Culture

BUFFALO, N.Y. - 3D printing is transforming everything from fashion and health care to transportation and toys. But this rapidly evolving technology, also known as additive manufacturing, can threaten national security and intellectual property rights.

To reduce illicit use of 3D printers, Zhanpeng Jin, PhD, associate professor in the Department of Computer Science and Engineering at the University at Buffalo, is developing a way to track the origin of 3D-printed items.

His concern was that, as long as people have the digital design for an item, which can be downloaded from the internet, sometimes as open-source material, people can print out anything they want, which can range from computer parts and toys to fully functional handguns and assault rifles.

"So, what would be the best way to protect our intellectual property from someone else printing the same design using their own printer?" says Jin. "We wanted to find something internal. What would be the inherent signatures printed by my own 3D printer instead of another 3D printer?"

3D printers build three-dimensional objects by adding successive layers of printing materials according to the digital design for a 3D model. Each 3D printer has an "extruder," which pushes the building material along. The extruder's hot end then melts the material, and places it on the print bed to build the model.

In a paper, "ThermoTag: A Hidden ID of 3D Printers for Fingerprinting and Watermarking," published in the journal IEEE Transactions on Information Forensics and Security, a research team led by Jin describes how each extruder's hot end has its own unique heating properties, which impact the precise way that the 3D model is constructed.

Those thermodynamic properties can be used to identify the specific extruder and, thus, the model of 3D printer, as uniquely as a human fingerprint, or, as Jin calls it, a "ThermoTag."

Jin compared the process to using a laptop to write a letter. Because software exists that can track keystrokes, an observer can see every step that went into the letter, including the writer's unique writing style. Similarly, because of the unique properties of each 3D printer's extruder, a researcher can examine the specific manner in which a 3D-printed object was made, and compare that to a database of various extruders until a match is made. From there, once the model printer is identified, the purchaser of said model can be tracked down if they had, say, used the printer to build an illegal assault rifle.

According to the research, Jin and his team discovered that, by examining and comparing the ThermoTag features of 45 different extruders of the same model, they were able to correctly identify the source printer with an accuracy rate of 92%.

"This ThermoTag will behave like the fingerprint of the 3D printer. When you print out a new product, you can use watermarking," Jin says, noting that watermarking can be used to invisibly embed such information as the printer's manufacturer, label and serial number in the product. "So that would make this watermark of this particular product unique."

It's possible, Jin says, that someone could replace their extruder to try to avoid detection. That's why it's important to create a database of these parts for comparison, he says.

BIRMINGHAM, Ala. - Treatment of an injured or diseased joint may require precise insertion of a syringe needle -- musculoskeletal sonography can help guide clinicians as they drain fluid from arthritic knees or inject corticosteroids into trigger fingers. However, there is a need for training simulators that allow practice on an inert model, before attempting treatment on a patient.

For ultrasound, such simulation trainers are called phantoms.

Researchers at the University of Alabama at Birmingham and University of South Carolina have now made a 3D-printed anatomical finger model, embedded in ballistic gelatin, as a low-cost ultrasound training phantom for procedural guidance of trigger finger injections. Though the finished product looks like a brick, the ultrasound image of the bones, ligament, tendons and the A1 annular pulley inside it appear anatomically and sonographically similar to images observed in a human finger, both pre- and post-injection. Ultrasound shows the anatomical landmarks as the needle is inserted.

This phantom cost less than $20, was easy to prepare, and mimics the human finger in anatomy and echogenic appearance. The striated appearance of the tendons was mimicked by a bundle of monofilament fishing line.

The A1 pulley is a sheath that holds the tendon that bends the finger close to the finger bone. Inflammation of the sheath can create trigger finger, where the bent finger becomes locked. The corticosteroid injection must be precisely placed inside the sheath to reduce inflammation.

The researchers found that the visual-spatial and tactile awareness required to inject the phantom under ultrasound guidance was similar to injecting human trigger fingers, say Alvin Lee Day, M.D., University of South Carolina School of Medicine, and David Resuehr, Ph.D., associate professor in the UAB Department of Cell, Developmental and Integrative Biology and leader of the research. They are unaware of any commercially available trigger finger models.

"Many universities have 3D printers available for use, which provides an accessible means of production," Resuehr said. "Additionally, all software, including computer-aided design, was open-source or free to use under educational licensing agreements."

"Because the only area of the phantom that could be punctured was the ballistic gelatin outer portion, the 3D-printed bones and soft tissue components remain intact," he said. "Repeated needle insertions and injections create faint needle tract tracings after several injections, and the use of a hair dryer resolves the needle tracts."

The usefulness of ultrasound guidance has been shown in two small studies, Resuehr says.

A prospective study showed that only 37 percent of patients treated without ultrasound guidance received all the injection within the sheath; 17 percent received no medication within the sheath. In contrast, 50 consecutive trigger fingers treated with ultrasound-guided A1 pulley corticosteroid injections showed complete resolution in 94 percent of fingers at six months.

Resuehr and colleagues have previous experience building phantoms. Two years ago, they created the first homemade ultrasound knee phantom -- a model that was also produced with computer-aided design and a 3D printer -- to let trainees practice synovial fluid aspiration.

Co-authors with Resuehr and Day for the finger phantom study, "An ultrasound phantom for stenosing flexor tenosynovitis," published in EMJ Radiology, are Joseph Gartrell Willis, James Barrett Harris and Jordan Austin George, UAB School of Medicine. Day holds a Registered in Musculoskeletal sonography certification.

This project was supported by the Department of Cell, Developmental and Integrative Biology.

Decades-old aerial photos of Yudong District, Datong City in Shanxi Province, Northern China have helped researchers in their search for a fault hidden underneath the city's buildings and cement roads, researchers said at the Seismological Society of America (SSA)'s 2021 Annual Meeting.

Analyzing these photos from the 1960s and 1970s allowed Junjie Ren and colleagues to reconstruct a digital elevation model along the Shuiyu fault, helping them identify the fault trace as it passes through Datong City.

Trenching along the revealed fault trace found evidence of five previously unknown earthquakes along the fault, ranging in age from 9930 years ago to 23,550 years ago, said Ren, a researcher at the National Institute of Natural Hazards, Ministry of Emergency Management of China.

"Our work is the first to determine the fault trace in the city area and find evidence of the past five surface-rupturing earthquakes in the latest Quaternary," he said.

"Given the elapsed time of about 10,000 years, the Shuiyu fault beneath the Yudong District will increase the risk of a large earthquake in the future," Ren added.

Previous mapping showed that the Shuiyu fault crossed the city, which is at the center of a basin bounded by several Holocene-age normal faults. But studies suggested the fault had not been active since 20,000 years ago, and landforms such as fault scarps that might have marked its extent had disappeared under rapid urbanization beginning in 2000.

"Generally, shallow seismic reflection imaging and drilling are used to explore the location of a potentially active fault beneath a city," Ren explained. "But these techniques are costly and time-consuming."

Aerial photos of the city from the 1960s and 1970s, however, revealed a much less densely populated and built area. Ren and his colleagues applied a technique called stereophotogrammetry to the images, using measurements from the photos to calculate the 3D coordinates of features on the landscape.

In this way, the scientists were able to recreate a digital elevation model of part of Datong City as it was before urbanization, making features like fault scarps visible again.

Ren recommends the technique for uncovering similar "invisible" potentially active faults in other densely populated and built urban areas. "A big earthquake beneath a big city will bring a massive loss to the economy and significant casualties," he said.

Concrete efforts to bring racial equity to the geosciences are receiving significant attention in the wake of new grassroots efforts and increased awareness of social justice issues in 2020, speakers said at the Seismological Society of America (SSA)'s 2021 Annual Meeting.

Last year's Black in Geoscience Week, for instance, began as a grassroots movement to increase representation and raise visibility among Black researchers, as well as to foster networks and connections across the world, said Louisa Brotherson, a leader of the Black in Geoscience group.

The need for community and awareness among Black geoscientists is critical, Brotherson said, especially in the face of severe underrepresentation in the field. In the United States, only 6% of geoscience doctoral degrees are awarded to students from underrepresented minorities, even as individuals in these groups make up 31% of the population. In the United Kingdom, Black students represent 1.6% of geology postgraduate researchers, compared to 3.8% of the 18 to 24 year-old-population in the country.

Brotherson, an experimental seismologist at the University of Liverpool, and her colleagues helped organize a variety of events for the week, held 6-12 September 2020, on social media channels and live on Zoom and YouTube. Each day focused on a different group within the geosciences broadly, including atmospheric and marine scientists, as well as the experiences of the global diaspora of Black scientists.

The week drew over 6.1 million Twitter impressions and a 3.2% engagement rate with tweets, and feedback was "overwhelmingly positive," Brotherson said. "And we are hoping that it has started longer-term changes in attitudes and further discussions."

The Black in Geoscience group is supporting new awareness campaigns and symposia by Black marine scientists and geographers, and hopes to reach out to black geoscientists working in industry as well.

Acknowledging the colonial roots of geoscience and encouraging more equal international research collaborations are among the "next big steps," Brotherson said.

"If you're planning on doing fieldwork, look for the local scientists who are already doing the work and get them on your papers," she urged. "Don't think of them as a sort of side note."

Brotherson said the week has generated essential discussions within her own university department. "It got them to re-think the way that they go about things and the way that they think about race in academia," she said, "and just being more empathetic about the people who are already there and what we can we do for people coming up."

At the SSA meeting, physicist Ben Fernando discussed how to identify barriers to inclusion and retention of underrepresented minorities in the geosciences based on a report he and others complied for his own Department of Earth Sciences at the University of Oxford.

The report offers specific recommendations to improve student and staff recruitment, inclusion, retention and academic experiences, with timelines and priorities attached to each recommendation.

The report brought to light "something that I think is quite difficult to talk about when there are so few people in the discipline to begin with, the importance of familial and cultural context," Fernando said.

For instance, "rather than think people from minority backgrounds don't hang out in the countryside and therefore don't go into the geosciences, we found some more fundamental reasons like the strained relationships that some of these communities have had with extractive industries in the past," he said.

One of the unexpected impacts of the report, Fernando said, is that its recommendations have been "helpful in making the department more pleasant for everyone."

Fernando cited the report's discussion of alcohol culture in the department, which tends to exclude those who do not drink for religious or cultural reasons. "There were older researchers, from what we might call more traditional backgrounds, who were like, 'actually, you know what, I think this is a problem too,'" he said, "and they would never have been able to say that if there hadn't been a forum where we were talking about it already."

The faculty has been supportive of the report recommendations, even though "by the head of the department's own admission, it was an uncomfortable experience for them at first, being faced with a list of more things we wanted them to do," Fernando said.

"The reason I think it's worked is that there was a list of suggestions, we clearly thought about how much time and effort they were going to take, and we told them specifically what they needed to do," he added.

Women who experience partner violence at a young age don't always show physical signs of abuse and don't always disclose -- or recognize -- the dangerous position they're in. A new study from Michigan State University is one of the first to examine multiple factors that influence young women's disclosure of partner violence that occurred during their first relationships, when they were just under 15 years old, on average.

"Physical abuse is widely understood as unhealthy, wrong and abusive, but sexual violence and coercive control are less understood and still pretty hidden, especially among young women," said Angie C. Kennedy, MSU associate professor of social work and lead author. "Raising awareness about these different types of partner violence is important, so survivors can label what they are experiencing, ideally early on during the relationship, share with someone and be met with nonjudgmental support."

The study was published in the Journal of Family Violence and includes co-authors Elizabeth Meier, a doctoral candidate in MSU's School of Social Work, and Kristen A. Prock, an assistant professor of social work at the University of Wisconsin-Whitewater.

The researchers interviewed a diverse group of young women between the ages of 18 and 24, all of whom had endured some form of partner violence with their first boyfriends. Overall, 91% experienced physical partner violence, 58% of which was severe; 91% experienced coercive control, which involves a partner having control over a survivor's life; and 50% experienced sexual partner violence, defined as rape or attempted rape.

Further, the interviews revealed four patterns of partner violence and disclosure:

1) Nearly 20% of women experienced both physical and coercive control that was severe. The coercive control included forced isolation from others, which made it very difficult to disclose, but they all eventually told someone and were able to escape the relationship.
2) Several women who were raped by their boyfriends had experienced a lot of abuse growing up, which led them to minimize the sexual violence. Additionally, some participants who had been raped noted they had been socialized to believe that forced sex was part of their role as a girlfriend. These factors resulted in limited or no disclosure.
3) More than 80% of the women reported feeling stigmatization such as shame or self-blame related to the partner violence, which was a barrier to them disclosing.
4) Only a few participants sought help from law enforcement. Those who sought help had experienced severe physical violence or coercive control, but not sexual violence. They also had a supportive friend or family member, or a personal connection to law enforcement, which aided in their disclosure.

"I was surprised by the severity of the partner violence many experienced, oftentimes at a young age. The partner rape was especially alarming," Kennedy said. "Some of these relationships can go on for years, and while the abuse stays secret, the suffering young women experience is immense."

Kennedy says that she is encouraged by survivors going public with their experiences and using the media to share their stories and hold their abusers accountable.

"Seeing people going public with their stories of partner violence -- especially recent examples of high-profile young women like FKA twigs and Evan Rachel Wood -- can help survivors make sense of their own experiences and lift the shame and self-blame they've been carrying," she said.

April 21, 2021 - Consuming a diet high in pro-inflammatory foods - including foods that contain refined carbohydrates and sugar as well as polyunsaturated fats - may be associated with increased odds of developing testosterone deficiency among men, suggests a study in The Journal of Urology®, Official Journal of the American Urological Association (AUA). The journal is published in the Lippincott portfolio by Wolters Kluwer.

The risk of testosterone deficiency is greatest in men who are obese and consume a refined diet that scores high on the dietary inflammatory index (DII), according to the new research by Qiu Shi, MD, Zhang Chichen, MD, and colleagues of West China Hospital, Sichuan University, Chengdu, Sichuan Province, China. "While these findings do not prove causation, they do support previous research suggesting a pro-inflammatory diet can contribute to testosterone deficiency, among other potentially debilitating health issues," Drs. Qiu and Zhang comment.

Does diet influence testosterone levels? New study discovers link

Testosterone is a male sex hormone that plays important roles in reproduction and sexual function. However, 20 to 50 percent of US men have testosterone deficiency - defined as a testosterone level less than 300 ng/dL (nanograms per deciliter). Symptoms of testosterone deficiency may include low libido, decreased energy, poor concentration and depression. Testosterone deficiency is also associated with chronic diseases, including cardiovascular disease and obesity.

Human and animal studies have linked testosterone deficiency with increased levels of inflammation in the body. Men with low testosterone have higher levels of pro-inflammatory cytokines: small proteins released by cells during injury, infection or in response to inflammatory factors in the environment. The DII has emerged as a tool for assessing the inflammatory potential of a person's diet, particularly in relation to other markers of health.

The researchers studied the association between the DII and testosterone deficiency in 4,151 men from the National Health and Nutrition Examination Survey, all of whom completed a 24-hour dietary interview and underwent sex hormone testing. Each participant's DII was calculated based on the dietary history interview.

Calculated DII scores ranged from ?5.05 (most anti-inflammatory) to +5.48 (most pro-inflammatory). Average total testosterone level was 410.42 ng/dL in men with the most pro-inflammatory diet versus 422.71 ng/dL in those with the most anti-inflammatory diet. Overall, about 26 percent of the men had testosterone deficiency.

For men with the most pro-inflammatory diet, the odds of testosterone deficiency were about 30 percent higher compared to men with the most anti-inflammatory diet. The associations remained significant after adjustment for other characteristics, including body mass index and smoking.

In a fully adjusted analysis, the risk of testosterone deficiency was greatest in men who were obese and had a higher DII. For this group, the odds of testosterone deficiency were nearly 60 percent higher compared to men with obesity who had a lower DII.

Drs. Qiu, Zhang, and coauthors note some important limitations of their study, including the fact that the DII was calculated based on a limited number of anti-inflammatory and pro-inflammatory food parameters.

"Our results suggest men who eat a pro-inflammatory diet, particularly those who are obese, are more likely to have testosterone deficiency," Drs. Qiu and Zhang comment. "Since men with obesity likely already experience chronic inflammation, physicians should be aware of contributing factors, like diet, that could likely worsen this inflammation and contribute to the risk of other health conditions, such as diabetes and heart disease."

Drs. Qiu and Zhang and colleagues call for further studies to verify the causal relationship between DII and testosterone deficiency. They also suggest that consuming a more anti-inflammatory diet "could be a feasible method to reduce the accumulated inflammatory burden, [potentially] leading to an increased testosterone level."

A national strategy to ensure that families have access to food could revolutionize Canada's farms, according to a new study from Simon Fraser University's Food Systems Lab. The study proposes implementing a "right to food" framework that would support the needed funding, infrastructure, and stability that can reduce losses of edible food at the farm, while creating better access to local foods for consumers.

The study, published in the journal Resources, Conservation and Recycling, looked at the reasons for on-farm losses of edible food. Approximately 14 per cent of the world's food is lost before it ever reaches store shelves. In Canada, 35.5 million metric tonnes of food are lost or wasted annually, costing the economy $49.5 billion.

With 32 per cent of this waste considered avoidable, Food Systems Lab research director Tammara Soma and her team, Rajiv Kozhikode and Rekha Krishnan from Beedie School of Business, interviewed 40 farmers and stakeholders in the food and agricultural industry to find out why some of this wasted food never even leaves the farm.

While the reasons for farm-level food waste varied greatly - from farmers overproducing to hedge against risks, to cancelled orders, weather disruptions and even produce being rejected because it is deemed "too ugly" to sell - the study identified policies governments could implement to provide stability for farmers.

The right to food approach would make local foods more accessible, stabilize prices, help farmers better plan, and connect farmers to alternative outlets and government-funded food procurement programs. This can ensure that perfectly good food goes to families instead of being left on the ground or composted.

"The right to food approach has the potential to ensure that access to food, especially for those who are marginalized, will not depend on the vagaries of donations and rejected produce," says Soma, an assistant professor at SFU's School of Resource and Environmental Management. "Re-orientating our values and regulatory structure to ensure that Canada lives up to its commitment to recognize food as a right could also benefit farmers. It would also reduce waste by challenging unfair trading practices, providing living wages and improve supply management."

Canada is already a signatory to the international human rights agreement and the International Covenant on Economic, Social and Cultural Rights, include includes the "right to food." However, Soma says Canada's implementation of the agreement is lacking. Non-market-based approaches, such as having farms provide directly to school food programs, could help Canada meet its commitment and help farmers reduce avoidable food waste.

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."