Historic Amazon rainforest fires threaten climate and raise risk of new diseases

by Kerry William Bowman, The Conversation

The South American tapir is in steep decline due to habitat fragmentation from deforestation, agriculture and human habitation. Credit: Shutterstock

The fires in the Amazon region in 2019 were unprecedented in their destruction. Thousands of fires had burned more than 7,600 square kilometers by October that year. In 2020, things are no better and, in all likelihood, may be worse.


According to the Global Fire Emissions Database project run by NASA, fires in the Amazon in 2020 surpassed those of 2019. In fact, 2020's fires have been the worst since at least 2012, when the satellite was first operated. The number of fires burning the Brazilian Amazon increased 28 percent in July 2020 over the previous year, and the fires in the first week of September are double those in 2019, according to INPE, Brazil's national research space agency.

Despite the surge in fires, international attention has waned in 2020, likely due to the COVID-19 pandemic. Yet the degradation of the Amazon rainforest has profound consequences from climate change to global health.

Global climate implications

The Amazon rainforest covers approximately eight million square kilometers—an area larger than Australia—and is home to an astounding amount of biodiversity.

It helps balance the global carbon budget by absorbing carbon dioxide from the atmosphere, and plays a key role in the global water cycle, stabilizing global climate and rainfall. A nine nation network of Indigenous territories and natural areas have protected a massive amount of biodiversity and primary forest.

Yet these lands are under siege. As of 2019, an estimated 17 percent of the Amazon's forest cover has been clear-cut or burned since the 1970s, when regular measurements began and the Amazon was closer to intact.


As the rainforest bleeds biomass through deforestation, it loses its ability to capture carbon from the atmosphere and releases carbon through combustion. If the annual fires burning the Amazon are not curtailed, one of the world's largest carbon sinks will progressively devolve into a carbon faucet, releasing more carbon dioxide than it sequesters.

While the global impacts are dire, the local impacts of these fires are also significant. Persistent poor air quality, which extends far into Brazil and other regions of South America, including in metropolitan centers like São Paulo, can lead to health problems.

As roads are built and forests are cleared for timber production and agriculture, a checkerboard of tropical forest edges is created. These destructive activities can lead to rapid extinctions and a severe loss of species richness anywhere that human encroachment occurs.

Many researchers predict that deforestation is propelling the Amazon towards a tipping point, beyond which it will gradually transform into a semi-arid savanna. If the deforestation of the rainforest continues past a threshold of 20-25 percent total deforestation, multiple positive feedback loops will spark the desertification of the Amazon Basin.

Global health implications

Zoonotic diseases, like SARS-CoV-2, the virus that causes COVID-19, are on the rise. Understanding the root causes of these spillover events that move viruses from animals to humans gives us insight into how to prevent future zoonotic outbreaks. The degradation and fragmentation of tropical rainforests such as the Amazon may be a key factor in this process.

The checkerboard of forest edges increases the potential points of contact between humans and wildlife, which in turn increases the likelihood of viral transmission and the emergence of novel human diseases. Intact forests and high levels of biodiversity, on the other hand, can provide a "dilution effect" associated with a lower prevalence and spread of pathogens.

The present pandemic may well have had an environmental genesis. Maintaining the Amazon's current high level of biodiversity is vital, both for the health of the global ecosystem and because, otherwise, the Amazon could become a future hotspot of emerging diseases. When we protect the global ecosystem, we also protect ourselves from emerging zoonotic diseases.

Interventions are complex, but the protection of Indigenous territories, the restoration of already degraded lands and, most importantly, continued international awareness of political dynamics and consumer choices, all offer us ways to avert oncoming tragedy. If we do not take a longer view of this pandemic and look upstream for drivers and causes, pandemics will continue to emerge.


Explore further Fires 'poisoning air' in Amazon: study

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Fires spike in Brazil's Amazon, scientists say

by Louis Genot

A member of an Indigenous group fights a forest fire in Brazil, which has seen an increase in wildfires over last year

The number of forest fires in Brazil's Amazon increased sharply in September, figures released Thursday show, fueling growing criticism of President Jair Bolsonaro's environmental policies.


The National Institute of Space Research (INPE) said satellite imagery showed an increase of 61 percent in the number of fires in September, compared to the same period last year.

Satellites used by the institute detected 32,017 outbreaks last month in the Amazon, compared to 19,925 in the same month in 2019.

In the first nine months of the year, the total number of fires increased by 14 percent over the same period in 2019, the INPE said.

Despite the data from INPE, a world-renowned public body, Bolsonaro has continued to denounce a campaign of "disinformation" about the Pantanal and the Amazon.

On Wednesday, Bolsonaro—an ally of US President Donald Trump—lashed out at US Democratic presidential candidate Joe Biden for "disastrous and unnecessary" comments on destruction of the rainforest.

Biden said during the first presidential debate that if elected in November, he would raise $20 billion to help Brazil to "stop tearing down" the Amazon, threatening "significant economic consequences" if it did not.

Bolsonaro backlash

Smoke rises from an illegally lit fire in the Amazon rainforest south of Novo Progresso in Brazil's Para State, in August 2020

Later, in a video address to a UN biodiversity summit, Bolsonaro said Brazil was "firm in its commitment to sustainable development and preserving our environmental wealth."

He accused "certain non-governmental organizations" of perpetrating "environmental crimes" to stain the country's image.

Most of the Amazon fires consist of agricultural burning on illegally deforested areas, even though the government banned all burning for four months from July.

Further south, in the Pantanal—the world's largest wetlands—the number of fires have almost tripled to 8,106, making September 2020 the worst month since the INPE began compiling statistics on the fires in 1998.

"Brazil is in flames. From the Amazon to the Pantanal, the environmental heritage of all Brazilians is being reduced to ashes," Christiane Mazzetti of Greenpeace in a statement.

"The is a consequence of the policy of the Bolsonaro government, which despite the predictions of drought in the Pantanal, has not used the necessary means of fire protection," she said.


The situation in the Pantanal, straddling Brazil, Paraguay and Bolivia, has been exacerbated by the worst drought in half a century.

The fires have ravaged 23 percent of the Brazilian part of the Pantanal, acording to data collected by scientists at the Laboratory for the Application of Environmental Satellites (LASA).

An aerial view of a deforested area close to Sinop, in Brazil's Mato Grosso State in August 2020

Growing investor pressure

The wildfires that devastated the rainforest last year triggered an international outcry, forcing Bolsonaro onto the defensive. He ultimately deployed the army to the Amazon to fight the fires.

So far this year, despite an increase in fires, the deforestation rate is down by about five percent.

But Brazil is coming under increasing pressure from allies, trading partners, international investors and powerful voices in the business world over the scale of the deforestation.

In June, 29 global investment firms managing nearly $4 trillion in assets sent an open letter to Bolsonaro, urging him to change policies blamed for accelerating the destruction of the rainforest.

Environmental destruction by Brazilian agribusiness firms is also threatening a long-sought trade deal between the European Union and the Mercosur bloc, of which Brazil is a member.


Explore further Fires triple in Brazil's Pantanal wetlands in 2020

New research explores how multinational firms can manage corruption

by Emily Collins, Lehigh University

Credit: CC0 Public Domain

For many developing countries, it is difficult to break the cycle of corruption on their own. Historically, multinational firms have assumed that they have two options available when dealing with corruption in developing countries: "play the game," meaning pay bribes or engage in corrupt activities, or "leave the table" by avoiding investing in countries where corruption is widespread. New research from Charles E. Stevens, associate professor of management in Lehigh's College of Business, shows firms taking a third approach-managing corruption by promoting positive engagement with the host country.


The study, "Avoid, acquiesce ... or engage? New insights from sub-Saharan Africa on MNE strategies for managing corruption," funded by a Social Sciences and Humanities Research Council of Canada grant, is published in the latest issue of Strategic Management Journal.

Using an inductive, qualitative research design, Stevens, in collaboration with Aloysius Newenham-Kahindi, associate professor at the University of Victoria, was able to better understand how and why issues relating to corruption arose and how firms dealt with them. According to Stevens, firms may typically "tread lightly," but his research shows firms having success by making deeper, long-term commitments.

"Within the last decade, a number of developing country firms, many of them from China, were taking a different approach that we termed an engagement strategy that, in many ways, was unexpected and counter-intuitive because it tended to involve greater commitment and greater investment to countries where there was more corruption," said Stevens.

Stevens and Newenham-Kahindi were curious to see if these firms were less concerned with corruption, but research found that was not the case.

"Many of these firms were following rather interesting and complex strategies, many that involved multiple actors that were designed at minimizing the ability of host-country actors to request bribes by maximizing their bargaining power or by minimizing the motivation of host-country actors to request bribes by increasing their legitimacy," explained Stevens.

Facing challenges related to studying corruption due to the illegal activity often being hidden, Stevens and Newenham-Kahindi surveyed those who experience dealing with corruption directly. Among those interviewed for the study were 445 individuals representing industries such as construction, mining, manufacturing, energy, and telecommunications in both developed and developing country firms; 126 host country government officials and employees; 34 local private sector employees; 44 local institutional researchers; and 142 members of the general public.

According to Stevens, this paper fills an important gap in corruption literature by increasing the understanding of the options and strategies that firms have at their disposal when they invest in countries where corruption is a greater problem.

With this study, the researchers are hoping to change policies and practices by both firms and governments.

"We hope that this research allows firms, governments, and the general public to achieve economic prosperity, reduce corruption, and create mutually-beneficial solutions through investment and growth," said Stevens. "Firms shouldn't automatically be afraid to invest in countries where risks like corruption are present. Such countries present many challenges, but for firms that go in with a comprehensive plan, are prepared to make a long-term commitment, and find ways to leverage partnerships with governments and other firms, the rewards can be worth the risks."

Explore further

State-level public corruption affects firm value, transparency: study

More information: Charles E. Stevens et al, Avoid, acquiesce … or engage? New insights from sub‐Saharan Africa on MNE strategies for managing corruption, Strategic Management Journal (2020). DOI: 10.1002/smj.3228

Provided by Lehigh University

Forest darkness helps stave off effects of nitrogen pollution – but this is set to change

by Aisling Irwin, Horizon: The EU Research & Innovation Magazine

The life that grows underfoot accounts for 80% of the biodiversity in a temperate forest. Credit: pikist.com/licenced under CC0

Europe's forests are sitting on a pollution timebomb which could rewrite their ecology when it explodes, say researchers.

Delicate forest floor plants such as wood sorrel or violet, and the balance among the tree species that tower above them, are all threatened by decades of accumulated nitrogen pollution. A study has found that the darkness of the forest has subdued the effects of nitrogen. But forests are destined to let in more light in the future as trees succumb to drought and disease.

Forests cover 40% of the European Union's land area and are expanding in some countries, mostly because of active restoration or the abandonment of agricultural land. Forests provide services such as controlling erosion and cycling water but they are also increasingly threatened by droughts and diseases such as ash dieback.

To understand how they are responding to these challenges it is vital to study the forest floor, says Professor Kris Verheyen, an ecologist at Ghent University in Belgium.

"This herb layer is very often forgotten. Some people call it the step-over layer—you step over it to look at the trees," he said.

Yet, in temperate forests, the life underfoot includes 80% of a forest's biodiversity. The herb layer cycles key nutrients such as phosphorous, potassium and nitrogen, helps decompose tree litter and filters the next generation of trees—since seedlings need to pass through it to embark on their journey to the canopy, says Prof. Verheyen.

Records

In trying to understand more about the forest floor, he led a team that retrieved records, going back in some cases as far as 50 years, of 4,000 forest plots across Europe. For those whose locations were easily identified, the researchers visited to make updated measurements.

The team also carted forest soils from around the continent to their research station where they incorporated them into outdoor experimental environments, called mesocosms, in which they varied the plants' access to nitrogen, temperature and light.


"The basic question we wanted to answer was how do multiple global change drivers determine the trajectories of change over time," says Prof. Verheyen, who led the project, known as PASTFORWARD.

Forest dieback can open up protective canopies. When more light is let in, forests can succumb to drought and disease. Credit: High Contrast/Wikimedia, licenced under CC BY 3.0 DE

Overall, the team found that the key controlling factor in forest life was light, which acts as a bottleneck preventing other changes from exerting an effect.

Nitrogen pollution

One powerful example of this was the way it has held back the effects of nitrogen pollution.

Nitrogen deposition is a chronic problem caused by ammonia emissions from agricultural fertiliser and the creation of nitrogen oxides as a by-product of burning fossil fuels. It draws certain nutrients out of soils, acidifies land, and causes algae to grow in waterways.

The researchers found plenty of nitrogen deposition in forests and documented its consequences for species. But 'the effects are not as strong as we expected because … the nitrogen is available but the plants (on the forest floor) can't really benefit because they are limited by the amount of light that is available," said Prof. Verheyen.

Some plants—types that tend to be widespread and can survive in a variety of environments including non-native species—have the machinery to take advantage of an excess of nitrogen and grow more; others—which tend to be specialists with small ranges—do not. In shaded forests they are on an equal footing. But as soon as the canopy opens up and light pours in, those that can exploit the nitrogen pollution have an advantage.

As a result, European forests are already losing their more specialist species and thus experiencing a drop in biodiversity. Prof. Verheyen is concerned that forest canopies are in danger of opening up as trees die from drought and disease which may open the floodgates to nitrogen.

"That will lead to rapid and very large changes in the herb layer," he said.

Drought—itself a result of climate change—has had a 'massive' effect killing trees in spruce forests in Germany, Belgium and France in recent years although broadleaf forests have been more resistant for now.

This does not mean that broadleaf forests are free from canopy-opening—one example is ash dieback disease. "We do have evidence that because of the dying off of the ash you get a lot of light and then the understorey really explodes because light is no longer a limiting resource," said Prof. Verheyen.

Some experts consider there to be seven layers in a forest, while Prof. Verheyen's team have based their work on three interconnected layers. Credit: Horizon

"These large and probably abrupt changes that may happen in the herb layer will affect the tree regeneration and will certainly determine which species will be able to pass the herb layer filter and which not. It will have its consequences for nutrient cycling because this herb layer really impacts rate of decomposition."

Buffering

The researchers also discovered that forests have so far done a remarkable job of buffering plants against the broader climate change going on outside them.

Temperature measurements revealed that forests often have significantly different temperatures from what weather stations—always placed far from trees—record. In summer, for example, they are on average 4°C cooler. This is not only because thick canopies keep out the light, but also because evapotranspiration of water through the leaves and into the atmosphere sucks heat out of the forest, and the vegetation keeps out breezes that would mix warm air into the cool.

Climate models don't take into account this buffering, despite the fact that two thirds of the world's species live in forests and forest processes such as carbon and nutrient cycling depend on temperature, says Professor Pieter de Frenne, a bioscientist also at Ghent University, who is leading the parallel FORMICA project investigating forest microclimates.

This, in turn, explains why, in intact forest, there has been less 'reshuffling' of forest species than was predicted as Europe warms, he says—forest-buffering has allowed many species to cling on.

"We would have expected that forest plants would have responded already to a stronger degree—so that more warm-adapted species would have come into the community and more cold affinity species would have declined or even become locally extinct."

But the effect can't last forever and if the canopy is opened up these species will have a rude awakening as their world warms up to the temperature outside the forest.

"Buffering is buying us time so species get a chance to adapt to the new climate," he said.

The work has practical implications for the way forests are managed and the PASTFORWARD and FORMICA teams are now hoping to develop a tool to help forest managers work out how much of the canopy they can remove—for example for harvesting or as part of the cycle of tree-thinning known as coppicing—without triggering this explosive growth.


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Satellite images display changes in the condition of European forests

Provided by Horizon: The EU Research & Innovation Magazine
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Crickets were the first to chirp 300 million years ago

by Wageningen University
 

Credit: Wageningen University & Research

An international team, led by Dr. Sabrina Simon (Wageningen University & Research) and Dr. Hojun Song (Texas A&M), succeeded in tracing the evolution of acoustic communication in the insect family of crickets and grasshoppers (Orthoptera). The results show that crickets were the first species to communicate, approximately 300 million years ago. The results are also significant because it was the first time this analysis has been done on such a large scale. The publication by Dr. Simon et al. appeared in the prominent scientific journal Nature Communications today.


"Insects have a vital role in terrestrial ecosystems. To understand how insects influence, sustain or endanger ecosystems, and what happens when they decline or even disappear, we first need to understand why insects are so species-rich and how they evolved," says Dr. Simon.

Orthoptera is a charismatic insect group of high evolutionary, ecological and economic importance such as crickets, katydids, and grasshoppers. They are a prime example of animals using acoustic communication. Using a large genomic dataset, the team established a phylogenetic framework to analyze how hearing and sound production originated and diversified during several hundred million years of evolution.

Chirping

The familiar sound of crickets was first experienced 300 million years ago, the researchers found. It was experienced because specialized and dedicated hearing organs were developed later. Sound production originally served as a defense mechanism against enemies, who were startled by the vibrating cricket in their mouths. Later on, the ability to produce sound started to play a prominent role in reproduction, because sound-producing crickets had a greater chance of being located by a female.

Insects are one of the most species-rich groups of animals. They are crucial in almost every ecosystem. The number of insects is rapidly declining. Insect species are becoming invasive or disappearing due to climate change. That—in itself—has an impact on ecosystems and eventually on humans. "We need to understand the evolutionary history of this amazingly successful animal group. This is also important for our (daily) economic life because only then can we understand what happens when insect species decline or even disappear," says Dr. Simon.

1KITE-project

"We have access to a lot of genomic data on crickets and grasshoppers, thanks to the 1KITE project and a collaboration with the Song Lab at Texas A&M University, U.S.," Dr. Simon says. "This enables us to sanalyse how different species relate to each other. We generated a genealogical tree of when what species of crickets, grasshoppers and their allies lived on earth. On top of that, we know what species were able to produce sound and hear. That allowed us to create a timeline that shows when the first crickets could communicate: around 300 million years ago."

The 1KITE (1K Insect Transcriptome Evolution) project aims to study the transcriptomes (that is the entirety of expressed genes) of more than 1,000 insect species encompassing all srecognised insect orders. Overall, scientists from eleven nations (Australia, Austria, China, France, Germany, Japan, Mexico, the Netherlands, New Zealand, UK and the US) are closely collaborating in the 1KITE project.


Explore further What did the katydids do when picking up bat sounds?

More information: Hojun Song et al. Phylogenomic analysis sheds light on the evolutionary pathways towards acoustic communication in Orthoptera, Nature Communications (2020). DOI: 10.1038/s41467-020-18739-4
Provided by Wageningen University

Healthy corals in Biscayne Bay surprised scientists. They may help reefs survive

by Adriana Brasileiro

Credit: CC0 Public Domain

During a scouting mission to check on coral colonies in inshore Biscayne Bay last year, Caroline Dennison and a few other marine biology graduate students found something astounding: healthy populations of brain corals.


There were no signs of white spots or bleaching and the vivid yellowish brown colors indicated that the corals were untouched by yet another mysterious disease that's ravaging reefs along the Florida coast. Even more extraordinary was that these corals were thriving in shallow and warm water right off the seawall at Bill Baggs Cape Florida State Park, near a bustling seaside metropolis.

"That was pretty amazing because you wouldn't imagine that type of coral living successfully in a foot of water, at that location, considering all the issues affecting reefs in the area," said Dennison, a coral researcher at the University of Miami Rosenstiel School of Marine and Atmospheric Science. "It was just astonishing, I couldn't believe it."

What's protecting these corals? The discovery has opened up a world of research possibilities on what's killing Florida reefs and the water quality problems making it harder for corals to survive in troubled Biscayne Bay.

Dennison is hoping the thriving colonies will shed some light on a myriad of threats to corals: from the impact of rising temperatures and nutrient pollution on reefs to the relationship between corals and the algae that live within them. Findings could also help scientists develop new coral restoration strategies to replenish this key natural protection infrastructure for coastlines against erosion and storms.

The surprisingly good shape of the nearshore corals also highlighted Biscayne Bay's diverse ecosystem, which has pockets of healthy habitats. Not far from these corals, or an artificial reef right next to Port Miami, is the Coral City Camera, which livestreams a constant parade of colorful fish, manatees and sharks near a channel used by huge cruise ships.

Those areas with abundant marine life aren't far from where a massive fish kill happened in August.

The sight of thousands of fish carcasses floating in the northern part of the bay and the algae blooms that followed alarmed residents and triggered a reckoning over critical issues plaguing Miami-Dade's treasured turquoise waters: contamination from crumbling sewage pipes and failing septic tanks, stormwater runoff and a seagrass die-off that's drastically reducing the bay's ability to handle pollution and regenerate.


The Bay is very sensitive to nutrient pollution because historically it didn't have that much phosphorus and nitrogen going into its waters. The Everglades ecosystem filtered these nutrients before the water flowed to the coast. That means that plants and other bay organisms like corals grew slowly because of the nutrient limitation.

Once development and draining altered the flow of the Everglades and population growth led to a jump in nutrient pollution flowing to Florida's coasts, life began to change in Biscayne Bay: slow-growing turtle grass, for example, with its long and broad blades, was replaced by microalgae which grows faster. The bay has lost over 20 square miles of seagrass over the past decade.

"If things grow faster they are competitively dominant; what we've seen over the past decades is a change in species composition from slow-growing things to fast-growing things and now in the northern part of the bay we've gone over the edge," said Jim Fourqurean, a professor of biology and director of the Center for Coastal Oceans Research at Florida International University.

Slower-growing corals like the brain species, which used to be common over the Florida reef tract, have also suffered because of the apparent shift in the bay to a nutrient-rich system, he said during a virtual town hall organized by Commissioner Daniella Levine Cava earlier this week.

"We just gotta stop doing that, we have to stop putting nutrients into the bay so we can return to the system that we used to have," Fourqurean added.

To be sure, nutrient pollution is just one stress factor affecting Florida's coral reefs. A disease that was first observed in 2014 off Virginia Key has been destroying the soft tissue of many stony coral species, killing them within months of becoming infected. Colonies in the U.S. Virgin Islands, the Bahamas, Puerto Rico and as far as Mexico have been affected, and the disease has advanced along the Florida Keys. The causal agent is still unknown.

Brain corals are particularly vulnerable, and that's why Dennison was so ecstatic to find vigorous colonies just steps away from the hiking trail and fishing docks on the seawall at Bill Baggs park.

Water circulation patterns and big tidal variations are some of the environmental factors at play in the area, which led her to wonder if the colonies were ever exposed to what's causing the disease long enough or at high enough concentrations to become infected. Water temperatures in those shallow areas are also 2 to 3 degrees Celsius higher than in offshore reefs, which may have boosted the corals' resilience, she said.

"It also could do with turbidity, or sedimentation. Water quality factors change a lot when you come in from offshore Miami-Dade reefs into these indoor locations, so it could be any number of these environmental factors, either working alone or working together."

And then there's the complex relationship between the corals and their symbiotic algae. This could well be a disease of the algae, and how that symbiosis affects the hosts' immune systems, said UM Rosenstiel School Professor Andrew Baker.

"They seem to be less susceptible to the disease but it's still early days in our research; there are several hypotheses," he said.

One could be that the algae inside the coral are actually the targets of the disease, and when they become infected, "it causes the coral to freak out," Baker said. The symbiosis with corals is so tight that the algae actually live inside the cells of their hosts.

But it could also be that certain types of algae under certain conditions trigger vulnerabilities in the corals, he said. Answers to these questions will be hugely valuable for coral restoration efforts, which have taken on a heightened sense of urgency because of the fast-spreading disease.

"At the rate things are going, we humans need to help out corals. We need to interfere. And genetic manipulation is one way to strengthen these crucial species so they have a chance of surviving what's coming and what's already here," said Liv Williamson, a coral researcher at the Rosenstiel School.

This year, for the first time, UM researchers including Williamson watched the spawning of staghorn corals that had been raised in a lab and transplanted to a restoration reef off Key Biscayne. The corals released their eggs and sperm - gametes as those are collectively called - into the water where they fertilized and made little baby coral larvae in early August. The babies then settled on the reef and formed little new polyps with mouths and tentacles. And that's how they build brand new colonies.

Dennison also checked on her naturally resilient nearshore Biscayne Bay corals during the latest spawning event. Every evening during a whole week in September, she went diving with other researchers in the shallow waters of the bay looking for gametes. With the help of dive lights and equipped with nets and large syringes to collect specimens, small groups of researchers combed the area just off the seawall for hours each night, but no sign of coral sex, she said.

"We may have missed the window this time but we'll be watching these guys very closely," she said. "Finding them really gave us hope that they can teach us something about restoration and continue to help us answer questions about the disease outbreak and water quality issues."


Explore further Lab-grown and replanted corals to spawn in the Florida Keys

©2020 Miami Herald
Distributed by Tribune Content Agency, LLC.

Exploring prediction errors that can influence human perceptions of time

by Ingrid Fadelli , Medical Xpress
  

Image showing activation in the Basal Ganglia. In the highlighted location, brain activation is opposite for positive and negative prediction errors in correct/incorrect time perception. The researchers suggest that the bias in time perception due to the presence of prediction errors might have originated from the interaction between time and PE in this brain region. Credit: Toren, Aberg & Paz.

Humans can sometimes perceive the passing of time differently, for instance, feeling as though an hour passed very quickly or that a few minutes went by extremely slowly. This suggests that the human perception of time is subjective and can be affected by many factors that can cause people to perceive the same amount of time as longer or shorter than it actually is.

Researchers at the Weizmann Institute of Science in Israel have recently carried out a fascinating study exploring if and how prediction errors can bias how different individuals perceive the passing of time. Their paper, published in Nature Neuroscience, shows that time perception can be influenced by both positive and negative prediction errors, while also identifying the putamen as a brain region responsible for biased time perception.

"Our lab studies, among other things, the process of learning from errors (reinforcement learning)," Rony Paz, head of the lab that carried out the study, told MedicalXpress. "Dopaminergic brain activation in a structure called the basal ganglia (BG) is known to be related to reinforcement learning in general, and reward prediction errors processing in particular. BG activation is also related to time perception required for motor functions that our brain controls."

For many years, time perception and human prediction errors were seen as almost entirely independent processes. The study by Paz and his colleagues challenges this idea, suggesting that these two elements are, in fact, deeply interlinked.

"Time perception and prediction error computation have often been considered to be mostly independent processes," Paz said. "The core idea of our study was to challenge this notion. Since the perception of time is subjective and was shown to be biased by many factors, and since both functions are processed in the same brain circuits, the two might interact and either aid or interfere with each other."
  

The main behavioral result collected by the researchers (i.e., how participants estimated time in different conditions). Higher location in the plot indicates higher error-rate in time perception. The orange line shows time perception when outcome is expected, while red/blue lines are time perception during PE-/PE+ respectively. It can be seen that time perception is biased for both PE-/PE+ (compared to expectation PE0) but in opposite directions. Credit: Toren, Aberg & Paz.

The key objective of the recent work by Paz and his colleagues was to investigate whether time perception is influenced by prediction errors, and if it is, to identify the neural underpinnings of this process. To achieve this, the researchers designed a behavioral task executed inside an fMRI scanner, in which participants are presented with different pairs of images on a screen, displayed for various amounts of time.


During each trial, the group of participants they recruited were asked to decide which of two images they saw on the screen was displayed for the longer amount of time. The images were overlaid with numbers that represented monetary gains and losses, as these would lead to predictions and errors.

"This design allowed us to measure time perception with a wide range of time differences, and importantly, in the presence of predicted vs. unpredicted outcomes," Paz explained. "The use of monetary gains and losses offers the possibility to differentiate between positive prediction errors (i.e., getting more than you expect) and negative prediction errors (i.e., getting less than you expect)."

As those who took part in their experiment were inside an fMRI scanner, the researchers were able to collect brain imaging data that could shed some light on the neural underpinnings of biased time perception. They then used computational modeling approaches to analyze the data they collected and investigate brain activation in the presence of positive or negative prediction errors. These analyses yielded a number of interesting results, highlighting the link between time perception and positive/negative prediction errors and identifying the putamen (located within the BG) as the brain region responsible for this interaction.

"Firstly, we found that prediction errors do indeed bias time perception, which was not known before," Paz said. "Moreover, we were able to identify the characteristics of this cognitive bias: Time is overestimated when positive errors occur (i.e., when a user receives more than he expected) and is underestimated when negative errors occur. The observation that two different functions processed in the same brain circuits can interact might have implications on many other processes executed in similar brain circuits."

Paz and his colleagues are among the first to provide evidence of the interaction between time perception and human prediction errors, while also identifying the brain region where this interaction 'takes place' (i.e., the putamen). The results they gathered could serve as a basis for other studies exploring the neural underpinnings of time perception biases. In addition, this study could shed light on the complexities and neural dynamics of diseases associated with dysfunctions of the BG, such as Parkinson's disease (PD), which affects people's ability to learn and accurately perceive the passing of time.


Explore further Why visual perception is a decision process

More information: Ido Toren et al. Prediction errors bidirectionally bias time perception, Nature Neuroscience (2020). DOI: 10.1038/s41593-020-0698-3
Journal information: Nature Neuroscience

Researchers probe how aggression leads to more aggression

by Lori Dajose, California Institute of Technology
 

Credit: Pixabay/CC0 Public Domain

Like a champion fighter gaining confidence after each win, a male mouse that prevails in several successive aggressive encounters against other male mice will become even more aggressive in future encounters, attacking faster and for longer and ignoring submission signals from his opponent.


This phenomenon is interesting to people who study the neuroscience of behavior, because aggression is an innate, hard-wired behavior in the brain. This means that a mouse does not need to learn aggressive behaviors before it engages in them; aggression is instinctive upon reaching adulthood. However, experiences (say, repeated successful aggressive encounters) are able to alter this innate behavior.

Now, a team of Caltech researchers has discovered that hard-wired neural circuits governing aggression in mice are strengthened following their victories in aggressive encounters, and has identified a learning mechanism operating in the hypothalamus—a brain region traditionally viewed as the source of instincts, rather than learning.

The research was conducted in the laboratory of David Anderson, Seymour Benzer Professor of Biology, Tianqiao and Chrissy Chen Institute for Neuroscience Leadership Chair, Howard Hughes Medical Institute Investigator, and director of the Tianqiao and Chrissy Chen Institute for Neuroscience at Caltech.

A paper describing the research appears in the journal Proceedings of the National Academy of Sciences on September 24.

There is a difference between innate behaviors and those that are learned. For example, mice can be taught that performing certain behaviors (for example, pulling a lever) can result in a positive outcome (such as receiving food). On the other hand, innate behaviors like aggression are instinctive to male mice; the mice do not need to learn how to lunge and attack when confronted with other mice they deem a threat—they just react.

Previous studies have shown that a male mouse, once it has won in several aggressive encounters with other males, will exhibit increased aggression in future encounters. In other words, an innate behavior is altered by experience. This effect is termed "aggression training."


Led by postdoctoral scholar Stefanos Stagkourakis, the Caltech team examined a particular connection in the mouse brain where a group of synapses transfer signals from a little-studied region at the junction between the amygdala (a brain region notable for its role in fear-related behaviors) and the hippocampus (which plays a role in short-term memory) to a specific subdivision of the hypothalamus called the ventromedial hypothalamus (VMH), which controls aggressive behaviors in mice. (The hypothalamus also contains neurons in other subdivisions that mediate other social and homeostatic behaviors, such as mating, parental behavior, feeding, and thermoregulation, but these were not studied.)

The team found that after aggression training, these synapses show signs of long-term potentiation (LTP), which is similar to turning the volume knob up on the signal. Instead of just talking to the neurons in the hypothalamus, these synapses are shouting at them, causing them to react more strongly.

Using the Caltech Brain Imaging Center, the team studied the dendrites of neurons, protrusions extending from neurons that receive signals from other neurons, and in particular the dendrites' spines, structures that act like miniature radio antennae on the hypothalamic neurons to detect input from other brain regions. They examined the number, size, and shape of these structures before and after aggression training. They found that aggression training caused the growth of many additional dendritic spines on hypothalamic neurons. Such structural changes are expected to make these neurons more sensitive to incoming signals, and therefore more easily activated.

The team also experimentally prevented LTP from forming on these synapses during aggression training, and found that aggression-training no longer led to an increase in aggressive behaviors in these mice.

Although all of the male mice tested were genetically identical, about 25 percent never showed aggression and also were "immune" to the behavioral changes caused by aggression training. The authors further found that such behavioral heterogeneity among genetically identical mice is due to naturally occurring variations in serum testosterone levels: the non-aggressive mice had, on average, lower levels of testosterone than their aggressive siblings. Administration of supplemental testosterone to the non-aggressive mice caused both the appearance of aggressive behavior and LTP at the amygdala-hypothalamic synapses.

This work identifies changes in a very specific brain region after aggression training, but the adaptations that mediate the behavioral effect of aggression training likely occur at multiple sites in the brain. In future work, the team will examine how neural activity in different brain areas changes following social experience and will attempt to identify brain nodes of high significance in the neural circuit of aggression. The team also hopes to investigate how testosterone levels can vary among otherwise genetically identical mice, since the hormone is synthesized by genetically encoded enzymes.

The paper is titled "Experience-dependent plasticity in an innate social behavior is mediated by hypothalamic LTP."


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Neural circuit for detecting male pheromone cues relevant to inter-male aggression
More information: Stefanos Stagkourakis et al. Experience-dependent plasticity in an innate social behavior is mediated by hypothalamic LTP, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2011782117

Journal information: Proceedings of the National Academy of Sciences


Provided by California Institute of Technology

Songbirds sing, like humans flock, for opioid reward

by University of Wisconsin-Madison

Dosed with the opioid fentanyl, swallows like these would “sing like crazy” — but fall silent when researchers switched off their brains’ opioid receptors. Credit: Lauren Riters

What do songbirds and humans have in common? We crave social interaction, and the chemical rewards that flood our brain when we get it.

In a study recently published in Scientific Reports, University of Wisconsin–Madison researchers led by Lauren Riters, professor of integrative biology, found that when songbirds sing during non-mating seasons, it's because singing releases an opioid naturally produced in their brain —that's right, a compound with the same biological makeup of the highly addictive painkillers.

People have naturally-produced—or endogenous—opioids in our brain released in certain situations, like social situations, that make us feel good. That's why we like hanging out with friends, Riters says.

These naturally produced, feel-good compounds are also why many songbirds like to sing in large flocks, says Riters, after years of careful study.

"Animals—including birds, including humans—we produce our own endogenous opioids, and they reward behaviors naturally, like sexual behavior or feeding behavior," Riters says. "Studies show that endogenous opioids also make play rewarding. Songbirds learn their songs, and must practice. When we listened to birds practicing in flocks, it almost sounded as if they were playing around with the notes. Darwin even suggested that birds in flocks may be singing for 'their own amusement.' So, we thought if singing is a playful behavior, it should involve opioids."

About six years ago, a researcher in Riters' lab found a way to reduce the resonse of the Mu opioid receptors in European Starlings, a type of songbird. This receptor, a protein on the surface of a nerve cell, controls responses to endogenous opioids, and they wanted to figure out if it might regulate what sounded like playful song in birds.

To put this to the test, they had to develop a method in starlings to measure reward associated with singing. Riters' team used a method called CPP, a conditioned place preference test, where they trained the birds to associate a certain cage with singing. Later, when given a choice between two cages, birds showed a preference for the cage that they learned to associate with their own singing behavior. This shows that birds think of singing in flocks as a positive experience, Riters says.


"How do you ask a bird if it's feeling good?" Riters says. "This method is really important to studies that we've been running. It comes from studies in psychology, and is commonly used to study reward associated with drug use. We adapted it to ask questions about reward associated with singing behavior."

Once they could recognize what the birds looked like in the reward state, they administered tiny doses of fentanyl, a type of opioid that also binds to the Mu receptor, and found the drug made the birds "sing like crazy." Then they reduced the response of the opioid receptors and found that starlings no longer showed a CPP for song. This shows, Riters says, that endogenous opioids regulate intrinsically-rewarding bird song.

Riters' team ran tests over 2 years. They set up the experiment in an outdoor aviary where they'd observe the birds. Sometimes, Riters says, it proved challenging, since so many other factors contributed to the birds singing or not. Riters says her team had to make the environment as welcoming and relaxing as possible for the birds. For example, if a hawk landed near the aviary, the songbirds wouldn't sing because they'd get stressed out.

The results stood out amongst other research, because most studies of starling song involve the mating season and sexual selection, while the new study focused on song outside the breeding season in large flocks, and its connection with endogenous opioids.

"In terms of communication, not that many people are looking at the rewarding aspects, but definitely people are looking at dopamine, and how that regulates the motivation to communicate," Riters says. "Dopamine is something that, in humans, motivates your behavior and directs it towards reward."

She says her results might suggest that, in starlings, endogenous opioid-prompted song is evolutionarily advantageous, because singing in flocks allows them an opportunity to practice their song to prepare for the mating season. It might not be the most beautiful to listen to—Riters likened their chaotic song to freeform jazz—but that's okay. To them, it's just a warm-up for when they start looking for a mate.

"When the birds are singing they're also practicing motor patterns that they will later use in more serious adult contexts," Riters says. "They're also learning how to produce a vocalization that gets a social response, and they also learn how to attract a female, for example."

Riters thinks the release of opioids might also encourage sociable behavior for these songbirds. Humans have endogenous opioids that do just that, and Riters' research may also have implications for human sociality and even mental health. When humans interact in a social context, like hanging out with friends, their brains also release endogenous opioids, just like the songbirds.

Riters believes birds and mammals share the common ancestor in which these social rewards evolved, so there's a chance parts of their work can be generalized to humans.

In this case, the importance of sociality to both humans and songbirds cannot be understated. When humans don't receive enough social interaction, they might become depressed or experience other negative mental health conditions because their brains aren't producing those endogenous chemicals anymore. For example, people with social anxiety might not want to hang out in social groups, because they might have negative interactions. By studying birds, Riters says, maybe they can find ways to promote positive social interactions.

"We think that studying this kind of gregarious positive social play in songbirds is providing a unique way to come up with new ideas for treatments that might promote positive interactions in humans," Riters says. "During this pandemic and social distancing, we are missing our flockmates, right? And without contact with our flockmates, without socializing in our groups, I think we're really deprived of opioid release."


Explore further

Researchers ID chemical that influences songbirds' song choice
More information: Sharon A. Stevenson et al. Endogenous opioids facilitate intrinsically-rewarded birdsong, Scientific Reports (2020).

DOI: 10.1038/s41598-020-67684-1

Journal information: Scientific Reports


Provided by University of Wisconsin-Madison

New type of plastic made from reclaimed waste

by Claudia Engel, Fraunhofer-Gesellschaft

Compounded and granulated polyhydroxybutyrate (PHB). Credit: Fraunhofer-Gesellschaft

A new type of plastic made of reclaimed waste readily degrades in less than a year. The substance that will soon serve to manufacture and break down mainly disposable products in an ecofriendly way goes by the name of polyhydroxybutyrate. This innovative material can be produced on an industrial scale in a new process developed by the Fraunhofer Institute for Production Systems and Design Technology IPK and its partners.


Everyday life devoid of plastics—that would be hard to imagine. They figure prominently in packaging and consumer goods, and are indispensable to industry applications such as automotive and medical engineering. Reuse and recycling of plastics from fossil resources is hardly common practice. On top of that, they degrade at a glacial pace and pollute the environment for a long time to come. The great patches of plastic waste floating on our oceans attest to their power to pollute. Plastic bottles and bags despoil beaches and, in many places, entire stretches of land.

The Bioeconomy International research initiative

The need for global recycling strategies is urgent, given plastics' heavy use all over the world. More and more governments are resorting to bans to curb the swelling tide of plastic waste. A viable option to replace fossil-based plastics on a large scale has yet to be found. This is why the German Federal Ministry of Education and Research (BMBF) launched the "Bioökonomie International" (Bioeconomy International) research initiative in close cooperation with Fraunhofer IPK, the Department of Bioprocess Technology of the Technical University of Berlin, regional industrial partners and international research partners from Malaysia, Columbia and the U.S.. These researchers are developing a method of manufacturing polymers without drawing on premium resources such as mineral, palm and rapeseed oils, the production of which is very detrimental to the environment.

The Fraunhofer IPK team developed this injection molding tool to replicate prototype components made of polyhydroxybutyrate. Credit: Fraunhofer-Gesellschaft

A new plastic much like polypropylene

This new process turn industrial leftovers such as waste fats that contain a lot of mineral residue into polyhydroxybutyrate (PHB). Microorganisms can metabolize these residues in special fermentation processes. They deposit the PHB in their cells to store energy. "Once the plastic has been dissolved from the cell, it is still not ready for industrial use, because the hardening process takes far too long," says Christoph Hein, head of the Microproduction Technology department at Fraunhofer IPK. The raw material has to be mixed with chemical additives downstream in post-production stages. For example, the research team adjusted the plasticizing and processing parameters to trim the recrystallization time to fit the timing of industrial processing. The resultung biopolymer's properties resemble those of polypropylene. But unlike PP, this plastic degrades fully in six to twelve months.


In this method of producing plastic, microorganisms synthesize the entire polymer in a biotechnical process. "To this end, we convert biogenic residues such as waste fats into polyesters that can be put to technical use," says Hein. The researcher and his team opted for microorganisms, genetically modified with molecular methods, to serve as biocatalysts. With the help of chemical purification processes and an extensively optimized material, they have been able to develop a novel family of materials that satisfy the demands of technical plastics.

No petroleum-based synthetic components needed

The new process not only dispenses with petroleum-based synthetic components altogether; it also enables green plastic alternatives. Naturally occurring microorganisms can break down these newly developed plastics, so they need not be subjected to the special conditions that serve to degrade matter in industrial composting plants. They offer an ecofriendly alternative to making and degrading single-use products and other disposable items.

The process also lends itself to producing high-quality plastic parts for certain technical applications and periods of use. The specifications for this sort of product are more demanding. They may have to exhibit specific geometric tolerances and surface qualities or be reproducible with great precision. The researchers developed highly specialized replication processes to meet these requirements.

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Provided by Fraunhofer-Gesellschaft

Transforming waste into bio-based chemicals

by Emily Scott, Lawrence Berkeley National Laboratory

Credit: Pixabay/CC0 Public Domain

Researchers at Berkeley Lab have transformed lignin, a waste product of the paper industry, into a precursor for a useful chemical with a wide range of potential applications.

Lignin is a complex material found in plant cell walls that is notoriously difficult to break down and turn into something useful. Typically, lignin is burned for energy, but scientists are focusing on ways to repurpose it.

In a recent study, researchers demonstrated their ability to convert lignin into a chemical compound that is a building block of bio-based ionic liquids. The research was a collaboration between the Advanced Biofuels and Bioproducts Process Development Unit, the Joint BioEnergy Institute (both established by the Department of Energy and based at Berkeley Lab), and the Queens University of Charlotte.

Ionic liquids are powerful solvents/catalysts used in many important industrial processes, including the production of sustainable biofuels and biopolymers. However, traditional ionic liquids are petroleum-based and costly. Bio-based ionic liquids made with lignin, an inexpensive organic waste product, would be cheaper and more environmentally friendly.

"This research brings us one step closer to creating bio-based ionic liquids," said Ning Sun, the study's co-corresponding author. "Now we just need to optimize and scale up the technology."

According to Sun, bio-based ionic liquids also have a broad range of potential uses outside of industry. "We now have the platform to synthesize bio-based ionic liquids with different structures that have different applications, such as antivirals," Sun said.

Explore further Making biodiesel with green solvents

More information: Shihong Liu et al. Statistical design of experiments for production and purification of vanillin and aminophenols from commercial lignin, Green Chemistry (2020). DOI: 10.1039/D0GC01234C

Journal information: Green Chemistry

Provided by Lawrence Berkeley National Laboratory

Bacteria fed on a customized diet produce biodegradable polymers for alternative packaging in the cosmetics industry

by Claudia Vorbeck, Fraunhofer-Gesellschaft

Freeze-dried bacteria (Cupriavidus necator) before cell disruption. Credit: Fraunhofer-Gesellschaft

Germany generates around 38 kilograms of plastic waste per capita each year. In a joint project with the University of Stuttgart and LCS Life Cycle Simulation, researchers from the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB and the Fraunhofer Institute for Process Engineering and Packaging IVV are now working to establish a holistic concept for the sustainable use of biologically degradable packaging materials in the cosmetics industry. The project is focusing on polyhydroxyalkanoates (PHAs), which have similar properties to conventional plastics but are produced from microorganisms and without the use of fossil-based raw materials.


To date, the bacteria in Dr. Susanne Zibek's lab at Fraunhofer IGB in Stuttgart have been fed on a whole variety of waste materials, ranging from wood waste and oil and sugar residues to glycerol from biodiesel production. Each of these carbon-based feed sources causes the bacteria to produce specific intracellular storage granules. These so-called polyhydroxyalkanoates (PHAs) are the focus of SusPackaging, a research project that is being conducted in cooperation with Fraunhofer IVV in Freising, the University of Stuttgart and LCS Life Cycle Simulation, which is located in the town of Backnang. Researchers from Fraunhofer IGB are seeking to create biologically based, biodegradable polymers as a replacement for plastic packaging in the cosmetics industry. What sets the project apart is its attempt to establish a wholly green value chain. As Dr. Ana Lucía Vásquez-Caicedo from Fraunhofer IGB explains, a holistic concept with a focus on sustainability is new: "A lot of studies concentrate on individual aspects, but it's rare to see a consideration of the entire process chain all the way up to an evaluation of the quality of materials."

The process begins with cultivation of the bacteria. Dr. Susanne Zibek, group manager of the Food Processing Technology Group, and her colleague Dr. Thomas Hahn are investigating how specific microorganisms can be used to produce different PHAs with different structures, and how the choice of feed influences their characteristics. "Basically, we're trying to create new structural variants, so that we can then see whether the polymer produced is suitable as a packaging material," Zibek explains. The working group has support from researchers at the University of Stuttgart, who are taking a closer look at various characteristics of the microorganisms, including the extent to which they can adapt to toxic substances that might be contained in the natural feed sources.

Replacing harmful solvents with pressure change technology

Before the PHAs can be processed and tested, they must first be extracted from the microorganisms. This is the specialist field of Vásquez-Caicedo, group manager of the Food Processing Technology Group at Fraunhofer IGB. As a rule, this so-called purification process uses solvents such as chloroform. However, as she explains, the aim is to move away from environmentally harmful solvents. Instead, she has developed a purely mechanical/physical method of cell disruption. Known as pressure change technology (PCT), this involves the addition of a process gas to the fermentation broth containing the microorganisms. The broth is then pressurized, with the result that the gas penetrates the cytoplasm of the cells. A rapid lowering of pressure in the broth destroys the cells and releases the PHA.

Lab equipment for cell disruption and extraction of functional materials at Fraunhofer IGB. Credit: Fraunhofer-Gesellschaft

Following purification, the PHA is sent in the form of a white powder to Fraunhofer IVV in Freising. Here, it is turned first into granules and then into a polymer film. Initial testing on small sheets of this polymer has examined material characteristics such as thermal stability, plasticity and various barrier properties—essential if future packaging is to provide cosmetic ingredients with, for example, effective protection against desiccation.


Dr. Cornelia Stramm from Fraunhofer IVV is happy with the results so far: "In terms of their mechanical properties, some PHA types are still proving somewhat difficult to process. We need to make a few adjustments there. But in terms of their barrier properties, PHAs show great potential compared to other biopolymers." At the end of each testing cycle, she sends the results back to Stuttgart along with recommendations for further action, and then the process begins again.

Based on this feedback from Fraunhofer IVV, Zibek's working group at Fraunhofer IGB has modified its feed strategy. The bacteria are now given an additional cosubstrate, which increases the PHA's valerate content, thereby making the end product more pliable.

Further enhancement with every feedback loop

While volumes are still very low and production takes a lot of time, the process is steadily improving with each feedback loop.

Once the various steps have been finalized, a life cycle analysis conducted by external project partner LCS Life Cycle Simulation will evaluate the energy efficiency and sustainability of the entire process in order to compare it with existing processes. All three researchers from Fraunhofer see big potential for PHAs. In the future, particularly for small items of disposable packaging, they could offer a genuine alternative to conventional petroleum-based plastics.


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Insects supply chitin as a raw material for the textile industry

Provided by Fraunhofer-Gesellschaft