OREGON STATE UNIVERSITY

scientific research and advances

New algorithm, metrics improve autonomous underwater vehicles’ energy efficiency

CORVALLIS, Ore. – Robotics researchers have found a way for autonomous underwater vehicles to navigate strong currents with greater energy efficiency, which means the AUVs can gather data longer and better.

AUVs such as underwater gliders are valuable research tools limited primarily by their energy budget – every bit of battery power wasted via inefficient trajectories cuts into the time they can spend working.

“Historically, a lot of oceanography data sets and sampling came from using ships, which are expensive and can only really be out for a few days at a time,” said Dylan Jones, a third-year Ph.D. student in Oregon State University’s robotics program and lead author on the study. “With autonomous underwater vehicles, you can get months-long monitoring. And a way to extend those vehicles’ missions is through smarter planning for how they get from one point of interest to another.”

Jones and Ph.D. advisor Geoff Hollinger, assistant professor of mechanical engineering in OSU’s College of Engineering, have built a framework for the vehicles to plan energy-efficient trajectories through disturbances that are strong and uncertain, like ocean currents and wind fields.

The framework involves an algorithm that samples alternate paths, as well as comparison metrics that let a vehicle decide when it makes sense to switch paths based on new information collected about environmental disturbances.

The researchers tested the framework in a simulated environment – a data set of currents from the Regional Ocean Modeling System – and also on a windy lake with an autonomous boat.

The results, recently published in IEEE Robotics and Automation Letters, show that the algorithm can plan vehicle paths that are more energy efficient than ones planned by existing methods, and that it’s robust enough to deal with environments for which not much data is available.

Findings also indicate that three of the framework’s five path comparison metrics can be used to plan more efficient routes compared to planning based solely on the ocean current forecast.

“We generalized past trajectory optimization techniques and also removed the assumption that trajectory waypoints are equally spaced in time,” Jones said. “Removing that assumption improves on the state of the art in energy-efficient path planning. 

“These are under-actuated vehicles – they don’t go fast in relation to the strong ocean currents, so one way to get them to travel more efficiently is to go with the flow, to coast and not use energy,” he added. “We’re building more intelligence into these vehicles so they can more reliably accomplish their missions.”

Jones notes that overcoming strong disturbances is a critical component of putting any kind of robot in a real-life environment. Past planning algorithms haven’t always considered the dynamics of the vehicle they were planning for, he said.

“Sometimes we make assumptions in the lab or do simulations that don’t translate in the real world,” Jones said. “Sometimes a disturbance is too strong to be overcome, or sometimes it can be overcome but the path deviates so significantly that it would put the robot in a danger area. We have to consider all the possible locations of a robot. There are smarter ways of considering these various disturbances, and this gives us a better way of planning paths that are least affected by disturbances.”

Any disconnect between the controller and the planner can be dangerous, Jones said.

“The way we see this work going is to bridge that gap – how do we look at paths that are easier for controllers to follow, and how do we make controllers follow paths better?” he said. “We can be more energy efficient when we consider the whole environment, planning paths so that the controller of the vehicle doesn’t have to work as hard.”

Future research will also deal with “informative path planning” – planning paths that initially gather information about the environment and disturbances that the algorithm can use later to plan more energy-efficient routes.

“How do we combine these two ideas – planning a path for energy efficiency while also trying to gather information that will inform efficient path planning?” Jones said. “There will be tradeoffs and it might come down to, do I pay five hours now to save six hours later on? Another possible research direction is to look at a multivehicle situation where one vehicle can scout ahead and relay information to one or more others – they could possibly have a low shared energy cost by intelligently assigning goals and sharing information.”

Media Contact: 

Steve Lundeberg, 541-737-4039

Source: 
Multimedia Downloads
Multimedia: 

ROMS_sim

AUV paths planned by framework

New assessment identifies global hotspots for water conflict

CORVALLIS, Ore. – More than 1,400 new dams or water diversion projects are planned or already under construction and many of them are on rivers flowing through multiple nations, fueling the potential for increased water conflict between some countries.

A new analysis commissioned by the United Nations uses a comprehensive combination of social, economic, political and environmental factors to identify areas around the world most at-risk for “hydro-political” strife. This river basins study was part of the U.N.’s Transboundary Waters Assessment Program.

Researchers from the United States, Spain and Chile took part in the analysis, which has been recommended by the U.N. Economic Commission for Europe as an indicator for the U.N.’s sustainable development goals for water cooperation.

Results of the study have just been published in the journal Global Environment Change. 

The analysis suggests that risks for conflict are projected to increase over the next 15 to 30 years in four hotspot regions – the Middle East, central Asia, the Ganges-Brahmaputra-Meghna basin, and the Orange and Limpopo basins in southern Africa.

Additionally, the Nile River in Africa, much of southern Asia, the Balkans in southeastern Europe, and upper South America are all areas where new dams are under construction and neighboring countries face increasing water demand, may lack workable treaties, or worse, haven’t even discussed the issue.

“If two countries have agreed on water flow and distribution when there’s a dam upstream, there usually is no conflict,” said Eric Sproles, an Oregon State University hydrologist and a co-author on the study. “Such is the case with the Columbia River basin between the United States and Canada, whose treaty is recognized as one of the most resilient and advanced agreements in the world. 

“Unfortunately, that isn’t the case with many other river systems, where a variety of factors come into play, including strong nationalism, political contentiousness, and drought or shifting climate conditions.”

The conflict over water isn’t restricted to human consumption, the researchers say. There is a global threat to biodiversity in many of the world’s river systems, and the risk of species extinction is moderate to very high in 70 percent of the area of transboundary river basins.

Asia has the highest number of dams proposed or under construction on transboundary basins of any continent with 807, followed by South America, 354; Europe, 148; Africa, 99; and North America, 8. But Africa has a higher level of hydro-political tension, the researchers say, with more exacerbating factors.

The Nile River, for example, is one of the more contentious areas of the globe. Ethiopia is constructing several dams on tributaries of the Nile in its uplands, which will divert water from countries downstream, including Egypt. Contributing to the tension is drought and a growing population more dependent on a water source that may be diminishing.

“When you look at a region, the first thing you try to identify is whether there is a treaty and, if so, is it one that works for all parties and is flexible enough to withstand change,” Sproles said. “It’s easy to plan for water if it is the same every year – sometimes even when it’s low. When conditions vary – and drought is a key factor – the tension tends to increase and conflict is more likely to occur.”

In addition to environmental variability and lack of treaties, other factors leading to conflict include political and economic instability, and armed conflict, the analysis shows.

Sproles said one reason the Columbia River Basin treaty between the U.S. and Canada has worked well is the relative stability of the water supply. In contrast, climate models suggest that the Orinoco River Basin in northern Brazil and the Amazon Basin in upper South America may face drier conditions, which could lead to more strife.

Sproles is a courtesy faculty member in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences, where he received his doctorate.

More information on the United Nations Transboundary Waters Assessment Program is available at: http://www.geftwap.org/.

A shorter version of the paper was published July 13 on the Sustainable Security website.

Story By: 
Media Contact: 

Mark Floyd, 541-737-0788

Source: 

OSU inks largest research grant in its history to begin ship construction

CORVALLIS, Ore. – Oregon State University has just received a grant of $121.88 million from the National Science Foundation to spearhead the construction of a new class of research vessels for the United States Academic Research Fleet. It is the largest grant in the university’s history.

This grant will fund the construction of the first of three planned vessels approved by Congress for research in coastal regions of the continental United States and Alaska. When funding for the next two vessels is authorized, the total grant to OSU could increase to as much as $365 million. The first vessel is slated to be operated by OSU for research missions focusing on the U.S. West Coast. The NSF will begin the competitive selection of operating institutions for the second and third vessels later this year – likely to universities or consortia for operations on the U.S. East Coast and the Gulf of Mexico.

“Oregon State University is extremely proud to lead this effort to create the next generation of regional ocean-going research vessels funded by NSF,” said OSU President Edward J. Ray. “Our exceptional marine science programs are uniquely positioned to advance knowledge of the oceans and to seek solutions to the threats facing healthy coastal communities – and more broadly, global ecological well-being – through their teaching and research.”

OSU was selected by the National Science Foundation in 2013 to lead the initial design phase for the new vessels, and to develop and execute a competitive selection for a shipyard in the United States to do the construction. Gulf Island Shipyards, LLC, in Louisiana was chosen and will conduct the detailed design verification over the next year. Officials hope to have a keel-laying ceremony for the first vessel in the spring of 2018, with the ship delivered to OSU for a year of extensive testing in 2020.

This new class of modern well-equipped ships is essential to support research encompassing marine physical, chemical, biological and geologic processes in coastal waters, said Roberta Marinelli, dean of Oregon State’s College of Earth, Ocean, and Atmospheric Sciences.

“Rising sea levels, ocean acidification, low-oxygen waters or ‘hypoxia,’ declining fisheries, offshore energy, and the threat of catastrophic tsunamis are issues not only in the Pacific Northwest but around the world,” Marinelli said. “These new vessels will provide valuable scientific capacity for better understanding our changing oceans.”

The ships will be equipped to conduct detailed seafloor mapping, to reveal geologic structures important to understanding processes such as subduction zone earthquakes that may trigger tsunamis. The Pacific Northwest is considered a high-risk region because of the Cascadia Subduction Zone, which has produced about two dozen major earthquakes of magnitude 8.0 or greater over the past 10,000 years.

The new ships will also be equipped with advanced sensors that will be used to detect and characterize harmful algal blooms, changing ocean chemistry, and the interactions between the sea and atmosphere. The emerging fields of wave, tidal and wind energy will benefit from ship observations. Oregon State is the site of the Northwest National Marine Renewable Energy Center, which in December was awarded a grant of up to $35 million from the U.S. Department of Energy to create the world’s premier wave energy test facility in Newport.

Some characteristics of the new regional class research vessels (RCRVs), which were designed by The Glosten Associates, a naval architecture firm based in Seattle:

  • 193 feet long with a 41-foot beam;
  • Range of approximately 7,000 nautical miles;
  • Cruising speed is 11.5 knots with a maximum speed of 13 knots;
  • 16 berths for scientists and 13 for crew members;
  • Ability to stay out at sea for at least 21 days before returning to port;
  • High bandwidth satellite communications for streaming data and video to shore;

“This class of ships will enable researchers to work much more safely and efficiently at sea because of better handling and stability, more capacity for instrumentation and less noise,” said Clare Reimers, a professor in the College of Earth, Ocean, and Atmospheric Sciences and project co-leader. “The design also has numerous ‘green’ features, including an optimized hull form, waste heat recovery, LED lighting, and variable speed power generation.”

Oregon State is expected to begin operating the first of the new ships in the fall of 2021, after a year of testing and then official Academic-Fleet designation by the University-National Oceanographic Laboratory System (UNOLS), according to Demian Bailey, also a project co-leader for OSU.

“There will be a full year of testing because there are many interconnected systems to try out,” Bailey said. “Any new ship needs to have shakedown cruises, but we’ll have to test all of the scientific instrumentation as well, from the acoustic multibeam seafloor mapping system to its seawater and meteorological data collection, processing and transfer capabilities.

“These ships will be very forward-looking and are expected to support science operations for 40 years or longer. They will be the most advanced ships of their kind in the country.”

OSU previously operated the 184-foot R/V Wecoma from 1975 until 2012, when it was retired. The university then assumed operations of Wecoma’s sister ship, R/V Oceanus, from Woods Hole Oceanographic Institution; that ship will be retired when the new ship is ready.

The tentative timetable for the new ships:

  • Ship No. 1 keel laying – spring 2018;
  • Ship No. 1 transition to OSU for a year of testing – fall 2020;
  • Ship No. 1 should be fully tested, have UNOLS designation and be fully operational by fall 2021;
  • Ship No. 2 – Keel laying in winter of 2018, delivery in spring 2021, and UNOLS designation in late spring 2022;
  • Ship No. 3 – Keel laying in fall 2020, delivery in spring 2022, and UNOLS designation in spring 2023.

More information on the ships and the project is available at: http://ceoas.oregonstate.edu/ships/rcrv/.

Story By: 
Media Contact: 

Mark Floyd, 541-737-0788

Multimedia Downloads
Multimedia: 

Regional class research vessel

Regional class research vessel

OSU researcher studies cross-laminated timber as seismic retrofit tool

CORVALLIS, Ore. – Safer historic buildings and more jobs for the timber industry are the goals of a partnership between an Oregon State University structural engineering researcher and a newly formed nonprofit group in Corvallis, Oregon.

Andre Barbosa of the OSU College of Engineering is collaborating with Cascadia Seismic Strategies on a $150,000 project to study the use of cross-laminated timber panels for seismic retrofits on unreinforced masonry buildings. 

A grant coordinated through the Downtown Corvallis Association and Oregon Main Street is covering roughly two-thirds of the cost of the project, which will result in mockups of CLT retrofit systems at the 107-year-old Harding Building at Third Street and Madison Street in Corvallis.

“We’ll build prototypes that will provide details that will let engineers and construction folks see how things go together,” said Barbosa, a volunteer with Cascadia Seismic Strategies.

Barbosa is one of the original members of the group, named after the subduction zone that lies off the coast of Oregon. The major Cascadia earthquake that experts say is on the horizon would be particularly damaging to vintage masonry structures like the Harding Building, the cornerstone of the original Third Street business district.

“The DCA is concerned about the potential devastation that a Cascadia Subduction Zone mega-quake would wreak,” said Cascadia Seismic Strategies spokeswoman Roz Keeney. “Members of the DCA’s design committee recruited structural engineers, historic architects and other building professionals to join in a conversation about earthquake preparedness and historic building preservation. This group went on to form Cascadia Seismic Strategies, which is now focused on this cutting-edge project to develop a low-cost reinforcement method using local wood products and off-the-shelf steel connectors.”

Engineering work is scheduled to start in August. The grant for the 34-month project underwrites multiple design and construction strategies for dealing with weaknesses in unreinforced masonry buildings, as well as production of a video demonstrating how to implement upgrades that can serve as a guide for other communities wanting to use similar strategies in preservation and retrofitting efforts.

“This project identifies seismic retrofits for historic buildings that improve their safety performance without compromising their historic integrity,” said project manager and historic preservation architect Sue Licht. “It also demonstrates that historic rehabilitation can create local, site-specific jobs that cannot be outsourced.”

Barbosa notes that OSU is a leader in developing new wood products such as cross-laminated timber and in growing forest-products jobs amid reduced harvest levels.

“It’s important to bring jobs back to the timber industry in Oregon and to find new applications for mass timber,” he said. “This could potentially be one of them, while improving the resiliency of downtowns and the older buildings that give us liveliness and history.”

Portland firm KPFF Consulting Engineers will handle most of the structural engineering, led by Reid Zimmerman, with Barbosa lending his expertise in cross-laminated timber and seismic retrofits.

“This comes from what we’ve been learning by visiting different earthquake sites, like Napa (California) and Nepal,” Barbosa said. “We keep learning and try to bring back that knowledge and share it with communities, including by creating a model for affordable seismic retrofits for historic buildings. This is a grass-roots, community-driven solution for a big problem, a huge Cascadia quake.” 

The primary funding organization, Oregon Main Street, is a Main Street America coordinating program administered by the State Historic Preservation Office. It works with Oregon communities to “develop comprehensive, incremental revitalization strategies based on a community’s unique assets, character and heritage.”

Its goal is to build “high-quality, livable and sustainable communities that will grow Oregon’s economy while maintaining a sense of place.”

Media Contact: 

Steve Lundeberg, 541-737-4039

Multimedia Downloads
Multimedia: 

Timber research

Cross-laminated timber

Scientists name new species of fish from the Orinoco region after singer Enya

CORVALLIS, Ore. – In 1988, Irish singer and songwriter Enya released a lead single titled “Orinoco Flow” from her second studio album, which went on to become an international hit, earn a Grammy Award nomination, and help launch her wildly successful career.

Now a team of scientists have named a new species of fish from the Orinoco River drainage after her.

Leporinus enyae is a “beautiful little fish,” said Michael Burns, a doctoral candidate at Oregon State University and lead author on the paper describing the new species, as well another from the Xingu River of Brazil. It was published this week in the journal Neotropical Ichthyology by researchers from Oregon State and Brazil.

“Whenever we were in the lab at Oregon State working on the fishes, Ben Frable would always play ‘Orinoco Flow,” said Burns, referring to another graduate student in the lab.

“I heard the song so often in the lab it got stuck in my head,” co-author Marcus Chatfield said. “Then I just started listening to it on purpose when I was taking measurements of the specimens. When the time came around for choosing names, it just felt right to name this new beautiful fish from the Orinoco after the artist who wrote that beautiful song.”

“We’re also big fans of her music,” added co-author Brian Sidlauskas, the curator of fishes at Oregon State University as well as an amateur Celtic harper.

The second newly discovered fish has been named Leporinus villasboasorum, in honor of the pioneering efforts of brothers Orlando, Cláudio and Leonardo Villas-Bôas a half-century ago to protect the Xingu River’s biodiversity and the rights of indigenous peoples there.

Leporinus is the largest and most diverse genus in the characiform family Anostomidae and includes roughly 90 species across most of South America. New species are described yearly and the genus includes many “poorly understood” species complexes, according to Sidlauskas.

“We thought it would be fairly straightforward to look at populations of similar fishes from the Orinoco River basin in Venezuela, the Essequibo River of Guyana, and several of the tributaries of the Amazon River in Brazil and see if they are taxonomically the same or different,” Sidlauskas said. “It turns out that there are at least two new distinct species, and there may be more.”

Both new species are comparatively small – about 8 to 10 inches long – although some members of their family can reach two feet in length. Smaller species are sold as aquarium fish, though in the wild, these omnivores prefer moving water – both for feeding and protection from predators.

The term Leporinus literally means “little hare,” in reference to the large teeth that protrude from the mouth, much like those of a rabbit. The bottom teeth of the two new species are particularly long, and while no one is sure why, the researchers note that it may relate to their foraging on plants, worms and other invertebrates.

It isn’t unusual to discover new fish species, especially in the tropical river basins of South America, the scientists say. The region is vast and the network of rivers and tributaries flows through many different types of terrain and microhabitats, leading to speciation on a fine scale.

To an outsider, the new fish species are not remarkably different from two previously established species, Leporinus desmotes and Leporinus jatuncochi. However, there are significant differences in body shape, coloration, scale counts and genetics, Burns said.

“The differences and divergence between the two new Leporinus species and the established ones may trace back several million years,” Sidlauskas said.

“Preserving these different lineages may be very important because one species may have developed evolutionary traits that the others don’t have,” Burns added.

Sidlauskas said Brazil has recently built the Belo Monte Dam on the Xingu River inside the range of the newly discovered Leporinus villasboasorum. Belo Monte is the fourth-largest dam in the world and has the potential to significantly alter habitats on a huge scale. Such anthropogenic influences can threaten fish species that are geographically distinct and limited in range. The impact of the Belo Monte Dam on the recently named Leporinus villasboasorum has yet to be evaluated.

“There also is a lot of local influence on these major rivers and, in turn, the fish species,” Sidlauskas said.

The study was funded by the National Science Foundation, Fundação Araucária (Brazil) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brazil). Co-author on the study was José Birindelli of Universidade Estadual de Londrina in Brazil. The OSU authors are all affiliated with the Department of Fisheries and Wildlife in the College of Agricultural Sciences. Fish in the study were provided by 28 collections in the United States, South America, Europe and Canada.

Story By: 
Media Contact: 

Mark Floyd, 541-737-0788

Source: 
Multimedia Downloads
Multimedia: 

Leporinus enyae

Leporinus enyae

Diatoms have sex after all, and ammonium puts them in the mood

CORVALLIS, Ore. – New research shows a species of diatom, a single-celled algae, thought to be asexual does reproduce sexually, and scientists learned it’s a common compound – ammonium – that puts the ubiquitous organism in the mood.

The findings, published today in PLOS One, may be a key step toward greater understanding of the evolution of sexual behavior and also have important biotechnology implications.

“Our discoveries solve two persistent mysteries that have plagued diatom researchers,” said corresponding author Kimberly Halsey, a microbiologist at Oregon State University. “Yes, they have sex, and yes, we can make them do it.”

Diatoms hold great potential as a bioenergy source and also for biosensing. In addition, their intricate, silica cell walls offer promising nanotechnology applications for materials chemists and drug-delivery researchers.

There are more than 200,000 species of diatoms, and the organisms are abundant nearly everywhere water is found, forming huge blooms in the spring and fall that help drive the marine carbon cycle.

“Diatoms are amazing; their silica frustules are beautiful and exquisite,” Halsey said. “Now that we can control their sexual pathway, that should open the door to being able to make crosses between different diatoms with different characteristics. We should be able to breed them just like we do with corn or rice or strawberries to select for traits that are really desirable.”

Halsey and collaborators in botany and statistics from OSU’s colleges of Science and Agricultural Sciences studied the “centric” Thalassiosira pseudonana species of diatom, a model organism for researchers; it’s one of two diatoms, the other being the “pennate” diatom Phaeodactulum tricornutum, to have had its genome sequenced.

Centric diatoms are radially symmetrical – think of them as shaped like a soup can, Halsey says – and pennate diatoms are bilaterally symmetrical: elongated in the manner of a pea pod.

“Everybody said Thalassiosira pseudonana was asexual, because they’d never seen anything else,” Halsey said. “The general thinking was that it just lost the ability or need to go through sex.”

Other scientists, Halsey notes, had showed T. pseudonana retained genes necessary for meiosis, a type of genetic replication specific to sexual reproduction, and concluded the diatom wasn’t using those genes.

“But we started seeing very different morphologies,” changes in cell structure, Halsey said, in this case related to sexual activity. “We also saw genes expressed that are involved in flagellar structures and assembly, which would only happen with sperm cells.”

Graduate student Eric Moore, lead author on the research, was astonished to learn “these single-celled organisms can differentiate into male and female cells, completely changing their morphologies.”

“In fact, I was convinced my cultures were contaminated before I realized what was actually going on,” he said.

Previous work by other researchers studying different types of centric diatoms showed that growth stress – interruptions of light, changes in salinity, shifts in nutrients – can sometimes, but not reliably, cause cells to become sexual.

“Lab efforts to induce sex in centric diatoms have ranged from sweet talk to torture,” Halsey said.

But manual, microscopic analysis by Halsey’s team found that ammonium, a common compound that’s a metabolic waste product of animals, reliably caused two strains of T. pseudonana and two other centric diatoms to change their cell structures, making eggs and sperm; ammonium caused the diatoms to get ready for sex when at least one other cell growth factor – such as light, phosphorus or silica – was in short supply.

In addition, RNA sequencing showed more than 1,200 diatom genes that changed in activity when ammonium lit the algae’s sexual fires. Halsey suggests that in nature, the protists that graze on the diatom blooms excrete the ammonium that triggers the diatoms’ sexualization.

“The specific collection of environmental factors that make diatoms have sex aren’t yet known,” she said. “But identifying ammonium as a sexuality inducer potentially opens the door to new avenues of research into breeding and genetic modification to control important traits.”

Collaborators also included Brianna Bullington of OSU’s Department of Microbiology, Alexandra Weisberg of the Department of Botany and Plant Pathology, and Yuan Jiang of the Department of Statistics.

Media Contact: 

Steve Lundeberg, 541-737-4039

Multimedia Downloads
Multimedia: 

diatom sperm cells -- 2

Thalassiosira pseudonana

Study finds Earth’s magnetic field ‘simpler than we thought’

CORVALLIS, Ore. – Scientists have identified patterns in the Earth’s magnetic field that evolve on the order of 1,000 years, providing new insight into how the field works and adding a measure of predictability to changes in the field not previously known.

The discovery also will allow researchers to study the planet’s past with finer resolution by using this geomagnetic “fingerprint” to compare sediment cores taken from the Atlantic and Pacific oceans.

Results of the research, which was supported by the National Science Foundation, were recently published in Earth and Planetary Science Letters.

The geomagnetic field is critical to life on Earth. Without it, charged particles from the sun (the “solar wind”) would blow away the atmosphere, scientists say. The field also aids in human navigation and animal migrations in ways scientists are only beginning to understand. Centuries of human observation, as well as the geologic record, show our field changes dramatically in its strength and structure over time.

Yet in spite of its importance, many questions remain unanswered about why and how these changes occur. The simplest form of magnetic field comes from a dipole: a pair of equally and oppositely charged poles, like a bar magnet.

“We’ve known for some time that the Earth is not a perfect dipole, and we can see these imperfections in the historical record,” said Maureen “Mo” Walczak, a post-doctoral researcher at Oregon State University and lead author on the study. “We are finding that non-dipolar structures are not evanescent, unpredictable things. They are very long-lived, recurring over 10,000 years – persistent in their location throughout the Holocene.

“This is something of a Holy Grail discovery,” she added, “though it is not perfect. It is an important first step in better understanding the magnetic field, and synchronizing sediment core data at a finer scale.”

Some 800,000 years ago, a magnetic compass’ needle would have pointed south because the Earth’s magnetic field was reversed. These reversals typically happen every several hundred thousand years.

While scientists are well aware of the pattern of reversals in the Earth’s magnetic field, a secondary pattern of geomagnetic “wobble” within periods of stable polarity, known as paleomagnetic secular variation, or PSV, may be a key to understanding why some geomagnetic changes occur. 

The Earth’s magnetic field does not align perfectly with the axis of rotation, which is why “true north” differs from “magnetic north,” the researchers say. In the Northern Hemisphere this disparity in the modern field is apparently driven by regions of high geomagnetic intensity that are centered beneath North America and Asia.

“What we have not known is whether this snapshot has any longer-term meaning – and what we have found out is that it does,” said Joseph Stoner, an Oregon State University paleomagnetic specialist and co-author on the study. 

When the magnetic field is stronger beneath North America, or in the “North American Mode,” it drives steep inclinations and high intensities in the North Pacific, and low intensities in Europe with westward declinations in the North Atlantic. This is more consistent with the historical record.

The alternate “European mode” is in some ways the opposite, with shallow inclination and low intensity in North Pacific, and eastward declinations in the North Atlantic and high intensities in Europe.

“As it turns out, the magnetic field is somewhat less complicated than we thought,” Stoner said. “It is a fairly simple oscillation that appears to result from geomagnetic intensity variations at just a few recurrent locations with large spatial impacts. We’re not yet sure what drives this variation, though it is likely a combination of factors including convection of the outer core that may be biased in configuration by the lowermost mantle.”

The researchers were able to identify the pattern by studying two high-resolution sediment cores from the Gulf of Alaska that allowed them to develop a 17,400-year reconstruction of the PSV in that region. They then compared those records with sediment cores from other sites in the Pacific Ocean to capture a magnetic fingerprint, which is based on the orientation of the magnetite in the sediment, which acts as a magnetic recorder of the past.

The common magnetic signal found in the cores now covers an area spanning from Alaska to Oregon, and over to Hawaii.

“Magnetic alignment of distant environmental reconstructions using reversals in the paleomagnetic record provides insights into the past on a scale of hundreds of thousands of years,” Walczak said. “Development of the coherent PSV stratigraphy will let us look at the record on a scale possibly as short as a few centuries, compare events between ocean basins, and really get down to the nitty-gritty of how climate anomalies are propagated around the planet on a scale relevant to human society.”

The magnetic field is generated within the Earth by a fluid outer core of iron, nickel and other metals that creates electric currents, which in turn produce magnetic fields. The magnetic field is strong enough to shield the Earth from solar winds and cosmic radiation. The fact that it changes is well known; the reasons why have remained a mystery.

Now this mystery may be a little closer to being solved.

Walczak and Stoner are in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences. Other authors on the study are Alan Mix, also of OSU; John Jaeger, Gillian Rosen and James Channell of the University of Florida; David Heslop of Australian National University; and Chuang Xuan of the University of Southampton.

Story By: 
Media Contact: 

Mark Floyd, 541-737-0788

Special Olympians will help OSU researchers gain further health insights

CORVALLIS, Ore. – More than 2,000 athletes will descend on Corvallis on July 8 and 9, competing in the Special Olympics Oregon Summer State Games while also helping to further research into the health of people with intellectual disabilities.

“There still is this misconception that if you have a disability, then you cannot be healthy,” said Gloria Krahn, the Barbara Emily Knudson Endowed Chair in Family Policy Studies at Oregon State University. “I would’ve thought that after 25 years, we would be past some of that. Special Olympics is helping bring about that change.”

Oregon State is hosting the Summer State Games, which feature track and field, bocce, golf and softball, with events split between Corvallis High School and the OSU campus.

Special Olympics Oregon’s Healthy Athletes program will also be part of the Summer State Games, providing free health screenings for the athletes. The screenings involve six areas called Fit Feet, FUNfitness, health promotion, Healthy Hearing, Opening Eyes and Special Smiles. Strength, flexibility, balance and endurance will be tested, and athletes will be given a take-home program based on their results that aims to improve and encourage their participation in sports and recreational activities.

Special Olympics Oregon regularly hosts Healthy Athletes programs around the state.

Special Olympics Oregon also provides a program called Oregon Team Wellness for those with intellectual disabilities. The program incorporates incentives and rewards to reach benchmarks, with the ultimate goal of lifelong healthy choices and habits.

The program, which started in Oregon, has spread to other states in the Northwest. Researchers at OSU, including Alicia Dixon-Ibarra, a post-doctoral scholar in OSU’s College of Public Health and Human Sciences, and Krahn, are working with Special Olympics to evaluate the program.

Dixon-Ibarra is working on the research and practical side of the games.

She will gather information used in research designed to further improve the health of people with intellectual disabilities. All the information from the weekend will go into one of the largest data sets for people with intellectual disabilities in the world, and can show discrepancies between different countries and their health issues. One area of the world could have issues relating to tooth decay, for example, while another may have higher rates of obesity.    

“I find this job really rewarding,” Dixon-Ibarra said. “I know there’s a huge need for health care and health promotion for this population based on my own research and the research of others in my area, and that this is a big need that we’re fulfilling with these programs.”

Dixon-Ibarra said a common misconception is that people with intellectual disabilities can’t be as healthy as those without. Also, Krahn notes that until relatively recently, trying to keep a person with a disability active and healthy fell solely on the family, without much help from school districts or other groups that organize sports and other recreational activities.

Helping to change attitudes, the researchers say, are programs like the Special Olympics, founded by Eunice Kennedy Shriver in 1968. From a small beginning – just 1,000 athletes competed in the first Special Olympics World Games – the Special Olympics are now in 169 nations and encourage more than 4 million people with developmental disabilities to be active and healthy. Shriver will be posthumously honored for her work on July 12 at the 25th annual ESPYS on ABC. 

Athletes and coaches will stay in OSU residence halls during the Summer State Games. Parking is free around Reser Stadium, and admission is free to all events. The public is invited to watch the athletes compete, and a complete schedule of the events can be found here.

People interested in volunteering with the Special Olympics Oregon Summer State Games should contact LouAnne Tabada, senior director of volunteer services for Special Olympics Oregon, at Itabada@soor.org or volunteer@soor.org.    

Media Contact: 

Lanesha Reagan, 425-359-3054

Krill hotspot fuels incredible biodiversity in Antarctic region

CORVALLIS, Ore. – There are so many Antarctic krill in the Southern Ocean that the combined mass of these tiny aquatic organisms is more than that of the world’s 7.5 billion human inhabitants.

Scientists have long known about this important zooplankton species, but they haven’t been certain why particular regions or “hotspots” in the Southern Ocean are so productive. One such hotspot exists off Anvers Island – along the western Antarctic Peninsula – where high densities of Antarctic krill episodically concentrate near the shore close to a number of Adélie penguin breeding colonies. 

As it turns out, a perfect combination of tides and wind is responsible, according to scientists who just published a study on the krill in the journal Deep Sea Research. The research was funded by the National Science Foundation.

“This region off the western Antarctic Peninsula has been a known breeding area for Adélie penguins for thousands of years,” said Kim Bernard, a biological oceanographer at Oregon State University and lead author on the study. “We know it today as a krill hotspot and it probably has been for some time.

“But despite their abundance, there is growing concern about krill not only because of climate change, but because they are now being harvested for human food, nutritional supplements and aquaculture feed. Yet historically we’ve known little about what makes this particular area so productive for krill. So we set out to learn more about it.”

Bernard and a team of colleagues spent four consecutive summer seasons in the Antarctic mapping the patterns in distribution and biomass of Antarctic krill, also known as Euphausia superba. They also sought to identify the environmental conditions responsible for the hotspot. 

What they discovered is a near-perfect system in which krill aggregations situated over the Palm Deep Canyon – a region of nutrient-rich waters that produce a lot of food for the krill – are delivered close to shore by tidal currents and winds. When the winds are westerly and the tides are diurnal – one high tide and one low tide each day – the krill biomass close to shore is at its peak and krill aggregations are huge.

“It’s neat – we can predict exactly when humpback whales will be close to shore off Palmer Station just based on the tides,” Bernard said. “When there are diurnal tides, you’ll see krill from the surface to the ocean floor – they are everywhere. And when they are, the whales are there, too.

“This concentration and transport toward shore are particularly important for the penguins that breed there. The farther they have to go to forage, the less their chicks have to eat and chick weight is a huge factor in their survival. A difference of a few hundred grams in chick weight is the difference between life and death.”

When the tides shift to semi-diurnal – two high and two low tides daily – currents move the krill away from shore and their predators follow. Likewise, a shift to southerly winds keeps the krill farther from shore and more spread out.

Antarctic krill can live five to seven years, and grow to a length of a little more than two inches. They don’t reach sexual maturity for two years, and when they reproduce, they must release their eggs in water roughly 1,000 meters (or about 3,200 feet) deep. That’s because they need a certain period of time to develop as they drift to the ocean floor, and another period of time to go through different life stages as they re-ascend to the surface.

Studies have shown that sea ice may be critical to their survival, but scientists are not exactly sure why, Bernard said.

“We see very strong correlations between krill biomass and sea ice,” she noted. “When the sea ice is low, the krill populations crash the next summer. It could be a change in algae or other food for them, or it could be that sea ice provides shelter from predators, or affects the currents in some way. We just don’t yet know.

“It would be nice to find out, because sea ice abundance may vary greatly in the future.”

Bernard is on the faculty of OSU’s College of Earth, Ocean, and Atmospheric Sciences.

Story By: 
Media Contact: 

Mark Floyd, 541-737-0788

Multimedia Downloads
Multimedia: 

Palmer_Dec2012_145

Penguins rely on close-to-shore krill

Participants sought for study on family dogs and physical activity for kids with disabilities

CORVALLIS, Ore. – Oregon State University researchers are recruiting children with disabilities and their family dogs for a research study that will test a new intervention to see if pairing the dog and the child can help the child become more physically active.

The project is led by Megan MacDonald of OSU’s College of Public Health and Human Sciences and Monique Udell of OSU’s College of Agricultural Sciences. The researchers recently received a two-year, $375,000 grant from the National Institutes of Health’s Eunice Kennedy Shriver National Institute of Child Health and Human Development to support the project.

Children with disabilities spend less time participating in physical activity compared to their peers and are considered a health disparity group, meaning they generally face more health concerns than their peers. And physical activity tends to drop among all children around age 12. The goal of the study is to see if the partnership with the family dog leads to improvements in children’s physical activity levels, which in turn could lead to other health improvements.

“We need to find creative ways to engage kids in physical activity,” MacDonald said. “And beyond physical activity, animal companionship can have a significant impact on health and well-being.” 

The new study builds on the researchers’ earlier work exploring how a family dog might serve as a partner to help a child with disabilities become more active. In a recent case study of one 10-year-old boy with cerebral palsy and his family’s dog, the researchers found the intervention program led to a wide range of improvements for the child, including physical activity as well as motor skills, quality of life and human-animal interactions. They also found that the dog’s behavior and performance on cognitive and physical tasks improved alongside the child’s.

The new intervention is aimed at children with disabilities who are 10 to 16 years old and have a family dog that also could participate in the study. The children will learn how to train their dog in new behaviors with the “Do As I Do” method, which uses positive reinforcement. “Do As I Do” is similar to the game “Simon Says,” in which the dog follows the lead of the child.

“It’s really about the child and the dog being active together as a team,” MacDonald said. “The program also could help the relationship between the child and the dog grow.”

Families will come to OSU for one hour daily for two weeks during the study, which is expected to begin later this summer. There is some flexibility to the schedule depending on families’ needs. The children also will have homework such as walking the dog each day at home. Not all families selected for the study will participate in the “Do as I Do” training this year but all families will have a chance to participate in the training over the course of the two-year study.

“Participating children need to be able to follow basic instructions but beyond that, we want to be as inclusive as possible,” MacDonald said. “Parents who have questions about whether their child and their pet are a good fit for the study should feel free to give me a call so we can discuss their individual needs.”

Families interested in learning more about the study or participating in it should contact MacDonald at 541-737-3273 or Megan.MacDonald@oregonstate.edu

Story By: 
Media Contact: 

Michelle Klampe, 541-737-0784