Volume 3, Issue 20 April/May 2006
Improving Impoverished Children's Brains
Marian Diamond is the co-author of the book Magic Trees of the Mind: How to Nurture Your Child's Intelligence, Creativity, and Healthy Emotions from Birth Through Adolescence
For the last four decades, UC Berkeley integrative biologist Marian Diamond has studied how the brains of rats are affected by enriched environments. In groundbreaking research, she quantified how good diet, stimulating games and objects, and, well, fun, spur the growth of better brains. Recently, Diamond has been applying what she learned in her laboratory to a group of people whose environment is anything but enriched: young orphans living in a Cambodian forest. The project is called Enrichment In Action
"After forty years of research, I had gotten what I wanted from impoverished rat brains," says Diamond. "When I had the results of all these studies, I realized that now was the time to transfer all these data to help impoverished humans."
Diamond's original plan was to launch her Enrichment In Action program at a hospital in Siem Reap, Cambodia where landmine-injured children had recovered. The director of the hospital introduced Diamond to a child with bandaged legs who would have to remain in the bed for six weeks.
"In our animal studies, we showed the brain could be statistically decreased in four days with a lack of stimulation," Diamond says. "What would happen to his brain in six weeks?"
As it turned out, there were actually very few children injured by land mines in the area at the time, but there were many orphans. Several years ago, the hospital directed Diamond to the Wat Racha Sin Khon orphanage in the forest near the temple of Angkor Wat in northwestern Cambodia. Managed by monks, the orphanage had no electricity, running water, or septic change. Conditions were brutal for the children living there, aged 10 to 17.
The children of the Racha Sin Khon orphanage.
Diamond's first step was to get the kids on a better diet. In studies in Africa and elsewhere, Diamond had determined that nerve cells in the brain depend on healthy diets to form the branches, called dendrites, that enable learning. The orphans' meals of fish and rice, with the rare vegetable, wouldn't do the trick. The researchers' first action was to provide the children with vitamins and mineral supplements. Since then, the children planted a vegetable garden and the children's diet, Diamond says, has greatly improved.
"Meanwhile, the kids line up to take their vitamins that are handed out each day by the older children," she says.
Since the middle of last century, UC Berkeley has pioneered rat studies where the impact of sensory stimuli on development is analyzed in controlled environments. Rats kept in roomy cages with a variety of toys and objects to play with are compared to animals alone in small cages. The studies have proven that interaction with learning games also increases the number of dendrites in the brain.
"Sure, the kids at the orphanage could play games with sticks and stones, but they really needed much more stimulating objects to change their brains," Diamond says.
On an early visit with the children, Diamond and her colleagues brought the visual perception game SET that is based solely on colors, numbers, and shapes. This was perfect as Diamond does not speak their native language of Khmer. Quickly, she says, the children began to play SET as well as the kids she worked with in Berkeley. After a series of other lessons in art and geography, Diamond realized that an appreciation of the human body could encourage the kids to better care for themselves.
"The cook at the hotel where I stayed would go to the butcher and pick up hearts, lungs, and kidneys for me to use to teach anatomy," she says.
As her first experience with the children drew to a close, Diamond asked them what they were most interested in learning. The answers were almost unanimously English and computer skills.
Marian Diamond teachers the children anatomy.
"The government pays for education through sixth grade, but after that the kids get nothing," Diamond says. "The boys become rice farmers, the girls become prostitutes or maybe get low-paying work like sewing. My purpose is to get them fluent enough in a skill so they can get good jobs."
Through donor support, Diamond was able to hire two Cambodian men she met during her first visit—one was her driver, the other her translator—to teach the children while she's back at Berkeley. With his salary from the project, one of the men is now also studying computer science at the local university.
He's also helping the children become computer literate. As of last year, the orphanage is now wirelessly online via two PCs and a laptop computer powered by car batteries. Recently, Diamond says, a nurse in London who had previously worked at the Angkar Hospital was surprised and delighted to receive an email from one of the kids she had met at the orphanage.
For Diamond, it's these little steps that bring her closer to her goal of developing an Enrichment In Action program that could be used by other orphanages and tailored to the specific needs of the children who live there.
"It's all within the culture of the Cambodian community that these children are now able to grow," Diamond says. "Ever since I was a young woman, I knew I didn't want my research to sit on a library shelf where only a handful of scientists would appreciate it. I always wanted to put it into action."
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Island Tales
Patrick Kirch holds the Class of 1954 Chair in Archaeology.
UC Berkeley professor Patrick Kirch spends a great deal of time digging in garbage heaps. The discarded bits of plants, animal bones, and other detritus that he discovers give him great insight into the people behind the rubbish. Kirch, an archaeologist, isn't after stinky, urban garbage though. His field research takes him to the Pacific Islands where trash heaps that are hundreds or thousands of years old hold clues about how humans may have impacted their environments, and vice versa.
"I use islands as models for how people and the environment dynamically interact over time scales of centuries and millennia," says Kirch, professor of anthropology and director of UC Berkeley's Oceanic Archaeology Laboratory.
Recently, Kirch and his colleagues pieced together a mystery about the ecosystem of Mangareva, a cluster of islands in southeastern Polynesia. And it's not an isolated story. What he found in Mangareva may help scientists determine what caused the ecological destruction of nearby Easter Island, as described in Jared Diamond's bestselling book, Collapse.
In this photo, Kirch records stratigraphy at the Mangareva site where the extinct bird bones were recovered. (courtesy the researcher)
Mangareva is a small group of volcanic islands surrounded by a barrier reef and lagoon system. Thousands of years ago, Mangareva had a thriving ecosystem. After the Polynesians settled there around 1,000 AD, things got ugly rather quickly. Islanders cut down the trees, stifling their own agriculture in the process and triggering a downward spiral that resulted in the degraded grass land that still exists today.
"It's basically a terminally ill ecosystem," Kirch says.
The question is how it got that way and why it didn't heal itself. For example, why didn't the trees ever grow back, even to this day? Are humans to blame? Kirch and his colleagues found the answer in the garbage, seabird bones long since picked clean by humans.
"I dig these up while being very careful to take note of the stratigraphic layers, the dating, and all of these pieces of data," he says. "Then I collaborate with natural scientists to identify what I find and what it may mean."
A large basalt "table" sits atop the Paepae, or floor of a house, at Atituiti Ruga, Mangareva. (Patrick Kirch photo)
For millions of years before humans arrived, large populations of seabirds roosted and nested on the islands. The researchers have discovered the bones of nearly two dozen species, most of which no longer exist in Mangareva. The seabirds, Kirch explains, fished in the surrounding ocean and returned to roost on the island, peppering the terrain with their droppings, an excellent source of nutrients for the soil. Then the settlers came.
"The birds were a wonderful food source for settlers and probably completely naive about human predation," Kirch says.
The settlers also brought with them a small species of rat that could have feasted on the fledglings, eggs, and vegetation. Within 200 years of settlement, the seabirds were gone. Meanwhile, logging had left the land bare and the soil lacked the nutrients necessary for regeneration. That in turn severely limited the Mangarevans' ability to grow crops. Kirch's research doesn't stop there though.
"I'm also interested in the reciprocal question," he says. "Once people change their environment, how do they adapt their social and cultural systems in response?"
The Mangarevans responded by becoming fishermen. With that as their only real natural resource left, the social importance of the fisherman became much greater there than anywhere else in Polynesia, Kirch says.
"The missionary accounts say that the fisherman, by withholding gifts of fish to the chief, could bring down the chief's power," he says. "This is an example of what happens when people come onto islands that have been isolated and undergoing natural evolution for millions of years."
A map depicting the islands where Kirch conducts research.
Mangareva is only one of many groups of islands that Kirch has explored in decades of fieldwork. He's currently principal investigator on a major cross-disciplinary project to study human ecodynamics in the Hawaiian ecosystem. The Hawaiian Biocomplexity Project is a collaboration with scientists from Stanford University, the University of Hawaii, University of Washington, University of Wisconsin, and University of California, Santa Barbara.
The researchers are studying how the Polynesian settlers, who arrived 1200 years ago, interacted with the pristine dryland areas of Maui and Hawaii. Already, the scientists have begun to discern how intense cultivation strained soil nutrients and that those early agricultural systems helped give rise to certain hierarchical, aggressive, and territorially expansive chiefdoms on the islands.
"Looking at the archaeology in these places is like a window into another world," Kirch says.
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Nanowired
Peidong Yang is an associate professor of chemistry. (courtesy Berkeley Lab)
The future of tomorrow's electronic devices, from microchips to biosensors to solar cells, may be a tiny wire that's 4,000 times thinner than a human hair. UC Berkeley chemist Peidong Yang has pioneered methods to grow these nanowires from the bottom-up. At such a small scale, unusual physical properties emerge that could lead to solar cell paint, labs-on-a-chip that analyze single cells to detect disease, and new computer processors thousands of times faster than today's speediest PCs.
"We're attacking three fundamental issues," Yang says. "Can we make these building blocks of nanodevices? Can we identify and harness useful physical properties in them? And can we integrate them in parallel? Individual devices are fundamentally interesting. But more importantly, we need massive numbers of them to work together as one system."
Cross-sectional scanning electron micrograph image of vertically-grown silicon nanowires off of a silicon substrate. (courtesy the researchers)
Yang and his colleagues have had a string of successes on all fronts. Just this month, the researchers reported that they had designed a brand new kind of nanowire transistor. Transistors are the basic building block of computer circuits. The more transistors that can be packed on a silicon chip, the faster that chip's processing power. Transistors usually are planar–they're fabricated horizontally onto the surface of a chip. While transistors made from nanowires are not new, Yang's innovation is to change the design to three-dimensional, dramatically increasing how densely they can be packed into the same area. The device sprouts vertically from the surface. The other components of the transistor, responsible for controlling the flow of the electricity, surround the vertical wire.
"The transistor occupies just the space taken up by the footprint of the wire," says Yang, who is also a chemist with Lawrence Berkeley National Laboratory's Materials Sciences Division.
Already, the researchers have demonstrated that their first-generation Vertically Integrated Nanowire Field Effect Transistors (VINFETs) are comparable in performance to other nanowire FETs. And with just a 5 nanometer footprint, they're far tinier than the transistors that traditional semiconductor fabrication techniques can crank out. The next step, Yang says, is to stack the devices so that each wire can function as multiple transistors or devices, further increasing performance.
Cross-sectional scanning electron micrograph image of a VINFET device. The false color is added just for clarity. (courtesy the researchers)
Last year, Yang devised another very different kind of transistor. Traditional transistors are essentially valves that control the flow of electricity to perform calculations. But what if, instead of voltages, a transistor could manipulate the flow of biological molecules like proteins and DNA? Yang and Arun Majumdar, professor of mechanical engineering, developed the world's first nanofluidic transistor. Fabricated from hollow nanotubes or glass tubes, this nanofluidic transistor might someday detect cancer in a drop of blood much smaller than the period at the end of this sentence.
The researchers demonstrated that minute voltages could control the flow of ions through the nanoscale plumbing system. In the future, the same technique might be used to shuttle proteins or pieces of DNA from a biological sample through the tubes in a lab-on-a-chip. Yang is currently developing a technique to conduct optical sensing within the nanofluidic channels so that the whole lab is self-contained in one device. Several years ago, Yang's group built the world's smallest ultraviolet laser. Now, he's researching the use of nanowires as sub-wavelength optical waveguides, channels that can steer laser light to the sample for analysis. The light would then bounce off the biological molecules trapped in the microfluidic channel.
A prototype nanofluidic transistor. (courtesy the researchers)
"By detecting how a molecule inside the microfluidic channel interacts with the light carried by sub-wavelength nanowire waveguides, we can determine its chemical signature and identify it," Yang says.
The VINFET and nanofluidic transistor are only two of the myriad devices enabled by Yang's nanowires. He and his colleagues are exploring how the nanowires may be used in longer-lasting batteries and ultra-sensitive detectors for poison in drinking water. Recently, he's demonstrated that sunlight-absorbing nanowires can harvest solar energy.
The nanowire wave guide has been demonstrated guiding red, green, and blue light. (courtesy the researchers)
"To me, the most important thing is that we're not just making nanoscale devices that are simply scaled down versions of traditional devices," Yang says. " All of these devices have new physics or chemistry inside of them that will enhance their performance."
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