Posts tagged National Science Foundation
Boulder County’s moratorium on oil and gas drilling permits is scheduled to expire on June 10
0May 4, 2013
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CU study: Bug-eyed lenses capture wide view with no distortion
0May 1, 2013
Lenses shaped like the bulging, bowl-shaped eyes possessed by dragonflies, praying mantises, houseflies and other insects can take exceptionally wide-angle photos without distorting the image.
To create the innovative camera, which also allows for a practically infinite depth of field, the scientists used stretchable electronics and a pliable sheet of microlenses made from a material similar to that used for contact lenses. The researchers described the camera in an article published today in the journal Nature.
Conventional wide-angle lenses, such as fisheyes, distort the images they capture at the periphery, a consequence of the mismatch of light passing through a hemispherically curved surface of the lens only to be captured by the flat surface of the electronic detector.
For the digital camera described in the new study, the researchers were able to create an electronic detector that can be curved into the same hemispherical shape as the lens, eliminating the distortion.
“The most important and most revolutionizing part of this camera is to bend electronics onto a curved surface,” said Jianliang Xiao, assistant professor of mechanical engineering at CU-Boulder and co-lead author of the study. “Electronics are all made of silicon, mostly, and silicon is very brittle, so you can’t deform the silicon. Here, by using stretchable electronics we can deform the system; we can put it onto a curved surface.”
Creating a camera inspired by the compound eyes of arthropods — animals with exoskeletons and jointed legs, including all insects as well as scorpions, spiders, lobsters and centipedes, among other creatures — has been a sought-after goal. Compound eyes typically have a lower resolution than the eyes of mammals, but they give arthropods a much larger field of view than mammalian eyes as well as high sensitivity to motion and an infinite depth of field.
Compound eyes consist of a collection of smaller eyes called ommatidia, and each small eye is made up of an independent corneal lens as well as a crystalline cone, which captures the light traveling through the lens. The number of ommatidia determines the resolution and varies widely among arthropods. Dragonflies, for example, have about 28,000 tiny eyes while worker ants have only in the neighborhood of 100.
Imitating the corneal lens-crystalline cone pairings, the camera created by Xiao and his colleagues has 180 miniature lenses, each of which is backed with its own small electronic detector. The number of lenses used in the camera is similar to the number of ommatidia in the compound eyes of fire ants and bark beetles.
The electronics and the lenses are both flat when fabricated, said Xiao, who began working on the project as a postdoctoral researcher in John Roger’s lab at the University of Illinois at Urbana-Champaign. This allows the product to be manufactured using conventional systems.
“This is the key to our technology,” Xiao said. “We can fabricate an electronic system that is compatible with current technology. Then we can scale it up.”
The lens sheet and the electronics sheet are integrated together while flat and then molded into a hemispherical shape afterward. Each individual electronic detector and each individual lens do not deform, but the spaces between the detectors and lenses can stretch and allow for the creation of a new 3-D shape. The electronic detectors are all attached with serpentine filament bridges, which are not compromised as the material stretches and bends.
In the pictures taken by the new camera, each lens-detector pairing contributes a single pixel to the image. Moving the electronic detectors directly behind the lenses — instead of having just one detector sitting farther behind a single lens, as in conventional cameras — creates a very short focal length, which allows for the near-infinite depth of field.
The new paper demonstrates that stretchable electronics can be used as the foundation for a distortion-free hemispherical camera, but commercial production of such a camera may still be years away, Xiao said.
The three other co-lead authors of the paper are Young Min Song, Yizhu Xie and Viktor Malyarchuk, all of the University of Illinois. Other co-authors are Ki-Joong Choi, Rak-Hwan Kim and John Rogers, also of Illinois; Inhwa Jung, of Kyung Hee University in Korea; Zhuangjian Liu, of the Institute of High Performance Computing A*star in Singapore; Chaofeng Lu, of Zhejiang University in China and Northwestern University; Rui Li, of Dalian University of Technology in China; Kenneth Crozier, of Harvard University; and Yonggang Huang, of Northwestern University.
The research was funded by the Defense Advanced Research Projects Agency and the National Science Foundation.
CU news release
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CU -Boulder to update 20-year-old groundbreaking STEM study with $4.3 million grant
0February 26, 2013
Early next month, researchers from the University of Colorado Boulder will begin the painstaking process of interviewing hundreds of undergraduates in an effort to understand why the rates of students switching out of science, technology, engineering and math majors has remained troublingly high over the last couple of decades despite widespread efforts to address the problem.
The five-year, $4.3 million project, undertaken in partnership with the University of Wisconsin-Madison, replicates and expands on a study begun by a couple of CU-Boulder researchers two decades ago and published in 1997 as a book. “Talking About Leaving: Why Undergraduates Leave the Sciences” has since become a seminal text in the field of STEM education.
“Part of the reason why we’re undertaking this study is that the rates of students switching out of STEM majors has remained so persistent,” said Anne-Barrie Hunter, co-director of Ethnography and Evaluation Research at CU-Boulder and principal investigator for the Colorado research team. “Here we are now, 20 years on, and the rates are still roughly the same. They’re very, very stubborn.”
The study, which is being funded by the National Science Foundation and the Alfred P. Sloan Foundation, is the first to be run out of CU-Boulder’s new Center for STEM Learning.
When the original study began in the early 1990s, the high rates of students leaving STEM majors — between 40 and 60 percent, depending on the discipline — were known, but the reasons for the switching were just conjecture. Some thought that the students who switched didn’t have the necessary ability to succeed in tough science classes, while others blamed teaching assistants with difficult-to-understand accents or the lack of experience of teaching assistants in general.
CU-Boulder researchers Nancy Hewitt and Elaine Seymour set out to determine whether any of the speculation was true by asking those who should know: the students. The pair led a research team that interviewed more than 400 undergraduates, both “switchers” and “persisters.”
“Our evidence didn’t support what they thought,” said Seymour, who is also involved with the new study. “We were really surprised.” As it turned out, “switchers” and “persisters” were equally bright and teaching assistants were often a much-needed lifeline for struggling students. In fact, both sets of students faced the same set of challenges, the largest of which was the way science classes were taught.
“What we discovered was that an incoming interest in the sciences was dissipated over the course of the first two years by the way the courses were taught,” Seymour said. “The teaching in those days was predominantly stand-and-deliver lecturing.”
Since Seymour and Hewitt’s book was published, there has been a nationwide effort to improve the quality of undergraduate science education. “Change is going on all across the country,” Seymour said. “But it may not be sufficient to move the needle.”
For “Talking About Leaving Revisited,” the researchers will interview undergraduates at the seven institutions that hosted the original study to find out if the reasons for switching have changed. But the new study will also go further by interviewing course instructors, observing classroom teaching practices and analyzing the transcripts of students across institutions to look for patterns among switchers and persisters. When the study is concluded, the research team plans to publish another book.
Talking About Leaving Revisited is one of the inaugural grants affiliated with CU-Boulder’s Center for STEM Learning, which was officially formed in December. The center, which was organized over four years with the backing of a $1 million institutional transformation grant from the National Science Foundation, aims to provide an infrastructure that will support the more than 75 existing STEM education programs on campus and allow them to more easily collaborate.
“We will provide a network and support structure designed to catalyze and provide links among these people, ideas, tools and resources,” said physics Professor Noah Finkelstein, one of the people who helped lead the effort to create the new center.
The Center for STEM Learning, which will also strive to be a state, regional and national resource, has three main thrusts: to transform the way STEM classes are delivered, to support research into the best practices for STEM education, and to help recruit the brightest to become STEM teachers.
For more information on the study visit http://wceruw.org/projects/projects.php?project_num=956.
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CU-Boulder team develops swarm of pingpong ball-sized robots
0December 14, 2012
University of Colorado Boulder Assistant Professor Nikolaus Correll likes to think in multiples. If one robot can accomplish a singular task, think how much more could be accomplished if you had hundreds of them.
Correll and his computer science research team, including research associate Dustin Reishus and professional research assistant Nick Farrow, have developed a basic robotic building block, which he hopes to reproduce in large quantities to develop increasingly complex systems.
Recently the team created a swarm of 20 robots, each the size of a pingpong ball, which they call “droplets.” When the droplets swarm together, Correll said, they form a “liquid that thinks.”
To accelerate the pace of innovation, he has created a lab where students can explore and develop new applications of robotics with basic, inexpensive tools.
Similar to the fictional “nanomorphs” depicted in the “Terminator” films, large swarms of intelligent robotic devices could be used for a range of tasks. Swarms of robots could be unleashed to contain an oil spill or to self-assemble into a piece of hardware after being launched separately into space, Correll said.
Correll plans to use the droplets to demonstrate self-assembly and swarm-intelligent behaviors such as pattern recognition, sensor-based motion and adaptive shape change. These behaviors could then be transferred to large swarms for water- or air-based tasks.
Correll hopes to create a design methodology for aggregating the droplets into more complex behaviors such as assembling parts of a large space telescope or an aircraft.
In the fall, Correll received the National Science Foundation’s Faculty Early Career Development award known as “CAREER.” In addition, he has received support from NSF’s Early Concept Grants for Exploratory Research program, as well as NASA and the U.S. Air Force.
He also is continuing work on robotic garden technology he developed at the Massachusetts Institute of Technology in 2009. Correll has been working with Joseph Tanner in CU-Boulder’s aerospace engineering sciences department to further develop the technology, involving autonomous sensors and robots that can tend gardens, in conjunction with a model of a long-term space habitat being built by students.
Correll says there is virtually no limit to what might be created through distributed intelligence systems.
“Every living organism is made from a swarm of collaborating cells,” he said. “Perhaps some day, our swarms will colonize space where they will assemble habitats and lush gardens for future space explorers.”
For a short video of Correll’s team developing swarm droplets visit http://www.colorado.edu/news/multimedia/researchers-creating-team-tiny-robots. For more information about CU-Boulder’s computer science department visit http://www.colorado.edu/engineering/academics/degree/computer-science.
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CU study: Graphene membranes may lead to enhanced natural gas production, less CO2 pollution
0October 8, 2012
Engineering faculty and students at the University of Colorado Boulder have produced the first experimental results showing that atomically thin graphene membranes with tiny pores can effectively and efficiently separate gas molecules through size-selective sieving.
The findings are a significant step toward the realization of more energy-efficient membranes for natural gas production and for reducing carbon dioxide emissions from power plant exhaust pipes.
Mechanical engineering professors Scott Bunch and John Pellegrino co-authored a paper in Nature Nanotechnology with graduate students Steven Koenig and Luda Wang detailing the experiments. The paper was published Oct. 7 in the journal’s online edition.
The research team introduced nanoscale pores into graphene sheets through ultraviolet light-induced oxidative “etching,” and then measured the permeability of various gases across the porous graphene membranes. Experiments were done with a range of gases including hydrogen, carbon dioxide, argon, nitrogen, methane and sulphur hexaflouride — which range in size from 0.29 to 0.49 nanometers — to demonstrate the potential for separation based on molecular size. One nanometer is one billionth of a meter.
“These atomically thin, porous graphene membranes represent a new class of ideal molecular sieves, where gas transport occurs through pores which have a thickness and diameter on the atomic scale,” said Bunch.
Graphene, a single layer of graphite, represents the first truly two-dimensional atomic crystal. It consists of a single layer of carbon atoms chemically bonded in a hexagonal “chicken wire” lattice — a unique atomic structure that gives it remarkable electrical, mechanical and thermal properties.
“The mechanical properties of this wonder material fascinate our group the most,” Bunch said. “It is the thinnest and strongest material in the world, as well as being impermeable to all standard gases.”
Those characteristics make graphene an ideal material for creating a separation membrane because it is durable and yet doesn’t require a lot of energy to push molecules through it, he said.
Other technical challenges will need to be overcome before the technology can be fully realized. For example, creating large enough sheets of graphene to perform separations on an industrial scale, and developing a process for producing precisely defined nanopores of the required sizes are areas that need further development. The CU-Boulder experiments were done on a relatively small scale.
The importance of graphene in the scientific world was illustrated by the 2010 Nobel Prize in physics that honored two scientists at Manchester University in England, Andre K. Geim and Konstantin Novoselov, for producing, isolating, identifying and characterizing graphene. Scientists see a myriad of potential for graphene as research progresses, from making new and better display screens and electric circuits to producing tiny biomedical devices.
The research was sponsored by the National Science Foundation; the Membrane Science, Engineering and Technology Center at CU-Boulder; and the DARPA Center on Nanoscale Science and Technology for Integrated Micro/Nano Electromechanical Transducers at CU-Boulder.
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Leading quantitative conservation biologist named CU’s first Colorado Chair in Environmental Studies
0October 1, 2012
The University of Colorado Boulder has hired its first Colorado Chair in Environmental Studies, an endowed chair awarded to Daniel Doak, a conservation biologist known for his quantitative analysis of how different government policies could affect the populations of species ranging from sea otters, California condors, corals and rare plants.
The endowed chair in environmental studies was made possible by $4 million in gifts made anonymously in 2009 and 2010 toward the chair.
Dr. Daniel Doak
Sharon Collinge, professor and director of the CU-Boulder Environmental Studies Program, called Doak a perfect match. “He epitomizes what we’re looking for,” she said.
Doak is especially skilled in interdisciplinary research, she said. He brings expertise in policy to his analyses of risks of energy development, for example. And he is widely cited for his research in quantitative conservation biology, which combines sophisticated computer modeling with varying policy scenarios to project changes in populations of rare species.
For instance, the Proceedings of the National Academies of Science recently published a study co-authored by Doak concluding that the California condor is chronically endangered by lead exposure from hunters’ spent ammunition.
While the free-flying condor population has risen in the last three decades, that increase has been achieved through captive breeding, monitoring and veterinary care, the study found. Meanwhile, the primary threat to the endangered bird — lead poisoning from bullets and shotgun shells lodged in carrion — has gone largely unmitigated, the study said.
Doak and his fellow researchers found no evidence that California’s 2008 partial ban on lead ammunition yielded any decrease in lead exposure and poisoning in condors.
Since 2007, Doak has served as a professor of zoology and physiology at the University of Wyoming. Previously, he was a faculty member at the University of California, Santa Cruz. His research has been funded by the National Science Foundation, U.S. Fish and Wildlife Service, U.S. Forest Service, California Department of Fish and Game and the U.S. Bureau of Land Management. Scholarly papers have cited his work more than 3,000 times since 1998.
Doak said he was drawn to CU-Boulder’s Environmental Studies Program because of its breadth, spanning disciplines ranging from biogeochemistry to political science to philosophy. This interdisciplinary focus is necessary to confront some of the world’s most intractable problems, Doak and Collinge said.
“That’s the only way we can really address and resolve some of the major environmental challenges that we face,” Collinge said.
Working with experts from a wide range of disciplines, Doak added, provides a motivation and opportunity “not once a year but every day to confront your own ignorance and thus to appreciate and learn new ideas and approaches.”
It is not that interdisciplinary work is always best, he added. “We need to train ourselves and our students to determine when the problem we are confronting requires an interdisciplinary approach. If you want to build a bridge that won’t fall down, you don’t need an interdisciplinary team. You need a good engineer.”
The critical question, he said, is the following: “Is this problem a nail that requires a hammer, or is this a problem that requires a lot of tools? And most environmental problems require an entire chest of tools and the different people who know how to use them.”
Collinge said students sometimes grasp this distinction better than professors do. “Students who are interested in the environment understand very deeply that they have to know something about politics and policies and how we make choices and why we make choices,” she said. “They’ve essentially pushed us, encouraged us to provide that broad and deep training for them.”
Of the donor’s gift, Collinge said, “This was incredibly generous. And we are really grateful.
“For me, it validates or speaks to the importance of what we’re doing,” she said. “With more than 1,000 undergraduate majors in environmental studies and 50 graduate students, enthusiasm was abundant even before the gift that enabled the endowed chair.”
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Wrap your mind around this! photo origami CU Boulder
0August 27, 2012
CU-Boulder ‘photo origami’ proposal
wins $2 million NSF grant
The art of origami has inspired children and artists all over the world because of the amazing objects that can be created by folding a simple piece of paper.
Now an engineering research team at the University of Colorado Boulder has won a $2 million grant from the National Science Foundation to develop a light-controlled approach for “self-assembly” mechanisms in advanced devices based on the same principles.
Known as “photo origami,” the idea is supported by NSF’s Emerging Frontiers in Research and Innovation program, which supports interdisciplinary teams working on rapidly advancing frontiers of fundamental engineering research.
CU-Boulder associate professor of mechanical engineering Jerry Qi will lead the team developing the photo origami technique. Collaborators will include CU faculty Robert McLeod of electrical engineering, Kurt Maute of aerospace engineering sciences and Elisabeth “Beth” Stade of mathematics, along with Patrick Mather of Syracuse University.
The ability to transform a flat polymer sheet into a sophisticated, mechanically robust 3-D structure will enable new approaches to manufacturing and design of devices from the microscopic to centimeter scales, according to the team. Examples include using extremely low-weight, high-strength materials to create micro-electromechanical systems with complicated 3-D architectures that can be used for microscopic sensors such as antennas or microphones, and miniature robotic devices for environmental monitoring.
Present barriers to the development of folding and unfolding mechanisms stem from the lack of understanding of scaling laws that allow researchers to generalize results obtained at various size scales, the inability to easily cause matter to “reorient” itself to achieve the desired folding patterns, and challenges in automated, sequential folding.
To overcome these challenges, the CU team will make use of recent fundamental advances in the control of polymer architecture through light-triggered chemical reactions.
“One has to accurately control how much deformation a material should have in order to obtain a precise folding angle and to determine where to fold or stop folding in order to avoid interference in the folding path and form the desired structure,” said McLeod, who will use the interaction of light with material deformation to develop optical waveguide transistors.
In this new form of logic circuit, light triggers the deformation of a soft polymer, which in turn switches the light on or off. In this way, the optical waveguide transistor will enable a structure to be pre-programmed with a folding pattern through a sequential set of switching events controlled by the shape of an origami sheet.
In recent years, CU researchers and their collaborators have made significant progress in using light to control and alter the structure of a polymer. They are able to both bend and stiffen polymer structures and to develop new, soft, shape-memory composite materials through photo-initiation techniques. Shape-memory composites are “smart” materials that have the ability to return from a temporary, deformed shape to their original shape when induced by a trigger.
In addition, the team will work with the local school district to provide research and educational opportunities for K-12 students and teachers.
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CU Boulder — LA air pollution has a surprise problem
0March 2, 2012
Gasoline worse than diesel when it
comes to some types of air pollution
The exhaust fumes from gasoline vehicles contribute more to the production of a specific type of air pollution — secondary organic aerosols — than those from diesel vehicles, according to a new study by scientists from the University of Colorado Boulder’s Cooperative Institute for Research in Environmental Sciences, or CIRES, NOAA’s Earth System Research Laboratory and other colleagues.
“The surprising result we found was that it wasn’t diesel engines that were contributing the most to the organic aerosols in L.A.,” said CIRES research scientist Roya Bahreini who led the study and also works at the National Oceanic and Atmospheric Administration’s ESRL. “This was contrary to what the scientific community expected.”
SOAs are tiny particles that are formed in air and make up typically 40-60 percent of the aerosol mass in urban environments. This is important because fine-particle pollution can cause human health effects, such as heart or respiratory problems.
Due to the harmful nature of these particles and the fact that they can also impact the climate and can reduce visibility, scientists want to understand how they form, Bahreini said. Researchers had already established that SOAs could be formed from gases released by gasoline engines, diesel engines and natural sources — biogenic agents from plants and trees — but they had not determined which of these sources were the most important, she said.
“We needed to do the study in a location where we could separate the contribution from vehicles from that of natural emissions from vegetation,” Bahreini said.
Los Angeles proved to be an ideal location. Flanked by an ocean on one side and by mountains to the north and the east, it is, in terms of air circulation, relatively isolated, Bahreini said. At this location, the scientists made three weekday and three weekend flights with the NOAA P3 research aircraft, which hosted an arsenal of instruments designed to measure different aspects of air pollution.
“Each instrument tells a story about one piece of the puzzle,” Bahreini said. “Where do the particles come from? How are they different from weekday to weekend, and are the sources of vehicle emissions different from weekday to weekend?”
From their measurements, the scientists were able to confirm, as expected, that diesel trucks were used less during weekends, while the use of gasoline vehicles remained nearly constant throughout the week. The team then expected that the weekend levels of SOAs would take a dive from their weekday levels, Bahreini said.
But that was not what they found.
Instead, the levels of SOA particles remained relatively unchanged from their weekday levels. Because the scientists knew that the only two sources for SOA production in this location were gasoline and diesel fumes, the study’s result pointed directly to gasoline as the key source.
“The contribution of diesel to SOA is almost negligible,” Bahreini said. “Even being conservative, we could deduce from our results that the maximum upper limit of contribution to SOA would be 20 percent.”
That leaves gasoline contributing the other 80 percent or more of the SOA, Bahreini said. The finding was published online March 1 in Geophysical Research Letters. “While diesel engines emit other pollutants such as soot and nitrogen oxides, for organic aerosol pollution they are not the primary culprit,” Bahreini said.
If the scientists were to apply their findings from the L.A. study to the rest of the world, a decrease in the emission of organic species from gasoline engines may significantly reduce SOA concentrations on a global scale as well. This suggests future research aimed at understanding ways to reduce gasoline emissions would be valuable.
The study was funded by NOAA’s Climate Change and Air Quality Programs, the California Air Resources Board and the National Science Foundation.
CIRES coauthors on the team include Joost de Gouw, Carsten Warneke, Harald Stark, William Dube, Jessica Gilman, Katherine Hall, John Holloway, Anne Perring, Joshua Schwarz, Ryan Spackman and Nicholas Wagner.
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CU Boulder study: fossils show evolution of bug hearing
0January 3, 2012
50-MILLION-YEAR-OLD CRICKET AND KATYDID FOSSILS
FROM COLORADO HINT AT ORIGIN OF INSECT HEARING
How did insects get their hearing? A new study of 50-million-year-old cricket and katydid fossils sporting some of the best preserved fossil insect ears described to date are helping to trace the evolution of the insect ear, says a new study involving the University of Colorado Boulder and the University of Illinois at Chicago.
According to University of Colorado Museum of Natural History paleontologist Dena Smith and University of Illinois Professor Roy Plotnick, who collaborated on the new study at the National Evolutionary Synthesis Center, or NESCent, in Durham, N.C., insects hear with help from some very unusual ears.
Grasshoppers have ears on their abdomens. Lacewings have ears on their wings. The ears of the tachinid fly are tucked under the chin. “Insects have ears on pretty much every part of their body except on their head proper,” Plotnick said.
Insects have evolved ears at least 17 times in different lineages, said Smith, also an assistant professor in CU-Boulder’s geological sciences department. Smith and Plotnick are trying to figure out when different insects got their ears, and whether predators may have played a role.
Modern insects use their ears to tune in to each other’s chirps, trills and peeps. Think of the chorus of crickets, or the love songs of cicadas. But many species can also pick up sounds beyond the range of human hearing, such as the high-pitched sonar of night-hunting bats, according to Smith and Plotnick.
Crickets, moths and other flying insects have ultrasound-sensitive hearing and can hear bats coming, diving or swerving in midflight to avoid being eaten. Insects that evolved such supersensitive hearing would have had a crucial survival advantage, the researchers said.
“The big evolutionary trigger for the appearance of hearing in many insects is thought to be the appearance of bats,” Plotnick said. “Prior to the evolution of bats we would expect to find ears in relatively few insects, but after that we should see ears in more insect groups,” he explained.
Did insect ears get an upgrade when bats came to be? Before this study the fossil evidence for insect hearing was too poorly preserved or scantily described to know for sure, according to the researchers.
To find out, Plotnick and Smith turned to remarkably well-preserved fossils from a series of lake deposits in Wyoming, Utah and Colorado known as the Green River Formation, where some of the earliest bats are found.
Roughly 50 million years ago, fine-grained sediment covered and buried the animals that lived there and managed to preserve them in exquisite detail. “You can see every tiny feature down to the veins in their wings and the hairs on their legs,” said Smith, who has been studying Green River fossils for more than 15 years.
For this study, the researchers examined fossils from a Green River site in Colorado, focusing on crickets and katydids, which have ears on their front legs, just below their knees.
The team scoured more than 500 museum drawers of Green River fossils for crickets and katydids with intact front legs, looking for evidence of ears. “You can just make them out with the naked eye,” Plotnick said. “They look like the eye of a needle.”
In crickets and katydids living today, the ear is a tiny oval cavity with a thin membrane stretched over it that vibrates in response to sound, much like our own eardrum.
The fossil ears measured half a millimeter in length, and were virtually identical in size, shape and position to their modern counterparts. The findings suggest that this group of insects evolved their supersensitive ultrasonic hearing long before bat predators came to be, the researchers say. “Their bat-detecting abilities may have simply become apparent later,” Smith said. “The next step is to look for ears in other insect groups.”
The study appears in this month’s issue of the Journal of Paleontology. NESCent is a nonprofit science center dedicated to cross-disciplinary research in evolution and is jointly operated by Duke University, the University of North Carolina at Chapel Hill and North Carolina State University, with funding from the National Science Foundation.
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CU team discovers ancient road
0October 5, 2011
CU-BOULDER TEAM DISCOVERS ANCIENT ROAD AT MAYA
VILLAGE BURIED BY VOLCANIC ASH 1,400 YEARS AGO
A University of Colorado Boulder-led team excavating a Maya village in El Salvador buried by a volcanic eruption 1,400 years ago has unexpectedly hit an ancient white road that appears to lead to and from the town, which was frozen in time by a blanket of ash.
The road, known as a “sacbe,” is roughly 6 feet across and is made from white volcanic ash from a previous eruption that was packed down and shored up along its edges by residents living there in roughly A.D. 600, said CU-Boulder Professor Payson Sheets, who discovered the buried village known as Ceren near the city of San Salvador in 1978. In Yucatan Maya, the word “sacbe” (SOCK’-bay) literally means “white way” or “white road” and is used to describe elevated ancient roads typically lined with stone and paved with white lime plaster and that sometimes connected temples, plazas and towns.
“Until our discovery, these roads were only known from the Yucatan area in Mexico and all were built with stone linings, which generally preserved well,” said Sheets of CU’s anthropology department. “It took the unusual preservation at Ceren to tell us the Maya also made them without stone. I’d like to say we saw some anomaly in the ground-penetrating radar data that guided us to the Ceren sacbe, but that was not the case. This was a complete surprise.”
The sacbe was struck almost dead-on by the excavators of the 3-meter by 3-meter test pit, said Sheets, with the full width of road visible. In order to follow the sacbe, two subsequent test pits were excavated to the north and confirmed the sacbe had a minimum length of at least 148 feet long — about half the length of a football field.
The sacbe appears to be headed toward two Ceren ceremonial structures less than 100 feet away — buildings that were unearthed in Ceren by Sheets and his team in 1991. One structure is believed to have been used by a female shaman. The adjacent community ceremonial structure contained evidence — including the bones of butchered deer, a deer headdress painted red and blue and a large alligator-shaped pot — that large quantities of food and drink were being prepared and dispensed to villagers in the town plaza during what Sheets believes was a crop-harvesting ceremony.
“We know there was a celebration going on when the eruption hit,” said Sheets. “And we’ve found no evidence of anyone going back to their houses, gathering up valuables, and fleeing, because all the household doors were tied shut. We think people may have left the plaza and run south, possibly on the sacbe, because the danger was to the north.”
Radiocarbon dates from Ceren indicate the eruption occurred in roughly A.D. 630, and CU researchers have even pinpointed the month and time of day the fiery mass of ash and debris from the Loma Caldera volcano rained down on the town from less than a third of a mile away. Sheets believes the eruption hit at roughly 7 p.m. on an August evening because of the mature corn stalks preserved in ash casts, the fact that the farming implements had been brought inside, the sleeping mats had not yet been rolled out, meals had been served but the dishes were not yet washed, and corn was set into pots to soak in water overnight.
Sheets said it is logical that the villagers in the plaza might have used the white sacbe as an emergency route to flee the destruction of the volcano in the dark of night. “How far they might have gotten, I don’t know,” said Sheets. “It would have been a footrace. I think it is very likely we will find bodies as we follow the sacbe southward in future excavations.” To date, no human remains have been found at the village.
Sacbeob, the plural of sacbe, had strong practical, political and spiritual connotations in the Pre-Columbian Yucatan, said Sheets. Some were fairly long — up to 40 miles — while others stretched less than 50 feet. Because of the high level of preservation at Ceren, the researchers can see hand marks of farmers who were repairing the edges of the sacbe.
While there is speculation the Ceren sacbe may have led to the Maya center of San Andres roughly three miles to the south, there is no evidence of that yet, Sheets said.
While some refer to Ceren as “The New World Pompeii,” Sheets is quick to point out the differences. Pompeii was an affluent Roman resort community with multi-story concrete houses, stone streets and marble statues, while Ceren was a modest farming community. Because tiny particles of hot, moist ash blanketed Ceren and packed the thatch-roofed structures, gardens and agricultural fields, the preservation of organic materials is greater than at Pompeii, where dry, pea-sized particles rained down in the Mount Vesuvius eruption of A.D. 79.
Sheets has visited Pompeii, and researchers from Pompeii have visited Ceren, analyzing the similarities and differences at the sites. “When they tell me they wish they had this kind of preservation level at Pompeii, I tell them I wouldn’t mind finding a marble statue or two at Ceren,” said Sheets.
The Ceren preservation is so great that researchers have found marks of finger swipes in ceramic bowls, human footprints in gardens hosting ash casts of plants like corn and manioc, thatched roofs, woven baskets and pots filled with beans. Researchers have found the remains of mice that lived in the thatched roofs of kitchen areas, and entomologists have even been able to discern that two species of ants inhabited the village, Sheets said.
While much of the Maya archaeological record points to rigid, top-down societies where the elite made most political and economic decisions, there is evidence of some autonomy at Ceren, including divergent choices by farmers regarding crop cultivation techniques that were discovered this summer, said Sheets. He believes a community building with two large benches in the front room may have hosted village elders when it came time to make community decisions at Ceren.
In addition to Sheets, the 2011 team included CU-Boulder graduate students Christine Dixon, Alexandria Halmbacher and Theresa Heindel, University of Cincinnati Professor David Lentz, University of Cincinnati graduate student Christine Hoffer, Celine Lamb from the Sorbonne in Paris and 23 local Salvadoran workers. The 2011 field season was funded by the National Science Foundation.
“Students on the project are essential,” said Sheets. “They put up with less than ideal living conditions and they do valuable work, sometimes pursuing their own research paths based on discoveries they make at the site.” Since 1978, more than 30 undergraduate and graduate students have worked under Sheets at Ceren, including 14 who have received or are pursuing master’s or doctoral degrees.
“When I first heard about Ceren, I immediately wanted to know more,” said master’s degree candidate Theresa Heindel, who came to CU-Boulder after graduating from the University of Wisconsin-Madison and who spent the 2011 field season assessing crop cultivation in Ceren’s agricultural fields that were frozen in time by ash. “We don’t see this type of cultivation anywhere in Central America, and we don’t see this level of preservation anywhere in the world.”
In 2009 Sheets and his team discovered a previously unknown Maya agriculture system at Ceren — intensively cultivated manioc fields that yielded at least 10 tons of manioc shortly before the eruption 1,400 years ago. It was the first and only evidence of intense manioc cultivation at any New World archaeology site and Sheets and others believe such large manioc crops could have played a vital role in feeding indigenous societies living throughout tropical Latin America, he said.
Sheets has collaborated with the National Science Foundation, the National Geographic Society, the Smithsonian Institution, the Getty Conservation Institute and a number of universities since 1978. The 10-acre Joya de Ceren Archaeological Park was declared a UNESCO World Heritage Site in 1993.
“When the radiocarbon dates on the thatched roofs came back in 1978, I saw the rest of my professional life. I knew I did not need to look for any more new archaeological sites,” said Sheets. “There is well over a century of research still to be done at Ceren — in some ways we’ve only scratched the surface.”
A video news story on Ceren is available by going to http://www.colorado.edu/news/ and clicking on the story headline.
-CU-
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CU wins solar observatory HQ
0September 30, 2011
CU-BOULDER WINS BID TO HOST NATIONAL
SOLAR OBSERVATORY HEADQUARTERS
The University of Colorado Boulder was selected today to host the headquarters for the National Solar Observatory, the nation’s leading scientific research program in ground-based solar astronomy.
The National Solar Observatory, or NSO, provides scientists access to the world’s largest collection of optical and infrared solar telescopes and auxiliary instruments to observe the sun in detail. NSO scientists conduct theoretical and observational research focused on understanding the underlying causes of solar variability and its impact on the Earth and the Earth’s space environment.
NSO is operated under the auspices of the Association of Universities for Research in Astronomy, or AURA, on behalf of the National Science Foundation, with key observing facilities in New Mexico and Arizona, and is currently leading the effort to build the 4-meter Advanced Technology Solar Telescope, a technological innovation scheduled to begin observations from Haleakala on Hawaii’s Maui island in 2016.
In April 2011, CU-Boulder was selected as one of two finalists along with the University of Alabama in Huntsville. CU-Boulder partnered with the New Jersey Institute of Technology and the University of Hawaii on the winning bid and will implement a collaborative graduate education program that will enhance the role of NSO in research and education on a national level.
“We are delighted to be named host of the National Solar Observatory, which is of great importance to the nation and world in terms of better understanding solar physics and space weather,” said CU-Boulder Provost Russell Moore, who submitted the proposal on behalf of the university. “Landing this vital research center is a testimony to the strength of CU-Boulder’s world-class faculty in space science and solar research, the support of the city of Boulder’s leadership, and the vital assistance and support of Congressmen Ed Perlmutter and Jared Polis and U.S. Senators Mark Udall and Michael Bennett.”
Stein Sture, vice chancellor for research at CU-Boulder, echoed Moore, saying that the NSO’s presence will benefit CU’s research and teaching mission in dynamic ways.
“As one of the world’s leading institutions in solar research, we now will have even greater access to ground-based observing facilities and will be able to continue to provide unrivaled opportunities for our students and research scientists alike,” said Sture.
The NSO’s mission is to advance knowledge of the sun both as an astronomical object and as the dominant external influence on Earth by providing forefront observational opportunities to the research community. The mission includes the operation of cutting-edge facilities and the continued development of advanced instrumentation both in-house and through partnerships, as well as conducting solar research and educational and public outreach, said Moore.
NSO currently has offices and ground-based observing facilities at Kitt Peak, Ariz., and Sacramento Peak, N.M., which will cease operations when the new Advanced Technology Solar Telescope is completed. The new CU-Boulder headquarters for NSO will be the primary science, instrument development and data analysis site for the new solar telescope.
“The educational and collaborative opportunities that will be enabled by the relocation of the NSO headquarters in Boulder are exceptional,” said Associate Professor Mark Rast of CU-Boulder’s Department of Astrophysical and Planetary Sciences and leader of the team that wrote the proposal to AURA. “The sun is the only star close enough to allow detailed observations of magnetic and dynamical processes central to many phenomena in the universe. The NSO’s unique capabilities will add to and augment ongoing efforts in Boulder, ranging from stellar astrophysics and the space environments of extra-solar planets to space weather prediction here at Earth. We are very excited by the possibilities, and thrilled that Boulder was chosen as host.”
Several CU-Boulder departments were involved in the NSO headquarters bid: the Department of Astrophysical and Planetary Sciences, the Department of Physics and the Department of Aerospace Engineering Sciences. The quality of students in these departments was likely a significant consideration in the decision to bring the NSO headquarters to Boulder, and major research opportunities for both graduate and undergraduate students will accompany the NSO move, particularly once the Advanced Technology Solar Telescope comes on line, Rast said.
“Students will have the opportunity to participate in discovery science using a telescope with about 10 times better spatial resolution than the best current space-borne solar imagers,” Rast said.
In addition to the university, Colorado and Boulder offer a host of national laboratories as potential collaborators with the NSO. Other laboratories and centers in Colorado expected to participate and benefit include the National Oceanic and Atmospheric Administration, the National Center for Atmospheric Research and the National Institute for Standards and Technology.
“This is extremely exciting for the university, the state of Colorado and solar scientists around the world,” said LASP Director Dan Baker, an internationally known expert in space physics and space weather. “CU-Boulder researchers have been studying the sun for more than 50 years. Our continued leadership in this area is a tremendous asset for our students. Solar research represents a branch of science that is crucial for our nation’s future. The sun is a driver of Earth’s weather and climate and its extreme behavior can have immense economic and societal consequences through its impact on the space environment.”
The consolidation of NSO into a single site located on CU-Boulder’s East Campus is expected to result in jobs for up to 70 scientists, engineers and staff with an annual payroll of roughly $20 million. The new facility will bolster an already formidable high-tech and aerospace industry in the state. Colorado is third behind California and Washington, D.C., in aerospace industry presence.
“The NSO is an excellent addition to the dynamic research and entrepreneurial activity in Boulder,” said Boulder City Manager Jane Brautigam. “The federal labs and nationally recognized CU-Boulder, combined with an aggressive environment for financing high-tech startups, have made Boulder a hot spot nationally for its intellectual capital and business environment. We are delighted to welcome the NSO to our vibrant community.”
FACT SHEET
NATIONAL SOLAR OBSERVATORY
• The National Solar Observatory is the primary provider of key ground-based facilities to the United States solar science community to probe all aspects of the sun. The NSO is operated by the Associated Universities for Research in Astronomy, or AURA, under a cooperative agreement with the National Science Foundation for the benefit of the astronomical community.
• NSO’s mission is to advance the understanding of the sun both as an astronomical object and the dominant external influence on Earth. The mission includes the operation of cutting-edge facilities and the continued development of advanced instrumentation to conduct solar research, education and outreach.
• NSO goals include understanding the mechanisms generating solar cycles, the relationships between the sun’s interior, surface and outer envelope, and events like coronal heating, solar flares and coronal mass ejections.
• NSO currently has offices and observatories in Sunspot and at Sacramento Peak (the Dunn Solar Telescope) in New Mexico and in Tucson and at Kitt Peak (the McMath-Pierce Solar Telescope) in Arizona.
• NSO also oversees a community-based research effort called the Global Oscillation Network Group, or GONG, a six-station network that uses helioseismology to continuously observe the sun’s five-minute oscillations from California, Hawaii, Chile, the Canary Islands, India and Australia.
• NSO has begun work on the 4-meter Advanced Technology Solar Telescope that will be placed on the summit of Haleakala on Maui, Hawaii, taking the place of the two primary observing facilities in New Mexico and Arizona. The summit of Haleakala is 10,000 feet in altitude — which is above one-third of Earth’s atmosphere — providing great clarity, dryness and air stillness for precise solar observations.
• AURA is a consortium of universities and other research institutions that operates world-class astronomical observatories. There are 38 U.S. institutions and seven international affiliates. In addition to NSO, AURA manages three other centers – the National Optical Astronomy Observatory at Kitt Peak, Ariz., and Cerra Tololo, Chile; the Space Telescope Science Institute in Baltimore; and the AURA Observatory, a complex of Chilean observing facilities.
• The relocation of the NSO headquarters from New Mexico and Arizona to CU-Boulder is not expected to begin until 2016.
-CU-
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UNEXPECTED ADHESION PROPERTIES OF GRAPHENE MAY LEAD TO NEW NANOTECHNOLOGY DEVICES
0August 23, 2011
by Ron Baird, news editor
in News
Graphene, considered the most exciting new material under study in the world of nanotechnology, just got even more interesting, according to a new study by a group of researchers at the University of Colorado Boulder.
The new findings — that graphene has surprisingly powerful adhesion qualities — are expected to help guide the development of graphene manufacturing and of graphene-based mechanical devices such as resonators and gas separation membranes, according to the CU-Boulder team. The experimentsshowed that the extreme flexibility of graphene allows it to conform to the topography of even the smoothest substrates.
Graphene consists of a single layer of carbon atoms chemically bonded in a hexagonal chicken wire lattice. Its unique atomic structure could some day replace silicon as the basis of electronic devices and integrated circuits because of its remarkable electrical, mechanical and thermal properties, said Assistant Professor Scott Bunch of the CU-Boulder mechanical engineering department and lead study author.
A paper on the subject was published online in the Aug. 14 issue of Nature Nanotechnology. Co-authors on the study included CU-Boulder graduate students Steven Koenig and NarasimhaBoddeti and Professor Martin Dunn of the mechanical engineering department.
“The real excitement for me is the possibility of creating new applications that exploit the remarkable flexibility and adhesive characteristics of graphene and devising unique experiments that can teach us more about the nanoscale properties of this amazing material,” Bunch said.
Not only does graphene have the highest electrical and thermal conductivity among all materials known, but this “wonder material” has been shown to be the thinnest, stiffest and strongest material in the world, as well as being impermeable to all standard gases. It’s newly discovered adhesion properties can now be added to the list of the material’s seemingly contradictory qualities, said Bunch.
The CU-Boulder team measured the adhesion energy of graphene sheets, ranging from one to five atomic layers, with a glass substrate, using a pressurized “blister test” to quantify the adhesion between graphene and glass plates.
Adhesion energy describes how “sticky” two things are when placed together. Scotch tape is one example of a material with high adhesion; the gecko lizard, which seemingly defies gravity by scaling up vertical walls using adhesion between its feet and the wall, is another. Adhesion also canplay a detrimental role, as in suspended micromechanical structures where adhesion can cause device failure or prolong the development of a technology, said Bunch.
The CU research, the first direct experimental measurements of the adhesion of graphene nanostructures, showed that so-called “van der Waals forces” — the sum of the attractive or repulsive forces between molecules — clamp the graphene samples to the substrates and also hold together the individual graphene sheets in multilayer samples.
The researchers found the adhesion energies between graphene and the glass substrate were several orders of magnitude larger than adhesion energies in typical micromechanical structures, an interaction they described as more liquid-like than solid-like, said Bunch.
The CU-Boulder study was funded primarily by the National Science Foundation and the Defense Advanced Research Projects Agency.
The importance of graphene in the scientific world was illustrated by the 2010 Nobel Prize in physics that honored two scientists at Manchester University in England, Andre K. Geim and Konstantin Novoselov, for producing, isolating, identifying and characterizing graphene.
There is interest in exploiting graphene’s incredible mechanical properties to create ultrathin membranes for energy-efficient separations such as those needed for natural gas processing or water purification, while graphene’s superior electrical properties promise to revolutionize the microelectronics industry, said Bunch.
In all of these applications, including any large-scale graphene manufacturing, the interaction that graphene has with a surface is of critical importance and a scientific understanding will help push the technology forward, he said.
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Evidence of global climate in Southern Hemisphere
0August 22, 2011
by Ron Baird, news editor
in News
Aug. 22, 2011
SOUTHERN SOUTH AMERICAN WILDFIRES
EXPECTED TO INCREASE, SAYS CU STUDY
A new University of Colorado Boulder study indicates a major climate oscillation in the Southern Hemisphere that is expected to intensify in the coming decades will likely cause increased wildfire activity in the southern half of South America.
The research team used tree rings dating to 1506 to track past wildfire activity in the forests of Patagonia tied to the Southern Annular Mode, or SAM, a climate oscillation that creates low atmospheric pressure in the Antarctic that is tied to warmer and drier conditions in southern South America. The tree rings showed that when SAM was in its positive phase, there were widespread fires in both dry woodlands and rainforests in Patagonia, a region that straddles Argentina and Chile, said CU-Boulder Research Associate Andres Holz, lead study author.
“Our study shows for about the past 250 years, the Southern Annular Mode has been the main driver in creating droughts and fires in two very different ecosystems in southern South America,” said Holz. “Climate models suggest an increase in SAM beginning in the 1960s due to greenhouse gas increases and Antarctic ozone depletion probably will cause this region to be drought-prone and fire-prone for at least the next 100 years.”
A paper on the subject by Holz and CU-Boulder geography Professor Thomas Veblen was published in Geophysical Research Letters.
Holz and Veblen compared past wildfire records for two ecologically distinct regions in Patagonia — the relatively dry region of southern Patagonia in Argentina and the temperate rainforest of Patagonia in northern Chile. While the tree ring historical record showed increased fires in both regions correlated with a positive SAM, the trend has been less pronounced in northern Patagonia in the past 50 years, likely because of fire-suppression efforts there, Holz said.
But the decades of fire suppression have caused the northern Patagonian woodlands to become denser and more prone towildfire during hot and dry years, Holz said.
“Even in areas of northern Patagonia where fire suppression previously had been effective, record surface areas of woodlands and forests have burned in recent years of extreme drought,” said Veblen. “And since this is in an area of rapid residential growth into wildland-urban interface areas, this climate-driven trend towards increasing fire risk is becoming a major problem for land managers and homeowners.”
The two CU-Boulder researchers studied reconstructions of tree rings going back more than 500 years from 432 trees at 42 sample sites in northern Argentina and southern Chile — the largest available data set of annual, readable tree ring records in the Southern Hemisphere. The tree rings, which indicate climate cycles and reveal the scars of old fires, showed that wildfires generally increased in both regions when SAM was in its strong, positive phase.
Although the Antarctic ozone hole stopped growing in about 2000 as a result of a ban on ozone-depleting gases and now appears to be slowly repairing itself, a 2011 paper by researchers at the National Center for Atmospheric Research in Boulder indicates ozone recovery and greenhouse gas influences essentially will cancel each other out, preventing SAM from returning to its pre-1960s levels.
“Before the Industrial Revolution, SAM intensified naturally at times to create drought situations in Patagonia,” Holz said. “But in the last 80 years or so, the natural variation has been overwhelmed by a bias toward a positive SAM phase because of ozone-depleting chemicals and greenhouse gases we have put in the atmosphere.”
The research effort was supported by the National Geographic Society, the National Science Foundation, the CU Beverly Sears Small Grants Program and the Council on Research and CreativeResearch of the CU Graduate School.
“As warming and drying trends continue, it is likely that wildfire activity will increase even in woodland areas where fire suppression has previously been effective,” Holz and Veblen wrote in Geophysical Research Letters.
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NEW CU-BOULDER STUDY REVEALS BACTERIA FROM DOG FECES IN OUTDOOR AIR OF URBANIZED AREAS
0August 18, 2011
NEW CU-BOULDER STUDY REVEALS BACTERIA FROM DOG FECES IN OUTDOOR AIR OF URBANIZED AREAS
Bacteria from fecal material — in particular, dog fecal material — may constitute the dominant source of airborne bacteria in Cleveland’s and Detroit’s wintertime air, says a new University of Colorado Boulder study.
The CU-Boulder study showed that of the four Midwestern cities in the experiment, two cities had significant quantities of fecal bacteria in the atmosphere — with dog feces being the most likely source.
“We found unexpectedly high bacterial diversity in all of our samples, but to our surprise the airborne bacterial communities of Detroit and Cleveland most closely resembled those communities found in dog poop,” said lead author Robert Bowers, a graduate student in CU-Boulder’s ecology and evolutionary biology department and the CU-headquartered Cooperative Institute for Research in Environmental Sciences, or CIRES. “This suggests that dog poop may be a potential source of bacteria to the atmosphere at these locations.”
The study was published July 29 in Applied and Environmental Microbiology. Co-authors on the study included Noah Fierer, an assistant professor in CU-Boulder’s ecology and evolutionary biology department and a CIRES fellow; Rob Knight, an associate professor in CU-Boulder’s chemistry and biochemistry department; Amy Sullivan and Jeff Collett Jr. of Colorado State University; and Elizabeth Costello of the Stanford University School of Medicine.
Scientists already knew that bacteria exist in the atmosphere and that these bacteria can have detrimental effects on human health, triggering allergic asthma and seasonal allergies, Fierer said. But it is only in recent years that researchers have realized that there is an incredible diversity of bacteriaresiding in the air, he said.
“There is a real knowledge gap,” said Fierer. “We are just starting to realize this uncharted microbial diversity in the air — a place where you wouldn’t exactly expect microbes to be living.”
To gain further understanding of just what microbes are circulating in urban environments, the team analyzed the local atmosphere in the summer and winter at four locations in the Great Lakes region of the U.S. Three of the locations — Chicago, Cleveland and Detroit — are major cities with populations of greater than 2 million, and one location, Mayville, Wis., is a small town with a population of less than 6,000.
The team used nearly 100 air samples collected as part of a previous study conducted by Colorado State University. The CSU experiment investigated the impact of biomass burning and involved studying the impacts of residential wood burning and prescribed fires on airborne fine particle concentrations in the midwestern United States.
“What we’ve been looking at are the numbers and the types of bacteria in the atmosphere,” Fierer said. “We breathe in bacteria every minute we are outside, and some of these bugs may have potential health implications.”
The researchers analyzed the bacteria’s DNA in the collected air samples and compared the bacteria they found against a database of bacteria from known sources such as leaf surfaces, soil, and human, cow and dog feces. They discovered that the bacterial communities in the air were surprisingly diverse and also that, in two of the four locations, dog feces were a greater than expected source of bacteria in the atmosphere in the winter.
In the summer, airborne bacteria come from many sources including soil, dust, leafsurfaces, lakes and oceans, Bowers said. But in the winter, as leaves drop and snow covers the ground, the influence that these environments have as sources also goes down. It is during this season that the airborne communities appeared to be more influenced by dog feces than the other sources tested in the experiment, he said.
“As best as we can tell, dog feces are the only explanation for these results,” Fierer said. “But we do need to do more research.”
The team plans to investigate the bacterial communities in other cities and to build a continental-scale atlas of airborne bacterial communities, Fierer said. “We don’t know if the patterns we observed in those sites are unique to those cities,” he said. “Does San Francisco have the same bacteria as New York? Nobody knows as yet.”
Fierer believes it is important to pin down the types of bacteria in the air, how these bacteria vary by location and season, and where they are coming from.With this information, scientists can then investigate the possible impacts on human health, he said.
“We need much better information on what sources of bacteria we are breathing in every time we go outside,” Fierer said.
The study was funded by the CIRES Innovative Research Program, the U.S.
Environmental Protection Agency, the National Science Foundation, the Howard Hughes Medical Institute and the National Institutes of Health. The aerosol sample collection for this project was supported by the Lake Michigan Air Directors Consortium.
