Leveraging the 5G network to wirelessly power IoT devices

Rotman lens-based 'rectenna' capable of millimeter-wave harvesting at 28-GHz with high efficiency from all directions for first time

GEORGIA INSTITUTE OF TECHNOLOGY

Research News

VIDEO: RESEARCHERS AT GEORGIA TECH'S ATHENA LAB DISCUSS AN INNOVATIVE WAY TO TAP INTO THE OVER-CAPACITY OF 5G NETWORKS, TURNING THEM INTO "A WIRELESS POWER GRID " FOR POWERING INTERNET OF THINGS... view more 

CREDIT: CHRISTOPHER MOORE

Researchers at the Georgia Institute of Technology have uncovered an innovative way to tap into the over-capacity of 5G networks, turning them into "a wireless power grid" for powering Internet of Things (IoT) devices that today need batteries to operate.

The Georgia Tech inventors have developed a flexible Rotman lens-based rectifying antenna (rectenna) system capable, for the first time, of millimeter-wave harvesting in the 28-GHz band. (The Rotman lens is key for beamforming networks and is frequently used in radar surveillance systems to see targets in multiple directions without physically moving the antenna system.)

But to harvest enough power to supply low-power devices at long ranges, large aperture antennas are required. The problem with large antennas is they have a narrowing field of view. This limitation prevents their operation if the antenna is widely dispersed from a 5G base station.

"We've solved the problem of only being able to look from one direction with a system that has a wide angle of coverage," said senior researcher Aline Eid in the ATHENA lab, established in Georgia Tech's School of Electrical and Computer Engineering to advance and develop novel technologies for electromagnetic, wireless, RF, millimeter-wave, and sub-terahertz applications.

The findings were reported in the Jan.12 issue of the journal Scientific Reports.

The FCC has authorized 5G to focalize power much more densely compared with previous generations of cellular networks. While today's 5G was built for high-bandwidth communication, the high-frequency network holds rich opportunity to "harvest" unused power that would otherwise be wasted.

CAPTION

A Georgia Tech ATHENA group member holds an inkjet-printed prototype of a mm-wave harvester. The researchers envision a future where IoT devices will be powered wirelessly over 5G networks.

CREDIT

Christopher Moore, Georgia Tech

Tapping Into 5G High-frequency Power

"With this innovation, we can have a large antenna, which works at higher frequencies and can receive power from any direction. It's direction-agnostic, which makes it a lot more practical," noted Jimmy Hester, senior lab advisor and the CTO and co-founder of Atheraxon, a Georgia Tech spinoff developing 5G radio-frequency identification (RFID) technology.

With the Georgia Tech solution, all the electromagnetic energy collected by the antenna arrays from one direction is combined and fed into a single rectifier, which maximizes its efficiency.

"People have attempted to do energy harvesting at high frequencies like 24 or 35 Gigahertz before," Eid said, but such antennas only worked if they had line of sight to the 5G base station; there was no way to increase their angle of coverage until now.

Operating just like an optical lens, the Rotman lens provides six fields of view simultaneously in a pattern shaped like a spider. Tuning the shape of the lens results in a structure with one angle of curvature on the beam-port side and another on the antenna side. This enables the structure to map a set of selected radiation directions to an associated set of beam-ports. The lens is then used as an intermediate component between the receiving antennas and the rectifiers for 5G energy harvesting.

This novel approach addresses the tradeoff between rectenna angular coverage and turn-on sensitivity with a structure that merges unique radio frequency (RF) and direct current (DC) combination techniques, thereby enabling a system with both high gain and large beamwidth.

In demonstrations, Georgia Tech's technology achieved a 21-fold increase in harvested power compared with a referenced counterpart, while maintaining identical angular coverage.

This robust system may open the door for new passive, long-range, mm-wave 5G-powered RFID for wearable and ubiquitous IoT applications. The researchers used inhouse additive manufacturing to print the palm-sized mm-wave harvesters on a multitude of everyday flexible and rigid substrates. Providing 3D and inkjet printing options will make the system more affordable and accessible to a broad range of users, platforms, frequencies, and applications.

Replacing Batteries With Over-the-air Charging

"The fact is 5G is going to be everywhere, especially in urban areas. You can replace millions, or tens of millions, of batteries of wireless sensors, especially for smart city and smart agricultural applications," said Emmanouil (Manos) Tentzeris, Ken Byers Professor in Flexible Electronics in the School of Electrical and Computer Engineering.

Tentzeris predicts that power as a service will be the next big application for the telecom industry, just as data overtook voice services as a major revenue producer.

The research team is most excited by the prospect of service providers embracing this technology to offer power on demand "over the air," eliminating the need for batteries.

"I've been working on energy harvesting conventionally for at least six years, and for most of this time it didn't seem like there was a key to make energy harvesting work in the real world, because of FCC limits on power emission and focalization," Hester said. "With the advent of 5G networks, this could actually work and we've demonstrated it. That's extremely exciting -- we could get rid of batteries."

###

This work was supported by the Air Force Research Laboratory and the National Science Foundation (NSF) - Emerging Frontiers in Research and Innovation program. The work was performed in part at the Georgia Tech Institute for Electronics and Nanotechnology, a member of the National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the NSF (Grant ECCS-1542174).

 

Should you take fish oil? Depends on your genotype

UGA-led research shows benefits only with a specific genetic makeup

UNIVERSITY OF GEORGIA

Research News

Fish oil supplements are a billion-dollar industry built on a foundation of purported, but not proven, health benefits. Now, new research from a team led by a University of Georgia scientist indicates that taking fish oil only provides health benefits if you have the right genetic makeup.

The study, led by Kaixiong Ye and published in PLOS Genetics, focused on fish oil (and the omega-3 fatty acids it contains) and its effect on triglycerides, a type of fat in the blood and a biomarker for cardiovascular disease.

"We've known for a few decades that a higher level of omega-3 fatty acids in the blood is associated with a lower risk of heart disease," said Ye, assistant professor of genetics in the Franklin College of Arts and Sciences. "What we found is that fish oil supplementation is not good for everyone; it depends on your genotype. If you have a specific genetic background, then fish oil supplementation will help lower your triglycerides. But if you do not have that right genotype, taking a fish oil supplement actually increases your triglycerides."

Ye's team, including first author and graduate student Michael Francis, examined four blood lipids (fats)--high-density lipoprotein, low-density lipoprotein, total cholesterol and triglycerides--that are biomarkers for cardiovascular disease. The data for their sample of 70,000 individuals was taken from UK Biobank, a large-scale cohort study collecting genetic and health information from half a million participants.

The team divided the sample into two groups, those taking fish oil supplements (about 11,000) and those not taking fish oil supplements. Then they performed a genome-wide scan for each group, testing for 8 million genetic variants to compare. After running over 64 million tests, their results revealed a significant genetic variant at gene GJB2. Individuals with the AG genotype who took fish oil decreased their triglycerides. Individuals with the AA genotype who took fish oil slightly increased their triglycerides. (A third possible genotype, GG, was not evident in enough study volunteers to draw conclusions.)

Determining your genotype is not as far-fetched as it sounds, thanks to direct-to-consumer genetic testing companies. Companies may not report that specific genetic variant yet, but a tech-savvy consumer should be able to download the raw data and look at the specific position to discover the genotype, according to Ye. The ID for the variant is rs112803755 (A>G).

Looking at earlier fish oil studies

The study's findings may also shed light on previous trials, most of which found that fish oil provides no benefit in preventing cardiovascular disease.

"One possible explanation is that those clinical trials didn't consider the genotypes of the participants," Ye said. "Some participants may benefit, and some may not, so if you mix them together and do the analysis, you do not see the impact."

Now that Ye has identified a specific gene that can modify an individual's response to fish oil supplementation, his next step will be directly testing the effects of fish oil on cardiovascular disease.

"Personalizing and optimizing fish oil supplementation recommendations based on a person's unique genetic composition can improve our understanding of nutrition," he said, "and lead to significant improvements in human health and well-being."

###

Co-authors for the study include Yitang Sun and Jingqi Zhou at the University of Georgia; Changwei Li and Xiang Li at Tulane University; and J. Thomas Brenna at Cornell University and the University of Texas at Austin.

 

Global evidence for how EdTech can support pupils with disabilities is 'thinly spread'

Report reveals 'astonishing' shortage of information about how rapid advances in educational technology could help pupils with disabilities in low and middle-income countries

UNIVERSITY OF CAMBRIDGE

Research News

 

An 'astonishing' deficit of data about how the global boom in educational technology could help pupils with disabilities in low and middle-income countries has been highlighted in a new report.

Despite widespread optimism that educational technology, or 'EdTech', can help to level the playing field for young people with disabilities, the study found a significant shortage of evidence about which innovations are best-positioned to help which children, and why; specifically in low-income contexts.

The review also found that many teachers lack training on how to use new technology, or are reluctant to do so.

The study was carried out for the EdTech Hub partnership, by researchers from the Universities of Cambridge, Glasgow and York. They conducted a detailed search for publications reporting trials or evaluations about how EdTech is being used to help primary school-age children with disabilities in low- and middle-income countries. Despite screening 20,000 documents, they found just 51 relevant papers from the past 14 years - few of which assessed any impact on children's learning outcomes.

Their report describes the paucity of evidence as 'astonishing', given the importance of educational technologies to support the learning of children with disabilities. According to the Inclusive Education Initiative, as many as half the estimated 65 million school-age children with disabilities worldwide were out of school even before the COVID-19 pandemic, and most face ongoing, significant barriers to attending or participating in education.

EdTech is widely seen as having the potential to reverse this trend, and numerous devices have been developed to support the education of young people with disabilities. The study itself identifies a kaleidoscopic range of devices to support low vision, sign language programmes, mobile apps which teach braille, and computer screen readers.

It also suggests, however, that there have been very few systematic attempts to test the effectiveness of these devices. Dr Paul Lynch, from the School of Education, University of Glasgow, said: "The evidence for EdTech's potential to support learners with disabilities is worryingly thin. Even though we commonly hear of interesting innovations taking place across the globe, these are not being rigorously evaluated or documented."

Professor Nidhi Singal, from the Faculty of Education, University of Cambridge, said: "There is an urgent need to know which technology works best for children with disabilities, where, and in response to which specific needs. The lack of evidence is a serious problem if we want EdTech to fulfil its potential to improve children's access to learning, and to increase their independence and agency as they progress through school."

The report identifies numerous 'glaring omissions' in the evaluations that researchers did manage to uncover. Around half were for devices designed to support children with hearing or vision difficulties; hardly any addressed the learning needs of children with autism, dyslexia, or physical disabilities. Most were from trials in Asia or Africa, while South America was underrepresented.

Much of the evidence also concerned EdTech projects which Dr Gill Francis, from the University of York and a co-author, described as 'in their infancy'. Most focused on whether children liked the tools, or found them easy to use, rather than whether they actually improved curriculum delivery, learner participation and outcomes. Attention was also rarely given to whether the devices could be scaled up - for example, in remote and rural areas where resources such as electricity are often lacking. Few studies appeared to have taken into account the views or experiences of parents or carers, or of learners themselves.

The studies reviewed also suggest that many teachers lack experience with educational technology. For example, one study in Nigeria found that teachers lacked experience of assistive technologies for students with a range of disabilities. Another, undertaken at 10 schools for the blind in Delhi, found that the uptake of modern low-vision devices was extremely limited, because teachers were unaware of their benefits.

Despite the shortage of information overall, the study did uncover some clear evidence about how technology - particularly portable devices - is transforming opportunities for children with disabilities. Deaf and hard-of-hearing pupils, for instance, are increasingly using SMS and social media to access information about lessons and communicate with peers; while visually-impaired pupils have been able to use tablet computers, in particular, to magnify and read learning materials.

Based on this, the report recommends that efforts to support children with disabilities in low- and middle-income countries should focus on the provision of mobile and portable devices, and that strategies should be put in place to ensure that these are sustainable and affordable for parents and schools - as cost was another concern that emerged from the studies cited.

Critically, however, the report states that more structured evidence-gathering is urgently needed to ensure EdTech meets the UN's stated goal to 'ensure inclusive and equitable quality education and promote lifelong learning for all'. The authors suggest that there is a need to adopt more robust research designs, which should address a full range of disabilities, and involve pupils, carers and teachers in the process.

"There is no one-size-fits-all solution when working with children with disabilities," Singal added. "That is why the current lack of substantive evidence is such a concern. It needs to be addressed so that teachers, parents and learners are enabled to make informed judgements about which technological interventions work, and what might work best for them."

###

 

Wisdom, loneliness and your intestinal multitude

It may take guts -- or more precisely, a diverse gut microbiome -- to achieve wisdom and fend off loneliness. Or perhaps it's the other way around, report UC San Diego researchers

UNIVERSITY OF CALIFORNIA - SAN DIEGO

Research News

IMAGE: GREATER DIVERSITY OF GUT MICROBES MAY BE ASSOCIATED WITH GREATER WISDOM OR VICE VERSA; SIMILARLY LESS DIVERSITY MIGHT MEAN HIGHER LIKELIHOOD OF BEING LONELY. view more 

CREDIT: UC SAN DIEGO HEALTH SCIENCES

The evolving science of wisdom rests on the idea that wisdom's defined traits correspond to distinct regions of the brain, and that greater wisdom translates into greater happiness and life satisfaction while being less wise results in opposite, negative consequences.

Scientists have found in multiple studies that persons deemed to be wiser are less prone to feel lonely while those who are lonelier also tend to be less wise. In a new study, published in the March 25, 2021 issue of the journal Frontiers in Psychiatry, researchers at University of California San Diego School of Medicine take the connection between wisdom, loneliness and biology further, reporting that wisdom and loneliness appear to influence -- and/or be influenced by -- microbial diversity of the gut.

The human gut microbiota is comprised of trillions of microbes -- bacteria, viruses, fungi -- that reside within the digestive tract. Researchers have known for a while about the "gut-brain axis," which is a complex network that links intestinal function to the emotional and cognitive centers of the brain.

This two-way communication system is regulated by neural activity, hormones and the immune system; alterations can result in disruptions to stress response and behaviors, said the authors, from emotional arousal to higher-order cognitive abilities, such as decision-making.

Past studies have associated gut microbiota with mental health disorders including depression, bipolar disorder and schizophrenia, as well as personality and psychological traits regarded as key, biologically based components of wisdom. Recent research has connected the gut microbiome to social behavior, including findings that people with larger social networks tend to have more diverse gut microbiotas.

The new Frontiers in Psychiatry study involved 187 participants, ages 28 to 97, who completed validated self-report-based measures of loneliness, wisdom, compassion, social support and social engagement. The gut microbiota was analyzed using fecal samples. Microbial gut diversity was measured in two ways: alpha-diversity, referring to the ecological richness of microbial species within each individual and beta-diversity, referring to the differences in the microbial community composition between individuals.

"We found that lower levels of loneliness and higher levels of wisdom, compassion, social support and engagement were associated with greater phylogenetic richness and diversity of the gut microbiome," said first author Tanya T. Nguyen, PhD, assistant professor of psychiatry at UC San Diego School of Medicine.

The authors said that the mechanisms that may link loneliness, compassion and wisdom with gut microbial diversity are not known, but observed that reduced microbial diversity typically represents worse physical and mental health, and is associated with a variety of diseases, including obesity, inflammatory bowel disease and major depressive disorder.

A more diverse gut microbiota may be less susceptible to invasion by outside pathogens, which could contribute to and help promote better resilience and stability of the community.

"It is possible that loneliness may result in decreased stability of the gut microbiome and, consequently, reduced resistance and resilience to stress-related disruptions, leading to downstream physiological effects, such as systemic inflammation," the authors wrote.

"Bacterial communities with low alpha-diversity may not manifest overt disease, but they may be less than optimal for preventing disease. Thus, lonely people may be more susceptible to developing different diseases."

The relationship between loneliness and microbial diversity was particularly strong in older adults, suggesting that older adults may be especially vulnerable to health-related consequences of loneliness, which is consistent with prior research.

Conversely, the researchers said that social support, compassion and wisdom might confer protection against loneliness-related instability of the gut microbiome. Healthy, diverse gut microflora may buffer the negative effects of chronic stress or help shape social behaviors that promote either wisdom or loneliness. They noted that animal studies suggest that gut microbiota may influence social behaviors and interactions, though the hypothesis has not been tested in humans.

The complexity of the topic and study limitations, such as the absence of data about individuals' social networks, diet and degree of objective social isolation versus subjective reports of loneliness, argue for larger, longer studies, wrote the authors.

"Loneliness may lead to changes in the gut microbiome or, reciprocally, alterations of the gut milieu may predispose an individual to become lonely," said Dilip V. Jeste, MD, Distinguished Professor of Psychiatry and Neurosciences at UC San Diego School of Medicine and senior author of the paper. "We need to investigate much more thoroughly to better understand the phenomenon of the gut-brain axis."

###

Co-authors include: Xinlian Zhang, Tsung-Chin Wu, Jinyuan Liu, Collin Le, Xin M. Tu and Rob Knight, all at UC San Diego.

New discoveries of deep brain stimulation put it on par with therapeutics

Possibly speeding the process and allowing personalized treatment

UNIVERSITY OF HOUSTON

Research News

 

IMAGE: NURI INCE, ASSOCIATE PROFESSOR OF BIOMEDICAL ENGINEERING, IS REPORTING THAT ELECTRICAL STIMULATION OF THE BRAIN AT HIGHER FREQUENCIES (ABOVE 100HZ) INDUCES RESONATING WAVEFORMS WHICH CAN SUCCESSFULLY RECALIBRATE DYSFUNCTIONAL CIRCUITS CAUSING... view more 

CREDIT: UNIVERSITY OF HOUSTON

Despite having remarkable utility in treating movement disorders such as Parkinson's disease, deep brain stimulation (DBS) has confounded researchers, with a general lack of understanding of why it works at some frequencies and does not at others. Now a University of Houston biomedical engineer is presenting evidence in Nature Communications Biology that electrical stimulation of the brain at higher frequencies (>100Hz) induces resonating waveforms which can successfully recalibrate dysfunctional circuits causing movement symptoms.

"We investigated the modulations in local ?eld potentials induced by electrical stimulation of the subthalamic nucleus (STN) at therapeutic and non-therapeutic frequencies in Parkinson's disease patients undergoing DBS surgery. We ?nd that therapeutic high-frequency stimulation (130-180 Hz) induces high-frequency oscillations (~300 Hz, HFO) similar to those observed with pharmacological treatment," reports Nuri Ince, associate professor of biomedical engineering.

For the past couple of decades, deep brain stimulation (DBS) has been the most important therapeutic advancement in the treatment of Parkinson's disease, a progressive nervous system disorder that affects movement in 10 million people worldwide. In DBS, electrodes are surgically implanted in the deep brain and electrical pulses are delivered at certain rates to control tremors and other disabling motor signs associated with the disease.

Until now, the process to find the correct frequency has been time consuming, with it taking sometimes months to implant devices and test their abilities in patients, in a largely back and forth process. Ince's method may speed the time to almost immediate for the programming of devices at correct frequencies.

"For the first time, we stimulated the brain and while doing that we recorded the response of the brain waves at the same time, and this has been a limitation over the past years. When you stimulate with electrical pulses, they generate large amplitude artifacts, masking the neural response. With our signal processing methods, we were able to get rid of the noise and clean it up," said Ince. "If you know why certain frequencies are working, then you can adjust the stimulation frequencies on a subject-specific basis, making therapy more personalized."

###

DBS is also being explored for the treatment of many other neurological and psychiatric indications, including Obsessive-Compulsive Disorder.

Additional authors of the article are Ince's doctoral student Musa Ozturk; and Ashwin Viswanathan and Sameer Sheth, Baylor College of Medicine.

Narcissism driven by insecurity, not grandiose sense of self

NEW YORK UNIVERSITY

Research News

 

Narcissism is driven by insecurity, and not an inflated sense of self, finds a new study by a team of psychology researchers. Its research, which offers a more detailed understanding of this long-examined phenomenon, may also explain what motivates the self-focused nature of social media activity.

"For a long time, it was unclear why narcissists engage in unpleasant behaviors, such as self-congratulation, as it actually makes others think less of them," explains Pascal Wallisch, a clinical associate professor in New York University's Department of Psychology and the senior author of the paper, which appears in the journal Personality and Individual Differences. "This has become quite prevalent in the age of social media--a behavior that's been coined 'flexing'.

"Our work reveals that these narcissists are not grandiose, but rather insecure, and this is how they seem to cope with their insecurities."

"More specifically, the results suggest that narcissism is better understood as a compensatory adaptation to overcome and cover up low self-worth," adds Mary Kowalchyk, the paper's lead author and an NYU graduate student at the time of the study. "Narcissists are insecure, and they cope with these insecurities by flexing. This makes others like them less in the long run, thus further aggravating their insecurities, which then leads to a vicious cycle of flexing behaviors."

The survey's nearly 300 participants--approximately 60 percent female and 40 percent male--had a median age of 20 and answered 151 questions via computer.

The researchers examined Narcissistic Personality Disorder (NPD), conceptualized as excessive self-love and consisting of two subtypes, known as grandiose and vulnerable narcissism. A related affliction, psychopathy, is also characterized by a grandiose sense of self. They sought to refine the understanding of how these conditions relate.

To do so, they designed a novel measure, called PRISN (Performative Refinement to soothe Insecurities about SophisticatioN), which produced FLEX (perFormative seLf-Elevation indeX). FLEX captures insecurity-driven self-conceptualizations that are manifested as impression management, leading to self-elevating tendencies.

The PRISN scale includes commonly used measures to investigate social desirability ("No matter who I am talking to I am a good listener"), self-esteem ("On the whole, I am satisfied with myself"), and psychopathy ("I tend to lack remorse"). FLEX was shown to be made up of four components: impression management ("I am likely to show off if I get the chance"), the need for social validation ("It matters that I am seen at important events''), self-elevation ("I have exquisite taste"), and social dominance ("I like knowing more than other people").

Overall, the results showed high correlations between FLEX and narcissism--but not with psychopathy. For example, the need for social validation (a FLEX metric) correlated with the reported tendency to engage in performative self-elevation (a characteristic of vulnerable narcissism). By contrast, measures of psychopathy, such as elevated levels of self-esteem, showed low correlation levels with vulnerable narcissism, implying a lack of insecurity. These findings suggest that genuine narcissists are insecure and are best described by the vulnerable narcissism subtype, whereas grandiose narcissism might be better understood as a manifestation of psychopathy.

###

The paper's other authors were Helena Palmieri, an NYU psychology doctoral student at the time of the study, and Elena Conte, an NYU psychology undergraduate student.

DOI: 10.1016/j.paid.2021.110780

The 'great leveler' revisited: Why the Corona pandemic might boost inequality in society

UTRECHT UNIVERSITY

Research News

 

How will Covid-19 affect inequality in countries worldwide? The current pandemic is sometimes marked as 'great equalizer', but scientists from Utrecht and Wageningen University show why the opposite might be true. A study by prof. Bas van Bavel and prof. Marten Scheffer shows that throughout history, most disasters and pandemics have boosted inequality instead of levelling it. Whether such disastrous events function as levellers or not, depends on the distribution of economic wealth and political leverage within a society at the moment of crisis. Their findings on the historical effects of crises on equality in societies are now published open access in Nature HSS Communications.

It is often thought that the main levellers of inequality in societies were natural disasters such as epidemics or earthquakes, and social turmoil such as wars and revolutions. The most salient example is the Black Death of 1347-1352, a large-scale pandemic that killed up to half of the Eurasian population. In several European societies, wealth disparities seem to have been reduced afterwards. The suggested logic behind that equitable effect is the decimation of people while capital remained intact, thereby shifting the economic balance in favour of labour. Crises as windows of opportunity In most cases throughout history, the opposite is true. Bas van Bavel: "In spite of the marked differences in character and direct impact of the shocks we studied, most historical disasters were followed by a widening of wealth gaps." In their article, historian Bas van Bavel (Utrecht University) and ecologist Marten Scheffer (Wageningen University) critically review evidence of the effects of catastrophes such as the plague on inequality, from medieval times till the present. Van Bavel and Scheffer used empirical data to study the long term effects of shocks on inequality.

Their research shows a twofold effect. First, the wealth distribution and institutional outlay of these societies at the moment of the shock to a large extent shaped the impact. Subsequently, the distribution of political leverage in society came into play in determining the institutional responses. Van Bavel explains: "Upon a crisis, rules tend to be rewritten. Social groups and organizations with the greatest leverage can therefore use that window of opportunity to adapt institutional rules, thereby shaping long-term wealth distribution. As most societies were historically unequal, in most cases the result was a further widening of disparities."

Power to the people: the importance of bottom-up organisations Over the centuries, exceptions have occurred in situations where the ordinary people had strong leverage in shaping the response to the crisis - through organizations such as guilds, fraternities, trade unions, cooperatives, and political movements. Scheffer: "Our results provide empirical support for the view that in nations where such leverage of ordinary people is weak, the responses to novel crises such as the COVID-19 pandemic may increase inequality instead of diminishing it. Furthermore, when explaining the effects of a disaster on equality, we need to distinguish between the immediate impact, the medium-term effects of the institutional measures taken in response to the disaster, and the indirect outcomes in the long run."

What history suggests about the current pandemic Their insights also hold relevance when thinking about the effects of the COVID 19-crisis. Van Bavel: "The direct impact and long term effects are likely to enlarge material inequalities. The social and economic context at present is much more similar to that during the 2008 crisis than to the context during the twentieth-century disasters - when societies were more equitable both in wealth distribution and societal leverage than at present."

###

The article 'Historical effects of shocks on inequality: the great leveler revisited' is published open access and is now available online: http://www.nature.com/articles/s41599-021-00763-4.

When synthetic evolution rhymes with natural diversity

GMI - GREGOR MENDEL INSTITUTE OF MOLECULAR PLANT BIOLOGY OF THE AUSTRIAN ACADEMY OF SCIENCES

Research News

 

IMAGE: THE MOTILITY OF PLANT-COLONIZING BACTERIA IS LARGELY DEPENDENT ON FLAGELLIN. IN A. THALIANA, A SHORT ANTIGENIC COMPONENT FROM FLAGELLIN, TERMED FLG22, IS SUFFICIENT TO INDUCE A PLANT IMMUNE RESPONSE THROUGH... view more 

CREDIT: PARYS/GMI/UNC-CHAPEL HILL

Researchers at GMI - Gregor Mendel Institute of Molecular Plant Biology of the Austrian Academy of Sciences, the University of North Carolina at Chapel Hill and The Howard Hughes Medical Institute (HHMI) use two complementary approaches to unveil a co-evolutionary mechanism between bacteria and plants and also explain complex immune response patterns observed in the wild. Together the papers change the way scientists have been thinking about the relationship of a bacterial antigenic component with its plant immune receptor. The two papers are published back to back in the journal Cell Host & Microbe.

Immune responses have developed in virtually all organisms over evolutionary time scales to protect them from foreign invaders. A central aspect of the immune response of higher organisms, i.e., plants and animals, is the use of sensory systems that detect and respond to "non-self" molecular signals. These molecular signals generally determine the survival chances of the pathogen, a factor that prevents them from being eliminated by natural selection as a means to evade host recognition. Their evolutionary conservation is thus due to the functionality of these molecular signals to the foreign invader. However, the negative evolutionary pressure to maintain this functionality is counterbalanced by the positive evolutionary pressure to mediate the pathogen's immune evasion. The dissection of these co-evolutionary forces through synthetic and reverse evolutionary methods is one of the two research approaches that researchers from the Belkhadir lab at GMI and the Dangl lab at UNC- Chapel Hill team up to investigate. In an orthogonal approach, they also inquire into the natural diversity of molecular antigenic determinants (epitopes) in plant-colonizing bacterial communities (commensal communities) and map the complex immune response patterns they trigger in the plants. Jeffery Dangl, John N. Couch Distinguished Professor at UNC-Chapel Hill and an HHMI investigator explains: "To date, most science in this field has used a handful of epitopes. We sampled thousands, derived from synthetic biology and commensal communities. This depth of analysis allowed us to uncover a rich diversity of host response mediated by a single receptor."

Reverse evolution and new insights on co-evolution

The researchers examine how the Arabidopsis immune sensor FLS2 (flagellin sensing 2) influenced the evolution of its interacting epitope on the Pseudomonas flagellin, and how this, in turn, influenced Pseudomonas motility. Using reverse evolutionary methods, Parys et al. uncover a new mechanism of co-evolutionary force between FLS2 and flagellin, and frame it as a molecular form of the scarcely studied theory of antagonistic pleiotropy (AP) in plant immunology. AP is the ability of a gene to induce opposing effects in different contexts, a prevailing theory for the evolutionary origin of aging in humans. The researchers demonstrate that AP fosters stable colonization of Arabidopsis by commensal communities by weighing out bacterial motility against sensor detection. This strategy results in flagellin epitopes that either mildly activate or outright block the receptor (gain in virulence), while losing in motility as a trade-off (loss in virulence). Even more excitingly, they find signatures of these synthetic experiments in naturally occurring commensal communities, suggesting that natural microbiomes might be less dependent on flagella-mediated motility and willing to trade it off against another form of immune evasion in order to stay in harmony with the plant.

Friend or foe?

In the second, natural sampling approach, Colaianni et al. demonstrate that immune evasion mechanisms in plant root commensal communities are rampant and are a determining factor of the community's structure. Moreover, this conceptual breakthrough is accompanied by the corroborating findings of complex immune response fine-tuning mechanisms in Arabidopsis. The diversity of the ligand epitopes is translated in a complexity of the immune responses engaged by the plant, which is capable of detecting threshold variations in its microbiome, and thus, discriminating between "friend and foe."

On immune evasion and plant growth promotion

Asked about possible applications of this joint work, GMI group leader Youssef Belkhadir elaborates: "Sometimes, it is good to know how to turn on an immune response, but we often forget that, sometimes, it might also be good to turn it off. For example, you could help a growth-promoting microbe better colonize the plant by providing it with an additional way to evade the plant's immune response. And here we discovered synthetic antagonistic peptides that could do just that."

CAPTION

Plant-colonizing bacterial communities (commensal communities) can produce diverse variants of the flg22 peptide, the antigenic determinant that induces diverse immune response outputs from the Arabidopsis immune sensor FLS2. Colaianni et al. propose that FLS2 monitors the proportionality of the flg22 diversity present in a commensal community to identify the presence pathogens.

CREDIT

Colaianni/GMI/UNC-Chapel Hill

Back to the (plant) roots

This collaboration draws on an exchange in expertise between the alternating first authors of the two publications, but also refreshes long-dating, outstanding, scientific contacts. In fact, Nicholas Colaianni, Ph.D. student in the Dangl lab at UNC-Chapel Hill, is a computational expert, whereas the main fields of expertise of Katarzyna Parys (former Ph.D. student in the Belkhadir lab) lie in biochemistry and wet lab genetics. Colaianni also visited the Belkhadir lab at GMI and both he and Parys benefited from hands-on training in each other's field of expertise. In addition, as a third co-first author on both publications, Ho-Seok Lee, postdoctoral fellow in the Belkhadir lab, contributed his skills in microscopy imaging.

After many years of separate research, the two main principal investigators who share seniority and alternate corresponding authorships on the two publications, decided to make a comeback together. The shared seniority also includes Corbin Jones, Biology Professor at UNC-Chapel Hill and Colaianni's co-mentor. Youssef Belkhadir is a UNC-Chapel Hill alumnus who worked with Jeffery Dangl as a Ph.D. student. Referring to the UNC Tar Heels basketball team that Dangl loves, Belkhadir says "17 years after I co-authored my first paper with Jeff, it was a lot of fun to get on the court and 'slam-dunk' it with him once more!". Dangl adds "Just like basketball, science is a team effort and the best teams play fluidly together."

An international consortium

GMI and UNC-Chapel Hill share a deep commitment to international collaboration and the present work rallied an international consortium of scientists spearheaded by Youssef Belkhadir, including the University of Geneva and the University of Lausanne in Switzerland, the Max Perutz Labs of the University of Vienna in Austria and the University of Würzburg in Germany. The researchers also acknowledge the contribution of the Vienna Biocenter member institutes and facilities.

###

Original publications:

Parys et al., "Signatures of antagonistic pleiotropy in a bacterial flagellin epitope", Cell Host & Microbe, 2021. DOI: https://doi.org/10.1016/j.chom.2021.02.008

Colaianni et al., "A complex immune response to flagellin epitope variation in commensal communities", Cell Host & Microbe, 2021. DOI: https://doi.org/10.1016/j.chom.2021.02.006

 

Pediatric heart transplant method developed by U of A doctors allows for more surgeries, better outcomes: Study

Blood type-incompatible heart transplant surgery for infants under the age of two pioneered in Canada, now used worldwide

UNIVERSITY OF ALBERTA FACULTY OF MEDICINE & DENTISTRY

Research News

 

IMAGE: U OF A RESEARCHER SIMON URSCHEL WITH PATIENT GEORGE KEMP, WHO RECEIVED A HEART TRANSPLANT AS A BABY AND IS NOW FOUR YEARS OLD. (PHOTO TAKEN PRE-COVID-19) view more 

CREDIT: LINDSEY KEMP

A pediatric heart transplant procedure pioneered by Canadian doctors--once deemed impossible--has been shown to be at least as effective as the traditional approach, according to newly published research in The Lancet Child & Adolescent Health.

ABO-incompatible heart transplantation was developed in the mid-1990s, after a Canadian transplant team led by Lori West realized that infants under the age of two have immature immune systems that would allow them to accept life-saving replacements for their defective hearts from donors with incompatible blood types.

"It's really important to see it has not only helped these very sick babies to get transplants faster, but also to live as long, with no more rejections, and better outcomes with regards to infections, as children who received a matched blood group heart," said principal investigator Simon Urschel, associate professor of pediatrics in the University of Alberta's Faculty of Medicine & Dentistry, director of pediatric cardiac transplantation at the Stollery Children's Hospital and member of the Women and Children's Health Research Institute (WCHRI).

ABO-incompatible heart transplantation is now routinely carried out in Canada and some other countries, but not everywhere. That should change thanks to these new study results, Urschel said.

"For example, Eurotransplant (the agency responsible for transplants in eight European countries) still considers it an inferior option to be used with caution," he said. "That concern will probably be relieved in those last places that were reluctant to do it, now that we have shown it is safe."

About 50 per cent of the population is born with type O blood, while 35 per cent has A type and 15 per cent has B or AB type blood. Organs from a donor with type O blood can be accepted by anyone, but adult type O patients can receive only type O organs. The development of ABO-incompatible pediatric heart transplantation meant that twice as many organs would be available to type O infants born with heart defects.

Urschel and his team analyzed data from more than 2,200 infant transplant recipients in Canada, the United Kingdom and the United States from 1999 to 2018. The records were from the Pediatric Heart Transplant Society registry, an international research collaboration that collects data from 58 transplant centres. This resulted in more than 11,000 cumulative patient-years of observation, by far the largest study of its kind.

Three hundred sixty-four of the babies received ABO-incompatible transplants, while 1,842 received ABO-compatible hearts. "We wanted to compare apples with apples, so the children were matched by characteristics such as their underlying disease and the age at which they underwent surgery," Urschel said.

The researchers found the survival rate was the same between the two groups, as were the rates of acute and chronic organ rejection and the risk of developing leukemia after transplant. They also examined the rates of post-transplant bacterial, viral and fungal infections, which they were concerned might be higher among the ABO-incompatible transplant recipients.

"Interestingly, we found that there were fewer of the infections that we were worried about in the ABO-incompatible patients," Urschel said.

Earlier work by Urschel's research team showed that wait times for these patients were significantly shortened, with the average time to transplant being about 50 per cent shorter thanks to the innovative transplant technique.

"It's easier and faster to find a heart for these patients, which is crucial because they are extremely sick, often on mechanical heart support devices or on ventilators in intensive care units," he said. "This gives them a chance not only to survive, but to stay healthier and be in better condition before and after transplantation."

The pioneering pediatric heart surgeons who started it all in 1996--West and Ivan Rebeyka--refined their method after being recruited to join the U of A faculty, with help from other faculty members such as Urschel. Urschel and West's work has received funding from the Stollery Children's Foundation through WCHRI.

CAPTION

Pediatric heart surgeon Lori West led a team that pioneered ABO-incompatible heart transplants after realizing that infants' immature immune systems wouldn't reject organs from donors of a different blood type.

CREDIT

Laughing Dog Photography

The "rule" requiring ABO-compatible donors was instituted for older patients and had never been revisited from the perspective of the immunologic immaturity of infants, said West, now Canada Research Chair (Tier 1) in Cardiac Transplantation, and director of the Alberta Transplant Institute and the Canadian Donation and Transplantation Research Program.

"This, in combination with an extremely high mortality for infants on our transplant waiting list, is why we instituted the first ABO-incompatible transplant protocol," she said.

"Transplantation has always been about pushing the boundaries of risks in order to offer reasonable options to patients who would otherwise have no options."

Urschel will continue his work to understand the mechanism in infant immune systems that allows them to accept blood type-incompatible hearts, in hopes of being able to one day use what is learned to help older transplant recipients. He is also involved in projects to improve the quality of life of young transplant patients and their families.

"It's a real lesson in the need for scientific vigour to guide our operationalization of clinical protocols, not just the blind adoption of previously accepted regulations," said West.

The fact that heart transplant recipients can now survive with a normal lifespan is a credit to both West and Rebeyka, who has a clinical faculty position with the U of A's Cardiovascular Research Centre, said Urschel, who continues to provide clinical care for teenage and young adult patients who received ABO-incompatible transplants as babies.

"It's just amazing to see them, knowing that at one time they were so sick in the intensive care unit that they might not make it to the next day," Urschel said.

###