A GPS app can plan the best route between two subway stops if it has been specifically programmed for the task. But a new artificial intelligence system can figure out how to do so on the fly by learning general rules from specific examples, researchers report October 12 in Nature.

Artificial neural networks, computer programs that mimic the human brain, are great at learning patterns and sequences, but so far they’ve been limited in their ability to solve complex reasoning problems that require storing and manipulating lots of data. The new hybrid computer links a neural network to an external memory source that works somewhat like RAM in a regular computer.

Scientists trained the computer by giving it solved examples of reasoning problems, like finding the shortest distance between two points on a randomly generated map. Then, the computer could generalize that knowledge to solve new problems, like planning the shortest route between stops on the London Underground. Rather than being programmed, the neural network, like the human brain, responds to training: It can continually integrate new information and change its response accordingly.

The development comes from Google DeepMind, the same team behind the Alpha Go computer program that beat a world champion at the logic-based board game.

The Schiaparelli Mars lander remains silent since its attempted landing October 19 on the Red Planet. All data transmitted by the lander during its descent have been relayed to Earth, and mission scientists are now in the thick of trying to figure out what went wrong.

“I am extremely confident that we’ll be able to fully understand what happened,” ESA spacecraft operations manager Andrea Accomazzo said at an October 20 news briefing. Schiaparelli is most likely on the surface, but its condition remains unknown.

Early data indicate that Schiaparelli survived most of its parachute entry, but in the last few seconds before jettisoning the chute, something unexpected happened. Mission scientists cannot say yet what that “something” was. The retrorocket designed to slow it down further did appear to fire, but for a shorter time than expected. Mission scientists also don’t yet know if all the rockets fired as planned. Further details will come with the analysis of data received from the lander.

Other spacecraft orbiting Mars will continue to listen for a signal from Schiaparelli, which has enough battery power to last a few Martian days, maybe more. The lander was designed as an experiment to test technologies and protocols for safely dropping a payload on the surface of the Red Planet, such as a rover planned to arrive in 2021.

The Trace Gas Orbiter, which also arrived as part of the ExoMars mission, appears healthy and in orbit around the Red Planet, ready to undertake an investigation of trace gases in the Martian atmosphere.

Clever chemistry could take the salt out of water softening.

Aluminum ions can strip minerals from water without the need for sodium, researchers report online October 4 in Environmental Science & Technology. The new technique could sidestep health and environmental concerns raised about the salt released by existing sodium-based water softening systems, says study coauthor Arup SenGupta.

“This is a global need that hasn’t been met,” says SenGupta, an environmental engineer at Lehigh University in Bethlehem, Pa. “We’re just changing the chemistry by adding aluminum ions, which is not something outlandish, but with that we can reduce the environmental impact.”
Hard water contains dissolved minerals such as calcium and magnesium that make it harder for soap to lather and that can leave scaly deposits inside faucets and showerheads. Many water softening systems combat these problems by passing water through a special tank containing beads covered in sodium ions, charged particles that can swap places with the calcium and magnesium, resulting in softer water.

This technique adds extra sodium to the outgoing water, though, which can raise blood pressure when used as drinking water (SN Online: 3/12/14). The system also has to be recharged periodically using a sodium-rich brine. That extra salt can end up in local groundwater and streams, prompting bans on salt-based water softeners in many areas, including many counties in California.
While some sodium-free substitutes exist, many are expensive while others are “snake oil” and don’t actually work, SenGupta says. He and colleagues decided to try aluminum, a counterintuitive choice based on its chemistry. An aluminum ion has a net positive charge of three, meaning that it has three fewer negatively charged electrons than a neutral aluminum atom. That charge difference makes it less likely for aluminum to swap places with a calcium or magnesium ion, which each have a positive charge of two.
But when an ion exchange does happen, the aluminum often quickly precipitates back onto the water softener’s beads rather than dissolving into the water and being swept away. The process allows the same aluminum ion to swap in for multiple calcium and magnesium ions.
Setting up a prototype water softening system in the laboratory, the researchers successfully reduced the amount of calcium and magnesium in a groundwater-like mixture using aluminum ions. Recharging the system also resulted in fewer wasted ions than sodium-based systems, the researchers found, lowering the potential environmental impact. The process uses a similar setup to sodium-based systems, SenGupta says, meaning existing systems could be easily retrofitted to use aluminum ions.

While an exciting idea, the new design might not work as well in real life as it does in the lab, says Steven Duranceau, an environmental engineer at the University of Central Florida in Orlando. Bacteria and other substances in groundwater can reduce effectiveness, and strict guidelines surrounding drinking water could prove an unsurmountable hurdle, he says. “I see these great things all the time, but a lot of them just don’t make it financially.”

SenGupta remains optimistic, though. “This is not a magic bullet; there are shortcomings, but none of these problems are impossible to overcome.”

This forlorn-looking face of a 4-day-old zebrafish embryo represents “a whole new avenue of research” for geneticist Oscar Ruiz, who studies how faces and facial abnormalities develop at the cellular level.

The research is possible thanks to a new method, developed by Ruiz and colleagues at the University of Texas MD Anderson Cancer Center in Houston, for mounting embryos in a gel that allows for clear, head-on pictures. A technique called confocal microscopy captures images like the one above, the first-place winner of this year’s Nikon Small World photography contest.
The embryo was euthanized before having its picture taken. But Ruiz is experimenting with taking time-lapse images of live, anesthetized zebrafish embryos. The camera snaps an image every five minutes for up to 48 hours, meaning that “we’re able to watch the development happening,” Ruiz says.

So far, the team has looked at embryos ranging from 1 to 6 days old. The researchers are compiling the images into an atlas documenting the developmental stages of the zebrafish face. They plan to use CRISPR/Cas9, a powerful gene-editing tool, to alter genes involved in facial abnormalities in the fish and then watch what changes, if any, occur. The research could one day be used to help scientists understand how a cleft lip or cleft palate develops in humans and possibly help treat it, Ruiz says.

In the image above, shown at 10x magnification, basal cells (green) in the bottom layer of skin give rise to more developed surface skin cells (red). Cell nuclei appear in blue.

“Everyone’s first impression is that those two holes in the center are its developing eyes,” Ruiz says. But they’re not. Those deceptive hollows are nascent olfactory tissue, used to smell. The eyes are actually the big bulges on either side of the face.
Although this was the first time Ruiz entered the microscopy photography contest, he is an amateur photographer. Landscape or travel photos — not fish photos — are his subject matter of choice.

Here are more finalists and honorable mentions from the competition:

More vaccines promised — “The decline of poliomyelitis among more than 350 million people of the world … (offers) a promise of vaccines that will soon be used against other diseases considered hopeless or untreatable until recently. Vaccines against some of the many viruses causing the common cold, as well as those causing rubella, mumps and other diseases are on the way.” — Science News, November 19, 1966

UPDATE
In 1971, vaccines against mumps and rubella were combined with the measles vaccine into one MMR shot. All three diseases are now very rare in the United States. But persistent pockets of lower vaccination rates (spurred in part by the repeatedly debunked belief that vaccines cause autism) have allowed sporadic outbreaks of all three illnesses. A vaccine against the common cold has not yet materialized. Creating one vaccine that protects against the hundred or so strains of rhinoviruses that can cause colds is not easy. But some scientists are giving it a shot, along with vaccines against HIV, Ebola and Zika.

El Niño’s meteorological sister, La Niña, has officially taken over.

This year’s relatively weak La Niña is marked by unusually cool sea surface temperatures in the central and eastern equatorial Pacific Ocean. That cold water causes shifts in weather patterns that can cause torrential downpours in western Pacific countries, droughts in parts of the Americas and more intense Atlantic hurricane seasons.

The event has about a 55 percent chance of sticking around through the upcoming Northern Hemisphere winter and is expected to be short-lived, the National Oceanic and Atmospheric Administration’s Climate Prediction Center reported November 10.

Picture a learning curve. Most of us imagine a smooth upward slope that rises with steady mastery. It is the ultimate image of progress.
But that image, as behavioral sciences writer Bruce Bower reports in “Kids learning curve not so smooth” (SN: 11/26/16, p. 6), may well be an illusion of statistics, created when people look at averages of a group instead of how individuals actually learn. That’s what scientists at the University of Cambridge found when quizzing preschoolers’ developing ability to understand that other people can have false beliefs, an important milestone in the development of a theory of mind.
For many learners, the study suggests, mastery comes in fits and starts, a graphical zigzagging that denotes steps forward and back. Insight into a problem can be quick for some, but many people follow a more meandering path to knowledge and understanding.

I recognize the truth of this in my own life, be it learning about a new subject or (especially) a new skill. I see it in my 5-year-old daughter as she learns to read. If you are not struck by a single dramatic aha! you can still make it work by moving forward, then back, aiming for progress and mastery.

Scientific advances also do not always follow a smooth upward curve. As staff writer Meghan Rosen writes in “Dinosaurs may have used color as camouflage” (SN: 11/26/16, p. 24), paleontologists did have a fairly sudden insight into how to get clues about the colors that decorated dinosaur skin: Look for pigment-containing structures called melanosomes. But identifying these microscopic structures in well-preserved fossils of soft tissue, while distinguishing them from bacteria that might have feasted on the fresh dead dino skin, has been a bit of a zigzag. There’s an ongoing back-and-forth critique between those scientists who claim they’ve discovered melanosomes and those who question such claims. It may be a long time before we know whether we will be able to truly repaint dinosaurs’ colors accurately, or use that information to better understand their lifestyles or habitats (as many scientists working in the field hope). But current investigations are already taking us closer to that goal, even if via a meandering path.

The danger of looking at the average, as evidenced in Bower’s news story, is also at play in Amy McDermott’s story “Lichens are an early warning system for forest health” (SN: 11/26/16, p. 20). Lichens are very sensitive to air pollution, a quality exploited for decades to monitor the air quality of forests and alert forest managers to looming issues. But if you were to look at overall lichen abundance you might not see any problem. Air pollution tends to encourage some species while discouraging others — a subtlety that a lichen average growth rate might miss. With on-the-scene reporting in the Pacific Northwest, McDermott details the history of lichen use in environmental quality studies and the new effort to use lichens as an indicator of climate change in forests.

Looking at averages can tell you part of a story, but it rarely tells you the whole story. What you may miss is the rich variety found in the real world — be it in students or lichens or even scientific perspectives.

That past-its-prime bag of spinach buried in the back of your fridge should probably hit the compost heap instead of your dinner plate. The watery gunk that accumulates at the bottom of bagged salad mix is the perfect breeding ground for Salmonella bacteria that could make people sick, researchers report November 18 in Applied and Environmental Microbiology.

The culprit? The juice that oozes out of cut or damaged leaves. After five days in the fridge, small amounts of plant juice sped up Salmonella growth. The bacteria grew avidly on the bag and stuck persistently to the salad leaves, so much so that washing didn’t remove the microbes.

Salmonella’s success inside bagged salads means it’s important for producers to avoid bacterial contamination from the get-go — and for consumers to eat those greens before they get soggy. Popeye would approve.

Clearing tropical forests may raise the risk of people being exposed to a gruesome disease called Buruli ulcer, a new study suggests.

Mycobacterium ulcerans, the bacteria that cause Buruli skin lesions and bone deformities, can thrive in a wide range of wild creatures, especially tiny insects grazing on freshwater algae, says Aaron Morris, now at Imperial College London. Surveying more than 3,600 invertebrates and fish from both pristine forests and cleared land in French Guiana, Morris and colleagues found the bacteria flourishing in altered landscapes. As species are lost from once-complex food webs, there’s an intermediate zone where bacteria-friendly species thrive, Morris and colleagues propose online December 7 in Science Advances.
When people push into tropical forests to build farms, roads and towns, the food web of the forest grows simpler, Morris says. Aquatic predators that once kept smaller predators and grazers in check have dwindled, the analysis suggests. This shift in the food web allows some grazers that bacteria multiply abundantly in to thrive in the environment. Thus people might face more risk of picking up the disease. (The exact routes of transmission aren’t clear, according to the U.S. Centers for Disease Control and Prevention.)

Yet the relationship between forest loss and bacterial boom times isn’t a straight line, the researchers found. As people change the landscape even more drastically toward urbanization, the niches for the bacteria-carriers appears to start shrinking again. This may mean that some of the bacteria’s favorite hosts are dwindling away, too.

Other work has examined the way that landscape change affects people’s risks of catching infectious diseases, says Kate Jones of University College London, who has studied Lassa fever in Africa. Yet she cautions that recent research suggests that the interplay of infectious disease and disturbance depends strongly on the location. Some evidence has linked degraded ecosystems to rising numbers of small rodents that spread, for instance, Lyme disease. But in cases with diseases spread by monkeys and apes, their habitat needs mean they tend to be among the first animals to disappear as people take over land, taking particular disease risks with them.

Just how the rise in bacteria for Buruli ulcer translates into numbers of human cases will take more study. The new study focused on the animals and landscape and did not look at human prevalence of the disease. Worldwide, some 5,000 to 6,000 new cases of Buruli ulcer are reported each year from a total of 15 countries, says the CDC. The disease is also found in at least 18 more countries not included in the statistics. Buruli ulcer can occur in temperate as well as tropical regions but is especially a risk for children and young teens in sub-Saharan Africa.

In a hotel ballroom in Seoul, South Korea, early in 2016, a centuries-old strategy game offered a glimpse into the fantastic future of computing.

The computer program AlphaGo bested a world champion player at the Chinese board game Go, four games to one (SN Online: 3/15/16). The victory shocked Go players and computer gurus alike. “It happened much faster than people expected,” says Stuart Russell, a computer scientist at the University of California, Berkeley. “A year before the match, people were saying that it would take another 10 years for us to reach this point.”
The match was a powerful demonstration of the potential of computers that can learn from experience. Elements of artificial intelligence are already a reality, from medical diagnostics to self-driving cars (SN Online: 6/23/16), and computer programs can even find the fastest routes through the London Underground. “We don’t know what the limits are,” Russell says. “I’d say there’s at least a decade of work just finding out the things we can do with this technology.”

AlphaGo’s design mimics the way human brains tackle problems and allows the program to fine-tune itself based on new experiences. The system was trained using 30 million positions from 160,000 games of Go played by human experts. AlphaGo’s creators at Google DeepMind honed the software even further by having it play games against slightly altered versions of itself, a sort of digital “survival of the fittest.”

These learning experiences allowed AlphaGo to more efficiently sweat over its next move. Programs aimed at simpler games play out every single hypothetical game that could result from each available choice in a branching pattern — a brute-force approach to computing. But this technique becomes impractical for more complex games such as chess, so many chess-playing programs sample only a smaller subset of possible outcomes. That was true of Deep Blue, the computer that beat chess master Garry Kasparov in 1997.

But Go offers players many more choices than chess does. A full-sized Go board includes 361 playing spaces (compared with chess’ 64), often has various “battles” taking place across the board simultaneously and can last for more moves.

AlphaGo overcomes Go’s sheer complexity by drawing on its own developing knowledge to choose which moves to evaluate. This intelligent selection led to the program’s surprising triumph, says computer scientist Jonathan Schaeffer of the University of Alberta in Canada. “A lot of people have put enormous effort into making small, incremental progress,” says Schaeffer, who led the development of the first computer program to achieve perfect play of checkers. “Then the AlphaGo team came along and, incremental progress be damned, made this giant leap forward.”

Real-world problems have complexities far exceeding those of chess or Go, but the winning strategies demonstrated in 2016 could be game changers.