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Fri, 23 Jun 2017
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Nebula

Confirmation: LIGO detects gravitational waves a third time

© LIGO/Caltech/MIT/Sonoma State (Aurore Simonnet)
This artist's conception shows two merging black holes similar to those detected by LIGO. The black holes are spinning in a nonaligned fashion, which means they have different orientations relative to the overall orbital motion of the pair. LIGO found hints that at least one black hole in the system called GW170104 was nonaligned with its orbital motion before it merged with its partner.
The Laser Interferometer Gravitational-wave Observatory (LIGO) has made a third detection of gravitational waves, ripples in space and time, demonstrating that a new window in astronomy has been firmly opened. As was the case with the first two detections, the waves were generated when two black holes collided to form a larger black hole. The newfound black hole, formed by the merger, has a mass about 49 times that of our sun. This fills in a gap between the masses of the two merged black holes detected previously by LIGO, with solar masses of 62 (first detection) and 21 (second detection).

"We have further confirmation of the existence of stellar-mass black holes that are larger than 20 solar masses -- these are objects we didn't know existed before LIGO detected them," says MIT's David Shoemaker, the newly elected spokesperson for the LIGO Scientific Collaboration (LSC), a body of more than 1,000 international scientists who perform LIGO research together with the European-based Virgo Collaboration. "It is remarkable that humans can put together a story, and test it, for such strange and extreme events that took place billions of years ago and billions of light-years distant from us. The entire LIGO and Virgo scientific collaborations worked to put all these pieces together."

Brain

Let's connect: Neuroscientists rewire brain of one species to another

© Ralph and Dale Marie Gonzales
A Giant Nudibranch, Dendronotus iris.
Scientists at Georgia State University have rewired the neural circuit of one species and given it the connections of another species to test a hypothesis about the evolution of neural circuits and behavior.

Neurons are connected to each other to form networks that underlie behaviors. Drs. Akira Sakurai and Paul Katz of Georgia State's Neuroscience Institute study the brains of sea slugs, more specifically nudibranchs, which have large neurons that form simple circuits and produce simple behaviors. In this study, they examined how the brains of these sea creatures produce swimming behaviors. They found that even though the brains of two species -- the giant nudibranch and the hooded nudibranch -- had the same neurons, and even though the behaviors were the same, the wiring was different.

The researchers blocked some of the connections in the giant nudibranch using curare, a paralyzing poison used on blow darts by indigenous South Americans. This prevented the brain of the giant nudibranch from producing the pattern of impulses that would normally cause the animal to swim. Then, they inserted electrodes into the neurons to create artificial connections between the brain cells that were based on connections from the hooded nudibranch. The brain was able to produce rhythmic, alternating activity that would underlie the swimming behavior, showing these two species produce their swimming behavior using very different brain mechanisms.

Comment: Slugging away at neural connectivity!


Monkey Wrench

DragonflEye: Genetically engineered dragonfly drone

© IEEE Spectrum
Draper's Genetically Modified Cyborg DragonflEye Takes Flight
The smaller a drone gets, the more places it can be easily flown. But while many researchers have been trying to tackle the monumental challenge of building drones that look and behave like tiny insects, a new approach has engineers giving Mother Nature's existing creations drone-like upgrades.

The biggest hurdle with building tiny drones that can fly almost anywhere is powering them. A small flying craft is only strong enough to carry a small battery, which dramatically limits its flight time. But somehow that mosquito in your tent while camping can buzz your ear for hours on end before refueling—on you.

We can only make electronics so small, though, so upgrading a mosquito isn't currently feasible. But a dragonfly? Researchers at Charles Stark Draper Laboratory and Howard Hughes Medical Institute have created something they call DragonflEye: a remote control drone built on a living dragonfly.

Info

How ancestry shapes our immune cells

© S. Leah Etheridge/University of York
Erythrocyte progenitors express ACKR1 (yellow) on their surface.
A genetic variant that is particularly prevalent in people of African ancestry confers protection against malaria. LMU researchers have now shown how it modulates the properties of white blood cells that play a major role in immune defenses and inflammation.

Virtually the entire population of sub-Saharan Africa, and some 70% of African Americans, carry a gene variant (allele) which results in a trait referred to as Duffy-negative. It has long been known that carriers of this version of the gene are relatively protected from some strains of malaria. In addition, the allele has recently been linked to benign neutropenia - a mild reduction in the numbers of neutrophilic granulocytes (neutrophils), a type of white blood cells present in the circulation.

Although neutrophils are known to play an important part in the innate immune defenses against pathogens, Duffy-negative individuals do not show any obvious increase in susceptibility to infections. In a new study led by LMU's Dr. Johan Duchêne, Professor Christian Weber and Professor Antal Rot (also at University of York), an international team of biomedical researchers has now shown how the Duffy-negative variant affects the differentiation of white blood cells and why it leads to a relative paucity of circulating neutrophils. The findings appear in the current issue of the journal Nature Immunology.

Comet

Comet simulation reveals the effect of the Sun's solar wind


Icy visitor: A view of comet Hale-Bopp, as seen from California in 1997, shows the matchhead and feathery tail.
Historically, the shape of comets revealed the presence of the solar wind in the 1950s

In our exploration of the space and the Sun, an important aspect is to understand how emanated gases behave when they are close to the sun. To study this, a simulation of a comet interacting with solar wind has been made by researchers. The work, published in Physical Review Letters, reveals how the electrons and ions in the comet's body interact with the electrons and protons in the solar wind. This is interesting as comet observations have a history of revealing even the existence of the solar wind.

Solar wind consists of a plasma of electrons and protons flowing away from the sun at hypersonic speeds. Its existence was first inferred indirectly in the 1950s by observing the shapes of comet tails. Only later was its existence confirmed by the Mariner 2 spacecraft.

Comment: Looks like mainstream science is edging close to an electrical theory for cometary behavior.


Beaker

Hundreds of giant ocean bed craters produced by explosive methane seeps

© K. Andreassen/CAGE
Several hundred craters were documented in the area, of which around one hundred were up to one kilometer wide.
Researchers working in the Barents Sea have discovered hundreds of craters on the Arctic Sea floor, some measuring over a kilometer in width. These craters, which date back to the end of the last Ice Age, were formed when large reserves of methane exploded in the wake of retreating ice sheets. Because methane is a potent greenhouse gas, this discovery is a potential warning of things to come in our warming world.

Around 12,000 years ago, the Barents Sea—an area north of Scandinavia—was covered by a thick layer of ice. When the planet warmed and these ice sheets receded, enormous quantities of methane trapped below were abruptly released. The result was a series of explosive methane blowouts that littered the seafloor with craters. The details of this finding now appear in the latest edition of Science.

Today, these craters are still seeping methane, which is a concern to climate researchers. A colorless, odorless gas produced during microbial decomposition, methane is around 30 times more effective at trapping heat in the atmosphere than carbon dioxide. Moreover, the same geological processes responsible for the historic methane blowouts are still happening elsewhere in the world today, leading to speculation that methane explosions could amp up due to human-caused climate change.

Comment: Unlike the fake global warming scam, the release of massive amounts of methane into the atmosphere is a real danger.


Fireball 5

Retired Georgia professor says meteor may have caused unexplained boom that shook Athens

© SkyandTelescope.com, Rick Scott and Joe Orman/Associated Press
The loud unexplained sound that rattled homes and unnerved people across the Athens area on Saturday may have been a sonic boom created by a meteor, a retired University of Georgia professor said Wednesday.

"I think if it wasn't the military, it may well have been a meteor, which may have been natural or a piece of space junk returning to Earth," said Michael Covington, an artificial intelligence expert who's been involved in astronomy for 50 years.

Because the boom was deafening across a wide area, a ground-based explosion could be ruled out as the cause, according to Covington.

"It seemed to be loud at a bunch of different places from the Athens Country Club to the Epps Bride Parkway area" in a north-to-south direction, he said.

Covington heard rattling in his Athens home at 1:26 p.m. Saturday.

Info

Human organ you've never heard of - The omentum

© Getty Images
The omentum, a sheet of fatty tissue that stretches over the abdomen, plays a surprising role in immune response and the growth of certain cancers.
The omentum is one of the human body's largest organs, but also arguably one of its least familiar - to scientists as well as the rest of us.

Now, however, it is coming under increased scrutiny as researchers strive to understand how it functions as an important part of the immune system but also, perversely, as a nursery for cancer cells.

The organ is effectively a large apron-like expanse of fatty tissue that encases the liver, intestine and stomach.

In a review published in the journal Trends in Immunology, Troy Randall and Selene Meza-Perez of the University of Alabama, in the US, look at the omentum's role in resisting infection, and at how its toxin-fighting mechanism inadvertently serves to protect, rather than destroy, certain cancer cells.

Key to the organ's activity are discrete white patches that cover its surface. Known as "milky spots", they were recorded by anatomists as far back as 1874, although their function wasn't deduced until rather more recently.

Info

Vision continues to develop until mid-life: Brain research extends timeline for visual cortex maturity

The visual cortex, the human brain's vision-processing centre that was previously thought to mature and stabilize in the first few years of life, actually continues to develop until sometime in the late 30s or early 40s, a McMaster neuroscientist and her colleagues have found. Kathryn Murphy, a professor in McMaster's department of Psychology, Neuroscience and Behaviour, led the study using post-mortem brain-tissue samples from 30 people ranging in age from 20 days to 80 years.

Her analysis of proteins that drive the actions of neurons in the visual cortex at the back of the brain recasts previous understanding of when that part of the brain reaches maturity, extending the timeline until about age 36, plus or minus 4.5 years.

The finding was a surprise to Murphy and her colleagues, who had expected to find that the cortex reached its mature stage by 5 to 6 years, consistent with previous results from animal samples and with prevailing scientific and medical belief.

Nebula

Mini black hole created in laboratory by world's most powerful X-ray laser

© DESY Science Communication Lab
Scientists were in for a surprise when they tested the world's most powerful X-ray laser on a single molecule, and created a 'molecular black hole' (artist's impression).
Scientists were in for a surprise when they tested the world's most powerful X-ray laser on a single molecule, and created a 'mini black hole.' The intense laser destroyed the molecule from the inside out, leaving a void, similar to a black hole in space. Researchers hope that this unexpected insight could advance the imaging of whole viruses and bacteria, which could help scientists to develop medicines.

The 'molecular black hole' was created by researchers from Kansas State University, who were testing the X-ray laser on a small molecule. The single laser pulse stripped all but a few electrons out of the molecule's biggest atom from the inside out, leaving a void that started pulling in electrons from the rest of the molecule, like a black hole gobbling a spiraling disk of matter.

And within 30 femtoseconds - millionths of a billionth of a second - the molecule lost more than 50 electrons, causing it to blow up.