Study: Speaking, breathing might spread COVID-19

WASHINGTON – Scientists have known for several months the new coronavirus can become suspended in microdroplets expelled by patients when they speak and breathe, but until now there was no proof that these tiny particles are infectious.

A new study by scientists at the University of Nebraska that was uploaded to a medical preprint site this week has shown for the first time that SARS-CoV-2 taken from microdroplets, defined as under five microns, can replicate in lab conditions.

This boosts the hypothesis that normal speaking and breathing, not just coughing and sneezing, are responsible for spreading COVID-19 – and that infectious doses of the virus can travel distances far greater than the sixfeet (two meters) urged by social distancing guidelines.

The results are still considered preliminary and have not yet appeared in a peer-reviewed journal, which would lend more credibility to the methods devised by the scientists.

The paper was posted to the medrxiv.org website, where most cutting-edge research during the pandemic has first been made public.

The same team wrote a paper in March showing that the virus remains airborne in the rooms of hospitalized COVID-19 patients, and this study will soon be published in a journal, according to the lead author.

“It is actually fairly difficult” to collect the samples, Joshua Santarpia,

an associate professor at the University of Nebraska Medical Center told AFP.

The team used a device the size of a cell phone for the purpose, but “the concentrations are typically very low, your chances of recovering material are

small.”

The scientists took air samples from five rooms of bedridden patients, at a height of about a foot (30 centimeters) over the foot of their beds.

The patients were talking, which produces microdroplets that become suspended in the air for several hours in what is referred to as an “aerosol,” and some were coughing.

The team managed to collect microdroplets as small as one micron in diameter.

They then placed these samples into a culture to make them grow, finding that three of the 18 samples tested were able to replicate.

For Santarpia, this represents proof that microdroplets, which also travel

much greater distances than big droplets, are capable of infecting people.

“It is replicated in cell culture and therefore infectious,” he said.

Why we wear masks

The potential for microdroplet transmission of the coronavirus was at one stage thought to be improbable by health authorities across the world.

Later, scientists began to change their mind and acknowledge it may be a possibility, which is the rationale for universal masking.

The World Health Organization was among the last to shift its position, doing so on July 7.

“I feel like the debate has become more political than scientific,” said Santarpia.

“I think most scientists that work on infectious diseases agree that there’s likely an airborne component, though we may quibble over how large.”

Linsey Marr, a professor at Virginia Tech who is a leading expert on aerial transmission of viruses and wasn’t involved in the study, said it was rare to obtain measurements of the amount of virus present in air.

“Based on what we know about other diseases and what we know so far about SARS-CoV-2, I think we can assume that if the virus is ‘infectious in aerosols,’ then we can become infected by breathing them in,” she told AFP.

Agence France-Presse

Britain gives scientist go-ahead to genetically modify human embryos

LONDON -- Scientists in Britain have been given the go-ahead to edit the genes of human embryos for research purposes, using a technique that some say could eventually be used to create "designer babies."

Less than a year after Chinese scientists caused an international furor by saying they had genetically modified human embryos, Kathy Niakan, a stem cell scientist from London's Francis Crick Institute, was granted a license to carry out similar experiments.

"The Human Fertilization and Embryology Authority has approved a research application from the Francis Crick Institute to use new 'gene editing' techniques on human embryos," Niakan's lab said on Monday.

It said the work carried out "will be for research purposes and will look at the first seven days of a fertilized egg's development, from a single cell to around 250 cells."

The scientists will not be allowed to develop the modified embryos for clinical purposes or implant them into any women.

Niakan plans to carry out her experiments using what is known as CRISPR-Cas9, a technology that is already the subject of fierce international debate because of fears that it could be used to create babies to order.

CRISPR can enable scientists to find and modify or replace genetic defects. Many experts have called it "game-changing."

David King, director of the UK campaign group Human Genetics Alert, said Niakan's plans would eventually lead to "a future of consumer eugenics.”

"This research will allow the scientists to refine the techniques for creating GM babies," he said in a statement.

But Sarah Norcross, director of Progress Educational Trust, which campaigns for ethically sound research in genetics, said the HFEA's decision was "a victory for level-headed regulation over moral panic.”

Niakan says she has no intention of genetically altering embryos for use in human reproduction, but wants to deepen scientific understanding of how a healthy human embryo develops, something that could, in the long term, help to improve infertility treatments such as in vitro fertilization.

The work will be carried out on embryos that have become surplus to donor patients IVF treatment.

At a briefing for reporters in London last month, she said the first gene she planned to target was one called October 4, which she believes may have a crucial role in the earliest stages of human fetal development.

Bruce Whitelaw, a professor of animal biotechnology at Edinburgh University's Roslin Institute on Scotland, said the HFEA's decision had been reached "after robust assessment.”

"This project, by increasing our understanding of how the early human embryo develops and grows, will add to the basic scientific knowledge needed for devising strategies to assist infertile couples and reduce the anguish of miscarriage," he said in an emailed comment.

source: interaksyon.com

European space probe lands on comet, but fails to anchor down

BERLIN/FRANKFURT - The European Space Agency landed a probe on a comet on Wednesday, a first in space exploration and the climax of a 10-year-odyssey, but an anchoring system problem may hamper planned investigations into the origins of Earth and the solar system.

The 100-kg (220-pound) lander - virtually weightless on the comet's surface - touched down on schedule at about 11 a.m. ET after a seven-hour descent from its orbiting mothership Rosetta, now located a half-billion kilometers (300 million miles) from Earth.

But during the free-fall to the comet’s surface, harpoons designed to anchor the probe, named Philae, failed to deploy. Flight directors are considering options to ensure the lander does not drift back into space.

“The lander may have lifted off again,” Stefan Ulamec, Philae lander manager at the DLR German Aerospace Center, told reporters. "Maybe today we just didn’t land once, but landed twice. Hopefully we are sitting there on the surface … and can continue our science sequence.”

Scientists hope that samples drilled out from the comet, known as 67P/Churyumov-Gerasimenko, will unlock details about how the planets – and possibly even life – evolved, as the rock and ice that make up comets preserve ancient organic molecules like a time-capsule.

Comets date back to the formation of the solar system some 4.6 billion years ago. Scientists suspect impacting comets delivered water to early Earth.

"How audacious, how exciting, how unbelievable to be able to dare to land on a comet," NASA's director of Planetary Science, Jim Green, said at the European Space Operations Centre in Germany after the successful touchdown.

Manmade craft have now landed on seven bodies in space: the moon, Mars, Venus, Saturn's moon Titan, two asteroids and comet Tempel-1, which was hit by a NASA probe.

Among several records set by the mission, Rosetta has become the first spacecraft to orbit a comet rather than just flying past to take pictures.

Rosetta reached the comet, a roughly 3-by-5 km rock discovered in 1969, in August after a journey of 6.4 billion km that took 10 years, five months and four days - a mission that cost close to 1.4 billion euros or $1.8 billion. ($1 = 0.8022 euro)

"What really nails this experience for me are the images," Daniel Brown, an expert in astronomy at Nottingham Trent University, said via email after three-legged Philae had relayed data and images back to Earth as it moved toward the comet.

"Especially exciting will be getting the results of the samples recovered from below the surface and seeing their chemical composition," he said. (Additional reporting by Irene Klotz in Cape Canaveral, Florida)

source: interaksyon.com

Quiet Sun prompts questions about impact on Earth

WASHINGTON DC - The surface of the sun has been surprisingly calm of late -- with fewer sunspots than anytime in in the last century -- prompting curious scientists to wonder just what it might mean here on Earth.

Sunspots have been observed for millennia -- first by Chinese astronomers and then, for the first time with a telescope, by Galileo in 1610.

The sunspots appear in roughly 11-year cycles -- increasing to a daily flurry and then subsiding drastically, before amping up again.


But this cycle -- dubbed cycle 24 -- has surprised scientists with its sluggishness.

The number of spots counted since it kicked off in December 2008 is well below the average observed over the last 250 years. In fact, it's less than half.

"It is the weakest cycle the sun has been in for all the space age, for 50 years," National Oceanic and Atmospheric Association physicist Doug Biesecker told AFP.

The intense electromagnetic energy from sunspots has a significant impact on the sun's ultraviolet and X-ray emissions as well as on solar storms.

Solar storms can interrupt telecommunications and electronic networks on Earth. Sunspot activity can also have an impact on the Earth's climate.

Cycle 23 hit its maximum in April 2000 with an average of 120 solar spots a day. The cycle then wound down, hitting bottom around December 2008, the point at which scientists marked the start of the current cycle.

The minimal solar activity at the end of cycle 23 led astronomers to predict a slow cycle 24. But the reality fell even below expectations.

In the first year of the cycle, during which solar activity should have risen, astronomers counted 266 days without a single sun spot.

"The forecast peak was 90 sunspots," Biesecker said, noting that even though the activity has risen over the past year, "it's very clear it is not going to be close to 90."

"The sunspots number peaked last year at 67, almost half a typical cycle," he added.

The last time a sunspot cycle was this slow was in February 1906, the peak of cycle 14, with just 64 spots a day.

The "very long minimum: three years, three times more than the previous three cycles of the space age" was a major surprise, said University of Montana physicist Andres Munoz-Jamillio.

A magnetic switch

Cycle 24 has also diverged from the norm in another surprising way.

Typically, around the end of each 11-year sunspot cycle, the sun's magnetic fields switch direction. The northern and southern hemispheres change polarity, usually simultaneously.

During the swap, the strength of the magnetic fields drops to near zero and reappears when the polarity is reversed, scientists explain.

But this time, something different seems to be happening. The north pole already reversed its polarity several months ago -- and so it's now the same polarity as the south pole.

According to the most recent satellite measurements, "the south hemisphere should flip on the near future," said Todd Hoeksema, director of the Wilcox Solar Observatory at Stanford University.

He didn't seem concerned about the phenomenon.

But scientists are watching the sun carefully to see whether cycle 24 is going to be an aberration -- or if this solar calmness is going to stretch through the next cycle as well.

"We won't know that for another good three or four years," said Biesecker.

Some researchers speculate this could be the start of a prolonged period of weak solar activity.

The last time that happened, during the so-called "Maunder Minimum" between 1650 and 1715, almost no sunspots were observed. During the same period, temperatures dropped sharply on Earth, sparking what is called the "Little Ice Age" in Europe and North America.

As the sunspot numbers continue to stay low, it's possible the Earth's climate is being affected again.

But thanks to global warming, we're unlikely to see another ice age. "Things have not started to cooling, they just have not risen as quickly," Biesecker said.

source: interaksyon.com

Scientists find farthest galaxy so far

CAPE CANAVERAL, Florida -- Astronomers have found the most distant galaxy yet, a discovery that pushes back scientists' view of the universe to about 700 million years after it is thought to have come into existence.

Light from the galaxy, designated by scientists as z8_GND_5296, took about 13.1 billion years to reach the orbiting Hubble Space Telescope and the Keck Observatory in Hawaii, both of which detected the galaxy in infrared light.

"We are learning so much about a region so far back in time it's hard to comprehend. This galaxy we're seeing is almost 13.1 billion years ago and so this was something like 8 billion years before our sun was even born and of course much longer after that until life came around," said lead researcher Steven Finkelstein, an assistant professor with the University of Texas at Austin.

Surprisingly, out of a pool of 43 candidate distant galaxies, z8_GND_5296 was the only one that revealed the key chemical evidence needed to confirm its distance.

That left Finkelstein and colleagues wondering if they had uncovered a clue to a bigger mystery: How soon did light from the universe's first stars and galaxies pierce an obscuring veil of hydrogen gas that existed early in its history?

Scientists believe that at some point, high-energy ultraviolet radiation from exploded stars split the intergalactic hydrogen atoms into electrons and protons. Once ionized, the hydrogen would be electrically conductive and no longer scatter light.

That may have happened about the time of z8_GND_5296's existence.

The galaxy, which is about a billion times as massive as the sun, has two unusual characteristics, which may be a factor in why it is visible, while potential sister galaxies are not.

First, z8_GND_5296 is forming stars at a very fast pace, pumping out about 100 times more stars than the Milky Way galaxy, so it may be brighter than the other candidate galaxies.

Second, it contains a surprisingly high percentage of elements heavier than hydrogen and helium.

Those elements are forged by nuclear fusion inside stars, so either the galaxy contains the exploded remains of lots of massive stars or it formed in a region of space that had been previously seeded with the remnants of a prior generation of stars, scientists said.

"It could be that this one galaxy lives in an over-dense region of (ionized hydrogen) so we can see it ... but that's a little bit of conjecture. For all we know these other galaxies have just a lot more hydrogen gas within the galaxies themselves and that's why we can't see them," Finkelstein said.

He and colleagues hope to conduct a wider survey for ancient galaxies with Hubble, but more details about z8_GND_5296 will likely have to wait until NASA launches its successor observatory, the James Webb Space Telescope, targeted for launch in 2018.

The research appears this week in the journal Nature.

source: interaksyon.com

'Too much math' - Scientists find proof

WASHINGTON - Artistic types are not the only ones whose eyes glaze over when confronted with too many numbers, according to research out Monday that suggests scientists, too, find lots of equations hard to read.

The study by researchers at the University of Bristol analyzed nearly 650 studies on ecology and evolution published in three leading journals in 1998.

They found that papers with more equations in the text were less likely to be cited in future papers, signaling that scientists may not be paying attention to research that is jammed with mathematical details.

Studies with the most math in them were referenced 50 percent less often than those with little or no math, said the study in the Proceedings of the National Academy of Sciences, a US peer-reviewed journal.

"This is an important issue," said Tim Fawcett, lead author of the study titled: "Heavy use of equations impedes communication among biologists."

"Nearly all areas of science rely on close links between mathematical theory and experimental work," he said.

"If new theories are presented in a way that is off-putting to other scientists, then no one will perform the crucial experiments needed to test those theories. This presents a barrier to scientific progress."

Co-author Andrew Higginson suggested that adding a bit of verbal flourish might help experts get their point across.

"Scientists need to think more carefully about how they present the mathematical details of their work," he said.

"The ideal solution is not to hide the maths away, but to add more explanatory text to take the reader carefully through the assumptions and implications of the theory."

source: interaksyon.com

Aspirin may inhibit spread of cancer

SYDNEY —Aspirin and other household drugs may inhibit the spread of cancer because they help shut down the chemical “highways” which feed tumors, Australian researchers say.

Scientists at Melbourne’s Peter MacCallum Cancer Centre said they have made a biological breakthrough helping explain how lymphatic vessels—key to the transmission of tumors throughout the body—respond to cancer.

“We’ve shown that molecules like the aspirin… could effectively work by reducing the dilation of these major vessels and thereby reducing the capacity of tumors to spread to distant sites,” researcher Steven Stacker said.

Doctors have long suspected that non-steroidal anti-inflammatory drugs such as aspirin may help inhibit the spread of cancer but they have been unable to pinpoint exactly how this is done.

By studying cells in lymphatic vessels, the researchers found that a particular gene changed its expression in cancers which spread, but not when the cancer did not spread.

The results published in Cancer Cell journal reveal that the gene is a link between a tumor’s growth and the cellular pathway which can cause inflammation and dilation of vessels throughout the body.

Once these lymphatic vessels widen, the capacity for them to act as “supply lines” to tumors and become more effective conduits for the cancer to spread is increased.

But aspirin acts to shut down the dilation of the vessels.

“So it seems like we have found a pivotal junction point in a biochemical sense between all these different contributors,” Stacker said.

The discovery could lead to new and improved drugs which could help contain many solid tumors, including breast and prostate cancer, as well as potentially provide an “early warning system” before a tumor begins to spread.

Last year, a study published in medical journal The Lancet found that rates of cancer of the colon, prostate, lung, brain and throat were all reduced by daily aspirin use.

Many doctors recommend regular use of aspirin to lower the risk of heart attack, clot-related strokes and other blood flow problems. A downside of extended daily use is the risk of stomach problems.

source: japantoday.com