News this Week

Science  10 Jan 2014:
Vol. 343, Issue 6167, pp. 122
  1. Around the World

    1 - Sydney, Australia
    Stranded Antarctic Team Rescued
    2 - Washington, D.C.
    USDA Moving Forward With GM Crops for Weed Contro
    3 - Western Australia
    New Sanctuary to Fence in Native Species
    4 - New York City
    U.S. Cancer Centers Receive Magnate's Final Endowments
    5 - Melbourne, Australia
    2013 Temperature Sets All-Time High
    6 - Jhajjar, India
    Indian Cancer Institute Under Way

    Sydney, Australia

    Stranded Antarctic Team Rescued

    Safe passage.

    Members of the marooned Australasian Antarctic Expedition board a Chinese helicopter.


    After an experience he describes as "sobering," climate scientist Chris Turney of the University of New South Wales, along with 51 other scientists, doctoral students, tourists, and reporters, was airlifted to safety last week following 10 days stuck in Antarctic ice. Their ship, the Akademik Shokalskiy, was on the final leg of a privately funded expedition retracing Australian geologist Douglas Mawson's 1911 to 1914 adventure when it hit thick ice from a 2010 collision between an iceberg and the Mertz Glacier Tongue. The team is now aboard the Australian icebreaker Aurora Australis, due to reach Hobart, Tasmania, between 18 and 20 January.

    Despite the delay, "every science target set was virtually nailed," says Alvin Stone, the expedition's Sydney-based spokes person. Detailed analysis will begin on shore, but a paper based on new observations about the impact of ocean temperatures on seabird populations is already under way.

    The Akademik Shokalskiy eventually freed itself, as did the Chinese icebreaker Xue Long that assisted in the rescue but itself became trapped.

    Washington, D.C.

    USDA Moving Forward With GM Crops for Weed Control

    The U.S. Department of Agriculture (USDA) wants to approve three new and controversial varieties of genetically modified (GM) crops in order to help farmers deal with a growing weed problem. In a draft environmental impact statement released last week, USDA said its preference is to fully deregulate corn and soybean varieties that can tolerate 2,4-D and other herbicides. Dow AgroSciences created the varieties because weeds have evolved to survive glyphosate, a cheap and relatively benign herbicide that farmers have used on GM crops for nearly 20 years. But critics fear the new crops because they could increase the use of 2,4-D by as much as 300% and lead to further resistance in weeds.

    USDA has authority to regulate GM crops only if they pose a risk to other plants, which these do not. The agency will be accepting public comments until 17 February. Meanwhile, the Environmental Protection Agency is conducting a risk assessment of the proposed use of 2,4-D on crops.

    Western Australia

    New Sanctuary to Fence in Native Species


    Woylies and bilbies and numbats. Oh my. The Australian Wildlife Conservancy (AWC) is building a 43-kilometer-long fence to help protect these three endangered mammals and six others threatened by foxes and feral cats. The fenced sanctuary inside the 7800-hectare Mount Gibson Wildlife Sanctuary in Western Australia is part of a landmark effort to reintroduce regionally extirpated species. A $1.2 million grant for the project was announced 27 December by the mining company Top Iron Pty Ltd., as compensation for environmental damage near Perth.

    The planned residents include the woylie (Bettongia penicillata), also called the brush-tailed bettong; the bilby (Macrotis lagotis); and the termite-eating numbat (Myrmecobius fasciatus). They'll be joined by the nocturnal western barred bandicoot (Perameles bougainville), which jumps straight up when startled. And if AWS reaches its target of nurturing 1200 greater stick-nest rats (Leporillus conditor), the country's population will increase 40%.

    New York City

    U.S. Cancer Centers Receive Magnate's Final Endowments

    Six medical centers got $540 million—$90 million each—this week to study cancer in perpetuity or until it is no longer a problem, as specified in the will of Daniel K. Ludwig, who died in 1992. Through his estate, the shipping magnate has contributed $2.5 billion to cancer research. The new money goes to centers launched in 2006 with Ludwig support at Harvard Medical School in Boston, Johns Hopkins University in Baltimore, the Massachusetts Institute of Technology in Cambridge, the Memorial Sloan-Kettering Cancer Center in New York City, Stanford University in Palo Alto, and the University of Chicago.

    The sheer size of the Ludwig endowments makes a difference, says cancer immunologist Jedd Wolchok of Memorial Sloan-Kettering, who figures that the endowment will increase his annual budget by several million dollars. His group plans to use the money to investigate cancer–immune system interactions through an upcoming clinical trial testing a new therapeutic antibody that could be used to modulate T cells.

    Melbourne, Australia

    2013 Temperature Sets All-Time High

    Maxed out.

    Dark orange areas reached their highest average temperature on record.


    After a string of record-breaking days and an especially destructive bushfire season, a new report makes it official: 2013 was Australia's warmest year on record. An annual climate statement released last week by the country's Bureau of Meteorology reports that the year's average temperature outstripped every previous year since data collection began in 1910 and exceeded the national long-term average by 1.20°C. Climate scientists say global warming has played an undeniable role in the record-breaking conditions. The warming effect of greenhouse gas emissions "vastly increased the odds" of setting a new high, wrote climate scientist David Karoly of the University of Melbourne in a statement. "[I]t is NOT possible to reach such a temperature record due to natural climate variations alone," he said, adding that the record is especially remarkable because it occurred without the warming effect of an El Niño.

    Jhajjar, India

    Indian Cancer Institute Under Way

    Concerned about rising cancer rates in the country, Indian Prime Minister Manmohan Singh laid the foundation stone for a new National Cancer Institute last week, to be set up 60 kilometers from New Delhi. Styled after its U.S. counterpart, the $500 million institute is expected to be operational in 4 years. Singh said it will be the "single biggest health institute of the country" with more than 700 hospital beds and 500 doctors and researchers.

    According to the Indian Ministry of Health and Family Welfare, the nation's cancer treatment facilities have lagged behind World Health Organization standards. The institute will focus on cancers especially prevalent in India: tobacco-related cancers of the mouth and lungs, and cervical, gallbladder, and liver cancers.

  2. Random Sample


    Join us on Thursday, 16 January, at 3 p.m. EST for a live chat with experts about new data on how college students drop in and out of science and engineering.

    Bridges That Breathe


    Fire ants sometimes arrange themselves into living structures—floating rafts or bridges that help them traverse gaps in their paths. Those bridges are self-repairing, Sulisay Phonekeo, a graduate student at the Georgia Institute of Technology in Atlanta, reported this week at the annual meeting of the Society for Integrative and Comparative Biology in Austin. Using time-lapse videography, he observed that even without a leader, fire ants gather to mend any holes in their bridges. And when a bridge starts to vibrate too fast, as can happen when wind or water currents shake the leaves or stems at its base, the ants close ranks, curling their legs more tightly around their neighbors to shorten and stiffen the bridge. "The construction rules followed by the ants represent a formidable source of inspiration for people working on self-assembling robots and self-repairing materials," says Simon Garnier, a complex systems scientist at Rutgers University in Newark, New Jersey.

    They Said It

    "A big win for ignorance. General Mills falls to pressure on Cheerios."

    —Tweet from biologist J. Craig Venter after news that the company has dropped genetically modified corn and beets from its original Cheerios recipe.

    Science-Powered Super-Sidekicks


    Ask card-carrying geeks about the science in comic books and you'll get an angry rant. "When Superman catches people falling from skyscrapers just before they hit the street, why don't they go splat right in his Kryptonian arms? And don't even get me started on the Hulk's flagrant violation of the first law of thermodynamics …." But then they'll gush about their most beloved comic books. See the tension? Now, scientists and comic book artists in the United Kingdom are teaming up to create an antidote: Hero Lab.

    The idea is to create superheroes and villains whose powers are grounded in real science and distribute them as a comic book to schoolchildren. Scientists at the University of Central Lancashire in the United Kingdom and two professional comic book artists have created a pair of characters, Mecha-man and Doktor Darkness, who are now recruiting teams of good and evil sidekicks, respectively. Children worldwide have until 28 February to propose heroes and villains with science-based powers. One of the entries received so far, Magma Man, can harness the energy of underground magma to shoot heat blasts. (Sure, the scheme has a few scientific gaps, but you have to learn some geology to appreciate his power.) Keep tabs on the action at

    By the Numbers

    6 tons — Confiscated elephant ivory pulverized in the first destruction by the Chinese government—an attempt to reduce poaching in other countries amid high Chinese demand.

    42% — Decrease in cigarette smoking prevalence in women worldwide between 1980 and 2012, according to a new report (versus a 25% decrease for men).

  3. Newsmakers

    Battery Innovators, Science Educators Nab Engineering Prizes


    The National Academy of Engineering (NAE) announced the winners of its two top engineering prizes this week, recognizing the creators of the lithium-ion battery and the developers of an innovative education curriculum. The Charles Stark Draper Prize for Engineering, awarded for accomplishments that have significantly benefited society, went to John B. Goodenough, Yoshio Nishi, Rachid Yazami, and Akira Yoshino, who will share a $500,000 award. NAE noted that each scientist played a critical role in developing the now prevalent lithium-ion battery technology.


    The Bernard M. Gordon Prize for Innovation in Engineering and Technology Education went to the Dartmouth Engineering Entrepreneurship Program at the university's Thayer School of Engineering. NAE recognized John Collier, Robert Graves, Joseph Helble, and Charles Hutchinson for fostering entrepreneurship and leadership in the department's undergraduate and graduate engineering programs. The awardees share half of the $500,000 prize; the rest will go to their institution.

  4. Mariners of the Lost Sea

    1. Jane Qiu*

    Charting the rise and fall of the ancient Paratethys Sea may help explain how Central Asia's lush forests gave way to steppe and desert.

    Leaving its mark.

    This pale green limestone outcrop in southwestern Tajikistan marks the last stand of the Paratethys, which vanished some 37 million years ago.


    CHILDARA, TAJIKISTAN—Under a broiling midday sun, Guillaume Dupont-Nivet pushes a drill into a sloping outcrop near this village in southwestern Tajikistan. Dozens of soldiers in olive drab uniforms rush by, a reminder of the turmoil across the nearby Afghan border. Unfazed, Dupont-Nivet, a geologist at the National Center for Scientific Research (CNRS) in Rennes, France, painstakingly removes the drill and cradles his prize: a cylinder of fine, greenish sedimentary rock. "This is a perfect core," he says, wiping mud from his face.

    The core is a remnant of the bottom of the Paratethys Sea, a vast body of water that vanished long before humans walked the earth. At its peak 50 million years ago, the shallow sea covered much of Eurasia, from present-day northwestern China to the Mediterranean. In a project launched in 2008, Dupont-Nivet and his colleagues have been crisscrossing Central Asia's isolated basins, extracting hundreds of cores on a quest to "unveil the mystery of why Central Asia has become such an arid, desolate land," he says. "It's a story of a paradise lost."

    In the days of the Paratethys, Central Asia was covered in warm, damp forest inhabited by horses with long front limbs that knuckle-walked like gorillas and gargantuan rhinos that dwarfed modern elephants. Within a few million years—a geological eye blink—Central Asia's climate turned cooler and drier. Lush forests gave way to grasslands, and rodents and rabbits supplanted the megafauna. The lurch toward a more arid climate was "among the most dramatic events since the extinction of the dinosaurs," says Jin Meng, a paleontologist at the American Museum of Natural History in New York City.

    Scientists have long blamed the drying of Central Asia on rain shadows—parched areas in the lee of mountainous terrain—that formed as the Tibetan Plateau rose during the collision of Eurasia and the Indian subcontinent starting about 50 million years ago. Dupont-Nivet and others argue that the retreat of the Paratethys Sea was equally important, if not more so, in driving the shift. They suspect that the loss of a moisture source during the sea's disappearance turned much of the region into the desert it is today.

    The Paratethys Sea's importance extends beyond Central Asia. The sea connected the Indian and Atlantic oceans; its demise therefore "should have [caused] a pretty big change in global climate," says David Battisti, a climate scientist at the University of Washington, Seattle. Reconstructing the Paratethys's rise and fall, he predicts, "will change many aspects of our fundamental understanding of the Earth's climate system."

    Until recently, the region's political instability kept geologists from tracing the ancient sea and its history in detail. But fieldwork in once-inaccessible corners of Tajikistan and neighboring countries has enabled the CNRS team to begin piecing together when the Paratethys inundated Central Asia, how extensive it was, and when it vanished. Such data, Dupont-Nivet says, are "critical for linking the sea fluctuations to climate and environmental changes in Central Asia."

    The effort to paint a more nuanced picture of the Paratethys, says Carmala Garzione, a geologist at the University of Rochester in New York who is not affiliated with the project, is "long overdue."

    Disappearing acts

    The Paratethys formed about 150 million years ago, when global sea levels rose and water from the Tethys Ocean separating two supercontinents—Laurasia and Gondwana—spilled into present-day Eurasia. Rock layers spanning tens of millions of years contain a "fantastic encyclopedia" of the sea's geological history, says project member Jean-Noël Proust, a sedimentologist at CNRS in Rennes. Sediments deposited in seas and on exposed land differ in appearance and have distinct chemical compositions and fossil assemblages, making it easy to distinguish them. By measuring the direction of ancient magnetic fields frozen in rocks, the team can date the shift from marine sediments to continental rock and thus infer when the sea retreated. The embedded fossils, meanwhile, open a window on the links between the sea's retreat and regional climate.

    For the CNRS team, gaining access to inhospitable terrain is only half the battle. To precisely date the Paratethys Sea's advances and retreats, Proust says, the researchers must locate intact outcrops that haven't been twisted by mountain building.

    About a week into their field campaign in Tajikistan, the researchers stumble upon just such a rock sequence. Below the rim of a canyon, they identify a massive section of marlstone, a type of soft lime-rich mudstone formed in shallow water. "Welcome to the Paratethys," says Jovid Aminov, a graduate student at the Institute of Geology in Dushanbe, Tajikistan's capital. Several meters away lies another clue that the area was once submerged: scads of fossilized oyster shells, some topping 14 centimeters in length, embedded in the marlstone.

    High and dry.

    Laurie Bougeois examines an oyster shell, which may yield clues to the ancient marine environment.


    Deeper in the canyon, Dupont-Nivet crouches on a slab of green rock, examining its fine grain studded with fossilized fish scales. "This was likely a deep marine environment with quiet waters," he says. Alternating layers of green limestone (seabed) and red continental sandstone (dry land) divulge when the Paratethys advanced and retreated, until the beginning of continuous continental rock demarcating the end of the final sea incursion.

    To connect other dots on the map, the researchers have surveyed in western China and southern Kyrgyzstan. "The sequences of the rock layers are exactly the same, and they host very similar fossils," says team member Roderic Bosboom, a graduate student at Utrecht University in the Netherlands. This suggests that "the rocks shared the same history" and were once connected by the Paratethys before the rise of big mountains, he says.

    Beginning of the Big Dry.

    Researchers have dated the Paratethys's final two retreats. Now they hope to decipher why the sea vanished and how its loss shaped Central Asia's climate.


    Dating the limestone-sandstone transition at various locations, the team has found that the Paratethys Sea retreated westward, from China to Kyrgyzstan and finally to Tajikistan. The retreat wasn't uniform: The sea shrank and expanded five times, with each expansion more anemic than the previous one, as revealed by thinner and thinner marlstone layers and more dominant fossils of shallow-water fauna. "The sea got shallower and receded more rapidly," Bosboom says. The researchers peg the last two retreats from Central Asia to 41 million and 37 million years ago (see map).

    Other team members are probing whether the sea's demise triggered the drying in Central Asia. The giant oysters may have a story to tell. For instance, in summertime, when the mollusks have an ample food supply, they accumulate calcite, forming light-colored layers in their shells. In winter, as they conserve energy, their shells tend to store darker organic matter. Thus, the thicknesses of the alternating light and dark bands in the shells reflect seasonal temperature variations. Meanwhile, a shell's magnesium and oxygen isotopes reveal precisely the temperature and salinity of surrounding seawater. By analyzing hundreds of oyster shells collected across Central Asia, the scientists intend to piece together how environmental conditions changed at different stages of the sea's retreat.

    One clear signal in the fossil record is pollen recovered from 40-million- to 30-million-year-old rock layers showing that plants that thrive in dry climates came to dominate Central Asia. That shift has been commonly attributed to the rise of the Tibetan Plateau, which impedes moisture transport from the south. That the drying took place at the same time as the Paratethys Sea's death throes is surely no coincidence, says Matthew Huber, a climate scientist at Purdue University in West Lafayette, Indiana, who is not affiliated with the project. East of the Paratethys, he says, "a drying signal may have nothing to do with the uplift, but rather may be related to how far away the sea was."

    Paleoclimate data may also hold clues to another mystery: why the Paratethys retreated. The sea, Dupont-Nivet says, receded at a time when global atmospheric CO2 levels fluctuated before falling precipitously, transforming the hothouse world tens of millions of years ago into one more closely resembling the present day. This "triggered glaciation in Antarctica and caused a massive drop in the global sea level," Dupont-Nivet says, and "might have led to the ultimate demise of the Paratethys."

    The driver for the sharp decline in CO2 levels is "one of the greatest riddles in the Earth's climate history," says William Ruddiman, a climate scientist emeritus at the University of Virginia in Charlottesville. In 1998, he and colleagues proposed that mountain building accelerated the process of chemical weathering, which sucks CO2 out of the air as the gas reacts with freshly exposed rock. Ancient marine deposits also point to a boom in chemical weathering and a decline in CO2 concentrations, says Jérôme Gaillardet, a geochemist at Université Paris Diderot. But there is still plenty of uncertainty. "The global carbon cycle is extremely complicated," he says. "It's a matter of the balance between processes that absorb CO2 and those that release it."

    Over a dinner of lamb stew and flatbread in a hilltop camp, Dupont-Nivet explains how his team hopes to reveal the entire history of the Paratethys. Little is known, he says, about the sea's first three advances and retreats. And there is plenty of work to be done in paleoclimate modeling, which he expects will show how the sea's retreat and the Tibetan Plateau's rise conspired with other climate factors to transform Eurasia. In the quest to truly understand the legacy of the long-lost Paratethys Sea, Dupont-Nivet says, we're "only at the beginning."

    • * Jane Qiu is a writer in Beijing. Her trip to Tajikistan was supported by a journalism fellowship from the European Geosciences Union.

  5. Time Capsule in the Desert

    1. Jane Qiu

    Deep beneath western China's Qaidam Basin are traces of gigantic freshwater lakes and lush forests that gave way to steppe and desert tens of millions of years ago.

    Martian-like chronicles.

    Desolate Qaidam Basin contains fossil and climate records tracing the transformation of Central Asia over tens of millions of years.


    BEIJING—Wind-sculpted mounds and bizarre rock formations dot the Qaidam Basin, a mineral-rich swath of the northern Tibetan Plateau spanning 125,000 square kilometers of western China. "Setting foot in the Qaidam is like landing on Mars," says Fang Xiaomin, a geologist here at the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences. But deep beneath this forbidding landscape are lost worlds: traces of gigantic freshwater lakes and lush forests that gave way to steppe and desert over tens of millions of years.

    Fossils tell part of that story. Over the past 23 million years, "massive faunal turnovers" in the region accompanied the shift to a more arid climate, says Wang Xiaoming, a paleontologist at the Natural History Museum of Los Angeles County in California. One strange denizen was a shovel-tusked elephant that inhabited the swampy edges of lakes 16 million years ago, indicating that substantial freshwater bodies persisted long after the final retreat of the Paratethys Sea about 37 million years ago (see main story). The death knell for these lakes came in the last few million years, as reflected in a fish species whose bones were so stout that they left little room for flesh. Its bones thickened, apparently, as mineral concentrations soared in the shrinking lakes. "Their body just couldn't get rid of so much minerals and, therefore, stored them in the bones," Wang says.

    To develop a more complete picture of the region's climate convulsions, Fang and his colleagues over the past 5 years have been drilling into Qaidam's 15-kilometer-thick sediments. So far, they have retrieved cores from as deep as 4.3 kilometers below the surface: "the first continuous terrestrial records going back to the base of the Miocene," 23 million years ago, Fang says.

    These "pristine records" should help tease out the factors that triggered and sustained the drying in Central Asia, says Guillaume Dupont-Nivet, a geologist at the National Center for Scientific Research in Rennes, France, who is not involved in the project. So far, one intriguing finding from the sediment cores is a pronounced stretch of aridity about 7 million years ago that was out of step with global climate as written in marine records. Around that time, the northern Tibetan Plateau was rising to full height, says Fang, who suspects that "mountain building might have played a dominant role" in the drying by blocking moisture from the south.

    Fang hopes to muster support to drill down another 5 kilometers, into 50-million-year-old sediments. That would allow the team to penetrate a formative time for Eurasia, when the Tibetan Plateau was first rising, levels of atmospheric carbon dioxide were falling, and the Paratethys Sea was beginning to retreat. There, they might find clues to how those forces conspired to turn a verdant Asia into today's austere landscape.

  6. Medicine

    A Pancreas in a Box

    1. Daniel Clery

    Sophisticated sensors, insulin pumps, and algorithms may help give type 1 diabetics a more normal life while researchers work on a cure.

    Rest easy.

    An artificial pancreas will protect diabetics from low blood sugar while sleeping.


    One morning last April, a woman named Jane checked out after an overnight stay in Addenbrooke's Hospital in Cambridge, U.K. She had spent 24 hours connected by tubes to several medical devices—mostly bored, she says, but also "mildly apprehensive." Now, she was taking them home to do something she hadn't done for 3 decades, something that she and the rest of the world's 30 million type 1 diabetics are never able to do: forget about her diabetes.

    The devices—an insulin pump, a blood glucose sensor, and a computer about the size of a paperback book—make up a prototype of what researchers call an artificial pancreas. Together, they replicate the function of the pancreas that is lacking in diabetics: producing insulin in response to rises in blood glucose level. Groups in Europe, the United States, and elsewhere are now testing such systems in small groups of patients, hoping to show that the technology can work efficiently and safely. If so, it could transform the lives of diabetics, improving their health and allowing them something closer to an ordinary life. After controlling her diabetes with blood tests and injections for most of her life, having an artificial pancreas "would be magical," Jane says.

    With its tubes and needles and gadgets, an artificial pancreas is not an elegant solution to the problem of diabetes. But researchers say it could provide a valuable stopgap until effective biological treatments—or even cures—come along. The principle is simple: Connect a commercially available glucose sensor to a commercially available insulin pump via a computer programmed to interpret the sensor readings and decide how much of the drug is needed. But implementing it has turned out to be far from straightforward. Controlling the level of sugar in the blood from outside the body is fiendishly difficult because sensors are slow and error-prone, while injected insulin can take hours to have an effect and overdoses can be fatal. For a person with diabetes, used to calculating insulin doses multiple times every day and dealing with the consequences, handing over that responsibility to a computer is daunting. Patients may be clamoring for such a solution, but researchers will have to convince them that it is safe.

    "We're trying to do this invisibly and automatically. But we need faster insulin and we need faster [sensors]."


    Glucose, ingested in the form of sugar and other carbohydrates, is the body's energy source. But without the hormone insulin to help glucose out of the bloodstream and into cells, muscle and brain can't consume it, and liver and fat tissue can't store it for later use. Type 1 diabetics, whose condition develops early in life, lack insulin because their own immune system has attacked insulin-producing cells in their pancreas known as β cells. (Another form of diabetes, type 2, usually affects older people and results from insensitivity to insulin rather than a lack of it.)

    Before the discovery of insulin in the early 1920s, type 1 diabetics would simply wither away, fall into a coma, and die within months or years. In the developed world at least, today's diabetics (including the writer of this article) can live a relatively normal life—although one dominated by a never-ending round of blood sugar tests, usually achieved with a finger prick to draw blood and an electronic meter, insulin injections, and meals carefully weighed to estimate how much carbohydrate is being eaten.

    The consequences of getting it wrong can be severe. Give slightly too much insulin and glucose in the blood drops to low levels. Starved of fuel, the brain first shows symptoms similar to drunkenness, followed by unconsciousness and even death. Allow sugar levels to get too high and the syrupy blood can damage delicate blood vessels, leading to long-term complications that include heart disease, blindness, kidney failure, and limb amputation. Completely uncontrolled blood sugar leads to a coma and a trip to the hospital by ambulance, which is how many type 1 diabetics find out that they have the disease. So living with diabetes is a continual balancing act: trying to keep blood sugar levels close to those of a normal person using sporadic and erratic information (finger-prick tests) and inadequate tools (injected insulin).

    Researchers worldwide are working on biological cures for type 1. But progress is slow, and it could be many years or even decades before they are ready for widespread use. So, over the past decade, many researchers and physicians have begun working on a technological solution—the artificial pancreas—to fill the gap. Their job has been made easier by huge advances in diabetes management—new types of insulin, insulin pumps, blood glucose sensors—introduced by drug companies and medical device manufacturers.

    On target.

    A diabetic's main goal is to keep his or her blood glucose level within the same levels as a normal person. An artificial pancreas does this better than manual control, with fewer potentially dangerous excursions.


    The first insulin pumps that patients could take home and manage themselves emerged in the 1980s. Today's models, the size of a pager, pump insulin via a thin tube into the body through a cannula: a needle or tube inserted a few millimeters into subcutaneous tissue, usually in the stomach area. Pumps trickle in tiny doses of insulin—known as a basal dose—day and night, just as a pancreas does. Meals call for a much larger and immediate dose of insulin, known as a bolus, which patients program into the pump depending on how large the meal is. Pumps provide better control of blood sugar levels than insulin injections do, but their high cost has limited their popularity.

    Pumps don't eliminate the need for finger-prick glucose testing, but continuous glucose monitors (CGMs) do. Introduced in the late 1990s, these devices use a sensor that projects through the skin into the interstitial fluid between cells and measures its electrical characteristics to determine blood glucose levels. A transmitter attached to the body sends the results to a handheld receiver. CGMs give better real-time data on blood glucose levels than finger-prick tests do—but again, because of their high cost very few diabetics now use them.

    "The advent of a portable, reliable CGM was the missing link" that encouraged funders to take the idea of an artificial pancreas seriously, says Aaron Kowalski, vice president for treatment therapies at JDRF, a worldwide diabetes research foundation. JDRF set up an artificial pancreas project in 2006 to fund research in centers and companies in the United States and Europe.

    But it was the medical device industry that took the first step. In 2009, device manufacturer Medtronic released the most basic type of artificial pancreas system: an insulin pump able to receive signals from a CGM transmitter. The hybrid device isn't smart enough to control blood sugar to within a narrow range, but it can avert emergencies. The company adapted it to set off an alarm when blood sugar gets low; if no action is taken, the system simply stops the basal insulin dose for 2 hours.

    Such a system is ideally suited to dealing with low-glucose events—otherwise known as hypoglycemia or "hypos"—during the night. Nighttime hypos are particularly worrisome because people are unaware they are happening and respond too slowly or not at all, which can result in coma or hypoglycemic seizures. Medtronic's system was approved for use in Europe relatively quickly; the U.S. Food and Drug Administration (FDA), which is more cautious about medical devices, followed suit in September 2013.

    Medtronic's system can stop hypos from getting worse, but it doesn't prevent them in the first place. For that, you need an intelligent algorithm that can analyze what a user's blood sugar is doing and predict what it will do in the future. Groups around the world have been working on such algorithms for a number of years.

    Algorithms fall into three main types. The simplest is a common feedback loop used in the industrial control industry called a proportional-integral-derivative (PID) controller. This looks at a user's past and current blood glucose level and, based on the rate of change, calculates the best insulin dose to restore a target glucose level. "It's very simple, very intuitive," Kowalski says, but many now think PID controllers are too simplistic for the complex array of factors involved in controlling blood sugar, including food ingested, the slowness of insulin absorption, amount of insulin already in circulation, and exercise.

    Many groups are working on a second algorithm type, which forecasts future blood sugar levels on the basis of the diabetic's own physiology. Such model predictive control (MPC) algorithms "incorporate a model of insulin and carbohydrate absorption, tuned to the particular patient," says Lalantha Leelarathna of the Institute of Metabolic Science at the University of Cambridge in the United Kingdom. The third type of algorithm attempts to replicate how a physician would advise a patient to control his or her blood sugar and applies the recommendation using fuzzy logic, which makes decisions based not on binary yes-no answers but on truth variables that range between 0 and 1. "We took our experience and incorporated it into an algorithm," says Moshe Phillip of the Schneider Children's Medical Center of Israel in Petah Tikva.

    Researchers are now testing these more advanced systems by inviting subjects for short stays in the hospital. In 2013, several teams let subjects take the systems home for a few days, as Jane did, or test them in hotels or at a children's "diabetes camp." Not all the results of these trials have been published yet, but Kowalski says that "the results have been amazing, showing a dramatic decrease in hypos and hypers [high blood glucose] and a positive effect on the social aspects of diabetes," such as a freedom from worry and a chance to lead a "normal" life.

    Some of the systems tested were designed to be used only at night. "Night is the most dangerous time," Phillip says. Some parents rise several times every night to test a sleeping child's blood sugar. The "Glucositter" system that he and his team are developing "will change the quality of life for parents," he says.

    Systems designed to work round the clock, however, still require some input from the user to deal with daytime activities such as eating or exercise. The huge influx of carbohydrate in a meal poses perhaps the biggest challenge. In a nondiabetic person, the β cells in the pancreas are relatively dormant between meals. Other cells known as α cells take charge and produce a hormone called glucagon, a sort of anti-insulin that signals the liver to release stores of glucose to keep the body ticking over. When the person sees and smells food and knows that a meal is on the way, the body starts getting ready. The brain turns off the α cells and sets the β cells producing insulin, which in turn tells the liver to switch from secreting glucose to storing it. Within 10 minutes, the body is primed and ready to digest the meal.

    Technological fix.

    In an artificial pancreas, a glucose sensor (on stomach, left) transmits readings to a controller (here in a smartphone), which instructs an insulin pump to administer the required dose.


    In a diabetic, the body can't prepare in this way. And because injected insulin can take up to 2 hours to reach peak activity, a patient's blood sugar level often rises above the target range in the hours after a meal before leveling off as the insulin takes effect. With an artificial pancreas, the situation is even worse because the CGM takes time to detect the meal: half an hour or more for the carbohydrate to reach the bloodstream, 15 minutes for it to reach the interstitial fluid where it can be detected, and another 6 to 15 minutes for signal processing. Algorithms also have trouble gauging the size of a meal from the scanty information the CGM provides early in the digestive process. So the device could easily administer too much insulin and—because the hormone remains active in the body for up to 4 hours—trigger a hypo hours later.

    To get around this problem, some researchers require users to warn the system that a meal is on the way. The artificial pancreas can then either base a dose on a user's estimate of how much carbohydrate he or she is about to eat, or simply administer a starter dose of insulin and then top up as necessary once blood sugar readings begin to rise. Users may soon be able to assist the system by taking a premeal puff from an insulin inhaler. The drug company MannKind Corp. has developed a very quick-acting inhalable insulin called AFREZZA. FDA turned AFREZZA down for approval in 2011 because the agency wanted more information, but MannKind resubmitted the product in October and hopes for approval in April 2014.

    Such approaches help reduce postmeal blood sugar peaks and later troughs. Many researchers, however, want to provide a fully hands-free system. "We're trying to do this invisibly and automatically. But we need faster insulin, and we need faster CGMs," says chemical engineer Frank Doyle of the University of California, Santa Barbara. Companies are working on ways to speed insulin into the bloodstream by altering its molecular structure or using drugs or small electric heaters to change the properties of skin and tissue.

    Perhaps the fastest approach is to inject insulin straight into the abdominal cavity near the liver and pancreas, where it can get to work instantly and signal the liver to halt releasing glucose before a meal. "This would speed up considerably what you can do with a fully automatic system," Doyle says. The pharmaceuticals company Roche has developed a permanent injector called DiaPort, but because of the complications of a permanently inserted device, only a tiny number of diabetics now use it.

    Others are working on making CGMs faster and especially more reliable. Current systems are not only slow to respond but can also make mistakes. Miscalibration, a dislodged sensor, or a loss of sensor sensitivity can cause spuriously high readings of blood glucose, resulting in a serious hypo. "Outliers are the main problem," says Kowalski, who believes developers will have to use techniques from critical systems engineering, such as redundant sensors and failure analysis, to spot erroneous readings.

    Alternatives to the electrochemical signals now used to detect glucose could also yield better CGMs. Some makers are developing sensors that shine light through the skin and look for wavelengths that glucose absorbs. Other systems inject proteins that fluoresce in the presence of glucose and use light sensors to spot the telltale glow. JDRF is now working with several companies to develop a single sensor that uses both electrochemical and optical techniques as a fail-safe.

    Another safety mechanism employs a pump that can separately dispense both insulin and the anti-insulin hormone glucagon. When blood glucose readings dip too low, a squirt of glucagon quickly brings them up again. A team at Boston University tested the idea using two pumps in 2013 with "very, very impressive results," Kowalski says. JDRF is working with the device manufacturer Tandem Diabetes Care on a dual-hormone pump. Right now, glucagon is not stable in solution for long periods, but drug companies are working on a reformulated long-lasting version of the hormone.

    Whether developers will ever get to a fully automated system that diabetics can insert and forget remains to be seen. But "we shouldn't let perfect be the enemy of good," Kowalski says. Stuart Weinzimer of the Yale University School of Medicine agrees: "We don't need these things to be perfect. It doesn't matter what system is best. Just make them available to market and let clinicians decide." As for those who stand to benefit from an artificial pancreas, Jane says, all that matters is that the devices work. In that case, pump and tubes notwithstanding, "it will feel like not having diabetes."

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