Influenza viruses represent a major risk to human and animal health. Their potential for mutation makes them particularly elusive. ”We already knew that the influenza A virus binds to sugar structures on the cell surface, then rolls along the cell surface until it finds a suitable entry point into the host cell. However, we did not know which proteins on the host cell surface marked this entry point, and how they favoured the entry of the virus,” explains Mirco Schmolke, Associate Professor in the Department of Microbiology and Molecular Medicine and in the Geneva Centre for Inflammation Research (GCIR) at the UNIGE Faculty of Medicine, who led this work.

A receptor as a key to infection

The scientists first identified cell surface proteins present in the vicinity of the viral haemagglutinin, the protein used by the influenza A virus to enter the cell. One of these proteins stood out: transferrin receptor 1. This acts as a revolving door transporting iron molecules into the cell, which are essential for many physiological functions.

”The influenza virus takes advantage of the continuous recycling of the transferrin receptor 1 to enter the cell and infect it,” explains Béryl Mazel-Sanchez, a former post-doctoral researcher in Mirco Schmolke’s laboratory and first author of this work. ”To confirm our discovery, we genetically engineered human lung cells to remove the transferrin receptor 1, or on the contrary to overexpress it. By deleting it in cells normally susceptible to infection, we prevented influenza A from entering. Conversely, by overexpressing it in cells normally resistant to infection, we made them easier to infect”.

Inhibiting this mechanism

The research team then succeeded in reproducing this mechanism by inhibiting the transferrinreceptor 1 using a chemical molecule. ”We tested it successfully on human lung cells, on human lung tissue samples and on mice with several viral strains,” says Béryl Mazel-Sanchez. ”In the presence of this inhibitor, the virus replicated much less. However, in view of its potentially oncogenic characteristics, this product cannot be used to treat humans.” On the other hand, anti-cancer therapies based on the inhibition of the transferrin receptor are under development and could also be interesting in this context.

”Our discovery was made possible thanks to the excellent collaboration within the Faculty of Medicine as well as with the University Hospitals of Geneva (HUG) and the Swiss Institute of Bioinformatics (SIB),” the authors add. In addition to the transferrin receptor 1, scientists have identified some 30 other proteins whose role in the influenza A entry process remains to be deciphered. It is indeed likely that the virus uses a combination involving other receptors. ”Although we are still far from a clinical application, blocking the transferrin receptor 1 could become a promising strategy for treating influenza virus infections in humans and potentially in animals.”

In a set of experiments, individual plant cells responded to the touch of a very fine glass rod by sending slow waves of calcium signals to other plant cells, and when that pressure was released, they sent much more rapid waves. While scientists have known that plants can respond to touch, this study shows that plant cells send different signals when touch is initiated and ended.

“It is quite surprising how finely sensitive plants cells are — that they can discriminate when something is touching them. They sense the pressure, and when it is released, they sense the drop in pressure,” said Michael Knoblauch, WSU biological sciences professor and senior author of the study in the journal Nature Plants. “It’s surprising that plants can do this in a very different way than animals, without nerve cells and at a really fine level.”

Knoblauch and his colleagues conducted a set of 84 experiments on 12 plants using thale cress and tobacco plants that had been specially bred to include calcium sensors, a relatively new technology. After placing pieces of these plants under a microscope, they applied a slight touch to individual plant cells with a micro-cantilever, essentially a tiny glass rod about the size of a human hair. They saw many complex responses depending on the force and duration of the touch, but the difference between the touch and its removal was clear.

Within 30 seconds of the applied touch to a cell, the researchers saw slow waves of calcium ions, called cytosolic calcium, travelling from that cell through the adjacent plant cells, lasting about three to five minutes. Removal of the touch showed an almost instant set of more rapid waves that dissipated within a minute.

The authors believe these waves are likely due to the change in pressure inside the cell. Unlike animal cells with permeable membranes, plant cells also have strong cellular walls that cannot be easily breached, so just a light touch will temporarily increase pressure in a plant cell.

The researchers tested the pressure theory mechanically by inserting a tiny glass capillary pressure probe into a plant cell. Increasing and decreasing pressure inside the cell resulted in similar calcium waves elicited by the start and stop of a touch.

“Humans and animals sense touch through sensory cells. The mechanism in plants appears to be via this increase or decrease of the internal cell pressure,” said Knoblauch. “And it doesn’t matter which cell it is. We humans may need nerve cells, but in plants, any cell on the surface can do this.”

Previous research has shown that when a pest like a caterpillar bites a plant leaf, it can initiate the plant’s defensive responses such as the release of chemicals that make leaves less tasty or even toxic to the pest. An earlier study also revealed that brushing a plant triggers calcium waves that activate different genes.

The current study was able to differentiate the calcium waves between touch and letting go, but how exactly the plant’s genes respond to those signals remains to be seen. With new technologies like the calcium sensors used in this study, scientists can start to untangle that mystery, Knoblauch said.

“In future studies, we have to trigger the signal in a different way than has been done before to know what signal, if touch or letting go, triggers downstream events,” he said.

This study was supported by grants from the National Science Foundation. The international team included researchers from the Technical University of Denmark; Ludwig Maximilian Universitaet Muenchen and Westfaelische Wilhelms-Universitaet Muenster in Germany; and University of Wisconsin-Madison as well as WSU.

Walk-in freezers and refrigerated trucks generally maintain their set temperatures, but accidents can happen. Wireless sensors can monitor the temperature of individual products, but these devices produce a lot of electronic waste. Recently, researchers have suggested using materials that act as visual indicators to provide this information with less waste. Yet some current options using colorful reactions or dyes produce hues that can fade. Or they only track above-freezing temperatures, which isn’t useful for some COVID-19 vaccines that can actually start breaking down below freezing — above -4 or -94 degrees Fahrenheit. So, Yadong Yin, Xuemin Du and colleagues wanted to develop a better color-changing material with tunable melting to track a wide range of temperatures.

The researchers used structural colors, instead of dyes, for their indicator system. The team made glycerol-coated silicon dioxide nanoparticles, which appeared bright green or red when they clustered together into microcrystals in water. Next, they created liquids with variable melting points by mixing different proportions of polyethylene glycol or ethylene glycol and water. When these two parts were put together, they could produce an irreversible color loss when the temperature-triggered solution melted and the microcrystals broke apart. The materials could be customized to track temperature exposures from -94 to +99 degrees Fahrenheit that lasted from a few minutes to multiple days. In other experiments, the two-part indicator systems were packaged into flexible round vial labels and a QR code. These systems were very sensitive and successfully indicated when the materials got too warm. The researchers say that structural color-changing materials hold promise for the diverse scenarios encountered in medical cold supply chains.

The authors acknowledge funding from the National Natural Science Foundation of China, the National Key R&D Program of China, the Youth Innovation Promotion Association of Chinese Academy of Sciences, the Guangdong Regional Joint Fund-Key Project, the Chinese Academy of Sciences Key Laboratory of Health Informatics, the Shenzhen Institutes of Advanced Technology and the Fundamental Research Program of Shenzhen.

A team of Japanese, Australian, Dutch, and Italian researchers has set a new speed record for an industry standard optical fibre, achieving 1.7 Petabits over a 67km length of fibre. The fibre, which contains 19 cores that can each carry a signal, meets the global standards for fibre size, ensuring that it can be adopted without massive infrastructure change. And it uses less digital processing, greatly reducing the power required per bit transmitted.

Macquarie University researchers supported the invention by developing a 3D laser-printed glass chip that allows low loss access to the 19 streams of light carried by the fibre and ensures compatibility with existing transmission equipment.

The fibre was developed by the Japanese National Institute of Information and Communications Technology (NICT, Japan) and Sumitomo Electric Industries, Ltd. (SEI, Japan) and the work was performed in collaboration with the Eindhoven University of Technology, University of L’Aquila, and Macquarie University.

All the world’s internet traffic is carried through optical fibres which are each 125 microns thick (comparable to the thickness of a human hair). These industry standard fibres link continents, data centres, mobile phone towers, satellite ground stations and our homes and businesses.

Back in 1988, the first subsea fibre-optic cable across the Atlantic had a capacity of 20 Megabits or 40,000 telephone calls, in two pairs of fibres. Known as TAT 8, it came just in time to support the development of the World Wide Web. But it was soon at capacity.

The latest generation of subsea cables such as the Grace Hopper cable, which went into service in 2022, carries 22 Terabits in each of 16 fibre pairs. That’s a million times more capacity than TAT 8, but it’s still not enough to meet the demand for streaming TV, video conferencing and all our other global communication.

“Decades of optics research around the world has allowed the industry to push more and more data through single fibres,” says Dr Simon Gross from Macquarie University’s School of Engineering. “They’ve used different colours, different polarisations, light coherence and many other tricks to manipulate light.”

Most current fibres have a single core that carries multiple light signals. But this current technology is practically limited to only a few Terabits per second due to interference between the signals.

“We could increase capacity by using thicker fibres. But thicker fibres would be less flexible, more fragile, less suitable for long-haul cables, and would require massive reengineering of optical fibre infrastructure,” says Dr Gross.

“We could just add more fibres. But each fibre adds equipment overhead and cost and we’d need a lot more fibres.”

To meet the exponentially growing demand for movement of data, telecommunication companies need technologies that offer greater data flow for reduced cost.

The new fibre contains 19 cores that can each carry a signal.

“Here at Macquarie University, we’ve created a compact glass chip with a wave guide pattern etched into it by a 3D laser printing technology. It allows feeding of signals into the 19 individual cores of the fibre simultaneously with uniform low losses. Other approaches are lossy and limited in the number of cores,” says Dr Gross.

“It’s been exciting to work with the Japanese leaders in optical fibre technology. I hope we’ll see this technology in subsea cables within five to 10 years.”

Another researcher involved in the experiment, Professor Michael Withford from Macquarie University’s School of Mathematical and Physical Sciences, believes this breakthrough in optical fibre technology has far-reaching implications.

“The optical chip builds on decades of research into optics at Macquarie University,” says Professor Withford. “The underlying patented technology has many applications including finding planets orbiting distant stars, disease detection, even identifying damage in sewage pipes.”

In a new study published in Nature Climate Change, environmental economists including the University of Exeter’s Professor Ben Groom found consensus between the two academic disciplines over an aspect of climate policy known as the ‘social discount rate’, with philosophers offering support for a rate of 2% — a value predominantly backed by economists, and which is in line with UN climate targets.

Social discount rates are used by governments to determine how costs and benefits that occur in the future — such as the impacts of climate mitigation projects, policies and programmes — are valued in the present.

A low discount rate places greater value on the benefits to future generations, such as those created by avoiding burning fossil fuels, and increases the costs of carbon emissions used in public investment appraisal.

The researchers analysed survey data from over 200 economists and philosophers with expertise in social discounting, who provided a range of qualitative and quantitative answers.

They found considerable agreement between the two disciplines for a long-term social discount rate of 2% and on analysing the survey data they found in each discipline the median discounting value resulted in temperature changes of around 1.4 degrees C by the end of the century, a figure in line with the UN Paris climate targets.

Small changes to the SDR have significant policy implications: the Trump administration’s increase of the SDR from 3% to 7% reducing the social cost of carbon by a factor of seven, whereas New York State’s decision to reduce its SDR to 2% rather than 3% made the social cost of carbon increase from $40 to $125 per tonne of CO₂.

The study is the first to attempt to build expert consensus on social discount rates outside the field of economics.

Expert advice — predominantly from economists — plays a key role in discounting and its application to climate policy, but the underlying ethical issues at stake fall outside most economists’ expertise.

The findings therefore strengthen economists’ arguments for a social discount rate of 2% by underpinning it with ethical concerns for the welfare of future generations and ‘intergenerational equity’.

Professor Ben Groom, Dragon Capital Chair in Biodiversity Economics at the University of Exeter said: “That economists and philosophers can agree on policy outcomes builds academic expert consensus, and the paper will help build consensus in favour of the new guidance as it works its way through the US government.

“The different perspectives of philosophers are complementary to those of economists and offer ethical checks and balances within integrated assessment models to narrow the set of acceptable climate policies, or offer altogether different procedural lenses through which to evaluate climate policy. These insights will be overlooked if economists continue to dominate the social discounting debate.”

The study, published in the latest issue of the journal Gerontologist, is the first to longitudinally track sexual satisfaction in tandem with sexual health and cognition, the researchers state, and its findings point to a potential novel risk factor for cognitive decline.

“What was unique about our approach is that we measured memory function and sexual function at each point in the longitudinal study, so we could look at how they changed together over time,” said Martin Sliwinski, professor of human development and family studies at Penn State and co-author on the study. “What we found connects to what scientists are beginning to understand about the link between life satisfaction and cognitive performance.”

The study explored the relationship between physical changes like the microvascular changes relevant for erectile function, and psychological changes, such as lower sexual satisfaction, to determine how the changes relate to cognition. They examined the shifts starting in middle age because it represents a transition period where declines in erectile function, cognition and sexual satisfaction begin to emerge.

Sliwinski added that while the team discovered a strong correlation between the three health factors, they can only speculate as to the cause.

“Scientists have found that if you have low satisfaction generally, you are at a higher risk for health problems like dementia, Alzheimer’s disease, cardiovascular disease and other stress-related issues that can lead to cognitive decline,” he said. “Improvements in sexual satisfaction may actually spark improvement in memory function. We tell people they should get more exercise and eat better foods. We’re showing that sexual satisfaction also has importance for our health and general quality of life.”

For the study, the researchers used survey data from 818 men who participated in the Vietnam Era Twin Study of Aging. Through neuropsychological tests, such as tests of memory and processing speed, they examined cognitive changes of participants over the 12-year span from age 56 to 68, adjusting for participants’ cognitive ability in young adulthood. Their erectile function and sexual satisfaction were measured alongside cognition, using the International Index of Erectile Function, a self-reported assessment for male sexual health. The researchers then built a statistical model to understand how the three variables changed as individuals aged.

“Research on sexual health has historically focused on quantifiable facets of sexuality like number of sexual partners or frequency of sexual activity,” said Riki Slayday, a doctoral candidate at Penn State and lead author on the study. “What we were interested in is the perception of that activity, how someone feels about their sex life, and how that influences cognitive function, because multiple people could be in the same situation physically but experience completely different levels of satisfaction.”

The study found that decreases in erectile function and sexual satisfaction were both associated with memory decline, which the researchers say points to a connection between psychological and physical health.

“When we mapped the relationship over time, we found increases or decreases in erectile function and sexual satisfaction were associated with concurrent increases or decreases in cognitive function,” Slayday said. “These associations survived adjustment for demographic and health factors, which tells us there is a clear connection between our sex lives and our cognition.”

Prior studies have found a link between microvascular changes and changes in erectile function over time. In fact, the active ingredient in Viagra (Sildenafil) was originally developed to treat cardiovascular problems, Sliwinski explained, so the connection between vascular health and erectile function is well understood. How erectile function connects to other aspects of health should be an area of focus for future research, he added.

Increasing the assessment and monitoring of erectile function as a vital sign of health may help identify those at risk of cognitive decline before their 70s, he said. The researchers note that the older adult population in the U.S. is expected to double over the next 30 years, which means twice as many people will likely enter their 60s and experience declines in erectile function and sexual satisfaction.

“We already have a pill for treating erectile dysfunction. What we don’t have is an effective treatment for memory loss,” Sliwinski said. “Instead of the conversation being about treating ED, we should see that as a leading indicator for other health problems and also focus on improving sexual satisfaction and overall well-being, not just treating the symptom.”

Other co-authors on the paper are Tyler Bell, Teresa Warren, William Kremen and Carol Franz of the University of California San Diego; and Michael Lyons, Rosemary Toomey and Richard Vandiver of Boston University.

The work was supported the National Institute on Aging at the National Institutes of Health.