Tag: biology

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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Fake images in biology research papers

9:38 am

The uncertainty of peer review: A new study has found that since 1995 as many as 5.5% of all biomedical research papers per year contain duplicate or faked images.

Bik, who is at Stanford University in California, spent two years looking at articles published from 1995 to 2014 in 40 different journals, hunting for instances in which identical images were used to represent different experiments within the same paper. She cross-checked the duplications that she found with her two co-authors, both microbiologists.

Overall, 4% of the inspected papers contained such images, the researchers found. But rates ranged from over 12% in the International Journal of Oncology, to 0.3% in the Journal of Cell Biology, which has since 2002 systematically scanned images in its accepted papers before publication. Journals with higher impact factors generally had lower rates of duplicated images.

…Many of the problems were probably sloppy mistakes where people selected the wrong photograph, says Bik. But half or more look deliberate — because images are flipped or rotated or the same features occur twice in the same photograph. [emphasis mine]

Essentially, a significant number of scientists in medical research are purposely faking data.

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Avoiding the period in space

9:37 am

New research has outlined the techniques available to female astronauts to prevent menstruation in space.

Rather than researching the consequences of women having a period in space, the researchers are recommending that women avoid them completely, something that appears to have been the policy of NASA on ISS. This is a big mistake. The whole point of having a space station is to find out the consequences to the human body imposed by weightlessness. Future space explorers will need to reproduce. We need to know now if that will be possible.

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China grows mouse embryos in space

10:51 am

During a two week unmanned biology satellite mission, Chinese scientists successfully demonstrated that mouse embryos can develop in weightlessness.

The team developed an embryo culture system and placed it within a small enclosed chamber [on the spacecraft] that provides the ideal conditions for the embryos to develop in space. While the chamber was in orbit, a camera attached to the experiment took photographs of the embryos as they developed in microgravity, and sent these images back to Earth. With the aid of their imaging technology, the researchers were able to observe how the mammalian two-cell stage embryos developed into blastocysts under microgravity after four days. Blastocysts are structures formed in the very early development of mammals. In humans blastocysts begin to form five days after fertilization.

The researchers will now compare their space-developed embryos to those cultured in normal laboratory environments on Earth to see what differences there are between the two at both a cellular and molecular level.

None of this proves that life can be conceived and grow in weightlessness. It does however suggest that it might be possible.

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Liver damage from weightlessness?

11:28 pm

The uncertainty of science: Mice flown for almost two weeks on the last space shuttle mission in 2011 have shown evidence of the early symptoms of liver disease.

The mice spent time orbiting the Earth on the final space shuttle flight in 2011. Once they returned home, teams of scientists were allowed to share and study their internal organs.

Jonscher’s team found that spaceflight resulted in increased fat storage in the liver, comparing pair-fed mice on Earth to those on the shuttle. This was accompanied by a loss of retinol, an animal form of Vitamin A, and changes to levels of genes responsible for breaking down fats. As a result, mice showed signs of nonalcoholic fatty liver disease (NAFLD) and potential early indicators for the beginnings of fibrosis, which can be one of the more progressive consequences of NAFLD. “It generally takes a long time, months to years, to induce fibrosis in mice, even when eating an unhealthy diet,” Jonscher said. “If a mouse is showing nascent signs of fibrosis without a change in diet after 13 ½ days, what is happening to the humans?”

This result doesn’t prove that weightlessness causes liver damage. It only suggests that more research is needed, though the data from six month to year long missions suggest that the liver harm to humans is either non-existent or temporary.

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Tetanus boosters can work for almost thirty years

9:17 am

The uncertainty of science: A new study has found that tetanus vaccine booster shots might last three times longer than previously believed.

The study looked for tetanus antibodies in 546 adults who had received the tetanus vaccine at some point in the past. Of those 546 adults, the researchers found that 97 percent still had sufficient antibodies to fight off tetanus. Since tetanus boosters are also designed to fight diphtheria, the same percentage also had antibodies to fight off that disease.

The researchers then looked at the amount of antibodies present in each individual compared to the amount of time that had passed since they received their vaccines. The result was that the study determined the half-life of a tetanus booster to be about 14 years, which means that the average person should be able to go about 28 years between boosters, or almost three times as long as the current CDC recommendation.

The half-life for diphtheria immunity was found to be even longer, at about 27 years, or roughly 54 years between boosters.

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White nose syndrome found on Washington state bat

4:08 pm

Bad news for bats: Scientists have confirmed a bat with white nose syndrome in the state of Washington, 1,300 miles further west than the previous detection.

On March 11, hikers found the sick bat about 30 miles east of Seattle near North Bend, and took it to Progressive Animal Welfare Society (PAWS) for care. The bat died two days later, and had visible symptoms of a skin infection common in bats with WNS. PAWS then submitted the bat for testing to the USGS National Wildlife Health Center, which confirmed through fungal culture, molecular and pathology analyses that it had WNS.

I hate to express such a thought, but I can’t help wonder about the legitimacy of this detection. It is so far west and so far from the nearest other bat with white nose syndrome I cannot understand how this bat came to be infected, naturally. In order for this discovery to be confirmed they are going to have to detect it again, and more than once, on a number of bats. Otherwise, it will remain suspect and a possible false positive.

The worst part of this is that the government is surely going to begin instituting draconian measures to protect the bats in Washington, as well as across the entire western United States, even before this detection is confirmed. Having this single detection will make it much easier for government officials to ban humans from many more places, even though white nose syndrome is nowhere close.

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Does captivity hurt or help killer whales? Scientists disagree

9:21 am

The uncertainty of science: Two different science research teams strongly disagree about the positive or negative effects of living in captivity for killer whales.

In a decision hailed by animal-rights groups, the US marine-park company SeaWorld Entertainment announced last week that it will no longer breed killer whales. But whether captivity harms the planet’s biggest predator is an area of active scientific debate.

The latest arguments centre on two 2015 studies that drew dramatically different conclusions about the lifespans of captive killer whales (Orcinus orca), relative to those of wild populations. Although many factors affect well-being, an apparent discrepancy between the survival of captive and wild animals has long been cited by activists as evidence of the poor welfare of captive killer whales.

One of the studies is authored by a team largely made up of researchers at SeaWorld, which is headquartered in Orlando, Florida, and owns several animal parks that keep killer whales; the other is by two former killer-whale trainers at the company who feature in the 2013 documentary film Blackfish, which is critical of SeaWorld. In letters published last week, authors from each paper accuse the others of cherry-picking data to support positions on whether the animals should be captive — charges that each team in turn rejects.

Obviously, each science team has its own agendas. The result unfortunately is that the science is cloudy and unclear.

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Injected stem cells cure osteoporosis in mice

9:22 am

Scientists have discovered that an injection of stem cells into mice with osteoporosis was able to completely cure them of the bone disease.

Researchers at the University of Toronto and The Ottawa Hospital had previously found a causal effect between mice developing age-related osteoporosis and a deficiency in mesenchymal stem cells (MSCs). One of the promising attributes of MSCs is that, while they can grow into different cells in the body just like other stem cells, they can be transplanted without the need for a match. “We reasoned that if defective MSCs are responsible for osteoporosis, transplantation of healthy MSCs should be able to prevent or treat osteoporosis,” says William Stanford, senior scientist at The Ottawa Hospital and Professor at the University of Ottawa.

To put this reasoning to the test, the scientists injected MSCs into mice with the condition. Six months later, which is one quarter of the life span of the animal, they observed a healthy functional bone in place of the damaged one. “We had hoped for a general increase in bone health,” says John E. Davies, co-author of the study. “But the huge surprise was to find that the exquisite inner ‘coral-like’ architecture of the bone structure of the injected animals – which is severely compromised in osteoporosis – was restored to normal.”

The importance of this discovery for space travel is that it might eventually allow scientists to use it to somehow prevent the loss of bone density during weightlessness.

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First step in producing silicon-based life

9:04 am

The Horta live! Scientists have succeeded in creating a bacteria that can produce hydrocarbon compounds that incorporate silicon into their make-up.

To get biology to adopt silicon, Frances Arnold, a chemist at the California Institute of Technology (Caltech) in Pasadena, along with postdoctoral assistant Jennifer Kan and graduate student Rusty Lewis, started by isolating a so-called thermophilic bacterium, which grows in hot springs. Like many organisms, the bacterium contains an enzyme called cytochrome c, which shuttles electrons to other proteins, making it widely useful in biochemistry. In some cases, however, enzymes in thermophilic bacteria expand their roles to carry out other reactions on the side. So the Caltech researchers tested their microbe and found that in rare cases its cytochrome c also added silicon to hydrocarbons.

In nature, Arnold notes, cytochrome c’s silicon-adding ability is so feeble that it’s probably just a byproduct of the enzyme’s function—not even close to its primary role. To try to beef it up, the team incubated the bacteria with silicon and carbon compounds and selected the organisms that produced the most hydrocarbons that incorporated silicon. After only three rounds of this artificial selection, the enzymes had evolved to churn out silicon-containing hydrocarbons 2000 times as readily as natural cytochrome c. “The power of evolution really shows up when a new function appears and then is forced to adapt via directed evolution,” Arnold says.

For now, the silicon-spiked hydrocarbon compounds, called organosilanes, probably aren’t useful either to the bacteria or to industry. They’re short and stubby, unlike the long chainlike versions that chemical companies make for uses such as adhesives, caulks, and sealants.

As the article notes, they really are very far from creating a silicon-based life. Still, to get silicon incorporated into carbon-based organic chemistry is a significant first step, as it demonstrates that the theory of silicon-based life might very well have merit.

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