Earth

LAWRENCE -- A new paper appearing in Biology Letters describes the oldest-known fragmentary bat fossils from Asia, pushing back the evolutionary record for bats on that continent to the dawn of the Eocene and boosting the possibility that the bat family's "mysterious" origins someday might be traced to Asia.

A team based at the University of Kansas and China performed the fieldwork in the Junggar Basin -- a very remote sedimentary basin in northwest China -- to discover two fossil teeth belonging to two separate specimens of the bat, dubbed Altaynycteris aurora.

The new fossil specimens help scientists better understand bat evolution and geographic distribution and better grasp how mammals developed in general.

"Bats show up in the fossil record out of the blue about 55-ish million years ago -- and they're already scattered on different parts of the globe," said lead author Matthew Jones, a doctoral student at the KU Biodiversity Institute and Department of Ecology & Evolutionary Biology. "Before this, the earliest bats are known from a couple of places in Europe -- Portugal and southern France -- and Australia. So, when they show up early in the fossil record as these fragmentary fossils they're already effectively worldwide. By the time we get their earliest known full skeletons, they look modern -- they can fly, and most of them are able to echolocate. But we don't really know anything about this transitional period from non-bats to bats. We don't even really know what their closest living relatives are among mammals. It's a really big evolutionary mystery where bats came from and how they evolved and became so specialized."

Jones' co-authors were K. Christopher Beard, senior curator at the KU Biodiversity Institute and Foundation Distinguished Professor of Ecology & Evolutionary Biology at KU; and Qiang Li and Xijun Ni of the Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences and the Center for Excellence in Life and Paleoenvironment at the Chinese Academy of Sciences.

The ancient bat teeth were discovered through painstaking fieldwork in the Junggar Basin, where the KU researchers worked at an isolated field site established by their Chinese colleagues, one of two sites in the region the team hope will continue yielding interesting fossils.

"This was concerted effort over a long period of time by our Chinese colleagues," Jones said.

"They suspected that there were fossiliferous deposits from the Paleocene and Eocene, and they spent several years going out there, identifying where to find fossils. Chris was a part of several seasons of fieldwork there. I was a part of one season of fieldwork there. What we did was collect a bunch of sediment to screen wash, which is sort of like panning for gold. You pour a bunch of sediment into a sievelike apparatus and let all the dirt and everything fall out, and you're only left with particles of a certain size, but also fossils."

Beard said the fieldwork was an outgrowth of long-standing relationships between the KU team and its Chinese counterparts.

"We've been fortunate enough to be able to host our Chinese colleagues here in Lawrence for extended research visits, and they've more than reciprocated by hosting us for research and fieldwork in China. This work in the Junggar Basin is really trailblazing work because the fossil record in this part of China is only just barely beginning to emerge, and this area is very removed and isolated. It's just a giant empty place. There are some camels, some snakes and lizards, but you don't see many people there. That remoteness makes the logistics to do fieldwork there quite difficult and expensive because you've got to bring in all your food and water from far outside -- all of that hindered research in this area previously."

Following the challenging fieldwork, the residue left behind from the screen washing at the site was sorted at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing.

"In 2017, after we got back from the field, Xijun said. 'Hey, one of the technicians picking through this sediment thinks they found a bat,'" Jones said. "Knowing I was interested in bats, they showed it to me. The next year, the other tooth was found -- so there's two teeth."

Through meticulous morphological analysis of the teeth, along with biostratigraphy -- or analyzing the position of layers of fossil remains in the deposits -- the authors were able to date the specimens to the advent of the Eocene, the earliest period when bat fossils have been found anywhere on Earth. Indeed, the presence of these ancient bat fossils in Asia bolsters a theory that bats could have emerged from there in the first place, then distributed themselves worldwide when they later developed flight.

More fieldwork in the area is ongoing, and Jones and Beard said they were hopeful to find even older specimens, perhaps even dating to the Paleocene, the epoch before the Eocene, when researchers believe bats probably originated. Yet the particulars of Altaynycteris aurora remain hazy -- for instance, it's impossible to say from teeth fragments if the animal could fly or echolocate.

"These teeth look intermediate, in between what we would expect a bat ancestor to look like -- and in fact, what a lot of early Cenozoic insectivorous mammals to do look like -- and what true bat looks like," Jones said. "So, they have some features that are characteristic of bats that we can point to and say, 'These are bats.' But then they have some features that we can call for simplicity's sake 'primitive.'"

The researchers said the new fossils help fill in a gap to understanding the evolution of bats, which remains a puzzle to experts -- and could teach us more about mammals in general.

"I can think of two mammal groups that are alive today that are really weird," Beard said. "One of them is bats, because they fly -- and that's just ridiculous. The other one is whales, because they're completely adapted to life in the ocean, they can swim, obviously, and they do a little bit of sonar echolocation themselves. We know a lot about transitional fossils for whales. There are fossils from places like Pakistan that were quadrupedal mammals that looked vaguely doglike. We have a whole sequence of fossils linking these things that were clearly terrestrial animals walking around on land, through almost every kind of transitional phase you can imagine, to a modern whale. This isn't true for bats. For bats, literally you've got a normal mammal and then you've got bats -- and anytime you've got a fossil record that's a giant vacuum, we need work that can fill partly that. This paper is at least a step along that path."

The Arctic is warming at approximately twice the global rate. A new study led by researchers from McGill University finds that cold-adapted Arctic species, like the thick-billed murre, are especially vulnerable to heat stress caused by climate change.

"We discovered that murres have the lowest cooling efficiency ever reported in birds, which means they have an extremely poor ability to dissipate or lose heat," says lead author Emily Choy, a Postdoctoral Fellow in the Natural Resource Sciences Department at McGill University.

Following reports of the seabirds dying in their nests on sunny days, the researchers trekked the cliffs of Coats Island in northern Hudson Bay to study a colony of 30,000 breeding pairs. They put the birds' heat tolerance to the test and found that the animals showed signs of stress at temperatures as low as 21C.

Until now few studies have explored the direct effects of warming temperatures on Arctic wildlife. The study, published in Journal of Experimental Biology, is the first to examine heat stress in large Arctic seabirds.

Bigger not always better

By measuring breathing rates and water loss as the murres were subjected to increasing temperatures, the researchers found that larger birds were more sensitive to heat stress than smaller birds.

Weighing up to one kilogram, murres have a very high metabolic rate relative to their size, meaning when they pant or flap their wings to cool off, they expend a very high amount of energy, producing even more heat.

These seabirds nest in dense colonies, often breeding shoulder to shoulder along the narrow ledges of cliffs. Male and female birds take turns nesting on 12-hour shifts. According to the researchers, the thick-billed murres' limited heat tolerance may explain their mortalities on warm weather days.

"Overheating is an important and understudied effect of climate change on Arctic wildlife," says Choy. "Murres and potentially other Arctic species are poorly adapted for coping with warming temperatures, which is important as the Arctic continues to warm."

From above, the Antarctic Ice Sheet might look like a calm, perpetual ice blanket that has covered Antarctica for millions of years. But the ice sheet can be thousands of meters deep at its thickest, and it hides hundreds of meltwater lakes where its base meets the continent's bedrock. Deep below the surface, some of these lakes fill and drain continuously through a system of waterways that eventually drain into the ocean.

Now, with the most advanced Earth-observing laser instrument NASA has ever flown in space, scientists have improved their maps of these hidden lake systems under the West Antarctic ice sheet--and discovered two more of these active subglacial lakes.

The new study provides critical insight for spotting new subglacial lakes from space, as well as for assessing how this hidden plumbing system influences the speed at which ice slips into the Southern Ocean, adding freshwater that may alter its circulation and ecosystems.

NASA's Ice, Cloud and land Elevation Satellite 2, or ICESat-2, allowed scientists to precisely map the subglacial lakes. The satellite measures the height of the ice surface, which, despite its enormous thickness, rises or falls as lakes fill or empty under the ice sheet.

The study, published July 7 in Geophysical Research Letters, integrates height data from ICESat-2's predecessor, the original ICESat mission, as well as the European Space Agency's satellite dedicated to monitoring polar ice thickness, CryoSat-2.

Hydrology systems under the Antarctic ice sheet have been a mystery for decades. That began to change in 2007, when Helen Amanda Fricker, a glaciologist at Scripps Institution of Oceanography at the University of California San Diego, made a breakthrough that helped update classical understanding of subglacial lakes in Antarctica.

Using data from the original ICESat in 2007, Fricker found for the first time that under Antarctica's fast flowing ice streams, an entire network of lakes connect with one another, filling and draining actively over time. Before, these lakes were thought to hold meltwater statically, without filling and draining.

"The discovery of these interconnected systems of lakes at the ice-bed interface that are moving water around, with all these impacts on glaciology, microbiology, and oceanography--that was a big discovery from the ICESat mission," said Matthew Siegfried, assistant professor of geophysics at Colorado School of Mines, Golden, Colo. and lead investigator in the new study. "ICESat-2 is like putting on your glasses after using ICESat, the data are such high precision that we can really start to map out the lake boundaries on the surface."

Scientists have hypothesized subglacial water exchange in Antarctica results from a combination of factors, including fluctuations in the pressure exerted by the massive weight of the ice above, the friction between the bed of the ice sheet and the rocks beneath, and heat coming up from the Earth below that is insulated by the thickness of the ice. That's a stark contrast from the Greenland ice sheet, where lakes at the bed of the ice fill with meltwater that has drained through cracks and holes on the surface.

To study the regions where subglacial lakes fill and drain more frequently with satellite data, Siegfried worked with Fricker, who played a key role in designing the way the ICESat-2 mission observes polar ice from space.

Siegfried and Fricker's new research shows that a group of lakes including the Conway and Mercer lakes under the Mercer and Whillans ice streams in West Antarctica are experiencing a draining period for the third time since the original ICESat mission began measuring elevation changes on the ice sheet's surface in 2003. The two newly found lakes also sit in this region.

In addition to providing vital data, the study also revealed that the outlines or boundaries of the lakes can change gradually as water enters and leaves the reservoirs.

"We're really mapping out any height anomalies that exist at this point," Siegfried said. "If there are lakes filling and draining, we will detect them with ICESat-2."

'Helping Us Observe' Under the Ice Sheet

Precise measurements of basal meltwater are crucial if scientists want to gain a better understanding of Antarctica's subglacial plumbing system, and how all that freshwater might alter the speed of the ice sheet above or the circulation of the ocean into which it ultimately flows.

An enormous dome-shaped layer of ice covering most of the continent, the Antarctic ice sheet flows slowly outwards from the central region of the continent like super thick honey. But as the ice approaches the coast, its speed changes drastically, turning into river-like ice streams that funnel ice rapidly toward the ocean with speeds up to several meters per day. How fast or slow the ice moves depends partly on the way meltwater lubricates the ice sheet as it slides on the underlying bedrock.

As the ice sheet moves, it suffers cracks, crevasses, and other imperfections. When lakes under the ice gain or lose water, they also deform the frozen surface above. Big or small, ICESat-2 maps these elevation changes with a precision down to just a few inches using a laser altimeter system that can measure Earth's surface with unprecedented detail.

Tracking those complex processes with long-term satellite missions will provide crucial insights into the fate of the ice sheet. An important part of what glaciologists have discovered about ice sheets in the last 20 years comes from observations of how polar ice is changing in response to warming in the atmosphere and ocean, but hidden processes such as the way lake systems transport water under the ice will also be key in future studies of the Antarctic Ice Sheet, Fricker said.

"These are processes that are going on under Antarctica that we wouldn't have a clue about if we didn't have satellite data," Fricker said, emphasizing how her 2007 discovery enabled glaciologists to confirm Antarctica's hidden plumbing system transports water much more rapidly than previously thought. "We've been struggling with getting good predictions about the future of Antarctica, and instruments like ICESat-2 are helping us observe at the process scale."

'A Water System That Is Connected to the Whole Earth System'

How freshwater from the ice sheet might impact the circulation of the Southern Ocean and its marine ecosystems is one of Antarctica's best kept secrets. Because the continent's subglacial hydrology plays a key role in moving that water, Siegfried also emphasized the ice sheet's connection to the rest of the planet.

"It's not just the ice sheet we're talking about," Siegfried said. "We're really talking about a water system that is connected to the whole Earth system."

Recently, Fricker and another team of scientists explored this connection between freshwater and the Southern Ocean--but this time by looking at lakes near the surface of an ice shelf, a large slab of ice that floats on the ocean as an extension of the ice sheet. Their study reported that a large, ice-covered lake collapsed abruptly in 2019 after a crack or fracture opened from the lake floor to the base of Amery Ice Shelf in East Antarctica.

With data from ICESat-2, the team analyzed the rugged change on the landscape of the ice shelf. The event left a doline, or sinkhole, a dramatic depression of about four square miles (about 10 square kilometers), or more than three times the size of New York City's Central Park. The crack funneled nearly 200 billion gallons of freshwater from the surface of the ice shelf into the ocean below within three days.

During the summer, thousands of turquoise meltwater lakes adorn the bright white surface of Antarctica's ice shelves. But this abrupt event occurred in the middle of the winter, when scientists expect water on the surface of the ice shelf to be completely frozen. Because ICESat-2 orbits Earth with exactly repeating ground tracks, its laser beams can show the dramatic change in the terrain before and after the lake drained, even during the darkness of polar winter.

Roland Warner, a glaciologist with the Australian Antarctic Program Partnership at the University of Tasmania, and lead author of the study, first spotted the scarred ice shelf in images from Landsat 8, a joint mission of NASA and the U.S. Geological Survey. The drainage event was most likely caused by a hydrofracturing process in which the mass of the lake's water led to a surface crack being driven right through the ice shelf to the ocean below, Warner said.

"Because of the loss of this weight of water on the surface of the floating ice shelf, the whole thing bends upwards centered on the lake," Warner said. "That's something that would have been difficult to figure out just staring at satellite imagery."

Meltwater lakes and streams on Antarctica's ice shelves are common during the warmer months. And because scientists expect these meltwater lakes to be more common as air temperatures warm, the risk of hydrofracturing could also increase in coming decades. Still, the team concluded it's too early to determine whether warming in Antarctica's climate caused the demise of the observed lake on Amery Ice Shelf.

Witnessing the formation of a doline with altimetry data was a rare opportunity, but it is also the type of event glaciologists need to analyze in order to study all of the ice dynamics that are relevant in models of Antarctica.

"We have learned so much about ice sheet dynamic processes from satellite altimetry, it is vital that we plan for the next generation of altimeter satellites to continue this record," Fricker said.

Bahamian mosquitofish in habitats fragmented by human activity are more willing to explore their environment, more stressed by change and have smaller brain regions associated with fear response than mosquitofish from unaffected habitats. The new study from North Carolina State University shows that these fish have adapted quickly in specific ways to human-driven change, and cautions that environmental restoration projects should understand these changes so as not to damage adapted populations.

The Bahamas mosquitofish is a small, coastal fish species that frequently inhabits tidal creeks - shallow, tidally influenced marine ecosystems. In the 1960s and 70s, road construction in The Bahamas caused many of these habitats to become "fragmented," or largely cut off from the ocean.

"Mosquitofish in these fragmented areas suddenly found themselves in a much different environment than previously, in terms of things like predation and tidal dynamics," says Brian Langerhans, associate professor of biology at NC State and corresponding author of the study. "We set out to determine how natural variation in structural habitat complexity and human-induced fragmentation influenced exploratory behavior, stress response, and brain anatomy."

Langerhans and a team of NC State researchers observed about 350 mosquitofish from seven different populations: three fragmented and four non-fragmented. The habitats varied in complexity, from simple mud-bottomed spaces to those that included a large number of rocks and vegetation, such as mangroves.

"We were testing predictions based upon our understanding of natural selection," Langerhans says. "For instance, in a fragmented space with fewer natural predators, we hypothesized that those fish would be more exploratory, since exploratory behavior could be rewarded in terms of competing for food. We also wanted to see if there were physiological changes to the areas of the brain that are associated with those and other similar behaviors."

The team measured stress response and exploratory behavior by temporarily placing mosquitofish in a different environment and observing changes in respiration and their willingness to explore. They also compared brain size in fish from the different habitats.

They found that overall, fish from a more complex environmental habitat were more willing to explore new environments. But for a given level of habitat complexity, fish in fragmented sites were more exploratory than those from unfragmented sites. In addition, fish from fragmented habitats had a higher stress response to change.

"These findings were in line with our expectations," Langerhans says. "Exploratory behavior can reward fish in habitats with few predators by helping them compete for food, and can give fish in complex habitats an advantage in locating safety and hard-to-find food resources. As for the stress response, fish in unfragmented tidal creeks with lots of predators and high tidal dynamics have a higher level of everyday stress than those in more static, predator-free habitats. Change will be much more stressful for fish in the latter areas, since they're less stressed to begin with."

They also noted that while there were no overall differences in brain size between fish from differing habitats, fish from fragmented environments had a smaller telencephalon - the region of the brain associated with fear response, while fish in complex environments had a larger optic tectum and cerebellum, brain regions associated with responding to visual stimuli, motor skills, and associative learning.

"Brain tissue is expensive for an organism to produce," Langerhans says. "If fish in fragmented or simple environments no longer experience major demands for behaviors such as avoiding predation or navigating complex situations, seeing changes in these brain areas isn't that surprising."

The study also highlights how quickly organisms adapt to new environments, and how those environments affect the biological makeup of their inhabitants - something that restoration project planners should keep in mind when attempting to restore habitats to their ancestral state.

"Everything that humans plan to do to these environments should have a lot of forethought put into it," Langerhans says. "If local adaptations occurred over a 50-year period in response to an altered environment and we quickly restore it to 'normal,' you could do more harm than good to some of its inhabitants."

The research appears in the Journal of Animal Ecology, and was supported by NC State's W.M. Keck Center for Behavioral Biology, the Helge Axson Johnson Foundation, and the Swedish Research Council (Grant 2015-00300). NC State graduate student Matthew Jenkins is first author. NC State undergraduates John Cummings and Alex Cabe, fisheries and wildlife professor Nils Peterson, and former NC State postdoctoral researcher Kaj Hulthén, also contributed to the work.

By 2050, faster adoption of electric vehicles (EVs) and faster generation of renewable energy will result in 99% less fossil fuel consumed and 93% less CO2 emissions from passenger and freight vehicles on O?ahu. That's under the most ambitious scenario in an article published in World Electric Vehicle Journal, by University of Hawai?i at Mānoa School of Ocean and Earth Science and Technology (SOEST) faculty member Katherine McKenzie.

McKenzie, based at the Hawai?i Natural Energy Institute in SOEST, created mathematical models of four scenarios based on projections for the switch to electric passenger and freight vehicles, and renewable power generation. She quantified the impacts of fossil fuel use and CO2 emissions on O?ahu and found that scenarios with a slower transition to EVs result in billions more gallons of gasoline consumed, and tens of millions more tons of CO2 emitted.

As with many other remote communities still dependent on oil for both transportation and power, there remains a lack of critical analysis to determine the benefits of transitioning from internal combustion engine vehicles to plug-in electric vehicles (EVs). In 2020, average passenger EVs were found to consume the equivalent of 66 gallons of gasoline, seven times less fossil fuel than their gasoline-powered counterparts, which used 455 gallons. Average EVs also cut emissions in half, two metric tons of CO2 versus four metric tons of CO2.

"Continuing to purchase anything powered by petroleum locks in emissions and energy insecurity for years to come, at a time when decarbonization is a climate imperative," said McKenzie. "A shift is needed to energy efficient modes of travel--such as bicycling, walking and transit, along with reducing vehicle miles traveled (by "smart" city planning and remote work for example)."

The newly developed method lets researchers rapidly and accurately measure stress hormones in snow leopards without the need for bulky equipment or specialised knowledge. It uses widely available equipment that can be carried into the field, allowing hormone extraction from faecal samples and analysis to be done on site.

This differs from existing approaches to hormone monitoring in wild animals, where faecal samples must be taken to laboratories for hormone extraction and analysis. These approaches are particularly limiting in remote locations, such as the Himalayas.

"Because conventional hormone monitoring methods require frozen and refrigerated chemical reagents, and laboratory equipment, it is almost impossible to use them on-site." explained Dr Kodzue Kinoshita of Kyoto University and author of the study.

The new method developed by Dr Kinoshita extracts hormones from snow leopard faeces by shaking a container with the sample mixed with ethanol by hand. A process called immunochromatography, which is used in pregnancy tests, is used to detect hormone concentrations using test strips and a smartphone application then analyses them.

The accuracy of the new method was tested on faecal samples from captive snow leopards at Kohu Yuki Zoo, Asahikawa City Asahiyama Zoo, and Nagoya Higashiyama Zoo and Botanical Gardens in Japan. Comparisons to conventional methods found that similar hormone concentrations were extracted and changes in these concentrations were also accurately detected.

Stress in animals can be associated with reduced reproductive function, so finding out what in the environment stresses animals is important for conservation.

"Simple methods like this, will allow researchers, rangers, and zookeepers, to quickly and easily assess the stress status of snow leopards." said Dr Kinoshita. "Getting this insight will be useful for the management of animal welfare and conservation planning."

Dr Kinoshita added that the new technique could also be applied to captive snow leopards and other animals. "The hormone analysed in this method is generally not species-specific, so this method can be used to assess various species, including domestic, experimental, zoo, and wild animals."

Snow leopards are listed as 'vulnerable' on the IUCN red list and are threatened by poaching, retaliatory killings for livestock attacks and climate change. It's feared these continued pressures will increase stress in snow leopards, further contributing to population declines.

Snow leopards are also notoriously difficult to study, the mountainous regions in central Asia they inhabit make finding the big cats hard and limits researchers' access to laboratories.

The novel method Dr Kinoshita developed in this study involves adding ethanol to collected snow leopard faeces and then shaking the container with two zirconia beads by hand for two minutes to extract the hormones. The extract is then dropped onto the immunochromatography test strip which turns red as a result of an antigen-antibody reaction, indicating the presence of adrenocortical stress hormones. A smartphone app is used to measure the hormone concentration from the intensity of the colour.

Although this novel method could be applied to the other species, Dr Kinoshita warns that this will need to be tested for each species to ensure the stress hormones detected in the faeces accurately reflects the stress of the animal, as these levels will vary between species.

"As a next step, I would like to apply this method to various other animals and make it more reliable." said Dr Kinoshita. "I would also like to apply it to not only to wild animals, but also to zoo animals and pets to clarify the stress of these animals and improve their living environment."

Scientists at the University of Cambridge have identified rare genetic variants - carried by one in 3,000 people - that have a larger impact on the risk of developing type 2 diabetes than any previously identified genetic effect.

Type 2 diabetes is thought to be driven in part by inherited genetic factors, but many of these genes are yet unknown. Previous large-scale studies have depended on efficient 'array genotyping' methods to measure genetic variations across the whole genome. This approach typically does a good job at capturing the common genetic differences between people, though individually these each confer only small increases in diabetes risk.

Recent technical advances have allowed more comprehensive genetic measurement by reading the complete DNA sequences of over 20,000 genes that code for proteins in humans. Proteins are essential molecules that enable our bodies to function. In particular, this new approach has allowed for the first time a large-scale approach to study the impact of rare genetic variants on several diseases, including type 2 diabetes.

By looking at data from more than 200,000 adults in the UK Biobank study, researchers from the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge used this approach to identify genetic variants associated with the loss of the Y chromosome. This is a known biomarker of biological ageing that occurs in a small proportion of circulating white blood cells in men and indicates a weakening in the body's cellular repair systems. This biomarker has been previously linked to age-related diseases such as type 2 diabetes and cancer.

In results published today in Nature Communications, the researchers identified rare variants in the gene GIGYF1 that substantially increase susceptibility to loss of the Y chromosome, and also increase an individual's risk of developing type 2 diabetes six-fold. In contrast, common variants associated with type 2 diabetes confer much more modest increases in risk, typically much lower than two-fold.

Around 1 in 3,000 individuals carries such a GIGYF1 genetic variant. Their risk of developing type 2 diabetes is around 30%, compared to around 5% in the wider population. In addition, people who carried these variants had other signs of more widespread ageing, including weaker muscle strength and more body fat.

GIGYF1 is thought to control insulin and cell growth factor signalling. The researchers say their findings identify this as a potential target for future studies to understand the common links between metabolic and cellular ageing, and to inform future treatments.

Dr John Perry, from the MRC Epidemiology Unit and a senior author on the paper, said: "Reading an individual's DNA is a powerful way of identifying genetic variants that increase our risk of developing certain diseases. For complex diseases such as type 2 diabetes, many variants play a role, but often only increasing our risk by a tiny amount. This particular variant, while rare, has a big impact on an individual's risk."

Professor Nick Wareham, Director of the MRC Epidemiology Unit, added: "Our findings highlight the exciting scientific potential of sequencing the genomes of very large numbers of people. We are confident that this approach will bring a rich new era of informative genetic discoveries that will help us better understand common diseases such as type 2 diabetes. By doing this, we can potentially offer better ways to treat - or even to prevent - the condition."

Ongoing research will aim to understand how the loss of function variants in GIGYF1 lead to such a substantial increase in the risk of developing type 2 diabetes. Their future research will also examine other links between biomarkers of biological ageing in adults and metabolic disorders.

Coastal communities across the world are increasingly facing up to the huge threats posed by a combination of extreme storms and predicted rises in sea levels as a result of global climate change.

However, scientists at the University of Plymouth have developed a simple algorithm-based model which accurately predicts how coastlines could be affected and - as a result - enables communities to identify the actions they might need to take in order to adapt.

The Forecasting Coastal Evolution (ForCE) model has the potential to be a game-changing advance in coastal evolution science, allowing adaptations in the shoreline to be predicted over timescales of anything from days to decades and beyond.

This broad range of timescales means that the model is capable of predicting both the short-term impact of violent storm or storm sequences (over days to years), as well as predicting the much longer-term evolution of the coast due to forecasted rising sea levels (decades).

The computer model uses past and present beach measurements, and data showing the physical properties of the coast, to forecast how they might evolve in the future and assess the resilience of our coastlines to erosion and flooding.

Unlike previous simple models of its kind that attempt forecasts on similar timescales, ForCE also considers other key factors like tidal, surge and global sea-level rise data to assess how beaches might be impacted by predicted climate change.

Beach sediments form our frontline of defence against coastal erosion and flooding, preventing damage to our valuable coastal infrastructure. So coastal managers are rightly concerned about monitoring the volume of beach sediment on our beaches.

The new ForCE model opens the door for managers to keeping track of the 'health' of our beaches without leaving their office and to predict how this might change in a future of rising sea level and changing waves.

Model predictions have shown to be more than 80% accurate in current tests, based on measurements of beach change at Perranporth, on the north coast of Cornwall in South West England.

It has also been show to accurately predict the formation and location of offshore sand bars in response to extreme storms, and how beaches recover in the months and years after storm events.

As such, researchers say it could provide an early warning for coastal erosion and potential overtopping, but its stability and efficiency suggests it could forecast coastal evolution over much longer timescales.

The study, published in Coastal Engineering, highlights that the increasing threats posed by sea level rise and coastal squeeze has meant that tracking the morphological evolution of sedimentary coasts is of substantial and increasing societal importance.

Dr Mark Davidson, Associate Professor in Coastal Processes, developed the ForCE model having previously pioneered a traffic light system based on the severity of approaching storms to highlight the level of action required to protect particular beaches.

He said: "Top level coastal managers around the world have recognised a real need to assess the resilience of our coastlines in a climate of changing waves and sea level. However, until now they have not had the essential tools that are required to make this assessment. We hope that our work with the ForCE model will be a significant step towards providing this new and essential capability."

The University of Plymouth is one of the world's leading authorities in coastal engineering and change in the face of extreme storms and sea-level rise.

Researchers from the University's Coastal Processes Research Group have examined their effects everywhere from the coasts of South West England to remote islands in the Pacific Ocean.

They have shown the winter storms of 2013/14 were the most energetic to hit the Atlantic coast of western Europe since records began in 1948, and demonstrated that five years after those storms, many beaches had still not fully recovered.

CASE STUDY - PERRANPORTH, NORTH CORNWALL

Researchers from the University of Plymouth have been carrying out beach measurements at Perranporth in North Cornwall for more than a decade. Recently, this has been done as part of the £4million BLUE-coast project, funded by the Natural Environment Research Council, which aims to address the importance of sediment budgets and their role in coastal recovery.

Surveys have shown that following extreme storms, such as those which hit the UK in 2013/14, beaches recovered to some degree in the summer months but that recovery was largely wiped out in the following winters. That has created a situation where high water shorelines are further landward at sites such as Perranporth.

Sea level is presently forecast to rise by about 0.5m over the next 100 years. However, there is large uncertainty attached to this and it could easily be more than 1m over the same time-frame. If the latter proves to be true, prominent structures on the coastline - such as the Watering Hole bar - will be under severe threat within the next 60 years.

In the line-up of wild African fruits, the marula is the best known. For thousands of years, people have depended on the trees for food, medicines, and more. It is also exported globally as the rockstar ingredient of a cream liqueur. The fruit is a success story far beyond the savannas and bushveld where the trees grow.

But there is a whole choir of other wild, indigenous fruits in Southern Africa. And some exceed daily nutritional values recommended by the WHO and others.

Research from the University of Johannesburg uncovers a variety of building blocks for protein in the fruit of 14 species. Several are analyzed for the first time for nutritional value.

The study published in Plants uncovers the essential amino acids in the fruits. These nutrients are essential for healthy development in children, and to maintain health in adults.

One is a very good candidate to boost immune function against viruses, because it contains so much lysine.

"The majority of these are considered essential amino acids because they cannot be made by the human body. We humans need to eat them, so they need to be included in our diets.

"We can improve the nutrition quality of our diets with wild fruit," says Prof Annah Moteetee. She is from the University of Johannesburg and lead author of the study.

"We can eat the fruits by themselves, or use them together with other foods," she adds.

The amino acid supplement: The White olive

The fruit of the white olive grow directly out of the tree bark. The unusual berries pack an essential amino acid punch, this first analysis of the nutritional value reveals. Its scientific name is Halleria lucida.

The sweet, soft fruit is delicious to birds and humans, so humans make sure they get to the trees before the birds do, adds Moteetee. But it was more complicated than just getting to the fruit first. A very specific ripening process is crucial to make the berries edible.

"I grew up in Lesotho eating these fruits," she says. "As kids, we would collect them while they are green and unripe. Because by the time they are ripe, the competition with birds and other people is stiff. We would dig a hole in the ground, line it with big leaves, and put the fruit in there," she says.

"So you harvest as much as you can, while you can. You would mark the spot so you could find it the next time. We really enjoyed these fruits as kids. It is one of the reasons I decided to include this fruit in the study. Some researchers say it dries your mouth, but I don't remember that."

The berries look plain but contain several of the essential amino acids recommended by the WHO.

Of all the wild fruits in the study, the white olive had the highest quantities of histidine at 1.56 mg/100 g. Histidine is an essential amino acid for infants.

Of all the species studied, Halleria lucida also had the highest amounts of isoleucine (0.30 g/100 mg), leucine (0.47 g/100 g), phenyalanine (0.31 g/100 g), and valine (0.39 g/100 g). In all instances, the amounts exceed the WHO recommended daily intakes (RDAs).

The analysis showed that the fruit contain protein at 6.98 mg/100g and carbohydrates at 36.98 mg/100 g.

However, the white olive fruit is more suited as a general supplement of essential amino acids, since it contains most of these in lower quantities than the recommended daily intake.

The tree occurs next to rivers in the wild. In South Africa it is also planted in suburban gardens for its flowers or trimmed into hedges.

The carbohydrate supplement: The Lowveld milkberry

The Lowveld Milkberry, or Manilkara mochisia, turned out to be the best source of carbohydrates among the fruits studied, says Moteetee. The fruit is also analyzed for the first time for its nutritional value.

A 100 g portion of the fruit contains 169 kJ of energy. Of that, the proximate value of carbohydrates is 36.98 g per 100g.

However, at best the fruit can be a supplement to a diet, since an average adult would have to eat 5 kg of it every day to meet the RDA value of 2000 kcal.

The immune booster: The jacket plum

The jacket plum's fruit is so packed with lysine, it far exceeds the required daily intake for adults, the researchers found. The jacket plum is also known as Pappea capensis.

Lysine supports healthy growth and development in young children. It is also needed to maintain a healthy immune function, especially against viruses.

Each fruit tested in the study exceeded the WHO RDA for 24 hours in adults, says Moteetee. The highest lysine sampled in the study was 0.77 g per 100 g portion. This is far higher than the required daily intake of 0.0003 g/100 g recommended by the WHO.

Pappea capensis also had the highest quantities of methionine (0.15 g/100 mg) and threonine (0.31 g/mg). Its methionine value is equivalent to the WHO RDA, but lower than recommended by the FDA.

Accompanying the protein is also good dollop of fat, at 5.11 g per 100 g portion.

Like the white olive, the jacket plum contains several of the essential amino acids recommended by the WHO.

The tree looks like an ordinary African tree. But sheep like the leaves so much, they trim trees in the Karoo into lollipop shapes, says Prof Ben-Erik van Wyk. He holds a National Research Chair in Indigenous Plant Use at the University of Johannesburg. He has published a series of books about Southern African plants and their medicinal and traditional uses.

"The tree is used by many cultures in Southern Africa for traditional medicine. The plant is related to the lychee, in the family Sapindaceae. The edible part in both is not the fruit itself but a fleshy attachment to the seed, which is called an aril," he adds.

Immune boost from wild fruit

All 14 of the fruits in the study contain lysine, an essential amino acid for healthy immune function in people, says Moteetee. Even better, all of them significantly exceed the RDA guideline from the WHO.

The jacket plum has the highest lysine content and is also easy to grow.

"These fruits need to be studied further to determine their commercial potential," says Moteetee.. "Measuring protein quality will tell us how digestible and bioavailable the amino acids in these fruits are, for example."

The surprising results of a decade-long investigation by Alessandro Vezzosi and Agnese Sabato provide a strong basis for advancing a project researching Leonardo da Vinci's DNA.

Their extensive study, published by the journal "Human Evolution" (Pontecorboli Editore, Florence), documents with new certainty the continuous male line, from father to son, of the Da Vinci family (later Vinci), from progenitor Michele (born 1331) to grandson Leonardo (6th generation, born 1452) through to today -- 21 generations in all, including five family branches -- and identifies 14 living descendants.

The work fills gaps and corrects errors in previous genealogical research into Leonardo's family, while offering new discoveries and family tree updates.

This text deepens and enormously expands the discovery announced in Vinci, Italy, in 2016 by the same Vezzosi and Sabato of numerous living but indirect descendants including only two males in direct line, up to the 19th generation, from a single branch of the Vinci family.

It also provides for the first time the documentary data and information sources over seven centuries to the present day registry office, with work on additional family branches ongoing.

Leonardo himself had at least 22 half-brothers but no children; a new unpublished document shows that "Paolo di Leonardo da Vinci da Firenze" was a case of homonymy. The five family branches are traced from Leonardo's father, ser Piero (5th generation), and half-brother Domenico (6th). Since the 15th generation, data have been collected on over 225 individuals. The study, with the collaboration of the living descendants, contributes to the work of the Leonardo Da Vinci Heritage Association.

This extraordinary, authoritative 690-year genealogical investigation is fundamental to affiliated scientific work Vezzosi and Sabato have underway with the international Leonardo da Vinci DNA project, supported by The Richard Lounsbery Foundation. The project involves the J. Craig Venter Institute of La Jolla, California and several other high-profile universities and research centers, including the Department of Biology of the University of Florence, directed by David Caramelli.

The Y chromosome, passed on to male descendants, is known to remain almost unchanged through 25 generations. Comparing the Y chromosome of today's male relatives with that of their ancestors in ancient and modern burial sites would both verify the uninterrupted family line and certify Leonardo's own Y chromosome marker.

Questions potentially probed once Leonardo's DNA is confirmed include reasons behind his genius, information on his parents' geographical origins, his physical prowess, premature aging, left-handedness, diet, health and any hereditary diseases, and his extraordinary vision, synaesthesia and other sensory perceptions.

Comparison of biological data could also potentially help verify the authenticity of artwork and materials handled by Leonardo.
The paper, “The New Genealogical Tree of the Da Vinci Family for Leonardo’s DNA” is published
in the journal Human
Evolution, DOI: 10.14673/HE2021121077.

Researchers have devised a way to multiply by more than ten-fold the accessible details of gene activity in individual cells. It's a big leap in the effort to understand cancer development, brain function, immunity and other biological processes driven by the complex interactions of multitudes of different cell types.

Organs and tissues are made up of cells that may look the same, but individual cells can actually differ dramatically. Single-cell analysis allows the study of this cell-to-cell variation within an organ, tissue or cancerous tumor. But the research has been hampered by limits on the depth of information that can be gleaned at the single-cell level when working with large numbers of cells.

"The downside has been the low-quality of single-cell profiles. Our method allows us to get a much more complete profile of any given single cell," said Andrew Adey, Ph.D., senior author of a paper in Nature Biotechnology describing the innovation. Adey is an associate professor of molecular and medical genetics in the OHSU School of Medicine.

He said the new method delivers about a ten-fold improvement in the amount of DNA that can be recovered from a single cell to be sequenced and interpreted. The genetic code is written in DNA in a sequence of units, called bases, that are like letters of an alphabet. Sequencing DNA reveals the order of the bases, and it is the first step to understanding the genetic makeup of a cell and whether particular genes are active or silent.

Single-cell studies are particularly important in understanding cancer. The cells of a tumor can be strikingly diverse. Different cells pick up different DNA mutations as the tumor grows, and some of the mutations and changes in gene activity give rise to sub-populations of tumor cells with new qualities, such as the ability to spread to other body parts or resist anti-cancer drugs.

Adey and colleagues showed that their method can be used to reveal DNA alterations that have emerged in a subset of cells in tumor samples taken from patients with pancreatic cancer. That's important because it can help researchers understand how populations of tumor cells evolve and become deadly.

"For example, you can potentially identify rare cell subtypes within a tumor that are resistant to therapy," Adey said. His team has already begun working with OHSU Knight Cancer Institute researchers testing the single-cell method as a way find out if some of the cells in a patient's tumor have evolved resistance to a particular chemo drug or targeted therapy. That knowledge could be used to develop individualized treatment plans for patients.

"If you are working with something like a cancer biopsy from a patient, a very small piece of tissue, you really want to make every cell count, you really have to get a lot of info from each single cell," Adey said.

The new method builds on a technique called single-cell combinatorial indexed sequencing, which Adey and colleagues developed earlier. It's a way to generate DNA libraries - collections of DNA fragments that can be used to analyze genes and mutations - for thousands of single cells at the same time. The process uses an enzymatic reaction to attach primers to the ends of the DNA fragments. "They are kind of like handles the sequencer uses to start reading," Adey says.

While the technique greatly increases the number of single cells that can be analyzed in one experiment, it comes with the tradeoff of sparse coverage of readable DNA sequences per cell. To be readable, a primer must be attached at both ends of the DNA fragment, which the reaction accomplishes only half of the time.

The new method results in all library fragments having primers on both ends, while also improving efficiency in other ways. The researchers said the efficiency has the added benefit of reducing sequencing costs by about one third.

The adapters are designed such that standard sequencing recipes can be used instead of the custom workflows and primers that are required for competing methods. That makes the method compatible with many different tests commonly used to explore the state of single cells.

"This chemistry can just slot into many other assays," Adey said. "People can just start using it."

Sleep problems are common in the general population with up to half of Singaporean adults reporting insufficient or unsatisfying sleep. Sleep quality tends to worsen with age and poor sleep is a modifiable risk factor for multiple disorders, including cardiovascular disease and cognitive impairment.

Currently, insomnia is treated with either medication or psychological interventions. However, even frontline treatments such as cognitive-behavioural therapy have limitations - up to 40% of patients do not get relief from their insomnia symptoms after undergoing this treatment. Furthermore, in Singapore, the waiting time to receive such treatment is long, as it is typically delivered as individual therapy and there are limited available local providers.

To search for alternative approaches to treat insomnia, Principal Investigator Assistant Professor Julian Lim from the Centre for Sleep and Cognition at the National University of Singapore's (NUS) Yong Loo Lin School of Medicine, together with the Singapore General Hospital's Department of Psychology, looked towards mindfulness-based treatment. Mindfulness is the awareness of moment-to-moment thoughts, feelings, and bodily sensations, and the practice of accepting these experiences without judging or reacting to them. Backed by scientific evidence, practicing mindfulness is becoming increasingly popular as a means to reduce stress, treat mental health problems, and improve general well-being.

The randomised controlled study compared a Mindfulness-Based Therapy for Insomnia (MBTI) with an active Sleep Hygiene, Education, and Exercise Programme (SHEEP) to see if the former could improve sleep outcomes in older adults with sleep complaints. A total of 127 participants, aged 50-80, were randomised and allocated between the two programmes - 65 received MBTI while 62 went through SHEEP. Both interventions consisted of eight weekly sessions which were of two hours duration each.

The MBTI course included formal mindfulness exercises such as mindful eating, sitting meditation, mindful movement and body scans. This was followed by a group discussion of their experiences during the past week, as well as the application of practices and principles of mindfulness which directly addressed their sleep difficulties. In addition, participants were taught good sleep habits and behavioural strategies that they could use to improve their sleep.

On the other hand, the SHEEP course provided participants with information about sleep biology, self-monitoring of sleep behavior and taught changes to make in their habits and environment that could improve sleep quality. Participants also learned and practised sleep-promoting exercises such as diaphragmatic breathing, morning and evening stretching movements, and progressive muscle relaxation.

Although sleep quality improved across the board, the study found MBTI to be more effective in reducing insomnia symptoms than SHEEP. Additionally, MBTI led to observable improvements when sleep was measured objectively - using wrist-worn activity monitors, and by recording electrical brain activity while participants slept at home. These objective measurements showed that MBTI participants took less time to fall asleep, and spent less time awake during the night, while this was not seen among SHEEP participants.

Explaining the study's findings, Assistant Professor Julian Lim said: "Insomnia is strongly linked to hyperarousal, or a failure to switch off the "fight-or-flight" system when it's time to sleep. It typically starts because of a triggering stressful event, and persists because some individuals go on to develop bad sleep habits and dysfunctional thoughts about sleep. MBTI uses behavioural strategies to address the bad sleep habits directly, such as encouraging people to get out of bed if they have difficulty sleeping to rebuild the association between the bed and good sleep, and mindfulness techniques to equip people with more flexible strategies to deal with the dysfunctional or arousing thoughts."

Assistant Professor Lim added, "The demonstration of the Mindfulness-Based Therapy as a viable treatment for insomnia presents possible valid alternatives for people who have failed or have no access to standard frontline therapies. Such treatment can be delivered in groups within and outside of a medical setting, providing members of the public with sleep issues easier and more efficient access to seek help."

[Background]

Aryl halides*1) with a benzene ring directly bonded to a halogen atom are readily available and chemically stable, so they are used as a source of benzene rings in organic synthesis. For example, a chemical reaction that generates a highly reactive aryl radical*2) from an aryl halide using a toxic tin compound has long been known as a method for supplying a benzene ring (Figure 1A). In recent years, chemical reactions have been developed, in which an aryl halide is reduced using a metal catalyst or a photocatalyst*3) followed by cleavage of the bond between the benzene ring and the halogen atom to generate an aryl radical. However, since the methods previously reported require metal salts and/or excess amounts of an oxidizing agent or a reducing agent, chemical reactions with less environmental impact are desirable.

[Results]

The research group of Kanazawa University led by Prof. Ohmiya has been developing novel chemical reactions using newly developed metal-free organic catalysts*4) to produce various useful chemicals in a much easier manner than with conventional methods (see EurekAlert! webpages such as https://www.eurekalert.org/pub_releases/2020-08/ku-otc081020.php and https://www.eurekalert.org/pub_releases/2019-04/ku-mct040219.php). In the present study, the group succeeded in generating aryl radicals from aryl iodides, a type of aryl halide, under mild conditions without the need for light or metal salts, using an N-heterocyclic carbene*5) catalyst and the aryl radicals thus formed were used for organic syntheses (Figure 1B).

A single electron transfer from an enolate*6) intermediate consisting of a thiazolium-type N-heterocyclic carbene catalyst and an aldehyde to an aryl iodide and the subsequent cleavage of the bond between the benzene ring and the iodine atom generate an aryl radical in a catalytic manner. Considering the oxidation potential of the enolate intermediate (Eox = -0.97 V) and the reduction potential of the aryl iodide (Ered = -2.24 V), single electron transfer from the enolate intermediate to the aryl iodide, i.e. single electron reduction, is thermodynamically unfavorable. However, it is considered that the reaction took place due to kinetic factors because the two reaction steps, i.e. 1) single electron transfer from the enolate intermediate to the aryl iodide and 2) cleavage of the bond between the benzene ring and the iodine atom, proceed rapidly. The aryl radical generated acts as a source of the benzene ring, the difunctionalization of the alkene*7) proceeds, and a benzene-ring substituted ketone is obtained. In addition, by using the aryl radical generated for the intramolecular hydrogen abstraction reaction, the dehydrogenative acylation*8) of the amide proceeds, and an α-aminoketone compound can be obtained. Substrates with various functional groups can be used in these molecular conversion reactions. Derivatives of pharmaceuticals can also be synthesized by the dehydrogenative acylation of amides (Figure 2).

[Future prospects]

The results of this study are the development of a chemical reaction that cleaves the bond between the benzene ring of an aryl halide and the halogen atom by using an organic catalyst that has a low impact on the environment, leading to generation of an aryl radical. Since aryl radicals can be easily generated from aryl halides that are widely used in organic synthesis, this is expected to be a powerful technology for precisely synthesizing medical and agricultural drugs as well as chemical materials.

Recently, Prof. WANG Zhenyang's research group from the Hefei Institutes of Physical Science (HFIPS) of the Chinese Academy of Sciences (CAS) has prepared macroscopic thick three-dimensional (3D) porous graphene films.

Using high-energy electron beam as the energy source and taking advantages of high kinetic energy and low reflection characteristics of e-beam, the researchers directly induced polyimide precursor into a 3D porous graphene crystal film with a thickness of up to 0.66 mm. Related research results were published in the journal Carbon.

Graphene has been proved to be a new strategic material owing to its numerous exceptional chemical and physical properties. Integrating dimensional (3D) porous graphene network can prevent restacking of graphene sheets and enables easy access and diffusion of ions. However, efficient synthesis of macroscopic thick 3D porous graphene films is still a challenge.

The high instantaneous energy of laser can induce the direct carbonization of the carbon-containing matrix to form high crystalline quality graphene. But the penetration depth of the laser into the carbon-containing matrix is quite low, resulting in insufficient thickness of the prepared graphene film, which limits its application in actual devices. Therefore, exploring a more effective energy source is a key problem that needs to be solved urgently for the industrial application of high-energy beam induced graphene.

In this research, the researchers used high-energy e-beam as a new energy source to realize efficient preparation of macroscopic thick 3D porous graphene crystal films on the polyimide precursor.

Compared with lasers, high-energy e-beam possessed lots of advantages including zero reflection, high kinetic energy, injection effect, and simple focus control, making the e-beam to be a possible better energy source than laser, which could quickly induce carbonization of polyimide precursors to produce graphene.

Hydrogen, oxygen and some other components in polyimide can rapidly escape in the form of gas, resulting in abundant 3D pore structure of graphene.

This study exhibits that the thickness of e-beam-induced graphene (EIG) film is as high as 0.66 mm, and the synthesis rate is 84 cm2/min, which is significantly larger than laser. Furthermore, EIG has been successfully applied to the field of supercapacitor electrodes, which shows excellent electrochemical storage capacity.

With prominent photothermal performance, EIG can also be applied to the field of solar photothermal anti-icing and deicing. The temperatures can be -40 °C, which is ultra-low.

Singapore, 7 July 2021 - In 1966, The Beatles cemented the plight of lonely older people in the popular imagination with the iconic 'Eleanor Rigby', a song that turned pop music on its head when it stayed at number one on the British charts for four weeks. Today, the impact of loneliness in old age on life and health expectancy has been categorically quantified for the first time in a study by scientists at Duke-NUS Medical School (Singapore), Nihon University (Tokyo, Japan) and their collaborators, published in the Journal of the American Geriatrics Society.

"We found that lonely older adults can expect to live a shorter life than their peers who don't perceive themselves as lonely," summarised the study's lead author, Assistant Professor Rahul Malhotra, Head of Research at Duke-NUS' Centre for Ageing Research and Education (CARE). "Furthermore, they pay a penalty for their shorter life by forfeiting potential years of good health."

Associate Professor Angelique Chan, Executive Director of CARE and a senior author of the study, noted, "Besides being the year associated with the coronavirus disease, 2019 was also when the number of adults aged over 30 made up half the total global population for the first time in recorded history, marking the start of an increasingly ageing world. In consequence, loneliness among seniors has become an issue of social and public health concern."

Research Project Professor Yasuhiko Saito, from the College of Economics, Nihon University, a senior co-author of the study, added, "This study is timely because stay-at-home and physical distancing measures instituted since the start of the COVID-19 pandemic have only intensified concern for the mental and physical well-being of older persons."

Key findings: Loneliness has real, physical consequences

The study findings show that people aged 60, who perceive themselves to be sometimes lonely or mostly lonely, can expect to live three to five years less, on average, compared to peers who perceive themselves as never lonely. Similarly, at ages 70 and 80, lonely older persons can, on average, expect to live three to four and two to three years less, respectively, compared to non-lonely peers.

Using the same dataset, the researchers found that the perception of loneliness has a similar impact on two types of health expectancy--remaining years of life lived in a self-rated state of good health as well as remaining years of life lived without being limited when going about 'activities of daily living'. Such activities include routines like bathing and dressing, rising from or settling into a bed or chair, and preparing meals.

At age 60, sometimes lonely or mostly lonely seniors can expect to spend three to five fewer years of their remaining life, on average, without limitations in daily living activities, compared to never-lonely peers. At age 70, their active life expectancy goes down to two to four fewer years, on average. At age 80, it is at one to three fewer years, on average.

How common is loneliness among older adults in Singapore?

Singapore is a particularly relevant setting for studying how loneliness impacts older adults because the country has a rapidly ageing population, and a 'collectivistic' culture, in which relationships and the interconnectedness between people are central--in contrast to an 'individualistic' culture, where each individual's needs and desires are considered to be more important. Previous studies found levels of loneliness to be higher in collectivistic societies, suggesting loneliness may have a more detrimental impact in Singaporean society.

In 2016 and 2017, CARE researchers conducted a study--known as the Transitions in Health, Employment, Social Engagement, and Intergenerational Transfers in Singapore (THE SIGNS) study--to look into factors influencing health, well-being, and activity and productivity levels in older Singaporeans. Nationally representative data, collected from more than 2,000 older Singapore citizens and permanent residents, showed that a third (34 per cent) perceived themselves to be lonely. This proportion increased with age, from 32 per cent among those aged 60-69 years, to 40 per cent among those aged 80 and above.

More males (37 per cent) were lonely, relative to females (31 per cent). Across education levels, the proportion of lonely older Singaporeans was lowest (33 per cent) among those with no formal education, and highest (38 per cent) among those with higher-than-tertiary education. This proportion was nearly 10 per cent higher among seniors who lived alone (43 per cent) compared to those who did not live alone (33 per cent).

"Building on THE SIGNS study, our recent findings highlight the population health impact of loneliness, and the importance of identifying and managing it among older adults," said Asst Prof Malhotra. "This is part of a series of studies to assess the impact of important health and social constructs, like loneliness, sensory impairments, obesity, gender and education, on life and health expectancy among older adults."

"With older persons at potentially greater risk of loneliness as a result of pandemic control measures, there has been increasing policy interest in loneliness around the world," said Assoc Prof Chan. "In 2018, the UK launched a national strategy for tackling loneliness and, in 2021, Japan appointed a 'Minister of Loneliness'. We hope this study helps galvanise more policies to tackle loneliness among older persons."