Researchers from the University of Toronto Mississauga have found evidence that one of the reasons carnivorous theropod dinosaurs, like Tyrannosaurus rex, were such successful predators was due to the unique structure of their teeth.
The Canadian researchers found that T-Rex and related dinosaurs’ teeth were deeply serrated or saw-like in structure, giving them the ability to effortlessly chomp on the bones and rip the flesh of larger animals and reptiles.
Their uniquely structured teeth helped the theropods to become the terrifying predators that ruled the prehistoric world for about 165 million years.
A team of astronomers studying an exploding star have discovered the chemical element lithium for the first time within material ejected by a bright nova located in the constellation Centaurus.
The team made their discovery through observations of Nova Centauri 2013 made with telescopes at the European Southern Observatory’s La Silla Observatory, near Santiago in Chile.
According to the researchers, this discovery may help explain why so many young stars have more of this element than is expected.
The discovery is thought to provide clues to astronomers who are trying to get an understanding of the chemical elements that make up the stars in our Milky Way galaxy.
Scientists say lithium happens to be one of the few chemical elements that were created by the Big Bang some 13.8 billion years ago.
Researchers from the University of Vermont have verified that land located beneath the Chesapeake Bay is rapidly sinking, leading them to predict that Washington, D.C., could drop 15 centimeters or more within the next century.
It’s thought that dropping land beneath the U.S. capital city could add to problems related to a forecasted rise in sea-level due to melting ice sheets and climate change.
Geologists have thought for decades that the land surrounding the Chesapeake Bay once pushed upward by the mass of a pre-historic ice sheet is now settling back down since the ice has long since melted.
The University of Vermont team pointed out that their data indicates that the land sinking around the Washington area is not primarily due to human-related activities such as the removal of groundwater. Instead, they find that it is due to a long and drawn out geological process that will relentlessly continue for tens of thousands of years, regardless of human land use or climate change.
New research from Australia’s University of Adelaide has provided evidence that plants, which don’t have a nervous system like animals, send out animal-like signals when they’re under some kind of stress.
The findings, published in the journal Nature Communications, shows that plants respond to stress in their environment with a similar combination of chemical and electrical signals emitted by animals under stress, by using mechanisms that are specific to plants.
“We’ve known for a long-time that the animal neurotransmitter GABA (gamma-aminobutyric acid) is produced by plants under stress, for example when they encounter drought, salinity, viruses, acidic soils or extreme temperatures,” said senior author Associate Professor Matthew Gilliham, of the University’s School of Agriculture, Food and Wine.
Gilliham said that he and his team found that plants bind the GABA to receptors in a similar way as animals which produces electrical signals that wind up regulating plant growth whenever it is exposed to a stressful environment.
Previous research has suggested that both the thickness and extent of Arctic summer sea ice have dramatically declined over the past 30 years. The data includes measurements taken by the National Snow and Ice Data Center in Boulder, Colorado.
But now, some British scientists have found the volume of Arctic sea ice has actually increased by a third after 2013’s unusually cool summer. That’s the conclusion of a new study conducted by researchers at University College London and the University of Leeds, and published in the journal Nature.
Rachel Tilling, the study’s lead author from the Center for Polar Observation and Modelling at the University College London, said that the much cooler temperatures in the summer of 2013 were more like those recorded back in the late 1990s.
“This allowed thick sea ice to persist northwest of Greenland because there were fewer days when it could melt,” she said in a press release. “Although models have suggested that the volume of Arctic sea ice is in long-term decline, we know now that it can recover by a significant amount if the melting season is cut short.”
In an email to Science World, Julienne Stroeve, a research scientist at the National Snow and Ice Data Center, said she is “very cautious about these results (of the UK study)” because much of the processing used in the study was not well-described, which makes it difficult for others to fully reproduce their results. However, Stroeve said she doesn’t doubt that the overall Arctic ice thickness was larger in 2013 and 2014 than in 2012, because not as much ice melted.
According to the Nature study, the sudden increase in sea ice volume after just one cool summer suggests that Arctic sea ice may be more resilient than has been previously considered.
Stroeve doesn’t quite agree. “I think the statement that sea ice is more resilient is a bit premature as it’s based on only 5 years of data, and it does not take into account variable precipitation as they assume climatological snow depth,” she said.
To make their findings, the British researchers used measurements taken by the European Space Agency’s CryoSat satellite between 2010 and 2014, as well as maps of sea ice extent.
CryoSat’s primary instrument, according to ESA’s website, is the Synthetic Aperture Interferometric Radar Altimeter. It was designed to meet the measurement requirements for ice-sheet elevation and the height of sea ice protruding from the water.
Stroeve says that one does not measure ice thickness directly with radar or a laser altimeter. “You need to also know snow depth and density, both of which are not known over the Arctic Ocean,” she says.
Professor Andrew Shepherd, Director of Center for Polar Observation and Modelling said that while it is doubtful the Arctic region will be ice-free this summer, due to the jump in sea ice volume, temperatures are expected to rise again in the future. He likens the effects of the cool summer of 2013 as simply “winding the clock back a few years” on long-term Arctic sea ice decline.
“Understanding what controls the amount of Arctic sea ice takes us one step closer to making reliable predictions of how long it will last, which is important because it is a key component of Earth’s climate system,” he says.
The researchers said that they are planning to use CryoSat’s measurements of changing sea ice thickness not only to help improve models that are used to forecast future climate change, but also to help sailors steer their ships in the potentially dangerous Arctic region.
Fear that a floating piece of space junk could impact the ISS sent astronauts the station’s crew scrambling onto a docked Soyuz TMA-16M spacecraft on Friday (07/17). Luckily, the debris passed the station harmlessly, and the crew was back at work.
Houston’s Mission Control was tracking a chunk of what used to be a weather satellite when they noticed that it was headed to toward the space station for possible impact Thursday (07/16) at 1201 UTC.
Food has always been scarce for polar bears, but the quickening loss of sea ice during the summer months could lead to even less food available.
While the bears have certain amount of stored energy, a new study suggests they may not be able to rely on that reserve to get them through the melt season. The bears also can reduce the amount of energy they use to help prolong their supply of stored energy, but the study indicates it isn’t enough to make up for any food shortages they experience during the summer.
A new study from the California Institute of Technology (Caltech) has found that blood-feeding mosquitoes have evolved to where they can use three senses to zero-in on the human or animal host for their next meal.
Many insects, including mosquitoes, are drawn in by the odor of carbon dioxide released by humans and other animals when they exhale. But, the study found mosquitoes can also use their vision to see their host and detect body heat with their thermal sensory abilities.
Climate scientists from NASA’s Jet Propulsion Laboratory (JPL) and UCLA, who studied ocean temperatures, have found that some of the heat generated by greenhouse gases has been trapped and held beneath the surface of the Pacific and Indian Oceans.
The researchers suggest this may explain the slowdown in the rise of global surface temperatures that have been observed over the past decade.
They found a layer beneath the surface Pacific and Indian Oceans, located between 91 and 305 meters, is gathering more heat than previously observed. According to the researchers, movement of the warm subsurface ocean water has produced an unusually cooler surface which in turn has also cooled the air temperature above.
Professional astronomers with help from amateur stargazers have discovered a fascinating binary star system containing a very hot and dense white dwarf that is actually devouring its larger companion star.
Named Gaia-14aae, the rare star system is located some 730 light years away from Earth in the Draco constellation.
Another factor that sets this star system apart from others is that it contains a large amount of helium but no hydrogen, which is very strange since hydrogen is the most common element in the Universe.
While most binary systems consist of two stars orbiting a common center of mass, V404 Cygni is made up of a black hole and a star that orbit each other, with the black hole devouring matter from its companion.
In a system like V404 Cygni, material from the star pours out, heads toward the black hole and collects in an accretion disk, a circular object made of material that gathers around a black hole.
The incredibly powerful gravity produced by the black hole heats the disk and causes it to brilliantly shine at optical, ultraviolet and X-ray wavelengths until it spirals into the black hole and disappears.
But not all of the disk material winds up in the black hole. Scientists said some of it is ejected in the form of two powerful jets of particles
Once detected, the unexpected blast of extremely high frequency radiation then activated the satellite’s X-ray telescope to begin its observations of V404 Cygni.
A short time later, an X-ray flare originating from the same area as V404 Cygni was spotted by MAXI – Monitor of All-sky X-ray Image, part of the International Space Station’s Japanese Experiment Module.
The initial flurry of interest then set off a series of observations from ground-based and space telescopes around the world to monitor the black hole and its companion star at a variety of wavelengths that span the electromagnetic spectrum.
Erik Kuulkers, Integral project scientist at the European Space Agency (ESA), said V404 Cygni’s current behavior astonishes him and his colleagues, particularly its recurring flashes of bright light that last for less than an hour – something rarely seen in other black hole systems.
“In these moments, it becomes the brightest object in the X-ray sky – up to 50 times brighter than the Crab Nebula, normally one of the brightest sources in the high-energy sky,” said Kuulkers in an ESA press release.
Scientists said the last time the V404 Cygni system was as active and bright was back in 1989, when it was observed with the Japanese X-ray satellite Ginga, along with high-energy instruments mounted aboard the Mir space station.
Following that period of activity, the binary system began to quiet down again, allowing astronomers to finally see the black hole’s companion star, which had been obscured by the bright light produced by the outburst.
Referring back to the archival data gathered during the 20th century by various optical telescopes, astronomers found two previous outbursts. One occurred in 1938 and the other in 1956.
Scientists believe that the outbursts are triggered once the sheer amount of material within the surrounding accretion disk forces the black hole to dramatically increase its feeding mechanism – an event that takes place every two or three decades, said the scientists.
“Now that this extreme object has woken up again, we are all eager to learn more about the engine that powers the outburst we are observing,” said Carlo Ferrigno from the Integral Science Data Center at the University of Geneva, Switzerland.