Once again the time has come for one and all to gather around. Science talk is here. New discoveries, new takes on old knowledge, and other bits of news are all available for the perusing in today's information world. Over the fold are selections from the past week from a few of the many excellent science news sites around the world. Today's tidbits include collision with a companion moon may have formed the Moon's mountainous far side, what steers vampire bats to blood, crop breeding could slash CO2 levels, large variations in Arctic ice over the centuries, the manzanita plant once thought extinct is still hanging on, new light shed on South Pole dinosaurs, and DNA strands that select nanotubes are a first step to a practical 'quantum wire.' Gather yourselves around. Pull up that comfy chair and bask in the sunshine. There is plenty of room for everyone. Get ready for one more session of Dr. Possum's science education and entertainment.
Featured Stories
The lunar highlands, a mountainous region on the far side of the Moon may have been formed by collision with a smaller, companion moon.
The striking differences between the near and far sides of the Moon have been a longstanding puzzle. The near side is relatively low and flat, while the topography of the far side is high and mountainous, with a much thicker crust.
The new study, published in the August 4 issue of Nature, builds on the "giant impact" model for the origin of the Moon, in which a Mars-sized object collided with Earth early in the history of the solar system and ejected debris that coalesced to form the Moon.
The study suggests that this giant impact also created another, smaller body, initially sharing an orbit with the Moon, that eventually fell back onto the Moon and coated one side with an extra layer of solid crust tens of kilometers thick.
Vampire bats are known to attack the best parts of animals to get their blood feeding.
In appearance, the furry, bean-shaped bat with its rodent-like face resembles a rat with wings, but bats are actually more closely related in evolution to dogs and horses. In fact, vampire bats in the wild will gallop and leap across the ground much in the same way that horses do.
In South America where they are common, vampire bats approach their prey on the ground, galloping quickly and quietly as they sneak up on, bite, and drink the blood from sleeping cows, goats and birds.
(snip)
(Researchers) sequenced genes from samples of nose tissue from wild vampire bats in Venezuela, determining that TRPV1 is the molecule responsible for their ability to detect heat.
They also determined that it was not just TRPV1 but an evolutionary genetic variation of it that allows vampire bats to detect low temperature heat. Through a mechanism known as “alternative splicing” a special form of the molecule emerged in the noses of the bats, becoming a sensitive detector for finding the hottest spots.
According to researchers the breeding of crops with roots a meter deeper in the ground could slash CO2 levels in the atmosphere.
The soil represents a reservoir that contains at least twice as much carbon as does the atmosphere, yet mainly just the above-ground plant biomass is harvested in agriculture, and plant photosynthesis represents the effective origin of the overwhelming bulk of soil carbon.
Breeding crop plants with deeper and bushy root ecosystems could simultaneously improve both the soil structure and its steady-state carbon, water and nutrient retention, as well as sustainable plant yields.
While the disappearance of Arctic sea ice is a concern today some researchers conclude there was much less ice in the past.
Regarding the research results, (researcher) Funder says, "Our studies show that there have been large fluctuations in the amount of summer sea ice during the last 10,000 years. During the so-called Holocene Climate Optimum, from approximately 8000 to 5000 years ago, when the temperatures were somewhat warmer than today, there was significantly less sea ice in the Arctic Ocean, probably less than 50% of the summer 2007 coverage, which was absolutely lowest on record. Our studies also show that when the ice disappears in one area, it may accumulate in another. We have discovered this by comparing our results with observations from northern Canada. While the amount of sea ice decreased in northern Greenland, it increased in Canada. This is probably due to changes in the prevailing wind systems. This factor has not been sufficiently taken into account when forecasting the imminent disappearance of sea ice in the Arctic Ocean."
More to come on this subject as we continue to learn about our changing climate and the past.
Among one species of the low growing shrub, manzanita, only a single specimen survives but the plant is not extinct as once thought.
Today, the manzanita occupies a 7-square-foot patch of hillside in a 1,500-acre national park known as the Presidio of San Francisco. There is no sign attesting to its presence. It is not marked on any map. Coast live oak trees guard the weedy lot where California icons, serpentine rock and bright orange poppies, keep the modest bush company.
Park officials speak proudly of the manzanita, its ecological import, its improbable, now-you-see-it-now-you-don't story. Do not, however, ask them where it grows in their outpost at the foot of the Golden Gate Bridge. They will not tell you. Secrecy, and a nursery rich with seeds and rooted cuttings, are cornerstones of the Presidio's plan to reintroduce the rare plant.
Once upon a time dog-sized dinosaurs lived at the South Pole.
Dog-sized dinosaurs that lived near the South Pole, sometimes in the dark for months at a time, had bone tissue very similar to dinosaurs that lived everywhere on the planet..."But based on bone tissues, dinosaurs living within the Antarctic Circle were physiologically similar to dinosaurs living everywhere else."
"This tells us something very interesting; that basically from the very start, early dinosaurs, or even the ancestors of dinosaurs, evolved a physiology that allowed an entire group of animals to successfully exploit a multitude of environmental conditions for millions of years"
“Quantum wires” for low-loss, long distance electricity transmission and wiring are very desirable for the future of communication and other electronics.
Single-wall carbon nanotubes are usually about a nanometer in diameter, but they can be millions of nanometers in length. It’s as if you took a one-atom-thick sheet of carbon atoms, arranged in a hexagonal pattern, and curled it into a cylinder, like rolling up a piece of chicken wire. If you’ve tried the latter, you know that there are many possibilities, depending on how carefully you match up the edges, from neat, perfectly matched rows of hexagons ringing the cylinder, to rows that wrap in spirals at various angles—“chiralities” in chemist-speak.
Chirality plays an important role in nanotube properties. Most behave like semiconductors, but a few are metals. One special chiral form—the so-called “armchair carbon nanotube”—behaves like a pure metal and is the ideal quantum wire.
Certain DNA strands have been found to have an affinity for the peculiar nanotube shape. Once the DNA and nanotubes associate common techniques may be used to separate the two.
Other Worthy Stories of the Week
Giant asteroid spins in new NASA video
NASA satellite tracks severity of African drought
Reservoirs of ancient lava shaped Earth
Fukishima plant now leaking highest radiation levels to date
New Salmonella superbugs spreading fast
VISTA finds 96 star clusters hidden behind dust
Is our universe inside a bubble?
6 mysteries of Jupiter NASA's new spacecraft may answer
New conducting properties of bacteria-produced wires
The nanoscale secret to stronger alloys
Making sperm from stem cells in a dish
New field of hydrothermal vents discovered along the mid-Atlantic ridge
Sea lampreys fear the smell of death leading to possible new means of controlling the invasive species
For even more science news:
General Science Collectors:
Alpha-Galileo
BBC News Science and Environment
Eureka Science News
LiveScience
New Scientist
PhysOrg.com
SciDev.net
Science/AAAS
Science Alert
Science Centric
Science Daily
Scientific American
Space Daily
Blogs:
A Few Things Ill Considered Techie and Science News
Cantauri Dreams space exploration
Coctail Party Physics Physics with a twist.
Deep Sea News marine biology
Laelaps more vertebrate paleontology
List of Geoscience Blogs
ScienceBlogs
Space Review
Techonology Review
Tetrapod Zoologyvertebrate paleontology
Science Insider
Scientific Blogging.
Space.com
Wired News
Science RSS Feed: Medworm
The Skeptics Guide to the Universe--a combination of hard science and debunking crap
At Daily Kos:
This Week in Science by DarkSyde
Overnight News Digest:Science Saturday by Neon Vincent. OND tech Thursday by rfall.
Pique the Geek by Translator Sunday evenings about 9 Eastern time
All diaries with the DK GreenRoots Tag.
All diaries with the eKos Tag
A More Ancient World by matching mole
Astro Kos
SciTech at Dkos.
Sunday Science Videos by palantir
NASA picture of the day. For more see the NASA image gallery or the Astronomy Picture of the Day Archive
Rock Mounds in Gale Crater, NASA, Public Domain