Girls and Autism: One of Lynne Malcolm’s favourite programs


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Most people tend to think of autism as a male disorder, and the character in the film Rain Man often comes to mind. But emerging research shows that girls often have different symptoms which cause them to slip through the net—misdiagnosed or undiagnosed by clinicians. We look at why girls on the autism spectrum present differently, and whether these sex differences are biological or environmental.

This program was originally broadcast in June 2015,Duration: 29min 5secBroadcast: Sun 17 Jan 2021, 12:30pm

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  • One of the best known women with autism is Temple Grandin pictured speaking at TED in 2010Red Maxwell, Flickr, CC BY NC 2.0
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external linkSpectrumexternal linkSpectrum social thinking masterclassesexternal linkAnorexia nervosa and autism spectrum disordersexternal linkThe female protective factor in autism (PNAS)external linkHow different are girls and boys above and below the diagnostic threshold for autism spectrum disorders?external linkPrevalence of Autism in Australiaexternal linkTemple Grandin’s website

Music of memory

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Our relationship with music begins at birth, if not before, and plays a role in the formation of our identity when we are young. Now a heart-warming movement called Music & Memory is creating personalised music playlists for residents with dementia in nursing homes—who use their mobile device to hear it. Eyes light up and bodies start to move with the rhythm as the music awakens memories of their forgotten lives. There are hopes that this movement could vastly improve the mood and happiness of many people.Duration: 29min 6secBroadcast: Sun 31 Jan 2021, 12:30pm

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  • Music of memoryMusic is being used to reawaken the memories of nursing home residents with dementia as Lynne Malcolm and Olivia Willis write.

Can’t sleep? You’re not alone


PUBLISHED: 19:03 EST, 30 January 2021 | UPDATED: 19:03 EST, 30 January 2021

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After a year that’s turned life upside down, the huge increase in sleeplessness is completely normal, says psychologist Emma Kenny. And accepting this is the first step to a great night’s rest  

If there is one thing I feel we can all agree on, it is that the events of the past 12 months have been shocking for all of us. Since March 2020 life as we knew it has morphed into something barely recognisable. This pandemic has understandably affected us in many different ways. You may be trying to home educate your children while running your business from your kitchen, or struggling with the way the day seems to stretch forever during furlough. Some will be facing financial fears and job losses, but what connects each of us is that we are all dealing with some level of struggle. You have been told that the people you love may be taken from you; even going out for a coffee has become a challenging and, at times, illegal activity. A trip to the shops now feels different.

Whether or not you realise it, your brain will have become so overloaded with this ‘new normal’ that even when you think you are doing OK, the likelihood is that you have simply grown used to a state of not being OK at all.




In order to feel a sense of security and contentment, human beings require some basic needs to be met. These include spending time outdoors with nature, getting natural light on your skin, having time with your nearest and dearest so you feel a sense of belonging, and micro-interactions with other humans – for instance, a chat at the shop checkout. These, added to a nutritious diet and regular activity, form the basis of wellbeing. If you reflect on that list, you will see how many of these essential ingredients are potentially absent from your life. It also explains why, for many of you, the sleep pattern you once took for granted feels as if it has evaporated. It has long been accepted that sleep is an important aspect of what makes us human, which is why, having worked as a psychological therapist for over 20 years, one of the questions I ask new clients is to describe their sleep pattern. It often gives me a short cut to the way they may be feeling.

Everyone recognises that delicious feeling when you wake up fully rested after a glorious night’s slumber: you feel almost as though you have been on a mini-break somewhere peaceful. This is the reason why we fall asleep in the first place, so we can relax and unwind. Since lockdown began, more and more people have been reporting that their sleep pattern has become problematic, so much so that Google has seen a 60 per cent increase in searches relating to insomnia. Some of you say that, having never struggled with sleep, you are now spending hours tossing and turning. Many of you who are managing to initially fall asleep, find yourselves waking wide-eyed and full of nervous energy in the early hours of the morning. Even those of you who are sleeping are struggling to get out of bed in the morning – and when you finally make it from beneath your duvet, you still feel absolutely exhausted.

Wherever you fit on that spectrum, it’s important to remember that you’re not alone and, crucially, that you’re completely normal. It has been a really challenging time for all of us, and it is OK to admit that. When you find that nodding off has become more of a chore than a comfort, then this is an alarm call. Sleep isn’t just important for the body to rest and recuperate, it is also a chance for the brain to unconsciously work things through emotionally in a housekeeping role. When you fail to get a good night’s rest, your body can’t attend to these important restorative tasks, meaning you end up feeling like you are running on empty – which in many ways you are. Very often, as opposed to practising self-compassion and listening to what your body is telling you, you find yourself feeling guilty that you’re struggling, particularly if you are in a financially stable position or have a loving family. You compare yourself to people worse off and feel ashamed for not being grateful for the life you have. But that isn’t how our emotions work and by rejecting them, all you will do is increase your anxiety levels, meaning sleep is even harder to achieve.

You will face any pressures far more successfully when you have knocked your sleep back into shape. Instead of feeling powerless over your insomnia, this is actually an area of your life that you do have a level of control over and, when you get back in the driving seat where rest and recuperation is concerned, this will remind you that you can also apply similar strategies to other areas of your life. Yes, you may have to do a little work, and some things will work better than others, but you can master a good night’s sleep when you make a conscious effort to attend to your body’s physical, emotional and psychological needs.

Right now, each and every one of us needs to put that extra effort into looking after ourselves. Learn to listen to your body without judgment, and accept that you are entitled to your feelings – because that is the first step in processing them. A great starting point is right here. Over the following pages, you can digest all the tips, tricks and advice from people who know how to ensure you get the perfect night’s sleep. Because even when life isn’t going to plan, a great sleep can ensure you start each new day energised and empowered.

Physicists Are Reinventing the Laser

Sophia ChenYesterday 9:00AM233

Illustration for article titled Physicists Are Reinventing the Laser
Illustration: Benjamin Currie/Gizmodo

In the 1950s, when physicists were racing to invent the first laser, they found that the rules of quantum mechanics restricted how pure the color of their light could be. Since then, physicists and engineers have always built lasers with those restrictions in mind. But new theoretical research from two independent groups of physicists indicates that nature is more lax than previously thought. The findings could lead to improved, more monochromatic lasers for applications such as quantum computing, which the researchers illustrate in two proposed laser designs.

The work “overthrows 60 years of understanding about what limits lasers,” said physicist Howard Wiseman of Griffith University in Australia, whose group published their work in Nature Physics last October.

A laser, in essence, is a megaphone for light. The word itself, originally an acronym, reflects this function: “light amplification by stimulated emission of radiation.” Send in a photon of the right frequency, and the laser makes copies of it, multiplying the original signal.

These photon clones exit the laser in sync with each other, traveling “in phase,” as the experts call it. You can think of it this way: Each photon is a wave, with its crest and trough lined up with its neighbor, marching together in lock-step out of the laser. This contrasts with most other light sources, such as your reading lamp or even the Sun, which both emit photons that disperse randomly.

The longer photons stay in sync, the more monochromatic the light. The color of a light source corresponds to the wavelength of its photons, with green light spanning roughly the 500 to 550 nanometer range, for example. For multiple photons to stay in sync a long time, their wavelengths must line up very precisely—meaning the photons need to be as close to one color as possible.
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This synchrony of laser photons, known as temporal coherence, is one of the device’s most useful properties. Many technologies make use of laser light’s ridiculously fast and steady rhythm, its wave pattern repeatingat hundreds of trillions of times a second for visible lasers. For example, this property underpins the world’s most precise timekeeping devices, known as optical lattice clocks.
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But photons gradually lose sync after they leave the laser; how long they stick together is known as the laser’s coherence time. In 1958, physicists Arthur Schawlow and Charles Townes estimated the coherence time of a perfect laser. (This is a common physicist design strategy: Consider the most ideal version of something before building a far more lacking real-world device.) They found an equation thought to represent an ultimate coherence time limit for lasers, set by the laws of physics. Physicists refer to this as the Schawlow-Townes limit.

The two new papers find that the Schawlow-Townes limit is not the ultimate limit. “In principle, it should be possible to build lasers which are significantly more coherent,” said physicist David Pekker of the University of Pittsburgh, who led the other group. Their paper, currently under peer review, is posted as a pre-print on arXiv.

Both groups argue that the Schawlow-Townes limit rests on assumptions about the laser that are no longer true. Schawlow and Townes basically thought of the laser as a hollow box, in which photons multiply and leave at a rate proportional to the amount of light inside the box. Put another way, the photons flow out of Schawlow and Townes’s laser like water drains from a hole in a barrel. Water flows faster when the barrel is fuller, and vice versa.

But Wiseman and Pekker both found that if you place a valve on the laser to control the rate of the photon flow, you can actually make a laser coherent for much longer than the Schawlow-Townes limit. Wiseman’s paper takes this a step further. Allowing for these photon-controlling valves, his team re-estimates the coherence time limit for the perfect laser. “We show that ours is the ultimate quantum limit,” said Wiseman, meaning the true physical limit dictated by quantum mechanics.

Schawlow and Townes’s estimate, while not the fundamental restriction on lasers physicists originally thought, was reasonable for its time, said Wiseman. No one had any means for precisely controlling the flow of light out of a laser in the way that Wiseman and Pekker propose. But today’s lasers are a different story. Physicists can now control light with a multitude of devices developed for the budding quantum computing industry.

Pekker has teamed up with physicist Michael Hatridge, also of the University of Pittsburgh, to bring the new laser design to life. Hatridge’s expertise involves building circuits out of superconducting wire for storing and controlling microwave-frequency photons. They plan to build a microwave-emitting laser—known as a maser—for programming qubits inside a quantum computer made of superconducting circuits. Though building this new maser will take years of work and troubleshooting, Hatridge said they have all the tools and knowledge to make it possible. “That’s why we’re excited about it, because it’s just another engineering project,” Hatridge said.

Wiseman is looking for collaborators to build his design, also a maser. “I would really, really like this to happen, but I recognize it’s a long-term goal,” he said.

The designs are “completely feasible,” said physicist Steven Touzard of the National University of Singapore, who was not involved in either of the new papers. However, Pekker and Wiseman’s work may not directly lead to useful commercial lasers, according to Touzard. He pointed out that builders of lasers do not commonly use the Schawlow-Townes limit to direct their designs. So overturning the limit could be more of a theoretical advancement than an engineering one, he said.

Curiously, the two new designs also contradict another conventional wisdom about lasers. The devices do not produce light via so-called stimulated emission, which makes up the “s” and “e” in the acronym laser. Stimulated emission is a type of interaction between light and matter, in which a photon impinges upon an atom and “stimulates” the atom to emit an identical photon. If we imagine a laser as a box of light, as before, a laser that amplifies light using stimulated emission multiplies the signal proportionally to the amount of light already in the box. Another type of laser invented in 2012, known as a superradiant laser, also does not use stimulated emission to amplify light, according to Touzard.

The idea of a laser has outgrown its name. It is no longer exclusively “light amplification by stimulated emission of radiation.”

Of course, many such examples exist in the English language. The change in meaning is known as semantic shift and is common “wherever new technology is involved,” according to linguist Micha Elsner of the Ohio State University. “Ships still sail across the ocean, even when no actual sails are involved,” Elsner said in an email. “You can still dial someone’s number even though your phone doesn’t have a dial.”

“Even though a word’s etymology—its origin—certainly gives it a starting point, it does not determine its destiny forever going forward,” linguist Brian Joseph of the Ohio State University said in an email.

As Cold War goals transitioned into 21st century ones, lasers have evolved, too. They’ve been around long enough to integrate into nearly all aspects of modern life: They can correct human vision, read our grocery barcodes, etch computer chips, transmit video files from the Moon, help steer self-driving cars, and set the mood at psychedelic ragers. And now, the laser could be reinvented again. A 60-year-old device remains a symbol of a sci-fi future.

Peace during the pandemic: Some people turning to psychedelics to cope

The Canadian PressStaff

ContactPublished Sunday, January 31, 2021 8:50AM MSTPsilocybin mushrooms

In this Aug. 3, 2007, file photo, psilocybin mushrooms are seen in a grow room at the Procare farm in Hazerswoude, central Netherlands. (AP Photo/Peter Dejong, File)



EDMONTON — Jen Burke lost her full-time job as a clothing store manager because of COVID-19, but says the pandemic has been the most peaceful time in her life.

“There’s so many people who were struggling and having a hard time with it. But I felt great,” the 30-year-old biology student says from her home in Edmonton.

The reason, says Burke, is psychedelic drugs, which she has been micro-dosing along with about two dozen other members of the Edmonton Hiking and Psychedelic Society.

As facilitator of the group, Burke says she has seen an increasing number of participants in online monthly group discussions about the psychoactive or hallucinogenic drugs.

Members talk about exploring substances such as DMT, psilocybin, LSD and MDMA, commonly known as ecstasy or molly.

“They come from all ages and backgrounds, people you wouldn’t expect, like one woman … she’s 75 years old. There’s nurses that come out, like a lot of nurses, and people from different trades.”

It’s illegal to possess, obtain or produce psychedelics without a prescription or licence in Canada. But Burke says group members get them through the black market and use test kits to identify any suspicious substances.

They’re taking precautions, she adds, and not concerned they’ll get arrested.

The Canadian Drug Policy Coalition website says research of psychedelics in the 1950s and ’60s showed promise for the treatment of mental health problems such as post-traumatic stress disorder, depression and anxiety. But former United States president Richard Nixon declared a war on drugs in the early ’70s, which dried up research funding and cha nged attitudes toward the drugs.

Recently, even before the pandemic, there’s been a resurgence in interest in psychedelics, says Peter Facchini, chief scientific officer of MagicMed Industries Inc., a Calgary biotech company that develops psychedelic-derived medicine.

Last year, the doctor counted close to 250 people around the world who were given the green light by medical agencies to test psychedelics and its derivatives in clinical trials.

Among them is Thomas Hartle of Saskatoon, who received a one-year exemption from the Controlled Drugs and Substances Act last August to use psilocybin to treat anxiety.

More recently, Health Canada received an application from a Ontario soldier to access psilocybin-assisted psychotherapy to treat mental health conditions resulting from his long military career. If granted, Master Cpl. Scott Atkinson will be the first Canadian without a terminal illness to legally receive psilocybin-assisted psychotherapy.

Since August, the health agency has approved at least 25 applications from cancer patients for psychedelic treatment.

Facchini and Brian Welling, an Edmonton psychologist, both say the stress of COVID-19 may be contributing to an even bigger boom in psychedelic consumption because of the mental health crisis the pandemic has created.

Welling provides “psychedelic integration” sessions, during which he helps patients understand what to expect during drug trips and meets them after to discuss their needs.

Welling says an increasing number of people have come to him asking for help in preparing to take psychedelics. A year ago, he saw a patient for integration once in awhile. Now, he sees them at least once a week.

“You experience things there that are foreign to your ego, foreign to your ordinary way of looking at things, and can often bring you insights about yourself and about how to live,” he says.

“Maybe it doesn’t make sense to you, and you need some time to process it, and often some help to do so.”

Some studies show psychedelics are overall considered physiologically safe and do not lead to dependence or addiction.

But Facchini says people need to be careful when consuming the powerful substances, which can alter perception, mood and cognitive processes and may not necessarily target mental health issues.

“They could have a variation in how strong the trip is, just like how people with mental health issues are varied. PTSD is different, depression, and so on. So even people that suffer from PTSD are not necessarily affected the same way.”

For Burke, going on trips has been life changing.

“The biggest difference psychedelics have made in my life – and this has been echoed by others – is how much more self aware it makes you because of this new-found humility,” she says.

“A lot of us have improved relationships with family and loved ones. (Psychedelics) didn’t change me. They just made me more me.”

This report by The Canadian Press was first published Jan. 31, 2021.

Extreme Events in Quantum Cascade Lasers Enable an Optical Neuron System 10,000× Faster Than Biological Neurons



Quantum cascade photonic device. Credit: Spitz et al., doi 10.1117/1.AP.2.6.066001

QCLs Exhibit Extreme Pulses

Extreme events occur in many observable contexts. Nature is a prolific source: rogue water waves surging high above the swell, monsoon rains, wildfire, etc. From climate science to optics, physicists have classified the characteristics of extreme events, extending the notion to their respective domains of expertise. For instance, extreme events can take place in telecommunication data streams. In fiber-optic communications where a vast number of spatio-temporal fluctuations can occur in transoceanic systems, a sudden surge is an extreme event that must be suppressed, as it can potentially alter components associated with the physical layer or disrupt the transmission of private messages.

Recently, extreme events have been observed in quantum cascade lasers, as reported by researchers from Télécom Paris (France) in collaboration with UC Los Angeles (USA) and TU Darmstad (Germany). The giant pulses that characterize these extreme events can contribute the sudden, sharp bursts necessary for communication in neuromorphic systems inspired by the brain’s powerful computational abilities. Based on a quantum cascade laser (QCL) emitting mid-infrared light, the researchers developed a basic optical neuron system operating 10,000× faster than biological neurons. Their report is published in Advanced Photonics.

Giant pulses, fine tuning

Olivier Spitz, Télécom Paris research fellow and first author on the paper, notes that the giant pulses in QCLs can be triggered successfully by adding a “pulse-up excitation,” a short-time small-amplitude increase of bias current. Senior author Frédéric Grillot, Professor at Télécom Paris and the University of New Mexico, explains that this triggering ability is of paramount importance for applications such as optical neuron-like systems, which require optical bursts to be triggered in response to a perturbation.

The team’s optical neuron system demonstrates behaviors like those observed in biological neurons, such as thresholding, phasic spiking, and tonic spiking. Fine tuning of modulation and frequency allows control of time intervals between spikes. Grillot explains, “The neuromorphic system requires a strong, super-threshold stimulus for the system to fire a spiking response, whereas phasic and tonic spiking correspond to single or continuous spike firing following the arrival of a stimulus.” To replicate the various biological neuronal responses, interruption of regular successions of bursts corresponding to neuronal activity is also required.

Quantum cascade laser

Grillot notes that the findings reported by his team demonstrate the increasingly superior potential of quantum cascade lasers compared to standard diode lasers or VCSELs, for which more complex techniques are currently required to achieve neuromorphic properties.

Experimentally demonstrated for the first time in 1994, quantum cascade lasers were originally developed for use under cryogenic temperatures. Their development has advanced rapidly, allowing use at warmer temperatures, up to room temperature. Due to the large number of wavelengths they can achieve (from 3 to 300 microns), QCLs contribute to many industrial applications such as spectroscopy, optical countermeasures, and free-space communications.

According to Grillot, the physics involved in QCLs is totally different than that in diode lasers. “The advantage of quantum cascade lasers over diode lasers comes from the sub-picosecond electronic transitions among the conduction-band states (subbands) and a carrier lifetime much shorter than the photon lifetime,” says Grillot. He remarks that QCLs exhibit completely different light emission behaviors under optical feedback, including but not limited to giant pulse occurrences, laser responses to modulation, and frequency comb dynamics.

Reference: “Extreme events in quantum cascade lasers” by Olivier Spitz, Jiagui Wu, Andreas Herdt, Grégory Maisons, Mathieu Carras, Wolfgang E. Elsäßer, Chee-Wei Wong and Frédéric Grillot, 21 October 2020, Advanced Photonics.
DOI: 10.1117/1.AP.2.6.066001

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  1. Recent progress in optoelectronic neuromorphic devices*Yan-Bo Guo et al., Chinese Physics B, 2020
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Our Gut-Brain Connection Revealed by “Organs-on-a-Chip” System

TOPICS:Biomedical EngineeringBiotechnologyMicrobiomeMITNeuroscienceParkinson’s Disease


MIT researchers have developed an “organs-on-a-chip” system that replicates interactions between the brain, liver, and colon. Credit: Martin Trapecar, MIT

‘Organs-on-a-chip’ system sheds light on how bacteria in the human digestive tract may influence neurological diseases.

In many ways, our brain and our digestive tract are deeply connected. Feeling nervous may lead to physical pain in the stomach, while hunger signals from the gut make us feel irritable. Recent studies have even suggested that the bacteria living in our gut can influence some neurological diseases.

Modeling these complex interactions in animals such as mice is difficult to do, because their physiology is very different from humans’. To help researchers better understand the gut-brain axis, MIT researchers have developed an “organs-on-a-chip” system that replicates interactions between the brain, liver, and colon.

Using that system, the researchers were able to model the influence that microbes living in the gut have on both healthy brain tissue and tissue samples derived from patients with Parkinson’s disease. They found that short-chain fatty acids, which are produced by microbes in the gut and are transported to the brain, can have very different effects on healthy and diseased brain cells.

“While short-chain fatty acids are largely beneficial to human health, we observed that under certain conditions they can further exacerbate certain brain pathologies, such as protein misfolding and neuronal death, related to Parkinson’s disease,” says Martin Trapecar, an MIT postdoc and the lead author of the study.

Linda Griffith, the School of Engineering Professor of Teaching Innovation and a professor of biological engineering and mechanical engineering, and Rudolf Jaenisch, an MIT professor of biology and a member of MIT’s Whitehead Institute for Medical Research, are the senior authors of the paper, which appears today (January 29, 2021) in Science Advances.

MIT researchers have developed an “organs-on-a-chip” system that replicates interactions between the brain, liver, and colon. Credit: Martin Trapecar, MIT

The gut-brain connection

For several years, Griffith’s lab has been developing microphysiological systems — small devices that can be used to grow engineered tissue models of different organs, connected by microfluidic channels. In some cases, these models can offer more accurate information on human disease than animal models can, Griffith says.

In a paper published last year, Griffith and Trapecar used a microphysiological system to model interactions between the liver and the colon. In that study, they found that short-chain fatty acids (SCFAs), molecules produced by microbes in the gut, can worsen autoimmune inflammation associated with ulcerative colitis under certain conditions. SCFAs, which include butyrate, propionate, and acetate, can also have beneficial effects on tissues, including increased immune tolerance, and they account for about 10 percent of the energy that we get from food.

In the new study, the MIT team decided to add the brain and circulating immune cells to their multiorgan system. The brain has many interactions with the digestive tract, which can occur via the enteric nervous system or through the circulation of immune cells, nutrients, and hormones between organs.

Several years ago, Sarkis Mazmanian, a professor of microbiology at Caltech, discovered a connection between SCFAs and Parkinson’s disease in mice. He showed that SCFAs, which are produced by bacteria as they consume undigested fiber in the gut, sped up the progression of the disease, while mice raised in a germ-free environment were slower to develop the disease.

Griffith and Trapecar decided to further explore Mazmanian’s findings, using their microphysiological model. To do that, they teamed up with Jaenisch’s lab at the Whitehead Institute. Jaenisch had previously developed a way to transform fibroblast cells from Parkinson’s patients into pluripotent stem cells, which can then be induced to differentiate into different types of brain cells — neurons, astrocytes, and microglia.

More than 80 percent of Parkinson’s cases cannot be linked to a specific gene mutation, but the rest do have a genetic cause. The cells that the MIT researchers used for their Parkinson’s model carry a mutation that causes accumulation of a protein called alpha synuclein, which damages neurons and causes inflammation in brain cells. Jaenisch’s lab has also generated brain cells that have this mutation corrected but are otherwise genetically identical and from the same patient as the diseased cells.

Griffith and Trapecar first studied these two sets of brain cells in microphysiological systems that were not connected to any other tissues, and found that the Parkinson’s cells showed more inflammation than the healthy, corrected cells. The Parkinson’s cells also had impairments in their ability to metabolize lipids and cholesterol.

Opposite effects

The researchers then connected the brain cells to tissue models of the colon and liver, using channels that allow immune cells and nutrients, including SCFAs, to flow between them. They found that for healthy brain cells, being exposed to SCFAs is beneficial, and helps them to mature. However, when brain cells derived from Parkinson’s patients were exposed to SCFAs, the beneficial effects disappeared. Instead, the cells experienced higher levels of protein misfolding and cell death.

These effects were seen even when immune cells were removed from the system, leading the researchers to hypothesize that the effects are mediated by changes to lipid metabolism.

“It seems that short-chain fatty acids can be linked to neurodegenerative diseases by affecting lipid metabolism rather than directly affecting a certain immune cell population,” Trapecar says. “Now the goal for us is to try to understand this.”

The researchers also plan to model other types of neurological diseases that may be influenced by the gut microbiome. The findings offer support for the idea that human tissue models could yield information that animal models cannot, Griffith says. She is now working on a new version of the model that will include micro blood vessels connecting different tissue types, allowing researchers to study how blood flow between tissues influences them.

“We should be really pushing development of these, because it is important to start bringing more human features into our models,” Griffith says. “We have been able to start getting insights into the human condition that are hard to get from mice.”

Reference: “Human physiomimetic model integrating microphysiological systems of the gut, liver, and brain for studies of neurodegenerative diseases” by Martin Trapecar, Emile Wogram, Devon Svoboda, Catherine Communal, Attya Omer, Tenzin Lungjangwa, Pierre Sphabmixay, Jason Velazquez, Kirsten Schneider, Charles W. Wright, Samuel Mildrum, Austin Hendricks, Stuart Levine, Julien Muffat, Meelim Jasmine Lee, Douglas A. Lauffenburger, David Trumper, Rudolf Jaenisch and Linda G. Griffith, 29 January 2021, Science Advances.
DOI: 10.1126/sciadv.abd1707

The research was funded by DARPA, the National Institutes of Health, the National Institute of Biomedical Imaging and Bioengineering, the National Institute of Environmental Health Sciences, the Koch Institute Support (core) Grant from the National Cancer Institute, and the Army Research Office Institute for Collaborative Biotechnologies.

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  1. Interaction between microbiota and immunity in health and diseaseDanping Zheng et al., Cell Research, 2020
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Just one more piece of evidence that a bowl of fruit won’t do you any harm.


THE AGING GLOBAL POPULATION is the greatest challenge faced by 21st-century healthcare systems. Even COVID-19 is, in a sense, a disease of aging.



It turns out that a major hallmark of the aging process in many mammals is inflammation. By that, I don’t mean intense local response we typically associate with an infected wound, but a low grade, grinding, inflammatory background noise that grows louder the longer we live. This “inflammaging” has been shown to contribute to the development of atherosclerosis (the buildup of fat in arteries), diabetes, high blood pressure , frailtycancer and cognitive decline.

Now a new study published in Nature reveals that microglia — a type of white blood cells found in the brain — are extremely vulnerable to changes in the levels of a major inflammatory molecule called prostaglandin E2(PGE2). The team found that exposure to this molecule badly affected the ability of microglia and related cells to generate energy and carry out normal cellular processes.

Fortunately, the researchers found that these effects occurred only because of PGE2’s interaction with one specific receptor on the microglia. By disrupting it, they were able to normalize cellular energy production and reduce brain inflammation. The result was improved cognition in aged mice. This offers hope that the cognitive impairment associated with growing older is a transient state we can potentially fix, rather than the inevitable consequence of aging of the brain.


Levels of PGE2 increase as mammals age for a variety of reasons — one of which is probably the increasing number of cells in different tissues entering a state termed cellular senescence. This means they become dysfunctional and can cause damage to tissue by releasing PGE2 and other inflammatory molecules.

Macrophage cell.Kateryna Kon/Shutterstock

But the researchers also found that macrophages — another type of white blood cells related to microglia — from people over the age of 65 made significantly more PGE2 than those from young people. Intriguingly, exposing these white blood cells to PGE2 suppressed the ability of their mitochondria — the nearest thing a cell has to batteries — to function. This meant that the entire pattern of energy generation and cellular behavior was disrupted.

Although PGE2 exerts its effects on cells through a range of receptors, the team were able to narrow down the effect to interaction with just one type (the “EP2 receptor” on the macrophages). They showed this by treating white blood cells, grown in the lab, with drugs that either turned this receptor on or off. When the receptor was turned on, cells acted as if they had been exposed to PGE2. But when they were treated with the drugs that turned it off, they recovered. That’s all fine, but it was done in a petri dish. What would happen in an intact body?

The researchers then carried out one of the cleanest experiments it is possible to perform in biology and one of the best reasons for working on mice. They took genetically modified animals in which the EP2 receptor had been removed and allowed them to grow old. They then tested their learning and memory by looking at their ability to navigate mazes (something of a cliche for researchers) and their behavior in an “object location test.” This test is a bit like someone secretly entering your house, swapping your ornaments around on the mantelpiece and then sneaking out again. The better the memory, the longer the subject will spend looking suspiciously at the new arrangement, wondering why it has changed.

It turned out that the old genetically modified mice learned and remembered just as well as their young counterparts. These effects could be duplicated in normal old mice by giving them one of the drugs that could turn the EP2 receptor off for one month. So it seems possible that inhibiting the interaction of PGE2 with this particular receptor may represent a new approach to treating late-life cognitive disorders.

There is a long way to go before we are in a position to start using these compounds in humans — even though the prostaglandin systems are very similar. But this study has shed light on a fascinating set of observations linking diet and cognition.

It has been known for some years that eating blueberries and other fruit and vegetables, such as strawberries and spinach, improves cognition in rodents and older people. These foods are rich in molecules such as resveratrolfisetin, and in quercetin, which have been shown either to kill or rescue senescent cells.

There is also evidence that they block PGE2 at the cellular level, providing another route by which these compounds may exert their beneficial effects. Until something better comes along, this is one more piece of evidence that a bowl of fruit won’t do you any harm. Though it’s probably wise to go easy on the cream.

Being wary of wearables, or the pros and cons of the fitness tracker revolution

Before you throw money at a Fitbit or Apple Watch, you need to figure out what these devices can and cannot do.

ByVinay Aravind30 Jan, 2021Anubhooti Gupta


A mathematician on Twitter has a favourite term she uses to describe reducing anything and everything one encounters in life to numbers: “mathfuckery”. To quote from what I consider a seminal Twitter thread, people who indulge in mathfuckery “like the flashy terms and ideas, and the fancy graphs and apps, but they have no desire to grapple with reality, and how little we actually know.”

This always reminds me of wearables and, specifically, the ones that people use for fitness tracking.

From the most extravagant Apple Watch that costs over Rs 50,000 down to the obscure Chinese smart bands (with sketchy names like Digibuff and Welrock) that cost in the region of Rs 500, they all broadly perform some of the same functions: tracking your sleep, your steps, your fitness activities, measuring some health parameters like heart rate, blood oxygen, etc, and offering some measure of interaction with your smartphone.

The history of fitness wearables as we know them today can be roughly traced back to the 2008 launch of Fitbit’s first device (called simply the Fitbit) which you clipped onto your clothing. From there, it has grown to be a $32 billion industry worldwide, propelled in no small measure due to the outsize success of the Apple Watch.

This phenomenon has embedded the idea in the public consciousness that you can and should “math” your way to fitness. As with all mathfuckery, this is a complex beast and it’s useful to have an understanding of what fitness trackers can and cannot do before you plonk down a certain amount of money on your next new gadget.

To get my personal biases out of the way, I don’t believe it’s worth spending tens of thousands of rupees on a fitness tracker or wearable. But since my brief is not to scold rich people for spending their money, I’ll get down to the actual functional aspects of these devices and where they do and don’t live up to their promise.


This was the main selling point of the original Fitbit, and the thing most trackers do quite well. They count steps and mostly do a solidly reliable job of it. This also gave rise to the 10,000-steps dogma, which is very popular around the world, and I have mixed feelings about. On the one hand, this target is extremely useful to motivate people, and strapping on a tracker and cranking out these steps is one of the simplest ways to introduce movement into an otherwise sedentary lifestyle. But the simple fact is that 10,000 is a very arbitrary number, and does not and should not be treated as some sort of holy grail.

Placing something like the number of steps you do within a broader fitness context is much more likely to give you a good understanding of its significance and utility. For instance, I try to hit a certain number of steps in a day to supplement my strength training workouts.


Many fitness trackers nowadays come with the ability to use your phone’s GPS to accurately track the distance that you have run, walked or jogged. There are even some (pricier) models that have an in-built GPS module so that you can go for a run without being weighed down by your phone. These (mostly quite accurate) measurements, combined with time, etc, give you a very good and reliable indicator of the work you’ve put in and the progress you’re making, so it’s a useful feature if running or walking is a part of your fitness regimen.


Most fitness trackers track your sleep with varying degrees of sophistication. Some will stop at telling you what time you fell asleep and woke up, others will tell you the duration of your sleep cycles (deep, light, REM, etc) and yet others will even give you suggestions on what you can do to sleep better. There is some utility in this, but here it’s worth remembering that tracking your sleep is less precise than tracking your steps or distance, and in some devices it can be wildly inaccurate.

This functionality is less usable in devices like the Apple Watch that have less than a single day’s battery life, and more so in devices like the Xiaomi Mi Band which last for weeks, so you don’t have to decide between charging your device overnight and learning about your sleep.

Heart rate

Most trackers these days also include an optical heart rate sensor. By and large, these do a good job of giving you an idea of your heart rate during various times of the day including when you are active, but there are some limitations to the accuracy of this data. It’s still a useful feature and there are many known cases of the feature providing an actionable early warning sign for people regarding underlying health issues. The Apple Watch also has an EKG function but unlike the heart rate function, it’s not very accurate, and having the feature on your device can be a double-edged sword with false negatives providing a potentially false sense of comfort.

Blood oxygen

This is the latest hot feature among wearables, especially in light of the Covid pandemic when everyone has been rushing (sensibly) to buy pulse oximeters to keep tabs on the oxygen saturation in their blood. In short, do not rely on your wearable for SpO2 measurements. They need to be perfectly positioned to even take a shot at doing the measurement and can do a far worse job than the fingertip pulse oximeters. And for something like SpO2, where the margins are so fine, it’s best to pay no heed to the readings from an unreliable device.

Calories burnt

Wearables use a combination of data and algorithms to try and work out the energy that you expend. But according to a 2017 Stanford study “no wrist-worn monitoring devices report energy expenditure within an acceptable error range”. So, it’s best to not get hung up on the “calories” number that your tracker throws up beyond it being a rough guideline number.

Our instinct for mathfuckery drives us to place too much of a reliance on these numbers. If your game of football felt really strenuous but you “only burnt 250 calories”, don’t worry about it. Your tracker probably also told you the steps and the distance you ran and even your heart rate, which are all more useful numbers for you to draw conclusions from.

There are several more functions that these devices perform, but these are some of the headline features for which people buy fitness tracking wearables. And as you can see, they don’t quite deliver on all fronts equally.

So, while evaluating the data that your fitness tracker throws up (and, of course, while evaluating whether you should spend on a cheap tracker or a fancy smartwatch), it’s very important to keep these limitations in mind. It’s also important to not let numbers dictate your fitness regimen. For instance, if you lift weights, a fitness tracker adds very little value, whereas if you’re a runner, they can be very useful. Remember to keep these aspects in mind as well before you make a purchasing decision.