Poverty alleviation breakthrough: How a switch to a 'growth mindset' empowers entrepreneurs in developing nations

Peer-Reviewed Publication

BRIGHAM YOUNG UNIVERSITY

 

IMAGE: ADDING A GROWTH MINDSET TRAINING TO THE TECHNICAL ENTREPRENEURSHIP TRAINING IN TANZANIA EMPOWERED SMALL BUSINESS OWNERS THERE TO BE MORE CONFIDENT AND ADVANCE THEIR BUSINESSES FORWARD. view more 

CREDIT: CHALET MOLENI/BYU

Although millions are spent each year on entrepreneurship training that is intended to help alleviate poverty and elevate the quality of life of entrepreneurs in developing nations, these programs often fail to make an impact.

Brigham Young University professors Shad Morris and Chad Carlos, along with three other colleagues, were invited by the Tanzania Social Action Fund (“TASAF”) to see if they could help figure out why TASAF’s entrepreneurship trainings were not producing the results they were hoping for.

In order to assist TASAF, Morris, Carlos, and colleagues Geoff Kistruck, Elly Tumsifu and Bob Lount, carried out an extensive research project that involved field interviews and a randomized controlled experiment with entrepreneurs from several villages in rural Tanzania.

Initially the researchers suspected that perhaps the training material was too complex, or not well suited for the context. However, through their interviews, they discovered that training recipients understood and retained a knowledge of the principles learned in previous entrepreneurship trainings, but few put that knowledge into action because they lacked the confidence to apply the new information and skills learned.

“A lot of the entrepreneurs were saying they didn’t believe in themselves and they didn’t think they had the ability to be successful,” said Morris, a BYU professor of organizational behavior and human resources. “They would tell us, ‘If God wanted me to be rich, then I would be rich.’ Or ‘my neighbor is smarter than me and I’m sure that they can do this, but my family has always done things this way and that is what I am destined to do.”

Those interviewed by Morris, Carlos and their colleagues who were more succesful in their respective businesses said that their success was due in part to their belief that “you have to try things and realize you are going to fail along the way.”

It was this response which led the researchers to conduct an experiment testing whether providing “growth mindset” training, in addition to business skills training, would help training recipients overcome the psychological barrier that they were incapable of applying the skills that they had learned. While a growth mindset doesn’t solve all problems related to poverty, such as lack of access to capital, education or healthcare, it teaches that talents can be developed and that failure brings new opportunities to learn.

“It’s about helping people understand that they have the ability to do hard things, overcome challenges, and learn from those challenges,” Morris said. “This helps them accomplish their goals through trial and error.”

The results of the experiment found that there was indeed a significant impact of the growth mindset training in improving the confidence of training participants. This bolstered confidence ultimately led participants to take more action in applying new skills in their businesses.

This implementation of a growth mindset is helping to counteract something known as the scarcity mindset, the idea of not having enough of something such as resources or ability, which plagues necessity entrepreneurs in places like Tanzania and prevents them from becoming more successful. “The scarcity mindset dwindles our ability to plan long term because we are just in survival mode,” Morris said.

People exposed to short- or long-term poverty develop a scarcity mindset because their cognitive bandwidth is overloaded with immediate concerns, leaving little space for the exploration or evaluation of a broader set of alternative actions. For example, the effort of getting enough money for food to eat today prevents creative planning for future food sourcing.

Researchers found those who worked on changing their mindset from a scarcity mindset to a growth mindset saw increased self-confidence and were able to break their previous habits of when they saw risk as a danger rather than an opportunity to create something new.

Beyond the implications for entrepreneurship training, Carlos sees these findings as important for teaching and learning more generally because “knowledge alone may have a limited impact if individuals do not have the confidence to take action in applying what they have learned. If we want to make a difference as teachers, parents, and leaders helping others to develop the confidence to act on what they have learned is critical.”

---

JOURNAL

Strategic Entrepreneurship Journal

DOI

10.1002/sej.1472 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

The impact of growth mindset training on entrepreneurial action among necessity entrepreneurs: Evidence from a randomized control trial

Study reveals patients hospitalized with COVID-19 faced nearly twice the rates of death after discharge as patients with flu

Post-discharge risk of death has declined over the course of the pandemic, though inequities persist

Peer-Reviewed Publication

BETH ISRAEL DEACONESS MEDICAL CENTER

BOSTON – As of June 2023, more than 1.1 million Americans have died of COVID-19. Adults older than 65 —who make up just 16 percent of the population—account for more than 75 percent of U.S. COVID-19 deaths and were hospitalized at three times the rate of younger people, highlighting the heightened vulnerability of this population.

In a new study, researchers from the Richard A. and Susan F. Smith Center for Outcomes Research at Beth Israel Deaconess Medical Center (BIDMC) used national Medicare data to characterize the long-term risk of death and hospital readmission after being hospitalized with COVID-19 among beneficiaries 65 years and older. The study, which appears in the BMJ, demonstrates that among individuals who were admitted to the hospital with COVID-19 and were discharged alive, the risk of post-discharge death was nearly twice that observed in those who were discharged alive from an influenza-related hospital admission.

“Since the early days of the pandemic, it has been evident that older adults bear a disproportionate burden of COVID-19 and our study provides several important insights into the longer-term clinical consequences of the disease in this vulnerable population,” said co-senior author Dhruv S. Kazi, MD, MSc, MS, associate director of the Smith Center and director of the Cardiac Critical Care Unit at BIDMC. “We know that patients who require hospital admission for COVID-19 have more comorbidities, more severe initial disease and worse short-term outcomes compared with patients who are asymptomatic or mildly symptomatic, and they may be more vulnerable to late complications of infection. Our goal was to better understand long-term outcomes after patients are discharged from the hospital so as to help tailor support strategies and guide resource allocation for future surges of COVID-19 or during future pandemics.”

The research, led by Smith Center investigators and funded by the National Health, Lung, and Blood Institute, compared outcomes for more than one million Medicare beneficiaries admitted to the hospital with COVID-19 between March 2020 and August 2022 and a historical cohort of nearly 58,000 Medicare beneficiaries admitted to the hospital for influenza between March 2018 and August 2019.

The physician-researchers observed that patients hospitalized for COVID-19 had a higher in-hospital mortality compared with the influenza cohort (17% vs 3%), but this increased risk of death after COVID-19 hospitalization persisted at 30 days, 90 days, and 180 days after discharge. The greatest difference in risk between the two groups being concentrated in the first 30 days after discharge.

Within the COVID-19 cohort, significant differences were found in the 180-day risk of post discharge, death by race and socioeconomic status. Individuals enrolled in both Medicaid and Medicare had higher risk of death. Black patients had a higher risk of death or rehospitalization compared with white patients, largely driven by an increased risk of rehospitalization. In contrast, the risk of death was slightly lower in Black patients compared with white patients.

“Individuals with low income and those from racial/ethnic minority populations have been shown to be at increased risk for adverse events associated with acute COVID-19, including higher rates of infection, hospital admissions and in-hospital death,” said co-senior author Robert W. Yeh, MD, MSc, director of the Smith Center for Outcomes Research at BIDMC. “We found that many of these inequalities persist among a cohort of patients who were discharged alive after COVID-19-related hospital admissions.”

The COVID-19 cohort also experienced a higher risk of hospital readmission at 30 days, and 90 days compared to the flu patients; however, by 180 days, the rate of readmissions were similar between the two groups. The most common reasons for readmission were circulatory conditions, respiratory conditions, sepsis, heart failure and pneumonia. Within the COVID-19 cohort, Black individuals and dual-eligible beneficiaries were more likely to be readmitted than white patients.

Encouragingly, the scientists demonstrated a decline in post-discharge death over the course of the study period. The scientists note that there may be several epidemiological factors that explain this trend: clinicians have made major advances in treating patients hospitalized with severe cases of COVID-19, that vaccination campaigns targeting high-risk patient populations including older adults may have prevented many infections from becoming severe and potentially fatal cases of COVID-19, and that the virus itself may be undergoing changes in virulence.

“While we did find that rates of death following a hospitalization for COVID-19 steadily declined over the course of the pandemic, the substantial in-hospital and early post-discharge risk of death associated with COVID-19 in this sample of Medicare beneficiaries highlights the need for preventative interventions, particularly in patients at increased long-term risk for adverse outcomes,” said lead author Andrew S Oseran, MD, MBA, a research fellow at the Smith Center now at Massachusetts General Hospital. “Our findings suggest the continued need to evaluate clinical and societal interventions that address the glaring inequities in post-discharge outcomes among older adults hospitalized with COVID-19.”

Co-authors included Yang Song, Jiaman Xu, Issa J. Dahabreh, Rishi K. Wadhera, and Tianyu Sun of the Smith Center for Outcomes Research at BIDMC; James A. de Lemos and Sandeep R. Das of the University of Texas Southwestern Medical Center.

This work was supported in part by grants from the National Heart, Lung and Blood Institute (R01HL157530) and Patient-Centered Outcomes Research Institute (PCORI) (ME-1502- 27704). Sun is currently employed by Moderna; his involvement in this project occurred while he was employed at the Richard A. and Susan F. Smith Center for Outcomes Research before his employment at Moderna. Dahabreh is the principal investigator of research agreement between Harvard and Sanofi on statistical methods for vaccine trials with applications to influenza and has received consulting fees from Moderna. The other authors report no financial relationships with any organizations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

About Beth Israel Deaconess Medical Center

Beth Israel Deaconess Medical Center is a patient care, teaching and research affiliate of Harvard Medical School and consistently ranks as a national leader among independent hospitals in National Institutes of Health funding. BIDMC is the official hospital of the Boston Red Sox.

Beth Israel Deaconess Medical Center is a part of Beth Israel Lahey Health, a health care system that brings together academic medical centers and teaching hospitals, community and specialty hospitals, more than 4,800 physicians and 38,000 employees in a shared mission to expand access to great care and advance the science and practice of medicine through groundbreaking research and education.

---

JOURNAL

BMJ

DOI

10.1136/bmj-2023-076222 

 

UC Irvine biologists find what colors a butterfly’s world

Study identifies first known gene change in sex-differentiated vision

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - IRVINE

Irvine, Calif., Aug. 10, 2023 — As butterflies flit among flowers, they don’t all view blossoms the same way. In a phenomenon called sexually dimorphic vision, females of some butterfly species perceive ultraviolet color while the males see light and dark. University of California, Irvine biologists have discovered that in at least one species, the variation results from a vision gene’s jump onto a sex chromosome. It’s the first known finding that this kind of genetic change causes sexually dimorphic vision.

The study appears in Proceedings of the National Academy of Sciences. (Link to study: https://www.pnas.org/doi/10.1073/pnas.2301411120)

The UCI team determined this while investigating the Heliconius butterfly genus. Some of its species see ultraviolet color, an array wider than the visible light spectrum that humans perceive. A substance produced by the opsin gene accounts for these butterflies’ visual capacity. In Heliconius species with sexually dimorphic vision, ultraviolet color perception is only present in females.

In searching for the genetic mechanism behind this difference, the UCI biologists selected as their subject Heliconius charithonia, in which visual capacity is sexually dimorphic. When they finished assembling the first complete genome for this species, they learned that its W – or female – chromosome contained the opsin gene.

“This is the first known instance where dimorphic color vision in animals comes from a single gene moving to a sex chromosome,” said first author Mahul Chakraborty, an assistant project scientist in ecology and evolutionary biology. “Besides the discovery’s scientific significance, it highlights the complexities of automated genetic sequencing and the crucial role of validation.”

He did much of his work on the project while a postdoctoral researcher in the laboratories of co-corresponding authors Adriana Briscoe and J.J. Emerson, both faculty members in the Department of Ecology and Evolutionary Biology.

Previously assembled genomes for Heliconius charithonia were fragmentary. None included the W chromosome, whose highly repetitive code can pose stumbling blocks for automatic sequencing. UCI researchers began their study by automatically sequencing the species genome, but this failed to reveal all expected copies of the opsin gene. Undeterred, they next examined the coding manually.

“I went through every bit of the sequencing,” said Angelica Lara, who was an ecology and evolutionary biology undergraduate when she started working with the investigative team. Lara continued to participate in the project as a postbaccalaureate researcher after earning her degree. “I still couldn’t find the opsin after all that review. Then I realized a part of the code for the W chromosome had not been well formatted, and I believed the opsin had to be located there,” she said.

Lara’s efforts cued Chakraborty to examine that segment more closely. It turned out that the automatic sequencing had dropped that section of the chromosome’s coding, likely stymied by its repetitiveness. Restoring it revealed the opsin gene, and the team confirmed the finding with additional tests.

“Without this manual annotation and investigation, we would have made assumptions that were incorrect and misleading,” said Briscoe, professor of ecology and evolutionary biology. “Now that we’ve made this discovery, we can dig much deeper into the mechanics behind the dimorphism and understanding its purpose.”

Scientists believe the vision difference may be the reason that females and males within some butterfly species feed on different types of flowers. So far, the only other creatures known to have sexually dimorphic vision are certain kinds of primates.

The research was supported by the National Science Foundation, the National Institutes of Health, the UCI Optical Biology Core Facility and Texas A&M University startup funding.

About the University of California, Irvine: Founded in 1965, UCI is a member of the prestigious Association of American Universities and is ranked among the nation’s top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UCI has more than 36,000 students and offers 224 degree programs. It’s located in one of the world’s safest and most economically vibrant communities and is Orange County’s second-largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on UCI, visit www.uci.edu.

NOTE TO EDITORS: PHOTOS AVAILABLE AT
https://news.uci.edu/2023/08/10/uc-irvine-biologists-find-what-colors-a-butterflys-world/

---

JOURNAL

Proceedings of the National Academy of Sciences

ARTICLE TITLE

Sex-linked gene traffic underlies the acquisition of sexually dimorphic UV color vision in Heliconius butterflies

A climate-orchestrated early human love story

Peer-Reviewed Publication

INSTITUTE FOR BASIC SCIENCE

 

IMAGE: PHOTO OF THE REMAINING DENISOVA 11 (DENNY) BONE FRAGMENT FROM DENISOVA CAVE IN RUSSIA, THAT COMES FROM A DAUGHTER TO A NEANDERTHAL MOTHER AND A DENISOVAN FATHER. (PHOTO CREDIT: KATERINA DOUKA, TOM HIGHAM). view more 

CREDIT: INSTITUTE FOR BASIC SCIENCE

A new study published in the journal Science by an international team finds that past changes in atmospheric CO2 and corresponding shifts in climate and vegetation played a key role in determining when and where early human species interbred.

Modern-day people carry in their cells a small quantity of DNA deriving from other human species, namely the Neanderthals and the elusive Denisovans. Back in 2018, scientists announced to the world the discovery of an individual [Figure 1], later nicknamed Denny, who lived 90,000 years ago and who was identified as a daughter to a Denisovan father and a Neanderthal mother [Slon et al. 2018]. Denny, along with fellow mixed-ancestry individuals found at Denisova cave, testifies that interbreeding was probably common among hominins, and not limited to our own species Homo sapiens.

To unravel when and where human hybridization took place, scientists usually rely on paleo-genomic analysis of extremely rare fossil specimens and their even scarcer ancient DNA content. In the new Science paper, the team of climate experts and paleo-biologists from South Korea and Italy pursued a different approach. Using existing paleo-anthropological evidence, genetic data and supercomputer simulations of past climate, the team found that Neanderthals and Denisovans had different environmental preferences. More specifically, Denisovans were much more adapted to cold environments, characterized by boreal forests and even tundra, compared to their Neanderthal cousins who preferred temperate forests and grassland. “This means that their habitats of choice were separated geographically, with Neanderthals typically preferring southwestern Eurasia and Denisovans the northeast”, says Dr. Jiaoyang Ruan, postdoctoral researcher at the IBS Center for Climate Physics (ICCP), South Korea and lead author of the study.

However, according to their realistic computer simulations the scientists found that in warm interglacial periods, when Earth’s orbit around the Sun was more elliptic and northern hemisphere summer occurred closer to the Sun, the hominin habitats began to overlap geographically. “When Neanderthals and Denisovans shared a common habitat, there were more encounters and interactions among the groups, which would have increased the chance of interbreeding”, adds Prof. Axel Timmermann, corresponding author of the study and director of the ICCP and professor at Pusan National University.

The simulation of past habitat overlaps does not only put the first generation Neanderthal/Denisovan hybrid Denny into a climatic context, but it also agrees with other known episodes of interbreeding ~78, 120 thousand years ago. Future paleo-genetic reconstructions can be used to test the robustness of the new supercomputer model-based predictions of potential interbreeding intervals around 210 and 320 thousand years ago.

To further determine the climate drivers of the east-west interbreeding seesaw, the scientists looked more closely at how vegetation patterns changed over Eurasia during the past 400 thousand years. They discovered that elevated atmospheric CO2 concentrations and mild interglacial conditions caused an eastward expansion of temperate forest into central Eurasia which created dispersal corridors for Neanderthals into Denisovan lands. “It is as if glacial-interglacial shifts in climate created the stage for a unique and long-lasting human love story, whose genetic traces are still visible today”, comments Dr. Ruan.

One of the key challenges the researchers faced in their study was to estimate the preferred climatic conditions for Denisovans. “To deal with the very sparse Denisovan dataset, we had to devise new statistical tools, which could also account for known ancestral relationships amongst human species”, says Prof. Pasquale Raia from University of Naples, Federico II in Italy, co-author of the study. “This allowed us for the first time to estimate where Denisovans could have lived. To our surprise, we found that, apart from areas in Russia and China, also northern Europe would have been a suitable environment for them”, he adds [Figure 2].

Whether Denisovans ever lived west of the Altai mountains is unknown; but it can be tested using large-sample genetic analyses of Denisovan ancestry in European populations. Such analysis is expected to shed new light on the relationship between early dispersal, habitat encroachment and human genetic diversification.

Illustration of Neanderthal (redscale) /Denisovan (greenscale) preferred habitats. Potential interbreeding areas in Central Asia and northern Europe are indicated by overlapping colors and baby-shapes.

CREDIT

Institute for Basic Science

---

JOURNAL

Science

DOI

10.1126/science.add4459 

ARTICLE TITLE

Climate shifts orchestrated hominin interbreeding events across Eurasia

ARTICLE PUBLICATION DATE

11-Aug-2023

 

Extreme cooling ended the first human occupation of Europe

Peer-Reviewed Publication

UNIVERSITY COLLEGE LONDON

 

VIDEO: VIDEO HIGHLIGHTING HOW PALEOCLIMATE EVIDENCE SHOWS THAT AROUND 1.1 MILLION YEARS AGO, THE SOUTHERN EUROPEAN CLIMATE COOLED SIGNIFICANTLY AND LIKELY CAUSED AN EXTINCTION OF EARLY HUMANS ON THE CONTINENT, ACCORDING TO A NEW STUDY LED BY UCL RESEARCHERS. view more 

CREDIT: UCL

Paleoclimate evidence shows that around 1.1 million years ago, the southern European climate cooled significantly and likely caused an extinction of early humans on the continent, according to a new study led by UCL researchers.

Published in the journal Science, the team of researchers discovered the occurrence of previously unknown extreme glacial conditions around 1.1 million years ago. The glacial cooling pushed the European climate to levels beyond what archaic humans could tolerate, emptying the continent of human populations.

The oldest known human remains in Europe have previously been recovered from Iberia and suggest that early humans had arrived from southwest Αsia by about 1.4 million years ago. The climate around that time would have generally been warm and wet, punctuated by mild cold periods. Up to now, the prevailing theory has been that once humans arrived, they were able to survive through multiple climate cycles and adapt to increasingly harsh conditions after 900,000 years ago.

Senior author Professor Chronis Tzedakis (UCL Geography) said: “Our discovery of an extreme glacial cooling event around 1.1 million years ago challenges the idea of continuous early human occupation of Europe.”

Paleoclimate scientists from UCL, University of Cambridge and CSIC Barcelona analysed the chemical composition of marine micro-organisms and examined the pollen content in a deep-sea sediment core recovered from off the coast of Portugal. This revealed the presence of abrupt climate changes that culminated in an extreme glacial cooling, with ocean surface temperatures off Lisbon dropping below 6°C and semi-deserts expanding on the adjacent land.

Lead author Dr Vasiliki Margari (UCL Geography) said: “To our surprise, we found that this cooling at 1.1 million years ago was comparable to some of the most severe events of recent ice ages.”

Co-author Professor Nick Ashton of the British Museum said: “A cooling of this magnitude would have placed small hunter-gatherer bands under considerable stress, especially since early humans may have lacked adaptations such as sufficient fat insulation and also the means to make fire, effective clothing or shelters.”

To assess the climate impact on early human populations, co-corresponding author Professor Axel Timmermann and his team from the IBS Center for Climate Physics at Pusan National University ran a climate simulation on their supercomputer Aleph to capture the extreme conditions during this time. Combining the output of the simulation with fossil and archaeological evidence of human occupation in southwest Eurasia, the team then developed a human habitat model, which predicts how suitable the environment was for early human occupation.

Professor Axel Timmermann said: “The results showed that 1.1 million years ago climate around the Mediterranean became too hostile for archaic humans.”

Together, the paleoclimate data and human habitat model results indicate that Iberia, and more generally southern Europe, was depopulated during the Early Pleistocene. An apparent lack of stone tools and human remains over the next 200,000 years further raises the possibility of a long-lasting hiatus in European occupation.

Co-author Professor Chris Stringer of the Natural History Museum in London said: “According to this scenario, Europe may have been recolonized around 900,000 years ago by more resilient humans with evolutionary or behavioural changes that allowed survival in the increasing intensity of glacial conditions.”

The research was led by scientists at UCL Geography and the IBS Center for Climate Physics, Pusan National University, South Korea in partnership with researchers from the Cambridge University, CSIC Barcelona, the Natural History Museum, London, the British Museum and the UCL Institute of Archaeology.

 

Notes to Editors

For more information or to speak to the researchers involved or to get a copy of the paper, please contact Michael Lucibella, UCL Media Relations. T: +44 (0)753 941 0389, E: m.lucibella@ucl.ac.uk

Margari, V., Hodell, D.A., Parfitt, S.A., Ashton, N.M., Grimalt, J.O., Kim, H., Yun, K.-S., Gibbard, P.L., Stringer, C.B., Timmermann, A. & Tzedakis, P.C. (2023) ‘Extreme glacial cooling likely led to hominin depopulation of Europe in the Early Pleistocene’ will be published in Science on Thursday 10 August 2023, at 19:00 (7:00 pm) British Summer Time / 14:00 (2:00 pm) U.S. Eastern Time and is under a strict embargo until this time.

The DOI for this paper will be: 10.1126/science.adf4445

 

Additional material

Video: https://www.dropbox.com/scl/fi/by3uu2i4rb5hd05grtw2k/UCL-Vas-v9.mp4?rlkey=kpchx03auqvkmpde4p7iyqqpn&dl=0

More information, including a copy of the paper, can be found online at the Science press package at https://www.eurekalert.org/press/scipak/

 

About UCL – London’s Global University

UCL is a diverse community with the freedom to challenge and think differently.

Our community of more than 41,500 students from 150 countries and over 12,500 staff pursues academic excellence, breaks boundaries and makes a positive impact on real world problems.

We are consistently ranked among the top 10 universities in the world and are one of only a handful of institutions rated as having the strongest academic reputation and the broadest research impact.

We have a progressive and integrated approach to our teaching and research – championing innovation, creativity and cross-disciplinary working. We teach our students how to think, not what to think, and see them as partners, collaborators and contributors.  

For almost 200 years, we are proud to have opened higher education to students from a wide range of backgrounds and to change the way we create and share knowledge.

We were the first in England to welcome women to university education and that courageous attitude and disruptive spirit is still alive today. We are UCL.

www.ucl.ac.uk| Follow @uclnews on Twitter | Watch our YouTube channel | Listen to UCL podcasts on SoundCloud | Find out what’s on at UCL Minds | #MadeAtUCL

Find out how UCL is helping lead the global fight against COVID-19 www.ucl.ac.uk/covid-19-research

---

JOURNAL

Science

DOI

10.1126/science.adf4445 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Extreme glacial cooling likely led to hominin depopulation of Europe in the Early Pleistocene

ARTICLE PUBLICATION DATE

11-Aug-2023

Soil microbiome, Earth’s ‘living skin’ under threat from climate change

Novel approach to measuring microbe activity in wetted soil leads to better understanding of vulnerability, researchers report

Peer-Reviewed Publication

PENN STATE

 

IMAGE: PENN STATE GRADUATE STUDENT RYAN TREXLER COLLECTS CORES OF BIOCRUST FROM THE FIELD BEFORE BRINGING THEM BACK TO THE LAB TO STUDY. view more 

CREDIT: PENN STATE

UNIVERSITY PARK, Pa. — Using a novel method to detect microbial activity in biological soil crusts, or biocrusts, after they are wetted, a Penn State-led research team in a new study uncovered clues that will lead to a better understanding of the role microbes play in forming a living skin over many semi-arid ecosystems around the world. The tiny organisms — and the microbiomes they create — are threatened by climate change.  

The researchers published their findings in Frontiers of Microbiology.

“Biocrusts currently cover approximately 12% of Earth’s terrestrial surface, and we expect them to decrease by about 25% to 40% within 65 years due to climate change and land-use intensification,” said team leader Estelle Couradeau, Penn State assistant professor of soils and environmental microbiology. “We hope this work can pave the way to understanding the microbial functions supporting biocrust resilience to the rapidly changing climate patterns and more frequent droughts.”

Biological soil crusts are assemblages of organisms that form a perennial, well-organized surface layer in soils. They are widespread, occurring on all of the continents wherever a shortage of water limits the growth of common plants, allowing light to reach bare soil. But there is still sufficient water to support the growth of microorganisms that perform valuable ecosystem services such as taking carbon and nitrogen from the air and fixing them in the soil, recycling nutrients and holding soil particles together, which helps prevent dust.

That soil-stabilizing function — which reduces erosion by providing the means for soil to clump and not break down into dust — is extremely important, according to Couradeau. Her research group, now in Penn State’s College of Agricultural Sciences, has been intensively studying biocrusts for a decade.

“Most dust is generated in drylands, and studies suggest that the presence of biocrusts in drylands greatly reduce the amount of dust that would otherwise make its way into the atmosphere,” she said. “We think losing biocrusts would cause a 5% to 15% increase in global dust emission and deposition — which would affect the climate, environment and human health.”

In the semi-arid regions where biocrusts exist, the organisms — tiny mosses, lichens, green algae, cyanobacteria, other bacteria and fungi — may experience just a few rain or snow events a year, explained Ryan Trexler, a doctoral degree candidate in the Intercollege Graduate Degree Program in ecology and in biogeochemistry, who spearheaded the research.

“When the soil is dry, for the most part, the microbes in the soil are dormant, not doing much,” he said. “But as soon as they sense water, they're resuscitated very quickly, within seconds to minutes. And they are actively making chlorophyll and fixing carbon and nitrogen until the soil is dry again — and then the microbes go dormant again. They go through cycles of activity every time it rains.”

To study biocrusts, the researchers took samples from three plots of undisturbed, cyanobacteria-dominated biocrusts located on the Colorado Plateau near Moab, Utah. Biocrust samples were taken in fall following rain that wetted the soil sufficiently to activate the microbes. The samples were subsequently dried and stored in the dark and then rewetted much later in the research.

“We sampled what we call ‘a cold desert,’ because it’s very arid, but in the winter, it sometimes snows,” Trexler said. “So, it's not as hot as many other arid places, but still plants cannot thrive there because there's not enough water. And so, the only community that we find in soils at the site are microbial.”

To determine which microorganisms are active within soil communities, the researchers coupled bioorthogonal non-canonical amino acid tagging — known as BONCAT — with fluorescence-activated cell sorting. BONCAT is a powerful tool for tracking protein synthesis on the level of single cells within communities and whole organisms, while fluorescence-activated cell sorting sorts cells based on whether they are producing new proteins.

The researchers combined these processes with shotgun metagenomic sequencing, which allowed them to comprehensively sample all genes in all organisms present in biocrust samples. They applied this method to profile the diversity and potential functional capabilities of both active and inactive microorganisms in a biocrust community after being resuscitated by a simulated rain event. The researchers found that their novel approach can discern active and inactive microorganisms in wetted biocrusts.

The active and inactive components of the biocrust community differed in species richness and composition at both four hours and 21 hours after the wetting event, the researchers reported.

Contributing to the research were Marc Van Goethem, Lawrence Berkeley National Laboratory, and King Abdullah University of Science and Technology, Jeddah, Saudi Arabia; Danielle Goudeau, Nandita Nath, Trent Northen and Rex Malmstrom, Lawrence Berkeley National Laboratory, U.S. Department of Energy Joint Genome Institute.

The U.S. Department of Energy supported this research.

 

A cross-section of biocrust taken by confocal scanning laser microscopy. Soil particles are visible as various shades of gray, while the bundles of cyanobacterial filaments (fluorescent red) are situated between them.

A view of the Colorado Plateau near Moab, Utah, where biocrust samples were taken in fall following rain that wetted the soil sufficiently to activate the microbes.

CREDIT

Penn State

---

JOURNAL

Frontiers in Microbiology

DOI

10.3389/fmicb.2023.1176751 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

BONCAT-FACS-Seq reveals the active fraction of a biocrust community undergoing a wet-up event

Interdisciplinary team studies decomposition effects on soil

Peer-Reviewed Publication

UNIVERSITY OF TENNESSEE INSTITUTE OF AGRICULTURE

 

IMAGE: POSTDOCTORAL RESEARCHER STACY TAYLOR CONDUCTS RESEARCH ON SOIL SAMPLES COLLECTED FROM THE ANTHROPOLOGICAL RESEARCH FACILITY. view more 

CREDIT: UT, KNOXVILLE

Forensic researchers at the University of Tennessee Knoxville’s famous Anthropological Research Facility, popularly known as the “Body Farm,” have made headlines for decades in their discoveries of what happens to human bodies after death. Now, a multidisciplinary team—engineers, soil scientists, and biologists—digs in with them for a deeper look at what happens to the soil underneath a decomposing body. Their study, “Soil Elemental Changes During Human Decomposition,” published in June 2023 by PLOS One, could benefit investigators searching for human remains in remote or hard-to access-vegetated areas.

“This study was part of a larger project where we were investing environmental changes in the vicinity of a decomposing body,” said Jennifer DeBruyn, co-author and professor in the Herbert College of Agriculture Department of Biosystems Engineering and Soil Science (BESS). “Our bodies are concentrated in nutrients and other elements compared to the surrounding environment. As they break down, these nutrients are released into the environment, resulting in changes to soil and vegetation nearby.”

A greater understanding of how and when soil and vegetation changes in the presence of decomposing human remains may offer clues to both locating bodies and estimating how long they have been there.

To test their ideas, this study asks: What elements are released from the human body during decomposition and how does it influence the local soil environment?

“We have previously looked at the major elements of the body, namely carbon and nitrogen,” said DeBruyn, “But we know there are lots more in our bodies.”

The next most abundant elements in the body are sulfur, phosphorus, sodium, and potassium. As the soft tissues in test bodies decomposed, the team observed an expected pulse of these elements in the soils as they were released into the environment.

“What we were surprised to see was that we also had higher concentrations of calcium and magnesium than what we would expect from the input of the body alone,” said Stacy Taylor, lead author on the study and a postdoctoral researcher in DeBruyn’s lab. “While we do have calcium (Ca) and magnesium (Mg) in our bodies, much of it is tied up in our bones, which would take years or decades break down. Soils have capacity to bind cations like Ca2+ and Mg2+, so our hypothesis is that the changing conditions resulted in the release of these elements from the soil itself.”

They were also surprised to see an increase in some trace metals a few months into the soil testing, after soft tissues were largely decomposed.

“Again, the concentrations in soil were higher than what we would expect based on just what would be coming from the body,” said Taylor. “Decomposition fluids result in a gradual acidification of the soil over time, so our hypothesis is that as the pH was dropping, these trace metals were slowly being solubilized from mineral complexes in the soil.”

The big-picture take-away from their study could lead to new approaches in finding missing persons or in determining how long remains have been in a location.

“This study was an important documentation of the types of elements released during human decomposition and how they changed over time,” said DeBruyn. “It contributes to our broader understanding of local environmental changes during human decomposition, which may ultimately help us understand the timing of decomposition in cases where human remains are found outdoors.”

DeBruyn and her students and postdocs have been conducting research at the Anthropological Research Facility for over a decade, investigating the microbiological and environmental changes during human decomposition.

Their team for the study included DeBruyn, Taylor, and Michael Essington from BESS; Scott Lenaghan and Neal Stewart from the Center for Agricultural Synthetic Biology within the UT Institute of Agriculture; Amy Mundorff and Dawnie Steadman of the Forensic Anthropology Center, and Adrian Gonzalez, manager of the Water Quality Core Facility (WQCF) in the Department of Civil and Environmental Engineering.

The WQCF analyzed hundreds of soil samples that originated from underneath deceased human donors—those whose decision to volunteer their remains offers ongoing contribution to the furthering of this investigative science.

---

JOURNAL

PLoS ONE