Archive for August, 2013

Blueberries Each Day May Keep the Doctor Away

Tuesday, August 27th, 2013


Eating 2 cups of wild blueberries a day for two months can reduce chronic inflammation, improve metabolism of fat and lower LDL cholesterol and triglycerides, according to research by a University of Maine clinical nutritionist.

Additionally, UMaine professor Dorothy Klimis-Zacas says a diet enriched with the fruit can normalize gene expression of inflammatory markers and those related to lipid and lipoprotein metabolism.

The findings from her research with obese Zucker rats have promising implications for people wanting to reduce inflammation and thus their risk of coronary heart disease and Type 2 diabetes, says Klimis-Zacas.

The obese male Zucker rat is a valid experimental model for human metabolic syndrome (MetS), which is characterized by chronic inflammation, obesity, hypertension, glucose intolerance and insulin resistance.

The results are significant in light of the MetS epidemic in the United States, which affects an estimated 37 percent of adults, says Klimis-Zacas. That figure is expected to increase in direct relationship with the rate of obesity, according to National Health Statistics Reports.

Heart disease alone annually kills 600,000 people in the United States, according to the Centers for Disease Control and Prevention.

Being able to improve health by eating blueberries rich in antioxidants and anti-inflammatory agents that prevent degenerative disease, rather than relying on pharmaceuticals, is a great benefit, she says.

Klimis-Zacas is the first to report that wild blueberries lowered triglycerides (fatty materials) in the rats’ blood in vivo.

The fruit lowered low-density lipoprotein (LDL) cholesterol — which clogs people’s blood vessels and increases the risk of a heart attack — while maintaining the level of beneficial high-density lipoprotein (HDL) cholesterol, says Klimis-Zacas, who has studied nutritional benefits of wild blueberries for 15 years.

There was an overall anti-inflammatory effect in the obese rats, she says. Circulating levels of inflammatory markers were reduced in their blood, fatty tissues and livers. She found the blueberry-enriched diet improved abnormal overall blood lipid profiles and the genetic expression of enzymes that regulate lipids and cholesterol.

The multiple benefits for obese Zucker rats eating a wild blueberry-enriched diet are detailed in two research articles recently authored by Klimis-Zacas.

The study “Wild blueberry (Vaccinium angustifolium) consumption improves inflammatory status in the obese Zucker rat model of the metabolic syndrome,” was published in SciVerse ScienceDirect, a Journal of Nutritional Biochemistry. Stefano Vendrame, Allison Daugherty and Alekandra S. Kristo, all UMaine graduate students, as well as Patriza Riso of the Universita degli Studi di Milano in Italy, participated in the research.

The study “Wild blueberry (Vaccinium angustifolium)-enriched diet improves dyslipidaemia and modulates the expression of genes related to lipid metabolism in obese Zucker rats” was published in the British Journal of Nutrition. Vendrame, Daugherty and Kristo are co-authors.

Contact: Beth Staples, 207.581.3777

Ten-State Study Focuses on Hurricane Sandy’s Effects on Tidal Marsh Birds, Plants

Monday, August 5th, 2013


The effects of Hurricane Sandy’s devastation on plant and bird communities in coastal marshes from Maine to Virginia are the focus of a 10-state study by researchers from the University of Maine, University of Connecticut, University of Delaware and Maine Department of Inland Fisheries and Wildlife.

Information gathered from more than 1,700 sites before and after the October 2012 hurricane will advance researchers’ understanding of how major disturbances affect these populations and what characteristics make a marsh more vulnerable.

The data will also provide information on the allocation of millions of dollars of federal restoration funds, coastal management planning and the status of species at risk of endangerment.

The yearlong study was awarded nearly $200,000 from the National Science Foundation and is part of the Saltmarsh Habitat and Avian Research Program, which was founded by a group of academic, governmental and nonprofit collaborators — including UMaine — to provide tidal-marsh bird conservation information.

Brian Olsen, assistant professor in UMaine’s School of Biology and Ecology, is a co-principal investigator of the study. Maureen Correll, an ecology and environmental Ph.D. student in Olsen’s lab, is working on the project as part of her dissertation. Two additional student researchers from UMaine are expected to participate in the study.

Other co-principal investigators include Tom Hodgman, senior wildlife biologist at the Maine Department of Inland Fisheries and Wildlife; Chris Elphick, associate professor of ecology and evolutionary biology at the University of Connecticut; and Greg Shriver, associate professor in the Department of Entomology and Wildlife Ecology at the University of Delaware.

Before Hurricane Sandy, Olsen’s team was working on a study to assess the distribution and densities of tidal-marsh birds from Maine to Virginia. The study was intended to give the U.S. Fish and Wildlife Service more information on bird populations that are in danger due to the loss of tidal marshes from sea level rise, particularly the saltmarsh sparrow, Olsen says.

Hurricane Sandy struck in the middle of the researchers’ survey range after they had collected data for two years, giving them information from both inside and outside the storm’s path. The team sought NSF funds to conduct the surveys again to see which birds and marshes were most affected within the hurricane’s range. The marshes outside the storm’s path will serve as control sites, Olsen says.

“What predicts whether you’re a winner or a loser if a hurricane hits you is really an open question,” Olsen says.

The study will also test two common ecosystem stress hypotheses among researchers. One of those hypotheses, Olsen says, is that stresses on an ecosystem build up over time, making the addition of any new stress more dramatic than if it were to act alone. Multiple stresses can bring any species of the entire community closer to collapse with every additional stress.

“The hurricane ends up being the straw that broke the camel’s back,” he says.

Another common theory says multiple stresses eliminate the weak players, leaving only the strong ones.

“When the hurricane comes in, all the sensitive players have already been eliminated by previous stressors and you’re only left with the ones that are robust to stress; they can handle it, and the hurricane has little effect,” Olsen says.

Based on this theory, the pristine tidal marshes — ones that have more sensitive plants and animals that aren’t accustomed to stress — may appear to have been more affected by the hurricane, he says.

“I’d really like to understand what makes marshes sensitive to large-scale disturbances and how marshes are likely to respond to the predicted increase in storm frequency and intensity in the future,” Olsen says. “What makes them sensitive and what’s likely to happen as the climate changes?”

Researchers will also pay attention to whether urban development had any effect on how the storm affected the marshes.

“You get the same hurricane that’s barreling down on two different marshes. Do marshes that are completely developed right up to the marsh edge fare better, worse or the same as those that are in pristine habitats in national parks? Does conservation do anything to birds that are still around or does that not matter when there’s a wall of water coming down on you? We get to ask that for a fleet of different species,” Olsen says.

Saltmarsh sparrows, clapper rails, Nelson’s sparrows, seaside sparrows, willets and black ducks are the six major bird species in the study. Plant species the team will study include smooth cordgrass (Spartina alterniflora), salt hay (Spartina patens), seashore saltgrass (Distichlis spicata) and black needlerush (Juncus gerardii).

The surveying of saltmarsh sparrows is important because the team is able to track the species’ entire range and population. The species is also declining fast and talks have begun on whether to list them under the Endangered Species Act. The team’s data on the birds will be used to help make that determination, Olsen says.

Using the information from hundreds of marshes with different characteristics, Olsen’s team hopes to be able to predict what causes ecosystems to shift from one type of tidal marsh to another following a major storm, or more dramatically, what causes shifts from tidal marsh to open water or beach dunes. By determining these factors, researchers will have a better understanding of where to focus energy for conservation and where to expect ecosystem shifts in the future, Olsen says.

“We’ve visited a couple places already this summer where last year it was a beautiful tidal marsh with picturesque streams, and now it’s sand dunes or open water; it’s just gone,” he says.

The team hopes their information will help influence agencies using Hurricane Sandy relief funds to restore wildlife communities by prioritizing the marshes that would benefit the most from conservation efforts and have the lowest chance of being destroyed by a similar storm in the future.

Contact: Elyse Kahl, 207.581.3747

Glacier’s Past Offers Clues to the Future

Monday, August 5th, 2013


Editor’s note: A narrated slideshow about the collaborative research by UMaine, Dartmouth and the University of New Hampshire is online.

University of Maine climate change scientist Karl Kreutz seeks to glean insight into future sea level rise on the planet.

To do that, this past spring he was part of a research team that hiked a 14,000-foot mountain in Alaska, drilled through a glacier and collected two 700-foot, 3-inch-diameter ice cores encasing 1,000 years of regional climate history.

“The Arctic is warming rapidly and Alaskan glaciers are shrinking as a result,” says Kreutz. “If we have a better understanding of the snowfall and climate change the last 1,000 years, we can better predict what will happen to glaciers in Alaska in the future as global warming continues, and how that will impact global sea level rise.”

UMaine is collaborating with Dartmouth University and the University of New Hampshire in the ice core-drilling project in Alaska’s Denali National Park. The multiyear endeavor is funded with a $1.1 million grant from the National Science Foundation (NSF).

In addition to Kreutz, UMaine participants are Research Assistant Professor Sean Birkel and graduate students Seth Campbell and Tim Godaire. UMaine graduate Erich Osterberg, now an assistant professor at Dartmouth, as well as University of New Hampshire scientist Cameron Wake and graduate student Elizabeth Burakowski, Dartmouth students, the National Park Service and the U.S. Ice Drilling Program Office are also participating.

“These ice cores will provide our first long-term annual record of snowfall in this region,” says Wake, a research associate professor at the UNH Institute for the Study of Earth, Oceans, and Space Earth Systems Research Center (ESRC).

The field season started at the beginning of May, when team members climbed and skied 14,000 feet up then down Denali to acclimate to the altitude. Daytime temperatures were around 32 F and nighttime temps dropped to about 13 below zero F during the excursion, says Kreutz.

A helicopter operator delivered the team’s equipment and supplies to the drill site on Mount Hunter. The National Park Service requested that power for the drilling be supplied by renewable power — in this case, a combination of solar and wind.

Kreutz says the team drilled right to the bedrock. “You know you’ve got the longest climate record from the glacier at that point,” he says. “When you hold a piece of 1,000-year-old ice, it’s hard not to think about world history and what was happening when that ice was being formed.”

Kreutz credits Campbell, a doctoral student in glaciology, for selecting the prime drilling spot on the plateau. Campbell used ground-penetrating radar to map the geometry of glaciers and determine the velocity at which they’re moving in order to select a site where layers inside the glacier were as flat as possible.

Like tree rings, ice cores can provide data from their annual layers. Studies of the ice cores will concentrate on the chemistry of the ice — how much dust is in it, how much sea salt is in it — and determine the relative amounts of chemical elements, including pollutants.

In mid-June, the ice cores, drilling personnel and equipment were transported from Mount Hunter via helicopter to base camp and then on a ski plane to Talkeetna, Alaska. The cores were then packed in freezer trucks and hauled to the National Ice Core Laboratory in Denver, Colo., where they are in frozen storage.

This fall, Kreutz and other participating scientists will travel to the lab in Colorado where they’ll cut the ice cores into square sticks, which will then be transported to the respective university labs.

During the next couple of years, scientists at UMaine, UNH and Dartmouth will melt the ice and analyze thousands of samples using mass spectrometers, ion chromatographs and other instruments. Researchers will interpret the data using statistical analyses. They’ll compare the data with other records, incorporate it into glacier and climate models and share it with the broader paleoclimate and scientific community.

Collaborators have been working on the project for six years. The team is maintaining a weather station in Denali National Park, with the goal of relating the weather in the mountains to the snow chemistry.

— Beth Staples, 207.581.3777