Michigan Agricultural Experiment Station

Netting Mosquitoes to Prevent Malaria

MAES scientist Ned Walker is taking on one of the biggest killers in the world: malaria. And he believes he can help win the battle to save lives, especially the lives of children.

With a recent $1.7 million grant from the National Science Foundation, Walker will lead a research team studying how insecticide-treated bed nets can disrupt the population dynamics of the parasite that causes the deadly disease, as well as the mosquito that transmits the parasite. The scientists will focus on an area of western Kenya.

According to statistics from the World Health Organization, malaria kills about 3,000 children each day in Africa. Research has shown that using bed nets may cut mortality in half.

Walker, a microbiology and molecular genetics and entomology researcher, focuses his research on how infectious diseases are transmitted, especially those that use mosquitoes as a mechanism to spread.

"We'll be evaluating the effectiveness of the bed nets over the long term," Walker explained. "Malaria has resisted past attempts to control it. But the bed nets have emerged as a powerful and simple control tool. They cost only about $10 apiece. The big question is whether the bed nets will continue to work over time. That's what we'll be studying."

So far, Anopheles gambiae, the mosquito species responsible for transmitting malaria to humans in Africa, hasn't demonstrated any resistance to the insecticide used in the bed nets.

"It appears that the Anopheles gambiae population declines and doesn't recover," Walker said. "So the parasites that cause malaria shift into a different mosquito that feeds mainly on cattle. These mosquitoes don't bite people as often and cattle don't support the malaria infection, so malaria transmission goes way down."

Walker and his colleagues also will be looking at the population structure of the malarial parasites to see how the population responds to decreasing mosquito populations.

"The parasites have a deep population structure -- males outnumber females by about 8 to 1," Walker explained. "If there is a drop in total parasite numbers, it could be even harder for the parasites to mate."

This is important for two reasons, he explained. Malarial parasites are notorious for developing antibiotic resistance. Restricting the population would restrict the gene flow, which would limit the spread of resistance. Walker's team will be using genetic markers to track the flow of genes. Second, when malaria transmission goes down, it tends to be the more virulent strains of the disease that survive.

"We don't want that to happen, so we'll be studying virulence factors to monitor it," Walker said.

The study also will examine how well people accept and use bed nets in their daily routines.

"I'm very excited to begin the project," he continued. "Bed nets are an inexpensive, easy-to-use method to control the disease. This research is international in scope and will help us help people, which is one of our land-grant principles."

Joseph Messina, associate professor of geography, also is participating in the project.

This research is funded by the National Science Foundation Ecology of Infectious Disease program and supported by the Michigan Agricultural Experiment Station. The Kenya Medical Research Institute and the U.S. Centers for Disease Control and Prevention are collaborators.

Thelen Named First MSU Bioenergy Crop Agronomist

As the state's interest in growing field crops for fuel and energy has increased, MSU agronomist Kurt Thelen's research has followed suit. In addition to studying how to grow corn, canola and soybeans for maximum yield with minimal environmental impact, he began analyzing crop components for energy quality and looking at fatty acid profiles in relation to potential biofuel production. He also began studying whether marginal land -- land that couldn't be used to grow food crops -- could be used to grow bioenergy crops.

On Jan. 1, Thelen's title changed from cropping systems agronomist to bioenergy crop agronomist in formal recognition of his research focus on bioenergy crops.

"I'm very excited to start, but my research program won't change dramatically," he said. "We'll begin more intensive agronomic studies of some other bioenergy crops, such as switchgrass and miscanthus, in addition to corn, canola and soybeans. We'll also begin researching new energy crops that haven't been studied in Michigan before, such as camelina, which is a type of canola."

In addition to focusing on maximum yield, Thelen will study growing methods that produce maximum energy output for a crop. For the spring 2009 semester, Thelen also will begin teaching a new undergraduate class on bioenergy crop production.

In his new role, Thelen will be making significant contributions to the Great Lakes Bioenergy Research Center (GLBRC), the $125 million Department of Energy-funded research facility that is a partnership between MSU and the University of Wisconsin-Madison. Thelen is the team leader for the GLBRC research area evaluating novel bioenergy crop production systems. As plant breeders develop new varieties of energy crops, Thelen and his research team will conduct field research under a variety of Michigan conditions. Because many potential energy crops, including switchgrass and miscanthus, haven't been cultivated to maximize biofuel yield, basic agronomic information is lacking, and Thelen plans to fill that void.

"I like working with farmers, and my new role will still have a significant outreach component," Thelen said. "One of the goals is to get research results on bioenergy crops out to growers as soon as possible."

"If Michigan is going to be a player in the bioeconomy, we must be able to grow energy crops efficiently," said Steve Pueppke, director of the Office of Biobased Technologies and the Michigan Agricultural Experiment Station. "We're very pleased that Kurt is willing to use his expertise to tackle this key problem."

MAES Researcher to Help Edit Special Bioeconomy Issue of the Journal of Environmental Engineering

Steve Safferman MAES biosystems and agricultural engineering researcher Steven Safferman and fellow MSU scientists Wei Liao and Christopher Saffron will edit a special issue of the Journal of Environmental Engineering focused on engineering the bioeconomy.

"Because of the demand for high-priced energy and the need for energy security, there's much interest in biobased products, including biofuels produced from agricultural and forestry commodities," Safferman explained. "There's also renewed interest in converting domestic waste and animal manure to energy technologies. We need advanced systems research that considers all energy inputs and valuable energy and chemical products to facilitate the development of a sustainable bioeconomy."

The special issue will feature bioeconomy system analyses, review state-of-the-art technologies building the bioeconomy, and present original advances on process, infrastructure and environmental considerations associated with biomass conversion.

Safferman said the editorial team is soliciting abstracts for the special issue and will accept them through January 25. Invitations to prepare manuscripts will then be issued. The special issue will be published in late 2008.

Those who would like to submit an abstract or serve as peer reviewers for the special issue should e-mail Safferman.

Sucking It Up: New Prototype Machine Aims to Simplify Chestnut Harvesting

Dan Guyer Michigan's young chestnut industry continues to grow by leaps and bounds -- this year’s crop is the largest in the industry's short history. Growers may soon have another reason to celebrate, thanks to efforts by an MAES biosystems and agricultural engineering researcher who is evaluating various approaches for a semiautomated harvesting machine.

Edible chestnuts may be a profitable commodity, but harvesting the sweet nut by hand is backbreaking work. Dan Guyer, MAES biosystems and agricultural engineering scientist, is collaborating with Whoa Seug Kang, professor of agricultural engineering on sabbatical from Kangwon National University in South Korea, to design a prototype of a harvesting unit to simplify and expedite the harvesting process.

Kang developed the concept for the harvesting machine. He reasoned that, to thrive and prosper, the burgeoning industry needed an affordable small- to medium-sized harvesting machine that could easily maneuver between trees. The prototype is partially modeled after larger, more expensive European machines.

In the past, not enough chestnuts were grown in the Midwest to warrant investigating less labor-intensive harvesting systems. But as hopes rise that the market will become increasingly profitable, interest in putting in orchards is growing.

"As the trees mature and reach full production capacity, there will be a greater need for modern harvesting equipment, but purchasing the larger European system is cost-prohibitive, at least for now," Guyer said. "Having an efficient and affordable device to expedite the harvesting process is critical as the state’s chestnut industry continues to grow."

The prototype sucks up the nuts and their spiky burrs off of the ground and puts them into crates. The machine roughly resembles a 5-foot cube and is about one-third the size of its European counterpart.

The next step is to devise a way for the harvester to separate the nuts from everything else the machine picks up. Like a vacuum cleaner, the machine picks up everything, including soil, leaves, sticks and the chestnuts' burr casings. Guyer and Kang are working on separation techniques based on the density of the nuts.

The project was funded by Project GREEEN, Michigan's plant agriculture initiative.

Work on the chestnut harvester evolved from an integrated research and outreach effort initiated several years ago by MAES plant pathologist Dennis Fulbright to reintroduce the edible chestnut crop to Michigan and develop a market in the state.

A Really Inconvenient Truth: Divorce Is Not Green

Jack Liu The data are in. Divorce is bad for the environment.

A novel study that links divorce with the environment shows a global trend of soaring divorce rates has created more households with fewer people, has taken up more space and has gobbled up more energy and water. The findings of MAES scientist Jianguo "Jack" Liu and Eunice Yu at Michigan State University were published in the December 4 online edition of the Proceedings of the National Academy of Sciences.

A statistical remedy: fall back in love. Cohabitation means less urban sprawl and softens the environmental hit.

"Not only the United States but also other countries, including developing countries such as China and places with strict religious policies regarding divorce, are having more divorced households,” Liu said. “The consequent increases in consumption of water and energy and using more space are being seen everywhere."

Liu and his research assistant Yu started with the obvious -- that divorce rates across the globe are on the rise. Housing units, even if they have few people in them, require resources to construct them and take up space. They require fuel to heat and cool. A refrigerator uses roughly the same amount of energy whether it belongs to a family of four or a family of two.

When they calculated the cost in terms of increased utilities and unused housing space per capita, they discovered that divorce tosses out economy of scale. Among the findings:

In the United States alone in 2005, divorced households used 73 billion kilowatt-hours of electricity and 627 billion gallons of water that could have been saved had household size remained the same as that of married households. Thirty-eight million extra rooms were needed with associated costs for heating and lighting.
In the United States and 11 other countries such as Brazil, Costa Rica, Ecuador, Greece, Mexico and South Africa between 1998 and 2002, if divorced households had combined to have the same average household size as married households, there could have been 7.4 million fewer households in these countries.
The numbers of divorced households in these countries ranged from 40,000 in Costa Rica to almost 16 million in the United States around 2000.
The number of rooms per person in divorced households was 33 percent to 95 percent greater than in married households.

To track what happens when divorced people returned to married life, the study compared married households with households whose members had weathered marriage, divorce and remarriage. The results: the environmental footprint shrank back to that of consistently married households.

Liu, a university distinguished professor of fisheries and wildlife and Rachel Carson chair in ecological sustainability at the MSU Center for Systems Integration and Sustainability, has spent more than two decades integrating ecology with social sciences to understand the complex interrelationships between nature and humans and how those interactions affect the environment and biodiversity. Liu and Yu began to discuss this research project when Yu was a high school student.

This new work also acknowledges that divorce is not the only lifestyle trend changing family living structures -- the demise of multigenerational households and people remaining single longer are other examples.

"People’s first reaction to this research is surprise, and then it seems simple," Liu said. "But a lot of things become simple after research is done. Our challenges were to connect the dots and quantify their relationships. People have been talking about how to protect the environment and combat climate change, but divorce is an overlooked factor that needs to be considered."

The research, Liu said, shows that environmental policy is more complex than one single solution. Governments across the world may need to start factoring in divorce when examining environmental policy, Liu said.

"Solutions are beyond a single idea," Liu said. "Consider the production of biofuel. Biofuel is made from plants, which also require water and space. We're showing divorce has significant competition for that water and space. On the other hand, more divorce demands more energy. This creates a challenging dilemma and requires more creative solutions."

The research was funded by the National Science Foundation, the National Institutes of Health and the Michigan Agricultural Experiment Station.