Amazing Science

A team — led by David Sobral from the Institute of Astrophysics and Space Sciences, the Faculty of Sciences of the University of Lisbon in Portugal, and Leiden Observatory in the Netherlands — peered back into the ancient universe, to the reionization period approximately 800 million years after the Big Bang. Instead of conducting a narrow and deep study of a small area of the sky, the team broadened their scope to produce the widest survey of very distant galaxies ever attempted.

Astronomers have long theorized the existence of a first generation of stars known as Population III stars that were born out of the primordial material from the Big Bang. All the heavier chemical elements essential to life — including oxygen, nitrogen, carbon and iron — were forged in the bellies of stars. This means the first stars must have formed out of the only elements to exist prior to stars: hydrogen, helium and trace amounts of lithium.

These massive, brilliant, and previously purely theoretical objects were the creators of the first heavy elements in history — the elements necessary to forge the stars around us today, the planets that orbit them, and life as we know it. The newly found galaxy, named CR7, is three times brighter than the brightest distant galaxy known up to now.

Scientists theorized these Population III stars would have been enormous: several hundred or even a thousand times more massive than the Sun; blazing hot, and transient; and exploding as supernovae after only about two million years. But until now, the search for physical proof of their existence had been inconclusive. In addition to CR7 being by far the brightest galaxy ever observed at this stage in the universe, further inspection provided additional exciting news.

“Keck Observatory was tremendously important in spectroscopically confirming what are now the most luminous of these distant sources, including the most luminous, the CR7 galaxy (COSMOS Redshift 7),” said Sobral. “Impressively, the Keck II telescope fitted with the DEIMOS instrument spectroscopically confirmed CR7 in 15 minutes, even though the galaxy is 13 billion light years away.”

A viral image in its own right, the Hubble Deep Field image has been passed around by scientists and stargazers alike as a symbol that (given the enormous probabilities) we are probably not alone in the universe. Some estimates put the total number of stars in the universe at around 1,000,000,000,000,000,000,000 (1 sextillion).

But what's not readily apparent to most viewers is how incredibly small the field of view is relative to the entire night sky. According to Hubble, the field of view is 4.6 square arcminutes (arcminutes are used to measure angular size). With the entire sky coming in at 148,510,800 square arcminutes, that means the Hubble Deep Field photos make up about 0.000003% of the entire night sky!!!1 That is very small!! 

On Aug. 26, the Dragon space capsule dropped into the Pacific Ocean somewhere off the coast of Baja California, Mexico. Onboard were payloads containing fungi that had now grown in two of the most extreme conditions known to man: outer space and the Chernobyl Atomic Energy Station.

These fungi are radiation resistant. Thirty years ago, they survived when a routine test led to an explosion that blasted radioactive material throughout northern Ukraine. By sending these fungi to the International Space Station, Kasthuri Venkateswaran, a research scientist at NASA’s Jet Propulsion Lab, and Clay Wang, a professor at the USC School of Pharmacy, have tried to push them to adapt again.

The day the capsule landed, Venkateswaran and Wang made the hour-long drive to Long Beach, Calif., to pick up the samples, loading the cylindrical tubes of fungi into coolers. Back in the lab, Venkateswaran and Wang have spent the past month studying how the trip changed the fungi. Their goal is to use these impressively resilient organisms to point the way to drugs that could impart similar resilience to humans, such as those getting cancer treatment. But to repurpose a different space metaphor, it’s one small step.

Forest fires are burning longer and stronger across the western United States, lighting up the landscape with alarming frequency. Residents are forced to flee, homes are incinerated, wildlife habitats are destroyed, lives are lost. Last year, the Forest Service spent more than half its annual budget fighting fires.

Scientists have long theorized that climate change has contributed to the longer fire seasons, the growing number and destructiveness of fires and the increasing area of land consumed, though some experts suggest that the current fire phenomenon is not just a result of a changing climate, but also fire-suppressing policies practiced by the government for the last century or more.

In a new study published Monday in Proceedings of the National Academy of Sciences, scientists from the University of Idaho and Columbia University have calculated how much of the increased scope and intensity of Western wildfires can be attributed to human-caused climate change and its effects. They state that, since 1979, climate change is responsible for more than half of the dryness of Western forests and the increased length of the fire season. Since 1984, those factors have enlarged the cumulative forest fire area by 16,000 square miles, about the size of Massachusetts and Connecticut combined, they found.

At present, the range in published eukaryote genome sizes is between about 0.0023pg in the parasitic microsporidium Encephalitozoon intestinalis (Vivares 1999), and 1,400pg in another protist, the free-living amoeba Chaos chaos (Friz 1968) – a greater than 600,000-fold difference. The largest genome size is often attributed to Amoeba dubia at 700pg, conveniently 200 times larger than a human’s (e.g., Gregory and Hebert 1999), and sometimes Encephalitozoon cuniculi is considered the smallest at about 0.0029pg (Biderre et al. 1995), for a more than 200,000-fold range (e.g., Gregory 2001b). Many previous publications have taken brewer’s yeast Saccharomyces cerevisiae at 0.008pg to be the lowest eukaryotic C-value, for a range of about 80,000-fold (e.g., Gregory and Hebert 1999; Pagel and Johnstone 1992), although some authors calculate the range as 40,000-fold (e.g., Cavalier-Smith 1978).

In any case, a few caveats are in order regarding the high end of this range. First, these values for amoebae were based on rough biochemical measurements of total cellular DNA content (Friz 1968), which probably includes a significant fraction of mitochondrial DNA. The accuracy of this method is brought into question when one considers that Friz's (1968) value of 300pg for Amoeba proteus is an order of magnitude higher than those reported in subsequent studies (Byers 1986). Second, some amoebae (e.g., A. proteus) contain 500-1000 small chromosomes and are quite possibly highly polyploid (Byers 1986), in which case these values would be inappropriate for a comparison of haploid genome sizes among eukaryotes. Of course, this has little impact on the need to explain variation in genome size; it may just mean that these impressive examples will require replacement by some based on more reliable estimates.

A newly discovered Japanese plant spends most of its life hidden underground and steals nutrients from fungi rather than getting its energy from the sun.

Kenji Suetsugu of Kobe University came across the previously unknown plant in an evergreen forest on the subtropical Japanese island of Yakushima while documenting other fungi-parasitizing – mycoheterotrophic – plants in Japan.

The plant’s stem is about 3-9 centimeters long and has between nine and 15 purple star-shaped flowers, which push up above the ground. Suetsugu has named it Sciaphila yakushimensis after the island.

The plant can’t photosynthesize and, like other mycoheterotrophs, steals the carbon it needs from a fungal host. The parasitic plant attracts strands of mycorrhizal fungus into its many hairy roots and then feeds off fungus growing inside the roots.

Soap opera experiment suggests chimps, bonobos, and orangutans can predict what others are thinking.

All great mind reading begins with chocolate. That’s the basis for a classic experiment that tests whether children have something called theory of mind—the ability to attribute desires, intentions, and knowledge to others. When they see someone hide a chocolate bar in a box, then leave the room while a second person sneaks in and hides it elsewhere, they have to guess where the first person will look for the bar. If they guess “in the original box,” they pass the test, and show they understand what’s going on in the first person’s mind—even when it doesn’t match reality.

For years, only humans were thought to have this key cognitive skill of attributing “false belief,” which is believed to underlie deception, empathy, teaching, and perhaps even language. But three species of great apes—chimpanzees, bonobos, and orangutans—also know when someone holds a false belief, according to a new study published today in Science. The groundbreaking study suggests that this skill likely can be traced back to the last common ancestor of great apes and humans, and may be found in other species.

“Testing the idea that nonhuman animals can have minds has been the Rubicon that skeptics have again and again said no nonhuman has ever, or will ever, cross,” says Brian Hare, an evolutionary anthropologist at Duke University in Durham, North Carolina, who was not involved in the study. “Well, back to the drawing board!”

For nearly 40 years, animal cognition researchers have had mixed results in showing that our close ape relatives—and animals such as monkeys, jays, and crows—understood that their fellows had minds, a talent thought to come in handy in complex societies, where figuring out another’s plans can help animals thrive. Some tests have shown that chimpanzees had some building blocks of theory of mind: They can deceive, recognize others’ motives, and remember who is a good partner on collaborative tasks. They can also tell what another chimp can and cannot see, and they can reason about the movement of objects they themselves can’t directly see. But they—and other primates—had not been shown to hold false belief.

Tumors are subject to the same rules of natural selection as any other living thing. Clinicians are now putting that knowledge to use.

About six years ago, Alberto Bardelli fell into a scientific slump. A cancer biologist at the University of Turin in Italy, he had been studying targeted therapies — drugs tailored to the mutations that drive the growth of a tumor. The strategy seemed promising, and some patients started to make dazzling recoveries. But then, inevitably, their tumors became resistant to the drugs. Time and time again, Bardelli would see them relapse. “I stumbled into a wall,” he says. The problem wasn't the specific mutations, Bardelli realized: it was evolution itself. “Unfortunately, we are facing one of the most powerful forces on this planet,” he says.

Physicists' model proposes evolutionary role for cancer

Researchers have long understood that tumors evolve. As they grow, mutations arise and populations of genetically distinct cells emerge. The cells that are resistant to treatment survive and expand. No matter what medication physicians apply, it seems, the tumor adapts. And it has been difficult for researchers to unpick this process, because cancer evolves inside the body over the course of years. “We used to say to patients all the time that cancers are evolving in a Darwinian manner, but we didn't have a huge amount of evidence at our disposal to really formally prove that,” says Charles Swanton, a cancer researcher at the Francis Crick Institute in London.

When the engineers had at last finished their work, Eugenia Kuyda opened a console on her laptop and began to type. “Roman,” she wrote. “This is your digital monument.”

It had been three months since Roman Mazurenko, Kuyda’s closest friend, had died. Kuyda had spent that time gathering up his old text messages, setting aside the ones that felt too personal, and feeding the rest into a neural network built by developers at her artificial intelligence startup. She had struggled with whether she was doing the right thing by bringing him back this way. At times it had even given her nightmares. But ever since Mazurenko’s death, Kuyda had wanted one more chance to speak with him.

A message blinked back on the screen. “You have one of the most interesting puzzles in the world in your hands,” it said. “Solve it.” Kuyda promised herself that she would.

Giant rings around an exoplanet could remain stable for more than 100,000 years – but only if the rings orbit in the direction opposite to that of the planet's orbit around the star. That is the claim made by researchers in Japan and the Netherlands, who last year discovered the exoplanet J1407b with rings more than 100 times larger than those of Saturn.

Steven Rieder at RIKEN in Japan and Matthew Kenworthy at Leiden University in the Netherlands focussed their attention on the young, sun-like star J1407 after it underwent a series of strange eclipses in 2007. The researchers realized that the observations could only be explained if the star hosted a planet with a gigantic ring system. The only problem with such a hypothesis was that rings would not be stable for very long because the planet's very eccentric orbit brings it close enough to its star to disrupt the rings.

Now, the duo have carried out simulations and found that the massive ring system can persist for more than 10,000 11 year orbits, as long as the rigs rotate in the direction opposite to the orbit of the planet. Such retrograde rings are not common and the researchers conclude that some kind of catastrophe caused either the planet or its rings to reverse its orbit. Their findings have been accepted for publication in the journal Astronomy & Astrophysics.

Simulated "Martian gardens" are helping NASA scientists learn which plants astronauts might be able to grow on the Red Planet. 

A human round-trip journey to Mars may take as long as two and a half years, and one major challenge for these kinds of extended missions is determining how to pack enough food for those astronauts. As such, scientists are studying ways for astronauts to grow their own crops and extend their food supply, because seeds take up less room and have a longer shelf life on spacecraft than full-grown plants do. 

Simulated "Martian gardens," developed at NASA's Kennedy Space Center and the Florida Tech Buzz Aldrin Space Institute, are helping researchers overcome food production challenges associated with Mars' barren landscape.

A megadrought spanning several decades could be almost certain to hit the American southwest this century if greenhouse gas emissions are not curbed, a new study says.

Rising temperatures will “load the dice” in favor of a megadrought in the region, the researchers say. Combined with a decline in rainfall, warming conditions could put risk levels at 99% for much of the region, the study finds, while moderate increases in rainfall would still leave risk levels above 70%.

But there is a “glimmer of hope” another scientist tells Carbon Brief. The study also shows that keeping global temperature rise to no more than 2C above pre-industrial levels would cut this risk by half.

Researchers have built and demonstrated a novel configurable computing device that uses a thousand times less electrical power – and can be built up to a hundred times smaller – than comparable digital floating-gate configurable devices currently in use.

The new device, called the Field-Programmable Analog Array (FPAA) System-On-Chip (SoC), uses analog technology supported by digital components to achieve unprecedented power and size reductions. The researchers said that for many applications these low-power analog-based chips are likely to work as well as or better than configurable digital arrays.

Currently, field programmable gate arrays (FPGAs) – digital devices widely used in consumer devices, defense systems and more – dominate the configurable chip market. These floating-gate integrated circuits can be altered internally at any time, and techniques to reconfigure them for many different forms and functions are well established.

Professionals familiar with FPGAs will find the programming interface of the new analog chip surprisingly like the digital circuits in many ways, said Jennifer Hasler, a professor in the Georgia Tech School of Electrical and Computer Engineering (ECE) and leader of the research team that produced the new analog architecture.

“But in other ways the FPAA is going to seem quite different,” she said. “In terms of the power needed, it's extremely different because you need only milliwatts to run the analog device, while it’s hard to get an FPGA to work on less than a watt.”

A paper on the new FPAA system-on-chip device has been published on the IEEE Xplore website. Another paper focusing on the details of programming FPAA devices was also published on the Xplore site. In addition a third paper, detailing a high-level open-source programming toolset developed by Hasler and her team for programming analog arrays, has also been published online in the Journal of Low Power Electronics and Applications.

Will astronauts traveling to Mars remember much of it? That’s the question concerning University of California, Irvine scientists probing a phenomenon called “space brain.”

UCI’s Charles Limoli and colleagues found that exposure to highly energetic charged particles – much like those found in the galactic cosmic rays that will bombard astronauts during extended spaceflights – causes significant long-term brain damage in test rodents, resulting in cognitive impairments and dementia.

Their study appears today in Nature’s Scientific Reports. It follows one last year showing somewhat shorter-term brain effects of galactic cosmic rays. The current findings, Limoli said, raise much greater alarm. (Link to study: www.nature.com/articles/srep34774)

“This is not positive news for astronauts deployed on a two-to-three-year round trip to Mars,” said the professor of radiation oncology in UCI’s School of Medicine. “The space environment poses unique hazards to astronauts. Exposure to these particles can lead to a range of potential central nervous system complications that can occur during and persist long after actual space travel – such as various performance decrements, memory deficits, anxiety, depression and impaired decision-making. Many of these adverse consequences to cognition may continue and progress throughout life.”

For the study, rodents were subjected to charged particle irradiation (fully ionized oxygen and titanium) at the NASA Space Radiation Laboratory at New York’s Brookhaven National Laboratory and then sent to Limoli’s UCI lab.

The smell of a dying honey bee may not sound appealing, but one species of plant uses it to lay a clever trap, according to a new study. About 5% of plants use deceiving tactics to attract pollinators, including sporting flowers that look like female bees to attract eager male pollinators. But the distinctive-looking Ceropegia sandersonii, or parachute plant (pictured above), takes things to the next level. It plays on the behavior of female flies of the genus Desmometopa, which eat the juices secreted by bees trapped in carnivorous plants. Using a mixture of four compounds, C. sandersonii was able to imitate the smell released by worker honey bees from their glands when they try to bite or sting to defend themselves, researchers report today in Current Biology. Desmometopa flies are then attracted into the flower of C. sandersonii, where they end up coated in the plant's pollen. But the plant allows them to escape—and be lured into yet another C. sandersonii plant’s flower, which the insects then pollinate. Thus, the circle of life and deception continues.

Lineages of all known species on Earth are finally pieced together.

Since Charles Darwin's day, biologists have depicted how new organisms evolve from old ones by adding branches to numerous trees that represent portions of the animal, plant and microbial kingdoms. Researchers from a dozen institutions recently completed a three-year effort to combine tens of thousands of trees into one diagram, most readable as a circle (below). The lines inside the circle represent all 2.3 million species that have been named. Biologists have genetic sequences for only about 5 percent of them, however; as more are finished, the relationships within and across groups of species may change. Experts estimate that up to 8.7 million species may inhabit the planet (about 15,000 are discovered every year). “We expect the circle to broaden,” says Karen Cranston, a computational evolutionary biologist at Duke University.

Anyone can propose updates to the database (OpenTreeOfLife.org). Greater detail could improve understanding of evolution and help scientists invent drugs, make crops more productive and better control infectious diseases.

A subsurface ocean lies deep within Saturn’s moon Dione, according to new data from the Cassini mission to Saturn. Two other moons of Saturn, Titan and Enceladus, are already known to hide global oceans beneath their icy crusts, but a new study suggests an ocean exists on Dione as well.

In this study, researchers of the Royal Observatory of Belgium show gravity data from recent Cassini flybys can be explained if Dione’s crust floats on an ocean located 100 kilometers below the surface. The ocean is several tens of kilometers deep and surrounds a large rocky core. Seen from within, Dione is very similar to its smaller but more famous neighbor Enceladus, whose south polar region spurts huge jets of water vapor into space. Dione seems to be quiet now, but its broken surface bears witness of a more tumultuous past. The study is published in Geophysical Research Letters.

The authors modeled the icy shells of Enceladus and Dione as global icebergs immersed in water, where each surface ice peak is supported by a large underwater keel. Scientists have used this approach in the past but previous results have predicted a very thick crust for Enceladus and no ocean at all for Dione. “As an additional principle, we assumed that the icy crust can stand only the minimum amount of tension or compression necessary to maintain surface landforms,” said Mikael Beuthe, lead author of the new study. “More stress would break the crust down to pieces.”

According to the new study, Enceladus’ ocean is much closer to the surface, especially near the south pole where geysers erupt through a few kilometers of crust. These findings agree well with the discovery last year by Cassini that Enceladus undergoes large back-and-forth oscillations, called libration, during its orbit. Enceladus’ libration would be much smaller if its crust was thicker. As for Dione, the new study finds it harbors a deep ocean between its crust and core. “Like Enceladus, Dione vibrates but below the detection level of Cassini,” said Antony Trinh, co-author of the new study. “A future orbiter hopping around Saturn’s moons could test this prediction.”

The inside of every cell in our body is like a crowded city, filled with tracks, transports, libraries, factories, power plants, and garbage disposal units. The city’s workers are protein machines, which metabolize food, take out the garbage, or repair DNA.

Cargo is moved from one place to another by molecular machines that have been observed walking on two legs along protein tightropes. As these machines go about their business, they are surrounded by thousands of water molecules, which randomly crash into them a trillion times a second. This is what physicists euphemistically call “thermal motion.” Violent thermal chaos would be more apt.

How any well-meaning molecular machine could do good work under such intolerable circumstances is puzzling. Part of the answer is that the protein machines of our cells, like tiny ratchets, turn the random energy they receive from water bombardment into the very directed motion that makes cells work. They turn chaos into order.

In this sense, life pits biology against physics in mortal combat. So why do living things die? Is aging the ultimate triumph of physics over biology? Or is aging part of biology itself?

Medawar himself argued for the “wearing out” theory—the physics viewpoint on aging. First, he said, it is difficult to see how natural selection could have selected for senescence, because we don’t reproduce in our elderly years and natural selection is driven by differences in reproduction rates. Second, it is unnecessary to actively kill off older individuals to keep an aging population small. Random chance can accomplish this on its own.

Medawar argued that a biological master clock for aging is unnecessary. To illustrate why, he pointed to a decidedly non-living example: Test tubes in a lab. Assume test tubes break from time to time by accident. To keep the total number of test tubes constant, a fresh supply is purchased every week. After a few months pass, how many young test tubes are there, and how many are old? If we assume that the probability of accidental breakage is independent of age (a sensible assumption), and plot the number of test tubes versus the age of each test tube, we get a concave, exponential decay curve that looks like a child’s slide. This “life curve” has a steep drop at the top, and it’s flat on the bottom.

Due to increasing antibiotic resistance, microbiologists are on the lookout for unconventional ways to kill bacteria.

Atypical methods range from phage therapy, in which bacteria-killing viruses are unleashed upon the microbes, to the use of "bed-of-nails" surfaces that physically rip bacteria apart.

Such out-of-the-box thinking was displayed yet again by a team of scientists from the University of Manitoba who created a hybrid antibiotic by tying together two different antibiotics with a molecular "rope."

One strategy to fight resistance is to hit a bacterium with multiple antibiotics at the same time. The reasoning is that, while it is relatively simple for a bacterium to spontaneously mutate to avoid the lethal effect of one antibiotic, it is very unlikely that multiple mutations will occur simultaneously that protect it against more than one. In other words, a bacterium may become resistant to antibiotic A or antibiotic B if they are used separately; but if used together, antibiotics A + B present a formidable challenge to resistance.

To create their hybrid, the researchers subjected the antibiotic tobramycin to a series of chemical reactions that (1) attached a molecular "rope" (a chain of 12 carbon atoms) to the center of the molecule and (2) tied the rope to a second antibiotic, moxifloxacin. Then, they tested how the hybrid antibiotic performed against clinically isolated samples of Pseudomonas aeruginosa, a bacterium that is both highly resistant to multiple antibiotics and is commonly transmitted in hospitals.

Susceptibility to antibiotics is measured using the minimum inhibitory concentration (MIC, measured in micrograms per milliliter), which indicates the lowest amount of antibiotic necessary to prevent the bacteria from growing. Thus, the higher the number, the more resistant the bacteria are to that antibiotic. Most clinical isolates of P. aeruginosa were highly resistant to both moxifloxacin (red box) and tobramycin (blue box) but that the hybrid antibiotic (purple box) was quite effective at inhibiting bacterial growth. The authors inferred that whatever molecular mechanisms allow these bacteria to be resistant to each antibiotic individually do not apply to the hybrid antibiotic. 

So the team was curious to discover how exactly their hybrid antibiotic worked. Their investigation suggested that it operated in a completely different way than the original antibiotics. Instead of blocking protein synthesis (like tobramycin) or inhibiting DNA replication (like moxifloxacin), the hybrid exhibited an entirely new mode of action: It pokes holes in a bacterium's outer membrane and disrupts the electrical field potential (called the proton motive force) associated with the inner membrane. The former causes the bacterium to literally disintegrate (see below), and the latter disrupts various aspects of bacterial physiology.