Sea-level rise solutions

Stanford researchers map how sea-level rise adaptation strategies impact economies and floodwaters

STANFORD UNIVERSITY

Research News

IMAGE: NEW RESEARCH MAPS HOW SEAWALLS AND OTHER TRADITIONAL APPROACHES TO COMBATING SEA-LEVEL RISE CAN CREATE A DOMINO EFFECT OF ENVIRONMENTAL AND ECONOMIC IMPACTS FOR NEIGHBORING COMMUNITIES. view more 

CREDIT: DJPERRY/ISTOCK

Communities trying to fight sea-level rise could inadvertently make flooding worse for their neighbors, according to a new study from the Stanford Natural Capital Project.

The research, published in Proceedings of the National Academy of Sciences, shows how seawalls constructed along the San Francisco Bay shoreline could increase flooding and incur hundreds of millions of dollars in damages for communities throughout the region. The researchers emphasize how non-traditional approaches, like choosing to flood certain areas of land rather than build walls, are smarter, more sustainable solutions for the Bay Area and similar coastal bay communities.

"It's not practical to keep building taller and taller seawalls to hold back the ocean," said Anne Guerry, chief strategy officer and lead scientist at the Stanford Natural Capital Project and senior author on the paper. "Our goal was to show how the threat of sea-level rise is interconnected with the whole social-ecological system of the Bay Area. Communities need to coordinate their approaches to sea-level rise adaptation so we can find solutions that are best for the whole bay."

By 2100, sea levels are projected to rise by almost seven feet in the Bay Area. Millions of people live and work in buildings that are collectively worth hundreds of billions of dollars within the Bay Area's projected sea-level rise zone. As water levels increase, governments are looking for ways to protect their communities and economies.

Following the flow

The researchers used complex mathematical models to map how floodwaters - and the economic damages related to floods - would flow depending on where new seawalls were built. They found that blocking certain areas of the bay's shoreline would be particularly damaging to communities throughout the region. For instance, if a seawall were built along the San Jose shoreline, communities throughout the bay, from Redwood City to Napa and Solano counties, would face an additional $723 million in flood damage costs after just one high tide, according to the models.

Damages to buildings and homes aren't the only losses that could result from walling shorelines - it also can cut off habitat for important bird and fish species, limit the natural area available to store carbon and create water quality issues by destroying wetlands that naturally provide water treatment.

"You may be protecting your immediate community, but you may be creating serious costs and damages for your neighbors," said Robert Griffin, an economist at the Natural Capital Project and co-author on the paper. "When it comes to current sea-level rise planning, there's some incomplete cost-benefit accounting going on."

CAPTION

The researchers modeled what would happen if a seawall were to be built along different parts of the San Francisco Bay shoreline. This map shows the increase in flooding that would result throughout the Bay Area if a seawall were built in the San Jose region.

CREDIT

Michelle Hummel et al.

Guiding the flood

The researchers identified places where Bay Area communities could strategically choose to guide floodwaters, rather than holding them back with walls. These strategic flood areas would act as overflow zones, absorbing the increased water and avoiding damage to communities.

One example is along the Napa-Sonoma shoreline, where Highway 37 is under threat of impending sea-level rise. Decision-makers are trying to decide how to adapt the road to prevent flooding in the future: either by building a taller embankment to raise the road or by rebuilding it as a causeway that allows water to flow between the bay and marshlands on the other side. The researchers modeled what would happen if the Napa-Sonoma shoreline were blocked by a concrete embankment and found that it would worsen flooding for almost all the Bay Area communities studied, from Martinez to San Jose. Building a causeway, on the other hand, would provide a natural absorption area for extra water to flow.

A Bay-wide strategy

"It's critical to consider the regional impacts of local actions," said Michelle Hummel, assistant professor at the University of Texas at Arlington and lead author on the paper. "Studies like ours can identify actions that will have large impacts, either positive or negative, on the rest of the bay and help to inform decisions about how to manage the shoreline."

Not every city or county has a landscape suitable for strategic flooding, which requires wide plains or valleys where water will naturally flow. Therefore, the researchers say it's crucial that Bay Area communities work together to identify the places where nature-based solutions like flooding make the most sense.

The researchers also looked at demographic information in their models to better understand who would be affected by possible strategic flooding plans. They say avoiding adaptation plans that add more pressure to poor or otherwise overburdened communities - by forcing them to move or creating increased economic stress - is key.

To understand the broader impacts of climate resilience decisions, including investments in nature, the researchers plan to model how sea-level rise adaptation strategies are connected with infrastructure, employment, community dynamics and more.

"Our plans should be as interconnected as our ecosystems," said Guerry.

CAPTION

A seawall built in the San Jose region would cause an increase in economic damages due to flooding. This map shows the millions of dollars in damages that would result throughout the Bay Area.

CREDIT

Michelle Hummel et al.

Katherine Arkema, lead scientist at the Stanford Natural Capital Project, is an author on the paper. Anne Guerry is also a Senior Research Associate in the Stanford Woods Institute for the Environment. Robert Griffin is also a Research Assistant Professor at the University of Massachusetts Dartmouth.

 

Ecosystem destruction endangers local soy agriculture in Brazil

New research: Agriculture-driven ecosystem destruction turns up local temperatures, eats up billions in soy revenue in Brazil

REPORT AUTHORS

Research News

Destroying tropical ecosystems and replacing them with soybeans and other crops has immediate and devastating consequences for soybeans, according to new peer-reviewed research in the journal World Development. With 35.8 million hectare currently under soy cultivation in Brazil, extreme heat--which adjacent tropical forests help keep in check--has reduced soybean income by an average of approximately US$100 per hectare per year.

The study, Conserving the Cerrado and Amazon biomes of Brazil protects the soy economy from damaging warming, shows that protecting the Amazon and Cerrado can prevent the sort of high temperatures that damages the productivity of crops--estimated to cost the sector US$3.55 billion.

Another recent study found annual agricultural losses associated with deforestation-driven declines in precipitation at US$1 billion. Taken together, the two estimates reveal the massive economic impacts of destroying ecosystems on Brazil's agricultural sector; the annual losses are likely to be even higher than $US4.55 billion, which is only a conservative estimate.

"Destroying forests and other ecosystems instantly turns up the heat and reduces precipitation in the immediate vicinity where the destruction takes place, scorching soybean plants and inflicting great harm on the sector's profitability," said Rafaela Flach, the study's lead author.

"The economic fallout is big--and getting bigger, with serious impacts on global and local economics and food security. It's a local problem with global ramifications, and it's happening in tropical regions worldwide."

The research comes as Brazil faces its worst drought in almost a century, while deforestation in the Brazilian Amazon has also expanded dramatically, setting new records for each of the past three months. With the fire season fast approaching, the overall trend has been one of accelerated ecosystem destruction with scant protection offered by the government. In three years, the Bolsonaro Administration has weakened 57 environmental laws, slashing environmental fines for illegal operations by 70% from March 2020 to August 2020 alone.

Scientists already have a well-established understanding of how tropical deforestation contributes to global climate change through emitting carbon and reducing the ability of the world's forests to take more carbon out of the atmosphere. A new body of research is emerging, showing how tropical deforestation has climate impacts beyond carbon: Deforestation immediately increases extreme heat locally and decreases regional and local rainfall.

These cascading impacts parch soil and harm crops and livestock, threatening agriculture both nearby and far away--with billion-dollar ramifications, as the report shows.

"The economic impacts of deforestation on extreme heat and reduced rainfall taken in isolation are troubling. But when we look at the impacts together and include climate change, the total effect can be overwhelming to the economy," said Flach. "While the global impacts should not be underestimated, the damage from ecosystem loss already being done to the Brazilian economy alone is severe."

In the new research, scientists analyzed the value of native vegetation in providing extreme heat regulation for soy production using two complementary approaches: soy revenue lost from the destruction of forests and other ecosystems and soy revenue gained from the conservation of these ecosystems.

For the analysis focused on ecosystem loss, they estimated the increased exposure to extreme heat for the amount of vegetation that was removed. For the conservation analysis, they modeled the value of standing forests and other ecosystems based on estimated regulation of extreme heat.

Soybean cultivation has expanded dramatically in Brazil, which is now the world's largest producer with 37% of global market share. Brazilian farmers have increased crop yields per hectare--from 1.7 to 3.2 tons per hectare between 1990 and 2019--while also expanding the land being planted--from 11.5 to 35.8 million ha between 1990 and 2019.

By 2019, soy constituted 49% of Brazilian cropland area and 41% of agricultural revenues. The two new studies reveal that farmers would have increased yields even more if they had not deforested, which would have held extreme heat at bay and maintained rainfall.

"The good news is that there's a win-win here. In the past and even today a lot of land is cleared to the detriment of food production and the climate" said Dr. Michael Obersteiner, a study co-author and the Director of the Environmental Change Institute at the University of Oxford. "The soy sector has a powerful opportunity to reduce this risk by stopping deforestation. In so doing, they benefit their industry--to say nothing of the major contribution to slowing global climate change."

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 CAN YOU STAY FRIENDS AFTER THE BREAK UP

Two-thirds of romantic couples start out as friends, study finds

SOCIETY FOR PERSONALITY AND SOCIAL PSYCHOLOGY

Research News

Movies and television often show romance sparking when two strangers meet. Real-life couples, however, are far more likely to begin as friends. Two-thirds of romantic relationships start out platonically, a new study in Social Psychological and Personality Science finds.

This friends-first initiation of romance is often overlooked by researchers. Examining a sample of previous studies on how relationships begin, the authors found that nearly 75 percent focused on the spark of romance between strangers. Only eight percent centered on romance that develops among friends over time.

"There are a lot of people who would feel very confident saying that we know why and how people choose partners and become a couple and fall in love, but our research suggests that is not the case," says lead author Danu Anthony Stinson, a psychology professor at the University of Victoria, Canada. "We might have a good understanding of how strangers become attracted to each other and start dating, but that's simply not how most relationships begin."

The team analyzed data from nearly 1,900 university students and crowdsourced adults, with 68 percent reporting that their current or most recent romantic relationship began as a friendship. There was little variation across gender, level of education, or ethnic groups, but the rate of friends-first initiation was even higher among 20-somethings and within LGBTQ+ communities, with 85 percent of such couples beginning as friendships.

Among university students, "friends-first initiators" were friends for one-to-two years before beginning a romantic relationship. Researchers noted that the vast majority of these participants reported that they did not enter their friendships with romantic intentions or attraction. Stinson also noted that the average length of pre-romance friendships means it is likely that the couples were genuine, platonic friends before transitioning to romance.

Nearly half of the students reported that starting as friends was their preferred way of developing a romantic relationship, making it far and away more popular than other options presented, such as meeting at a party or online.

Given the prevalence of romantic relationships that begin platonically, Stinson would like to see further studies examining this kind of relationship initiation. She also hopes that this research will push people to revisit their preconceived notions about love and friendship. Stinson notes that we are often taught that romance and friendship are dissimilar types of relationships that form in different ways and meet distinct needs.

"Our research suggests that the lines between friendship and romance are blurry," says Stinson, "and I think that forces us to rethink our assumptions about what makes a good friendship but also what makes a good romantic relationship."

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Social Psychological and Personality Science (SPPS) is an official journal of the Society for Personality and Social Psychology (SPSP), the Association for Research in Personality (ARP), the European Association of Social Psychology (EASP), and the Society for Experimental Social Psychology (SESP). Social Psychological and Personality Science publishes innovative and rigorous short reports of empirical research on the latest advances in personality and social psychology.

About the University of Victoria

UVic is one of Canada's leading research-intensive universities, offering life-changing, hands-on learning experiences to more than 21,000 students on the edge of the spectacular BC coast. As a hub of transformational research, UVic faculty, staff and students make a critical difference on issues that matter to people, places and the planet. UVic consistently publishes a higher proportion of research based on international collaborations than any other university in North America, and our community and organizational partnerships play a key role in generating vital impact, from scientific and business breakthroughs to achievements in culture and creativity. Find out more at uvic.ca. Territory acknowledgement

 

Coastal ecosystems worldwide: 

Billion-dollar carbon reservoirs

Climate and ecosystem change lead to a global redistribution of wealth

GERMAN CENTRE FOR INTEGRATIVE BIODIVERSITY RESEARCH (IDIV) HALLE-JENA-LEIPZIG

Research News

 

According to the study, Australia, Indonesia and the USA provide the largest carbon storage potential with their coastal ecosystems. The team also calculated which countries benefit most from the coastal CO2 uptake worldwide. The different ways in which countries are affected by climate change are quantified by using the so-called social costs of carbon.

"If we take into account the differences in marginal climate damages that occur in each country, we find that Australia and Indonesia are clearly the largest donors in terms of globally avoided climate damages originating from coastal CO2 uptake, as they themselves derive comparatively little benefit from the high storage potential of their coasts," says Wilfried Rickels, who heads the Global Commons and Climate Policy Research Center at the Kiel Institute. "The U.S., on the other hand, also store a lot of carbon in their coastal ecosystems, but at the same time benefit the most from natural sinks behind India and China. In monetary terms, the three countries realize annual welfare gains of about 26.4 billion US dollar (India), 16.6 billion US dollar (China) and 14.7 billion US dollar (U.S.) thanks to global coastal ecosystems and the resulting lower climate impact costs."

The basis for the monetary calculations are the so-called social cost of carbon, which allow assessing the contribution of coastal carbon uptake in the "inclusive wealth" concept. 'Inclusive wealth' is defined as the totality of all natural and man-made capital stocks, valued with so-called shadow prices, i.e. the contributions to social welfare. Among other factors, the absolute scarcity of resources plays an important role for shadow prices. Atmospheric CO2 has a negative impact on welfare primarily through climate change. However, countries are differently affected by climate change and accordingly country-specific shadow prices are used in the study.

The analysis does not include other carbon sinks or emissions from energy and industry. When carbon emissions from energy and industry are also considered, only Guinea-Bissau, Belize, Vanuatu, Sierra Leone, Solomon Islands, Guinea, Comoros, Samoa, Madagascar, and Papua New Guinea make a net positive contribution through their coastal ecosystems, since they store more CO2 in coastal ecosystems than they emit in total.

The study also emphasizes that carbon storage is only a small part of positive impacts of coastal ecosystems for humans. "Coastal ecosystems are an essential component of marine ecosystems and are therefore particularly important for marine biodiversity and for fisheries. At the same time, they contribute to flood and coastal protection and are therefore important for adaptation to climate change," emphasizes Martin Quaas, who heads the Biodiversity Economics research group at iDiv and UL.

In any case, there is currently still a very strong focus on afforestation on land when it comes to the challenges of achieving the Paris climate goals. "Marine CO2 uptake as well as its enhancement requires more attention in the debate on net-zero greenhouse gas emissions and net-negative CO2 emissions targets," Rickels points out. Especially a possible weakening of the marine carbon sinks would require even more significant mitigation and carbon dioxide removal efforts. "The coasts, with their numerous different user groups as well as possible conflicts of use, have a special role to play here."

The natural capital approach used in the study is suitable for assessing the redistribution resulting from CO2 emissions and CO2 sinks, which, unlike existing market-based assessments, is not influenced by the stringency of the underlying climate policy. The researchers plan to explore this question in further studies.

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Original publication:

Bertram, C., Quaas, M., Reusch, T. B. H., Vafeidis, A. T., Wolff, C., Rickels, W. (2021): The blue carbon wealth of nations. Nature Climate Change. DOI: 41558-021-01089-4

 

New research suggests explosive volcanic activity on Venus

CORNELL UNIVERSITY

Research News

 

ITHACA, N.Y. - Traces of the gas phosphine point to volcanic activity on Venus, according to new research from Cornell University.

Last autumn, scientists revealed that phosphine was found in trace amounts in the planet's upper atmosphere. That discovery promised the slim possibility that phosphine serves as a biological signature for the hot, toxic planet.

Now Cornell scientists say the chemical fingerprint support a different and important scientific find: a geological signature, showing evidence of explosive volcanoes on the mysterious planet.

"The phosphine is not telling us about the biology of Venus," said Jonathan Lunine, professor of physical sciences and chair of the astronomy department at Cornell. "It's telling us about the geology. Science is pointing to a planet that has active explosive volcanism today or in the very recent past."

Lunine and Ngoc Truong, a doctoral candidate in geology, authored the study, "Volcanically Extruded Phosphides as an Abiotic Source of Venusian Phosphine," published July 12 in the Proceedings of the National Academy of Sciences.

Truong and Lunine argue that volcanism is the means for phosphine to get into Venus' upper atmosphere, after examining observations from the ground-based, submillimeter-wavelength James Clerk Maxwell Telescope atop Mauna Kea in Hawaii, and the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile.

If Venus has phosphide - a form of phosphorous present in the planet's deep mantle - and, if it is brought to the surface in an explosive, volcanic way and then injected into the atmosphere, those phosphides react with the Venusian atmosphere's sulfuric acid to form phosphine, Truong said.

Lunine said their phosphine model "suggests explosive volcanism occurring," while "radar images from the Magellan spacecraft in the 1990s show some geologic features could support this."

In 1978, on NASA's Pioneer Venus orbiter mission, scientists uncovered variations of sulfur dioxide in Venus' upper atmosphere, hinting at the prospect of explosive volcanism, Truong said, similar to the scale of Earth's Krakatoa volcanic eruption in Indonesia in 1883.

But, Truong said, "confirming explosive volcanism on Venus through the gas phosphine was totally unexpected."

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Funding for the research was provided by the NASA Goddard Space Flight Center in Greenbelt, Maryland.

 

Haziness of exoplanet atmospheres depends on properties of aerosol particles

A laboratory study of haze particles produced under different conditions helps explain why some exoplanets may be obscured by hazy atmospheres

UNIVERSITY OF CALIFORNIA - SANTA CRUZ

Research News

IMAGE: XINTING YU, A 51 PEGASI B POSTDOCTORAL FELLOW AT UCSC, MEASURED THE PROPERTIES OF HAZE PARTICLES PRODUCED IN THE LABORATORY UNDER CONDITIONS REPRESENTATIVE OF EXOPLANET ATMOSPHERES. view more 

CREDIT: PHOTO COURTESY OF HEISING-SIMONS FOUNDATION

Many exoplanets have opaque atmospheres, obscured by clouds or hazes that make it hard for astronomers to characterize their chemical compositions. A new study shows that haze particles produced under different conditions have a wide range of properties that can determine how clear or hazy a planet's atmosphere is likely to be.

Photochemical reactions in the atmospheres of temperate exoplanets lead to the formation of small organic haze particles. Large amounts of these photochemical hazes form in Earth's atmosphere every day, yet our planet has relatively clear skies. The reason has to do with how easily haze particles are removed from the atmosphere by deposition processes.

"It's not just haze production but also haze removal that determines how clear the atmosphere is," said Xinting Yu, a postdoctoral fellow at UC Santa Cruz and lead author of the study, published July 12 in Nature Astronomy.

Yu and her colleagues measured the properties of haze particles produced in the laboratory under conditions representative of exoplanet atmospheres, including a range of gas compositions, temperatures, and energy sources. Coauthor Xi Zhang, assistant professor of Earth and planetary sciences at UC Santa Cruz, said laboratory experiments like this are essential for understanding haze formation and its impact on observations.

"We can't bring haze samples back from exoplanets, so we have to try to mimic the atmospheric conditions in the laboratory," he said.

According to Yu, haze removal depends on a critical material property of the particles called surface energy. "Surface energy describes how cohesive or 'sticky' the material is," she said.

Sticky haze particles readily bond with each other when they collide, growing into larger particles that fall out of the atmosphere onto the surface of the planet (a process called dry deposition). They also make good condensation nuclei for cloud droplets and are easily removed by wet deposition. Hazes produced on Earth typically have high surface energy and are therefore 'sticky' and efficiently removed from the atmosphere.

Yu's laboratory experiments show that the hazes produced in exoplanet atmospheres are highly diverse, with properties that depend on the conditions in which they are produced.

"Some of them are similar to the Earth haze, have high surface energy, and are easy to remove, leading to clear skies," she said. "But some of them have very low surface energy, like a non-stick pan; they do not bond with other particles very well and remain as small particles hanging in the atmosphere for a long time."

The study found that a critical factor is the temperature at which the haze particles are created. Hazes produced at around 400 Kelvin (260°F) tended to have the lowest surface energies, leading to less efficient removal and hazier atmospheres. This finding actually corresponds with observed trends, Yu said, noting that exoplanets at temperatures of 400 to 500 K tend to be the haziest.

Cooler planets located in the habitable zones of their host stars are more likely to have clear atmospheres, she said. "We may not have to worry about habitable exoplanets being too hazy for future observations, as hazes tend to have higher surface energies at lower temperatures," Yu said. "So it is easy to remove these hazes, leaving relatively clear atmospheres."

Astronomers are looking forward to having a powerful tool for characterizing exoplanet atmospheres with the upcoming James Webb Space Telescope (JWST). When an exoplanet transits across the face of its star, its atmosphere filters the light from the star, giving astronomers with a sensitive enough telescope (like JWST) an opportunity to identify the chemical components of the atmosphere using transmission spectroscopy.

A hazy atmosphere would interfere with transmission spectroscopy, but the hazes themselves may still yield valuable information, according to Zhang.

"Hazes are not featureless," he said. "With better telescopes, we may be able to characterize the composition of exoplanet hazes and understand their chemistry. But the observations will be very hard to explain without data from laboratory experiments. This study has revealed the huge diversity of haze particles, and understanding their optical properties will be a high priority for future studies."

CAPTION

Researchers measured the refractive indices at visible wavelengths (n) for haze samples created under a range of conditions.

CREDIT

Yu et al., Nature Astronomy, 2021

In addition to Yu and Zhang, the coauthors of the paper include UCSC undergraduate Austin Dymont, astronomy professor Jonathan Fortney, and graduate student Diana Powell at UC Santa Cruz, as well as scientists at Johns Hopkins University, Cornell University, University of Texas at Austin, and University of Grenoble Alpes, France. This work was supported by NASA and the Heising-Simons Foundation.

 

A fermented-food diet increases microbiome diversity and lowers inflammation, study finds

STANFORD MEDICINE

Research News

A diet rich in fermented foods enhances the diversity of gut microbes and decreases molecular signs of inflammation, according to researchers at the Stanford School of Medicine.

In a clinical trial, 36 healthy adults were randomly assigned to a 10-week diet that included either fermented or high-fiber foods. The two diets resulted in different effects on the gut microbiome and the immune system.

Eating foods such as yogurt, kefir, fermented cottage cheese, kimchi and other fermented vegetables, vegetable brine drinks, and kombucha tea led to an increase in overall microbial diversity, with stronger effects from larger servings. "This is a stunning finding," said Justin Sonnenburg, PhD, an associate professor of microbiology and immunology. "It provides one of the first examples of how a simple change in diet can reproducibly remodel the microbiota across a cohort of healthy adults."

In addition, four types of immune cells showed less activation in the fermented-food group. The levels of 19 inflammatory proteins measured in blood samples also decreased. One of these proteins, interleukin 6, has been linked to conditions such as rheumatoid arthritis, Type 2 diabetes and chronic stress.

"Microbiota-targeted diets can change immune status, providing a promising avenue for decreasing inflammation in healthy adults," said Christopher Gardner, PhD, the Rehnborg Farquhar Professor and director of nutrition studies at the Stanford Prevention Research Center. "This finding was consistent across all participants in the study who were assigned to the higher fermented food group."

Microbe diversity stable in fiber-rich diet

By contrast, none of these 19 inflammatory proteins decreased in participants assigned to a high-fiber diet rich in legumes, seeds, whole grains, nuts, vegetables and fruits. On average, the diversity of their gut microbes also remained stable. "We expected high fiber to have a more universally beneficial effect and increase microbiota diversity," said Erica Sonnenburg, PhD, a senior research scientist in basic life sciences, microbiology and immunology. "The data suggest that increased fiber intake alone over a short time period is insufficient to increase microbiota diversity."

The study will be published online July 12 in Cell. Justin and Erica Sonnenburg and Christopher Gardner are co-senior authors. The lead authors are Hannah Wastyk, a PhD student in bioengineering, and former postdoctoral scholar Gabriela Fragiadakis, PhD, who is now an assistant professor of medicine at UC-San Francisco.

A wide body of evidence has demonstrated that diet shapes the gut microbiome, which can affect the immune system and overall health. According to Gardner, low microbiome diversity has been linked to obesity and diabetes.

"We wanted to conduct a proof-of-concept study that could test whether microbiota-targeted food could be an avenue for combatting the overwhelming rise in chronic inflammatory diseases," Gardner said.

The researchers focused on fiber and fermented foods due to previous reports of their potential health benefits. While high-fiber diets have been associated with lower rates of mortality, the consumption of fermented foods can help with weight maintenance and may decrease the risk of diabetes, cancer and cardiovascular disease.

The researchers analyzed blood and stool samples collected during a three-week pre-trial period, the 10 weeks of the diet, and a four-week period after the diet when the participants ate as they chose.

The findings paint a nuanced picture of the influence of diet on gut microbes and immune status. On one hand, those who increased their consumption of fermented foods showed similar effects on their microbiome diversity and inflammatory markers, consistent with prior research showing that short-term changes in diet can rapidly alter the gut microbiome. On the other hand, the limited change in the microbiome within the high-fiber group dovetails with the researchers' previous reports of a general resilience of the human microbiome over short time periods.

Designing a suite of dietary and microbial strategies

The results also showed that greater fiber intake led to more carbohydrates in stool samples, pointing to incomplete fiber degradation by gut microbes. These findings are consistent with other research suggesting that the microbiome of people living in the industrialized world is depleted of fiber-degrading microbes.

"It is possible that a longer intervention would have allowed for the microbiota to adequately adapt to the increase in fiber consumption," Erica Sonnenburg said. "Alternatively, the deliberate introduction of fiber-consuming microbes may be required to increase the microbiota's capacity to break down the carbohydrates."

In addition to exploring these possibilities, the researchers plan to conduct studies in mice to investigate the molecular mechanisms by which diets alter the microbiome and reduce inflammatory proteins. They also aim to test whether high-fiber and fermented foods synergize to influence the microbiome and immune system of humans. Another goal is to examine whether the consumption of fermented food decreases inflammation or improves other health markers in patients with immunological and metabolic diseases, and in pregnant women and older individuals.

"There are many more ways to target the microbiome with food and supplements, and we hope to continue to investigate how different diets, probiotics and prebiotics impact the microbiome and health in different groups," Justin Sonnenburg said.

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Other Stanford co-authors are Dalia Perelman, health educator; former graduate students Dylan Dahan, PhD, and Carlos Gonzalez, PhD; graduate student Bryan Merrill; former research assistant Madeline Topf; postdoctoral scholars William Van Treuren, PhD, and Shuo Han, PhD; Jennifer Robinson, PhD, administrative director of the Community Health and Prevention Research Master's Program and program manager of the Nutrition Studies Group; and Joshua Elias, PhD.

Researchers from Chan-Zuckerberg Biohub also contributed to the study.

The work was supported by donations to the Center for Human Microbiome Research; Paul and Kathy Klingenstein; the Hand Foundation; Heather Buhr and Jon Feiber; Meredith and John Pasquesi; the National Institutes of Health (grant T32 AI 7328-29); a Stanford Dean's Postdoctoral Fellowship; a National Science Foundation Graduate Student Fellowship; and seed funding from the Institute for Immunity, Transplantation and Infection and from the Sean N. Parker Center for Allergy and Asthma Research.

The Stanford University School of Medicine consistently ranks among the nation's top medical schools, integrating research, medical education, patient care and community service. For more news about the school, please visit http://med.stanford.edu/school.html. The medical school is part of Stanford Medicine, which includes Stanford Health Care and Stanford Children's Health. For information about all three, please visit http://med.stanford.edu.

 

Want to avoid running overuse injuries? Don't lean forward so much, says CU Denver study

Researchers found that greater trunk flexion has significant impact on stride length, joint movements, and ground reaction forces

UNIVERSITY OF COLORADO DENVER

Research News

The ubiquitous overuse injuries that nag runners may stem from an unlikely culprit: how far you lean forward.

Trunk flexion, the angle at which a runner bends forward from the hip, can range wildly--runners have self-reported angles of approximately -2 degrees to upward of 25. A new study from the University of Colorado Denver (CU Denver) found that greater trunk flexion has significant impact on stride length, joint movements, and ground reaction forces. How you lean may be one of the contributors to your knee pain, medial tibial stress syndrome, or back pain.

"This was a pet peeve turned into a study," said Anna Warrener, PhD, lead author and assistant professor of anthropology at CU Denver. Warrener worked on the initial research during her postdoc fellowship with Daniel Liberman, PhD, in the Department of Human Evolutionary Biology at Harvard University. "When [Lieberman] was out preparing for his marathons, he noticed other people leaning too far forward as they ran, which had so many implications for their lower limbs. Our study was built to find out what they were."

The study was published in Human Movement Science.

A New Angle on Overuse Injuries

The head, arms and trunk constitute roughly 68% of total body mass. Small changes in trunk flexion have the potential to substantially alter lower-limb kinematics and ground reaction forces (GRF) during running.

To study the downstream effects, Warrener and her team recruited 23 injury-free, recreational runners between the ages of 18 and 23. They recorded each participant running 15-second trials at their self-selected trunk position and three others: a 10-, 20-, and a 30-degree angle of flexion. But to make the study work, they had to first figure out how to get each runner to bend at the right slant.

"We had to create a way in which we could reasonably force someone into a forward lean that didn't make them so uncomfortable that they changed everything about their gait," said Warrener. The team hung a lightweight, plastic dowel from the ceiling just above the runners' heads, moving it up or down, depending on the angle needed.

Contrary to the team's original hypothesis, the average stride length decreased 13 cm and stride frequency increased from 86.3 strides/min to 92.8 strides/min. Overstride relative to the hip increased 28%.

"The relationship between strike frequency and stride length surprised us," said Warrener. "We thought that the more you lean forward, your leg would need to extend further to keep your body mass from falling outside the support aera. As a result, overstride and stride frequency would go up. The inverse was true. Stride length got shorter and stride rate increased."

Warrener believes this may be due to a decrease in the aerial phase (if they're not getting as much air time, runners will take shorter steps), which means leg swings quickened as a result of reduced forward movement.

"The act of swinging your leg is really expensive as you're running," said Warrener. "Swinging it faster as you lean forward may mean a higher locomotor cost."

Compared to the participants' natural trunk flexion, increased angles led to a more flexed hip and bent knee joint. A bigger lean also changed the runners' foot and lower limb position, leading to an increased impact of GRF on the body (rate of loading by 29%; vertical ground reaction force impact transients by 20%).

The combination of trunk flexion angle, foot and leg placement, and GRF variables, shows that excessive trunk flexion could be one cause of injurious running form and, according to Warrener, is key for understanding how diverse running forms optimize economy and performance.

"The big picture takeaway is that running is not all about what is happening from the trunk down--it's a whole-body experience," said Warrener. "Researchers should think about the downstream effects of trunk flexion when studying running biomechanics."

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Childhood lead exposure may adversely affect adults' personalities

UNIVERSITY OF TEXAS AT AUSTIN

Research News

AUSTIN, Texas -- Lead exposure in childhood may lead to less mature and less healthy personalities in adulthood, according to a new study lead by psychology researchers at The University of Texas at Austin.

The study, published in the Proceedings of the National Academy of Sciences, sampled more than 1.5 million people in 269 U.S. counties and 37 European nations. Researchers found that those who grew up in areas with higher levels of atmospheric lead had less adaptive personalities in adulthood -- lower levels of conscientiousness and agreeableness and higher levels of neuroticism.

"Links between lead exposure and personality traits are quite impactful, because we take our personalities with us everywhere," said Ted Schwaba, a postdoctoral fellow in the Department of Psychology at UT Austin. "Even a small negative effect of lead on personality traits, when you aggregate it across millions of people and all the daily decisions and behaviors that our personality influences, can have really massive effects on well-being, productivity and longevity."

In the study, researchers linked historical atmospheric lead data from the Environmental Protection Agency to online personality questionnaire responses from people who grew up in the sampled locations. Results showed that adults who were raised in U.S. counties with higher levels of atmospheric lead were less agreeable and conscientious and, among adults in their 20s and 30s, more neurotic than those who had less lead exposure during childhood.

"These three traits -- conscientiousness, agreeableness and low neuroticism -- make up a large part of what we would consider a mature, psychologically healthy personality and are strong predictors of our success or failure in relationships and at work," Schwaba said. "Normally, across the lifespan, people become more conscientious and agreeable, and less neurotic."

To further test whether lead exposure causes these differences, the researchers examined the effects of the 1970 Clean Air Act, finding that people born after atmospheric lead levels began to decline in their counties had more mature, psychologically healthy personalities in adulthood than those born before their counties phased out lead-based products.

To ensure these findings weren't simply reflecting cohort effects -- characteristics resulting from shared historical or social experiences -- researchers replicated their study in Europe, where lead was phased out later than in the U.S. There, they found that people who grew up in areas with more atmospheric lead were also less agreeable and more neurotic in adulthood, although the findings regarding conscientiousness did not replicate.

"For a long time, we've known lead exposure is harmful, but each new wave of research seems to identify new ways in which lead exposure harms society," Schwaba said. "Though there's much less lead in the atmosphere today, lead remains in pipes, the topsoil and groundwater. And these sources of lead exposure tend to disproportionately harm people of color -- Black children are twice as likely to have high levels of lead in their blood as white children. From an economic standpoint, from a social justice standpoint, or really any way you look at it, it's incredibly important to limit lead exposure as much as possible."

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FIRE THE BOSS! RUN IT YOURSELVES

Study reveals ways to preserve employee morale during cost-cutting

WASHINGTON STATE UNIVERSITY

Research News

IMAGE: JEFF JOIREMAN, PROFESSOR AND CHAIR OF THE DEPARTMENT OF MARKETING AND INTERNATIONAL BUSINESS, WASHINGTON STATE UNIVERSITY'S CARSON COLLEGE OF BUSINESS view more 

CREDIT: WASHINGTON STATE UNIVERSITY

PULLMAN, Wash. - After cutbacks and layoffs, remaining employees were more likely to feel they were treated fairly if the companies invested in them - and morale was less likely to plunge, according to new research.

Those investments can include training for workers, team-building exercises or improving company culture. Even keeping workloads manageable after layoffs can help employees' job attitudes, according to the Journal of Organizational Behavior study.

"Whenever possible, cost-cutting is best combined with signals that people remain the firm's most prized asset," said Jeff Joireman, the study's co-author and a professor in Washington State University's Carson College of Business.

Researchers reviewed 137 previous studies examining job attitudes before, during and after cost-cutting events or people-focused investments. By focusing on longitudinal studies that followed employees for up to two years after the events, they were able to document persistent changes in attitudes.

Layoffs, offshoring and other cost-cutting measures affect morale longer than most companies realize, according to Joireman and his co-authors from Vrije University in Amsterdam and Brussels.

For at least two years after the cost-cutting event, workers reported reduced job satisfaction and less loyalty toward the organization - with implications for the firms' productivity and employee turnover.

Cost-cutting measures shook up the employer-employee relationship, researchers found. Workers felt their employer had treated them unfairly, didn't care about them and had broken promises. Upgrading technology to reduce costs was the exception, generating a positive response from employees.

Investments in workers, on the other hand, led to employees feeling cared for and valued by their organizations, resulting in lasting improvements in job attitudes.

When investing in workers was combined with cost-cutting, employee job attitudes remained relatively stable over time. Company support for workers after downsizing was perceived as helping reestablish the employee-employer bond, the researchers found.

Joireman said the study's findings challenge assumptions that shifts in job attitudes are temporary.

"The prevailing attitude is that cost-cutting is really bad for employees' attitudes in the short-run, but in the long-run, employee's attitudes will return to the baseline," he said.

Without this kind of analysis, firms remain in the dark about the negative effects of cost-cutting over the long haul, and whether people-oriented interventions provide lasting benefits, Joireman added.

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