|Giant Pinwheel Galaxy! |
MiCRoN Nanorobots? CSI - NASA?
Cocoa is Good! Pot for Diabetics!
Pulsar Winds! Universal Evolution!
|Hubble Reveals Giant Pinwheel Galaxy! |
Image credit: European Space Agency & NASA
NASA News Release
February 28, 2006 - This new Hubble image reveals the gigantic Pinwheel galaxy, one of the best known examples of "grand design spirals", and its supergiant star-forming regions in unprecedented detail. The image is the largest and most detailed photo of a spiral galaxy ever released from Hubble.
Giant galaxies weren’t assembled in a day. Neither was this Hubble Space Telescope image of the face-on spiral galaxy Messier 101 (the Pinwheel Galaxy). It is the largest and most detailed photo of a spiral galaxy beyond the Milky Way that has ever been publicly released from Hubble. The galaxy’s portrait is actually composed from 51 individual Hubble exposures, in addition to elements from images from ground-based photos. The final composite image measures a whopping 16,000 by 12,000 pixels.
The Hubble observations that went into assembling this image composite were retrieved from the Hubble archive and were originally acquired for a range of Hubble projects: determining the expansion rate of the universe; studying the formation of star clusters in giant starbirth regions; finding the stars responsible for intense X-ray emission and discovering blue supergiant stars. As an example of the many treasures hiding in this immense image, a group led by K.D. Kuntz (Johns Hopkins University and NASA) recently catalogued nearly 3000 previously undetected star clusters in it.
The giant spiral disk of stars, dust and gas is 170,000 light-years across or nearly twice the diameter of our Milky Way. The galaxy is estimated to contain at least one trillion stars. Approximately 100 billion of these stars alone might be like our Sun in terms of temperature and lifetime. Hubble’s high resolution reveals millions of the galaxy’s individual stars in this image.
The Pinwheel’s spiral arms are sprinkled with large regions of star-forming nebulae. These nebulae are areas of intense star formation within molecular hydrogen clouds. Brilliant young clusters of sizzling newborn blue stars trace out the spiral arms. The disk of the galaxy is so thin that Hubble easily sees many more distant galaxies lying behind the foreground galaxy.
The Pinwheel Galaxy lies in the northern circumpolar constellation, Ursa Major (The Great Bear) at a distance of 25 million light-years from Earth. We are seeing the galaxy from Earth today as it was at the beginning of Earth's Miocene Period when mammals flourished and the Mastodon first appeared on Earth. The galaxy fills an area on the sky of one-fifth the area of the full moon.
The newly composed image was assembled from archived Hubble images taken with the Advanced Camera for Surveys and the Wide Field and Planetary Camera 2 over nearly 10 years: in March 1994, September 1994, June 1999, November 2002 and January 2003. The Hubble exposures have been superimposed onto ground-based images, visible at the edge of the image, taken at the Canada-France-Hawaii Telescope in Hawaii, and at the 0.9-meter telescope at Kitt Peak National Observatory, part of the National Optical Astronomy Observatory in Arizona. Exposures taken through a blue filter are shown in blue, through a green filter in green and through a red filter in red.
Large image of spiral galaxy Messier 101, suitable for desktop background - http://www.spacetelescope.org/images/screen/heic0602a.jpg
|MiCRoN Nanorobots |
The goal of the MiCRoN Project is to develop a system that is based on a
cluster (5 to 10) of small (cmł) mobile autonomous robots. These wireless
microrobots, each equipped with onboard electronics for control and
communication, can co-operate to accomplish a range of tasks associated
with assembly and processing from the nano- to the micro-range. (MiCRoN)
Information Society News Release
From cell manipulation to micro assembly, micro robots devised by an international team of researchers offer a glimpse of the future.
The MICRON project team, led by the Institute for Process Control and Robotics (IPR), Karlsruhe, Germany, brought together eight international partners. Funded under the European Commission’s FET (Future and Emerging Technologies) initiative of the IST programme, MICRON set out to build a total of five to ten micro robots, just cubic centimetres in size.
"Each one would measure about 1.5cm by 3 cm," says IPR´s Joerg Seyfried. "They were designed to be complete robots, with different kinds of actuators for gripping, cell manipulation, and so on. Each one would be wireless, with lots of electronics on board, and an infrared control system – rather like a TV remote, but two-way in this case. They would be able to cooperate together on a range of tasks."
Building the robots involved developing many custom applications, he adds. "One of these was the wireless powering system, the ‘power floor’, which allows the robot to get energy from its surroundings," he says. "It uses a coil system to transmit the electricity through the air."
The robots were designed as part of a networked system: "The individual robots are not that intelligent," explains Seyfried. "They don’t, for example, know where they are, although they know which direction they are moving in. We developed a special positioning system, so that we know where each robot is. It views them from 40 to 50 cm above. They are controlled by a central robot control system, with several networked computers for planning and commands – this could theoretically control many robots."
The hardest part of the project was "getting the hardware integrated and running – our goal was to have five robots operational, but this couldn’t be done in our three-year timeframe owing to the extreme complexity of the task," he says.
Microrobts jump into cell manipulation
Nevertheless, the one fully functional robot that the project did achieve could be tested in three different scenarios. "The first was a medical or biological application, in which the robot was handling biological cells, injecting liquid into them," Seyfried explains. "The second scenario was micro-assembly, in which the robot soldered tiny parts. The final scenario looked at atomic force, with the robot mounting atomic force and doing experiments on it."
The results were encouraging. "Our experiments showed that the cell injection is entirely feasible, as is the micro soldering," says Seyfried. Although the MICRON robots are clearly not a mass market product, commercialisation – though still far off – would be perfectly possible, he believes: "Robots with this sort of capability, and mobility, would be perfectly suited to lab work, such as the micro assembly of prototypes. Tasks such as cell injection could be performed on a mass scale."
With MICRON now having run its course, the project team is currently working on the project reports and evaluation. "What’s missing is the integration work, and this is what we will try to do next within the [also FET-funded] I-Swarm project," says Seyfried. "This will build on MICRON to produce robots with a ‘swarm’ intelligence – that is, with limited capabilities, but able to communicate with each other."
The tiny robots of science fiction tales might be smarter, but, as Seyfried points out, "We’re working on the smallest size range currently being worked on by a few other groups worldwide – like MIT. On a European level, MICRON is unique."
MICRON Project - http://wwwipr.ira.uka.de/~micron
|CSI - NASA? |
The Laser Scaling Device attaches directly to a camera
and projects a pattern of dots into the field of view.
This pattern appears in the photograph along with
the image of the object under investigation, enabling
the viewer to measure the size of the object. Credit: NASA
NASA News Release
February 27, 2006 - What do a NASA engineer and a detective have in common? The answer is a new NASA photographic laser device that helps look for damages on NASA’s Space Shuttle that can also be used to "shoot" more details in crime scenes.
Engineers at NASA's Kennedy Space Center (KSC), Kennedy Space Center, Fla., developed the Laser Scaling and Measurement Device for Photographic Images (LSMDPI) to assist scientists who were unable to determine the exact scale of hailstorm damages to the Space Shuttle’s external tank by viewing photographs of the spacecraft on its launch pad.
The LSMDPI is a half-pound black box, powered by a single nickel-cadmium battery that attaches directly to a camera’s tripod mount. Twin lasers, an inch apart, shoot from the box, and add scale to photographs. In other words, the laser offers the ability for someone to look at these special photographs and have a better understanding of just how big or small objects really are. In the case of the Space Shuttle, engineers are now able to measure the distance from one part of the shuttle to a dent from a hailstorm.
Typically, when you use a camera to zoom in on an object, you lose track of the scale that informs you of an object’s actual size. When a picture is taken with the LSMDPI, the image loads into software designed by NASA electrical design engineer Kim Ballard. The user chooses a set of reference points such as a laser pattern of reference point dots that will appear along with the image of the target object. The user also inputs the distance between the reference points. The software then sets the scale based on that distance. This allows the viewer quantifiable perspective on the size of the object. The size of the object’s features can then be found and measured by using the computer software to mark the laser points.
By having the ability to measure the size of
an object in a photograph, the Scaling Device
helps crime scene investigators analyze
information. Credit: NASA
"I think that the greatest contribution that the Laser Scaling Measurement software offers to law enforcement is it ‘un-cuffs’ the investigators hands with digital image evidence by facilitating fast and accurate measurement analysis of anything in a crime scene photo, not just the intended target," said Ballard. "This aspect opens up the possibility for serendipitous evidence detection after the fact that may not have been obvious at the crime scene. For example, the software may be instrumental in attaining dimensions of articles or their proximity locations within a room that were not previously part of the investigation."
As it is useful at NASA, the laser device is very helpful for law enforcement. Contractor Jeffrey Kohler of ASRC Aerospace, a company that supports NASA's Innovative Partnership Office, and his colleagues did an assessment to review the technology and how it could apply to potential commercial markets. "Forensics was at the top of the list," said Kohler.
Not only can they use it to fully view photos of components from crime scenes such as blood-spatter patterns and graffiti, but can also see the images from different angles (including diagonally, horizontally and vertically) to better analyze and understand the scenes.
In fact, just recently, Ballard was asked by the U.S. Federal Bureau of Investigations (FBI) to add more capabilities to the LSMDPI software to enable forensics experts to zoom in and out of the image to measure blood spatter details across a wall as well as specific areas. At the FBI’s request, NASA has also enabled compatibility of the image files with.tiff, .png, .gif, and .bmp files as add-ons to .jpg images.
Armor Holdings, Inc. of Jacksonville, Fla., is a leading manufacturer of crime scene investigation accessories, including the new LSMDPI. They manufacture a variety of instruments used by industries that rely on technology to perform efficient and safe tasks. Through Armor, LSMDPI is not only benefiting crime scene investigations, but also photographers and surveillance personnel. It is also becoming increasingly popular in crime laboratories around the world. Following a recent request from Armor, NASA also included English/Metric units -- millimeters, centimeters, meters, and kilometers -- to support European customers and aerial photography.
Today's crime investigations often rely on the device to scale evidence since its unique laser beams allow viewers to see image components much more clearly than traditional camera images. Similar technology is also useful in oil and chemical tank monitoring and aerial photography.
|Cocoa Is Good for You! |
|JAMA and Archives Journals News Release |
February 27, 2006 - A study of elderly Dutch men indicates that eating or drinking cocoa is associated with lower blood pressure and a reduced risk of death, according to an article in the February 27 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
Cocoa has been linked to cardiovascular health benefits since at least the 18th century, but researchers are just beginning to collect scientific evidence for these claims, according to background information in the article. Cocoa is now known to contain chemicals called flavan-3-ols, which have been linked to lower blood pressure and improved function of the cells lining the blood vessels.
Brian Buijsse, M.Sc., National Institute for Public Health and the Environment, Bilthoven, the Netherlands, and colleagues examined cocoa's relationship to cardiovascular health in 470 Dutch men aged 65 to 84 years. The men underwent physical examinations and were interviewed about their dietary intake when they enrolled in the study in 1985 and at follow-up visits in 1990 and 1995. The researchers then placed them into three groups based on their level of cocoa consumption. Information about their subsequent illnesses and deaths were obtained from hospital or government data.
Over the next 15 years, men who consumed cocoa regularly had significantly lower blood pressure than those who did not. Over the course of the study, 314 men died, 152 due to cardiovascular diseases. Men in the group with the highest cocoa consumption were half as likely as the others to die from cardiovascular disease. Their risk remained lower even when considering other factors, such as weight, smoking habits, physical activity levels, calorie intake and alcohol consumption. The men who consumed more cocoa were also less likely to die of any cause.
Although blood pressure is usually linked with risk of cardiovascular death, that was not the case in this study. "The lower cardiovascular mortality risk associated with cocoa intake could not be attributed to the lower blood pressure observed with cocoa use," the authors write. "Our findings, therefore, suggest that the lower cardiovascular mortality risk related with cocoa intake is mediated by mechanisms other than lowering blood pressure." The benefits associated with flavan-3-ols may play a role.
The link between chocolate and overall lower risk of death suggests that other mechanisms also may be involved. "Because cocoa is a rich source of antioxidants, it may also be related to other disease that are linked to oxidative stress (e.g. pulmonary diseases, including chronic obstructive pulmonary disease, and certain types of cancer)," the authors conclude. "However, this merits further investigation."
JAMA and Archives Journals - http://www.jamamedia.org
|Marijuana for Diabetics |
Medical College of Georgia News Release
By Toni Baker
February 27, 2006 - A compound found in marijuana won’t make you high but it may help keep your eyes healthy if you’re a diabetic, researchers say.
Early studies indicate cannabidiol works as a consummate multi-tasker to protect the eye from growing a plethora of leaky blood vessels, the hallmark of diabetic retinopathy, says Dr. Gregory I. Liou, molecular biologist at the Medical College of Georgia.
"We are studying the role of cannabinoid receptors in our body and trying to modulate them so we can defend against diabetic retinopathy," Dr. Liou says. Diabetic retinopathy is the leading cause of blindness in working-age adults and affects nearly 16 million Americans.
High glucose levels resulting from unmanaged diabetes set in motion a cascade ultimately causing the oxygen-deprived retina to grow more blood vessels. Ironically, the leaky surplus of vessels can ultimately destroy vision.
Dr. Liou, who recently received a $300,000 grant from the American Diabetes Association, wants to intervene earlier in the process, as healthy relationships inside the retina first start to go bad.
Cannabinoid receptors are found throughout the body and endogenous cannabinoids are produced to act on them. "Their function is very different from organ to organ but in the central nervous system, cannabinoid receptors are responsible for the neutralization process that should occur after a nerve impulse is finished," says Dr. Liou.
Nerves come together at a point of communication called a synapse. Glutamate is a neurotransmitter that excites these nerves to action at their point of communication. "There are also inhibitory neurotransmitters such as GABA," Dr. Liou says. Endogenous cannabinoids help balance the excitation and inhibition, at least until oxygen gets scarce.
In the face of inadequate oxygen, or ischemia – another hallmark of diabetes – nerve endings start producing even more glutamate, setting in motion an unhealthy chain of events. Pumps that keep the right substances inside or outside of cells start to malfunction. Excess nitric oxide and superoxides are produced, which are toxic to the cells. Another irony is the heightened activity increases the retina’s need for oxygen. "We are talking about nerve cell death," Dr. Liou says. "In the retina, if a lot of our nerve cells die, our vision is directly affected."
And that’s not all that goes wrong in the nerve-packed retina. Glial cells, which support nerve cells by supplying nutrients and oxygen, are closely attuned to their charges. When they sense something is amiss, microglia, one type of glial cells, start eating the dying nerve cells.
"Microglial cells become voracious. They eat dying nerve cells, making the whole thing irreversibly bad," says Dr. Liou. Interestingly, the body start producing more endogenous cannabinoids to stop the role reversal, then produces an enzyme to destroy the cannabinoids because of concern there are too many of them. The same thing happens in the brain after a stroke. "Long before all these blood vessels start growing, the partnership between glial cells and nerve cells starts breaking down," says Dr. Liou.
That’s why cannabidiol, an antioxidant, may help save the retina. Test-tube studies by others, as well as Dr. Liou’s pilot studies in diabetic animal models show cannabidiol works to interrupt essentially all these destructive points of action.
"What we believe cannabidiol does is go in here as an antioxidant to neutralize the toxic superoxides. Number two, it inhibits the self-destructive system and allows the self-produced endogenous cannabinoids to stay there longer by inhibiting the enzyme that destroys them." Cannabidiol also helps keep microglial cells from turning on nerve cells by inhibiting cannabinoid receptors on microglial cells that are at least partially responsible for their ability to destroy rather than support the cells.
"Cannabinoids are trying to ease the situation on both sides. They help save the neuron and, at the same time, make sure the microglial cells stay in microglial form. How good do you want a drug to be?" Dr. Liou says.
His earliest studies in animal models, published in the January issue of the American Journal of Pathology, indicate it may be very good.
Co-authors on the study include Dr. Azza B. El-Remessy, MCG Department of Pharmacology and Toxicology; Drs. Mohamed Al-Shabrawey, Nai-Tse Tsai and Ruth B. Caldwell, MCG Vascular Biology Center; and Dr. Yousuf Khalifa, MCG Department of Ophthalmology.
"We are very pleased," he says of studies in which cannabidiol is injected into the stomachs of diabetic rats and mice.
He hopes the compound in marijuana may one day be given along with insulin to stop the early changes that set the stage for damaged or destroyed vision.
Medical College of Georgia - http://www.mcg.edu
|Pulsar Winds |
Pulsar PSR B1259-63 is a radio pulsar, which means most of the time
it emits only radio waves. The binary system lies in the general direction
of the Southern Cross about 5000 light-years away. (ESA)
European Space Agency News Release
February 28, 2006 - Astronomers have witnessed a never-seen-before event in observations by ESA’s XMM-Newton spacecraft - a collision between a pulsar and a ring of gas around a neighbouring star.
The rare passage, which took the pulsar plunging into and through this ring, illuminated the sky in gamma- and X-rays.
It has revealed a remarkable new insight into the origin and content of ‘pulsar winds’, which has been a long-standing mystery. The scientists described the event as a natural but ‘scaled-up’ version of the well-known Deep Impact satellite collision with Comet Tempel 1.
Their final analysis is based on a new observation from XMM-Newton and a multitude of archived data which will lead to a better understanding of what drives well-known ‘pulsar nebulae’, such as the colourful Crab and Vela pulsars.
"Despite countless observations, the physics of pulsar winds have remained an enigma," said lead author Masha Chernyakova, of the Integral Science Data Centre, Versoix, Switzerland.
"Here we had the rare opportunity to see pulsar wind clashing with stellar wind. It is analogous to smashing something open to see what’s inside."
A pulsar is a fast-spinning core of a collapsed star that was once about 10 to 25 times more massive than our Sun. The dense core contains about a solar mass compacted in a sphere about 20 kilometres across.
The pulsar in this observation, called PSR B1259-63, is a radio pulsar, which means most of the time it emits only radio waves. The binary system lies in the general direction of the Southern Cross about 5000 light-years away.
Pulsar wind comprises material flung away from the pulsar. There is ongoing debate about how energetic the winds are and whether these winds consist of protons or electrons. What Chernyakova’s team has found, although surprising, ties in neatly with other recent observations.
The team observed PSR B1259-63 orbiting a ‘Be’ star named SS 2883, which is bright and visible to amateur astronomers. ‘Be’ stars, so named because of certain spectral characteristics, tend to be a few times more massive than our Sun and rotate at astonishing speeds.
They rotate so fast that their equatorial region bulges and they become flattened spheres. Gas is consistently flung off such a star and settles into an equatorial ring around the star, with an appearance somewhat similar to the planet Saturn and its rings.
The pulsar plunges into the Be star’s ring twice during its 3.4-year elliptical orbit; but the plunges are only a few months apart, just before and after ‘periastron’, the point when the two objects in orbit are closest to each other. It is during the plunges that X-rays and gamma rays are emitted, and XMM-Newton detects the X-rays.
"For most of the 3.4-year orbit, both sources are relatively dim in X-rays and it is not possible to identify characteristics in the pulsar wind," said co-author Andrii Neronov. "As the two objects draw closer together, sparks begin to fly."
The new XMM-Newton data was collected nearly simultaneously with a HESS observation. HESS, the High Energy Stereoscopic System, is a new ground-based gamma-ray telescope in Namibia.
Announced last year, the HESS observation was puzzling in that the gamma-ray emission fell to a minimum at periastron and had two maximums, just before and after the periastron, the opposite of what scientists were expecting.
The XMM-Newton observation supports the HESS observation by showing how the maximums were generated by the double plunging into the Be star’s ring. By combining these two observations with radio observations from the last periastron event, the scientists now have a complete picture of this system.
ESA's XMM-Newton is the most sensitive X-ray
telescope ever built. Its high-technology design
uses over 170 wafer-thin cylindrical mirrors
spread over three telescopes. Its orbit takes it
almost a third of the way to the Moon, so that
astronomers can enjoy long, uninterrupted
views of celestial objects. (ESA)
Tracing the rise and fall of X-rays and gamma rays day after day as the pulsar dug through the Be star’s disk, the scientists could conclude that the wind of electrons at an energy level of 10-100 MeV is responsible for the observed X-ray light. (1 MeV represents one million electron volts.)
Although 10-100 MeV is energetic, this is about 1000 times less than the expected energy level of 100 TeV. Even more puzzling is the multi-TeV gamma-ray emission, which, although surely emanating from the 10-100 TeV wind electrons, seems to be produced differently to how it was thought before.
"The only fact that is crystal clear at the moment is that this is the pulsar system to watch if we want to understand pulsar winds," said Chernyakova.
"Never have we seen pulsar wind in such detail. We are continuing with theoretical models now. We have some good explanation of the radio-to-TeV-gamma-ray behaviour of this funny system, but it is still ‘under construction.’"
A team led by Dr Masha Chernyakova of the Integral Science Data Centre, Versoix, Switzerland, discusses these results in an article in the scientific journal Monthly Notices of the Royal Astronomical Society.
The paper is at http://xxx.lanl.gov/abs/astro-ph/0601241
European Space Agency - http://www.esa.int
|Universal Evolution? |
Vermeij thinks that these principles are universal
UC Davis News Release
February 24, 2006 - If the history of life were to play out again from the beginning, it would have a similar plot and outcomes, although with a different cast and timing, argues UC Davis paleontologist Geerat Vermeij in a new paper in the Proceedings of the National Academy of Sciences.
"Evolution at this level, like the rest of history, is predictable, perhaps more predictable than people want to imagine," Vermeij said. "Many traits are so advantageous under so many circumstances that you are likely to see the same things again and again."
Vermeij's view contrasts with that put forward by the late Stephen Jay Gould and others, who argued that the history of life is so dependent on improbable events and includes so many possible paths that the chances of repetition are vanishingly small. Vermeij argues that some innovations, such as photosynthesis, plant seeds, mineralized bones and even human language are just such good ideas that they would reappear, although at different times and in somewhat different forms.
Barnacles, for example, "desperately want to be mollusks," Vermeij said, although they are actually crustaceans related to crabs and lobsters. As adults, they have evolved a lifestyle similar to that of clams, mussels and another entire group of animals, the brachiopods.
Vermeij reviewed 23 evolutionary innovations thought to be unique, including the genetic code, sex, human language and feathers, and another 55 that turn up repeatedly. Most of the unique innovations -- with the exception of human language -- are ancient, more than half a billion years old. Many of the repeated innovations are known only from a few specimens that were part of much larger groups. Vermeij said that many of life's "unique" developments might just appear to be so because other species died out and were not preserved as fossils.
A "unique" innovation might also be the result of intense natural selection. For example, once the genetic code appeared, primitive organisms readily swapped genes, as bacteria still do today. Any variants or competitors to the genetic code that arose later would have been unable to spread and establish.
Vermeij thinks that these principles are universal.
"If we had an Earth-like planet, I think we'd see phenotypes and outcomes that parallel those on Earth," he said.
UC Davis News Service - http://www.news.ucdavis.edu