Tag: biology

Methane detected on Enceladus could come from microbes

8:38 am

The uncertainty of science: New research has found that the methane that Cassini detected being released from Enceladus’s interior could conceivably come from at least one Earth-type microbe.

Using various mixtures of gases held at a range of temperatures and pressures in enclosed chambers called “bioreactors,” Rittmann and his co-authors cultivated three microorganisms belonging to the oldest branch of Earth’s tree of life, known as Archaea. In particular, they focused on Archaean microbes that are also methanogens, which are able to live without oxygen and produce methane from that anaerobic metabolism. The team examined the simplest types of microbes, which could be the primary producers of methane at the base of a possibly more complex ecological food chain within the moon.

They tried to simulate the conditions that could exist within and around Enceladus’s hydrothermal vents, which are thought to resemble those found at a few deep-sea sites on Earth, often near volcanically active mid-oceanic ridges. According to their tests, only one candidate, the deep-sea microbe Methanothermococcus okinawensis, could grow there—even in the presence of compounds such as ammonia and carbon monoxide, which hinder the growth of other similar organisms.

There are a lot of fake news stories today trumpeting this result as proof that alien microbes can exist on Enceladus. The data does no such thing. All it shows that one methane producing microbe could possibly live in an environment that researchers guess might somewhat resemble the situation on Enceladus. However, as the article admits,

Scientists do not really know the precise conditions on Enceladus yet, of course. And in any case it is possible any life there, if it exists, is nothing like any DNA-based organism on our planet, rendering our Earth-based extrapolations moot. What’s more, these findings only show microbial life might exist in one particular subset of possible environments within the moon’s dark ocean.

This result is interesting, but it really proves nothing about Enceladus itself.

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Microbes found that survive in the driest desert on Earth

6:18 am

Scientists have found that certain microbes can remain dormant for years in the Atacama Desert and then come to life during the rare times water is available.

The Atacama Desert stretches inland 1000 kilometers from the Pacific coast of Chile, and rainfall can be as low as 8 millimeters per year. There’s so little precipitation that there’s very little weathering, so over time the surface has built up a crusty layer of salts, further discouraging life there. “You can drive for 100 kilometers and not see anything like a blade of grass,” Neilson says. Although she and others have found some bacteria there, many biologists have argued that those microbes are not full-time residents, but were blown in, where they die a slow death.

But that didn’t deter Dirk Schulze-Makuch, an astrobiologist at the Technical University of Berlin. “I like to go to places where people say nothing is alive,” he says. “We decided to take a shotgun approach and throw all the new [analytical] approaches at everything—fungi, bacteria, viruses”—that might be there. He and his team collected samples from eight places in the Atacama—from the coast eastward to the driest places—over 3 years. They first gathered material a month after a record-setting rain in 2015, and then followed up with yearly collections in some of the same places in 2016 and 2017. They sequenced all the copies of a gene known to distinguish microbial species to determine what was in those samples and even recovered some full genomes. The researchers also did a test to determine the proportion of DNA that came from intact, living cells. Finally, they assessed the amount of cellular activity; of adenosine triphosphate (ATP), a molecule the fuels this activity; and of byproducts—including fatty acids and protein building blocks—that resulted from that activity to look for additional evidence of life.

The coastal samples contained the most number and diversity of microbes, but in 2015, there were signs of life even in the driest spots, Schulze-Makuch and his colleagues report today in the Proceedings of the National Academy of Sciences. “Following a rainfall event, there is a flush of activity and [cells] are replicating,” Neilson says.

The researchers, as well as the article, push the idea that this result makes life on Mars more possible, but I think that is pushing things quite a bit. The Earth is so filled with life that to find a spot that doesn’t have life on it is almost impossible. The odds work in the favor of hardy life in difficult places. Mars however appears generally lifeless, which makes the odds of there being life more unlikely. Moreover, while the Atacama has many similarities to Mars, the differences are quite profound. To extrapolate any possibilities to Mars from this research is a big overstatement.

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Curiosity images small tubelike rock features on Vera Rubin Ridge

12:24 pm

tubes on Mars

During Curiosity’s extended science observations in the past month on Vera Rubin Ridge the rover has found a number of rocks with strange tubelike features that remind some scientists of fossils. The image on the right, taken by the rover’s Mars Hand Lens Imager (MAHLI) and cropped and reduced to post here, shows some of these weird tubes.

The origin of these odd features — geological or biological processes — is in TBD limbo at the moment. Regarding trace fossils on Mars, “we don’t rule it out,” Vasavada said, “but we certainly won’t jump to that as our first interpretation.”

Close-up looks at these features show them to be angular in multiple dimensions. That could mean that they are related to crystals in the rock, perhaps “crystal molds” that are also found here on Earth, Vasavada added. Crystals in rock that are dissolved away leave crystal molds, he said.

Still, that’s just one of a few possibilities, Vasavada explained. “If we see more of them … then we begin to say that this is an important process that’s going on at Vera Rubin Ridge,” he said.

The article outlines a number of other possible explanations, including fossil remains. None are convincing at this time, based on the limited data. Nor does Curiosity have the equipment to clarify things much.

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A short dose of ultraviolet light might save North America’s bats

8:24 am

Researchers have found that the fungus that has been decimating bat populations in the eastern United States for the past decade is easily killed by a short dose of ultraviolet light.

Upon being compared to six non-pathogenic Pseudogymnoascus species, it was found that P. destructans lacks a key enzyme that allows it to repair DNA damage caused by ultraviolet light. When samples of the fungus were exposed to a low dose of UV-C light from a handheld source, the survival rate was only about 15 percent – this dropped to less than 1 percent when the dose was moderate. In both cases, the duration of exposure was a matter of no more than a few seconds.

Next comes a control group experiment. If this proves true, than it might be possible to safely sterilize both bat populations and caves of the fungus. To work, however, the task will likely require repeated yearly visits to bat hibernation sites to kill the fungus before it causes the bats to wake up in the winter. Such visits have their own problems, and would be difficult to pay for. However, I am sure the caving community across the U.S. would be glad to volunteer for this effort, and could handle it.

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Worms on Mars!

9:09 am

Scientists growing plants on Earth using a simulated Martian soil have found that earthworms like it.

These slimy invertebrates play a key role in making Earth soil healthy by digesting dead organic matter and excreting a potent fertilizer that helps release nutrients like nitrogen and phosphorus. Their constant burrowing also helps lighten up the soil, allowing air and water to seep through better.

That’s an important improvement for the simulated Mars soil, which water struggled to soak through in previous tests. Altogether, the tests showed that the combination of worms and pig slurry helped the plants grow in Martin soil, and the worms not only thrived but reproduced. “Clearly the manure stimulated growth, especially in the Mars soil simulant, and we saw that the worms were active,” says Wamelink. “However, the best surprise came at the end of the experiment when we found two young worms in the Mars soil simulant.”

Obviously, we do not know yet how the worms would respond to the lower Martian gravity, but it sure would be a significant experiment to see them reproduce there.

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Russia astronauts have found bacteria living on the outside of ISS

8:42 am

Russia astronauts have found bacteria that was not intentionally brought into space living on the outside of ISS.

They are being studied on Earth but most likely they don’t pose any sort of danger, Russian cosmonaut Anton Shkaplerov told TASS on Monday. According to him, during spacewalks from the International Space Station under the Russian program, the cosmonauts took samples with cotton swabs from the station’s external surface. In particular, they took probes from places where the accumulation of fuel wastes were discharged during the engines’ operation or at places where the station’s surface is more obscure. After that, the samples were sent back to Earth.

“And now it turns out that somehow these swabs reveal bacteria that were absent during the launch of the ISS module. That is, they have come from outer space and settled along the external surface.”

I suspect it is a bit of hyperbole to say the bacteria came from outer space. It more likely came from either the station itself, or later spacecraft docking with the station. At the same time, the article is vague about what has been discovered. For example, it says nothing about the bacteria itself.

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A simple and inexpensive skin cancer detector wins award

10:10 am

A simple and inexpensive skin cancer detector has won the $40,000 2017 James Dyson award.

Designed by a team from McMaster University in Canada, the sKan can make more accurate diagnoses quickly and reasonably cheaply. It’s based around the fact that cancer cells have a faster metabolic rate than healthy cells, meaning they release more heat. To check if a patch of skin has the beginnings of a melanoma, the suspected area is first cooled with an ice pack before the sKan device is placed against the skin.

Using an array of temperature sensors called thermistors, the sKan will then monitor the area as the skin warms back up. If there’s a melanoma present, it will warm up faster than the surrounding skin, revealing itself on a heat map and temperature difference time plot created through a connected computer program.

Once this device is in the hands of dermatologists, they will be able to very quickly diagnose whether a skin mole or freckle is dangerous or not.

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NASA forces retraction of astronaut vision study due to privacy issues

9:01 pm

NASA has forced the retraction of an important science paper researching the damage to vision for astronauts on long spaceflights because of a concern the privacy of the astronauts might be violated.

According to the first author, the paper included information that could identify some of the astronauts that took part in the study — namely, their flight information. Although the author said he removed the identifying information after the paper was online, NASA still opted to retract it. But a spokesperson at NASA told us the agency did not supply the language for the retraction notice. The journal editor confirmed the paper was retracted for “research subject confidentiality issues,” but referred a question about who supplied the language of the notice back to NASA.

…According to first author Noam Alperin of the University of Miami Miller School of Medicine in Florida, the paper “Role of Cerebral Spinal Fluid in Space Flight Induced Ocular Changes and Visual Impairment in Astronauts” showed that visual damage caused by long space flights resulted from tiny shifts in the volume of spinal fluid — not vascular changes, as many experts had previously thought.

Protecting the health privacy of the astronauts is something NASA and the doctors that work with them are legally required to do. However, in this case the paper had been scrubbed of this information a long time ago. To force its retraction now when the actual. research was valid and important and the privacy of the astronauts was now protected seems an over reaction to me. Then again, NASA might be under legal pressure from the astronauts themselves, and thus forced to act.

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Tupperware in space!

9:20 am

Capitalism in space: Tupperware and NASA have partnered to provide space-grown gardens an artificial material for roots to grow and be watered.

First flown to the ISS in 2014, the Vegetable Production System, (aka the “Veggie” facility), is an experiment for growing plants in zero gravity in a plastic greenhouse. It consists of a collapsible plastic tent with a controllable atmosphere lit by red, blue, and green LED lamps to promote growth. Since dirt and space travel don’t mix, the seeds are embedded in rooting “pillows” that take the place of soil to retain water and give the roots somewhere to grow.

The problem is that the pillows don’t hold onto water very well, so the hydroponic system keeps drying out unless it’s tended regularly. Given how much it costs to keep an astronaut on the station, time spent watering the lettuce is about as economical as hiring a brain surgeon to mow the lawn, so a team led by Howard Levine at the Kennedy Space Center is working on some upgrades for the system.

One key example is the semi-hydroponic Passive Orbital Nutrient Delivery System (PONDS) being produced by Tupperware. With over 75 years of experience working with food-grade plastics as well as injection molding and other plastic manufacturing processes, Tupperware is producing a new disposable pillow made of plastic mesh that uses capillary forces and unusual geometries to replace gravity and hold water in like a zero gravity sponge while permitting root formation.

In other words, rather than design and built the pillows itself, as it would have in the past, NASA has hired Tupperware to build them. I am willing to bet this is saving NASA both time and money.

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Growing cucumbers in space

9:48 am

New research growing cucumbers on ISS has found that the roots of these plants grew in the direction of water in weightlessness.

Plant roots grow to find water, according to a process known as hydrotropism. Roots are also influenced by gravity and tend to grow downwards, called gravitropism. To find out whether gravity or water had the greater influence on root growth, investigators grew cucumber plants in the microgravity environment on board the International Space Station. In their experiments, water (or hydrotropism) had more influence in controlling root growth.

“We will be able to utilize roots’ ability to sense moisture gradients for controlling root growth orientation and efficiently growing plants in future space farms,” said Dr. Hideyuki Takahashi, senior author of the New Phytologist study.

You can read the full science paper here.

This might sound obvious, but it isn’t. Past plant growth experiments on Mir and ISS had tended to show that plant roots did not know where to grow in weightlessness, suggesting that they needed gravity to guide the roots to water. Because of this, later experiments in space provided the roots complicated engineering to guide the roots to the water.

This experiment shows that maybe that complex engineering is not necessary, or at least could be simplified a bit. At a minimum it is crucial information engineers will need to design any future gardens for interplanetary spaceships with long term weightlessness.

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How cats used humans to conquer the world

8:42 am

Link here. The bottom line is this:

Compared to many other animals, cats have also changed very little in the domestication process. Behaviorally, they’ve become more tolerant of humans. Physically, though, they’re still about the same size and shape. They still like to pounce on small prey. “Cats have done since before they were domesticated what we needed them to do,” says Leslie Lyons, a feline geneticist at the University of Missouri. In other words, unlike dogs that herd sheep or hunt badgers, cats didn’t need humans to breed them to become good mouse hunters.

In other words, cats did what they want (as they always do), and humans paid them with food and companionship, while providing them the transportation they needed to reach every continent.

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Worm grows 2 heads on ISS

5:29 pm

The uncertainty of science: For reasons that are not yet understood, a flatworm fragment flown to ISS in a microgravity experiment regenerated with two heads.

But the most dramatic difference was a type of regeneration observed in one of the 15 worm fragments sent to the ISS. That worm returned to the scientists with two heads (one on each end of its body), a type of regeneration so rare as to be practically unheard of — “normal flatworms in water never do this,” Levin told Live Science. When the researchers snipped both heads off back on Earth, the middle portion regenerated into a two-headed worm again.

“And these differences persist well over a year after return to Earth!” Levin said. “Those could have been caused by loss of the geomagnetic field, loss of gravity, and the stress of takeoff and landing — all components of any space-travel experience for living systems going to space in the future,” he said.

The flatworms that flew in space showed other significant differences from the control group that stayed on Earth, further suggesting that for flatworms at least the environment of weightlessness causes more problems that were expected.

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How NIMH policy effects research

8:24 am

The uncertainty of science: A policy change in how the National Institute of Mental Health (NIMH) awards grants during the Obama administration has had a profound influence on the research of mental-health in the United States.

An analysis by Nature suggests that the number of clinical trials funded by the NIMH dropped by 45% between 2009 and 2015. This coincides with the agency’s launch, in 2011, of the Research Domain Criteria (RDoC) — a framework for research on the mechanisms of mental illness. The NIMH’s roll-out of RDoC included asking researchers to focus more on the biological bases of behaviour — such as brain circuitry and genetics — than on the broader symptoms that clinicians typically use to define and classify mental illness.

The NIMH’s embrace of fundamental research has infuriated many clinical researchers, who see it as an attempt to invalidate their methods — and say that there is scant evidence to support the idea that using RDoC will lead to greater insight or better treatments for mental illness. Many of these researchers also note that NIMH funding for clinical trials has declined steadily over the past decade, adding to the perception that the agency now favours research that uses the RDoC framework.

Read the article. I have no idea if the change in NIMH policy is a good or bad thing. What disturbs me however is the federal government’s overall top-down control over mental-health research. Rather than obtain funding from many different sources — which would allow for the greatest flexibility and the most creativity — this research field appears to depend almost entirely on NIMH grants. Thus, the particular preferences of that agency dictates the nature of the research, whether or not its preferences are right.

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Rat sperm exposed to weightlessness still produces healthy rats

8:46 am

An experiment that flew on ISS has found that rat sperm exposed to weightlessness and space radiation and then used on Earth to fertilize eggs still produce healthy rats.

The first issue for the researchers was how best to get the sperm up there. They decided to have the samples freeze-dried, just like instant coffee. This meant the sperm weighed almost nothing and could be kept at room temperature, ideal for travel on a rocket, or on a distant planet. The mouse sperm then spent 288 days on the ISS before coming back to Earth to be compared with fresh sperm from the same mice.

First, the scientists analysed how space travel affected the integrity of the DNA within the sperm. We know that high levels of fragmentation of sperm DNA are associated with male infertility. As expected, the scientists discovered that the space sperm had higher amounts of fragmented DNA than the sperm which had stayed on Earth. However, when used to fertilise a mouse egg, the space sperm resulted in a similar number of healthy embryos being generated – and these offspring had the ability to develop into normal, fertile adult mice. A final test the researchers did was to compare the patterns of genes being expressed within the brains of the adult mice. Here, the researchers saw no overall differences and concluded the space sperm was equally capable of generating offspring.

Obviously, this result is encouraging, but we are still a long way from nonchalantly letting women get pregnant and give birth in space. The risks on the child remain too great and are unknown.

In fact, I suspect the first time a child is born and raised in space will be an event that is unplanned.

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Irreplaceable plant specimens destroyed by Australian customs.

10:29 am

Do the paperwork! Because the proper paperwork was not completed, and then mailed to the wrong address, Australian customs officials destroyed six daisy specimens, some collected in the 1700s.

Earlier this week, many botanists learned about the destruction of six type specimens of daisies—some collected during a French expedition to Australia from 1791 to 1793—which the National Museum of Natural History (NMNH) in Paris had mailed along with 99 other specimens to the Queensland Herbarium in Brisbane, Australia.

After the package arrived in Brisbane in early January, the specimens were held up at customs because the paperwork was incomplete. Biosecurity officers asked the Queensland Herbarium for a list of the specimens and how they were preserved, but the herbarium sent its responses to the wrong email address, delaying the response by many weeks. In March, the officers requested clarification, but then incinerated the samples. “It’s like taking a painting from the Louvre and burning it,” says James Solomon, herbarium curator at the Missouri Botanical Garden in St. Louis.

According to Australia’s Department of Agriculture and Water Resources, which enforces biosecurity rules, part of the problem was that the samples had a declared value of $2—and its agents routinely destroy low-value items that have been kept longer than 30 days. Michel Guiraud, director of collections at NMNH, says his museum’s policy is to put minimal values on shipments. “If it is irreplaceable, there is no way to put an insurance value on it,” he says.

It appears that the fault here is not entirely limited to Australian customs. Both the Paris and Brisbane museums appear to have been very sloppy in this matter.

The result, for now, is that some research organizations are now ceasing all shipments to Australia.

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ISS twin study suggests weightlessness stresses the body in unexpected ways

9:21 am

The first preliminary results from NASA’s comparison of Scott Kelly, who spent 340 days on ISS, and his twin brother Mark, who did not, suggests that weightlessness stresses the body’s genetic system in ways not previously measured.

Preliminary results are in from NASA’s unprecedented twin study — a detailed probe of the genetic differences between astronaut Scott Kelly, who spent nearly a consecutive year in space, and his identical twin Mark. Measurements taken before, during and after Scott Kelly’s mission reveal changes in gene expression, DNA methylation and other biological markers that are likely attributable to his time in orbit.

From the lengths of the twins’ chromosomes to the microbiomes in their guts, “almost everyone is reporting that we see differences”, says Christopher Mason, a geneticist at Weill Cornell Medical College in New York City. He and other project scientists reported the early results on 26 January in Galveston, Texas, at a meeting of scientists working in NASA’s Human Research Program. “The data are so fresh that some of them are still coming off the sequencing machines,” Mason says.

It remains unclear at this point the medical consequences of these genetic changes. The data from this first experiment is still too preliminary, and it only involves looking at two people, a sample that is obviously too small. Nonetheless, it is a beginning, and of some significance.

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Cause of vision problems in space pinpointed?

9:12 am

New research suggests that scientists have pinpointed the cause of the vision problems astronauts experience from long term weightlessness.

The new research showed that intracranial pressure in zero-gravity conditions, such as exists in space, is higher than when people are standing or sitting on Earth, but lower than when people are sleeping on Earth. The researcher’s finding suggests that the constancy of pressure on the back of the eye causes the vision problems astronauts experience over time.

More important, the research has also suggested a possible cure.

“The information from these studies is already leading to novel partnerships with companies to develop tools to simulate the upright posture in space while astronauts sleep, thereby normalizing the circadian variability in intracranial pressure, and hopefully eliminating the remodeling behind the eye,” said Dr. Levine, who holds the Distinguished Professorship in Exercise Sciences.

The researchers have continued studying whether it is possible to lower intracranial pressure by means of a vacuum device that pulls blood away from the head. They previously showed that a negative pressure box that snuggly fits the lower body can lower intracranial pressure when applied for 20-minute periods. They will soon be testing the effect of the lower body negative pressure device on eye remodeling when negative pressure is applied for eight-hour periods. “Astronauts are basically supine the entire time they are in space. The idea is that the astronauts would wear negative pressure clothing or a negative pressure device while they sleep, creating lower intracranial pressure for part of each 24 hours,” said first author Dr. Justin Lawley, Instructor in Internal Medicine at UT Southwestern and a researcher at the IEEM.

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A centrifuge costing 20 cents based on a toy

9:22 am

Scientists at Stanford have developed a centrifuge costing 20 cents to make, based on a child’s toy, that can be used in the field to separate blood samples.

According to Stanford, Prakash and post-doctoral fellow Saad Bhamla came up with the “paperfuge” while looking at toys like tops and yo-yos for inspiration. Noticing how the disc of a whirligig spins when the cords on either side are pulled, they decided to make a slow motion video of one, only to discover that it rotated at 10,000 to 15,000 RPM.

The pair started developing prototypes using a blood capillary tube mounted on a paper disc, but they went beyond simple tinkering as they recruited three undergraduate engineering students from MIT and Stanford to create mathematical models of how the whirligig could change a pulling motion into a rotary motion. Looking at variables like disc size, string elasticity, and pulling force, they combined this with equations from the physics of supercoiling DNA to gain a better understanding of the whirligig’s mechanism.

The result was a centrifuge made of 20 cents of paper, twine, and plastic that could spin at 125,000 RPM, generate 3,000 G’s, and process samples in 1.5 minutes.

I have embedded a video explaining the paperfuge below the fold. I wonder if a variation of this on ISS could do low gravity experiments.
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Possible cause of microgravity vision problems identified

10:11 pm

Scientists think they may have located the cause of the vision problems experienced by nearly two-thirds of all astronauts after long missions in weightlessness.

Prof Alperin has been looking at another potential source of the problems – the cerebrospinal fluid (CSF). This helps cushion the brain and spinal cord, and can accommodate the changes when a person moves from a lying to a standing position. “In space the system is confused by the lack of the posture-related pressure changes,” Prof Alperin explained.

The team performed high-resolution MRI scans before and shortly after spaceflights for seven long-duration astronauts. They compared the results with nine astronauts who flew into orbit for short stints on the space shuttle. The results showed that long-duration astronauts had significantly greater post-flight increases in the volume of CSF within the bony cavity of the skull that holds the eye, and also in the volume of CSF in the cavities of the brain where the fluid is produced.

The sample size is small, and the study has not yet been peer reviewed, so these results must still be taken with some skepticism.

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Birds that can fly practically forever

10:01 am

New research using data loggers tagged to thirteen common swifts has revealed that these birds were capable of remaining airborne for months at a time.

The researchers found that some of the birds made a few brief night landings in winter but remained airborne for 99% of the time. Three birds didn’t touch down once in the entire ten months….“Common swifts have evolved to be very efficient flyers, with streamlined body shapes and long and narrow wings, generating lift force at low cost,” says Anders Hedenström, a study co-author and a biologist at Lund University in Sweden. The birds even eat while airborne, snatching flying termites, ballooning spiders and other aerial insects for in-flight meals.

Hedenström says that common swifts have adapted to a low-energy lifestyle, but his team does not yet know whether the birds sleep while aloft. “Most animals suffer dramatically from far less sleep loss,” says Niels Rattenborg, a neurobiologist at Max Planck Institute for Ornithology in Seewiesen, Germany. “But these birds seem to have found a trick through evolution that allows them to get by on far less sleep.”

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The effect of weightlessness on the spine

9:04 am

New observations of astronauts before and after four to seven month long missions to ISS has found the back pain many astronauts experience appears to be caused by significant muscle atrophy.

The MRI scans indicated significant atrophy of the paraspinal lean muscle mass —which plays a critical role in spinal support and movement—during the astronauts’ time in space. The lean muscle, or “functional,” cross-sectional area of the lumbar paraspinal muscles decreased by an average of 19 percent from preflight to immediate postflight scans. A month or two later, only about two-thirds of the reduction had recovered. There was an even more dramatic reduction in the functional cross-sectional area of the paraspinal muscles relative to total paraspinal cross-sectional area. The ratio of lean muscle decreased from 86 percent preflight to 72 percent immediately postflight. At follow-up, the ratio recovered to 81 percent, but was still less than the preflight value.

In contrast, there was no consistent change in the height of the spinal intervertebral discs. Dr. Chang and coauthors write, “These measurements run counter to previous hypotheses about the effects of microgravity on disc swelling.” Further studies will be needed to clarify the effects on disc height, and whether they contribute to the increase in body height during space missions, and to the increased risk of herniated disc disease.

These results are very encouraging, because they indicate that the back problems seen are mostly attributable to weakened muscles, not actual spinal damage, and can therefore be more easily mitigated by new exercises while in orbit.

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Breakthrough increases plant yields by one third

9:29 am

Plant scientists have found a way to encourage plants to better use atmospheric nitrogen, thus increasing yields by more than one third.

For years, scientists have tried to increase the rate of nitrogen fixation in legumes by altering rhizobia bacterioid function or interactions that take place between the bacterioid and the root nodule cells.

Tegeder took a different approach: She increased the number of proteins that help move nitrogen from the rhizobia bacteria to the plant’s leaves, seed-producing organs and other areas where it is needed. The additional transport proteins sped up the overall export of nitrogen from the root nodules. This initiated a feedback loop that caused the rhizobia to start fixing more atmospheric nitrogen, which the plant then used to produce more seeds. “They are bigger, grow faster and generally look better than natural soybean plants,” Tegeder said. “Some evidence we have suggests they might also be highly efficient under stressful conditions like drought.”

The technique not only produces healthier plants and more seeds, it reduces the need for fertilizer, the overuse of which can be an environmental issue.

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Cosmic rays a threat to Mars travel

8:45 am

The uncertainty of science: New research using rats has found that cosmic rays might damage human brains during a long mission to and from Mars.

Radiation oncologist Charles Limoli and his colleagues at the University of California Irvine bombarded mice and rats with low-doses of ionized oxygen or titanium. These charged particles have similar energies to those of cosmic rays that can pass right through the shielding on spacecraft. The dosage levels that the researchers used were similar to what astronauts would be exposed to during a three-year round-trip mission to Mars, Limoli says.

The researchers looked at the prefrontal cortex, the brain region linked to decision-making, executive function, and long-term memory. They saw significant damage and inflammation in the brains of exposed animals as long as six months after the exposure. The radiation damaged the tiny branches on neurons that help transmit electric signals to the nerve cell body. This led to a loss in learning and memory. The exposed animals performed poorly on behavioral tests that measure intelligence, and they showed higher, constant anxiety levels.

Though the uncertainties here are enormous, the research here has essentially discovered the obvious. The radiation experienced during a long interplanetary voyage is unhealthy, and any interplanetary vessel for carrying humans on such a voyage must be designed with sufficient shielding to protect its passengers. That this research has proven that cosmic rays are a threat also means that providing a ship with a safe room where passengers can take refuge during solar storms is not sufficient. Cosmic rays are random and come at all times in an unpredictable manner. The research suggests that the shielding will have to protect the ship’s entire living quarters.

The payload weight requirements for any rocket that will launch the first interplanetary ships just went up significantly. This means that space stations we have been building (Mir, ISS, and Tiangong) are not even close to sufficient for interplanetary travel, and need significant redesign to make them work. This also means that human interplanetary travel will require cost-efficient heavy lift rockets such as the Falcon Heavy.

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How cats conquered the world

8:47 am

Link here. This first large scale study of the DNA of ancient cat remains tracks how felines initially spread through human society in the ancient world.

The article and the researchers appear to make one mistake, however, in questioning whether cats have been domesticated. Anyone who owns a cat can answer that question unequivocally: No! Cats merely agree to live with us, on the condition that we treat them as they demand.

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Polio returns to Nigeria

12:35 pm

Two years after the last previous case and only one year from declaring Nigeria polio-free, two children have been diagnosed with the crippling virus.

They are going to immediately begin immunizing 5 million children in the affected region.

Coincidentally, that area has been the epicenter of an insurgency waged by Boko Haram, an Islamist militant group that has killed tens of thousands of people and displaced more than 2 million since their fight began in 2009. During Boko Haram’s time in Borno, the group has been responsible for destroying hundreds of health centers, and has caused so much damage in some areas that it has become hard for vaccinators to do their jobs effectively.

One can’t help wondering if these new cases occurred because of this Islamic insurgency.

Posted on the road from Tucson to the Grand Canyon.

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Vision problems from weightlessness

6:03 pm

This article provides an excellent review of the vision problems caused by long term exposure to weightlessness, including the efforts to study the problem on Earth.

Bottom line:

Before a human trip to Mars — a journey of six-to-nine months that NASA says it wants to achieve by the 2030s — researchers agree that VIIP [the name given to this problem] must be understood much better. VIIP could be the first sign of greater dangers to the human body from microgravity. “We’re seeing the visual and neural, ophthalmic manifestations of it,” Barratt said. “I’m fairly certain this is a bit more global than that.”

Richard Williams, the chief health and medical officer at NASA, agrees that what we do not know about VIIP still poses the biggest threat. Ironically, one of the only ways to get more knowledge is spend more time in microgravity. “The longer we stay in space, the more we’re going to learn,” Williams said.

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Kelly describes medical issues from weightlessness

8:50 am

In prepared remarks to a congressional subcommittee today, astronaut Scott Kelly described the medical problems he has experienced since returning from his 340 day mission on ISS.

Kelly claimed in these remarks that weightlessness caused permanent effects (which this news article decides to emphasize), but I think that might be an overstatement. None of the specific problems he experienced appear to be permanent ones, and in my interviews with Russian astronauts who stayed even longer on Mir they noted no permanent effects. One did say however that the recovery time tended to match the mission time, so that if you spent a year in space it took a year to completely recover. Kelly has only been back about three months, so his recovery is certainly not over yet.

Update: Kelly’s remarks were part of a hearing promoting legislation that would give astronauts lifetime medical coverage from the government. Thus, there is a bit of lobbying going on here.

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New jellyfish spotted at 2 miles depth

2:04 pm

A NOAA mapping robot working two miles beneath the ocean surface recently captured video of a species of jellyfish previously unknown.

The newly discovered jellyfish has two sets of tentacles, short and long. When the the long tentacles are even and extended outward, and the bell is motionless, this could mean it’s readying to ambush its prey, scientists speculate. Inside the bell, red radial canals connect what scientists say looks like the bright yellow gonads.

I have posted the video below the fold.
» Read more

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