubbles like supernova exhaust? In short, we still have no idea.

In a paper published in the Astrophysical Journal today, Stanford University researchers say they need a better view of the gamma-ray radiation near the core of the Milky Way before we can better understand the bubbles’ source, but it will be a very hard task to subtract other gamma-ray sources from the region.

Read more at Discovery News

How Life Made the Leap From Single Cells to Multicellular Animals

For billions of years, single-celled creatures had the planet to themselves, floating through the oceans in solitary bliss. Some microorganisms attempted multicellular arrangements, forming small sheets or filaments of cells. But these ventures hit dead ends. The single cell ruled the earth.

Then, more than 3 billion years after the appearance of microbes, life got more complicated. Cells organized themselves into new three-dimensional structures. They began to divide up the labor of life, so that some tissues were in charge of moving around, while others managed eating and digesting. They developed new ways for cells to communicate and share resources. These complex multicellular creatures were the first animals, and they were a major success. Soon afterward, roughly 540 million years ago, animal life erupted, diversifying into a kaleidoscope of forms in what’s known as the Cambrian explosion. Prototypes for every animal body plan rapidly emerged, from sea snails to starfish, from insects to crustaceans. Every animal that has lived since then has been a variation on one of the themes that emerged during this time.

How did life make this spectacular leap from unicellular simplicity to multicellular complexity? Nicole King has been fascinated by this question since she began her career in biology. Fossils don’t offer a clear answer: Molecular data indicate that the “Urmetazoan,” the ancestor of all animals, first emerged somewhere between 600 and 800 million years ago, but the first unambiguous fossils of animal bodies don’t show up until 580 million years ago. So King turned to choanoflagellates, microscopic aquatic creatures whose body type and genes place them right next to the base of the animal family tree. “Choanoflagellates are to my mind clearly the organism to look at if you’re looking at animal origins,” King said. In these organisms, which can live either as single cells or as multicellular colonies, she has found much of the molecular toolkit necessary to launch animal life. And to her surprise, she found that bacteria may have played a crucial role in ushering in this new era.

Nicole King, a biologist at the University of California, Berkeley, studies the origins of animals, one of the big mysteries in the history of life.
In a lengthy paper that will be published in a special volume of Cold Spring Harbor Perspectives in Biology in September, King lays out the case for the influence of bacteria on the development of animal life. For starters, bacteria fed our ancient ancestors, and this likely required those proto-animals to develop systems to recognize the best bacterial prey, and to capture and engulf them. All of these mechanisms were repurposed to suit the multicellular lives of the first animals. King’s review joins a broad wave of research that puts bacteria at the center of the story of animal life. “We were obliged to interact intimately with bacteria 600 million years ago,” said King, now an evolutionary biologist at the University of California, Berkeley, and an investigator with the Howard Hughes Medical Institute. “They were here first, they’re abundant, they’re dominant. In retrospect we should’ve expected this.”

Multicellular Motivation

Although we tend to take the rise of animals for granted, it is reasonable to ask why they ever emerged at all, given the billions of years of success of unicellular organisms. “For the last 3.5 billion years, bacteria have been around and abundant,” said Michael Hadfield, a professor of biology at the University of Hawaii, Manoa. “Animals never showed up until 700 or 800 million years ago.”

The technical demands of multicellularity are significant. Cells that commit to living together need a whole new set of tools. They have to come up with ways of sticking together, communicating, and sharing oxygen and food. They also need a master developmental program, a way to direct specific cells to take on specialized jobs in different parts of the body.

Nonetheless, during the course of evolution, the transition to multicellularity happened separately as many as 20 different times in lineages from algae to plants to fungi. But animals were the first to develop complex bodies, emerging as the most dramatic example of early multicellular success.

To understand why this might have happened the way it did, King began studying choanoflagellates, the closest living relative to animals, nearly 15 years ago as a postdoc at the University of Wisconsin, Madison. Choanoflagellates are not the most charismatic of creatures, consisting of an oval blob equipped with a single taillike flagellum that propels the organism through the water and also allows it to eat. The tail, thrashing back and forth, drives a current across a rigid, collarlike fringe of thin strands of cell membrane. Bacteria get caught up in the current and stick to the collar, and the choano engulfs them.

What intrigued King about choanoflagellates was their lifestyle flexibility. While many live as single cells, some can also form small multicellular colonies. In the species Salpingoeca rosetta, which lives in coastal estuaries, the cell prepares to divide but stops short of splitting apart, leaving two daughter cells connected by a thin filament. The process repeats, creating rosettes or spheres containing as many as 50 cells in the lab. If this all sounds familiar, there’s a reason for it — animal embryos develop from zygotes in much the same way, and spherical choanoflagellate colonies look uncannily like early-stage animal embryos.

When King began studying S. rosetta, she couldn’t get the cells to consistently form colonies in the lab. But in 2006, a student stumbled on a solution. In preparation for genome sequencing, he doused a culture with antibiotics, and it suddenly bloomed into copious rosettes. When bacteria that had been collected along with the original specimen were added back into a lab culture of single choanoflagellates, they too formed colonies. The likely explanation for this phenomenon is that the student’s antibiotic treatment inadvertently killed off one species of bacteria, allowing another that competes with it to rebound. The trigger for colony formation was a compound produced by a previously unknown species of Algoriphagus bacteria that S. rosetta eats.

S. rosetta seems to interpret the compound as an indication that conditions are favorable for group living. King hypothesizes that something similar could have happened more than 600 million years ago, when the last common ancestor of all animals started its fateful journey toward multicellularity. “My suspicion is that the progenitors of animals were able to become multicellular, but could switch back and forth based on environmental conditions,” King said. Later, multicellularity became fixed in the genes as a developmental program.

King’s persistence in studying this humble organism, which was overlooked by most contemporary biologists, has won her the admiration of many of her fellow scientists (as well as a prestigious MacArthur fellowship). “She strategically picked an organism to gain insight into early animal evolution and systematically studied it,” said Dianne Newman, a biologist at the California Institute of Technology in Pasadena, who studies how bacteria coevolve with their environment. King’s research offers a thrilling glimpse into the past, a rare window into what might have been going on during that mysterious period before the first fossilized animals appeared. The research is a “beautiful example” of how bacteria shape even the simplest forms of complex life, Newman said. “It reminds us that even at that level of animal development, you can expect triggers from the microbial world.” The bacteria system in S. rosetta can now be used to answer more specific questions, such as what the benefit of multicellularity might be — a question King and her collaborators at Berkeley are now working to answer.

The first bacteria may date back as far as 3.5 billion years. But animals, the first complex multicellular life form, took much longer to emerge.
Of course, just because bacteria trigger modern choanoflagellates into group living, that doesn’t mean they had the same effect on the first proto-animals. King’s finding is “really cool,” said William Ratcliff, a biologist at the Georgia Institute of Technology in Atlanta who experimentally induces yeast to form multicellular colonies. “I think she’s doing some of the most interesting research in the origins of animals.” But, he cautions, it’s possible that choanoflagellates evolved this mechanism long after they diverged from the creatures that became the first ancestors of animals. “We don’t have a clear picture of when the bacterial response evolved,” he explained. “It’s hard to know if something happened before the split between choanoflagellates and animals, or after.”

“I think there is enough evidence to allow us to hypothesize that bacteria were an important influence on animal origins — they were abundant, diverse, and they exert important signaling influences on diverse animal lineages as well as on non-animals,” King said. “But I think it is premature to say what the nature of that influence was.”

One strong hint that bacteria may have prompted that ancient transition to multicellularity is that many of today’s simplest animals are governed by microbial messages. Corals, sea squirts, sponges and tube worms all begin life as larvae floating in the water, and other research teams have shown that they too respond to compounds released by bacteria as signals to attach themselves to rocks or other surfaces and transition to a new life form. If this kind of relationship is so common among animals from the most ancient families, it seems plausible that the first animals were equally attuned to their bacterial neighbors. Figuring out how, exactly, the bacteria trigger this response will help clarify whether they played a similar role long ago. “It was a radical thought to me when we first started studying it, and now I don’t know why it’s a surprise,” King said. “The more I think about host-microbe interactions, the less surprised I become.”

What Took Animals So Long?

What triggered the explosion of complex multicellular life in the Cambrian period? Increased oxygen undoubtedly had something to do with it — prior to a period sometime before 800 million years ago, atmospheric oxygen levels were too low to diffuse easily into organisms with multiple layers of cells, limiting the size of all life forms. But an increase in oxygen is probably not the whole story, said Andrew Knoll, a professor of earth and planetary sciences at Harvard University. Once oxygen levels rose past this low level, predation likely provided a strong incentive for animals to get bigger and more complicated, and to develop new body plans. It was an ecological arms race of size and complexity: Bigger predators have an advantage in catching prey, while larger prey can more easily avoid being eaten. The need to escape or repel predators also likely inspired the first scales, spines and body armor, as well as some of the wilder body plans seen in Cambrian fossils.

 King’s discovery about choanoflagellates is just one of the latest insights into the intimate relationships between bacteria and animals (or, in this case, animal-like organisms). Historically, photosynthetic bacteria pumped oxygen into the oceans for billions of years, setting the stage for complex multicellular life. And according to the endosymbiotic theory, proposed in the 20th century and now widely accepted, the mitochondria inside every eukaryotic cell were once free-living bacteria. At some point more than a billion years ago, they took up residence inside other cells in a symbiotic relationship that endures in nearly every animal cell to this day. In their role as dinner, bacteria also likely provided raw genetic material for the first animals, which probably incorporated chunks of microbial DNA directly into their own genomes as they digested their meals.

But the full story of the microbial-animal relationship is even broader and deeper, argues Margaret McFall-Ngai, a biologist at the University of Wisconsin, Madison, and it’s a story that is only beginning to be told. In her view, animals should rightly be considered host-microbe ecosystems. Several years ago McFall-Ngai, along with Hadfield, convened a broad group of developmental biologists, ecologists, environmental biologists and physiologists, including King, and asked them to formulate a microbial manifesto — a declaration of bacterial significance. The paper, which appeared late last year in the Proceedings of the National Academy of Sciences, cites evidence from many corners of biology to argue that the influence of microbes on the origin, evolution and function of animals is pervasive and essential to understanding how animal life evolved. “They evolved in a world saturated with bacteria,” Hadfield said.

The biology of choanoflagellates resembles that of animals in other unexpected ways, King found. In 2008 she led the team that published the genome of Monosiga brevicollis, a choanoflagellate that doesn’t form colonies. The sequence revealed genes for dozens of sections of proteins that also appear in multicellular animals, where they help cells stick together and also guide development and differentiation. What are they doing in single cells? King’s work suggests they arose in single-celled organisms to monitor environmental conditions and recognize other cells such as bacterial prey. In multicellular animals, the gene domains found new purposes, such as allowing cells to signal one another. Single cells used these tools to listen in on the environment. Later on, the first cells to adopt a multicellular lifestyle probably repurposed the same systems to pay attention to their sister cells, King suggested.

Read more at Discovery News

Jul 31, 2014

Getting Small the Key for Dinos that Became Birds

How did some dinosaurs go from being impossibly huge, Earth-bound creatures to winged masters of the sky? The answer, a new study suggests, is simple: They got small, and kept on getting smaller.

A study out of the University of Southampton just published in the journal Science involved an examination of 1,500 dinosaur traits by researchers, who reassembled the dinosaur family tree and used mathematical models to track adaptations and body size over time, and across branches of the dino family tree.

They observed that the therpod branch of dinosaurs, from which ultimately evolved modern birds, was the only branch that kept getting smaller in size, sustaining the shrinkage for 50 million years.

"Being smaller and lighter in the land of giants, with rapidly evolving anatomical adaptations, provided these bird ancestors with new ecological opportunities, such as the ability to climb trees, glide and fly," said lead author Associate Professor Michael Lee, from the University of Adelaide's School of Earth and Environmental Sciences and the South Australian Museum, in a press release.

The adaptations taken on by early bird ancestors included such features as wishbones, feathers, and wings. These changes came "four times faster than other dinosaurs," observed the study's co-author Darren Naish, vertebrate palaeontologist at the University of Southampton.

When it got right down to it, the researchers say, the branch of dinosaurs that became birds simply knew how to innovate, evolutionarily speaking, and then put the changes into a microwave on high. "Birds out-shrank and out-evolved their dinosaurian ancestors, surviving where their larger, less evolvable relatives could not," said Lee.

"Ultimately, this evolutionary flexibility helped birds survive the deadly meteorite impact which killed off all their dinosaurian cousins," he added.

From Discovery News

Warriors' Bones Reveal Bizarre Iron Age Rituals

The bones of dozens of Iron Age warriors found in Denmark were collected and ritually mutilated after spending months on the battlefield, archaeologists say.

At least six months after the soldiers died, their bones were collected, scraped of remaining flesh, sorted and dumped in a lake. Some were handled in a truly bizarre manner; for instance, four pelvises were found strung on a stick.

"We think it's a kind of ritual closure of the war," said Mads Kähler Holst, project manager at the dig and head of the department of archaeology at the Moesgård Museum in Denmark. The victors seem to have carried out their gruesome work on a spit of land extending into the lake where the bones were dumped, the researchers said.

The site of the boneyard is in East Jutland, in a wetland area known as Alken Enge. Drainage work and peat digging have been turning up ancient human remains in this bog for decades, Holst told Live Science.

Formal excavation of the site finds it to be a mass grave dating back about 2,000 years, to the transition from B.C. to A.D. At the time, the area was about 186 miles (300 kilometers) north of the farthest reach of the Roman Empire, Holst said, and would have been occupied by Germanic tribes.

Archaeologists have turned up at least 60 skeletonsor parts of skeletons in what used to be the bed of Lake Mossø at the site. The lake still exists, but it's smaller than it was 2,000 years ago. The 60 catalogued remains don't include bones found previously — or the many more skeletons archaeologists expect to discover.

"We have trenches going through different areas, so we know we are only touching on a small part of what is actually there," Holst said.

Most of the bones are found disarticulated from one another, and many bear the marks of the battlefield: trauma from swords, spears and axes. Spearheads, an ax, the tip of a sword and shields have also been found at the site, Holst said. All of the bodies are male.

All of the evidence points to a straightforward defeat in battle. But the bones also bear strange marks of tampering after the soldiers' death.

First, many have been gnawed by animals, including large predators such as wolves, dogs and badgers, Holst said. The species present and amount of scavenging suggest the bodies stayed out in the open for at least six months to a year, he said.

After this time, someone collected the corpses and sorted at least some of the bones by type. Marks of cutting and scraping suggest the bones were separated deliberately, and that they had any remaining flesh removed. Animal sacrifices and ceramic pots mixed in with the remains suggest some sort of religious ritual, Holst said. Along with the pelvises strung like beads on a stick, there is evidence that leg bones and thighbones were sorted, too, he said.

From a land spit extending into what was then the lake, the ancient people conducted these rituals and then dumped the bones. Holst and his colleagues know nothing for sure about the victors and the slaughtered, but they suspect that the winners had a geographical attachment to the area, given that they were around long enough to conduct these rituals. There are examples of ritual treatment of defeated enemies in what is now France, Switzerland and England in the centuries prior to this find, Holst said, but nothing like it has ever been seen in Denmark or the surrounding areas.

Read more at Discovery News

Oetzi the Iceman Had Heart Disease Gene

Ötzi the Iceman, a well-preserved mummy discovered in the Alps, may have had a genetic predisposition to heart disease, new research suggests.

The new finding may explain why the man — who lived 5,300 years ago, stayed active and certainly didn't smoke or wolf down processed food in front of the TV — nevertheless had hardened arteries when he was felled by an arrow and bled to death on an alpine glacier.

"We were very surprised that he had a very strong disposition for cardiovascular disease," said study co-author Albert Zink, a paleopathologist at the Institute for Mummies and the Iceman at the European Academy of Bozen/Bolzano in Italy. "We didn't expect that people who lived so long ago already had the genetic setup for getting such kinds of diseases."

Iceman scrutiny

Otzi was discovered in 1991, when two hikers stumbled upon the well-preserved mummy in the Ötztal Alps, near the border between Austria and Italy. Since then, every detail of the iceman has been scrutinized, from his last meal and moments (Ötzi was bashed on the head before being pierced by the deadly arrow blow), to where he grew up, to his fashion sense.

Past research has revealed that Ötzi likely suffered from joint pain, Lyme disease and tooth decay, and computed tomography (CT) scanning revealed calcium buildups, a sign of atherosclerosis, in his arteries.

Initially, the atherosclerosis was a bit of a surprise, because much research has linked heart disease to the couch-potato lifestyle and calorie-rich foods of the modern world, Zink said. But in recent research, as scientists conducted CT scans on mummies from the Aleutian Islands to ancient Egypt, they realized that heart disease and atherosclerosis were prevalent throughout antiquity, in people who had dramatically different diets and lifestyles, he said.

"It really looks like the disease was already frequent in ancient times, so it's not a pure civilizational disease," Zink told Live Science.

Heart troubles

Scientists recently took a small sample of Ötzi's hipbone and sequenced the Neolithic agriculturalist's entire genome, to see where he fell on Europe's family tree. As part of that research, they found that the iceman had 19 living relatives in Europe.

In the new study, Zink and his colleagues found that Ötzi had several gene variants associated with cardiovascular disease, including one on the ninth chromosome that is strongly tied to heart troubles, the researchers reported today (July 30) in the journal Global Heart.

Read more at Discovery News

Large Waves Recorded in Arctic Ocean for First Time

For the first time ever, loss of sea ice is leading to large waves in the Arctic Ocean. During a peak period, an average of 16-foot waves were recorded. Waves as tall as 29 feet were recorded in an area that was not long ago permanently covered in ice.

The findings, from a study published in Geophysical Research Letters, is concerning not only because it appears to be a fast-moving sign of climate change, but the large waves can also lead to more sea-ice loss.

“As the Arctic is melting, it’s a pretty simple prediction that the additional open water should make waves,” lead author Jim Thomson, an oceanographer with the UW Applied Physics Laboratory, said in a statement. Wave size increases with travel distance over open water.

The possibility of an ice-free season in the Arctic opens the possibility of shipping in the region. But large waves increase risk.

“Almost all of the casualties and losses at sea are because of stormy conditions, and breaking waves are often the culprit,” Thomson said.

The new research was taken in deep water in the Beaufort Sea north of Alaska. The researchers plan to be part of an international group that will place dozens of sensors in the Arctic Ocean to learn more about ice retreat in the region.

“The melting has been going on for decades. What we’re talking about with the waves is potentially a new process, a mechanical process, in which the waves can push and pull and crash to break up the ice,” Thomson said.

From Discovery News

Rebooted Spacecraft to Tackle Interplanetary Science

A private team is priming a 36-year-old NASA spacecraft to perform new science as it travels through interplanetary space after attempts to move the probe into a position closer to Earth failed.

The volunteer team initially hoped to park the vintage International Sun-Earth Explorer 3 spacecraft, called ISEE-3 for short, in a stable location between the Earth and the sun called L-1. But those attempts ended when controllers discovered there wasn't enough nitrogen pressurant left in the probe's tanks to help make course corrections.

"We're disappointed we couldn't put it in the L-1 orbit, but we had a lot of scientists saying we're more interested in interplanetary space," Keith Cowing, co-leader of the ISEE-3 Reboot Project, told

That's because at least five of the 13 instruments on the ISEE-3 spacecraft are still working, even after more than three decades in space. They could allow scientists to do things such as listen for gamma-ray bursts, which are the brightest explosions in the universe and often take place over just a few minutes.

Pinpointing the source of gamma-ray bursts requires a coordinated effort among several observatories, so having one more probe in space "listening" will be valuable, Cowing said.

Building a Global Network

Getting data quickly, however, will in part depend on the number of radio antennas on Earth listening to the signal from ISEE-3. Cowing said there is good coverage in the United States in Europe, but coverage is missing in two-thirds of the globe, in areas such as Africa, Australia and Japan.

The ISEE-3 Reboot Project plans to turn to crowdsourcing to ask for citizen scientists to set up radio dishes to listen in. The information ISEE-3 yields will be open source and perhaps the first such global citizen radio science project, Cowing said. After all, it was crowdfunding on the website RocketHub that allowed the group to raise $160,000 for its initial attempts to salvage the abandoned ISEE-3 spacecraft in the first place.

NASA's ISEE-3 spacecraft originally launched in 1978 to study interactions between the Earth's magnetic field and the solar wind, then had its mandate changed to see how the wind influences comet atmospheres. It flew through Comet Giacobini-Zinner in 1985 and also gathered data on Halley's Comet in 1986 before being put into hibernation in 1998.

Cowing pledged the data will be "semi-live," depending on how much processing it will take for the data to be useable after being picked up by the dish. Already, the spacecraft's magnetometer has picked up disturbances in space that can be linked back to solar activity.

The science campaign is slated to begin Aug. 10, when ISEE-3 swings by the moon, and will continue for as much of its orbit as can be heard from Earth. ISEE-3 will travel in a 300-day orbit around the sun, but the final coordinates are still being determined.

Cowing added that the group will publicize the results of the science with external entities, and those partnerships will be announced shortly.

Funding a Volunteer Space Mission

As for the $160,000 raised through RocketHub, Cowing said it's just about gone. The money went to renting time on NASA's Deep Space Network of dishes, flying four people to the giant Arecibo Observatory in Puerto Rico for a week to set up communications, and other miscellaneous costs.

Read more at Discovery News

Jul 30, 2014

Old Amber Collection Reveals Locust Evolution in Action

In the late 1950s, an entomologist collected an impressive 160 pounds of Dominican amber. Upon his return to Illinois, Milton Sanderson described some of the samples in a paper published in Science in 1960. Then the mother lode of amber went back into buckets -- and into storage at the Illinois Natural History Survey.

Now, some 50 years later, scientists are meticulously digging through and analyzing each piece. Among their finds so far is a specimen of pygmy locust that lived 18 to 20 million years ago. It represents a transitional stage in this insect's evolution since earlier versions of the grasshopper had wings, while modern versions do not. The specimen contained in the amber sported what appear to be vestigial wings -- remnant structures that had already lost their main function.

"Grasshoppers are very rare in amber and this specimen is extraordinarily well-preserved," said Sam Heads, a paleontologist at the Illinois Natural History Survey, in a press release.

Heads named the new pygmy locust Electrotettix attenboroughi, the genus name is a combination of electrum (Latin from Greek, meaning "amber") and tettix (Greek, meaning "grasshopper"). The species is named for Sir David Attenborough, a British naturalist and filmmaker. Attenborough was interviewed about the newly named species in an interview by INHS.

"I'm very tickled pink," Attenborough said in a video about the new species' name. "It shows you that that family has been evolving 30 million years ago or wherever you date it, it had wings and today, all the members of the family don't."

The discovery is reported in the journal ZooKeys.

Among the other specimens Heads and lab technician Jared Thomas have found are fungus gnats, mosquitoes, spiders, a few mammal hairs, stingless bees and flowers. And they've only just begun -- so far they've analyzed less than 1 percent of the massive collection. As Thomas said, "We're looking through even the tiniest of pieces. There are tiny insects that could be hidden there, so we don’t want to miss anything."

Read more at Discovery News

If Ebola Arrives in U.S., What Happens?

Last week, a former Minnesota resident died of Ebola in Nigeria. This week, the what-ifs are rampant.

The victim's wife said her husband had been scheduled to fly to Minneapolis in mid-August to attend a birthday party for two of their children. "He could have brought Ebola here," she told The Daily Beast.

Two other Americans in Africa have been diagnosed with the disease, and Sierra Leone's leading Ebola doctor died of it yesterday.

While the Centers for Disease Control and Prevention on Monday issued both a Level 2 travel alert, recommending those traveling to Africa "avoid contact with blood and bodily fluids," and a Health Alert Notice to U.S. health care workers, experts and officials believe there's no need for panic. Far from it, in fact: "It's extremely unlikely," said Thomas Geisbert, a virologist with the University of Texas in Galveston, Texas, who studies Ebola and other hemorrhagic fevers.

And, if someone were diagnosed anywhere in the United States, "every infectious disease doctor in any hospital would be on full alert for signs and symptoms," Geisbert said. "For containing outbreaks, with quarantine and prevention we're 90 percent of the way there."

Even if someone with Ebola got on an airplane to the United States, "it's very unlikely that they would be able to spread the disease to fellow passengers," said Dr. Stephan Monroe, deputy director of CDC National Center for Emerging & Zoonotic Diseases in a press conference call.

"The Ebola virus spreads through direct contact with the blood, secretions, or other body fluids of ill people, and indirect contact -- for example with needles and other things that may be contaminated with these fluids. Most people who become infected with Ebola are those who live with and care for people who have already caught the disease and are showing symptoms."

On the off-chance that the situation did occur, here's what would happen: The patient would be transferred to an isolation ward, and all health care workers coming in contact with the person would wear full personal protective equipment. Ebola is classified as a biosafety level 4 virus, so testing for the virus would happen in one of a few labs in the nation qualified to safely handle the virus in air-controlled rooms.

Once a diagnosis was confirmed, contact tracing would begin: Anyone the person had contact with -- on an airplane, at a market, at a family gathering -- would be informed of the situation and monitored. That's a much easier task in a developed country that has ready access to communication than it's been in Africa, where cultural, language, communication and transportation hurdles must be overcome to relay information.

This spring, for example, a man with Middle East Respiratory Syndrome (MERS) landed in Indiana, and a man checked into a hospital in Minnesota with Lassa fever. In both cases, health workers followed contact tracing protocol (requiring getting in touch with 140 people), and the viruses were contained.

In the Indiana case, the Indiana Department of Public Health traced everybody on the bus the patient traveled on, on his flights, in the waiting room, visitors to the hospital, and family. The CDC tested over 50 people and found one with mild MERS. In the Minnesota case, over 140 people were contacted and no one else was diagnosed with the disease.

Because the incubation period of Ebola is relatively long -- up to 21 days, the list of contacts gets extensive quickly.

Read more at Discovery News

Violent Young Earth Created Oasis for Life

Asteroids and comets that repeatedly smashed into the early Earth covered the planet's surface with molten rock during its earliest days, but still may have left oases of water that could have supported the evolution of life, scientists say.

The new study reveals that during the planet's infancy, the surface of the Earth was a hellish environment, but perhaps not as hellish as often thought, scientists added.

Earth formed about 4.5 billion years ago. The first 500 million years of its life are known as the Hadean Eon. Although this time amounts to more than 10 percent of Earth's history, little is known about it, since few rocks are known that are older than 3.8 billion years old.

Earth's Violent Youth

For much of the Hadean, Earth and its sister worlds in the inner solar system were pummeled with an extraordinary number of cosmic impacts.

"It was thought that because of these asteroids and comets flying around colliding with Earth, conditions on early Earth may have been hellish," said lead study author Simone Marchi, a planetary scientist at the Southwest Research Institute in Boulder, Colorado. This imagined hellishness gave the eon its name — Hadean comes from Hades, the lord of the underworld in Greek mythology.

However, in the past dozen years or so, a radically different picture of the Hadean began to emerge. Analysis of minerals trapped within microscopic zircon crystals dating from this eon "suggested there was liquid water on the surface of the Earth back then, clashing with the previous picture that the Hadean was hellish," Marchi said. This could explain why the evidence of the earliest life on Earth appears during the Hadean — maybe the planet was less inhospitable during that eon than previously thought.

Cosmic Bombardment History

The exact timing and magnitude of the impacts that smashed Earth during the Hadean are unknown. To get an idea of the effects of this bombardment, Marchi and his colleagues looked at the moon, whose heavily cratered surface helped model the battering that its close neighbor Earth must have experienced back then.

"We also looked at highly siderophile elements (elements that bind tightly to iron), such as gold, delivered to Earth as a result of these early collisions, and the amounts of these elements tells us the total mass accreted by Earth as the result of these collisions," Marchi said. Prior research suggests these impacts probably contributed less than 0.5 percent of the Earth's present-day mass.

The researchers discovered that "the surface of the Earth during the Hadean was heavily affected by very large collisions, by impactors larger than 100 kilometers (60 miles) or so — really, really big impactors," Marchi said. "When Earth has a collision with an object that big, that melts a large volume of the Earth's crust and mantle, covering a large fraction of the surface," Marchi added.

These findings suggest that Earth's surface was buried over and over again by large volumes of molten rock — enough to cover the surface of the Earth several times. This helps explain why so few rocks survive from the Hadean, the researchers said.

However, although these findings might suggest that the Hadean was a hellish eon, the researchers found that "there were time gaps between these large collisions," Marchi said. "Generally speaking, there may have been something on the order of 20 or 30 impactors larger than 200 km (120 miles) across during the 500 million years of the Hadean, so the time between such impactors was relatively long," Marchi said.

Read more at Discovery News

Weirdly Wonky Binary Star System Discovered

There’s some weird things floating around in our galaxy, but this has to be one of the weirdest. A double star system with misaligned protoplanetary disks around 450 light-years from Earth has been discovered, potentially explaining why some exoplanet orbits can be wildly eccentric.

Using data from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, astronomers have gotten a detailed look into the binary star system HK Tauri.

The majority of stars form with a stellar buddy in tow, creating binary star systems, so that’s not the weird thing. On viewing the protoplanetary disks surrounding each star of the HK Tauri system, astronomers found, counter-intuitively, that their disks are out of alignment by 60 degrees. That’s the weird thing.

Normally, when you have two stars evolved from the same proto-stellar nebula, any planet forming material that settles gravitationally into a protoplanetary disk around each star should fall into alignment. HK Tauri completely bucks this expectation.

“ALMA has now given us the best view yet of a binary star system sporting protoplanetary discs — and we find that the discs are mutually misaligned!” said astronomer Eric Jensen, of Swarthmore College in Pennsylvania, in an ESO press release.

HK Tauri B is the dimmer of the binary pair, but its protoplanetary disk has been relatively easy to observe through infrared and optical wavelengths as the disk can be seen edge-on from our perspective — a dark band of dusty material can therefore be seen passing in front of the star. HK Tauri A’s protoplanetary disk, however, is not so easy to see as the disk is face-on from our perspective — any reflected light from the disk is therefore swamped by the blinding light from the star.

With the help of ALMA, millimeter wavelengths of light being emitted directly from the disk could be resolved, revealing just how wonky the star system has become.

At less than 5 million years old, these stars are a real head-scratcher. They orbit each other at a distance of only 36 billion miles (or 388 AU — approximately 13 times the distance that Neptune orbits the sun), so through gravitational interactions in the system, the protoplanetary disks should be ‘leveling off’.

“This clear misalignment has given us a remarkable look at a young binary star system,” said Rachel Akeson of the NASA Exoplanet Science Institute at Caltech, in Pasadena, Calif. “Although there have been earlier observations indicating that this type of misaligned system existed, the new ALMA observations of HK Tauri show much more clearly what is really going on in one of these systems.”

Now astronomers need to find more of these young star systems to see if misaligned protoplanetary disks are common, or if HK Tauri is an oddity. Though this discovery will force some tweaks to planetary formation models, it may help explan some of the crazy orbits of exoplanets that keep getting discovered.

Read more at Discovery News

Jul 29, 2014

Rare Pangolins May Be Eaten to Extinction

They've been described as walking artichokes and the most trafficked mammals in the world. Now, conservationists warn that pangolins, or scaly anteaters, could be eaten out of existence if illegal hunting and poaching continue.

In the latest update of the International Union for Conservation of Nature's (IUCN) Red List of Threatened Species, all eight pangolin species were listed as "critically endangered," "endangered" or "vulnerable." Today (July 29), a group of scientists and conservationists tasked with studying pangolins for the IUCN issued an action plan outlining steps that should be taken to save the armored, insect-eating creatures.

"In the 21st century, we really should not be eating species to extinction — there is simply no excuse for allowing this illegal trade to continue," Jonathan Baillie, co-chair of the pangolin specialist group for the IUCN's Species Survival Commission and conservation programs director at the Zoological Society of London, said in a statement.

Pangolins, native to Asia and Africa, are the world's only mammals with true scales made of keratin. Despite international trade bans, pangolin meat and scales still fetch high prices on the black market. Demand is especially high in China and Vietnam, where pangolin parts are used in medicine and served as a culinary delicacy.

Last August, more than six tons of live pangolins were seized as they headed from Indonesia to Vietnam in a shipping container labeled as frozen fish, fins and fish bones, AFP reported at the time. In April 2013, a Chinese fishing vessel was found carrying as many as 2,000 of the toothless creatures, after the vessel ran aground in the protected Tubbataha Reefs off the coast of the Philippines, according to the World Wildlife Fund.

Though the scope of the black market is difficult to quantify, conservationists estimate that more than 1 million pangolins have been taken from the wild in just the last decade. The four species in Asia are the most severely threatened. The Chinese pangolin and the Sunda pangolin are now considered critically endangered, while the Indian pangolin and Philippine pangolin are now listed as endangered. But as the populations of Asian pangolin species are becoming more scarce, traders are increasingly looking to Africa to meet the demand for pangolin.

Dan Challender, co-chair of the pangolin specialist group, has witnessed that demand firsthand. In 2012, just a few days after he arrived in Ho Chi Minh City in Vietnam, Challender said he watched a man in a restaurant drop the equivalent of about $700 U.S. to have a 4.4-pound (2 kilograms) live pangolin killed and served to him. As pangolin meat is often the most expensive item on a menu in Vietnam, businessmen and women might order it to celebrate the signing of a contract or deal, or to impart status, Challender said. While recent studies have indicated that delicacies like shark fin soup are losing their status, Challender suspects conservationists have a long way to go in changing public opinion about consuming pangolins.

Read more at Discovery News

Bid to Save Tigers Threatened by Poor Data

Efforts to save the tiger are being undermined by a lack of information about how many of the endangered cats live in the wild, the conservation group WWF said on Tuesday.

In 2010, a "tiger summit" in St. Petersburg, Russia, set the goal of doubling the number of wild tigers by 2022, against a baseline population believed at the time to be as few as 3,200.

"This figure was just an estimate," Michael Baltzer, head of WWF's "Tigers Alive Initiative" said in a press release coinciding with Global Tiger Day.

"In 2010 many countries had not undertaken systematic national tiger surveys. Now many have or are doing so, but not all, leaving major, worrying gaps in our knowledge.

"Until we know how many tigers we have and where they are, we can't know how best to protect them."

WWF praised India, Nepal and Russia for carrying out regular national surveys that gave a reliable indicator of their tiger populations.

Bhutan, Bangladesh and China will shortly release the results from their own surveys, it said.

On the other hand, "wild tiger populations for Malaysia, Indonesia, Thailand, Myanmar, Laos, Cambodia and Vietnam are unknown," it said.

Read more at Discovery News

Tree Rings Solve Mystery of World Trade Center Ship

In July 2010, amid the gargantuan rebuilding effort at the site of the World Trade Center in Lower Manhattan, construction workers halted the backhoes when they uncovered something unexpected just south of where the Twin Towers once stood.

At 22 feet (6.7 meters) below today's street level, in a pit that would become an underground security and parking complex, excavators found the mangled skeleton of a long-forgotten wooden ship.

Now, a new report finds that tree rings in those waterlogged ribs show the vessel was likely built in 1773, or soon after, in a small shipyard near Philadelphia. What's more, the ship was perhaps made from the same kind of white oak trees used to build parts of Independence Hall, where the Declaration of Independence and U.S. Constitution were signed, according to the study published this month in the journal Tree-Ring Research.

Archaeologists had been on-site throughout the excavation of the World Trade Center's Vehicular Security Center. They had found animal bones, ceramic dishes, bottles and dozens of shoes, but the excitement really kicked up when the 32-foot-long (9.75 m) partial hull of the ship emerged from the dirt.

The vessel was quickly excavated, to prevent damage from exposure to the air. Piece by piece, the delicate oak fragments were documented and taken out of the rotten-smelling mud. The timbers were sent to the Maryland Archaeological Conservation Laboratory, where they would be soaked in water to keep the wood from cracking and warping.

A few timbers were sent back to New York, just 20 miles (32 kilometers) north of the World Trade Center, to the Tree Ring Laboratory at Columbia University's Lamont-Doherty Earth Observatory in Palisades, New York. Researchers at the lab dried the fragments slowly in a cold room and cut thick slices of the wood to get a clear look at the tree rings.

The team established that the trees used to build the ship — some of which had lived to be more than 100 years old — were mostly cut down around 1773. Then, to determine where the wood came from, the researchers had to find a match between the ring pattern in the timbers and a ring pattern in live trees and archaeological samples from a specific region.

"What makes the tree-ring patterns in a certain region look very similar, in general, is climate," said the leader of the new study, Dario Martin-Benito, who is now a postdoctoral fellow at the Swiss Federal Institute of Technology (ETH) in Zurich. Regional ring patterns arise from local rain levels and temperatures, with wetter periods producing thicker rings and drier periods producing smaller rings, he said.

Martin-Benito and his colleagues at Columbia's Tree Ring Lab narrowed their search to trees in the eastern United States, thanks to the keel of the ship, which contained hickory, a tree found only in eastern North America and eastern Asia. Otherwise, the researchers would have had much more difficulty in limiting their search, as oak is found all over the world.

The ship's signature pattern most closely matched with the rings found in old living trees and historic wood samples from the Philadelphia area, including a sample taken during an earlier study from Independence Hall, which was built between 1732 and 1756.

"We could see that at that time in Philadelphia, there were still a lot of old-growth forests, and [they were] being logged for shipbuilding and building Independence Hall," Martin-Benito told Live Science. "Philadelphia was one of the most — if not the most — important shipbuilding cities in the U.S. at the time. And they had plenty of wood so it made lots of sense that the wood could come from there."

Historians still aren't certain whether the ship sank accidently or if it was purposely submerged to become part of a landfill used to bulk up Lower Manhattan's coastline. Oysters found fixed to the ship's hull suggest it at least languished in the water for some time before being buried by layers of trash and dirt.

Read more at Discovery News

Saturn Moon's 101 Geysers Blast From Hidden Ocean

New observations from NASA’s Saturn-orbiting Cassini spacecraft have revealed at least 101 individual geysers erupting from Enceladus’ crust and, through careful analysis, planetary scientists have uncovered their origin.

Over a period of seven years, Cassini has been gradually building up a map of the small icy world. One of Enceladus’ most famous features — its south polar “tiger stripes” — have been of special interest.

From the cracked ice in this region, fissures blast out water vapor mixed with organic compounds as huge geysers. Associated with these geysers are surface “hotspots,” but until now, there has been some ambiguity as to whether the hotspots are creating the geysers or whether the geysers are creating the hotspots.

In two new publications published in the Astrophysical Journal today (July 29), this Saturnian “chicken or the egg” conundrum has now been solved.

Enceladus’ tiger stripes were first spotted in 2005 during a Cassini flyby. During each consecutive flyby, astronomers have been carefully studying these 80-mile-long, 1.5-mile-wide depressions in the ice. Associated with each linear stripe is a heat signature, from which the geysers are actively ejecting vapor into space.

One theory suggests that the heat signature is caused by large fissures along the stripes rubbing against one another through tidal interactions with Saturn. This frictional heating causes the surface ice to heat up and vent into space.

However, there was always a more compelling alternative: what if frictional heating isn’t causing the geysers? Perhaps the geysers are actually carrying the heat from a sub-surface ocean.

Through the combination of survey data with high-resolution hotspot data from Cassini’s head-sensing instruments, individual geysers coincided with small-scale hotspots, according to the researchers. The resolution of the observations is so fine that 101 individual geyser sources were counted. But the hotspots were only a few dozen feet long, corresponding to very small fractures. This proves that the features are too small to create enough frictional heating to produce geysers — the opposite is actually true. The geysers are transporting the heat from deep inside the moon, creating the heated fissures.

“Once we had these results in hand, we knew right away heat was not causing the geysers, but vice versa,” said Carolyn Porco, leader of the Cassini imaging team from the Space Science Institute in Boulder, Colo., and lead author of one of the research papers. “It also told us the geysers are not a near-surface phenomenon, but have much deeper roots.”

So where are the geysers’ roots? Like Jupiter’s moon Europa, Enceladus appears to be hiding an ocean that's trapped deep inside a thick crust of ice.

A second paper published in the Astrophysical Journal also reports on observations of Enceladus’ geysers, supporting the idea that a heated ocean is trapped inside the ice. During the moon’s orbit around Saturn, the brightness of the water vapor plume created by the geysers appear to wax and wane.

According to the researchers, this brightness change corresponds to increased and decreased water vapor output through fissures in the ice — fissures that may be opened and closed through tidal flexing of the icy crust.

Read more at Discovery News

Jul 28, 2014

How Texas Man Survived 1,000 Killer Bees

A municipal worker who got stung by an estimated 1,000 bees while mowing a park lawn on Thursday (July 24) was in stable condition. So how did he survive the buzzing attack?

Turns out, the man's attackers — probably Africanized honeybees, according to the local fire department — are not as deadly as their name may suggest. To be lethal, the bees would likely have had to sting the man several hundred more times, experts say. In addition, the victim seems not to have been allergic to the bees. (The bees also stung two other workers who tried to help the man, according to Wichita Falls' News Channel 6.)

Not-so-killer bees

Africanized honeybees, or "killer bees," have been in the United States since about 1990, according to May Berenbaum, head of the department of entomology at the University of Illinois. But despite their dramatic nickname, these insects aren't that deadly.

An estimated 40 people in the United States die every year from stings by hymenoptera species. That group of insects includes some 150,000 species of bees (and killer bees), wasps, ants and other bugs, Berenbaum said.

It's hard to pin down specific data on the number of people attacked annually in the United States by Africanized honeybees: As Berenbaum explained, this is partly because not all attacks are reported and partly because, oftentimes, people aren't quite sure what stung them.

Furthermore, it's difficult to pin the blame on a particular species of bee in instances of injuries or deaths caused by insects, because some species don’t leave any telltale evidence. While honeybee stingers stay behind in the body of the victim, many species take their stingers with them after attacking, Berenbaum explained.

Fierce defenders

Though Africanized honeybees don't always attack, when they do, the results can be devastating. While the victim of Thursday's attack in Wichita Falls, Texas, survived the incident, not all killer bee victims have been as lucky.

Last year in Waco, Texas, about three hours south of Wichita Falls, an estimated 40,000 Africanized honeybees attacked a local farmer who was mowing a neighbor's pasture with tractor, ABC News reported. Larry Goodwin, 62, sustained more than 3,000 stings before collapsing to the ground. He was pronounced dead at the scene.

The number of stings that Goodwin sustained likely caused his unfortunate death, Berenbaum explained. The average person can sustain 10 bee stings per pound of body weight, both Berenbaum and the U.S. Department of Agriculture note. As such, 500 stings might be enough to kill a child, but the 1,000 stings suffered by the man in Wichita Falls did not deliver a lethal dose of venom, given his body weight.

"With honeybees, in particular, the venom isn't really designed to kill. It's designed to educate — basically, to drive away an enemy and make sure the enemy doesn't repeat the threat," Berenbaum told Live Science.

Unfortunately for the victims of killer bee attacks, the insects aren't very good at distinguishing between a true threat and an accidental nudge from a noisy mower. Africanized honeybees are extremely protective of their hive and brood, much more so than European honeybees. And their "home turf" is much larger than that of their calmer cousins. About 100 yards (91 meters), or the length of a four-lane highway, is usually a safe distance from these insects, according to the U.S. Department of Agriculture.

In addition to number of stings, other factors also play roles in determining a person's chances of surviving a killer bee attack. These include the general health of the victims, and their weight and sensitivity to bee venom.

Furthermore, people who are allergic to bee stings can experience a severe physiological reaction after just one sting, Berenbaum said.

Called anaphylactic shock, this severe allergic reaction can prove lethal for some people attacked by bees. Berenbaum describes anaphylaxis as an "immune response running amuck," and while she said that everyone is likely to experience some kind of allergic reaction to bee venom, only some individuals experience anaphylactic shock.

Allergic to bees or not, anyone who encounters a swarm of these defensive insects should "run away," she said. "And don't zigzag. That serpentine move you see in movies all the time just slows you down."

Read more at Discovery News

Colossal Bad Luck Caused Dinosaurs To Go Extinct

Dinosaurs would likely still be around today if the 6.2-mile-wide Chicxulub asteroid had crashed into Earth just a little while before or after it did, concludes an international team of some of the world's leading paleontologists.

In short, dinosaurs were victims of colossal bad luck, according to University of Edinburgh vertebrate paleontologist and evolutionary biologist Stephen Brusatte, who led the study that is published in the latest issue of Biological Reviews.

"The asteroid almost certainly did it," meaning wiped out the dinosaurs, he told Discovery News, "but it just so happened to hit at a bad time when dinosaur ecosystems had been weakened by a loss of diversity."

"If the asteroid hit a few million years earlier, when dinosaurs were more diverse, or a few million years later, when they had a chance to recover as they often had done before after diversity losses, then dinosaurs probably wouldn't have gone extinct," he said.

Brusatte and his team came to this conclusion after studying an updated catalog of dinosaur fossils to create a picture of how dinosaurs, and the environment, changed over the few million years before the asteroid struck what is now Mexico.

The researchers found that during the years prior to the asteroid hit, Earth was undergoing huge volcanic eruptions and extreme changes in temperature and sea level. The changes were, at least in some respects, interconnected. For example, major volcanic eruptions, especially in what is now India, likely affected global temperatures.

Tectonic events, such as mountain formation, also led to the disappearance of a large seaway that had covered much of the interior of North America during most of the Cretaceous.

All of these changes impacted dinosaur populations, with large plant-eating dinosaurs that were at the base of the food chain particularly experiencing a dramatic drop in number. This, in turn, would have weakened the entire dino ecosystem.

"I think there is a perception that when the asteroid smashed into the Yucatan Peninsula 66 million years ago, it hit a static world, something of a paradise in which dinosaurs had been thriving for millions of years," Brusatte said. "But the asteroid actually hit a planet that was experiencing a lot of turmoil."

Paleontologists may be coming to a consensus on how non-avian dinosaurs--which flourished for over 150 million years--bit the dust, but they still don't know why certain birds survived the end of the Cretaceous onslaught.

"A lot of dinosaurs really looked and behaved like birds," he said. "If we were standing around in the Cretaceous, I don't think we would have made a distinction between a Velociraptor-type dinosaur and a true bird, and that is true of these feathered dinosaurs: these things were basically birds, and the line between them and birds is an arbitrary one."

Many species of birds did go extinct around 66 million years ago--just not all of them--reminded Richard Butler of the University of Birmingham's School of Geography, Earth and Environmental Sciences. Butler was not a co-author of the new paper.

Some birds might have survived because they were small, had more offspring, or possessed certain other characteristics and behaviors that permitted their survival, Butler and Brusatte theorize.

They both think that, without the asteroid impact and all of the other climatic and environmental upheaval, dinosaurs would still be roaming the planet today.

Read more at Discovery News

River in China Turns Red in an Hour

A river in China that's normally considered quite clean turned blood red in just an hour last week.

Residents were shocked at the turn of events, in part because there are no factories or chemical plants in the area and it was considered unpolluted.

The water looked fine, residents said, early in the morning last Thursday. But then about 200-300 meters of the river began turning red and had a strange smell.

"The really weird thing is that we have always been able to catch fish and you can even drink the water because it's just normally so good," local Na Wan told NBC News. "Nobody has any idea how it could have ended up being polluted because there are no factories that dump anything in the water here."

NBC reported that experts were on the scene taking samples and one suggested that the cause was likely some sort of dye that had been dumped in the river.

From Discovery News

'Family on All Fours' Not an Evolutionary Throwback

When Turkish evolutionary biologist Uner Tan introduced the world to a Turkish family with some members who could walk only on all fours, in a "bear crawl," he and other scientists speculated this odd gait was the resurgence of a trait lost during human evolution.

Not so, a new study finds.

The family and other people with Uner Tan syndrome do not represent "a backward stage in human evolution," as Tan wrote in a 2006 paper in the International Journal of Neuroscience, said Liza Shapiro, a professor of anthropology at the University of Texas at Austin. In new research, Shapiro and her colleagues compared videos of the family's gait with the gaits of nonhuman primates, such as chimpanzees or gorillas. They found the gait patterns did not match. Instead of recreating ape walks, people with Uner Tan are simply adapting to their disorder, Shapiro and her colleagues reported July 16 in the journal PLOS ONE.

Tan first noticed the syndrome that now bears his name in a family of 19 living in rural southern Turkey. Five of the family members walk using their feet and hands, and also have cognitive disabilities. The family was the subject of the 2006 BBC2 documentary, "The Family That Walks on All Fours."

Research has since revealed that the disorder is caused by a genetic mutation on chromosome 17, which affects the cerebellum, part of the brain responsible for movement and balance. From the beginning, Tan's statements about the evolutionary nature of the affected family's walking patterns were controversial. The affected children never had physical therapy or adaptive technology such as wheelchairs, making their gait a necessity.

But no one ever challenged the primary claim: that the affected children walked like nonhuman primates. Primates that walk on all fours do so differently than most other mammals, Shapiro told Live Science. Primates walk in a diagonal sequence, putting down a hind limb and then the opposite front limb: left foot, right hand, right foot, left hand.

Most other mammals walk in a lateral sequence, with the same-side limbs following each other: left foot, left hand, right foot, right hand. Human babies and adults asked to "bear crawl" on hands and feet typically walk in a lateral sequence, too, Shapiro said.

Shapiro said she became interested in studying the gait of people with Uner Tan Syndrome in 2006 after seeing the documentary on the Turkish family.

"It was all about whether or not it was evolutionary reversal, which kind of horrified me," she said. Immediately, though, she could see that the family was not using the primate diagonal gait.

Shapiro did not have access to good video of the family's walking patterns until recently, when one of her co-authors told her he had footage from the BBC. From that video, she and her colleagues were able to analyze more than 500 strides made by the five family members with the disorder.

About 99 percent of the strides were lateral, not diagonal — a blow against the notion that the family members had "rediscovered" an ancestral primate way of walking. Instead, they were walking like any typical adult would if asked to move on hands and feet.

A lateral gait is handy for long-limbed animals (such as humans) when walking on all fours, she said, because it helps keep the limbs from bumping into one another.

Read more at Discovery News

Monster Hawaii Telescope Construction Begins

The construction phase of the world’s biggest optical telescope has begun atop Mauna Kea, Hawaii.

Final approval by the Hawaii Board of Land and Natural Resources for a sublease on July 25 has green-lighted building work for the Thirty Meter Telescope (TMT) to begin in October.

With a primary mirror spanning 30 meters, the TMT will dwarf all optical telescopes on Earth and in space. The twin-telescope Keck Observatory is the next biggest telescope on Mauna Kea with mirrors measuring 10 meters across. Not only will the TMT dwarf Keck, it will also be able to acquire observations 12-times sharper than the Hubble Space Telescope.

Initiated ten years ago by the Association of Canadian Universities for Research in Astronomy (ACURA), the California Institute of Technology (Caltech) and the University of California, the TMT’s international scope has expanded to include partners around the globe. Chinese and Japanese institutions are working to build components for the TNT and India is also expected to join the collaboration.

“Design of the fully articulated main science steering mirror system in the telescope, as well as development of the lasers, laser guide star systems and other high-tech components, is proceeding in China,” said Yan Jun, Director General of the National Astronomical Observatories of China, in a TNT press release.

“Japan has seen to the production of over 60 mirror blanks made out of special zero-expansion glass that does not alter its shape with temperature changes,” said Masanori Iye, TMT International Observatory Board Vice Chair and TMT Japan Representative for the National Astronomical Observatory of Japan. “The blanks will be highly polished for use in the telescope’s 30-meter diameter primary mirror. The final design of the telescope structure itself is nearing completion.”

The TMT’s 492-segment mirror will observe the Cosmos in wavelengths from near-infrared, through optical to ultraviolet, allowing us an unprecedented view of objects in our galaxy and the first stars that were forming after the Big Bang. Like Keck, the TMT will use adaptive optics (AO) to compensate for atmospheric turbulence.

AO utilizes a powerful laser that cuts through the upper atmosphere, creating an artificial star from the telescope’s perspective, detecting turbulence. It is this turbulence that is responsible for twinkling stars — interference that can blur celestial targets for telescopes on the ground. Atmospheric aberrations can then be compensated for by rapid adjustments by each telescope segment.

Read more at Discovery News