Is Our Leaf Left-Handed? Previously Overlooked Asymmetry in Arabidopsis and Tomato Leaves
|2:44:03 AM, Sunday, June 24, 2012|
"(Phys.org June 22, 2012) Research published in the Plant Cell shows that the spiral pattern of leaf formation from the point of growth affects the developing leaf's exposure to the plant hormone auxin; This exposure leads to measurable left-right asymmetry in leaf development, in species previously assumed to have symmetric leaves.
The front of a leaf is different from the back of a leaf and the tip is different from the base. However, a leaf from a tomato or an Arabidopsis plant superficially appears to be bilaterally symmetrical, or the same on the left and right sides. Don't let its appearance fool you; there is an underlying asymmetry between the left and right sides of such leaves—it just took a while for scientists to discover it. The story begins with the mechanism by which leaves form along a stem. In broad-leafed plants, dicots, leaves form from the meristem, an actively dividing tissue at the top of the plant, so that as you look down the stem, the oldest leaves are at the bottom. Leaves don't just become arranged by random chance either—phyllotaxis, the arrangement of leaves or flowers along a stem, affects key plant characteristics, such as how much light can filter through to lower leaves. Leaves can form opposite each other, or in alternation, or in whorls; often leaves form in spirals where the next leaf is offset by roughly 137 degrees, known as the "golden angle", which is related to the Fibonacci sequence..."
Moon Mystery Solved? Hovering Soil Linked to Glass Bubbles
|2:32:50 AM, Sunday, June 24, 2012|
"(Nat. Geo. June 21, 2012) Soil on the moon can hover over the surface, and the temperature six feet (two meters) deep can be more than 300 degrees Fahrenheit (167 degrees Celsius) colder than the topsoil.
Now researchers in Australia think they've solved the puzzle of moon soil's odd behavior: nanosize particles of lunar glass.
Small bubbles of glass form on the moon when micrometeorites hit the lunar surface.
Since the moon has no atmosphere to slow the projectiles, each one, no matter how tiny, "wreaks havoc," said Paul Warren, a research geochemist at the University of California, Los Angeles, who wasn't involved in the new study.
Particles about a hundred microns wide—the size of a fine grain of beach sand—hit with enough force to melt bits of moon rock, forming tiny glass bubbles.
In a new study, Marek Zbik of the Queensland University of Technology analyzed glass bubbles collected by Luna 16, the first Soviet probe to return a sample from the moon.
Using a special type of x-ray microscope, Zbik constructed 3-D images of the bubbles' insides.
Instead of containing gas, as bubbles usually do on Earth, the moon bubbles are "filled with a highly porous network of alien-looking glassy particles that span the bubbles' interior," Zbik said in a press statement..."
How Curiosity Will Land on Mars, Part 1: Entry
|2:13:05 AM, Sunday, June 24, 2012|
"(www.planetary.org 2012/06/22) Much of the space world, including my blog, is increasingly shifting its view toward the incredibly important event that will unfold on August 5 and 6: the landing of the gigantic Curiosity rover on Mars. For some of us, it's the culmination of years of anticipation. But for an awful lot of people out there, some moment in the next six weeks will be the first time that they've heard of this mission and how it's going to land. And nearly all of those people are going to ask the same question: Are they nuts?
When you watch the marvelous computer animation of Curiosity's landing, or today's viral video about the "Seven Minutes of Terror" (which I embedded below) you gain an appreciation for just how many little events in a seven-minute Rube Goldberg sequence must go perfectly in order for landing day to be a good one. With that appreciation comes fear. What if something goes wrong? Why is it so complicated?
I've decided that the best thing I can do to help people understand what it takes to land on Mars is to explain the landing in excruciating detail, copying from and explaining the content of this paper by Ravi Prakash and coauthors, with some additions from the launch press kit. I can't do it all in one post, so I'm going to split it over several, probably three or four. It helps that the rover's engineers make their own distinctions between different phases. Being acronym-ophiles, they refer to it all as "EDL," which stands for Entry, Descent, and Landing. Today, I'll talk about Curiosity's approach to Mars and its entry into the atmosphere..."
Research Finds Stonehenge Was Monument Marking Unification of Britain
|4:14:27 PM, Friday, June 22, 2012|
(Phys.org, June 22, 2012) After 10 years of archaeological investigations, researchers have concluded that Stonehenge was built as a monument to unify the peoples of Britain, after a long period of conflict and regional difference between eastern and western Britain.
Its stones are thought to have symbolized the ancestors of different groups of earliest farming communities in Britain, with some stones coming from southern England and others from west Wales.
The teams, from the universities of Sheffield, Manchester, Southampton, Bournemouth and University College London, all working on the Stonehenge Riverside Project (SRP), explored not just Stonehenge and its landscape but also the wider social and economic context of the monument's main stages of construction around 3,000 BC and 2,500 BC.
"When Stonehenge was built", said Professor Mike Parker Pearson of the University of Sheffield, "there was a growing island-wide culture – the same styles of houses, pottery and other material forms were used from Orkney to the south coast. This was very different to the regionalism of previous centuries. Stonehenge itself was a massive undertaking, requiring the labour of thousands to move stones from as far away as west Wales, shaping them and erecting them. Just the work itself, requiring everyone literally to pull together, would have been an act of unification."
Stonehenge may have been built in a place that already had special significance for prehistoric Britons. The SRP team have found that its solstice-aligned Avenue sits upon a series of natural landforms that, by chance, form an axis between the directions of midsummer sunrise and midwinter sunset...
Researchers Estimate Ice Content of Crater at Moon's South Pole
|1:25:39 AM, Thursday, June 21, 2012|
"(Phys.org, June 20, 2012) -- NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft has returned data that indicate ice may make up as much as 22 percent of the surface material in a crater located on the moon's south pole.
The team of NASA and university scientists using laser light from LRO's laser altimeter examined the floor of Shackleton crater. They found the crater's floor is brighter than those of other nearby craters, which is consistent with the presence of small amounts of ice. This information will help researchers understand crater formation and study other uncharted areas of the moon. The findings are published in Thursday's edition of the journal Nature.
"The brightness measurements have been puzzling us since two summers ago," said Gregory Neumann of NASA's Goddard Space Flight Center in Greenbelt, Md., a co-author on the paper. "While the distribution of brightness was not exactly what we had expected, practically every measurement related to ice and other volatile compounds on the moon is surprising, given the cosmically cold temperatures inside its polar craters."
The spacecraft mapped Shackleton crater with unprecedented detail, using a laser to illuminate the crater's interior and measure its albedo or natural reflectance. The laser light measures to a depth comparable to its wavelength, or about a micron. That represents a millionth of a meter, or less than one ten-thousandth of an inch. The team also used the instrument to map the relief of the crater's terrain based on the time it took for laser light to bounce back from the moon's surface. The longer it took, the lower the terrain's elevation..."
Earliest Record of Mating Fossil Vertebrates: Nine Pairs of Fossilized Turtles Died While Mating 47 Million Years Ago
|12:53:30 AM, Thursday, June 21, 2012|
"ScienceDaily (June 20, 2012) - The fossil record consists mostly of the fragmentary remains of ancient animals and plants. But some finds can provide spectacular insights into the life and environment of ancient organisms. The Messel Fossil Pit, a UNESCO world heritage site south of Frankfurt in western Germany, is well known for yielding fossils of unusual quality, including early horses complete with embryos and insects and birds with fossilized colors.
In the latest edition of Biology Letters, a group of scientists lead by Dr. Walter Joyce of the University of Tübingen announces the discovery at Messel of nine pairs of fossilized turtles that perished in the act of mating. Dr. Joyce, a geoscientist from the University of Tübingen, heads the discovery team which includes researchers from the Senckenberg Research Institute Frankfurt and the Hessische Landesmuseum Darmstadt..."
Chemical Analysis of Pottery Reveals First Dairying in Saharan Africa in the Fifth Millennium BC
|12:46:18 AM, Thursday, June 21, 2012|
"(Phys.org June 20, 2012) The first unequivocal evidence that humans in prehistoric Saharan Africa used cattle for their milk nearly 7,000 years ago is described in research by an international team of scientists, led by the University of Bristol, UK, published today in Nature.
By analysing fatty acids extracted from unglazed pottery excavated from an archaeological site in Libya, the researchers showed that dairy fats were processed in the vessels. This first identification of dairying practices in the African continent, by prehistoric Saharan herders, can be reliably dated to the fifth millennium BC.
Around 10,000 years ago the Sahara Desert was a wetter, greener place; early hunter-gatherer people in the area lived a semi-sedentary life, utilising pottery, hunting wild game and collecting wild cereals. Then, around 7,000-5,000 years ago as the region became more arid, the people adopted a more nomadic, pastoral way of life, as the presence of cattle bones in cave deposits and river camps suggests.
Domesticated animals were clearly significant to these people: the engraved and painted rock art found widely across the region includes many vivid representations of animals, particularly cattle. However, no direct proof that these cattle were milked existed – until now.
Researchers at the Organic Geochemistry Unit in Bristol's School of Chemistry, with colleagues at Sapienza, University of Rome, studied unglazed pottery dating from around 7,000 years ago, found at the Takarkori rock shelter in the Tadrart Acacus Mountains, Libya..."
Researchers Use Nanotechnology to Harness Power of Fireflies
|1:11:54 AM, Saturday, June 16, 2012|
"(PHYS.ORG June 15, 2012) What do fireflies, nanorods and Christmas lights have in common? Someday, consumers may be able to purchase multicolor strings of light that don't need electricity or batteries to glow. Scientists in Syracuse University's College of Arts and Sciences found a new way to harness the natural light produced by fireflies (called bioluminescence) using nanoscience. Their breakthrough produces a system that is 20 to 30 times more efficient than those produced during previous experiments.
It's all about the size and structure of the custom, quantum nanorods, which are produced in the laboratory by Mathew Maye, assistant professor of chemistry in SU's College of Arts and Sciences; and Rabeka Alam, a chemistry Ph.D. candidate. Maye is also a member of the Syracuse Biomaterials Institute.
"Firefly light is one of nature's best examples of bioluminescence," Maye says. "The light is extremely bright and efficient. We've found a new way to harness biology for nonbiological applications by manipulating the interface between the biological and nonbiological components."
Their work, "Designing Quantum Rods for Optimized Energy Transfer with Firefly Luciferase Enzymes," was published online May 23 in Nano Letters and is forthcoming in print. Collaborating on the research were Professor Bruce Branchini and Danielle Fontaine, both from Connecticut College.
Fireflies produce light through a chemical reaction between luciferin and its counterpart, the enzyme luciferase. In Maye's laboratory, the enzyme is attached to the nanorod's surface; luciferin, which is added later, serves as the fuel. The energy that is released when the fuel and the enzyme interact is transferred to the nanorods, causing them to glow. The process is called Bioluminescence Resonance Energy Transfer (BRET)..."
ASPCA Ad Features Hovercat Dancing to Dubstep
|1:04:56 AM, Saturday, June 16, 2012|
-- “Millions of viral videos waiting to be adopted.”
Nice tagline! <3
Spinning Hard Drive Filmed at 1000FPS
|12:57:47 AM, Saturday, June 16, 2012|
Neutrons Escaping to a Parallel World?
|12:29:36 AM, Saturday, June 16, 2012|
"ScienceDaily (June 15, 2012) — In a paper recently published in European Physical Journal (EPJ) C, researchers hypothesised the existence of mirror particles to explain the anomalous loss of neutrons observed experimentally. The existence of such mirror matter had been suggested in various scientific contexts some time ago, including the search for suitable dark matter candidates.
Theoretical physicists Zurab Berezhiani and Fabrizio Nesti from the University of l'Aquila, Italy, reanalysed the experimental data obtained by the research group of Anatoly Serebrov at the Institut Laue-Langevin, France. It showed that the loss rate of very slow free neutrons appeared to depend on the direction and strength of the magnetic field applied. This anomaly could not be explained by known physics.
Berezhiani believes it could be interpreted in the light of a hypothetical parallel world consisting of mirror particles. Each neutron would have the ability to transition into its invisible mirror twin, and back, oscillating from one world to the other. The probability of such a transition happening was predicted to be sensitive to the presence of magnetic fields, and could therefore be detected experimentally.
This neutron-mirror-neutron oscillation could occur within a timescale of a few seconds, according to the paper. The possibility of such a fast disappearance of neutrons -- much faster than the ten-minute long neutron decay -- albeit surprising, could not be excluded by existing experimental and astrophysical limits..."
Particles Point Way for Nasa's Voyager: Close to Crossing Into Interstellar Space
|11:42:47 PM, Friday, June 15, 2012|
(BBC 15 June 2012) The Nasa mission, which launched from Earth in 1977, could leave our Solar System at any time.
It is now detecting a sharp rise in the number of high-energy particles hitting it from distant exploded stars.
The observation was predicted, and is another indication that Voyager will soon reach its historic goal.
"The laws of physics say that someday Voyager will become the first human-made object to enter interstellar space, but we still do not know exactly when that someday will be," Ed Stone, the Voyager project scientist at the California Institute of Technology in Pasadena, said in a Nasa statement.
"The latest data indicate that we are clearly in a new region where things are changing more quickly. It is very exciting. We are approaching the Solar System's frontier."
Voyager 1 is travelling at about 17 km per second (38,000 mph), and is almost 18 billion km (11 billion miles) from Earth.
The vast separation means a signal from the probe takes more than 16 and a half hours to arrive at Nasa's receiving network..."
Famous Cave Paintings Might Not Be From Humans
|11:24:45 PM, Friday, June 15, 2012|
"(NPR June 15, 2012) The famous paintings on the walls of caves in Europe mark the beginning of figurative art and a great leap forward for human culture.
But now a novel method of determining the age of some of those cave paintings questions their provenance. Not that they're fakes — only that it might not have been modern humans who made them.
The first European cave paintings are thought to have been made over 30,000 years ago. Most depict animals and hunters. Some of the eeriest are stencils of human hands, apparently made by blowing a spray of pigment over a hand held up to a wall.
But now scientists are suggesting those aren't human hands, at least in some caves in Spain.
Alistair Pike, an archaeologist at the University of Bristol in England who used a novel technique to get new dates for some of those paintings, says they're older than people thought, and they may just predate the arrival of humans in Europe.
"What we are saying is that we must entertain the possibility that these paintings were made by Neanderthals," Pike says. Those were humans' closest relatives, but they are not our species..."
Seen in 3D: The Ants of the World
|4:30:02 PM, Monday, June 11, 2012|
"(BBC 9 June 2012) Scientists from the US are embarking on a mission to capture a detailed 3D image of every ant species known to exist.
The team is visiting museums throughout the world to photograph all the ant specimens in their collections.
Their aim is to produce an online graphic catalogue open to both scientists and the public.
Victoria Gill went to meet the team at London's Natural History Museum."
Texas Tries to Lure Drivers With First 85 mph Speed Limit
|4:11:47 PM, Monday, June 11, 2012|
"Motorists with a need for speed will be pleased to hear that Texas (yeehaw!) has OK'd the first road in the country with a posted 85 mph speed limit. According to the Texas Department of Transportation, State Highway 130 is being constructed to ease the load on the gridlocked Interstate 35 between San Antonio and Austin. Officials hope the breakneck-speed posting on the toll road will attract motorists away from the sluggish I-35, but critics with common sense fear the higher speed limit will just cause more fatal accidents. Permission to floor it in the Lone Star State is going over well with Tweeps. @ivanayelich gleefully proclaims, "Just another reason to move to Texas.""
-- I approve.
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