Culture

Organizations that use ad hoc groups or committees to make decisions might do better to crowdsource their decisions, says UC Riverside-led research.

The study found that people trust groups even though they are susceptible to manipulation and can make poor decisions. Information markets, in which people bet on potential outcomes, tend to make more accurate decisions, but people trust them less. Once people get used to using markets, however, they trust them more, making markets a useful decision-making tool for large organizations.

"Our key finding was that transparency and trust are why people prefer groups even though markets outperform them," said first author Boris Maciejovsky, an associate professor of management in UC Riverside's School of Business. "People are skeptical of algorithms. Markets will be used less until people get used to them."

The research raises additional questions for future research about the productivity of working from home during COVID-19 pandemic. The fact that people have less trust in computer-mediated markets than in face-to-face interactions might lead to a reduction in communication efficiency and thus potentially work performance while working remotely.

Information markets work like a game. People place bets on predicted outcomes in an online forum. Familiar types of prediction markets include those for the Oscars or elections. Markets, for example, often do better than exit polls at predicting the outcome of elections. Markets make accurate predictions by pooling and aggregating the diverse beliefs of many participants.

Groups and committees, by contrast, are typically smaller and therefore contain more homogenous knowledge and information. Groups are also easier to manipulate. Conflicts among members, misalignment of organizational and individual goals, and persuasive negotiation or voting can all lead to poor decisions.

In large companies or organizations that use information markets, all employees are typically given the same amount of money and place odds-based bets on the potential outcomes of a situation or strategy in an online forum that everyone can see. Markets receive truthful information by asking participants to "put their money where their mouth is," and do not require alignment of organizational and personal goals. People who bet on the winning outcome get paid, giving an incentive to participate in the market. As in any betting situation, both correct and incorrect decisions have financial consequences.

Given their decision-making success, Maciejovsky and co-author David Budescu, a psychology professor at Fordham University, wondered why information markets are not used more widely by large organizations, which usually prefer groups and committees.

The first experiment had college students select a candidate for a managerial position in either a face-to-face group or an online market. Each category had the same information about the candidate. Group participants were given various roles and financial incentives, which were manipulated by the researchers in different ways. Market participants were manipulated with various financial incentives. Control groups and markets were not manipulated.

The results showed that groups outperform markets when the members share incentives and interests. However, markets outperform groups when conflicts of interest exist among members. Interestingly, people overlooked or failed to notice the detrimental effect of conflict within groups and put more trust on groups than markets.

Participants in the next experiment were either asked to watch a video of three people discussing job candidates or to watch market trading on a screen. Half the participants in the video cohort were told about conflicts of interest some of the candidates had. The market cohort was told that they could infer the merits of the candidates by observing market activity. Afterward, all participants were asked to evaluate their group or market on a number of attributes including transparency, benevolence, efficiency, familiarity, fairness, integrity, and predictability. The results confirmed the findings of the first study: People perceive groups to be more transparent, fair, and honest than markets.

To find out why people trust groups in spite of the demonstrably bad effects of intragroup conflicts, the third experiment recruited people who worked for a large forecasting project that sometimes uses information markets to make predictions and sometimes relies on teams or individual predictions. The forecasters from this project participated in a replication of the second study described above. The results showed a halo effect--everyone trusted the institution with which they were most familiar, which was committees. However, the more experience people had using information markets, the more they trusted them.

"It's hard at first to trust abstract mechanisms like markets," Maciejovsky said. "But our research shows that markets are reliable and less susceptible to bias. Large organizations could benefit from using information markets."

The research also hints at an unexpected potential outcome of the COVID-19 pandemic, where working from home has made in-person meetings impossible.

"Perhaps as people become more comfortable making business decisions in an environment of decreased interpersonal contact and increased reliance on technology decision markets will be seen as less threatening and find wider use in American organizations," Maciejovsky said.

The chances of a commercial airliner crashing are vanishingly small -- and yet many people are uncomfortable flying. Vaccination for many common childhood diseases entail almost no risk -- but parents still worry. Human perception of probabilities -- especially very small and very large probabilities -- can be markedly distorted and these distortions can lead to potentially disastrous decisions.

But why we distort probability is unclear. While the question has been previously studied, there is no consensus on its causes.

A team of scientists from New York University and Peking University, using experimental research, has now concluded that our cognitive limitations lead to probability distortions and to subsequent errors in decision-making. The researchers have developed a model of human cognitive limitations and tested its predictions experimentally, as reported in the latest issue of the journal Proceedings of the National Academy of Sciences.

The team, which included New York University's Laurence Maloney as well as the University of Peking University's Hang Zhang, a professor, and Xiangjuan Ren, a post-doctoral fellow, initiated the analysis by examining the nature of distortions as a potential clue for explaining this phenomenon.

"Probability distortion limits human performance in many tasks, and we conjectured that the observed changes in probability distortion with task was a kind of partial compensation for human limitations," explains Maloney. "A marathon runner with a sprained ankle will not run as well as she might have with ankle intact, but the awkward, limping gait we observe could in fact be an optimal compensation for injury."

The key step in the model is the recoding of probabilities that depends on the range of probabilities in a task.

"Much like a variable magnification microscope, the brain can represent a wide range of probabilities, but not very accurately, or a narrow range at high precision," explains Maloney. "If, for example, a task involves reasoning about the probability of various causes of death, for example, then the probabilities are all very small (thankfully) and small differences are important. We can set the microscope to give us high resolution over a limited window of very small probabilities. In another task we might accept less precision in return for the ability to represent a much wider range of probabilities."

Zhang, Ren, and Maloney set out to test this model in two experiments, one in which subjects made typical economic decisions under risk (e.g. choosing between a 50:50 chance of $200 and the certainty of $70) and one involving judgements of relative frequency (the relative frequency of black and white dots appearing on a computer screen). The two experiments together tapped into the basic ways we use probability and frequency in everyday life. The researchers found that their model predicted human performance far better than any previous model.

They discovered that -- like the marathon runner -- people's limitations were costly but, subject to those limitations, we do as well as we possibly can.

With over 170,000 COVID-19 deaths to date, and 1,000 more each day, America's life expectancy may appear to be plummeting. But in estimating the magnitude of the pandemic, University of California, Berkeley, demographers have found that COVID-19 is likely to shorten the average U.S. lifespan in 2020 by only about a year.

Seeking to put current COVID-19 mortality rates into historic, demographic and economic perspective, UC Berkeley demographers Ronald Lee and Joshua Goldstein calculated the consequences of U.S. lives lost to COVID-19 in 2020 using two scenarios. One was based on a projection of 1 million deaths for the year, the other on the more likely projection of 250,000 deaths.

Their findings, published online last week in the Proceedings of the National Academy of Sciences journal, conclude that 1 million deaths in 2020 would cut three years off the average U.S. life expectancy, while 250,000 deaths would reduce lifespans by about a year.

That said, without the societal efforts that have occurred to lessen the impact of COVID-19, there could have been 2 million deaths projected by the end of 2020, a reduction of the average U.S. lifespan by five years, the researchers pointed out.

Their estimated drop in life expectancy is modest, in part, because 250,000 deaths is not a large increase on top of the 3 million non-COVID-19 deaths expected for 2020, and because older people, who typically have fewer remaining years of life than others do, represent the most COVID-19 fatalities, the study notes.

Still, while COVID-19 mortality rates remain lower than those of the 1918 Spanish flu pandemic, the coronavirus epidemic could be just as devastating as the longer-lasting HIV and opioid epidemics if mitigation efforts fail, the researchers said.

"The death toll of COVID-19 is a terrible thing, both for those who lose their lives and for their family, friends, colleagues and all whom their lives touched. Those are real people, not abstract statistics," said Lee, a UC Berkeley professor emeritus of demography and associate director of the campus's Center for the Economics and Demography of Aging.

"But the population perspective helps put this tragedy in a broader context. As we work to contain this epidemic, it is important to know that we have been through such mortality crises before," he added.

Goldstein's and Lee's measures are based on factors that include a current U.S. population of 330 million, age-specific death rates and the economic valuation of saved lives.

Among their other findings:

One million COVID-19 deaths in the U.S. in 2020 would be the equivalent of U.S. mortality levels in 1995, adding three years to each American's biological age, albeit temporarily.

The age gap (old versus young) for people dying from COVID-19 is marginally wider than during pre-pandemic times, while the male-female gap is slightly narrower. The researchers found similar death-by-age patterns across several countries.

The economic cost of lives lost to COVID-19 in the U.S. is in the trillions of dollars. According to standard government measures, the demographers estimated that the loss of 1 million lives in 2020 would amount to between $10.2 and $17.5 trillion, while the amount for 250,000 deaths would range from $1.5 to $2.5 trillion.

When UC Santa Barbara materials scientist Omar Saleh and graduate student Ian Morgan sought to understand the mechanical behaviors of disordered proteins in the lab, they expected that after being stretched, one particular model protein would snap back instantaneously, like a rubber band.

Instead, this disordered protein relaxed slowly, taking tens of minutes to relax into its original shape -- a behavior that defied expectations, and hinted at an inner structure that was long thought to exist, but has been difficult to prove.

"The speed of relaxation is important because it gives us some insight into the structural organization of the protein," said Morgan, the lead author in a paper published in Physical Review Letters. "This is important because the structural organization of a protein is usually related to its biological function."

While a protein with fixed 'folds' -- a well-defined three-dimensional structure -- is associated with its function, disordered proteins, with their unstable structures, derive their functions from their dynamics.

"More than 40% of human proteins are at least partially unfolded, and they are often linked to critical biological processes as well as debilitating diseases," Morgan said.

The slow relaxation is in fact a behavior typically reserved for folded proteins.

"In the 1980s it was discovered that folded proteins exhibit slow relaxations," Morgan said, in a behavior typical of glasses -- a class of materials that are neither truly liquid nor crystalline solid states, but can exhibit characteristics of either state.

"We have been studying folded proteins for a long time and have developed a lot of good tools for them, so it was quickly figured out that the slow relaxations could be explained by a mechanism by which 'frustrated' molecules trying to fit themselves in a small space," Morgan said -- a mechanism called "jamming." "This explanation helped us better understand the structure of folded proteins and explain glassy behavior in a lot of other systems."

However, the protein, which the researchers were trying to stretch by means of a device known as a magnetic tweezer, was a disordered protein. By definition, it wasn't trying to pack many molecules into a small space, so it shouldn't run into the jamming problem, Saleh said.

"So, when we observed slow relaxations, it either meant our definition of the protein was wrong or there had to be another mechanism," Morgan said.

Furthermore, by allowing the stretched protein to relax but stretching it again with less force before it had a chance to fully relax, the researchers found that the protein "remembered" its previous stretching -- initially lengthening, as expected with more force, but eventually slowly relaxing again lengthening as expected with less force, but then slowly relaxing over time. Conceptually, Morgan explained, the longer the protein is stretched the longer it takes to relax, hence it "remembers" how long it was pulled.

To explain these unexpected, glassy behaviors, the researchers drew inspiration from some rather mundane objects: crumpled paper and memory foam. Both structurally disordered systems, they exhibit a similar slow, logarithmic relaxation after being subjected to forces, and particularly in the case of the foam, a "memory" effect.

For the researchers the behaviors suggested that like memory foam and crumpled paper, the internal structure of the protein was not one of a single, fixed unit, but one of several, independent substructures of a range of strengths between strong and weak that respond to a range of forces exerted on the material along different lengths of time. For instance, strong structures may withstand a certain amount of strain before being pulled apart and be the first to relax, whereas weak structures will stretch with smaller forces and take longer to relax.

Based on this notion of multiple substructures and confirmed with experimental data, the researchers determined that the protein's logarithmic relaxation rate is inversely proportional to the stretching force.

"The stronger the stretching force applied to the disordered protein, the more the protein relaxed in the same amount of time," Saleh explained.

"Mechanical disordered systems with similar structural arrangements tend to be remarkably durable," Morgan said. "They also have different mechanical properties depending on how much you pull and compress them. This makes them very adaptable, depending on the magnitude and frequency of the force." Understanding the structure behind this ability to adapt could open the door to future dynamic materials, that, Morgan said, "just like your brain, helps them filter out unimportant information and makes them more efficient at storing repeated stimuli."

An international team of researchers led by the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL) has upgraded a key computer code for calculating forces acting on magnetically confined plasma in fusion energy experiments. The upgrade will be part of a suite of computational tools that will allow scientists to further improve the design of breakfast-cruller-shaped facilities known as stellarators. Together, the three codes in the suite could help scientists bring efficient fusion reactors closer to reality.

The revised software lets researchers more easily determine the boundary of plasma in stellarators. When used in concert with two other codes, the code could help find a stellarator configuration that improves the performance of the design. The two complementary codes determine the optimal location for the plasma in a stellarator vacuum chamber to maximize the efficiency of the fusion reactions, and determine the shape that the external electromagnets must have to hold the plasma in the proper position.

The revised software, called the "free-boundary stepped-pressure equilibrium code (SPEC)," is one of a set of tools scientists can use to tweak the performance of plasma to more easily create fusion energy. "We want to optimize both the plasma position and the magnetic coils to balance the force that makes the plasma expand while holding it in place," said Stuart Hudson, physicist, deputy head of the Theory Department at PPPL and lead author of the paper reporting the results in Plasma Physics and Controlled Fusion.

"That way we can create a stable plasma whose particles are more likely to fuse. The updated SPEC code enables us to know where the plasma will be for a given set of magnetic coils."

Fusion combines light elements in the form of plasma -- the hot, charged state of matter composed of free electrons and atomic nuclei -- and in the process generates massive amounts of energy in the sun and stars. Scientists are seeking to replicate fusion in devices on Earth for a virtually inexhaustible supply of safe and clean power to generate electricity.

Plasma stability is crucial for fusion. If plasma bounces around inside a stellarator, it can escape, cool, and tamp down the fusion reactions, in effect quenching the fusion fire. An earlier version of the code, also developed by Hudson, could only calculate how forces were affecting a plasma if the researchers already knew the plasma's location. Researchers, however, typically don't have that information. "That's one of the problems with plasmas," Hudson said. "They move all over the place."

The new version of the SPEC code helps solve the problem by allowing researchers to calculate the plasma's boundary without knowing its position beforehand. Used in coordination with a coil-design code called FOCUS and an optimization code called STELLOPT -- both of which were also developed at PPPL -- SPEC lets physicists simultaneously ensure that the plasma will have the best fusion performance and the magnets will not be too complicated to build. "There's no point optimizing the shape of the plasma and then later finding out that the magnets would be incredibly difficult to construct," Hudson said.

One challenge that Hudson and colleagues faced was verifying that each step of the code upgrade was done correctly. Their slow-and-steady approach was crucial to making sure that the code makes accurate calculations. "Let's say you are designing a component that will go on a rocket to the moon," Hudson said. "It's very important that that part works. So you test and test and test."

Updating any computer code calls for a number of interlocking steps:

First, scientists must translate a set of mathematical equations describing the plasma into a programming language that a computer can understand;

Next, scientists must determine the mathematical steps needed to solve the equations;

Finally, the scientists must verify that the code produces correct results, either by comparing the results with those produced by a code that has already been verified or using the code to solve simple equations whose answers are easy to check.

Hudson and colleagues performed the calculations with widely different methods. They used pencil and paper to determine the equations and solution steps, and powerful PPPL computers to verify the results. "We demonstrated that the code works," Hudson said. "Now it can be used to study current experiments and design new ones."

A new study published in BMJ Open found that opioid prescription rates for outpatient knee surgery vary widely across the country, but the strength of the average prescription in the United States is at a level that has been linked to an increased risk of overdose death.

While the nationwide rate at which patients - who had not already been taking opioids - received an opioid prescription after an arthroscopic knee surgery was found to be more than 70 percent across the United States between 2015 and 2019. The variation at the state level was stark, bottoming out at 40 percent in South Dakota and reaching 85 percent in Nebraska, the study showed. The strength of the typical prescription, though, was revealed to be high, equal to 50 milligrams of morphine per day, the level that the Centers for Disease Control and Prevention has identified as being the threshold for increased risk of opioid overdose death.

"We found massive levels of variation in the proportion of patients who are prescribed opioids between states, even after adjusting for nuances of the procedure and differences in patient characteristics," said the study's senior author, M. Kit Delgado, MD, an assistant professor of Emergency Medicine and Epidemiology in the Perelman School of Medicine at the University of Pennsylvania. "We've also seen that the average number of pills prescribed was extremely high for outpatient procedures of this type, particularly for patients who had not been taking opioids prior to surgery."

The latter is of increased concern because it is especially prone to contributing to the opioid epidemic. It has been shown that giving patients who have never been on opioids before a high-dosage prescription can be associated with a transition to long term opioid use, higher numbers of leftover pills, and even higher rates of overdose among family members. As such, the research team - which included lead author Benjamin Ukert, MD, then a post-doctoral researcher at Penn and now an assistant professor of Health Policy and Management at Texas A&M - chose arthroscopic knee surgery as the lens through which to examine this because arthroscopies are in the top three of most common outpatient procedures in the United States.

To gauge prescription rates, the researchers accessed a large, national database of insurance claims. They were able to identify nearly 100,000 patients who had arthroscopic knee surgery and had not used any opioid prescriptions in the six months before the surgery.

The team found that, nationwide, 72 percent of patients filled an opioid prescription within three days of their procedure. There was very little variation in the fill-rate between non-invasive (which might include the removal of torn cartilage) and invasive procedures (which requires work cutting or drilling into bone) such as ACL repair.

Significant differences in prescribing rates were found from state to state. High prescription rates (77 percent or above) extended across the Midwest into the Rocky Mountain region, from Ohio to Utah, and extended into Arizona and Washington state. Lower rates, below 70 percent, tended to be on either coast, but also includes the Dakotas, Texas, and other states. There was also wide variation in the number of tablets in each single prescription, ranging from 24 (in Vermont) to 45 (Oklahoma).

"Some factors that may contribute to state variation are policies, such as mandates to check prescription drug monitoring program data, which have shown to affect the opioid prescribing rate," Ukert said. "However, most state policies are aimed at patients with a history of opioid use, and our study focuses on patients who do not have that history. Thus, practice and organizational styles may be more important factors for this population."

While the prescription rate varied greatly, the average prescription translated to roughly 250 milligrams of morphine over a five-day period, above the CDC's threshold for risky opioid prescription. Approximately 25,000 of the patients studied, 36 percent, were receiving this dosage level or more.

With that in mind, a different study involving Delgado and another co-author of this study, Brian Sennett, MD, chief of Sports Medicine at Penn Medicine, is currently being conducted. Using automated text messages to directly check in with patients, it is examining how many opioid tablets they actually do take from their prescription after knee surgeries. So far, they're observing that most patients take less than 10 tablets, which jells with what's been found by other groups.

"These studies suggest that current prescribing patterns are still resulting in a significant number of opioid tablets in the community that could be misused and potentially diverted to others," Delgado said. "The data we've collected show that there's ample opportunity to reduce excessive prescribing for this common outpatient procedure."

Moving forward, both Ukert and Delgado feel there needs to be more definitive work done to nail down what is the right prescription to prevent pain but also protect against potential dependence and overdose.

"Given that most arthroscopies are not invasive, there seems to be room to reduce the prescribing rate and the strength of the prescription," Ukert said.

A new paper in The Economic Journal, published by Oxford University Press, develops a theory of how people's social network structure impacts productivity and earnings. While large and loosely connected networks lead to better access to information, smaller and tighter networks lead to more peer pressure. Information is relatively more beneficial in uncertain work environments while for peer pressure the opposite is the case.

Researchers here also document significant network difference by gender, showing that loose networks are more common for men, and tight networks are more common among women. Based on this fact, the theory provides a new rationale for why men self-select more frequently into occupations involving high-risk decisions, such as finance and research, while women prefer safer settings such as health and education.

Different types of social networks are associated with distinct advantages and disadvantages in the workplace. Loose connections grant greater access to information and are therefore especially valuable in an uncertain work environment with high but risky project returns. Those with looser social networks receive more information about the value of a project beforehand, allowing them to identify which projects are worth working hard on.

In turn, a tight network, where connections are interlinked and clustered, leads to a relatively better performance in stable workplaces, where information acquisition is not crucial. The reason is that workers with tighter networks face more peer pressure as failures lead to tension not only among partners on that specific project, but also throughout the entire group. So generally, workers with tight networks put more effort into projects to prevent failure.

Academic disciplines, requiring the design and completion of projects with a-priori unknown outcomes, are an example of an uncertain work environment that favors looser networks; and so are management positions, jobs in finance or in the arts and entertainment. The proposed theory argues that individuals with large and loose networks should outperform those with small and tight networks in those settings.

The authors uncover the new fact that men and women differ in the way they build their social networks. They examine data from the Digital Bibliographic Library Browser's computer science set (438,531 men and 146,829 women), email communications from Enron (1,628 women and 2,298 men), and AddHealth's friendship networks which is composed of information from roughly 140 US schools (73,244 students). On average, women had tighter, more interconnected networks with high clustering, while men were more likely to form larger networks with looser connections. The study thus found this trend throughout very different environments -- academia, private company and schools -- showing the pervasiveness of these gender disparities in network structures.

This study then shows that women perform poorly relative to men in high risk occupations and connects the differences in networking structures to their labour market outcomes. This suggests that networking differences across gender may be an overlooked source of wage differences, especially in high risk occupations.

"We were surprised to learn that men's and women's networks differ in these drastic ways, with the differences being robust across very distinct environments," said the paper's authors Ilse Lindenlaub and Anja Prummer. "We hope that our findings spark more research into the importance of network structure for labour market outcomes, not only but also to better understand gender gaps in the labour market.''

(Title: Stronger together in the microbiome: how gut microbes feed each other to overcome dietary deficiencies, change host behavior, and improve reproduction)

To study how the microbiome affects their host behavior, a group of researchers at the Champalimaud Centre for the Unknown, in Lisbon - Portugal, used the fruit fly combined with high-tech tools to show that two gut bacteria establish a metabolic cross-feeding that enables them to grow in diets that lack the nutrients that are essential for their growth and to allow them to change host decision making and reproduction. Results reveal a mechanism through which the right combination of bacteria can lead to microbiome resiliency to dietary perturbations and changes in brain function.

A balanced intake of essential amino acids is crucial to ensure the well-being and health of all animals. The essential amino acids are the building blocks of proteins but they also influence how much offspring animals produce, and what animals decide to eat. Intriguingly, researchers at the Champalimaud Centre for the Unknown had previously shown that the microbiome plays an important role in dictating how amino acids affect the brain. What was most puzzling was that bacteria could only affect the decisions of the animal when they were present in specific combinations. It is widely known that the microbiome often contains many different species of bacteria but why different types of bacteria are needed to influence brain function and alter host physiology remains a mystery. This is the puzzle Carlos Ribeiro and his team at the Champalimaud Centre for the Unknown set out to tackle: . "To study how bacteria affect their host physiology is a daunting task in organisms with very complex microbiomes. This is where the fly and its less complex microbiome emerges as a powerful tool. It allows us to precisely dissect the mechanisms used by the microbiota to change the host's feeding decisions.", points out Sílvia Henriques, post-doctoral researcher and author of this study published today (August 25th) in the journal Nature Communications.

In the laboratory led by Carlos Ribeiro, principal investigator and senior author of this study, it was previously found that flies deprived of single essential amino acids develop a strong appetite for protein rich foods. However, in flies that were associated with two bacteria that are very abundant in the microbiome (Acetobacter pomorum and Lactobacillus plantarum) their preference for protein was drastically reduced and they prefered to eat sugar. "Interestingly, the association of flies with any of these bacteria alone could not reduce yeast appetite. Thus, in this new study our main focus was to understand why these two particular bacteria need to be present to change the feeding behaviour of the fly." says Ribeiro.

Work from several groups working on the microbiome, including the Ribeiro Lab, has shown that it is typically necessary for a community of bacteria, rather than isolated bacteria, to produce an effect on the host behaviour - and this was most likely due to specific substances bacteria produce, so called metabolites. Therefore the team set out to measure the metabolic interactions established between the bacteria within the microbiome and to map how specific bacteria and their metabolites affect the animal.

To tackle these, the authors runned a series of elegant experiments. To follow the feeding choices of the flies, researchers took advantage of a sensor developed in the lab - the flyPAD - and used it to measure with great detail the feeding pattern of individual flies. Then they used bacterial mutants to understand the impact of specific functions of the bacterial cells in the behavior of the host. And at last with collaborators at the University of Glasgow, they have also used a sophisticated technique called 'Isotope-resolved metabolomics' that enabled them to track the metabolites that were exchanged between the two different bacteria.

"We found that the two bacteria exchange metabolites and that this cross-feeding (syntrophy) enables them to grow and act on the animal even if diets lack the nutrients that are essential for them. Specifically, we now understand that Lactobacillus strains produce lactate which is used by the Acetobacter strains to synthetize amino acids and other metabolites. These are then used by the Lactobacillus strain which cannot synthetize them to continue to produce lactate. Furthermore, these bacterial amino acids are very likely used by the animal for egg production. But most importantly, we now understand that the lactate is also used by the Acetobacter bacteria to change the behaviour of the fly." explains Darshan Dhakan, post-doctoral researcher and author of this study.

By establishing this cross-feeding relation, the bacterial community becomes resilient to drastic dietary changes enabling their growth in the intestines of animals that ingest diets that lack nutrients that are essential to their survival. Ribeiro adds, "It is well established that our diet affects both the microbiome and our brain. What makes it complicated is the microbiome then in turn affects how diet affects us and what animals decide to eat. This makes it a very complex puzzle to solve. But by combining the right technologies with the right experimental system we can get at the heart of the mechanisms by which the microbiome interacts with our diet to affect our brain and our body. Importantly we show that the right associations of bacteria can make the microbiome resilient to dietary perturbations explaining why some animals and people might be more sensitive to the nutrient content of food than others. It is also a beautiful example of how nature establishes circular economies where nothing gets wasted and everybody gains."

In conclusion, this study emerges as an important example of how model organisms can be used to disentangle the influence of diet on the microbiome and to understand the individual contributions of gut bacterial species on brain function and behaviour. "The methodologies that were used in this study will allow us to identify all the metabolic interactions established amongst bacteria and will allow us to understand the precise mechanisms responsible for altering what animals decide to eat and brain function. Those insights can then be used to guide the search for similar mechanisms in animals with much more complex microbiomes, including in humans.", concludes Ribeiro.

UNIVERSITY PARK, Pa. -- Rainfall and temperature drive agricultural activity, which, in turn, influences patterns of measles outbreaks in the West African nation of Niger, according to an international team of researchers. The findings may be useful for improving vaccine coverage for seasonally mobile populations within Niger and other countries.

"Measles is a major cause of child mortality in sub-Saharan Africa, responsible for about 62,000 deaths in the region in 2017," said Alexandre Blake, graduate student in biology, Penn State. "Yet, current immunization strategies achieve low coverage, in part, because they were designed for higher-income countries where children are vaccinated prior to attending school, instead of for highly mobile populations where the median infection age is below school age."

The researchers analyzed weekly reported measles cases at the district level in Niger from 1995 to 2004, as well as weekly cumulative rainfall and average temperature data from the National Oceanic and Atmospheric Administration. Next, they used wavelet analysis, a mathematical tool for uncovering temporal patterns hidden in large amounts of data, and regression, a statistical tool, to investigate the associations between the measles cases and the environmental data. Their findings will appear on July 26) in the Journal of the Royal Society Interface.

The team discovered a strong and consistent annual pattern of measles outbreaks that was associated with rainfall. Specifically, they found that the rainy season was associated with a lower risk of measles case reporting, whereas measles cases were higher during the dry season.

"The timing of the beginning of the measles season is consistent with a phase of annual agricultural labor migrations, when people move from rural areas to urban areas," said Blake. "Vaccination strategies that target migrating populations at this point in the season could be very powerful to break the annual pattern of outbreaks."

The researchers also observed a second weaker and more inconsistent pattern of outbreaks occurring every 2-3 years.

"This second outbreak pattern tells us that other mechanisms are at play," said Nita Bharti, assistant professor of biology. "So even if we could vaccinate everybody before the annual agricultural migration event, there would still be measles cases that are related to other factors."

Blake noted that some of those factors could be inequalities in access to care and movement between adjacent countries, such as Nigeria, where vaccine coverage is also low.

"Niger and Northern Nigeria share languages, culture and economic activities, and as a result, there is a lot of human movement across the border," he said. "But they do not have synchronous measles vaccination efforts, which likely permits the reintroduction of the virus on both sides."

The team concluded that targeting seasonally mobile populations for immunizations could reduce the strong seasonal pattern of outbreaks in Niger and across similar settings.

"Human health and the environment are often stitched together with human behavior," said Bharti. "Understanding the nature of those relationships in sub-Saharan Africa will provide valuable insights on how to tailor interventions in this setting."

Journal

Nature Machine Intelligence

DOI

10.1038/s42256-020-0203-4

Most adults with systemic lupus erythematosus (SLE) are not at increased risk of hospitalization from COVID-19 due to medications used to dampen their altered immune system, the cause of their disease. Nor are most people with more common types of arthritis, such as rheumatoid, psoriatic and spondyloarthritis, at greater risk of hospitalization from COVID-19, a pair of new reports shows.

SLE, known widely as lupus, along with common forms of arthritis, are autoimmune conditions caused by the immune system's mistaken attack on a person's own tissues, leading to inflammation in the joints, skin, kidneys, and other parts of the body. The majority of those affected by these diseases are women.

Although the new studies, led by NYU Grossman School of Medicine researchers, show that for some of those affected the use of steroid medications to reduce inflammation slightly increased the likelihood of needing hospital care, researchers say the results should be reassuring to patients overall.

Many people are taking steroids or other immunosuppressing medications, especially newer biologic drugs, to prevent their immune system's attack on their tissues. And the researchers say their patients report feeling added anxiety that their treatments make them more susceptible to the dangers of coronavirus infection.

In the first study, published recently in the journal Arthritis and Rheumatology, researchers closely monitored the health of 226 adult patients, mostly Black, Hispanic, and female, undergoing treatment at NYU Langone Health clinics or NYC Health + Hospitals Bellevue Hospital for mild to severe forms of lupus. All were surveyed by phone or email, or had their medical records checked between April 13 and June 1, when the pandemic peaked in the New York City region. Twenty-four were hospitalized out of 41 who were formally diagnosed with COVID-19, and four of them died. Another 42 had COVID-19-like symptoms but were not formally tested.

For the second study, published in the same journal, researchers monitored 103 mostly white women being treated at NYU Langone Health clinics between March 3 and May 4 for inflammatory arthritis, which unlike common osteoarthritis, does not primarily result from joint wear and tear. All tested positive for COVID-19 or had symptoms highly suggesting they were infected. Twenty-seven (26 percent) were hospitalized, with four deaths (4 percent).

Researchers say their latest study findings showed that lupus patients taking immune-suppressing medications, such as mycophenolate mofetil (Cellcept) and azathioprine (Imuran), had no greater risk of hospitalization (15 out of 24) than lupus patients not using the medications (nine of 17). Similarly, hospitalization rates for people with inflammatory arthritis (26 percent) and COVID-19 were also no greater than seen for all New Yorkers (25 percent, according to city figures).

Among the research team's other findings was that patients taking biologic drugs for arthritis, such as adalimubab (Humira) and etanercept (Enbrel), which are made from living cells, or the antiviral hydroxychloroquine, were at no greater or lesser risk of hospitalization than those not taking the drugs. However, those taking glucocorticoids, a type of steroid, even in mild doses, were upwards of 10 times more likely to be hospitalized than arthritis patients not using steroids. The researchers caution that although statistically significant, the study's small size may overestimate the actual risk.

"Our findings represent the largest of its kind for American patients with lupus or arthritis and COVID-19, and should reassure most patients, especially those on immunosuppressant therapy, that they are at no greater risk of having to be admitted to hospital from COVID-19 than other lupus or arthritis patients," says one of the studies' co-lead investigators, Ruth Fernandez-Ruiz, MD.

"People with lupus or inflammatory arthritis have the same risk factors for getting seriously ill from COVID-19 as people without these disorders," says Fernandez-Ruiz, a postdoctoral fellow in rheumatology in the Department of Medicine at NYU Langone.

These shared risk factors, she says, which overall more than double people's risk of hospitalization from COVID-19, are having multiple underlying health conditions, such as obesity, hypertension, and diabetes.

"Patients receiving therapy for lupus and inflammatory arthritis should not automatically stop taking their medications for fear that they would be worse off if they also caught the coronavirus," says another of the studies' co-lead investigators, Rebecca Haberman, MD. "Instead, rheumatology patients should consult with their medical provider about their overall risk factors for COVID-19 and make plans accordingly," says Haberman, a clinical instructor in rheumatology in the Department of Medicine at NYU Langone.

The use of antibiotics in people with COVID-19 could result in increased resistance to the drugs' benefits among the wider population, a new study suggests.

Patients hospitalised as a result of the virus are being given a combination of medications to prevent possible secondary bacterial infections.

However, research by the University of Plymouth and Royal Cornwall Hospital Trust suggests their increased use during the pandemic could be placing an additional burden on waste water treatment works.

Writing in the Journal of Antimicrobial Chemotherapy, scientists say this could lead to raised levels of antibiotics within the UK's rivers or coastal waters which may in turn result in an increase in antimicrobial resistance (AMR), where bacteria become resistant to the action of antibiotics.

This would be particularly acute in receiving waters from waste water treatment works serving large hospitals, or emergency 'Nightingale' hospitals, where there is a concentration of COVID-19 patients.

The findings are based on reports that up to 95% of COVID-19 inpatients are being prescribed antibiotics as part of their treatment, and concerns that such a large-scale drug administration could have wider environmental implications.

Sean Comber, Professor of Environmental Chemistry in Plymouth and the article's lead author, said: "COVID-19 has had an impact on almost every aspect of our lives. But this study shows its legacy could be felt long after the current pandemic has been brought under control. From our previous research, we know that significant quantities of commonly prescribed drugs do pass through treatment works and into our water courses. By developing a greater understanding of their effects, we can potentially inform future decisions on prescribing during pandemics, but also on the location of emergency hospitals and wider drug and waste management."

The COVID-19 guidance issued by the National Institute for Health and Care Excellence (NICE) suggests patients with COVID-19 should be treated with doxycycline and either amoxicillin or a combination of other medications if a bacterial infection is suspected, but to withhold or stop antibiotics if a bacterial infection is unlikely.

Neil Powell, Consultant Pharmacist at the Royal Cornwall Hospital said: "Common with other hospitalised patients in the UK, and other countries, the majority of our patients with COVID symptoms were prescribed antibiotics because it is very difficult to know whether a patient presenting with symptoms of COVID has an overlying bacterial infection or not. We did a lot of work to try and identify those patients who were unlikely to have a bacterial infection complicating their viral COVID infections in an attempt to reduce the amount of antibiotic exposure to our patients and consequently the environment."

This research combined patient numbers for UK emergency hospitals set up temporarily around the country with waste water treatment work capacity and available river water dilution serving the emergency hospital and associated town.

Using available environmental impact data and modelling tools developed by the UK water industry, it focussed on one UK emergency hospital - Harrogate, geared up to treat around 500 people - and showed the risks posed by doxycycline was low, assuming the hospital was at full capacity.

Tom Hutchinson, Professor of Environment and Health at the University and a co-author on the research, added: "This is a comprehensive environmental safety assessment which addresses potential risks to fish populations and the food webs they depend on. The data for amoxicillin indicated that while there was little threat of direct impacts on fish populations and other wildlife, there is a potential environmental concern for selection of AMR if at 100% capacity."

Amoxicillin is used to treat everything from pneumonia and throat infections to skin and ear infections.

Mathew Upton, Professor of Medical Microbiology at the University and a co-author on the research, added: "Antibiotics underpin all of modern medicine, but AMR is an issue that could impact millions of lives in the decades to come. Currently, the COVID-19 pandemic is causing immense suffering and loss of life across the globe, but AMR has been - and will remain - one of the most significant threats to global human health. We conducted this study so that we can begin to understand the wider impact of global pandemics on human health. It is clear that mass prescribing of antibiotics will lead to increased levels in the environment and we know this can select for resistant bacteria. Studies like this are essential so that we can plan how to guide antibiotic prescription in future pandemics."

Record drought and heat have some farmers worried about where and when crops can be grown in the future, even in California where unprecedented microclimate diversity creates ideal growing conditions for many of the most popular items in America's grocery stores. A third of the vegetables and two-thirds of fruits and nuts consumed by Americans are now grown on more than 76,000 farms across the state, yet 20 years from now certain California regions may simply become too hot and dry for continued production.

New research from Lawrence Berkeley National Laboratory (Berkeley Lab) shows that by the years 2045-2049 future temperatures will have more of an effect on when cool-season crops, such as broccoli and lettuce, can be grown than on where, while for warm-season crops (cantaloupe, tomatoes, carrots) the impact will be greater for where they can be grown versus when. The scientists describe pairing computer modeling with information about historic and ideal growing temperatures for five important California crops in their paper, "Projected temperature increases may require shifts in the growing season of cool-season crops and the growing locations of warm-season crops," which appeared in the journal Science of the Total Environment earlier this month.

"To ensure food security for California and the rest of the country, it's important to predict how future warming will affect California agriculture," said the paper's lead author Alison Marklein. "We need reliable information about how future climate conditions will impact our crops in order for the agricultural system to develop an adequate response to ensure food security. For instance, one major challenge when considering relocating crops is that growers have specialized knowledge of their land and crops. If crops can no longer be grown in their current locations, then the farmer has to either move to a new area or grow a different crop, which presents a practical and economic burden on the farmer."

Now a scientist at UC Riverside, Marklein had previously led the project while completing a postdoctoral fellowship at Berkeley Lab and collaborating with Peter Nico, a study co-author and staff scientist in Berkeley Lab's Earth and Environmental Sciences Area. Scientists from the U.S. Department of Agriculture and UC Davis also contributed. Funded by the University of California's Global Food Initiative, the research represents a significant research focus for Berkeley Lab: sustainable agriculture. Another current Berkeley Lab study applies machine learning to developing microbial amendments that could replenish soils depleted of nutrients like carbon and phosphorus.

Growing accustomed to climate extremes

In carrying out the study, the researchers first selected five annual crops that are produced more in California than any other state - lettuce, broccoli, carrots, tomatoes, and cantaloupe. These nutrient-dense crops contributed 64% of the state's cash value of vegetable and melon crops in 2016 and are essential to food security, as evidenced by their place among the top vegetables and fruits donated to four studied California food banks.

The team then obtained 15 years of air temperature data beginning in 1990 from locations across the state, as well as information about crop temperature thresholds - or maximum and minimum air temperatures beyond which crop failure occurs - and growing locations for each of the five crops going back seven years. They also considered a crop's optimal growing-season length: for example, broccoli requires four consecutive months of minimum 39 degrees Fahrenheit and maximum 95 degrees.

Setting out to compare how each crop would do across California under different possible climate scenarios, one hot-dry and another cool-wet, the researchers looked at how higher temperatures may affect the crops in their historical growing locations. Next, they identified possibilities to expand any crop to a more ideal growing location based on that crop's temperature threshold, looking at all areas where that crop has not been grown, even where land had not previously been used for agriculture.

Finally, the team calculated how much of the land historically used for growing each of the five crops can be maintained under future warming scenarios (hot-dry, cool-wet); how much of the land used would be untenable due to temperature rise; and how much land not formerly used for agriculture could potentially support each of the five crops in comparison to historical agricultural land where these crops have not yet been grown.

Tomatoes could face some growing pains

"We found differences in how warmer temperatures will affect the cool-season crops versus the warm-season crops," Marklein said. "For cool-season crops like broccoli and lettuce, it may be possible to extend their growing seasons. But it may become too warm to grow warm-season tomatoes where they have been historically farmed in summer, and may require moving them to milder climates warm enough for growing tomatoes under the new climate scenarios."

The team found that both cool-season crops, broccoli and lettuce, are currently grown nearer to their lower temperature thresholds during fall and spring. The climate models predict an increase in winter temperatures above the minimum temperature threshold for both crops, suggesting that by mid-century these crops could also be grown into winter, even in areas where they have not historically been grown.

The warmer temperatures in fall and spring suggest that tomatoes might benefit from a shift in growing season. But that could prove harder than it appears.

"Looking at the hot-dry future climate scenario, although temperatures in fall and spring are likely to increase as will summer temperatures, a shift in growing season isn't a viable solution because the summer temperatures are likely to exceed the critical temperatures for tomatoes," Marklein said. "Tomatoes need four consecutive months for their growing season, so the gap in the middle filled by summer makes this unfeasible."

Opportunities could crop up all over

While it's true that some of the crops studied, tomatoes especially, will lose areas where they have been traditionally farmed due to future warming, there could be some ways to mitigate these potential challenges. For example, because their analysis focused on air temperature rather than crop temperature, in practice irrigation may be able to reduce some negative heat effects.

In total, Marklein said this study gives agricultural planners a lot to think about. "This is really a first step in planning for future climate scenarios. This work could be used to help prioritize resources like cropland and water to maximize agricultural productivity and food security," she said. "It's critical to plan ahead for future warming scenarios, particularly in areas like California that feed the nation."

DALLAS - Aug. 25, 2020 - Breastfeeding secures delivery of sugar and fat for milk production by changing the insulin sensitivity of organs that supply or demand these nutrients, a new study led by UT Southwestern scientists suggests. The findings, published in this month's print issue of Diabetes, could explain how different tissues cooperate to start and maintain lactation and offer strategies to help improve breastfeeding success for mothers who have insufficient milk production.

Epidemiologic studies suggest that breastfeeding protects women from developing Type 2 diabetes, even decades after their children have been weaned. But how this benefit arises has been unclear, explains Maria A. Ramos-Roman, M.D., an associate professor of internal medicine in the division of endocrinology at UT Southwestern.

One hypothesis is that breastfeeding changes how the body uses insulin, the hormone that allows cells to take in glucose from the bloodstream. (Glucose is a type of sugar that powers cells.) Detailed metabolic studies have shown that although pregnancy reduces the body's sensitivity to insulin, lactation may restore insulin sensitivity to a pre-pregnancy state. But it is unclear how this process happens and how it affects highly insulin-sensitive organs, such as the liver or fat tissue.

To learn more, Ramos-Roman and her colleagues recruited 18 women who had recently given birth. Twelve of these women were either exclusively breastfeeding or giving their babies less than 6 ounces of formula per day. The remaining six were exclusively formula feeding.

At five weeks postpartum, each of these women came to UT Southwestern for a detailed medical exam to make sure they were healthy and could safely participate in other parts of the study. One week later, the volunteers returned for a second visit in which they underwent a hyperinsulinemic-euglycemic clamp, a test that quantifies insulin sensitivity. Although the test measures insulin sensitivity for the body overall, these women also received stable isotopes during the test - tracers that helped measure insulin sensitivity specifically for organs of interest, such as the liver, or fat. At a third visit by eight weeks postpartum, the study participants underwent a type of imaging called magnetic resonance spectroscopy that measured the amount of fat in their livers.

The researchers found that all of the women had low blood insulin concentrations characteristic of the postpartum period, regardless of how they were feeding their new babies. However, even at these low insulin levels, after a 12-hour fast, the lactating mothers produced 2.6-fold more glucose and released 2.3-fold more fatty acids from storage in their fat tissue - a process known as lipolysis - than that of the formula feeders. Both glucose production and lipolysis were suppressed in both groups when the researchers mimicked a "fed state" by delivering insulin through the clamp. But suppression of lipolysis was heightened by higher levels of prolactin - the hormone that stimulates milk production - in the lactating mothers, accompanied by lower levels of fatty acids in the blood and lower amounts of fat in their livers.

These results suggest that breastfeeding appears to increase insulin sensitivity in highly insulin-sensitive organs, Ramos-Roman explains. After a 12-hour fast, the liver and fat tissues of lactating mothers release more sugar and fat into the bloodstream than formula-feeding mothers; however, after food intake or under the conditions of a hyperinsulinemic-euglycemic clamp, lactating mothers respond to small increases in insulin levels by holding on to more stored fat than formula-feeding mothers. Both conditions maximize the nutrients available for making milk in breastfeeding women, providing a steady stream from either stored resources or food intake.

These changes in insulin levels and sensitivity might also provide the legacy benefit observed in epidemiologic studies in women who have breastfed, offering a buffer against insulin resistance even decades later, Ramos-Roman says. (These previous studies showed an association between intensity or duration of breastfeeding and a lower incidence of Type 2 diabetes in the mothers.)

In addition, she adds, better understanding of this process could help researchers find new ways to help encourage it in mothers who would like to breastfeed but are having problems with low milk supply - finding ways to stimulate insulin-sensitive tissues to supply more nutrients into or demand less nutrients from the bloodstream could boost milk production.

"Lactation is millions of years old, but we still have a long way to go before we understand all there is to learn," Ramos-Roman says. "If we know better how it happens in the body, we can help improve the health of women and children."

Painless magnetic stimulation of nerves that regulate muscles in the anus and rectum appears to improve their function and dramatically reduce episodes of fecal incontinence, a debilitating problem affecting about 10% of the population, investigators report.

They have early evidence that TNT, or translumbosacral neuromodulation therapy, is a promising, novel, safe, low-cost treatment for strengthening key nerves and reducing or even eliminating episodes of stool leakage, Medical College of Georgia investigators report in the American Journal of Gastroenterology.

"We have identified that nerve damage is an important mechanism in the pathogenesis of stool leakage, and we have identified a noninvasive and targeted treatment to correct the nerve damage and address this pervasive problem," says Dr. Satish S.C. Rao, director of neurogastroenterology/motility and the Digestive Health Clinical Research Center at the Medical College of Georgia at Augusta University.

"We found there was significant improvement in fecal incontinence across the board," says Rao, after six sessions of weekly TNT treatment to key nerves, "which told us something is happening with this treatment. There is an effect on nerve function which, in turn, is leading to improvement of symptoms."

The rectum is the connector between the colon and the anus, where stool exits, and the muscles directly involved in moving feces along then holding it in place until we are ready to go to the bathroom, have been a focal point for treating fecal incontinence. However current strategies are largely unsatisfactory for at least half of patients because they do not directly address the causes, including nerve dysfunction in the anus and rectum, the investigators say.

Rao and his team decided to take a step back and look at the function of the nerves controlling those muscles. He developed a relatively benign test, called TAMS, or translumbosacral anorectal magnetic stimulation, to look at nerve activity by placing a probe in the rectum and a coil on the back to deliver magnetic stimulation to nerves in the anus and rectum and watch the response. When they found that nerve function was an issue in 80-90% of patients they assessed, they began exploring a similar approach using external, repetitive magnetic stimulation to help heal those nerves.

This first study was in 33 participants, including 23 women, who tend to have more problems with fecal incontinence, and, who were an average of about 60 years old. Age also is a risk factor. They used the same four sites on the upper and lower back they used to test the function of the relevant lumbar and sacral nerves, which are about two inches below the skin, after some surface mapping to find an exact location in each individual.

Patients lie comfortably face down and the machine makes a steady 'tock, tock' sound. Treatment lasts 15 minutes to an hour depending on the frequency. The 15-minute version meant, for example, 15 stimulations per second, or 15 hertz, clearly the quickest but, surprisingly, not the most effective frequency for this purpose.

Rather, while all participants derived some benefit, it was those receiving the lowest frequency, one hertz, over an hour who benefited most.

The investigators defined responders as those with at least a 50% reduction in the number of episodes of stool leakage per week. The one-hertz group experienced about a 90% reduction in weekly episodes as well as significantly improved ability to sense a need to defecate and in their ability to hold more stool. Those in the one hertz and midrange five-hertz group also reported the most improvement in quality of life issues.

"We measured several parameters including their leakage events, we measured their nerve and muscle function, quality of life, all of those were measured," Rao says. Participants also kept stool diaries, with some reporting zero incontinence episodes following TNT.

"It's still in the early stage, but it's quite remarkable what we are seeing," he says.

Like the patients he sees in his practice, study participants had a variety of issues that likely contributed to their lack of fecal control including diabetes, back injuries, hysterectomies and bladder and hemorrhoid surgeries. Childbirth is a common cause of both fecal and urinary incontinence. One of the females in the study had never had a baby, 18 others had vaginal deliveries and three of those also had a C-section, and four others only had a C-section. Eleven of the women with a vaginal delivery had vaginal tears and six had a forceps-assisted delivery.

While they didn't selectively pick people with nerve damage for the study, the investigators again found that whatever the cause, those with significant stool leakage had problems with delayed and weakened nerve conduction compared to healthy controls.

TNT dramatically shortened the time it takes those nerves to activate the muscle by several important milliseconds, particularly in the one-hertz group, where the response time consistently returned to normal.

"We have always tended to blame the anal muscle as the problem," Rao says of key controls needed to keep stool contained until we are in the bathroom. But they also know from women who experience muscle tears during childbirth, which is common, that repairing the muscle does not guarantee the woman will not have problems with leakage, he says. Sometimes muscle repair works temporarily, but when you follow up five years later, about half are incontinent, and nearly 90% are incontinent in 10 years, he says. "Ideally you want to treat all the mechanisms that are not working. We have not really approached it like that," Rao says.

His team suspected their repeated stimulation of the nerves would induce their innate ability to adapt in response to a variety of stimulations, called neuroplasticity, a skill that exists in nerves throughout the brain and body that enables both learning as well as recovery from injury or disease. They had preliminary evidence of this including studies indicating that magnetic stimulation improves neuropathy and pain in a condition called levator ani syndrome, in which patients experience burning pain in the rectal or perianal region.

They suspected high frequency stimulation, like 15 hertz, already used in the brain to treat problems like depression and stroke recovery, would work best, which is why they were surprised to find that the relevant nerves in this case were most responsive to longer periods of low frequency 1 hertz. Rao surmises one reason may be that the nerves that help control defecation are not as active as typical brain cells, although laboratory studies are needed to confirm that theory, he says. He also wants to learn more about underlying mechanisms for how the nerve changes occur with magnetic stimulation and, along with colleague Dr. Amol Sharma, MCG gastroenterologist and a study coauthor, look at its potential in other gastrointestinal motility problems caused by conditions like Parkinson's disease and the stomach-paralyzing problem gastroparesis.

How long benefits of TNT hold, and how often follow-up sessions may be needed are already being pursued in a larger study of 132 participants now underway at MCG and AU Health System and Harvard University's Massachusetts General Hospital in Boston, on which Rao is also the project director and principal investigator.

Participants for the published study were recruited from MCG's adult teaching hospital, AU Medical Center, and from the University of Manchester's Manchester Academic Health Sciences Centre in the United Kingdom, under the supervision of Dr. Shaheen Hamdy, professor of neurogastroenterology, although all participants were ultimately enrolled at the Augusta facility.

They went through extensive screening to ensure there weren't other medical problems, like severe diarrhea or inflammatory bowel disease, that could contribute to their incontinence, as well as a host of other serious medical conditions. To qualify, individuals had to have a history of recurrent fecal incontinence for six months that did not respond to approaches like diet modifications and diarrhea medication, and a two-week diary that reported at least one episode of fecal incontinence per week. As part of the study, investigators performed several tests to assess nerve and muscle function, including Rao's TAMS test, at the start and finish of the trial. They also used TAMS to ensure the participant's nerves were responding to the stimulation.

The only reported side effect of TNT was some temporary tingling in the treatment area, probably prompted by rejuvenating nerves, Rao says. He notes penetrability of the magnetic stimulations can be problematic with obesity or in patients with significant scarring from problems like back injury and/or surgeries. He also notes poor nerve conduction likely is a factor in some patients with constipation.