OREGON STATE UNIVERSITY

scientific research and advances

Flame retardant chemicals may affect social behavior in young children

CORVALLIS, Ore. – Some chemicals added to furniture, electronics and numerous other goods to prevent fires may have unintended developmental consequences for young children, according to a pilot study released today.

Researchers from Oregon State University found a significant relationship between social behaviors among children and their exposure to widely used flame retardants, said Molly Kile, an environmental epidemiologist and associate professor in the College of Public Health and Human Sciences at OSU.

“When we analyzed behavior assessments and exposure levels, we observed that the children who had more exposure to certain types of the flame retardant were more likely to exhibit externalizing behaviors such as aggression, defiance, hyperactivity, inattention and bullying,” said Kile, the corresponding author of the study, which was published today in the journal Environmental Health.

“This is an intriguing finding because no one had previously studied the behavioral effects of organophosphate classes of flame retardants, which have been added to consumer products more recently.”

Flame retardants are found throughout the built environment in furniture, mattresses, carpeting, electronics, vehicles and more. The chemicals are added to the products and are not bound in the material, which causes them to be released into indoor environments.

Manufacturers began adding flame retardants in 1975, in response to new legislation in California designed to reduce flammability in common household items. The state updated its flammability standards in 2014, and now allows furniture manufacturers to meet the standards without adding flame retardant chemicals to their products, but the chemicals are still widely used and they linger in the indoor environment.

There are growing concerns that some flame retardants may have unintended impacts on health and development in children, and this study contributes to that body of research.

The most common types of flame retardants found in the built environment are brominated diphenyl ethers (BDEs) and organophosphate-based flame retardants (OPFRs). OPFRs emerged as an alternative to BDEs in an effort to address some of the environmental health concerns posed by BDEs, which tend to remain in the environment for long periods.

Past research has shown that both BDEs and OPFRs are linked to poorer cognitive function in children. But less is known about the relationship between the flame retardants and children’s social and emotional health, particularly during early childhood, a key developmental period for learning.

“The social skills children learn during preschool set the foundation for their success in school, and also for their social and emotional health and well-being later in life,” said Shannon Lipscomb, an associate professor and lead of the human development and family sciences program at OSU-Cascades and a co-author of the study.

For this study, the OSU research team recruited 92 Oregon children between ages 3-5 to wear a silicone wristband for seven days to measure exposure to flame retardants.

The team included Kile, Lipscomb; Megan McClelland and Megan MacDonald of the OSU College of Public Health and Human Sciences; Kim Anderson of the OSU College of Agricultural Sciences; and Andres Cardenas of the Harvard T.H. Chan School of Public Health and an OSU doctoral graduate. The research was supported by OSU’s Hallie E. Ford Center for Healthy Children and Families and the Environmental Health Science Center at OSU.

The wristbands, developed by Anderson at OSU, have a porous surface that mimics a cell, absorbing chemicals that people are exposed to through their environment. When the wristbands are returned, Anderson can screen for up to 1,200 chemicals that may accumulate. The wristband is an easy and non-invasive way to sample children’s chemical exposure.

The researchers had parents or primary caregivers complete questionnaires about socio-demographics and the home environment, and preschool teachers completed behavior assessments for each participating child. In all, researchers had complete data and wristband results for 69 children.

Their analysis showed that all of the children were exposed to some level of flame retardant. Children who had higher exposure rates of OFPRs showed less responsible behavior and more aggression, defiance, hyperactivity, inattention and bullying behaviors. Children with higher exposure to BDEs were seen as less assertive by their teachers. All of these social skills play an important role in a child’s ability to succeed academically and socially.

“We detected these links between flame retardant and children’s social behaviors while controlling for differences in family demographics, home learning environments and adversity,” Lipscomb said. “This suggests that flame retardants may have a unique effect on development apart from the effects of children’s early social experiences.”

Further study is needed to better understand the links between flame retardants and children’s social skill development, the researchers said. They plan to pursue funding for a new study that continues for a longer period of time and considers how other aspects of children’s lives might affect the impact of flame retardants on their development.

“The results of this research to date have shown potential impacts for child health and warrant a more thorough investigation,” Kile said.

“If scientists find strong evidence that exposure to flame retardants affects children’s behaviors, we can develop strategies that prevent these exposures and help improve children’s lives. This type of public health science is needed to figure out how to address the root causes of behavioral concerns that can affect children’s school readiness and overall well-being.”

Story By: 
Source: 

Molly Kile, 541-737-1443, molly.kile@oregonstate.edu; Shannon Lipscomb, 541-322-3137, Shannon.lipscomb@osucascades.edu

Multimedia Downloads
Multimedia: 

Child wearing a wristband

Keeping Kids Safe

You Tube video:

https://youtu.be/pMvOKVoDA94

 

 

Fish and mercury: Detailed consumption advisories would better serve women across U.S.

CORVALLIS, Ore. – Among women of childbearing age in the U.S., fish consumption has increased in recent years while blood mercury concentrations have decreased, suggesting improved health for women and their babies, a new study shows.

The research at Oregon State University also indicates fish consumption advisories tailored to specific regions and ethnic groups would help women of childbearing age to eat in even more healthy ways, including better monitoring of mercury intake.

Food from the ocean has a unique and valuable nutritional profile. Among seafood’s many benefits are the omega-3 fatty acids that promote neurodevelopment, and the nutrients in seafood are especially important for pregnant women to pass on to developing fetuses.

But the main way people are exposed to toxic methylmercury – a mercury atom with a methyl group, CH3, attached to it – is through eating seafood. Thus the need for precise, nuanced fish consumption advisories, said Leanne Cusack of Oregon State University, the corresponding author on the study. 

Comparatively less-toxic elemental mercury enters the ocean from natural sources such as volcanic eruptions and also from human activities like the burning of fossil fuels, which accounts for about two-thirds of the mercury that goes into the water.

Once in the ocean, the mercury is methylated, diffuses into phytoplankton and passes up the food chain, accumulating along the way.

A scallop or a shrimp, for example, can have a mercury concentration of less than 0.003 parts per million. A large predator like a tuna, on the other hand, can contain roughly 10 million times as much methylmercury as the water that surrounds it and have a concentration of many parts per million.

Exactly how the mercury in the ocean becomes methylated, scientists don’t know.

Fish advisories are usually aimed at women of childbearing age because a developing fetus has greater sensitivity to the neurotoxic effects of methylmercury. Jointly, the U.S. Environmental Protection Agency and the Food and Drug Administration recommend women in that group eat two meals of low-mercury fish per week.

Using data from the ongoing National Health and Nutrition Examination Survey, Cusack’s research group looked at fish consumption patterns with regard to blood mercury levels in U.S. women of childbearing age from 1999 to 2010.

Findings were recently published in the journal Environmental Health.

Women in the coastal regions, particularly the Northeast, were found to have the highest blood mercury concentrations; women living away from the sea, especially in the inland Midwest, had the lowest.

Coastal residents also ate fish the most frequently, with the species consumed varying by region. The type of fish most often consumed was shellfish in every part of the U.S. except for the inland West and inland Midwest.

As women’s age and household income increased, so did their fish consumption frequency and blood mercury concentrations. Among ethnic groups, Asian Americans, Pacific Islanders, Alaska Natives and Native Americans ate fish the most often and showed the most mercury, and Mexican Americans consumed fish the least often and showed the smallest concentration of mercury.

“We also found total monthly fish consumption by women of reproductive age was higher than it had been in recent years, with women consuming more marine fish and shellfish but with no appreciable difference in the mean consumption of freshwater fish, tuna, swordfish and shark,” said Cusack, a postdoctoral scholar in OSU’s College of Public Health and Human Sciences.

“That’s encouraging because marine and shellfish are associated with smaller increases in blood mercury. And also encouragingly, an average women who’d eaten fish nine or more times in the previous month had lower blood mercury levels than women who’d had fish at the same rate in 1999-2000.”

The differences in consumption and mercury levels by race and region illustrate the need for tailored fish advisories, she said.

“They need to have information about fish types and quantities you can safely eat,” Cusack said. “The more detailed they can be, the better.

“The main thing is we do need to increase fish consumption in this demographic,” Cusack added. “It has been increasing since 1999, but it’s still not at the level where we want to see it. People need to start consuming fish, and advisories need to focus on the benefits of consumption and not just the risks by providing a broad range of fish that are low in methylmercury and high in omega-3’s.” 

Media Contact: 

Steve Lundeberg, 541-737-4039

Source: 

Leanne Cusack, 541-737-5565
Leanne.Cusack@oregonstate.edu

Multimedia Downloads
Multimedia: 

filets

Salmon filets

Altered lipids, skin infections may point to new personalized therapy for atopic dermatitis

CORVALLIS, Ore. – Researchers have discovered a new way to identify the lipids, or fats found in the skin of people who have atopic dermatitis, and compare them to people with healthy skin.

This is a fundamental advance in dermatology that could lead to new therapies for millions of people with this debilitating skin problem - atopic dermatitis is one of the most common forms of eczema.

The findings were just announced in the British Journal of Dermatology.

The new technology should open the door to the formulation of personalized treatments, scientists say. Patents have been applied for, and researchers are working with university officials to begin the process of licensing and commercialization.

As another part of this advance, the scientists also discovered a clear link between atopic dermatitis, altered lipid profiles and some types of bacterial infections such as staphylococcus aureus, or a staph infection. This had never before been reported.

They believe these staph infections may both lead to atopic dermatitis problems and make people more prone to further infections – a cycle of skin inflammation that can disrupt the skin microbiome and be one component of this disease that has been so resistant to long-term treatment.

“These findings about altered lipid profiles and the link to bacterial infections could be a breakthrough to ultimately help many people who struggle with atopic dermatitis and related skin problems,” said Arup Indra, an associate professor in the College of Pharmacy at Oregon State University, an expert on inflammatory skin disease and lead author of the study.

“For the first time we will be able to identify the individual lipids that may be needed to help someone’s skin return to health,” Indra said. “This may be of value not only to patients with atopic dermatitis or other skin diseases, but even for normal individuals who simply want their skin to be more healthy, well hydrated and resistant to aging.”

Lipids, or fats, are a vital part of healthy skin, serving almost as a “blanket” to help protect its integrity. They can also act as a natural barrier to infection; are part of the innate immune system; and when properly balanced and healthy can help prevent skin cancer. Skin lipids include ceramides, free fatty acids, cholesterol and triglycerides.

When these lipids are not available in the right type or amount, skin inflammation can occur. In atopic dermatitis patients this can range from mild, intermittent rashes to severe, almost continual skin problems over significant portions of a person’s body. Some amount of atopic dermatitis is common in infants, but in some people it’s a lifelong issue.

Steroid drugs, either topical or systemic, have been one of the few ways to treat atopic dermatitis, but they have a wide range of side effects that make long-term treatment a concern. Moisturizing creams, lotions, special diets and other approaches have shown limited success.

With the new technology, however, researchers can identify a person’s individual skin lipid profile with some simple tests. A type of tape has been developed that can pull some lipids off a person’s skin; allow testing of them with the use of a mass spectrometer; and have the results compared to the skin lipid profiles of generally healthy patients.

With this information, researchers in the future should be able to determine quite specifically what lipids are deficient, and develop topical compounds to replace them – either individually, or with compounds that could aid groups of people who share similar lipid profiles.

Researchers say they hope to interrupt the cycle of skin inflammation and staph infections through the use of personalized lipid-replacing compounds, and create a new, promising approach to therapy.

“This has the potential to remove any guess work that might have existed in the past regarding the correct combination of lipids required to improve skin health,’ Indra said, “and will help restore to people’s skin the right quantity and type of lipids they need.”

This research has been supported by the Atopic Dermatitis Research Network, funded by the National Institutes of Health and the Oregon Nanoscience and Microtechnologies Institute.

Collaborators on the research are from the Oregon Health & Science University, OSU’s Linus Pauling Institute, the University of Rochester Medical Center, National Jewish Health, and Rho, Inc.

 

Story By: 
Source: 

Arup Indra, 541-737-5775

arup.indra@oregonstate.edu

Multimedia Downloads
Multimedia: 

Atopic dermatitis
Atopic dermatitis

Maintaining an active sex life may lead to improved job satisfaction, engagement in work

CORVALLIS, Ore. – Maintaining a healthy sex life at home boosts employees’ job satisfaction and engagement at the office, underscoring the value of a strong work-life balance, an Oregon State University researcher has found.

A study of the work and sex habits of married employees found that those who prioritized sex at home unknowingly gave themselves a next-day advantage at work, where they were more likely to immerse themselves in their tasks and enjoy their work lives, said Keith Leavitt, an associate professor in OSU’s College of Business.

“We make jokes about people having a ‘spring in their step,’ but it turns out this is actually a real thing and we should pay attention to it,” said Leavitt, an expert in organizational behavior and management.  “Maintaining a healthy relationship that includes a healthy sex life will help employees stay happy and engaged in their work, which benefits the employees and the organizations they work for.”

The study also showed that bringing work-related stress home from the office negatively impinges on employees’ sex lives. In an era when smart phones are prevalent and after-hours responses to work emails are often expected, the findings highlight the importance of leaving work at the office, Leavitt said. When work carries so far into an employee’s personal life that they sacrifice things like sex, their engagement in work can decline.

The researchers’ findings were published this month in the Journal of Management. Co-authors are Christopher Barnes and Trevor Watkins of the University of Washington and David Wagner of the University of Oregon.  

Sexual intercourse triggers the release of dopamine, a neurotransmitter associated with the reward centers in the brain, as well as oxytocin, a neuropeptide associated with social bonding and attachment. That makes sex a natural and relatively automatic mood elevator and the benefits extend well into the next day, Leavitt said.

To understand the impact of sex on work, the researchers followed 159 married employees over the course of two weeks, asking them to complete two brief surveys each day. They found that employees who engaged in sex reported more positive moods the next day, and the elevated mood levels in the morning led to more sustained work engagement and job satisfaction throughout the workday.

The effect, which appears to linger for at least 24 hours, was equally strong for both men and women and was present even after researchers took into account marital satisfaction and sleep quality, which are two common predictors of daily mood.

“This is a reminder that sex has social, emotional and physiological benefits, and it’s important to make it a priority,” Leavitt said. “Just make time for it.”

Twenty years ago, monitoring sleep or daily step counts or actively practicing mindful meditation might’ve seemed odd but now they are all things people practice as part of efforts to lead healthier, more productive lives. It may be time to rethink sex and its benefits as well, he said.

“Making a more intentional effort to maintain a healthy sex life should be considered an issue of human sustainability, and as a result, a potential career advantage,” he said.

U.S. employers probably won’t follow the lead of a town councilman in Sweden who recently proposed that local municipal employees be allowed to use an hour of their work week for sex. The councilman’s hope is to boost the town’s declining population as well as improve employee moods and productivity.

But employers here can steer their employee engagement efforts more broadly toward work-life balance policies that encourage workers to disconnect from the office, Leavitt said. The French recently enacted a law that bars after-hours email and gives employees a “right to disconnect.”

“Technology offers a temptation to stay plugged in, but it’s probably better to unplug if you can,” he said. “And employers should encourage their employees to completely disengage from work after hours.”

Story By: 
Source: 

Keith Leavitt, 206-245-5798, keith.leavitt@bus.oregonstate.edu

Photos show promise as dietary assessment tool, but more training needed

CORVALLIS, Ore. – Research at Oregon State University suggests that photographs of your food are good for a lot more than just entertaining your friends on social media – those pictures might help improve your health and also national nutrition policy.

But before that can happen, universities that educate the dietitians who review the photos need to provide more consistent, formal training, particularly hands-on work in food measurement and preparation and the use of computerized nutrient database systems.

A shortage of formalized, standardized training in these skills is problematic, the study shows. Results were recently published in the journal Nutrients.

The research tested the ability of 114 nutrition and dietetics students in the U.S. and Australia to identify foods and determine serving sizes by looking at photos of food on plates. They chose their food identification answers from entries in the U.S. Department of Agriculture’s Food and Nutrient Database for Dietary Studies.

The students correctly identified the nine different foods nearly 80 percent of the time but struggled with serving size; only 38 percent of the estimates were within 10 percent of the actual weight of the food, with foods of amorphous shape or higher energy density, such as ice cream, proving the hardest to assess.

Image-based dietary assessment, or IBDA, aims to reduce or eliminate the inaccuracies that commonly accompany traditional methods such as written dietary records, 24-hour dietary recalls and food frequency questionnaires.

Dietary intake information is important both to individuals using nutrition-based therapy for conditions such as diabetes and heart disease, and to entire populations for identifying nutrition and disease risk.

The U.S. Centers for Disease Control and Prevention uses information from its National Health and Nutrition Examination Survey to set policy for everything from school lunch programs to nutrition education for food-stamp recipients. The survey gathers data about dietary patterns and potential food intake inadequacies.

“We need to know where there are inadequacies in these surveys to identify nutrition and food policy and research needs,” said the study’s corresponding author, Mary Cluskey, an associate professor in OSU’s College of Public Health and Human Sciences and a registered dietitian.

With the prevalence of smartphones, photography is emerging as a means of augmenting food-intake information gathering. A pre-diabetes patient, for example, could take a picture of everything he ate for three days, and a dietitian could then analyze those photos to make recommendations for dietary improvements.

“If you’re providing me with your dietary intake information, you may not be trying to falsify the information, because you’re sincerely interested in improving your diet,” Cluskey said. “But I’m depending on your ability to recall what you ate and your ability to correctly tell me what portions and specific ingredients you had – there are all kinds of things that can make it go wrong.

“Images can facilitate your recall,” Cluskey added, “and they also prompt important questions from a dietitian: ‘Was that low-fat dressing or high-fat?’ Plus, images make dietary assessments more entertaining because people do like to take pictures of food.”

Students with a food preparation background that included cooking from recipes and frequently measuring portions performed better than those without that type of background, suggesting that future training of dietetics students should incorporate more of those types of experiences.

“We also need to work with people on their ability to take photos,” Cluskey said. “Shoot at a 45-degree angle to the food, preferably while you’re standing, and make sure you have adequate light. We want to make it as easy as possible for people to provide information that’s as accurate as possible.”

Media Contact: 

Steve Lundeberg, 541-737-4039

Source: 
Multimedia Downloads
Multimedia: 

Jelly

Dietary assessment photo

More funding for long-term studies necessary for best science, environmental policy

CORVALLIS, Ore. – Environmental scientists and policymakers value long-term research to an extent that far outstrips the amount of funding awarded for it, according to a study published today.

Graduate students and faculty members in the Oregon State University College of Science were part of a collaboration that evaluated the perceived benefits of long-term ecological and environmental studies – known as LTEES – to both researchers and those who determine environmental policy. 

The issue is particularly important because support for LTEES by agencies such as the National Science Foundation is declining even though such research is disproportionately valued in comparison to the one- to five-year studies the agencies tend to support.

The OSU group was among 36 researchers who collectively analyzed the perceived value of LTEES, which can run for multiple decades, in research published in BioScience. The evaluation noted the policymaking and scientific communities’ growing appreciation and demand for studies that last much longer than the ones typically being funded.

Specifically, the scientists found:

 

  • The greater a scientific journal’s impact factor – the frequency with which its articles are cited in other scholarly articles – the higher its percentage of articles dealing with long-term studies;
  • The longer a study lasts, the more an article about it is cited;
  • In the policy-informing ecological reports of the U.S. National Research Council, long-term environmental studies have representation that’s greater than their frequency in scientific journals;
  • The authors of those reports expressed more demand for LTEES than they did for short-term research.

 

“For a long time, ‘monitoring’ has been a word you never put in a grant proposal, simply because if you did your work was perceived as not being hypothesis-driven research,” said Mark Novak, assistant professor of integrative biology at Oregon State.

“But many environmental scientists have long known from personal experience that you can’t know the value of new events unless you’ve studied a system long enough. The relative investment in LTEES by ecologists and funders needs to be seriously reconsidered, because LTEES advance our understanding of ecology the most, and contribute disproportionately to informing policy.”

The collaboration also found that among the comparatively few long-term studies that do exist, most are limited to single species or pairs of species.

“It’s not that short-term research isn’t important,” said Bruce Menge, the Wayne and Gladys Valley Professor of Marine Biology at Oregon State. “Both short- and long-term are really valuable. A shorter term can give you a more mechanistic understanding of long-term patterns. But the longer time series you have, the more power you have to understand changes.

“Ideally short- and long-term should go hand in hand,” Menge said. “We’re hoping to provide a prod to funding agencies, and give at least those in an agency who do appreciate long-term research some ammunition for reconsidering the allocation of funds.”

Menge has been studying intertidal rocky zones at numerous sites on the Oregon coast for more than three decades, analyzing ecological processes and patterns of community structure. The intertidal community includes sea stars, whose population was nearly wiped out three years ago by an epidemic of sea star wasting disease.

“One of the consequences of the disease was a huge influx of baby sea stars after the peak of the wasting was over,” Menge said. “We wouldn’t have really known the significance of that if we hadn’t been keeping track of how abundant sea stars were over the last 20-some years. The influx would have been remarkable, but we’d have had no idea how remarkable it truly was.”

Species studied by another of Menge’s OSU colleagues, assistant professor Kirsten Grorud-Colvert, are rockfishes, important commercial fishes whose long lifespan is a challenge for researchers being funded for only a few years.

“Rockfish can live for more than 100 years,” she said. “Three years doesn’t do it for us. If we want environmental research that effectively informs policy, that means we need funding cycles – and funding agencies – to help build that long-term storehouse of science. That’s how we can meet the demand for policy-relevant data.”

Graduate students and faculty from the University of California, Santa Cruz, joined the Oregon State scientists in the collaboration.

Media Contact: 

Steve Lundeberg, 541-737-4039

Source: 
Multimedia Downloads
Multimedia: 

LTEES

Intertidal invertebrate research

Often the villain, fructose may play hero’s role in muscular dystrophy treatment

CORVALLIS, Ore. – A substance widely known as a villain for its role in causing obesity-related health problems has emerged as a possible hero in the fight against a debilitating genetic disorder.

Research suggests that fructose, a sugar found in honey, fruits and vegetables, makes a type of molecular treatment for Duchenne muscular dystrophy more effective.

Progressive muscle degeneration and weakness characterize Duchenne muscular dystrophy, which is caused by the absence of a protein, dystrophin, that helps keep muscles intact.

Symptoms usually appear around age 4, first affecting the shoulders, upper arms, hips and thighs. Patients have a hard time rising from the floor, climbing stairs, keeping their balance and raising their arms.

Ultimately, they require use of a wheelchair, and most die in their 30s when their cardiac and respiratory systems fail. Duchenne primarily affects males, and about one boy in 3,500 will be born with it.

Hong Moulton of the Oregon State University College of Veterinary Medicine was part of an international collaboration that looked at fructose’s ability to enhance the uptake and activity of antisense oligonucleotides, or AOs. Therapy with those molecules has been shown to restore some production of dystrophin, but efficiently delivering the molecules to the muscle cells has been a challenge.

This research, which addressed the delivery challenge, involved dystrophin-deficient rodents known as mdx mice. Findings suggest that when fructose is administered along with a type of AO known as a phosphorodiamidate morpholino oligomer, or PMO, the AO gets into muscle cells four times better. This results in more production of dystrophin and better recovery of some muscle use. Fructose also enhanced delivery of a PMO conjugated to a cell-penetrating peptide, a molecule known as a PPMO.

“We don’t yet understand the mechanism,” Moulton said. “Maybe it’s that the fructose is an energy source that enhances uptake, because uptake in muscle cells requires energy. But right now the mechanism is unknown.”

Compared with other delivery technologies, fructose has low toxicity, making it both safe and efficient. No weight gain or any abnormal behavior was observed in the mice in the study.

The findings by Moulton, HaiFang Yin’s research group at China’s Tianjin Medical University and collaborators at Singapore’s Agency for Science Technology and Research were recently published in the journal Molecular Therapy – Nucleic Acids. The results follow the Food and Drug Administration’s 2016 approval of Eteplirsen – the first drug approved for Duchenne muscular dystrophy in the United States.

Eteplirsen is also the first PMO to win FDA approval, as well as the first oligonucleotide that modulates gene splicing – which is how PMOs can promote the production of dystrophin.

Soon the delivery-enhanced PPMO, a drug type pioneered by Moulton, will enter clinical trials for Duchenne muscular dystrophy.

“Currently the approved drug has minimal efficacy, and the underlying problem is the morpholino by itself has very limited muscle uptake,” Moulton said. “If you can get more material into the muscle, then you can have more dystrophin produced. The fructose approach we studied can do that.”

Media Contact: 

Steve Lundeberg, 541-737-4039

Multimedia Downloads
Multimedia: 

hongmoulton 2

Hong Moulton

Reducing pressure on predators, prey simultaneously is best for species’ recovery

CORVALLIS, Ore. – Reducing human pressure on exploited predators and prey at the same time is the best way to help their populations recover, a new study indicates.

The findings about synchronous recovery are important because historically about half the attempts at species restoration have amounted to a sequential, one-species-at-a-time tactic – usually the prey species first, then the predator.

This study suggests that a synchronous approach almost always produces a recovery that is more rapid and more direct – faster than predator-first recovery and less prone to volatile population fluctuations than prey-first recovery. Just as crucial, synchronous is also better for the humans who earn a living harvesting the two species.

Findings of the research were published today in Nature Ecology and Evolution.

“You might think the loss of income associated with reducing harvest on both species at the same time would be greater than reducing harvest on one species after another, but our work suggests that synchronous recovery is ultimately better for recovering the ecosystem, and better from an economic perspective as well,” said Mark Novak of the Oregon State University College of Science.

Because of overharvest, declines of multiple animal populations – including at least one species that consumes other harvested species – characterize many ecosystems, Novak notes.

Examples of paired population collapses wholly or partially attributable to trophy hunting, industrial fisheries or the fur trade are lions and wildebeest; Steller sea lions and Pacific herring; and mink and muskrat.

Novak, assistant professor of integrative biology, notes that in both terrestrial and marine resources management, population restoration and the setting of harvest quotas has long been a single-species endeavor.

Even in the more holistic ecosystem-based rebuilding of food webs – the interconnected chains of who eats whom – the dominant strategy has been to release pressure at the bottom, letting prey populations return to the point where they ought to sustain the top predators more readily, Novak said.

Collaborators at the National Marine Fisheries Center, including Shannon Hennessey, now a graduate student at OSU, led the study, which points out the limitations of both of these philosophies. It also highlights the room for improvement in policy tools that synchronous recovery management could fill.

Media Contact: 

Steve Lundeberg, 541-737-4039

Source: 
Multimedia Downloads
Multimedia: 

Young Steller sea lion

Steller sea lions

Scientists: Warming temperatures could trigger starvation, extinctions in deep oceans by 2100

CORVALLIS, Ore. – Researchers from 20 of the world’s leading oceanographic research centers today warned that the world’s largest habitat – the deep ocean floor – may face starvation and sweeping ecological change by the year 2100.

Warming ocean temperatures, increased acidification and the spread of low-oxygen zones will drastically alter the biodiversity of the deep ocean floor from 200 to 6,000 meters below the surface. The impact of these ecosystems to society is just becoming appreciated, yet these environments and their role in the functioning of the planet may be altered by these sweeping impacts. 

Results of the study, which was supported by the Foundation Total and other organizations, were published this week in the journal Elementa.

“Biodiversity in many of these areas is defined by the meager amount of food reaching the seafloor and over the next 80-plus years – in certain parts of the world – that amount of food will be cut in half,” said Andrew Thurber, an Oregon State University marine ecologist and co-author on the study. “We likely will see a shift in dominance to smaller organisms. Some species will thrive, some will migrate to other areas, and many will die. 

“Parts of the world will likely have more jellyfish and squid, for example, and fewer fish and cold water corals.”

The study used the projections from 31 earth system models developed for the Intergovernmental Panel on Climate Change to predict how the temperature, amount of oxygen, acidity (pH) and food supply to the deep-sea floor will change by the year 2100. The authors found these models predict that deep ocean temperatures in the “abyssal” seafloor (3,000 to 6,000 meters deep) will increase as much as 0.5 to 1.0 degrees (Celsius) in the North Atlantic, Southern and Arctic oceans by 2100 compared to what they are now. 

Temperatures in the “bathyal” depths (200 to 3,000 meters deep) will increase even more – parts of this deep-sea floor are predicted to see an increase of nearly 4 degrees (C) in the Pacific, Atlantic and Arctic oceans.

“While four degrees doesn’t seem like much on land, that is a massive temperature change in these environments,” Thurber said. “It is the equivalent of having summer for the first time in thousands to millions of years.” 

The over-arching lack of food will be exacerbated by warming temperatures, Thurber pointed out.

“The increase in temperature will increase the metabolism of organisms that live at the ocean floor, meaning they will require more food at a time when less is available.” 

Most of the deep sea already experiences a severe lack of food, but it is about to become a famine, according to Andrew Sweetman, a researcher at Heriot-Watt University in Edinburgh and lead author on the study.

“Abyssal ocean environments, which are over 3,000 meters deep, are some of the most food-deprived regions on the planet,” Sweetman said. “These habitats currently rely on less carbon per meter-squared each year than is present in a single sugar cube. Large areas of the abyss will have this tiny amount of food halved and for a habitat that covers half the Earth, the impacts of this will be enormous.” 

The impacts on the deep ocean are unlikely to remain there, the researchers say. Warming ocean temperatures are expected to increase stratification in some areas yet increase upwelling in others. This can change the amount of nutrients and oxygen in the water that is brought back to the surface from the deep sea. This low-oxygen water can affect coastal communities, including commercial fishing industries, which harvest groundfish from the deep sea globally and especially in areas like the Pacific Coast of North America, Thurber said.

“A decade ago, we even saw low-oxygen water come shallow enough to kill vast numbers of Dungeness crabs,” Thurber pointed out. “The die-off was massive.” 

Areas most likely to be affected by the decline in food are the North and South Pacific, North and South Atlantic, and North and South Indian oceans.

“The North Atlantic in particular will be affected by warmer temperatures, acidification, a lack of food and lower oxygen,” Thurber said. “Water in the region is soaking up the carbon from the atmosphere and then sending it on its path around the globe, so it likely will be the first to feel the brunt of the changes.” 

Thurber, who is a faculty member in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences and the OSU College of Science, has previously published on the “services” or benefits provided by the deep ocean environments. The deep sea is important to many of the processes affecting the Earth’s climate, including acting as a “sink” for greenhouse gases and helping to offset growing amounts of carbon dioxide emitted into the atmosphere.

These habitats are not only threatened by warm temperatures and increasing carbon dioxide; they increasingly are being used by fishing and explored by mining industries for extraction of mineral resources. 

“If we look back in Earth’s history, we can see that small changes to the deep ocean caused massive shifts in biodiversity,” Thurber said. “These shifts were driven by those same impacts that our model predict are coming in the near future. We think of the deep ocean as incredibly stable and too vast to impact, but it doesn’t take much of a deviation to create a radically altered environment.

Story By: 
Source: 

Andrew Thurber, 541-737-4500, athurber@coas.oregonstate.edu; Andrew Sweetman, +44 (0) 131 451 3993, a.sweetman@hw.ac.uk

Multimedia Downloads
Multimedia: 

Sea pig (Image Courtesy of Ocean Networks Canada)

SeaPig

Methane seep (Image by Andrew Thurber, OSU)

CRSeep

“Late-life” genes activated by biological clock to help protect against stress, aging

CORVALLIS, Ore. – Researchers at Oregon State University have discovered that a subset of genes involved in daily circadian rhythms, or the “biological clock,” only become active late in life or during periods of intense stress when they are most needed to help protect critical life functions.

The findings, made in research done with fruit flies and published today in Nature Communications, are part of a unique stress response mechanism that was previously unknown.

These genes may help to combat serious stresses associated with age, disease or environmental challenges, and help explain why aging is often accelerated when the biological clock is disrupted.

This group of genes, whose rhythmic activity late in life had not previously been understood, were named “late-life cyclers,” or LLCs, by former OSU graduate student and lead author of the study, Rachael Kuintzle. At least 25 such genes become rhythmic with age, and the function of some of them remains unclear.

“This class of LLC genes appear to become active and respond to some of the stresses most common in aging, such as cellular and molecular damage, oxidative stress, or even some disease states,” said Jadwiga Giebultowicz, a professor in the OSU College of Science, co-senior author on the study and international expert on the mechanisms and function of the biological clock.

“Aging is associated with neural degeneration, loss of memory and other problems, which are exacerbated if clock function is experimentally disrupted. The LLC genes are part of the natural response to that, and do what they can to help protect the nervous system.”

The increased, rhythmic expression of these genes during times of stress, scientists said, are another example of just how biologically important circadian rhythms are, as they help to regulate the activity of hundreds of genes essential to the processes of life. And as aging brings with it a host of new problems, the LLC genes become more and more active.

According to David Hendrix, an assistant professor in the OSU College of Science and College of Engineering, and co-senior author on the study, some LLC genes are known to play roles in sequestering improperly “folded” proteins or helping them refold. This could help prevent formation of protein aggregates that can lead to age-related neurodegeneration.

“Discovery of LLC genes may provide a missing link, the answer to why the disruption of circadian clocks accelerates aging symptoms,” Hendrix said.

The study also showed that intense stress at any point in life can cause some of the LLC genes to spring into action.

“In experiments where we created artificial oxidative stress in young fruit flies, the LLC genes were rhythmically activated,” said Eileen Chow, an OSU faculty research assistant and co-author. “Some of these same genes are known to be more active in people who have cancer. They appear to be a double-edged sword, necessary during times of stress but possibly harmful if activated all the time.”

Circadian rhythms, which are natural to an organism but synchronized by the light/dark cycle of a 24-hour day, are so important to life that the same genes controlling biological processes have been traced from fruit flies to humans, retained through millions of years of evolution.

These genes are found throughout the nervous system and peripheral organs, and affect everything from sleep to stress reaction, feeding patterns, DNA repair, fertility and even the effectiveness of medications.

People with routine disruptions of their circadian rhythms and sleep patterns have been found to have a shorter lifespan and be more prone to cancer.

This research was supported by the National Institutes of Health.

Story By: 
Source: 

Jadwiga Giebultowicz, 541-737-5530

giebultj@science.oregonstate.edu

Multimedia Downloads
Multimedia: 

More active with age
Rhythms change with age