








I am affronted. No laser badge. No supercomputer badge. No simulation badge. What sort of science scout operation IS this?!
Yes, Julia is at fault for me posting this.
Scientists are now seeing signals that the Sahara desert and surrounding regions are greening due to increasing rainfall.
If sustained, these rains could revitalize drought-ravaged regions, reclaiming them for farming communities.
This desert-shrinking trend is supported by climate models, which predict a return to conditions that turned the Sahara into a lush savanna some 12,000 years ago.
The green shoots of recovery are showing up on satellite images of regions including the Sahel, a semi-desert zone bordering the Sahara to the south that stretches some 2,400 miles (3,860 kilometers).
Images taken between 1982 and 2002 revealed extensive regreening throughout the Sahel, according to a new study in the journal Biogeosciences.
The study suggests huge increases in vegetation in areas including central Chad and western Sudan.
The transition may be occurring because hotter air has more capacity to hold moisture, which in turn creates more rain, said Martin Claussen of the Max Planck Institute for Meteorology in Hamburg, Germany, who was not involved in the new study.
"The water-holding capacity of the air is the main driving force," Claussen said.
He added that the greening trend is supported by other satellite data.
The Fermi Paradox focuses on the existence of advanced civilisations elsewhere in the galaxy. If these civilisations are out there--and many analyses suggest the galaxy should be teaming with life--why haven't we seen them?
Today Carlos Cotta and Álvaro Morales from the University of Malaga in Spain add an another angle to the discussion. One line of thought is the speed at which a sufficiently advanced civilisation could colonise the galaxy. Various analyses suggest that using spacecraft that travel at a tenth of the speed of light, the colonisation wavefront could take some 50 million years to sweep the galaxy. Others have calculated that it may be closer to 13 billion years, which may explain ET's absence.
Cotta and Morales take a different tack by studying how automated probes sent ahead of the colonisation could explore the galaxy. Obviously, this could advance much faster than the colonisation wavefront. The scenario involves a civilisation sending out 8 probes, each equipped with smaller subprobes for studying regions that the host probe visits.
This is not a new scenario. One previous calculation suggests that in about 300 millions years these 8 probes could explore just 4 per cent of the galaxy. The question that Cotta and Morales ask is: what if several advanced civilisations were exploring the galaxy at the same time? Surely, if enough advanced civilisations were exploring simultaneously, one of their probes would end up visiting the solar system. So that fact we haven't seen one places a limit on how many civilisations can be out there.
The numbers that Cotta and Morales come up with depend crucially on the lifetime of the probes doing the exploring (and obviously on the number of probes each civilisations ends out). They say that if each probe has a lifetime of 50 million years and that evidence of them visiting the solar system lasts for about a million years, there can be no more than about 1000 advanced civilisations out there now.
But if these probes can leave evidence of a visit that lasts for 100 million years, then there can be no more than about 10 civilisations out there.
Russian President Dmitry Medvedev on Tuesday called for promoting the development of supercomputers in Russia, ITAR-TASS reported.
"We should stimulate the demand (for supercomputers) in every way not because it's fashionable, but because competitive products can't be created in any other way," he said at a meeting of the Security Council.
Medvedev said he believed that both the government and private businesses should invest in supercomputers. Medvedev also said most government officials and businessmen were not familiar with supercomputer technology and added that businesses often use outdated equipment.
Meanwhile, Arkady Dvorkovich, an assistant to the president, said the government would submit proposals on the development of supercomputers and their unification into a single national grid to the president within six weeks.
Dvorkovich also said a supercomputer with a capacity of 1 petaFLOPS might be created in Russia within 18 months.
Evidence for middle Eocene Arctic sea ice from diatoms and ice-rafted debris
Catherine E. Stickley (1,3)
Kristen St John(2)
Nalân Koç(1,3)
Richard W. Jordan(4)
Sandra Passchier(5)
Richard B. Pearce(6)
Lance E. Kearns(2)
1. Department of Geology, University of Tromsø, N-9037 Tromsø, Norway
2. Department of Geology and Environmental Science, James Madison University, Harrisonburg, Virginia 22807, USA
3. Norwegian Polar Institute, Polar Environmental Centre, N-9296 Tromsø, Norway
4. Department of Earth and Environmental Sciences, Yamagata University, Yamagata 990-8560, Japan
5. Department of Earth and Environmental Studies, Montclair State University, Montclair, New Jersey 07043, USA
6. National Oceanography Centre, Southampton, University of Southampton, Southampton SO14 3ZH, UK
Correspondence to: Catherine E. Stickley1,3 Correspondence and requests for materials should be addressed to C.E.S. (Email: catherine.stickley@npolar.no).
Abstract:
Oceanic sediments from long cores drilled on the Lomonosov ridge, in the central Arctic1, contain ice-rafted debris (IRD) back to the middle Eocene epoch, prompting recent suggestions that ice appeared in the Arctic about 46 million years (Myr) ago2, 3. However, because IRD can be transported by icebergs (derived from land-based ice) and also by sea ice4, IRD records2, 3 are restricted to providing a history of general ice-rafting only. It is critical to differentiate sea ice from glacial (land-based) ice as climate feedback mechanisms vary and global impacts differ between these systems: sea ice directly affects ocean–atmosphere exchanges5, whereas land-based ice affects sea level and consequently ocean acidity6. An earlier report3 assumed that sea ice was prevalent in the middle Eocene Arctic on the basis of IRD, and although somewhat preliminary supportive evidence exists2, these data are neither comprehensive nor quantified. Here we show the presence of middle Eocene Arctic sea ice from an extraordinary abundance of a group of sea-ice-dependent fossil diatoms (Synedropsis spp.). Analysis of quartz grain textural characteristics further supports sea ice as the dominant transporter of IRD at this time. Together with new information on cosmopolitan diatoms and existing IRD records2, our data strongly suggest a two-phase establishment of sea ice: initial episodic formation in marginal shelf areas approx47.5 Myr ago, followed approx0.5 Myr later by the onset of seasonally paced sea-ice formation in offshore areas of the central Arctic. Our data establish a 2-Myr record of sea ice, documenting the transition from a warm, ice-free3 environment to one dominated by winter sea ice at the start of the middle Eocene climatic cooling phase7.
The late Precambrian greening of the Earth
L. Paul Knauth (1)
Martin J. Kennedy (2)
1. School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287-1404, USA
2. Department of Earth Science, University of California, Riverside, Riverside, California 92557, USA
Correspondence to: L. Paul Knauth1 Correspondence and requests for materials should be addressed to L.P.K. (Email: Knauth@asu.edu).
Many aspects of the carbon cycle can be assessed from temporal changes in the 13C/12C ratio of oceanic bicarbonate. 13C/12C can temporarily rise when large amounts of 13C-depleted photosynthetic organic matter are buried at enhanced rates1, and can decrease if phytomass is rapidly oxidized2 or if low 13C is rapidly released from methane clathrates3. Assuming that variations of the marine 13C/12C ratio are directly recorded in carbonate rocks, thousands of carbon isotope analyses of late Precambrian examples have been published to correlate these otherwise undatable strata and to document perturbations to the carbon cycle just before the great expansion of metazoan life. Low 13C/12C in some Neoproterozoic carbonates is considered evidence of carbon cycle perturbations unique to the Precambrian. These include complete oxidation of all organic matter in the ocean2 and complete productivity collapse such that low-13C/12C hydrothermal CO2 becomes the main input of carbon4. Here we compile all published oxygen and carbon isotope data for Neoproterozoic marine carbonates, and consider them in terms of processes known to alter the isotopic composition during transformation of the initial precipitate into limestone/dolostone. We show that the combined oxygen and carbon isotope systematics are identical to those of well-understood Phanerozoic examples that lithified in coastal pore fluids, receiving a large groundwater influx of photosynthetic carbon from terrestrial phytomass. Rather than being perturbations to the carbon cycle, widely reported decreases in 13C/12C in Neoproterozoic carbonates are more easily interpreted in the same way as is done for Phanerozoic examples. This influx of terrestrial carbon is not apparent in carbonates older than approx 850 Myr, so we infer an explosion of photosynthesizing communities on late Precambrian land surfaces. As a result, biotically enhanced weathering generated carbon-bearing soils on a large scale and their detrital sedimentation sequestered carbon5. This facilitated a rise in O2 necessary for the expansion of multicellular life.
Energy Secretary Steven Chu wants to kill research and development on cars that run on hydrogen fuel cells, but a spending bill approved by the House this month and another scheduled for a Senate vote this week would restore funding for the program.
Mr. Chu has said that hydrogen fuel cells are an impractical technology for vehicles, partly because they would require the creation of a network of hydrogen fueling stations.
A Nobel-Prize winning physicist and former director of the Lawrence Berkeley National Laboratory, which conducts federal energy research, Mr. Chu argues that improved internal-combustion engines and plug-in electric vehicles are more realistic technologies for cutting oil consumption over the next 20 to 30 years.
The Late Permian herbivore Suminia and the early evolution of arboreality in terrestrial vertebrate ecosystems
Jorg Frobisch(1)*
Robert R. Reisz(2)
1 Department of Geology, The Field Museum, Chicago, IL 60605, USA
2 Department of Biology, University of Toronto at Mississauga, Mississauga, ON L5L 1C6, Canada
Vertebrates have repeatedly filled and partitioned the terrestrial ecosystem, and have been able to occupy new, previously unexplored habitats throughout their history on land. The arboreal ecospace is particularly important in vertebrate evolution because it provides new food resources and protection from large ground-dwelling predators. We investigated the skeletal anatomy of the Late Permian (approx. 260 Ma) herbivorous synapsid Suminia getmanovi and performed a morphometric analysis of the phalangeal proportions of a great variety of extant and extinct terrestrial and arboreal tetrapods to discern locomotor function and habitat preference in fossil taxa, with special reference to Suminia. The postcranial anatomy of Suminia provides the earliest skeletal evidence for prehensile abilities and arboreality in vertebrates, as indicated by its elongate limbs, intrinsic phalangeal proportions, a divergent first digit and potentially prehensile tail. The morphometric analysis further suggests a differentiation between grasping and clinging morphotypes among arboreal vertebrates, the former displaying elongated proximal phalanges and the latter showing an elongation of the penultimate phalanges. The fossil assemblage that includes Suminia demonstrates that arboreality and resource partitioning occurred shortly after the initial establishment of the modern type of terrestrial vertebrate ecosystems, with a large number of primary consumers and few top predators.
Keywords: Synapsida; Anomodontia; arboreality; terrestrial ecosystem; evolution
Virgin Galactic unveiled a new partnership Tuesday that pushes the throttle forward on its plans for commercial suborbital space travel and a new small satellite launch capacity.
The deal involves Abu Dhabi's Aabar Investments and Virgin Galactic, the commercial spaceliner group bankrolled by British billionaire Sir Richard Branson to fly "pay-per-view" customers to the edge of space.
Specifics of the partnership, which includes Aabar investing $280 million in Virgin Galactic in return for an equity stake, were outlined today at the Experimental Aircraft Association's (EAA) AirVenture convention in Oshkosh, Wisc., which is now under way.
There is a lot of hysteria on the Internet these days that the ancient Mayan calendar, which ends in 2012, portends the end of the world through a variety of possible astronomical events: rogue comets, supernovae, or even supposed "energy" from the galactic center. The reality is that the Mayans simply tracked astronomical cycles. They were not psychic.
This preoccupation with doomsday has inspired science fiction tales depicting the end of Earth, including a recent TV miniseries Impact, and the upcoming motion picture 2012 that is described as "an epic adventure about a global cataclysm that brings an end to the world and tells of the heroic struggle of the survivors."
Today's astronomers don't need the Mayan calendar, or Nostradamus, or Hollywood's imagination to explore the solar system's far future fate. Observations of planets around other stars, combined with stellar evolution theory and supercomputer simulations give us a reasonable prediction of what's in store for the solar system.
As their parent stars inevitability age and burn out, every inhabited planet across our galaxy faces the ultimate apocalypse due to fundamental changes in a star's energy output and its physical diameter.
Yet the emerging view of what happens to planets at the end of a star's life is more complex than scientists once thought. What's more, the ever-shifting fortunes of survivability in the universe suggest one planet's apocalypse may be another world's genesis.
A fossil of a four-legged cat- sized reptile that was found in Germany may be a missing link in the evolution of mammals, palaeontologists said Monday.
The Bromacker stone formation at Tambach-Dietharz in central Germany is one of the world's richest spots for fossils, giving clues to life 300 million years ago before either mammals or dinosaurs walked the earth.
Excavation director Thomas Martens said only the 6-centimetre-long skull of the creature was found, but it was thought to have been a reptile 50 to 70 centimetres long.
'It could be a key stage in the development from reptiles to mammals,' he said.
Scientists have been excavating land vertebrates from the Bromacker for 30 years and have found 40 individuals of 13 species. Martens said the fossils were better preserved than at sites of comparable age in North America and Mexico.
"Russia has to make some very difficult, calculated decisions," Biden told the Wall Street Journal at the end of a four-day trek to Russia and Ukraine. "They have a shrinking population base, they have a withering economy, they have a banking sector and structure that is not likely to be able to withstand the next 15 years, they're in a situation where the world is changing before them and they're clinging to something in the past that is not sustainable."
Conventional wisdom has it that the first animals evolved in the ocean.
Now researchers studying ancient rock samples in South China have found that the first animal fossils are preserved in ancient lake deposits, not in marine sediments as commonly assumed.
These new findings not only raise questions as to where the earliest animals were living, but what factors drove animals to evolve in the first place.
For some 3 billion years, single-celled life forms such as bacteria dominated the planet. Then, roughly 600 million years ago, the first multi-cellular animals appeared on the scene, diversifying rapidly.
The oldest known animal fossils in the world are preserved in South China's Doushantuo Formation. These fossil beds have no adult specimens - instead, many of the fossils appear to be microscopic embryos.
"Our first unusual finding in this region was the abundance of a clay mineral called smectite," said researcher Tom Bristow, now at the California Institute of Technology in Pasadena. "In rocks of this age, smectite is normally transformed into other types of clay. The smectite in these South China rocks, however, underwent no such transformation and have a special chemistry that, for the smectite to form, requires specific conditions in the water - conditions commonly found in salty, alkaline lakes."
The researchers collected hundreds of rock samples from several locations in South China. All their analyses suggest these rocks were not marine sediments.
"Moreover, we found smectite in only some locations in South China, and not uniformly as one would expect for marine deposits," Bristow said. "Taken together, several lines of evidence indicated to us that these early animals lived in a lake environment."
This discovery raises questions as to how and why animals appeared when they did.
"It is most unexpected that these first fossils do not come from marine sediments," said researcher Martin Kennedy, a geologist at the University of California at Riverside.
"Lakes are typically short-lived features on the Earth's surface, and they are not nearly as consistent environments as oceans are," he explained. "So it's surprising that the first evidence of animals we find is associated with lakes, which are far more variable environments than the ocean. You'd expect the first appearance of animals to be in the most conservative, stable environments we could imagine."
It remains possible, Kennedy noted, that animal fossils of similar or older age exist that remain to be found that are marine in origin. However, at the very least, this work suggests "that animals had already taken on the ability to deal with the environmental fluctuations one sees in lake environments," he said. "That suggests that their evolutionary response is much more rapid that I would have supposed, and that the earliest animals were far more diverse than imagined."
If animals did first develop in lakes, one aspect of lake environments that could have spurred on their evolution is how much easier it is for air to percolate through them, given how much shallower they typically are than the ocean.
The newest supercomputer in town is almost 15 times faster than its predecessor and ready to take on problems in areas such as climate science, hydrogen storage and molecular chemistry. The $21.4 million Chinook supercomputer was built by HP, tested by a variety of researchers, and has now been commissioned for use by Pacific Northwest National Laboratory and the Department of Energy.
Housed at EMSL, DOE's Environmental Molecular Sciences Laboratory on the PNNL campus, Chinook can perform more than 160 trillion calculations per second, ranking it in the top 40 fastest computers in the world (see the Top 50). Its predecessor, EMSL's MPP2, could run 11.2 trillion calculations per second.
The Office of Biological and Environmental Research within DOE's Office of Science funded EMSL's supercomputer upgrade. Although housed at the Pacific Northwest National Laboratory, scientists the world over can use Chinook, competing for time through a peer review process. Users generally conduct research that supports the DOE's missions in energy, the environment, or national security.
"When combined with EMSL's experimental capabilities, the new Chinook supercomputer will provide scientists from academia, national laboratories, and industry with an unprecedented research tool," said Anna Palmisano, DOE Associate Director for Biological and Environmental Research. "This new supercomputer will allow scientists to develop a molecular-level understanding of the complex biological, chemical and physical processes that underlie the environmental and energy challenges facing DOE and the nation."
Chinook is fast and dexterous. Its designers tailored its architecture to handle scientific problems whose complexity require more than just power or speed. For example, climate scientists who are trying to understand the tiniest particles in the atmosphere or chemists watching how atoms tug at each other in a molecule need a different kind of supercomputer than physicists studying questions like the birth of the universe.
Chinook's top job is to run NWChem, a computational chemistry program that allows researchers to simulate and predict the chemistry within and between molecules. But a wide variety of programs can run on the supercomputer. Scientists are using Chinook to tackle problems such as:
Gas hydrates: Pockets of fuels such as methane are often found deep under the sea, trapped in a lattice of water molecules. Researchers hope to understand these gas hydrates both as a fuel source and as a way to store fuels. But for such a simple molecule, water has pretty complex chemistry. Researchers are using Chinook to help understand how water molecules form stable clusters. The work also gives researchers insight into how small particles in the air form clouds or break them up.
Bacterial transformers: Communities of bacteria live and grow in the soil. And some bacteria have a taste for metals, a talent that can be used to clean up toxic substances in contaminated ground. Researchers use Chinook to understand the inner workings of these bacteria and how they form communities in order to take advantage of their clean-up skills.
Green plastics: Industrial chemists can turn propane gas into plastics and generate only water as a byproduct with the help of compounds called catalysts. Chinook is helping scientists develop a new catalytic material based on small clusters of platinum atoms that does this at least 40 times more efficiently than older materials.
A few weeks ago, I wrote on this blog about an 1967 MIT study called Project Icarus. The study, performed by MIT students as an exercise in systems engineering, assumed that the mile-wide asteroid Icarus would not merely pass Earth at a distance of four million miles on June 19, 1968, but would instead strike in the Atlantic Ocean east of Bermuda. The resulting big splash would have inundated ocean-front property around the world and cast debris high into the atmosphere, cooling our planet for several years.
I've been thinking about this as a point of departure for an alternate history. What if Icarus actually had been found in early 1967 to be 18 months from a collision with Earth? And, what if the U.S. - probably the only human agency at the time capable of intervening - had made every effort to destroy and/or deflect it?
Among the survivors of FCS’s collapse is the billion-dollar Non-Line-of-Sight Launch System — the so-called “Missile in a Box.” This impressive bit of tech passed an important test at the White Sands test range in New Mexico this week, when one of its 100-pound missiles flew five miles and destroyed a T-72 tank traveling in a convoy of several other vehicles.
Missiles in a Box is a collaboration between Raytheon and Lockheed Martin, doesn’t look like much. Popular Mechanics compared the 1.5-ton launcher to a “Port-O-Potty-size crate.” The individual missiles are packed 15-to-a-box and can be left lying around on the ground, carted around on flat-bed trucks or even installed on the Navy’s shore-hugging Littoral Combat Ships. The launcher stays logged onto a network via the newfangled, “universal” Joint Tactical Radio System. Soldiers, drones or choppers send a target’s coordinates to the launcher, out pops a missile (or five, or 15). The missile gets an update while en route, in case the target is moving — and can even pass back pictures of the bad guys. Each projectile can home in with laser, infrared or GPS guidance, and “dial” its warhead to kill armored or unarmored targets.
The oil and gas that fuels our homes and cars started out as living organisms that died, were compressed, and heated under heavy layers of sediments in the Earth's crust. Scientists have debated for years whether some of these hydrocarbons could also have been created deeper in the Earth and formed without organic matter. Now for the first time, scientists have found that ethane and heavier hydrocarbons can be synthesized under the pressure-temperature conditions of the upper mantle —the layer of Earth under the crust and on top of the core. The research was conducted by scientists at the Carnegie Institution's Geophysical Laboratory, with colleagues from Russia and Sweden, and is published in the July 26, advanced on-line issue of Nature Geoscience.
Methane (CH4) is the main constituent of natural gas, while ethane (C2H6) is used as a petrochemical feedstock. Both of these hydrocarbons, and others associated with fuel, are called saturated hydrocarbons because they have simple, single bonds and are saturated with hydrogen. Using a diamond anvil cell and a laser heat source, the scientists first subjected methane to pressures exceeding 20 thousand times the atmospheric pressure at sea level and temperatures ranging from 1,300 F° to over 2,240 F°. These conditions mimic those found 40 to 95 miles deep inside the Earth. The methane reacted and formed ethane, propane, butane, molecular hydrogen, and graphite. The scientists then subjected ethane to the same conditions and it produced methane. The transformations suggest heavier hydrocarbons could exist deep down. The reversibility implies that the synthesis of saturated hydrocarbons is thermodynamically controlled and does not require organic matter.
The scientists ruled out the possibility that catalysts used as part of the experimental apparatus were at work, but they acknowledge that catalysts could be involved in the deep Earth with its mix of compounds.
It's been just a little over two months since Rackable Systems acquired SGI and merged the two product lines. From all appearances, it has been a fairly smooth transition. A lot of that has to do with the fact that the new company has left both sets of product offerings intact, although the future "Ultraviolet" system will change that somewhat. I'll get to that plot line in a moment.
According to Geoffrey Noer, senior director of product marketing at SGI, they "have not discontinued any of the products and have no immediate plans to do so." The product continuity is a reflection of the company's intent to combine Rackable's established customers in the Internet/cloud computing space with SGI's strength in the high performance computing market. Even before the merger deal, Rackable was looking at the HPC technical and federal government markets as a way to grow the business. Now that they have the SGI Altix products in tow, they get to those markets by default.
[...]
the next generation shared memory system will be based on the new Ultraviolet architecture. That design will use Intel Nehalem EX chips along with the next generation NUMAlink interconnect. Presumably this means the future "Tukwila" quad-core Itanium chips will never find a home at SGI. Although the 4700 line will continue to be offered for some period of time, the idea is to eventually migrate all the current users to the new architecture. "The intention is that Ultraviolet is the future of the shared memory systems line," says Noer.
According to him, more information about Ultraviolet will be publicly revealed later this year (although SGI customers have been privy to some of the details for awhile now). I would expect to see the introduction of the first new machines coincident with Intel's release of the Nehalem EX processors, which probably means early 2010.
A 17-member team has found what may be the smoking gun of a much-debated proposal that a cosmic impact about 12,900 years ago ripped through North America and drove multiple species into extinction.
In a paper appearing online ahead of regular publication in the Proceedings of the National Academy of Sciences, University of Oregon archaeologist Douglas J. Kennett and colleagues from nine institutions and three private research companies report the presence of shock-synthesized hexagonal diamonds in 12,900-year-old sediments on the Northern Channel Islands off the southern California coast.
These tiny diamonds and diamond clusters were buried deeply below four meters of sediment. They date to the end of Clovis -- a Paleoindian culture long thought to be North America's first human inhabitants. The nano-sized diamonds were pulled from Arlington Canyon on the island of Santa Rosa that had once been joined with three other Northern Channel Islands in a landmass known as Santarosae.
The diamonds were found in association with soot, which forms in extremely hot fires, and they suggest associated regional wildfires, based on nearby environmental records.
Such soot and diamonds are rare in the geological record. They were found in sediment dating to massive asteroid impacts 65 million years ago in a layer widely known as the K-T Boundary. The thin layer of iridium-and-quartz-rich sediment dates to the transition of the Cretaceous and Tertiary periods, which mark the end of the Mesozoic Era and the beginning of the Cenozoic Era.
"The type of diamond we have found -- Lonsdaleite -- is a shock-synthesized mineral defined by its hexagonal crystalline structure. It forms under very high temperatures and pressures consistent with a cosmic impact," Kennett said. "These diamonds have only been found thus far in meteorites and impact craters on Earth and appear to be the strongest indicator yet of a significant cosmic impact [during Clovis]."
The age of this event also matches the extinction of the pygmy mammoth on the Northern Channel Islands, as well as numerous other North American mammals, including the horse, which Europeans later reintroduced. In all, an estimated 35 mammal and 19 bird genera became extinct near the end of the Pleistocene with some of them occurring very close in time to the proposed cosmic impact, first reported in October 2007 in PNAS.
In the Jan. 2, 2009, issue of the journal Science, a team led by Kennett reported the discovery of billions of nanometer-sized diamonds concentrated in sediments -- weighing from about 10 to 2,700 parts per billion -- in six North American locations.
"This site, this layer with hexagonal diamonds, is also associated with other types of diamonds and with dramatic environmental changes and wildfires," said James Kennett, paleoceanographer and professor emeritus in the Department of Earth Science at the University of California, Santa Barbara.
"There was a major event 12,900 years ago," he said. "It is hard to explain this assemblage of materials without a cosmic impact event and associated extensive wildfires. This hypothesis fits with the abrupt cooling of the atmosphere as shown in the record of ocean drilling of the Santa Barbara Channel. The cooling resulted when dust from the high-pressure, high-temperature, multiple impacts was lofted into the atmosphere, causing a dramatic drop in solar radiation."
The Amazon River originated as a transcontinental river around 11 million years ago and took its present shape approximately 2.4 million years ago. These are the most significant results of a study on two boreholes drilled in proximity of the mouth of the Amazon River by Petrobras, the national oil company of Brazil. A team from the Institute for Biodiversity and Ecosystem Dynamics (IBED) of the University of Amsterdam, the University of Liverpool and Petrobras used this new oceanic data to reconstruct the history of the Amazon River. The study was published in the scientific journal Geology in July 2009.
Hundreds of tiny footprints left by mammals some 190 million years ago have been found on a canyon wall in a remote part of Dinosaur National Monument, park officials said Thursday.
The tracks are a rare find, mostly because they were left at a time when the area was a hostile, vast Sahara-like desert where towering sand dunes seldom preserved signs of animal life.
“It’s just astonishing,” Dan Chure, a paleontologist at the monument, said Thursday. “We were giggling like kids.”
He and paleontologist George Engelmann of the University of Nebraska at Omaha spotted the tracks July 8 while scouring the area for fossils and other evidence from the early Jurassic period. Dinosaur National Monument, founded because of its rich and plentiful supply of dinosaur bones, straddles the Utah-Colorado border.
Most of the tracks are the size of a dime or smaller. A few include impressions of up to four toes. The mammals — perhaps the size of a rat — were among the few species that were able to survive between large sand dune fields where there was water, dinosaurs and a few plants, Chure said.
Because they were living in a forbidding desert environment, most animals probably came out at night, including the small mammals who left the tracks, Chure said. He said it’s reasonable to assume the tracks were preserved by a layer of moisture that created a slight crust on the dune and kept the prints from blowing away.
The U.S. House Natural Resources Committee gave the green light Wednesday to Resident Commissioner Pedro Pierluisi’s status bill, clearing the way for the measure to pass to the full House for a vote.
The bill was cleared in a voice vote among members of the committee, which has jurisdiction over Puerto Rico issues. It is the second status bill passed by the panel in as many years. The other, a measure co-authored by then-Resident Commissioner Luis Fortuño and U.S. Rep. José Serrano, D-N.Y., was blocked from reaching the House floor by House Speaker Nancy Pelosi citing a lack of consensus.
Pierluisi’s four-page HR-2499, also known as the Puerto Rico Democracy Act of 2009, authorizes the island government to hold a referendum in which voters will choose whether they think Puerto Rico should continue its current status. If voters choose that Puerto Rico keep the same status, then the local government is authorized to hold a vote every eight years to determine if public opinion has changed.
If voters say they want a change in status, then a second vote would be held in which voters can choose between statehood, independence and a third option of sovereignty in association with the United States that is not subject to the territorial clause.
The commonwealth supporting Popular Democratic Party is staunchly against the bill, arguing it is skewed toward statehood. The Puerto Rican Independence Party has argued that the lack of consensus on the mechanism to resolve status among island political parties has doomed Pierluisi’s bill to failure.
Pelosi has said that status legislation needs “consensus” among Puerto Rican Democrats in the House in order to move forward. President Barack Obama has said he supports resolving the island’s status dilemma during his first term in office.
The wound that ultimately killed a Neandertal man between 50,000 and 75,000 years was most likely caused by a thrown spear, the kind modern humans used but Neandertals did not, according to Duke University-led research.
"What we've got is a rib injury, with any number of scenarios that could explain it," said Steven Churchill, an associate professor of evolutionary anthropology at Duke. "We're not suggesting there was a blitzkrieg, with modern humans marching across the land and executing the Neandertals. I want to say that loud and clear."
But Churchill's analysis indicates the wound was from a thrown spear, and it appears that modern humans had a thrown-weapons technology and Neandertals didn't. "We think the best explanation for this injury is a projectile weapon, and given who had those and who didn't that implies at least one act of inter-species aggression."
Churchill is the first author of a new report now posted online in the Journal of Human Evolution on the long-ago incident in what is now Iraq. He and four other investigators used a specially calibrated crossbow, copies of ancient stone points and numerous animal carcasses to make their deductions.
Neandertals, stoutly-built and human-like, lived at the same time and in the same areas as some modern humans before going extinct. Anthropologists have been puzzling over Neandertal's fate for many years, proposing that perhaps they inter-bred with modern humans, failed to compete for food or resources, or were possibly hunted to extinction by the humans.
While narrowing the range of possible causes for the Iraqi Neandertal's wound, and raising the possibility of an encounter between humans and a now-extinct close cousin, the research does not definitively conclude who did it, or why.
The victim was one of nine Neandertals discovered between 1953 and 1960 in a cave in northeastern Iraq's Zagros Mountains. Now called "Shanidar 3," he was a 40- to 50-year-old male with signs of arthritis and a sharp, deep slice in his left ninth rib.
The wounded Neandertal's rib had apparently started healing before he died. Comparing the wound to medical records from the American Civil War, a time before modern antibiotics, suggested to the researchers that he died within weeks of the injury, perhaps due to associated lung damage from a stabbing or piercing wound.
"People have been speculating about that rib injury for going on 50 years now," Churchill said. "Some said it was interpersonal violence. Others said it could have been an accident. Did it involve only Neandertals? Now we, for the first time, have brought some experimental evidence to bear on these questions."
Last year, U.S. Special Operations Command quietly began taking delivery of 10 Boeing-built Hummingbird robotic helicopters, and outfitting them for two-gigapixel spy cameras, foliage-penetrating radars, small guided missiles and even 800-pound-capacity cargo pods.
Now the command has announced it will buy another 10 Hummingbirds, re-designated MQ-18, by 2017 — and deploy three of them to an “undisclosed location” next year, according to British aviation magazine Air Forces Monthly. But it’s a safe bet that the undisclosed location is west of Pakistan, east of Iran, south of the former Soviet Union and crawling with Taliban. A small fleet of quiet, lethal robots, each with a 30-hour endurance and a bunch of equipment options, could come in quite handy there.
The tremendous diversity of life continues to puzzle scientists, long after the 200 years since Charles Darwin's birth. However, in recent years, consistent patterns of biodiversity have been identified over space, time organism type and geographical region.
Two views of the process of "speciation" -- the evolutionary process by which new biological species arise -- dominates evolutionary theory. The first requires a physical barrier such as a glacier, mountain or body of water to separate organisms enabling groups to diverge until they become separate species. In the second, an environment favors specific characteristics within a species, which encourages divergence as members fill different roles in an ecosystem.
In a new study, "Global patterns of speciation and diversity," just published in Nature, Les Kaufman, Boston University professor of biology and associate director of the BU Marine Program along with a team of researchers from The New England Complex Systems Institute, have collaborated and found a way to settle the debate which deals with the origin of species independent of geographic isolation.
They demonstrated, using a computer model, how diverse species can arise from the arrangement of organisms across an area, without any influence from geographical barriers or even natural selection. Over generations, the genetic distance between organisms in different regions increases, the study noted. Organisms spontaneously form groups that can no longer mate resulting in a patchwork of species across the area. Thus the number of species increases rapidly until it reaches a relatively steady state.
"Our biodiversity results provide additional evidence that species diversity arises without specific physical barriers," the study states.
The computer simulations, the authors, note showed the distribution of species formed patterns similar to those that have occurred with real organisms all around the world.
"The model we put forward in the paper lays the groundwork for more powerful tests of the role played by natural and sexual selection, as well as habitat complexity in shaping the patterns of biological diversity that we see around us today," said Kaufman. Our insights can be applied to the immense challenge that we now face -- not only to prevent the extinction of a large chunk of life, but also to prevent ourselves from quenching the very forces that fuel the continuous creation of new life forms on earth."
This study is also the fourth in a series from The New England Complex Systems Institute on the role of complexity in species coexistence and evolutionary diversification.
Fujitsu Ltd. alone will build Japan's next-generation supercomputer after its two partners withdrew from a government-sponsored project to develop the computer for the Institute of Physical and Chemical Research, Fujitsu and the institute said Friday.
The independent administrative institution known as RIKEN has decided to employ Fujitsu's scalar processing architecture for the supercomputer as NEC Corp. and Hitachi Ltd. (NYSE:HIT) have withdrawn from an earlier attempt to combine their vector architecture with the Fujitsu system, they said.
As originally planned, Fujitsu and RIKEN said they will complete the supercomputer at a facility in Kobe, Hyogo Prefecture, by fiscal 2012 ending in March 2013 under the 115.4 billion yen project. The total cost is expected to top the planned level.
The supercomputer is designed to use a 128-gigaflop central processing unit, the world's fastest at present, to achieve the world's highest performance of 10 petaflops.
When the Russian government adopted a program several years ago intended to boost the country’s low birthrate, some commentators worried that it would increase that rate among non-Russians where it was already high and do little to raise it among ethnic Russians where the current fertility rate is far below replacement levels.
And while there has been some anecdotal evidence that the “maternal capital” program has led to an increase in the number of births, if not the fertility rate, among ethnic Russians, there are indications the program may be working just as these commentators feared and leading to an increase in both the total number of births and the fertility rate among non-Russians.
Given the increasing acceptability in Russia of openly nationalist arguments, some Russians, including at least one scholar at the Russian Academy of Sciences, are now prepared to argue in public and without apology that the Russian government should provide monetary assistance only to women of ethnic Russian nationality.
Were Moscow to follow such advice, it would be violating the Russian constitution and setting the stage for a new and possibly more violent set of inter-ethnic conflicts. But even proposals to take this step from ostensibly “respectable” sources, especially if they are not immediately denounced, will further exacerbate ethnic tensions in the Russian Federation.
Today, Vladimir Lavrov, the deputy director of the Institute of Russian History of the Russian Academy of Sciences, told a meeting of the World Russian Peoples Assembly in Yekaterinburg that the government should pay subsidies only to ethnic Russian women who give birth and not to anyone else.
According to Lavrov, “the Russian nation is the state forming state, and its fall threatens terrible conflicts like those which took place in Kondopoga and Kosovo.” The “salvation of the nation,” he continued, requires the saving of the [ethnic] Russian family and boosting the willingness of [ethnic] Russian couples to have children.
The academic historian sharply criticized the current system of giving out what the Russian government calls “maternal capital” to women without regard to their ethnic background. In fact, some of the posters advertising this program feature women with “non-Russian” images. Lavrov said any funds must go “only to mothers of Russian nationality.”
By accurately modeling Earth's last major global warming — and answering pressing questions about its causes — scientists led by a University of Wisconsin-Madison climatologist are unraveling the intricacies of the kind of abrupt climate shifts that may occur in the future.
"We want to know what will happen in the future, especially if the climate will change abruptly," says Zhengyu Liu, a UW-Madison professor of atmospheric and oceanic sciences and director of the Center for Climatic Research in the Nelson Institute for Environmental Studies. "The problem is, you don't know if your model is right for this kind of change. The important thing is validating your model."
To do so, Liu and his colleagues run their mode back in time and match the results of the climate simulation with the physical evidence of past climate.
Starting with the last glacial maximum about 21,000 years ago, Liu's team simulated atmospheric and oceanic conditions through what scientists call the Bølling-Allerød warming, the Earth's last major temperature hike, which occurred about 14,500 years ago. The simulation fell in close agreement with conditions — temperatures, sea levels and glacial coverage — collected from fossil and geologic records.
"It's our most serious attempt to simulate this last major global warming event, and it's a validation of the model itself, as well," Liu says.
The results of the new climate modeling experiments are presented today (July 17) in the journal Science.
The group's simulations were executed on "Phoenix" and "Jaguar," a pair of Cray supercomputers at Oak Ridge National Laboratory in Oak Ridge, Tenn., and helped pin down the contributions of three environmental factors as drivers of the Bølling-Allerød warming: an increase in atmospheric carbon dioxide, the jump-start of stalled heat-moving ocean currents and a large buildup of subsurface heat in the ocean while those currents were dormant.
The climate dominoes began to fall during that period after glaciers reached their maximum coverage, blanketing most of North America, Liu explains. As glaciers melted, massive quantities of water poured into the North Atlantic, lowering the ocean salinity that helps power a major convection current that acts like a conveyor belt to carry warm tropical surface water north and cooler, heavier subsurface water south.
As a result, according to the model, ocean circulation stopped. Without warm tropical water streaming north, the North Atlantic cooled and heat backed up in southern waters. Subsequently, glacial melt slowed or stopped as well, and eventually restarted the overturning current — which had a much larger reserve of heat to haul north.
"All that stored heat is released like a volcano, and poured out over decades," Liu explains. "That warmed up Greenland and melted (arctic) sea ice."
The model showed a 15-degree Celsius increase in average temperatures in Greenland and a 5-meter increase in sea level over just a few centuries, findings that squared neatly with the climate of the period as represented in the physical record.
"Being able to successfully simulate thousands of years of past climate for the first time with a comprehensive climate model is a major scientific achievement," notes Bette Otto-Bliesner, an atmospheric scientist and climate modeler at National Center for Atmospheric Research (NCAR) and co-author of the Science report. "This is an important step toward better understanding how the world's climate could change abruptly over the coming centuries with increasing melting of the ice caps."
The rate of ice melt during the Bølling-Allerød warming is still at issue, but its consequences are not, Liu says. The modelers simulated both a slow decrease in melt and a sudden end to melt run-off. In both cases, the result was a 15-degree warming.
"That happened in the past," Liu says. "The question is, in the future, if you have a global warming and Greenland melts, will it happen again?"
A new study of 30 million year old fossil 'mega-dung' from extinct giant South American mammals reveals evidence of complex ecological interactions and theft of dung-beetles' food stores by other animals.
[...]
f the modern dung beetle deserves praise for these global sanitation efforts, then the extinct dung beetles of ancient South America deserve a medal. 30 million years ago the continent was home to what is known to palaeontologists as the South America Megafauna, including some truly giant extinct herbivores: bone covered armadillos the size of a small car, ground sloths 6 metres tall and elephant-sized hoofed-mammals unlike anything alive today. And of course, megafauna would have produced mega-dung! The beetles certainly had their work cut out for them and although the dung-beetles themselves did not fossilize, we know they were fully engaged in business because, amazingly, the results of their activities are preserved as fossil dung balls, some more than 40 million years old, and some as large as tennis balls.
Now palaeontologists in Argentina studying these dung balls have discovered that they have even more to tell us about the ecology of this lost world of giant mammals, but at a rather different scale. In a study published in the latest issue of the journal Palaeontology, Graduate Student Victoria Sánchez and Dr Jorge Genise report traces made by other creatures within fossil dung balls.
"Some of these are just the results of chance interactions" explains Dr Sánchez. "Burrowing bees, for example, dug cells in the ground where the dung balls were buried, and some of these happen to have been dug into the balls. But other traces record the behaviour of animals actively stealing the food resources set aside by the dung beetles. The shapes and sizes of these fossilized burrows and borings in the dung balls indicate that other beetles, flies and earthworms were the culprits. Although none of these animals is preserved in these rocks, the fossil dung balls preserve in amazing detail a whole dung-based ecosystem going on right under the noses of the giant herbivores of 30 million years ago."