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Meet the 2011 Nobel Laureates in Science

October 10, 2011 Leave a comment

Medicine

Bruce A. Beutler
Jules A. Hoffmann
Ralph M. Steinman

The Nobel Prize in Physiology or Medicine 2011 was divided, one half jointly to Bruce A. Beutler and Jules A. Hoffmann “for their discoveries concerning the activation of innate immunity” and the other half to Ralph M. Steinman “for his discovery of the dendritic cell and its role in adaptive immunity”.


Physics

Saul Perlmutter
Brian P Schmidt
Adam G Riess

The Nobel Prize in Physics 2011 was divided, one half awarded to Saul Perlmutter, the other half jointly to Brian P. Schmidt and Adam G. Riess “for the discovery of the accelerating expansion of the Universe through observations of distant supernovae”.


Chemistry

Dan Shechtman

The Nobel Prize in Chemistry 2011 was awarded to Dan Shechtman “for the discovery of quasicrystals”.

Graphene “Big Mac” Sandwich May Replace Silicon Chips

October 10, 2011 Leave a comment

“The world’s thinnest, strongest and most conductive material, discovered in 2004 at the University of Manchester by Professor Andre Geim and Professor Kostya Novoselov, has the potential to revolutionize material science.

Demonstrating the remarkable properties of graphene won the two scientists the Nobel Prize for Physics last year and UK’s Chancellor of the Exchequer George Osborne has just announced plans for a £50m graphene research hub to be set up.

Now, writing in the journal Nature Physics, the University of Manchester team have for the first time demonstrated how graphene inside electronic circuits will probably look like in the future.

By sandwiching two sheets of graphene with another two-dimensional material, boron nitrate, the team created the graphene ‘Big Mac’ – a four-layered structure which could be the key to replacing the silicon chip in computers.

Because there are two layers of graphene completed surrounded by the boron nitrate, this has allowed the researchers for the first time to observe how graphene behaves when unaffected by the environment.”

Graphene Found to be Generating Electricity Under Light

October 8, 2011 Leave a comment

“Graphene, an exotic form of carbon consisting of sheets a single atom thick, exhibits a novel reaction to light, MIT researchers have found: Sparked by light’s energy, the material can produce electric current in unusual ways.

The finding could lead to improvements in photodetectors and night-vision systems, and possibly to a new approach to generating electricity from sunlight.

This current-generating effect had been observed before, but researchers had incorrectly assumed it was due to a photovoltaic effect, says Pablo Jarillo-Herrero, an assistant professor of physics at MIT and senior author of a new paper published in the journal Science.

The paper’s lead author is postdoc Nathaniel Gabor; co-authors include four MIT students, MIT physics professor Leonid Levitov and two researchers at the National Institute for Materials Science in Tsukuba, Japan.

Instead, the MIT researchers found that shining light on a sheet of graphene, treated so that it had two regions with different electrical properties, creates a temperature difference that, in turn, generates a current.

Graphene heats inconsistently when illuminated by a laser, Jarillo-Herrero and his colleagues found: The material’s electrons, which carry current, are heated by the light, but the lattice of carbon nuclei that forms graphene’s backbone remains cool.

It’s this difference in temperature within the material that produces the flow of electricity. This mechanism, dubbed a “hot-carrier” response, “is very unusual,” Jarillo-Herrero says.”

New Machine Can Perform DNA Tests Within 3 Minutes

October 8, 2011 Leave a comment

“The Polymerase Chain Reaction, which amplifies specific DNA sequences out of mixtures (starting with as little as a single molecule), has revolutionized molecular biology, enabling DNA-based tests that once took months to be performed in an afternoon.

But even an afternoon is pretty slow for some purposes, such as diagnostic kits for infectious agents.

A team of impatient researchers at Lawrence Livermore National Lab has now managed to cut the time needed for a PCR reaction down from a few hours to less than three minutes.

PCR relies on a cyclical amplification process: high temperatures reset the DNA-copying reaction, lower ones let a new round of reactions start, and they proceed at an intermediate step.

The proteins that catalyze these reactions are actually very fast; the delay comes from the time neeed to shift the reactions between these temperatures.

Small machines called thermocyclers heat and chill metal blocks as quickly as they can, but it still takes minutes to get through a single cycle.

When a typical PCR reaction runs for 30 cycles, that can soak up a lot of time. This not only slows individual PCR reactions down, but also means that the thermocycler isn’t available for anyone else’s use.

The Livermore team tackled the heating and cooling very simply: their device has two reservoirs of water kept at the high and low temperatures needed during the cycle.

The water is pumped through a foamed copper block that contains the sample, enabling it to quickly equillibrate to the target temperature.

They also eliminated the time spent at the intermediate temperature, figuring the samples will pass through there long enough on their way between the two extremes.”

OPERA May Have Ignored Einstein for Neutrino Speed Calculation

October 7, 2011 Leave a comment

The OPERA experiment's stopwatch is coming under scrutiny.CERN

“Less than two weeks after the revelation that ghostly particles called neutrinos had been spotted travelling faster than the speed of light, physicists are saying they have found flaws in the analysis that would stop the claim in its tracks…

Since the OPERA group’s 22 September announcement, more than 30 papers attempting to explain the result using various exotic theoretical models have been posted to the physics preprint server at arXiv.org.

But one paper2, posted on 28 September by theorist Carlo Contaldi of Imperial College London, bears the distinction of being the first to challenge the experimental calculations.

The OPERA team timed the neutrinos using clocks at each location that were synchronized using GPS (Global Positioning System) signals from a single satellite. Contaldi’s paper says the group’s calculations do not take into account one aspect of Albert Einstein’s general theory of relativity: that slight differences in the force of gravity at the two sites would cause the clocks to tick at different rates.

Because of its location relative to the centre of Earth, the CERN site feels a slightly stronger gravitational pull than Gran Sasso. Consequently, a clock at the beginning of the neutrinos’ journey would actually run at a slower rate than a clock at the end. “It would reduce the significance of the result,” Contaldi says.”

Brain Cells Injected into Pancreas May Cure Diabetes

October 7, 2011 1 comment

“Scientists in Japan have shown that implanting brain cells into a rat pancreas was a successful treatment for diabetes – rat diabetes.

In humans, the disease affects nearly 26 million people in the United States, 200 million worldwide. It costs us about $174 billion per year (that figure from 2007, it has likely increased), and in that same year it was the seventh leading cause of death. So if the the results could be repeated in humans, that would obviously be amazing.

In a press release, the scientists suggest that exactly that is their goal.

Tomoko Kuwabars and his colleagues at AIST Institute in Tsukuba, Japan, extracted neural stem cells from the hippocampus of rats, then injected them directly into the animals’ pancreases. The rats, which had been engineered to exhibit symptoms of diabetes, showed lower blood sugar levels (a good thing, since diabetes can dangerously increase blood sugar levels) after the brain cell injection. The scientists tested their theory that the neuronal cells were pumping out insulin by removing them, after which blood sugar levels went back up.”

Was Earth’s Water Imported from Space?

October 6, 2011 Leave a comment

“The composition of the Earth-Moon system indicates that the Moon probably formed from a collision between the proto-Earth and a Mars-sized body.

That collision was incredibly violent, and left the Earth hot enough that its atmosphere would primarily consist of vaporized silicate rock.

Once it solidified, those conditions would have left the planet very dry, with our current water largely delivered by smaller bodies that have impacted the Earth since.

So far, only a single type of meteorite has been found to have hydrogen and oxygen isotopes that matched those found in the oceans.

But researchers have now checked a comet derived from the Kuiper belt, and showed that it also is a good match for the Earth’s oceans…

Now, using the ESA’s Herschel observatory, researchers have gotten a good reading on the comet 103P/Hartley 2, which orbits near Jupiter but probably got its start in the Kuiper belt, just outside the orbit of Neptune.

And it turns out that the deuterium/hydrogen ratio is nearly an exact match for that in Earth’s oceans.

That means a large population of comets have just become candidates for seeding our planet with water.”