Even Polar Bears say "Aww, hell no!"

Researchers Just Measured an Atom with a Half-Life of 18 Sextillion Years

Deep inside a mountain in central Italy, scientists are laying a trap for dark matter. The bait? A big metal tank full of 3.5 tons (3,200 kilograms) of pure liquid xenon. This noble gas is one of the cleanest, most radiation-proof substances on Earth, making it an ideal target for capturing some of the rarest particle interactions in the universe.

It all sounds vaguely sinister; said Christian Wittweg, a doctoral candidate at the University of Münster in Germany, who has worked with the so-called Xenon collaboration for half a decade, going to work every day feels like "paying a Bond villain a visit." So far, the mountain-dwelling researchers haven't captured any dark matter. But they recently succeeded in detecting one of the rarest particle interactions in the universe. [11 Biggest Unanswered Questions About Dark Matter]

According to a new study published today (April 24) in the journal Nature, the team of more than 100 researchers measured, for the first time ever, the decay of a xenon-124 atom into a tellurium 124 atom through an extremely rare process called two-neutrino double electron capture. This type of radioactive decay occurs when an atom's nucleus absorbs two electrons from its outer electron shell simultaneously, thereby releasing a double dose of the ghostly particles called neutrinos.

By measuring this unique decay in a lab for the first time, the researchers were able to prove precisely how rare the reaction is and how long it takes xenon-124 to decay. The half-life of xenon-124 — that is, the average time required for a group of xenon-124 atoms to diminish by half — is about 18 sextillion years (1.8 x 10^22 years), roughly 1 trillion times the current age of the universe.

Over 20 million children worldwide missed out on measles vaccine annually in past 8 years, creating a pathway to current global outbreaks - UNICEF

An estimated 169 million children missed out on the first dose of the measles vaccine between 2010 and 2017, or 21.1 million children a year on average, UNICEF said today.

Widening pockets of unvaccinated children have created a pathway to the measles outbreaks hitting several countries around the world today.

"The ground for the global measles outbreaks we are witnessing today was laid years ago," said Henrietta Fore, UNICEF Executive Director. "The measles virus will always find unvaccinated children. If we are serious about averting the spread of this dangerous but preventable disease, we need to vaccinate every child, in rich and poor countries alike."

In the first three months of 2019, more than 110,000 measles cases were reported worldwide – up nearly 300 per cent from the same period last year. An estimated 110,000 people, most of them children, died from measles in 2017, a 22 per cent increase from the year before.

Two doses of the measles vaccine are essential to protect children from the disease. However, due to lack of access, poor health systems, complacency, and in some cases fear or skepticism about vaccines, the global coverage of the first dose of the measles vaccine was reported at 85 per cent in 2017, a figure that has remained relatively constant over the last decade despite population growth. Global coverage for the second dose is much lower, at 67 per cent. The World Health Organization recommends a threshold of 95 per cent immunization coverage to achieve so-called 'herd immunity'.

Cataracts, small brains, and DNA damage — Chernobyl's wildlife 33 years after the meltdown

In the 33 years since the world's largest nuclear disaster at Chernobyl Power Plant, the area around the abandoned city has become a fascinating laboratory for biologists. In the absence of humans, plants and animals have reclaimed the landscape.

On first glance it seems the wildlife there was thriving. But if you dig a little deeper, according to Canadian scientist Timothy Mousseau, what you see paints a more disturbing picture.

He's been part of a long-term collaboration looking at the effects of prolonged, residual radiation on wildlife.

"We really know very little of the sort of larger landscape-scale ecological and community ecosystem level effects." said Mousseau, a professor of biological sciences at the University of South Carolina, in conversation with Quirks & Quarks host Bob McDonald.
What's happening with Chernobyl's rodents

Mousseau said Chernobyl is the ideal place to study the effects of prolonged radiation exposure because surrounding the city is a 2,600 sq km exclusion zone where human habitation is forbidden. In that zone, the radiation levels vary, making it easy for biologists to compare different levels of radiation effects.

"It's a quilt work of contamination with some areas that are really, really radioactive — some of the more radioactive parts of the world, in fact. In other areas, within a kilometer or two, might be really clean."

. . .

Effects on Chernobyl's birds

Of the dozens of scientific papers Mousseau has published on the effects of radiation on the area's wildlife, he said they know the most the birds.

One of the early questions they were interested in was whether the birds had developed any kind of adaptation to deal with the effects of the radiation.

"We thought, well maybe there is some kind of magical adaptations that allow these birds to tolerate the radiation," said Mousseau. "We went to test that and quickly found out that there was no such evidence of any kind of [direct] adaptation."

Instead, he found the birds, especially in the more radioactive areas, showed many abnormalities:

Change in colouration, particularly with patches of albinism, not seen anywhere else
Genetic damage in many species
Elevated rates of cataracts and tumours
A five per cent smaller brain, linked to poorer survival
Lower sperm counts
Reduced population sizes

"Almost everything we've looked at ends up showing some consequence in the more radioactive areas," said Mousseau.

Dark matter exists: Observations disprove alternate explanations




As fascinating as it is mysterious, dark matter is one of the greatest enigmas of astrophysics and cosmology. It is thought to account for 90 percent of the matter in the universe, but its existence has been demonstrated only indirectly, and has recently been called into question. New research conducted by SISSA removes the recent doubts on the presence of dark matter within galaxies, disproving the empirical relations in support of alternative theories. The study, published in the Astrophysical Journal, also offers new insights into understanding the nature of dark matter and its relationship with ordinary matter.

From the expansion of the universe to the movement of stars in the galaxies, there are many phenomena that cannot be explained by the presence of baryonic matter alone. The attractive force generated by matter is insufficient to explain observable gravitational effects. This had led to the theory of the existence of undetectable dark matter, and the idea that galaxies are embedded in its spherical halo.

I'll believe it when I see it.

UK generates usable electricity from americium

Americium is an element not found in nature, but which is produced by the radioactive decay of plutonium - which itself is produced during the operation of nuclear reactors. A team led by NNL has extracted americium from some of the UK's plutonium stocks, and used the heat generated from this highly radioactive material to generate electric current, which in turn lit up a small light bulb - all within a specially shielded area of NNL's Central Laboratory in Cumbria, England.

Space batteries are power sources for space probes which would use the heat from americium pellets to power sensors and transmitters as the probes head into deep space where other power sources such as solar panels will no longer function, NNL said. In this way, such probes can carry on sending back vital images and data to Earth for many decades - far longer than would otherwise be possible.

The breakthrough means potential use of americium in radioisotope power systems for missions which would use the heat from americium pellets to power spacecraft heading into deep space or to challenging environments on planet surfaces where other power sources, such as solar panels, no longer function. In this way, NNL said, such space missions can carry on sending back vital images and data to Earth for many decades, far longer than would otherwise be possible.

Science Minister Chris Skidmore said: "This remarkable breakthrough sounds like something from a science fiction film but it is another brilliant testament to our world leading scientific and university communities and their commitment to keeping the UK at the very frontier of developments in space technology and research for energy requirements in difficult environments. It is on the foundations of such discoveries that we can create the highly skilled jobs of the future, supported through our modern Industrial Strategy and record level of government investment in R&D."

The technical programme to deliver this world first has been running for several years, supported by funding from the European Space Agency (ESA), and has seen NNL working very closely with the University of Leicester. The work of European Thermodynamics Ltd in helping to develop the thermoelectric generator unit was a vital part of this collaboration, and support from the Nuclear Decommissioning Authority, who permitted the use of plutonium from the UK stockpile under their stewardship, was also essential.

. . .

The plutonium is not recycled, Tinsley noted. "We 'clean' the americium from it, which would have been a waste. With sufficient applications, all of the UK plutonium could be 'cleaned' of the americium. The returned plutonium is in a better condition, ready for further storage or reuse as nuclear fuel."

Filming how our immune system kill bacteria



To kill bacteria in the blood, our immune system relies on nanomachines that can open deadly holes in their targets. UCL scientists have now filmed these nanomachines in action, discovering a key bottleneck in the process which helps to protect our own cells.

The research, published in Nature Communications, provides us with a better understanding of how the immune system kills bacteria and why our own cells remain intact. This may guide the development of new therapies that harness the immune system against bacterial infections, and strategies that repurpose the immune system to act against other rogue cells in the body.

In earlier research, the scientists imaged the hallmarks of attack in live bacteria, showing that the immune system response results in 'bullet holes' spread across the cell envelopes of bacteria. The holes are incredibly small with a diameter of just 10 nanometres.

For this study, the researchers mimicked how these deadly holes are formed by the membrane attack complex (MAC) using a model bacterial surface. By tracking each step of the process, they found that shortly after each hole started to form, the process stalled, offering a reprieve for the body's own cells.

"It appears as if these nanomachines wait a moment, allowing their potential victim to intervene in case it is one of the body's own cells instead of an invading bug, before they deal the killer blow," explained Dr. Edward Parsons (UCL London Centre for Nanotechnology).

Drug-testing device gives false positives on poppy seeds, CBD oil, says Vancouver lawyer

A device the RCMP uses to test driver saliva for drugs is fooled by innocuous substances such as tea or poppy seeds, warns a Vancouver lawyer who tested the device this weekend.

But the maker of the device says the lawyer's tests are misleading and inaccurate. They say the device used for the tests was probably calibrated for different country — not the Canadian version specifically designed to test only for cannabis or cocaine.

The Dräger DrugTest 5000 is being tested as a screening device by officers in places such as Nova Scotia and Manitoba to fight drug-impaired driving.

This device has the potential to test saliva for seven types of the most commonly abused drugs. In Canada it is only used for two drugs — cannabis and cocaine.

It's touted as non-invasive and hassle-free compared to getting blood samples. That sounds like a useful tool for police, with new data from Statistics Canada showing more people getting behind the wheel within a few hours of ingesting or smoking cannabis.

But Kyla Lee of Acumen Law in Vancouver warns that the device is also triggered in some cases by other substances in people's oral fluids.

"People are at risk of being wrongfully arrested," she said.

Lee said people tested positive after they drank certain teas, ate commercially made lemon poppy seed cake or used CBD oil, which has none of the main psychoactive ingredient in cannabis.

"Nobody is getting high on poppy-seed cake! So it's obviously a concern," said Lee.

Space Invaders!