Arkenor on December 16th, 2007

The reconstructed kiln

A Cardiff University archaeology team has recreated a 3,000-year-old glass furnace, showing that Ancient Egyptian glassmaking methods were much more sophisticated than thought previously.

Dr Paul Nicholson, of the University’s School of History and Archaeology, is leader of an Egypt Exploration Society team working on the earliest fully excavated glassmaking site in the world. The site, at Amarna, on the banks of the Nile, dates back to the reign of Akhanaten (1352 – 1336 B.C.), just a few years before the rule of Tutankhamun.

It was previously thought that the Ancient Egyptians may have imported their glass from the Near East at around this time. However, the excavation team believes the evidence from Amarna shows they were making it themselves, possibly in a single stage operation. Dr Nicholson and his colleague Dr Caroline Jackson of Sheffield University demonstrated this was possible, using local sand to produce a glass ingot from their own experimental reconstruction of a furnace near the site.

The team have also discovered that the glassworks was part of an industrial complex which involved a number of other high temperature manufacturing processes. The site also contained a potter’s workshop and facilities for making blue pigment and faience – a material used in amulets and architectural inlays. The site was near one of the main temples at Amarna and may have been used to produce materials in state buildings.

Dr Nicholson, who has been working at Amarna since 1983, said: “It has been argued that the Egyptians imported their glass and worked it into the artefacts that have been discovered from this time. I believe there is now enough evidence to show that skilled craftsmen could make their own glass and were probably involved in a range of other manufacturing industries as well.”

Brilliant Things for Akhenaten by Dr Paul Nicholson.

Once again, it turns out that the ancient civilisations were a fair bit more technologically advanced than we had previously given them credit for.

Tags: , , , , ,

Arkenor on December 12th, 2007

Record-breaking amounts of ice-free water have deprived the Arctic of more of its natural “sunscreen” than ever in recent summers. The effect is so pronounced that sea surface temperatures rose to 5 C above average in one place this year, a high never before observed, says the oceanographer who has compiled the first-ever look at average sea surface temperatures for the region.

Such superwarming of surface waters can affect how thick ice grows back in the winter, as well as its ability to withstand melting the next summer, according to Michael Steele, an oceanographer with the University of Washington’s Applied Physics Laboratory. Indeed, since September, the end of summer in the Arctic, winter freeze-up in some areas is two months later than usual.

The extra ocean warming also might be contributing to some changes on land, such as previously unseen plant growth in the coastal Arctic tundra, if heat coming off the ocean during freeze-up is making its way over land, says Steele, who is speaking Wednesday at the American Geophysical Union meeting in San Francisco.

He is lead author of “Arctic Ocean surface warming trends over the past 100 years,” accepted for publication in AGU’s Geophysical Research Letters. Co-authors are physicist Wendy Ermold and research scientist Jinlun Zhang, both of the UW Applied Physics Laboratory. The work is funded by the National Science Foundation.

“Warming is particularly pronounced since 1995, and especially since 2000,” the authors write. The spot where waters were 5 C above average was in the region just north of the Chakchi Sea. The historical average temperature there is -1 C – remember that the salt in ocean water keeps it liquid at temperatures that would cause fresh water to freeze. This year water in that area warmed to 4 C, for a 5-degree change from the average.

That general area, the part of the ocean north of Alaska and Eastern Siberia that includes the Bering Strait and Chukchi Sea, experienced the greatest summer warming. Temperatures for that region were generally 3.5 C warmer than historical averages and 1.5 C warmer than the historical maximum.

Such widespread warming in those areas and elsewhere in the Arctic is probably the result of having increasing amounts of open water in the summer that readily absorb the sun’s rays, Steele says. Hard, white ice, on the other hand, can work as a kind of sunscreen for the waters below, reflecting rather than absorbing sunlight. The warming also may be partly caused by increasing amounts of warmer water coming from the Pacific Ocean, something scientists have noted in recent years.

The Arctic was primed for more open water since the early 1990s as the sea-ice cover has thinned, due to a warming atmosphere and more frequent strong winds sweeping ice out of the Arctic Ocean via Fram Strait into the Atlantic Ocean where the ice melts. The wind effect was particularly strong in the summer of 2007.

Now the situation could be self-perpetuating, Steele says. For example, he calculates that having more heat in surface waters in recent years means 23 to 30 inches less ice will grow in the winter than formed in 1965. Since sea ice typically grows about 80 inches in a winter, that is a significant fraction of ice that’s going missing, he says.

Then too, higher sea surface temperatures can delay the start of freeze-up because the extra heat must be discharged from the upper ocean before ice can form. “The effect on net winter growth would probably be negligible for a delay of several weeks, but could be substantial for delays of several months,” the authors write.

As the report states, there is a serious risk of this being a vicious circle. Increased sea temperature causes less ice to be formed during winter than otherwise, causing an even great rise in sea temperature in the following summer. Makes you wonder how many more years til it’s effectively gone. At least the Northwest Passage will be clear, I guess.

Tags: ,

Arkenor on December 10th, 2007

While the biological basis for homosexuality remains a mystery, a team of neurobiologists reports they may have closed in on an answer — by a nose.

The team led by University of Illinois at Chicago researcher David Featherstone has discovered that sexual orientation in fruit flies is controlled by a previously unknown regulator of synapse strength. Armed with this knowledge, the researchers found they were able to use either genetic manipulation or drugs to turn the flies’ homosexual behaviour on and off within hours.

Featherstone, associate professor of biological sciences at UIC, and his co-workers discovered a gene in fruit flies they called “genderblind,” or GB. A mutation in GB turns flies bisexual.

Featherstone found the gene interesting initially because it has the unusual ability to transport the neurotransmitter glutamate out of glial cells — cells that support and nourish nerve cells but do not fire like neurons do. Previous work from his laboratory showed that changing the amount of glutamate outside cells can change the strength of nerve cell junctions, or synapses, which play a key role in human and animal behaviour.

But the GB gene became even more interesting when post-doctoral researcher Yael Grosjean noticed that all the GB mutant male flies were courting other males.

“It was very dramatic,” said Featherstone. “The GB mutant males treated other males exactly the same way normal male flies would treat a female. They even attempted copulation.”

Other genes that alter sexual orientation have been described, but most just control whether the brain develops as genetically male or female. It’s still unknown why a male brain chooses to do male things and a female brain does female things. The discovery of GB provided an opportunity to understand why males choose to mate with females.

“Based on our previous work, we reasoned that GB mutants might show homosexual behaviour because their glutamatergic synapses were altered in some way,” said Featherstone. Specifically, the GB mutant synapses might be stronger.

“Homosexual courtship might be sort of an ‘overreaction’ to sexual stimuli,” he explained.

To test this, he and his colleagues genetically altered synapse strength independent of GB, and also fed the flies drugs that can alter synapse strength. As predicted, they were able to turn fly homosexuality on and off — and within hours.

“It was amazing. I never thought we’d be able to do that sort of thing, because sexual orientation is supposed to be hard-wired,” he said. “This fundamentally changes how we think about this behavior.”

Featherstone and his colleagues reasoned that adult fly brains have dual-track sensory circuits, one that triggers heterosexual behavior, the other homosexual. When GB suppresses glutamatergic synapses, the homosexual circuit is blocked.

Further work showed precisely how this happens — without GB to suppress synapse strength, the flies no longer interpreted smells the same way.

“Pheromones are powerful sexual stimuli,” Featherstone said. “As it turns out, the GB mutant flies were perceiving pheromones differently. Specifically, the GB mutant males were no longer recognizing male pheromones as a repulsive stimulus.”

Featherstone says it may someday be possible to domesticate insects such as fruit flies and manipulate their sense of smell to turn them into useful pollinators rather than costly pests.-Press release from Nature Neuroscience

Fascinating research that has turned up an accidental discovery that could revolutionise pest control. Spraying sexuality-switching chemicals sounds to me an incredibly bad idea, even if it only affects insects, but I have no doubt that someone will try it. I’m more interested, however, in the aspect of this that proves that, in insects at least, homosexuality can be induced and repressed. With this being proved in insects, it is probably only a matter of time before similar discoveries are made for humans, though it is likely to be a far more complex combination of genes, and that will open up a whole can of ethical worms.

There are some people who view homosexuality to be a mental disorder rather than an aspect of diversity, and seek to provide a cure. Currently there are any number of therapies on offer, some more bizarre than others. They are especially popular amongst conservative christians and similar groups. Conversion therapy, as it is called, (or sometimes reparitive therapy), is not particularly effective, with frequent psychological side-effects, and only rarely results in a permanent conversion with no relapses. In spite of their ineffectiveness, and sometimes methods that in other circumstances might be described as torture, they are overwhelmingly endorsed by the evangelical movement. Should a reliable drug be found that changes sexual inclinations, it will find eager cheerleaders, and more importantly perhaps, extremely deep pockets where funding is concerned. It is likely that such research is already underway.

There are some homosexuals who, for religious and other reasons, really do desire to be “cured”. In such cases I suppose it would be right to provide such medication, just as sex-change operations are made available. But such a medication is also another tool in the arsenal of intolerance. No longer would people be able to claim that homosexuality is not a choice. One can imagine a state such as Iran, which already claims to contain no homosexuals, making such a drug mandatory for those with tendencies deemed deviant by the state. Of course, that could never possibly happen in our enlightened western world. (Insert laughter track here.)

Where homosexuality is now grudgingly tolerated, it is easy to imagine more and more pressure, from family, church, or employers, being heaped upon individuals to get themselves “fixed”. Consider that the US army, never shy about trying out interesting new drugs upon its troops, is utterly opposed to having homosexuals within its ranks. Currently they are fired upon discovery, but a conversion drug would allow someone to keep his or her job. It’s not hard to imagine that someone might make that choice in order to keep alive their career and their tight-knit support network. Someone in that position is incredibly vulnerable to coercion from their superior officers.

I wanted to keep this blog politics free, and just about science, but sometimes science and politics get intertwined. I apologise for the intrusion, but the ethics of science are always worthy of thought. We should always consider the darker possibilities of a discovery, as well as the hopeful ones.

What do you think? Should such a drug for humans even be researched in the first place, or is it too dangerous to our liberties? Myself, I find it a pretty scary thought.

Tags: , , , ,

Arkenor on December 8th, 2007

Emerald Spring in Yellowstone National Park

A new species of bacteria discovered living in one of the most extreme environments on Earth could yield a tool in the fight against global warming.

In a paper published today in the prestigious science journal Nature, U of C biology professor Peter Dunfield and colleagues describe the methane-eating microorganism they found in the geothermal field known as Hell’s Gate, near the city of Rotorua in New Zealand. It is the hardiest “methanotrophic” bacterium yet discovered, which makes it a likely candidate for use in reducing methane gas emissions from landfills, mines, industrial wastes, geothermal power plants and other sources.

“This is a really tough methane-consuming organism that lives in a much more acidic environment than any we’ve seen before,” said Dunfield, who is the lead author of the paper. “It belongs to a rather mysterious family of bacteria (called Verrucomicrobia) that are found everywhere but are very difficult to grow in the laboratory.”

Methanotrophic bacteria consume methane as their only source of energy and convert it to carbon dioxide during their digestive process. Methane (commonly known as natural gas) is 20 times more potent a greenhouse gas than carbon dioxide and is largely produced by decaying organic matter. Scientists have long known that vast amounts of methane are produced in acidic environments, not only geothermal sites but also marshes and peat bogs. Much of it is consumed by methanotrophic bacteria, which serve an important role in regulating the methane content of the world’s atmosphere.

“Scientists are interested in understanding what conditions cause these bacteria to be more or less active in the environment” says Dunfield, “Unfortunately, few species have been closely studied. We now know that there are many more out there.”

Dunfield has tentatively named the new bacterium Methylokorus infernorum to reflect the ‘hellish’ location of its discovery where it lives in boiling waters filled with chemicals that are toxic to most life forms. The Maori caretakers of the site, the Tikitere trust, have supported scientific study of the area. The study was conducted while Dunfield was working for GNS Science, a geological research institute owned by the New Zealand government. He recently joined the U of C’s Department of Biological Sciences as a professor of environmental microbiology.

The bacterium’s genome has been completely sequenced by researchers at the University of Hawaii and Nankai University in China, which could help develop biotechnological applications for this organism.

Dunfield said he plans to pursue his work in Canada by hunting for new life forms in extreme environments such as northern peatlands, the oilsands of northern Alberta and the hot springs of Western Canada.

“Hot springs are exotic and extreme habitats, where you find a lot of bizarre organisms,” he said. “Bacteria are a fascinating group to work with because 95 per cent of them have never been studied in a lab and we have very little idea about what this huge amount of biodiversity is capable of.”

Could be a relatively cheap method to remove methane emisions from everything from cattle-houses to landfill sites. Currently, some folks use the methane as fuel, which isn’t a bad tactic, as carbon dioxide is far less powerful a greenhouse gas, and it saves burning fossil fuels. Given that these bacteria also turn the methane into carbon dioxide, but without providing energy for human consumption I’m not entirely sure that theres much practical benefit to using bacteria over burning, though it might be useful in situations where the amount of methane is too small to make a miniature powerplant impractical. Perhaps the bacteria can be turned into animal feed or somesuch. Still, it’s an avenue of research well worth investigating.

Tags: , , ,

Arkenor on November 27th, 2007

Interesting, if a bit grim!

From the Telegraph

It must be one of the most stomach-churning medical treatments ever devised.

A grandmother who contracted a potentially fatal superbug in Scotland has been saved after a hospital fed her daughter’s faeces to her.

Ethel McEwan, an 83-year-old from Guardbridge, Fife, was near death after contracting Clostridium Difficile, the Daily Record reported.

But she was saved after receiving a “faecal transplant” from her daughter, Winnifred.

The treatment involves liquidising a sample of faeces from a close relative of the patient, and feeding the liquid down a tube into the stomach.

The treatment restores the bacteria to levels at which they help the recovery process.

“When you tell people about the treatment, they wrinkle their noses,” Mrs McEwan told the Daily Record.

“But it’s not like they put it on a plate and have you eat it. You don’t ever see or smell a thing.

“People will have a blood transplant or a kidney transplant – what’s the difference with this?”

I’m not sure whether the medicine wasn’t almost as bad as the affliction, but it seems to have worked! There are a lot of helpful bacteria in the human gut, performing a variety of useful tasks, including assisting with digestion. Some convert calcium into a form more easily absorbed by our bodies, while others help to break down fats, proteins, or carbohydrates. Some others are simply non-harmful, but help by outcompeting more dangerous bacteria.

I’m a bit surprised that there wasn’t a better way to boost the woman’s probiotic levels than the course they took though.

Tags: , ,

Arkenor on November 27th, 2007

The BBC reports: An emergency shelter which can be set up in 40 minutes as a solid concrete structure will be made in south Wales after winning worldwide interest.
Its creators were on BBC TV’s Dragon’s Den, but they refused investment from the show’s entrepreneurs because they wanted too much of their company.

Will Crawford and Peter Brewin’s design will go into production at their new plant near Pontypridd next summer.

It is made by adding water, pumping it into shape and waiting for it to dry. Their “concrete canvas” shelters have already drawn interest from aid agencies and the military.

After 12 hours, the shelter becomes completely solid, and can even withstand being shot at with handguns.

How incredibly useful! has more. I’m not sure why they chose to film their demonstration video at night though. Has a rather sinister feel to it.

Concrete Cloth (CC) is a unique proprietary material that has been developed by Concrete Canvas. It has a very wide range of applications throughout the building and civil engineering industry.

By adding water, CC hardens to become a strong, durable, waterproof and fireproof concrete surface.

CC consists of a 3-dimensional fibre matrix containing a specially formulated dry concrete mix. A PVC backing on one surface of the cloth ensures the material is completely waterproof; while hydrophilic fibres on the opposite surface aid hydration by drawing the water into the cement.

The material can be hydrated either by spraying or by being fully immersed in water. Once hydrated the material remains flexible and workable for 4 hours. It can be easily nailed, stapled through, or coated with an adhesive for easy attachment to other surfaces. It has good drape characteristics allowing complex surfaces with a double curvatures to be produced.

This could be a great step forward for disaster relief. Oftentimes, more people die from following winter, than do from the earthquake that preceeded it. Ordinary tents do little against an Afghan winter, but these tents sounds like they should be relatively cheap, and long-lasting, and a lot easier to keep warm.

I hope full scale production is not far off. For a simple sounding idea, these could do a lot of good.

Tags: ,

Arkenor on November 26th, 2007

The Pleaides

Rocky terrestrial planets, perhaps like Earth, Mars or Venus, appear to be forming or to have recently formed around a star in the Pleiades (“seven sisters”) star cluster, the result of “monster collisions” of planets or planetary embryos.

Astronomers using the Gemini Observatory in Hawaii and the Spitzer Space Telescope report their findings in an upcoming issue of the Astrophysical Journal, the premier journal in astronomy.

“This is the first clear evidence for planet formation in the Pleiades, and the results we are presenting may well be the first observational evidence that terrestrial planets like those in our solar system are quite common,” said Joseph Rhee, a UCLA postdoctoral scholar in astronomy and lead author of the research.

The Pleiades star cluster, in the constellation Taurus, is well-known in many cultures. It is named for the seven daughters of Atlas and Pleione, who were placed by Zeus among the stars in Greek mythology and is cited in the Bible — “Can you bind the beautiful Pleiades” Can you loose the cords of Orion”" (Job 38:31). The automaker Subaru’s name is the Japanese word for the Pleiades, Rhee said.

The Pleiades is probably the best known star cluster and the most striking to the naked eye. “You’ve seen it many times, and it’s now easily visible in the evening sky,” said research co-author Benjamin Zuckerman, UCLA professor of physics and astronomy.

Although referred to as the “seven sisters,” “the cluster actually contains some 1,400 stars,” said co-author Inseok Song, a staff scientist at NASA’s Spitzer Science Center at the California Institute of Technology and a former astronomer with the Gemini Observatory.

Located about 400 light-years away, the Pleiades is one of the closest star clusters to Earth. One of the cluster’s stars, known as HD 23514, which has a mass and luminosity a bit greater than those of the sun, is surrounded by an extraordinary number of hot dust particles — “hundreds of thousands of times as much dust as around our sun,” Zuckerman said. “The dust must be the debris from a monster collision, a cosmic catastrophe.”

The astronomers analyzed emissions from countless microscopic dust particles and concluded that the most likely explanation is that the particles are debris from the violent collision of planets or planetary embryos.Song calls the dust particles the “building blocks of planets,” which can accumulate into comets and small asteroid-size bodies and then clump together to form planetary embryos, eventually becoming full-fledged planets.“In the process of creating rocky, terrestrial planets, some objects collide and grow into planets, while others shatter into dust,” Song said. “We are seeing that dust.”

HD 23514 is the second star around which Song and Zuckerman recently have found evidence of terrestrial planet formation. They and their colleagues reported in the journal Nature in July 2005 that a sun-like star known as BD +20 307, located 300 light-years from Earth in the constellation Aries, is surrounded by one million times more dust than is orbiting our sun.

In an effort to uncover comparably dusty stars after their 2005 research, Rhee, Song and Zuckerman began looking through thousands of publicly accessible, deep-infrared images obtained by the Spitzer Space Telescope and soon discovered HD 23514. The astronomers then used the Gemini North telescope, located on Hawaii’s dormant volcano Mauna Kea, to measure the heat radiation coming from the dust; the heat emerges at infrared wavelengths, just as the heat from our bodies does, Song said.

“The Gemini and Spitzer data were crucial in identifying and establishing the amount and location of dust around the star,” Song said.

While our sun is 4.5 billion years old, the Pleiades Aries stars are “adolescents,” about 100 million and 400 million years old, respectively, Rhee said. Based on the age of the two stars and the dynamics of the orbiting dust particles, the astronomers deduce that most adolescent sun-like stars are likely to be building terrestrial-like planets through recurring violent collisions of massive objects. The cosmic debris from only a small percentage of such collisions can be seen at any one time — currently, only HD 23514 and BD +20 307 have visible debris.

“Our observations indicate that terrestrial planets similar to those in our solar system are probably quite common,” Zuckerman said.

The astronomers calculate that terrestrial planets or planetary embryos in the Pleiades collided within the last few hundred thousand years — or perhaps much more recently — but they cannot rule out the possibility that multiple, somewhat smaller collisions occurred.

Many astronomers believe our moon was formed through the collision of two planetary embryos — the young Earth and a body about the size of Mars. That crash created tremendous debris, some of which condensed to form the moon and some of which went into orbit around the young sun, Zuckerman said.

By contrast, the collision of an asteroid with Earth 65 million years ago, the most favored explanation for the final demise of the dinosaurs, was a mere pipsqueak, he said.

“Collisions between comets or asteroids wouldn’t produce anywhere near the amount of dust we are seeing,” Song said.

HD 23514 and BD +20 307 are by far the dustiest not-so-young stars in the sky. “Nothing else is even close,” Song said.

Very young stars — those 10 million years old or younger — may have a similar amount of dust around them as a result of the star-formation process. However, by the time a star is 100 million years old, this “primordial” dust has dissipated because the dust particles get blown away or dragged onto the star, or the particles clump together to form much larger objects.

“Unusually massive amounts of dust, as seen at the Pleiades and Aries stars, cannot be primordial but rather must be the second-generation debris generated by collisions of large objects,” Song said.

The Pleiades have been considered important by many cultures throughout history.

“To the Vikings, the Pleiades was Freyja’s hens,” Rhee said. In Bronze Age Europe, the Celts and others associated the Pleiades with mourning and funerals because the cluster rose in the eastern night sky between the autumnal equinox and the winter solstice, which was a festival devoted to the remembrance of the dead. The ancient Aztecs of Mexico and Central America based their calendar on the Pleiades.

The astronomers’ research results are based on mid- and far- infrared observations made with the Gemini 8-meter Frederick C. Gillett Telescope at Gemini North and the space-based infrared observatories Infrared Astronomical Satellite (IRAS), Infrared Space Observatory (ISO) and NASA’s Spitzer Space Telescope.

The Gemini Observatory is an international collaboration utilizing two identical 8-meter telescopes. The Frederick C. Gillett Gemini Telescope is located at Mauna Kea, Hawaii (Gemini North); the other is at Cerro Pachón in central Chile (Gemini South). Together they provide full coverage of both hemispheres of the sky. Both telescopes incorporate new technologies that allow large, relatively thin mirrors under active control to collect and focus both optical and infrared radiation from space.

That was from a press release from the UCLA.

I’ve always found the Pleiades fascinating. You can just about see them with the naked eye in the Northern hemisphere. I find it helps if you don’t look directly at them, but rather a few degrees to the side. To find them, look for Orion. They’re a bit up and to the right from there, in the Taurus constellation, and should be fairly obvious as a somewhat fuzzy little area.

The Pleiades

Tags: , ,

Arkenor on November 25th, 2007

Do you like interesting things?

I do! My regular blog is kind of cluttered with lots of different subjects, so I thought I’d make a seperate one for my science related ones. Right now, I’m working on making this place look nice, and work properly, but fairly soon, I hope to be able to share with you lots of things I find most interesting indeed! We live in a fascinating world, and not every mystery has yet been solved. Let’s investigate and learn together!

And this link is just to prove to Technorati that I’m the site owner. Technorati Profile

Tags: ,