This is the first evidence of a link between self-control and intelligence in birds.

Self-control – the ability to resist temptation in favour of a better but delayed reward – is a vital skill that underpins effective decision-making and future planning.

Jays are members of the corvid family, often nicknamed the ‘feathered apes’ because they rival non-human primates in their cognitive abilities. Corvids hide, or ‘cache’, their food to save it for later. In other words, they need to delay immediate gratification to plan for future meals. The researchers think this may have driven the evolution of self-control in these birds.

Self-control has been previously shown to be linked to intelligence in humans, chimpanzees and – in an earlier study by these researchers – in cuttlefish. The greater the intelligence, the greater the self-control.

The new results show that the link between intelligence and self-control exists across distantly related animal groups, suggesting it has evolved independently several times.

Of all the corvids, jays in particular are vulnerable to having their caches stolen by other birds. Self-control also enables them to wait for the right moment to hide their food without being seen or heard.

The results are published today in the journal Philosophical Transactions of the Royal Society B.

To test the self-control of ten Eurasian jays, Garrulus glandarius, researchers designed an experiment inspired by the 1972 Stanford Marshmallow test – in which children were offered a choice between one marshmallow immediately, or two if they waited for a period of time.

Instead of marshmallows, the jays were presented with mealworms, bread and cheese. Mealworms are a common favourite; bread and cheese come second but individuals vary in their preference for one over the other.

The birds had to choose between bread or cheese – available immediately, and mealworm that they could see but could only get to after a delay, when a Perspex screen was raised. Could they delay immediate gratification and wait for their favourite food?

A range of delay times was tested, from five seconds to five and a half minutes, before the mealworm was made available if the bird had resisted the temptation to eat the bread or cheese.

All the birds in the experiment managed to wait for the worm, but some could wait much longer than others. Top of the class was ‘JayLo’, who ignored a piece of cheese and waited five and a half minutes for a mealworm. The worst performers, ‘Dolci’ and ‘Homer’, could only wait a maximum of 20 seconds.

“It’s just mind-boggling that some jays can wait so long for their favourite food. In multiple trials, I sat there watching JayLo ignore a piece of cheese for over five minutes – I was getting bored, but she was just patiently waiting for the worm,” said Dr Alex Schnell at the University’s Department of Psychology, first author of the report.

The jays looked away from the bread or cheese when it was presented to them, as if to distract themselves from temptation. Similar behaviour has been seen in chimpanzees and children.

JayLo patiently ignores the cheese (in right box) to wait for the worm (in left box).

The researchers also presented the jays with five cognitive tasks that are commonly used to measure general intelligence. The birds that performed better in these tasks also managed to wait longer for the mealworm reward. This suggests that self-control is linked with intelligence in jays.

“The birds’ performance varied across individuals – some did really well in all the tasks and others were mediocre. What was most interesting was that if a bird was good at one of the tasks, it was good at all of them – which suggests that a general intelligence factor underlies their performance,” said Schnell.

The jays also adjusted their self-control behaviour according to the circumstances: in another experiment where the worm was visible but always out of reach, the jays always ate the immediately available bread or cheese. And the length of time they were willing to wait for the worm fell if it was pitted against their second most preferred food as the immediate treat, compared to their third. This flexibility shows that jays only delay gratification when it is warranted.

Research by other scientists has found that children taking the Stanford marshmallow test vary greatly in their self-control, and this ability is linked to their general intelligence. Children that can resist temptation for longer also get higher scores in a range of academic tasks.

This research was approved by the University of Cambridge Animal Ethics Review Committee, and performed in accordance with the Home Office Regulations and the ASAB Guidelines for the Treatment of Animals in Behavioural Research and Teaching.

The research was funded by the Royal Society, Fyssen Foundation, and European Research Council.

Reference

Schnell, A.K., Boeckle, M., Clayton, N.S. ‘Waiting for a better possibility: delay of gratification in corvids and its relationship to other cognitive capacities.’ Philosophical Transactions of the Royal Society B, October 2022.

Corporate pledges not to buy soybeans produced on land deforested after 2006 have reduced tree clearance in the Brazilian Amazon by just 1.6% between 2006 and 2015.

This equates to a protected area of 2,300 km2 in the Amazon rainforest: barely the size of Oxfordshire.

The findings, made by tracing traders’ soy supplies back to their source, are published today in the journal Environmental Research Letters. The work involved a team from the University of Cambridge, Boston University, ETH Zurich and New York University.

The researchers also discovered that in the Cerrado, Brazil’s tropical savannah, zero-deforestation commitments have not been adopted effectively – leaving over 50% of soy-suitable forests and their biodiversity without protection.

Brazil has the largest remaining tropical forests on the planet, but these are being rapidly cleared to rear cattle and grow crops including soybean. Demand for soy is surging around the world, and an estimated 4,800 km2 of rainforest is cleared each year to grow soybeans.

The majority of soy is consumed indirectly by humans: soybean is widely used as feed for factory-farmed chickens, pigs, fish and cattle. It also accounts for around 27% of global vegetable oil production, and as a complete protein source it often forms a key part of vegetarian and vegan diets.

By 2021, at least 94 companies had adopted zero-deforestation commitments – pledging to eliminate deforestation from their supply chains. But the study revealed that many of these commitments are not put into practice.

And the researchers say that adoption of zero-deforestation commitments is lagging among small and medium sized food companies.

“Zero-deforestation pledges are a great first step, but they need to be implemented to have an effect on forests – and right now it’s mainly the bigger companies that have the resources to do this,” said Professor Rachael Garrett, Moran Professor of Conservation and Development at the University of Cambridge Conservation Research Institute, a joint senior author of the report.

She added: “If soybean traders actually implemented their global commitments for zero-deforestation production, current levels of forest clearance in Brazil could be reduced by around 40 percent.”

Deforestation is the second largest contributor to global greenhouse gas emissions after fossil fuel use. It also causes the loss of diverse animal and plant life, threatens the livelihoods of indigenous groups, and increases inequality and conflict.

The researchers say that the supply chains of other food products including cattle, oil palm and cocoa supply chains are more complex than soy, making them even more difficult to monitor.

“If supply chain policies intend to contribute to the task of tackling deforestation in Brazil, it’s crucial to expand zero-deforestation supply chain policies beyond soy,” said Garrett, who is also Professor of Environmental Policy at ETH Zurich.

A ‘soy moratorium’ was the first voluntary zero-deforestation commitment in the tropics – by signing it, companies agreed not to buy soybeans produced on land deforested after 2006. But while the commitment was implemented in the Brazilian Amazon, most Brazilian soy is produced in the Cerrado – which is rich in biodiversity.

The researchers say their findings suggest private sector efforts are not enough to halt deforestation: supportive political leadership is also vital to conservation efforts.

“Supply chain governance should not be a substitute for state-led forest policies, which are critical to enable zero deforestation monitoring and enforcement, have better potential to cover different crops, land users, and regions,” said Garrett.

In 2021, the COP26 Glasgow Leaders’ Declaration on Forests and Land Use committed to halt and reverse deforestation by 2030. It was signed by over 100 countries, representing 85% of global forests.

This research was funded by the US National Science Foundation, NASA Land-Cover and Land-Use Change Program, and US Department of Agriculture’s National Institute of Food and Agriculture.

Reference

Gollnow, F., Cammelli F., Carlson, K.M., and Garrett, R. D. ‘Gaps in Adoption and Implementation Limit the Current and Potential Effectiveness of Zero-Deforestation Supply Chain Policies for Soy.’ October 2022, Environmental Research Letters. DOI: 10.1088/1748-9326/ac97f6

A team from the University of Cambridge’s Minderoo Centre for Technology and Democracy created the new audit tool to evaluate “compliance with the law and national guidance” around issues such as privacy, equality, and freedom of expression and assembly.

Based on the findings, published in a new report, the experts are joining calls for a ban on police use of facial recognition in public spaces.

“There is a lack of robust redress mechanisms for individuals and communities harmed by police deployments of the technology,” said the report’s lead author Evani Radiya-Dixit, a visiting fellow at Cambridge’s Minderoo Centre.

“To protect human rights and improve accountability in how technology is used, we must ask what values we want to embed in technology.”

Researchers constructed the audit tool based on current legal guidelines – including the UK’s Data Protection and Equality acts – as well as outcomes from UK court cases and feedback from civil society organisations and the Information Commissioner’s Office.

They applied their ethical and legal standards to three uses of facial recognition technology (FRT) by UK police. One was the Bridges court case, in which a Cardiff-based civil liberties campaigner appealed against South Wales Police’s use of automated FRT to live-scan crowds and compare faces to those on a criminal “watch list”.

The researchers also tested the Metropolitan Police’s trials of similar live FRT use, and a further example from South Wales Police in which officers used FRT apps on their smartphones to scan crowds in order to identify “wanted individuals in real time”.

In all three cases, they found that important information about police use of FRT is “kept from view”, including scant demographic data published on arrests or other outcomes, making it difficult to evaluate whether the tools “perpetuate racial profiling” say researchers.

In addition to lack of transparency, the researchers found little in the way of accountability – with no clear recourse for people or communities negatively affected by police use, or misuse, of the tech. “Police forces are not necessarily answerable or held responsible for harms caused by facial recognition technology,” said Radiya-Dixit.

Some of the FRT uses lacked regular oversight from an independent ethics committee or indeed the public, say the researchers, and did not do enough to ensure there was a reliable “human in the loop” when scanning untold numbers of faces among crowds of thousands while hunting for criminals.

In the South Wales Police’s smartphone app trial, even the “watch list” included images of people innocent under UK law – those previously arrested but not convicted – despite the fact that retention of such images is unlawful.

“We find that all three of these deployments fail to meet the minimum ethical and legal standards based on our research on police use of facial recognition,” said Radiya-Dixit.

Prof Gina Neff, Executive Director at the Minderoo Centre for Technology and Democracy, said: “Over the last few years, police forces around the world, including in England and Wales, have deployed facial recognition technologies. Our goal was to assess whether these deployments used known practices for the safe and ethical use of these technologies.”

“Building a unique audit system enabled us to examine the issues of privacy, equality, accountability, and oversight that should accompany any use of such technologies by the police,” Neff said.

Officers are increasingly under-resourced and overburdened, write the researchers, and FRT is seen as a fast, efficient and cheap way to track down persons of interest.

At least ten police forces in England and Wales have trialled facial recognition, with trials involving FRT use for operational policing purposes – although different forces use different standards.

Questions of privacy run deep for policing technology that scans and potentially retains vast numbers of facial images without knowledge or consent. The researchers highlight a possible “chilling effect” if FRT leads to a reluctance to exercise fundamental rights among the public – right to protest, for example – for fear of potential consequences.

Use of FRT also raises discrimination concerns. The researchers point out that, historically, surveillance systems are used to monitor marginalised groups, and recent studies suggest the technology itself contains inherent bias that disproportionately misidentifies women, people of colour, and people with disabilities.

Given regulatory gaps and failures to meet minimum standards set out by the new audit toolkit, the researchers write that they support calls for a “ban on police use of facial recognition in publicly accessible spaces”.

A characteristic of diseases such as Alzheimer’s and Parkinson’s – collectively known as neurodegenerative diseases – is the build-up of misfolded proteins. These proteins, such as amyloid and tau in Alzheimer’s disease, form ‘aggregates’ that can cause irreversible damage to nerve cells in the brain.

Protein folding is a normal process in the body, and in healthy individuals, cells carry out a form of quality control to ensure that proteins are correctly folded and that misfolded proteins are destroyed. But in neurodegenerative diseases, this system becomes impaired, with potentially devastating consequences.

As the global population ages, an increasing number of people are being diagnosed with dementia, making the search for effective drugs ever more urgent. However, progress has been slow, with no medicines yet available that can prevent or remove the build-up of aggregates.

In a study published today in Nature Communications, a team led by scientists at the UK Dementia Research Institute, University of Cambridge, has identified a new mechanism that appears to reverse the build-up of aggregates, not by eliminating them completely, but rather by ‘refolding’ them.

“Just like when we get stressed by a heavy workload, so, too, cells can get ‘stressed’ if they’re called upon to produce a large amount of proteins,” explained Dr Edward Avezov from the UK Dementia Research Institute at the University of Cambridge.

“There are many reasons why this might be, for example when they are producing antibodies in response to an infection. We focused on stressing a component of cells known as the endoplasmic reticulum, which is responsible for producing around a third of our proteins – and assumed that this stress might cause misfolding.”

The endoplasmic reticulum (ER) is a membrane structure found in mammalian cells. It carries out a number of important functions, including the synthesis, folding, modification and transport of proteins needed on the surface or outside the cell. Dr Avezov and colleagues hypothesised that stressing the ER might lead to protein misfolding and aggregation by diminishing its ability to function correctly, leading to increased aggregation.

They were surprised to discover the opposite was true.

“We were astonished to find that stressing the cell actually eliminated the aggregates – not by degrading them or clearing them out, but by unravelling the aggregates, potentially allowing them to refold correctly,” said Dr Avezov.

“If we can find a way of awakening this mechanism without stressing the cells – which could cause more damage than good – then we might be able to find a way of treating some dementias.”

The main component of this mechanism appears to be one of a class of proteins known as heat shock proteins (HSPs), more of which are made when cells are exposed to temperatures above their normal growth temperature, and in response to stress.

Dr Avezov speculates that this might help explain one of the more unusual observations within the field of dementia research. “There have been some studies recently of people in Scandinavian countries who regularly use saunas, suggesting that they may be at lower risk of developing dementia. One possible explanation for this is that this mild stress triggers a higher activity of HSPs, helping correct tangled proteins.”

One of the factors that has previous hindered this field of research has been the inability to visualise these processes in live cells. Working with teams from Pennsylvania State University and the University of Algarve, the team has developed a technique that allows them to detect protein misfolding in live cells. It relies on measuring light patterns of a glowing chemical over a scale of nanoseconds – one billionth of a second.

“It’s fascinating how measuring our probe’s fluorescence lifetime on the nanoseconds scale under a laser-powered microscope makes the otherwise invisible aggregates inside the cell obvious,” said Professor Eduardo Melo, one of the leading authors, from the University of Algarve, Portugal.

The research was supported by the UK Dementia Research Institute, which receives its funding from the Medical Research Council, Alzheimer’s Society and Alzheimer’s Research UK, as well as the Portuguese Foundation for Science and Technology.

Reference
Melo, EP, et al. Stress-induced protein disaggregation in the Endoplasmic Reticulum catalysed by BiP. Nature Comms; 6 May 2022; DOI: 10.1038/s41467-022-30238-2

Based in Toronto, and working across national and disciplinary boundaries, CIFAR brings together some of the world’s best researchers to address the most pressing and complex issues facing individuals and societies.

Under Professor Toope’s leadership at Cambridge, sustainability and widening student access have been key areas of focus for the University, with several new and exciting research and teaching initiatives launched. These include the ambitious climate initiative Cambridge Zero, and the creation of the landmark Cambridge Foundation Year. Professor Toope has also led the university sector in pushing towards a carbon-neutral endowment fund, and has overseen remarkable progress on a £500 million Student Support Initiative. During his tenure, the “Dear World… Yours, Cambridge” fundraising campaign for the collegiate University surpassed its £2 billion target. He has guided the University through a global pandemic and into a programme of recovery that will help build the Cambridge of the future.

Professor Toope said: “CIFAR is an extraordinary organisation, and I am honoured to be offered this opportunity to lead it. While I look forward to this new challenge, I am immensely proud of what we as a university community have achieved in a remarkable five years. The University of Cambridge is without question a force for good in the world. It has been a great privilege to work with so many gifted people carrying out such extraordinary work.”

Professor Toope will take on the new role from 1 November 2022. The process to recruit a new Vice-Chancellor is under way.

In October, the University hopes to welcome upwards of 20 students affected by the war on Ukraine. They will be funded by a range of scholarships including The Rowan Williams Cambridge Studentship, which is a programme established by the Cambridge Trust to support undergraduate and postgraduate students applying to study at Cambridge from a conflict zone.

The Rowan Williams Scholarships will be fully-funded covering tuition fees and maintenance and will also assist with students’ upfront expenses such as travel, visa costs and the immigration health surcharge. The Cambridge Trust is working with other funders to maximise the number of offers we can make. All recipients of these funds must have a conditional offer from the University to be considered for funding.

The School of Clinical Medicine has made a twinning agreement with Kharkiv National Medical University to accept medical students on six week clinical placements in Cambridge. Students will be placed at either Cambridge University Hospitals NHS Foundation Trust or Cambridgeshire and Peterborough NHS Foundation Trust. Each student will be hosted by a member of the University or one of the hospitals, who have volunteered to provide accommodation during their visit. Ten students will take part initially, with further cohorts expected to follow. The first students are expected to arrive within the next one to two months, subject to the government granting visiting visas.

The Collegiate University has so far submitted two applications to the British Academy and Council for At-Risk Academics (Cara) Researchers at Risk Fellowship Scheme. If successful, the fellowships will bring two scholars and their dependents to Cambridge for up to two years. These applications were generously supported by Darwin College and Trinity College.

The University is also in conversations with Ukrainian institutions to establish non-residential scholarships for up to fifteen Ukrainian scholars who have been displaced by the war and are living in Ukraine or neighbouring countries. The scholarships will provide a stipend, formal links to Cambridge academics and remote access to resources that will enable them to continue academic study.

Some 21 students currently studying in Cambridge have been identified as having been directly affected by the war. They are being supported through the University’s Ukrainian Conflict Student Hardship Fund.

In response to conversations with Ukrainian university representatives, the University Library and Cambridge University Press and Assessment are identifying specific ways in which they can assist in partnership with their national professional bodies. Cambridge University Press and Assessment has made the majority of its academic journal content free to institutions registered in Ukraine.

Additional programmes are in development, and the University remains ready to sponsor and host displaced doctoral students and academic staff as soon as the government visa scheme enables the University to act as a visa sponsor. Thank you to those University institutions that have come forward with offers of support.

“I have been heartened by the generosity displayed by colleagues across Cambridge who have raised funds or proposed activities to support those affected by the tragic war on Ukraine,” said Professor Kamal Munir, Pro-Vice-Chancellor for University Community and Engagement. “I know many within the University have worked tirelessly to put these programmes in place and we will continue to identify opportunities for the Collegiate University to provide further support in the medium to long-term.”

The number of fires inside protected conservation areas across the island of Madagascar shot up dramatically when COVID-19 lockdowns led to the suspension of any on-site management for five months during 2020.

The findings suggest that governments should consider keeping some staff in protected areas at all times as an “essential service”, even during periods of health crisis and travel restriction, argue the scientists behind the study.

They say that more attention must be paid to the management of protected areas, not just expanding their coverage, at the long-delayed convention to set international biodiversity goals later this year.

Madagascar is a renowned biodiversity “hotspot”, home to species such as its famous lemur populations that don’t exist anywhere else. The island is also a frontline in the fight between wildlife protection and habitat loss.

The study, published today in Nature Sustainability, is the first to gauge the effects of the pandemic on protected conservation areas.

An international team of scientists led by Cambridge and Helsinki universities used historical and contemporary fire and weather data to predict rates of burning in Madagascar’s protected areas for every month during 2012-2020.

They compared this data modelling to counts of actual blazes collected by satellites to detect periods when fires raged far beyond what might be expected from the climate and previous patterns of burning.

When the first lockdowns of 2020 halted the on-site management of protected areas, the numbers of fires – much of it in threatened forest habitat – soared by 209% in March, 223% in April, 78% in May, 248% in June and 76% in July.

However, burning quickly returned to normal levels as predicted by the modelling once management operations resumed – despite continued border closures and economic hardships as a result of the ongoing pandemic.

Researchers describe this scale of burning inside protected areas as “unprecedented” in recent Malagasy history. The only comparable periods were during two spells of civil unrest in 2013 and 2018 in the run-up to elections, but even then the fieriest month was just a 134% increase in burning.

“The disruption caused by COVID-19 clearly demonstrates the dramatic impact that interruptions to the management of protected areas can have on habitats,” said senior author Prof Andrew Balmford from the University of Cambridge.

“Over the last twenty years, excess fires in Malagasy protected areas have been limited to occasional blocks of one or two months.

“When all staff were pulled out of protected areas in March 2020 the fires spiked dramatically and continued at a ferocious level for an unprecedented five months, falling away exactly as staff started to return,” he said.

While the team says they cannot know for sure what caused all the fires during the early months of COVID-19, lead author Dr Johanna Eklund from the University of Helsinki said that local communities already struggling economically would have come under further pressure from lockdowns.

“Madagascar has very high rates of poverty, and has a history of conflict between the livelihoods of vulnerable people and saving unique biodiversity,” said Eklund, currently a visiting researcher at Cambridge.

“The pandemic increased economic insecurity for many, so it would not be surprising if this led some to encroach on protected lands while on-site management activities were on hold.”

Eklund suggests that a lack of on-site patrolling to prevent any fires from spreading combined with communities resorting to “swidden” – or slash-and-burn – agriculture may be behind much of the spike in lockdown fires. These techniques clear vegetation for crops and cattle-grazing but are illegal inside protected areas.

“Importantly, the study did not measure fires outside conservation sites, so we cannot measure how much protected areas actually mitigated burning compared to areas without protection,” Eklund said.

The team used imaging data from NASA satellite systems capable of detecting “thermal anomalies” and noted for near real-time fire management alerts.

Eklund, who has conducted research in Madagascar for close to a decade, realised she could still remotely assist those protecting the forests. “Satellites pick up fires really well and show where protected areas are under pressure.”

Co-author Domoina Rakotobe, former coordinator for the Malagasy organisation Forum Lafa, the network of terrestrial protected area managers, added: “The high levels of burning during the lockdowns clearly shows the value of on-the-ground management, with protected area teams working with communities to support local livelihoods and safeguard natural resources.”

Working in collaboration with domestic appliances manufacturer Beko, researchers from the University of Cambridge trained their robot chef to assess the saltiness of a dish at different stages of the chewing process, imitating a similar process in humans.

Their results could be useful in the development of automated or semi-automated food preparation by helping robots to learn what tastes good and what doesn’t, making them better cooks.

When we chew our food, we notice a change in texture and taste. For example, biting into a fresh tomato at the height of summer will release juices, and as we chew, releasing both saliva and digestive enzymes, our perception of the tomato’s flavour will change.

The robot chef, which has already been trained to make omelettes based on human taster’s feedback, tasted nine different variations of a simple dish of scrambled eggs and tomatoes at three different stages of the chewing process, and produced ‘taste maps’ of the different dishes.

The researchers found that this ‘taste as you go’ approach significantly improved the robot’s ability to quickly and accurately assess the saltiness of the dish over other electronic tasting technologies, which only test a single homogenised sample. The results are reported in the journal Frontiers in Robotics & AI.

The perception of taste is a complex process in humans that has evolved over millions of years: the appearance, smell, texture and temperature of food all affect how we perceive taste; the saliva produced during chewing helps carry chemical compounds in food to taste receptors mostly on the tongue; and the signals from taste receptors are passed to the brain. Once our brains are aware of the flavour, we decide whether we enjoy the food or not.

Taste is also highly individual: some people love spicy food, while others have a sweet tooth. A good cook, whether amateur or professional, relies on their sense of taste, and can balance the various flavours within a dish to make a well-rounded final product.

“Most home cooks will be familiar with the concept of tasting as you go – checking a dish throughout the cooking process to check whether the balance of flavours is right,” said Grzegorz Sochacki from Cambridge’s Department of Engineering, the paper’s first author. “If robots are to be used for certain aspects of food preparation, it’s important that they are able to ‘taste’ what they’re cooking.”

“When we taste, the process of chewing also provides continuous feedback to our brains,” said co-author Dr Arsen Abdulali, also from the Department of Engineering. “Current methods of electronic testing only take a single snapshot from a homogenised sample, so we wanted to replicate a more realistic process of chewing and tasting in a robotic system, which should result in a tastier end product.”

The researchers are members of Cambridge’s Bio-Inspired Robotics Laboratory run by Professor Fumiya Iida of the Department of Engineering, which focuses on training robots to carry out the so-called last metre problems which humans find easy, but robots find difficult. Cooking is one of these tasks: earlier tests with their robot ‘chef’ have produced a passable omelette using feedback from human tasters.

“We needed something cheap, small and fast to add to our robot so it could do the tasting: it needed to be cheap enough to use in a kitchen, small enough for a robot, and fast enough to use while cooking,” said Sochacki.

To imitate the human process of chewing and tasting in their robot chef, the researchers attached a conductance probe, which acts as a salinity sensor, to a robot arm. They prepared scrambled eggs and tomatoes, varying the number of tomatoes and the amount of salt in each dish.

Using the probe, the robot ‘tasted’ the dishes in a grid-like fashion, returning a reading in just a few seconds.

To imitate the change in texture caused by chewing, the team then put the egg mixture in a blender and had the robot test the dish again. The different readings at different points of ‘chewing’ produced taste maps of each dish.

Their results showed a significant improvement in the ability of robots to assess saltiness over other electronic tasting methods, which are often time-consuming and only provide a single reading.

While their technique is a proof of concept, the researchers say that by imitating the human processes of chewing and tasting, robots will eventually be able to produce food that humans will enjoy and could be tweaked according to individual tastes.

“When a robot is learning how to cook, like any other cook, it needs indications of how well it did,” said Abdulali. “We want the robots to understand the concept of taste, which will make them better cooks. In our experiment, the robot can ‘see’ the difference in the food as it’s chewed, which improves its ability to taste.”

“Beko has a vision to bring robots to the home environment which are safe and easy to use,” said Dr Muhammad W. Chughtai, Senior Scientist at Beko plc. “We believe that the development of robotic chefs will play a major role in busy households and assisted living homes in the future. This result is a leap forward in robotic cooking, and by using machine and deep learning algorithms, mastication will help robot chefs adjust taste for different dishes and users.”

In future, the researchers are looking to improve the robot chef so it can taste different types of food and improve sensing capabilities so it can taste sweet or oily food, for example.

The research was supported in part by Beko plc and the Engineering and Physical Sciences Research Council (EPSRC) Centre of Doctoral Training on Agri-Food Robotics (Agriforwards CDT). EPSRC is part of UK Research and Innovation (UKRI). Fumiya Iida is a Fellow of Corpus Christi College, Cambridge.

Reference:
Grzegorz Sochacki, Arsen Abdulali, and Fumiya Iida. ‘Mastication-Enhanced Taste-Based Classification of Multi-Ingredient Dishes for Robotic Cooking.’ Frontiers in Robotics & AI (2022). DOI: 10.3389/frobt.2022.886074

A major scientific assessment, published by the Global Forest Expert Panels (GFEP) Programme, led by the International Union of Forest Research Organizations (IUFRO), has evaluated the world’s progress on reducing emissions from deforestation and forest degradation.

The report analyses the past 10 years of REDD+ implementation – a global action plan to reduce emissions from deforestation and forest degradation primarily in tropical and sub-tropical regions – with respect to forest governance, carbon measurements and effects on biodiversity and livelihoods. The findings are presented during World Forestry Congress week, taking place this week in Seoul.

One major conclusion is that while REDD+ has provided a convenient umbrella for many forest and land use related activities aimed at reducing deforestation and forest degradation – and associated greenhouse gas emissions – the interlinkages and complexities of relationships between forests, land use and climate are profound.

The report, which aims to inform ongoing policy discussions on the 2030 Agenda for Sustainable Development, comes at a pivotal time: Human-induced climate change and increases in extreme weather events are impacting nature and people faster and more severely than had been expected 20 years ago.

However, there is still a chance to reverse this trend and avoid further global warming, according to the Intergovernmental Panel on Climate Change. This requires drastic reductions in greenhouse gas emissions, particularly CO2, most of which stem from burning fossil fuels.

Forests also play an important role in the global carbon cycle: they absorb carbon as they grow and emit carbon when they are destroyed. Every year nearly one-third of the global carbon emissions produced by humans can be absorbed by forests, yet deforestation and forest degradation are responsible for up to 10% of the annual man-made CO2 emissions.

In addition, interest in forests as a ‘nature-based solution’ has probably never been higher and the number of initiatives aimed at conserving, sustainably managing and restoring forests has increased considerably.

“This report is being launched at a very important moment, and feeds directly into international discussions on climate change and biodiversity,” said lead author Professor Bhaskar Vira, Head of Cambridge’s Department of Geography. “There is an urgent focus on the role of land use and forests as part of our transitions towards a net zero future, and on the contributions that forests can make to biodiversity and livelihoods.

“REDD+ will only be effective if we learn the lessons from existing efforts and interventions in the forest sector, and the challenges they have faced. This report offers key insights into the ways in which new and innovative sources of funding and finance should be organised and governed to ensure equitable and sustainable future pathways that benefit all, especially the Indigenous Peoples and local communities who live in and around forests.”

In addition to promoting forest protection and carbon sink enhancement, a key focus of REDD+ is to move the scope of interventions beyond climate impacts towards an integrated view of climate, biodiversity and livelihoods. REDD+ can deliver numerous environmental benefits, including reduced soil erosion, enhanced water quality and quantity, and increased resilience to drought and floods. It can potentially deliver important biodiversity benefits, although the availability of up-to-date biodiversity data remains a major challenge.

“Such benefits have significant economic importance and may increase both the value of REDD+ programs and people’s willingness to engage with them. However, in the implementation of REDD+, greater attention to biodiversity and livelihood outcomes is needed,” said lead author and IUFRO President John Parrotta of the USDA Forest Service.

Evidence from social evaluations of REDD+ interventions indicates that, where direct and indirect benefits are clearly visible to local stakeholders, and have been delivered, community engagement is strong and projects have achieved positive carbon and social outcomes, at least in the short term. Furthermore, explicit attention to rights and tenure issues provides more transparent mechanisms for the reporting and monitoring of environmental and social co-benefits, as well as better, more equitable outcomes, particularly for more vulnerable communities.

Case studies from Indonesia show that insecure tenure can exacerbate distrust between resource users and the government, and can keep local people from further participating in REDD+ activities. Evidence from Latin America and the Caribbean suggests that deforestation is lower in areas where Indigenous and Tribal Peoples’ collective land rights are recognised.

“Since 2012, implementation of REDD+ has advanced considerably in many countries but ultimately it is REDD+ governance that determines its performance. Yet, governance is distributed across a complex landscape of institutions with different sources of authority and power dynamics that influence its outcomes,” said GFEP Programme Coordinator Christoph Wildburger.

REDD+ is being applied in a wide diversity of contexts with an equally wide diversity of governance strategies, which are changing over time. Brazil, for example, was initially a leading global source of deforestation, then a world leader in reducing deforestation, and is now experiencing rising deforestation once again. While Brazil’s federal government has played a key role in these swings in deforestation rates, a number of Brazilian states are pursuing their own REDD+ initiatives with positive outcomes. Ghana, a relatively small country where deforestation has been strongly linked to the production of cocoa for export, is pursuing the ‘world’s first commodity-driven’ REDD+ strategy with private sector investments in ‘climate smart cocoa’. Both Brazil and Ghana illustrate the important role that actors other than national governments may play in shaping REDD+, such as sub-national state actors or private companies trading in forest risk commodities like cocoa.

Adapted from an IUFRO press release.

The findings, published in the journal eClinicalMedicine, emerge from the NIHR COVID-19 BioResource. The results of the study suggest the effects are still detectable more than six months after the acute illness, and that any recovery is at best gradual.

There is growing evidence that COVID-19 can cause lasting cognitive and mental health problems, with recovered patients reporting symptoms including fatigue, ‘brain fog’, problems recalling words, sleep disturbances, anxiety and even post-traumatic stress disorder (PTSD) months after infection. In the UK, a study found that around one in seven individuals surveyed reported having symptoms that included cognitive difficulties 12 weeks after a positive COVID-19 test.

While even mild cases can lead to persistent cognitive symptoms, between a third and three-quarters of hospitalised patients report still suffering cognitive symptoms three to six months later.

To explore this link in greater detail, researchers analysed data from 46 individuals who received in-hospital care, on the ward or intensive care unit, for COVID-19 at Addenbrooke’s Hospital, part of Cambridge University Hospitals NHS Foundation Trust. 16 patients were put on mechanical ventilation during their stay in hospital. All the patients were admitted between March and July 2020 and were recruited to the NIHR COVID-19 BioResource.

The individuals underwent detailed computerised cognitive tests an average of six months after their acute illness using the Cognitron platform, which measures different aspects of mental faculties such as memory, attention and reasoning. Scales measuring anxiety, depression and post-traumatic stress disorder were also assessed. Their data were compared against matched controls.

This is the first time that such rigorous assessment and comparison has been carried out in relation to the after effects of severe COVID-19.

COVID-19 survivors were less accurate and with slower response times than the matched control population – and these deficits were still detectable when the patients were following up six months later. The effects were strongest for those who required mechanical ventilation. By comparing the patients to 66,008 members of the general public, the researchers estimate that the magnitude of cognitive loss is similar on average to that sustained with 20 years ageing, between 50 and 70 years of age, and that this is equivalent to losing 10 IQ points.

Survivors scored particularly poorly on tasks such as verbal analogical reasoning, a finding that supports the commonly-reported problem of difficulty finding words. They also showed slower processing speeds, which aligns with previous observations post COVID-19 of decreased brain glucose consumption within the frontoparietal network of the brain, responsible for attention, complex problem-solving and working memory, among other functions.

Professor David Menon from the Division of Anaesthesia at the University of Cambridge, the study’s senior author, said: “Cognitive impairment is common to a wide range of neurological disorders, including dementia, and even routine ageing, but the patterns we saw – the cognitive ‘fingerprint’ of COVID-19 – was distinct from all of these.”

While it is now well established that people who have recovered from severe COVID-19 illness can have a broad spectrum of symptoms of poor mental health – depression, anxiety, post-traumatic stress, low motivation, fatigue, low mood, and disturbed sleep – the team found that acute illness severity was better at predicting the cognitive deficits.

The patients’ scores and reaction times began to improve over time, but the researchers say that any recovery in cognitive faculties was at best gradual and likely to be influenced by a number of factors including illness severity and its neurological or psychological impacts.

Professor Menon added: “We followed some patients up as late as ten months after their acute infection, so were able to see a very slow improvement. While this was not statistically significant, it is at least heading in the right direction, but it is very possible that some of these individuals will never fully recover.”

There are several factors that could cause the cognitive deficits, say the researchers. Direct viral infection is possible, but unlikely to be a major cause; instead, it is more likely that a combination of factors contribute, including inadequate oxygen or blood supply to the brain, blockage of large or small blood vessels due to clotting, and microscopic bleeds. However, emerging evidence suggests that the most important mechanism may be damage caused by the body’s own inflammatory response and immune system.

While this study looked at hospitalised cases, the team say that even those patients not sick enough to be admitted may also have tell-tale signs of mild impairment.

Professor Adam Hampshire from the Department of Brain Sciences at Imperial College London, the study’s first author, said: “Around 40,000 people have been through intensive care with COVID-19 in England alone and many more will have been very sick, but not admitted to hospital. This means there is a large number of people out there still experiencing problems with cognition many months later. We urgently need to look at what can be done to help these people.”

Professor Menon and Professor Ed Bullmore from Cambridge’s Department of Psychiatry are co-leading working groups as part of the COVID-19 Clinical Neuroscience Study (COVID-CNS) that aim to identify biomarkers that relate to neurological impairments as a result of COVID-19, and the neuroimaging changes that are associated with these.

The research was funded by the NIHR BioResource, NIHR Cambridge Biomedical Research Centre and the Addenbrooke’s Charitable Trust, with support from the NIHR Cambridge Clinical Research Facility.

Reference
Hampshire, A et al. Multivariate profile and acute-phase correlates of cognitive deficits in a COVID-19 hospitalised cohort. eClinicalMedicine; 28 Apr 2022; DOI: 10.1016/j.eclinm.2022.101417

Children’s attitudes towards learning languages and their willingness to see themselves as ‘multilingual’ are influenced far more by the views of their parents than by their teachers or friends, new research indicates.

The finding implies that parents may have an important part to play in reversing the national decline in language-learning. The authors of the study, which was led by researchers at the University of Cambridge, say that efforts to increase uptake in these subjects would benefit from involving families, as well as schools.

Entry rates for modern languages have declined steadily, at both GCSE and A-Level, since the early 2000s. GCSE entry data, for example, show that the combined total number of pupils taking French, German, Spanish and other Modern Languages last year was almost half that of 2001.

The new study surveyed more than 1,300 Year 8 students, aged 12-13, to understand what makes them self-identify as ‘multilingual’: as capable learners and users of other languages. The responses revealed that their parents’ beliefs about languages had almost twice as much influence as the opinions of their teachers, and were also significantly more influential than the views of their peers.

Specifically, parental attitudes help students who are still forming a view about languages work out whether these subjects matter personally to them. In general, the study shows that they are more likely to consider themselves ‘multilingual’ if they identify with languages at this personal level and see them as relevant to their own lives. Simply learning languages at school and being told that they are useful appears to make less difference.

Professor Linda Fisher, from the Faculty of Education, University of Cambridge, said: “Students’ personal commitment to languages is determined by their experiences, their beliefs, and their emotional response to speaking or using them. Slightly surprisingly, the people who feed into that most appear to be their parents.”

“This can be a positive or negative influence depending on the parents’ own views. Its importance underlines the fact that if we want more young people to learn languages, we need to pay attention to wider social and cultural attitudes to languages beyond the classroom. Waning interest in these subjects is a public communication challenge; it’s not just about what happens in schools.”

Some language-learning specialists argue that most people are fundamentally “multilingual”. Even if they do not speak another language fluently, they may know assorted words and phrases, or another kind of ‘language’: such as a dialect, sign language, or computer code.

Recognising that they have this multilingual capability appears to strengthen students’ self-belief when they encounter modern languages at school. There is also evidence that students who self-identify as multilingual perform better across the school curriculum, including in non-language subjects.

The study explored what leads students to see themselves in these terms, and whether this varies between different groups – for example, those who have ‘English as an Additional Language’ (EAL), and typically speak another language at home.

In the survey, students were asked to state how strongly they agreed or disagreed with various statements, such as: “Learning other languages is pointless because everyone speaks English”, and: “My parents think that it’s cool to be able to speak other languages.” They were also asked about their own experience with languages, and how multilingual they considered themselves to be. The researchers then developed a model showing the relative importance of different potential influences on their self-identification as language-learners.

Although some influences – such as that of peers – differed for EAL and non-EAL students, that of parents was consistently strong. Across the board, the relative impact of parents’ attitudes on students’ willingness to see themselves as multilingual was found to be about 1.4 times greater than that of their friends, and almost double that of their teachers.

The researchers suggest that encouraging more parents to recognise their own multilingual capabilities would positively affect their children’s own language-learning. “In an ideal world we should be encouraging adults, as well as children, to see themselves as having a repertoire of communicative resources,” Fisher said. “It’s remarkable how quickly attitudes change once you start asking: ‘What words do you already know, what dialect do you speak; can you sign?’”

More broadly, the study found that young people are more likely to see themselves in these terms if they are exposed to meaningful experiences that involve other languages – for example by hearing and using them in their communities, or while travelling abroad. This, along with their personal and emotional response to the idea of languages, informs the degree to which they self-describe as multilingual.

The researchers argue that this raises questions about recent Government reforms to language GCSEs, which are meant to help students “grow in confidence and motivation”. The new measures focus narrowly on so-called linguistic “building blocks”: for example, requiring students to learn 1,700 common words in the target language. Head teachers’ bodies have already criticised them as “prescriptive and grinding” and liable to alienate pupils further.

The new study similarly indicates that encouraging more young people to learn languages requires a broader-minded approach.

“There’s no evidence that if you just focus on the mechanics – phonics, grammar and so on – you’re going to motivate students or, for that matter, teachers,” Fisher said. “Students need to discover what languages mean to them, which means they also need to learn about culture, identity and self-expression. Simply drilling verb forms into them will only persuade a swathe of the school population that these subjects are not for them. That is especially likely if their parents don’t value languages either.”

The research is published in the International Journal of Multilingualism.

A study has found that children who increased their connection to nature during the first COVID-19 lockdown were likely to have lower levels of behavioural and emotional problems, compared to those whose connection to nature stayed the same or decreased – regardless of their socio-economic status.

The study, by researchers at the University of Cambridge and the University of Sussex, also found that children from affluent families tended to have increased their connection to nature during the pandemic more than their less affluent peers.

Nearly two thirds of parents reported a change in their child’s connection to nature during lockdown, while a third of children whose connection to nature decreased displayed increased problems of wellbeing – either through ‘acting out’ or by increased sadness or anxiety.

The results strengthen the case for nature as a low-cost method of mental health support for children, and suggest that more effort should be made to support children in connecting with nature – both at home and at school.

The researchers’ suggestions for achieving this include: reducing the number of structured extracurricular activities for children to allow for more time outside, provision of gardening projects in schools, and funding for schools, particularly in disadvantaged areas, to implement nature-based learning programmes.

The study, published today in the journal People and Nature, also offers important guidance in relation to potential future restrictions during the COVID-19 pandemic.

“We know that access to and engagement with nature is associated with wide-ranging benefits in children and adults, including lowering levels of anxiety and depression, and reducing stress,” said Samantha Friedman, a researcher in the University of Cambridge’s Centre for Family Research, first author of the study.

She added: “The COVID-19 lockdowns meant that children no longer had their normal school activities, routines and social interactions. The removal of these barriers gave us a novel context to look at how changes in connection with nature affected mental health.

“Connecting with nature may have helped buffer some UK children against the effects of the lockdown, but we found that children from less affluent families were less likely to have increased their connection to nature during that time.”

An increased connection to nature was reflected in reports of children spending time gardening, playing in the garden or doing physical activities outdoors. This was commonly linked to having more time available for these activities during lockdown. Conversely, according to parents, a decreased connection to nature was explained by an inability to access some natural spaces due to travel restrictions in place at the time.

“Connecting to nature may be an effective way of supporting children’s wellbeing, particularly as children return to normal routines, such as school and extracurricular activities,” said Dr Elian Fink, a Lecturer in Psychology at the University of Sussex who was also involved in the study.

She added: “Our findings could be helpful in redesigning lockdown rules should the UK need to return to these conditions in the future, and particularly to countries whose lockdown restrictions prevented children from accessing nature at all.

“Extending the amount of time that children can access nature, or extending the distance that children could be allowed to travel to access nature, could have a beneficial impact on their mental health.”

The study used an online survey to collect responses from 376 families in the UK, with children between three and seven years old, between April and July 2020. Over half of these families reported that their child’s connection to nature increased during the first COVID-19 lockdown. The remaining parents whose children’s connection to nature decreased or stayed the same during this period also reported that their children were experiencing greater wellbeing problems.

A widely-used, gold standard questionnaire was used as a measure of each child’s mental health – assessing emotional problems such as unhappiness, worrying, anxiety and depression; and behavioural problems such as anger and hyperactivity.

“Mental health problems can manifest in different ways in different children. We found that a greater connection with nature was associated with reductions in both emotional and behavioural problems,” said Fink.

She added: “In reality the contrasting experiences of access to nature between different socio-economic groups may be even starker than our study found because respondents to our online study were largely drawn from more affluent societal groups.”

Parents with children between three and seven years old responded to the study survey with reference to one particular child. The researchers focused on this age group because they were likely to experience a lot of disruption due to the pandemic, and also have less understanding of what was happening.

“Our study revealed the wide range of ways that parents can help children get more connected to nature. This might be a bit daunting to some, but it doesn’t have to be camping in the woods and foraging for food – it really can be as simple as going for a walk near your house or sitting outside for ten minutes a day,” said Friedman.

This research was funded by Newnham College, University of Cambridge.

source: www.cam.ac.uk

Reference

Friedman, S. et al: ‘Understanding changes to children’s connection to nature during the Covid-19 pandemic and implications for child well-being.’ People and Nature, Oct 2021. DOI: 10.1002/pan3.10270

Overall, the study supports the hypothesis that the widespread destruction of forests following the asteroid’s impact favoured ground-dwelling mammals over their arboreal counterparts. However, it also provides strong evidence that some tree-dwelling animals also survived the cataclysm, possibly nesting in branches through the Cretaceous-Paleogene (K-Pg) extinction event.

“The recovery of terrestrial vertebrate life following the end-Cretaceous asteroid impact was one of the most important events in the history of life on Earth,” said senior author Dr Daniel Field, from Cambridge’s Department of Earth Sciences. “In this study, we drew on our previous work at Cambridge to investigate whether there were similarities in the ecological attributes of avian and mammalian survivors of the end-Cretaceous mass extinction.”

The K-Pg mass extinction event occurred when a meteor slammed into Earth at the end of the Cretaceous period. The impact and its aftereffects killed roughly 75% of the animal and plant species on the planet, including whole groups like the non-avian dinosaurs.

For the study, the researchers analysed patterns of substrate preferences among all modern mammals and their ancestors, working backwards from the present day to before the K-Pg extinction event by tracing these traits along numerous phylogenetic trees — diagrams that illustrate the evolutionary relationships among species.

“Our study takes advantage of an ongoing revolution in our understanding of the tree of life, only made possible by researchers working in association with natural history collections,” said co-lead author Jacob Berv, from the University of Michigan. “By integrating data from such collections with modern statistical techniques, we can address new questions about major transitions in evolutionary history.”

The researchers classified each mammalian species as arboreal, non-arboreal, or semi-arboreal. To be considered arboreal, the species had to nearly always nest in trees. Categorising some species could be tricky. For example, many bat species spend a lot of time among trees but nest in caves, so bats were mostly categorised as non-arboreal or semi-arboreal.

“We were able to see that leading up to the K-Pg event, there was a spike in transitions from arboreal and semi-arboreal to non-arboreal habitat use across our models,” said co-lead author Jonathan Hughes, from Cornell University.

The work builds on a previous study led by Field, which used the same analytical method — known as ancestral state reconstruction — to show that all modern birds evolved from ground-dwelling ancestors after the asteroid strike.

“The fossil record of many vertebrate groups is sparse in the immediate aftermath of the extinction,” said Field, who is also curator of ornithology at the Cambridge Museum of Zoology. “Analytical approaches like ancestral state reconstruction allow us to establish hypotheses for how groups like birds and mammals made it through this cataclysm, which palaeontologists can then test when additional fossils are found.”

The analysis helps illuminate ecological selectivity of mammals across the K-Pg boundary despite the relatively sparse fossil record of mammalian skeletal elements from the periods immediately preceding and following the asteroid’s impact.

How the tree-dwelling ancestors of primates survived the asteroid’s destruction is unclear. According to the authors, it’s possible that some forest fragments survived the calamity or that early primates and their relatives were ecologically flexible enough to modify their substrate preferences in a world mostly denuded of trees.

source: www.cam.ac.uk

Reference:
Jonathan J. Hughes et al. ‘Ecological selectivity and the evolution of mammalian substrate preference across the K–Pg boundary.’ Ecology and Evolution (2021). DOI: 10.1002/ece3.8114

Adapted from a Yale news release.

Cytotoxic T cells are specialist white blood cells that are trained by our immune system to recognise and eliminate threats – including tumour cells and cells infected with invading viruses, such as SARS-CoV-2, which causes COVID-19. They are also at the heart of new immunotherapies that promise to transform cancer treatment.

Professor Gillian Griffiths from the Cambridge Institute for Medical Research, who led the research, said: “T cells are trained assassins that are sent on their deadly missions by the immune system. There are billions of them in our blood, each engaged in a ferocious and unrelenting battle to keep us healthy.

“Once a T cell has found its target, it binds to it and releases its toxic cargo. But what is particularly remarkable is that they are then able to go on to kill and kill again. Only now, thanks to state-of-the-art technologies, have we been able to find out how they reload their weapons.”

Today, in a study published in Science, the team have shown that the refuelling of T cells’ toxic weapons is regulated by mitochondria. Mitochondria are often referred to as a cell’s batteries as they provide the energy that power their function. However, in this case the mitochondria use an entirely different mechanism to ensure the killer T cells have sufficient ‘ammunition’ to destroy their targets.

Professor Griffiths added: “These assassins need to replenish their toxic payload so that they can keep on killing without damaging the T cells themselves. This careful balancing act turns out to be regulated by the mitochondria in T cells, which set the pace of killing according to how quickly they themselves can manufacture proteins. This enables killer T cells to stay healthy and keep on killing under challenging conditions when a prolonged response is required.”

Understanding the details of this basic process could ultimately help in the long-term scientific goal of designing and engineering T cells that are better at killing cancer cells, say the researchers.

To accompany the study, Professor Griffiths and colleagues have released footage showing killer T cells as they hunt down and eliminate cancer cells.

One teaspoon full of blood alone is believed to have around 5 million T cells, each measuring around 10 micrometres in length, about a tenth the width of a human hair. The cells, seen in the video as red or green amorphous ‘blobs’, move around rapidly, investigating their environment as they travel.

When a T cell finds an infected cell or, in the case of the film, a cancer cell, membrane protrusions rapidly explore the surface of the cell, checking for tell-tale signs that this is an uninvited guest. The T cell binds to the cancer cell and injects poisonous ‘cytotoxin’ proteins down special pathways called microtubules to the interface between the T cell and the cancer cell, before puncturing the surface of the cancer cell and delivering its deadly cargo.

The research was funded by Wellcome.

source: www.cam.ac.uk

Reference
Lisci, M et al. Mitochondrial translation is required for sustained killing by cytotoxic T cells. Science; 14 Oct 2021; DOI: 10.1126/science.abe9977

The researchers, led by the University of Cambridge, identified a loss pathway in organic solar cells which makes them less efficient than silicon-based cells at converting sunlight into electricity. In addition, they identified a way to suppress this pathway by manipulating molecules inside the solar cell to prevent the loss of electrical current through an undesirable state, known as a triplet exciton.

Their results, reported in the journal Nature, suggest that it could be possible for organic solar cells to compete more closely with silicon-based cells for efficiency.

Organic solar cells, which are flexible, semi-transparent, and cheap, can greatly expand the range of applications for solar technology. They could be wrapped around the exteriors of buildings and can be used for the efficient recycling of the energy used for indoor lighting, neither of which are possible with conventional silicon panels. They are also far more environmentally friendly to produce.

“Organic solar cells can do lots of things that inorganic solar cells can’t, but their commercial development has plateaued in recent years, in part due to their inferior efficiency,” said Dr Alexander Gillett from Cambridge’s Cavendish Laboratory, the paper’s first author. “A typical silicon-based solar cell can reach efficiencies as high as 20 to 25%, while organic solar cells can reach efficiencies of around 19% under laboratory conditions, and real-world efficiencies of about 10 to 12%.”

Organic solar cells generate electricity by loosely mimicking the natural process of photosynthesis in plants, except they ultimately use the energy of the sun to create electricity rather than convert carbon dioxide and water into glucose. When a light particle, or photon, hits a solar cell, an electron is excited by the light and leaves behind a ‘hole’ in the material’s electronic structure. The combination of this excited electron and hole is known as an exciton. If the mutual attraction between the negatively charged electron and the positively charged hole in the exciton, akin to the attraction between the positive and negative poles of a magnet, can be overcome, it is possible to harvest these electrons and holes as an electrical current.

However, electrons in solar cells can be lost through a process called recombination, where electrons lose their energy – or excitation state – and fall back into the empty ‘hole’ state. As there is a stronger attraction between the electron and hole in carbon-based materials than in silicon, organic solar cells are more prone to recombination, which in turn affects their efficiency. This necessitates the use of two components to stop the electron and hole from recombining rapidly: an electron ‘donor’ material and an electron ‘acceptor’ material.

Using a combination of spectroscopy and computer modelling, the researchers were able to track the mechanisms at work in organic solar cells, from the absorption of photons to recombination. They found that a key loss mechanism in organic solar cells is caused by recombination to a particular type of exciton, known as a triplet exciton.

In organic solar cells, triplet excitons present a difficult problem to overcome, as it is energetically favourable for them to form from the electrons and holes. The researchers found that by engineering strong molecular interactions between the electron donor and electron acceptor materials, it is possible to keep the electron and hole further apart, preventing recombination into triplet excitons from occurring.

Computational modelling suggests that by tuning the components of the organic solar cells in this way, the timescales of recombination to these triplet exciton states could be reduced by an order of magnitude, allowing for more efficient solar cell operation.

“The fact that we can use the interactions between components in a solar cell to turn off the triplet exciton loss pathway was really surprising,” said Gillett. “Our method shows how you can manipulate molecules to stop recombination from happening.”

“Now, synthetic chemists can design the next generation of donor and acceptor materials with strong molecular interactions to suppress this loss pathway,” said co-author Dr Thuc-Quyen Nguyen from the University of California, Santa Barbara, USA. “The work shows the path forward to achieve higher device efficiency.”

The researchers say their method provides a clear strategy to achieve organic solar cells with efficiencies of 20% or more by stopping recombination into triplet exciton states. As part of their study, the authors were also able to provide design rules for the electron donor and electron acceptor materials to achieve this aim. They believe that these guidelines will allow chemistry groups to design new materials which block recombination into triplet excitons, enabling organic solar cells with efficiencies closer to silicon to be realised.

source: www.cam.ac.uk

Reference:
Alexander J Gillett et al. ‘The role of charge recombination to triplet excitons in organic solar cells.’ Nature (2021). DOI: 10.1038/s41586-021-03840-5

In their roles as consumers, investors, role models, organisational participants, and citizens, people in this group can help shape the choices available to themselves and others, providing options that either exacerbate or mitigate climate change.

Most research into how we can reduce our climate impact has focused on changing the consumer behaviour of the masses – recycling and switching off lights at home, for example. The authors say that the focus must shift to finding ways of motivating people of high socioeconomic status to change many kinds of behaviours, because what they do can have a much greater impact on carbon emissions.

The study defines high socioeconomic status as a person’s position in the structure of society, including not only their wealth and income, but also their ‘social resources’, which include social class, occupation, and social network. It encompasses a much broader spectrum of people than just the super-rich, including everyone with an annual income of US $109,000 and above.

“High socioeconomic status people aren’t just those with more money, but those with better social networks. Their connections can enable them to influence behaviours and policies to help mitigate climate change – and we need to find ways to encourage them to do this,” said Dr Kristian Nielsen, a postdoctoral researcher in the University of Cambridge’s Department of Psychology, first author of the paper.

He added: “By saying it’s only the super-rich that need to change their behaviour, we ignore the power that others have to help tackle climate change though their influence.”

The climate impact of air travel is now well known, but over 50% of greenhouse gas emissions from flying are caused by just 1% of the world’s population. The study highlights the need to change social norms associated with frequent flying – usually by people of high socio-economic status – but also to look beyond their role as consumers.

“People of higher socioeconomic status could also act as role models, making more climate-friendly choices that influence others – for example driving electric cars or eating a vegan diet. You don’t need a massive income to be a role model, you just need to be well-connected,” said Nielsen.

Investments also provide an opportunity for those of higher socioeconomic status to mitigate climate change. Although attention has focused on shifting the investment of large pension funds away from fossil fuel companies, the researchers say that the investment portfolios of individuals – particularly those with immense wealth – can also have a very significant influence.

In addition, high socioeconomic status individuals – whether owners or employees – can help to mitigate climate change through their organisations, for example by changing suppliers, business culture and investments.

And as citizens, people of high socioeconomic status have the networks to help them organise social movements, and better access politicians and decision-makers. Their financial resources also help: making donations helps smooth the path to advancing social change.

“Our study focused on people of high socioeconomic status because they have generated many of the problems of fossil fuel dependence and associated climate change, which affect the rest of humanity. And they are also well positioned to do something about it,” said Nielsen.

He added: “When certain people change their behaviour for the good of the climate it can have spill-over effects that go way beyond the effects of the average person, and lead to systemic change.”

This research was funded by the Carlsberg Foundation.

Reference
Nielsen, K.S. et al: ‘High socioeconomic status people are key to locking in or rapidly reducing energy-driven greenhouse gas emissions.’ Nature Energy, Sept 2021. DOI: 10.1038/s41560-021-00900-y

source: www.cam.ac.uk

Delivering the Annual Address to the University, Prof Toope said Cambridge was determined to be a champion of free speech; a University that is thinking carefully about how and why it engages with the world; and a University committed to taking academic achievement to new heights.

He said: “Impact is not just a buzzword, or an aspiration – it is a concrete outcome, and Cambridge has it in spades. It is about the technologies we create, and the discoveries we make. It is about the ideas we develop, and the shared cultural legacies we interpret and pass on. It is about making a difference in the world – even when that difference is not immediate. It is at the heart of the story we need to be telling about our University. It is what we will continue to pursue as we set out on our journey of renewal and recovery.”

During his address, Prof Toope also reflected on the challenges and successes of the past year, describing the University’s resourceful and resilient response to the COVID-19 global pandemic, and paying tribute to Cambridge researchers’ work in leading the national COVID-19 Genomics UK consortium (COG-UK) to understand how the COVID virus is transmitted, and how it evolves.

The work of Cambridge Zero – the University’s flagship climate change initiative – which has been taking an active role in advising the government and shaping the international climate agenda ahead of COP26 was also highlighted, as was the launch of the Cambridge Foundation Year, offering talented students from backgrounds of educational and social disadvantage a new route to university.

Navigating the complexities of international engagement

source: www.cam.ac.uk

The study, published in the Journal of the Royal Society Interface and led by researchers from the University of Cambridge, is based on time-series models developed using classical statistical methods. The models produce ‘nowcasts’ and forecasts of the daily number of new cases and deaths that have already proved successful in predicting new COVID-19 waves and spikes in Germany, Florida in the USA, and several states in India.

The study is co-authored by Andrew Harvey and Paul Kattuman, whose time-series model reflecting epidemic trajectories, known as the Harvey-Kattuman model, was introduced last year in a paper published in Harvard Data Science Review.

“The basic R rate quickly wanes in usefulness as soon as a pandemic begins,” said Kattuman, from Cambridge Judge Business School. “The basic R rate looks at the number of infections expected to result from a single infectious person in a completely susceptible population, and this changes as immunity builds up and measures such as social distancing are imposed.”

In later stages of a pandemic, the researchers conclude that use of the effective R rate which takes these factors into account is also not the best route: the focus should be not on contagiousness, but rather on the growth rate of new cases and deaths, examined alongside their predicted time path so a trajectory can be forecasted.

“These are the numbers that really help guide policymakers in making the crucial decisions that will hopefully save lives and prevent overcrowded hospitals as a pandemic plays out – which, as we have seen with COVID-19, can occur over months and even years,” said Kattuman. “The data generated through this time-series model has already proved accurate and effective in countries around the world.”

The study examines waves and spikes in tracking an epidemic, noting that after an epidemic has peaked, daily cases begin to fall as policymakers seek to prevent new spikes morphing into waves. The monitoring of waves and spikes raises different issues, primarily because a wave applies to a whole nation or a relatively large geographical area, whereas a spike is localised.

Therefore, a localised outbreak in a country with low national infection numbers can result in a jump in the national R rate, as occurred in the Westphalia area of Germany in June 2020 after an outbreak at a meat processing factory. However, this sort of jump does not indicate that there has been a sudden change in the way the infection spreads and so has few implications for overall policy.

The Harvey-Kattuman model has been adapted into two trackers. The two Cambridge academics worked with the National Institute of Economic and Social Research to produce a UK tracker which is published biweekly by the National Institute of Economic and Social Research. In addition, they produce an India tracker which is published by the Centre for Health Leadership and Excellence at Cambridge Judge Business School. District-level pandemic trajectory forecasts using the model are used by public health policymakers in three states in India – Punjab, Tamil Nadu and Kerala – to identify regions at high risk and to frame containment and relaxation policies.

source: www.cam.ac.uk

Reference:
Andrew Harvey and Paul Kattuman. ‘A Farewell to R: Time Series Models for Tracking and Forecasting Epidemics.’ Journal of the Royal Society Interface (2021). DOI: 10.1098/rsif.2021.0179