Culture

We've all heard the news stories of how what you eat can affect your microbiome. Changing your diet can shift your unique microbial fingerprint. This shift can cause a dramatic effect on your health. But what about the microbiome of the plants you eat? Scientists are beginning to see how shifts in plant microbiomes also impact plant health. Unlocking the factors in plant microbial assemblage can lead to innovative and sustainable solutions to increase yield and protect our crops.

In a new study published in the Phytobiomes Journal, "Influence of plant host and organ, management strategy, and spore traits on microbiome composition," Dr. Frances Trail and her research group are interested in three factors that might attribute to microbial assemblage: the age of the plant, the organ or tissue type, and the management strategy. They followed a 3-year crop rotation that included corn, wheat, and soybean planted in a single field. They looked at a total of 24 plots under 4 different management strategies (6 plots/strategy): till, no-till, reduced chemicals, and organic.

Many factors drive crop microbial assemblage. Many researchers have looked at organic management strategies and how they might provide more diversity compared to conventional ones. Scientists believe that plant genetics also play a role in assemblage as each plant has a unique microbial fingerprint. Researchers have also shown microbes have adapted to a particular niche within the plant. Stems and leaves have a different nutrient niche than belowground compartments. The microbial profile of a leaf is often less diverse and different than the soil. What makes Trail's research unique is it's one of the first studies to look at all these factors (management strategy, host genetics, and tissue type) in one study.

The lead author on the paper, Dr. Kristi Gdanetz, was surprised by what she found to be the most important factor for microbial assemblage. She said, "the influence of management practices was not as strong an effect as I expected. It appears host genetics and plant location are more important indicators of community composition." Their research found that growth stages and tissue all had distinct microbial communities, particularly with bacterial communities.

The soil is the major reservoir for bacterial inhabitants of the plant with a few bacteria being carried by insects. Several studies, including Trail's, have shown bacterial profiles are most diverse and abundant within the soil. Above-ground organs, like the stem and leaf, are less diverse and harbor fewer microbes. Many bacterial inhabitants can be traced back to the soil, which suggests that the plant grants some microbes access to its tissues or the microbes may trick the plant to let them in.

The fungal route to the plant is more complicated. The roots and soil do not appear to be a major source of plant-associated fungi. Dr. Trail's research found that the alpha diversity of fungal communities did not decline from below- to above-ground tissues. Many fungal species form spores that wind, insects, and even humans can transport from one plant to the next. One major finding is that the shape, size, and other traits of the spore influence the host's fungal community. Specific sport traits may drive fungal assemblage to a specific niche (stem, leaf roots) within the plant.

Trail says, "When I realized that I could tie spore traits with the microbiome data, I was very excited, because this adds important information for how fungal microbiomes assemble, and the assembly of bacterial microbiomes as well." This unique finding became a focus of their research.

As this research unfolds there are many directions for future applications in sustainable agriculture, food production, and microbiology. Already we know several roles microbes play in crop health, such as enhancing immunity and nutrient cycling. Interacting and competing microbes might mask these roles. Dr. Trail is the first to show spore phenotypes influence the plant microbiome. With this knowledge, researchers can better understand microbial assemblage and use this information to increase yield. The researchers hope this knowledge will help develop new products to enhance crop sustainability.

HERSHEY, Pa. -- Next time you make a salad, you might want to consider adding mushrooms to it. That's because higher mushroom consumption is associated with a lower risk of cancer, according to a new Penn State study, published on March 16 in Advances in Nutrition.

The systematic review and meta-analysis examined 17 cancer studies published from 1966 to 2020. Analyzing data from more than 19,500 cancer patients, researchers explored the relationship between mushroom consumption and cancer risk.

Mushrooms are rich in vitamins, nutrients and antioxidants. The team's findings show that these super foods may also help guard against cancer. Even though shiitake, oyster, maitake and king oyster mushrooms have higher amounts of the amino acid ergothioneine than white button, cremini and portabello mushrooms, the researchers found that people who incorporated any variety of mushrooms into their daily diets had a lower risk of cancer. According to the findings, individuals who ate 18 grams of mushrooms --or about 1/8 to 1/4 cup-- daily had a 45% lower risk of cancer compared to those who did not eat mushrooms.

"Mushrooms are the highest dietary source of ergothioneine, which is a unique and potent antioxidant and cellular protector," said Djibril M. Ba, a graduate student in epidemiology at Penn State College of Medicine. "Replenishing antioxidants in the body may help protect against oxidative stress and lower the risk of cancer."

When specific cancers were examined, the researchers noted the strongest associations for breast cancer as individuals who regularly ate mushrooms had a significantly lower risk of breast cancer. Ba explained that this could be because most of the studies did not include other forms of cancer. Moving forward, this research could be helpful in further exploring the protective effects that mushrooms have and helping to establish healthier diets that prevent cancer.

"Overall, these findings provide important evidence for the protective effects of mushrooms against cancer," said coauthor John Richie, a Penn State Cancer Institute researcher and professor of public health sciences and pharmacology. "Future studies are needed to better pinpoint the mechanisms involved and specific cancers that may be impacted."

Cisgender sexual minority men and transgender women are aware of pre-exposure prophylaxis (PrEP), a daily pill for HIV-negative people to prevent HIV infection, but few are currently taking it, according to researchers at Rutgers.

The study, published in the journal AIDS and Behavior, surveyed 202 young sexual minority men and transgender women - two high-priority populations for HIV prevention - to better understand why some were more likely than others to be taking PrEP.

According to the Centers for Disease Control and Prevention, sexual minority men are the community most impacted by HIV, making up 69 percent of all new diagnoses in 2018, and transgender populations are disproportionately affected by HIV and prevention challenges. While Black and Hispanic/Latinx populations are mostly likely to be newly diagnosed with HIV, PrEP users are more likely to be white.

The researchers, who are part of the Rutgers School of Public Health's Center for Health, Identity, Behavior and Prevention Studies (CHIBPS), found that while 98 percent of the study's participants were aware of PrEP, less than 25 percent were currently taking it.

"It was surprising that so few participants were using PrEP, but we were happy to see that there were no racial or ethnic disparities in who was using it," said study coauthor Caleb LoSchiavo, a doctoral candidate at the Rutgers School of Public Health. "I think the study results point to the effectiveness of local efforts to increase the use of PrEP for those who need it most."

While the study found unexpected equity in PrEP use, it also pointed to racial and ethnic differences in factors associated with its use. White participants' likelihood of using PrEP increased with age and decreased if they reported concerns about daily medication use. However, participants of color were more likely to take PrEP if they received information about the HIV prevention pill from a health care provider and if they had more positive beliefs about its use.

"Our study highlights the importance of clinicians in expanding the use of HIV prevention methods like PrEP among those who need it most, both through informing their patients about PrEP and through combating stigmatizing beliefs about PrEP use," said senior study author Perry N. Halkitis, dean of the Rutgers School of Public Health and director of CHIBPS.

The study underscores the importance of PrEP education in clinical settings, the researchers said.

"Positive public health messaging about PrEP must reframe risk, combat stigma and normalize preventive healthcare," LoSchiavo said.

Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and the University of Illinois Urbana-Champaign (UIUC) have developed a new mathematical model for predicting how epidemics such as COVID-19 spread. This model not only accounts for individuals’ varying biological susceptibility to infection but also their levels of social activity, which naturally change over time. Using their model, the team showed that a temporary state of collective immunity—which they termed “transient collective immunity”—emerged during the early, fast-paced stages of the epidemic. However, subsequent “waves,” or surges in the number of cases, are predicted to appear because of changing social behaviors due to pandemic fatigue or variations in imposed mitigations. Their results appeared online on April 8, 2021 in advance of publication in the Proceedings of the National Academy of Sciences.

The COVID-19 epidemic reached the United States in early 2020, rapidly spreading across several states by March. To mitigate the spread of the coronavirus, states issued stay-at-home orders, closed schools and businesses, and put in place mask mandates. In major cities like New York City and Chicago, the first wave ended in June. In the winter, a second wave broke out in both cities; indeed subsequent waves of COVID-19 have emerged throughout the world. Epidemics frequently show this common pattern of an initial wave that ends, only to be followed unexpectedly by subsequent waves, but it has been challenging to develop a detailed and quantitative understanding of this generic phenomenon.

Mathematical models of epidemics were first developed almost 100 years ago, but necessarily cannot perfectly capture reality. One of their flaws is failing to account for the structure of person-to-person contact networks, which serve as channels for the spread of infectious diseases.

“Classical epidemiological models tend to ignore the fact that a population is heterogenous, or different, on multiple levels, including physiologically and socially,” said lead author Alexei Tkachenko, a physicist in the Theory and Computation Group at the Center for Functional Nanomaterials (CFN), a DOE Office of Science User Facility at Brookhaven Lab. “We don’t all have the same susceptibility to infection because of factors such as age, preexisting health conditions, and genetics. Similarly, we don’t have the same level of activity in our social lives. We differ in the number of close contacts we have and in how often we interact with them throughout different seasons. Population heterogeneity—these individual differences in biological and social susceptibility—is particularly important because it lowers the herd immunity threshold.”

Herd immunity is the percentage of the population who must achieve immunity in order for an epidemic to end. “Herd immunity is a controversial topic,” said Sergei Maslov, a CFN user and professor and Bliss Faculty Scholar at UIUC, with faculty appointments in the Departments of Physics, Bioengineering, and at the Carl R. Woese Institute for Genomic Biology. “Since early on in the COVID-19 pandemic, there have been suggestions of reaching herd immunity quickly, thereby ending local transmission of the virus. However, our study shows that apparent collective immunity reached in this way will not last.”

According to Nigel Goldenfeld, Swanlund Professor of Physics at UIUC, and leader of the Biocomplexity Group at the Carl R. Woese Institute for Genomic Biology, the concept of herd immunity doesn’t apply in practice to COVID-19.“People’s social activity waxes and wanes, especially due to lockdowns or other mitigations. So, a wave of the epidemic can seem to die away due to mitigation measures when the susceptible or more social groups collectively have been infected—something we termed transient collective immunity. But once these measures are relaxed and people’s social networks are renewed, another wave can start, as we’ve seen with states and countries opening up too soon, thinking the worst was behind them.”

Ahmed Elbanna, a Donald Biggar Willett Faculty Fellow and professor of civil and environmental engineering at UIUC, noted, transient collective immunity has profound implications for public policy. “Mitigation measures, such as mask wearing and avoiding large gatherings, should continue until the true herd immunity threshold is achieved through vaccination,” said Elbanna. “We can’t outsmart this virus by forcing our way to herd immunity through widespread infection because the number of infected people and number hospitalized who may die would be too high.”

The nuts and bolts of predictive modelling

Over the past year, the Brookhaven-UIUC team has been carrying out various projects related to a broader COVID-19 modeling effort. Previously, they modeled how the epidemic would spread through Illinois and the UIUC campus, and how mitigation efforts would impact that spread. However, they were dissatisfied with the existing mathematical frameworks that assumed heterogeneity remains constant over time. For example, if someone is not socially active today, it would be assumed that they won’t be socially active tomorrow or in the weeks and months ahead. This assumption seemed unrealistic, and their work represents a first attempt to remedy this deficiency.

“Basic epidemiological models only have one characteristic time, called the generation interval or incubation period,” said Tkachenko. “It refers to the time when you can infect another person after becoming infected yourself. For COVID-19, it’s roughly five days. But that’s only one timescale. There are other timescales over which people change their social behavior.”

In this work, the team incorporated time variations in individual social activity into existing epidemiological models. Such models work by assigning each person a probability of how likely they are to become infected if exposed to the same environment (biological susceptibility) and how likely they are to infect others (social activity). A complicated multidimensional model is needed to describe each group of people with different susceptibilities to disease. They compressed this model into only three equations, developing a single parameter to capture biological and social sources of heterogeneity.

“We call this parameter the immunity factor, which tells you how much the reproduction number drops as susceptible individuals are removed from the population,” explained Maslov.

The reproduction number indicates how transmissible an infectious disease is. Specifically, the quantity refers to how many people one infected person will in turn infect. In classical epidemiology, the reproduction number is proportionate to the fraction of susceptible individuals; if the pool of susceptible individuals drops by 10 percent, so will the reproduction number. The immunity factor describes a stronger reduction in the reproduction number as the pool of susceptible individuals is depleted.

To estimate the social contribution to the immunity factor, the team leveraged previous studies in which scientists actively monitored people’s social behavior. They also looked at actual epidemic dynamics, determining the immunity factor most consistent with data on COVID-19-related hospitalizations, intensive care unit (ICU) admissions, and daily deaths in NYC and Chicago. The team were also able to extend their calculations to all 50 U.S. states, using earlier analyses generated by scientists at Imperial College, London.

At the city and state level, the reproduction number was reduced to a larger extent in locations severely impacted by COVID-19. For example, when the susceptible number dropped by 10 percent during the early, fast-paced epidemic in NYC and Chicago, the reproduction number fell by 40 to 50 percent—corresponding to an estimated immunity factor of four to five.

“That’s a fairly large immunity factor, but it’s not representative of lasting herd immunity,” said Tkachenko. “On a longer timescale, we estimate a much lower immunity factor of about two. The fact that a single wave stops doesn’t mean you’re safe. It can come back.”

This temporary state of immunity arises because population heterogeneity is not permanent. In other words, people change their social behavior over time. For instance, individuals who self-isolated during the first wave—staying home, not having visitors over, ordering groceries online—subsequently start relaxing their behaviors. Any increase in social activity means additional exposure risk. As shown in the figure, the outcome can be that there is a false impression that the epidemic is over, although there are more waves to come.

After calibrating the model using COVID-19 data from NYC and Chicago, the team forecast future spread in both cities based on the heterogeneity assumptions they had developed, focusing on social contributions.

“Generally, social contributions to heterogeneity have a stronger effect than biological contributions, which depend on the specific biological details of the disease and thus aren’t as universal or robust,” explained Tkachenko.

In follow-on work, the scientists are studying epidemic dynamics in more detail. For example, they are feeding statistics from “superspreader” events—gatherings where a single infected person causes a large outbreak among attendees—into the model. They are also applying their model to different regions across the country to explain overall epidemic dynamics from the end of lockdown to early March 2021.

“Our model can be seen as a universal patch that can be applied to conventional epidemiological models to easily account for heterogeneity,” said Tkachenko. “Predicting future waves will require additional considerations, such as geographic variabilities, seasonal effects, the emergence of new strains, and vaccination levels.”

DALLAS, April 21, 2021 -- A smartphone-based electrocardiogram (ECG) screening accurately detected previously unknown atrial fibrillation in American Indians, and more than half who were diagnosed with the irregular heart rhythm were younger than the recommended screening age of 65, according to new research published today in the Journal of the American Heart Association, an open access journal of the American Heart Association.

About one-third of ischemic strokes, those triggered by blood clots, are caused by atrial fibrillation, the most common heart rhythm disorder. Since many people don't have symptoms and are unaware of its presence, atrial fibrillation often goes undiagnosed. In some cases, a stroke is the first sign that a person has the disorder. American Indians are more at risk for atrial fibrillation than people in other racial and ethnic groups. As a population, American Indians also have substantially higher rates of obesity, diabetes and high blood pressure - all risk factors for atrial fibrillation.

"We know the risk of atrial fibrillation is high in people who are from racial and ethnic groups, especially among American Indians, so we wanted to see if we could identify silent atrial fibrillation," said lead study author Stavros Stavrakis, M.D., Ph.D., a cardiologist at the Heart Rhythm Institute of the University of Oklahoma Health Sciences Center and associate professor of medicine at the University of Oklahoma College of Medicine in Oklahoma City. "Systemic screening among American Indians has never been done before, and the true rate of atrial fibrillation in this population is unknown."

Researchers enrolled 1,019 American Indians, ages 50 and older, 63% female, who received care at one of four tribal primary care clinics in the Absentee Shawnee Tribal Health System in Oklahoma between January 2019 to June 2020, to examine the feasibility and effectiveness of atrial fibrillation screening using a mobile, smart device. Participants underwent a 30-second, single-lead ECG using the mobile device paired with a tablet or smartphone at the clinic. An ECG measures the electrical activity of the heart, which can identify abnormal heart rate and rhythm including atrial fibrillation. Researchers compared the ECG results of the screened participants to the results of a control group: 1,267 American Indian adults, ages 50 and older, who received care at the Absentee Shawnee Tribal System clinics during the same time period but did not receive the mobile-based ECG screening.

Their analysis comparing the two patient groups found:

Of the 1,019 participants who received the mobile-based ECG screening, atrial fibrillation was found in 15 patients (1.5%). In contrast, only four of the 1,267 (0.3%) patients in the control group (standard care, based on clinical symptoms alone) were diagnosed with atrial fibrillation.

About half of those diagnosed with atrial fibrillation by mobile-based ECG (eight of 15 patients) were younger than 65.

Patients diagnosed with atrial fibrillation by mobile device were slightly older than those who were not screened with a smart device and did not have the condition.

Of the 15 patients diagnosed with atrial fibrillation, 14 had a high risk of stroke, as measured by the CHADS2-VASc score (the standard measure to calculate stroke risk) and met the criteria for initiation of blood thinning medication according to current guidelines.

"Our study shows that we have a very simple and accurate method to screen and diagnose atrial fibrillation that is easy to implement at tribal clinics," Stavrakis said. "This widely-available, low-cost approach has real potential to improve health outcomes among American Indians."

American Indians develop cardiovascular diseases at earlier ages than the national average. More than one-third of deaths attributed to cardiovascular disease in American Indians occur before the age of 65, which is the recommended age to begin atrial fibrillation screening according to guidelines from the U.S. Preventive Services Task Force.

"In a targeted, high-risk population such as American Indians, our results showed screening at a younger age found many cases of atrial fibrillation that would have been missed following current age recommendations," Stavrakis said. "We have the potential to improve outcomes in this population by initiating early treatment."

A major limitation of the study is that it was not a randomized intervention. The next step will be to do a randomized, controlled trial to get more robust data, Stavrakis said.

This study's findings reinforce the American Heart Association's November 2020 Presidential Advisory, "Call to Action: Structural Racism as a Fundamental Driver of Health Disparities." The advisory details the Association's immediate and ongoing actions to accelerate social equity and health care and outcomes for all people.

People with atrial fibrillation are five times more likely to suffer stroke than those without atrial fibrillation. So it's vital to be familiar with stroke symptoms. Call 911 immediately if you notice one or more of these symptoms, even if the symptoms are temporary or seem to disappear.

Details:
Walking is a fundamental physical activity in humans. A research team at Toyohashi University of Technology, in collaboration with researchers at the University of Tokyo, has developed a virtual walking system for seated observers which allows them to experience walking without moving their limbs. A walking-avatar, in first-person and mirrored perspectives, enhanced illusory walking sensations by combining rhythmic foot vibrations to simulate footsteps. The "invisible" avatar, made of only hands and feet, also improved the illusion of walking. This system may provide virtual walking experience for people with walking disabilities. This study will be published in Frontiers in Virtual Reality on April 21st, 2021.

Various virtual reality (VR) walking systems have been developed. However, most of these require physical leg movements. Such systems are usually too large, heavy and complex to use at home, making it difficult for people with disabilities to operate them.

Researchers at Toyohashi University of Technology and the University of Tokyo have proposed a virtual walking system that does not require limb action for seated users. It comprises a head-mounted display (HMD) and four vibrators on which the observers position their feet.

A walking-avatar or virtual person was generated in the virtual environment, and the viewing direction of the virtual camera and the head of the avatar were linked to the real head motion of the user. The avatar was viewed from a first-person perspective and in mirrors placed in the virtual environment. When the avatar's foot struck the ground, the foot vibrations were applied rhythmically to the heel and forefoot of the user's foot. The combination of the walking-avatar and foot vibrations was the most effective way to induce walking sensation and telepresence.

The "invisible" avatar, made of only hands and feet, also improved the virtual walking experience compared to the no-avatar state.

However, when the avatar was presented away from and in front of the user without mirrors from a third-person perspective, the avatar did not improve the illusory walking sensation.

Development Background:
Project Assistant Professor Yusuke Matsuda said, "It may be abstruse that mirrors are placed at regular intervals in a virtual environment. However, it is important to make users feel as if the avatar is their own body. Walking people typically view a limited part of the avatar's body (such as their hands and insteps in the periphery) from a first-person perspective. Mirrors allow users to view the entire body from a first-person perspective." Junya Nakamura, a graduate student, said, "The hand-and-feet only avatar has been developed in the laboratory that I belong to, to induce illusory body ownership to an invisible body (Kondo et al., 2018). This method is easy to implement, requires low computing power, and can potentially minimize the conflict between the appearance of the physical and virtual body. Thus, in addition to the full-body avatars, I used hands-and-feet-only avatars in experiments."

Future Outlook:
The research team believes that a virtual walking system without limb movement will provide an enjoyable experience for people with walking disabilities and improve their quality of life (QOL) in the future. If the portability of the system can be improved, it can be used at home.

An analysis of published studies indicates that pharmacist-led efforts can reduce medication-related harms--such as cognitive impairment, falls, drug-drug interactions, and bacterial infections--in older adults in residential aged care facilities. The findings are published in the British Journal of Clinical Pharmacology.

In the analysis of 23 studies, investigators found several pharmacist-led interventions that reduce various medication-related harms in older people permanently living in residential aged care facilities.

The most frequent single-component pharmacist-led intervention involved performing medication reviews with patients and clinicians. Medication reviews and education programs for healthcare professionals were the most common components in multicomponent interventions.

Following a school shooting, the risk for additional school shootings in the same and neighboring states increases in the next year, according to an analysis published in Contemporary Economic Policy.

The analysis included information on U.S. school shootings between 1990 and 2017. The copycat effect revealed by the analysis indicates that the media should find a way to cover these events while minimizing the risk of provoking additional shootings.

"Studying copycat effects in state-level school shootings data helps us to better understand to what extent school shooters are influenced by prior shootings," said corresponding author Karsten Schweikert, PhD, of the University of Hohenheim, in Germany. "Our results can help to guide the response of authorities to school shooting incidents."

An article published in Geographical Research examines how the COVID-19 pandemic has impacted international higher education and the mobility of students around the globe, noting that universities face the urgent task of reimagining alternative futures for themselves.

While much hope is invested in vaccines, travel restrictions and health concerns may continue to hamper student mobility and encourage more remote learning. New study destinations, different modes of study, and partnerships with technology providers can be anticipated.

With these changes, regulatory and ethical oversight will be required. "Policymakers and university leaders must look beyond goals of revenue generation and education exports. A commitment to student learning and wellbeing is overdue," said corresponding author Ravinder Sidhu, PhD, of the University of Queensland, in Australia. "The pandemic has revealed the need for more sustainable, ethical, and socially just modes of global higher education."

Microplastics--small plastic pieces less than 5 millimeters in length--are ubiquitous in the environment, and they can have significant effects on wildlife. A new study published in Environmental Toxicology and Chemistry reveals that there are multiple impacts of different microplastics--with varying sizes, shapes, and chemical makeup--to the survival, growth, and development of larval fathead minnows, an important prey species in lakes and rivers in North America.

By demonstrating that microplastics are both physical and chemical stressors, the study supports the need for research that considers microplastics a multiple stressor rather than a single contaminant. Importantly, current test methods used in most microplastic studies do not sufficiently investigate the chemical dimension of microplastic pollution.

"The chemical cocktail that is associated with microplastics in the environment consists of additives from manufacturing and contaminants sorbed from the surrounding environment; however this dimension is often missing from toxicity testing, where pristine microplastics purchased from a manufacturer are often used," said corresponding author Kennedy Bucci, a PhD candidate at the University of Toronto. "Our research shows that the chemical cocktail is an important driver of effects, and suggests that a new framework for risk assessment that captures the multi-dimensionality of microplastic pollution may be necessary."

Kiwi are iconic birds that have been severely impacted by deforestation and predation from invasive mammals since the arrival of humans in New Zealand. The remaining kiwi can be split into 14 clusters that are now treated as separate conservation management units. A review published in Ibis examines the latest information on kiwi genetics to investigate the legitimacy for maintaining these differences.

Although studies indicate that kiwi differ genetically between areas, there is little understanding of the extent of local adaptations and breeding changes on populations. The work highlights the need for a more detailed understanding of the genetics of different species for wildlife conservation.

"Using kiwi as an example, we hope to convey that results from any genetic studies cannot be easily translated into genetic management policy. On the contrary, studies using informative markers and strategic sample regimes are required if the goal is diverse and long-term successful populations," said lead author Malin Undin, PhD, of Massey University, in New Zealand.

Despite virtual reality (VR) technology being more affordable than ever, developers have yet to achieve a sense of full immersion in a digital world. Among the greatest challenges is making the user feel as if they are walking.

Now, researchers from the Toyohashi University of Technology and The University of Tokyo in Japan have published a paper to the journal Frontiers in Virtual Reality describing a custom-built platform that aims to replicate the sensation of walking in VR, all while sitting motionlessly in a chair.

"Walking is a fundamental and fun activity for human in everyday life. Therefore, it is very worthwhile to provide a high-quality walking experience in a VR space," says Yusuke Matsuda.

Matsuda is a project assistant professor at the Department of Computer Science and Engineering at the Toyohashi University of Technology and a corresponding author of the paper.

"We believe that the general public is also very likely to be interested in this study that combines walking and VR experiences which has seen rapid growth in demand as a result of Covid-19," he adds.

How it works

The purpose of the study was to investigate whether a full-body or hands-and-feet-only walking avatar seen through either the first-person or third-person perspective can convey the sensation of walking in a virtual environment through optic flows and rhythmic foot vibrations.

When the participant moves their digital avatar, the platform syncs with these movements to "feel as if the hands-and-feet-only avatar is their own body", the researchers wrote.

40 participants were split evenly between both the first-person and third-person perspective experiments. What they saw in the virtual world and the head of their full-body avatar were linked to the user's actual head movements.

While sitting down on a stool, each participant was connected to 4 vibro-transducers made from aluminum springs and wood plates, each placed on their feet. When their avatar moved, the pads would vibrate to replicate movement.

To eliminate the sound of the vibration system, participants wore headphones emitting white noise. They then travelled down a virtual corridor which consisted of a textured floor and sidewalls made of wood, with mirrors regularly distributed on either side of their avatar's path.

VR mirrors

The researchers said that not being able to see their avatar had a significant impact on a person's perception of walking while sitting motionlessly. However, the inclusion of mirror reflections mitigated this.

"Our study showed that a walking avatar in a first-person perspective enhanced the sensation of walking," Matsuda said.

"The effects were observed not only when the full-body avatar was used, but also when only the hands and feet were presented without the hands-and-feet-only avatar."

The researchers noted participants felt no walking-like sensation when seeing the avatar from the third-person perspective.

The researchers said that from this perspective, both the full-body and hands-and-feet avatars "impaired the self-motion sensation and telepresence, irrespective of the foot vibrations in comparison to the no-avatar condition".

Easier than walking

Looking to the future, Matsuda and the rest of his team sees the concept - once further developed - as being a way to enhance VR users at home.

"We believe that low cost and miniaturization can be accomplished," Matsuda said. "The proposed device consists of 4 vibro-transducers and amplifiers. The configuration is relatively simple, inexpensive - between $300 and $500) - and compact."

In addition to gamers, the researchers see its potential among those who may live with mobility issues.

"One of the most important features of the walking device we proposed is that it gives tactile and visual stimuli to seated users," Matsuda said.

"Besides, for those without mobility issues, the proposed method is simply less fatiguing than moving the legs by oneself. Therefore, we will be able to easily experience virtual walking for a relatively long time."

Marine ecosystems are in the midst of a conservation crisis, with coral reefs in particular facing numerous challenges as a result of climate change. In an effort to better understand these environments and the threats they face, researchers collect huge image libraries of these underwater environments, using 3D imagery collected from divers and snorkelers, as well as 2D images collected from satellites. These approaches provide researchers with huge amounts of data, but to extract value from these libraries requires a method to quickly analyze for patterns or 'classifications'.

In a new study in Frontiers in Marine Science, researchers at NASA's Ames Research Center's Laboratory for Advanced Sensing automated this process through the use of an artificial intelligence tool called a convolutional neural network (CNN), as lead author Jarrett van den Bergh of the Bay Area Environmental Research Institute explains:

"Vast amounts of 3D coral reef imagery need to be classified so that we can get an idea of how coral reef ecosystems are faring over time. Making this classification process as efficient as possible drove us to look at automation with CNNs."

CNNs are an artificial intelligence model loosely based on biological neurons and brains that are used to analyze images and look for features, such as different coral species on a reef, or even fish swimming through an underwater scene, as well as where these features are in relation to everything else in the image. This layered depth is what makes CNNs such a good fit for analyzing complex images, such as coral reefs.

Jarrett van den Bergh explains, however, that using CNNs can also present additional challenges when classifying data: "CNNs require lots of training data to function correctly, so it was vital for us to build a large database of data that we could use to train the CNN on how to classify these complex 3D images of coral reefs."

To overcome this challenge, the researchers used a citizen science approach in the form of a video game called NeMO-Net, which harnesses the power of citizen scientists to generate training datasets. As players explore virtual underwater worlds, they can learn about and classify coral species, and their classification labels are then used to train NeMO-Net's CNN.

Mr van den Bergh also highlights the more rewarding aspects of the NeMO-Net project: "NeMO-Net collects data primarily, but it is also an educational tool that gives people a more intimate understanding of our coral reefs. To date the game has reached over 300 million people in the 7 months since release."

The researchers are hopeful that their work in developing the NeMO-Net video game and CNN will be valuable for other conservation and mapping projects, and further research into the potentials of machine learning should be explored:

"As our technology progresses, machine learning might be able to give us a good estimation of what our coral reefs will look like 2 or 5 years from now. This could be extremely useful for coral reef conservationists who want to see the impact of their work. We are only just beginning to see the impacts of machine learning in conservation."

Humans and animals have a preferred walking speed. This is, in part, influenced by the amount of energy required: they prefer to walk at the speed at which they use the lowest possible amount of energy. One of the ways to achieve this is using something called resonance.

You already know how it works: when you are on a swing, you can't just swing at any speed. If you want to do it properly, you have to get the timing right, and swing in the rhythm of the swing. In other words: you have to resonate with it. And when you're on a nice relaxing walk, the parts of your body resonate, too. Walking slightly slower doesn't require less energy: you notice that it's actually harder.

This works for animals that walk on four feet, and for two-legged animals like humans and ostriches. Pasha van Bijlert, student Human Movement Sciences at the Vrije Universiteit in Amsterdam (VU), applied the idea to an animal that walked differently from anything walking the earth right now: Tyrannosaurus rex. These carnivorous dinosaurs didn't just have two legs, they also had an enormous tail that helped them move around.

Like the bones in our necks, the bones in tails are held together by ligaments. "You could compare it with a suspension bridge", Van Bijlert explains. "A suspension bridge with a ton of muscle in it." Every step the tail swings up and down. That means that like the swing, it has a natural frequency at which it resonates.

To find out what that frequency is, Van Bijlert and his professors Anne Schulp (Naturalis/Utrecht University) and Knoek van Soest (VU) built a 3D model of Trix, the Tyrannosaurus rex on display at the Dutch National Museum of Natural History, Naturalis. They added digital muscles to the famous skeleton, and on this muscular model they could perform biomechanical analyses. From these, they derived the natural frequency and a prefered walking speed: 4.6 km/h (2.9 mph). So, when Trix was out on a stroll, she walked at roughly the same speed as you do. If you had a pet T. rex, you would have no problem walking it - in terms of speed, at least.

Van Bijlert, Van Soest and Schulp published their findings in the journal Royal Society Open Science this Wednesday. "There were already some studies investigating dinosaur walking speed, but they mostly looked at the legs and ignored the tail - which is what makes dinos so unique", Van Bijlert says. "They usually found much higher walking speeds. The one we calculated is lower, but it's similar to that of other animals."

Listening to music before going to be can improve sleep quality among older adults, according to an analysis of all relevant published clinical trials.

In the analysis, which is published in the Journal of the American Geriatrics Society, five randomized trials met the investigators' criteria. Older adults who listened to music experienced significantly better sleep quality than those who did not listen to music. Also, older adults who listened to sedative music experienced a greater improvement in sleep quality than those who listened to more rhythmic music. Furthermore, listening to music for longer than four weeks was especially effective at improving sleep quality.

"Music intervention is an effective strategy and is easy to administer by a caregiver or healthcare worker," the authors wrote. "Music therapy might be the first line of therapy to recommend in older adults with sleep disturbances, which would reduce the need for dependence on sedatives and sleeping medication."