Oxygenation of the Archean atmosphere: New paleosol constraints from eastern India
Mukhopadhyay et al
It is widely believed that atmospheric oxygen saturation rose from less than 10–5 present atmospheric level (PAL) in the Archean to greater than 10–2 PAL at the Great Oxidation Event (GOE) at ca. 2.4 Ga, but it is unclear if any earlier oxygenation events occurred. Here we report U-Pb zircon data indicating that a pyrophyllite-bearing paleosol, from Keonjhar in the Precambrian Singhbhum Craton of eastern India, formed between 3.29 and 3.02 Ga, making it one of very few known Archean paleosols globally. Field and geochemical evidence suggests that the upper part of the paleosol was eroded prior to unconformable deposition of an overlying sequence of shallow-marine siliciclastic sediments. A negative cerium anomaly within the currently preserved level of the paleosol indicates that ancient oxidative weathering occurred in the original upper soil profile. The presence of redox-sensitive detrital uraninite and pyrite together with a complete absence of pyrophyllite in the overlying sediments indicate that the mineralogical and geochemical features of the paleosol were established prior to the unconformable deposition of the sediments and are not related to subsequent diagenetic or hydrothermal effects. We suggest that a transient atmospheric oxygenation event occurred at least 600 m.y. prior to the GOE and ∼60 m.y. prior to a previously documented Archean oxygenation event. We propose that several pulsed and short-lived oxygenation events are likely to have occurred prior to the GOE, and that these changes to atmospheric composition arose due to the presence of organisms capable of oxygenic photosynthesis.
Tuesday, September 02, 2014
Due to global warming, scientists say, the chances of the southwestern United States experiencing a decade long drought is at least 50 percent, and the chances of a "megadrought" – one that lasts over 30 years – ranges from 20 to 50 percent over the next century.
The study by Cornell University, University of Arizona and U.S. Geological Survey researchers will be published in a forthcoming issue of the American Meteorological Society's Journal of Climate.
"For the southwestern U.S., I'm not optimistic about avoiding real megadroughts," said Toby Ault, Cornell assistant professor of earth and atmospheric sciences and lead author of the paper. "As we add greenhouse gases into the atmosphere – and we haven't put the brakes on stopping this – we are weighting the dice for megadrought conditions."
As of mid-August, most of California sits in a D4 "exceptional drought," which is in the most severe category. Oregon, Arizona, New Mexico, Oklahoma and Texas also loiter between moderate and exceptional drought. Ault says climatologists don't know whether the severe western and southwestern drought will continue, but he said, "With ongoing climate change, this is a glimpse of things to come. It's a preview of our future."
Ault said that the West and Southwest must look for mitigation strategies to cope with looming long-drought scenarios. "This will be worse than anything seen during the last 2,000 years and would pose unprecedented challenges to water resources in the region," he said.
In computer models, while California, Arizona and New Mexico will likely face drought, the researchers show the chances for drought in parts of Washington, Montana and Idaho may decrease.
The number of people living in poverty in Ghana halved between 1992 and 2013, the government said Friday, with the country meeting a key developmental benchmark even as its economy struggles.
Just under a quarter, or 24.2 percent, of Ghanaians were living in poverty in 2013 compared to 51.7 percent in 1992, new data from the national statistics body showed.
The figures were based on Ghana's own measure of poverty which for 2013 counted individuals living on less than 3.60 cedis -- equivalent last year to an average of $2.34 or 2.21 euros -- a day.
The UN measure for poverty counts those living on an even smaller amount, of less than $1.25 per day.
By halving the poverty rate, Ghana becomes one of the few African countries to achieve the first of the United Nations Millennium Development Goals, a set of benchmarks that developing countries are aiming to meet by next year.
INDIA’S restless prime minister, Narendra Modi, likes to brag that he sleeps for only three or four hours a night and replenishes his energy with yoga. He will need all the vigour he can muster in the coming month, during a punishing diplomatic tour to the rest of Asia. By the end, if he keeps up the pace, Mr Modi may have clarified what sort of policy he intends for India in a region where it punches below its weight.
The marathon begins in Japan on August 30th, where India’s leader travels with a delegation of billionaires and industrialists for a five-day trip. Mr Modi is close to Japan’s prime minister, Shinzo Abe, a fellow nationalist with whom he shares suspicions of China. He gratefully visited Mr Abe in 2007 and 2012 as chief minister for Gujarat, even as Western politicians shunned him after Hindu-Muslim riots in his state in 2002. Gleeful Indian pundits note that social media give a clue to their friendship. Mr Abe follows only three people on Twitter; one of them is his eager fellow tweeter, Mr Modi.
Monday, September 01, 2014
India is commissioning a plant to produce up to 5,000 tonnes of rare earths a year, a state company official told Reuters, which could help it contribute about 5 percent to the global supply of the metals used in cameras, cars, iPhones and wind turbines.
India's emergence as a supplier, albeit a small one, would be good news for countries like Japan, which up to now have had to rely mostly on China for rare earths production.
The plant in the state of Odisha would produce rare earth oxides by processing monazite from beach sand, said S. Surya Kumar, head of the Rare Earths Division for state-owned Indian Rare Earths, part of the Department of Atomic Energy.
Up to half of the output would be processed into products like lanthanum and cerium, which are used in camera lenses and glass polishing agents, Kumar said.
Kumar did not give a timeline for when rare earth oxides will start flowing from the Odisha plant.
The Australian tax commissioner has left open the possibility that the digital payment system bitcoin could be considered legal tender in Australia.
Bitcoin has been described as a type of “virtual currency” where users can pay for goods and services, and can even create their own bitcoins to generate more currency.
But countries around the world have continued to grapple with whether bitcoin could be considered currency or some other form of personal property.
How bitcoin – and other cryptocurrencies – are defined will have broad ramifications for how they are handled by consumers and governments, including how they are dealt with under national taxation systems.
At an inquiry on Wednesday the Australian tax commissioner, Chris Jordan, conceded there was a push by some proponents to have bitcoin treated like money, but added it did not meet the current definition of legal tender. However he left open the possibility that this could be changed in the future.
“There’s a definition in the Tax Act of money. It’s got to be the legal tender of a country. We can’t say it’s money. If this grows more and more maybe the definition needs to change,” he said.
A change to the definition of legal tender would require amendments to the Tax Act by the federal parliament.
When the Air Force issued a Request for Information about an engine to replace the RD-180 it began to look as if they were serious about committing to build the first new rocket engine in decades.
But we also received two new RD-180 engines from Russia the same day as the RFI went out, the United Launch Alliance announced. That bolstered those who argue that Russia needs the revenue so much and is so committed to space cooperation that our sanctions against Russia to punish them for Ukraine will not stop the flow of the cheap, highly reliable engines. Three more engines are due to arrive this fall, and I’m betting they arrive.
Just to make sure the Air Force or OSD hadn’t snuck something past us, I checked to see if any policy decisions had been made or memos approved to allow spending for a new engine.
Here are the responses to my questions about whether a policy decision has been made to proceed with a new engine or to create a budget line to find one from Maj. Eric Badger, Air Force spokesman:
“No, there has not been a policy decision made to buy a new engine.”
According to this report from Xinhua, China’s sole aircraft carrier Liaoning is capable of carrying up to 36 aircraft.
The ship’s air wing is made up of four Z-18J airborne early warning helicopters, six Z-18F antisubmarine warfare helicopters, two Z-9C search-and-rescue helicopters and 24 J-15 fighter jets.
The same article said the Z-18F has a 4 by 8 sonobuoy rack on the aft of the cabin. The helicopter is also capable of being armed with four Yu-7K lightweight torpedos.
Glacial–interglacial climatic variations at the Schirmacher Oasis, East Antarctica: The first report from environmental magnetism
Kumar Warrier et al
We discuss in this paper the first detailed environmental magnetic record of glacial–interglacial climatic variations in the Schirmacher Oasis, East Antarctica. We determined environmental magnetic properties and inter-parametric ratios (χlf, χfd %, χARM, SIRM, χARM/SIRM, χARM/χlf, χARM/χfd, SIRM/χlf, S-ratio and HIRM) for sediment samples of a core from the Sandy Lake. Accelerator mass spectrometer (AMS) 14C dates were obtained on the organic matter from bulk sediment samples. The sediment core spans the past ~ 42.5 cal. ka B.P. The magnetic minerals are mainly detrital and catchment-derived, as there is no evidence for the presence of authigenic greigite, bacterial magnetite or diagenetic dissolution. The last glacial period is characterized by a high concentration of ferrimagnetic minerals such as titanomagnetite (high values of χlf, SIRM etc.) and coarse magnetic grain size (low χARM/SIRM and χARM/χlf values and high S-ratio values). Deglaciation in the Schirmacher Oasis began around 21 cal. ka B.P. as suggested by the low magnetic mineral concentration. The Holocene period is characterized by relatively warm climatic events as seen in the low values of magnetic susceptibility which is primarily contributed by fine-grained titanomagnetite resulting from pedogenesis (high χfd % values). Several of the relatively warm and cold events that we deciphered from the environmental magnetic data are correlatable with lake sediments from the Schirmacher Oasis and other ice-free areas in East Antarctica and from ice-core records on the Antarctic Plateau.
Three factors make exploring Europa hard. First, we want to explore an entire complex world, and mapping its features requires acquiring vast amounts of data. Second, Europa lies far from the Earth, which necessitates capable communications and power systems (read, “expensive”) to return the data to Earth. Third, Europa lies well within the harsh radiation fields surrounding Europa, which both requires significant radiation hardening (again, read, “expensive”) and limits the life of any spacecraft that explores this world. These factors can make a mission concept that seems like less actually be more.
The limiting factor on science for most planetary orbiters is not the time the instruments can make observations. Rather it is the time available to return data to Earth because many instruments can gather data far faster than the communications system can transmit it to antennas on Earth. (There also are a limited number of antennas to listen to planetary spacecraft, so few missions receive continuous coverage, and spacecraft often cannot continuously transmit either because they must turn to observe the planet or the planet itself blocks communication.)
Age of Barrier Canyon-style rock art constrained by cross-cutting relations and luminescence dating techniques
Pederson et al
Rock art compels interest from both researchers and a broader public, inspiring many hypotheses about its cultural origin and meaning, but it is notoriously difficult to date numerically. Barrier Canyon-style (BCS) pictographs of the Colorado Plateau are among the most debated examples; hypotheses about its age span the entire Holocene epoch and previous attempts at direct radiocarbon dating have failed. We provide multiple age constraints through the use of cross-cutting relations and new and broadly applicable approaches in optically stimulated luminescence dating at the Great Gallery panel, the type section of BCS art in Canyonlands National Park, southeastern Utah. Alluvial chronostratigraphy constrains the burial and exhumation of the alcove containing the panel, and limits are also set by our related research dating both a rockfall that removed some figures and the rock’s exposure duration before that time. Results provide a maximum possible age, a minimum age, and an exposure time window for the creation of the Great Gallery panel, respectively. The only prior hypothesis not disproven is a late Archaic origin for BCS rock art, although our age result of A.D. ∼1–1100 coincides better with the transition to and rise of the subsequent Fremont culture. This chronology is for the type locality only, and variability in the age of other sites is likely. Nevertheless, results suggest that BCS rock art represents an artistic tradition that spanned cultures and the transition from foraging to farming in the region.
Thalassodromeus sebesensis - a new name for an old turtle. Comment on “Thalassodromeus sebesensis, an out of place and out of time Gondwanan tapejarid pterosaur”, Grellet-Tinner and CodreaOriginal authors stick to their guns, but not nicely.
Dyke et al
In a recent Gondwana Research article Grellet-Tinner and Codrea (2014) (hereafter “GTC”) describe a single bone (UBB ODA-28, collections of Babeş-Bolyai University, Cluj Napoca, Romania) from the Upper Cretaceous Şard Formation (= middle section of the Sebeş Formation) (Transylvanian Basin, Romania) as a pterosaur premaxillary cranial crest. They assign this fossil to a new species of small pterosaur, Thalassodromeus sebesensis (a name first coined in a conference abstract published in 2013; Grellet-Tinner et al., 2013). GTC build a taxonomic argument on the basis of this single incomplete specimen that posits the presence of a major group of pterosaurs hitherto entirely restricted to the Early Cretaceous of South America - thalassodromines (Kellner and Campos, 2007) or thalassodromids (Witton, 2009) - in the European Late Cretaceous. GTC note that “this important discovery doubles the thalassadromine fossil record and demonstrates a 42 million years temporal displacement between the Romanian species and its older Aptian Gondwanan congener Thalassodromeus sethi”. If GTC are correct, this new fossil represents a remarkably unexpected and potentially very important discovery that could rewrite aspects of pterosaur evolutionary history.
We have assembled a large international team who disagree with the arguments presented by GTC. As we demonstrate, the fossil fragment they describe is misidentified; it is, firstly, not from a pterosaur but is clearly a piece of the shell of the turtle Kallokibotion Nopcsa, 1923 and, secondly, is therefore not the groundbreaking discovery of an ‘anachronistic’ Gondwanan pterosaur in Europe as claimed. Because ODA-28 is not a pterosaur, yet alone a Thalassodromeus, GTC’s conclusions on migration routes and insular dwarfism are also unsupported.
Discovery of shallow-marine biofacies conodonts in a bioherm within the Carboniferous-Permian transition in the Omalon Massif, NE Russia near the North paleo-pole: Correlation with a warming spike in the southern Hemisphere
Davydov et al
The conodont genera Hindeodus and Streptognathodus are reported for the first time within the Carboniferous-Permian transition in the northern high latitudes of the Paren’ River, Omolon Massif, NE Russia. Several fossil groups, including brachiopods, bivalves, scaphopods and microgastropods were found to be prolific in the invertebrate-dominated bioherms. These bioherms occur within predominantly siliciclastic sequences with extremely poor fauna, whereas in the studied bioherms the diversity of the bivalves and brachiopods exceeded observed diversity elsewhere in coeval facies in NE Russia. The bioherms are biostratigraphically constrained as uppermost Pennsylvanian to lowermost Cisuralian based on ammonoids. The very unusual peak of bivalve and brachiopod diversity and the occurrence of conodonts that require minimum sea water temperatures of at least 10-12 °C indicate a short lived, but significant warming event at that time, at least of provincial significance. This event most likely corresponds with a short-lived warming event recently discovered in the east of the southern hemisphere, in Timor and Australia. Thus, the event is possibly of global significance.
Tectonic restoration of the Precambrian crystalline rocks along the west coast of India: Correlation with eastern Madagascar in East Gondwana
Rekha et al
New structural–mineralogical data and U–Th-total Pb monazite chemical ages in 27 samples in a 430 km long corridor along the west coast of India are combined with existing data to reconstruct the tectonic set up of the Meso/Neoarchean crystalline rocks in the Western Dharwar Craton (WDC). The data helps to delineate two NW-trending Paleoproterozoic ductile shear zones that limit the southern and the northern margins of the WDC. The southern shear zone (metamorphic age: 2.3–2.4 Ga) separates the greenschist facies supracrustal belts (2.5 and 3.3 Ga), foliated granitoids (2.5 and 2.9 Ga) and amphibolite facies anatectic gneisses ( greater than 3.0 Ga) of the WDC from the greater than 2.9 Ga granulite facies ortho/para-gneisses of the Coorg Block. This shear zone is correlated with the ∼2.4 Ga Betsimisaraka suture zone in east-central Madagascar that demarcates the accretion zone between the Antongil Block (≈WDC) and the granulite facies lithologies of the Antananarivo domain (≈Coorg Block). The northern shear zone system (metamorphic age: 2.2–1.8 Ga) extending NW into Madagascar possibly exists as a hitherto undiscovered tectonic zone forming the basement of the Mesoproterozoic Sahantaha Formation underlying the Neoproterozoic Bemarivo Belt supracrustals in NE Madagascar.
Within the WDC, the Meso/Neoproterozoic ages retrieved from poorly-defined margins in monazite are uncommon, dispersed within the craton, and do not define localized zones within the craton. The chemical ages of metamorphic monazites formed at greenschist/amphibolite facies conditions preclude metamorphism–deformation associated with accretion of crustal blocks within the WDC during the Rodinia assembly.
Researchers from North Carolina State University have found that century-old museum specimens hold clues to how global climate change will affect a common insect pest that can weaken and kill trees – and the news is not good.
"Recent studies found that scale insect populations increase on oak and maple trees in warmer urban areas, which raises the possibility that these pests may also increase with global warming," says Dr. Elsa Youngsteadt, a research associate at NC State and lead author of a paper on the work.
"More scale insects would be a problem, since scales can weaken or kill the trees they live on," Youngsteadt says. "But cities are unique, so we wanted to know whether warming causes scale insect population explosions in rural forests, the way it does in cities."
Support for Scottish independence appears to be gaining ground three weeks ahead of the historic referendum, according to a poll published on Friday.
The Survation survey found 47 percent of respondents would vote "Yes" to independence, compared to 53 percent who would vote "No", excluding people who were undecided.
This was a considerable narrowing of the gap between the two sides in a Survation poll three weeks earlier, in which 43 percent said they would vote "Yes", versus 57 percent who would vote to remain in the union.
The poll was commissioned by the Scottish Daily Mail newspaper to assess reaction to the final public debate between the leaders of the pro and anti-independence campaigns.
"Yes" campaign leader and Scottish First Minister Alex Salmond was widely seen to have won the debate against "No" campaign leader Alistair Darling.
The survey was of 1,001 people of voting age, and found 11 percent of respondents said they remained undecided, a drop of 2 percent from the previous poll.
JIN JIANG is one of the world’s biggest hotel groups, managing five-star properties across China, a budget motel chain and a travel agency. It is also a state-owned enterprise (SOE), controlled by the Shanghai government. It has seen better days. The company’s best hotels played host to hundreds of foreign leaders in the past century, including Richard Nixon in 1972, when America and China began their historic rapprochement. But in recent years visiting dignitaries have opted for newer hotels over Jin Jiang’s musty rooms and tired furnishings.
When people think of Chinese state companies, they often have its giant banks or oil companies in mind. But most of the 155,000 enterprises still owned by the central and local governments are more akin to Jin Jiang: they are businesses that have little to do with the country’s economic or political priorities, and they have had a run of bad years, losing ground to private-sector rivals. That may be about to change. China is in the midst of the biggest attempt in more than a decade to fix the country’s brand of state capitalism, attempting to breathe new life into Jin Jiang and dozens, if not hundreds or even thousands, more like it.
Saturday, August 30, 2014
Friday, August 29, 2014
As the Russians push deeper into Ukraine, the Ukrainians have begun reacting. its not merely a panic, but its not a cohesive response yet.
In Mariupol, the people and National Guard have started digging in, preparing for the defense.
Outside of Mariupol, Ukrainian troops retreated from Novoazovsk.
A local counterattack took place at Komsomol'ske in the Donetsk Oblast.
Supposedly, Ilovaysk was reinforced as well.
Ukrainian troops were ambushed in Debaltseve though.
Ukraine lost at least one Su-25. The rebels have claimed downing four.
Ukraine lost at least one Su-25. The rebels have claimed downing four.
Rumors are the Russian troops in Novoazovsk have orders to roll all the way to Odessa. The Russian offensive is continuing.
Putin is getting out there with some of his statements. Despite his statements to let the Ukrainians to retreat, anything but is happening: in fact, a 'corridor' was opened and once some Ukrainian troops went in, artillery began to fall. At least 100 were killed.
Poland refused permission for Russia's Minister of Defense's aircraft to enter its airspace.
JPMorgan Chase suggests if the situation deteriorates more then Russia might face a 'Lehman-style shock.'
There are moments when I have to think this is the Spanish Civil War writ 21st Century.
The poliovirus strain that caused an outbreak in the Republic of the Congo in 2010 is able to resist the immune responses generated by a commonly used vaccine. The finding could explain why the outbreak, which killed nearly half of the 445 people infected, was so severe.
Christian Drosten at the University of Bonn Medical Centre in Germany and his colleagues analysed the virus strain responsible for the outbreak. They found a combination of two mutations, both in the proteins of the strain's 'coat', which make it harder for certain antibodies to stick to the virus. People who died in this outbreak had been vaccinated in the past, but people who were freshly re-vaccinated could fight off the virus.
Bitcoin price action has, since publication of this week’s in-depth report, provided some clues as to what the market may do next. Price returned to below $510 today with a brief dip below $500 (on the leveraged exchanges) during the European market session.link.
A common wisdom in the market says:
“Periods of low momentum precede periods of volatility.”
The visual pattern is unmistakable – a contracting consolidation moving sideways. We’ve witnessed this pattern twice since the beginning of July, and its conclusion has been the same each time: a drop, as if over a cliff, and each time by at least $20 within an hour or two. At the extremes of each contracting wave price can be seen to equalize amongst exchanges, as shown in the snapshot on the right (BTC-e (top), BitFinex, Bitstamp and BTC-China (bottom).)
Google is continuing its journey into the world of unmanned air vehicles (UAVs), as it introduces a parcel-delivery UAV prototype developed under its two-year Project Wing effort.
The technology company is developing the concept through its Google X research division, and the announcement follows on from the company’s April 2014 acquisition of Titan Aerospace – a high-altitude, long endurance (HALE) solar-powered UAV manufacturer.
“Throughout history there have been a series of innovations that have each taken a huge chunk out of the friction of moving things around,” says Google X Moonshots captain Astro Teller in a promotional video posted on 28 August. “Project Wing aspires to take another big chunk of the remaining friction out of moving things around the world.”
Testing took place in Australia as recently as two weeks ago, during which first aid kits and food were delivered to Australian farmers.
In the video the fixed-wing prototype (pictured above) is shown to make a controlled drop of the parcel from a height using a tether, and so far Google says the development has “resulted in a reliable system that can do autonomous delivery”.
Google admits it is “years from a product”, but is confident in this first prototype, which it describes as more akin to a driverless car – which Google is also researching – than to other remote-controlled UAVs.
Dave Vos, the founder of Athena Technologies - a company that developed control software for UAVs and was purchased by Rockwell Collins in 2008 - has been named as lead on the project. The next stage of Project Wing will see Google X working to prove a UAV can quickly and safely deliver items.
Artificial intelligence will likely feature prominently onboard the Pentagon’s next-generation successors to the Boeing F/A-18E/F Super Hornet and the Lockheed Martin F-22 Raptor.
“AI is going to be huge,” said one U.S. Navy official familiar with the service’s F/A-XX effort to replace the Super Hornet starting around 2030.
Further, while there are significant differences between the U.S. Air Force’s vision for its F-X air superiority fighter and the Navy’s F/A-XX, the two services agree on some fundamental aspects about what characteristics the jet will need to share.
“I think we all agree that we have to work on PNT [Positioning, Navigation and Timing], comms, big data movement between both services,” the official said.
It is unclear how advanced technology like artificial intelligence might help a tactical fighter accomplish its mission. But it is possible that the AI would be a decision aid to the pilot in a way similar in concept to how advanced sensor fusion onboard jets like the F-22 and Lockheed Martin F-35 work now.
However, the visions for both the Navy and Air Force are technologically ambitious and there are differences between the services that still need to be resolved.
Cool equatorial terrestrial temperatures and the South Asian monsoon in the Early Eocene: Evidence from the Gurha Mine, Rajasthan, India
Shukla et al
Early Eocene (~ 55–52 Ma) laminated lacustrine sediments overlying lignites in the Gurha Mine (27.87398°N, 72.86709°E), Rajasthan, India, yield a diversity of fossil leaves, flowers, fruits, seeds and insects. CLAMP (multivariate foliar physiognomic) analysis of two horizons separated by an estimated several tens of thousands of years of deposition indicates cool equatorial (~ 10°N) temperatures and a pronounced monsoon signature. A lower assemblage consisting of 54 leaf morphotypes and an upper assemblage of 57 leaf forms yielded mean annual temperatures (MAT) of 24.7 and 23.9 °C, respectively. The uncertainty (± 2.82 °C) means these temperature regimes are identical despite few similarities in the morphotypes between the two assemblages.The mean annual range of temperature (MART) was approximately 9.7 °C for both assemblages. When corrected for evapotranspirational cooling these temperature regimes are similar to those experienced today at 10°N on the west coast of India and surprisingly cool for the tropics at a time of extreme global warmth. Growth was year round. The tropical to paratropical fossil floras also suggest a moist regime (80% annual relative humidity) and high mean annual precipitation of ~ 1800 mm for both assemblages but with a pronounced wet/dry seasonality indicative of a pronounced monsoonal regime. The lower assemblage has a stronger monsoon index (11.8) than the upper assemblage (8.8). The two assemblages seem to have been deposited less than 100 ka apart. This suggests that not only a pronounced South Asian monsoon existed when India and Asia first made contact, but also a variation in monsoon strength existed that cannot be ascribed to tectonic drivers.
Dissolution of benzene, naphthalene, and biphenyl in a simulated Titan lake
Malasaka et al
We constructed a laboratory apparatus capable of measuring the saturation equilibrium concentration (csat) and dissolution rate constants (keff) of organic solutes in ethane at 94 K. We determined a csat of 18.5 ± 1.9 mg L−1, 0.159 ± 0.003 mg L−1, and 0.039 ± 0.006 mg L−1 for benzene, naphthalene, and biphenyl, respectively. The derived csat and keff can be used to predict the dissolution behavior of the materials in ethane under Titan conditions. The aromatic materials dissolved relatively quickly in liquid ethane at 94 K, reaching saturation in less than 2 h. The dissolution characteristics of benzene in ethane at 94 K are compared to those of terrestrial karst-forming materials in water at 298 K, and are used to constrain Titan surface processes. We discuss the implications of our measurements on the formation of karst on Titan, the concentration of organics in Titan’s lakes, and the formation of evaporite deposits during lake evaporation.
Grade school history lessons often have it that American Indians largely were wiped out by diseases such as whooping cough, chicken pox, influenza and tuberculosis brought to the New World by European explorers.
One report says, while estimates vary, about 20 million people lived in the Americas shortly before Europeans arrived, and roughly 95 percent of them were killed by European diseases.
But new research led by anthropological geneticists Anne Stone of Arizona State University and Johannes Krause of the University of Tubingen in Germany indicates the diagnosis of what devastated American Indian populations is a little more complicated, particularly when it comes to tuberculosis.
Their study of pre-Columbian Mycobacterial tuberculosis genomes published today in the journal Nature reveals that tuberculosis may have had a hand in American Indian deaths prior to the influx of European diseases. The research concludes seals and sea lions likely brought the disease to South America and spread it to people there long before Christopher Columbus arrived in 1492.
"What we found was really surprising," said Stone, referring to her team's examination of tuberculosis DNA from roughly 1,000-year-old human skeletons found in Peru that produced the discovery.
The results, the researchers write, provide unequivocal evidence that a member of the M. tuberculosis complex caused human disease in the pre-contact New World.
"Skeletal evidence of tuberculosis is present in the archaeological records in both the Old World and New World," said Elizabeth Tran, Biological Anthropology program director in the National Science Foundation's Division of Behavioral and Cognitive Sciences.
"The source of tuberculosis in the New World long has been a question for researchers. This paper provides strong evidence that marine mammals may have been the likely culprits, bringing tuberculosis to South America long before Europeans arrived there."
The ancestors of today's crocodiles colonised the seas during warm phases and became extinct during cold phases, according to a new Anglo-French study which establishes a link between marine crocodilian diversity and the evolution of sea temperature over a period of more than 140 million years.
The research, led by Dr Jeremy Martin from the Université de Lyon, France and formerly from the University of Bristol, UK is published this week in Nature Communications.
Today, crocodiles are 'cold-blooded' animals that mainly live in fresh waters but two notable exceptions, Crocodylus porosus and Crocodylus acutus venture occasionally into the sea. Crocodiles occur in tropical climates, and they are frequently used as markers of warm conditions when they are found as fossils.
While only 23 species of crocodiles exist today, there were hundreds of species in the past. On four occasions in the past 200 million years, major crocodile groups entered the seas, and then became extinct. It is a mystery why they made these moves, and equally why they all eventually went extinct. This new study suggests that crocodiles repeatedly colonized the oceans at times of global warming.
Lead author of the report, Dr Jeremy Martin said: "We thought each of these evolutionary events might have had a different cause. However, there seems to be a common pattern."
Paleoproterozoic S-type granites in the Helanshan Complex, Khondalite Belt, North China Craton: Implications for rapid sediment recycling during slab break-off
Dan et al
S-type granites, typically derived from the rapid recycling of sedimentary rocks, are sometimes accompanied by contemporary mafic magmatism and granulite metamorphism. However, the geodynamic context for such rock suites is often highly disputed, with various model proposed, including back-arc basin opening, lithospheric delamination, mantle plume and continental rifting. The Paleoproterozoic Khondalite Belt in the North China Craton provides an example of synchronous mafic and felsic magmatism that was accompanied by granulite-facies metamorphic events for which the tectonic affinities of these rocks remains unclear. This study integrates in situ zircon Hf–O isotope analyses, whole-rock geochemistry and Nd isotope results for the earliest two-mica granites (ca. 1.95 Ga) in order to provide constraints on the above issues. The granites are strongly peraluminous (A/CNK value greater than 1.1), and characterized by high zircon δ18O values of 7.3 to 10.6‰, corresponding to calculated magmatic δ18O values of 9.1 to 12.3‰, similar to those of typical S-type granites. They have relatively high and homogeneous ɛNd(t) values of -1.1 to +0.9 and highly variable zircon ɛHf(t) values ranging from -1.0 to +8.3. In situ zircon Hf-O isotopic compositions indicate that the S-type granites may contain some mantle or juvenile crustal components in addition to a sediment component. Based on the new results and published data, a slab break-off model is proposed to explain the rapid recycling of sedimentary precursors and the generation of the ca. 1.95 Ga S-type granites
Recent anthropogenic and climatic history of Nunatsiavut fjords (Labrador, Canada).
Richerol et al
This study aimed at reconstructing past climatic and environmental conditions of a poorly known and documented subarctic region, the Nunatsiavut (northern Labrador). A multi-proxy approach was chosen, using fossil dinoflagellate cysts, diatoms and pollen from sediment cores taken into three fjords (Nachvak 59°N; Saglek 58.5°N; Anaktalak 56.5°N). It allowed estimating terrestrial and marine influences in each fjord and documenting the recent history of human activities of the southern fjords (Saglek and Anaktalak). Fossil pollen and dinoflagellate cyst assemblages allowed depicting the climate history of the region over the last ~200-300 years. In contrast to the general warming trend observed in the Arctic and sub-Arctic Canada since the beginning of the Industrial Era, the Nunatsiavut has experienced relative climate stability over this period. Fossil pollen data show a shift of the tree limit to the south illustrating the cooling of terrestrial conditions. Our reconstructions suggest that the Labrador region has remained climatically stable over the last ~150-300 years, with just a slight cooling trend of the reconstructed sea-surface temperatures, only perceptible in Saglek and Anaktalak fjords.
I have a brief column on Russia and the INF violation at the European Leadership Network - Don't help Russia destroy the INF Treaty. I don't think the main point I'm trying to make there is particularly controversial - while the United States appears to have reasons to call Russia's noncompliance, the infraction does not seem to be serious enough to press the case too forcefully. Indeed, leaning too hard would only help Russia slam the door and leave the treaty. For what it's worth, the U.S. administration made a smart move - now that the accusation has been made, Russia will find it more difficult to leave the treaty, even if it has been the idea all along. Not impossible, of course, but still.
A couple of points that are probably worth emphasizing. First, as I suspected, the alleged violation is not about the R-500 cruise missile or the Iskander system - U.S. officials were said to informally confirm that. Russian sources also say that the deployed Iskander/R-500 cruise missiles are treaty-compliant.
Second, the evidence presented by the United States to Russia is apparently rather thin - in fact, one Russian official said scornfully that they have to deal with Twitter messages and photos. Some sources say that the United States did not even tell Russia what particular cruise missile this is about. This is somewhat hard to believe, especially since Anatoly Antonov said (my apologies for a link to RT) that the issue was discussed at the end of 2013 and his understanding is that the United States accepted Russia's explanations. So, Russia must know what the issue is. As for the Twitter evidence, I wouldn't be surprised if the United States did not show all its cards - it is quite careful about protecting methods and sources.
In any event, it appears that Russia took the issue seriously and agreed to discuss it at what appears to be a fairly high-level meeting in September. We will see what that meeting produces. But as I understand, Russia is not in the mood to make any corrective actions - it wants the United States to take the accusations back and is perfectly prepared to leave the treaty if this doesn't happen.
The 2010 British Strategic Security and Defence Review (SDSR) begun with an unambiguous statement of intent; ‘Our country has always had global responsibilities and global ambitions. We have a proud history of standing up for the values we believe in and we should have no less ambition for our country in the decades to come’. It then goes on to outline how this might be achieved. Britain must be ‘more thoughtful, more strategic and more coordinated in the way we advance our interests and protect our national security’. But since 2010 the record has not reflected these aims. If anything, it seems the British government is becoming less and less clear about what it wishes to achieve in the international arena in service of British national interests. Written in the light of recent adventures in Iraq and Afghanistan, the document admits that Britain’s ‘Armed Forces – admired across the world – have been overstretched, deployed too often without appropriate planning, with the wrong equipment, in the wrong numbers and without a clear strategy. In the past, underfunded spending pledges created a fundamental mismatch between aspiration and resources’. The murderous march of Islamic State (previously ISIS) through Iraq, the ever present and resurgent Taliban threat in Afghanistan and the declining civil order in Libya all demonstrate the damaging consequences of ill-conceived and ill-planned military intervention. Professionalism, success and sacrifice at the tactical level have not translated into success at the strategic level, largely due to the simple fact there has been no overarching strategic direction, set at the political level, guiding operational and tactical planning. The consequences of Britain’s twenty-first century interventionist wars are yet to be fully felt, but they are unlikely to lead to the stability and peace in the Middle East, and security at home, that was envisaged.
The key reason for defeat in these campaigns was a failure of British policymakers to fully appreciate the military, political and cultural dimensions of the regions and conflicts in which they were getting involved. This inevitably led to an inability to develop a singular strategic aim and appropriately plan for contingent outcomes, leading to confusion around how to respond both politically or militarily to evolving contexts. Ultimately, this bewilderment was an predictable consequence of fighting the wrong conflicts, conflicts that did not directly serve British or indeed, global interests, or in fighting them in the wrong way (as in Afghanistan where limited intervention led to strategic creep – ‘nation building’ – and a blurring of aims and means, and in Libya where short term kinetic intervention has led to long term instability). For these reasons, Britain and her allies could never secure long-term victory. If London did not set criteria for victory, how could it possibly achieve it? As the British naval thinker Admiral Sir Herbert Richmond once cautioned in his 1946 study ‘Statesmen and Seapower’; ‘If the statesman misinterprets the nature of national defence or the ultimate object of a war, or fails to make the necessary preparations; if, in war, he misdirects the strategy employed for the attainment of the object; the results will be far more injurious than those of errors in minor strategy or tactics: for they are more far-reaching’. These words have acquired fresh resonance.
Thursday, August 28, 2014
It has been a while since I posted an update for what is happening in Ukraine. I have been dealing with a lot in the rocket business, some zaniness with the day job and working on the evac of contacts out of Gorlovka.
That said, in the time since I posted, a lot has happened. Very little of it is good for the Ukrainians. On the cusp of victory, crushing the rebels wherever they fought, they are now in process of being routed and the Russian army, at least the soldiers, are in the Donbass.
The best description of I have seen of what Russia's actions is Putin is 'boiling the frog.' The frog, in this case, is NOT Ukraine, but rather the world. He has been ratcheting up the intervention in Ukraine, turning up the heat, and done so in small enough increments the world has failed to notice the radical changes. He has a convert invasion under way. This is much more than even the LGM scenario. Right now, the Russians claim their soldiers are fighting in Ukraine when they are on leave. Sources from inside Russia are claiming over 10k troops are now fighting and in many cases dying in Ukraine. The next temperature raise is...an overt invasion.
The Ukrainian army was stopped in its tracks and made little progress save, perhaps, around Gorlovka. On the other hand, they faced significant losses everywhere else. Their pincer movements to cut Lugansk and Donetsk off from the Russian border have been pushed back and forced to massively retreat. They are going to lose the southern portion of their conquests in the DNR. The Russians are even pushing onto Mariupol.
Little Green Men started popping up all over the place.
Poroshenko met with Putin in Belarus. There are some pictures of them shaking hands. The talks were futile. Putin even attempts a Mr Burns level of evil. Or at least the look of it. If not for the horror of it all, it would be comical.
The Ukrainians have reinstituted the draft. Poroshenko has stated he now has arms coming in, but has not revealed the source. He has also requested an alliance with the US outside of NATO like Australia, Philippines or Japan. Ukraine has captured over 12 Russian soldiers. NATO showed satellite images of Russian troops in Ukraine.
Russia has buried over 100 soldiers already in a single engagement: the Ukrainians hit them with GRADs. Twice as many wounded were taken back to Russia.
Unfortunately, Obama stopped short of calling a spade a spade (unlike the Lithuanians) and did NOT call what is happening in Ukraine an invasion. I guess there is still more salami to slice. Or the frog can boil a bit longer.
An interesting rumor is Poland is calling up its reserves.
The Racetrack Playa — a barren lakebed in Death Valley National Park — is home to one of the world’s natural wonders: “sailing stones” that mysteriously meander across the dried mud, leaving tracks in their wake. Since the 1940s, these rocks have fueled wonder and speculation because no one had seen them in action — until now.
A team of U.S. scientists recorded the first observation of these boulders in motion, using GPS monitors and time-lapse photography. By meticulously tracking weather data, scientists also explained how these rocks slog across the playa. What was one of the world’s natural wonders now appears to be the perfect combination of rain, wind, ice and sun.
When the recording industry smashed Napster with a $20 billion lawsuit more than a decade ago, filesharing morphed into Bittorrent, a fully peer-to-peer system with no central server for law enforcement to attack. Now the developers behind one software project are trying to pull off a similar trick with the anarchic model of bitcoin e-commerce pioneered by the billion-dollar Silk Road black market. And just as with Bittorrent, their new system may be so decentralized that not even its creators can control exactly how it will be used.
This weekend, the developers behind OpenBazaar plan to release a beta version of the software designed to let anyone privately and directly buy and sell goods online with no intermediary. They describe it as “pseudonymous, uncensored trade.” Rather than hosting its commerce on any server, OpenBazaar installs on users’ PCs, and allows them to list products in a file stored in a so-called “distributed hash table,” a database spread across many users’ machines. Everything will be paid in bitcoin. The result of that peer-to-peer architecture, they hope, will be a marketplace that no one—–no government, no company, not even the OpenBazaar programmers—can regulate or shut down.
“We’re just really passionate about allowing peer-to-peer trade to happen online. We want that to exist,” says Sam Patterson, the operations lead for the non-profit project. “The internet allowed you to communicate directly. Bitcoin allowed you to send money directly. Now you can trade directly.”
And just what will you trade on OpenBazaar? A good first guess might be drugs. The multi-headed marketplace, after all, is designed to thwart law enforcement seizures or takedowns that arrest any one person or group. And though it doesn’t currently offer much anonymity by default, Patterson says its initial version can be used through a VPN to hide users’ IP addresses, and it will soon integrate the anonymity software Tor or I2P.
In fact, OpenBazaar was first launched in April as a spinoff of another open-source prototype called DarkMarket. That project’s anarchist creator, Amir Taaki, says he was inspired by the FBI’s takedown of the Silk Road and designed DarkMarket to “equip the people with the tools needed for the next generation of digital black markets.”
But Patterson and OpenBazaar founder Brian Hoffman adamantly insist OpenBazaar isn’t designed for selling narcotics, guns, or other contraband. They see their invention as a freer, more democratic eBay or Craigslist, with no seller fees and no one to arbitrarily change the rules or censor products. “We’re not the ‘Super Silk Road.’ We’re trying to replace eBay in a better form,” says Patterson. “We recognize that people may choose to use that technology in a way we see as distasteful, immoral, and illegal, but we’re giving them the option to engage in a kind of human interaction that doesn’t exist right now.”
An AV-8B Harrier aircraft damaged during a hard landing on board a US Navy amphibious assault ship has been rapidly repaired and returned to service using additive manufacturing (AM) technology, according to Naval Air Systems Command (NAVAIR).
Technicians at Fleet Readiness Centre East (FRCE), part of the US Marine Corps Air Station Cherry Point in North Carolina, employed AM techniques - otherwise known as 3-D printing - to create the forming tools that were required to shape metal repair parts for the Harrier's nose cone.
Constructed by a process of fused deposition modelling, polymer form blocks were used to produce sheet metal reinforcements, or doublers, for the aircraft.
Boeing has been awarded a USD9.4 million contract modification to continue refining its design of the experimental vertical take-off and landing (VTOL) Phantom Swift X-Plane, according to a 26 August Department of Defense (DoD) announcement.
The DoD's Defense Advanced Research Projects Agency (DARPA) awarded the funds for a 16-month option on an existing 7-month base contract, according to the announcement.
The Holocene temperature conundrum
Liu et al
A recent temperature reconstruction of global annual temperature shows Early Holocene warmth followed by a cooling trend through the Middle to Late Holocene [Marcott SA, et al., 2013, Science 339(6124):1198–1201]. This global cooling is puzzling because it is opposite from the expected and simulated global warming trend due to the retreating ice sheets and rising atmospheric greenhouse gases. Our critical reexamination of this contradiction between the reconstructed cooling and the simulated warming points to potentially significant biases in both the seasonality of the proxy reconstruction and the climate sensitivity of current climate models.
NASA just announced an 11-month delay in the first Space Launch System flight from December 2017 to November 2018 in the fourth paragraph of a press release.
This decision comes after a thorough review known as Key Decision Point C (KDP-C), which provides a development cost baseline for the 70-metric ton version of the SLS of $7.021 billion from February 2014 through the first launch and a launch readiness schedule based on an initial SLS flight no later than November 2018.
The full press release is below.
In an environment where others struggle to survive, Tibetans thrive in the thin air on the Tibetan Plateau, with an average elevation of 14,800 feet. A University of Utah led discovery that hinged as much on strides in cultural diplomacy as on scientific advancements, is the first to identify a genetic variation, or mutation, that contributes to the adaptation, and to reveal how it works. The research appears online in the journal Nature Genetics on Aug. 17, 2014.
“These findings help us understand the unique aspects of Tibetan adaptation to high altitudes, and to better understand human evolution,” said Josef Prchal, M.D., senior author and University of Utah professor of internal medicine.
For his research, Prchal needed Tibetans to donate blood, from which he could extract their DNA, a task that turned out to be more difficult than he ever imagined. It took several trips to Asia, meeting with Chinese officials and representatives of exiled Tibetans in India, to get the necessary permissions to recruit subjects for the study. But he quickly learned that official documents would not be enough. Wary of foreigners, the Tibetans refused to participate.
To earn the Tibetans’ trust, Prchal obtained a letter of support from the Tibetan spiritual leader, the Dalai Lama. “The Dalai Lama felt that a better understanding of the adaptation would be helpful not only to the Tibetan community but also to humanity at large,” said Prchal. He also enlisted the help of native Tibetan Tsewang Tashi, M.D., an author and clinical fellow at the Huntsman Cancer Institute at the University of Utah. More than 90 Tibetans, both from the U.S. and abroad, volunteered for the study.
Published in Science in 2010, Prchal’s group was the first to establish that there was a genetic basis to Tibetan high altitude adaptation. In the intervening years, first author Felipe Lorenzo, M.D., Ph.D., pioneered new techniques to tease out the secret to one of the adaptations from a “GC-rich” region of the Tibetans’ DNA that was particularly difficult to penetrate.
Their efforts were worth it; the DNA had a fascinating story to tell. About 8,000 years ago, the gene EGLN1 changed by a single DNA base pair. Today, a relatively short time later on the scale of human history, the vast majority of Tibetans – 88 percent - have the genetic variation, and it is virtually absent from closely related lowland Asians. The findings indicate the tiny genetic change endows its carriers with a selective advantage.
Ancient dates or accelerated rates? Morphological clocks and the antiquity of placental mammals
Beck et al
Analyses of a comprehensive morphological character matrix of mammals using ‘relaxed’ clock models (which simultaneously estimate topology, divergence dates and evolutionary rates), either alone or in combination with an 8.5 kb nuclear sequence dataset, retrieve implausibly ancient, Late Jurassic–Early Cretaceous estimates for the initial diversification of Placentalia (crown-group Eutheria). These dates are much older than all recent molecular and palaeontological estimates. They are recovered using two very different clock models, and regardless of whether the tree topology is freely estimated or constrained using scaffolds to match the current consensus placental phylogeny. This raises the possibility that divergence dates have been overestimated in previous analyses that have applied such clock models to morphological and total evidence datasets. Enforcing additional age constraints on selected internal divergences results in only a slight reduction of the age of Placentalia. Constraining Placentalia to less than 93.8 Ma, congruent with recent molecular estimates, does not require major changes in morphological or molecular evolutionary rates. Even constraining Placentalia to less than 66 Ma to match the ‘explosive’ palaeontological model results in only a 10- to 20-fold increase in maximum evolutionary rate for morphology, and fivefold for molecules. The large discrepancies between clock- and fossil-based estimates for divergence dates might therefore be attributable to relatively small changes in evolutionary rates through time, although other explanations (such as overly simplistic models of morphological evolution) need to be investigated. Conversely, dates inferred using relaxed clock models (especially with discrete morphological data and MrBayes) should be treated cautiously, as relatively minor deviations in rate patterns can generate large effects on estimated divergence dates.
Edestus, the Strangest Shark? First Report from New Mexico, North American Paleobiogeography, and a New Hypothesis on its Method of Predation more
Two incomplete teeth of the chondrichthyan genus Edestus are reported. They were collected fromthe Gray Mesa Formation (Pennsylvanian, late Desmoinesian), Socorro County, New Mexico, in 1996.The better-preserved tooth belongs to Edestus sp. cf. E. heinrichi. The other cannot be identifiedbeyond the generic level. These are the first specimens of the genus known to be reported from NewMexico. The only other specimens known from the Rocky Mountain region are from Colorado. Boththe New Mexico and Colorado collections are from marine limestones. In North America, Edestus ismost common in marine black shales of the Illinois Basin, but to date has not been found in marinegray shales or limestones in the Appalachian Basin. The failure to find Edestus remains in the Appalachian Basin is probably the result of the precise timing and limited extent of marine incursionsinto that region. Edestus might have been less tolerant of restricted marine environments than otherchondrichthyans collected from Pennsylvanian deposits in the Appalachian Basin. The function of thesymphyseal tooth whorls of Edestus is obscure, inasmuch as their convex curvature makes them poorly-adapted to the “scissors” function proposed in some previous studies. Alternatively, it is pro-posed here that Edestus teeth were used to disable prey with a slicing action carried out with a verticalmotion of the head, with jaws fixed relative to each other, and not with a scissors-like action of thejaws moving relative to each other. This hypothesis is supported by the author’s observations of wearand damage on the teeth of the holotype of Edestus newtoni. Helicoprion tooth whorls are similar to those of Edestus in that they contain sharp, serrated tooth crowns along the convex margin of the whorls and extend outside the oral cavity. The whorls might have functioned similarly to the mannerthat is hypothesized for Edestus,that is, to slash prey with a downward motion of the head, with jawsfixed. This proposed similarity in form and function would likely represent convergence
Lucernaria quadricornis (extant) and Haootia quadriformis (ediacaran)
Haootia quadriformis n. gen., n. sp., interpreted as a muscular cnidarian impression from the Late Ediacaran period (approx. 560 Ma)
Liu et al
Muscle tissue is a fundamentally eumetazoan attribute. The oldest evidence for fossilized muscular tissue before the Early Cambrian has hitherto remained moot, being reliant upon indirect evidence in the form of Late Ediacaran ichnofossils. We here report a candidate muscle-bearing organism, Haootia quadriformis n. gen., n. sp., from approximately 560 Ma strata in Newfoundland, Canada. This taxon exhibits sediment moulds of twisted, superimposed fibrous bundles arranged quadrilaterally, extending into four prominent bifurcating corner branches. Haootia is distinct from all previously published contemporaneous Ediacaran macrofossils in its symmetrically fibrous, rather than frondose, architecture. Its bundled fibres, morphology, and taphonomy compare well with the muscle fibres of fossil and extant Cnidaria, particularly the benthic Staurozoa. Haootia quadriformis thus potentially provides the earliest body fossil evidence for both metazoan musculature, and for Eumetazoa, in the geological record.
Global agriculture and carbon trade-offs
Johnson et al
Feeding a growing and increasingly affluent world will require expanded agricultural production, which may require converting grasslands and forests into cropland. Such conversions can reduce carbon storage, habitat provision, and other ecosystem services, presenting difficult societal trade-offs. In this paper, we use spatially explicit data on agricultural productivity and carbon storage in a global analysis to find where agricultural extensification should occur to meet growing demand while minimizing carbon emissions from land use change. Selective extensification saves ∼6 billion metric tons of carbon compared with a business-as-usual approach, with a value of approximately $1 trillion (2012 US dollars) using recent estimates of the social cost of carbon. This type of spatially explicit geospatial analysis can be expanded to include other ecosystem services and other industries to analyze how to minimize conflicts between economic development and environmental sustainability.
Singapore appears to have quietly boosted the size of its F-15SG fleet from 24 aircraft to 40, according to Boeing financial statements, aircraft registration filings, and US congressional reports.
Singapore originally bought 12 F-15SGs - with an option for eight more - under a contract signed in December 2005. In October 2007 the city-state modified this option by buying 12 more to give it a total of 24.
These aircraft have all been confirmed as delivered and have US-type serial numbers running from 05-0001 to 05-0024. Several remain in the United States with the Republic of Singapore Air Force's (RSAF's) 428th Fighter Squadron at Mountain Home Air Force Base (AFB) in southwestern Idaho, while the remainder are active in Singapore with 149 Squadron.
Aircraft operating in Singapore use four-digit serial numbers in the 83xx sequence, starting at 8301, although these do not run consecutively.
In January 2014, several aircraft with new serial numbers - 05-0025, 05-0028, 05-0030, 05-0031, and 05-0032 - were seen at Mountain Home AFB. These had not been previously reported and suggest that Singapore has obtained another batch of eight aircraft.
Meanwhile, a 26 November 2012 letter from the US State Department to House of Representatives Speaker John Boehner under the Arms Export Control Act refers to the "sale, modification, and follow-on support of eight F-15SG aircraft to the Government of Singapore".
Figures released by Boeing show that eight F-15s were delivered to an unspecified customer in 2012.
Boeing financial data also shows that a total of 93 F-15s were delivered from 2005 to 2012. South Korea has confirmed that it received 61 and Singapore that it received 24 for a total of 85, leaving eight unaccounted for in public records.
In World War II, this country served the allied cause as a giant aircraft carrier and port, providing planes, men and materiel to deploy throughout the Pacific. Allied aircraft flew from the northeastern town of Cairns during the Battle of the Coral Sea — known by some as the “battle that saved Australia.”
The Battle of Milne Bay on the eastern tip of New Guinea, little known to Americans, marked the first time allied troops turned back what had been the unstoppable Japanese. Australians fought that battle, aided by allied aircraft flying from an airstrip inland of the port of Townsville, which played crucial roles in virtually every battle of the Pacific.
Today, the strategic situation is very different. The greatest threats to peace in the region are North Korea and an increasingly assertive China. Indonesia has replaced Japan as the central threat faced by the Australia, although relations between the two states have improved considerably over the last two decades. Defense policymakers still consider the Aussie military’s ability to defeat Indonesia a primary benchmark.
What does all this translate into? Defend Australia from the north (hence the carefully circumscribed agreement to allow US Marines to operate from Darwin but not to be based there) and ensure Australian submarines can avoid its enormous shoal waters and deploy undetected from the deep water ports in the south to help protect the country.
That has been the essential model for a long time but some basic strategic facts have recently changed.
Wednesday, August 27, 2014
Quantum imaging with undetected photons
Lemos et al
Information is central to quantum mechanics. In particular, quantum interference occurs only if there exists no information to distinguish between the superposed states. The mere possibility of obtaining information that could distinguish between overlapping states inhibits quantum interference. Here we introduce and experimentally demonstrate a quantum imaging concept based on induced coherence without induced emission. Our experiment uses two separate down-conversion nonlinear crystals (numbered NL1 and NL2), each illuminated by the same pump laser, creating one pair of photons (denoted idler and signal). If the photon pair is created in NL1, one photon (the idler) passes through the object to be imaged and is overlapped with the idler amplitude created in NL2, its source thus being undefined. Interference of the signal amplitudes coming from the two crystals then reveals the image of the object. The photons that pass through the imaged object (idler photons from NL1) are never detected, while we obtain images exclusively with the signal photons (from NL1 and NL2), which do not interact with the object. Our experiment is fundamentally different from previous quantum imaging techniques, such as interaction-free imaging or ghost imaging, because now the photons used to illuminate the object do not have to be detected at all and no coincidence detection is necessary. This enables the probe wavelength to be chosen in a range for which suitable detectors are not available. To illustrate this, we show images of objects that are either opaque or invisible to the detected photons. Our experiment is a prototype in quantum information—knowledge can be extracted by, and about, a photon that is never detected.
While awareness of cryptocurrencies is rising, very few people have actually used them. A new survey, from the Conference of State Bank Supervisors and the Massachusetts Division of Banks, found that 51% of people in the U.S. were aware of bitcoin and other currencies, albeit only about 3% had said they used it.
Still, that’s a big change from earlier this year. Back in February, another survey found that about three-quarters of the population hadn’t heard of bitcoin, and 80% said they’d never even consider using it.
The CSBS survey was taken in May, and canvassed 1,000 online consumers.
Some of the findings aren’t surprising; men, for instance, were more likely (64%) than women (38%) to be aware of virtual currencies. Only a limited number said they’d buy or use them – 65% of the overall respondents said they were “unlikely” to ever use them. Younger respondents were more likely to have purchased bitcoins or other currencies, and Hispanics (30%) and African Americans (24%) were also more likely than whites (14%) to be willing to purchase virtual currencies.
While people in households where the income is over $100,000 were more likely to have heard of bitcoin (70%) than those in lower-income households (43%), they were less likely to say they’d purchase bitcoins (11%) than those in households with incomes of less than $100,000 (19%).
Textron AirLand plans to enter a modified version of its Scorpion aircraft into the US Air Force’s T-X trainer replacement competition, a top company official said.
The company is also eyeing the international training market as an area of growth for its jet, which is still working on signing its first customer.
Textron executives have largely danced around the question of whether the Scorpion would enter the T-X competition, hinting it was under consideration but not giving confirmation. The comments from Stephen Burke, regional vice president for military business development at Textron AirLand, were the clearest and most decisive made by an executive about plans to enter the trainer market.
“We will compete for T-X,” Burke told Defense News Aug. 23 at the National Guard Association of the United States annual conference in Chicago.
Hypersonic vehicles seems all the rage these days - China reportedly tested one, named Wu-14 on August 7, the United States made an attempt to test its own on August 25. Neither of these tests was a success, but it is clear that the tests will continue. What about Russia?
Russia first went public with its "hypersonic weapon" more than ten years ago - in February 2004 it tested a warhead that according to the Kremlin "will fly at hyper-sonic speed and will be able to change trajectory both in terms of altitude and direction, and missile defence systems will be powerless against them".
The warhead in question appears to go all the way back to the 1980s. One of the projects developed by the Chelomey Design Bureau (NPOmash) after 1987, an Albatross (solid-propellant) ICBM, included some kind of a maneuverable warhead. In 1989 the Albatross missile system was transferred to other design bureaus (and became Universal, which then became Topol-M), but NPOmash apparently kept the warhead. It was tested at least twice - on 28 February 1990 and 5 March 1990. Katayev's notes are a bit cryptic on these tests, but he noted that both tests were conducted "without separation" and mentions "70-80 km altitude." The vehicles flew to Kamchatka. Additional flight tests, including ones "with separation," were planned, but it looks like the first two flights were the last ones for some time.
Eustatic, tectonic, and climatic signatures in the Lower Cretaceous siliciclastic succession on the Eastern Russian Platform
A methodical approach to identifying major abiotic events in the siliciclastic succession accumulated in the shallow epicontinental basin on the Eastern Russian Platform during the Early Cretaceous is presented. On the basis of a reliable chronostratigraphic framework a comparison between global and regional sea level curves was undertaken. The intervals during which the global and regional sea level curve trends are similar correspond to a predominance of eustasy in the particular basin. Alternatively, tectonic activity dominates during intervals when there is no similarity between the trends of the global and regional sea level curves. Three intervals of noncoincidences of trends of these two curves matched with major tectonic events that took place within the Eastern Russian Platform in the Early Cretaceous: the Early Hauterivian tectonic uplift, subsequent Late Hauterivian subsidence and the Late Albian uplift. The main consequences of the tectonic activity were two large regional unconformities and hiati. The comparison of main global and regional sea level trends also reveals major climatic events. “The cold snaps” that occurred during the Early Cretaceous greenhouse world (Hu et al., 2012) coincided with simultaneous global and regional sea level lowstands, peak shallowing of the basin and the almost complete absence of sediments. “The cold snap” is identified in the Late Aptian sedimentary sequences on the Eastern Russian Platform.
Laboratory insights into the chemical and kinetic evolution of several organic molecules under simulated Mars surface UV radiation conditions
Poch et al
The search for organic carbon at the surface of Mars, as clues of past habitability or remnants of life, is a major science goal of Mars’ exploration. Understanding the chemical evolution of organic molecules under current martian environmental conditions is essential to support the analyses performed in situ. What molecule can be preserved? What is the timescale of organic evolution at the surface? This paper presents the results of laboratory investigations dedicated to monitor the evolution of organic molecules when submitted to simulated Mars surface ultraviolet radiation (190–400 nm), mean temperature (218 ± 2 K) and pressure (6 ± 1 mbar) conditions. Experiments are done with the MOMIE simulation setup (for Mars Organic Molecules Irradiation and Evolution) allowing both a qualitative and quantitative characterization of the evolution the tested molecules undergo (Poch, O. et al. . Planet. Space Sci. 85, 188–197). The chemical structures of the solid products and the kinetic parameters of the photoreaction (photolysis rate, half-life and quantum efficiency of photodecomposition) are determined for glycine, urea, adenine and chrysene. Mellitic trianhydride is also studied in order to complete a previous study done with mellitic acid (Stalport, F., Coll, P., Szopa, C., Raulin, F. . Astrobiology 9, 543–549), by studying the evolution of mellitic trianhydride. The results show that solid layers of the studied molecules have half-lives of 10–103 h at the surface of Mars, when exposed directly to martian UV radiation. However, organic layers having aromatic moieties and reactive chemical groups, as adenine and mellitic acid, lead to the formation of photoresistant solid residues, probably of macromolecular nature, which could exhibit a longer photostability. Such solid organic layers are found in micrometeorites or could have been formed endogenously on Mars. Finally, the quantum efficiencies of photodecomposition at wavelengths from 200 to 250 nm, determined for each of the studied molecules, range from 10−2 to 10−6 molecule photon−1 and apply for isolated molecules exposed at the surface of Mars. These kinetic parameters provide essential inputs for numerical modeling of the evolution of Mars’ current reservoir of organic molecules. Organic molecules adsorbed on martian minerals may have different kinetic parameters and lead to different endproducts. The present study paves the way for the interpretation of more complex simulation experiments where organics will be mixed with martian mineral analogs.
A question of timing: spatio-temporal structure and mechanisms of early agriculture expansion in West Africa
Ozainne et al
Although understanding the emergence of agriculture in West Africa has recently benefited from major advances, the reasons for its fast diffusion south of the Sahara remain to be explained. We propose here a reconstruction of African agriculture expansion built from a spatialization of available archaeological data and associated radiocarbon dates. With this approach, we can show that the initial spread of food production occurred with some specific rhythms. From this structure, we discuss the potential underlying processes. Our work suggests that the spread of agriculture in West Africa cannot be explained by a simple response to an abrupt environmental change at the beginning of the Late Holocene, but rather by a combined climate-culture mechanism. In addition, cord-wrapped roulette-impressed pottery appears to be a good indicator of the expansion of agro-pastoralist populations in Sub-Saharan regions. Our results are also consistent with the assumption of a monophyletic origin of domestic pearl millet in south-western Sahara and strengthen the idea that the first cultivators were Saharan pastoralists.