New findings on the formation of body pigment

Photo credit: Freda Miller, Skin derived precursor cells.

The skin’s pigment cells can be formed from completely different cells than has hitherto been thought, a new study from the Swedish medical university Karolinska Institutet shows. The results, which are published in the journal Cell, also mean the discovery of a new kind of stem cell.

The body’s pigment gives essential protection against UV radiation. It is made up of a substance called melanin, which is produced by pigment cells in the skin called melanocytes. According to the established theory of body pigmentation, these melanocytes bud off from the spinal cord at an early foetal stage and then migrate to the skin where they remain for the rest of their lives.

Scientists at Karolinska Institutet in Stockholm have now shown that most melanocytes actually appear later on in foetal development from an immature cell type that exists in the skin’s nerve fibres. These cells, called Schwann cell precursors (SCPs), can also be found in adults. In addition to this, the scientists have demonstrated how neuronal damage in adults can excite the maturation of melanocytes to form hyperpigmentation around the affected nerves.

“Our findings can provide new knowledge of how changes in skin pigmentation occur, not least of the links that have been observed between neurological disease and changes in pigmentation,” says Professor Patrik Ernfors, who led the study.

Their results also shed new light on SCP cells, which were previously seen as an immature form of supportive cells the nervous system. The researchers describe how a change in cell signalling can make the SCP cells in the skin develop into pigment cells instead, and argue that SCP cells are really a kind of stem cell.

“This can help science to understand the development of diseases such as melanoma,” says Professor Ernfors. “We’ve always believed that it develops from melanocytes, but maybe it actually originates in the SCP cells.”

via New findings on the formation of body pigment.

Fish vision discovery makes waves in natural selection

Emory University researchers have identified the first fish known to have switched from ultraviolet vision to violet vision, or the ability to see blue light. The discovery is also the first example of an animal deleting a molecule to change its visual spectrum.

Their findings on scabbardfish, linking molecular evolution to functional changes and the possible environmental factors driving them, were published Oct. 13 in the Proceedings of the National Academy of Sciences.

“This multi-dimensional approach strengthens the case for the importance of adaptive evolution,” says evolutionary geneticist Shozo Yokoyama, who led the study. “Building on this framework will take studies of natural selection to the next level.”

The research team included Takashi Tada, a post-doctoral fellow in biology, and Ahmet Altun, a post-doctoral fellow in biology and computational chemistry.

Vision ‘like a painting’

For two decades, Yokoyama has done groundbreaking work on the adaptive evolution of vision in vertebrates. Vision serves as a good study model, since it is the simplest of the sensory systems. For example, only four genes are involved in human vision.

“It’s amazing, but you can mix together this small number of genes and detect a whole color spectrum,” Yokoyama says. “It’s just like a painting.”

The common vertebrate ancestor possessed UV vision. However, many species, including humans, have switched from UV to violet vision, or the ability to sense the blue color spectrum.

From the ocean depths

Fish provide clues for how environmental factors can lead to such vision changes, since the available light at various ocean depths is well quantified. All fish previously studied have retained UV vision, but the Emory researchers found that the scabbardfish has not. To tease out the molecular basis for this difference, they used genetic engineering, quantum chemistry and theoretical computation to compare vision proteins and pigments from scabbardfish and another species, lampfish. The results indicated that scabbardfish shifted from UV to violet vision by deleting the molecule at site 86 in the chain of amino acids in the opsin protein.

“Normally, amino acid changes cause small structure changes, but in this case, a critical amino acid was deleted,” Yokoyama says.

More examples likely

“The finding implies that we can find more examples of a similar switch to violet vision in different fish lineages,” he adds. “Comparing violet and UV pigments in fish living in different habitats will open an unprecedented opportunity to clarify the molecular basis of phenotypic adaptations, along with the genetics of UV and violet vision.”

Scabbardfish spend much of their life at depths of 25 to 100 meters, where UV light is less intense than violet light, which could explain why they made the vision shift, Yokoyama theorizes. Lampfish also spend much of their time in deep water. But they may have retained UV vision because they feed near the surface at twilight on tiny, translucent crustaceans that are easier to see in UV light. …

via Fish vision discovery makes waves in natural selection.

Minn. man suspected of encouraging suicides

A nurse who authorities say got his kicks by visiting Internet suicide chat rooms and encouraging depressed people to kill themselves is under investigation in at least two deaths and could face criminal charges that could test the limits of the First Amendment.

Investigators said William Melchert-Dinkel, 47, feigned compassion for those he chatted with, while offering step-by-step instructions on how to take their lives.

“Most importatn is the placement of the noose on the neck … Knot behind the left ear and rope across the carotid is very important for instant unconciousness and death,” he allegedly wrote in one Web chat.

He is under investigation in the suicides of Mark Drybrough, 32, who hanged himself at his home in Coventry, England, in 2005, and Nadia Kajouji, an 18-year-old from Brampton, Ontario, who drowned in a river in Ottawa, where she was studying at Carleton University.

While the victims’ families are frustrated that no charges have been filed, legal experts said prosecuting such a case would be difficult because Melchert-Dinkel didn’t physically help kill them. In the meantime, he has been stripped of his nursing license.

“Nothing is going to come of it,” Melchert-Dinkel said of the allegations during a brief interview with The Associated Press. “I’ve moved on with my life, and that’s it.”

The case came to the attention of Minnesota authorities in March 2008 when an anti-suicide activist in Britain alerted them that someone in the state was using the Internet to manipulate people into killing themselves.

Last May, a Minnesota task force on Internet crimes searched Melchert-Dinkel’s computer and found a Web chat between him and the young Canadian woman describing the best way to tie knots. In their search warrant, investigators said Melchert-Dinkel “admitted he has asked persons to watch their suicide via webcam but has not done so.”

Authorities said he used such online aliases as “Li Dao,” “Cami” and “Falcon Girl.”

The Minnesota Board of Nursing, which revoked his license in June, said he encouraged numerous people to commit suicide and told at least one person that his job as a nurse made him an expert on the most effective way to do it. …

via Minn. man suspected of encouraging suicides – Yahoo! News.

Perhaps he is trying to help with the world population problem, but I think family planning is the way to go. We must change with the times. Let’s have a worldwide “fewer babies” drive.  We should avoid bringing new human life to the planet for the next 25 years.  Get our numbers down. Give tax breaks to people with no kids, etc.  Those who spawn uncontrollably will need to have their children run on treadmills to provide power for their homes.

EU officials warn of disappearing cod

Cod is slipping closer to disappearing from key European fishing grounds, officials warned Friday, saying that only steep catch cuts will prevent the disappearance of a species prized for centuries for its flaky white flesh.

The European Union’s executive body called for sharp cuts in the amount of cod fisherman can catch next year — up to 25 percent in some areas. The European Commission said recent studies showed cod catches in some areas are far outstripping the rate of reproduction.

Scientists estimated that in the 1970s there were more than 250,000 tons of cod in fishing grounds in the North Sea, eastern English Channel and Scandinavia’s Skagerrak strait. In recent years, however, stocks have dropped to 50,000 tons.

“We are not that far away from a situation of complete collapse,” said Jose Rodriguez, a marine biologist with the environmental group Oceana. He and other environmentalists said pressure from the fishing industry had kept quotas at levels too high to sustain a viable populations around Europe, while lack of enforcement meant illegal fishing made the problem worse.

The European Commission said Friday it would seek in 2010 to cut the catch in some fishing grounds around Britain, France, Spain and much of Scandinavia from 5,700 tons to 4,250 tons.

In the Mediterranean, bluefin tuna has been overfished for years to satisfy increasing world demand for sushi and sashimi. The tuna population is now a fraction of what it was a few decades ago, but the EU’s Mediterranean nations last month refused to impose even a temporary ban.

Oceana estimated that illegal fishing doubled the amount of tuna caught.

Meanwhile Cod, which once sustained vibrant fishing communities from Portugal to Britain to Canada, is increasingly consumed by the ton as salt cod and fish-and-chips.

“People don’t ask for fish and chips, they ask for cod and chips,” said Mike Guo, a manager at Great Fish and Chips in Essex, England. “It’s a traditional dish.”

via EU officials warn of disappearing cod – Yahoo! News.

There are simply too many humans. Birth control is the answer.  Use a condom, save a fish.

Huge asteroid crashing off Indian coast may have wiped out dinos

A massive asteroid crashing off the western coast of India, creating the planet’s largest known crater 40 km across, may have obliterated dinosaurs 65 million years ago, an Indian American has found.

Most of the crater lies submerged on India’s continental shelf, in the area known as Bombay High. The impact appears to have sheared or destroyed much of the 48 km-thick granite layer in the western coast of India.

Sankar Chatterjee of Texas Tech University and his team took a close look at the massive Shiva basin, a submerged depression west of India that is intensely mined for its oil and natural gas. Some complex craters are among the most productive hydrocarbon sites on the planet.

“If we are right, this is the largest crater known on our planet,” Chatterjee said. “A bolide of this size, perhaps 40 km in diameter, creates its own tectonics.”

In contrast, the object that struck Mexico’s Yucatan Peninsula, and is commonly thought to have killed the dinosaurs, was between eight and 10 km wide.

It’s hard to imagine such a cataclysm. But if the team is right, the Shiva impact vaporised earth’s crust at the point of collision, leaving nothing but ultra-hot mantle material to well up in its place.

The cataclysmic impact from outer space possibly triggered the nearby Deccan Traps volcanic eruptions that once covered much of western India. What’s more, the impact broke the Seychelles islands off of the Indian tectonic plate, and sent them drifting toward Africa.

The geological evidence is dramatic. Shiva’s outer rim forms a rough, faulted ring some 500 km in diameter, encircling the central peak, known as the Bombay High, which would be nearly five km higher than the ocean floor, said a Texas Tech release.

“Rocks from the bottom of the crater will tell us the telltale sign of the impact event from shattered and melted target rocks. And we want to see if there are breccias, shocked quartz, and an iridium anomaly,” Chatterjee said. Asteroids are rich in iridium, and such anomalies are thought of as the fingerprint of an impact.

via Huge asteroid crashing off Indian coast may have wiped out dinos.

When the next big one hits the renaming humans world-wide will refer to the year as AI. “65 AI” is 65 years After Impact.

2012 doomsday prediction nothing but a hoax

A NASA scientist has said that the prophecy by the ancient Mayans that the world might end in the year 2012, is nothing but a hoax, which is only helping the promoters of the conspiracy theory to rake in huge profits.

NASA scientist David Morrison’s concise summary of the claims and the scientific response to the widespread Internet belief that December 21, 2012, will be doomsday for planet Earth, determines that the whole thing is nothing but a hoax.

For several months, NASA and many astronomers have received increasingly worried letters and e-mails from members of the public about the possibility, widely touted on the Internet that the world will end in 2012.

Many mechanisms for doomsday are being proposed, including a collision with a fictional planet called Nibiru, deadly activity on the surface of the Sun that lashes out at Earth, alignments with the center of our galaxy, and many more.

David Morrison has coined the term “cosmophobia” – fear of the cosmos – for these concerns, and has seen a huge increase in the phenomenon this year.

Dr. Morrison, a world-renowned expert on the solar system (and asteroid impacts), also serves as the public scientist for NASA’s “Ask an Astrobiologist” service, where he answers questions for the public.

He has received so many questions about 2012 and the end of the world, that he felt he had to investigate and set the record straight.

One of his most interesting findings is that the distributors of the science fiction motion picture “2012”, to be released this November, are purposely feeding the flames of the Internet panic, in what is called a viral marketing campaign.

They have created fake science websites and encouraging people to search for “2012” on the Web, all for the sake of some publicity for the movie, the findings indicate.

Also, most of the sites based on the 2012 theory are full of nonsense and misunderstanding, often by people who have written books on coming disaster that they are trying to sell, the findings reveal.

via 2012 doomsday prediction nothing but a hoax.

Researchers find way round Mars communication problem

Engineers have found a way to communicate continuously with Mars in a research project to help manned space missions.

Continuous communication with Mars had not previously been possible for several weeks at a time as the sun obscures the Earth’s view of the planet, but researchers at the University of Strathclyde have found a way to allow continuous communication with just one spacecraft.

The breakthrough centres on Lagrange points, five areas in space where an object such as a satellite or observatory can stay fixed in the same location relative to the Earth and the sun.

Dr Malcolm Macdonald, a member of the research team, said: “One of the key barriers to manned exploration of Mars is communication. When the sun obscures the Earth’s view of Mars, it also prevents any possibility of ground controllers making contact with astronauts.

“But by moving a spacecraft with a continuous thrusting propulsion system into Lagrange point one, we’ve calculated that it’s possible to enable continuous communication from the Earth to the spacecraft, and from the spacecraft to the surface of Mars.

“We’ve also shown that, by using a similar technique, but with two spacecraft, we can further improve communications.

“Hovering directly above Mars limits communications to just one polar region. But by using two spacecraft, we can enable communication to a much wider area of the planet.”

The finding is being released this week at the 60th International Astronautical Congress, the world’s biggest space conference, being held in Daejeon, South Korea.

The research was funded by the European Space Agency, in a bid to establish how technology can be used to radically enhance space science, from improving telecommunications to monitoring the Arctic

via Researchers find way round Mars communication problem | Glasgow and West | STV News.

House roof debris ‘fell from space’

A lump of metal which smashed through the roof of a house is believed to have come from space, the RAF has said.

The 4lb object was investigated by the RAF Flight Safety Branch after it landed in the loft of Peter and Mair Welton’s home in Forester Way, Hull, in July this year.

The branch has now identified it as space debris and said this was the only incident of its kind investigated by the RAF in the last five years.

The metal was reported to the RAF as it was initially thought it may have fallen off an aircraft.

But the investigation found the debris had not come from a plane and was more likely to have fallen to earth from space – although it is unknown what the metal was from.

An RAF spokeswoman said: “In the last five years the RAF has become involved in only one incident involving suspected space debris.

“If requested the RAF will investigate incidents of space debris but they do not have a standing remit to do so.”

via House roof debris ‘fell from space’ – News – Virgin Media.

About this image:

People gather around a spherical object, which may be a hydrogen containment tank, on a chicken farm in Nacogdoches, Texas, USA in 2003. The object fell from the disintegrating Space Shuttle Columbia

Natural nukes may have crippled early life

Ancient nuclear reactors buried in lake and shallow ocean sediments may have cooked early microbes, according to a new study. And radiation from the deposits could have delayed the onset of our modern-day, oxygen-rich atmosphere, and even had a hand in shaping the genetics of primordial life.

Natural nuclear reactors dating to 2 billion years ago have been found in Gabon, Africa. Though long since exhausted, scientists know from the unusually low quantity of the Uranium-235 isotope in the rock that they once went critical, and hosted a sustained fission reaction that went on for as long as two hundred thousand years.

A billion years earlier, such deposits could have been common, say Laurence Coogan and Jay Cullen of the University of Victoria. The first oxygen-producing bacteria colonized lakes and shallow seas, and likely created oxygen ‘oases’ in an otherwise nitrogen-dominated world.

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“Oxygen oases would have been hot spots for uranium concentration,” Cullen said, because oxygen dissolved in water would draw uranium out of rocks and sediments. “Back then, there was so much more 235U that a softball-sized chunk of uranium would be enough for it to go critical.”

If the researchers are right, wherever there were oxygen-producing bacteria, there were also natural nuclear reactors. Radiation could have damaged the bugs’ DNA, either directly from the reactors or as leftover atoms of radioactive strontium (Sr) and iodine (I) made their way into the food chain.

In short, organisms that produced oxygen 3 billion years ago were shooting themselves in the foot by spawning toxic nuclear reactors. That may explain why it wasn’t until around 2.3 billion years ago that oxygen finally started building up in the atmosphere. By then, Cullen said, most of the readily available nuclear fuel was used up.

However, it’s also possible the reactors had a positive effect on early life.

via Natural nukes may have crippled early life – Discovery.com- msnbc.com.

Video Camera That Records At The Speed Of Thought

European researchers who created an ultra-fast, extremely high-resolution video camera have enabled dozens of medical applications, including one scenario that can record ‘thought’ processes travelling along neurons.

The Megaframe project scored a staggering number of breakthroughs to create the world’s first 1024 pixel, photon-resolution, million-frame-per-second CMOS camera.

Their work has pushed the boundaries of CMOS (a type of semiconductor) miniaturisation and sophistication. But it is in the application of their technology that the most stunning impacts of the Megaframe project will be seen, particularly in medical applications.

That is because the camera can detect a single photon at a million times a second, and so it can record molecular processes in unprecedented detail. “We need this sort of detail because biomedical scientists are studying processes at the intra-cellular and molecular levels,” underlines Edoardo Charbon, coordinator of the EU-funded Megaframe project.

Scientists have developed extremely ingenious ways to infer or deduce what is happening at the molecular level, and Megaframe could make that process even more detailed. Essentially, scientists use a variety of emissive materials to see what is happening in microscopic biomedical processes.

Take Fluorescence Lifetime Imaging Microscopy (FLIM). Here, a fluorescent material is introduced to the area of interest. Fluorescence has some interesting properties, for example a particular spectrum of emission and a rate of decay.

One particular fluorophore, Oregon Green Bapta (OGB-1), decays at a rate proportionate to the presence of calcium. Interestingly, calcium is an important indicator of neuron activity.

“So it is possible, for example, to go inside neurons and look at their ion channels. These are the channels that allow neurons to communicate with other neurons. And you can basically see the amount of calcium that is present. You can probe optically how neurons communicate with other neurons just by looking at the concentrations of calcium in real time,” explains Charbon.

So scientists can use the OGB-1 to indicate the presence and concentration of calcium, and the whole process can be recorded in ultra-fine detail thanks to single-photon detectors, such as the ones present in the Megaframe camera. The camera is recording at the speed of thought.

“Biomedical scientists could in principle use this microscopic information about calcium to learn about macroscopic conditions like Parkinson’s, or Alzheimer’s or epilepsy,” Charbon stresses.

Megaframe could have a significant impact on any medical science that uses visible light emissive scanning technologies like FLIM. But it can even have an impact where visible light is not present….

via Video Camera That Records At The Speed Of Thought.