Scientists have uncovered the first strong evidence that the amount of plastic polluting the oceans has risen vastly in recent decades -- by analyzing 60 years of log books for plankton-tracking vessels. Nature reports: Data recorded by instruments known as continuous plankton recorders (CPRs) -- which ships have collectively towed millions of kilometres across the Atlantic Ocean -- show that the trackers have become entangled in large plastic objects, such as bags and fishing lines, roughly three times more often since 2000 than in preceding decades. This is the first time that researchers have demonstrated the rise in ocean plastics using a single, long-term data set, says Erik van Sebille, an oceanographer at Utrecht University in the Netherlands. "I'm excited that this has been finally done," he says. The analysis was published on 16 April in Nature Communications.

Van Sebille says that because the study focused on large plastic items, it doesn't reveal much about the quantity of microplastics -- fragments fewer than 5 millimetres long -- in the oceans. These tiny contaminants come from sources such as disposable plastic packaging, rather than from fishing gear. Nevertheless, he adds, the study demonstrates that fisheries play a major part in plastic pollution, and will provide useful baseline data for tracking whether policy changes affect the levels of plastic in the oceans. "As fisheries become more professional, especially in the North Sea, hopefully we might see a decrease," he says.

Just days after Pepsi announced that it would advertise its products in space using a Russian startup, the company now says it will no longer pursue the plans, avoiding what likely would have resulted in significant public criticism. Slashdot reader schwit1 shares a report from SpaceNews: The publication Futurism reported April 13 that PepsiCo's Russian subsidiary was working with a startup there called StartRocket to advertise an energy drink called "Adrenaline Rush" using satellites. The company has proposed flying a set of small satellites in formation, reflecting sunlight with Mylar sails to create logos or other advertising messages visible from the ground after sunset and before sunrise.

PepsiCo's headquarters in the United States has shot down the idea. "We can confirm StartRocket performed an exploratory test for stratosphere advertisements using the Adrenaline GameChangers logo," a company spokesperson told SpaceNews April 15. "This was a one-time event; we have no further plans to test or commercially use this technology at this time." The company didn't elaborate on the "exploratory test for stratosphere advertisements," but it appears to refer to a high-altitude balloon test of the technology that StartRocket says on its website it planned to carry out in April in cooperation with Russia's Skolkovo Institute of Science and Technology, or Skoltech. "People have a visceral dislike of space-based advertising," adds schwit1.

In a study that raises profound questions about the line between life and death, researchers have restored some cellular activity to brains removed from slaughtered pigs. From a report: The brains did not regain anything resembling consciousness: There were no signs indicating coordinated electrical signaling, necessary for higher functions like awareness and intelligence. But in an experimental treatment, blood vessels in the pigs' brains began functioning, flowing with a blood substitute, and certain brain cells regained metabolic activity, even responding to drugs [Editor's note: the link may be paywalled; alternative source]. When the researchers tested slices of treated brain tissue, they discovered electrical activity in some neurons.

The work is very preliminary and has no immediate implications for treatment of brain injuries in humans. But the idea that parts of the brain may be recoverable after death, as conventionally defined, contradicts everything medical science believes about the organ and poses metaphysical riddles. "We had clear lines between 'this is alive' and 'this is dead,'" said Nita A. Farahany, a bioethicist and law professor at Duke University. "How do we now think about this middle category of 'partly alive'? We didn't think it could exist." For decades, doctors and grieving family members have wondered if it might ever be possible to restore function to a person who suffered extensive brain injury because of a severe stroke or heart attack. Were these brains really beyond salvage?

An anonymous reader quotes a report from Scientific American: Scientists have detected tiny pieces of plastic falling out of the air like artificial dust. A first-of-its-kind study finds these particles have blown in on the wind from at least 100 kilometers away and likely much farther. This is a clear indication that atmospheric transport is yet another way plastic pollution is being distributed around the planet, even to remote areas. "And it suggests that this is a far bigger problem than we have currently thought about," says study co-author Deonie Allen, of the Ecole Nationale Superieure Agronomique de Toulouse (ENSAT).

The study, published Monday in Nature Geoscience, is one of only a handful that have attempted to measure how much plastic is falling from the atmosphere. It marks the first wave in what is likely to be a flood of such studies in the coming years, in an effort to fill in the picture of how microplastics move around the environment and how humans might be exposed to them. Allen and her colleagues knew microplastics had been found in rivers and sediments in the French Pyrenees, but no one had determined the sources. The bulk could not have come from local sources because of the small human population and limited industrial activity, so Allen was struck by a key question: "Why haven't we looked up?" That is what she and her colleagues did, taking advantage of atmospheric measuring equipment already in place in the Pyrenees and sampling over five months. They found plastic fibers, films and shards, all in a range of sizes. Most of the polymers that turned up in the samples were polystyrene, polyethylene and polypropylene, which are all common in single-use plastic products such as bags and foam food containers. The study used computer models of atmospheric currents to attempt to backtrace the air that brought the microplastics in the Pyrenees, which is considered a pristine environment. It was clear that the relatively small towns and villages nearby "were unlikely to account for all of the plastic they detected, which suggests the ultimate sources are more distant," reports Scientific American.

Last year, NBA superstar LeBron James opened an experimental school that focuses on teaching a STEM curriculum to students who have a higher probability of failing academically or dropping out of school. The New York Times is now reporting that "the inaugural classes of third and fourth graders at [the I PROMISE School] posted extraordinary results in their first set of district assessments. Ninety percent met or exceeded individual growth goals in reading and math (Warning: source may be paywalled; alternative source), outpacing their peers across the district." From the report: The students' scores reflect their performance on the Measures of Academic Progress assessment, a nationally recognized test administered by NWEA, an evaluation association. In reading, where both classes had scored in the lowest, or first, percentile, third graders moved to the ninth percentile, and fourth graders to the 16th. In math, third graders jumped from the lowest percentile to the 18th, while fourth graders moved from the second percentile to the 30th.

The 90 percent of I Promise students who met their goals exceeded the 70 percent of students districtwide, and scored in the 99th growth percentile of the evaluation association's school norms, which the district said showed that students' test scores increased at a higher rate than 99 out of 100 schools nationally. The students have a long way to go to even join the middle of the pack. And time will tell whether the gains are sustainable and how they stack up against rigorous state standardized tests at the end of the year. To some extent, the excitement surrounding the students' progress illustrates a somber reality in urban education, where big hopes hinge on small victories.

Researchers have 3D-printed a heart using a patient's cells, providing hope that the technique could be used to heal hearts or engineer new ones for transplants. "This is the first time anyone anywhere has successfully engineered and printed an entire heart replete with cells, blood vessels, ventricles and chambers," Professor Tal Dvir of Tel Aviv University's School of Molecular Cell Biology and Biotechnology said in a statement. Dvir is senior author of the research, published Monday in the journal Advanced Science. CNN reports: The process of printing the heart involved a biopsy of the fatty tissue that surrounds abdominal organs. Researchers separated the cells in the tissue from the rest of the contents, namely the extracellular matrix linking the cells. The cells were reprogrammed to become stem cells with the ability to differentiate into heart cells; the matrix was processed into a personalized hydrogel that served as the printing "ink."

The cells and hydrogel were first used to create heart patches with blood vessels and, from there, an entire heart. Next, the researchers plan to train the hearts to behave like hearts, Dvir explained. "The cells need to form a pumping ability; they can currently contract, but we need them to work together." If researchers are successful, they plan to transplant the 3D-printed heart in animal models and, after that, humans.

A new study from physicists at Harvard and Stanford says that wormholes can exist but they're not very useful for humans to travel through. "It takes longer to get through these wormholes than to go directly, so they are not very useful for space travel," said the author of the study, Daniel Jafferis. From the report: Despite his pessimism for pan-galactic travel, he said that finding a way to construct a wormhole through which light could travel was a boost in the quest to develop a theory of quantum gravity. The new theory was inspired when Jafferis began thinking about two black holes that were entangled on a quantum level, as formulated in the ER=EPR correspondence by Juan Maldacena from the Institute for Advanced Study and Lenny Susskind from Stanford. Although this means the direct connection between the black holes is shorter than the wormhole connection -- and therefore the wormhole travel is not a shortcut -- the theory gives new insights into quantum mechanics.

"From the outside perspective, travel through the wormhole is equivalent to quantum teleportation using entangled black holes," Jafferis said. Jafferis based his theory on a setup first devised by Einstein and Rosen in 1935, consisting of a connection between two black holes (the term wormhole was coined in 1957). Because the wormhole is traversable, Jafferis said, it was a special case in which information could be extracted from a black hole. "It gives a causal probe of regions that would otherwise have been behind a horizon, a window to the experience of an observer inside a spacetime, that is accessible from the outside," said Jafferis. The physicists presented their results at the 2019 American Physical Society April Meeting in Denver, Colorado.

Researchers at the University of Toronto have found that cavities may be collateral damage from an overzealous immune system. New Atlas reports: Traditionally, bacteria have taken most of the blame for cavities and tooth decay. The bugs cling to your teeth as plaque and produce acid as waste, which dissolves tooth enamel, dentin and even filling material. But the new study suggests the story is more complicated than that. Oral immune cells called neutrophils are dispatched by the body in response to invading bacteria -- but the researchers found that they might be a little careless in the battle.

On their own, neutrophils can't damage teeth but the problems arise after acids from bacteria demineralize them. Once weakened, enzymes released by the neutrophils could wreak havoc on other tooth substances. Damage was found to appear in a matter of hours, and worse still, it also seems to apply to tooth-colored fillings, which may explain why they tend to fail within five to seven years. The silver lining of the discovery is that it could lead to new types of treatment, or new standards for testing materials that are to be used in fillings. The research was published in the journal Acta Biomateralia.

John Timmer from Ars Technica got a chance to take a look at Trek's new bicycle helmet that they claim offers "the first major change in helmet technology in years," and is backed up with peer-reviewed science. Here's an excerpt from Timmer's report: WaveCel is the product of orthopedic surgeon Steve Madey and a biomedical engineer named Michael Bottlang. The two had been working on a variety of ideas related to medical issues and protective gear, funded in part by federal grant money. When considering the idea of a lightweight material that could evenly distribute forces, Bottlang told Ars that they first focused on a honeycomb pattern. But they found that it was actually too robust -- the honeycomb wouldn't collapse until a lot of force had been applied, and then it would fail suddenly.

The design they eventually developed has a shape that allows flexing almost immediately when force is applied. "It starts to glide right away," Bottlang said. The manufacturing technique creates a clear point of failure that allows more extensive flexing once a certain level of force is exceeded -- part of the structure will fold over rather than experiencing a complete failure. Then, once folded, the polymer it's made of will allow neighboring cells to glide over each other. This provides some resistance even after the structure has collapsed. For the helmet, a patch of this material is attached to the inside of a more traditional EPS helmet, which provides impact resistance. But the WaveCel mesh is allowed to float within the helmet and can absorb much of the force of off-axis impacts. The thin strips of soft material that cushion the helmet where it rests on the head (also found in more traditional helmets) are attached directly to the WaveCel mesh.

It looks more uncomfortable than it is. Madey, the orthopedic surgeon, said they've done tests that show that, even if placed directly on the skin, the WaveCel mesh wouldn't break the skin under most impact forces. How does their new helmet work? According to a paper authored by Bottlang and Madey, helmets including the material reduced rotational acceleration from impacts by 73 percent compared to a normal helmet. A slip pad within a normal helmet (MIPS) only dropped acceleration by 22 percent, which seems like a substantial difference.

An anonymous reader quotes a report from The Verge: SpaceX successfully landed the center core of its Falcon Heavy rocket on a drone ship last week, but the vehicle accidentally fell into the ocean while in transit to the Florida coast. The company blamed the loss on choppy seas. "Over the weekend, due to rough sea conditions, SpaceX's recovery team was unable to secure the center core booster for its return trip to Port Canaveral," SpaceX said in a statement to The Verge. "As conditions worsened with eight to ten foot swells, the booster began to shift and ultimately was unable to remain upright. While we had hoped to bring the booster back intact, the safety of our team always takes precedence. We do not expect future missions to be impacted."

SpaceX does have ways to secure the rockets it lands in the ocean, including a robot known as the "octagrabber" that latches on to the base of the boosters. But because the center core connects to two side boosters, it has a different design than a normal Falcon 9 booster. So the octagrabber cannot hold on to it in the same way. The center core is a modified Falcon 9 booster -- one of three that make up the Falcon Heavy rocket -- which flew last week during the second flight of the Falcon Heavy. "Following takeoff, all three cores of the rocket successfully landed back on Earth: the two outer cores touched down on dual concrete landing pads at the Cape while the center core touched down on the company's drone ship named Of Course I Still Love You in the Atlantic," reports The Verge.

NASA administrator Jim Bridenstine has congratulated the team which sent the first privately-funded mission into lunar orbit -- even though it crashed into the surface of the moon. Its final photo was taken Thursday just 7.5 kilometers above the surface of the moon.

But Space.com reports that's not the end of the story: On Saturday Morris Kahn, the billionaire businessman, pilanthropist and SpaceIL president, confirmed that the SpaceIL team is meeting this weekend to begin planning the Beresheet 2.0 mission. "In light of all the support I've got from all over the world, and the wonderful messages of support and encouragement and excitement, I've decided that we're going to actually build a new halalit -- a new spacecraft," Kahn said in a video statement posted on Twitter by SpaceIL. "We're going to put it on the moon, and we're going to complete the mission."

The team behind Beresheet knew all along that the mission's design included risks. In order to keep the spacecraft small enough to piggyback with another spacecraft on a Falcon 9 rocket, the engineering team had to design the craft without any backup systems. Nevertheless, before its ultimate failure, the spacecraft withstood multiple glitches while in Earth orbit and during the early stages of landing.... NASA knows as well as anyone just how difficult spaceflight can be. The moon's surface is littered with dozens of expired spacecraft, and although many ended their missions smoothly, several made unplanned crash landings, including NASA's own Surveyor 2 and 4 missions during the 1960s.
Somewhere in the spacecraft's wreckage are 25 data disks backing up crucial human knowledge that were meant to last one billion years. The group behind the disk notes that "airplane black boxes survive stronger impacts, and our disc is less breakable... It was probably thrown a few kilometers away -- a 30 million page frisbee on the moon."

They're now assembling a team of crash experts, engineers, "and even a treasure hunter or two... to figure out what might remain, and then track it down." Their preliminary response from several experts: their Lunar Library "is definitely on the Moon, and it is also likely to be intact...."

"We have either installed the first library on the moon, or we installed the first archaeological ruins of early human attempts to build a library on the moon..."

DevNull127 writes: Research scientist James Heathers is a postdoctoral research associate working on bio-signals and meta-science research at Northeastern University, with a PhD from the University of Sydney. He's also pretending to be a mouse on Twitter. And every tweet consists of the exact same two words...

Heathers retweets articles about scientific studies — usually articles with glossy photos and enticing headlines like "Exercise during pregnancy protects children from obesity, study finds." His tweets add the two crucial missing words. "In mice."

In this case a doctoral student at Washington State University measured a specific protein's level in the offspring of mice that performed 60 minutes of moderate-intensity exercise every morning during pregnancy — and in regular mice. On the basis of that he recommended "that women — whether or not they are obese or have diabetes — exercise regularly during pregnancy because it benefits their children's metabolic health."

The name of the Twitter feed: JustSaysInMice.
Other mouse-based studies turning up on the Twitter feed:

• How Fatty Diets Stop the Brain From Saying 'No' To Food

• Reused Cooking Oil Ups Risk of Metastases In Breast Cancer Patients

• Keto Diet Not Effective, Causes Blood Sugar Problems In Women

• Growth Hormone Acts To Foil Weight Loss: Study

When you read those headlines, just remember to add those two words...

"In mice."

West Virginia University assistant professor Zachariah Etienne is launching "a global volunteer computing effort" analyzing gravitational waves from colliding black holes, reports Phys.org: "As our gravitational wave detectors become more sensitive, we're going to need to greatly expand our efforts to understand all of the information encoded in gravitational waves from colliding binary black holes," Etienne said. "We are turning to the general public to help with these efforts, which involve generating unprecedented numbers of self-consistent simulations of these extremely energetic collisions. This will truly be an inclusive effort, and we especially hope to inspire the next generation of scientists in this growing field of gravitational wave astrophysics."

His team -- and the scientific community in general -- needs computing capacity to run the simulations required to cover all possibilities related to the properties and other information contained in gravitational waves. "Each desktop computer will be able to perform a single simulation of colliding black holes," said Etienne. By seeking public involvement through use of vast numbers of personal desktop computers, Etienne and others hope to dramatically increase the throughput of the theoretical gravitational wave predictions needed to extract information from observations of the collisions.

Etienne and his team are building a website with downloadable software based on the same Berkeley Open Infrastructure for Network Computing, or BOINC, system used for the SETI@Home project and other scientific applications. The free middleware system is designed to help harness the processing power of thousands of personal computers across the globe. The West Virginia team has named their project BlackHoles@Home and expects to have it up and running later this year.

They have already established a website where the public can begin learning more about the effort.

"Stratolaunch, the aerospace venture founded by the late Microsoft co-founder Paul Allen, sent the world's biggest airplane into the air today for its first flight test," report GeekWire. The twin-fuselage plane, which incorporates parts from two Boeing 747 jumbo jets and has a world-record wingspan of 385 feet, took off from Mojave Air and Space Port in California for a flight that lasted two and a half hours. For more than seven years, Stratolaunch has been working with Mojave-based Scaled Composites on the project, which aims to use the plane as a flying launch pad for orbital-class rockets. The first flight test had been anticipated for months. "We finally did it," Stratolaunch CEO Jean Floyd said today during a briefing.

Stratolaunch's plane, which has been nicknamed Roc after a giant mythical bird, took off at 6:58 a.m. PT and went through a series of in-flight maneuvers, including roll doublets, yawing maneuvers, pushovers and pull-ups, steady heading side slips and simulated landing approach exercises. Stratolaunch said it reached a maximum speed of 189 mph and maximum altitude of 17,000 feet.... The plan ahead calls for further tests over the next 12 to 18 months, with the aim of getting the plane fully certified by the Federal Aviation Administration. Stratolaunch has already struck a deal to use Northrop Grumman's Pegasus XL rocket to send payloads weighing as much as 816 pounds (370 kilograms) to low Earth orbit...

Stratolaunch's air-launch system is designed to carry multiple rockets up to an altitude of about 40,000 feet, and then drop them into the air to fire up their rocket engines. The advantage of such a system is that it can take off from any runway that's long enough to accommodate the plane, fly around bad weather if need be, and launch a satellite into any orbital inclination.
Stratolaunch CEO Jean Floyd said their team had dedicated the flight to Paul Allen.

"[A]s the plane lifted gracefully from the runway, I did whisper a 'thank you' to Paul for allowing me to be part of this remarkable achievement."

At a flat-earth conference in May, Mad Mike Hughes will announce details of "an Antarctic expedition with the goal of reaching the edge of the world...to prove once and for all that this Earth is flat." But before that, he's heading for outer space.

An anonymous reader quotes PhillyVoice: If you recognize the name Mad Mike Hughes, it's likely because he strapped himself into a rocket last March and traveled three-tenths of a mile into the heavens in the name of Flat Earth awareness. (See for yourself!) Well, nearly a year to the date after that momentous achievement, the limousine-driving daredevil and gubernatorial candidate has announced he's building upon the lessons learned last year and pushing the limits even further...

We caught up with him Thursday afternoon on the phone from California where he was "putting decals on the rocket right now!" Before any sort of Antarctica excursion, he's planning for a May 9 launch either in New Mexico "or the middle of the ocean if the government tries to stop me..." He hopes to reach the Kármán line, some 62.8 miles above Earth where space begins. "That way, we'll see what shape this rock really is," he said.

"More people will watch this than those who watched the fake moon landing. It will be an incredible, incredible event. People will see what I'm seeing for three hours up there and back and they'll be able to make up their own minds.... I'm the only guy capable of actually proving what shape this rock is, and that's by going up into space to do it."
The Science Channel is now filming Hughes' progress. (Here's a slick trailer for an upcoming documentary called "Rocketman".)

And Hughes says he's also claimed the legal entities that famous people are operating under, including Elon Musk, Mark Zuckerberg, and Warren Buffett, putting these powerful people in a precarious position because now "they can't even exist..."

"I have a lot of court cases going on."

arnieswap quotes TFIR's report on the black hole image: Free and Open Source software was at the heart of this image. The team used three different imaging software libraries to achieve the feat. Out of the three, two were fully open source libraries. The source code of the software is publicly available on GitHub.

Richard M Stallman, the founder of the GNU Project will be glad to see that both libraries (Sparselab and ehtim) are released under GNU GPL v3. Yes, you read it right – GNU GPL v3.

"New York City officials on Tuesday declared a public health emergency and ordered mandatory measles vaccinations" in an area where most of the state's 285 measles cases have occurred. The Washington Post reports: New York's mandatory vaccination order in four Brooklyn zip codes is by far the toughest action to date by state or local officials, as the disease's tally grows to 465 cases in 19 states. Officials there and elsewhere have sought to bar unvaccinated children from schools and other public places but have had limited success... The mandate orders all unvaccinated people in four zip codes to receive inoculations, including children as young as 6 months. Anyone who resists faces a misdemeanor charge and could be fined up to $1,000.
Long-time Slashdot reader Major Blud shares a BBC report that under the order, "any person living in the affected areas who has not been vaccinated must be immunised within 48 hours."

A baby with DNA from three people has been born in Greece following a controversial fertility treatment. "The doctors behind the treatment, from Greece and Spain, say it marks a historic advance -- it is the first time an in vitro fertilization (IVF) technique involving DNA from three people has been used with the aim of addressing fertility problems," reports The Guardian. From the report: The experimental IVF treatment, known as mitochondrial donation, involves using an egg from the mother, sperm from the father and another egg from a female donor. The vast majority of a person's genes -- about 99.8% -- are found on the 23 pairs of chromosomes that sit inside the nucleus in each cell in the body, and in the IVF procedure this DNA comes from the two parents. However, a tiny proportion of genetic material also resides in a cell's mitochondria, small structures that act as the cell's batteries and float around freely in the cell body. In mitochondrial donation, the mother's mitochondria are removed from her egg and replaced by a donor's.

The treatment was originally developed as a treatment that could prevent women with debilitating or even fatal mitochondrial diseases from passing them on to their children. The doctors behind the latest treatment claim that mitochondria also play a role in successful pregnancy and suggest that the technique could be applied more broadly as a fertility treatment. The 32-year old woman in the latest case had previously undergone four unsuccessful rounds of IVF.

Researchers at New York University and Princeton have developed a framework that evaluates clinical notes and autonomously assigns a risk score indicating whether patients will be readmitted within 30 days. They claim that the code and model parameters, which are publicly available on Github, handily outperform baselines. VentureBeat reports: As the researchers point out in a preprint paper on Arxiv.org, clinical notes use abbreviations and jargon, and they're often lengthy, which poses an AI system design challenge. To overcome it, they used a natural language processing method -- Google's bidirectional encoder representations from transformers, or BERT -- that captures interactions between distant words in sentences by incorporating global, long-range information. Each clinical note is represented as a collection of tokens, or subword units extracted from text in a preprocessing step. From multiple sequences of these, ClinicalBERT identifies which tokens are associated with which sequence. It also learns the position of tokens from variables corresponding to the sequences, and inserts a special token used in classification tasks in front of every sequence.

To train ClinicalBERT, the team sourced a corpus of clinical notes and masked 15 percent of the input tokens, forcing the model to predict the concealed tokens and whether any two given two sentences were in consecutive order. Then, drawing on the Multiparameter Intelligent Monitoring in Intensive Care (MIMIC-III), an electronic health records data set comprising over two million notes from 58,976 hospital admissions of 38,597 patients, the researchers fine-tuned the system for clinical forecasting tasks. Tested on a sample set consisting of 30 pairs of medical terms designed to assess medical term similarity, the authors report, ClinicalBERT achieved a high correlation score, indicating that its tokens captured similarity between medical concepts terms. Heart-related concepts like myocardial infarction, atrial fibrillation, and myocardium were close together, they say, and renal failure and kidney failure were also close.

The final findings of the NASA Twins Study, which compared 50-year-old astronaut Scott Kelly, who spent a year aboard the International Space Station in 2015, and his identical twin brother, who stayed on Earth, were published in Science. Gizmodo reports: NASA found that Scott Kelly was about as mentally, physically, and genetically healthy as his brother during his trip to space, and that the vast majority of small changes spotted in Scott (relative to himself before the mission) went back to normal within six months time. But the differences seen in Scott while up in space and after his return home could provide NASA important leads on how to keep astronauts safe during longer missions to Mars and beyond.

Preliminary results from the study were released in 2017. But it was the second round of findings, released in January 2018, that really caught the attention of media outlets, some of which misrepresented what was found. In particular, outlets like Newsweek reported that a whopping "seven percent of [Scott Kelly's] genes did not return to normal after he landed." Others implied that Scott Kelly had become a different person from his twin brother. But the researchers were never talking about a seven percent difference between the twins' genes. They were saying that some of Scott Kelly's genes had changed in their expression -- the carrying out of instructions in a cell's genome -- during his time up in space. And that roughly 7 percent of this overall change in gene expression could still be seen six months after he returned home. The remaining change in gene expression six months out was actually closer to 10 percent, but NASA clarified that this was still a relatively tiny change in his epigenetics. "Given that the majority of the biological and human health variables remained stable, or returned to baseline, these data suggest that human health can be mostly sustained over this duration of spaceflight," said NASA in a statement.