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I stand with the climate striking students – it’s time to create a new economy

I stand with the climate striking students – it’s time to create a new economy

Striking for the climate. Paapaya/Shutterstock

I initiated a letter of support to climate striking students – an English version of the German letter coordinated by ecologist Gregor Hagerdorn, signed by more than 1,000 academics – for many reasons.

My role as a university lecturer means that I am committed to fostering better lives and opportunities for each generation. I am also a parent, so when I hear the request from youth, including my students and child to stand with them, I am naturally inclined to give their case fair consideration.

But I am a scientific researcher, too. The first, core demand of the striking students, led by 16-year-old Swedish climate activist Greta Thunberg, is to “unite behind the science”. How could I not recognise the significance of this demand in a communication landscape too often dominated by short-term sensationalism, rather than the core challenges facing society and the living planet?

But there’s a deeper, more fundamental reason to support the global strike for climate, grounded in my own field of political and ecological economics.

My research focuses on how, if at all, we can create an economy that is focused on achieving human well-being and avoiding damage to the environment. The current prospect is not good. No country yet meets most needs of citizens at a sustainable level of resource use.

But my research also shows that it may be possible to do this and more. We have the capability to meet basic needs and achieve high levels of human well-being at modest levels of energy use. And beyond this moderate amount, there is no reliable relationship between energy use and well-being. In many cases, added energy can even harm human health and well-being through air pollution, climate impacts, road accidents, and lack of exercise.

A rapid, radical reduction in energy demand could perhaps fulfil both goals of addressing climate breakdown and enabling our students and children to live good lives: what Kate Raworth calls living within the “doughnut”. So why is this option not debated and put forward through an ambitious policy agenda?

A different future

The answer is both simple and profound. My research area remains marginal, and its results neglected, because to accept it would require a fundamental transformation of the prevailing economic philosophy. We would need to pay less attention to growth and profit as the measures of prosperity, and replace them with sufficiency and equity – a fair division of resources to provide what is sufficient for well-being and not more. After centuries of entrenchment, that’s no easy feat.

But neoclassical economics itself is not the main culprit in our planetary predicament. When we look deeper, and seek to understand the factors underpinning the rise in consumption culture that drives our energy use, we are confronted with a problem of the way production relates to politics.

Read more:
Surviving climate change means transforming both economics and design

The production, pricing, and consumption of goods and services are not simply driven by the natural balancing of supply and demand. The economy is best understood as a social and political arena. In this arena, highly productive industries invest heavily in advertising to artificially grow consumption. As my upcoming research shows, they coalesce in aligned mega-sectors, such as the automotive, road-building and real estate industries, all of which wield outsize political influence, and have a vested interest in trapping consumers in car-intensive, road-intensive, suburban housing.

The paradox of high resource use that results in little or no human benefits has its roots in the very structure of our political economy, and the industries that are some of its most important mainstays. Transforming this structure means challenging these sectors, and finding ways to counter their excessive influence in our democracies.

This is why we must support the students’ strike this Friday, and every Friday for the foreseeable future. Significant change will not come into being without protests and solidarity movements that rigorously question unacceptable modes of living and politics. It is time for all of us to wake politicians, businesses, and institutions up to the immense task of transforming our societies.

This article is part of The Covering Climate Now series

This is a concerted effort among news organisations to put the climate crisis at the forefront of our coverage. This article is published under a Creative Commons license and can be reproduced for free – just hit the “Republish this article” button on the page to copy the full HTML coding. The Conversation also runs Imagine, a newsletter in which academics explore how the world can rise to the challenge of climate change. Sign up here.

The Conversation

Julia K. Steinberger receives funding from the Leverhulme Trust.

source: The Conversation: Environment

How sleep makes the brain forget things – new research on mice

How sleep makes the brain forget things – new research on mice

Neurons in a rodent brain. Heiti Paves/shutterstock

What a nuisance is a faulty memory. How many times have you forgotten where you parked the car? A few years ago, probably as a sign that my retirement was overdue, I spent literally half a day trying to find my car at a major New York airport. Fortunately, I am not alone. When people find out I am an expert on memory, the first thing they ask me is normally whether I can help them be less forgetful.

Indeed, excessive forgetting is a major problem, but “normal” forgetting is actually necessary. After all, it is more crucial to remember what is important right now than to remember everything. There’s no point in remembering the phone number of the house you lived in 10 years ago – that may in fact block your memory for your current phone number.

But exactly how the brain forgets unnecessary memories has long been unclear. Now a beautiful and rather exhaustive series of studies, just published in Science, offers a clue.

Research does indeed show that, in order to remember what is important, we need to forget what isn’t important. This can happen at two levels in the brain, a “cleaning” of irrelevant information as we retain and consolidate our memories, and a “blocking” of irrelevant information when we try to retrieve a memory. The positive effect on memory of blocking irrelevant information has been known since the 1950s.

The new study, which was carried out in mice, seems to finally reveal the secret mechanisms of forgetting during retention of memory. The authors claim that forgetting is due to the activation of specific “melatonin-concentrating hormone (MCH) neurons” located in the brain’s hypothalamus, which is involved in releasing hormones. We know that melatonin affects sleep – and MCH neurons are indeed involved in the shift between the two main sleep cycles: NREM to REM (REM sleep commonly associated with dreaming).


The authors demonstrate that forgetting happens only during retention (not when we encode or retrieve memories), and that sleep is the period of the day when MCH neurons clean the memory of all the irrelevant clutter. They obtained the results by injecting chemicals into the brain of mice in order to inhibit these very neurons. Amazingly, the mice performed better on two specific memory tasks as a result – recognising new objects and a fear conditioning test (this involves making association between stimuli and their adverse consequences).

What’s more, when the researchers completely removed these neurons from the brain, the mice’s memory also improved, over the long term. On the other hand, a boosted activity of these neurons instead hindered the mice’s memory performance. The researchers therefore argue that the neuronal process may one day be used to treat memory problems.

Read more: Why do you feel like you’re falling when you go to sleep?

This finding, if true and confirmed by other studies, represents a major breakthrough in understanding a fundamental memory mechanism. The methodology is rigorous and results convincing. There are some caveats though. How can we be absolutely sure that these neurons are involved in cleaning out irrelevant information in particular, rather than just impairing memory performance?

It seems that MCH neurons, when activated, just impair memory – and not necessarily with a good effect. This is important: the results do not say much about the positive role of forgetting during retention. In addition, whose memory are we talking about here? Mice memory – and necessarily so, given the highly invasive nature of most of the reported experiments. While animal models are indispensable for memory studies, it is too early to extend these findings to human memory.


For example, in humans the role of sleep in memory is still unclear. Also, forgetting occurs during retrieval of memories too and that is not explained by this new research.

Nevertheless, the new study does show for the first time that MCH neurons are strongly involved in making memory worse. That said, while we are on an exciting track thanks to this research, it is highly unlikely that we can improve human memory for a parked car by simply inhibiting a few neurons.

The Conversation

Giuliana Mazzoni received funding from Wellcome, Leverhulme, ESRC, SSHRC (Canada), Portuguese Science Foundation, British Academy.

Source: The Conversation: Technology http://theconversation.com/how-sleep-makes-the-brain-forget-things-new-research-on-mice-123636

Study finds hub linking movement and motivation in the brain

Study finds hub linking movement and motivation in the brain

Our everyday lives rely on planned movement through the environment to achieve goals. A new study by MIT neuroscientists at the Picower Institute for Learning and Memory at MIT identifies a well-connected brain region as a crucial link between circuits guiding goal-directed movement and motivated behavior.

Published Sept. 19 in Current Biology, the research shows that the lateral septum (LS), a region considered integral to modulating behavior and implicated in many psychiatric disorders, directly encodes information about the speed and acceleration of an animal as it navigates and learns how to obtain a reward in an environment.

“Completing a simple task, such as acquiring food for dinner, requires the participation and coordination of a large number of regions of the brain, and the weighing of a number of factors: for example, how much effort is it to get food from the fridge versus a restaurant,” says Hannah Wirtshafter PhD ’19, the study’s lead author. “We have discovered that the LS may be aiding you in making some of those decisions. That the LS represents place, movement, and motivational information may enable the LS to help you integrate or optimize performance across considerations of place, speed, and other environmental signals.”

Previous research has attributed important behavioral functions to the LS, such as modulating anxiety, aggression, and affect. It is also believed to be involved in addiction, psychosis, depression, and anxiety. Neuroscientists have traced its connections to the hippocampus, a crucial center for encoding spatial memories and associating them with context, and to the ventral tegmental area (VTA), a region that mediates goal-directed behaviors via the neurotransmitter dopamine. But until now, no one had shown that the LS directly tracks movement or communicated with the hippocampus, for instance by synchronizing to certain neural rhythms, about movement and the spatial context of reward.

“The hippocampus is one of the most studied regions of the brain due to its involvement in memory, spatial navigation, and a large number of illnesses such as Alzheimer’s disease,” says Wirtshafter, who recently earned her PhD working on the research as a graduate student in the lab of senior author Matthew Wilson, Sherman Fairchild Professor of Neurobiology. “Comparatively little is known about the lateral septum, even though it receives a large amount of information from the hippocampus and is connected to multiple areas involved in motivation and movement.”

Wilson says the study helps to illuminate the importance of the LS as a crossroads of movement and motivation information between regions such as the hippocampus and the VTA.

“The discovery that activity in the LS is controlled by movement points to a link between movement and dopaminergic control through the LS that that could be relevant to memory, cognition, and disease,” he says.

Tracking thoughts

Wirtshafter was able to directly observe the interactions between the LS and the hippocampus by simultaneously recording the electrical spiking activity of hundreds of neurons in each region in rats both as they sought a reward in a T-shaped maze, and as they became conditioned to associate light and sound cues with a reward in an open box environment.

In that data, she and Wilson observed a speed and acceleration spiking code in the dorsal area of the LS, and saw clear signs that an overlapping population of neurons were processing information based on signals from the hippocampus, including spiking activity locked to hippocampal brain rhythms, location-dependent firing in the T-maze, and cue and reward responses during the conditioning task. Those observations suggested to the researchers that the septum may serve as a point of convergence of information about movement and spatial context.

Wirtshafter’s measurements also showed that coordination of LS spiking with the hippocampal theta rhythm is selectively enhanced during choice behavior that relies on spatial working memory, suggesting that the LS may be a key relay of information about choice outcome during navigation.

Putting movement in context

Overall, the findings suggest that movement-related signaling in the LS, combined with the input that it receives from the hippocampus, may allow the LS to contribute to an animal’s awareness of its own position in space, as well as its ability to evaluate task-relevant changes in context arising from the animal’s movement, such as when it has reached a choice point, Wilson and Wirtshafter said.

This also suggests that the reported ability of the LS to modulate affect and behavior may result from its ability to evaluate how internal states change during movement, and the consequences and outcomes of these changes. For instance, the LS may contribute to directing movement toward or away from the location of a positive or negative stimulus.

The new study therefore offers new perspectives on the role of the lateral septum in directed behavior, the researchers added, and given the known associations of the LS with some disorders, it may also offer new implications for broader understanding of the mechanisms relating mood, motivation, and movement, and the neuropsychiatric basis of mental illnesses.

“Understanding how the LS functions in movement and motivation will aid us in understanding how the brain makes basic decisions, and how disruption in these processed might lead to different disorders,” Wirtshafter says.

A National Defense Science and Engineering Graduate Fellowship and the JPB Foundation funded the research.


Perception of musical pitch varies across cultures

Perception of musical pitch varies across cultures

People who are accustomed to listening to Western music, which is based on a system of notes organized in octaves, can usually perceive the similarity between notes that are same but played in different registers — say, high C and middle C. However, a longstanding question is whether this a universal phenomenon or one that has been ingrained by musical exposure.

This question has been hard to answer, in part because of the difficulty in finding people who have not been exposed to Western music. Now, a new study led by researchers from MIT and the Max Planck Institute for Empirical Aesthetics has found that unlike residents of the United States, people living in a remote area of the Bolivian rainforest usually do not perceive the similarities between two versions of the same note played at different registers (high or low).

The findings suggest that although there is a natural mathematical relationship between the frequencies of every “C,” no matter what octave it’s played in, the brain only becomes attuned to those similarities after hearing music based on octaves, says Josh McDermott, an associate professor in MIT’s Department of Brain and Cognitive Sciences.

“It may well be that there is a biological predisposition to favor octave relationships, but it doesn’t seem to be realized unless you are exposed to music in an octave-based system,” says McDermott, who is also a member of MIT’s McGovern Institute for Brain Research and Center for Brains, Minds and Machines.

The study also found that members of the Bolivian tribe, known as the Tsimane’, and Westerners do have a very similar upper limit on the frequency of notes that they can accurately distinguish, suggesting that that aspect of pitch perception may be independent of musical experience and biologically determined.

McDermott is the senior author of the study, which appears in the journal Current Biology on Sept. 19. Nori Jacoby, a former MIT postdoc who is now a group leader at the Max Planck Institute for Empirical Aesthetics, is the paper’s lead author. Other authors are Eduardo Undurraga, an assistant professor at the Pontifical Catholic University of Chile; Malinda McPherson, a graduate student in the Harvard/MIT Program in Speech and Hearing Bioscience and Technology; Joaquin Valdes, a graduate student at the Pontifical Catholic University of Chile; and Tomas Ossandon, an assistant professor at the Pontifical Catholic University of Chile.

Octaves apart

Cross-cultural studies of how music is perceived can shed light on the interplay between biological constraints and cultural influences that shape human perception. McDermott’s lab has performed several such studies with the participation of Tsimane’ tribe members, who live in relative isolation from Western culture and have had little exposure to Western music.

In a study published in 2016, McDermott and his colleagues found that Westerners and Tsimane’ had different aesthetic reactions to chords, or combinations of notes. To Western ears, the combination of C and F# is very grating, but Tsimane’ listeners rated this chord just as likeable as other chords that Westerners would interpret as more pleasant, such as C and G.

Later, Jacoby and McDermott found that both Westerners and Tsimane’ are drawn to musical rhythms composed of simple integer ratios, but the ratios they favor are different, based on which rhythms are more common in the music they listen to.

In their new study, the researchers studied pitch perception using an experimental design in which they play a very simple tune, only two or three notes, and then ask the listener to sing it back. The notes that were played could come from any octave within the range of human hearing, but listeners sang their responses within their vocal range, usually restricted to a single octave.

Western listeners, especially those who were trained musicians, tended to reproduce the tune an exact number of octaves above or below what they heard, though they were not specifically instructed to do so. In Western music, the pitch of the same note doubles with each ascending octave, so tones with frequencies of 27.5 hertz, 55 hertz, 110 hertz, 220 hertz, and so on, are all heard as the note A.

Western listeners in the study, all of whom lived in New York or Boston, accurately reproduced sequences such as A-C-A, but in a different register, as though they hear the similarity of notes separated by octaves. However, the Tsimane’ did not.

“The relative pitch was preserved (between notes in the series), but the absolute pitch produced by the Tsimane’ didn’t have any relationship to the absolute pitch of the stimulus,” Jacoby says. “That’s consistent with the idea that perceptual similarity is something that we acquire from exposure to Western music, where the octave is structurally very important.”

The ability to reproduce the same note in different octaves may be honed by singing along with others whose natural registers are different, or singing along with an instrument being played in a different pitch range, Jacoby says.

Limits of perception

The study findings also shed light on the upper limits of pitch perception for humans. It has been known for a long time that Western listeners cannot accurately distinguish pitches above about 4,000 hertz, although they can still hear frequencies up to nearly 20,000 hertz. In a traditional 88-key piano, the highest note is about 4,100 hertz.

People have speculated that the piano was designed to go only that high because of a fundamental limit on pitch perception, but McDermott thought it could be possible that the opposite was true: That is, the limit was culturally influenced by the fact that few musical instruments produce frequencies higher than 4,000 hertz.

The researchers found that although Tsimane’ musical instruments usually have upper limits much lower than 4,000 hertz, Tsimane’ listeners could distinguish pitches very well up to about 4,000 hertz, as evidenced by accurate sung reproductions of those pitch intervals. Above that threshold, their perceptions broke down, very similarly to Western listeners.

“It looks almost exactly the same across groups, so we have some evidence for biological constraints on the limits of pitch,” Jacoby says.

One possible explanation for this limit is that once frequencies reach about 4,000 hertz, the firing rates of the neurons of our inner ear can’t keep up and we lose a critical cue with which to distinguish different frequencies.

“The new study contributes to the age-long debate about the interplays between culture and biological constraints in music,” says Daniel Pressnitzer, a senior research scientist at Paris Descartes University, who was not involved in the research. “This unique, precious, and extensive dataset demonstrates both striking similarities and unexpected differences in how Tsimane’ and Western listeners perceive or conceive musical pitch.”

Jacoby and McDermott now hope to expand their cross-cultural studies to other groups who have had little exposure to Western music, and to perform more detailed studies of pitch perception among the Tsimane’.

Such studies have already shown the value of including research participants other than the Western-educated, relatively wealthy college undergraduates who are the subjects of most academic studies on perception, McDermott says. These broader studies allow researchers to tease out different elements of perception that cannot be seen when examining only a single, homogenous group.

“We’re finding that there are some cross-cultural similarities, but there also seems to be really striking variation in things that a lot of people would have presumed would be common across cultures and listeners,” McDermott says. “These differences in experience can lead to dissociations of different aspects of perception, giving you clues to what the parts of the perceptual system are.”

The research was funded by the James S. McDonnell Foundation, the National Institutes of Health, and the Presidential Scholar in Society and Neuroscience Program at Columbia University.


Drug use in England and Wales is up for the fourth year in a row

Drug use in England and Wales is up for the fourth year in a row

Cocaine is the third most commonly used drug among people aged 16 to 24. Christopher Elwell/Shutterstock

Once a year we get a glimpse of how many people are using drugs such as heroin and cocaine in England and Wales. The Home Office conducts an annual household survey that asks people if they have used drugs and, if they have, to provide some details about which drugs and how often they have consumed them. For the fourth year in a row, overall drug use has risen. An interesting fact on its own, but as always, the devil is in the detail.

Class A drugs including cocaine are proving to be popular, second only to cannabis in popularity. Nearly a million people now report using the drug. Fewer people report using opiates, such as heroin – but this is largely due to limitations of the survey which, as a household exercise, will not pick up certain groups, such as the homeless or other transient populations. Equally, the survey will not capture the experience of students – another important cohort.

Class A drug use including cocaine.
Home Office

One of the most striking elements of the data is the ease with which people, especially young people, can obtain controlled drugs. In 2018-19, almost 19% of respondents to the survey reported that it was “very easy” to get drugs within 24 hours. This a significant increase on the previous year’s figure of 14.5%.

Like ordering pizza

More than half of all young people, aged 16-24 years, said they could get drugs within 24 hours. This increased access to the drugs market could be as a result of more online availability through the dark web. Equally, the drugs market has developed in the way other legal markets have in the 21st century. Drugs can now be delivered straight to your door, often faster than pizza and there have been reports that suppliers are offering loyalty cards to customers.

Class A drugs such as cocaine carry the most severe penalties under current drug laws, so why are an increasing number of people willing to break the law? Perhaps recent high-profile political confessions of drug use have added to people’s perception that it’s acceptable – or at least not as frowned upon – to use drugs.

Cannabis use is at its highest in almost 10 years.
The Adaptive/Shutterstock

A recent YouGov poll suggests that most people think the current drug laws are ineffective in deterring drug use. And they would be right. The Home Office’s own evidence shows that tough law enforcement does not deter drug use, and the drug laws certainly did not deter any of those high-profile politicians from using cannabis or cocaine.

Despite changes in attitudes to drug use, government policy towards drugs has remained the same for half a century, so it’s hardly the evidence-based legislation it should be.

We can reduce harm

Current policy approaches drug use as a criminal matter when all the evidence points to the need for a health and education-based approach. Most people will use drugs for pleasure and not come to any harm – but some will. The difficulty is predicting – prior to exposure – who is at risk, something that we are still struggling to get data on. Until then we need to think about how we can reduce the potential for harm that drugs pose to some people.

This is where we do have some evidence that we can use to reduce harm, but it is based on facilitating the safe use of drugs rather than trying to prevent drug use. Despite the public polling suggesting most people think current drug laws are ineffective, it is less clear what they would be willing to support.

It’s easy to say you support change, but would you be willing to see a drug consumption facility open up in your neighbourhood or see your taxes used to increase specialist drug treatment? Yet these are just two ways that we know could halt the record numbers dying because of drug use. With 11 people a day dying as a result of drugs, this matters more than ever.

The Conversation

Ian Hamilton is affiliated with Alcohol Change UK.

Niamh Eastwood is Executive Director of Release, the UK's centre of expertise on drugs and drugs law.


Why is climate change still not top of the news agenda?

Why is climate change still not top of the news agenda?

Big news. Zerbor via Shutterstock

Climate breakdown threatens the lives of us all. Scientific research has suggested that we are in the process of a “mass extinction” event that could lead to “biological annihilation” on a large scale. Records indicate that population decay and the rapid extinction of a large number of vertebrates in recent years amount to “a massive anthropogenic erosion of biodiversity and of the ecosystem services essential to civilisation”.

Studies find that 97% of published climate scientists agree that climate change is driven by human activity. If the scientific predictions are correct, much of human society is in grave danger though our own actions. So, why isn’t climate change the biggest news story in the world?

The parable of the boiling frog tells us that if a frog is placed in boiling water it will leap to safety. However, if the frog is placed in tepid water which is heated slowly, it will not sense the danger until it is too late.

When it comes to climate breakdown journalists play the role of the frog. If we take a literal understanding of the word news as the plural of new – that is, news = things that are new – then the ongoing gradual (in newsroom terms) breakdown of the climate does not meet the criteria. The effects of climate disruption, such as increased occurrences of extreme weather events or individual species extinctions have news value, the wider issue does not.

Nevertheless, this issue cannot be explained in these terms alone. The most recent study into news values suggests that “bad news” and “magnitude” are two of the key elements in stories that become news. The extinction of much of the life on earth certainly meets both of these criteria. But when it comes to climate breakdown, these important news values can clash with the values of what the same study describes as the “newspaper agenda” and “the power elite”. This means that power structures within the mass media prevent climate change being covered as a topic of great importance.

Power structures within the mass media

One of the most common claims about the role of journalists is that they “speak truth to power” or give “a voice to the voiceless”. But most academic research into the role of the mass media in wider society runs counter to these romantic notions of journalism’s role as a “fourth estate”.

Indeed, the commercial nature of most mass media organisations means that they are reliant on advertising revenue to survive. An article about how human consumption is driving increasing levels of atmospheric carbon dioxide looks editorially problematic alongside an advert for a 3D pancake printer. Likewise, an article explaining the connection between global meat consumption and climate breakdown sits awkwardly alongside adverts for discounted beef burgers for the summer BBQ.

Media research has also demonstrated that a significant amount of news can be traced to the public relations activity of powerful corporate and state actors. This can be partially explained by cuts to newsroom staff alongside the growth of the public relations industry. In their new roles as public relations advisors, many experienced former journalists with a detailed understanding of newsroom culture and news values are able to supply journalists with useful quotations, sound bites and even partly-written stories. In some cases, the news media’s overreliance on powerful sources has given undue prominence to organisations with a vested interest in playing down news about climate change.

Newspaper reporter jobs are disappearing, often replaced by jobs in PR.
US Bureau of Labor Statistics

Strategic rituals and lobbying

In an important piece of research about objectivity in the news, the media sociologist Gaye Tuchman looked at how journalists defend their craft by appealing to notions of “objectivity”. Tuchman described how one of the problems with journalistic objectivity is that, to avoid allegations of bias, journalists present a range of “conflicting possibilities”. This often means that journalists give space to both sides of a particular debate without making a judgement on their relative merits. To do so would make them subject to allegations of bias.

In their book, Merchants of Doubt, Eric Conway and Naomi Oreskes, two historians of science, investigated why human-made climate change was presented in the news media as an unsettled debate when the scientific literature supporting it was overwhelming.

They found that a group of scientific experts challenged the consensus on climate change on behalf of corporations and conservative think tanks. Some of the individuals involved in this had previously challenged scientific consensus on a range of issues including the negative health implications of tobacco smoke. Corporations engage in this creation of doubt through public relations activity because climate change requires international cooperation on environmental legislation.

By performing what Tuchman calls a “strategic ritual” of objectivity, journalists obscure the scientific consensus on climate change by reporting it as a debate. This framing makes climate breakdown seem less urgent and therefore less newsworthy.

How can we improve? The notion of objectivity needs to be reclaimed through good journalism which invests resources in providing analysis and verification. News organisations are in an important position to explain complex scientific concepts in a language that most people understand, but they need to improve their scientific literacy in order to verify the relative merit of competing claims.

Journalists with a better grasp of the science (and indeed social science) of climate change would be less reliant on press releases, reducing the impact of corporate lobbyists and the need to include their public relations activity as part of the news. However, these suggestions are optimistic considering the wider power structures that constrain how journalists operate.

This article is part of The Covering Climate Now series

This is a concerted effort among news organisations to put the climate crisis at the forefront of our coverage. This article is published under a Creative Commons license and can be reproduced for free – just hit the “Republish this article” button on the page to copy the full HTML coding. The Conversation also runs Imagine, a newsletter in which academics explore how the world can rise to the challenge of climate change. Sign up here.

The Conversation

Steven Harkins has received funding from the Economic and Social Research Council in the past.

source: The Conversation: Environment

How a Centuries-Old Sculpting Method Is Helping 3D Print Organs With Blood Vessels

How a Centuries-Old Sculpting Method Is Helping 3D Print Organs With Blood Vessels

Blood vessels are the lifeline of any organ.

The dense web of channels, spread across tissues like a spider web, allow oxygen and nutrients to reach the deepest cores of our hearts, brains, and lungs. Without a viable blood supply, tissues rot from the inside. For any attempt at 3D printing viable organs, scientists have to tackle the problem of embedding millions of delicate blood vessels throughout their creation.

It’s a hideously hard problem. Although blood vessels generally resemble tree-like branches, their distribution, quantity, size, and specific structure vastly differs between people. So far, the easiest approach is to wash out cells from donated organs and repopulate the structure with recipient cells—a method that lowers immunorejection after transplant. Unfortunately, this approach still requires donor organs, and with 20 people in the US dying every day waiting for an organ transplant, it’s not a great solution.

This week, a team from Harvard University took a stab at the impossible. Rather than printing an entire organ, they took a Lego-block-like approach, making organ building blocks (OBBs) with remarkably high density of patient cells, and assembled the blocks into a “living” environment. From there, they injected a “sacrificial ink” into the proto-tissue. Similar to pottery clay, the “ink” hardens upon curing—leaving a dense, interconnected 3D network of channels for blood to run through.

As a proof of concept, the team printed heart tissue using the strategy. Once the block fused, the lab-made chunk of heart could beat in synchrony and remained healthy for at least a week.

The technology, SWIFT (an eyebrow-raising backcronym of “sacrificial writing into functional tissue”), is a creative push into a new generation of 3D biofabrication. Although OBBs have been around, the team explained, little attention was previously paid to putting the Lego pieces together with blood vessels.

“This is an entirely new paradigm for tissue fabrication,” said study author Dr. Mark Skylar-Scott. The focus is on vessels, which will support 3D printed living tissue that may eventually be used to repair damaged parts of a natural body, or even replace entire human organs with lab-grown versions, he added.

“[It’s] beautiful work,” commented tissue engineer Dr. Jordan Miller at Rice University, who was not involved in the study.

A Wild Mashup

SWIFT straddles two wildly diverse fields across centuries: organoids and 15th-century lost-wax sculpturing.

You’ve heard of organoids. Often dubbed mini-organs, these lentil-sized blobs of tissue remarkably mimic particular aspects of entire organs—brain organoids, for example, show the characteristic nerve cell types of firings of a preemie baby. The cellular inhabitants that make up organoids are what especially caught the team’s attention: most are grown from induced pluripotent stem cells (iPSCs), which are often skin cells “de-aged” in a way that they can develop into almost any cell type with a little chemical prodding.

Because organoids are built from a patient’s own cells, they’re completely compatible with the host for an immune standpoint. That particular strength caught the team’s attention: organoids, they reasoned, make the “ideal” OBB—or Lego pieces—to biomanufacture patient- and organ-specific tissues with all the desired properties.

For example, the team explained, organoids are packed with a high density of cells, which is usually hard to achieve with traditional 3D tissue printing. Under the right conditions, they also develop similarly to real organs in terms of cellular composition and microarchitecture to support function…for about a year. Without a blood vessel network, all organoids die.

Artistic Inspiration

Here’s where lost-wax technique comes in.

First, a very brief explainer. Throughout the Renaissance, the majority of Italian sculptors used the technique to fabricate bronze statues. In the simplest method, a statuette is first modeled in beeswax and covered in potter’s clay. Once dried, the assembly is heated—the clay is “fired” into ceramics, and the wax melts and flows away (hence, “lost”). Once cooled, the entire project is now a hollow ceramic mold, through which the artist can pour in molten metal.

Now, replace beeswax with “sacrificial bio-ink,” and that’s pretty much how SWIFT carves out its intricate tunnels of blood vessels.

The entire fabrication process is two main steps. The team first grew hundreds of thousands of proto-organoids inside culture dishes. These tiny blobs are so small they don’t yet need to be churned inside a bioreactor, but they’re mightily packed with roughly 200 million cells every milliliter—about the bottom bit of a teaspoon. These make up the technique’s building blocks, or OBBs.

Next, roughly 400,000 OBBs are mixed with a dense, gel-like liquid with the consistency of mayonnaise at a low temperature. The liquid is filled with collagen, a protein that keeps our skin elastic, and other synthetic versions. The OBBs are now somewhat suspended inside the gel-like matrix, which is “ideally suited for creating vascular channels,” the team said. Altogether, the organoids and gel are compacted into a density similar to human tissue, making up the raw material for further sculpting.

Lost-Wax Vessels

Now the fun second step. Using a 3D printer, the team moved a tiny nozzle containing both harmless red ink and gelatin into the mixture, depositing both in a pre-programmed manner. In this way, the team was able to “draw” intricate branch-like patterns into the organoid-gel mixture. Similar to squeezing frosting out of a bag, the team was able to adjust the diameter of the gelatin ink by nearly two-fold, mimicking the usual structure of blood vessels—thick main channels that increasingly become tinier.

Once the network was fully printed, they then gently heated the mixture to body temperature.  The matrix stiffens, and the gelatin ink—acting like Jello left under the sun for too long—melts and is washed away. What remains is a network of OBBS, or organoids, linked with a vascular structure that can now be filled with blood.

3D Printing SWIFT cardiac tissue cross section
A cross-section image shows living cells (green) surrounding a hollow channel that has been 3D printed and evacuated using the SWIFT method. Image Credit: Wyss Institute at Harvard University / CC BY-NC-ND 4.0.

As a proof of concept, the team went straight for the heart—cardiac tissue, that is. They repeated the steps using heart-derived cells, and kept the resulting chunk of heart, a little bigger than half an inch inside a chamber, filled with a nutritious, oxygen-rich bath.

Within a week, individual organoids embedded inside the gel fused together into a collective: the tissue was able to contract almost 50 percent better than immediately after printing, and the beating rhythm synchronized, suggesting that the lab-grown tissue had further matured.

The tissue even reacted similarly to a normal heart. When the team infused a drug that increases heart rate into those printed vessels, the tissue doubled in its “heartbeat.” Similarly, drugs that normally decrease heart muscle contraction also worked on the mini-heart. As a final proof of concept demo, the team printed a chunk of heart tissue with a branch of the coronary artery—a main blood vessel branch that normally wraps the heart.

A Bio-Renaissance

The new study is hardly the first try at printing organs with blood vessels. Miller, for example, biomanufactured a hydrogel that mimicked a lung air sac earlier this May. Layer by layer, the precise anatomy of the lung-mimicking structure is constructed with liquid hydrogel, and solidified using light.

The new study stands out in its sheer creativity. By combining organoids with an ancient sculpture technique, the team was able to pack far more cells into the resulting structure, while tapping into the natural mini-organization that stems from organoids. The results aren’t just promising for printing larger, more intricate human organs with a blood supply—they could also help inform organoid research, which has struggled to keep the pseudo-organs alive.

The team is planning to transplant their SWIFT tissue into animals to further examine their function and health. But to the team, the main goal is to finally bring 3D-printed organs to people desperately on the transplant waiting list.

“Our method opens new avenues for creating personalized organ-specific tissues with embedded vascular channels for therapeutic applications,” they said.

Image Credit: Wyss Institute at Harvard University / CC BY-NC-ND 4.0

Source: Singularity Hub:  https://singularityhub.com/2019/09/19/how-a-centuries-old-sculpting-method-is-helping-3d-print-organs-with-blood-vessels/

What does a healthy diet look like for me and the planet? It depends where you live

What does a healthy diet look like for me and the planet? It depends where you live

Africa Studio/Shutterstock

I want people to think about the food that they eat not just from “field to fork” but from “seed to soul”. I’ve studied how to make the world’s food supply sustainable for more than 30 years, so people often ask me what’s the best diet for the planet. The problem is, most people want easy answers to that question. Sadly, there are none.

For example, I’ve often thought about becoming vegetarian for ethical and environmental reasons. But I wouldn’t want to eat soya or other foodstuffs imported from the other side of the world because of the carbon emissions involved in transporting them. And if we’re going to acknowledge the ethical quandary of eating animals, what about the animals in the soil? Why is crushing, slicing, and dicing mini beasts in agricultural operations alright, but not for the big beasts? When I follow these arguments through to their full conclusions, I end up as an organic, temperate, fruitarian – only eating fruit grown close to home, without the use of pesticides.

Read more:
Should vegans avoid avocados and almonds?

When it comes to finding a sustainable diet, there are many contradictions. A concept such as food miles can be helpful for figuring out the carbon emissions involved in bringing particular food items to your plate. It’s simple to understand – but it’s also likely to be meaningless. After all, it’s not just about how far something has travelled, but the environmental cost of that journey and how it was originally produced.

It can be argued that New Zealand lamb consumed in the UK has less of an environmental impact than locally produced lamb. New Zealand lamb production involves fewer carbon “rich” inputs such as fertilisers. There is also a highly efficient transport system in New Zealand that is based on bigger farms and bigger lorries – producing and transporting more meat with less land and fewer emissions. This results in less greenhouse gas per kilogram of meat.

New Zealand lamb is exported all over the world.
Klanarong Chitmung/Shutterstock

But just because things are complicated, it doesn’t mean that we should give up. It’s clear that our health and the planet would benefit if people ate more fruit and vegetables and less meat. Eating seasonal produce, or food fresh from the fields, is a good idea too, particularly as it reconnects people with food and the land in which it’s produced. It forces us to engage with the reality that different crops are produced at different times of the year. Strawberries are a celebration of summer, spring greens of the spring.

But what does a seasonal diet look like for someone living in a temperate climate such as the UK’s? With the help of technology, we can grow many exotic crops in the UK which would otherwise perish in the climate. The problem is that much of this involves carbon-hungry technology, such as glasshouses heated by burning gas or vast fields of plastic polytunnels.

What would our diet look like if we grew all our food within the natural seasons and climate of our local area?

Dinner dates

Summer is great as we can feast on a wide range of fruits and vegetables. It’s easier during this season to follow the health advice to eat the rainbow. That is, to eat as broad a spectrum of colourful fruit and vegetables as possible. British summer affords strawberries, radishes, tomatoes and blueberries.

There are salads and summer puddings to enjoy for an injection of other colours, particularly green. If people are clever, many crops can be preserved for the coming winter. Ironically, during summer when much of our natural produce is plentiful, the UK still imports much of its food.

As we move into autumn, unless crops are protected by growing them inside a glasshouse or polytunnel, many of the more delicate foodstuffs start to wither away. We become increasingly dependent on roots such as beetroot, carrots, potatoes, swede and parsnips, and the leafy brassicas such as Brussels sprouts, cabbage, cauliflower and kale. Of course there are other ingredients – let’s not forget leeks and swiss chard – but this is a time to hunker down and embrace what the Scandinavians call “hygge”. Getting cosy and comfortable with stews, soups and broths.

Autumn – a time for root veg and brassicas.
Arnaldo Aldana/Unsplash, CC BY

Things get more austere as winter progresses. This is one reason why our ancestors had midwinter feasts around Christmas and the winter solstice. Nights were long, they needed to have a party to forget the winter and look forward to spring. Even in late February and March, when we start thinking of spring, there’s a hidden problem – the hunger gap. This is when the autumn crops that have survived through winter start to die off and the spring crops are yet to come.

Little things such as purple sprouting broccoli – also known as poor people’s asparagus – can offer some solace as they are ready to eat in winter. Of course, we can also preserve food from one season to another, but this requires energy. There are traditional skills that require less energy, but at the same time demand increasingly rare knowledge and time.

For example, how many people bottle their surplus fruit and vegetables or pickle eggs? Consuming local seasonal food in large amounts throughout the year will mean restructuring traditional food production systems and supply chains. These have been decimated by the concentration of food supply in the hands of fewer and fewer retailers and contract caterers. Winter would test our ability to preserve the bounty of summer and autumn, but spring would relieve us with artichokes, beetroot, new potatoes, rhubarb, rocket, sorrel and spinach. After that, the cycle begins again.

As I say, a truly sustainable food supply isn’t going to be simple. Much of it involves reviving cultural knowledge and processes that commercial supermarket chains have replaced. But the rewards of a local and seasonal food supply are great for nature and your health. Reconnecting with the land and its seasonal rhythms could do us all a great amount of good.

This article is part of The Covering Climate Now series

This is a concerted effort among news organisations to put the climate crisis at the forefront of our coverage. This article is published under a Creative Commons license and can be reproduced for free – just hit the “Republish this article” button on the page to copy the full HTML coding. The Conversation also runs Imagine, a newsletter in which academics explore how the world can rise to the challenge of climate change. Sign up here.

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Sean Beer does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.


Sail GP: how do supercharged racing yachts go so fast? An engineer explains

Sail GP: how do supercharged racing yachts go so fast? An engineer explains

Sailing used to be considered as a rather sedate pastime. But in the past few years, the world of yacht racing has been revolutionised by the arrival of hydrofoil-supported catamarans, known as “foilers”. These vessels, more akin to high-performance aircraft than yachts, combine the laws of aerodynamics and hydrodynamics to create vessels capable of speeds of up to 50 knots, which is far faster than the wind propelling them.

An F50 catamaran preparing for the Sail GP series recently even broke this barrier, reaching an incredible speed of 50.22 knots (57.8mph) purely powered by the wind. This was achieved in a wind of just 19.3 knots (22.2mph). F50s are 15-metre-long, 8.8-metre-wide hydrofoil catamarans propelled by rigid sails and capable of such astounding speeds that Sail GP has been called the “Formula One of sailing”. How are these yachts able to go so fast? The answer lies in some simple fluid dynamics.

As a vessel’s hull moves through the water, there are two primary physical mechanisms that create drag and slow the vessel down. To build a faster boat you have to find ways to overcome the drag force.

The first mechanism is friction. As the water flows past the hull, a microscopic layer of water is effectively attached to the hull and is pulled along with the yacht. A second layer of water then attaches to the first layer, and the sliding or shearing between them creates friction.

On the outside of this is a third layer, which slides over the inner layers creating more friction, and so on. Together, these layers are known as the boundary layer – and it’s the shearing of the boundary layer’s molecules against each other that creates frictional drag.

A yacht also makes waves as it pushes the water around and under the hull from the bow (front) to the stern (back) of the boat. The waves form two distinctive patterns around the yacht (one at each end), known as Kelvin Wave patterns.

These waves, which move at the same speed as the yacht, are very energetic. This creates drag on the boat known as the wave-making drag, which is responsible for around 90% of the total drag. As the yacht accelerates to faster speeds (close to the “hull speed”, explained later), these waves get higher and longer.

These two effects combine to produce a phenomenon known as “hull speed”, which is the fastest the boat can travel – and in conventional single-hull yachts it is very slow. A single-hull yacht of the same size as the F50 has a hull speed of around 12 mph.


However, it’s possible to reduce both the frictional and wave-making drag and overcome this hull-speed limit by building a yacht with hydrofoils. Hydrofoils are small, underwater wings. These act in the same way as an aircraft wing, creating a lift force which acts against gravity, lifting our yacht upwards so that the hull is clear of the water.

While an aircraft’s wings are very large, the high density of water compared to air means that we only need very small hydrofoils to produce a lot of the important lift force. A hydrofoil just the size of three A3 sheets of paper, when moving at just 10 mph, can produce enough lift to pick up a large person.

This significantly reduces the surface area and the volume of the boat that is underwater, which cuts the frictional drag and the wave-making drag, respectively. The combined effect is a reduction in the overall drag to a fraction of its original amount, so that the yacht is capable of sailing much faster than it could without hydrofoils.

The other innovation that helps boost the speed of racing yachts is the use of rigid sails. The power available from traditional sails to drive the boat forward is relatively small, limited by the fact that the sail’s forces have to act in equilibrium with a range of other forces, and that fabric sails do not make an ideal shape for creating power. Rigid sails, which are very similar in design to an aircraft wing, form a much more efficient shape than traditional sails, effectively giving the yacht a larger engine and more power.

As the yacht accelerates from the driving force of these sails, it experiences what is known as “apparent wind”. Imagine a completely calm day, with no wind. As you walk, you experience a breeze in your face at the same speed that you are walking. If there was a wind blowing too, you would feel a mixture of the real (or “true” wind) and the breeze you have generated.

The two together form the apparent wind, which can be faster than the true wind. If there is enough true wind combined with this apparent wind, then significant force and power can be generated from the sail to propel the yacht, so it can easily sail faster than the wind speed itself.

The combined effect of reducing the drag and increasing the driving power results in a yacht that is far faster than those of even a few years ago. But all of this would not be possible without one further advance: materials. In order to be able to “fly”, the yacht must have a low mass, and the hydrofoil itself must be very strong. To achieve the required mass, strength and rigidity using traditional boat-building materials such as wood or aluminium would be very difficult.

This is where modern advanced composite materials such as carbon fibre come in. Production techniques optimising weight, rigidity and strength allow the production of structures that are strong and light enough to produce incredible yachts like the F50.

The engineers who design these high-performance boats (known as naval architects) are always looking to use new materials and science to get an optimum design. In theory, the F50 should be able to go even faster.

The Conversation

Jonathan Ridley does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

Source: The Conversation: Technology http://theconversation.com/sail-gp-how-do-supercharged-racing-yachts-go-so-fast-an-engineer-explains-121902

NASA Awards $2.3 Million in Fellowships to US Universities for Aviation, Planetary, Space Research

[rNASA Awards $2.3 Million in Fellowships to US Universities for Aviation, Planetary, Space Research NASA has awarded fellowships to 14 minority-serving institutions through its Minority University Research and Education Project (MUREP) and five majority institutions through its Aeronautics Research Mission Directorate (ARMD), all totaling $2.3 million, to support graduate student research. Source: NASA Breaking news http://www.nasa.gov/press-release/nasa-awards-23-million-in-fellowships-to-us-universities-for-aviation-planetary-space