Archive for the ‘science’ Category

Might work, might not

February 8, 2009

Trial Begins for HIV Gene Therapy | Wired Science from

The naturally resistant people have mutant CCR5 genes that inhibit HIV.

Previously, scientists found that by cutting the CCR5 gene out of white blood cells involved in the immune response known as T-cells, they could protect a tube full of human cells from the virus. The gene editing technique relies on proteins called zinc finger nucleases that can delete any gene from a living cell.

In theory, zinc finger nucleases could give that immunity to anyone.

The procedure is simple: Take some healthy T-cells out of an HIV patient, clip out their CCR5 genes, grow more of these clipped T-cells in a dish, and then put them back in the patient.

“In this first study we will re-infuse approximately 10 billion of these cells back into the participants, and we will see if it is safe and if those cells inhibit HIV replication in vivo,” said Tebas. “We know they do in the test tube.”

We also don’t know how long the T cells will live in the host, but infusing them is probably less ugly than a lot of other therapies for HIV…

Not exactly quantum, but real computation?

February 5, 2009

Smallest Quantum Dots Ever Created

Composed of a single atom of silicon and measuring less than one nanometre in diameter, these are the smallest quantum dots ever created.

Quantum dots have extraordinary electronic properties, like the ability to bottle-up normally slippery and speedy electrons. This allows controlled interactions among electrons to be put to use to do computations. Until now, quantum dots have been useable only at impractically low temperatures, but the new atom-sized quantum dots perform at room temperature.

This is pretty darn cool, and a little funny. First you have an actual atom behaving like a quantum dot, which is in effect a synthesized atom. Then you have all this quantum behavior harnessed in the service of something (positioning single electrons) that can in many ways be understood in purely classical terms.

But what I didn’t know (although it’s not really surprising) is that the configurations required to turn these things into computing devices have all been pretty thoroughly worked out, so in a sense it’s just a matter of fabbing some stuff up and watching it go. You could build a ring oscillator or a bunch of simple logic circuits or even a small CPU tomorrow, assuming you could get the atoms to cooperate.

But the researcher is wrong about one thing: quantum-dot-based chips probably won’t be a thousandth the size of equivalent conventional ones. The basic four-dot block is a few nanometers across, or about 1/10 the minimum feature size of the newest generation of chips. So more like a hundredth. Oh, well…

Tab dump science-ish

January 29, 2009

Boffins monitor strato-weather from half-mile underground • The Register

This isn’t because the cosmic rays are affecting the atmosphere, but rather the other way round. If the stratosphere heats up, its density is reduced and fewer inbound cosmic particles collide with air molecules. In particular, incoming mesons are destroyed when they hit air – but if they don’t, they decay into muons.

Muons can be detected, provided the detector apparatus is well shielded from extraneous interference – in this case, by putting it in a disused iron mine half a mile underground in Minnesota. The NCAS boffins, analysing four years of records, found that an increased rainfall of ex-meson muons could be correlated in retrospect with sudden strato-heatwaves and their associated effects.

“Now we can potentially use records of cosmic-ray data dating back 50 years to give us a pretty accurate idea of what was happening to the temperature in the stratosphere over this time,” says Dr Scott Osprey of NCAS.

Lots of Pure Water Ice at Mars North Pole | Universe Today

The north polar cap is a dome of layered, icy materials, similar to the large ice caps in Greenland and Antarctica, consisting of layered deposits, with mostly ice and a small amount of dust. Combined, the north and south polar ice caps are believed to hold the equivalent of two to three million cubic kilometers (0.47-0.72 million cu. miles) of ice, making it roughly 100 times more than the total volume of North America’s Great Lakes, which is 22,684 cu. kms (5,439 miles).

Cape Wind Project Underway to Bring First U.S. Offshore Wind

The footprint for the proposed project covers 24 square miles, 15.8 miles from the island town of Nantucket. The project envisions 130 horizontal-axis wind turbines, each having a hub height of 440 feet higher than the Statue of Liberty, which stands at 305 feet. The blade diameter is 364 feet. The turbines would be sited between 4-11 miles offshore depending on the shoreline. This is enough to meet the needs of 420,000 homes.

Currently 45% of the Cape region’s electricity comes from the nearby Canal Power Plant in Sandwich, which burns bunker oil and natural gas. The Cape Wind proposal is relatively unique in that it would directly offset petroleum usage unlike most of the country where electrical power generation from oil is rare and coal power is more common.

Vehicles: ‘Mono Tiltrotor’ Combines Helicopter, Airplane and UFO

AeroCopter’s MTR vehicle has a single turbine driving a ducted fan pusher propeller and the electromagnetically driven 8.2m (27ft)-diameter ring that encircles the fuselage. Lift is generated by the rotor blades of the ring, which has counter-rotating upper and lower halves. A driveshaft linking the ring to the turbine uses permanent magnets to turn the ring, which has many more magnets located at short intervals around its circumference. Once at 1,000ft (305m) altitude the ring is tilted through 87° and locked in place.

Don’t read before going to bed

January 7, 2009

Final Report, CCSP Synthesis and Assessment Product 3-4

Chapter 1: Introduction: Abrupt Changes in the Earth’s Climate System [1.7 Mb]

Chapter 2: Rapid Changes in Glaciers and Ice Sheets and Their Impacts on Sea Level [1.7 Mb]

Chapter 3: Hydrological Variability and Change [2.2 Mb]

Chapter 4: The Potential for Abrupt Change in the Atlantic Meridional Overturning Circulation [2.8 Mb]

Chapter 5: Potential for Abrupt Changes in Atmospheric Methane [1.3 Mb]

These are all things that people in the know have been talking about for 20 years or more, but it’s just a tad frightening to think we haven’t just been blowing smoke.

Meteor too close for comfort?

January 7, 2009

Gems Point to Comet as Answer to Ancient Riddle –

Those three things are the extinction of the megafauna, the disappearance of the Clovis culture and the climate change of the Younger Dryas. The general thought has been that climate change played a key role in wiping out the large animals and perhaps undermining the Clovis people, though some scientists have argued that the animals were hunted to extinction (the Pleistocene overkill hypothesis). But the fossil record has been puzzling, for many species of megafauna had survived multiple ice ages until the cool spell of the Younger Dryas.

For decades, scientists have believed that meltwater at the end of the ice ages formed a huge lake in central North America, known to scientists as Lake Agassiz. At some point, the water from that lake may have surged into the North Atlantic and shut down the dominant ocean current that brought warmer water toward higher latitudes. That, in turn, could have created a long-term climate change.

The impact scenario incorporates the meltwater scenario. The scientists say that the impact could have destabilized and melted the edges of the ice sheet resting on the northern tier of the continent. An impact would also have created a short-term environmental disaster. Dust from the impact and soot from continent-spanning wildfires could have risen into the atmosphere, blocked sunlight and dramatically hampered plant growth. With vast portions of the landscape burned, large animals requiring a great deal of food may have died off, even if they had survived the initial catastrophe.

On the one hand, maybe that was our once every 50 million years hit and we’re all safe, or on the other maybe the smaller-but-still-destructive stuff is much more common than we would like to think.

It probably wouldn’t take even a continental catastrophe to wipe out a neolithic culture or a bunch of megafauna. All you need are a couple bad seasons for the whole house of cards to come down, especially because competitors from less-affected areas will be moving in immediately.

Kinda makes you think about how little it would take to disrupt the current house of cards.

Reconditioning lungs: OK, this is creepy

December 24, 2008

Boffins keep transplant lungs alive in glass dome • The Register

But now, with the Toronto XVIVO Lung Perfusion System, a set of lungs can be whipped out of the donor and put into a “protective, transparent bubble-like chamber”. Here they are hooked up to a “pump, ventilator and filters through which flow oxygen, nutrients and a special solution” and kept at human body temperature.

According to Dr Shaf Keshavjee of Toronto General Hospital, “lungs can be safely kept on this circuit for 12 hours in order to assess, maintain and treat them before successfully transplanting them”.

The two docs were pleased to announce the first full trial of their kit. Andy Dykstra, 56, received a pair of reconditioned lungs earlier this month and is now back at home. The XVIVO system had been tested before, but Dykstra was the first patient to receive lungs “which could not have been used if they had not been repaired first”.

And here’s the video, which really ought to be out of some science-fiction horror film about organlegging.

Not the magma they were looking for

December 22, 2008

Drillers break into magma chamber

They are not sure how large the magma chamber is, but some initial testing suggests it may have been put in place by activity from Kilauea in the 1950s, perhaps even the 1920s.

Professor Marsh said the chamber was docile and slowly cooling. The consistency of the magma was like chilled pancake syrup, he said.

It is hoped the site can now become a laboratory, with a series of cores drilled around the chamber to better characterise the crystallisation changes occurring in the rock as it loses temperature.

The magma is a dacite, making it chemically distinct from the basalt which forms nearly the entire mass of the Hawaiian Islands and the surrounding oceanic crust. It has a much higher silica content.

So they find magma nearer to the surface than they thought they would, and it’s related to an old eruption, and it’s not the kind of magma that usually reaches the surface in Hawaii at all. Very nice result, and it may even all make sense. (If I remember correctly, the lava that reaches the surface in Hawaii is distinctive for being much less viscous than continental magmas, so the more viscous stuff might just all be in big lens-like blobs cooling somewhere a couple kilometers down.

And from the geothermal energy point of view, getting 1000C instead of 200-300C is an incredibly useful result if it can be duplicated. Somewhere around double the efficiency, which means half the energy flow can produce the same amount of useful power.

Dummy’s guide to building your own supercomputer

December 19, 2008

PS3Cluster Guide: By The Cluster Workshop

Our community guide allows you to set up your own MPI (Message Passing Interface) based supercomputer cluster with the Playstation 3.

So how do they do it?

December 16, 2008

‘Pioneering’ arm for 7/7 victim

“The wonderful technology in Kira is the ability to put a piece of metal inside the body, then put it outside and stop it from becoming infected, and also allow the piece of metal to incorporate into the bone,” he told BBC One’s Breakfast.

‘Fabulous’ development

Mr Cannon – from the Royal National Orthopaedic Hospital in Stanmore, north London – said getting muscle and skin to grow onto the metal was a revolutionary technique.

I’m hoping they’ve got a paper in the works, because something that crosses the skin without getting infected (much less bonding to tissue and bone as well) is pretty much perfect for a long list of treatments. Everyone who uses a needle on a regular basis could have their lives changed by this.

Accidental agriculture?

December 13, 2008

Gobekli Tepe: The World’s First Temple? | History & Archaeology | Smithsonian Magazine

To Schmidt and others, these new findings suggest a novel theory of civilization. Scholars have long believed that only after people learned to farm and live in settled communities did they have the time, organization and resources to construct temples and support complicated social structures. But Schmidt argues it was the other way around: the extensive, coordinated effort to build the monoliths literally laid the groundwork for the development of complex societies.

The immensity of the undertaking at Gobekli Tepe reinforces that view. Schmidt says the monuments could not have been built by ragged bands of hunter-gatherers. To carve, erect and bury rings of seven-ton stone pillars would have required hundreds of workers, all needing to be fed and housed. Hence the eventual emergence of settled communities in the area around 10,000 years ago. “This shows sociocultural changes come first, agriculture comes later,” says Stanford University archaeologist Ian Hodder, who excavated Catalhoyuk, a prehistoric settlement 300 miles from Gobekli Tepe. “You can make a good case this area is the real origin of complex Neolithic societies.”

In a way this kinda makes sense. Hunter-gatherer life really kinda doesn’t suck compared to the close-living agquicultural follow-ons. And even modern hunter-gathers, such as they are, show no great yen to give over their ways. But if there’s a cultural/religious reason to start settling down, then you have to make the cruddy new way of live work somehow, and the rest follows.

Or not.


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