Culture

OAK BROOK, Ill. - A minimally invasive procedure that destroys cancer cells by freezing them is as effective as surgery for treating early-stage kidney cancer, offering similar 10-year survival rates with a lower rate of complications, according to a study published in the journal Radiology.

Kidney cancer is among the 10 most common cancers in men and women in the United States. About 70% of cases are found at stage 1, the earliest stage. Treatment typically involves surgical removal of the tumor from the kidney, also known as a partial nephrectomy. Radical nephrectomy, or removal of the entire kidney, is another surgical option.

Percutaneous cryoablation (PCA) has emerged as an alternative to surgery that kills the tumor by freezing it. In the procedure, an interventional radiologist inserts a hollow needle into the tumor under imaging guidance. Argon gas circulating through the needle freezes a small volume of tissue, including the tumor and a small amount of normal tissue around it. The tumor dies, and over time it turns into scar tissue that is absorbed by the body.

"We have been doing cryoablation with increasing frequency at Johns Hopkins," said study lead author Christos S. Georgiades, M.D., Ph.D., professor of radiology, oncology and surgery from the Department of Vascular and Interventional Radiology at Johns Hopkins University in Baltimore. "It's an outpatient procedure that takes about 30 to 40 minutes to perform. We observe the patient for three hours, and then they can go home."

For the study, Dr. Georgiades and colleagues looked at 134 patients who underwent cryoablation for early-stage kidney cancer and compared their outcomes over 10 years with those of patients who had either a radical or partial nephrectomy.

Disease-specific survival--that is, the proportion of patients who were still alive or had died from some other cause besides kidney cancer--was 94% at both five and 10 years after treatment, a figure comparable to that reported after radical or partial nephrectomy. Overall survival probability after percutaneous cryoablation at five and 10 years was longer than for radical or partial nephrectomy.?

"For certain patients, cryoablation is equivalent to surgery with fewer side effects," Dr. Georgiades said. "The risk of significant complications from this procedure is about 6%, compared to between 15 and 20% for surgery. In addition, recovery is much faster than with surgery."

The study also found that cryoablation was associated with a low 10-year risk of hemodialysis.

Dr. Georgiades emphasized that cryoablation is only appropriate for early-stage kidney cancer that is confined to the kidney and is up to about 4 centimeters in size. It would not be effective in larger tumors. He doesn't treat patients with cryoablation unless they see a urologist first to get briefed on the surgical option.

"If a patient is interested in hearing about cryoablation, I'll explain the risks, benefits and outcomes," Dr. Georgiades said. "At Johns Hopkins, we give patients all the options and, in the end, they make the final decision. I only offer cryoablation if I know it's going to be beneficial to the patient."

As of now, the standard of care for early-stage kidney cancer is partial nephrectomy. However, the study results from Johns Hopkins, along with results from other studies, are likely to be considered by medical societies as they update their guidelines.

"Studies like this may convince societies to make cryoablation the go-to option, at least for early-stage kidney cancer," Dr. Georgiades said.

An international study that has been carried out on nearly 3000 people in Norway, Germany, and Iceland, shows that our kidney function deteriorates with age, even if we do not have any other diseases. The results from the study have recently been published in the reputable journal for kidney diseases, Journal of the American Society of Nephrology (JASN). In the study, the researchers have examined the kidney function of a group of people between the ages of 50 and 70, and two groups of people between the ages of 70 to 95, to discover how the kidney function develops.

- What we see is that what happens in our kidneys when we age is representative of all the other things that happen in our bodies. The kidney function deteriorates, not because we get ill, but as part of ageing, Bjørn Odvar Eriksen explains, who is a Professor at the Department of Clinical Medicine at UiT and leader of the Metabolic and Renal Research Group.

Eriksen is the lead author of the article that has been published in JASN.

- Loss of kidney function is something that happens to all humans and is thus a way to determine ageing in general. There is still variation as to how quickly this happens, and we still do not have good answers as to why this variation occurs. We have examined many factors that can play a part as to why some of us experience larger loss of kidney function than others, he adds.

One of the groups that have participated in the study consists of over 1600 people and stems from The Tromsø Study, which is Norway's most comprehensive and best participated population study throughout 40 years. This group has been through the different examinations three times; between 2007 to 2009, 2013 to 2015, and 2018 to 2020. The last iteration of the study is still ongoing at The University Hospital of North Norway (UNN) and is lead by Associate Professor Toralf Melsom.

- No other study has done these kinds of examinations on a part of the normal population. That is why this study is so unique, Eriksen says.

The researchers use a precise method of measuring kidney function. They inject a substance into the blood veins that only separates into the kidneys, and let a few hours pass before they measure how much of the substance remains in the blood. This gives a measure of the kidney's ability to remove toxins and waste products. Eriksen explains that more people may experience loss of kidney function as it becomes more common to survive diseases like cancer and heart and vascular diseases.

- For those who experience loss of kidney function at a high age, this is a considerable burden. That is why this is an area that needs further research to find more answers. We are still looking for the fountain of youth, Eriksen says.

A new research letter reveals fewer people have been admitted to stroke centers in Michigan and northwest Ohio since the onslaught of the COVID-19 pandemic, and significantly fewer patients received a mechanical thrombectomy for their ischemic stroke.

The authors call COVID-19's influence on other critical illnesses like stroke a bystander effect. That's because time is of the essence for patients with stroke, but not everyone is getting to a comprehensive stroke center for needed care right now.

In the letter, researchers from Michigan Medicine with colleagues across the Michigan Stroke Treatment Improvement Collaborative reported a significant reduction in ischemic stroke admissions in March when compared both to February of this year (17.8%) and to March of 2019 . Similarly, rates of a procedure for ischemic stroke, mechanical thrombectomy, significantly declined this March compared to February and compared to March of 2019.

"A combination of patient fears, stringent patient transfer criteria, and health system strains may have contributed to lower ischemic stroke admissions as well as the near disappearance of thrombectomy procedures," the authors write.

The differences were most pointed in ischemic stroke and quantity of thrombectomy procedures, authors say, while there was less of a change compared to past months for hemorrhagic stroke.

Physician-scientists specializing in heart failure wanted to know: if their heart transplant patients contract COVID-19, would they have a different experience than the general public or others who are also immunosuppressed?

A team of Michigan Medicine Frankel Cardiovascular Center researchers, led by Matthew Konerman, M.D., identified 13 patients who had a previous heart transplant and were admitted to one of two hospitals in southeast Michigan in March or April for COVID-19 symptoms. All were black males.

"Despite immunosuppression, the clinical presentation and laboratory markers of disease severity showed similarities to what has been observed in the general population," says first author Scott Ketcham, M.D., an internal medicine resident physician. "However, almost half were critically ill and there was a higher rate of mortality than described among non-heart transplant recipients admitted with COVID-19."

The researchers recommend further research with a focus on racial and gender disparities in COVID-19 and on the identification of prognostic markers, treatments and appropriate immunosuppression management for patients with heart transplant with COVID-19.

Scientists have discovered new evidence for active volcanism next door to some of the most densely populated areas of Europe. The study 'crowd-sourced' GPS monitoring data from antennae across western Europe to track subtle movements in the Earth's surface, thought to be caused by a rising subsurface mantle plume. The work is published in Geophysical Journal International.

The Eifel region lies roughly between the cities of Aachen, Trier, and Koblenz, in west-central Germany. It is home to many ancient volcanic features, including the circular lakes known as 'maars'.

These are the remnants of violent volcanic eruptions, such as the one which created Laacher See, the largest lake in the area. The explosion that created this is thought to have occurred around 13,000 years ago, with a similar explosive power to the cataclysmic Mount Pinatubo eruption in 1991.

The mantle plume that likely fed this ancient activity is thought to still be present, extending up to 400km down into the Earth. However, whether or not it is still active is unknown: "Most scientists had assumed that volcanic activity in the Eifel was a thing of the past," said Prof. Corné Kreemer, lead author of the new study. "But connecting the dots, it seems clear that something is brewing underneath the heart of northwest Europe."

In the new study, the team - based at the University of Nevada, Reno and the University of California, Los Angeles in the United States - used data from thousands of commercial and state-owned GPS antennae all over western Europe, to map out how the ground is moving vertically and horizontally as the Earth's crust is pushed, stretched and sheared.

The research revealed that the region's land surface is moving upward and outward over a large area centred on the Eifel, and including Luxembourg, eastern Belgium and the southernmost province of the Netherlands, Limburg.

"The Eifel area is the only region in the study where the ground motion appeared significantly greater than expected," adds Prof. Kreemer. "The results indicate that a rising plume could explain the observed patterns and rate of ground movement."

The new results complement those of a previous study in Geophysical Journal International that found seismic evidence of magma moving underneath the Laacher See. Both studies point towards the Eifel being an active volcanic system.

The implication of this study is that there may not only be an increased volcanic risk, but also a long-term seismic risk in this part of Europe. The researchers urge caution however: "This does not mean that an explosion or earthquake is imminent, or even possible again in this area. We and other scientists plan to continue monitoring the area using a variety of geophysical and geochemical techniques, in order to better understand and quantify any potential risks."

Information about the new COVID-19 infection is constantly evolving based on what clinicians see firsthand. One constant, so far, is that the older population tends to fare worse than younger folks with this disease.

A team led by Daniel Goldstein, M.D., already studies aging and the influenza viral infection, and took this spring away from their lab to figure out if any of their other research, and other research they regularly read, could be helpful in the fight against COVID-19.

"Influenza is of course a different pathogen, but it may give some catalyst for research with the current SARS-CoV2 infection," says Goldstein, of the Michigan Medicine Frankel Cardiovascular Center. Goldstein, with Judy Chen, a doctoral student, and William Kelley, a postdoctoral research fellow, published a new review in the Journal of Immunology.

"We believe some of the phenomena that we're seeing with the current pandemic are similar to what we've seen in our research with aging," Goldstein says. "There seems to be a higher mortality because of dysregulated inflammation more than impaired viral control."

Additionally, increasing activation of neutrophils is reported in the current COVID-19 pandemic, which the authors have reported in their flu models. And how aging affects the immune system prior to infection is the same, and also potentially applicable in understanding the population afflicted by COVID-19, the authors say.

"However, there are certainly some unique things about this virus we're still learning," Goldstein says.

The effects of human presence on the social relationships of wild animals have rarely been studied. Even if the animals are not hunted or killed, increasing contact with humans could have profound indirect impacts. This is because proximity to humans could disturb the animals' ability to perform at tasks that are important for survival - such as feeding together or rearing young.

Researchers from the Department of Evolutionary Biology and Environmental Studies at the University of Zurich (UZH) have now taken a closer look at this topic by studying Masai giraffes in Tanzania. The study, carried out with researchers from the Max Planck Institute of Animal Behavior, the University of Konstanz and Pennsylvania State University, provides the first robust evidence that human presence affects the social structure in this iconic herbivore.

Mapping the social networks of giraffes

For their study, the scientists first needed to obtain large amounts of data from field research. "Detecting signals of natural versus human-caused influences on social relationships among wild animals is challenging," says Monica Bond, PhD candidate at the University of Zurich and first author of the study.

Over a period of six years, Bond and her research collaborators collected photographic data spanning 540 adult female Masai giraffes that live in a large, unfenced landscape in the Tarangire Ecosystem of Tanzania - an environment that features varying levels of anthropogenic (human-caused) disturbance. The researchers were able to identify individual giraffes by their unique and unchanging spot patterns. This resulted in one of the largest-scale social networks ever studied in a wild mammal.

Females live in groups

The field research sheds new light on the social relationships of giraffes: The female giraffes in Tarangire live in a complex multilevel society, with individuals preferring to associate with some females while avoiding others. These preferences result in discrete social communities of 60 to 90 females with little mixing among the groups, even when these share the same general area. "The study reveals that social structuring is clearly an important feature of female giraffe populations," says Barbara König, UZH professor and co-author of the study.

Humans disturb social groups

The data analysis also revealed that the social networks exhibit signs of disturbance when groups of giraffes are exposed to humans: Giraffes living closer to traditional compounds of indigenous Masai people have weaker relationship strengths and more exclusive social associations.

The researchers suspect that giraffes living near traditional human settlements are more likely to encounter livestock and humans. This potentially causes groups of giraffes to split up, even though they are tolerated by the Masai people. This disruption to the giraffes' social system - in addition to poaching, loss of habitat and changes in food supply - could be a reason why Masai giraffe populations have declined 50% in recent years.

Better protection for calves

In other research, the team found that groups of female giraffes with calves were more likely to occur closer to human settlements - possibly because this provides better protection from lions and hyenas. "It seems that female giraffes face a trade-off between maintaining important social bonds and reducing risk to their calves near these traditional settlements," explains Bond.

Overall, the study's results suggest that human presence could play an important role in determining the conservation future of this species of giraffe. Moreover, the study's leading-edge methodology highlights the importance of using the social network approach to reveal otherwise hidden potential causes of population declines.

Alcohol use disorders are associated with high social welfare and health care costs - but what causes them? A new Finnish study looks at the magnitude and reasons behind the economic burden alcohol use disorders have on society.

Earlier studies have shown that alcohol use disorders lead to various health and social problems, which cause an increase in the need and use of various services. However, the magnitude and distribution of the related costs have not been studied before.

Researchers at the University of Eastern Finland used a machine learning technique that is based on a Bayesian network model to analyse causal relationships between different risk factors and the costs associated with them. The analysis included a total of 16 risk factors, including socioeconomic variables such as age, gender, marital status, unemployment status, and social problems like homelessness, illicit drug use, criminal record, and drunk driving. The researchers also looked at what happens when a patient goes into remission, i.e., stops drinking altogether.

Funded by the Strategic Research Council at the Academy of Finland, the study was carried in collaboration between researchers at the University of Eastern Finland, the Finnish Institute for Health and Welfare, and Aalto University. They used a novel approach to control for confounding factors, allowing them to calculate a rough price tag for each risk factor.

The study population comprised 363 Finnish alcohol use disorder patients diagnosed in 2011-2012. Their data were collected from various patient information systems and social welfare databases over a period of five years.

Surprisingly, the number of diagnoses of chronic conditions played the biggest role in the overall cumulation of costs in patients with alcohol use disorder. In patients with at least two chronic conditions, the average 5-year costs of care were 26,000 euros (around 30,000 US dollars) higher than in patients without multiple diagnoses. The costs of care were also increased by earlier use of specialized care (and its high costs), receiving income support, and being over 55 years old. In addition, drug use, homelessness and the number of psychiatric diagnoses also increased the costs of care. Sustained abstinence, on the other hand, lowered the costs. A model created by the researchers shows that roughly 43% of alcohol use disorder patients who quit drinking belong to the lowest cost quartile, compared with the respective figure of 24% for current drinkers.

The findings shed light on how the cumulation of health and social problems increases the costs of social welfare and health care services.

"Since sustained abstinence reduces the costs of care, it would be wise to develop rehabilitation services and provide easy access to care. In addition, people with alcohol use disorders should also get better treatment for their non-alcohol related conditions," Early Stage Researcher and lead author of the article Elina Rautiainen from the University of Eastern Finland says.

Resistance to antibiotics has become a serious public health problem. Hospital infections, prostheses or surgical implants that become infected and do not respond to treatment are a real challenge to the research community, which has been seeking alternatives for effectively eliminating these bacteria for years. In 2012 the researchers from the Department of Chemical Engineering of the Universitat Rovira i Virgili, Vladimir Baulin and Sergey Pogodin, opened a line of research to develop antibacterial models that were inspired by insects. The wings of, for example, dragon flies are made up of complex structures of nanometric geometric shapes, which are highly efficient at killing bacteria. In their attempt to understand these forms and reproduce them as new anti-bacterial materials, a team consisting of Vladimir Baulin, Marc Werner, from the Leibniz-Institut für Polymerforschung (Dresden, Germany) and Elena Ivanova from the Australian university RMIT, discovered that the elasticity of nanopillars is a key factor because they can retain and release sufficient energy to kill the bacteria.

The line of research that had been initiated years before had already found that the wings of these insects are made up of a structure of nanopillars that eliminates bacteria mechanically, which is known as the biocide effect. These mechano-bactericidal properties, by which bacteria are killed almost instantly when they come into contact with the pillars without any need to use a chemical substance, raises numerous questions that researchers are attempting to answer by experimenting with different shapes and geometries that will help them to understand which has the most efficient bactericidal effect.

They investigated the bactericidal capacity on nanometric surfaces by varying the height of the pillars and keeping the other dimensions constant. The results, which have just been published in the journal PNAS, have shown that the flexibility of these pillars is closely connected to their appearance. "Even the solid and rigid materials become flexible if one of the dimensions is much longer than the others (for example, a guitar string or a long pillar)," says Vladimir Baulin. The researchers have developed a physical model that shows that when bacteria come into contact with these pillars they can accumulate elastic energy even at such a small scale. Thanks to this model it is now possible to calculate the elastic response of other structures and optimise their antibacterial properties.

The deformation forces of the pillar caused by the contact of the bacteria are so high that they can even break the bacteria's cell wall, thus providing a new mechanism for killing them. These forces are associated with surface tensions imposed on the bacterial cells. The pillars under the bacteria that approach stretch more at the edges, whereas the pillars located under the centre of the bacteria practically do not change. The study shows, then, that the gradual variation in the height of the pillars of a nanometric surface can determine their bactericidal efficacy.

This discovery may lead to a completely new class of antibacterial materials, which could range from packaging for food to filters or masks. Unlike traditional filters, where the bacteria remain but are not deactivated, the new nanoscale elastic material can safely kill the bacteria in a matter of minutes, which means that they cannot activate any defence mechanisms or give any resistance at all," concluded Baulin.

When humans get infected by pathogenic bacteria, the body's immune system tries to eliminate the intruders. One way of doing this is by launching an inflammatory response - a cascade of events that includes the expression of protective proteins, the activation of immune cells, and a process of controlled cell death when infected cells can't be saved.

Scientists including members of EMBL's Typas group, members of the group of EMBL alumnus Jeroen Krijgsveld at the German Cancer Research Center (DKFZ) in Heidelberg, and other collaborators have investigated how immune cells called macrophages respond to infection by the intracellular pathogen Salmonella enterica. The scientists applied a method recently developed in their labs to enrich, identify, and quantify all newly produced proteins from Salmonella-infected macrophages. They marked newly produced proteins with a specific chemical label and identified them using a technique called mass spectrometry, which allowed them to analyse the entire set of cellular proteins. Importantly, the scientists measured protein levels in macrophages at different infection stages and across different cell compartments. Their study, which is published in Nature Microbiology, shows that monitoring the dynamic changes in protein production and targeting can reveal new insights into the mechanisms by which cells respond to pathogens.

One of the unexpected findings of the study was that a well-known family of proteins called cathepsins move to a new location when cells get infected by Salmonella. Cathepsins are proteases - proteins that break down other proteins. They're normally kept inside small subcellular structures known as lysosomes and have previously been implicated in promoting cell death, although the mechanism or any link between the process and bacterial infection were unknown. The scientists have now discovered that Salmonella causes newly produced cathepsins to accumulate in the nuclei of infected cells. The protein-degrading activity of cathepsins in the nucleus is then required to initiate an inflammatory form of programmed cell death.

The new study shows the benefit of systematically following protein dynamics during infection, which can unravel new pathways and mechanisms the host uses to defend itself against pathogens.

Researchers at the Nanoscience Center and at the Faculty of Information Technology at the University of Jyväskylä in Finland have demonstrated that new distance-based machine learning methods, developed in the University of Jyväskylä, are capable of predicting structures and atomic dynamics of nanoparticles reliably. The new methods are significantly faster than traditional simulation methods used for nanoparticle research and will facilitate more efficient explorations of particle-particle reactions and particles' functionality in their environment. The study was published in a Special Issue devoted to machine learning in The Journal of Physical Chemistry on May 15, 2020.

The new methods were applied to ligand-stabilized metal nanoparticles, which have been long studied at the Nanoscience Center at the University of Jyväskylä. Last year, the researchers published a method that is able to successfully predict binding sites of the stabilizing ligand molecules on the nanoparticle surface. Now, a new tool was created that can reliably predict potential energy based on the atomic structure of the particle, without the need to use numerically heavy electronic structure computations. The tool facilitates Monte Carlo simulations of the atom dynamics of the particles at elevated temperatures.

Potential energy of a system is a fundamental quantity in computational nanoscience, since it allows for quantitative evaluations of system's stability, rates of chemical reactions and strengths of interatomic bonds. Ligand-stabilized metal nanoparticles have many types of interatomic bonds of varying chemical strength, and traditionally the energy evaluations have been done by using the so-called density functional theory (DFT) that often results in numerically heavy computations requiring the use of supercomputers. This has precluded efficient simulations to understand nanoparticles' functionalities, e.g., as catalysts, or interactions with biological objects such as proteins, viruses, or DNA. Machine learning methods, once trained to model the systems reliably, can speed up the simulations by several orders of magnitude.

The new method allowed simulations to be run on a laptop or desktop

In this work the researchers used the potential energies, predicted by the machine learning method, to simulate the atomic dynamics of thiol-stabilized gold nanoparticles. The results were in good agreement with the simulations performed by using the density functional theory. The new method allowed simulations to be run on a laptop or desktop in a time scale of a few hours while the reference DFT simulations took days in a supercomputer and used simultaneously hundreds or even thousands of computer cores. The speed-up will allow long-time simulations of the particles' structural changes and particle-particle reactions at elevated temperatures.

The researchers used a distance-based machine learning method developed in the group of professor Tommi Kärkkäinen in Jyväskylä. It describes each momentary atomic configuration of a nanoparticle by calculating a so-called descriptor, and compares distances between descriptors in a multi-dimensional numerical space. By using correlations to a training set created by the reference DFT simulations, the potential energy can be predicted. This approach, used now for the first time in nanoparticle research, is simpler and more transparent than traditionally used neural networks.

"It is extremely motivating that we can reduce the computational load from running simulations in supercomputers to running them with similar quality in a laptop or a home PC", says PhD student Antti Pihlajamäki who is the lead author of the study.

"It was a great surprise that our relatively simple machine learning methods work so well for complicated nanostructures", states professor Tommi Kärkkäinen.

"In the next phase, our target is to generalize the method to work well for nanoparticles of many different sizes and chemical compositions. We will still need supercomputers to generate enough high-quality data to train the machine learning algorithm, but we hope that in the future we can move to use these new methods primarily to studies of nanoparticle functionality in complicated chemical environments", summarizes Academy Professor Hannu Häkkinen, who coordinated the study.

Studies by Monash Biomedicine Discovery Institute (BDI), have provided a new understanding into the roles two essential amino acids play in metabolic health, which may help scientists in the fight against obesity.

Led by Dr Adam Rose , the recent finding, published in Nature Communications, shows that by reducing the amount of two amino acids - threonine and tryptophan - in young healthy mice, they were able to burn more calories than they consumed, without calorie reduction, keeping them lean and healthy and without the side-effect of lower muscle mass. A low-threonine diet even protected mice that were morbidly obese and prone to developing type 2 diabetes.

While a moderate reduction in dietary protein and therefore essential amino acids can enhance vitality, diets devoid of this component can make people sick very quickly and are not recommended. However, this study has shown that a reconsideration of the functions of these two amino acids in nutrition warrants further exploration.

"Once we understand which particular dietary components are needed for the health-promoting effects of these diets we can design strategies to mimic them, simulating the effects without having the negative side effects," Dr Rose said.

A highlight of the study was an experiment where Dr. Rose and his team genetically manipulated the mice to be able to synthesise the essential amino acid threonine, which blocked the health promoting effects of the low threonine diet and saw the mice gain weight, proving that these two amino acids can hold the key to a new diet approach.

Dr Matthew Piper, a key co-author adds, "We are finding an increasing number of situations in which essential amino acids are powerful modulators of lifelong health and lifespan. Our findings on their specific effects gives us exciting insights into how we might harness their benefits to drive better health."

Co-author Professor Stephen Simpson of the University of Sydney's Charles Perkins Centre said, "We are beginning to understand how critical the balance of dietary amino acids is to the control of appetite, health and ageing."

Scientists at Nanyang Technological University, Singapore (NTU Singapore) and the Harvard T. H. Chan School of Public Health (HSPH) have found that people who hold negative opinions of genetically-modified (GM) food are likely to feel the same about nano-enabled food - food with nano-additives to enhance flavour, nutrition or prolong shelf life.

In a survey of 1,000 respondents led by NTU comprising adult Singaporeans and permanent residents, close to a third found GM food unappealing, and their negative feelings influenced how they viewed nano-enabled food. Over a third felt neutral about GM food, while the remaining respondents welcomed it.

While the study focused specifically on reactions towards nano-enabled foods, lead investigator and NTU Associate Professor Shirley Ho said that the "spillover effect" they observed from GM food to nano-enabled food could possibly extend to other novel food technologies as well, given that mental associations that people make between similar technologies have shown to influence their behaviour towards a newer technology. This represents a cause for concern for policy makers as Singapore invests in food science and technology as one of its strategies to bolster food security.

With the COVID-19 outbreak extending into the second quarter of the year, the Food and Agriculture Organisation of the United Nations has warned of global disruption in food supply brought about by movement restrictions and border controls in a protracted crisis.

The global pandemic has thrust the issue of food security and the necessity to explore cutting edge research in novel food technologies into the spotlight, said Assoc Prof Ho of NTU's Wee Kim Wee School of Communication and Information.

"The COVID-19 pandemic has highlighted the importance of food security for a small country like Singapore, which imports more than 90 per cent of its food consumed in the country. We don't have the problem of disrupted food supply yet, but we have to anticipate the possibility," said Assoc Prof Ho.

"Our study is a timely examination of the public's reactions towards novel food technologies. We may soon be able to make food last longer with the help of science, or dine on lab-cultured meat, but all these would be futile if a sizeable group of people reject these new food innovations."

"This study highlights the challenge in communicating safety of new food technologies as innovations advance to meet global food needs for a growing world population," added Dr K. Viswanath, Lee Kum Kee Professor of Health Communication at Harvard T.H. Chan School of Public Health and a co-author on the paper.

The study was published in the Journal of Communication on 5 June.

Tech-enabled food doesn't go down well with some Singaporeans

To study public opinion on engineered food, the NTU-Harvard team first surveyed 1,000 Singapore citizens and permanent residents on their thoughts on GM food - for example, asking whether they consider it to be delightful, nutritious, fresh and appealing.

Close to a third, or 305 respondents, showed unfavourable attitudes towards GM food.

The team then investigated how the respondents' pre-existing attitudes towards GM food affected their feelings about nano-enabled food, and found that those who had unfavourable attitudes towards GM food were also unfavourable about nano-enabled food - what the scientists called a spillover effect.

The scientists also found that participants who were unfavourable towards technology-enabled food may not be swayed to do the same after watching others eat this food.

Assoc Prof Ho, who is also NTU's Research Director for Arts, Humanities, Education and Social Sciences, explained: "This spillover effect could potentially be due to a general rejection of technology-enabled food and other notions associated with it. The mental associations that people make between similar technologies may influence their behaviours toward a newer technology. This is especially so in cases where the technology from which people draw cues is socially contestable."

The findings also highlight the key role communication plays in bridging the gap between science and the public, she added.

The study was funded by the NTU-HSPH Initiative for Sustainable Nanotechnology, and done in collaboration with Prof K. Vish Viswanath and Dr Mesfin Awoke Bekalu at the Harvard T. H. Chan School of Public Health. Other NTU authors include PhD student Tong Jee Goh, research fellow Dr Agnes Chuah, and research associate Yan Wah Leung.

A similar survey is being conducted by the team in the US. The findings will provide a comparative study of attitudes towards tech-enabled food across different regions and populations.

For the first time, researchers at The Westmead Institute for Medical Research (WIMR) have identified and described a new and unique subset of human cells that are involved in the immune response against hepatitis B (HBV) infection. The discovery could help develop new treatments for HBV and inform future vaccine design.

Currently, HBV vaccination protects against subsequent infection through immunological memory - the vaccine 'trains' the immune system to eliminate pathogens when the body is exposed to the virus.

For years, immunological memory was thought to be driven by B and T immune cell responses. Recent studies in mice have suggested that natural killer (NK) cells can also 'remember' viral infections, but it remained unknown whether this applied to human viral infections.

Researchers from WIMR studied NK cells in humans who had been vaccinated against, or infected with HBV, and compared them to those who had not been exposed to the virus.

The study, undertaken by PhD student Ratna Wijaya and led by Professor Golo Ahlenstiel and Dr Scott Read, describes for the first time, the presence of memory NK cells (mNKs) in humans following exposure to HBV.

Professor Ahlenstiel said, "This finding is quite significant, as it helps our understanding of how the body fights against HBV following vaccination.

"Previously, we thought that the NK immune response was part of our 'innate' immune system. The innate immune system fights against all antigens (foreign bodies, such as viruses), rather than specifically targeting certain antigens. We have now confirmed that NK cells in humans can acquire an immunological 'memory', and specifically target HBV-infected cells in subsequent infections."

HBV is a virus that attacks the liver. Although some individuals who are infected with HBV can eliminate the virus from their body, others, particularly those who are infected in childhood, may develop chronic infections.

"Vaccines have been vital in preventing the spread of HBV," Professor Ahlenstiel said.

"However, not everyone who is vaccinated will experience the same level of protection. A percentage of those vaccinated - roughly five per cent - will not develop immunity against HBV. This means they can still develop an infection, including a chronic infection.

"Without proper treatment, chronic HBV can lead to serious complications, including liver cancer, and liver cirrhosis with chronic liver failure. It is vital that we prevent such infections where we can.

"We hope that, through our discovery, we can harness the anti-viral properties of mNKs to develop new treatments and improve vaccines so that everyone is protected against this virus."

Some of the world's largest, most spectacular and unheralded mammals are silently slipping away, species like Tibetan wild yaks and Patagonia's huemul, Bhutan's takin and Vietnam's saola. Even Africa's three species of zebras and wildebeest have suffered massive reductions over the last several decades.

The reasons for these losses are more than disease and habitat fragmentation, deforestation or wildlife trade, according to researchers. Ultimately, the cause is rampant human population growth. And unless human behavior changes in unprecedented ways, these scientists warn that future communities of these mammals will never resemble those of the recent past or even today.

The findings are based on a new study, "Disassembled food webs and messy projections: modern ungulate communities in the face of unabating human population growth," published June 9 in Frontiers in Ecology and Evolution.

Joel Berger, lead author of the study and a professor at Colorado State University, said that the time for action is now, and that touting past conservation achievements does little to better humanity's future.

"We all must realize we're members of a broad, beautiful and living planet, and we must find ways to subsist in this together or suffer more severe consequences than what we already see," said Berger, also a senior scientist at the Wildlife Conservation Society (WCS). "For many assemblages of animals, we are nearing a moment in time, when, like Humpty Dumpty, we will not be able to put things back together again." Berger is also the Barbara Cox Anthony University Chair of Wildlife Conservation at CSU.

Analyzing ecological, human disruptors

In this study, the research team - which also included Alejandro Vila, the director for Science for WCS's Patagonia Program; Cristobal Briceno, a professor and veterinarian at University of Chile; and Joanna Lambert, a professor at the University of Colorado Boulder - analyzed direct and indirect disruptions that lead to the changing roles of mammals in global ecosystems and noted how the nature of ecological interactions has changed and will do so, on an even larger scale, in coming decades.

More specifically, they looked at what has transpired with the huemul in Patagonia, takin in Bhutan, wild horses in deserts, wolves and coyotes in North America, and the inevitability of change in big ecosystems as large carnivores are extirpated.

Scientists said this is happening as the human population increases it footprint on land.

"Even in the remote reaches of the Himalayas, stray and feral dogs, a direct result of human intrusions, wreak havoc on wild and domestic species of high economic value and cultural importance," said Tshewang Wangchuk, a study co-author, conservation biologist and president of the Bhutan Foundation.

Humans only recently colonized parts of the Himalayas, areas where ice has receded due to warming temperatures. Yet, the authors also point to human population change at a global scale. In 1830 when Vice-Admiral Robert Fitzroy captained his ship, the Beagle, through the Magellan Straits of South America, fewer than 1.2 billion people inhabited Earth. By Earth Day in 1970, there were more than 3.5 billion.

Today, only 50 years later the world's population approaches eight billion. Livestock and humans now constitute a staggering 97 percent of the planet's mammal biomass.

Food webs irretrievably altered

The research team said worldwide food webs have become irretrievably altered by humans, with little hope to reconstitute even recent past conditions or to put back the ecological functions once created by native species.

Feral pigs, for instance, exist today on every continent except Antarctica, and in 70 percent of the states in the United States. These animals disrupt fish, reptiles, birds and other small mammals, plants and soils. In addition, climate change warms the oceans, which in turn foments marine algal blooms, reducing fishery catches. With less demand for fish, a consequent uptick in wildlife poaching on land occurs.

The scientists also documented how an appetite for fashion like cashmere increases imports to the west from Mongolia, India and China, resulting in economic incentives for desert pastoralists to produce more domestic goats in central Asia. These goats compete for food with native species and are in danger due to increasing numbers of dogs in these areas. The dogs are not only predators but also carry diseases, which jeopardizes endangered species like snow leopards, kiang and Przewalksi's gazelle.

Use 'ecological grief' to implement action

Berger and the study authors suggest that despite the grim findings, all is not yet lost.

The world has remarkable protected areas including: Serengeti and Kruger National Park in Africa, Yellowstone and Wrangell-St. Elias National Park & Preserve in North America, Madidi National Park in Bolivia, the Patagonia Ice Fields of Chile and Argentina, Chang Tang Nature Reserve in China, and Northeast Greenland National Park, the world's largest national park.

And although food webs with large mammals will be different from those of the past and operate differently today, there are options to shape the future.

"It is not too late and we simply do not have the luxury of time to mourn what we have lost," said Lambert. "We need to use our ecological grief to implement action and honor the exceptional biodiversity that remains. This can be done by protecting large tracts of the planet's wild places."