Friday, May 31, 2013
Frak Me! The Monterey Shale Could Have Up to 15.2 BILLION Barrels of Oil
It's easy to tick off the ways in which California is a leader in clean energy: It harvests more solar energy than any other state, has a program to curb greenhouse gas emissions from the vehicles on its famously long highways, and launched its own cap-and-trade system this year.
And yet, a move is afoot for a quite different type of new energy development in the Golden State, beneath the same valley that beckoned gold seekers and migrant farmers generations ago. That ever alluring land happens to lie atop the Monterey shale formation, a vast rock formation that is believed to hold one of the world's largest onshore reserves of shale oil.
Oil companies are seeking to stake their claim to this prize, plunging California into a debate on its energy and economic future. The U.S. trailblazer on renewable energy could well become the latest front in the nation's fracking-driven oil boom.
It's not yet clear whether hydraulic fracturing can unleash the same sort of oil rush in California's Monterey shale as the United States is now seeing in North Dakota and in Texas. The San Joaquin Valley, site of historic tension over river flow, aquifer-pumping, and irrigation, is a dubious location for a business that requires large volumes of water to fracture the underground rock.
As for the rock itself, it is deeper and thicker than other shales, formed by tectonic faulting millions of years ago. Today the geology's potential and risks are still not fully understood. But perhaps the biggest obstacles are above ground, as California grapples with questions fundamental to its identity. Should the state move aggressively to seize this new opportunity for jobs and industrial development, or take steps to preserve its remaining havens of undeveloped land and shun a new round of fossil fuel expansion?
Chemical Reaction, Atom by Atom, Bond by Bond
When Felix Fischer of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) set out to develop nanostructures made of graphene using a new, controlled approach to chemical reactions, the first result was a surprise: spectacular images of individual carbon atoms and the bonds between them.
“We weren’t thinking about making beautiful images; the reactions themselves were the goal,” says Fischer, a staff scientist in Berkeley Lab’s Materials Sciences Division (MSD) and a professor of chemistry at the University of California, Berkeley. “But to really see what was happening at the single-atom level we had to use a uniquely sensitive atomic force microscope in Michael Crommie’s laboratory.” Crommie is an MSD scientist and a professor of physics at UC Berkeley.
What the microscope showed the researchers, says Fischer, “was amazing.” The specific outcomes of the reaction were themselves unexpected, but the visual evidence was even more so. “Nobody has ever taken direct, single-bond-resolved images of individual molecules, right before and immediately after a complex organic reaction,” Fischer says.
The researchers report their results online in the May 30, 2013 edition of Science Express.
Ancient, Dry Streambed Found on Mars
Rounded pebbles on the surface of Mars indicate that a stream once flowed on the red planet, according to a new study by a team of scientists from NASA's Curiosity rover mission, including a University of California, Davis, geologist. The study will be published in the May 31 issue of the journal Science.Rounded pebbles of this size are known to form only when transported through water over long distances. They were discovered between the north rim of the planet's Gale Crater and the base of Mount Sharp, a mountain inside the crater.The finding represents the first on-site evidence of sustained water flows on the Mars landscape, and supports prospects that the planet could once have been able to host life.As a co-investigator for NASA's Mars Science Laboratory team, UC Davis geologist and study co-author Dawn Sumner played a key role in choosing Gale Crater as the landing site for Curiosity. Finding the rounded pebbles, which were deposited more than 2 billion years ago, was a matter of landing in the right place, she said."The main reason we chose Gale Crater as a landing site was to look at the layered rocks at the base of Mount Sharp, about five miles away," she said. "We knew there was an alluvial fan in the landing area, a cone-shaped deposit of sediment that requires flowing water to form. These sorts of pebbles are likely because of that environment. So while we didn't choose Gale Crater for this purpose, we were hoping to find something like this."The finding comes from Curiosity's exploration of the Mars surface during its first 100 sols (102.7 days on Earth), or Martian days. During that time, the rover traveled about a quarter mile from its landing site, examining multiple outcrops of pebble-rich slabs. Curiosity took high-resolution images of these pebbles at three locations known as Goulburn, Link and Hottah. The grain size, roundness and other characteristics of the pebbles led the researchers to conclude they had been transported by water.
US Army Starts Developing Powered Armor Under the TALOS Project
Army researchers are responding to a request from the U.S. Special Operations Command for technologies to help develop a revolutionary Tactical Assault Light Operator Suit.
The Tactical Assault Light Operator Suit, or TALOS, is an advanced infantry uniform that promises to provide superhuman strength with greater ballistic protection. Using wide-area networking and on-board computers, operators will have more situational awareness of the action around them and of their own bodies.
The U.S. Army Research, Development and Engineering Command, known as RDECOM, is submitting TALOS proposals in response to the May 15 request.
“There is no one industry that can build it,” said SOCOM Senior Enlisted Advisor Command Sgt. Maj. Chris Faris during a panel discussion at a conference at MacDill Air Force Base, Fla., recently, reported Defense Media Network.
The request, currently posted on Federal Business Opportunities, is looking for technology demonstration submissions from research and development organizations, private industry, individuals, government labs and academia to support the command-directed requirement issued by Adm. William McRaven, USSOCOM commander.
“[The] requirement is a comprehensive family of systems in a combat armor suit where we bring together an exoskeleton with innovative armor, displays for power monitoring, health monitoring, and integrating a weapon into that — a whole bunch of stuff that RDECOM is playing heavily in,” said. Lt. Col. Karl Borjes, an RDECOM science advisor assigned to SOCOM.
TALOS will have a physiological subsystem that lies against the skin that is embedded with sensors to monitor core body temperature, skin temperature, heart rate, body position and hydration levels.
Scientists at the Massachusetts Institute of Technology are currently developing armor made from magnetorheological fluids — liquid body armor — that transforms from liquid to solid in milliseconds when a magnetic field or electrical current is applied. Though still in development, this technology will likely be submitted to support TALOS.
“RDECOM cuts across every aspect making up this combat armor suit,” Borjes said “It’s advanced armor. It’s communications, antennas. It’s cognitive performance. It’s sensors, miniature-type circuits. That’s all going to fit in here, too.”
SOCOM demonstrations will take placeJuly 8-10, at or near MacDill Air Force Base.
The request asks participants to submit a white paper summary of their technology by May 31, describing how TALOS can be constructed using current and emerging technologies. A limited number of participant white papers will be selected and those selected will demonstrate their technologies.
How the Turtle Got Its Shell: A Study of the Permian's Eunotosaurus
Through careful study of an ancient ancestor of modern turtles, researchers now have a clearer picture of how the turtles' most unusual shell came to be. The findings, reported on May 30 in Current Biology, a Cell Press publication, help to fill a 30- to 55-million-year gap in the turtle fossil record through study of an extinct South African reptile known as Eunotosaurus.
"The turtle shell is a complex structure whose initial transformations started over 260 million years ago in the Permian period," says Tyler Lyson of Yale University and the Smithsonian. "Like other complex structures, the shell evolved over millions of years and was gradually modified into its present-day shape."
The turtle shell isn't really just one thing—it is made up of approximately 50 bones. Turtles are the only animals that form a shell through the fusion of ribs and vertebrae. In all other animals, shells are formed from bony scales on the surface; they don't stick their bones on the outsides of their bodies.
"The reason, I think, that more animals don't form a shell via the broadening and eventually suturing together of the ribs is that the ribs of mammals and lizards are used to help ventilate the lungs," Lyson says. "If you incorporate your ribs into a protective shell, then you have to find a new way to breathe!" Turtles have done just that, with the help of a muscular sling.
Until recently, the oldest known fossil turtles, dating back about 215 million years, had fully developed shells, making it hard to see the sequence of evolutionary events that produced them. That changed in 2008 with the discovery of Chinese Odontochelys semitestacea, a reptile about 220 million years old, which had a fully developed plastron—the belly side of the shell—but only a partial carapace on its back.
Eunotosaurus takes the turtle and its shell back another 40 million years or so. It had nine broadened ribs found only in turtles. And like turtles, it lacked the intercostal muscles running between its ribs. But Eunotosaurus didn't have other features common to Odontochelys and turtles, including broad spines on their vertebrae.
Lyson says he and his colleagues now plan to investigate various other aspects of turtles' respiratory systems, which allow them to manage with their ribs locked up into a protective outer shell. "It is clear that this novel lung ventilation mechanism evolved in tandem with the origin of the turtle shell," he says.
Thursday, May 30, 2013
Updating Pournelle's CoDominium: SinoIndian CoDo Ascendent Scenario
My post 4000 was a reimagining of Pournelle's classic scenario of the CoDominium. The original scenario was the United States and Soviet Union would unite to control the world to deal with the problem with convergence. There is no Soviet Union anymore. We don't have the Alderson Drive, we don't have fusion and we have not developed space nearly as much as the authors originally thought we would by now. Economic convergence has more than happened. Things are rather different than the original scenario.
That opened things up for a different scenario altogether. I outlined my conjectural scenario in the post. China and Indian come together to produce an alternate CoDominium. The proximate cause being the Republic of India and People's Republic of China had greatly outdistanced the rest of the world economically and with the technological revolution that was getting underway their great advantage, population, was going to be made less relevant. To suppress these breakthroughs, China and India came together to suppress the resurgence of the United States, Europe, Japan and possibly others.
However, Noel challenged me on this scenario: how, he asked, would the US fall from grace as the world's hyperpower to the distance second class power, albeit one undergoing a resurgence that forces the top two powers into CoDominium. Let's explain that, shall we? What are the causes for the relatively rapid American decline?
Political Sclerosis:
In this scenario the US undergoes another three more presidential cycles of political deadlock. This is mixed with the continued issues with the US being unable to undertake large projects without massive delays, cost overruns and ineptitude. This won't last forever. However it will be enough to stunt growth with the decaying infrastructure and lack of general progress. There are areas of glory and aptitude, but they are the few shining stars in the sea of bleakness. Let's dice roll it and state we are at a reduced GDP growth by a half percent per year by itself. The lack of infrastructure improvement or even replacement reduces the growth by a half percent. Already, we're a 'mature economy' and have taken it in the shorts by being reduced to a range of between 0 and 2.
The World Changed
I don't mean the human world, sociological or economic or political. I mean the physical world. Global Warming is set to whack us but good. The whole world, really, but it hurt the US more because of our political ossification. We're assuming the Neo Oligocene here: warmer and drier and the midwest's productivity nosedives and the California central valley is toast. LA became Detroit on a broad canvas (no water). Eastern Texas, inland, the Great Lakes States regained population. The population of the mid Atlantic and north states increased, but often inland.
India Ignites
I'm positing India's economy starts growing double digits at the start of the 2020s like China has. India surpasses the US around 2030 to 2035.
China Recovers and Continues
China's economy grows gangbusters in the double digit range again around the same time frame.
Economics Continue to Favour Large Populations...through the 2040s.
The robopocalypse doesn't happen at least until the 2040s. The more workers, in manufacturing and innovation, etc. you have the better so long as they are educated. Double check for India and China. Both will have populations far larger than the US.
Sum:
The economies of China and India grow gangbusters and get ahead through the 2040s. Between them, they have economies 5x to 6x the American one. They are the power houses. We are not. We're Britain at best, or Russia. Sorta.
So Why Form the CoDominium?
You just can't keep a good Yanqi down.
The economics shift out of favour for India and China. Three major events. An American led, but Japanese and European supported Robopocalypse. The US develops a real fusion drive and then the Alderson Drive. When the US started to get out of the funk in the late 2030s, after decades of decay, besides seeking ways to improve its economy, it trotted out some of its past glories to reprise and surpass. Space was one.
The Chinese and Indians were ahead, to be sure, and that's one reason the Americans were humored at first and even congratulated. There was a Chinese Moon base. Ditto for the Indians. At different edges of the Shackleton Crater. The Indians and Chinese even captured asteroids, though not for economic reasons: it didn't pay. The Americans pushed on. the watershed moment being when the US landed on Mars...in 2047. Using a fusion drive to get there. It was pathetic compared to the original CoDo scenario drives (topped out at .1 g and "only" had enough fuel for 25 hours of thrusting), but it got people to Mars in a couple weeks. And back when the planets aligned right. China and India caught up and landed in 2048 and 2049 respectively. Even so, this was...very troubling.
When the US economy growth jumped from the anemic 1 or 2 percent to 3 or 4 percent in from 3032 to 3040 and then really jumped to 5 to 6 percent in 3040 to 3048 with it seemingly going to jump again in the coming years, this brought together India and China. The world was far from being US dominated, but the structural reform needed to adopt the American, European and Japanese technologies was going to be problematic. At this point, there was talk of the Americans returning to an ascendant position. Population size? Piffle. Dynamism matters! The Indian and Chinese politicians knew something had to be done and they began to meet.
It was a theoretical paper published by Caltech in which tipped the balance. Esp when the US president impulsively and promptly built a probe and dispatched it on a 2nd generation fusion rocket to the potential jump point, it accelerated away at 1/4 g and reached the jump point in about six months. The countdown took place and...poof. The probe disappeared. It didn't come back, but vanishing in a flash of light ...
Add in the Americans prepping another expedition. Their radically growing economy. The Japanese building their own moon base (national pride!) and the Europeans deciding they made a bad Holy Roman Empire, but a better Federal Union...The Chinese and Indians pulled together to say ixnay on anymore.
The Chinese and Indians declared CoDominium. No more! The Indonesians, Russians and the Nigerians joined as junior partners. The Americans scrambled. They spit out a dozen ships and away they went to the Alderson Point: manned and large and ...armed After all, only the Americans could build something that fast, in a year! (name the dumb movie)
It was WWIII. No nukes flew. The attempt to shoot down the ships failed, but few missiles or bombs were used on earth: they were mostly EM weapons, but the deathtoll was still horrific. Cyberweaponry wrecked havoc. In the end, China and India prevailed. And suppressed. No AIs. No enhancements. No change. Or minimal possible. The status quo was not to be disturbed.
They built the Fleet. And the CoDo Marines. Conjured from the one military still in excellent shape, with good ties to India and China: Israel.
In time, they would compromise. There would be Americans in interstellar space. Even those which didn't travel with the never caught Fugitive Fleet. They would rule the world for over a century. It would end in old fashion nuclear fire. Aluf Lomann's efforts, the feats of Alam Cyrus Zagrosi and Zagrosi's Immortals, and the world of Dual Monarchy of Shiva and its Crown Prince Rama...from them and those would come the Empire of Man.
As for the Fugitive Fleet on Yudkowsky. They would be discovered by the Empire and peacefully absorbed. They would even contribute to the Empire. For a time. Through accurate knowledge comes power, so the natives of Yudkowsky would say: other wise # in # out. And the members of the Empire would say no problem could ever survive contact with a Yudkowskian.
Reimagineer's notes: I don't really buy it. I guess I am too much of a nationalist at heart. Its fun to play here, but don't make the mistake of thinking I swallow this whatsoever. I actually think the US has been through the squeeze and we're about to come out the other side...with a whole of new techniques, tech, and ideas which will revolutionize the world. In our favour. You see, its the dynamism that matters in the end and there's none like us.
Problems for Devonian Geochronology?
Latest Devonian (Famennian) Global Events in Western Laurentia: Variations in the Carbon Isotopic Record Linked to Diagenetic Alteration Below Regionally Extensive Unconformities
Authors:
1. Paul M. Myrow (a)
2. Anne Hanson (a)
3. Anna S. Phelps (a)
4. Jessica R. Creveling (b)
5. Justin V. Strauss (b)
6. David A. Fike (c)
7. Robert L. Ripperan (d)
Affiliations:
a. Department of Geology, Colorado College, Colorado Springs, CO 80903, USA
b. Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA
c. Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA
d. 1417 Fairbrook Drive, Des Peres, MO 63131, USA
Abstract:
Integrated analysis of the sedimentology, stratigraphy, and chemostratigraphy of the uppermost Devonian Chaffee Group of Colorado reveals the presence of two regionally extensive unconformity surfaces associated with globally recognized extinction/eustatic events. The contact between semi-restricted, marginal marine, mixed siliciclastic–carbonate deposits of the Parting Formation and open marine carbonate of the Dyer Formation is a major marine flooding surface across western Colorado. This flooding surface rests at the top of a ~ 5 m thick, transgressive, cross-bedded, shoreline sandstone unit that locally overlies a 2.5-m-thick paleokarst breccia. δ13C values shift lighter across the formation contact, in some cases by as much as 5‰. Oxygen isotopic values are extremely variable between measured stratigraphic sections, in cases invariant across the contact, and in other cases covarying with the δ13C values. At Ouray, CO, δ18O covaries with δ13C throughout the section, and reaches extreme values (less than −30‰) below the unconformity. An isotopic shift in rocks of this age in Utah, coined ALFIE, was previously correlated to the Parting–Dyer contact. This study demonstrates that the carbon and oxygen isotopic record of ALFIE is highly variable across western Laurentia, and that important carbonate chemostratigraphic variations result from diagenesis that is clearly linked to a regional unconformity and associated relative sea-level fall. This lowstand may be a signal of eustatic fall associated with the Dasberg Event, a late Famennian marine extinction event. Similar isotopic patterns exist for strata below and above a paleokarst breccia in the upper Dyer Formation that we link to the globally significant latest Famennian Hangenberg Event, which includes a eustatic lowstand and subsequent transgression. Similar to the Parting–Dyer contact, both carbon and oxygen isotopes in strata below this regional unconformity surface show the variable nature of diagenetic alteration of carbonate units during lowstand conditions. Our data also suggest that correlatable δ13C chemostratigraphic shifts can be diagenetically produced during lowstands across a regionally widespread (western U.S.) basin, and that these δ13C shifts may be expressed within outcrops that show no macroscopic sedimentological signature of subaerial exposure. This has broad implications for the evaluation of δ13C data in the rock record, particularly the assumption that extensive correlatable isotopic anomalies reflect global marine signatures.
Ordovician Glaciations Were Complex, Implicated in Mass Extinction
Nd isotope records of late Ordovician sea-level change—implications for glaciation frequency and global stratigraphic correlationAuthors:1. C. Holmden (a)2. C.E. Mitchell (b)3. D.F. LaPorte (a)4. W.P. Patterson (a)5. M.J. Melchin (c)6. S.C. Finney (d)Affiliations:a. Saskatchewan Isotope Laboratory, Department of Geological Sciences, University of Saskatchewan, Saskatoon, SK, S7N 5E2 966-5712b. Department of Geology, University at Buffalo, 876 Natural Science Complex, Buffalo, NY 14260c. Department of Earth Sciences, St. Francis Xavier University, Antigonish, NS, , B2G 2W5Canadad. Department of Geological Sciences, California State University at Long Beach2, 1250 Bellflower Boulevard, Long Beach, CA 90840Abstract:Detailed records of ice-sheet advances and retreats are reconstructed for the Hirnantian and Katian ages of the Late Ordovician using Nd isotopes (εNd) as a sea-level proxy in three study sections from the western margin of Laurentia: two shallow water platform sections located south and north of the paleo-equator, and one deep water section located in a continental slope-rise setting. When sea-level was high and paleo-shorelines had migrated eastward, the εNd value of seawater in the vicinity of each of the study sections shifted toward the εNd value of the eastern Panthalassa Ocean (~ –4.0). By contrast, when sea-level was low and paleo-shorelines had migrated westward, the εNd value of seawater shifted toward the εNd value of the continental weathering flux from Laurentia (–8.5 ± 0.2, 2σmean). These stratigraphic patterns of changing εNd values are interpreted to reflect the eustatic sea-level fluctuations that previous studies have documented in response to Gondwanan ice-sheet advances and retreats, thus linking the εNd sea-level proxy to Late Ordovician global-scale climate changes. The εNd profiles for the two platform sections yielded similar proxy sea-level curves with five cycles of oscillation recorded during the latest Katian and Hirnantian. Three additional cycles of late Katian sea-level change are recognized in the εNd profile of the deep water continental slope-rise section.The combination of εNd, δ13C and graptolite biostratigraphic data facilitates a precise interregional correlation of the Hirnantian Age and the paleoclimate changes that took place during this interval. The new correlations support previous findings that the Hirnantian ice age comprised two major glacial periods separated by a minor interglacial during the early part of the M. persculptus Biozone. The younger glacial (confined to mid M. persculptus Biozone time) led to more extensive sea surface cooling than did the earlier one, and resulted in extensive eustatic sea-level drawdown and C-cycle changes. It records the strata most often recognized as HICE (the Hirnantian Carbon Isotope Excursion) in sedimentary successions worldwide, such as Anticosti Island, Scotland, Estonia, Siberia, and South China. The results of this study support and strengthen the view that glaciation predated the Hirnantian Age in the Late Ordovician, and that the record of small positive δ13C excursions in Katian successions from Baltica and eastern North America are themselves proxy indicators of glaciation frequency and eustatic sea level changes.
More Evidence of a Toarcian Mass Extinction: Ammonites Had Low Diversity in Toarcian Jurassic Northern NeoTethys of Cacasian Russia
Spatial heterogeneity of the Early–Middle Toarcian (Jurassic) ammonite diversity and basin geometry in the Northwestern Caucasus (southwestern Russia; northern Neo-Tethys)
Author:
1. Dmitry A. Ruban (a)
Affiliation:
a. Division of Mineralogy and Petrography, Geology and Geography Faculty, Southern Federal University, Zorge Street 40, Rostov-na-Donu, 344090, Russian Federation
Abstract:
Palaeontological and geological information from the Northwestern Caucasus, a large region in southwestern Russia, allows to evaluate the spatial heterogeneity of the Early–Middle Toarcian ammonite diversity and its possible controls. The total number of ammonite species and genera is calculated for four time slices, which correspond to the D. semicelatum, H. falciferum, H. bifrons, and H. variabilis zones, in each of ten areas distinguished within the study region. These areas differ by the ammonite diversity, which indicates heterogeneity. The latter persisted through the entire Early–Middle Toarcian. This heterogeneity was relatively low in the beginning of the Toarcian, when the total regional diversity of ammonites was minimal. Long- and short-term landward shoreline shifts facilitated spatial distribution of ammonites and increase in their taxa number. Shallow-marine palaeoenvironments tended to sustain a higher diversity than those deep-marine, and, therefore, changes in the basin depth were also responsible for the observed spatial heterogeneity of the ammonite diversity. Interestingly, a more or less similar diversity dynamics is established in the areas of the Northwestern Caucasus. The distribution of ammonites in the study region indicates that these invertebrates migrated to there from the open sea(s) stretched along the northern margin of the Neo-Tethys Ocean. Results of the present analysis also imply that the mass extinction might have been responsible for the low diversity of ammonites (observed in the entire region and its particular areas) in the beginning of the Toarcian.
Robopocalypse Comes to Agriculture...in Australia
A robot effortlessly plucking fruit is some way off, though a range of simpler tasks are within reach to add to existing technology such as automatic steering of harvesters.
Salah Sukkarieh, Professor of Robotics and Intelligent Systems at the University of Sydney and developer of Mantis and Shrimp, says the next phase aims for robots to do increasingly complex jobs such as watering and ultimately harvesting.
"We have fitted them with a lot of sensors, vision, laser, radar and conductivity sensors - including GPS and thermal sensors," said Sukkarieh, speaking at his laboratory housing a collection of both ground robots and unmanned air vehicles.
The technology could have the biggest application in horticulture, Australia's third-largest agricultural sector with exports of $1.71 billion in the last marketing year, since a fixed farm layout lends itself better to using robots.
Robots and an unmanned air vehicle that are being developed at the University of Sydney had passed field tests at an almond farm in Mildura, Victoria state, said Sukkarieh.
Propelled by sets of wheels and about the height of a man, the robots were named after the native Mantis shrimp because of the marine crustacean's 16 different color receptors, capable of detecting up to 12 colors. Humans only have four, three of which pick up colors.
This capacity to recognize color already allows the robots to sense whether fruit is ripe.
The data can then be processed by computer algorithms to determine what action the robot should take. This could be to water or apply fertilizer or pesticides, or to sweep and prune vegetation, and eventually the aim is to harvest the crop.
"If tomorrow we got an apple, orange or tomato farmer that wants a robot to go up and down these tree crops reliably and accurately, we can do that within six months to a year."
"The question is can we make them more intelligent," added Sukkarieh, who also sees the technology being attached to standard farm vehicles and foresees a fully automated horticulture farm within 10 years.
Spinosaur vs Crocodilian Feeding Mechanics
Feeding Mechanics in Spinosaurid Theropods and Extant Crocodilians
Authors:
1. Andrew R. Cuff (a)
2. Emily J. Rayfield (a)
Affiliation:
a. School of Earth Sciences, University of Bristol, Bristol, United Kingdom
Abstract:
A number of extant and extinct archosaurs evolved an elongate, narrow rostrum. This longirostrine condition has been associated with a diet comprising a higher proportion of fish and smaller prey items compared to taxa with broader, more robust snouts. The evolution of longirostrine morphology and a bulbous anterior rosette of premaxillary teeth also occurs in the spinosaurid theropod dinosaurs, leading to suggestions that at least some members of this clade also had a diet comprising a notable proportion of fish or other small vertebrates. Here we compare the rostral biomechanics of the spinosaurs Baryonyx walkeri and Spinosaurus c.f. S. aegyptiacus to three extant crocodilians: two longistrine taxa, the African slender-snouted crocodile Mecistops cataphractus and the Indian gharial Gavialis gangeticus; and the American alligator Alligator mississippiensis.
Using computed tomography (CT) data, the second moments of area and moments of inertia at successive transverse slices along the rostrum were calculated for each of the species. Size-independent results tested the biomechanical benefits of material distribution within the rostra. The two spinosaur rostra were both digitally reconstructed from CT data and compared against all three crocodilians. Results show that African slender-snouted crocodile skulls are more resistant to bending than an equivalent sized gharial. The alligator has the highest resistances to bending and torsion of the crocodiles for its size and greater than that of the spinosaurs. The spinosaur rostra possess similar resistance to bending and torsion despite their different morphologies. When size is accounted for, B. walkeri performs mechanically differently from the gharial, contradicting previous studies whereas Spinosaurus does not. Biomechanical data support known feeding ecology for both African slender-snouted crocodile and alligator, and suggest that the spinosaurs were not obligate piscivores with diet being determined by individual animal size.
Rare Species May be Some of the Most Important to an Ecology
A new study, published 28 May in the open access journal PLOS Biology, has revealed the potential importance of rare species in the functioning of highly diverse ecosystems. Using data from three very different ecosystems—coral reefs, tropical forests and alpine meadows—a team of researchers led by David Mouillot at the University of Montpellier 2, France, has shown that it is primarily the rare species, rather than the more common ones, that have distinct traits involved in unique ecological functions. As biodiversity declines, these unique features are therefore particularly vulnerable to extinction because rare species are likely to disappear first.
"These unique features are irreplaceable, as they could be important for the functioning of ecosystems if there is major environmental change," explained Dr Mouillot.
Biodiverse environments are characterized by a large number of rare species. These rare species contribute to the taxonomic richness of the area, but their functional importance in ecosystems is largely unknown. Represented by few individuals or distributed over narrow geographic areas, rare species are generally considered to have little influence on the functioning of an ecosystem compared with more common species. Indeed, it is often assumed that they fulfill the same ecological roles as those of common species but have less impact because of their low abundance; a phenomenon known as 'functional redundancy'. This redundancy suggests that rare species merely serve as an "insurance" policy for the ecosystem, in the event of an ecological loss.
Something to pay attention to, paleo folks. Keystone species may not just be the most common. Something to think abotu when reconstructing ecosystems in Deep Time and working with mass extinctions. Its really not hard to imagine there was a keystone species (or three) whose loss caused the massive shift from the paleozoic marine ecosystems to the mesozoic style during the PT Extinction.
Wednesday, May 29, 2013
There is a Nontrivial Difference in Dinosauromorph and Other Archosauromorph Tracks
ANALYSIS OF TRIASSIC ARCHOSAURIFORM TRACKWAYS: DIFFERENCE IN STRIDE/FOOT RATIO BETWEEN DINOSAUROMORPHS AND OTHER ARCHOSAURIFORMS
Authors:
1. TAI KUBO (a)
2. MUGINO O. KUBO (b)
Affiliations:
a. Fukui Prefectural Dinosaur Museum, 51-11 Terao, Muroko, Katsuyama, Fukui 911-8601, Japan
b. The University Museum, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan,
Abstract:
Fossilized trackways have rarely been analyzed quantitatively to examine major trends and patterns in evolution despite their potential utility, especially in understanding locomotory evolution. In the present study, trackways of Triassic archosauriforms were analyzed. The analyses showed foot and stride lengths of archosauriforms increased from the Early to Middle Triassic, especially those of dinosauromorphs, which tripled. Dinosauromorphs were much smaller in foot length and stride length compared to other archosauriforms during the Early Triassic. They reached similar stride length compared with other archosauriforms during the Middle Triassic and similar foot length in the Late Triassic. Stride/foot ratio is significantly higher in dinosauromorphs compared to other archosauriforms throughout the Triassic. This relatively long stride length of dinosauromorphs is attributed to either faster speed or higher relative hip height that was probably caused by their digitigrade foot posture. Analyses of trackway data sets, especially in combination with precise trackmaker assignment and age determination, would bring us more thorough knowledge about locomotory evolution of tetrapods that complements body fossil evidence.
Aurornis xui: Feathered Relative of Early Birds, Proves Feathers Before Flight
Feathered dinosaurs used to be as valuable as gold dust. Now, so many specimens have been unearthed that museums are overflowing. But for all the specimens, a crucial question has remained unanswered: which species was the original ancestor of birds?
A new species found in China has shed light on the answer. The two-foot long Aurornis xui, the “daybreak bird,” fleshes out the relationships between bird-like dinosaurs and, along with its cousin species Archaeopteryx and Anchiornis, restores its lineage as the likely predecessors of birds.
The early relationships of a group called Avialae, the dinosaur line leading directly to modern birds, have been a hot point of debate. Over the last few years, with new bird-like dinosaur discoveries, some palaeontologists have even removed the iconic Archaeopteryx and its relatives from the Avialae group altogether. However, this shift would have meant that powered flight evolved multiple times in feathered dinosaurs, a less likely situation than one such adaptation.
Now, Aurornis xui, named in honor of dinosaur hunter Xu Xing, appears to have settled that part of the debate. Along with Anchiornis of the same age (about 155-160 million years), and Archaeopteryx (150 million years), Aurornis fits within the earliest ancestry of Avialae. The existence of three contemporary species allowed researchers to triangulate their relationships based on their appearance. Archaeopteryx was knocked off its perch as the oldest bird back in 2009 by Anchiornis, and now Aurornis has finished the dethroning, with the three species together sitting at the very base of the Avialae lineage that would later give rise to all other birds.
For a moment when I saw the reconstruction, I thought the chickensaurus project was successful!
China Pulls a Coupe, Builds 50 Petaflop Supercomputer: Tianhe-2
Yesterday, we took the plunge and reported on the pervasive rumor that a MIC-based Chinese system had been validated by Top 500 brass in person—proving dramatic LINPACK performance against the Titan and the rest of the leaders of the supercomputing pack.
There is currently a team from the Top500 in China and they have reported that they’ve examined the system and that indeed, it’s performance parallels the early reports.
This morning we’ve been able to confirm a number of details about the system, which for the sake of brevity, we’ll present here in rather short form. Before doing so, thanks to all of you who scurried around to send us emails late last night with confirmation, further details, and insight about the new top super.
The reported performance (we have four highly credible sources confirming) is between 53-55 peak and between 27-29 LINPACK sustained performance. This is actually better than we were led to believe yesterday when it felt a little wrong to make the "50 petaflop" claim, despite our best sources telling us it was so.
The odd thing is that this is the famed Tianhe-2 system—yes, the one that wasn’t even supposed to be completed until 2015. Further, the system’s grand unveiling was going to unleash 100 petaflops onto the world. While we’re still working on understanding the odd timing on this, the fact remains that there’s nothing on the horizon that is going to be able to touch it unless there are some major surprises, which sources emphatically say there will not be.
Will this be Earth Simulator 2?
Livermore and UC Santa Cruz Develop Carbon Sequestration Technique In Lab Which Helps De-Acidify Ocean Water
Lawrence Livermore scientists have discovered and demonstrated a new technique to remove and store atmospheric carbon dioxide while generating carbon-negative hydrogen and producing alkalinity, which can be used to offset ocean acidification.
The team demonstrated, at a laboratory scale, a system that uses the acidity normally produced in saline water electrolysis to accelerate silicate mineral dissolution while producing hydrogen fuel and other gases. The resulting electrolyte solution was shown to be significantly elevated in hydroxide concentration that in turn proved strongly absorptive and retentive of atmospheric CO2.
Further, the researchers suggest that the carbonate and bicarbonate produced in the process could be used to mitigate ongoing ocean acidification, similar to how an Alka Seltzer neutralizes excess acid in the stomach.
"We not only found a way to remove and store carbon dioxide from the atmosphere while producing valuable H2, we also suggest that we can help save marine ecosystems with this new technique," said Greg Rau, an LLNL visiting scientist, senior scientist at UC Santa Cruz and lead author of a paper appearing this week (May 27) in the Proceedings of the National Academy of Sciences.
When carbon dioxide is released into the atmosphere, a significant fraction is passively taken up by the ocean forming carbonic acid that makes the ocean more acidic. This acidification has been shown to be harmful to many species of marine life, especially corals and shellfish. By the middle of this century, the globe will likely warm by at least 2 degrees Celsius and the oceans will experience a more than 60 percent increase in acidity relative to pre-industrial levels. The alkaline solution generated by the new process could be added to the ocean to help neutralize this acid and help offset its effects on marine biota. However, further research is needed, the authors said.
"When powered by renewable electricity and consuming globally abundant minerals and saline solutions, such systems at scale might provide a relatively efficient, high-capacity means to consume and store excess atmospheric CO2 as environmentally beneficial seawater bicarbonate or carbonate," Rau said. "But the process also would produce a carbon-negative 'super green' fuel or chemical feedstock in the form of hydrogen."
Most previously described chemical methods of atmospheric carbon dioxide capture and storage are costly, using thermal/mechanical procedures to concentrate molecular CO2 from the air while recycling reagents, a process that is cumbersome, inefficient and expensive.
"Our process avoids most of these issues by not requiring CO2 to be concentrated from air and stored in a molecular form, pointing the way to more cost-effective, environmentally beneficial, and safer air CO2 management with added benefits of renewable hydrogen fuel production and ocean alkalinity addition," Rau said.
Interesting. Will it scale and deal with real world scenarios? It almost sounds too good to be true...
Sturtian Cryogenian Neoproterozoic Glaciations Started After 730 Million Years Ago
Geochronology and paleoenvironment of the pre-Sturtian glacial strata: Evidence from the Liantuo Formation in the Nanhua rift basin of the Yangtze Block, South China
Authors:
1. Qiuding Du (a, b)
2. Zhengjiang Wang (a, b)
3. Jian Wang (a, b)
4. Yansheng Qiu (c)
5. Xinsheng Jiang (a, b)
6. Qi Deng (a)
7. Fei Yang (a)
Affiliations:
a. Chengdu Institute of Geology and Mineral Resources, Chengdu 610082, China
b. Key Laboratory for Sedimentary Basin and Oil and Gas Resources, Ministry of Land and Resources, Chengdu 610082, China
c. Hubei Geological Survey, Wuhan 430034, China
Abstract:
The Yangtze Block is an important component in reconstructing the Proterozoic tectonic evolution of South China within the Rodinia supercontinent. The geochronology and paleoenvironment of the Liantuo Formation in the Yangtze Block are still highly controversial. An integrated approach of facies analysis, paleogeography and geochronology provides new insights into understanding the sedimentology and paleogeography of the formation. Here, results are presented from a detailed U–Pb zircon examination of geochronology and paleoenvironment of the Liantuo Formation in the Yangtze Block. The formation was deposited in the period of ca. 790–730 Ma, which coeval with the development of the Wuqiangxi Formation in the middle-upper part of the Banxi Group. The top of the Liantuo Formation gives a U–Pb age of 736 ± 5.8 Ma, which signifies an onset time of the Sturtian glaciation as ca. ≤730 Ma. The zircon U–Pb ages reveal magmatic events that were correlated with Neoproterozoic continental growth indicating that the Rodinia initiated rifting occurred at ca. 824 Ma and extensive rift-related magmatism took place at ca. 780 Ma in the northern Yangtze Block. Moreover, these results provide geochronological and petrologic evidence that confirms the stratigraphic framework of the Nanhuan System, thereby promoting a better understanding of the Neoproterozoic tectonic development of South China.
Tuesday, May 28, 2013
Flight of the Pterosaurs: An (old) Talk by Mike Habib
He likes to call it "Air Giants: Launch, flight, and ecology of Cretaceous pterosaurs." I think he ought to have it accompanied by some Wagnerian thematic music and ...hey! has anyone named a pterosaur after the Valkyries?
Super Drought Research Suggests Stronger Monsoon in the Southwest US With Global Warming?
Multidecadal to multicentury scale collapses of Northern Hemisphere monsoons over the past millenniumThat's interesting when combined with the projection of the monsoon being delayed under global warming. A stronger, but later monsoon could be...not so good. Oh my green chiles!
Authors:
1. Yemane Asmerom (a)
2. Victor J. Polyak (a)
3. Jessica B. T. Rasmussen (b)
4. Stephen J. Burns (c)
5. Matthew Lachniet (d)
Affiliations:
a. Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131;
b. Leander Independent School District, Leander, TX 78646;
c. Department of Geosciences, University of Massachusetts, Amherst, MA 01003; and
d. Department of Geoscience, University of Nevada, Las Vegas, NV 89154
Abstract:
Late Holocene climate in western North America was punctuated by periods of extended aridity called megadroughts. These droughts have been linked to cool eastern tropical Pacific sea surface temperatures (SSTs). Here, we show both short-term and long-term climate variability over the last 1,500 y from annual band thickness and stable isotope speleothem data. Several megadroughts are evident, including a multicentury one, AD 1350–1650, herein referred to as Super Drought, which corresponds to the coldest period of the Little Ice Age. Synchronicity between southwestern North American, Chinese, and West African monsoon precipitation suggests the megadroughts were hemispheric in scale. Northern Hemisphere monsoon strength over the last millennium is positively correlated with Northern Hemisphere temperature and North Atlantic SST. The megadroughts are associated with cooler than average SST and Northern Hemisphere temperatures. Furthermore, the megadroughts, including the Super Drought, coincide with solar insolation minima, suggesting that solar forcing of sea surface and atmospheric temperatures may generate variations in the strength of Northern Hemisphere monsoons. Our findings seem to suggest stronger (wetter) Northern Hemisphere monsoons with increased warming.
Ancient Stromalites Disappeared Because of the Evolution of Foraminifera
The widespread disappearance of stromatolites, the earliest visible manifestation of life on Earth, may have been driven by single-celled organisms called foraminifera.
The findings, by scientists at Woods Hole Oceanographic Institution (WHOI); Massachusetts Institute of Technology; the University of Connecticut; Harvard Medical School; and Beth Israel Deaconess Medical Center, Boston, were published online the week of May 27 in the Proceedings of the National Academy of Sciences.
Stromatolites ("layered rocks") are structures made of calcium carbonate and shaped by the actions of photosynthetic cyanobacteria and other microbes that trapped and bound grains of coastal sediment into fine layers. They showed up in great abundance along shorelines all over the world about 3.5 billion years ago.
"Stromatolites were one of the earliest examples of the intimate connection between biology—living things—and geology—the structure of the Earth itself," said WHOI geobiologist Joan Bernhard, lead author of the study.
The growing bacterial community secreted sticky compounds that bound the sediment grains around themselves, creating a mineral "microfabric" that accumulated to become massive formations. Stromatolites dominated the scene for more than two billion years, until late in the Proterozoic Eon.
"Then, around 1 billion years ago, their diversity and their fossil abundance begin to take a nosedive," said Bernhard. All over the globe, over a period of millions of years, the layered formations that had been so abundant and diverse began to disappear. To paleontologists, their loss was almost as dramatic as the extinction of the dinosaurs millions of years later, although not as complete: Living stromatolites can still be found today, in limited and widely scattered locales, as if a few velociraptors still roamed in remote valleys.
While the extinction of the dinosaurs has largely been explained by the impact of a large meteorite, the crash of the stromatolites remains unsolved. "It's one of the major questions in Earth history," said WHOI microbial ecologist Virginia Edgcomb, a co-author on the paper.
Just as puzzling is the sudden appearance in the fossil record of different formations called thrombolites ("clotted stones"). Like stromatolites, thrombolites are produced through the action of microbes on sediment and minerals. Unlike stromatolites, they are clumpy, rather than finely layered.
It's not known whether stromatolites became thrombolites, or whether thrombolites arose independently of the decline in strombolites. Hypotheses proposed to explain both include changes in ocean chemistry and the appearance of multicellular life forms that might have preyed on the microbes responsible for their structure.
Bernhard and Edgcomb thought foraminifera might have played a role. Foraminifera (or "forams," for short) are protists, the kingdom that includes amoeba, ciliates, and other groups formerly referred to as "protozoa." They are abundant in modern-day oceanic sediments, where they use numerous slender projections called pseudopods to engulf prey, to move, and to continually explore their immediate environment. Despite their known ability to disturb modern sediments, their possible role in the loss of stromatolites and appearance of thrombolites had never been considered.
The researchers examined modern stromatolites and thrombolites from Highborne Cay in the Bahamas for the presence of foraminifera. Using microscopic and rRNA sequencing techniques, they found forams in both kinds of structures. Thrombolites were home to a greater diversity of foraminifera and were especially rich in forams that secrete an organic sheath around themselves. These "thecate" foraminifera were probably the first kinds of forams to evolve, not long (in geologic terms) before stromatolites began to decline.
"The timing of their appearance corresponds with the decline of layered stromatolites and the appearance of thrombolites in the fossil record," said Edgcomb. "That lends support to the idea that it could have been forams that drove their evolution."
Next, Bernhard, Edgcomb, and postdoctoral investigator Anna McIntyre-Wressnig created an experimental scenario that mimicked what might have happened a billion years ago.
"No one will ever be able to re-create the Proterozoic exactly, because life has evolved since then, but you do the best you can," Edgcomb said.
They started with chunks of modern-day stromatolites collected at Highborne Cay, and seeded them with foraminifera found in modern-day thrombolites. Then they waited to see what effect, if any, the added forams had on the stromatolites.
After about six months, the finely layered arrangement characteristic of stromatolites had changed to a jumbled arrangement more like that of thrombolites. Even their fine structure, as revealed by CAT scans, resembled that of thrombolites collected from the wild. "The forams obliterated the microfabric," said Bernhard.
DARPA's Plan X: Making Cyber Weapons Easier to Use, Turning Soldiers into Script Kiddies
The target computer is picked. The order to strike has been given. All it takes is a finger swipe and a few taps of the touchscreen, and the cyberattack is prepped to begin.
For the last year, the Pentagon’s top technologists have been working on a program that will make cyberwarfare relatively easy. It’s called Plan X. And if this demo looks like a videogame or sci-fi movie or a sleek Silicon Valley production, that’s no accident. It was built by the designers behind some of Apple’s most famous computers — with assistance from the illustrators who helped bring Transformers to the silver screen.
Today, destructive cyberattacks — ones that cause servers to fry, radars to go dark, or centrifuges to spin out of control — have been assembled by relatively small teams of hackers. They’re ordered at the highest levels of government. They take months to plan. Their effects can be uncertain, despite all the preparation. (Insiders believe, for example, that the biggest network intrusion in the Pentagon’s history may have been an accidental infection, not a deliberate hack.)
With Plan X, the Defense Advanced Research Projects Agency is looking to change all that. It wants munitions made of 1s and 0s to be as simple to launch as ones made of metal and explosives. It wants cyberattack stratagems to be as predictable as any war plan can be. It wants to move past the artisanal era of hacking, and turn cyberwarfare into an industrial effort. Across the U.S. government, there are all kinds of projects to develop America’s network offense. None are quite like this.
When Did Plate Tectonics Begin and What Came Before? an essay
Two of my favorite topics of geoconversation are how new subduction zones get started and when in Earth’s history did plate tectonics begin? Both are fascinating geoscientific questions but we seem to be making more progress on the first topic than on the second. The plate tectonic revolution changed our science forever but in the excitement of the late 1960’s when the paradigm shifted, the question of what makes the plates move was neglected. Yes it was mantle convection, but was convection driven by hot deep mantle rising or cold dense lithosphere sinking? Geodynamicists soon began investigating and now they tell us that it is mostly the sinking of dense lithosphere in subduction zones, pulling the plates and moving them. The most important consideration is that hotter asthenospheric mantle is slightly (~1%) less dense than colder overlying lithospheric mantle, so these want to change places. This sometimes happens during detachment and delamination of lithospheric mantle but generally happens by subduction, the end-on sinking of lithosphere beneath asthenosphere.
Our modern understanding of what drives the plates shows us that the key to understanding how subduction zones form is by understanding the density and strength of oceanic lithosphere. It also tells us that we should be thinking about lithospheric strength and density when we try to answer the question “When did plate tectonics start on Earth?” Certainly the Archean mantle 2.5 to 3.8 Ga was hotter than is the modern mantle. Consequently, Archean lithosphere would have thinner and more buoyant, and on this basis alone a reasonable person would conclude that plate tectonics must have been more difficult back then. In spite of this, most geoscientists think that plate tectonics was underway in Archean time. Regardless of your opinion on this matter, the question of when did plate tectonics start (WDPTS?) is one of the most important – and exciting – unresolved questions in the history of the solid Earth. I find this to be a particularly interesting question because EVERYONE can get involved: graduate students, undergraduate students, K-12 students, professors, amateurs, the media. We can’t agree on the answer yet so let’s discuss it!
The key to answering WDPTS? must be to reconstruct Earth’s tectonic history, using both first-order understanding of how large silicate bodies cool and proper interpretation of the rock record, particularly those mineral and rock assemblages that are diagnostic of plate tectonic records of independent plate motions, subduction and collision.
Go. Read.
Evolution and Extinction of the Synapsids From the Carboniferous Through the Permian
The early evolution of synapsids, and the influence of sampling on their fossil record
Authors:
1. Neil Brocklehurst (a)
2. Christian F. Kammerer (a)
3. Jörg Fröbisch (a)
Affiliation:
a. Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstrae 43, D-10115 Berlin, Germany.
Abstract:
Synapsids dominated the terrestrial realm between the late Pennsylvanian and the Triassic. Their early evolution includes some of the first amniotes to evolve large size, herbivory, and macro-predators. However, little research has focused on the changes in diversity occurring during this early phase in their evolutionary history, with more effort concentrating on later events such the Permo-Triassic extinction. Here we assess synapsid diversity, at both the species and genus levels, between the Carboniferous (Moscovian) and the Middle Permian (Capitanian). A raw, taxic diversity (richness) estimate is generated, and we use two separate methods to correct for sampling biases in this curve. To remove the effect of anthropogenic sampling bias, we apply a recently published modification of the residual diversity method, and then generate a supertree, using matrix representation with parsimony to infer ghost lineages and obtain a phylogenetic diversity estimate. The general diversity pattern reflects the initial diversification of synapsids in the late Pennsylvanian and early Cisuralian, which was followed by an extinction event during the Sakmarian. Diversity recovered during the Artinskian and Kungurian, coinciding with the radiation of Caseidae, although other families begin to decline. A second extinction event occurred across the Kungurian/Roadian boundary, in which Edaphosauridae and Ophiacodontidae died out although Caseidae and Therapsida diversified. The sampling-corrected curves reveal further extinction during the Roadian, although therapsids were again unaffected. Pelycosaurian-grade synapsids survived during the Wordian and Capitanian, but were a minor part of an otherwise therapsid-dominated fauna. Evidence of significant anthropogenic sampling bias calls into question previous diversity studies that have not employed sampling correction.
Monday, May 27, 2013
Earliest Terrestrial Tetrapods Had A Weak Bite
What had the legs of a ‘gator and the jaws of a fish? Why, the earliest land animals. Because a new study shows that animals evolved weight-bearing limbs long before they had the chompers to really take advantage of a terrestrial diet. The research is in the journal Integrative and Comparative Biology. [Philip S. L. Anderson, Matt Friedman and Marcello Ruta, Late to the Table: Diversification of Tetrapod Mandibular Biomechanics Lagged Behind the Evolution of Terrestriality]
Scientists had suspected that the first four-legged creatures to haul their carcasses out of the ocean didn’t belly up to the salad bar straight away. But they lacked definitive proof.
Now, researchers have carefully examined the fossilized faces of 89 beasties that lived on land and sea some 300 to 400 million years ago. They probed the jaws for a range of biomechanical features, such as how much force they could give to their bite. The result: seems it took tens of millions of years after setting foot on land to come up with a mouth that could munch on the greenery.
Sunday, May 26, 2013
Is This the Model for the Post American World?
China is no longer merely a passive recipient of the world order, but it has become a key factor in determining the foreign and defense policy choices that are open to other international actors. Beijing seems to have positioned the country as a global great power in a political sense. It has achieved this position by means of a strategy of coexistence that was recently reiterated in the Chinese defense white paper. This strategy is designed to change the context for other states’ international behavior without promoting a completely new world order. Instead, China’s version of world order is founded in a revised interpretation of the existing UN system, invoking the principles of absolute sovereignty and non-interference. It is an interest-based order designed to protect China against overseas interference and maintain international peace and stability without any obligations for extensive cooperation. Beijing seeks to influence the context more often than directly shaping the behavior of other international actors. This coexistence strategy does not require economic and military capabilities at U.S. levels to exercise this type of influence, because it relies on the persuasiveness of its version of world order as an advantage for others without promoting a China-centric model of interaction.Go read. Its interesting. I have to wonder what the dynamics of nation states are, really, though when you compare their behavior when they are NOT in the top slot vs when they actually are. There's a signiciant difference between the US of 1830s and the 1990s.
Saturday, May 25, 2013
There's Something Funky About Exoplanet Formation
A PLATEAU IN THE PLANET POPULATION BELOW TWICE THE SIZE OF EARTH
Authors:
1. Erik A. Petigura (a)
2. Geoffrey W. Marcy (a)
3. Andrew W. Howard (b)
Affiliations:
a. Astronomy Department, University of California, Berkeley, CA 94720, USA
b. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA
Abstract:
We carry out an independent search of Kepler photometry for small transiting planets with sizes 0.5-8.0 times that of Earth and orbital periods between 5 and 50 days, with the goal of measuring the fraction of stars harboring such planets. We use a new transit search algorithm, TERRA, optimized to detect small planets around photometrically quiet stars. We restrict our stellar sample to include the 12,000 stars having the lowest photometric noise in the Kepler survey, thereby maximizing the detectability of Earth-size planets. We report 129 planet candidates having radii less than 6 RE found in three years of Kepler photometry (quarters 1-12). Forty-seven of these candidates are not in Batalha et al., which only analyzed photometry from quarters 1-6. We gather Keck HIRES spectra for the majority of these targets leading to precise stellar radii and hence precise planet radii. We make a detailed measurement of the completeness of our planet search. We inject synthetic dimmings from mock transiting planets into the actual Kepler photometry. We then analyze that injected photometry with our TERRA pipeline to assess our detection completeness for planets of different sizes and orbital periods. We compute the occurrence of planets as a function of planet radius and period, correcting for the detection completeness as well as the geometric probability of transit, R sstarf/a. The resulting distribution of planet sizes exhibits a power law rise in occurrence from 5.7 RE down to 2 RE , as found in Howard et al. That rise clearly ends at 2 RE . The occurrence of planets is consistent with constant from 2 RE toward 1 RE . This unexpected plateau in planet occurrence at 2 RE suggests distinct planet formation processes for planets above and below 2 RE . We find that $15.1^{+1.8}_{-2.7}$% of solar type stars—roughly one in six—has a 1-2 RE planet with P = 5-50 days.
Friday, May 24, 2013
Changes in Paleoenvironment Across the Neogene/Quaternary Boundary in Spain
Late Neogene and Early Quaternary Paleoenvironmental and Paleoclimatic Conditions in
Southwestern Europe: Isotopic Analyses on Mammalian Taxa
Authors:
1. Laura Domingo (a)
2. Paul L. Koch (a)
3. Manuel Hernández Fernández (b,c)
4. David L. Fox (d)
5. M. Soledad Domingo (e)
6. María Teresa Alberdi (f)
Affiliations:
a. Earth and Planetary Sciences Department. University of California Santa Cruz, Santa Cruz, California, United States of America
b. Departamento de Paleontología, Universidad Complutense de Madrid, Madrid, Spain
c. Departamento de Cambio Medioambiental, Instituto de Geociencias (UCM, CSIC), Madrid, Spain
d. Department of Earth Sciences. University of Minnesota, Minneapolis, Minnesota, United States of America
e. Museum of Paleontology, University of Michigan, Ann Arbor, Michigan, United States of America
f. Departamento de Paleobiología, Museo Nacional de Ciencias Naturales-CSIC, Madrid, Spain
Abstract:
Climatic and environmental shifts have had profound impacts on faunal and floral assemblages globally since the end of the Miocene. We explore the regional expression of these fluctuations in southwestern Europe by constructing long-term records (from ~11.1 to 0.8 Ma, late Miocene–middle Pleistocene) of carbon and oxygen isotope variations in tooth enamel of different large herbivorous mammals from Spain. Isotopic differences among taxa illuminate differences in ecological niches. The δ13C values (relative to VPDB, mean −10.3±1.1‰; range −13.0 to −7.4‰) are consistent with consumption of C3 vegetation; C4 plants did not contribute significantly to the diets of the selected taxa. When averaged by time interval to examine secular trends, δ13C values increase at ~9.5 Ma (MN9–MN10), probably related to the Middle Vallesian Crisis when there was a replacement of vegetation adapted to more humid conditions by vegetation adapted to drier and more seasonal conditions, and resulting in the disappearance of forested mammalian fauna. The mean δ13C value drops significantly at ~4.2−3.7 Ma (MN14–MN15) during the Pliocene Warm Period, which brought more humid conditions to Europe, and returns to higher δ13C values from ~2.6 Ma onwards (MN16), most likely reflecting more arid conditions as a consequence of the onset of the Northern Hemisphere glaciation. The most notable feature in oxygen isotope records (and mean annual temperature reconstructed from these records) is a gradual drop between MN13 and the middle Pleistocene (~6.3−0.8 Ma) most likely due to cooling associated with Northern Hemisphere glaciation.
Drivers of Mosasaur Evolution
Phylogeny vs Time
Oceanic Upwelling Locales
Mosasaur Fossil Locales
Physical Drivers of Mosasaur Evolution
Authors:
1. Michael J. Polcyn (a)
2. Louis L. Jacobs (a)
3. Ricardo Araújo (a, b)
4. Anne S. Schulp (c, d)
5. Octávio Mateus (b, e)
Affiliations:
a. Roy M. Huffington Department of Earth Sciences, Southern Methodist University, Dallas, Texas 75275, USA
b. Museu da Lourinhã Rua João Luis de Moura, 95. 2530–158 Lourinhã, Portugal
c. Natuurhistorisch Museum Maastricht, de Bosquetplein 6–7, NL-6211 KJ Maastricht, The Netherlands
d. Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, The Netherlands
e. Departamento de Ciências da Terra, FCT, Universidade Nova de Lisboa, Lisbon, Portugal
Abstract:
Mosasaurs are marine squamates with a 32.5 million-year history from their appearance at 98 Ma to their extinction at the K-Pg boundary (65.5 Ma). Using a database of 43 generic and 94 species-level taxa, we compare the taxonomic diversity and patterns of morphological disparity in mosasaurs with sea level, sea surface temperature, and stable carbon isotope curves for the Upper Cretaceous to explore factors that may have influenced their evolution. No single factor unambiguously accounts for all radiations, diversification, and extinctions; however, the broader patterns of taxonomic diversification and morphological disparity point to niche differentiation in a “fishing up” scenario under the influence of “bottom-up” selective pressures. The most likely driving force in mosasaur evolution was high productivity in the Late Cretaceous, driven by tectonically controlled sea levels and climatically controlled ocean stratification and nutrient delivery. When productivity collapsed at the end of the Cretaceous, coincident with bolide impact, mosasaurs became extinct.
New Locale Provides Insight to Floral Provincialism in Carnian Triassic Gondwana
A new Late Triasssic phytogeographical scenario in westernmost Gondwana
Authors:
1. Silvia N Césari (a)
2. Carina E Colombi (b)
Affiliations:
a. Museo Argentino de Ciencias Naturales, ‘B. Rivadavia’, Department of Palaeobotany, Avenida Ángel Gallardo 470, Buenos Aires 1405, Argentina
b. Instituto y Museo de Ciencias Naturales, Universidad Nacional de San Juan, San Juan 5400, Argentina
Abstract:
Floral provincialism within the Southern Hemisphere during the Late Triassic (230 Ma) is characterized by the Ipswich and Onslow provinces, recognized originally in eastern Gondwana. However, new palynological assemblages from the Ischigualasto Formation, northwestern Argentina (231–225 Ma), change the phytogeographic interpretation for the Carnian–Norian in the westernmost Gondwana, which was previously considered part of the southern floral Ipswich province. Here we show the presence of diagnostic Euramerican species within assemblages dominated by Gondwanan taxa that allows us to refer the palynofloras to the Onslow province. Our new data extend the Onslow floral belt, previously recognized from the western edge of Tethys to Timor, to the western margin of South America. This has implications for palaeophytogeography, palaeoclimate reconstructions and the palaeoecology of a Triassic ecosystem, which has yielded significant vertebrate remains and is regarded important in the early evolution of groups such as the Dinosauria.
Low Metallicities of K and M Dwarves Do Not Preclude Planetary Formation
TESTING THE METAL OF LATE-TYPE KEPLER PLANET HOSTS WITH IRON-CLAD METHODSAuthors:1. Andrew W. Mann (a)2. Eric Gaidos (b)3. Adam Kraus (c,d)4. Eric J. Hilton (a)Affiliations:a. Institute for Astronomy, University of Hawai'i, 2680 Woodlawn Dr, Honolulu, HI 96822, USAb. Department of Geology & Geophysics, University of Hawai'i, 1680 East-West Road, Honolulu, HI 96822, USAc. Harvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138, USAd. Clay FellowAbstract:It has been shown that F, G, and early K dwarf hosts of Neptune-sized planets are not preferentially metal-rich. However, it is less clear whether the same holds for late K and M dwarf planet hosts. We report metallicities of Kepler targets and candidate transiting planet hosts with effective temperatures below 4500 K. We use new metallicity calibrations to determine [Fe/H] from visible and near-infrared spectra. We find that the metallicity distribution of late K and M dwarfs monitored by Kepler is consistent with that of the solar neighborhood. Further, we show that hosts of Earth- to Neptune-sized planets have metallicities consistent with those lacking detected planets and rule out a previously claimed 0.2 dex offset between the two distributions at 6σ confidence. We also demonstrate that the metallicities of late K and M dwarfs hosting multiple detected planets are consistent with those lacking detected planets. Our results indicate that multiple terrestrial and Neptune-sized planets can form around late K and M dwarfs with metallicities as low as 0.25 solar. The presence of Neptune-sized planets orbiting such low-metallicity M dwarfs suggests that accreting planets collect most or all of the solids from the disk and that the potential cores of giant planets can readily form around M dwarfs. The paucity of giant planets around M dwarfs compared to solar-type stars must be due to relatively rapid disk evaporation or a slower rate of planet accretion, rather than insufficient solids to form a core.
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