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Eclectic Perambulations in the Noosphere
Quasicrystals : "Forbidden Symmetry"
"Resembling mosaic tile, this atomic model shows a type of quasicrystal, a material whose atoms display a regular but nonrepeating pattern—once thought impossible in crystals.
The discovery of quasicrystals earned Israeli scientist Daniel Shechtman the 2011 Nobel Prize in Chemistry Wednesday—and joins the list of Nobel-winning chemical discoveries with the potential to change the way we live."
"The Nacirema were supposedly a tribe of people living in North America, as described by Horace Miner in his anthropological paper, published in 1956.
The tribe Miner described had many odd rituals including "scraping and lacerating the surface of the face with a sharp instrument" and another ritual that "consists of inserting a small bundle of hog hairs into the mouth, along with certain magical powders, and then moving the bundle in a highly formalized series of gestures."
It was actually a satire of everyday American life. "Nacirema" is "American" spelled backward."
Electron micrograph of an array of gold antennas on a silicon surface. The array is created by repeating the sequence in yellow across the entire surface. Each antenna has a thickness of 50 nanometers (50 billionths of a meter). The scale bar is in microns, its length slightly shorter than a ten-thousandth of an inch. Image courtesy of Nanfang Yu.
An array of nanoscale resonators, much thinner than a wavelength, creates a constant gradient across the surface of the silicon. In this visualization, the light ray hits the surface perpendicularly, from below. The resonators on the left hold the energy slightly longer than those on the right, so the wavefront (red line) propagates at an angle. Without the array, it would be parallel to the surface. Image courtesy of Nanfang Yu.
06 September 2011
Exploiting a novel technique called phase discontinuity, researchers at the Harvard School of Engineering and Applied Sciences (SEAS) have induced light rays to behave in a way that defies the centuries-old laws of reflection and refraction.
"By incorporating a gradient of phase discontinuities across the interface, the laws of reflection and refraction become designer laws, and a panoply of new phenomena appear," says Zeno Gaburro, a visiting scholar in Capasso's group who was co-principal investigator for this work. "The reflected beam can bounce backward instead of forward. You can create negative refraction. There is a new angle of total internal reflection."
Moreover, the frequency (color), amplitude (brightness), and polarization of the light can also be controlled, meaning that the output is in essence a designer beam. The researchers have already succeeded at producing a vortex beam (a helical, corkscrew-shaped stream of light) from a flat surface. They also envision flat lenses that could focus an image without aberrations.
Image: Joseph R. Ecker, Salk Institute of Biological Studies. Plant Photo: Joe Belcovson, Salk Institute for Biological studies. Network Map: Mary Galli, Salk Institute for Biological Studies and Matija Dreze, Center for Cancer Systems Biology at the Dana-Faber Cancer Institute.
"The image shows an Arabidopsis plant overlaid on a network map of protein-protein interactions. The clusters of colors represent "communities" of interacting proteins that are enriched in specific plant processes.
Scientists have created the largest map of protein-to-protein interactions of the plant Arabidopsis thaliana:
"For this project, over 10,000 'open reading frame' clones were converted and sequence verified in preparation for protein-interaction screening," says Galli.
Vidal, Braun, Hill and their colleagues systematically ran these open reading frames through a high quality protein-interaction screening process, based on a test known as the yeast two-hybrid screen. Out of more than forty million possible pair combinations, they found a total of 6,205 Arabidopsis protein- protein interactions, involving 2,774 individual proteins. The researchers confirmed the high quality of these data, for example by showing their overlap with protein interaction datafrom past studies.
The new map of 6,205 protein partnerings represents only about two percent of the full protein- protein "interactome" for Arabidopsis, since the screening test covered only a third of all Arabidopsis proteins, and wasn't sensitive enough to detect many weaker protein interactions. "There will be larger maps after this one," says Ecker."
see also Largest-Ever Map of Plant Protein Interactions
"Fifteen uncoupled simple pendulums of monotonically increasing lengths dance together to produce visual traveling waves, standing waves, beating, and (seemingly) random motion.
The period of one complete cycle of the dance is 60 seconds. The length of the longest pendulum has been adjusted so that it executes 51 oscillations in this 60 second period. The length of each successive shorter pendulum is carefully adjusted so that it executes one additional oscillation in this period. Thus, the 15th pendulum (shortest) undergoes 65 oscillations."
