Athletic Frogs Have Faster-Changing Genomes
|1:21:28 AM, Friday, April 13, 2012|
“Physically fit frogs have faster-changing genomes, says a new study of poison frogs from Central and South America.
Stretches of DNA accumulate changes over time, but the rate at which those changes build up varies considerably between species, said author Juan C. Santos of the National Evolutionary Synthesis Center in Durham, North Carolina.
In the past, biologists trying to explain why some species have faster-changing genomes than others have focused on features such as body size, generation time, fecundity and lifespan. According to one theory, first proposed in the 1990s, species with higher resting metabolic rates are likely to accumulate DNA changes at a faster rate, especially among cold-blooded animals such as frogs, snakes, lizards and fishes. But subsequent studies failed to find support for the idea.
The problem with previous tests is that they based their measurements of metabolism on animals at rest, rather than during normal physical activity, Santos said.
"Animals rarely just sit there," Santos said. "If you go to the wild, you'll see animals hunting, reproducing, and running to avoid being eaten. The energetic cost of these activities is far beyond the minimum amount of energy an animal needs to function."
To test the idea, Santos scoured forests in Colombia, Ecuador, Venezuela, and Panama in search of poison frogs, subjecting nearly 500 frogs — representing more than 50 species — to a frog fitness test…”
Can You Identify All of Them: Video Game Planets [Video]
|12:59:04 AM, Friday, April 13, 2012|
Volcanic Plumbing Provides Clues on Eruptions and Earthquakes
|12:51:36 AM, Friday, April 13, 2012|
“Two new studies into the "plumbing systems" that lie under volcanoes could bring scientists closer to understanding plate ruptures and predicting eruptions—both of which are important steps for protecting the public from earthquake and volcanic hazards.
International teams of researchers, including two scientists from the University of Rochester, have been studying the location and behaviour of magma chambers on the Earth's mid-ocean ridge system—a vast chain of volcanoes along which the Earth forms new crust.
They worked in the tropical region of Afar, Ethiopia and the subarctic country of Iceland—the only places where mid-ocean ridges appear above sea level. Volcanic ridges (or "spreading centers") occur when tectonic plates "rift" or pull apart. This happens when magma (hot molten rock) injects itself into weaknesses in the brittle upper crust, erupting as lava and forming new crust upon cooling.
"These conclusions would not have been possible without the multi-disciplinary expertise of the researchers taking part in these studies," said Cynthia Ebinger, professor of geophysics at the University of Rochester.
The studies, published in Nature Geoscience, reveal new information about where magma is stored and how it moves through the geological plumbing network.
Magma chambers work like plumbing systems, channelling pressurized magma through networks of underground "pipes." Finding out where magma chambers lie and how they behave could help identify early warning signs of impending eruptions, according to the researchers…”
Study Shows Adaptive Capacity of Reef Corals to Climate Change May Be Widespread
|1:51:40 AM, Thursday, April 12, 2012|
“A new study by scientists at the University of Miami's Rosenstiel School of Marine & Atmospheric Science suggests that many species of reef-building corals may be able to adapt to warming waters by relying on their closest aquatic partners - algae. The corals' ability to host a variety of algal types, each with different sensitivities to environmental stress, could offer a much-needed lifeline in the face of global climate change.
Using a highly sensitive genetic technique, Ph.D. student Rachel Silverstein analyzed 39 coral species from DNA collected in the Indo-Pacific and Caribbean collected over the last 15 years. Most of these species had not previously been thought capable of hosting more than one type of the single-celled symbiotic algae, called zooxanthellae, which live inside the coral and help to supply them with energy. Silverstein's results revealed that at least one colony of all 39 species tested had at least two varieties of algae, including one thought to be heat tolerant. Over half of the species were found to associate with all four of the major types of algae found in corals.
"This study shows that more coral species are able to host multiple algal symbionts than we previously thought," said Andrew Baker, associate professor at UM's Rosenstiel School and co-author of the study. "The fact that they all seem to be capable of hosting symbionts that might help them survive warmer temperatures suggests they have hidden potential that was once thought to be confined to just a few special species."
More than 10 years ago, Baker was one of the first scientists to suggest that the ability of corals to associate with diverse algal symbionts may be one mechanism by which they are able to rapidly respond to environmental changes, such as increased ocean temperatures due to climate change.
"Although our study shows that different coral species do tend to have preferences in their algal partners, the fact that these preferences are not absolutely rigid means that we cannot ignore the possibility that most corals might change partners in response to environmental changes in the future," said Silverstein…”
Potato Chips Guy Breaks Up Subway Fight
|12:55:59 AM, Thursday, April 12, 2012|
The Race to Save the Rainforest Frogs so They Can Save Us
|12:07:24 AM, Thursday, April 12, 2012|
“Frogs matter - they play a vital role in the food chain, and some have been found to produce chemicals that cure human diseases. But a fungus dubbed "the amphibian smallpox" is making many species extinct. So scientists are mounting a rescue operation.
It's the middle of the night in the rainforests of central Panama.
Biologist Brian Gratwicke slogs through a stream with a group of researchers looking for little green blobs sitting on leaves.
"Anything that makes the leaf hang unusually," he says.
A colleague spots a pair of tiny eyes gleaming in the beam of a torch. But it's a false alarm - probably just a spider, and spiders are not the team's quarry.
The little green blobs they are looking for are frogs, and after 90 minutes in the jungle, they have yet to find a single one.
It might just be bad luck, but probably not. Frogs around the world are in decline. In recent years, scientists have documented frog population decreases of up to 80% in some areas.
Habitat loss, climate change and pollution, are all playing a role in the disappearances.
Another culprit is "chytrid" - a virulent fungal disease, thought to have originated in Africa, that's spreading around the globe.
In parts of Central America the fungus is moving at around 20 miles (32km) a year…”
Cells on the Move
|1:39:39 AM, Wednesday, April 11, 2012|
“Cells on the move reach forward with lamellipodia and filopodia, cytoplasmic sheets and rods supported by branched networks or tight bundles of actin filaments. Cells without functional lamellipodia are still highly motile but lose their ability to stay on track, report researchers at the Stowers Institute for Medical Research in the April 9, 2012, online issue of the Journal of Cell Biology.
Their study provides new insight into cell motility, a complex and integrated process, which, when gone awry, can lead to various disease conditions such as cancer metastasis, birth defects, cardiovascular disease and compromised immune function.
Many cell types migrate through surrounding tissue: nerve cells reaching for their final destination; immune cells on the prowl for intruding pathogens; fibroblast called in to close wounds and stray cancer cells that have escaped the confines of the primary tumor. They all use actin filaments to push at the front by constantly remodeling their actin cytoskeleton.
"Our work demonstrates that an actin-polymerizing factor known as the Arp2/3 complex plays a critical role in the formation of the dendritic array of actin fibers that forms the structural backbone of lamellipodia and helps drive the leading edge of the cell forward," says Stowers Investigator Rong Li, Ph.D., who led the study.
When pure actin polymerizes, elongation is energetically favored over nucleation resulting in long thin filaments. The Arp2/3 complex, which localizes to lamellipodia, was thought to help build the web of actin filaments that shapes lamellipodia by initiating the branching process. "But it had been unclear whether Arp2/3 is actually required for lamellipodia formation and how it would affect cell motility," Li explains.
Unlike previous studies, which had mostly relied on RNA interference to reduce the concentration of functional Arp2/3 complex and had reached conflicting conclusions, Li and her team opted for the genetic disruption of the ARP2/3 complex to determine its function in fibroblast cell motility…”
Study Finds Faster, Cheaper Way to Cool Electronic Devices
|1:34:22 AM, Wednesday, April 11, 2012|
“A North Carolina State University researcher has developed a more efficient, less expensive way of cooling electronic devices – particularly devices that generate a lot of heat, such as lasers and power devices.
The technique uses a "heat spreader" made of a copper-graphene composite, which is attached to the electronic device using an indium-graphene interface film "Both the copper-graphene and indium-graphene have higher thermal conductivity, allowing the device to cool efficiently," says Dr. Jag Kasichainula, an associate professor of materials science and engineering at NC State and author of a paper on the research. Thermal conductivity is the rate at which a material conducts heat.
In fact, Kasichainula found that the copper-graphene film's thermal conductivity allows it to cool approximately 25 percent faster than pure copper, which is what most devices currently use.
Dissipating heat from electronic devices is important, because the devices become unreliable when they become too hot.
The paper also lays out the manufacturing process for creating the copper-graphene composite, using an electrochemical deposition process. "The copper-graphene composite is also low-cost and easy to produce," Kasichainula says. "Copper is expensive, so replacing some of the copper with graphene actually lowers the overall cost."”
'Nanobubbles' Plus Chemotherapy Equals Single-Cell Cancer Targeting
|12:25:12 AM, Wednesday, April 11, 2012|
“Using light-harvesting nanoparticles to convert laser energy into "plasmonic nanobubbles," researchers at Rice University, the University of Texas MD Anderson Cancer Center and Baylor College of Medicine (BCM) are developing new methods to inject drugs and genetic payloads directly into cancer cells. In tests on drug-resistant cancer cells, the researchers found that delivering chemotherapy drugs with nanobubbles was up to 30 times more deadly to cancer cells than traditional drug treatment and required less than one-tenth the clinical dose.
"We are delivering cancer drugs or other genetic cargo at the single-cell level," said Rice's Dmitri Lapotko, a biologist and physicist whose plasmonic nanobubble technique is the subject of four new peer-reviewed studies, including one due later this month in the journal Biomaterials and another published April 3 in the journal PLoS ONE. "By avoiding healthy cells and delivering the drugs directly inside cancer cells, we can simultaneously increase drug efficacy while lowering the dosage."
Delivering drugs and therapies selectively so they affect cancer cells but not healthy cells nearby is a major obstacle in drug delivery. Sorting cancer cells from healthy cells has been successful, but it is both time-consuming and expensive. Researchers have also used nanoparticles to target cancer cells, but nanoparticles can be taken up by healthy cells, so attaching drugs to the nanoparticles can also kill healthy cells.
Rice's nanobubbles are not nanoparticles; rather, they are short-lived events. The nanobubbles are tiny pockets of air and water vapor that are created when laser light strikes a cluster of nanoparticles and is converted instantly into heat. The bubbles form just below the surface of cancer cells. As the bubbles expand and burst, they briefly open small holes in the surface of the cells and allow cancer drugs to rush inside. The same technique can be used to deliver gene therapies and other therapeutic payloads directly into cells…”
Space Station Used for Ardbeg Distillery Experiments
|10:30:40 PM, Tuesday, April 10, 2012|
““An island distillery has taken to space in a bid to discover the taste of the future.
Experiments using malt from the Ardbeg distillery on Islay are being carried out on the International Space Station to see how it matures without gravity.
Compounds of unmatured malt were sent to the station in an unmanned cargo spacecraft in October last year, along with particles of charred oak.
Scientists want to understand how they interact at close to zero gravity.
NanoRacks LLC, the US company behind the research, has said understanding the influence of gravity could help a number of industries, including the whisky industry, to develop new products in the future.
The experiment, unveiled at the Edinburgh International Science Centre, will last for at least two years.
The molecules are tiny parts of the two substances known as terpenes - a set of chemicals which are often aromatic and flavour-active.
It is believed the experiment is the first time anyone has ever studied terpenes and other molecules in near-zero gravity.
The researchers are also measuring the molecules' interaction at normal gravity on Earth so they can compare the way the particles mature.
Michael Johnson, chief technical officer of NanoRacks LLC, said: "By doing this microgravity experiment on the interaction of terpenes and other molecules with the wood samples provided by Ardbeg, we will learn much about flavours, even extending to applications like food and perfume.
"At the same time it should help Ardbeg find new chemical building blocks in their own flavour spectrum."
Dr Bill Lumsden, head of distilling and whisky creation at Ardbeg, which has been producing whisky for more than 300 years, said: "This experiment will throw new light on the effect of gravity on the maturation process.
"We are all tremendously excited by this experiment - who knows where it will lead?"”
Solar Dynamics Observatory and NASA's STEREO-B Spacecraft Spot Something New On the Sun
|7:28:32 PM, Tuesday, April 10, 2012|
“One day in the fall of 2011, Neil Sheeley, a solar scientist at the Naval Research Laboratory in Washington, D.C., did what he always does – look through the daily images of the sun from NASA's Solar Dynamics Observatory (SDO).
But on this day he saw something he'd never noticed before: a pattern of cells with bright centers and dark boundaries occurring in the sun's atmosphere, the corona. These cells looked somewhat like a cell pattern that occurs on the sun's surface -- similar to the bubbles that rise to the top of boiling water -- but it was a surprise to find this pattern higher up in the corona, which is normally dominated by bright loops and dark coronal holes.
Sheeley discussed the images with his Naval Research Laboratory colleague Harry Warren, and together they set out to learn more about the cells. Their search included observations from a fleet of NASA spacecraft called the Heliophysics System Observatory that provided separate viewpoints from different places around the sun. They describe the properties of these previously unreported solar features, dubbed "coronal cells," in a paper published online in The Astrophysical Journal on March 20, 2012 that will appear in print on April 10.
The coronal cells occur in areas between coronal holes – colder and less dense areas of the corona seen as dark regions in images -- and "filament channels" which mark the boundaries between sections of upward-pointing magnetic fields and downward-pointing ones. Understanding how these cells evolve can provide clues as to the changing magnetic fields at the boundaries of coronal holes and how they affect the steady emission of solar material known as the solar wind streaming from these holes.
"We think the coronal cells look like flames shooting up, like candles on a birthday cake," says Sheeley. "When you see them from the side, they look like flames. When you look at them straight down they look like cells. And we had a great way of checking this out, because we could look at them from the top and from the side at the same time using observations from SDO, STEREO-A, and STEREO-B."
The locations of STEREO–A, STEREO–B and SDO relative to the sun and Earth in 2011. Credit: NRLWhen the cells were discovered in the fall of 2011, the SDO and the two STEREO (short for Solar Terrestrial Relations Observatory) spacecraft each had widely different views of the sun. Thus, as the 27-day solar rotation carried the coronal cells across the face of the sun, they appeared first in STEREO-B data, then in SDO, and finally in STEREO-A, before starting over again in STEREO-B. In addition, when one observatory looked down directly on the cells, another observatory could see them from the side…”
-- Follow the link for a short clip!!!
How Dark Matter Interacts with the Human Body
|5:25:24 PM, Tuesday, April 10, 2012|
"(Technology Review Published by MIT 4/10/2012) Dark matter must collide with human tissue, and physicists have now calculated how often. The answer? More often than you might expect.
One of the great challenges in cosmology is understanding the nature of the universe's so-called missing mass.
Astronomers have long known that galaxies are held together by gravity, a force that depends on the amount of mass a galaxy contains. Galaxies also spin, generating a force that tends to cause this mass to fly apart.
The galaxies astronomers can see are not being torn apart as they rotate, presumably because they are generating enough gravity to prevent this.
But that raises a conundrum. Astronomers can see how much visible mass there is in a galaxy and when they add it all up, there isn't anywhere enough for the required amount of gravity. So something else must be generating this force.
One idea is that gravity is stronger on the galactic scale and so naturally provides the extra force to glue galaxies together.
Another is that the galaxies must be filled with matter that astronomers can't see, the so-called dark matter. To make the numbers work, this stuff needs to account for some 80 per cent of the mass of galaxies so there ought to be a lot of it around. So where is it?
Physicists have been racing to find out with detectors of various kinds and more than one group says it has found evidence that dark matter fills our solar system in quantities even more vast than many theorists expect. If they're right, the Earth and everything on it is ploughing its way through a dense sea of dark matter at this very instant…”
Wind At Sea Is Strangely Van Goghish, Says NASA
|5:16:37 PM, Tuesday, April 10, 2012|
“… Most of the surface currents in the ocean are shaped by wind. In this visualization from the folks at NASA, the ocean is rich with lazy spirals that move in great circular sweeps (called "gyres") clockwise in the northern hemisphere, counterclockwise in the south. Think of the ocean surface here as a reflection of the winds above, a kind of watery mirror (though the spinning of the Earth, tugs of sun and moon and obstruction of continents play a part.) Click on this video, and you'll see the dance of wind-on-water everywhere.
I like watching the Gulf Stream roar past the tip of Florida in the beginning, all white and purposeful, heading up the North American coast. There's something playful about water and wind bumping into large land masses likeAfrica, breaking into whirligig spirals, spinning along the shore. Then there's the equator, which in this version seems almost wall-like. As the winds approach it, they flatten into jet like streams racing along a corridor.
What this map doesn't show is the newest discovery created by ocean gyres. It's called the Great Pacific Garbage Patch, a vast, Texas-sized clump of human garbage floating in the Pacific. Created by a convergence of ocean currents and wind somewhere betweenHawaii andCalifornia, it's not visible from satellites. Apparently, a thick blanket of pop bottles and chemical sludge sinks a little below the surface so it can't be seen from above and, anyway, it turns out garbage doesn't clump in a spiral; it looks more like a Nickelodeon splat, so if we could see the Garbage Patch, it would ruin the mood created here.
This is an image of wild wind, water and spiral beauty. And what does it say about us that our first human mark is a splat that feels like we've dropped some mud onto a van Gogh painting?”
Discovery Could Improve Vaccines
|3:37:14 AM, Tuesday, April 10, 2012|
“The discovery of how a vital immune cell recognises dead and damaged body cells could modernise vaccine technology by ‘tricking’ cells into launching an immune response, leading to next-generation vaccines that are more specific, more effective and have fewer side-effects.
Scientists from the Walter and Eliza Hall Institute have identified, for the first time, how a protein found on the surface of immune cells called dendritic cells recognises dangerous damage and trauma that could signify infection.
Dendritic cells are critical for raising the alarm about the presence of foreign invaders in the body such as viruses, bacteria and parasites as well as tumour cells and other dead or damaged cells. Also known as antigen-presenting cells, they digest and present molecules from damaged cells to other immune cells that recognise foreign invaders and launch an immune response.
The research was a collaborative effort that involved a team of immunologists, protein chemists and structural biologists. The research team was led by Dr Mireille Lahoud (formerly from the Immunology division), Dr Jian-Guo Zhang (Cancer and Haematology division), Dr Peter Czabotar (Structural Biology division) and Professor Ken Shortman (Immunology division).
Dr Lahoud said the study, published today in the journal Immunity, demonstrated that the immune system has evolved a very clever way of detecting damaged and dead cells to help promote an immune response.
“Dr Irina Caminschi and I previously identified a protein called Clec9A (C-type lectin domain family 9A) that sits on the surface of specialised types of dendritic cells and responds to damaged and dying cells,” Dr Lahoud said. “In this study we discovered that Clec9A recognises and binds to fibres of actin, internal cell proteins that are found in all cells of the body. Actin is only exposed when the cell membrane is damaged or destroyed, so it is an excellent way of finding cells that could harbour potentially dangerous infections and exposing them to the immune system.”
Professor Shortman said that exploiting Clec9A could be used to generate a new, more modern class of vaccines that are more effective and have fewer side-effects. “The Clec9A protein is one of the best targets currently known for improving immune responses,” he said. “By creating vaccines that bind to Clec9A, we can trick dendritic cells to think they have encountered a damaged cell and help to launch an immune response to the infectious agent of our choice.”
Professor Shortman said targeting Clec9A could decrease the amount of vaccine needed by 100 to 1000 times. “Traditional vaccine technology for generating immunity, such as using inactivated whole viruses or parasites for immune recognition, requires large amounts of vaccine in the hopes it will encounter the correct immune cells, and incorporates other substances (adjuvants) that are needed to signal to the immune system that something foreign is happening. We are proposing a new type of vaccine that we know will head directly to the right cell to help stimulate an immune response, and doesn’t cause the same side-effects because it is more specific,” Professor Shortman said.
Dr Lahoud said that the finding could develop or increase the efficacy of vaccines for diseases that do not currently have good preventive options, such as malaria, or HIV. “There is also the possibility that the system could be used to develop therapeutic vaccines for treating diseases, such as some forms of cancer, as well as for preventing them,” she said.
Since completing this research, Dr Lahoud and Dr Caminschi have accepted positions at the Burnet Institute.
This work was supported by the National Health and Medical Research Council of Australia, the Australian Research Council and the Victorian Government.”
Evolution at Sea: Long-Term Experiments Indicate Phytoplankton Can Adapt to Ocean Acidification
|10:27:23 AM, Monday, April 09, 2012|
“ScienceDaily (Apr. 8, 2012) — Fossil fuel derived carbon dioxide has a serious impact on global climate but also a disturbing effect on the oceans, know as the other CO2 problem. When CO2 dissolves in seawater it forms carbonic acid and results in a drop in pH, the oceans acidify. A wealth of short-term experiments has shown that calcifying organisms, such as corals, clams and snails, but also micron size phytoplankton are affected by ocean acidification. The potential for organisms to cope with acidified oceanic conditions via evolutionary adaptations has so far been unresolved.
Scientists of the Helmholtz Centre for Ocean Research Kiel (GEOMAR) have now for the first demonstrated the potential of the unicellular algae Emiliania huxleyi to adapt to changing pH conditions and thereby at least partly to mitigate negative effects of ocean acidification. These results raised by the biologists Kai Lohbeck, Prof. Ulf Riebesell and Prof. Thorsten Reusch are published in the current issue of Nature Geoscience.
Experimental Emiliania huxleyi strains were isolated in Norwegian coastal waters and cultured in the laboratory under projected future ocean CO2 conditions. After about one year, which translates into 500 generations in this rapidly reproducing species, the biologists detected adaptation to high CO2 – adapted populations grew and calcified significantly better than non adapted control populations when tested under ocean acidification condition.
“From a biogeochemical perspective the most interesting finding was probably a partly restoration in calcification rates” GEOMAR scientist Prof. Ulf Riebesell notes. Emiliania huxleyi covers its cell surface with minute calcite scales that were found to decrease in weight under increased CO2 concentrations. “This is what we expected from the literature. But we were fascinated to find impaired calcification to partly recover after only 500 generations” says biologist Kai Lohbeck…”
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