Monday, Monday. Time once again to gather around and have a bit of science talk. 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 erratic day-to-day weather puts climate change in a new light, mimicing the brain in silicon, certain bats can change their ear shape instantly to improve their hearing, deforestation leads to cooling in more northern latitudes, the origins of Antarctica's ice covered mountains, the 'first complete' description of a black hole, study finds rehabilitating vacant lots improves urban health and safety, and predictions of a bleak future for San Francisco Bay marshes. Pull up that comfy chair and bask in the sunshine. There is plenty of room for everyone. Get ready for another session of Dr. Possum's science education and entertainment.
Featured Stories
A new study focusing on day-to-day change in weather suggests about a third of the world is affected by increasingly erratic weather patterns.
...swings from thunderstorms to dry days rose considerably since the late 1990s. These swings could have consequences for ecosystem stability and the control of pests and diseases, as well as for industries such as agriculture and solar-energy production, all of which are vulnerable to inconsistent and extreme weather, the researchers noted.
The day-to-day variations also could affect what scientists can expect to see as the Earth's climate changes, according to the researchers and other scientists familiar with the work. Constant fluctuations in severe conditions could alter how the atmosphere distributes heat and rainfall, as well as inhibit the ability of plants to remove carbon dioxide from the atmosphere, possibly leading to higher levels of the greenhouse gas than currently accounted for.
As the stuff of science continues to approach the predictions of science fiction now comes news of a computer chip designed in a way which allows simulation of the function of a single synapse (the connection of two nerve cells).
There are about 100 billion neurons in the brain, each of which forms synapses with many other neurons. A synapse is the gap between two neurons (known as the presynaptic and postsynaptic neurons). The presynaptic neuron releases neurotransmitters, such as glutamate and GABA, which bind to receptors on the postsynaptic cell membrane, activating ion channels. Opening and closing those channels changes the cell’s electrical potential. If the potential changes dramatically enough, the cell fires an electrical impulse called an action potential.
All of this synaptic activity depends on the ion channels, which control the flow of charged atoms such as sodium, potassium and calcium. Those channels are also key to two processes known as long-term potentiation (LTP) and long-term depression (LTD), which strengthen and weaken synapses, respectively.
The MIT researchers designed their computer chip so that the transistors could mimic the activity of different ion channels. While most chips operate in a binary, on/off mode, current flows through the transistors on the new brain chip in analog, not digital, fashion. A gradient of electrical potential drives current to flow through the transistors just as ions flow through ion channels in a cell.
Bats move through the air guided by echolocation in which ultrasonic pulses are gathered by the ear for brain translation.
"Certain bats can deform the shapes of their ears in a way that changes the animal's ultrasonic hearing pattern. Within just one tenth of a second, these bats are able to change their outer ear shapes from one extreme configuration to another."
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Acting as biosonar receiving antennas, the ears of bats perform a critical function in bringing about these ultrasonic sensing capabilities.
Using a combination of methods that included high-speed stereo vision and high-resolution tomography, the researchers from Virginia Tech and Shandong University have been able to reconstruct the three-dimensional geometries of the outer ears from live horseshoe bats as they deform in these short time intervals.
Using computer analysis of the deforming shapes, the researchers found that the ultrasonic hearing spotlights associated with the different ear configurations could suit different hearing tasks performed by the animals. Hence, the ear deformation in horseshoe bats could be a substrate for adapting the spatial hearing of the animals on a very short time scale.
The effects of deforestation vary with latitude according to a new study by researchers around the world.
The researchers calculated that north of Minnesota, or above 45 degrees latitude, deforestation was associated with an average temperature decrease of 1.5 degrees Fahrenheit. On the other hand, deforestation south of North Carolina, or below 35 degrees latitude, appeared to cause warming. Statistically insignificant cooling occurred between these two latitudes.
The researchers collected temperature data from a network of specialized weather stations in forests ranging from Florida to Manitoba and compared results with nearby stations situated in open grassy areas that were used as a proxy for deforested land.
The mountains of Antarctica are buried more than a mile below an icy surface.
An international team of scientists flew over Antarctica’s deep interior in 2008-2009 with ice-penetrating radar, gravity meters and magnetometers to reveal the peaks and valleys hidden below the ice. The data they gathered has provided insight into how the mountains arose. One billion years ago, before animals or plants appeared on land, several continents collided and the oldest rocks that make up the Gamburtsevs smashed together. From the collision, a thick crustal root formed deep beneath the mountain range. Over time, these ancient mountains were eroded but the cold dense root remained.
Between 250 and 100 million years ago – when dinosaurs walked the Earth –the supercontinent Gondwana, which included Antarctica, ripped apart, causing the old crustal root to warm. Reactivated, the crustal root and the East Antarctic Rift pushed land upwards again, reforming the mountains. Rivers and glaciers carved deep valleys and raised peaks to create a spectacular landscape that resembled the European Alps. The East Antarctic Ice Sheet, which formed 34 million years ago and at 10 million square kilometers covers an area the size of Canada, protected the mountains from erosion.
For the first time scientists have completed a series of precise measurements of a black hole, a mass so superdense that even light cannot escape its pull.
Using several telescopes, both ground-based and in orbit, the scientists unravelled longstanding mysteries about the object called Cygnus X-1, a famous binary-star system discovered to be strongly emitting X-rays nearly a half-century ago. The system consists of a black hole and a companion star from which the black hole is drawing material. The scientists' efforts yielded the most accurate measurements ever of the black hole's mass and spin rate.
(snip)
Armed with the new, precise distance measurement, scientists using the Chandra X-Ray Observatory, the Rossi X-Ray Timing Explorer, the Advanced Satellite for Cosmology and Astrophysics, and visible-light observations made over more than two decades, calculated that the black hole in Cygnus X-1 is nearly 15 times more massive than our Sun and is spinning more than 800 times per second.
The future of San Francisco Bay marshes may be bleak if the predicted ocean rises come to fruition.
Sediment is essential to the ability of marshes to grow as sea levels rise over time. With each tide, muddy waters are carried over the marsh surface and sediment is deposited. However, many acres of former baylands have limited or no tidal connection, cutting them off from this essential sediment supply. These degraded baylands, many of which have been used for agriculture or salt production, can be restored by re-connecting them to the tidal flow. Managers can help restore and preserve existing marsh by re-purposing non-polluted sediments from dredging projects.
(snip)
When sea levels rose during pre-modern times, tidal marshes gradually migrated into adjacent uplands. Today levees, development, roads, parking lots and other barriers prevent that movement, threatening the future of tidal marsh habitat and dependent wildlife.
Nearby residents may have improved lives as a result of rehabilitation of vacant urban lots.
Vacant lot greening was associated with significant reductions in gun assaults across all four sections of Philadelphia in the study and significant reductions in vandalism in one section of the city.
Greening was also associated with residents reporting significantly less stress and more exercise in certain sections of Philadelphia. Because newly greened vacant lots may serve as safe havens, residents may have felt less stress or may have seen greater outdoor opportunities for exercise in a cleaner, more attractive, and safer environment, say the authors. Even though these findings pertaining to stress and exercise only applied to certain sections of the city, they have potentially important implications for the future study of urban vacant lot greening as a tool to enhance health.
Other Worthy Stories of the Week
Moth's true colors shine after 47 million years
Leonardo's formula explains why trees don't splinter
Ancient stars shed light on the prehistory of the Milky Way
Newly found dwarf galaxies could help explain the nature of dark matter
Why the solar wind is rhombic-shaped
Evidence of ancient lake in California's Eel River emerges
Catching camels in the Gobi
Ancient bronze artifact from East Asia unearthed in Alaska
Gorgeous geological maps of volcanoes
Restoring ancient works with hungry bacteria
Magnetic fields set the stage for star birth
Lightning fast, efficient data transmission
Intel unveils 1-teraflop chip
Light created from a vacuum
Climate change effect from release of CO2 from peat far greater than assumed
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
Saturn's Northern Storm, NASA, Public Domain