Thursday, April 27, 2023

Researchers call for national governments to mandate real-time indoor air quality monitoring

Better ventilated indoor spaces protect against COVID-19 spread

TSINGHUA UNIVERSITY PRESS

In a response to the COVID-19 pandemic, a team of researchers has published an editorial calling for national governments to consider mandating real-time indoor air quality monitoring in at least all public buildings.

Their editorial is published in the journal Building Simulation on 25 April 2023.

The three-year-long COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has revealed that there is a global indoor-air crisis. Vaccination alone has not completely controlled the COVID-19 pandemic and the virus continues to threaten human health and life. Scientists now know most if not nearly all transmission occurs indoors in poorly ventilated spaces. The researchers note in their editorial that since more than 6.5 million people have been reported to die globally due to the SARS-CoV-2 infection and people continue to be infected, there is an urgent need to improve ventilation in buildings worldwide.

The researchers observe that while two years have passed since it was officially recognized that airborne transmission of SARS-CoV-2 spreads the virus and some efforts have been made, there have been no significant improvements in building ventilation. Some governments have taken steps toward addressing the issue. The U.S. government issued its “Clean Air in Buildings Challenge” in March 2022, and the Hong Kong SAR government set a policy that requires six air changes per hour in 20,000 dine-in restaurants in the city.

“In the absence of a worldwide effort to improve building ventilation, it is likely that poorly ventilated buildings will remain common, meaning that airborne transmission of SARS-CoV-2 will continue. Moreover, if another novel and highly contagious respiratory virus emerges in the future, another pandemic is likely to occur,” said Yuguo Li, a professor at The University of Hong Kong.

The researchers note that there are likely more than a billion indoor spaces in the world, and identifying those with poor ventilation remains a challenge. Understanding that SARS-CoV-2 is airborne is not enough—for effective improvement, technologies are needed to identify where ventilation is insufficient. They also note that any improvements in ventilation must also take into consideration the buildings’ energy efficiency. This is necessary because energy efficiency is needed to mitigate the effects of climate change.

The two key components of building energy performance are thermal performance and ventilation performance. Humans can detect thermal conditions by using a thermometer to measure the temperature. But even though humans can detect odors, they cannot sense or predict a building’s ventilation performance. So humans are not capable of detecting air pollutants, such as infection aerosols. This inability to detect most air pollutants contributes to the indoor air crisis, the researchers note.

The researchers suggest that without governments establishing mandatory requirements for building ventilation performance, building owners will unlikely choose to monitor their buildings’ ventilation performance. The researchers also note that monthly or annual data on building ventilation rates is not sufficient. Real-time hourly ventilation rates are needed to determine the ventilation performance of buildings. Taking into account the world’s current population of seven billion people, the researchers suggest there are likely more than one billion homes globally. Along with that number, there are hundreds of millions of other indoor spaces, such as office buildings and movie theaters. It is an unrealistic goal at present to attempt to conduct real-time hourly monitoring for all those indoor spaces.

Bringing the changes needed to improve building ventilation is highly challenging. If adequate ventilation data existed then a predictive tool could be used, at low cost, for many buildings. The Internet of Things technologies enable the collection of good quality real-time date in indoor spaces. Integrating predictive tools with Internet of Things, big data, and machine learning approaches would give scientists a way to assess the ventilation performance of buildings. “We remain optimistic that future innovation will result in advances in economic monitoring and predictive tools for determining ventilation performance in the billions of indoor spaces worldwide,” said Li.

The researchers who authored this editorial include Yuguo Li from the Department of Mechanical Engineering and the Faculty of Architecture, The University of Hong Kong; Pan Cheng, Ao Li, and Wei Jia from the Department of Mechanical Engineering, The University of Hong Kong; Li Liu from the School of Architecture, Tsinghua University; and Nan Zhang from the Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology.

The editorial was supported by an RGC collaborative research grant.

JOURNAL

Building Simulation

DOI

10.1007/s12273-023-1019-z

ARTICLE TITLE

Predicting building ventilation performance in the era of an indoor air crisis

ARTICLE PUBLICATION DATE

25-Apr-2023

The world’s first wood transistor

Electrical current modulation in wood electrochemical transistor

Peer-Reviewed Publication

LINKÖPING UNIVERSITY

Researchers at Linköping University and the KTH Royal Institute of Technology have developed the world’s first transistor made of wood. Their study, published in the journal PNAS, paves the way for further development of wood-based electronics and control of electronic plants.

Transistors, invented almost one hundred years ago, are considered by some to be an invention just as important to humanity as the telephone, the light bulb or the bicycle. Today, they are a crucial component in modern electronic devices, and are manufactured at nanoscale. A transistor regulates the current that passes through it and can also function as a power switch.

Researchers at Linköping University, together with colleagues from the KTH Royal Institute of Technology, have now developed the world’s first electrical transistor made of wood.

“We’ve come up with an unprecedented principle. Yes, the wood transistor is slow and bulky, but it does work, and has huge development potential,” says Isak Engquist, senior associate professor at the Laboratory for Organic Electronics at Linköping University.

In previous trials, transistors made of wood have been able to regulate ion transport only. And when the ions run out, the transistor stops functioning. The transistor developed by the Linköping researchers, however, can function continuously and regulate electricity flow without deteriorating.

The researchers used balsa wood to create their transistor, as the technology involved requires a grainless wood that is evenly structured throughout. They removed the lignin, leaving only long cellulose fibres with channels where the lignin had been.

These channels were then filled with a conductive plastic, or polymer, called PEDOT:PSS, resulting in an electrically conductive wood material.

The researchers used this to build the wood transistor and could show that it is able to regulate electric current and provide continuous function at a selected output level. It could also switch the power on and off, albeit with a certain delay – switching it off took about a second; on, about five seconds.

Possible applications could include regulating electronic plants, which is another strong research area at Linköping University. One advantage of the transistor channel being so large is that it could potentially tolerate a higher current than regular organic transistors, which could be important for certain future applications. But Isak Engquist wants to stress something:

“We didn’t create the wood transistor with any specific application in mind. We did it because we could. This is basic research, showing that it’s possible, and we hope it will inspire further research that can lead to applications in the future,” says Isak Engquist.

The study was financially supported by the Knut and Alice Wallenberg Foundation through the Wallenberg Wood Science Center.

JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2218380120

ARTICLE TITLE

Electrical current modulation in wood electrochemical transistor

ARTICLE PUBLICATION DATE

24-Apr-2023

As the California sea lion population got bigger, so did male sea lions

Unlike other marine mammals, male California sea lions have gotten bigger over the past 50 years as their population has grown

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SANTA CRUZ

Sea lion skulls — IMAGE: CALIFORNIA SEA LION SKULLS USED FOR THIS STUDY AT THE ORNITHOLOGY AND MAMMALOGY COLLECTION OF THE CALIFORNIA ACADEMY OF SCIENCES. view more
CREDIT: ANA VALENZUELA TORO

Animals tend to get smaller as their populations grow because of increased competition for food resources among members of the same species. That’s not what has happened with California sea lions, however, according to a new study led by scientists at UC Santa Cruz.

Published April 27 in Current Biology, the study found that male California sea lions have gotten bigger as the population grew over the past 50 years, while female body size has remained stable.

“It’s counterintuitive. You would expect that their body size would decrease as dietary resource competition intensified,” said coauthor Paul Koch, professor of Earth and planetary sciences at UCSC.

The number of California sea lions has increased dramatically since the Marine Mammal Protection Act was passed in 1972. In parts of their range, the sea lions may now be approaching the ecological “carrying capacity,” the largest number of animals an ecosystem can support.

In other marine mammal species, including northern fur seals, South American sea lions, and harbor seals, declines in adult body size have been observed as their population size increased, according to first author Ana Valenzuela-Toro. She led the study as a graduate student in ecology and evolutionary biology at UCSC, working with Koch and Daniel Costa, professor of ecology and evolutionary biology and director of the Institute of Marine Sciences at UCSC.

Valenzuela-Toro looked at the size and morphology of sea lion skulls collected between 1962 and 2008 in central California and now held at the California Academy of Sciences. She also analyzed bone samples for clues to changes in the animals’ diets. Stable isotopes of carbon and nitrogen in bone samples can yield information about where in the ocean the animals were foraging and what kinds of prey they were eating.

“We found that male California sea lions have expanded their ecological niche, which means they are now foraging on a more diversified group of prey and expanding the places where they are foraging," Valenzuela-Toro said. “Apparently they are now going farther north than they used to, which is consistent with observations reported by other researchers.”

By expanding the breadth of their diets, the sea lions have been able to get bigger even as their numbers increased. In theory, larger sea lions should be able to travel further, dive deeper, and handle larger prey. In addition, as their breeding sites became more crowded, increased competition between males during the breeding season may have favored larger males over time.

“Body size is very important in competition with other males to control territory at breeding sites. Being bigger also means they can fast longer and stay on the beach to defend their territory,” Valenzuela-Toro said.

Male and female California sea lions differ substantially in body size and foraging behavior. The males generally congregate in colonies only during the breeding season, after which they leave on long foraging trips. Females, meanwhile, stay in the colony to give birth and nurse their pups, so their foraging is restricted to areas near the colony.

“This creates different selection pressures on females and males,” Valenzuela-Toro said.

She noted that prey was abundant during the period covered in this study. That may not continue to be the case in the future as marine ecosystems respond to a changing climate.

“This has been a good period for sea lions, but if warm conditions become more frequent, we could see lower availability of their preferred prey, such as sardines and anchovies,” she said. “Then we might see their population size start to plateau or decrease, and we could even see body size start to decline.”

Costa noted that the study was only possible because of the 167 California sea lion skulls collected over 44 years and maintained at the California Academy of Sciences. “These results are important to help us understand how marine mammals are adapting as their habitat changes in response to a changing climate,” he said.

In addition to Valenzuela-Toro, Costa, and Koch, the coauthors of the paper include Rita Mehta at UC Santa Cruz and Nicholas Pyenson at the Smithsonian Institution’s National Museum of Natural History.

Male and female California sea lions differ substantially in body size and foraging behavior.

CREDIT

Illustration by Sarah Gutierrez

A male California sea lion at Año Nuevo Reserve.

CREDIT

Ana Valenzuela Toro

JOURNAL

Current Biology

DOI

10.1016/j.cub.2023.04.026

ARTICLE TITLE

Unexpected decadal density-dependent shifts in California sea lion size, morphology, and foraging niche

ARTICLE PUBLICATION DATE

27-Apr-2023

Male California sea lions are becoming bigger and better fighters as their population rebounds

Peer-Reviewed Publication

CELL PRESS

California sea lions resting at Año Nuevo Island. — IMAGE: A PHOTO OF CALIFORNIA SEA LIONS RESTING AT AÑO NUEVO ISLAND. view more
CREDIT: DANIEL COSTA

California sea lions have managed to maintain—and, in the case of males, increase—their average body size as their population grows and competition for food becomes fiercer. This is in contrast to other marine mammals, whose average body size tends to decrease as their numbers increase. Researchers report April 27 in the journal Current Biology that sexual selection was a strong driving force for males to grow bigger and to strengthen muscles in their neck and jaw that help them fight for mates. Both male and female sea lions evaded food shortages by diversifying their diets and, in some cases, foraging further from the shore.

“Body size reduction is not the universal response to population increase in marine predators,” says lead author Ana Valenzuela-Toro (@Avalenzuelatoro), a paleoecologist at the University of California Santa Cruz and the Smithsonian Institution. “California sea lions were very resilient over the decades that we sampled and were able to overcome increasing competition thanks to prey availability. They’re like the raccoons of the sea: they can consume almost everything, and they can compensate if something is lacking.”

While many marine mammal species have rebounded to some extent since the Marine Mammal Protection Act was passed in 1972, California sea lions are notable for the size and duration of their population increase: the number of breeding females, who have been most consistently counted, has more than tripled in the US since the 1970’s—from around 50,000 to nearly 170,000—and their population growth is only now beginning to plateau.

To explore how California sea lion ecology has changed as their population has grown, the researchers analyzed museum specimens of adult male and female California sea lions collected in central and northern California between 1962 and 2008. To estimate changes in body size, they compared the overall size of more than 300 sea lion skulls collected over the years. They also measured other skull features, such as the size of muscle attachment points, which allowed them to assess changes in sea lion neck flexibility and biting force.

The team additionally took tiny bone samples from some of the skulls and measured their stable carbon and nitrogen isotope composition, which allowed them to make inferences about where the sea lions were foraging and what they were consuming. “Carbon provides information about habitat use—whether they’re foraging along the coast or offshore—and nitrogen provides insights about the trophic level of their prey, for example if they’re consuming smaller or larger fish,” says Valenzuela-Toro.

Overall, the researchers found that male sea lions have increased in size, while female sea lion size has remained stable. This sex difference is probably due to the fact that size matters for male, but not female, mating success. “One male can breed with many females, and males in the breeding colony fight with each other to establish their territory,” says Valenzuela-Toro. “Bigger males are more competitive during physical fights, and they can go longer without eating, so they can stay and defend their territory for longer.”

Male sea lions also increased their biting force and neck flexibility over this same time period. “The neck muscles are really important because they allow them to move their head and neck more agilely, bite harder, and, eventually, win when they are fighting other males in the breeding colony,” says Valenzuela-Toro.

The isotopic analyses indicated that both male and female sea lions managed to meet their nutritional needs by diversifying their diet and feeding on a broader range of prey. Male sea lions also foraged further afield. “Over time, some male sea lions were foraging further north,” says Valenzuela-Toro. “This is consistent with some anecdotal records that they’ve even been seen in Alaska, where they were not known to go in the past.”

Female sea lions consistently had a more diverse diet compared to male sea lions. The authors suggest that this flexibility in food choice is what allowed females to maintain their average body size without foraging further away.

“They remain in a narrow zone around their breeding colony, but they still show a lot of flexibility in what they eat,” says Valenzuela-Toro. “We believe that skull morphology in the rostrum—which is related to the size and shape of the mouth—probably has something to do with this flexible foraging behavior. We found that the size and shape of the mouth of females is related to the size of the prey that they consume.”

However, this flexibility in diet can only take the sea lions so far, and the authors warn that the sea lions’ future may not be so rosy.

“All these dynamics occurred in an environment that was rich in prey: full of anchovies and sardines, two species that are super important for their diet,” says Valenzuela-Toro. “But over the last few years, the populations of these two fish have collapsed, so California sea lions are diversifying their diet to compensate, and apparently they are not doing so well.”

“As climate change progresses, prey availability of sardines and anchovies will decrease even more, and eventually we will have more permanent El Niño-like warming conditions, reducing the size and causing a poleward shift of these and other pelagic fishes,” she says. “It will be a really hostile environment for California sea lions, and eventually we expect that their population size will stop growing and actually decline.”

A photo of California sea lion skulls used for this study, taken at the Ornithology and Mammalogy Collection at the California Academy of Sciences.

CREDIT

Ana Valenzuela Toro

This research was supported by funding from the University of California Santa Cruz Division of Physical and Biological Sciences, the Graduate Student Association, and the Rebecca and Steve Sooy Graduate Fellowship; the Peter Buck Predoctoral Fellowship of the National Museum of Natural History, Smithsonian Institution; and ANID PCHA/Becas Chile.

Current Biology, Valenzuela-Toro et al. “Unexpected decadal density-dependent shifts in California sea lion size, morphology, and foraging niche” https://www.cell.com/current-biology/fulltext/S0960-9822(23)00474-8

Current Biology (@CurrentBiology), published by Cell Press, is a bimonthly journal that features papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. Visit: http://www.cell.com/current-biology. To receive Cell Press media alerts, contact press@cell.com.

JOURNAL

Current Biology

DOI

10.1016/j.cub.2023.04.026

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Unexpected decadal density-dependent shifts in California sea lion size, morphology, and foraging niche

ARTICLE PUBLICATION DATE

27-Apr-2023

Even as SARS-CoV-2 mutates, some human antibodies fight back

A 'cocktail' of human antibodies shows promise in fighting severe SARS-CoV-2 infections

Peer-Reviewed Publication

LA JOLLA INSTITUTE FOR IMMUNOLOGY

Antibodies against Omicron variants — IMAGE: ANTIBODIES 2A10 (YELLOW SHADES), 1H2 (BLUE SHADES), AND 1C3 WERE ISOLATED FROM A VACCINATED RESEARCH VOLUNTEER. THE LJI TEAM FOUND THESE ANTIBODIES CAN NEUTRALIZE MANY SARS-COV-2 VARIANTS BY BINDING TO VULNERABLE SITES ON THE VIRAL STRUCTURE (GREY). IMAGE FROM THE SAPHIRE LAB, LA JOLLA INSTITUTE FOR IMMUNOLOGY view more
CREDIT: SAPHIRE LAB, LA JOLLA INSTITUTE FOR IMMUNOLOGY

LA JOLLA, CA—An anonymous San Diego resident has become a fascinating example of how the human immune system fights SARS-CoV-2. In a new investigation, scientists from La Jolla Institute for Immunology (LJI) have shown how antibodies, collected from this clinical study volunteer, bind to the SARS-CoV-2 "Spike" protein to neutralize the virus.

Although studies have shown antibodies bound to Spike before, this new research reveals how the original Moderna SARS-CoV-2 vaccine could prompt the body to produce antibodies against the later Omicron variants of SARS-CoV-2. The researchers also capture highly detailed, 3D structures of three promising neutralizing antibodies bound to Spike.

This important work shows exactly where Spike is vulnerable to human antibodies—and how future vaccines and antibody therapeutics might exploit these weaknesses. In fact, studies in mice suggest some of these antibodies may help prevent severe cases of COVID-19.

“To blunt the next pandemic and protect people from seasonal re-emergence of this one, we need antibodies of the broadest possible capacity—ones that are not escaped," says LJI President and CEO Erica Ollmann Saphire, Ph.D., senior author of the new Cell Reports study. “We found those in a vaccinated San Diegan.”

"Studying that person’s immune response in detail uncovered antibodies that are still effective against many Omicron variants," adds LJI Instructor Kathryn Hastie, Ph.D., co-leader of the study and Director of the LJI Antibody Discovery Center. "We now have to figure out how to boost these antibodies that we want over others that are less effective."

Taking on viral variants

Throughout the pandemic, scientists at LJI have gathered blood samples here in San Diego, and from labs around the world, with the goal of understanding the roles of different immune cells in fighting SARS-CoV-2. [Learn more about LJI leadership of the Coronavirus Immunotherapy Consortium (CoVIC)]

Antibodies are among the immune system's most elite fighters. These molecules are made by B cells and each antibody has a specific structure meant to bind to a specific target on a pathogen. It's as if B cells see a bullseye on a pathogen and then go to work making their arrows.

For the new study, the antibodies came from a clinical studies volunteer who received two doses of the Moderna SARS-CoV-2 vaccine. The Moderna vaccine works by prompting the body to make the Spike protein—glimpses of the viral bullseye—so it can begin work on its antibodies and other weaponry against the real virus.

The samples from the study volunteer were collected in early 2021—before the emergence of Omicron. That means any antibodies made by the volunteer were a result of vaccination, rather than exposure to Omicron.

The SARS-CoV-2 Omicron variant emerged in late 2021 and spread quickly. Omicron stood out from other variants because it contained mutations that helped it evade immune cell protection. Many antibodies designed to fight earlier SARS-CoV-2 variants couldn't hit their mark on Omicron.

Finding winning antibodies

Luckily, not everyone produces the same types of antibodies. In fact, the composition of virus-fighting cells and antibodies varies wildly in each person. For the new study, the researchers began with a pool of antibodies from the San Diego volunteer. Like many people who received the first two Moderna vaccine shots, this individual produced a robust pool of antibodies capable of neutralizing the ancestral D614G variant of SARS-CoV-2.

As new viral variants of concern emerged, the researchers tested this pool to see how many antibodies could still bind to the mutated virus.

”We found that this pool of antibodies could also neutralize other variants, such as Delta and Omicron,” says Hastie.

They found that the subject maintained moderate to high levels of antibodies against Beta, Delta and Omicron lineages BA.1, BA.1.1 and BA.2. Among these surviving antibodies, the researchers uncovered five antibodies that actually decreased the infectivity of BA.1 by more than 85 percent.

The researchers then took these five remaining antibodies through another battery of tests. One antibody, called 1C3, showed promise in blocking part of the infection process (when the virus's receptor binding domain interacts with human protein ACE2) but only against BA.1 and BA.2 lineages. Another antibody, 1H2, could also neutralize some Omicron lineages, but did so in a different way than 1C3. Meanwhile, antibody 2A10 was reactive to all SARS-CoV-2 Omicron lineages tested, including those that are most common now: XBB and BQ1.

Mapping out antibody targets

The scientists went on to map out these vulnerabilities on Spike using a high-resolution imaging technique called cryo-electron microscopy. "We were really interested to see how these antibodies recognize the Spike protein and structure," says LJI Postdoctoral Fellow Xiaoying Yu, who co-led the new study with Hastie. "This structural work lets us see exactly how the antibodies interact with the protein and how they can neutralize the virus."

The imaging work revealed that two of the promising antibodies bind to the SARS-CoV-2 Spike by latching onto two parts of the protein at once. By capturing Spike in a sort of hug of death, these antibodies lock the viral structure in place to halt infection. This finding is consistent with another recent Cell Reports study from the Saphire Lab showing the importance of bivalent antibodies against SARS-CoV-2 variants.

Could these three promising antibodies be recreated in an antibody therapeutic to treat COVID-19? The results from a mouse model are encouraging. The LJI team found that each antibody by itself could indeed reduce the viral load in the lungs in mice infected with SARS CoV-2 BA.1 and BA.2.

Going forward, the researchers plan to run more human antibodies through this same pipeline at LJI—from antibody isolation to screening, structural analysis, and animal model experiments. "We can carry out the entire pipeline of antibody discovery now," says Yu. "This research will help us combat the variants we have right now and give us targets for future vaccine development and therapeutics."

Additional authors of the study, "Potent, omicron-neutralizing antibodies isolated from a patient vaccinated 6 months before omicron emergence," were Fernanda A. Sosa Batiz, Dawid Zyla, Stephanie S. Harkins, Chitra Hariharan, Hal Wasserman, Michelle A. Zandonatti, Robyn Miller, Erin Maule, Kenneth Kim, Kristen Valentine, and Sujan Shresta.

This research was supported by the National Institutes of Health (grant NIH U19 AI142790-02S1), the GHR Foundation, the Swiss National Science Foundation Early Postdoc Mobility Fellowship (P2EZP3_195680), a Postdoc Mobility Fellowship (P500PB_210992), and an American Association of Immunologists Career Reentry Fellowship.

DOI: 10.1016/j.celrep.2023.112421

JOURNAL

Cell Reports

DOI

10.1016/j.celrep.2023.112421

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Potent Omicron-neutralizing antibodies isolated from a patient vaccinated 6 months before Omicron emergence

COI STATEMENT

K.M.H, S.S.H., and E.O.S. have a patent pending for the antibodies described in this study.

Transparent labeling of training data may boost trust in artificial intelligence

Peer-Reviewed Publication

PENN STATE

UNIVERSITY PARK, Pa. — Showing users that visual data fed into artificial intelligence (AI) systems was labeled correctly might make people trust AI more, according to researchers. The findings also may pave the way to help scientists better measure the connection between labeling credibility, AI performance, and trust, the team added.

In a study, the researchers found that high-quality labeling of images led people to perceive that the training data was credible and they trusted the AI system more. However, when the system shows other signs of being biased, some aspects of their trust go down while others remain at a high level.

For AI systems to learn, they first must be trained using information that is often labeled by humans. However, most users never see how the data is labeled, leading to doubts about the accuracy and bias of those labels, according to S. Shyam Sundar, James P. Jimirro Professor of Media Effects in the Donald P. Bellisario College of Communications and co-director of the Media Effects Research Laboratory at Penn State.

“When we talk about trusting AI systems, we are talking about trusting the performance of AI and the AI's ability to reflect reality and truth,” said Sundar, who also is an affiliate of Penn State’s Institute for Computational and Data Sciences. “That can happen if and only if the AI has been trained on a good sample of data. Ultimately, a lot of the concern about trust in AI should really be a concern about us trusting the training data upon which that AI is built. Yet, it has been a challenge to convey the quality of training data to laypersons.”

According to the researchers, one way to convey that trustworthiness is to give users a glimpse of the labeling data.

“Often, the labeling process is not revealed to users, so we wondered what would happen if we disclosed training data information, especially accuracy of labeling,” said Chris (Cheng) Chen, assistant professor in communication and design, Elon University, and first author of the study. “We wanted to see whether that would shape people's perception of training data credibility and further influence their trust in the AI system.”

The researchers recruited a total of 430 participants for the online study. The participants were asked to interact with a prototype Emotion Reader AI website, which was introduced as a system designed to detect facial expressions in social media images. Researchers informed participants that the AI system had been trained on a dataset of almost 10,000 labeled facial images, with each image tagged as one of seven emotions — joy, sadness, anger, fear, surprise, disgust or neutral. The participants were also informed that more than 500 people had participated in data labeling for the dataset. However, the researchers had manipulated the labeling, so in one condition the labels accurately described the emotions, while in the other, half of the facial images were mislabeled.

To study AI system performance, researchers randomly assigned participants to one of three experimental conditions: no performance, biased performance and unbiased performance. In the biased and unbiased conditions, participants were shown examples of AI performance involving the classification of emotions expressed by two Black and two white individuals. In the biased performance condition, the AI system classified all images of white individuals with 100% accuracy and all images of Black individuals with 0% accuracy, demonstrating a strong racial bias in AI performance.

According to the researchers, the participants’ trust fell when they perceived that the system’s performance was biased. However, their emotional connection with the system and desire to use it in the future did not go down after seeing a biased performance.

Training data credibility

The researchers coined the term “training data credibility” to describe whether a user perceives training data as credible, trustworthy, reliable and dependable.

They suggest that developers and designers could measure trust in AI by creating new ways to assess user perception of training data credibility, such as letting users review a sample of the labeled data.

“It’s also ethically important for companies to show the users how the training data has been labeled, so that they can determine if it’s high-quality or low-quality labeling,” said Chen.

Sundar added that AI developers would need to devise creative ways to share training data information with users, but without burdening or misleading them.

“Companies are always concerned about creating an easy flow for the user, so that users continue to engage,” said Sundar, who also is director of the Penn State Center for Socially Responsible Artificial Intelligence, or CSRAI. “In calling for seamless ways to show labeling quality, we want interface designs that inform users and make them think rather than persuade them to blindly trust the AI system.”

The researchers presented their findings today (April 24) at the ACM CHI Conference on Human Factors in Computing Systems, and reported them in its proceedings, the premier publication for research on human-computer interaction.

DOI

10.1145/3544548.3580805

ARTICLE TITLE

Is this AI trained on Credible Data? The Effects of Labeling Quality and Performance Bias on User Trust

ARTICLE PUBLICATION DATE

19-Apr-2023

Gene that confers seed tolerance to salinity identified

Biotechnology could help farmers deal with inhospitable soils

Peer-Reviewed Publication

INSTITUTO GULBENKIAN DE CIENCIA

Gene that confers seed tolerance to salinity identified — IMAGE: EXPRESSION OF THE SCL30A GENE (IN BLUE) IN DEVELOPING ARABIDOPSIS THALIANA SEEDS. view more
CREDIT: © INÊS BARBOSA, IGC

Seeds only germinate when a series of internal and environmental needs are met. Otherwise, they get stuck in a state of dormancy. Researchers from the Instituto Gulbenkian de Ciência (IGC) led by Paula Duque just revealed a mechanism that allows plants to integrate environmental signals and decide whether they should initiate development. SCL30a is a gene behind this decision system.

The group’s interest in this gene came from gene expression studies in Arabidopsis thaliana, a model plant belonging to the cabbage and turnip family. The increased expression of SCL30a during germination made them suspect that it could define morphological and functional characteristics of seeds in response to stress.

To address this hypothesis, the researchers altered the expression of the SCL30a protein and assessed the seeds’ characteristics in a variety of settings. When they treated seeds lacking this protein with salt, these germinated less and later than normal seeds. By contrast, seeds overexpressing the protein germinated twice as fast, especially under adverse conditions.

The analyses the researchers carried out revealed that these outcomes stemmed from the inhibition of signals sent by abscisic acid (ABA), a hormone that restrains germination in stress conditions. By controlling the expression of genes induced by this hormone, the SCL30a protein reduces the plant’s sensitivity to high salinity, allowing seeds to germinate. “These findings are in line with accumulating evidence showing that regulation of gene expression by this class of proteins is crucial to control plant stress responses”, Tom Laloum, a postdoctoral researcher at the IGC and one of the first authors of the study, explains. The researchers also showed that this protein controls other aspects of plant development mediated by ABA, including seed size, which increased when SCL30a was overexpressed.

The principal investigator Paula Duque explains that these genetic functions “could be translated into crop species, resulting in larger seeds that germinate better under adverse environments”. This could solve limitations on crop productivity due to soil salinization, a problem that is expanding in different areas of the world, including Portugal.

JOURNAL

Plant Cell & Environment

DOI

10.1111/pce.14593

ARTICLE TITLE

The SCL30a SR protein regulates ABA-dependent seed traits and germination under stress

ARTICLE PUBLICATION DATE

25-Apr-2023

Deep impact: New diving suit could increase undersea range of Navy divers

Business Announcement

OFFICE OF NAVAL RESEARCH

IMAGE: A U.S. NAVY DIVER (CENTER) TESTS THE OFFICE OF NAVAL RESEARCH-SPONSORED DEEP SEA EXPEDITIONARY WITH NO DECOMPRESSION (DSEND) SYSTEM AT THE NAVY EXPERIMENTAL DIVING UNIT IN FLORIDA. DSEND INCLUDES A HARDENED YET LIGHTWEIGHT ATMOSPHERIC DIVE SUIT FEATURING ROTATING, DETACHABLE JOINTS ALLOWING FOR GREATER DEXTERITY, FLEXIBILITY AND MANEUVERABILITY. view more
CREDIT: (U.S. NAVY PHOTO BY RONNIE NEWSOME)

ARLINGTON, Va.—The lights above the water’s surface cast a ghostly glow on the bottom of the sprawling tank, as a U.S. Navy diver deftly swam through a sunken aircraft fuselage.

Wearing a special diving suit designed to protect against the crushing pressure of ocean depths, the diver found her target — a mannequin representing a human body. The exercise was part of a simulated crash recovery mission to test the capabilities of the Deep Sea Expeditionary with No Decompression (DSEND) system, which includes a hardened yet lightweight atmospheric dive suit featuring rotating, detachable joints allowing for greater dexterity, flexibility and maneuverability.

Sponsored by the Office of Naval Research (ONR) — in partnership with Naval Sea Systems Command (NAVSEA), Naval Undersea Warfare Center (NUWC) and Naval Surface Warfare Center (NSWC) Panama City — DSEND recently underwent demonstrations at NSWC Carderock Division in Maryland and at the Navy Experimental Diving Unit in Florida.

“DSEND is truly a game-changer because it’s a self-contained environment that keeps internal pressure steady, as a diver descends to depths with increasing external pressure,” said Dr. Sandra Chapman, a program officer in ONR’s Warfighter Performance Department. “It increases diver safety, allows them to expand the operational envelope and would eliminate lengthy decompression times.”

Navy diving missions include deep ocean salvage of vessels and aircraft, underwater rescues, explosive ordnance disposal, ship hull maintenance and recovery of sunken equipment.

The deeper divers descend, however, the greater the danger from increasing water pressure. In deep-water situations, Navy divers use a saturation system, or diving bell, that is pressurized with gas so the pressure inside the bell matches outside pressure.

The drawback is that, when returning to the surface, divers must ascend slowly and stop at intervals so they don’t suffer decompression sickness. This is a potentially lethal condition in which the inert gas dissolved in the blood and tissues by high pressure forms bubbles as pressure decreases. Although the time-consuming ascent safeguards divers, it limits the amount of hours they can spend at a site.

DSEND’s one-atmosphere environment presents a solution to this challenge. Equipped with a self-contained life support system, the DSEND suit encloses a diver in a stabilized pressure cocoon during the entire dive. The diver can work at great depths for many hours and ascend without the drawn-out process of decompression.

“Because DSEND maintains one consistent pressure atmosphere, the diver is never exposed to the negative physiological effects associated with deep diving, such as decompression sickness, cold and wet exposure,” said Paul McMurtrie, NAVSEA diving systems program manager. “A diver can work for long periods of time in deep water and rapidly return to the surface.”

Although constructed from hard, durable material, DSEND is lightweight and enables users to swim and walk on the bottom easily. This improves on atmospheric diving suits traditionally used by the Navy in the past, which were more rigid and powered by attached thrusters, making it difficult to move around.

The suit also is easier to don and remove, and can be adjusted to diver size. In addition, DSEND features joints, grippers and hand attachments made from novel materials that are strong, lightweight and mirror the natural movements of human joints, reducing diver fatigue.

“DSEND will allow divers to conduct harder missions by going deeper, executing faster and operating longer,” said Tom Hansen, a research engineer at NUWC Division Newport, “all while being protected by a sensorized suit of armor. It feels like we’re developing the futuristic smart armor you see in movies.”

During the Maryland and Florida demos, DSEND divers completed various exercises, including pulling a mannequin from an aircraft fuselage, rigging a piece of wreckage for salvage and traversing makeshift tunnels representing sunken vessels.

Within the next year, Chapman hopes to see DSEND undergo additional development, including at-sea demos in realistic operating environments.

Navy Master Chief Jericho Diego, a master diver and the senior enlisted leader at NUWC Division Keyport, said, “This system has the potential to be very advantageous to Navy divers. Eliminating the need for decompression increases safety, and the more flexible arm attachments allow us to retrieve targets and do our jobs more effectively.”