Antarctic explorers help make discovery 100 years after their epic adventures

One of the first aerial photographs of the Antarctic, this picture was obtained from a balloon in 1901. It shows Erich von Drygalski's ship, the logbooks of which were used in the study. Credit: National Oceanic and Atmospheric Administration/Department of Commerce

Heroes of Antarctic exploration have played a crucial role in research that suggests the area of sea ice around Antarctica has barely changed in size in 100 years.

Ice observations recorded in the ships' logbooks of explorers such as the British Captain Robert Scott and Ernest Shackleton and the German Erich von Drygalski have been used to compare where the Antarctic ice edge was during the Heroic Age of Antarctic Exploration (1897-1917) and where satellites show it is today.
The study, published in the European Geosciences Union journal The Cryosphere, suggests Antarctic sea ice is much less sensitive to the effects of climate change than that of the Arctic, which in stark contrast has experienced a dramatic decline during the 20th century.
The research, by climate scientists at the University of Reading, estimates the extent of Antarctic summer sea ice is at most 14% smaller now than during the early 1900s.
Jonathan Day, who led the study, said: "The missions of Scott and Shackleton are remembered in history as heroic failures, yet the data collected by these and other explorers could profoundly change the way we view the ebb and flow of Antarctic sea ice.
"We know that sea ice in the Antarctic has increased slightly over the past 30 years, since satellite observations began. Scientists have been grappling to understand this trend in the context of global warming, but these new findings suggest it may not be anything new.
"If ice levels were as low a century ago as estimated in this research, then a similar increase may have occurred between then and the middle of the century, when previous studies suggest ice levels were far higher."
The new study published in The Cryosphere is the first to shed light on sea ice extent in the period prior to the 1930s, and suggests the levels in the early 1900s were in fact similar to today, at between 5.3 and 7.4 million square kilometres. Although one region, the Weddell Sea, did have a significantly larger ice cover.
Published estimates suggest Antarctic sea ice extent was significantly higher during the 1950s, before a steep decline returned it to around 6 million square kilometres in recent decades.
The research suggests that the climate of Antarctica may have fluctuated significantly throughout the 20th century, swinging between decades of high ice cover and decades of low ice cover, rather than enduring a steady downward trend.
This study builds on international efforts to recover old weather and climate data from ships' logbooks. The public can volunteer to rescue more data at oldweather.org.
Day said: "The Southern Ocean is largely a 'black hole' as far as historical climate change data is concerned, but future activities planned to recover data from naval and whaling ships will help us to understand past climate variations and what to expect in the future."
Capt Scott perished along with his team in 1912 after missing out on being the first to reach the South Pole by a matter of weeks, while Shackleton's ship sank after becoming trapped in ice in 1915 as he and his crew journeyed to attempt the first ever cross-Antarctic trek.
In addition to using ship logbooks from three expeditions led by Scott and two by Shackleton, the researchers used sea-ice records from Belgian, German and French missions, among others. But the team was unable to analyse some logbooks from the Heroic Age period, which have not yet been imaged and digitised. These include the records from the Norwegian Antarctic expedition of 1910-12 lead by Roald Amundsen, the first person to reach both the south and north poles.

In highly lethal type of leukemia, cancer gene predicts treatment response

New research led by Washington University School of Medicine in St. Louis shows that patients with acute myeloid leukemia (AML) whose cancer cells carry TP53 mutations -- a feature that correlates with an extremely poor prognosis -- may live longer if they are treated with decitabine, a less intensive chemotherapy drug. The study's first author, John Welch, M.D., PhD, is pictured with Phillip Houghton, who is being treated for AML. Credit: Washington University

Patients with the most lethal form of acute myeloid leukemia (AML) - based on genetic profiles of their cancers - typically survive for only four to six months after diagnosis, even with aggressive chemotherapy. But new research indicates that such patients, paradoxically, may live longer if they receive a milder chemotherapy drug.

Treatment with the less intensive drug, decitabine, is not a cure. But surprisingly, AML patients whose leukemia cells carried mutations in a nefarious cancer gene called TP53 consistently achieved remission after treatment with decitabine. Their median survival was just over a year.
The study, by a team of scientists at Washington University School of Medicine in St. Louis, is published Nov. 24 in The New England Journal of Medicine.
In AML, treatment involves intensive chemotherapy to try to kill the patient's leukemia cells and put the cancer into remission. If successful, a follow-up bone-marrow transplant can offer a possible cure, but this course of treatment is recommended only for patients with a high risk of relapse because the procedure can cause severe complications, even death.
"What's really unique here is that all the patients in the study with TP53 mutations had a response to decitabine and achieved an initial remission," said the study's senior author, Timothy J. Ley, MD, the Lewis T. and Rosalind B. Apple Professor of Medicine, noting that in AML, TP53 mutations have been correlated with an extremely poor prognosis. "With standard aggressive chemotherapy, we only see about 20 to 30 percent of these patients achieving remission, which is the critical first step to have a chance to cure patients with additional therapies.
"The findings need to be validated in a larger trial," Ley added, "but they do suggest that TP53 mutations can reliably predict responses to decitabine, potentially prolonging survival in this ultra high-risk group of patients and providing a bridge to transplantation in some patients who might not otherwise be candidates."
In an accompanying editorial, Elihu Estey, MD, an AML expert at the University of Washington Medical Center and Fred Hutchinson Cancer Research Center in Seattle, noted that AML is not one disease but many, each driven by different genetic mutations. The results of the current trial, he said, point to the inevitable need to replace large cancer clinical trials evaluating homogeneous drug treatments with smaller trials that involve subgroups of patients, with treatments targeted to their specific mutations.

The current study involved 116 patients treated with decitabine at the Siteman Cancer Center at Washington University School of Medicine and Barnes-Jewish Hospital, and at the University of Chicago. The patients either had AML - a cancer of the bone marrow - or myelodysplastic syndrome (MDS), a group of blood cancers that often progresses to AML. This year, an estimated 20,000 people living in the U.S. will be diagnosed with AML, and at least 11,000 deaths will be attributed to the disease.
Decitabine often is given to older patients with AML or MDS because it is less toxic than standard chemotherapies. But fewer than half of patients who get the drug achieve an initial remission, so the researchers wanted to determine whether specific mutations in the patients' cancer cells could predict their responses to treatment.
To find out, they sequenced all the genes in patients' cancer cells or analyzed select cancer genes. They also conducted standard tests to look for broken, missing or rearranged chromosomes. Then, the researchers correlated these molecular markers with treatment response to identify subgroups of patients likely to benefit from decitabine.
Among the patients in the study, 46 percent achieved a remission with decitabine. But, remarkably, all 21 patients whose leukemia cells carried TP53 mutations went into remission.
Patients also were likely to respond to decitabine if they were deemed to have an "unfavorable risk" prognosis based on extensive chromosomal rearrangements in their cancer cells; many of these patients also had TP53 mutations. Indeed, 66 percent of patients with an unfavorable risk achieved remission, compared with 34 percent of patients who had more favorable prognoses.
"The challenge with using decitabine has been knowing which patients are most likely to respond," said co-author Amanda Cashen, MD, an associate professor of medicine who led an earlier clinical trial of decitabine in older patients with AML. "The value of this study is the comprehensive mutational analysis that helps us figure out which patients are likely to benefit. This information opens the door to using decitabine in a more targeted fashion to treat not just older patients, but also younger patients who carry TP53 mutations."
First author John Welch, MD, PhD, an assistant professor of medicine, added: "It's important to note that patients with an extremely poor prognosis in this relatively small study had the same survival outcomes as patients facing a better prognosis, which is encouraging. We don't yet understand why patients with TP53 mutations consistently respond to decitabine, and more work is needed to understand that phenomenon."
Responses to decitabine are usually short-lived, however, with remissions typically lasting for about a year. Decitabine does not completely clear all the leukemia cells that carry TP53 mutations, and these cells invariably become resistant to the drug, leading to relapse.
"Remissions with decitabine typically don't last long, and no one was cured with this drug," Ley explained. "But patients who responded to decitabine live longer than what you would expect with aggressive chemotherapy, and that can mean something. Some people live a year or two and with a good quality of life, because the chemotherapy is not too toxic."
Roughly 10 percent of AML patients carry TP53 mutations in their leukemia cells. Among patients in the study with such mutations, median survival was 12.7 months - which is not significantly different from the 15.4 months' survival seen in patients without the mutations - and is longer than the typical four- to six-month survival observed in such patients treated with more aggressive therapies.
Decitabine was approved by the FDA in 2006 as a treatment for MDS, but oncologists often prescribe it off-label as a treatment for AML, particularly in older patients. AML typically strikes in a person's mid-60s; the average age of people in the current study was 74.
"We're now planning a larger trial to evaluate decitabine in AML patients of all ages who carry TP53 mutations," Welch said. "It's exciting to think we may have a therapy that has the potential to improve response rates in this group of high-risk patients."

Best weather satellite ever built is lunched into space

This photo provided by United Launch Alliance shows a United Launch Alliance (ULA) Atlas V rocket carrying GOES-R spacecraft for NASA and NOAA lifting off from Space Launch Complex-41 at 6:42 p.m. EST at Cape Canaveral Air Force Station, Fla., Saturday, Nov. 19, 2016. The most advanced weather satellite ever built rocketed into space Saturday night, part of an $11 billion effort to revolutionize forecasting and save lives. (United Launch Alliance via AP) 

 

The most advanced weather satellite ever built rocketed into space Saturday night, part of an $11 billion effort to revolutionize forecasting and save lives.

This new GOES-R spacecraft will track U.S. weather as never before: hurricanes, tornadoes, flooding, volcanic ash clouds, wildfires, lightning storms, even solar flares. Indeed, about 50 TV meteorologists from around the country converged on the launch site—including NBC's Al Roker—along with 8,000 space program workers and guests.
"What's so exciting is that we're going to be getting more data, more often, much more detailed, higher resolution," Roker said. In the case of tornadoes, "if we can give people another 10, 15, 20 minutes, we're talking about lives being saved."
Think superhero speed and accuracy for forecasting. Super high-definition TV, versus black-and-white.
"Really a quantum leap above any satellite NOAA has ever flown," said Stephen Volz, the National Oceanic and Atmospheric Administration's director of satellites.
"For the American public, that will mean faster, more accurate weather forecasts and warnings," Volz said earlier in the week. "That also will mean more lives saved and better environmental intelligence" for government officials responsible for hurricane and other evacuations.

Cell phones light up the beaches of Cape Canaveral and Cocoa Beach, Fla., north of the Cocoa Beach Pier as spectators watch the launch of the NOAA GOES-R weather satellite, Saturday, Nov. 19, 2016. It was launched from Launch Complex 41 at Cape Canaveral Air Force Station on a ULA Atlas V rocket. (Malcolm Denemark/Florida Today via AP)

Airline passengers also stand to benefit, as do rocket launch teams. Improved forecasting will help pilots avoid bad weather and help rocket scientists know when to call off a launch.
NASA declared success 3 1/2 hours after liftoff, following separation from the upper stage.
The first in a series of four high-tech satellites, GOES-R hitched a ride on an unmanned Atlas V rocket, delayed an hour by rocket and other problems. NOAA teamed up with NASA for the mission.
The satellite—valued by NOAA at $1 billion—is aiming for a 22,300-mile-high equatorial orbit. There, it will join three aging spacecraft with 40-year-old technology, and become known as GOES-16. After months of testing, this newest satellite will take over for one of the older ones. The second satellite in the series will follow in 2018. All told, the series should stretch to 2036.

An Atlas V rocket lifts off from Complex 41 at Cape Canaveral Air Force Station, Fla., Saturday evening, Nov. 19, 2016. The rocket is carrying the GOES-R weather satellite. The most advanced weather satellite ever built rocketed into space Saturday night, part of an $11 billion effort to revolutionize forecasting and save lives. (Craig Bailey/Florida Today via AP)

GOES stands for Geostationary Operational Environmental Satellite. The first was launched in 1975.

GOES-R's premier imager—one of six science instruments—will offer three times as many channels as the existing system, four times the resolution and five times the scan speed, said NOAA program director Greg Mandt. A similar imager is also flying on a Japanese weather satellite.
Typically, it will churn out full images of the Western Hemisphere every 15 minutes and the continental United States every five minutes. Specific storm regions will be updated every 30 seconds.
Forecasters will get pictures "like they've never seen before," Mandt promised.

An Atlas V rocket lifts off from Complex 41 at Cape Canaveral Air Force Station, in Fla., Saturday evening, Nov. 19, 2016. The rocket is carrying the GOES-R weather satellite. The most advanced weather satellite ever built rocketed into space Saturday night, part of an $11 billion effort to revolutionize forecasting and save lives. (Craig Bailey/Florida Today via AP)

A first-of-its-kind lightning mapper, meanwhile, will take 500 snapshots a second.
This next-generation GOES program—$11 billion in all—includes four satellites, an extensive land system of satellite dishes and other equipment, and new methods for crunching the massive, nonstop stream of expected data.
Hurricane Matthew, interestingly enough, delayed the launch by a couple weeks. As the hurricane bore down on Florida in early October, launch preps were put on hold. Matthew stayed far enough offshore to cause minimal damage to Cape Canaveral, despite some early forecasts that suggested a direct strike.

This photo provided by United Launch Alliance shows a United Launch Alliance (ULA) Atlas V rocket carrying GOES-R spacecraft for NASA and NOAA lifting off from Space Launch Complex-41 at 6:42 p.m. EST at Cape Canaveral Air Force Station, Fla., Saturday, Nov. 19, 2016. The most advanced weather satellite ever built rocketed into space Saturday night, par

 

credit; Marcia Dunn