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Wednesday, July 30, 2008

Why are there no green stars?

Go outside on a dark, moonless night. Look up. Is it December or January? Check out Betegeuse, glowing dully red at Orion’s shoulder, and Rigel, a laser blue at his knee. A month later, yellow Capella rides high in Auriga.

Is it July? Find Vega, a sapphire in Lyra, or Antares, the orange-red heart of Scorpius.

There are no green stars!In fact, any time of the year you can find colors in the sky. Most stars look white, but the brightest ones show color. Red, orange, yellow, blue… almost all the colors of the rainbow. But hey, wait a sec. Where are the green stars? Shouldn’t we see them?

Nope. It’s a very common question, but in fact we don’t see any green stars at all. Here’s why.

Take a blowtorch (figuratively!) and heat up an iron bar. After a moment it will glow red, then orange, then bluish-white. Then it’ll melt. Better use a pot holder.

Why does it glow? Any matter above the temperature of absolute zero (about -273 Celsius) will emit light. The amount of light it gives off, and more importantly the wavelength of that light, depends on the temperature. The warmer the object, the shorter the wavelength.

Cold objects emit radio waves. Extremely hot objects emit ultraviolet light, or X-rays. At a very narrow of temperatures, hot objects will emit visible light (wavelengths from roughly 300 nanometers to about 700 nm).

Mind you — and this is critical in a minute — the objects don’t emit a single wavelength of light. Instead, they emit photons in a range of wavelengths. If you were to use some sort of detector that is sensitive to the wavelengths of light emitted by an object, and then plotted the number of them versus wavelength, you get a lopsided plot called a blackbody curve (the reason behind that name isn’t important here, but you can look it up if you care — just set your SafeSearch Filtering to "on". Trust me here). It’s a bit like a bell curve, but it cuts off sharply at shorter wavelengths, and tails off at longer ones.

Here’s an example of several curves, corresponding to various temperatures of objects (taken from online lecture notes at UW:

The x-axis is wavelength (color, if you like) color, and the spectrum of visible colors is superposed for reference. You can see the characteristic shape of the blackbody curve. As the object gets hotter, the peak shifts to the left, to shorter wavelengths.

An object that is at 4500 Kelvins (about 4200 Celsius or 7600 F) peaks in the orange part of the spectrum. Warm it up to 6000 Kelvin (about the temperature of the Sun, 5700 C or 10,000 F) and it peaks in the blue-green. Heat it up more, and the peaks moves into the blue, or even toward shorter wavelengths. In fact, the hottest stars put out most of their light in the ultraviolet, at shorter wavelengths than we can see with our eyes.

Now wait a sec (again)… if the Sun peaks in the blue-green, why doesn’t it look blue-green?

Ah, this is the key question! It’s because it might peak in the blue-green, but it still emits light at other colors.

Look at the graph for an object as hot as the Sun. That curve peaks at blue-green, so it emits most of its photons there. But it still emits some that are bluer, and some that are redder. When we look at the Sun, we see all these colors blended together. Our eyes mix them up to produce one color: white. Yes, white. Some people say the Sun is yellow, but if it were really yellow to our eyes, then clouds would look yellow, and snow would too (all of it, not just some of it in your back yard where your dog hangs out).

OK, so the Sun doesn’t look green. But can we fiddle with the temperature to get a green star? Maybe one that’s slightly warmer or cooler than the Sun?

It turns out that no, you can’t. A warmer star will put out more blue, and a cooler one more red, but no matter what, our eyes just won’t see that as green.

The fault lies not in the stars (well, not entirely), but within ourselves.

Our eyes have light-sensitive cells in them called rods and cones. Rods are basically the brightness detectors, and are blind to color. Cones see color, and there are three kinds: ones sensitive to red, others to blue, and the third to green. When light hits them, each gets triggered by a different amount; red light (say, from a strawberry) really gets the red cones juiced, but the blue and green cones are rather blasé about it.

Most objects don’t emit (or reflect) one color, so the cones are triggered by varying amounts. An orange, for example, gets the red cones going about twice as much as the green ones, but leaves the blue ones alone. When the brain receives the signal from the three cones, it says "This must be an object that is orange." If the green cones are seeing just as much light as the red, with the blue ones not seeing anything, we interpret that as yellow. And so on.

So the only way to see a star as being green is for it to be only emitting green light. But as you can see from the graph above, that’s pretty much impossible. Any star emitting mostly green will be putting out lots of red and blue as well, making the star look white. Changing the star’s temperature will make it look orange, or yellow, or red, or blue, but you just can’t get green. Our eyes simply won’t see it that way.

That’s why there are no green stars. The colors emitted by stars together with how our eyes see those colors pretty much guarantees it.

But that doesn’t bug me. If you’ve ever put your eye to a telescope and seen gleaming Vega or ruddy Antares or the deeply orange Arcturus, you won’t mind much either. Stars don’t come in all colors, but they come in enough colors, and they’re fantastically beautiful because of it.

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NASA launches online historical image gallery

By Brian Fonseca

July 29, 2008 (Computerworld) NASA last week launched a new interactive Web site, jointly developed with the non-profit Internet Archive, which initially combines some 21 separately stored and managed NASA imagery collections into a single online resource featuring enhanced search, visual and metadata capabilities.

The new portal, located here, stores more than 140,000 digitized high-resolution NASA photographs, audio and film clips. The launch of the site marks the end of the first phase of a five-year joint NASA-Internet Archive effort to ultimately make millions of NASA's historic image collection accessible online to the public and to researchers, noted Debbie Rivera, manager of strategic alliance at NASA.

The first content available on NASA's imagery Web site includes photos and video of the early Apollo moon missions, views of the solar system from the Hubble Space Telescope and photos and videos showing the evolution of spacecraft and in-flight designs.

A beautiful blue marble in space. This image shows our planet as it is seen in space. A combination of datasets from different satellites make it possible for us to view Earth from the safety of our own living rooms.
Space Station over the Ionian Sea
Click to view image gallery

The five-year joint development agreement signed in 2007 will also lead to the embedding of Web 2.0 tools into the site. For example, engineers are developing Wikis and blogs for users to share content. The team has already started adding metatags to improve search results, Rivera said. "There's a lot more to come," she added. "This is only the beginning."

In about a year, the partnership will tackle the enormous task of on-site digitizing of still images, films, film negatives and audio content currently stored on analog media devices across NASA field centers, Rivera said. Speed is essential, she noted, as some of NASA's older analog recordings and film footage of events as far back as 1915 are "disintegrating. This is one of the largest aspects of this partnership," she admitted.

Internet Archive, founded in 1996 to create an Internet-based library, will manage and host NASA's new interactive image gallery on the cluster of 2,000 Linux servers at its San Francisco headquarters, said John Hornstein, director of the NASA images project for the group. The non-profit currently runs 2 petabytes of storage, Hornstein said.

Hornstein acknowledged some hiccups following the launch of the site last week when servers crashed causing intermittently sluggish response times. In addition, software around the zoom-in functionality of thumbnail images on the NASA web site is still being de-bugged. He downplayed any lingering effects, however. "We're just finding where the issues are and we don't see any of this as an ongoing problem," remarked Hornstein.

Internet Archive is using software donated by Luna Imaging Inc. to help develop and support the NASA images project.

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The Uncertain Future of the International Space Station: Analysis

Still unfinished, engineers around the world ponder what to do with the space station—park it somewhere else, turn it into a lab or just let it burn. With calls to upconvert the ISS into a spaceship already hitting fever pitch, a leading aerospace expert checks in with some players from the space industry.

Humans Predicted to Make Contact with an Extraterrestrial Civilization Within Two Decades

610x_3 "That's 500 billion planets out there, and bear in mind there are 100 billion other galaxies. To think this [the Earth] is the only place where anything interesting is happening, you have got to be really audacious to take that point of view."

Seth Shostak, SETI senior astronomer


Some leading astronomers are quite confident that mankind will make contact with intelligent alien life within two decades. The search for extraterrestrial life will leap forward next year when NASA launches the Kepler space telescope. The instrument will be constantly scanning the same 100,000 stars over its four-year mission with the exciting objective of discovering Earth-sized planets in the habitable zones around suns.

This will allow SETI to hone in on where the odds of life are possibly greatest. Currently, SETI’s mission to find life on other planets is like trying to find the proverbial needle in a haystack. But now, whenever Kepler identifies planets most likely to sustain life, the team at SETI will be able to focus in on those solar systems using deep-space listening equipment. This will be a huge upgrade from their present work of randomly scanning the outer reaches of space for some kind of sign or signal. Also, upping the ante, is the recent discovery of Earth-like planets outside our solar system, which has led astrophysicists to conclude that Earth-like planets are likely relatively common in our galaxy.

"Everything has caused us to become more optimistic," said American astrophysicist Dr Frank Drake in a recent BBC documentary. "We really believe that in the next 20 years or so, we are going to learn a great deal more about life beyond Earth and very likely we will have detected that life and perhaps even intelligent life elsewhere in the galaxy."

However, some astrophysicists have warned that we humans may be blinded by our familiarity with carbon and Earthlike conditions. In other words, what we’re looking for may not even lie in our version of a “sweet spot”. After all, even here on Earth, one species “sweet spot” is another’s species worst nightmare. In any case, it is not beyond the realm of feasibility that our first encounter with extraterrestrial life will not be a solely carbon-based occasion.

Alternative biochemists speculate that there are several atoms and solvents that could potentially spawn life. Because carbon has worked for the conditions on Earth, we speculate that the same must be true throughout the universe. In reality, there are many elements that could potentially do the trick. Even counter-intuitive elements such as arsenic may be capable of supporting life under the right conditions. Even on Earth some marine algae incorporate arsenic into complex organic molecules such as arsenosugars and arsenobetaines. Several other small life forms use arsenic to generate energy and facilitate growth. Chlorine and sulfur are also possible elemental replacements for carbon. Sulfur is capably of forming long-chain molecules like carbon. Some terrestrial bacteria have already been discovered to survive on sulfur rather than oxygen, by reducing sulfur to hydrogen sulfide.

Nitrogen and phosphorus could also potentially form biochemical molecules. Phosphorus is similar to carbon in that it can form long chain molecules on its own, which would conceivably allow for formation of complex macromolecules. When combined with nitrogen, it can create quite a wide range of molecules, including rings.

So what about water? Isn’t at least water essential to life? Not necessarily. Ammonia, for example, has many of the same properties as water. An ammonia or ammonia-water mixture stays liquid at much colder temperatures than plain water. Such biochemistries may exist outside the conventional water-based "habitability zone". One example of such a location would be right here in our own solar system on Saturn's largest moon Titan.

Hydrogen fluoride methanol, hydrogen sulfide, hydrogen chloride, and formamide have all been suggested as suitable solvents that could theoretically support alternative biochemistry. All of these “water replacements” have pros and cons when considered in our terrestrial environment. What needs to be considered is that with a radically different environment, comes radically different reactions. Water and carbon might be the very last things capable of supporting life in some extreme planetary conditions.

At any rate, the odds of there being some type of life somewhere out there are good. As for intelligent life, well, that will depend on the definition of intelligence. There are a lot of other intelligent species here on Earth besides humans, that we don’t generally regard as such. In spite of many Star Trek episodes to the contrary, the odds of alien life forms having evolved to talk, look and act exactly like super hot humans are slim to none. If life is out there, it will have evolved according to it’s particular niche in the universe and will likely be quite foreign to us in the way it looks, communicates and thinks. We might not even be able to recognize hypothetical life forms as alive in the sense that we understand life. In fact, it would be more “miraculous” if we could effectively communicate with extraterrestrial life than to find that it exists. From that perspective, even if there are other life forms out there, we’d still be alone in the universe. Of course, that doesn’t mean we should look for the answers.


Posted by Rebecca Sato.

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Solar Power From Outer Space Could Reduce Fossil Fuel Dependence

Scientists find quick method to make magnets

Scientists find quick method to make magnets
(PhysOrg.com) -- Ultra-strong, high-temperature, high-performance permanent magnet compounds, such as Samarium Cobalt, are the mainstay materials for several industries that rely on high-performance motor and power generation applications, including the Department of Defense (DOD) and the automotive industry.

Until now, producing Samarium Cobalt has been a difficult and expensive multi-step process. Northeastern University researchers have broken new ground with an innovative invention of a rapid, high-volume and cost-effective one-step method for producing pure Samarium Cobalt rare earth permanent magnet materials.
Invented by lead scientist C.N. Chinnasamy, Ph.D., (right) at Northeastern’s Center for Microwave Magnetic Materials and Integrated Circuits, the direct chemical synthesis process is able to produce Samarium Cobalt rapidly and in large amounts, at a small fraction of the cost of the current industry method. Also, the process is environmentally friendly, with 100% recyclable chemicals, and readily scalable to large volume synthesis to meet the needs for the myriad of advanced permanent magnet applications. The study describing the invention is published in the latest issue of Applied Physics Letters (July 28, 2008).

“A single step chemical process has been pursued for decades with little success,” said Vincent Harris, William Lincoln Smith Chair Professor and Director of the Center for Microwave Magnetic Materials and Integrated Circuits at Northeastern University and Principal Investigator of the program. “This research breakthrough represents a potentially disruptive step forward in the cost-effective processing of these important materials.”

Samarium Cobalt magnets are superior to other classes of permanent magnetic materials for advanced high-temperature applications and the Northeastern invention goes beyond the currently known fabrication process of these nanostructured magnets. Unlike the traditional multi-step metallurgical techniques that provide limited control of the size and shape of the final magnetic particles, the Northeastern scientists’ one-step method produces air-stable “nanoblades” (elongated nanoparticles shaped like blades) that allow for a more efficient assembly that may ultimately result in smaller and lighter magnets without sacrificing performance.

“Such unusually shaped particles should prove valuable in the processing of anisotropic magnets that are highly sought in many DOD and commercial applications and are anticipated to lead to lighter and more energy-efficient end products,” said C.N. Chinnasamy.

“Northeastern’s new one-step process has the potential to reduce complexity and associated costs of processing Samarium Cobalt magnets, which are used in many advanced DOD weapon systems,” said Richard T. Fingers, Ph.D., Chief, Energy Power Thermal Division of the Air Force Research Laboratory.

Underscoring the significance of the Northeastern invention relative to the high-performance rare earth magnet industry, Jinfang Liu, Ph.D., Vice President of Technology and Engineering at Electron Energy Corporation, a leading developer of permanent magnetic materials, added, “The development of stable Samarium Cobalt nanoparticles using this one-step chemical synthesis method may motivate more scientists and engineers to work on the development of next generation magnets.”

This revolutionary invention is anticipated to not only revitalize the permanent magnet industry, it has the potential to bring major changes to several federal and commercial industries, including its potential to impact the size, weight, and performance of aircraft, ships, and land-based vehicles, as well as contribute to more efficient computer technologies and emerging biomedical applications.

“This work represents the most promising advance in rare earth permanent magnet processing in many years,” said Laura Henderson Lewis, Professor of Chemical Engineering and Chair of the Department of Chemical Engineering at Northeastern University and a collaborator on this project. “I expect it to revitalize international interest in the development of this important class of engineering materials.”

Strongly aligned with the goals set forth in Northeastern University’s Academic Plan, this invention has the potential to serve global and societal needs by crossing national boundaries and having a significant impact on the engineering discipline through academia and industry.

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A robot with feelings is star of science museum show

Heart Robot has a beating heart, a breathing belly, and sensors that respond to movement, noise and touch. Cuddle him, and he seems to soak up the affection. His limbs become limp, his eyelids lower, his breathing relaxes, and his heart beat slows down.

But if he is given a violent shake, or shouted at, he gets upset. He flinches, his hands clench, his breathing and heart rate speed up, and his eyes widen.

Heart Robot, created by scientists at the University of the West of England in Bristol, was designed to explore how humans react to a machine that appears to show feelings.

Holly Cave, who helped organise the Emotibots event at the Science Museum where the machine was unveiled, said: "Heart Robot looks like a cross between ET and Gollum and is about the size of a small child.

"He's half robot, half puppet. You move him around by hand, but he has innate responses that appear emotional.

"Different children react to him very differently. They either want to hug and cuddle him, and look after him like a doll or baby, or they just want to scare him."

Meanwhile Hexapod, a six-legged metallic spidery robot, was also a big hit because it could recognise and latch onto the faces of visitors who walked around it.

If a person holds Hexapod's gaze long enough what it sees is photographed and projected onto a plasma screen.

According to Matt Denton, its creator, a computer connected to a camera in the head of the robot has been trained - thanks to being bombarded with hundreds of facial images - to recognise when it comes across a face.

It then instructs another computer, which controls movement, to lock onto it and follow it around.

The robot has a starring role in Harry Potter as one of Hagrid's pets.

The organisers said the event coincided with the release of the new Pixar movie WALL-E, in which a lonely robot looks for love on a deserted planet Earth.

Ms Cave said: "Everyone's falling for the "lonely" robot WALL-E, but the idea of robots having emotions or a personality may no longer just be science fiction.

"How humans and robots might interact in the future is something that raises lots of interesting ethical and moral questions."

Emotibots is free and takes place in the Science Museum's Antenna gallery from today until Thursday.

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Genetically Engineered Tobacco Bio-Sensor to Detect Landmines

New Alzheimer's drug shows early promise

CHICAGO - For the first time, an experimental drug shows promise for halting the progression of Alzheimer’s disease by taking a new approach: breaking up the protein tangles that clog victims’ brains.

The encouraging results from the drug called Rember, reported Tuesday at a medical conference in Chicago, electrified a field battered by recent setbacks. The drug was developed by Singapore-based TauRx Therapeutics.

Even if bigger, more rigorous studies show it works, Rember is still several years away from being available, and experts warned against overexuberance. But they were excited.

“These are the first very positive results I’ve seen” for stopping mental decline, said Marcelle Morrison-Bogorad, director of Alzheimer’s research at the National Institute on Aging. “It’s just fantastic.”

The federal agency funded early research into the tangles, which are made of a protein called tau and develop inside nerve cells.

For decades, scientists have focused on a different protein — beta-amyloid, which forms sticky clumps outside of the cells — but have yet to get a workable treatment.

The drug is in the second of three stages of development, and scientists are paying special attention to potential treatments because of the enormity of the illness, which afflicts more than 26 million people worldwide and is mushrooming as the population ages.

The four Alzheimer’s drugs currently available just ease symptoms of the mind-robbing disease.

TauRx’s chief is Claude Wischik, a biologist at the University of Aberdeen in Scotland who long has done key research on tau tangles and studies suggesting that Rember can dissolve them.

He is an “esteemed biologist,” and the research “comes with his credibility attached to it,” said Dr. Sam Gandy of Mount Sinai School of Medicine in New York. He heads the scientific advisory panel of the Alzheimer’s Association.

In the study, 321 patients were given one of three doses of Rember or dummy capsules three times a day. The capsules containing the highest dose had a flaw in formulation that kept them from working, and the lowest dose was too weak to keep the disease from worsening, Wischik said.

However, the middle dose helped, as measured by a widely used score of mental performance.

“The people on placebo lost an average of 7 percent of their brain function over six months whereas those on treatment didn’t decline at all,” he said.

After about a year, the placebo group had continued to decline but those on the mid-level dose of Rember had not. At 19 months, the treated group still had not declined as Alzheimer’s patients have been known to do.

Two types of brain scans were available on about a third of participants, and they show the drug was active in brain areas most affected by tau tangles, Wischik said.

“This is suggestive data,” not proof, Wischik warned. The company is raising money now for another test of the drug to start next year.

The main chemical in Rember is available now in a different formulation in a prescription drug sometimes used since the 1930s for chronic bladder infections — methylene blue. However, it predates the federal Food and Drug Administration and was never fully studied for safety and effectiveness, and not in the form used in the Alzheimer’s study, Wischik and other doctors cautioned.

On Monday at the International Conference on Alzheimer’s Disease, other researchers reported encouraging results from a test of a different experimental drug that also targets tau tangles. That drug, by British Columbia-based Allon Therapeutics Inc., was tested in people with an Alzheimer’s precursor, mild cognitive impairment.

The tau-drug results are in stark contrast to the flop of Flurizan, which was aimed at blocking enzymes that form the beta-amyloid clumps. Myriad Genetics announced in June that it would abandon development of Flurizan after the failure. Full results were presented at the conference Tuesday.

Also, fuller results were given from a closely watched test of bapineuzumab, an experimental drug that aims to enlist the immune system to clear out the sticky brain clumps.

Its developers — New Jersey-based Wyeth and the Irish company Elan Corp. PLC — previously announced that the 240-patient study missed its main goal of improving patients’ mental performance at 18 months.

But the company found a silver lining — the drug appeared to help the roughly 60 percent of people in the study who did not have a gene that scientists think makes Alzheimer’s disease more severe.

The results back up the company’s claims of potential effectiveness in some patients, but now there are concerns about possible side effects. Twelve cases of a type of brain swelling occurred in those on bapineuzumab and none in the placebo group. The swelling caused few if any symptoms, company scientists said, but outside experts said it may have contributed to other side effects.

Those were two or more times more common in patients on bapineuzumab than people given the dummy drug. For example, cases of anxiety occurred in 11 percent versus 4 percent on placebo; paranoia, 7 versus 1 percent. Other complaints were vomiting, high blood pressure, weight loss, and back pain.

Three deaths occurred among the 124 patients given bapineuzumab, but they were not related to the drug, said Dr. Sid Gilman of the University of Michigan, who headed the study’s data safety monitoring board. One death was due to pneumonia and two others to worsening Alzheimer’s disease.

Investors reacted to the news by driving down Wyeth’s shares $5.01, or 11.1 percent, in after-hours trading.

Wyeth and Elan have already said they will move on to late-stage testing of bapineuzumab in more than 4,000 patients.

Copyright 2008 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

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Is Aging an Accident of Evolution? Stanford Scientists Say "Yes"

Main_2 "Everyone has assumed we age by rust. But how do you explain animals that don't age? Some tortoises lay eggs at the age of 100, there are whales that live to be 200 and clams that make it past 400 years."

Stuart Kim, PhD, Stanford University professor of developmental biology and genetics

Prevailing theory of aging challenged by Stanford University Medical School researchers. Their discovery contradicts the prevailing theory that aging is a buildup of tissue damage similar to rust. The Stanford findings suggest specific genetic instructions drive the process. If they are right, science might one day find ways of switching the signals off and halting or even reversing aging.

“We were really surprised,” said Stuart Kim, who is the senior author of the research.

Kim’s lab examined the regulation of aging in C. elegans, a millimeter-long nematode worm whose simple body and small number of genes make it a useful tool for biologists. The worms age rapidly: their maximum life span is about two weeks.

Comparing young worms to old worms, Kim’s team discovered age-related shifts in levels of three transcription factors, the molecular switches that turn genes on and off. These shifts trigger genetic pathways that transform young worms into social security candidates.

The question of what causes aging has spawned competing schools, with one side claiming that inborn genetic programs make organisms grow old. This theory has had trouble gaining traction because it implies that aging evolved, that natural selection pushed older organisms down a path of deterioration. However, natural selection works by favoring genes that help organisms produce lots of offspring. After reproduction ends, genes are beyond natural selection’s reach, so scientists argued that aging couldn’t be genetically programmed.

The alternate, competing theory holds that aging is an inevitable consequence of accumulated wear and tear: toxins, free-radical molecules, DNA-damaging radiation, disease and stress ravage the body to the point it can’t rebound. So far, this theory has dominated aging research.

But the Stanford team’s findings told a different story. “Our data just didn’t fit the current model of damage accumulation, and so we had to consider the alternative model of developmental drift,” Kim said.

The scientists used microarrays—silicon chips that detect changes in gene expression—to hunt for genes that were turned on differently in young and old worms. They found hundreds of age-regulated genes switched on and off by a single transcription factor called elt-3, which becomes more abundant with age. Two other transcription factors that regulate elt-3 also changed with age.

To see whether these signal molecules were part of a wear-and-tear aging mechanism, the researchers exposed worms to stresses thought to cause aging, such as heat (a known stressor for nematode worms), free-radical oxidation, radiation and disease. But none of the stressors affected the genes that make the worms get old.

So it looked as though worm aging wasn’t a storm of chemical damage. Instead, Kim said, key regulatory pathways optimized for youth have drifted off track in older animals. Natural selection can’t fix problems that arise late in the animals’ life spans, so the genetic pathways for aging become entrenched by mistake. Kim’s team refers to this slide as “developmental drift.”

“We found a normal developmental program that works in young animals, but becomes unbalanced as the worm gets older,” he said. “It accounts for the lion’s share of molecular differences between young and old worms.”

Kim can’t say for sure whether the same process of drift happens in humans, but said scientists can begin searching for this new aging mechanism now that it has been discovered in a model organism. And he said developmental drift makes a lot of sense as a reason why creatures get old.

“Everyone has assumed we age by rust,” Kim said. “But then how do you explain animals that don’t age?”

Some tortoises lay eggs at the age of 100, he points out. There are whales that live to be 200, and clams that make it past 400. Those species use the same building blocks for their DNA, proteins and fats as humans, mice and nematode worms. The chemistry of the wear-and-tear process, including damage from oxygen free-radicals, should be the same in all cells, which makes it hard to explain why species have dramatically different life spans.

“A free radical doesn’t care if it’s in a human cell or a worm cell,” Kim said.

If aging is not a cost of unavoidable chemistry but is instead driven by changes in regulatory genes, the aging process may not be inevitable. It is at least theoretically possible to slow down or stop developmental drift.

“The take-home message is that aging can be slowed and managed by manipulating signaling circuits within cells,” said Marc Tatar, PhD, a professor of biology and medicine at Brown University who was not involved in the research. “This is a new and potentially powerful circuit that has just been discovered for doing that.”

Kim added, “It’s a new way to think about how to slow the aging process.”

Posted by Casey Kazan.

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Rapid Evolution Gives Sperm the Advantage

By Jeanna Bryner, Senior Writer

Semen, the stuff that ferries sperm, contains proteins that evolve swiftly to help males compete for paternity, suggests new research on fruit flies.

The high-stakes competition between male fruit flies vying for a top mating spot with females could be driving the fast-evolving proteins, according to the study published in the July 29 issue of the journal PLoS Biology.

"They change with the quickness we would expect for the immune system, which has to respond fast to new pathogens," said researcher Michael MacCoss of University of Washington's Department of Genome Sciences in Seattle.

Though the study results are based on fruit flies, they do have implications for humans and other animals that also reproduce sexually.

"We think that if we can understand what are the pressures that are driving the rapid changes of these proteins in a system that's easier to study, like flies, we can get a handle on what may be causing the changes in humans," said lead study scientist Geoffrey Findlay, also of UW.

Findlay's team compared DNA sequences of semen proteins between closely related species of fruit flies, finding that the same proteins in different species had different arrangements. They also identified semen proteins that were unique to certain species.

They discovered more than 80 previously unknown proteins that play a role in reproduction, confirming 70 others that had been predicted to be involved, that get transferred to female fruit flies via semen.

Semen advantage

Female fruit flies mate with several males during their lifetimes, storing the sperm at different times in specialized organs.

"If you've got sperm from different males, all competing for fertilization success, than anything a male can do to increase the chances of his sperm winning and decrease the chances of other males' sperm winning is going to be advantageous," Findlay told LiveScience. "It could be that these proteins have evolved to increase that fitness."

Semen proteins could, for instance, cue the female to lay eggs immediately upon getting the semen goods, and could make females less likely to mate again with another male, the researchers explain. Perhaps certain proteins "disarm" the seminal proteins transferred to females by other males, they say.

Staying on top

There's a little twist, however. If a mutation imparts super-hero qualities to a male's sperm, over time that mutation would become a part of every male fruit fly's reproductive repertoire.

The researchers found that to counter this plateau of fitness, male fruit flies may have acquired duplicates of proteins.

"One copy can be held constant and in the other copy the mutation can play around with that copy and if it happens to hit on a beneficial mutation in the second copy, then that copy can diverge and maybe provide a new advantage," Findlay said.

They found 15 such duplications in the male reproductive genes. He added, "We think this is evidence of the continuing arms race, or sort of struggle, for reproductive success.

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U.S. food portions: Monuments of decadence?

By Jasmin Melvin

WASHINGTON (Reuters) - After having dinner at Clyde's in Washington's trendy Chinatown, a young boy sluggishly gets up to follow his family to the exit. His waitress jokes, "You're stuffed, huh?"

The boy lets out a grunt, saying, "Yeah, I'm full. I feel like I'm going to burst," as he ambles to the door.

Such is the response of many customers who venture into the popular restaurant. One waitress said, "It depends on the dish, but I've never gotten a complaint that it's too little."

But with soaring food prices sparking protests in many countries and more than 800 million people going hungry every day, U.S. food portions are under scrutiny. A lightening of the American plate could ease pressure on worldwide demand, but not everyone is hopeful change will be coming any time soon.

With a bombardment of food ads, many aimed at children, Americans are tempted with an array of food choices. One fast-food chain calls its massive burger a "monument to decadence" while the Wendy's chain calls its "Baconator" a "mountain of mouth-watering taste."

Portion sizes in the United States not only exceed those in less-developed countries, but also in the developed world. In fact, Americans have the highest per capita daily consumption in the world, eating 3,770 calories a day, more than a Canadian at 3,590 calories or an Indian at 2,440, according to data from the U.N. Food and Agricultural Organization.

"We've looked at large portion sizes almost entirely in terms of whether it's healthy for us, and now we have to consider is that sort of a demand going to be sustainable," said Paul Roberts, author of "The End of Food."

Roberts believes smaller portions would help. "It would probably be a way to take pressure off of grain markets if we somehow convinced people to take smaller portion sizes."

In the United States, food prices are expected to rise 4.5 percent to 5.5 percent this year, which would be the highest increase since 1990.

FEWER GROCERIES

Americans are putting more thought into food buying. High food prices coupled with a slowing economy have led 71 percent of Americans to eat out less and 48 percent are buying fewer groceries, according to the Food Marketing Institute.

Raj Patel, author of "Stuffed and Starved: The Hidden Battle for the World Food System," said consumer buying habits are changing, including in the United States.

"But, it's unusual to see it in the United States, where I've seen reports of low income American families doing what low income families in the third world do, which is skipping meals, particularly women skipping meals so their kids can eat," Patel said.

He said there is also a boom in Spam and other low quality meats. "There's certainly a sort of downshift in the quality and sometimes, for the poorest Americans, the quantity of food they're able to afford."

Restaurants are also being hit hard by the rise in food prices.

Between February 2006 and February 2008, wholesale food prices have soared 15.5 percent, according to Michael Donohue, a spokesman for the National Restaurant Association. But as of January, menu prices only increased by 3.9 percent, compared with the 5.8 percent increase in grocery store prices.

Donohue said some 133 million Americans eat out every day. "The typical adult eats at a restaurant nearly six times a week, and more than half say eating out is an essential part of their lifestyle," he said.

But restaurants are not making big reductions in portions, making only small moves like not automatically refilling bread baskets or introducing calorie counter options.

"I've seen some anecdotal reports in the press about restaurants saying they're making the portions a little bit smaller in order to save money, but I haven't seen that as a general trend in going into restaurants," said Margo Wootan, director of nutrition policy at the Center for Science in the Public Interest.

Wootan said large portion sizes are unlikely to fade away despite increasing food costs since the actual farm value of food is low for restaurants compared to other costs, such as labor, advertising and transportation.

"So if you pay a dollar for an order of French fries only about 20 cents goes for the potatoes, the oil and the salt," she said. "When a restaurant sells a large fry instead of a small fry, the cost of the potatoes themselves adds only a little bit of cost and all their other costs of doing business stay the same. So companies make a lot more profit off of big portion sizes."

President George W. Bush caused a stir earlier this year when he blamed India's growing wealth and demands for better food for raising food prices. But many worldwide pointed the finger back at Americans' tummies.

But author Patel said ironically it is the poor in America that are driving consumption.

"Yes, portion sizes are large in the U.S., but people who tend not to have choice about portion sizes are people who are on lower incomes who buy prepackaged food, which comes in those fixed portion sizes," Patel said. "Blaming the consumer for what is available on the market isn't a satisfactory explanation for why there's a food crisis."

Patel points the finger at large-scale agribusiness, whom he believes is profiting from the crisis.

To be sure, tight worldwide food supplies also weigh.

"U.S. food consumption hasn't changed in 10 years," said Ephraim Leibtag, a U.S. Department of Agriculture economist. He contends the problem is really due to rising worldwide consumption while supplies are not keeping pace.

But Leibtag did agree that U.S. food consumption is high.

"Potentially, and this is up for debate, a benefit of higher prices is lower consumption, and, in this country, that actually would not be a bad thing overall."

(Editing by Russell Blinch and Philip Barbara)

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Arctic Ice Shelf Sheds Biggest Chunk Since 2005, Globe Says

By Alex Morales

July 29 (Bloomberg) -- An ice shelf in northern Canada has shed its biggest chunk since 2005, a sign global warming is re- shaping the Arctic coastline, the Globe and Mail reported.

The 4-square-kilometer (1.5-square-mile) piece broke off last week, the newspaper said, citing Sami Soja, a surveyor working for Parks Canada who witnessed part of the event. It's the biggest piece shed since the entire Ayles shelf, one of Canada's six major ice shelves, broke off in 2005, creating a 66- square-kilometer frozen island, the newspaper said.

Over the past century, 9,000 square kilometers of ice attached to the Arctic coastline have shrunk to less than 1,000 square kilometers, the Globe and Mail said. The rest of the Ward Hunt shelf may continue to weaken over time and then suddenly break, the newspaper said, citing Derek Mueller, a scientist who has monitored ice in the area of the latest break.

To contact the reporter on this story: Alex Morales in London at amorales2@bloomberg.net.

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Commercially Raised Bees Spreading Disease

by Jason Sahler
Design can change the world for the better, but our wide reaching imprint on Mother Nature doesn’t always yield the best results. Case in point: the decline of bees. More specifically that commercially raised bumblebees are affecting the wild bee population. For years, researchers have been linking a decline in bees to everything from pesticides to genetically modified crops, and now the news is pointing to the bees themselves - the ones that humans “create” in greenhouses.

Researchers believe that some commercially raised bumblebees have escaped from greenhouses, foraged outside crops and spread diseases to their wild cousins. Crithidia bombi, a parasite that is common among commercial bees, is finding its way into the wild populations surrounding the greenhouses. Believed to be transfered from greenhouse bees, this parasite has been shown to weaken and kill wild bumblebees.

While this study has been done with bumblebee populations in southern Ontario, it may have far reaching implications. This type of transference may be one of the reasons that many honey bee colonies around the world have mysteriously disappeared, a phenomenon know as Colony Collapse Disorder (CCD).

Our designs flow through every built facet of this world; from the largest of buildings to the smallest of nano-tech devices. Our designs, even reach to the biological world. We have created genetically modified crops, we have cloned animals and we have commercially raised bees in greenhouses. Many of our designs have been widely accepted and benefited the world, but some have stirred controversy and have even had disastrous results. Unfortunately, it seems that commercially raising bees, in some instances, may have fallen into the latter category of harm.

It is a lesson that we need to heed. If we lose too many of our pollinators it could have extremely harmful effects for our crops and food supply. The bees in the study have been commercially raised, not even genetically altered. We must realize that our actions have consequences and our use of nature and how we design our agricultural systems can have lasting and far reaching effects, even with the seemingly benign act of raising commercial bees.

Via Reuters

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Spider vs. Bee... BBC vs. National Geographic

When The Ranger was young he enjoyed greatly the diverting summer sport of tossing hapless invertebrates into spiders' webs and seeing the ensuing fight. Even today he's not above the odd experiment, just to see what happens. Of course, we all know what's likely to happen. That's why it's such fun.

But putting flies in webs is relatively easy compared to watching the more peripatetic spiders making a kill. It was nearly twenty years, for example, before he got to see the bizarre spitting spider, Scytodes, in action. It's not surprising, then, that when spiders make an appearance on a nature documentary, it's often these hunters tracking down their prey that feature - fast, spectacular action. That's what we want to see, and of course the spiders are more than happy to deliver.

Take this clip from an American National Geographic documentary:

[More:]

What a dramatic adventure! Was there ever any doubt of the result? Well, if you believe the commentary, possibly there was.

Watching this film put The Ranger in mind of an interesting contrast that he has often noticed between natural history films intended for the US market, and those intended for the British (Sorry, but other English-speaking nations will have to chip in on the comments, he's never watched any others). There was a time when those kind folk at Warner Brothers gave a series of US DVD prizes for The Ranger to give out to lucky competition winners. Many of these were BBC films, and of course, he watched them first, and was amazed by how very different US wildlife films are - even when made by the BBC. Now, US readers are probably wondering what on earth The Ranger means. So, for comparison, here is Sir David Attenborough narrating a comparable clip from the BBC production Life in the Undergrowth:

More-or-less the same story - but what a different presentation. It's a wholly different style, calculated very much for education rather than entertainment. Now, as it happens, both BBC and National Geographic clips are highly educational and entertaining, but it's instructive to see how they place their emphasis. The NG clip emphasises the drama of the process, with prominent music building to a crescendo - taking a short diversion into eerie alien sounds when close-ups of the spider's eyes are shown. The chuckling commentary is unashamedly anthropomorphic, aiming to make the audience identify with the protagonists and feel the action for themselves.

"The jumping spider packs a ton of skulking pouncing killing fire-power in its tiny body."

"If this were a slasher film, the audience would be screaming, 'Look out behind you!'"

"How'd you like to stare into these eyes, with your life on the line? Ha! Yikes!"

Compare that with Attenborough's quiet, almost abstract delivery:

"A white crab spider sits, almost invisible, on a white flower, waiting in ambush. And it catches a bee."

"...ultra-violet markings on some flowers serve to guide insects to nectar."

"Honey-bees seem more likely to visit flowers with crab spiders on them than those without."

The music, such as it is, is almost imperceptible. The quiet buzzing of the insects mostly drowns it out. And even the flowers are apparently real flowers in a real field, as opposed to the quite obviously artificial scenario in the NG clip.

And yet both clips were superbly photographed, both accurately explained some quite complex information, and both clearly provided good entertainment to their viewers. So why are they so different?

It seems as though the difference lies in the vehicle which the programme-makers choose to deliver their message. In the case of Attenborough, both presenter and writer, he uses a simple scientific process in this clip: he makes observations, he forms a hypothesis. He doesn't even present his conclusion as fact, saying only "Honey-bees seem more likely to visit...". For Attenborough, the drama of the on-screen struggle speaks for itself. This is often the approach he takes, and BBC natural history films almost invariably follow this pattern, or at least this style. The NG film, by contrast, sets out to deliver a short, Hollywood-style set piece, as might be seen at the start of a James Bond film. Whether you understand what a retina is or not, you'll enjoy this fast-paced action, with camera work that borrows heavily from the human world of movie-making. As well as the narrator's jocular style, the long approach of the bee in flight; the view of the bee through the petals; the slow-motion jump of the spider - all are calculated to draw the viewer into the unfolding scene using visual cues that will be familiar and well-understood.

To The Ranger's British eyes, this American clip seems almost patronising and childish in its presentation. And yet the content is little different; the difference is purely stylistic. It represents another interesting cultural difference across the Atlantic. And of course, The Ranger is forced to wonder, what do viewers in the US and elsewhere think of the BBC's Attenborough style of natural history presentation? Do they find these scholarly discourses dull and dusty? Do they long for the commentator to chuckle in an avuncular manner or say "Whooa!"? Perhaps the Ranger's overseas readers can enlighten him.

Update: Whooa! Hello, Digg and Redditors. Thanks for your interest. You made my server go a little wobbly back then but it's all better now. Feel free to explore whilst you're here, and of course digg/upmod, it makes an old Ranger happy :)

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Wind Power Superhighway for West Texas

Written by Jaymi Heimbuch
Texas likes to do everything big, including wind farms and investing in clean energy. The states has been given the thumbs up for a $4.9 billion plan to set up transmission lines to carry the wind power generated in West Texas to surrounding urban areas.

The plan will account for enough lines to carry 18,000 MW – a serious amount of electricity. The state currently generates 5,000 MW, so these lines will leave plenty of room for growth, which T Boone Pickens will help to fill with this own wind plan.

The plan’s funding is coming (in part) from the people who will benefit from the electricity – citizens will pay and extra $3 to $4 each month on their electricity bills for he next few years, which is a pretty small price to pay for getting clean energy delivered to your home. The rest of the funding will come from other investors. Oncor, for example, filed with the Public Utility Commission to show it has its wallet on the table to help with a big chunk of the project. The lines would be up and running somewhere in the next 3 to 5 years, and after that, users would likely see some savings in their energy bills.

Since electricity costs are high, partly because of clogged transmission lines, the project really is practical, and will help out with energy costs as well as reducing pollution. Yet, the one person on the Texas Public Utilities Commission voting against the project, Julie Caruthers Parsley, said she worries this will delay other projects like the building of nuclear power plants. There’s always at least one…

Let’s just hope this project does exactly that. Should this plan come to fruition, Texas will without a doubt be the biggest contributor to wind energy, creating and distributing more than the next 14 states combined. The plan would also be the biggest investment in clean energy in US history. Everything’s bigger in Texas. With luck, more near-future investments in clean energy may soon overshadow even this project. With an investment like this comes more jobs, more trial-and-error knowledge, and much more public awareness for the need and potential of clean energy investments.

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