From Discovery News - Top Stories:
It's WISE to know your neighborhood, especially when countless pieces of rock are flying around. Millions of tiny meteors bombard the Earth every day, but burn up in the atmosphere long before they can cause anything other than a pretty light i
From Wired Top Stories:
Nobody likes to talk about airplane accidents, but it turns out most are survivable. We here at Autopia put together some examples of accidents where sometimes mistakes were made, other times amazing skills were displayed, but every time passengers survived
From BBC News - Science & Environment:
The British team hoping to drive a car faster than 1,000mph has unveiled a full-scale model of the vehicle. The 1:1 replica of the 12.8m-long (42ft) Bloodhound SuperSonic Car (SSC) is the result of three years of aerodynamic study. The m
What masters course deeply covers electrical equipments such as the CT Scan ?
From Newlaunches.com:
There are those ideas by the military that make us all sweaty and nervous and those that totally floor us by their brilliance! This insanely awesome 4x4 is something along the lines of the latter. A Texas based company called AVX Aircraft have pioneered these
From Yahoo! News: Science News:
Energy ministers or senior officials from 21 nations are gathering in Washington, DC Monday for a two-day meeting aimed at finding ways to work together on clean energy amid an impasse in drafting a new climate change treaty. The US Energy Departm
If you live in the northern hemisphere and go outside in the winter, hanging not too far from Orion’s left shoulder is a small, tight, configuration of stars. A lot of people mistake them for the Little Dipper — I get asked about it all the time — but really it’s the Pleiades (pronounced PLEE-uh-dees), an actual cluster of stars about 400 light years away. To the eye you can usually spot six of the stars (the seventh, seen in ancient times, may have faded a bit since then), and in binoculars you can see dozens.
But when NASA’s Wide Field Infrared Survey Explorer (WISE) looked at it in February, this is what it saw:
Coooool. Literally! WISE looks in the infrared, and can see cool objects that are invisible to our eyes. The Pleiades stars are bound together in a cluster by their own gravity, and are currently plowing through a dense cloud of dust and gas in the galaxy. The material has been warmed up by the hot stars, and glows in the infrared. Deep images in visible light also show the material, but it looks blue as it reflects the optical light from the stars. In the WISE images, we’re seeing the matter actually glowing on its own, emitting infrared light.
When I was younger it was thought that this material was the leftover stuff from which the stars formed. But it was later found that the stars are older than first thought; about 100 million years old. While still quite young — the Sun is 4.5 billion years old! — that’s long enough for the original cocoon of material that made up these stars’ nursery to have dispersed. So it’s a cosmic coincidence that we happen to see the cluster as it’s ramming through this material. On the other hand, the Milky Way galaxy is loaded with lots of junk floating out there, and the Pleiades are in an area of high traffic. It’s not too surprising we’d see something like this happening, and it’s nice that it’s going on close enough that we get a good view of it.
WISE doesn’t just get pointed wherever astronomers see something interesting: it’s an all-sky survey, spinning on its axis and taking snapshots continuously. These are stored, and astronomers on the ground can then put them together in a mosaic. This image is actually pretty big, covering 2×3° of the sky. That’s about the size of a postage stamp held at arm’s length, and is a fair bit bigger than the full Moon on the sky. This image was released to celebrate the fact that as of July 17, WISE has now scanned the entire sky, and its primary mission has been fulfilled. Yay!
Funny, too: I’ve observed the Pleiades a lot, and seen lots of pictures too, yet it’s difficult to identify the stars in the WISE image — I had to rotate the visible image to match the one from WISE, but even then it’s not entirely obvious how they line up. In the IR, stars are bright that might be dim in optical, and vice-versa! But I’d recognize the sheets and filaments of the disturbed dust anywhere. One of my favorite things in astronomy is seeing a familiar object in an unfamiliar way. It reminds me that there’s still plenty to learn about the Universe.
Image credits: NASA/JPL-Caltech/UCLA and NASA, ESA and AURA/Caltech
Related posts:
- A WISE flower blooms in space
- Two nearby galaxies peek out through the dust
- WISE uncovers its first near-Earth asteroid!
- First spectacular views of the sky from WISE
From Neatorama:
Photo: Chuck Sutherland [Flickr] Seven years ago, Horace Burgess prayed and received divine inspiration. God said unto him "If you build me a treehouse, I'll see you never run out of material." And so Horace built, and built, and built: The treehouse has 10 floo
All kinds of off-the-shelf technology — both commercial and consumer — has already been adapted for military projects in the U.S., thereby saving untold dollars. If COTS technology is implemented to fight the cyber war, more savings will be realized. What's your vote: Yes or No?
The pre
On June 17, 2010, the Federal Communications Commission voted to open a Notice of Inquiry that will solicit comments on what the commission should do with regard to "net neutrality." Proponents of net neutrality want all Net traffic to to be equal with regards to transmission and access. Opponents s
What is the specific heat capacity of a)Flyash , b)Microsilica or silica fumes, c) Pozzolona Portland Cement?
Generally what are output voltages of solar inverter for the grid connected system? Because we have to connect it to grid so for that we have to have some specific voltages! I want learn about Grid Connected solar Power please suggest me any site for this! Thanks a lot. .
Generally what are output voltages of solar inverter for the grid connected system? Because we have to connect it to grid so for that we have to have some specific voltages! I want learn about Grid Connected solar Power please suggest me any site for this! Thanks a lot. .
[An old post I'm fond of]
Scoop up some dirt, and you’ll probably wind up with some slime mold. Many species go by the common name of slime mold, but the ones scientists know best belong to the genus Dictyostelium. They are amoebae, and for the most part they live the life of a rugged individualist. Each slime mold prowls through the soil, searching for bacteria which it engulfs and digests. After gorging itself sufficiently, it divides in two, and the new pair go their separate, bacteria-devouring ways. But if the Dictyostelium in a stamp-size plot of soil should eat their surroundings clean, they send each other alarm signals. They then use the signals to steer toward their neighbors, and as many as a million amoebae converge in a swirling mound. The mound itself begins to act as if it were a single organism. It stretches out into a bullet-shaped slug the size of a sand grain, slithers up toward the surface of the soil, probes specks of dirt, and turns around when it hits a dead end. Its movements are slow – it needs a day to travel an inch – but the deliberateness of the movements eerily evokes an it rather than a they.
After several hours, the Dictyostelium slug goes through another change. The back end catches up with the tip, and the slug turns into a blob. About 20 percent of the cells move to the top of the blob and produce a slender stalk. In order to keep the stalk from flopping over, these cells must produce rigid bundles of cellulose. Unfortunately, this cellulose also tears apart the amoebae that make it. The remaining amoebae in the blob then take advantage of the suicide of their slugmates. They slide up to the top and form a globe. Each amoeba in the globe covers itself in a cellulose coat and becomes a dormant spore. In this form the colony will wait until something – a drop of rainwater, a passing worm, the foot of a bird – picks up the spores and takes them to a bacteria-rich place where they can emerge from their shells and start their lives over.
The individual amoebae forming the stalk make the ultimate sacrifice so that other Dictyostelium may live and perhaps reproduce. These stalk-formers are not marked for death when they are born. When the amoebae mix together and the slug takes shape, the individuals that wind up in the front end of the slug will be the ones that form the stalk. In other words, they get a losing ticket in the Dictyostelium lottery. Aside from their rotten luck, they are indistinguishable from the amoebae that will survive as spores.
It is remarkable that stalk-forming amoebae should remain loyal to their fellow amoebae. Why should they willingly join a group of other amoebae when their loyalty will end in its and their death? Why shouldn’t amoebae just stay away from the group and try to tough it out on their own? Of course, just joining a group is not a guarantee of loyalty. It’s not hard to imagine amoebae finding a way to avoid the lottery of death. Actually, we don’t even have to imagine them: scientists have discovered that some Dictyostelium will cheat their fellow amoebae, thanks to genes that ensure that they will form spores rather than stalks.
The puzzle of loyal amoebae is, at its foundation, a puzzle about evolution. In each generation, the members of a population will vary in all sorts of ways – in their size, in their shape, and in their behavior. Depending on the environment in which the population lives, some of these variations will give certain members an edge when it comes to surviving and reproducing. Genes that make successful variations possible will become more common, while the unsuccessful genes will become less common.
Imagine that a Dictyostelium divides in two, and one of its offspring undergoes a mutation that makes it cheat. It escapes the stalk lottery, and is guaranteed to become a spore. Over generations, its descendants would become more common because none of them have to die making a stalk. Its cheating gene would become more common in the population as a result. Other individuals might also mutate into cheaters on their own, and their offspring would thrive as well. Meanwhile, genes that promote cooperation would become less common. It might be possible for Dictyostelium to continue organizing slugs and stalks if only a small fraction of amoebae cheated. But in time natural selection could produce so many cheaters that a slug would fail to produce a stalk, dooming the spores to death. As plausible as this scenario may be, scientists don’t see it happening in the real world. Dictyostelium is thriving happily in forests around the world. Clearly betrayal has not evolved to catastrophic levels. Why not?
A paper in the new issue of Nature sheds some light on the answer. It comes from the laboratory of David Queller and Joan Strassman at Rice University in Texas. They and their students went to the Houston Arboretum and dug up dirt from various spots. They extracted Dictyostelium purpureum from the dirt and raised the isolates in a lab. Then they mixed the slime mold together, adding several million cells from different pairs of isolates to a single dish. To tell the slime mold apart, they added green fluorescent dye to one isolate in each pair.
The scientists then waited for the slime molds to use up their food and then start to seek out one another. The results were striking. In any given stalk, almost all the cells came from one isolate or the other. One stalk glowed green, while the other remained dark. This result was in stark contrast to the results the scientists got when they mixed together fluorescent and non-fluorescent cells from a single isolate. In those cases, the stalks were half and half.
The scientists conclude that the slime mold has some way of telling apart cells of its own isolate from others. It has an “us versus them” view of the world.
Recognizing kin can be a powerful weapon against the evolution of cheating. In the 1960s evolutionary biologists William Hamilton and George Williams recognized individuals that share a lot of genes may evolve seemingly altruistic behavior towards one another. Even if one individual doesn’t pass on its own genes, it may be able to help a relative pass on those genes more successfully. This dedidation to one’s kin is not such a big sacrifice from an evolutionary point of view, because even if you don’t get to reproduce, your sibling may. And some of your genes will be carried by your nephews and nieces. For these slime molds, becoming a stalk cell may not be such a terrible fate, evolutionarily speaking, because they help their kin survive as spores. It may pay more than cheating your way to the top. All these slime molds need is a way to tell which amoebae are kin and which are not. And the new study shows that they have a keen sense for us versus them.
What makes these results particularly interesting is that another species of slime mold, Dictyostelium discoideum, does not appear to stay with its kin so carefully. Queller and Strassman have found that unrelated D. discoideum will come together and form a single slug. Queller and Strassman suspect that amoebae join forces with strangers because they can form larger slugs. A larger slug can move farther and faster, possibly raising the odds that its spores will be able to reach fertile ground elsewhere.
But these mixed slugs offer more opportunities for cheaters, since kin selection is not so strong. One opportunity arises with the signals that tell each cell how to develop. Once amoebae become destined to develop into stalk cells, they still need to receive signals from neighboring cells to complete their development. You could well imagine that if a mutant amoeba became deaf to these signals it could avoid its fate as a dead stalk cell and become a spore instead.
Queller and Strassman have experimentally created these deaf amoebae by knocking out the gene D. discoideum needs to receive the development signal. (The gene is known as dimA.) The scientists mixed the dimA mutants with ordinary amoebae that were still able to receive the signal and turn into stalk cells. As they expected, the deaf amoebae did not become stalk cells. Instead, they prepared to become spores.
But when Queller and Strassman allowed these colonies to develop completely, they got a surprise. Most of the deaf amoebae failed to get into the ball of spores at the top of the stalk. The scientists don’t yet know exactly why deaf amoebae can’t become spores as well as ordinary ones. But what is clear is that dimA must have more than one role. In some cases, it acts as a signal that tells an amoeba to become a stalk cell. But in cells that are destined to become spores, it must also have some essential role in their development. It’s common for genes to play different roles, and this research on slime molds suggests it may pose a major obstacle to the evolution of cheaters. The advantages a cheating amoeba gains by losing one of dimA’s functions are wiped out by its losing another, equally important one.
It may also be difficult for D. discoideum to hide its cheating ways from its fellow slime mold. In another experiment, Queller and Strassman discovered that some mutant Dictyostelium cheat if they lose a gene called csA. Normally csA produces a sticky protein on the surface of amoebae. The csA mutants, by contrast, are slippery. When amoebae form a slug, these slippery mutants slide back to the rear, where they will have a good chance of becoming spores rather than stalk cells. The problem for a csA cheater is that this same sticky protein serves as a badge of loyalty. When individual Dictyostelium start moving toward one another in the soil, they recognize their neighbors by their csA badge. This sticky protein allows two Dictyostelium to glue themselves together and continue searching for other amoebae with the same badge. Cheating amoebae don’t have the csA badge, and so they are shunned. Cheating can only benefit slime mold once they’re in a group. If they can’t get in a group at all, they’re out of luck.
It looks like we’ll have to wait for future research to show why one species of slime mold is so careful to stay with its kin, while another mingles with strangers. But these results make Dictyostelium a great model for scientists to study to understand the evolution of cooperation in bigger creatures, such as ourselves.
Source: NJ Mehdiabadi et al, “Kin preference in a social microbe,” Nature, August 24, 2006, doi:10.1038/442881a
What type of welding is suitable for aircraft? (gas welding, arc,spot welding)? Otherwise is it a molded one?
The world is melting.
RIVERS OF ICE: Panoramic view of West Rongbuk Glacier and Mount Everest, taken in 1921 (top) by Major E.O. Wheeler and in 2009 (bottom) by David Breashears. (Photo courtesy of the Royal Geographical Society)
From Climate Progress and NOAA
NOAA: June is fourth month in a row of record HIGH Global Temperatures
10 warmest years on record all since 1995
NOAA’s National Climatic Data Center (NCDC) has posted its State of the Climate, Global Analysis for June. The results confirm NASA’s: The first half of 2010 breaks the thermometer.
Here are some highlights:
June was the fourth consecutive month that was the warmest on record for the combined global land and surface temperatures (March, April, and May were also the warmest). This was the 304th consecutive month with a combined global land and surface temperature above the 20th century average. The last month with below average temperatures was February 1985.
It was the warmest June on record for the land surfaces of the globe. Previous record was set in 2005. The land surface temperature exceeded the previous record by 0.11?C (0.20?F). This large difference over land contributed strongly to the overall global land and ocean temperature anomaly….
The year-to-date (January-June) combined global land and ocean temperature was the warmest on record…..
2010 surpassed 1998 (Feb, Jul, Aug) for the most “warmest months” in any calendar year….
Each of the 10 warmest average global temperatures recorded since 1880 have occurred in the last fifteen years. The warmest year-to-date on record, through June, was 1998, and 2010 is warmer so far (note: although 1998 was the warmest year through June, a late-year warm surge in 2005 made that year the warmest total year)
The temperatures will keep rising until something is done. t’s time for a climate and energy bill!
 The Patriot Ledger | SPIRITUAL LIFE: Visit to Buddhist center strengthens writer's Christianity The Patriot Ledger Buddha is enlightenment. Doing good things leads to enlightenment,” said Arjia Rinpoche. The monk further explained that Buddha is not a god, but rather an ... |
Sark on the joy and beauty of loving friendships.
by Eric Dondero
The National D-Day Memorial Foundation Park is located in Bedford County, Virginia. The National D-Day Foundation has sparked a controversy for including a bust of famed Soviet mass murderer Josef Stalin. A public-private partnership, the D-Day Park may soon become part of the National Parks if pending legislation is passed in Congress.
The Park lies within the District of Congressman Tom Perriello. But the Democrat has been careful in his criticisms of the Stalin bust, only saying that it's sparked "unneeded controversy." In a letter (pdf) to Foundation Chairman Robert M. Bradley, Perriello mentioned that he believed the bust was inconsistent with the goals of the Foundation, but made no mention of Stalin's atrocities, such as the mass starvations of the Kulaks, and his murderous record of ethnic cleansing against tens of millions of Poles, Ukraniuns, Jews and numerous other groups.
In stark contrast, the Republican Congressman from the neighboring district Rep. William Goodlatte however, has taken it on as a cause celebre.
From the Lynchburg News & Advance:
Goodlatte adds that he has heard from numerous constituents opposed to the Stalin bust, and in response, the Congressman wrote the D-Day Foundation multiple letters requesting that the bust be removed.
Goodlatte is quoted:
“Josef Stalin was a paranoid megalomaniac responsible for the slaughter of millions of his citizens and others. As leader of the Soviet Union, he led a campaign of terror including mass executions and forced labor in work camps at home in the Soviet Union and he oversaw the spread of communism throughout eastern Europe and is responsible for the Cold War. The appropriate location for the bust of such a dark and sinister man is off in a dark closet but the empty pedestal and telling plaque should remain as a reminder of this aspect of World War II history,“
Of course, FDR had a warm friendship with his pal "Joe" during the War. And his appeasement is credited with the handing over of Eastern Europe to Stalinist repression.
Only fitting; a member of the Party of Dwight D. Eisenhower gets it right, while a member of the FDR Party can only muster a half-hearted protest.
Photo from the 2007 film Katyn on the Soviet murderous rampages against Polish officers in 1939/40.
15,000 Poles murdered by the Socialists
An award-winning film by Wadja from 2007, with limited release in the United States.
Description:
In March 1940 Soviet leader Josef Stalin ordered the executions of 22,000 Polish army and police officers, intellectuals and clergy. The killings took place in the spring of the same year in the Katyn Forest. The victims, mostly from POW camps in Kozielsk, Starobielsk and Ostaszkow, were shot in the back of the head. The Nazis discovered the mass graves during their march on Moscow in the fall of 1941, but Soviet propaganda blamed the deaths on Adolf Hitler and punished anyone speaking the truth with harsh prison terms. In 1990, Moscow admitted that dictator Josef Stalin's secret police were responsible.
Note - U.S. President Franklin D. Roosevelt, a Democrat, deliberately covered up the massacre, and who was responsible, after the area was liberated from the Nazis in 1944. (Source: Katyn Forest Massacre film BBC).
The movie is available at Blockbuster.
