Daily Mail: The puzzling correlation between the mass of a galaxy’s central black hole and the number of stars in the galaxy may be explained by streams of fast-moving, highly ionized gas emitted from the black hole’s accretion disk. Francesco Tombesi of NASA’s Goddard Space Flight Center examined data gathered from the European Space Agency’s XMM-Newton x-ray observatory and discovered that these streams, called ultrafast outflows, exert a powerful influence on the number of stars in galaxies and the size of black holes at their center. The outflows establish a feedback mechanism in the host galaxy by taking material from around the black hole and ejecting it at speeds of up to 100 000 km/s. The ejected material would otherwise have been used in star formation or fallen into the black hole. Removing it limits both the size of the black hole and the number of stars in the galactic center.
BBC: Contrary to previous estimates, which suggested that the bite of a Tyrannosaurus rex was comparable to that of modern predators, the dinosaur’s bite exerted 3–6 tons of force, or 10 times the force of an alligator bite. Karl Bates of the University of Liverpool and Peter Falkingham of the University of Manchester created three-dimensional scans of an adult and a juvenile T. Rex, then mapped the muscles onto the scanned images. By digitally manipulating the muscles in the image, they were able to replicate the animal’s bite. Bates and Falkingham’s findings are published in Biology Letters.
Nature: Croatia’s system for funding science is in desperate need of renovation, writes Mićo Tatalović for Nature. Chief complaints are that it is overly centralized and it funds too many grant applicants instead of focusing on only the best. In addition, the last round of grants was issued in 2007 and that funding has now run out. To address those issues, newly elected science minister Željko Jovanović has set up an international advisory board to help develop the science and higher-education systems and is collaborating on a new science strategy with the Croatian Academy of Sciences and Arts in Zagreb. The next funding call will take place this summer, and by the end of the year, the ministry hopes to return to parliament three laws on science and higher education. After a period of stagnation, there is now “wide consensus that quick and efficient changes are necessary,” said Saša Zelenika, assistant minister of science.
Science: Because leatherback sea turtles are endangered, a group of researchers at Stanford University has started looking at their migratory patterns to try to determine ways to protect the aquatic reptiles. The group’s results have been published in Proceedings of the Royal Society B. Adult sea turtles lay their eggs on Costa Rican beaches along the eastern Pacific Ocean. Once hatched, the babies make their way to the sea. Because young turtles are too small to carry tracking devices, marine biologist George Shillinger and colleagues decided to focus on the ocean currents instead. They used computer simulations to study the movement of the water, and they placed virtual floating markers to simulate the swimming turtles. Apparently, the currents off Playa Grande in Costa Rica can take the turtles the farthest, nearly 1500 kilometers into the deep sea; the simulated turtles launched from beaches farther to the north and south barely left the shoreline. More work needs to be done, however, because currents are only one factor. Although the turtle simulations float, real turtles paddle and may go in directions the computer simulations can’t predict.
Science: A potential construction delay for ITER, the international fusion reactor, has been resolved. Tests run last year had determined that the superconducting cables, which generate the magnetic fields holding the superheated plasma in place at the heart of the machine, were lasting only one-tenth as long as needed. Three individual strands less than a millimeter across are wound together to form a triplet, and 288 triplets are combined to form a cable. Japan, the country responsible for providing the cables, made its triplets from two strands of niobium–tin and one of copper. The niobium–tin carries the current, and the copper provides an alternate path if the niobium–tin suddenly loses its superconducting ability, a process called quenching. Because only two-thirds of the cable then bears the load in normal operation, the cable degrades faster than planned. When ITER researchers combined copper and niobium–tin into a single strand, however, they found that the cables lasted almost twice as long as previously. The cables have proven to be only one of a number of stumbling blocks along the way, however. Last year’s earthquake and tsunami in Japan had already caused ITER’s scheduled start to be pushed back to 2020. And financial trouble could be ahead because the US government has just cut its promised funds.
Nature: Researchers at the Delft University of Technology in the Netherlands may be the first to have detected the long-sought Majorana fermion, which acts as its own antiparticle. Majorana fermions are not necessarily individual particles like electrons or protons. Quasiparticles—collective excitations of groups of particles—can also qualify as Majorana fermions. Leo Kouwenhoven presented the group’s findings yesterday at the American Physical Society’s March meeting in Boston. In their apparatus, the researchers connected indium antimonide nanowires to a circuit with a gold contact at one end and a slice of superconductor at the other. They then exposed the nanowires to a moderately strong magnetic field. Their measurements of the nanowires’ electrical conductance showed a peak at zero voltage that is consistent with the formation of a pair of Majorana quasiparticles, one at either end of the region of the nanowire in contact with the superconductor, writes Eugenie Samuel Reich for Nature. If the Majorana fermions the group created prove to be sufficiently long-lived, they could serve as the bits in quantum computers.
BBC: A group of researchers at IBM Research Zurich used Kelvin probe force microscopy, a variant of atomic force microscopy, to capture the intricate dance of electrons in a complex molecule. They scanned a tiny bar with a charged tip across the surface of a much larger, X-shaped molecule, naphthalocyanine. When the charged tip reacted to charges within the naphthalocyanine, the researchers were able to determine the locations of the electrons and even observe when two hydrogen atoms at the center swapped places and the electrons reshuffled themselves. The technique could prove important for the building of atomic- and molecular-scale devices. Indeed, naphthalocyanine is among the molecules being considered as a building block for molecular computing. Fabian Mohn and colleagues published their results in Nature Nanotechnology.
New York Times: Envia Systems in California announced today that it had made a major advance regarding electric vehicles—a more powerful and less expensive lithium-ion battery. At half the current cost, the new cells will have an energy density almost three times greater than conventional automotive cells. To develop such a battery, Envia was awarded $4 million in late 2009 by the US Department of Energy’s Advanced Research Projects Agency–Energy program. One of the company’s innovations is its use of manganese in the cathode, which stores more energy per unit of mass. When the cathode delivers more energy, fewer cells are needed, which results in a less-expensive battery. Another benefit of lighter batteries is extended range, because cars can carry more of them. “If it’s true, it’s a huge breakthrough, because the main problem for battery cars has been cost,” said David Cole, chairman emeritus of the nonprofit Center for Automotive Research in Michigan, in an interview with Jim Motavalli for the New York Times.
New York Times: From New York City to Washington, DC, to Chicago, plants and flowering bulbs are bursting out two to four weeks ahead of schedule, writes Lisa Foderaro for the New York Times. Although many people in the US are enjoying an unusually early spring, a mild winter is not necessarily good for plants. Buds and blooms may be triggered too early and suffer if temperatures suddenly plunge. Pollinators such as honeybees may not be ready to get to work yet, which can affect crop yield. Because the ground isn’t frozen, hungry squirrels start digging up the bulbs, and destructive insects get started ahead of schedule. Also, milder winters mean a more gradual, possibly less spectacular, spring—and evoke the issue of global warming. “This winter, when they do the final analysis, will be close to an all-time record breaker,” said David Wolfe, a professor of plant and soil ecology at Cornell University and an expert on climate change. “It’s a rare event. But I think it will become less rare.”
BBC: From about AD 250 to 800, Mayan civilization, which thrived in what is now southern Mexico and Guatemala, developed a culturally sophisticated empire made up of several independent city-states. Between AD 800 and 900, however, large-scale architectural construction ceased and the civilization went into lengthy decline, although Mayan civilization overall continued until the Spanish conquered the last city-state, Tayasal, in 1697. Many reasons for the decline have been proposed, ranging from severe drought to trade route collapse. Eelco Rohling of Southampton University in the UK and Martin Medina-Elizalde of the Yucatan Center for Scientific Research in Mexico have published a study in Science in which they suggest that a sustained but relatively mild drought was the cause. Using quantitative analysis to examine the paleoclimate records of the event, they were able to estimate rainfall and evaporation rates between AD 800 and 950. They found that a reduction of 25–40% in rainfall was enough to deplete the Mayan freshwater storage systems.