Rare, deadly genetic disease successfully treated in utero for first time

Toddler thriving after deaths of siblings with same disorder

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SAN FRANCISCO

NOTE TO EDITORS: Photos and video can be found in the media kit (tiny.ucsf.edu/187YiF) 

Using a protocol developed at UC San Francisco, physicians have successfully treated a fetus with a devastating genetic disorder for the first time, and the child is now thriving as a toddler, a case study in the New England Journal of Medicine reports. 

“This treatment expands the repertoire of fetal therapies in a new direction,” said co-senior and corresponding author Tippi MacKenzie, MD, a pediatric surgeon at UCSF Benioff Children’s Hospitals, co-director of UCSF’s Center for Maternal-Fetal Precision Medicine and director of the Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research. “As new treatments become available for children with genetic conditions, we are developing protocols to apply them before birth.”

The child’s disorder, infantile-onset Pompe disease, is one of several lysosomal storage diseases that begin to cause severe damage to major organs, such as the heart, before birth. By initiating enzyme replacement therapy during fetal development, physicians aimed for better outcomes than are typical with post-birth treatment—outcomes that can include death in early childhood, very low muscle tone or ventilator dependency.

After six prenatal enzyme replacement treatments at The Ottawa Hospital, the child, Ayla, was born at term. She is receiving postnatal enzyme therapy at CHEO (a pediatric hospital and research center in Ottawa, Canada), and doing well at 16 months of age. She has normal cardiac and motor function and is meeting developmental milestones. 

“When we were having Ayla, we didn't know if she'd be able to walk,” said Zahid Bashir, Ayla’s dad. “We didn't know if she'd be able to talk. We didn't know if she'd be able to eat. We didn't know if she'd be able to laugh. So, as she hits each of these milestones, we continue to be amazed at her progress. So, yeah, it's quite something, that I think sometimes we may take for granted, but most of the time we're quite aware that she's a miracle.”

A triumph of collaboration 

The successful treatment is a feat of collaboration between UCSF, where an ongoing clinical trial on the treatment is based; CHEO and The Ottawa Hospital, where the patient was diagnosed and treated; and Duke University, home to the world’s top experts on Pompe disease. 
 
 “We really needed this multidisciplinary group of people to lend their deep expertise to all aspects of care,” said MacKenzie, who holds a Benioff UCSF Professorship in Children’s Health and a John G. Bowes Distinguished Professorship in Stem Cell and Tissue Biology. “Enzyme replacement therapy is a new frontier in the field of fetal therapy; it has been exciting to see it grow from a research project in my laboratory to impact the outcome for this family ultimately. UCSF is considered the birthplace of fetal surgery, and it is a special privilege for us to continue to expand the technologies and treatments available to help families facing a difficult diagnosis during pregnancy.”

Under usual circumstances, the patient’s family would have traveled to the UCSF Benioff Children’s Hospital Fetal Treatment Center to participate in the clinical trial. When COVID-19 restrictions made international travel unfeasible, experts from the two Canadian and two American hospitals met the family as a team by video to discuss alternatives. UCSF shared the treatment protocol with the team in Ottawa, where the family lives. Throughout the process, the entire team met weekly by video to discuss the health of the mother and fetus and to monitor the response to treatment. 

“We have been treating our fetal patients using intrauterine therapy for more than 30 years,” said Karen Fung-Kee-Fung, MD, the family’s maternal-fetal medicine specialist at the Ottawa Hospital and professor of obstetrics and gynecology at the University of Ottawa. “The emergence of a new medical treatment to lift the burden of Pompe disease for this family, and potentially help other families affected by devastating genetic diseases, is both exciting and incredibly satisfying. We feel very privileged and honored to be a part of this international collaboration to help make this first-in-the-world treatment a reality.” 

Pranesh Chakraborty, MD, a pediatrician and metabolic geneticist at CHEO and co-lead of the case study, has provided care to the family for years.
 
"This treatment is very promising, and I am so happy for Ayla and her family,” said Chakraborty, who is also a researcher at the CHEO Research Institute and an associate professor at the University of Ottawa. “Having had the privilege and heartbreak of walking alongside families who have lost children to these devastating diseases, this work is very important to me.” 
 
A big step forward for fetal therapy 
  
Babies born with infantile-onset Pompe disease typically have enlarged hearts and die within two years if untreated. The disease is very rare, seen in less than 1/100,000 live births, and is caused by mutations in a gene that makes acid alpha-glucosidase, an enzyme that breaks down glycogen. Without it or with limited amounts, glycogen accumulates dangerously in the body. 
  
“From our long-standing work at Duke treating patients with Pompe disease, we know first-hand the critical importance of earlier initiation of treatment,” said Jennifer Cohen, MD, co-lead author of the study and assistant professor in the Division of Medical Genetics in the Department of Pediatrics at Duke University School of Medicine.  “Our ability to offer a new treatment opportunity to this family and potentially change the course of this difficult disease has made this collaboration and project groundbreaking,” added Cohen. 
 
Duke has played a pivotal role in many advances in the field of Pompe disease, including developing alglucosidase alfa as the first Food and Drug Administration-approved enzyme replacement therapy (ERT) for Pompe disease, identifying the role of high and sustained antibody titers to the ERT, using biomarkers to follow treatment response, and establishing immune tolerance induction protocols for the most severe patients, noted Priya Kishnani, MD, co-senior author, division chief of Medical Genetics at Duke University School of Medicine. 
 
“All of these advances were crucial to this particular patient’s treatment and response,” said Kishnani. “The intrauterine therapy represents a new frontier for patients with Pompe disease.” 

Pompe is one of eight lysosomal storage diseases that UCSF has received FDA approval to treat with enzyme replacement therapy in utero for a Phase 1 clinical trial of 10 patients. The other diseases are Mucopolysaccharidosis types 1, 2, 4a, 6 and 7, Gaucher disease types 2 and 3, and Wolman disease.  

The researchers hope the success of this first application and publication of the case study will increase awareness of the UCSF clinical trial among parents at known risk of passing on these diseases and the physicians who treat them. 

“Seeing how well Ayla is doing, it is important to pursue clinical trials to establish whether this kind of fetal therapy will be a good option for other families when treatment in the newborn period just isn’t early enough,” said Chakraborty, who directs the provincial program Newborn Screening Ontario based at CHEO. “We are working hard to try to improve access to this trial for other Canadian families.”  

Two additional patients with different lysosomal diseases have now been enrolled in the UCSF clinical trial and both have completed their course of prenatal enzyme replacement therapy. The first patient gave birth in late October 2022, and the second will deliver in early November 2022. Both are doing well. 

“It’s exciting to continue this research, which is an important step in the evolution of fetal therapy, from surgery for anatomic conditions to medical therapies for genetic conditions,” said MacKenzie.

Co-authors: Marisa Schwab, MD, and Billie Lianoglou, MS, in the UCSF Department of Surgery and Anita Moon-Grady, MD, and Paul Harmatz, MD, in the UCSF Department of Pediatrics, also contributed to this research. Please refer to the paper for additional co-authors.  

Funding: Please refer to the paper for full disclosures.  

Additional Media Contacts

Rebecca Abelson, The Ottawa Hospital, 343-576-0259 | rabelson@toh.ca
Sarah Avery, Duke, 919-724-5343 | sarah.avery@duke.edu

 

About UCSF Health: UCSF Health is recognized worldwide for its innovative patient care, reflecting the latest medical knowledge, advanced technologies and pioneering research. It includes the flagship UCSF Medical Center, which is ranked among the top 10 hospitals nationwide, as well as UCSF Benioff Children’s Hospitals, with campuses in San Francisco and Oakland, Langley Porter Psychiatric Hospital and Clinics, UCSF Benioff Children’s Physicians and the UCSF Faculty Practice. These hospitals serve as the academic medical center of the University of California, San Francisco, which is world-renowned for its graduate-level health sciences education and biomedical research. UCSF Health has affiliations with hospitals and health organizations throughout the Bay Area. Visit https://www.ucsfhealth.org/. Follow UCSF Health on Facebook or on Twitter

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JOURNAL

New England Journal of Medicine

Thirsty wheat needed new water management strategy in ancient China

Peer-Reviewed Publication

WASHINGTON UNIVERSITY IN ST. LOUIS

Research from Washington University in St. Louis shows that a practice of purposeful water management, or irrigation, was adopted in northern China about 4,000 years ago as part of an effort to grow new grains that had been introduced from southwest Asia.

But the story gets more complex from there. Wheat and barley arrived on the scene at about the same time, but early farmers only used water management techniques for wheat. The results, reported Nov. 9 in the journal Antiquity, raise awareness that the dispersal of domesticated crops and the knowledge of best using them can be traced independently across time and space.

“Pioneering farmers who cultivated wheat in this region managed water to meet the higher demand of this newly introduced grain,” said Xinyi Liu, an associate professor of archaeology in Arts & Sciences, who collaborated on this study with researchers from several prominent institutions in China and Australia, including Guanghui Dong from Lanzhou University, who led the field expedition on the Loess Plateau. “The water management may have been achieved either by deliberate watering or by strategic planting in soils with higher water retention.”

On the other hand, early farmers were able to grow the other new grain, barley, in a rainfed system as if it were just another kind of millet — the locally domesticated and most commonly grown grain in northern China at the time — without using any form of irrigation.

Liu published the study with Washington University graduate student Yufeng Sun. Other co-authors include Haiming Li and Petra Vaiglova, former members of Liu’s lab group.

Introducing irrigation

Both wheat and barley were domesticated in an area known to archaeologists as the hilly flanks of the Fertile Crescent in southwest Asia, where they originally were grown as winter crops. Traditionally, farmers there sowed their seeds in autumn — to avoid the summer drought period — and harvested them in late spring or early summer before the next drought season.

When these Fertile Crescent crops, wheat and barley, were introduced to East Asia about 4,000 years ago, they would have encountered a markedly different climate compared with where they originated.

“Every summer, the East Asian monsoon brings rains from the Pacific Ocean to a region otherwise arid throughout the rest of the year. This environment is perfect for rainfed millet cultivation as these local grains are drought tolerant but need considerable water in the summer growing season,” Liu said. “But it is a different story if you try to grow wheat there, not only because it is water demanding, but also the growing cycle doesn’t match the rainy season.”

Liu and his colleagues wanted to know: Did the farmers who sought to grow the new grains in northern China also introduce new systems of irrigation to support them?

“The introduction of a new irrigation system is something that scholars have speculated about, but now we have the technology to seek direct evidence,” Liu said.

Using relatively new techniques, the actual growing conditions of past crops — including past water and soil conditions during plant growth — can be measured using the stable carbon and nitrogen isotope compositions of charred plant remains. These methods initially were established in plant science for research concerning environmental conditions of modern-day agriculture and have been subsequently applied to archaeological research.

Previous studies using similar approaches have shed significant light on early crop management in Europe and the Middle East. This research is one of the first attempts to apply it to East Asian monsoon environments with innovative questions.

For this study, the scientists identified more than 35,000 charred seed remains of cereal plants, including wheat, barley and millet, from more than 50 archaeological sites excavated on the Loess Plateau of China spanning a timeframe over eight millennia. Selected plant remains from this collection were radiocarbon dated and isotopically measured.

The results showed major differences between wheat and barley.

Despite the arid local environment, the majority of the wheat samples from all time periods had isotopic values above an optimal watering threshold, indicating that their growth was not limited by water availability.

“We see this in the Qijia culture period, when wheat and barley were just introduced to this region,” Liu said. “The isotopic data of wheat show a significant level of water manipulation unambiguously since 4,000 years ago, indicating the new crop was introduced with water management strategies to support it.”

Simple ditches can be powerful

This evidence alone does not necessarily imply large-scale irrigation, Liu is quick to point out; instead, wheat crops may have been strategically sown in areas with the best water availability, either close to local springs or in soils with high water retention.

“In those locations, small ditches to diffuse water is sufficient,” Liu said. “This explains why there is no archaeological evidence of channels or other irrigation installations in the area until much later.”

Barley, on the other hand, appears to have been grown on the dry hills of the Loess Plateau without a special water management approach — a landscape and cultivation strategy that had been familiar to the Neolithic millet farmers since 8,000 years ago.

This and other evidence suggest to Liu and his collaborators that ancient farmers sought to optimize land use and crop yield by taking advantage of the different water demands of these two crops.

“Our results raise an awareness that the dispersal of domesticated crops and the knowledge of best using them can be traced independently across time and space,” Liu said.

“Central to our inquiry is the tension between non-native crops and indigenous farming practices,” he said. “When non-native innovations were adopted in another cultural and physical environment, they would have been transformed within the local context. How this happens is an enduring question that is relevant to globalization in the past and present.”

This study resonates with other archaeological investigations led by Liu’s research group, the Laboratory for the Analysis of Early Food-Webs at Washington University. For example, co-author Sun’s previous work with Washington University graduate student Melissa Ritchey demonstrated a similar geographic decoupling of the dispersal of grains and cuisines, such that wheat and barley dispersed into ancient China 4,000 years ago, but the western grinding-and-baking cuisines did not. The eastern movement of these grains involved selections of phenotypic traits adapted to ancient China’s cooking tradition of using steaming-and-boiling.

It has been a long time since some scholars assumed the association between the origin of bureaucracy and irrigation, and ancient China had been used as an example of “oriental despotism,” according to Liu. The “hydraulic empire” hypothesis speculated that a centralized government structure that maintained power would have been derived from the need for flood control and irrigation.

“Our results suggest otherwise, such that irrigation was a much more localized practice, which did not necessarily require central coordination and a specialized bureaucracy,” Liu explained. “Simple ditches and strategic planting can be as powerful as monopoly empires.”

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JOURNAL

Antiquity

DOI

10.15184/aqy.2022.138 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Water and soil management strategies and the introduction of wheat and barley to northern China: an isotopic analysis of cultivation on the Loess Plateau

ARTICLE PUBLICATION DATE

9-Nov-2022

New study suggests evolutionary forces are behind collective discrimination

Research paper recommends fostering environments in which desired behavior emerges naturally through evolutionary dynamics rather than regulating against undesired outcomes

Peer-Reviewed Publication

MIT SLOAN SCHOOL OF MANAGEMENT

 

IMAGE: PROFESSOR ANDREW W. LO, MIT SLOAN SCHOOL OF MANAGEMENT, IS THE CO-AUTHOR OF THE NEW RESEARCH PAPER, "THE WISDOM OF CROWDS VERSUS THE MADNESS OF MOBS: AN EVOLUTIONARY MODEL OF BIAS, POLARIZATION, AND OTHER CHALLENGES TO COLLECTIVE INTELLIGENCE" view more 

CREDIT: COURTESY OF MIT SLOAN

CAMBRIDGE, Mass., November 10, 2022–New research published in the inaugural issue of the academic journal Collective Intelligence suggests that evolutionary forces may be fueling collective tendencies to discriminate. MIT Sloan School of Management Professor Andrew W. Lo and Assistant Professor Ruixun Zhang of Peking University created a mathematical model of natural selection on behavior to study the controversial idea of “group selection,” in which evolutionary forces operate on groups of individuals. Their model shows that political polarization, bias and discrimination can emerge in environments where technological changes threaten the dominance of one group, while allowing newly emerging groups to rise in popularity.

The global rise of authoritarianism has intensified over the last few years, making their results more relevant than ever. The 2021 Freedom in the World Report found that countries with declines in political rights and civil liberties outnumbered those with gains by the largest margin in the past 15 years. Anti-immigration sentiment and policies have also continued or increased in many countries. (Gallup, September 2020) At the same time, social media use has continued to rise, with an estimated 470 billion users globally. (DataReportal, July 2020)

“One of the central ideas of economics—the Efficient Markets Hypothesis—is that the random interactions of many individuals can produce a remarkable degree of collective intelligence,” says Lo. “For instance, by harnessing this wisdom of crowds, financial markets fuel tremendous economic growth and innovation such as new cancer drugs, self-driving cars, smartphones, and the Mars rover among many others. But failures in collective intelligence also give us economic bubbles, crashes, and global financial crises—the madness of mobs rather than the wisdom of crowds.”

Groups can form based on hate—often unconsciously—through the forces of natural selection, and such alliances can reduce our collective intelligence and cause great societal harm, the researchers say.

Humans naturally tend to anchor toward their original beliefs. (Tversky and Kahnemen, 1974) Lo and Zhang’s research explores present-day implications of this principle. When people are presented with new information—whether via news services or social media posts—there will be a group that believes this information regardless of its accuracy. And despite the small size of the initial group, engagement-based recommender systems can quickly amplify these beliefs, causing exponential growth of populations with polarized beliefs via typical evolutionary dynamics.

“Simply put, evolution can drive our prejudices,” says Zhang. “Since Darwin’s publication of Origins of Species in 1859, we have known that groups compete in order to survive. Competition exists alongside cooperation in ways that can propel us to new heights—such as the global collaboration that produced our COVID-19 vaccines. But it can also plunge us to new lows—such as state-sponsored terrorism, societies with polarized opinions, and hate crimes toward underrepresented groups.”

The authors recommend fostering environments in which the desired behavior of collective intelligence will emerge naturally through evolutionary dynamics, rather than simply regulating against the undesired outcome—which could create selective pressures that make things worse. Strategies to encourage such environment include proactively providing social, educational and economic opportunities for underrepresented groups to counteract negative feedback loops, as well as providing lessons and activities for children to interact with each other with diverse backgrounds, to develop more accurate perceptions of people from other groups. The most effective policies will prevent negative feedback loops from emerging.

“Given today’s near-instantaneous transmission of news, it’s now more important than ever to make sure we have the right tools and the right environment in which the wisdom of crowds can emerge naturally to forestall the madness of mobs,” says Lo.

 

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JOURNAL

Collective Intelligence

DOI

10.1177/26339137221104785 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

People

ARTICLE TITLE

The wisdom of crowds versus the madness of mobs: An evolutionary model of bias, polarization, and other challenges to collective intelligence

New study finds our ancient relatives were not so simple after all

Researchers at the University of Nottingham have solved an important piece of the animal evolution puzzle, after a new study revealed that our ancient ancestors were more complex than originally thought

Peer-Reviewed Publication

UNIVERSITY OF NOTTINGHAM

Researchers at the University of Nottingham have solved an important piece of the animal evolution puzzle, after a new study revealed that our ancient ancestors were more complex than originally thought. 

Way back in our distant evolutionary history, animals underwent a major innovation. They evolved to have a left and right side, and two gut openings. This brought about a plethora of significant advantages in terms of propelling themselves directly forward at increased speed through the early seas, from finding food and extracting nutrients to avoiding being eaten themselves. It was such a successful strategy that, today, we share our planet with a huge diversity of other animals with bilateral symmetry and two gut openings just like us humans. They include animals as diverse as starfish, sea cucumbers, elephants, crickets, and snails. They also include an enigmatic group of very simple marine worms called Xenacoelomorphs, who lack many of the complex features of their fancier looking cousins. 

For years, scientists have debated who is more closely related to who in this diverse collection of bilaterally symmetrical animals. Some experts argue that Xenacoelomorphs mark the first group to branch in that major jump in innovation from animals with circular body plans (e.g. jelly fish and corals) to bilateral symmetry. If this was the case, then the first bilaterian itself was also a very simple animal. Others argued for different placements of Xenacoelomorphs on the family tree.  

However, a research team, led by Dr Mary O’Connell at the University of Nottingham has found that Xenacoelomorphs branch much later in time. They are not the earliest branch on the bilaterian family tree and their closest relatives are far more complex animals, like star fish. This means that Xenacoelomorphs have lost many of the complex features of their closest relatives, challenging the idea that evolution leads to ever more complex and intricate forms. Instead, the new study shows that loss of features is an important factor in driving evolution.  

Dr Mary O’Connell, Associate Professor in Life Sciences at the University of Nottingham says: “There are many fundamental questions about the evolution of animals that need to be answered. Many parts of this family tree that are not known or not resolved. But what an exciting time to be an evolutionary biologist with the availability of exquisite genome data from the beautiful diversity of species we currently have on our planet, allowing us to unlock secrets of our most distant past.”  

The paper, titled ‘Filtering artifactual signal increases support for Xenacoelomorpha and Ambulacraria sister relationship in the animal tree of life’ has been published in the peer-reviewed journal, Current Biology. It details the application of a special phylogenetic technique to help in extracting signal from noise over deep time, showing increased support for Xenacoelomorphs being sister to ambulacraria (e.g. star fish) rather than being the deepest diverging of the bilateria.  

The research team at the University of Nottingham will now explore other challenging family trees and other connections between genome changes and phenotypic diversity.  

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JOURNAL

Current Biology

METHOD OF RESEARCH

Meta-analysis

ARTICLE TITLE

Filtering artifactual signal increases support for Xenacoelomorpha and Ambulacraria sister relationship in the animal tree of life

ARTICLE PUBLICATION DATE

9-Nov-2022

Sub-hourly rainfall extremes are becoming more intense under climate change

Peer-Reviewed Publication

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)

Rainfall extremes at sub-hourly timescales are intensifying much faster than those on longer hourly or daily timescales, researchers report. Since these intense short-duration precipitation events are often to blame for damaging environmental hazards like flash flooding, understanding how they are being affected by our changing climate is crucial for effective climate adaptation and mitigation. Climate change is expected to alter the intensity and frequency of heavy rainfall worldwide. However, despite advances in understanding the effects of a warming climate on rainfall extremes at daily or longer timescales, less is known about its effect on short-duration or sub-daily rain fall totals. Heavy precipitation at these scales is often responsible for destructive natural hazards, including flash floods, landslides, and debris flows in urban and rural regions. Because sub-daily rainfall extremes often occur over small areas, they can be missed by rain gauge networks, overlooked by satellite measurements, and are poorly predicted by regional climate models. To better understand how climate change impacts sub-hourly rainfall totals, Hooman Ayat and colleagues used satellite-calibrated observations from three ground-based weather radars surrounding greater Sydney, Australia to evaluate trends in extreme rainfall down to the 10-minute scale over the last 20 years. Ayat et al. discovered that these short-duration rainfall extremes are becoming more intense – rainfall totals during these sub-hourly events are increasing – much faster than those over longer periods. According to the findings, despite no evidence of positive trends on the hourly or daily scales, sub-hourly extreme rainfall extremes in the Sydney area has been rising by at least 20% per decade.

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JOURNAL

Science

DOI

10.1126/science.abn8657 

ARTICLE TITLE

Intensification of subhourly heavy rainfall

ARTICLE PUBLICATION DATE

11-Nov-2022

SOS SAVE OUR SHARKS

Tunas, billfishes recover yet sharks’ extinction risk rises

Peer-Reviewed Publication

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)

Although some tunas and billfishes are recovering after decades of decline from overfishing, due in large part to successful fisheries management and conservation actions, shark biodiversity continues to decline, according to a new study evaluating yearly changes in these species’ extinction risk for the last 70 years. The findings simultaneously illustrate the value of conservation and management in protecting large ocean species and underscore the immediate need for these protections to be extended to sharks. It’s estimated that intense fishing across the planet’s oceans has led to roughly half of all commercially harvested fish and invertebrate stocks becoming overfished during the 20th century, including iconic large predatory fishes like tuna, billfishes, and sharks. However, while intense fishing activity has been increasingly monitored and managed, its overarching effects on ocean biodiversity are generally poorly understood. Based on International Union for Conservation of Nature (IUCN) Red List categories and criteria, Maria José Juan-Jordá and colleagues created a continuous Red List Index (RLI) of yearly changes in extinction risk of oceanic tunas, billfishes, and sharks spanning the last 70 years to better understand the health of oceanic biodiversity as well as the overall impacts of fishing mortality and conservation efforts on these populations. Juan-Jordá et al. found that after more than half a century of increasing risk of extinction due to increasing fishing pressure, effective fisheries management and conservation strategies have allowed populations of tuna and billfish to recover over the past decade. However, the extinction risk for sharks, which remain largely undermanaged, continues to rise. The findings suggest that while target species are increasingly and successfully sustainably managed to ensure maximum catch, other functionally important species like sharks, which are often captured as bycatch in these fisheries, continue to decline because of insufficient management actions. “The conservation statuses of threatened target species can be improved by managing the fishing industry, which can benefit the industry economically in the long run while allowing the threatened species to recover,” write Matthew Burgess and Sarah Becker in a related Perspective. “However, the protection of high-vulnerability bycatch and nontarget species is expected to be more difficult because they will require fisheries to invest in better fishing gear and targeting practices, or reduce fishing efforts, without directly benefiting from these changes.”

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JOURNAL

Science

DOI

10.1126/science.abj0211 

ARTICLE TITLE

Seventy years of tunas, billfishes, and sharks as sentinels of global ocean health

ARTICLE PUBLICATION DATE

11-Nov-2022

Hundred-year-old riddle in botany reveals key plant adaptation to dry land

Peer-Reviewed Publication

BOTANICKY USTAV AKADEMIE VED CESKE REPUBLIKY

 

VIDEO: SCHEMATIC ANIMATION OF EMBOLISM SPREADING BETWEEN CONDUITS IN TWO STEM CROSS-SECTIONS. IN BOTH, EMBOLISM CROSSES HALF OF THE CONDUIT WALLS IT ENCOUNTERS. THE PLANT ON THE LEFT DIES, THE ONE ON THE RIGHT LIVES. view more 

CREDIT: ANIMATION: MARTIN BOUDA, INSTITUTE OF BOTANY, CZECH ACADEMY OF SCIENCES

Průhonice, Czech Republic - The green world that we live in would not have been possible without hidden changes to the plant body over the last 400 million years. To grow beyond just centimetres tall outside of the wettest places on land, plants had to re-arrange their water-conducting tissues to keep them safe from drought. A new study by Martin Bouda of the Institute of Botany of the Czech Academy of Science and co-authors, published in the journal Science, shows how the solution to a hundred-year-old debate in botany reveals a key adaptation that allowed plants to colonise dry land.

Background: All but the tiniest plants need vascular tissues to supply water throughout their body and avoid drying out as they capture carbon from the surrounding air. If a plant is subjected to drought, the chain of water molecules being pulled up the stem can break, forming an embolism: a bubble of gas that blocks water transport in one entire vascular conduit. If embolism spreads from this conduit throughout the tissue, the plant’s water-supplying vasculature becomes effectively blocked, the plant dries out and dies.

The new discovery shows that the original arrangement of vascular tissues—a cylinder at the centre of the stem—becomes increasingly vulnerable to embolism spread with size. "If conduits are all bundled up together the plant may face exponential spread of embolism on the resulting vascular network. If they are strung out in a long narrow shape, embolism has to overcome many successive cell walls to go very far, which can save the plant’s life in a drought,” says Dr. Bouda, the lead author of the study

The first vascular plants were just centimetres tall and constrained to live where water was readily available. To grow taller and begin exploring the landscape, they first had to find alternatives to their ancestral vascular arrangement. “We were struck by the fact that only very few living plants have kept the original layout of the stem, which puts the vascular tissue in a cylinder right at the centre. That seeming detail actually held the key to deciphering this whole evolutionary episode,” adds Bouda.

The fossil record shows an increasing diversity in how the stem isassembled just as plant radiate out from water sources. Vascular tissue arrangements diversify to take on a vast array of shapes in the stem from ellipses and straps through stars to rings--divergent in form likely convergent in function. Plant lineages that succeeded on land had to each find their own solution to the problem of embolism. The strength of this evolutionary pressure increases with plant size.

The research resolves a hundred-year-old riddle in botany. The observation that vascular tissues assume increasingly complex shapes in larger plants was first made by F. O. Bower (president of the Royal Society of Edinburgh) and his student C. W. Wardlaw. Bower presented their results in his opening address at the Society’s meeting in 1920 but could not explain the finding.  A century of debate eventually settled on the uncomfortable consensus that the complexity of xylem arrangements simply increased coincidentally as plant bodies grew and branched. The new study shows that plants maintain drought-resistant vascular arrangements by restricting the tissue’s width. With increased size, the tissue must assume elongated, narrow, and increasingly complex shapes, which provides an answer to Bower and Wardlaw’s riddle.

The research was a collaborative effort led by Dr. Bouda and prof. Craig Brodersen of Yale University (School of the Environment). Other team members were Kyra Prats (Yale School of the Environment), Brett Huggett (Bates College), Jay Wason (U. of Maine), and Jonathan Wilson (Haverford College). To evaluate their hypothesis, the team of scientists sampled the xylem strands of living and extinct seedless vascular plants spanning over 400 million years of evolution. They examined the packing of conducting cells in different vascular strand shapes and analysed the topology of the resulting conduit networks. Numerical simulations of how drought-induced embolism spreads through the vascular networks of real and idealised plants to become lethal confirmed that hydraulic failure should select for narrower, increasingly complex shapes. “By developing new ways of quantifying how the topology of the conduit network affects embolism spread, and by applying those methods to both the early fossil record and living plants, we were finally able to ask the question in the right way,” closes Dr. Bouda.

Applications of this fundamental advance include the potential to secure drought-resistance in crop breeding programs for a changing climate. “Now that we have a better understanding of how the vascular systems are put together and how that influences a plant's ability to tolerate drought, that's the kind of thing that could be used as a target for breeding programs,” says prof. Brodersen.

Follow-up research will ask how plants evaded the newly discovered constraints to achieve woody growth forms.

 

About the Institute of Botany of the Czech Academy of Sciences

The Institute of Botany is a public research institution that is part of the Czech Academy of Science. It is the largest centre of botanical research in the Czech Republic. It is involved in the research of vegetation at the level of organisms, populations, communities and ecosystems. It presently hosts over 150 scientists and doctoral students spanning the range of research fields from taxonomy through evolutionary biology, ecology through to biotechnology. The main seat of the institute is at the Chateau in Průhonice but it also incorporates separate scientific campuses in Brno and Třeboň. The institute administers the park in Průhonice, which is listed as a National Cultural Heritage site and as a UNESCO World Heritage site, as well as the botanical gardens in Průhonice and in Třeboň. More information at www.ibot.cas.cz/en

A fossilized stem of Dernbachia brasiliensis, a tree fern of the Permian (250-300 million years ago). Water-conducting xylem tissue is highlighted in blue.

CREDIT

Photo: Ludwig Luthardt, Museum für Naturkunde, Berlin.

Artist’s impression of the landscape over 400 million years ago, when plants began diversifying the arrangement of their vascular tissues, increasing their overall stature, and exploring increasingly dry environments.

CREDIT

© Julian Kiely, 2022

JOURNAL

Science

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Hydraulic failure as a primary driver of xylem network evolution in early vascular plants

ARTICLE PUBLICATION DATE

11-Nov-2022

U$A

Food pantry access worth billions nationally, study finds

What is free food worth? A nonmarket valuation approach to estimating the welfare effects of food pantry services

Peer-Reviewed Publication

CORNELL UNIVERSITY

ITHACA, N.Y. – A research collaboration between Cornell University and the U.S. Department of Agriculture offers the first estimates of the economic value contributed by food pantries, and finds it is substantial – worth up to $1,000 annually to participating families and as much as $28 billion nationwide.

The totals underscore food bank systems’ important role in addressing food insecurity, a role that has grown during the pandemic and recent bouts of inflation, said David R. Just, the Susan Eckert Lynch Professor in Science and Business in the Charles H. Dyson School of Applied Economics and Management, part of the Cornell SC Johnson College of Business and the College of Agriculture and Life Sciences.

“Food pantries make a huge difference to the households they serve, for many representing a substantial portion of their income,” Just said. “This is important information for policymakers considering support for the national or local food banking system, like tax breaks for food donation, direct program support from USDA or other efforts.”

Just is the co-author of "What is Free Food Worth? A Nonmarket Valuation Approach to Estimating the Welfare Effects of Food Pantry Services,” published Nov. 9 in the American Journal of Agricultural Economics. The lead author is Anne Byrne, a research agricultural economist at the USDA’s Economic Research Service. The team has collaborated on multiple investigations of private food assistance.

“Private food assistance, especially food banking, has grown in recent decades,” Byrne said. “These organizations have a unique position within the food system and a specific role in food access because they offer quick relief in the form of free groceries to a wide variety of people, typically with minimal administrative hurdles.”

Food banks and pantries served 51 million people in 2021, according to the nonprofit Feeding America. Despite their importance, the researchers said, their economic value to the individuals and households that they serve hasn’t been estimated using rigorous economic methods.

Determining that value is challenging, the researchers said, since food pantries provide food and services at no cost. In addition, the market value of food may not accurately capture its value to people who can’t afford to access markets.

Byrne and Just thought they could get at the question using travel costs, a novel application of a methodology long used to value assets like national parks – where the cost of visiting isn’t primarily an entry fee – based on costs incurred to make the trip. They calculated the cost of travel to and from food pantries as a measure of households’ “willingness to pay” for the food, considering the distance, duration and frequency of their trips.

“We know they would be willing to give up at least this amount for the food they obtain, which enables us to identify demand in terms of price – travel costs – and quantity – visits,” Just said.

The scholars analyzed 13 years of data (2005-17) from a northern Colorado food bank that in 2017 served 10% of Larimer County residents at locations in Fort Collins and Loveland.

The data set included millions of pantry visits representing about 45,000 households – a population with lower incomes and more racial and ethnic minorities than the county overall, according to census data. To calculate travel costs, the researchers used Google maps for walking and driving distances and times, AAA data for vehicle costs, and reported incomes or the Colorado minimum wage to determine the opportunity cost of the time trips required.

The result was an estimated value to families of $40 to $60 per trip to a food pantry, and of $600 to $1,000 per year based on typical annual visit frequencies, with values increasing or decreasing with travel costs.

Extrapolated nationally – based on 389 million visits reported by Feeding America’s 2014 Hunger in America Study – the first-of-their-kind estimates confirm that “food bank services collectively represent a sizeable share of the food landscape,” the researchers wrote. Their estimated value of $19 to $28 billion is more than double the sales by farmers markets in 2020, and a significant fraction of federal food stamp (SNAP) benefits that year worth $74.2 billion, according to the research.

“Without such an estimate it is difficult to know whether food pantries are a worthwhile investment from a public policy perspective,” Just said. “Given the great number of families touched by these services and the significant investment and volunteer hours given, it is important to document and measure the value they are contributing to our economy.”

For additional information, see this Cornell Chronicle story.

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JOURNAL

American Journal of Agricultural Economics

DOI

10.1111/ajae.12355