FOR PROFIT HEALTHCARE U$A

Cost concerns keep older adults from seeking emergency care

People in their pre-Medicare years, especially those who are uninsured or have low incomes, are most likely to skip a trip to the ER because of what they might have to pay

Peer-Reviewed Publication

MICHIGAN MEDICINE - UNIVERSITY OF MICHIGAN

Worries about what emergency care might cost them have kept some older adults from seeking medical attention even when they felt they might need it, a new study shows.

In all, 22% of older adults who may have needed care from the emergency department didn’t go because of concerns about what they might have to pay, according to the new findings published in the American Journal of Managed Care.

People in their 50s and early 60s, women, those who lack health insurance, people with household incomes under $30,000, and those who say their mental health is fair or poor were most likely to say they’d avoided getting emergency care because of cost concerns.

The study, based on a survey conducted in June 2020, asked older adults to think back on the previous two years, including the first months of the COVID-19 pandemic.

Even among those who hadn’t had a medical emergency in this time, worries about what an emergency visit might cost them were high. Four out of five older adults said they were concerned about the cost of emergency care (35% somewhat concerned and 45% very concerned, and 18% were not confident they could afford a visit.

The data from the study come from the National Poll on Healthy Aging, based at the University of Michigan Institute for Healthcare Policy and Innovation and supported by AARP and Michigan Medicine, U-M’s academic medical center. The findings build on the poll report published earlier and are based on responses from a nationally representative sample of 2,074 people age 50 to 80.

The findings confirm the experience of lead author Rachel Solnick, M.D., M.Sc., who trained in IHPI’s National Clinician Scholars Program before joining the faculty at the Icahn School of Medicine at Mount Sinai Health System in New York.

“As an emergency physician, I have seen patients come to the emergency room having postponed their care. They often come in sicker than they would have been had they received care sooner,” she said. “That scenario is what I find most alarming in this survey’s findings. Some groups that are medically vulnerable or have suffered worse outcomes from COVID-19 were more likely to report cost-related avoidance of the ER than their counterparts. These findings highlight the importance of reducing the number of uninsured individuals and the need for insurers to clearly communicate coverage for emergency services.”

Keith Kocher, M.D., the study’s senior author and an associate professor of emergency medicine at U-M, notes that the federal No Surprises Act was enacted after the study was done. That act seeks to reduce “surprise billing” for emergency care when a privately insured person receives it from hospitals or providers outside their health insurance plan’s network. At the time of the study, Medicare and Medicaid already prohibited emergency care providers from doing this kind of “balance billing.”

Even so, a person with private insurance might owe hundreds of dollars in co-pays or deductibles for an emergency visit, the authors note. That’s especially true for people with high-deductible health plans, which are growing in enrollment.

Even though the percentage of older adults who lack any health insurance is small (4% of the study sample), they were 35% more likely to say they were not confident they could afford emergency care. Solnick notes that both the pandemic’s economic impacts, and the decision by more than a dozen states including Texas and Florida to not expand Medicaid to all low-income adults, mean that millions of people may face paying out of pocket for emergency visits.

American Journal of Managed Care, 2023;29(4): In Press, https://www.ajmc.com/view/older-adults-perspectives-on-emergency-department-costs-during-covid-19

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JOURNAL

The American Journal of Managed Care

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Older Adults’ Perspectives on Emergency Department Costs During COVID-19

ARTICLE PUBLICATION DATE

16-Dec-2022

Scientists discover what was on the menu of the first dinosaurs

Peer-Reviewed Publication

UNIVERSITY OF BRISTOL

 

IMAGE: THE THREE MAIN DINOSAUR LINEAGES AND THEIR TYPICAL TOOTH SHAPES view more 

CREDIT: ANTONIO BALLELL

The earliest dinosaurs included carnivorous, omnivorous and herbivorous species, according to a team of University of Bristol palaeobiologists.

By looking at the tooth shapes of the earliest dinosaurs and simulating their tooth function with computational modelling, experts were able to compare them to living reptiles and their diets. Their findings, published today in Science Advances, show that many groups of plant-eating dinosaurs were ancestrally omnivorous and that the ancestors of our famous long-necked herbivores, such as Diplodocus, ate meat. This ability to diversify their diets early in their evolution likely explains their evolutionary and ecological success.

The earliest dinosaurs are enigmatic: they were much smaller than their later relatives and for most of the Triassic they were in the shadow of the crocodile-like reptiles. It is unknown how diverse they were in terms of diets and ecology, but scientists know something must have happened in the Triassic that allowed dinosaurs to endure the Triassic–Jurassic mass extinction and adapt in its aftermath, becoming the dominant group for the rest of the Mesozoic.

Lead author Dr. Antonio Ballell from the University of Bristol said “Soon after their origin, dinosaurs start to show an interesting diversity of skull and tooth shapes. For decades, this has made palaeontologists suspect that different species were already experimenting with different kinds of diets. They have compared them to modern lizard species and tried to infer what they ate based on the similarities in their teeth.

“We investigated this by applying a set of computational methods to quantify the shape and function of the teeth of early dinosaurs and compare them to living reptiles that have different diets. This included mathematically modelling their tooth shapes and simulating their mechanical responses to biting forces with engineering software.”

Professor Mike Benton, co-author of the study, said: “With this battery of methods, we were able to numerically quantify how similar early dinosaurs were to modern animals, providing solid evidence for our inferences of diets. Theropod dinosaurs have pointy, curved and blade-like teeth with tiny serrations, which behaved like those of modern monitor lizards. In contrast, the denticulated teeth of ornithischians and sauropodomorphs are more similar to modern omnivores and herbivores, like iguanas.”

The study is also innovative in using machine learning models to classify the earliest dinosaurs in different diet categories based on their tooth shape and mechanics. For instance, Thecodontosaurus, the Bristol dinosaur, had teeth well adapted for a diet of plants.

Professor Emily Rayfield, senior co-author, said: “Our analyses reveal that ornithischians – the group that includes many plant-eating species like the horned dinosaurs, the armoured ankylosaurs and the duck-billed dinosaurs – started off as omnivores. And another interesting finding is that the earliest sauropodomorphs, ancestors of the veggie long-necked sauropods like Diplodocus, were carnivores. This shows that herbivory was not ancestral for any of these two lineages, countering traditional hypotheses, and that the diets of early dinosaurs were quite diverse.”

Dr. Ballell concluded: “It seems that one of the things that made the first dinosaurs special is that they evolved different diets throughout the Triassic, and we think this might have been key for their evolutionary and ecological success.”

Dinosaurs dominated the land during the Mesozoic era until their extinction 66 million years ago. They included giant veggie groups like the long-necked sauropods and meat-eating species like Tyrannosaurus rex and its relatives. However, their origins were much humbler and date back to the Triassic period, with the first definitive dinosaurs appearing approximately 235 million years ago.

Paper:

‘Dental form and function in the early feeding diversification of dinosaurs’ by Antonio Ballell, Michael J. Benton and Emily J. Rayfield in Science Advances.

DOI: 10.1126/sciadv.abq5201

Early dinosaurs and their diets. Lesothosaurus is an omnivore, Buriolestes is a carnivore and Thecodontosaurus is an herbivore.

CREDIT

Gabriel Ugueto

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JOURNAL

Science Advances

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Dental form and function in the early feeding diversification of dinosaurs’

ARTICLE PUBLICATION DATE

16-Dec-2022

Linking fossil climate proxies to living bacteria helps climate predictions

Missing link in climate reconstuctions, also helps understand early evolution of life

Peer-Reviewed Publication

ROYAL NETHERLANDS INSTITUTE FOR SEA RESEARCH

 

IMAGE: FLUORESCENT MICROSCOPY IMAGE OF A BACTERIUM FORMING MEMBRANE-SPANNING LIPIDS UTILIZED AS A MODEL ORGANISM IN THIS STUDY. THERMOTOGA MARITIMA CELLS STAINED WITH A DNA DYE (DAPI) (LEFT PANEL) AND WITH A MEMBRANE DYE (FM4-64) (RIGHT PANEL) SIMULTANEOUSLY. IMAGE: DIANA SAHONERO, NIOZ view more 

CREDIT: DIANA SAHONERO, NIOZ

Microbial skins are made out of lipids – fatty molecules – which can be preserved as fossils telling us stories about how these microbes lived in the past. “Some microbial lipids are widely used to reconstruct past climates. They have always been surrounded by mystery, as we did not know which microbes were making them and under which conditions. This lack of information limits the predictive power of these molecules to reconstruct past environmental conditions,” says Sahonero, Now, her study shows which bacteria make these lipids and also how they have evolved their lipid skin to adapt to environmental changes – another step towards reconstructing and predicting climate change in more detail.

Climate reconstructions

Lipids, the molecular building blocks of the cell membrane, are unique for each microbial species. “It works just like fingerprints, they can be used to identify microbial remains,” says Laura Villanueva, associate professor in the Faculty of Geosciences in Utrecht University and senior scientist at NIOZ. The lipids of ancient microbes can be found in old sediments. Once these molecules from the past are separated, identified and related to currently living groups of bacteria, the lipids can work like ‘biomarkers’. These markers can tell us about the atmospheric and oceanic conditions of the ancient earth, because we know from the living relatives of the microbes how they interact with their environment.

Who made these molecules and how?

For long, it was unclear precisely which bacteria were making these specific lipids, called branched Glycerol Dialkyl Glycerol Tetraethers (GDGTs). This type of lipids are often used in climate reconstructions. Diana and her colleagues have finally discovered the bacteria forming these lipids. And also how these bacteria actually make the lipids. “It was like looking for a needle in a haystack”, says Sahoreno. “From the start, we knew we had to answer this question with a massive approach. We needed to investigate more than 1850 proteins to identify microbes making these lipid molecules.”

Once researchers know which currently living bacteria make these lipid molecules, they can be used to make more accurate climate reconstructions. Researchers can measure the interactions of these living bacteria with their surrounding seawater or atmosphere. This information leads to ‘proxies’ – keys to correlate details of the lipid molecules (abundance for instance) to values of the environment. This is an important step in reconstructing past environmental and climate conditions, based on old sediment samples.

Early evolution of life

“Our study indicates that there are many species of currently living bacteria that can make these type of membrane lipids. Also, we found that those bacteria are all limited to environments where oxygen is absent,” says Sahonero. “This study into archaeal-like lipids of bacteria shows how this group of microbes that produces them evolved their lipid membrane billions of years ago. It is fantastic to get a glimpse of this part of life’s history. It was mostly a mystery until now.”

What next?

The work of Sahonero and her colleagues is still ongoing. “Now we know which bacteria form these molecular building blocks and we understand how they do that. Next, we need to find out how the production of these molecules depends on environmental factors like water temperature or pH,” says Villanueva. “Then, the proxy based on these bacterial lipids can be used more confidently by (paleo)climatologists. This gives them new possibilities to reconstruct and predict climate change in more detail.”

Publication in Science Advances

Disentangling the lipid divide: Identification of key enzymes for the biosynthesis of membrane-spanning and ether lipids in Bacteria
Diana X. Sahonero-Canavesi, Melvin F. Siliakus, Alejandro Abdala Asbun, Michel Koenen, F. A. Bastiaan von Meijenfeldt, Sjef Boeren, Nicole J. Bale, Julia C. Engelman, Kerstin Fiege, Lora Strack van Schijndel, Jaap S. Sinninghe Damsté and Laura Villanueva.
16 December 2022, 2pm EST

Lipids form the membrane of a microbe. 

Set-up of the growth experiments in serum bottles without oxygen for obtaining samples for omics analysis (lipidomic, transcriptomic and proteomics). Photo: Diana Sahonero, NIOZ

CREDIT

Photo: Diana Sahonero, NIOZ

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JOURNAL

Science Advances

DOI

10.1101/2022.04.21.487849v1 

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Disentangling the lipid divide: Identification of key enzymes for the biosynthesis of membrane-spanning and ether lipids in Bacteria

ARTICLE PUBLICATION DATE

16-Dec-2022

Underground Italian lab searches for signals of quantum gravity

FQXi-funded project in the Gran Sasso mountains hunts for evidence of violations of the ‘Pauli Exclusion Principle’

Peer-Reviewed Publication

FOUNDATIONAL QUESTIONS INSTITUTE, FQXI

 

IMAGE: CATALINA OANA CURCEANU IS SEARCHING FOR SIGNS OF RADIATION EMANATING FROM A LEAD TARGET. view more 

CREDIT: CATALINA CURCEANU

For decades physicists have been hunting for a quantum-gravity model that would unify quantum physics, the laws that govern the very small, and gravity. One major obstacle has been the difficulty in testing the predictions of candidate models experimentally. But some of the models predict an effect that can be probed in the lab: a very small violation of a fundamental quantum tenet called the Pauli exclusion principle, which determines, for instance, how electrons are arranged in atoms. An FQXi-funded project carried out at the INFN underground laboratories under the Gran Sasso mountains in Italy, has been searching for signs of radiation produced by such a violation, in the form of atomic transitions forbidden by the Pauli exclusion principle. In two papers appearing  in the journals Physical Review Letters (published on 19th September 2022) and Physical Review D (accepted for publication on 7th December 2022) the team reports that no evidence of violation has been found, thus far, ruling out some quantum-gravity models.

"You, me, we are Pauli-exclusion-principle-based. The fact we cannot cross walls is another consequence," says Curceanu.

“The Pauli exclusion principle is the main pillar of our comprehension of the structure of matter and of its stability,” says Catalina Curceanu, a member of the physics think-tank, the Foundational Questions Institute, FQXi, and the lead physicist on the experiments at INFN, Italy. In school chemistry lessons we are taught that electrons can only arrange themselves in certain specific ways in atoms, which turns out to be due to the Pauli exclusion principle. At the center of the atom there is the atomic nucleus, surrounded by orbitals, with electrons. The first orbital, for instance, can only house two electrons. The Pauli exclusion principle, formulated by Austrian physicist Wolfang Pauli in 1925, says that no two electrons can have the same quantum state; so, in the first orbital of an atom the two electrons have oppositely pointing 'spins' (a quantum internal property usually depicted as an axis of rotation, pointing up or down, although no literal axis exists in the electron). The happy result of this for humans is that it means matter cannot pass through other matter. “It is ubiquitous—you, me, we are Pauli-exclusion-principle-based,” says Curceanu. “The fact we cannot cross walls is another practical consequence.”

The principle extends to all elementary particles belonging to the same family as electrons, called fermions, and has been derived mathematically from a fundamental theorem known as the spin-statistics theorem. It has also been confirmed experimentally–thus far–appearing to hold for all fermions in tests. The Pauli exclusion principle forms one of the core tenets of the Standard Model of Particle Physics.

Violating the principle

But some speculative models of physics, beyond the Standard Model, suggest that the principle may be violated. For decades now, physicists have been searching for a fundamental theory of reality. The Standard Model is terrific at explaining the behavior of particles, interactions and quantum processes on the microscale. However, it does not encompass gravity. So, physicists have been trying to develop a unifying theory of quantum gravity, some versions of which predict that various properties that underpin the Standard Model, such as the Pauli exclusion principle, may be violated in extreme circumstances. “Many of these violations are naturally occurring in so-called 'noncommutative' quantum-gravity theories and models, such as the ones we explored in our papers,” says Curceanu. One of the most popular candidate quantum-gravity frameworks is string theory, which describes fundamental particles as tiny vibrating threads of energy in multidimensional spaces. Some string theory models also predict such a violation.

"The analysis we reported disfavors some concrete realizations of quantum gravity," says Curceanu.

It is traditionally thought to be hard to test such predictions because quantum gravity will usually only become relevant in arenas where there is a huge amount of gravity concentrated into a tiny space—think of the center of a black hole or the beginning of the universe. However, Curceanu and her colleagues realized that there may be a subtle effect—a signature that the exclusion principle and the spin-statistics theorem have been violated—that could be picked up in lab experiments on Earth.

Deep under the Gran Sasso mountains, near the town of L’Aquila, in Italy, Curceanu’s team is working on the VIP-2 (Violation of the Pauli Principle) lead experiment. At the heart of the apparatus is a thick block made of Roman lead, with a nearby germanium detector that can pick up small signs of radiation emanating from the lead. The idea is that if the Pauli exclusion principle is violated, a forbidden atomic transition will occur within the Roman lead, generating an X-ray with a distinct energy signal. This X-ray can be picked up by the germanium detector.

Cosmic silence

The lab must be housed underground because the radiation signature from such a process will be so faint, it would otherwise be drowned out by the general background radiation on Earth from cosmic rays. “Our laboratory ensures what is called ‘cosmic silence,’ in the sense that the Gran Sasso mountain reduces the flux of cosmic rays by a million times,” says Curceanu. That alone is not enough, however. “Our signal has a possible rate of just one or two events per day, or less,” says Curceanu. That means that materials used in the experiment must themselves be “radio-pure”—that is, they must not emit any radiation themselves—and the apparatus must be shielded from radiation from the mountain rocks and radiation coming from underground.

“What is extremely exciting is that we can probe some quantum-gravity models with such a high precision, which is impossible to do at present-day accelerators,” says Curceanu.

In their recent Physical Review Letters paper, published in September, and in a follow up paper in Physical Review D (accepted in December), the team reports having found no evidence for violation of the Pauli principle. “FQXi-funding was fundamental for developing the data analysis techniques,” says Curceanu. This allowed the team to set limits on the size of any possible violation and helped them constrain some proposed quantum-gravity models. In particular, the team analyzed the predictions of the so-called “theta-Poincaré” model and were able to rule out some versions of the model to the Planck scale (the scale at which the known classical laws of gravity break down). In addition, “the analysis we reported disfavors some concrete realizations of quantum gravity,” says Curceanu.

The team now plans to extend its research to other quantum-gravity models, with their theoretician colleagues Antonino Marcianò from Fudan University and Andrea Addazi from Sichuan University, both in China. “On the experimental side, we will use new target materials and new analysis methods, to search for faint signals to unveil the fabric of spacetime,” says Curceanu.

“What is extremely exciting is that we can probe some quantum-gravity models with such a high precision, which is impossible to do at present-day accelerators,” Curceanu adds. “This is a big leap, both from theoretical and experimental points of view.”

This work was partially supported through FQXi's Consciousness in the Physical World program. You can read more about the team’s grant in the FQXi article: “Can We Feel What It's Like to Be Quantum?” by Brendan Foster.

Journal reference, PRL: Strongest Atomic Physics Bounds on Noncommutative Quantum Gravity Models

Journal reference, PRD: Experimental test of noncommutative quantum gravity by VIP-2 Lead; preprint available.

The Gran Sasso low radioactivity underground lab.

CREDIT

Massimiliano De Deo, LNGS-INFN

ABOUT US

The Foundational Questions Institute, FQXi, catalyzes, supports, and disseminates research on questions at the foundations of science, particularly new frontiers in physics and innovative ideas integral to a deep understanding of reality but unlikely to be supported by conventional funding sources. Visit fqxi.org for more information.

Dr. Curceanu acknowledges the Gran Sasso underground laboratory of INFN, INFN-LNGS, and its Director, Ezio Previtali, the LNGS staff, and the Low Radioactivity laboratory for the experimental activities dedicated to the search for PEP violating signals.

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JOURNAL

Physical Review Letters

DOI

10.1103/PhysRevLett.129.131301 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Strongest Atomic Physics Bounds on Noncommutative Quantum Gravity Models

Atomic structure of a staphylococcal bacteriophage using cryo-electron microscopy

High-resolution knowledge of structure is a key link between viral biology and potential therapeutic use of the virus to quell bacterial infections.

Peer-Reviewed Publication

UNIVERSITY OF ALABAMA AT BIRMINGHAM

 

IMAGE: THE ANDHRA PHAGE view more 

CREDIT: UAB, DOKLAND LAB

BIRMINGHAM, Ala. – Cryo-electron microscopy by University of Alabama at Birmingham researchers has exposed the structure of a bacterial virus with unprecedented detail. This is the first structure of a virus able to infect Staphylococcus epidermidis, and high-resolution knowledge of structure is a key link between viral biology and potential therapeutic use of the virus to quell bacterial infections.

Bacteriophages or “phages” is the terms used for viruses that infect bacteria. The UAB researchers, led by Terje Dokland, Ph.D., in collaboration with Asma Hatoum-Aslan, Ph.D., at the University of Illinois Urbana-Champaign, have described atomic models for all or part of 11 different structural proteins in phage Andhra. The study is published in Science Advances.

Andhra is a member of the picovirus group. Its host range is limited to S. epidermidis. This skin bacterium is mostly benign but also is a leading cause of infections of indwelling medical devices. “Picoviruses are rarely found in phage collections and remain understudied and underused for therapeutic applications,” said Hatoum-Aslan, a phage biologist at the University of Illinois.

With emergence of antibiotic resistance in S. epidermidis and the related pathogen Staphylococcus aureus, researchers have renewed interest in potentially using bacteriophages to treat bacterial infections. Picoviruses always kill the cells they infect, after binding to the bacterial cell wall, enzymatically breaking through that wall, penetrating the cell membrane and injecting viral DNA into the cell. They also have other traits that make them attractive candidates for therapeutic use, including a small genome and an inability to transfer bacterial genes between bacteria.

Knowledge of protein structure in Andhra and understanding of how those structures allow the virus to infect a bacterium will make it possible to produce custom-made phages tailored to a specific purpose, using genetic manipulation.

“The structural basis for host specificity between phages that infect S. aureus and S. epidermidis is still poorly understood,” said Dokland, a professor of microbiology at UAB and director of the UAB Cryo-Electron Microscopy Core. “With the present study, we have gained a better understanding of the structures and functions of the Andhra gene products and the determinants of host specificity, paving the way for a more rational design of custom phages for therapeutic applications. Our findings elucidate critical features for virion assembly, host recognition and penetration.”

Staphylococcal phages typically have a narrow range of bacteria they can infect, depending on the variable polymers of wall teichoic acid on the surface of different bacterial strains. “This narrow host range is a double-edged sword: On one hand, it allows the phages to target only the specific pathogen causing the disease; on the other hand, it means that the phage may need to be tailored to the patient in each specific case,” Dokland said.

The general structure of Andhra is a 20-faced, roundish icosahedral capsid head that contains the viral genome. The capsid is attached to a short tail. The tail is largely responsible for binding to S. epidermidis and enzymatically breaking the cell wall. The viral DNA is injected into the bacterium through the tail. Segments of the tail include the portal from the capsid to the tail, and the stem, appendages, knob and tail tip.

The 11 different proteins that make up each virus particle are found in multiple copies that assemble together. For instance, the capsid is made of 235 copies each of two proteins, and the other nine virion proteins have copy numbers from two to 72. In total, the virion is made up of 645 protein pieces that include two copies of a 12th protein, whose structure was predicted using the protein structure prediction program AlphaFold.

The atomic models described by Dokland, Hatoum-Aslan, and co-first authors N’Toia C. Hawkins, Ph.D., and James L. Kizziah, Ph.D., UAB Department of Microbiology, show the structures for each protein — as described in molecular language like alpha-helix, beta-helix, beta-strand, beta-barrel or beta-prism. The researchers have described how each protein binds to other copies of that same protein type, such as to make up the hexameric and pentameric faces of the capsid, as well as how each protein interacts with adjacent different protein types.

Electron microscopes use a beam of accelerated electrons to illuminate an object, providing much higher resolution than a light microscope. Cryo-electron microscopy adds the element of super-cold temperatures, making it particularly useful for near-atomic structure resolution of larger proteins, membrane proteins or lipid-containing samples like membrane-bound receptors, and complexes of several biomolecules together.

In the past eight years, new electron detectors have created a tremendous jump in resolution for cryo-electron microscopy over normal electron microscopy. Key elements of this so-called “resolution revolution” for cryo-electron microscopy are:

• Flash-freezing aqueous samples in liquid ethane cooled to below -256 degrees F. Instead of ice crystals that disrupt samples and scatter the electron beam, the water freezes to a window-like “vitreous ice.”
• The sample is kept at super-cold temperatures in the microscope, and a low dose of electrons is used to avoid damage to the proteins.
• Extremely fast direct electron detectors are able to count individual atoms at hundreds of frames per second, allowing sample movement to be corrected on the fly.
• Advanced computing merges thousands of images to generate three-dimensional structures at high resolution. Graphics processing units are used to churn through terabytes of data.
• The microscope stage that holds the sample can also be tilted as images are taken, allowing construction of a three-dimensional tomographic image, similar to a CT scan at the hospital.

The analysis of Andhra virion structure by the UAB researchers started with 230,714 particle images. Molecular reconstruction of the capsid, tail, distal tail and tail tip started with 186,542, 159,489, 159,489 and 159,489 images, respectively. Resolution ranged from 3.50 to 4.90 angstroms.

Support for the study, “Structure and host specificity of Staphylococcus epidermidis bacteriophage Andhra,” came from National Institutes of Health phage therapy grant R21 AI156636.

The UAB Department of Microbiology is part of the Marnix E. Heersink School of Medicine.

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JOURNAL

Science Advances

DOI

10.1126/sciadv.ade0459 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Structure and host specificity of Staphylococcus epidermidis bacteriophage Andhra

Pitch-perfect: Study of World Cup’s turfgrass may help crops yield more from less

Experiments show grass’s resilience-building tricks work for corn, too

Peer-Reviewed Publication

UNIVERSITY OF NEBRASKA-LINCOLN

Grass is famously resilient. But Paspalum vaginatum, a species better known as seashore paspalum, can tolerate stresses diverse and deadly enough to rival camels and cactuses.

Salinity? It’s still worth its salt. Drought? Not thirsty. Heat? No sweat. Cold? It can chill.

How about 22 soccer players sprinting, kicking and sliding their way across it at the 2022 World Cup, all amid the desert climate of the Middle East? Game on.

A commercial variety of seashore paspalum has padded every pitch in Qatar. There, it’s withstood every steel-cleated footfall of Messi, Mbappé and Neymar, every sunbeaten day of temperatures creeping into the high 80s Fahrenheit.

Thanks to a new study led by the University of Nebraska–Lincoln, seashore paspalum may soon assist another goal: growing crops that yield more food with less of the fertilizer that imposes costs on farmers, ecosystems and drinking water.

Global application of fertilizers, especially the nitrogen and phosphorous essential to plant growth, has skyrocketed since the mid-20th century, around the time a teenage Pelé was leading Brazil to its first World Cup title. As it turns out, seashore paspalum doesn’t need much of those nutrients, either. That sets it apart from some of its surprisingly close relatives: corn and sorghum, among other grass crops.

After sequencing the full genetic blueprints of the hardy grass, a multi-institution research team has discovered the bag of tricks behind the plant’s fasting technique. What’s more, the researchers managed to recreate those tricks in corn seedlings, which responded by growing faster and larger than other, unmodified seedlings deprived of the nutrients.

“We finally are starting to understand just what makes this plant so resilient,” said James Schnable, one of the study’s authors and Charles O. Gardner Professor of Agronomy at Nebraska.

The species really began intriguing Schnable and his colleagues after an impressive showing at the Nebraska Innovation Greenhouse, where it seemed not to care that its caretakers were neglecting it.

“There was a period where no one remembered to water the paspalum plant for a couple of months,” Schnable said. “But the plant was completely fine. In fact, it usually grows so fast that it’ll try to invade the pots of neighboring plants, and the greenhouse manager has to yell at me or folks in my lab to come down and trim it.”

Guangchao Sun, a doctoral alumnus and former postdoc at Nebraska, took notice, too. He decided to put seashore paspalum’s resilience to the test with an experiment, growing it alongside corn and sorghum for several weeks under multiple conditions. When the corn and sorghum were denied nitrogen or phosphorous, their stunted development betrayed it. The seashore paspalum, meanwhile, continued “happily growing.”

Fortunately, the Schnable lab was also working with the Department of Energy’s Joint Genome Institute, the University of Georgia and the HudsonAlpha Institute for Biotechnology on mapping the species’ genome. Those strides cleared the way to studying seashore paspalum’s tolerance in greater detail.

Analyses of its genes and gene expression later revealed that the grass responds to a lack of nutrients by roughly doubling its production of a sugary molecule called trehalose. Though corn and sorghum naturally churn out some of that molecule, the team saw no change in its production among the two nutrient-starved crops.

While the finding suggested that trehalose was playing a central role in the plant’s resilience, Sun and the team pressed on for evidence that could meet a higher burden of proof. What if, they thought, we could increase trehalose in corn, then observe the results? But applying trehalose directly to the crop proved ineffective.

“So I thought about it in the opposite way,” said Sun, who now works as a bioinformatician at the Mayo Clinic. “If I cannot supply trehalose to the plants, what if I stopped its degradation in those plants?”

He turned to an antibiotic that can inhibit the enzyme responsible for degrading trehalose. The plan worked: Curbing the enzyme cranked up the trehalose levels in the corn. Within days, he noticed the crop growing more — regardless of whether it was nutrient-deprived. The results were so startling to Sun that he soon repeated the experiment multiple times. Each time, the corn responded the same way.

But the team had reason to suspect that the tolerance also relied on autophagy — what Schnable called “a recycling program” in plant cells that takes apart old or damaged proteins, then reassembles them into fresh, functioning ones. Eventually, the researchers developed a mutant of corn that lacked the ability to engage the final stage of that recycling. Even with a surplus of trehalose, the mutant failed to thrive when deprived of nitrogen or phosphorous, marking autophagy as an equally essential facet of the resilience.

“There are still other things to do,” Sun said, before the team resolves the complete picture of seashore paspalum’s world-class tolerance. He considers it only a matter of time, though, before researchers identify the genes that code for higher trehalose.

“And if you could (introduce) that genomic region into other elite corn varieties — say, some maize that has high yield but is really sensitive to nutrient stress — maybe now you get both a high yield and high resilience,” he said.

For now, Sun said he’s glad to bask in the team’s accomplishment. In true World Cup fashion, learning that the team’s study had been accepted for publication in Nature Communications brought on a few tears, a few hugs. And why not? Qualification for the 2022 World Cup may have kicked off in 2019, but the research team embarked on its project a year earlier.

“This was a long, long journey,” Sun said. “Honestly, it increased my resilience, too.”

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JOURNAL

Nature Communications

DOI

10.1038/s41467-022-35507-8