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Science &Technology

The california aggie

New anaerobic digester technology improves the atmosphere UC Davis professor Ruihong Zhang invents new process By BRIAN RILEY Aggie Science Writer

A new type of high-rate anaerobic digester system created by a UC Davis professor was given its first commercial application recently at a packaging plant in Sacramento. The digester allows organic solid waste to be recycled more efficiently. Ruihong Zhang, a professor in the department of biological and agricultural engineering, created the process in the lab at UC Davis. In 2006, a research and demonstration facility was built on South Campus to test and fine-tune the process to make it ready for public and commercial use. Plans are being made to use the facility as a model for a larger facility to be built on the site of the current UC Davis landfill. “I think it’s a very unique opportunity that we can take technology that has been developed right here on campus by

Zhongli Pan, left, and Ruihong Zhang at the anaerobic digester

Dr. Zhang and apply that to our own facilities,” said Sid England, Assistant Vice Chancellor of the UC Davis Environmental Stewardship and Sustainability program. The planned project would convert agricultural and landscape waste created on campus, as well as leftover food scraps from the dining halls, into a fuel mixture made of 90 percent methane that could be used to fuel Unitrans buses.


A mixture made of methane and carbon dioxide could also be converted into electricity for use on the campus grid, in order to be part of the West Village zero net energy project. “Dr. Zhang’s technologies allow material that is up to 50 percent solid with no additional water added,” said Michele Wong, CEO of Clean World Partners, which has licensed the technology from the University of California and runs the new

plant in Sacramento. “Other digesters require that you have material that is much lower in solid content (10 to 20 percent), so you must add water, [which] increases the capital costs,” Wong said. Initially foreseen as being a potentially valuable means of large-scale energy generation, anaerobic digester processing plants now are most highly valued for their ability to reduce landfill use. Reducing the amount of organic, or carbon-based, solid waste in landfills also reduces the amount of greenhouse gases released into the atmosphere, since methane, which is created when organic waste decomposes, is a highly potent greenhouse gas. Widespread use of more inexpensive anaerobic digester processes such as Zhang’s can reduce a significant portion of the smog in California air basins. The smog is caused by


You’re not us, you must be wrong Intergroup biases, school pride and humanity By HUDSON LOFCHIE Aggie Science Writer

Whether cheering on your favorite NBA team, wearing your university letters or hugging strangers at a political rally, it feels undeniably good to be part of a group. A university student might make a new friend while traveling thousands of miles away simply because they both go to the same school, and you might get beaten up for wearing team colors in a different city. All of these situations are examples of intergroup bias, a psychological phenomenon behind behavior ranging from racism to patriotism, from team spirit to school pride on Picnic Day. “Intergroup bias is a psychological or behavioral competition between two groups based on group membership,” said Jeff Sherman, a professor of psychology at UC Davis. “It amounts to treating people differently based on [group] membership.” Essentially, intergroup bias is the basis for all exclusionary behavior we exhibit. It is why racism exists, why private social clubs exist and why career favoritism exists. While modern human society has evolved millions upon millions of subgroups, this pref-

Evan Davis / Aggie

UC Davis students stand and cheer for Aggie Pride at sporting events. erential group treatment goes back to the most basal of survival instincts. “[Intergroup bias] has some evolutionary basis,” Sherman said. “There is an expectation of future interactions with group members, so individuals will share resources with their own group rather than an outgroup.” As group identification shifted

from pure survival into the more social realm of personal identity, intergroup biases shifted along with it. Differential treatment evolved to justify a bias, and biases emerged to justify differential treatment. The simple state of belonging to a group can

See PRIDE, page X

wednesday, May 2, 2012 3

but mine did not require lab reports, only answering online questions that slowly walked the student through the math and what the results could mean. Biology 2 Amy was even less demanding; Stewart though we had many worksheet questions to answer, there usually wasn’t an actual experiment or lab report. I suppose in freshman year of college, easing the students into writing full lab reports might be a good idea, since some high schools might have been less demanding than others. However, when ntroduction I, a microbiology ma- I compare my organic chemjor, live in an apartment istry class (Chemistry 118) to with a chemistry major. She the organic chemistry that often complains about the the chemistry majors take length of her lab reports — (Chemistry 128), the differsometimes in the hard work ences become even starker. required, occasionally in My organic chemistry class the context of how much only required a lab report for paper and ink that it uses a couple of the experiments; (as much as 10 to 15 pages her organic chemistry class required a full lab report for for the more hellish labs). I often don’t have much all experiments. One critique is that I’m to complain about back to her. I’m in my first micro- working with a sample of only two stubiology lab dents. This this quarNo one can learn to write is definiteter, and the ly a problem lab report I in a certain style ... without with drawcompleted practicing several times ... ing definitive a couple conclusions, of weeks although it ago was required to be a grand total of helps that we’re both doing well in our chosen majors three pages. How hard do we each (there isn’t one person slackwork? Consider this my lab ing off with grades to skew report. I won’t stick with the the results, for example). At first glance, this seems traditional layout of a research article, as this is The like an advantage for biology California Aggie, not Science majors. College students are Magazine. However, I’ll in- busy enough studying as it is, especially since on the quartroduce the majors. Ignoring the general ed- ter system it seems like we are ucation requirements, a always in midterm season. I know that requiring lab chemistry major requires 107 units total while the micro- reports in basic chemistry biology major requires 106 and biology classes seems to 120 units total. The vari- pointless, because the experation of the latter is mostly iments that they set up are due to which organic chem- ones for which the professors istry class you decide to take, already know the answer. This grind does have a and, if you’re an older major, which calculus courses you point though: practice. No took in your freshman year. one can learn to write in a certain style, especially the Materials and Methods My materials and methods very precise style of lab refor answering the question I ports, without practicing gave above, of how hard we several times on an easy exeach work, consisted just of periment or activity. Without my own observations of the this practice, many biology requirements for each class. students will end up going I can play fast and loose with into professional laboratothese rules as, again, this is ries with two or more years less experience looking afThe Aggie, not Science. ter experiments and writing Results We spend about the same their findings than chemisamount of time studying, but try or physics majors. If the findings are somethe chemistry majors spend far more time writing lab re- thing no one has ever seen ports than I do. We biology before, you’re not going to majors have fewer and short- have a computer program er lab reports, as well as labs there to slowly guide you that are nearly all discussion through the algebra. There with few or no experiments won’t be a worksheet to ask leading questions. Those (Physics 7, anyone?). things can be very useful Discussion Why do two science ma- tools, especially in the bejors, both with an emphasis ginning of a college career. on research, have such dif- But in the real world, it’s fering amounts of laboratory well-written lab reports that experience? We both took the count. Chemistry 2 series, which is the general chemistry class. AMY STEWART can be reached at science@ Every lab had an experiment,

In defense of reports


Modular robot receives NSF grant ‘Mobots’ help teach young students math and science By RACHEL KUBICA Aggie Science Writer

Barobo, Inc., a robotics company founded by UC Davis mechanical and aerospace engineering professor Harry Cheng and his former graduate student, Graham Ryland, has been awarded a $500,000 grant from the National Science Foundation (NSF) small business innovation research program for their small, versatile modu-

lar robot. Cheng and Ryland will be using the grant money to further develop their modular robot, “Mobot,” over the next two years. “With the funding from NSF, we will develop Mobot as a programmable universal building block for education, research and industrial applications,” Cheng said. A Mobot is a fully functional robot with four degrees of freedom, including the ability to move forward, roll around and bend forward. It uses two wheels at either end to move and can be modified using two hinges in the center of the module.

Modular robots could help kids learn math and science

“It can roll, crawl, stand, tumble, etc.,” Cheng said.


“In addition, like Lego, Mobot can also be used as

a building block to create a snake, tank, truck, humanoid and any systems you can imagine.” Cheng hopes to use the Mobot to teach young students robotics as early as kindergarten. “Each building block is fully programmable, which makes the combined system extremely flexible and versatile,” Cheng said. “Programming a single Mobot and multiple Mobots can be easily accomplished by K-12 students.” Cheng and Ryland have been working with 15 local schools in Davis and Sacramento to use Mobot in classes, demonstrating

to students how to build the robots using computers. “It’s really exciting to be part of something that inspires middle school and high school students to get into robotics through science, technology, engineering and math (STEM) subjects,” Ryland said. STEM is the acronym established by Cheng through his UC Davis K-14 Outreach Center for Computing and STEM Education. “The goal of the C-STEM Center is to broaden participation of students typically underrepresented in computing and to de-

See ROBOT, page X

UC Davis researchers find key tool in chromosome crossovers

Result could provide insight in treating a broad range of diseases By CLAIRE MALDARELLI

Aggie Science Writer

Researchers at UC Davis have discovered a key tool they believe helps sperm and eggs develop exactly 23 chromosomes

each. This work, which could lead to significant insight into fertility as well as spontaneous miscarriages, cancer and other developmental disorders, was published on April 13 in the journal Cell. Normally, if all goes according to plan, a human fetus develops into a healthy adult with exactly 46 chromosomes — 23 from the sperm and 23 from the egg. But just one small mistake in this process can have significant effects on the fetus, often developing into well-known disorders such

as Down syndrome, which is caused by an extra copy of chromosome 21. The developing process of a human fetus is complex, involving a multitude of processes, enzymes and other complexes that work together as one big unit. Because of its direct effect on many diseases, much research has gone into understanding this mechanism. “We are trying to understand how these proteins work together at a molecular level and how they are regulated to do the right thing at the right time,” said senior

author of the study Neil Hunter, a professor of microbiology and a member of the UC Davis Comprehensive Cancer Center research program. During meiosis, the sexual cell division that produces sperm and eggs, matching chromosomes pair up and connect through a process known as “crossing over” — much like when two long strands of spaghetti twist together when twirled with a

See CELL, page X

May 2, 2012