Archaeologists find prehistoric humans cared for sick and disabled Read more: Archaeologists find prehistoric humans cared for sick and disabled
|1:57:42 AM, Saturday, December 22, 2012|
(By James Gorman, The New York Times, 12/18/2012) "While it is a painful truism that brutality and violence are at least as old as humanity, so, it seems, is caring for the sick and disabled. And some archaeologists are suggesting a closer, more systematic look at how prehistoric people - who may have left only their bones - treated illness, injury and incapacitation. Call it the archaeology of health care.
The case that led Lorna Tilley and Marc Oxenham of Australian National University in Canberra to this idea is that of a profoundly ill young man who lived 4,000 years ago in what is now northern Vietnam and was buried, as were others in his culture, at a site known as Man Bac.
Almost all the other skeletons at the site, south of Hanoi and about 15 miles from the coast, lie straight. Burial 9, as both the remains and the once living person are known, was laid to rest curled in the fetal position. When Tilley, a graduate student in archaeology, and Oxenham, a professor, excavated and examined the skeleton in 2007 it became clear why. His fused vertebrae, weak bones and other evidence suggested that he lies in death as he did in life, bent and crippled by disease.
They gathered that he became paralyzed from the waist down before adolescence, the result of a congenital disease known as Klippel-Feil syndrome. He had little, if any, use of his arms and could not have fed himself or kept himself clean. But he lived another 10 years or so..."
Origin of Life Needs a Rethink, Scientists Argue
|11:17:25 PM, Sunday, December 16, 2012|
(LiveScience.com, By Tia Ghose, 11 December 2012) "Scientists trying to unravel the mystery of life's origins have been looking at it the wrong way, a new study argues.
Instead of trying to recreate the chemical building blocks that gave rise to life 3.7 billion years ago, scientists should use key differences in the way that living creatures store and process information, suggests new research detailed today (Dec. 11) in the Journal of the Royal Society Interface.
"In trying to explain how life came to exist, people have been fixated on a problem of chemistry, that bringing life into being is like baking a cake, that we have a set of ingredients and instructions to follow," said study co-author Paul Davies, a theoretical physicist and astrobiologist at Arizona State University. "That approach is failing to capture the essence of what life is about."
Living systems are uniquely characterized by two-way flows of information, both from the bottom up and the top down in terms of complexity, the scientists write in the article. For instance, bottom up would move from molecules to cells to whole creatures, while top down would flow the opposite way. The new perspective on life may reframe the way that scientists try to uncover the origin of life and hunt for strange new life forms on other planets.
"Right now, we're focusing on searching for life that's identical to us, with the same molecules," said Chris McKay, an astrobiologist at the NASA Ames Research Center who was not involved in the study. "Their approach potentially lays down a framework that allows us to consider other classes of organic molecules that could be the basis of life..."
Scientists claim that homosexuality is not genetic - but it arises in the womb
|9:25:53 PM, Sunday, December 16, 2012|
(io9.com, By George Dvorsky, Dec 11, 2012) “A team of international researchers has completed a study that suggests we will probably never find a ‘gay gene.' Sexual orientation is not about genetics, say the researchers, it's about epigenetics. This is the process where DNA expression is influenced by any number of external factors in the environment. And in the case of homosexuality, the researchers argue, the environment is the womb itself.
The Epigenetic Key
Writing in The Quarterly Review of Biology, researchers William Rice, a professor at the University of California, Santa Barbara, and Urban Friberg, a professor at Uppsala University in Sweden, believe that homosexuality can be explained by the presence of epi-marks — temporary switches that control how our genes are expressed during gestation and after we're born.
Specifically, the researchers discovered sex-specific epi-marks which, unlike most genetic switches, get passed down from father to daughter or mother to son. Most epi-marks don't normally pass between generations and are essentially "erased." Rice and Friberg say this explains why homosexuality appears to run in families, yet has no real genetic underpinning.
Epigenetic mechanisms can be seen as an added layer of information that clings to our DNA. Epi-marks regulate the expression of genes according to the strength of external cues. Genes are basically the instruction book, while epi-marks direct how those instructions get carried out. For example, they can determine when, where, and how much of a gene gets expressed.
Moreover, epi-marks are usually produced from scratch with each generation — but new evidence is showing that they can sometimes carryover from parent to child. It's this phenomenon that gives the impression of having shared genes with relatives…”
-- Follow the link below, or click on the image for the rest of the article.
Did Scientists Actually Find Two Higgs Bosons?
|9:07:42 PM, Sunday, December 16, 2012|
(scientificamerican.com, By Michael Moyer, December 14, 2012) "A month ago scientists at the Large Hadron Collider released the latest Higgs boson results. And although the data held few obvious surprises, most intriguing were the results that scientists didn’t share.
The original Higgs data from back in July had shown that the Higgs seemed to be decaying into two photons more often than it should—an enticing though faint hint of something new, some sort of physics beyond our understanding. In November, scientists at the Atlas and LHC experiments updated everything except the two-photon data. This week we learned why.
Yesterday researchers at the Atlas experiment finally updated the two-photon results. What they seem to have found is bizarre—so bizarre, in fact, that physicists assume something must be wrong with it. Instead of one clean peak in the data, they have found two. There seems to be a Higgs boson with a mass of 123.5 GeV (gigaelectron volts, the measuring unit that particle physicists most often use for mass), and another Higgs boson at 126.6 GeV—a statistically significant difference of nearly 3 GeV. Apparently, the Atlas scientists have spent the past month trying to figure out if they could be making a mistake in the data analysis, to little avail. Might there be two Higgs bosons?
Although certain extensions of the Standard Model of particle physics postulate the existence of multiple Higgs bosons, none of them would predict that two Higgs particles would have such similar masses. They also don’t predict why one should preferentially decay into two Z particles (the 123.5 GeV bump comes from decays of the Higgs into Zs), while the other would decay into photons.
The particle physicist Adam Falkowski (under the nom de plume Jester) writes that the results “most likely signal a systematic problem rather than some interesting physics.” (By “systematic problem” he means something like a poorly-calibrated detector.) The physicist Tommaso Dorigo bets that it’s a statistical fluke that will go away with more data. Indeed, he’s willing to bet $100 on it with up to five people, in case you’re the kind of person who likes to wager on the results of particle physics experiments with particle physicists. The Atlas physicists are well aware of both of these possibilities, of course, and have spent the past month trying to shake the data out to see if they can fix it. Still, the anomaly remains.
But let’s not let this intriguing blip distract us from the original scent of new physics. Back when the preliminary data seemed to show that the Higgs was decaying into two photons more often than it should, I wrote that it could be “a statistical blip that would wash away in the coming flood of data.” But more data has now arrived, and the blip hasn’t gone anywhere. The Higgs boson continues to appear to be decaying into two photons nearly twice as often as it should.
All the more reason to stay tuned for the next big data release, currently scheduled for March."
After 121 years, identification of 'grave robber' fossil solves a paleontological enigma
|8:59:00 PM, Sunday, December 16, 2012|
(Phys.org November 19, 2012) "An international team of researchers, including Carnegie Museum of Natural History scientist John Wible, has resolved the evolutionary relationships of Necrolestes patagonensis, whose name translates into "grave robber," referring to its burrowing and underground lifestyle. This much-debated fossil mammal from South America has been a paleontological riddle for more than 100 years.
Scientific perseverance, a recent fossil discovery, and comparative anatomical analysis helped researchers to correctly place the strange 16-million-year-old Necrolestes, with its upturned snout and large limbs for digging, in the mammal evolutionary tree. This finding unexpectedly moves forward the endpoint for the fossil's evolutionary lineage by 45 million years, showing that this family of mammals survived the extinction event that marked the end of the Age of Dinosaurs. This is an example of the Lazarus effect, in which a group of organisms is found to have survived far longer than originally thought. Situating Necrolestes among its relatives in the fossil record answers one long-held question, but creates others; it reminds us that there is a lot we don't yet know about the global impacts of the massive extinction event 65 million years ago and it challenges assumptions that the well-documented effects that occurred in western North America were experienced globally.
The scientific paper resolving the mystery of Necrolestes appears today in Proceedings of the National Academy of Sciences.
A paleontological riddle Since its discovery in Patagonia in 1891, Necrolestes has been an enigma. "Necrolestes is one of those animals in the textbooks that would appear with a picture and a footnote, and the footnote would say 'we don't know what it is,'" says co-author John Wible, Carnegie Museum of Natural History mammalogist and member of the discovery team that also includes researchers from Australia and Argentina. Wible is known for his work on the origins and evolutionary relationships among the three modern mammal groups: placentals (live-bearing mammals such as humans), marsupials (pouched mammals such as opossums), and egg-laying mammals (such as platypuses)..."
The Russians Didn’t Just Use Pencils in Space
|8:10:07 PM, Sunday, November 25, 2012|
(www.mentalfloss.com November 15, 2012) "A longstanding urban legend goes like this: During the space race of the 1960s, NASA spent millions developing a fancy “space pen” that could be used in zero gravity … but the Soviets just used a pencil. This story resonates with us because NASA did actually spend piles of money on writing utensils in space—in 1965 they paid $128 per mechanical pencil, according to NASA historians (for the record, the pencils had high-strength outer casings, but the writing guts were just regular mechanical pencils). It just seems logical that the thrifty Soviets would use a simpler, smarter solution. But the story about the government-funded space pen and Soviets using pencils instead is just plain wrong—both space programs used the Fisher Space Pen, and neither paid anything to develop it. Let’s dig into the real history here.
Why Don’t Regular Ballpoint Pens Work in Space?
The traditional ballpoint pen relies partially on gravity to get ink out of the cartridge, onto the ball, and ultimately onto paper. Within the cartridge, there is a reservoir of ink (you can see this in that clear-plastic “stick” in the middle of a typical Bic pen). But without gravity, there is no force to push the ink towards the ball—it just floats freely in the cartridge. This is why traditional ballpoint pens don’t write properly upside down (at least after the first few strokes) and often fail to write on vertical surfaces—the ink loses contact with the ball.
Why Not Use a Pencil?
Americans and Soviets actually did use pencils in space, before the Space Pen came around. Americans favored mechanical pencils, which produced a fine line but presented hazards when the pencil lead tips broke (and if you’ve ever used a mechanical pencil, you know that this happens a lot). That bit of graphite floating around the space capsule could get into someone’s eye, or even find its way into machinery or electronics, causing an electrical short or other problems. And if there’s one thing Houston didn’t need, it was more astronauts calling up with problems.
The Soviet space program used grease pencils, which don’t have breakage problems—to access more of the writing wax, cosmonauts simply peeled away another layer of paper. The problem with a grease pencil is that it’s imprecise and smudgy—it’s a lot like writing with a crayon. The peeled-away paper also created waste, and bits of paper floating around a Soyuz capsule were nearly as annoying as bits of graphite floating around an Apollo capsule.
The final mark against pencils has to do with fire. Any flammable material in a high-oxygen environment is a hazard, as we all learned after the terrible fire on Apollo 1. After that tragedy, NASA sought to minimize the use of flammable materials in space capsules—and every form of pencil (traditional, mechanical, or grease) involved some amount of flammable material, even if it was just the graphite.
The Fisher Space Pen
In 1965, engineer Paul C. Fisher patented a new pen design that changed everything. His Fisher Pen Company reportedly spent $1 million of its own money to develop what was first called the “Anti-Gravity” Space Pen, and later simply the “Space Pen.” Fisher happened to perfect his invention around the time that NASA had its $128 pencil problem, so Fisher capitalized on that bad press and publicized his heavy-duty pen as the obvious solution. And it worked.
Fisher’s Space Pen featured a series of technological improvements, making it suitable for use not just in space, but in other demanding environments. Its biggest innovation was its ink capsule—pressurized nitrogen forced the ink to flow, enabling the pen to write upside-down, in zero gravity, in a vacuum, or even underwater. The nitrogen was separated from the ink by a floating barrier, which served to keep the ink in the writing end of the capsule. The ink was itself different from typical materials; it had a thixotropic (highly viscous) consistency that resisted evaporation, and kept the ink stationary until the ball moved, at which point it turned into a more typical fluid.
To counterbalance the pressurized ink flow, Fisher also included a precision roller ball made of tungsten carbide, positioned to prevent leakage. The pens were made entirely of metal except for the ink, which reportedly had a flash point of 200° C—enough to meet NASA’s strict flammability requirements.
Fisher delivered samples of the Space Pen to NASA in 1965. NASA tested the pen to verify Fisher’s claims, and ultimately approved a later version for use starting in 1967. Wanting to avoid the earlier scandal about paying excessive amounts for pencils, NASA received a bulk discount for the pens, reportedly paying just $2.39 per pen for an order of 400 units in 1968. The Soviet space agency also purchased 100 pens. NASA astronauts began using the Space Pen on Apollo 7 in 1968. By 1969, both the American and Soviet space programs had Fisher Space Pens in space—and Fisher trumpeted that success in his Space Pen marketing, which continues today. (Among other odd achievements, a Space Pen was used on the Russian space station Mir in the mid-1990s for a promotion on QVC, as the first product “sold from space.”)"
Prehistoric arms race started earlier than previously thought
|6:04:34 PM, Sunday, November 25, 2012|
(independent.co.uk 16 November 2012) "Scientists have found evidence that human ancestors used stone-tipped weapons 200,000 years earlier than once thought, findings that may change notions about the capabilities of prehistoric people.
Spears topped with stone points were most likely used for hunting large game and self-defense and were an important advance in weaponry, according to Jayne Wilkins, lead author of the paper Thursday in the journal Science. The points came from one of the Stone Age archaeological sites in South Africa called Kathu Pan 1, and were used a half-million years ago.
Researchers first thought the early humans were using sharpened wooden spears or stone hand axes, Wilkins said. The steps required to put a sharp-tipped stone at the end of a wooden spear, called hafting, means these ancestors had to engage in planning and other goal-driven thought processes long before a hunt took place, she said.
"This expands the range of behavioral complexity known in human ancestors living 500,000 years ago," said Wilkins, a PhD candidate in the Department of Anthropology at the University of Toronto, in a Nov. 13 email. "The amount of fore-planning and goal-oriented behavior required for collecting stone, wood and bindings for hafting indicate capabilities much greater than was previously known. It also shows that stone-tipped spears were being used by the ancestors of both modern humans and Neanderthals, so the technology is probably not an independent invention nor something one group learned from the other."
The spears were an improvement because the hunters could get further out of harm's way and were more likely to make a successful kill, she said.
The stone tips were recovered between 1979 and 1982 during excavations. In 2010, researchers dated the site to about a half-million years ago.
In the study, researchers replicated the stone points, attached them to spears and then shot them at a dead animal using a calibrated crossbow. The damage to the researchers' stone points was similar to that seen on the 500,000-year-old points, Wilkins said. The stone points also fit the size and shape of Stone Age points used as spear tips.
"This technology would also have provided another layer of protection from other carnivores, Wilkins said. "Stone-tipped spears would have not only helped our ancestors get food, but would also protect them from becoming food. Some researchers have linked hafted technology - the attachment of stone tools to wooden or bone handles - to language because the sequential steps of combining materials to form a spear is like a recipe that must be followed exactly to produce a result that makes sense. In that way, hafting is analogous to creating a grammatical sentence.""
China lands first jet on aircraft carrier
|5:54:42 PM, Sunday, November 25, 2012|
(CNN 11/25/2012) "China announced Sunday that it had landed a fighter jet on the deck of an aircraft carrier for the first time, but it may be years before the ship is fully operational.
China's "first generation multi-purpose carrier-borne fighter jet," known as the J-15, successfully completed its first landing on the Liaoning, an aircraft carrier China built using an abandoned Soviet hull, according to China's official news agency Xinhua.
The J-15's capabilities are comparable to the Russian Su-33 jet and the U.S. F-18, Xinhua reported. The Chinese-designed jet can "carry multi-type anti-ship, air-to-air and air-to-ground missiles, as well as precision-guided bombs, the report said.
The U.S. military, in its latest annual assessment of China's military capability, predicted "it will still take several additional years for China to achieve a minimal level of combat capability for its aircraft carriers."
The Liaoning will be able to carry 30 J-15 fighter planes and will have a crew of 2,000, according to a People's Daily Online report published when it completed its first sea trials in August 2011.
China bought the shell of the carrier, then called the Varyag, from Ukraine in 1998. Its construction was begun under the Soviet military before the breakup of the Soviet Union.
The Pentagon report said another carrier, one made from components made in China, may already be under construction and ready to sail in 2015.
"China likely will build multiple aircraft carriers and associated support ships over the next decade," the U.S. assessment said.
The United States, Britain and Japan launched the first aircraft carriers nearly a century ago. The U.S. Navy, with 11, is the only fleet that currently operates more than one."
Radiation and potential life on Mars: Has NASA discovered something historic?
|4:48:37 PM, Friday, November 23, 2012|
"(thespacereporter.com Nov. 22, 2012) NASA has reportedly uncovered a significant finding on Mars, leading to speculation the U.S. space agency may hold evidence of past life on the Red Planet.
“This data is gonna be one for the history books. It’s looking really good,” geologist John Grotzinger of the California Institute of Technology, who said that NASA’s Curiosity rover has uncovered exciting new results from a sample of Martian soil recently scooped up and placed in the Sample Analysis at Mars (SAM) instrument.
It remains unclear exactly what NASA has discovered on the planet. The space agency is reportedly conducting various tests to confirm data streamed from Mars to Earth.
Speculation over the potential finding comes just after the U.S. space agency announced a series of major findings regarding the surface of Mars and its atmosphere. NASA researchers using the car-sized mobile laboratory identified transient whirlwinds, mapped winds in relation to slopes, tracked daily and seasonal changes in air pressure, and linked rhythmic changes in radiation to daily atmospheric changes. The knowledge being gained about these processes is thought to be key to allowing scientists to better interpret evidence about environmental changes on Mars that may have led to conditions favorable for life.
The announcement also follows a minor mistake by NASA officials. NASA’s Mars rover Curiosity failed to detect methane in its first analyses of the Martian atmosphere, a statement that was released after the space agency said initial signs pointed in the direction of the presence of methane.
Among the most interesting findings released by NASA in recent days relates to radiation levels found on Mars. According to NASA, initial reading of cosmic radiation on Mars shows that it’s almost the same as on the International Space Station.
“The astronauts can live in this environment,” Don Hassler, principal investigator on Curiosity’s Radiation Assessment Detector instrument (RAD), according to CNET.com on Monday.
The NASA radiation expert said the atmosphere on the planets serves as shield to block dangerous dose of cosmic in the space.
“Basically, we’re finding that the Mars atmosphere is acting as a shield for the radiation on the surface and as the atmosphere gets thicker, that provides more of a shield and therefore we see a dip in our radiation dose,” added Mr. Hassler.
More likely than not, the discovery will be the result of recent soil samples. The one-tone rover has spent the past several days collecting soil samples from around the region. During a Thanksgiving break, the team will use Curiosity’s Mast Camera (Mastcam) from Point Lake to examine possible routes and targets to the east. A priority is to choose a rock for the first use of the rover’s hammering drill, which will collect samples of powder from rock interiors.
Although Curiosity has departed the Rocknest patch of windblown sand and dust where it scooped up soil samples in recent weeks, the sample-handling mechanism on the rover’s arm is still holding some soil from the fifth and final scoop collected at Rocknest. The rover is carrying this sample so it can be available for analysis by instruments within the rover if scientists choose that option in coming days.
While the mystery is likely to persist, NASA assured followers that they will reveal their findings in during the first week of December. According to Wired.com, a number of scientists say they expect NASA to announce the discovery of organic material, a key finding that would significantly increase the odds of life existing on Mars.
“If it’s going in the history books, organic material is what I expect,” planetary scientist Peter Smith from the University of Arizona’s Lunar and Planetary Laboratory, said in an email. “It may be just a hint, but even a hint would be exciting.”
In an attempt to tamp down speculation, a spokesman for NASA’s Jet Propulsion Laboratory, which is managing the project, appeared to pour cold water Wednesday on the hopes of space enthusiasts looking forward to an earth-shattering discovery.
“John was delighted about the quality and range of information coming in from SAM during the day a reporter happened to be sitting in John’s office last week. He has been similarly delighted by results at other points during the mission so far,” spokesman Guy Webster told the Associated Press.
“The scientists want to gain confidence in the findings before taking them outside of the science team. As for history books, the whole mission is for the history books,” Mr. Webster said.
The $2.5 billion Curiosity rover landed inside Mars’ huge Gale Crater on August 5, kicking off a two-year mission to determine if Mars has ever been capable of supporting microbial life. The car-size robot carries ten different instruments to aid in its search for life."
Army to Congress: Thanks, but no tanks
|2:23:08 AM, Monday, October 15, 2012|
(HERLONG, California CNN 10/9/12) "If you need an example of why it is hard to cut the budget in Washington look no further than this Army depot in the shadow of the Sierra Nevada range.
CNN was allowed rare access to what amounts to a parking lot for more than 2,000 M-1 Abrams tanks. Here, about an hour's drive north of Reno, Nevada, the tanks have been collecting dust in the hot California desert because of a tiff between the Army and Congress.
The U.S. has more than enough combat tanks in the field to meet the nation's defense needs - so there's no sense in making repairs to these now, the Army's chief of staff Gen. Raymond T. Odierno told Congress earlier this year.
If the Pentagon holds off repairing, refurbishing or making new tanks for three years until new technologies are developed, the Army says it can save taxpayers as much as $3 billion.
That may seem like a lot of money, but it's a tiny sacrifice for a Defense Department that will cut $500 billion from its budget over the next decade and may be forced to cut a further $500 billion if a deficit cutting deal is not reached by Congress.
Why is this a big deal? For one, the U.S. hasn't stopped producing tanks since before World War II, according to lawmakers.
Plus, from its point of view the Army would prefer to decide what it needs and doesn't need to keep America strong while making tough economic cuts elsewhere.
"When a relatively conservative institution like the U.S. military, which doesn't like to take risks because risks get people killed, says it has enough tanks, I think generally civilians should be inclined to believe them," said Travis Sharp a fellow at the defense think tank, New American Security.
But guess which group of civilians isn't inclined to agree with the generals on this point?
To be exact, 173 House members - Democrats and Republicans - sent a letter April 20 to Defense Secretary Leon Panetta, urging him to continue supporting their decision to produce more tanks.
That's right. Lawmakers who frequently and loudly proclaim that presidents should listen to generals when it comes to battlefield decisions are refusing to take its own advice.
If the U.S. pauses tank production and refurbishment it will hurt the nation's industrial economy, lawmakers say."The combat vehicle industrial base is a unique asset that consists of hundreds of public and private facilities across the United States," the letter said. The outlook for selling Abrams tanks to other nations appears "stronger than prior years," the letter said. But those sales would be "inadequate to sustain the industrial base and in some cases uncertain. In light of this, modest and continued Abrams production for the Army is necessary to protect the industrial base."
Lima, Ohio, is a long way from this dusty tank parking lot. The tiny town in the northwestern part of the Buckeye State is where defense manufacturing heavyweight General Dynamics makes these 60-plus-ton behemoths..."
-- Don't you just love lobbies? See link below or click on the image for the full article.
Nasa's Curiosity rover finds 'unusual rock'
|2:15:40 AM, Monday, October 15, 2012|
(BBC Oct. 12, 2012) "It was expected to be just another lump of dull basalt, but the first rock examined up close by Nasa's Mars rover proved to be a little more interesting.
The pyramidal object, nicknamed "Jake Matijevic" after a recently deceased mission engineer, had a composition not seen on the planet before.
Scientists have likened it to some unusual but well known rocks on Earth.
These form from relatively water-rich magmas that have cooled slowly at raised pressures, said Edward Stolper.
"[The rock is] widespread on Earth, on oceanic islands such as Hawaii, and St Helena, and the Azores; and also in rift zones like the Rio Grande and so forth. So, again, it's not common, but it's very well known," the mission co-investigator from the California Institute of Technology, Pasadena, told reporters.
The Curiosity rover examined Jake Matijevic three weeks ago. At the time, the dark rock was not anticipated to have high science value; it was merely an early opportunity to use the robot's survey instruments in unison.
Jake Matijevic also had an interesting, weathered appearance that drew attention.
The rover first zapped the rock from a distance with its ChemCam laser, and then moved in close to study it with its X-ray spectrometer known as APXS. The latter device is held on the end of the rover's robotic arm; the laser is mounted on its mast.
Jake Matijevic was found to be high in elements consistent with the mineral feldspar, such as sodium and potassium, and low in elements such as magnesium and iron.
Prof Stolper compared the signatures with a catalogue containing thousands of Earth rocks, and determined the nearest match to be an igneous type, the formation of which he likened to the production of colonial apple jack liquor..."
-- See link below for the rest of the article!
New to Nature No 88: Euryplatea nanaknihali
|3:16:22 AM, Sunday, October 14, 2012|
"(www.guardian.co.uk 13 October 2012) A parasitoid discovered in Thailand is the world's smallest fly.
What is smaller than a 2mm-long ant? A parasitoid scuttle fly whose larva is so tiny that it can develop inside the ant's head. Not only is new species Euryplatea nanaknihali much smaller than its presumed ant host, at a mere 0.4mm it is the smallest fly in the world. This is an unusual fly in a family known for the unusual. Other Phoridae are predators on such delicacies as slug and spider eggs, snails, and aphids; parasitoids on millipedes and various insects; or saprophages feeding on dead hosts. Among the strangest phorid flies are species with grotesquely bloated soft abdomens reminiscent of queen termites, wingless and legless females that look more like larval ants than adult flies, and small flightless shield-shaped forms like E nanaknihali.
Before this discovery it was conjectured that extremely small ants were immune to phorid attacks. At 1-3 mm length, known phorid parasitoids were physically too large to develop inside the cranium of a minute ant. This new species, smaller than any known gnat, mosquito or midge, changed all that. If dwarfism in ants was a defence strategy, then it has been out-smalled and defeated by these diminutive attackers.
E nanaknihali was discovered in Thailand during an intensive insect collecting project, and described and named by Dr Brian V Brown of the Natural History Museum of Los Angeles County. Like the only other species of the genus, the fly is small with smoky grey wings and a pointed ovipositor. No males of either species have been seen. The type species of the genus, E eidmanni, lives in the nests of the ant Crematogaster impressa on Bioko island, Equatorial Guinea. Although the life history of the new species is not yet known, it is reasonable to infer that it has similar habits. E nanaknihali is only about a third the size of its sister species and differs also by a longer costal vein along the front edge of the wing and the absence of a visible scutellum, a trianglular-shaped sclerite on its back. The fly was found in a malaise trap in the Kaeng Krachan national park.
E nanaknihali is known only from a single slide-mounted specimen, expertly illustrated by Inna Strazhnik. Brown refers to the fly as the latest addition to the entomological "nanosphere", a world of ultra-small insects dominated by trichogrammatid and mymarid wasps. To date, the smallest known insects are mymarids. At a mere 0.14mm in length they are also the smallest multicellular animals. This species is a reminder of just how little we know about scuttle flies, which are among the most biologically diverse, anatomically adventurous and species-rich of any Diptera family.
Quentin Wheeler is director of the International Institute for Species Exploration."
Oldest Arthropod Brain Found in Buglike Creature
|2:50:48 AM, Sunday, October 14, 2012|
"(livescience.com Oct. 10, 2012) The oldest brain ever found in an arthropod — a group of invertebrates that includes insects and crustaceans — is surprisingly complex for its 520-million-year age, researchers report today (Oct. 10).
The fossilized brain, found in an extinct arthropod from China, looks very similar to the brains of today's modern insects, said study researcher Nicholas Strausfeld, the director of the Center for Insect Science at the University of Arizona.
"The rest of the animal is incredibly simple, so it's a big surprise to see a brain that is so advanced, as it were, in such a simple animal," Strausfeld told LiveScience.
The evolving insect brain
Arthropods include any animal with an exoskeleton, jointed legs and a segmented body, from lobsters to scorpions to beetles to butterflies. There is controversy about how these various creatures evolved, however. One theory holds that insects evolved from ancestors not unlike today's branchiopods, which are extremely simple crustaceans such as fairy shrimp and water fleas. Branchiopods have simpler brains than insects and higher crustaceans, Strausfeld said, so this theory of evolution holds that both higher crustaceans and insects evolved very similar complex brains after splitting off from this common branchiopod-like ancestor.
Alternatively, all of these groups — insects, branchiopods and higher crustaceans — could have evolved from an ancestor with a complex brain, with branchiopods regressing later.
"So the question was, 'What was the early brain, what did it look like? Did it look simple or did it look complex?'" Strausfeld said.
That's not an easy question to answer, given that brains rarely get fossilized. But Strausfeld's earlier work on arthropod fossils convinced him it could be done. He just had to go to China, home of an amazing collection of stunningly preserved ancient fossils.
In China's Yunnan province, paleontologists have long uncovered fossils from the Cambrian period, which ran from about 542 million to 488 million years ago. These fossils are very well-preserved.
For five days, Strausfeld and his colleagues poured through fossils, searching for dark silhouettes of preserved brains inside ancient arthropod heads. There was one fossil that remained elusive, however: A specimen Strausfeld had read about in a paper by Swedish researchers. They thought they'd seen a fossilized brain.
With only a few hours left in the lab, Strausfeld's colleague, Xiaoya Ma, of the Natural History Museum in London went hunting for the missing specimen. An hour and a half later, she returned with the fossil, an extinct armored creature just a few centimeters long called Fuxianhuia protensa.
"I looked at the microscope and I think I said something like, 'Whoopee, I think we've got the crown jewels!'" Strausfeld said. Under magnification, he could see the dark brown silhouette of preserved brain nestled in the arthropod's skull.
"It's pretty bloody marvelous, actually. … I was sitting looking at the thing, going, 'Oh my goodness gracious,'" Strausfeld said. With only five hours left before he had to leave to give a scheduled talk and fly home, Strausfeld got busy photographing the discovery.
An analysis of the brain revealed it to be in three parts, just as the brains of modern insects are in three parts (known as the protocerebrum, deutocerebrum and tritocerebrum). Nerves from the eyes extend into the protocerebrum, nerves from the antennaes feed into the ancient creature's deutocerebrum, and a third nerve root from further back in the body extends into the tritocerebrum. The researchers report the findings in this week's issue of the journal Nature.
This complex, insectlike brain suggests that rather than insects arising from simple branchiopods, today's arthropods descend from a complex-brained ancestor. Branchiopods would later have shed some of this complexity, Strausfeld said, while other crustaceans and insects kept it. In fact, he said, the brain may have evolved to segment into three parts very early on; mammals, including humans, have a forebrain, midbrain and hindbrain, suggesting a common organization.
"Lots of people don't like that idea, sharing a brain with a beetle, but there's good evidence suggesting that you do," Strausfeld said.
Bug brains may seem simple to us, but arthropods are at the base of many a food chain, making them crucial creatures, Strausfeld said. He and his team plan to return to China to hunt out more ancient arthropod brains.
"What we want to do, of course, is go deeper in time," Strausfeld said."
First single-molecule measurement of Van Der Waals interactions at metal-organic interface
|4:03:45 AM, Saturday, October 13, 2012|
(Phys.org August 12, 2012) "A team of researchers at Columbia Engineering, led by Applied Physics and Applied Mathematics Associate Professor Latha Venkataraman and in collaboration with Mark Hybertsen from the Center for Functional Nanomaterials at the U.S. Department of Energy's Brookhaven National Laboratory, has succeeded in performing the first quantitative characterization of van der Waals interactions at metal/organic interfaces at the single-molecule level.
In a study published online August 12 in the Advance Online Publication on Nature Materials's website , the team has shown the existence of two distinct binding regimes in gold-molecule-gold single-molecule junctions, using molecules containing nitrogen atoms at their extremities that are attracted to gold surfaces. While one binding mechanism is characterized by chemical interactions between the specific nitrogen and gold atoms, the other is dominated by van der Waals interactions between the molecule and the gold surface.
"A detailed understanding of van der Waals interactions is a key step towards design of organic electronic devices," says Sriharsha Aradhya, the study's lead author and a Ph.D. candidate working with Venkataraman. "Apart from the fundamental importance of these measurements, we are also excited about its applications. Understanding the effects of van der Waals interactions is tremendously important for creating and optimizing devices with organic building-blocks".
"Many proposals for future photovoltaic and flexible electronic devices are based on organic molecules because they are cost-effective," Venkataraman adds, "and scientists need to have a deeper understanding of these van der Waals interactions. Our work opens up the possibility of measuring and characterizing the strength of interaction between a variety of molecules and metallic surfaces a single-molecule at a time."
The forces of attraction between atoms and molecules come in different varieties and strengths, Aradhya explains. One of the most ubiquitous forms of attraction in nature is the van der Waals force. In contrast to specific interactions arising from bonding between atoms, van der Waals interactions represent non-specific interactions with subtler underpinnings. While originally intended to explain the apparent continuity between gaseous and liquid phases of matter, these forces have come to be recognized as an important aspect in answering such diverse questions as how does water boil inside a pressure cooker? How are geckos able to climb walls vertically? Or how can you control the organization of molecules for an organic LED smartphone display screen?
As devices like the latter become increasingly common, there has been a good deal of renewed interest in van der Waals interactions, known to lie at the heart of the structure and functionality in such devices. These interactions between organic molecules and metallic surfaces are central to a diverse range of phenomena such as catalysis of reactions, molecular electronic architectures, and molecular self-assembly in nature and engineered material. However, van der Waals interactions remain challenging to characterize directly at the fundamental, single-molecule level both in experiments and in theoretical calculations.
For this Columbia Engineering study, the researchers used their custom-built conducting atomic force microscope to make simultaneous measurements of force and conductance in single-molecule junctions. They combined their measurements with theoretical calculations and simulations, carried out in collaboration with Hybertsen at Brookhaven, in order to provide a unique quantitative measurement of the relative importance of specific and non-specific interactions at the single-molecule level, in a regime where both are comparable.
"In simple terms, conductance of the junction acts as a fingerprint of the structure," explains Aradhya. "At the same time, the measured force – especially the force needed to rupture the junction – can be used to deduce its mechanical properties."
While similar studies have been reported by a few research groups around the world, such precise studies have typically required the measurements to be carried out at very low temperatures and in high vacuum. Venkataraman's and Aradhya's experimental setup was optimized for very high sensitivities even at room temperature and ambient conditions. This allowed the team to perform thousands of individual single-molecule measurements, resulting in statistically robust results. The researchers then performed extensive density functional theory calculations to help them understand the mechanisms underlying their measurements..."
Invisible volcanic ash gives clues to Neanderthal demise
|3:51:52 AM, Saturday, October 13, 2012|
(Phys.org August 6, 2012) "Invisible to the human eye, cryptotephra is a fine volcanic glass that is blasted out of erupting volcanoes along with ash. It leaves behind a hidden layer, in the earth, which has now been detected, giving clues about why the Neanderthals died out.
About 40,000 years ago, a layer of cryptotephra particles carpeted a huge area of Central and Eastern Europe after a massive volcanic eruption in Italy called the Campanian Ignimbrite (CI).
This eruption, and the resulting environmental and climatic disruption, has been suggested as a factor in the extinction of the Neanderthals. Interaction with us, modern humans, is one of the other possibilities.
Neanderthals, who were our closest relatives, had been living in Europe for hundreds of thousands of years. But all physical evidence of them disappears after about 30,000 years ago.
Early modern humans were known to have arrived in Europe at least 35,000 years ago, having originated in Africa, but precise dates, and the length of time they overlapped with the last Neanderthals, are unclear.
Archaeological sites, many in caves, have revealed stone tools belonging to Neanderthals and to early modern humans.
Scientists have now used a new technique to detect CI cryptotephra in some of these sites across Europe and in Libya - the lighter particles of the glass means it spreads over much wider distances than ash.
The team of more than 40 scientists, including Prof Chris Stringer and Mark Lewis of the Natural History Museum, published their research in the Proceedings of the National Academy of Sciences last week..."
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Fossil of ancient spider attack only one of its type ever discovered
|3:44:32 AM, Saturday, October 13, 2012|
"(Phys.org Oct. 8, 2012) Researchers have found what they say is the only fossil ever discovered of a spider attack on prey caught in its web – a 100 million-year-old snapshot of an engagement frozen in time.
The extraordinarily rare fossils are in a piece of amber that preserved this event in remarkable detail, an action that took place in the Hukawng Valley of Myanmar in the Early Cretaceous between 97-110 million years ago, almost certainly with dinosaurs wandering nearby.
Aside from showing the first and only fossil evidence of a spider attacking prey in its web, the piece of amber also contains the body of a male spider in the same web.
This provides the oldest evidence of social behavior in spiders, which still exists in some species but is fairly rare. Most spiders have solitary, often cannibalistic lives, and males will not hesitate to attack immature species in the same web. "This juvenile spider was going to make a meal out of a tiny parasitic wasp, but never quite got to it," said George Poinar, Jr., a professor emeritus of zoology at Oregon State University and world expert on insects trapped in amber. He outlined the findings in a new publication in the journal Historical Biology.
"This was a male wasp that suddenly found itself trapped in a spider web," Poinar said. "This was the wasp's worst nightmare, and it never ended. The wasp was watching the spider just as it was about to be attacked, when tree resin flowed over and captured both of them."
Spiders are ancient invertebrates that researchers believe date back some 200 million years, but the oldest fossil evidence ever found of a spider web is only about 130 million years old. An actual attack such as this between a spider and its prey caught in the web has never before been documented as a fossil, the researchers said..."
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