Saturday, February 28, 2015
Friday, February 27, 2015
Augmented reality provides a live view of the real world with computer generated elements superimposed. Pilots have long used head-up displays to access air speed data and other parameters while they fly. Some smartphone cameras can superimpose computer-generated characters on to the view of the real world. And emerging technologies such as Google Glass aim to superimpose useful information on to a real world view, such as navigation directions and personal data.
But there’s a related problem that most people will not yet have considered. Imagine wearing a virtual reality headset and that you are immersed in a virtual world quite unlike the physical one around you. Now suppose you want to take a sip of water from a cup on the desk in front of you.
The only way to succeed is by feeling your way to the cup while still immersed in the virtual world or by removing the virtual reality headset and returning to the physical world. Neither of these is particularly good, say Pulkit Budhiraja and pals at the University of Illinois at Urbana-Champaign, who have come up with a solution.
These guys have been testing ways of superimposing physical reality onto a virtual reality experience. The goal is to find a way to allow users to interact with real physical objects while they remain immersed in a virtual world—a kind of augmented virtual reality
Budhiraja and co began by modifying an Oculus Rift virtual reality headset with a pair of cameras that produce a stereo view of the real world in front of the headset. They then came up with four different ways of superimposing the real world images onto the virtual world for the task of picking up and drinking from a cup, while remaining immersed.
Suppose you see a beautiful table in a museum and you would like to have the same one at home. What could you do? One strategy is to accurately measure all its properties — its form (length, height and width) and its appearance (material and colour) — and then reproduce an identical copy for your living room. But this 'measure-and-reproduce' strategy would fail if the table were a quantum particle, such as a photon or an electron orbiting an atomic nucleus. The no-cloning theorem of quantum mechanics tells us that it is impossible to copy such a particle perfectly. On page 516 of this issue, Wang et al. show how to get around this apparent limitation of quantum physics. In a beautiful extension of previous experiments, they demonstrate how to transfer the values of two properties of a photon — the spin angular momentum (the direction of the photon's electric field, generally referred to as polarization) and the orbital angular momentum (which depends on the field distribution) — through quantum teleportation onto another photon.
A prototype quantum radar that has the potential to detect objects which are invisible to conventional systems has been developed by an international research team led by a quantum information scientist at the University of York.
The new breed of radar is a hybrid system that uses quantum correlation between microwave and optical beams to detect objects of low reflectivity such as cancer cells or aircraft with a stealth capability. Because the quantum radar operates at much lower energies than conventional systems, it has the long-term potential for a range of applications in biomedicine including non-invasive NMR scans.
The research team led by Dr Stefano Pirandola, of the University's Department of Computer Science and the York Centre for Quantum Technologies, found that a special converter - a double-cavity device that couples the microwave beam to an optical beam using a nano-mechanical oscillator - was the key to the new system.
The device can either generate microwave-optical entanglement (during the signal emission) or convert a microwave into an optical beam (during the collection of the reflection beams from the object). The research is published in Physical Review Letters.
A new type of methane-based, oxygen-free life form that can metabolize and reproduce similar to life on Earth has been modeled by a team of Cornell University researchers.
Taking a simultaneously imaginative and rigidly scientific view, chemical engineers and astronomers offer a template for life that could thrive in a harsh, cold world - specifically Titan, the giant moon of Saturn. A planetary body awash with seas not of water, but of liquid methane, Titan could harbor methane-based, oxygen-free cells.
Their theorized cell membrane, composed of small organic nitrogen compounds and capable of functioning in liquid methane temperatures of 292 degrees below zero, is published in Science Advances, Feb. 27. The work is led by chemical molecular dynamics expert Paulette Clancy and first author James Stevenson, a graduate student in chemical engineering. The paper's co-author is Jonathan Lunine, director for Cornell's Center for Radiophysics and Space Research.
There is no geo-strategic relationship of more importance than that of the U.S. and China. Yet, tensions between Washington and Beijing over the last few years have been building. Over the last few weeks I have been exploring on these pages some of the pathways the unthinkable could happen: a U.S.-China war. We have also been exploring the various paths to victory both sides could utilize. While all of this is important, it is also important to take a step back and look at the U.S.-China relationship from another viewpoint of equal and possibly even greater value—a dilemma in the relationship that is creating its own set of tensions: the budding high-tech security dilemma pitting Washington and Beijing against one another.
While both sides have benefitted from decades of fruitful economic, cultural, and diplomatic ties since the restoration of formal relations in the 1970s, the dynamic of this important relationship is becoming increasingly competitive. Due to a host of factors such as the loss of a common foe (the Soviet Union), existing Asia-Pacific alliance dynamics, economic competition, territorial claims and counterclaims in the East and South China Sea and the rapid deployment of advanced conventional weapons platforms on both sides Washington and Beijing find themselves in an increasingly dangerous security dilemma.
Completing development of the classified Long-Range Strike Bomber (LRS-B) programme is essential to the US nuclear deterrent because of the advanced age of the US Air Force's (USAF's) existing bomber fleets, the military official responsible for US strategic deterrence said on 26 February.
"Our air leg is supported today by the B-2 and the B-52 aircraft," said US Strategic Command (STRATCOM) chief Admiral Cecil Haney during a House Armed Services Committee hearing. "The B-52, which was last off the assembly line in 1962, will be used out until at least the 2040 time period. It is very important we invest in the long-range bomber."
It’s a problem the US Navy wants to have, but it’s still a problem. If the service gets enough money both to build its top priority, the Ohio Replacement Program nuclear missile submarine, and to keep producing its vaunted Virginia-class attack subs, then so much new work will be hitting the shipyards so rapidly that they’ll be hard-pressed to ramp up production fast enough.
There are just two shipyards in the country that can build nuclear-powered submarines, Virginia’s Newport News and New England’s Electric Boat, which along with their network of specialized suppliers have recently ramped up to building two Virginias a year. But the Navy wants to start buying a bigger, more powerful, and correspondingly harder-to-build version of the Virginia no later than 2019. Then in 2021, the Navy will officially start its first Ohio replacement. That’s not just another sub: “An Ohio is about twice a Virginia in terms of the workload,” Assistant Secretary of the Navy Sean Stackley told reporters yesterday.
“It’s a fairly steep growth [in production] compared to what it’s been in the past 10 to 20 years, absolutely, ” Stackley said when I pressed him on the point.
Is it a potential bottleneck in production?
Rocky shore taphonomy—A comparative study of modern and Late Cretaceous analogues
Sørensen et al
Rocky shores are rare in the fossil record due to erosion under both sea-level rise and fall. In contrast, modern rocky shores are well-studied, but little is known about the evolution of their ecosystems due to the rarity of ancient counterparts. Reconstruction of these ancient ecosystems is thus essential to get an insight into their evolution. A high-diversity Late Cretaceous (Campanian) rocky shore fauna is found in southern Sweden. The original composition of the shelly fauna cannot be interpreted by direct examination of the preserved fauna due to the effects of taphonomic processes. Life and death assemblages from a modern rocky shore fauna from Thailand have previously been analysed and a hypothetical fossil assemblage was reconstructed in order to attempt an interpretation of the Campanian life assemblage. This study shows a low taxonomic agreement between the original Campanian life assemblage and the fossil assemblage, due to taphonomic processes, and high environmental fidelity with only a few out-of-habitat species represented. The modern life assemblage showed in an earlier study, a high loss of species before onset of fossilisation. This suggests that the faunal composition of the Campanian life assemblage cannot be easily reconstructed, and time averaging by generations of death assemblages makes this even more difficult. The Campanian aragonitic fauna is poorly represented and the rarity of moulds after aragonitic species is interpreted as due to taphonomic processes and not to lower richness of aragonitic species in the Cretaceous. This is supported by comparison with the high richness of aragonitic species found on a Late Cretaceous rocky shore in Germany. An originally high-diversity gastropod fauna is thus interpreted to have dominated the intertidal zone in the Campanian example, and the rare moulds of each of the aragonitic species indicate a high taphonomic loss in spite of rapid burial. Calcitic species-richness is higher in the Campanian fauna than in the modern life, death, and constructed hypothetical fossil assemblages. This is interpreted as reflecting time averaging of generations of calcitic species and low loss of calcitic species by taphonomic processes in the Campanian fauna. It is thus assumed that the original Campanian fauna experienced a change in faunal composition from a gastropod-dominated life assemblage to a bivalve-dominated fossil assemblage due to dissolution of aragonite and excellent preservation of calcite. Reconstruction of ancient rocky shore shelly faunas can thus be considerably improved by comparison with analogous modern rocky shore faunas.
Linking Europa's plume activity to tides, tectonics, and liquid water
Rhoden et al
Much of the geologic activity preserved on Europa's icy surface has been attributed to tidal deformation, mainly due to Europa's eccentric orbit. Although the surface is geologically young (30 - 80 Myr), there is little information as to whether tidally-driven surface processes are ongoing. However, a recent detection of water vapor near Europa's south pole suggests that it may be geologically active. Initial observations indicated that Europa's plume eruptions are time-variable and may be linked to its tidal cycle. Saturn's moon, Enceladus, which shares many similar traits with Europa, displays tidally-modulated plume eruptions, which bolstered this interpretation. However, additional observations of Europa at the same time in its orbit failed to yield a plume detection, casting doubt on the tidal control hypothesis. The purpose of this study is to analyze the timing of plume eruptions within the context of Europa's tidal cycle to determine whether such a link exists and examine the inferred similarities and differences between plume activity on Europa and Enceladus.
In the 16th century, during its conquest of South America, the Spanish Empire forced countless Incas to work extracting silver from the mountaintop mines of Potosí, in what is now Bolivia--then the largest source of silver in the world. The Inca already knew how to refine silver, but in 1572 the Spanish introduced a new technology that boosted production many times over and sent thick clouds of lead dust rising over the Andes for the first time in history.
Winds carried some of that pollution 500 miles northwest into Peru, where tiny remnants of it settled on the Quelccaya Ice Cap.
There it stayed--buried under hundreds of years of snow and ice--until researchers from The Ohio State University found it in 2003.
In the early online edition of the Proceedings of the National Academy of Sciences, they report discovery of a layer within a Quelccaya ice core that dates to the Spanish conquest of the Inca, contains bits of lead and bears the chemical signature of the silver mines of Potosí.
The core provides the first detailed record of widespread human-produced air pollution in South America from before the industrial revolution, and makes Quelccaya one of only a few select sites on the planet where the pre-industrial human impact on air quality can be studied today.
"This evidence supports the idea that human impact on the environment was widespread even before the industrial revolution," said Paolo Gabrielli, a research scientist at the Byrd Polar and Climate Research Center at Ohio State and corresponding author of the study.
Lonnie Thompson, Distinguished University Professor of earth sciences at Ohio State and co-author of the study, called the find "another keyhole into the past of human activity in that part of the world," and suggested that further investigation could ultimately help us better understand the fate of pollution circulating in the atmosphere today.
Previously, Thompson has called the Quelccaya ice cores a "Rosetta Stone" for gauging Earth's climate history. The samples were cut from ice that formed over 1,200 years as snow settled on the Peruvian Andes. Layer by layer, the ice captured chemicals from the air and precipitation during wet and dry seasons for all those years. Today, researchers analyze the chemistry of different layers to measure historical changes in climate.
For this study, the researchers used a mass spectrometer to measure the amount and type of chemicals present in the ice dating back to 800 AD. They looked for antimony, arsenic, bismuth, molybdenum and especially lead. That's because the refining process that the Spanish introduced to South America involved grinding silver ore--which contains much more lead than silver--into powder before mixing it with mercury in a process called amalgamation. So atmospheric pollution from silver production would chiefly contain traces of lead particulates.
The mass spectrometer revealed some spikes in the concentrations of these elements in the years before Spanish rule, but those layers all likely coincide with natural contamination sources, such as volcanic eruptions. Starting just before 1600, however, the Quelccaya ice began capturing much larger quantities of these elements, and the high amounts persisted until the early 1800s, when South American countries declared independence from Spain.
A new species of Ichthyosaurus from the Lower Jurassic of West Dorset, England, U.K.
Lomax et al
We describe a new species of Lower Jurassic (Hettangian/Sinemurian–Pliensbachian) ichthyosaur, Ichthyosaurus anningae, sp. nov., from west Dorset, England, U.K. The holotype of I. anningae (DONMG:1983.98), at least a subadult, is from the lower Pliensbachian Stonebarrow Marl Member (Charmouth Mudstone Formation). It is the most complete ichthyosaur known from this time interval worldwide. The species is assigned to Ichthyosaurus on the basis of humerus, forefin, and pectoral girdle morphologies. Diagnostic features of the species include a short, robust humerus with prominent processes; a femur in which the proximal width is almost as large as the distal width; and a very small femur relative to the humerus (humerus/femur ratio >1.7). Four other specimens, at least three of which are juveniles, are referred to this species. The new species may display sexual dimorphism in humeral morphology, but this cannot be confirmed due to a lack of stratigraphic information. With the recognition of I. anningae, at least three and possibly as many as five ichthyosaur species, representing three genera, are known from the Pliensbachian.
New material of the biomineralizing tubular fossil Sinotubulites from the late Ediacaran Dengying Formation, South China
Cai et al
Sinotubulites is a late Ediacaran biomineralizing tubular fossil with a probable animal affinity. It is characterized by millimeter- to centimeter-sized and multi-layered tubes open at both ends. The tube consists of two morphologically different walls: a multi-layered inner wall with weak ornamentations and a multi-layered outer wall with transverse or oblique corrugations and sometimes longitudinal ridges. The majority of previously published Sinotubulites species are considered as synonymous with the type species: S. baimatuoensis. Three new species—S. triangularis n. sp., S. pentacarinalis n. sp., and S. hexagonus n. sp.—are reported from the late Ediacaran Beiwan Member of the Dengying Formation in southern Shaanxi Province, South China. The three new species are similar to the type species in having nested, multilayered inner and outer tube walls. However, they are different in their polygonal cross sections and longitudinal ridges. S. baimatuoensis is more or less circular in cross section and lack longitudinal ridges on the outer tube wall, whereas S. triangularis, S. pentacarinalis, and S. hexagonus are respectively triangular, pentagonal, and hexagonal in cross section with three, five, and six longitudinal ridges on the exterior surface of the outer wall. The new material adds to the diversity of late Ediacaran biomineralizing animals. The triradial, pentaradial, and hexaradial tubes of S. triangularis, S. pentacarinalis, and S. hexagonus share some intriguing similarities in body symmetry with some early Cambrian tubular fossils, although these Cambrian tubes are not open at both ends. Still, it would be interesting to explore the tantalizing possibility of evolutionary continuity of triradial, pentaradial, and hexaradial tubular animals across the Precambrian–Cambrian boundary.
Thursday, February 26, 2015
The population of Japan is ageing, and fewer children being born. This creates a variety of problems -- not the least of which is a shortage of caregivers for the elderly, as the elderly population grows while the younger population shrinks. To help compensate, the country has been exploring a different solution: robots.
In the case of research institute RIKEN, cuddly teddy bear-faced robots that can lift and carry a mobility impaired patient, or help them stand and provide a support to lean on while walking.
ROBEAR is actually the third iteration of the bear-faced bots, the first and second of which were named RIBA and RIBA-II respectively -- although none have arrived on the market yet.
"The polar cub-like look is aimed at radiating an atmosphere of strength, geniality and cleanliness at the same time," research team leader Toshiharu Mukai told AFP. "We voted for this design among options presented by our designer. We hope to commercialise the robot in the not-too distant future."
There is little doubt that some of the world’s largest corporations are investigating 3D printing as a means to both make and save money across the board. Amazon, for example, has slowly been inching its way into the space, partnering with several key companies, including Mixee Labs, to offer customizable 3D printed products to their customers.link.
As the world’s leading ecommerce provider, Amazon seems to stay ahead of the curve when it comes to selling us anything from printer paper to giant $1 million robots. Thus far, it appears as if the company’s decision to enter the 3D printing space has paid off, as they continue to expand the program in both scale and scope.
If you know much about Amazon, then you know that they obsess with getting products to consumers as fast as physically possible. In fact, they have recently launched One-Hour Delivery in Manhattan, and is pushing for delivery via drones. Usually though, the faster a product is shipped, the more money it will cost the company that is shipping it, and ultimately this comes back to the consumer. For example, Amazon needs to stock literally millions of products at warehouse hubs as close to their customers as possible. Warehouse space is not cheap, especially when considering the millions of square feet needed by a company like Amazon.
What if Amazon could avoid same of these storage costs and get items to users even faster with the use of new, rapidly advancing technologies like 3D printing? Well, that’s just what they are looking into.
Late last week United States Patent and Trademark Office published a patent filing by Amazon Technologies, Inc. which outlines a method of 3D printing on-demand within mobile manufacturing hubs. According to Amazon, such a setup could save the company time and money on several fronts.
The multiplicity of items offered may require the electronic marketplace owner/operator to maintain a large inventory requiring sufficient space to store the inventory,” states the filing. “An electronic marketplace may also face the challenge of time delays related to the process of finding the selected item among a large inventory. Increased space to store additional inventory may raise costs for the electronic marketplace. Additionally, time delays between receiving an order and shipping the item to the customer may reduce customer satisfaction and affect revenues generated. Accordingly, an electronic marketplace may find it desirable to decrease the amount of warehouse or inventory storage space needed, to reduce the amount of time consumed between receiving an order and delivering the item to the customer, or both.”
By utilizing ‘mobile manufacturing apparatuses Amazon would be able to send an STL file to a mobile unit that’s closest to a customer, providing it with instructions to print out an item which was ordered. When the item has been completed, it could then be within miles of the customer who ordered it and quickly delivered or picked up.
Working with colleagues from Deakin University and CSIRO (Commonwealth Scientific and Industrial Research Organisation), researchers from Australia's Monash University have created the world's first 3D-printed jet engine. While they were at it, they created the world's second one, too. One of them is currently on display at the International Air Show in Avalon, Australia, while the other can be seen at the headquarters of French aerospace company Microturbo, in Toulouse.
A team from the Monash Centre for Additive Manufacturing and spin-off company Amaero started with an older gas turbine engine contributed by Microturbo. Still in working order, the small engine was used for auxiliary power in aircraft such as the Falcon 20 business jet.
Led by Prof. Xinhua Wu, the team proceeded to take the engine apart, and scan all the individual components. Using computer models obtained from those scans, a laser sintering process was then utilized to selectively melt metal alloy powder, building up two copies of each component in successive layers. When those parts were subsequently assembled, two metal replicas of the original engine were produced.
One of the more exciting ideas in high energy physics is the possibility that our three-dimensional universe is embedded in a much bigger multidimensional cosmos. Physicists call these embedded universes “branes” and say that it should be possible for stuff from our brane to leak into other branes nearby and vice versa.
Today, Michael Sarrazin at the University of Namur in Belgium and a few pals say they have worked out to detect this leakage by measuring whether neutrons can bypass barriers by leaping into another brane and back again.
These guys are proposing to measure this effect by placing a neutron detector close to a nuclear reactor to see whether neutrons appear unexpectedly as a result of being transported out of the reactor via another braneworld.
Researchers at the Department of Energy's Oak Ridge National Laboratory have developed a population distribution model that provides unprecedented county-level predictions of where people will live in the U.S. in the coming decades.
Initially developed to assist in the siting of new energy infrastructure, the team's model has a broad range of implications from urban planning to climate change adaptation. The study is published in the journal Proceedings of the National Academy of Sciences.
"We do a census every 10 years because those data help us do long-term socioeconomic planning," said Budhendra Bhaduri, who leads ORNL's Geographic Information Science and Technology group. "Population projection numbers are important, but many pressing societal needs also require an understanding of where people are going to be. This has always been a challenge; we've never had a good method to make future projections spatially explicit."
The new model builds on years of research in the development of two other ORNL technologies that supply geographical distribution of population: LandScan Global provides one-kilometer resolution for the world and LandScan USA provides 90-meter resolution for the U.S. Incorporating regional variables such as land cover, slope, distances to larger cities, roads and population movement allowed the researchers to refine future population distributions by county.
"We took the U.S. national population total and downscaled to the county level to examine how local population growths vary geographically," said ORNL's Jacob McKee, the study's lead author.
In the study's projections for 2030 and 2050, the researchers set constraints for each contiguous U.S. county under a business-as-usual scenario based on historical conditions. The team's analysis of this scenario found that sprawl growth was projected to be most prevalent in the following counties: El Dorado, CA, Maricopa, AZ, and Riverside, CA.
Despite notable differences in appearance and governance, ancient human settlements function in much the same way as modern cities, according to new findings by researchers at the Santa Fe Institute and the University of Colorado Boulder.
Previous research has shown that as modern cities grow in population, so do their efficiencies and productivity. A city's population outpaces its development of urban infrastructure, for example, and its production of goods and services outpaces its population. What's more, these patterns exhibit a surprising degree of mathematical regularity and predictability, a phenomenon called "urban scaling."
But has this always been the case?
SFI Professor Luis Bettencourt researches urban dynamics as a lead investigator of SFI's Cities, Scaling, and Sustainability research program. When he gave a talk in 2013 on urban scaling theory, Scott Ortman, now an assistant professor in the Department of Anthropology at CU Boulder and a former Institute Omidyar Fellow, noted that the trends Bettencourt described were not particular to modern times. Their discussion prompted a research project on the effects of city size through history.
To test their ideas, the team examined archaeological data from the Basin of Mexico (what is now Mexico City and nearby regions). In the 1960s -- before Mexico City's population exploded -- surveyors examined all its ancient settlements, spanning 2000 years and four cultural eras in pre-contact Mesoamerica.
Using this data, the research team analyzed the dimensions of hundreds of ancient temples and thousands of ancient houses to estimate populations and densities, size and construction rates of monuments and buildings, and intensity of site use.
While New Delhi negotiates for a small share of Sukhoi T-50 development, its defense ministry engineers prepare a fighter that would be 80% Indian.The designers have now frozen the configuration of a proposed medium-weight Indian fighter that they expect to fly early in the 2020s. General Electric is the preferred supplier of propulsion for the twin-engine, stealthy Advanced Medium Combat Aircraft (AMCA).
Launched from a fixed ALE-47 Countermeasures Dispense System, the HAPS Kill Vehicle (KV) was able to perform pitch maneuvers and fly to a detonation point that simulated the location of an incoming rocket-propelled grenade (RPG).
The HAPS system consists of an Engagement Management Module, a slightly-modified Counter Measures Dispense System, such as the ALE-47, and the KVs that launch from the counter-measures dispenser.
If it works for helicopters, you can bet it can for tanks. Whoa nelly then!
The Navy is looking into the feasibility of accelerating design and development work on the Virginia Payload Module (VPM) in case the service decides to begin production earlier than the 2019 planned start, Navy acquisition chief Sean Stackley said Wednesday at a House Armed Services Committee (HASC) hearing.
The VPM will add 28 missile tubes to Block V Virginia-class attack submarines (SSN-774), to provide more strike capability from undersea as the fleet prepares to lose the Ohio-class SSGN guided missile submarine fleet in the mid-2020s. The Navy planned to start VPM construction in conjunction with the next Virginia-class multiyear contract in 2019, but Stackley said that the SSGNs represent a 600-missile capacity and that sooner is better when it comes to rebuilding that strike capacity.
Stackley told the HASC seapower and projection forces subcommittee that he had spoken to the Program Executive Office for Submarines and to the submarine industrial base “to take a look at, can we in fact complete those design and development activities earlier than the 2019 timeframe to give the Navy and the nation the option to determine whether or not we want to advance Virginia Payload Modules earlier than the submarine build cycle.”
“We’re looking at first, can we pull [design and development] to the left a year, and the other aspect is what would be our ability to increase the rate of production of VPMs beyond one per year, which is in our current long-range plan.,” Stackley later elaborated. “Affordability comes into play, industrial base capacity comes into play.”
He said the discussions were ongoing and he would know by March or April what the options were in terms of accelerating VPM progress, though subcommittee chairman Rep. Randy Forbes (R-Va.) pressed for the information sooner to help inform ongoing budget discussions in Congress.
Record of Albian to early Cenomanian environmental perturbation in the eastern sub-equatorial Pacific
Navarro-Ramirez et al
The present paper documents and discusses a new Albian–early Cenomanian carbon isotope (δ13Ccarb and δ13Corg) curve from the subequatorial Eastern Pacific in Peru. Chemostratigraphic evidences for the expression of the OAE1b set and for OAE1c and OAE1d are presented. This dataset is relevant inasmuch as previous work is strongly biased towards study sites in North America (Western Interior Basin), in Europe (Tethys) and the Pacific realm. A comparison of the carbon isotope stratigraphy obtained in Peru with published sections from the Central and Western Pacific, the Western Atlantic and Northern and Western Tethys reveals an overall good agreement supporting the global nature of the isotope patterns described here. The δ13C from Peru record is constrained by biostratigraphic evidence and 87Sr/86Sr isotope stratigraphy using well-preserved oyster shells. Furthermore, we document the development of a heterozoan epeiric-neritic mixed carbonate-siliciclastic ramp in the Western Platform of Peru and its corresponding sedimentary facies associations. This dataset was used to elucidate the complex interplay of climatic changes, nutrient supply, and platform drowning, leading to the following conclusions: (i) An upper Aptian–lower Albian major change from siliciclastic-dominated to carbonate sedimentation coincided with the impact of the Kilian Level. (ii) A lower Albian incipient platform drowning linked to the impact of the Paquier Level. (iii) A lower middle Albian major demise of neritic carbonate production that coincides with the Leenhardt Level, followed by middle Albian condensed sedimentation that reports prominent negative values in δ13Ccarb prior to the onset of OAE1c. (4) Finally, renewed carbonate ramp production during the upper Albian–lower Cenomanian. The data shown here represent the foundation for future work documenting the mid–Cretaceous of Peru and its implications for the palaeoceanography of the SE subequatorial Pacific.
Record-breaking storm activity on Uranus in 2014
de Pater et al
In spite of an expected decline in convective activity following the 2007 equinox of Uranus, eight sizable storms were detected on the planet with the near-infrared camera NIRC2, coupled to the adaptive optics system, on the 10-m W.M. Keck telescope on UT 5 and 6 August 2014. All storms were on Uranus’ northern hemisphere, including the brightest storm ever seen in this planet at 2.2 μm, reflecting 30% as much light as the rest of the planet at this wavelength. The storm was at a planetocentric latitude of ∼15°N and reached altitudes of ∼330 mbar, well above the regular uppermost cloud layer (methane-ice) in the atmosphere. A cloud feature at a latitude of 32°N, that was deeper in the atmosphere (near ∼2 bar), was later seen by amateur astronomers. We also present images returned from our HST ToO program, that shows both of these cloud features. We further report the first detection of a long-awaited haze over the north polar region.
Monkeys are notoriously curious, and new research has quantified just how eager they are to gain new information, even if there are not immediate benefits. The findings offer insights into how a certain part of the brain shared by monkeys and humans plays a role in decision making, and perhaps even in some disorders and addictions in humans.
The study, by researchers at the University of Rochester and Columbia University, shows that rhesus macaques have such robust curiosity that they are willing to give up a surprisingly large portion of a potential prize in order to quickly find out if they selected the winning option at a game of chance.
A new metriorhynchoid (Crocodylomorpha, Thalattosuchia) from the Middle Jurassic of Oregon and the evolutionary timing of marine adaptations in thalattosuchian crocodylomorphs
Metriorhynchid thalattosuchians represent the most extreme archosaurian adaptation to the marine realm. Metriorhynchids possess aquatic adaptations throughout the skeleton. These adaptations were so extensive that some have suggested that they lost the ability to move on land, yet their evolutionary timing remains unresolved. The closest relatives of the metriorhynchoids, the teleosauroids, lack these aquatic adaptations, and the earliest metriorhynchoids are known exclusively from cranial material. Here I describe a partial skull with associated forelimb elements of a new marine crocodylomorph, Zoneait nargorum, gen. et sp. nov., of Aalenian–Bajocian age from the Snowshoe Formation of east-central Oregon. Phylogenetic analysis identifies Zoneait as the sister taxon to Metriorhynchidae. It possesses a derived skull with orbits that are more laterally directed and prefrontals that are more expanded than in other basal metriorhynchoids. The preserved forelimb elements are less derived. The humerus is elongate in comparison with that of other metriorhynchoids. The ulna is slightly reduced in length and flattened but resembles the teleosauroid condition more so than the plate-like element of metriorhynchids. This suggests that marine adaptations in metriorhynchoids were acquired in mosaic fashion, with modifications of the skull preceding forelimb reduction, with this forelimb reduction occurring first in the zeugopodial elements, prior to reduction of the humerus. This evolutionary timing has important implications for the transition from nearshore ambush predation to pelagic open-marine predation in Thalattosuchia, suggesting that adaptations related to prey detection and capture preceded the locomotor adaptations that allowed these organisms to fully invade the oceans.
Chemostratigraphy of the Shaler Supergroup, Victoria Island, NW Canada: A record of ocean composition prior to the Cryogenian glaciations
Thomson et al
A new δ13Ccarb curve combined with δ13Corg values is presented for the upper Shaler Supergroup (∼900 to ∼720 Ma), Amundsen Basin, northwestern Canada. The dataset fills gaps in the existing stratigraphic record and makes correlations with adjacent basins more robust. There is a pronounced negative δ13C excursion in the Wynniatt Formation that can be correlated with a putative worldwide negative carbon isotope excursion, namely the Bitter Springs stage. However, in the Amundsen Basin, the δ13Ccarb excursion drops to anomalously negative values (-14‰), which we attribute to local overprints wherein isotopically light carbon in pore waters, released by oxidation of methane and organic matter during sulphate and iron reduction, was incorporated into authigenic carbonate cement. We document basin euxinia and anoxia during the same time interval using a multi-proxy approach; specifically, Fe-speciation and redox-sensitive trace metal data. Patterns of pronounced enrichment in Mo, V, and U concentrations in euxinic black shales suggest that the Bitter Springs stage was a transitional period in Earth's redox evolution, from the more reduced global oceans during the mid-Proterozoic to the more oxygenated oceans during the Phanerozoic.
Extreme ocean anoxia during the Late Cryogenian recorded in reefal carbonates of Southern Australia
van Smeerdijk Hood et al
The Neoproterozoic was a time of great change in the Earth's surface and marine environments, including extensive climate variability, the widespread oxygenation of the oceans and the accompanying rise of animal life. However, the timing of ocean oxygenation remains uncertain, particularly in regard to Cryogenian seas, which were disrupted by large periods of global glaciation. Interglacial Cryogenian reef complexes in the Northern Adelaide Fold Belt of Australia contain abundant primary marine dolomite cements. These cements have well-preserved textural and growth zonation, indicating they preserve their original marine chemistry and can be used as geochemical proxies for Late Cryogenian paleooceanography. Analysis of marine cements from peritidal nearshore facies, shallow platformal facies and deep framework facies of the reef complexes reveals significant geochemical gradients with paleo-depth. While nearshore cements have low Fe contents and commonly contain iron-oxide inclusions, the shallow and deep cements have very high Fe concentrations. Chalcophile elements (Cu, Cd, Pb, Zn, etc.) are most abundant in the nearshore cements, whereas rare earth elements are found in highest concentrations in the deeper facies cements. Rare earth element profiles are unusual, with shallow and deep facies having convex profiles with negligible Ce/Ce* anomalies and positive Eu/Eu* anomalies.
Being constrained by sedimentology, this carbonate geochemistry provides a window into interglacial Cryogenian ocean chemistry and structure. The marine cements reveal pronounced chemical stratification in this Late Cryogenian ocean. A thin veneer of oxic surface waters existed at the ocean surface, in peritidal facies, with increasingly anoxic and Fe-rich seawater at depth. The distribution of strongly chalcophile elements like Cd and Cu across the chemocline suggests that although ferruginous, deeper anoxic waters probably contained some dissolved sulphide. These conditions describe a ferro-sulfidic ocean and encompass some of the most extreme anoxia yet documented during the late Precambrian. A return to Archean-like ocean conditions at this time suggests large-scale disruption of the ocean system during the Neoproterozoic.
I have to wonder if this is another example of a Great Dying.
Wednesday, February 25, 2015
Microsoft's recently announced futuristic holographic headset may pose a health risk to users, according to the CEO of Magic Leap, a secretive augmented-reality startup and newfound rival to Microsoft in the burgeoning AR space.
Microsoft's HoloLens uses an input system that does not fully replicate the physical connections between our eyes and our brains, possibly resulting in permanent effects on your brain, Magic Leap CEO Rony Abovitz wrote Tuesday in a Reddit AskMeAnything thread when asked about the device. As such, Abovitz recommended avoiding use of the headset and others like it.
"There are a class of devices (see-through and non-see-through) called stereoscopic 3D. We at Magic Leap believe these inputs into the eye-brain system are incorrect -- and can cause a spectrum of temporary and/or permanent neurologic deficits," Abovitz wrote, when asked how his company's technology compares to the HoloLens.
"I personally experienced a number of these stereoscopic-3D issues -- and would not wear these devices -- especially knowing that digital light-field systems are on the way and safe," he added.
Abovitz, of course, has a horse in the race. Magic Leap, which was virtually unknown until October, is designing its very own so-called augmented reality system that will create 3D objects and overlay them onto a standard scene, like in the palm of your hand or around your living room. Though, Abovitz says that his company's device will use "digital light-field signal technology that respects the biology of the human eye-brain system in a profound and safe way." Magic Leap has scooped up almost $600 million in funding, with Google leading the charge.
Microsoft, meanwhile, became the unlikely face of AR in January when it showed its HoloLens headset and impressed journalists (myself included) with full-blown demos that felt reasonably close to the envisioned final product. The HoloLens appears to work similarly to Magic Leap's technology by blending artificial light with the light your eyes receive from the real world, mashing the two scenes into one and creating life-like 3D objects and environments at scale.
Yet there is a dispute whether Microsoft's HoloLens is functioning the same as Magic Leap's purported technology. Magic Leap has refused to show off its device, and neither company has fully expressed how its devices generate 3D images -- be it through light blasted directly on to your eyes, a visor with projector-like technique or a full display in an enclosed headset.
The distinction is key to Abovitz's accusation, though Microsoft declined to explain whether his description of HoloLens was accurate. Instead, a Microsoft spokesperson said to look to its annual Build developers conference in April, "where we will share more details." Alex Kipman, who heads up the HoloLens project at Microsoft, notably name-dropped Magic Leap at the January 21 unveiling of the HoloLens, saying Microsoft was open to collaborating with others on the technology. Abovitz said Tuesday his company "had other plans."
The lack of information about such products, especially so with Magic Leap and its insistence on secrecy, has created an aura of mystery around AR and VR unrivaled in the tech industry. How these devices function, what they're actually doing to our eyes and our brains and what, if any, are the side effects remain open questions.
David Autor knows a lot about robots. He doesn’t think they’re set to devour our jobs.
As an economics professor at the Massachusetts Institute of Technology who focuses on the impact of automation on employment, he’s in a good position to know. He’s surrounded by people creating many of the machines behind the latest wave of techno-anxiety.
His is “the non-alarmist view,” he says.
The 50-year-old believes automation has hurt the job market—but in a more targeted way than most pessimists think. He also doesn’t see the automation wave killing a wider array of jobs as quickly as many predict. Machines are invading the workplace, but in many cases as tools to make humans more productive, not replace them.
His research—presented in August to a packed audience of international central bankers in Wyoming—shows middle-skill jobs like bookkeeping, clerical work and repetitive tasks on assembly lines are being rapidly gobbled up by automation. But higher-paying jobs that require creativity and problem-solving—often aided by computers—have grown rapidly, as have lower skilled jobs that are resistant to automation, resulting in a polarized labor market and stagnant wages.
But many other economists and tech-watchers are ringing a louder bell.
“We’re entering an era where human beings are becoming dispensable in more parts of the economy and at a faster rate than ever before,” said Vivek Wadwa, a futurist at the Rock Center for Corporate Governance at Stanford University.
A recent Pew survey found just under half of technology experts said automation would displace “significant numbers of both blue- and white-collar workers” over the next decade. Some said it would leave “masses of people who are effectively unemployable.” But the other half said it will create more jobs than it destroys.
Mr. Autor—who always sports a single gecko-shaped silver earring, his trademark symbol also pasted on his iPhone—says the fear has outpaced reality. Automation is advancing, but we are still far from the day when machines can do complex physical and mental tasks that are easily and cheaply done by humans.
He encourages people to watch online videos of robots developed for the Pentagon, some built by his MIT colleagues. “They’ll put them in the field and if a gust of wind unexpectedly nudges a door open, they tip over,” he says with a chuckle.
Stirring the latest wave of worry is a broad set of technologies ranging from mechanical robots that do specific tasks, like move semiconductors around a factory, to computer programs that can do legal research, write stock reports and translate conversations.
Mr. Autor’s latest paper, presented to a packed audience at this year’s meeting of central bankers at Jackson Hole, Wyo., emphasized how difficult it is to program machines to do many tasks that humans find often easy and intuitive. In it, he played off a paradox identified in the 1960s by philosopher Michael Polanyi, who noted that humans can do many things without being able to explain how, like identify the face of a person in a series of photographs as they age. Machines can’t do that, at least not with accuracy.
This is why big breakthroughs in automation will take longer than many predict, Mr. Autor told the bankers. If a person can’t explain how they do something, a computer can’t be programmed to mimic that ability.
Three Austrian men have become the first in the world to undergo a new technique called "bionic reconstruction", enabling them to use a robotic prosthetic hand controlled by their mind, according to new research published in The Lancet. All three men suffered for many years with brachial plexus injuries  and poor hand function as a result of motor vehicle and climbing accidents.
The new technique was developed by Professor Oskar Aszmann, Director of the Christian Doppler Laboratory for Restoration of Extremity Function at the Medical University of Vienna, together with engineers from the Department of Neurorehabilitation Engineering of the University Medical Center Goettingen. It combines selective nerve and muscle transfers, elective amputation, and replacement with an advanced robotic prosthesis (using sensors that respond to electrical impulses in the muscles). Following comprehensive rehabilitation, the technique restored a high level of function, in all three recipients, aiding in activities of daily living.
"In effect, brachial plexus avulsion injuries represent an inner amputation, irreversibly separating the hand from neural control. Existing surgical techniques for such injuries are crude and ineffective and result in poor hand function", explains Professor Aszmann. "The scientific advance here was that we were able to create and extract new neural signals via nerve transfers amplified by muscle transplantation. These signals were then decoded and translated into solid mechatronic hand function" 
Before amputation, all three patients spent an average of 9 months undergoing cognitive training, firstly to activate the muscles, and then to use the electrical signals to control a virtual hand. Once they had mastered the virtual environment, they practiced using a hybrid hand--a prosthetic hand attached to a splint-like device fixed to their non-functioning hand (Figure 1 page 3 and video).
Three months after amputation, robotic prostheses gave all three recipients substantially better functional movement in their hands, improved quality of life, and less pain. For the first time since their accidents all three men were able to accomplish various everyday tasks such as picking up a ball, pouring water from a jug, using a key, cutting food with a knife, or using two hands to undo buttons.
Tracking long-term human impacts on landscape, vegetal biodiversity and water quality in the lake Aydat catchment (Auvergne, France) using pollen, non-pollen palynomorphs and diatom assemblages
Miras et al
Palaeoenvironmental studies allow the assessment of long-term human-climate-environmental interactions, and furnish valuable tools for the sustainable management of lacustrine ecosystems. A good example is the multi-proxy studythat of Lake Aydat’s 19 m sedimentary core. Previous research revealed the role of climate and human activities on lake sedimentation, and identified two sedimentary units (6700 ± 200 to 3180 ± 90 and 1770 ± 60 cal. yr BP to present) separated by an erosive mass-wasting deposit (Lavrieux et al., 2013a). Pollen, non-pollen palynomorphs (e.g. fungal and algal spores, rotifer resting eggs), and diatom-based trophic reconstructionshave been used to track the impacts of past land use on landscape evolution, vegetal biodiversity and water quality. Palaeoenvironmental data were also compared with local archaeo-historical datasets which allowed refined landscape reconstructions, especially for late Antiquity. The results obtained demonstrate that even Neolithic and Bronze Age human activities (between ca 4600 and 4300 cal. yr BP and between ca 3900 and 3500 cal. yr BP) had a discernible influence on catchment vegetation and lacustrine trophic dynamics of Lake Aydat, underlining the vulnerability of the ecosystem. Recurrent and complex models of past vegetation changes, phases of water nutrient over-enrichment and lake resilience were identified and related to grazing activities, but also to land use practises, which have been overlooked in Auvergne, such as mountain agriculture and hemp retting.
The process, biotic impact, and global implications of the human colonization of Sahul about 47,000 years ago
O’Connell et al
Comprehensive review of archaeological data shows that Sahul (Pleistocene Australia-New Guinea) was first occupied by humans ca. 47 ka (47,000 years ago); evidence for earlier arrival is weak. Colonizing populations remained low – perhaps two orders of magnitude below those estimated at European contact – for many millennia, and were long restricted to relatively favorable habitats. Though human arrival coincided with changes in native flora and fauna, these were mainly the products of climatic factors, not human interference. The genetic makeup of founding populations and their arrival date are consistent with the Late Dispersal Model of anatomically modern humans beyond SW Asia, beginning ca. 50 ka. Early Dispersal Models (120-70 ka) are not refuted, but draw no support from the Sahul record as currently understood.
The recent relaxation of Tokyo’s ban on arms exports has introduced Japan as a budding player in the international arms market. The government of Prime Minister Shinzo Abe has given the go-ahead for Japanese firms to compete internationally for arms contracts.
The entry of Japan into the international arms bazaar could shift the balance of power in the Pacific, equipping Asian navies and air forces with affordable, technologically advanced ships and aircraft. It will also upset the status quo among defense exporters, as Japan will carve a niche among American, Chinese, European and Russian firms.
China is unhappy with the export loosening process. An editorial published in PLA Daily warned Southeast Asian countries that Japan was “going all out to break [its] Pacifist Constitution,” and that Japanese arms exports to the region would “deteriorate economic conditions and undermine social stability.”
The long-sought-after deal to upgrade and replace Saudi Arabia's Eastern Fleet has taken a major step forward, sources said, with the January delivery of a letter of request (LoR) to the US detailing Saudi wishes.
Rear Adm. Jim Shannon, head of the US Navy International Program Office, reportedly obtained the LoR during a visit to Saudi Arabia. The letter marks a major step forward after years of talks and negotiations with the Saudis, who have also strongly considered French proposals to replace their fleet.
The French hold the preponderance of contracts in support of the Saudi's western, or Red Sea, fleet. France and the US are considered the primary contenders for the Eastern Fleet contract, said to be worth as much as $16 billion or higher.
Several sources said the Saudi LoR did not list specific ship designs, but rather gave general guidelines. Among the highlights are:
• Four 3,500-ton frigate-like warships, armed with vertical launch systems (VLS), capable of anti-air warfare and speeds of 35 knots
• 12 1,150-ton corvette-like warships
• 24 or so smaller patrol craft
The deal would include MH-60R helicopters to operate from the frigates, along with support and training.
One condition is the shipbuilder would be the prime contractor.
The US Navy is reportedly working to define details of the LoR, including what air radar the Saudis want to fulfill the anti-air requirement. Sources said that while no specific radar is listed in the LoR, the only system that fits the requirement is the SPY-1F lightweight Aegis system from Lockheed Martin.
SPY-1F is fitted only to Norway's Fridtjof Nansen-class frigates. All other Aegis warships — US cruisers and destroyers, foreign ships including those from Spain, Korea, Japan and Australia — carry the heavier SPY-1D antenna. While there is a high degree of commonality between the two versions, the 1F features smaller antennas and less power, resulting in shorter range.
Lockheed Martin and Austal USA have offered versions of their littoral combat ships fitted with VLS and phased-array radars, including the SPY-1F, both for export and most recently for the US Navy's Small Surface Combatant (SSC) competition conducted in 2014. In the end, the US Navy chose to forego Aegis and VLS on its SSCs, now designated as frigates.
Other than the LCS/SSC/frigate designs, there are no other US projects that would fit the 3,500-ton parameters of the Saudi frigate.
If I were the SecDef, I'd have the Saudis pay for development costs of the LCS with the real firepower of a frigate and then just add the minor improvements, relatively speaking, the US Navy needs. Use those to replace the LCS with the minor upgrades that currently planned after the first 20 LCS. Then they actually will be FF or really FFGs and worthy successors to the Oliver Hazard Perry frigates.
Russia's space agency expects the International Space Station to stay in orbit through 2024, and plans to create its own space outpost with its segment of the station after that.
Roscosmos' scientific council concluded Tuesday that several Russian modules could eventually be undocked to "perform the task of ensuring Russia's guaranteed presence in space."
Note: the Zarya Module, while built by the Russians, is American owned.
Scientists today released evidence of historically unprecedented hurricane activity along the northeast coast of what would become the United States between about 800 to 1700 years ago, which was associated with warmer ocean temperatures similar to levels we may expect in coming centuries with climate change and ocean warming.
Geoscientists at the University of Massachusetts Amherst and Woods Hole Oceanographic Institute (WHOI) say new evidence they analyzed in sediment deposits from Cape Cod show that intense hurricanes, possibly more powerful than any storms New England has experienced in recorded history, frequently pounded the region from around 250 A.D. to about 1150.
Jon Woodruff and WHOI researcher Dana MacDonald, currently a visiting scholar at UMass Amherst, with lead author Jeff Donnelly of WHOI, say a warmer climate was associated with more intensity and frequent hurricanes on the U.S. East and Gulf coasts hundreds of years ago. They present a new record of sediment deposits in the current issue of Earth's Future, a journal of the American Geophysical Union.
Woodruff, MacDonald, Donnelly and colleagues report that 23 severe hurricanes hit the New England area between the years 250 A.D. and 1150, the equivalent of a severe storm on average about once every 40 years. Many were likely category 3 storms like Hurricane Katrina or category 4 storms like Hugo that would be catastrophic if they hit the region today, the authors add.
The study, the first to find evidence of historically unprecedented hurricane activity along the northeast coast, extends the hurricane record for the region by hundreds of years. Donnelly says the historical interval was "unlike what we've seen in the last few hundred years."
Pluto’s insolation history: Latitudinal variations and effects on atmospheric pressure
Earle et al
Since previous long-term insolation modeling in the early 1990s, new atmospheric pressure data, increased computational power, and the upcoming flyby of the Pluto system by NASA’s New Horizons spacecraft have generated new motivation and increased capabilities for the study of Pluto’s complex long-term (million-years) insolation history. The two primary topics of interest in studying Pluto’s insolation history are the variations in insolation patterns when integrated over different intervals and the evolution of diurnal insolation patterns over the last several decades. We find latitudinal dichotomies when comparing average insolation over timescales of days, decades, centuries, and millennia, where all timescales we consider are short relative to the predicted timescales for Pluto’s chaotic orbit. Depending on the timescales of volatile migration, some consequences of these insolation patterns may be manifested in the surface features revealed by New Horizons. We find the Maximum Diurnal Insolation (MDI) at any latitude is driven most strongly when Pluto’s obliquity creates a long arctic summer (or “midnight sun”) beginning just after perihelion. Pluto’s atmospheric pressure, as measured through stellar occultation observations during the past three decades, shows a circumstantial correlation with this midnight sun scenario as quantified by the MDI parameter.
Disc dark matter in the Galaxy and potential cycles of extraterrestrial impacts, mass extinctions and geological events
A cycle in the range of 26–30 Myr has been reported in mass extinctions, and terrestrial impact cratering may exhibit a similar cycle of 31 ± 5 Myr. These cycles have been attributed to the Sun's vertical oscillations through the Galactic disc, estimated to take from ∼30 to 42 Myr between Galactic plane crossings. Near the Galactic mid-plane, the Solar system's Oort Cloud comets could be perturbed by Galactic tidal forces, and possibly a thin dark matter (DM) disc, which might produce periodic comet showers and extinctions on the Earth. Passage of the Earth through especially dense clumps of DM, composed of Weakly Interacting Massive Particles (WIMPs) in the Galactic plane, could also lead to heating in the core of the planet through capture and subsequent annihilation of DM particles. This new source of periodic heating in the Earth's interior might explain a similar ∼30 Myr periodicity observed in terrestrial geologic activity, which may also be involved in extinctions. These results suggest that cycles of geological and biological evolution on the Earth may be partly controlled by the rhythms of Galactic dynamics.
Deep below the surface of a water-filled cave in Madagascar, divers and paleontologists have uncovered a boneyard full of extinct giant lemurs.
Hundreds of bones dot the silty bottom of Aven Cave in Tsimanampetsotse National Park. The remains include exotic species such as the extinct elephant bird, a flightless giant similar to an ostrich, but the most numerous bones are from long-lost giant lemurs.
The largest of the extinct lemurs were as big as gorillas, and paleontologists sometimes refer to the different types as sloth lemurs, koala lemurs, and monkey lemurs to describe their different lifestyles and the living animals they most closely resemble. Sometime between 2,000 and 500 years ago, all these giants disappeared, possibly at the hands of humans.
The underwater caves offer an unprecedented look at these lost species. "The preservation is really incredible," says Brooklyn College anthropologist Alfred Rosenberger, a National Geographic grantee who is leading the project.
Thirteen million years ago, as many as seven different species of crocodiles hunted in the swampy waters of what is now northeastern Peru, new research shows. This hyperdiverse assemblage, revealed through more than a decade of work in Amazon bone beds, contains the largest number of crocodile species co-existing in one place at any time in Earth's history, likely due to an abundant food source that forms only a small part of modern crocodile diets: mollusks like clams and snails. The work, published today in the journal Proceedings of the Royal Society B, helps fill in gaps in understanding the history of the Amazon's remarkably rich biodiversity.
"The modern Amazon River basin contains the world's richest biota, but the origins of this extraordinary diversity are really poorly understood," said John Flynn, Frick Curator of Fossil Mammals at the American Museum of Natural History and an author on the paper. "Because it's a vast rain forest today, our exposure to rocks--and therefore, also to the fossils those rocks may preserve--is extremely limited. So anytime you get a special window like these fossilized "mega-wetland" deposits, with so many new and peculiar species, it can provide novel insights into ancient ecosystems. And what we've found isn't necessarily what you would expect."
Before the Amazon basin had its river, which formed about 10.5 million years ago, it contained a massive wetland system, filled with lakes, embayments, swamps, and rivers that drained northward toward the Caribbean, instead of today's pattern of eastward river flow to the Atlantic Ocean. Knowing the kind of life that existed at that time is crucial to understanding the history and origins of modern Amazonian biodiversity. But although invertebrates like mollusks and crustaceans are abundant in Amazonian fossil deposits, evidence of vertebrates other than fish have been very rare.
Since 2002, Flynn has been co-leading prospecting and excavating expeditions with colleagues at fossil outcrops of the Pebas Formation in northeastern Peru. These outcrops have preserved life from the Miocene, including the seven species of crocodiles discussed in Proceedings B. Three of the species are entirely new to science, the strangest of which is Gnatusuchus pebasensis, a short-faced caiman with globular teeth that is thought to have used its snout to "shovel" mud bottoms, digging for clams and other mollusks. The new work suggests that the rise of Gnatusuchus and other "durophagous," or shell-crunching, crocodiles is correlated with a peak in mollusk diversity and numbers, which disappeared when the mega-wetlands transformed into the modern Amazon River drainage system.
"When we analyzed Gnatusuchus bones and realized that it was probably a head-burrowing and shoveling caiman preying on mollusks living in muddy river and swamp bottoms, we knew it was a milestone for understanding proto-Amazonian wetland feeding dynamics," said Rodolfo Salas-Gismondi, lead author of the paper and a graduate student at the University of Montpellier, in France, as well as researcher and chief of the paleontology department at the National University of San Marcos' Museum of Natural History in Lima, Peru.
Besides the blunt-snouted crocodiles like Gnatusuchus, the researchers also recovered the first unambiguous fossil representative of the living smooth-fronted caiman Paleosuchus, which has a longer and higher snout shape suitable for catching a variety of prey, like fish and other active swimming vertebrates.
"We uncovered this special moment in time when the ancient mega-wetland ecosystem reached its peak in size and complexity, just before its demise and the start of the modern Amazon River system," Salas-Gismondi said. "At this moment, most known caiman groups co-existed: ancient lineages bearing unusual blunt snouts and globular teeth along with those more generalized feeders representing the beginning of what was to come."
Dynamic redox conditions control late Ediacaran metazoan ecosystems in the Nama Group, Namibia
Wood et al
The first appearance of skeletal metazoans in the late Ediacaran (∼550 million years ago; Ma) has been linked to the widespread development of oxygenated oceanic conditions, but a precise spatial and temporal reconstruction of their evolution has not been resolved. Here we consider the evolution of ocean chemistry from ∼550 to ∼541 Ma across shelf-to-basin transects in the Zaris and Witputs Sub-Basins of the Nama Group, Namibia. New carbon isotope data capture the final stages of the Shuram/Wonoka deep negative C-isotope excursion, and these are complemented with a reconstruction of water column redox dynamics utilizing Fe-S-C systematics and the distribution of skeletal and soft-bodied metazoans. Combined, these inter-basinal datasets provide insight into the potential role of ocean redox chemistry during this pivotal interval of major biological innovation.
The strongly negative δ13 C values in the lower parts of the sections reflect both a secular, global change in the C-isotopic composition of Ediacaran seawater, as well as the influence of ‘local’ basinal effects as shown by the most negative δ13 C values occurring in the transition from distal to proximal ramp settings. Critical, though, is that the transition to positive δ13 C values postdates the appearance of calcified metazoans, indicating that the onset of biomineralization did not occur under post-excursion conditions.
Significantly, we find that anoxic and ferruginous deeper water column conditions were prevalent during and after the transition to positive δ13C that marks the end of the Shuram/Wonoka excursion. Thus, if the C isotope trend reflects the transition to global-scale oxygenation in the aftermath of the oxidation of a large-scale, isotopically light organic carbon pool, it was not sufficient to fully oxygenate the deep ocean.
Both sub-basins reveal highly dynamic redox structures, where shallow, inner ramp settings experienced transient oxygenation. Anoxic conditions were caused either by episodic upwelling of deeper anoxic waters or higher rates of productivity. These settings supported short-lived and monospecific skeletal metazoan communities. By contrast, microbial (thrombolite) reefs, found in deeper inner- and mid-ramp settings, supported more biodiverse communities with complex ecologies and large skeletal metazoans. These long-lived reef communities, as well as Ediacaran soft-bodied biotas, are found particularly within transgressive systems, where oxygenation was persistent. We suggest that a mid-ramp position enabled physical ventilation mechanisms for shallow water column oxygenation to operate during flooding and transgressive sea-level rise. Our data support a prominent role for oxygen, and for stable oxygenated conditions in particular, in controlling both the distribution and ecology of Ediacaran skeletal metazoan communities.
Tuesday, February 24, 2015
University of California, Berkeley, scientists have proved a fundamental relationship between energy and time that sets a "quantum speed limit" on processes ranging from quantum computing and tunneling to optical switching.
The energy-time uncertainty relationship is the flip side of the Heisenberg uncertainty principle, which sets limits on how precisely you can measure position and speed, and has been the bedrock of quantum mechanics for nearly 100 years. It has become so well-known that it has infected literature and popular culture with the idea that the act of observing affects what we observe.
Not long after German physicist Werner Heisenberg, one of the pioneers of quantum mechanics, proposed his relationship between position and speed, other scientists deduced that energy and time were related in a similar way, implying limits on the speed with which systems can jump from one energy state to another. The most common application of the energy-time uncertainty relationship has been in understanding the decay of excited states of atoms, where the minimum time it takes for an atom to jump to its ground state and emit light is related to the uncertainty of the energy of the excited state.
"This is the first time the energy-time uncertainty principle has been put on a rigorous basis - our arguments don't appeal to experiment, but come directly from the structure of quantum mechanics," said chemical physicist K. Birgitta Whaley, director of the Berkeley Quantum Information and Computation Center and a UC Berkeley professor of chemistry. "Before, the principle was just kind of thrown into the theory of quantum mechanics."
The new derivation of the energy-time uncertainty has application for any measurement involving time, she said, particularly in estimating the speed with which certain quantum processes - such as calculations in a quantum computer - will occur.
Researchers from Cambridge University and Israel’s Weizmann Institute of Science are claiming a stem cell research breakthrough that would allow a baby to be created from the skin cells from two adults, no matter their gender. This potentially allows for infertile couples to have their own children without resorting to sperm or egg donors, and may provide the means for same sex couples to produce their own babies.
Previously only successful in experiments on mice, the new research has been conducted on human cells for the first time. In this study, the researchers paired stem cell lines from embryos with the skin of a range of different adults, with the resultant cells compared to aborted fetuses to determine an identical match.
Techniques devised to create same-sex offspring are not new. Some experiments involve the manipulation of fibroblasts in mice resulting in offspring with the genetic traits of multiple male mice, whilst others have used bone marrow stem cells extracted from males to trigger spermatogonia.
However, in this latest research, stem cells and adult human skin have been combined for the first time to create an entire new germ-cell line (that is, cells that will become embryos). Derived from ten different donor sources, the new germ-cell lines were created from 10 different donor sources – five embryos and five adults.
The Indian Navy (IN) is fast-tracking plans to build its second, 65,000-tonne aircraft carrier at Cochin Shipyard Limited (CSL) in southern India.
Designated the Indigenous Aircraft Carrier-II (IAC-II) and likely to be named INS Vishal , the warship will take 10-12 years to build, according to naval officials.
Construction is expected to begin at CSL in 2018 after the IN commissions the 40,000-tonne carrier INS Vikrant following a five-year delay.
Rheinmetall's 10 Kilowatt High Energy Laser System Displayed Integrated With ARTEC Boxer 8x8 Armoured Vehicle
Rheinmetall has invested considerable funding in the design and development of high-energy lasers (HEL) for battlefield applications. Here at IDEX the company is showing a system integrated onto the ARTEC Boxer (8x8) multi-role armoured vehicle (MRAV).
During trials carried out in Switzerland in front of a number of high-ranking overseas delegations, Rheinmetall (Stand 09-A10) showed its HEL integrated onto three land platforms. In addition to the Boxer MRAV, the other two platforms comprised a RUAG Defence M113 fully tracked armoured personnel carrier and a Tatra (8x8) protected cross-country truck. During the demonstration in Switzerland, the Boxer HEL neutralised an oversized heavy machine gun mounted on a pick-up truck.
Currently the Boxer is configured for a 5kW or 10kW laser, which are identical with regard to mass and volume. Here at IDEX it is fitted with a 5kW HEL effector and is referred to as the Mobile HEL Effector Wheel XX. This features a special HEL effector module that takes full advantage of Rheinmetall’s proprietary knowhow, which is based on beam superimposing technology.
Known as the Mobile HEL Effector Track V, the RUAG M113 has been fitted with a 1kW HEL effector that has been successfully demonstrated in the remote explosive ordnance role.
The third application is the Tatra (8x8) vehicle fitted with a containerised 20kW HEL effector and this is referred to as the Mobile HEL Effector Container L. The Roman numerals V, XX and L correspond to the laser categories of 5kW, 20kW and 50kW.
Rheinmetall Air Defence has also fitted and tested its Skyshield air defence system with the 35mm cannon replaced by an HEL. During the demonstration in Switzerland, the Skyshield HEL effector enabled the successful engagement of a series of incoming generic mortar rounds.