Lifeboat Foundation

This is the best estimate scientists have made for the size of the invisible Higgs sector. The next step is to collect more data and hone their techniques to narrow in on these invisible decays.

“It’s like looking at something very small,” Rifki says. “Right now, we can’t see anything other than what we already know. But that doesn’t mean there is nothing new there. It could just mean that we need a more powerful lens.”

Lindert sees this collaboration as a good example of what theorists and experimentalists can accomplish when they combine their skills and work together.

Summary: Two key metrics of signal detection theory, perceptual certainty and response bias, correlate with changes in cognitive fatigue.

Source: Kessler Foundation.

A team of New Jersey researchers has shown that changes in perceptual certainty and response bias, two central metrics of signal detection theory (SDT), correlate with changes in cognitive fatigue. They also show that SDT measures change as a function of changes in brain activation.

A step towards ultra-precise measurements of antihydrogen.

These two constraints are so fundamental that it would be difficult to formulate a consistent understanding of nature without them. Nevertheless, it is worth testing whether they really hold up in ultra-precise measurements carried out using the most modern technologies, because any deviation, however small, would force scientists to radically rethink the basis of our theories of physics. Writing in Nature, Baker et al.¹ (members of the ALPHA collaboration) report a major step towards this goal. They have slowed down atoms of antihydrogen — the antimatter counterpart of hydrogen — to unprecedentedly low velocities by bathing them in a beam of ultraviolet laser light. This could allow measurements of the atoms to be made with exceptionally high precision.

Antihydrogen is the simplest stable atom that consists only of antimatter particles, namely an antiproton and an antielectron (a positron). Measurements of antihydrogen therefore provide an ideal way to test the symmetry between matter and antimatter, but such experiments present formidable obstacles. In 1995, 11 antihydrogen atoms were produced from reactions in a particle accelerator at CERN, Europe’s particle-physics laboratory near Geneva, Switzerland, and hurtled down a 10-metre-long vacuum tube at nine-tenths of the speed of light². Each atom existed for barely a few tens of nanoseconds before being destroyed by striking a particle detector.

Continue reading “Antimatter cooled by laser light” »

SpaceX’s new Starlink satellite internet service is being touted as a rural internet game changer. WSJ spent time with a few beta testers in a very remote area of Washington state to see if it’s truly the solution to the global broadband gap. Photo Illustration: Laura Kammermann.

Glass, rubber and plastics all belong to a class of matter called amorphous solids. And in spite of how common they are in our everyday lives, amorphous solids have long posed a challenge to scientists.

Since the 1910s, scientists have been able to map in 3D the atomic structures of crystals, the other major class of solids, which has led to myriad advances in physics, chemistry, biology, materials science, geology, nanoscience, drug discovery and more. But because amorphous solids aren’t assembled in rigid, repetitive atomic structures like crystals are, they have defied researchers’ ability to determine their atomic structure with the same level of precision.

Until now, that is.

The team found that feeding mice a high fat diet disrupted the circuit, which led not only to weight gain but also to signs of anxiety and depression on standard behavioral tests.

When the researchers used genetic techniques to restore the normal functioning of nerve receptors in the circuit, this resulted in weight loss and eliminated the animals’ signs of anxiety and depression.

A recent study in mice has found that eating a high fat diet may disrupt a newly discovered neural circuit that affects both mood and appetite.

Continue reading “Faulty brain circuit helps explain obesity–depression link” »

This genetic connection caught many scientists off guard, and it remains “one of the most intriguing and poorly understood events in human history,” the researchers wrote in the new study.

To investigate the Y signal further, a team of scientists in Brazil and Spain dove into a large dataset containing the genetic data of 383 Indigenous people from different parts of South America. The team applied statistical methods to test whether any of the Native American populations had “excess” genetic similarity with a group they called the Australasians, or Indigenous peoples from Australia, Melanesia, New Guinea and the Andaman Islands in the Indian Ocean.

In other words, the team was assessing whether “a given Native American population shared significantly more genetic variants with Australasians than other Native Americans do,” Hünemeier and Araújo Castro e Silva said. South American groups that did have more genetic similarities with Australasians were interpreted by the new researchers as being descendants of the first Americans and Australasian ancestors, who coupled together at least 15000 years ago.

A team of researchers from the Harbin Institute of Technology along with partners at the First Affiliated Hospital of Harbin Medical University, both in China, has developed a tiny robot that can ferry cancer drugs through the blood-brain barrier (BBB) without setting off an immune reaction. In their paper published in the journal Science Robotics, the group describes their robot and tests with mice. Junsun Hwang and Hongsoo Choi, with the Daegu Gyeongbuk Institute of Science and Technology in Korea, have published a Focus piece in the same journal issue on the work done by the team in China.

For many years, medical scientists have sought ways to deliver drugs to the brain to treat health conditions such as brain cancers. Because the brain is protected by the skull, it is extremely difficult to inject them directly. Researchers have also been stymied in their efforts by the BBB—a filtering mechanism in the capillaries that supply blood to the brain and spinal cord that blocks foreign substances from entering. Thus, simply injecting drugs into the bloodstream is not an option. In this new effort, the researchers used a defense cell type that naturally passes through the BBB to carry drugs to the brain.

To build their tiny robots, the researchers exposed groups of white blood cells called neutrophils to tiny bits of magnetic nanogel particles coated with fragments of E. coli material. Upon exposure, the neutrophils naturally encased the tiny robots, believing them to be nothing but E. coli bacteria. The microrobots were then injected into the bloodstream of a test mouse with a cancerous tumor. The team then applied a magnetic field to the robots to direct them through the BBB, where they were not attacked, as the immune system identified them as normal neutrophils, and into the brain and the tumor. Once there, the robots released their cancer-fighting drugs.

A breakthrough in synthetic biology could shed new light on mechanisms controlling the most basic processes of life.