January 28, 2011

Stanford scientists see the solar future, and it's all about 'nanodomes' and 'plasmonics'

Stanford engineers dance with plasmonics to yield new direction for thin, inexpensive solar cells.

(January 28, 2011)  Researchers in solar energy speak of a day when millions of otherwise fallow square meters of sun-drenched roofs, windows, deserts and even clothing will be integrated with inexpensive solar cells that are many times thinner and lighter than the bulky rooftop panels familiar today.

So, when your iPod is on the nod, you might plug it into your shirt to recharge. Lost in the Serengeti with a sapped cell phone? No problem; rolled in your backpack is a lightweight solar pad. Sailing the seven seas and your GPS needs some juice? Hoist a solar sail and be one with the gods of geosynchronous orbit.

It is not hard to envision a time when such technologies will be ubiquitous in our increasingly energy-hungry lives. That day may come a bit sooner thanks to a multidisciplinary team of Stanford engineers led by Mike McGehee, Yi Cui and Mark Brongersma, and joined by Michael Graetzel at the École Polytechnique Fédérale de Lausanne (EPFL).

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January 24, 2011

Out of mind in a matter of seconds

Surprising rate at which neuronal networks in the cerebral cortex delete sensory information

(January 24, 2011)  The dynamics behind signal transmission in the brain are extremely chaotic. This conclusion has been reached by scientists from the Max Planck Institute for Dynamics and Self-Organization at the University of Göttingen and the Bernstein Center for Computational Neuroscience Göttingen. In addition, the Göttingen-based researchers calculated, for the first time, how quickly information stored in the activity patterns of the cerebral cortex neurons is discarded. At one bit per active neuron per second, the speed at which this information is forgotten is surprisingly high. Physical Review Letters, 105, 268104 (2010)

The brain codes information in the form of electrical pulses, known as spikes. Each of the brain’s approximately 100 billion interconnected neurons acts as both a receiver and transmitter: these bundle all incoming electrical pulses and, under certain circumstances, forward a pulse of their own to their neighbours. In this way, each piece of information processed by the brain generates its own activity pattern. This indicates which neuron sent an impulse to its neighbours: in other words, which neuron was active, and when. Therefore, the activity pattern is a kind of communication protocol that records the exchange of information between neurons.

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January 14, 2011

New technique to visualize neurons of the deep brain for months at a time developed by Stanford researchers

Stanford researchers have developed a new technique that allows them to monitor the tiny branches of neurons in a live brain for months at a time. Neuroscientists will now be able to monitor the microscopic changes that occur over the course of progressive brain disease.

(January 14, 2011)  Travel just one millimeter inside the brain and you'll be stepping into the dark.

Standard light microscopes don't allow researchers to look into the interior of the living brain, where memories are formed and diseases such as dementia and cancer can take their toll.

But Stanford scientists have devised a new method that not only lets them peer deep inside the brain to examine its neurons but also allows them to continue monitoring for months.

The technique promises to improve understanding of both the normal biology and diseased states of this hidden tissue.