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How cells know which way to go

Two new studies shed light on how cells sense and respond to chemical trails

© Yulia Artemenko/Johns Hopkins Medicine
A lab-grown human leukemia cells move toward a pipette tip holding an attractive chemical.
Amoebas aren't the only cells that crawl: Movement is crucial to development, wound healing and immune response in animals, not to mention cancer metastasis. In two new studies from Johns Hopkins, researchers answer long-standing questions about how complex cells sense the chemical trails that show them where to go - and the role of cells' internal "skeleton" in responding to those cues.

In following these chemical trails, cells steer based on minute differences in concentrations of chemicals between one end of the cell and the other. "Cells can detect differences in concentration as low as 2 percent," says Peter Devreotes, Ph.D., director of the Department of Cell Biology at the Johns Hopkins University School of Medicine. "They're also versatile, detecting small differences whether the background concentration is very high, very low or somewhere in between."

Working with Pablo Iglesias, Ph.D., a professor of electrical and computer engineering at Johns Hopkins, Devreotes' research group members Chuan-Hsiang Huang, Ph.D., a research associate, and postdoctoral fellow Ming Tang, Ph.D., devised a system for watching the response of a cellular control center that directs movement. They then subjected amoebas and human white blood cells to various gradients and analyzed what happened. "Detecting gradients turns out to be a two-step process," says Huang. "First, the cell tunes out the background noise, and the side of the cell that is getting less of the chemical signal just stops responding to it. Then, the control center inside the cell ramps up its response to the message it's getting from the other side of the cell and starts the cell moving toward that signal." The results appear on the Nature Communications website on Oct. 27.
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New pathway found: Mutant cells fail to deliver new proteins to correct location

DNA
Proteins are the machinery that accomplishes almost every task in every cell in every living organism. The instructions for how to build each protein are written into a cell's DNA. But once the proteins are constructed, they must be shipped off to the proper place to perform their jobs. New work from a team of scientists led by Carnegie's Munevver Aksoy and Arthur Grossman, describes a potentially new pathway for targeting newly manufactured proteins to the correct location. Their work is published in The Plant Cell journal.

The team's discovery concerns a cellular organelle that has been called an acidocalcisome. It is a compartment that isolates potential harmful or disruptive compounds from the rest of the cell and is also involved in the turnover of cellular components (similar to the so-called lysosome in animals). They are rich in phosphate-containing molecules and the team noted that they build up to high levels when cells of the single-celled, green alga Chlamydomonas are deprived of sulfur. They discovered that acidocalcisomes are also, surprisingly, involved in targeting proteins out into the cell space between the cell's membrane and the cell wall.

Working with Chlamydomonas, the team, which also included Carnegie's Wirulda Pootakham, was examining the organism's responses to nutrient deficiency. They found that mutant cells lacking the ability to form these acidocalcisomes also lacked the ability to cope with sulfur and nitrogen deprivation adequately.

What appears to happen with these mutants is that the proteins that specialize in helping the cell survive a deficiency of sulfur or nitrogen don't get shipped out to the space between the membrane and cell wall where they are needed. Because of this, feedback is sent to stop construction of the proteins (and the messenger RNA that encodes those proteins) and the entire response to nutrient deficiency is derailed.
HAL9000

Elon Musk says 'With artificial intelligence we are summoning the demon'

© Reuters
FILE 2014: Elon Musk, CEO of Tesla Motors, says artificial intelligence probably the biggest threat to human existence.
Elon Musk, the chief executive of Tesla and founder of SpaceX, said Friday that artificial intelligence is probably the biggest threat to humans.

Musk, who addressed MIT Aeronautics and Astronautics department's Centennial Symposium for about an hour, mulled international oversight to "make sure we don't do something very foolish," The Washington Post reported.

He was not specific about any particular threat, but appeared to theorize out loud.

"With artificial intelligence we are summoning the demon," he said. "In all those stories where there's the guy with the pentagram and the holy water, it's like yeah he's sure he can control the demon. Didn't work out."
Fireball

House-sized asteroid to give Earth a very close shave Monday

2104 UF56
© Unknown
Get ready for a very close encounter as a house-sized asteroid 2014 UF56 will pass between the Earth and the Moon on Monday. The 15 meter wide space rock will miss our planet at a distance of about 160,000 km (0.4 lunar distances) at 9:12 p.m. UTC. The asteroid was discovered Saturday and despite passing so close to Earth, few if any of us will see the flyby with our eyes in a telescope. At brightest, 2014 UF56 will only reach magnitude +16, as it zips from Scutum constellation through Capricornus.

The asteroid, back in 2012 visited Mars at a distance of about 8 mln km. It will again approach the Earth on Feb. 12, 2018. This will be a very distant fly-by, at about 64 lunar distances.

Comment: Last week, Comet Siding Spring flew by Mars and we are frequently hearing the news of asteroids and fireballs. Is there anything happening in the solar system that is contributing to this phenomenon?



Info

World's largest snake species has 'virgin birth'

Python
© The Independent, UK
A python named Thelma hatched six offspring - without contact with a male.
A 20-foot python from a zoo in America has given birth without the help of a mate.

Thelma, an 11-year-old reticulated python - the longest species of snake in the world - laid 61 eggs in the summer of 2012. This is despite having had no contact with a male in her four years at Louisville Zoo in Kentucky, USA.

After six months of extensive tests on the shed skins of the mother and her daughters, a study published in July this year in the Biological Journal of the Linnean Society confirmed that Thelma was the sole parent, in the first recorded example of virgin birth in the species.

Bill McMahan, Curator of Ectotherms at Louisville Zoo, told National Geographic: "We didn't know what we were seeing. We had attributed it to stored sperm. I guess sometimes truth is stranger than fiction."
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Dietary cocoa flavanols reverse age-related memory decline in mice

Dietary cocoa flavanols -- naturally occurring bioactives found in cocoa -- reversed age-related memory decline in healthy older adults, according to a study led by Columbia University Medical Center (CUMC) scientists.

© Lab of Scott A. Small, M.D.
The brain area outlined in yellow is the hippocampus; the dentate gyrus is shown in green and the entorhinal cortex in purple. Previous work, including by the laboratory of senior author Scott A. Small, M.D., had shown that changes in a specific part of the brain's hippocampus -- the dentate gyrus -- are associated with normal age-related memory decline in humans and other mammals. The dentate gyrus is distinct from the entorhinal cortex, the hippocampal region affected in early-stage Alzheimer's disease.
The study, published today in the advance online issue of Nature Neuroscience, provides the first direct evidence that one component of age-related memory decline in humans is caused by changes in a specific region of the brain and that this form of memory decline can be improved by a dietary intervention.

As people age, they typically show some decline in cognitive abilities, including learning and remembering such things as the names of new acquaintances or where one parked the car or placed one's keys. This normal age-related memory decline starts in early adulthood but usually does not have any noticeable impact on quality of life until people reach their fifties or sixties. Age-related memory decline is different from the often-devastating memory impairment that occurs with Alzheimer's, in which a disease process damages and destroys neurons in various parts of the brain, including the memory circuits.

Previous work, including by the laboratory of senior author Scott A. Small, MD, had shown that changes in a specific part of the brain -- the dentate gyrus -- are associated with age-related memory decline. Until now, however, the evidence in humans showed only a correlational link, not a causal one. To see if the dentate gyrus is the source of age-related memory decline in humans, Dr. Small and his colleagues tested whether compounds called cocoa flavanols can improve the function of this brain region and improve memory. Flavanols extracted from cocoa beans had previously been found to improve neuronal connections in the dentate gyrus of mice.
Sun

Rapid fire X-Flares from Sunspot AR2192

Flares have been predicted, sunspot AR2192 has complied. In the past 24 hours, the giant active region has produced two X-class solar flares: X3 (Oct. 24 @ 2140 UT) and X1 (Oct 25 @ 1709 UT). Using a backyard solar telescope, Sergio Castillo of Corona, California, was monitoring the sunspot on Oct. 24th when it exploded, and he snapped this picture:
© Sergio Castillo
"This flare was so intense that it almost shorted out my computer! Well ... not really," says Castillo, "but I knew right away that it was an X-class eruption."

Both X-flares produced brief but strong HF radio blackouts over the dayside of Earth. Communications were disturbed over a wide area for appeoximately one hour after the peak of each explosion. Such blackouts may be noticed by amateur radio operators, aviators, and mariners.
Sun

Largest sunspot on sun in more than two decades unleashes massive solar flare

© NASA/SDO
A massive X3.1 solar flare erupts from the giant sunspot AR 12192 on Oct. 24, 2014 in this close-up view from NASA's Solar Dynamics Observatory, a spacecraft that constantly watches Earth's nearest star.
The biggest sunspot on the face of the sun in more than two decades unleashed a major flare on Friday (Oct. 24), the fourth intense solar storm from the active star in less than a week.

The solar flare occurred Friday afternoon, reaching its peak at 5:41 p.m. EDT (2141 GMT), and triggered a strong radio blackout at the time, according to the U.S. Space Weather Prediction Center. NASA's sun-watching Solar Dynamics Observatory captured stunning video of the huge solar flare.

The flare erupted from a giant active sunspot known as AR 12192 and was classified as an X3.1-class solar storm - one of the most powerful types of solar storms on the sun - but it is not the first time the sunspot has made its presence known.

"This is the fourth substantial flare from this active region since Oct. 19," NASA spokesperson Karen Fox wrote in a status update.

Comment: Monster Earth-facing Sunspot - solar flare alert with possible solar storm brewing

Heart

Australian doctors complete the world's first 'dead heart' transplant

heart in a box

The console where the heart is "reactivated" is being called the heart-in-a-box machine.
Two months ago, doctors in Australia transplanted a "dead heart" - a heart that had stopped beating inside a donor's chest - into a 57-year-old woman, reports the BBC. The operation, which has been deemed success, was unlike any other, because for the first time, it didn't involve a brain-dead donor who's heart was still beating.

Normally, heart transplants call for the removal of a still-beating heart that's put on ice for a few hours until it can be placed in a recipient. But two months ago, that didn't happen. Doctors removed a heart that had stopped beating, and placed in a machine called a "heart-in-a-box." That machine then revived the heart by pumping warm blood into it. "We removed blood from the donor to prime the machine," cardiologist Peter MacDonald told WebMD. "We then take the heart out, connect it to the machine, warm it up, and when we warm it up, the heart starts to beat." Once the recipient was ready, the doctors disconnected the warm heart from the machine, and placed it in the patient.
Question

Russian scientists suggest Siberian exploding holes 'are the key to Bermuda Triangle'

agujero yamal
© Elnuevodia.com
'The main element - and this is our working theory to explain the Yamal crater - was a release of gas hydrates'

Same phenomenon of discharge of gas hydrates 'led to crater formation in Russia and disappearance of ships in Atlantic'.


The craters - two in Yamal and one on the Taymyr peninsula - were revealed during the summer, leading to urgent analysis by scientists as well as a wave of speculation suggesting the cause was aliens from outer space, meteorites, or stray missiles.

Now respected Science in Siberia journal has come up with a coherent explanation for the northern craters and - sensationally - links it to the notorious Bermuda Triangle phenomenon, where ships and aircraft have disappeared under strange circumstances between Bermuda, Florida and Puerto Rico.

Heating from above the surface due to unusually warm climatic conditions, and from below, due to geological fault lines, led to a huge release of gas hydrates, say the scientists from the Trofimuk Institute of Petroleum-Gas Geology and Geophysics in Novosibirsk.

They subjected one of the two known craters in Yamal - a peninsula known to locals as 'the end of the world' - to detailed scrutiny.

'The main element - and this is our working theory to explain the Yamal crater - was a release of gas hydrates. It turned out that there are gas hydrates both in the deep layer which on peninsula is several hundred meters down, and on the layer close to the surface,' said scientist Vladimir Potapov.

Gas - notably methane - is trapped in the frozen hydrates under the permafrost and beneath some oceans.

'There might be another factor, or factors, that could have provoked the air clap. Each of the factors added up and gas exploded, leading to appearance of the crater. 'The crater is located on the intersection of two tectonic faults. Yamal peninsula is seismically quiet, yet the area of the crater we looked into has quite an active tectonic life', Potapov said.

Crucially, the surface ice and upper layers of permafrost were exposed to 'a much warmer summer than usual', as Tyumen scientist Marina Leibman earlier noted. Igor Yeltsov, the Trofimuk Institute's deputy head, stressed: 'There is a theory that the Bermuda Triangle is caused by gas hydrates.'

He explained: 'They start to actively decompose with methane ice turning into gas. It happens in an avalanche-like way, like a nuclear reaction, producing huge amounts of gas. That makes the ocean heat up, and ships sink in waters which are infused with huge amounts of gas. This leads to the air becoming supersaturated with methane, creating an extremely turbulent atmosphere, leading to aircraft crashes'.

Comment:

Irrespective of any possible role in the 'Bermuda Triangle' phenomena, increasing releases of methane gas are already having a devastating effect on our planet - as 'Earth opens up':

See: Creatures from the deep signal major Earth Changes: Is anyone paying attention?

Hundreds of methane plumes erupting along U.S. Atlantic coast

Casualties of seafloor methane gas release? Hundreds of thousands more fish found dead in Plymouth tidal pool, UK

See also: Earth is opening up: Mysterious Siberian crater attributed to methane

For an explosion you need two things: an igniter and combustible material. The Arctic, as with many other places on Earth is outgassing methane at never-before-seen rates. Lightning discharge events are also increasing in intensity and frequency because the solar wind is being grounded while comet dust loading of the atmosphere increases nucleation and resistance, leading to greater precipitation and greater charge-rebalancing respectively.

Then, consider the following excerpt from Superluminal Communications dated 26 of July, 2014:
Q: (Data) I would like to ask about this hole that opened up in Siberia that makes like a sinkhole that also has ejected material around. What caused this hole?

A: Gases exploding within the earth. We told you that an infinitesimal slowing of the earth rotation would cause things to "open up". Expect more of that in future as well. You did not ask what sparked the "explosion"? We can tell you to once again think of greater current flow.

Q: (L) So an electrically sparked inner earth explosion. That's creepy!

(Pierre) Earth opening up, gas released, and more electric current discharged.

(Perceval) I wonder could that be caused by a lightning strike, for example?

A: Yes.

Q: (L) So a lightning strike could strike the earth, and if the gas was within a...

(Pierre) These crazy fires everywhere... Gas, lightning, fireball, boom boom.

(Kniall) Did something like this happen in Harlem? There was a gas explosion in a building, and then the appearance of a sinkhole. It could have been the same kind of thing.

(L) Remember some time ago we asked about all the fires, and they talked about electrical sparking or something then? Even back then. It's not all necessarily fireballs.

(Perceval) They said that all those fires in like frozen land with scrub and bogs was gas.

(L) It's freakin' gas being released, and sparks.
These 'crater- holes' are not an indication of global warming. They're another indication of the planet opening up.

See Earth Changes and the Human Cosmic Connection: The Secret History of the World - Book 3 where this is explained in greater detail.

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