Science News: The origin of neutron-rich heavy elements in the universe remains a mystery. One possible source could be neutron stars, whose high-pressure, high-gravity interiors could stabilize atoms that could not form otherwise. Collisions between neutron stars would then disperse the atoms into space. Because neutron stars are too far away to study, scientists are trying to determine their composition via computer simulations using the properties of exotic isotopes created in particle accelerators. One such isotope, thought to exist in the crust of neutron stars, is zinc-82. Using a facility at CERN, Robert Wolf of the University of Greifswald in Germany and colleagues were able to isolate a pure sample of zinc-82 and determine its mass. By comparing the mass with predictions from computer modeling, the researchers were able to rule out zinc-82 as a constituent of neutron stars. Despite the negative result, the technique shows potential for “pin[ning] down the characteristics of other exotic nuclei that may exist in neutron stars,” writes Andrew Grant for Science News.
Telegraph: To study the way fish think, researchers in Japan genetically modified zebrafish larvae so that neurons in their brains gave off fluorescent green light. Because the larvae are transparent, the activity of their brain cells could then be filmed in real time with a microscope and a camera. The researchers, who watched the fish as they preyed on paramecium, were able to determine which networks of brain cells were involved in hunting behavior. By studying the brains of animals, the scientists seek to gain a better understanding of how the human brain works. Their paper appeared online yesterday in Current Biology.
BBC: A Zenit-3SL rocket, launched earlier today by Sea Launch AG, failed 40 seconds into its flight. The launch was the fifth by the company since 2011, when it had reemerged from bankruptcy—caused by a previous launch failure. Now owned by a Russian consortium, Sea Launch is one of many companies competing to launch geostationary telecommunications satellites. The Zenit-3SL rocket uses a mobile oceanic launch pad, which can be moved to the equator, where Earth’s rotational energy boosts the rocket’s lift capacity. The rocket has a reliable launch record, and the reason for the failure is unknown. It was carrying the Intelsat-27 satellite, a 6.4-ton communications satellite designed by Boeing, which would have helped provide direct-to-home television and internet signals.
Nature: Magnetic resonance imaging (MRI) devices determine the structure of a sample by measuring how its molecules resonate in response to specific wavelengths of electromagnetic radiation. The technique’s spatial resolution is limited, however, by the size of the radiation detector, whose magnetic coils are hard to make smaller than a few micrometers. Now Friedemann Reinhard of the University of Stuttgart in Germany and Daniel Rugar of IBM’s Almaden Research Center in San Jose, California, have each led teams that used defective diamonds to give MRI devices the ability to examine the atomic components of individual molecules. Instead of using a normal diamond with a regular crystal structure, however, both teams created crystals with missing carbon atoms and additional nitrogen atoms. But the teams used the crystals differently. Reinhard’s team placed different samples on the diamonds, measured how nuclear resonance influenced the spin of the electrons in the nitrogen atoms, and found that it was determined by a 5-nm section of the sample. Rugar’s team instead manipulated the electrons of their sample’s hydrogen atoms, which provided more structural information. Reinhard says the next step is to attach the diamond to the tip of a scanning microscope and generate images of the samples.