News
News from Boulder, Colorado and Boulder Channel 1 News editors To advertise please call 303-447-8531
CU research: Microchips using light instead of wires boosts speed exponentially
Sep 30th
CU, MIT breakthrough in photonics
could allow for faster and faster electronics
could allow for faster and faster electronics
A pair of breakthroughs in the field of silicon photonics by researchers at the University of Colorado Boulder, the Massachusetts Institute of Technology and Micron Technology Inc. could allow for the trajectory of exponential improvement in microprocessors that began nearly half a century ago—known as Moore’s Law—to continue well into the future, allowing for increasingly faster electronics, from supercomputers to laptops to smartphones.
The research team, led by CU-Boulder researcher Milos Popovic, an assistant professor of electrical, computer and energy engineering, developed a new technique that allows microprocessors to use light, instead of electrical wires, to communicate with transistors on a single chip, a system that could lead to extremely energy-efficient computing and a continued skyrocketing of computing speed into the future.
Popovic and his colleagues created two different optical modulators—structures that detect electrical signals and translate them into optical waves—that can be fabricated within the same processes already used in industry to create today’s state-of-the-art electronic microprocessors. The modulators are described in a recent issue of the journal Optics Letters.
First laid out in 1965, Moore’s Law predicted that the size of the transistors used in microprocessors could be shrunk by half about every two years for the same production cost, allowing twice as many transistors to be placed on the same-sized silicon chip. The net effect would be a doubling of computing speed every couple of years.
The projection has held true until relatively recently. While transistors continue to get smaller, halving their size today no longer leads to a doubling of computing speed. That’s because the limiting factor in microelectronics is now the power that’s needed to keep the microprocessors running. The vast amount of electricity required to flip on and off tiny, densely packed transistors causes excessive heat buildup.
“The transistors will keep shrinking and they’ll be able to continue giving you more and more computing performance,” Popovic said. “But in order to be able to actually take advantage of that you need to enable energy-efficient communication links.”
Microelectronics also are limited by the fact that placing electrical wires that carry data too closely together can result in “cross talk” between the wires.
In the last half-dozen years, microprocessor manufacturers, such as Intel, have been able to continue increasing computing speed by packing more than one microprocessor into a single chip to create multiple “cores.” But that technique is limited by the amount of communication that then becomes necessary between the microprocessors, which also requires hefty electricity consumption.
Using light waves instead of electrical wires for microprocessor communication functions could eliminate the limitations now faced by conventional microprocessors and extend Moore’s Law into the future, Popovic said.
Optical communication circuits, known as photonics, have two main advantages over communication that relies on conventional wires: Using light has the potential to be brutally energy efficient, and a single fiber-optic strand can carry a thousand different wavelengths of light at the same time, allowing for multiple communications to be carried simultaneously in a small space and eliminating cross talk.
Optical communication is already the foundation of the Internet and the majority of phone lines. But to make optical communication an economically viable option for microprocessors, the photonics technology has to be fabricated in the same foundries that are being used to create the microprocessors. Photonics have to be integrated side-by-side with the electronics in order to get buy-in from the microprocessor industry, Popovic said.
“In order to convince the semiconductor industry to incorporate photonics into microelectronics you need to make it so that the billions of dollars of existing infrastructure does not need to be wiped out and redone,” Popovic said.
Last year, Popovic collaborated with scientists at MIT to show, for the first time, that such integration is possible. “We are building photonics inside the exact same process that they build microelectronics in,” Popovic said. “We use this fabrication process and instead of making just electrical circuits, we make photonics next to the electrical circuits so they can talk to each other.”
In two papers published last month in Optics Letters with CU-Boulder postdoctoral researcher Jeffrey Shainline as lead author, the research team refined their original photonic-electronic chip further, detailing how the crucial optical modulator, which encodes data on streams of light, could be improved to become more energy efficient. That optical modulator is compatible with a manufacturing process—known as Silicon-on-Insulator Complementary Metal-Oxide-Semiconductor, or SOI CMOS—used to create state-of-the-art multicore microprocessors such as the IBM Power7 and Cell, which is used in the Sony PlayStation 3.
The researchers also detailed a second type of optical modulator that could be used in a different chip-manufacturing process, called bulk CMOS, which is used to make memory chips and the majority of the world’s high-end microprocessors.
Vladimir Stojanovic, who leads one of the MIT teams collaborating on the project and who is the lead principal investigator for the overall research program, said the group’s work on optical modulators is a significant step forward.
“On top of the energy-efficiency and bandwidth-density advantages of silicon-photonics over electrical wires, photonics integrated into CMOS processes with no process changes provides enormous cost-benefits and advantage over traditional photonic systems,” Stojanovic said.
The CU-led effort is a part of a larger project on building a complete photonic processor-memory system, which includes research teams from MIT led by Stojanovic, Rajeev Ram and Michael Watts, a team from Micron Technology led by Roy Meade and a team from the University of California, Berkeley, led by Krste Asanovic. The research was funded by the Defense Advanced Research Projects Agency and the National Science Foundation.
-CU-
[includeme src=”http://c1n.tv/boulder/media/bouldersponsors.html” frameborder=”0″ width=”670″ height=”300″]
CU study; Death of microbes could determine time of death
Sep 27th
An intriguing study led by the University of Colorado Boulder may provide a powerful new tool in the quiver of forensic scientists attempting to determine the time of death in cases involving human corpses: a microbial clock.
The clock is essentially the lock-step succession of bacterial changes that occur postmortem as bodies move through the decay process. And while the researchers used mice for the new study, previous studies on the human microbiome – the estimated 100 trillion or so microbes that live on and in each of us – indicate there is good reason to believe similar microbial clocks are ticking away on human corpses, said Jessica Metcalf, a CU-Boulder postdoctoral researcher and first author on the study.
“While establishing time of death is a crucial piece of information for investigators in cases that involve bodies, existing techniques are not always reliable,” said Metcalf of CU-Boulder’s BioFrontiers Institute. “Our results provide a detailed understanding of the bacterial changes that occur as mouse corpses decompose, and we believe this method has the potential to be a complementary forensic tool for estimating time of death.”
Dead and dying microbes could determine time of death for forensics pathologists
Currently, investigators use tools ranging from the timing of last text messages and corpse temperatures to insect infestations on bodies and “grave soil” analyses, with varying results, she said. And the more days that elapse following a person’s demise, the more difficult it becomes to determine the time of death with any significant accuracy.
Using high-technology gene sequencing techniques on both bacteria and microbial eukaryotic organisms like fungi, nematodes and amoeba postmortem, the researchers were able to pinpoint time of mouse death after a 48-day period to within roughly four days. The results were even more accurate following an analysis at 34 days, correctly estimating the time of death within about three days, said Metcalf.
A paper on the subject was published Sept. 23 in the new online science and biomedical journal, eLIFE, a joint initiative of the Howard Hughes Medical Institute, the Max Planck Society and the Wellcome Trust Fund. The study was funded by the National Institutes of Justice.
The researchers tracked microbial changes on the heads, torsos, body cavities and associated grave soil of 40 mice at eight different time points over the 48-day study. The stages after death include the “fresh” stage before decomposition, followed by “active decay” that includes bloating and subsequent body cavity rupture, followed by “advanced decay,” said Chaminade University forensic scientist David Carter, a co-author on the study.
“At each time point that we sampled, we saw similar microbiome patterns on the individual mice and similar biochemical changes in the grave soil,” said Laura Parfrey, a former CU-Boulder postdoctoral fellow and now a faculty member at the University of British Columbia who is a microbial and eukaryotic expert. “And although there were dramatic changes in the abundance and distribution of bacteria over the course of the study, we saw a surprising amount of consistency between individual mice microbes between the time points — something we were hoping for.”
As part of the project, the researchers also charted “blooms” of a common soil-dwelling nematode well known for consuming bacterial biomass that occurred at roughly the same time on individual mice during the decay period. “The nematodes seem to be responding to increases in bacterial biomass during the early decomposition process, an interesting finding from a community ecology standpoint,” said Metcalf.
“This work shows that your microbiome is not just important while you’re alive,” said CU-Boulder Associate Professor Rob Knight, the corresponding study author who runs the lab where the experiments took place. “It might also be important after you’re dead.”
The research team is working closely with assistant professors Sibyl Bucheli and Aaron Linne of Sam Houston State University in Huntsville, Texas, home of the Southeast Texas Applied Forensic Science Facility, an outdoor human decomposition facility known popularly as a “body farm.” The researchers are testing bacterial signatures of human cadavers over time to learn more about the process of human decomposition and how it is influenced by weather, seasons, animal scavenging and insect infestations.
The new study is one of more than a dozen papers authored or co-authored by CU-Boulder researchers published in the past several years on human microbiomes. One of the studies, led by Professor Noah Fierer, a co-author on the new study, brought to light another potential forensic tool — microbial signatures left on computer keys and computer mice, an idea enthralling enough it was featured on a “CSI: Crime Scene Investigation” television episode.
“This study establishes that a body’s collection of microbial genomes provides a store of information about its history,” said Knight, also an associate professor of chemistry and biochemistry and a Howard Hughes Medical Institute Early Career Scientist. “Future studies will let us understand how much of this information, both about events before death — like diet, lifestyle and travel — and after death can be recovered.”
In addition to Metcalf, Fierer, Knight, Carter and Parfrey, other study authors included Antonio Gonzalez, Gail Ackerman, Greg Humphrey, Mathew Gebert, Will Van Treuren, Donna Berg Lyons and Kyle Keepers from CU-Boulder, former BioFrontiers doctoral student Dan Knights from the University of Minnesota, and Yan Go and James Bullard from Pacific Biosciences in Menlo Park, Calif. Keepers participated in the study as an undergraduate while Gonzalez, now a postdoctoral researcher, was a graduate student during the study.
“There is no single forensic tool that is useful in all scenarios, as all have some degree of uncertainty,” said Metcalf. “But given our results and our experience with microbiomes, there is reason to believe we can get past some of this uncertainty and look toward this technique as a complementary method to better estimate time of death in humans.”
Gene sequencing equipment for the study included machines from Illumina of San Diego and Pacific Biosciences of Menlo Park, Calif. The Illumina data were generated at CU-Boulder in the BioFrontiers Next Generation Sequencing Facility.
To access a copy of the paper visit http://dx.doi.org/10.7554/eLife.01104. For more information on the BioFrontiers Institute visit http://biofrontiers.colorado.edu.
-CU-
[includeme src=”http://c1n.tv/boulder/media/bouldersponsors.html” frameborder=”0″ width=”670″ height=”300″]
City/County: Look east and south for rentals
Sep 27th
Those impacted by flooding encouraged to seek housing rentals along U.S. 36 corridor (south and southeast of the City of Boulder)
Boulder County, Colo. – Boulder County residents displaced from their homes by the recent flooding are being encouraged to search for affordable rental housing outside the county as soon as possible. Prior to the flooding, rental vacancy rates across Boulder County were between one and three percent, and have already fallen further due to competition created by the flooding. In particular, residents needing affordable rental units are urged to search southeast and south of Boulder County along the U.S. 36 corridor.
“We don’t know right now how long repairs will take for both houses and roads, and we want our impacted residents to have a realistic view of what’s necessary in terms of finding temporary housing,” said Frank Alexander, Director of the Boulder County Department of Housing and Human Services (BCDHHS). “The sooner the rental search begins in places like Broomfield, Westminster, Arvada, Brighton, and Golden, the better it will be for those who’ve had to move from their homes because of the flooding.”
Polling of rental property owners indicates few affordable rental units are currently available in Boulder County. Residents are encouraged to broaden searches to include smaller units and apartments, and to discuss their options for shorter-term leases with property owners. Residents are also urged to be sure they know their rights as renters. Boulder County has a list of available housing assistance resources, including information for renters, atwww.BoulderCountyFlood.org.
“Unfortunately, there is no quick solution to the shortage of rental units in Boulder County,” said Boulder County Commissioner Cindy Domenico. “We want to be sure our residents know they may need to look outside Boulder County to meet their housing needs.”
Many displaced residents may be able to find housing with family, friends, or neighbors. As with other rental types, those who qualify for financial assistance from the Federal Emergency Management Agency (FEMA) may have the option of using the funds to help cover up to two months of rent payments. A legal lease is required to obtain FEMA funding to help cover rent payments.
Boulder County continues to help operate two Disaster Assistance Centers: 1) Twin Peaks Mall (1250 S. Hover Road at Highway 119) in Longmont, and at 5495 Arapahoe Avenue (near the intersection of 55th and Arapahoe) in Boulder. Among other services, both locations offer FEMA assistance as well as resources for food, financial help, volunteer cleanup, and other housing options.
[includeme file=”/media/boulderfloodsponsors.txt]
