Will your electric car burst into flames? A solid-state battery would reduce the risk

Source: The Conversation – Canada – By Taiana Lucia Emmanuel Pereira, Postdoc Fellow, Chemistry, McMaster University

Canada recently signed a new trade agreement with China, reducing tariffs on up to 49,000 Chinese electric vehicles (EVs) each year. By 2030, half of these imported vehicles are anticipated to be “affordable EVs” costing less than $35,000.

This could make electric cars a more budget-friendly option for Canadians. However, public trust remains fragile, shaped largely by fears of EV battery fires.

In 2024, when a high-speed crash on Toronto’s Lake Shore Boulevard resulted in a Tesla bursting into flames, killing four passengers, the images circulated widely online. Months later, another Tesla caught fire on Highway 403 in Ontario, again shutting down traffic.

Evidence shows that the risks of EVs bursting into flames while you drive are low. However, these events have caused some public anxiety.

Solid-state batteries offer a promising new solution. They replace the flammable liquid in existing EV batteries with a solid electrolyte. This reduces the risks of spontaneous combustion when batteries are damaged or when they overheat.

Mercedes-Benz recently trialled an EQS sedan with a solid-state battery. The car drove 1,205 kilometres from Stuttgart in Germany to Malmö in Sweden without a charging stop.

Chinese automaker Chery says it plans to release its first electric vehicle with a solid-state battery later this year. The company says the design could boost energy density and cold-weather performance, with targeted ranges of up to 1,500 kilometres even in sub-zero temperatures.

Canadian researchers are also playing an important role in advancing solid-state technology. I am part of a research team at McMaster University studying battery chemistry at the atomic level to help turn solid-state batteries into a practical technology.

How do lithium-ion batteries work?

EVs rely on lithium-ion batteries rather than gasoline but the basic idea is similar. They store energy and release it when you need it. These batteries are made up of two electrodes: one positive (cathode) and one negative (anode), separated by an electrolyte that allows lithium ions to move between them.

When the battery powers a device or a vehicle, electrons flow through the external circuit to produce electricity, while lithium ions travel inside the battery from the anode to the cathode. Charging the battery simply reverses this process, pushing the lithium ions back to where they started.

How lithium-ion batteries work. (PhysicsLearning)

How much power a battery can deliver depends largely on how quickly and how many lithium ions can move between the two electrodes.

Today’s batteries rely on liquid electrolytes. This allows lithium ions to move easily and efficiently, giving the car quick acceleration, steady highway performance and consistent response when you press the pedal. How far a car can go on a single charge, however, depends mainly on how much lithium the electrodes can store.

Why do batteries catch fire?

When lithium-ion batteries are damaged or experience internal failures, they can overheat and enter a process known as thermal runaway. This can trigger intense fires that are hard to extinguish and may even reignite hours later.

A major reason is the liquid electrolyte, which is typically made from flammable organic solvents. If the battery overheats, the liquid can act as fuel, worsening the fire. Solid-state battery technology replaces the flammable liquid with a solid electrolyte.

This video shows five cylindrical lithium ion battery cells, forced into thermal runaway in test conditions.

Safer batteries with higher performance?

Solid electrolytes are generally non-volatile and mechanically robust. They reduce the risk of leakage and limit the formation of oxygen-rich volatile decomposition products. They can act as a physical barrier that slows the growth of the lithium filaments that can short-circuit a battery.

Together, these features reduce two major triggers of thermal runaway: internal short circuits and rapid heat-releasing chemical reactions in the electrolyte.

In our research group, we use solid-state nuclear magnetic resonance to understand how lithium ions move inside solid electrolytes. These experiments let us track both the local chemistry and the longer-range ion transport that determine how well a material will work in a battery. By linking these atomic-scale insights to battery performance, we can help design better solid electrolytes for safer electric vehicles.

Beyond safety, solid electrolytes also enable higher-performance batteries. They make it possible to use lithium metal anodes and high-voltage cathodes, which can increase energy density compared to today’s graphite-based batteries.

For EVs, this could mean longer driving range or smaller, lighter battery packs without sacrificing performance.

Why liquid electrolytes still dominate

Despite their safety, liquid electrolytes remain the industry standard.

They provide high ionic conductivity at room temperature, ensuring fast charging, strong acceleration and reliable performance across a wide range of conditions. They also connect well with the electrodes, allowing electricity to flow easily and keeping the battery’s design simpler. Decades of industrial experience have made them relatively inexpensive and easy to manufacture at scale.

In contrast, many solid electrolytes suffer from mechanical brittleness, which means they can crack during battery cycling and lose contact with the electrodes. In addition, solid electrolytes often struggle to make good connections with electrode materials, and chemical reactions at these interfaces can form resistive layers that reduce battery performance.

As a result, while solid-state batteries show great promise, liquid electrolytes have offered the best balance of performance, cost and ease of manufacturing in EVs to date.

Canada’s role in the transition

The recent trade agreement with China could give Canada faster access to the advanced battery technologies already developed at scale in China.

However, many Canadian researchers are already playing an important role in advancing EV battery technology by investigating new electrolyte materials and battery interfaces. Canadian federal programs are supporting battery research, clean-energy initiatives and domestic battery manufacturing, positioning Canada within the global EV transition.




Read more:
Lower tariffs on Chinese electric vehicles could boost adoption and diversify Canada’s trade


Advances in materials science, interface engineering and battery chemistry are improving the performance and durability of solid electrolytes. What once existed only in laboratories is moving into pilot production and early vehicle testing.

In the long run, solid electrolytes could reduce fire risk while enabling longer ranges and lighter battery packs, helping EVs become safer.

The Conversation

Taiana Lucia Emmanuel Pereira receives funding from NSERC and MITACS.

ref. Will your electric car burst into flames? A solid-state battery would reduce the risk – https://theconversation.com/will-your-electric-car-burst-into-flames-a-solid-state-battery-would-reduce-the-risk-277042

What you need to know about Mexico’s drug cartels amid escalating violence

Source: The Conversation – UK – By Raul Zepeda Gil, Research Fellow in the War Studies Department, King’s College London

The recent killing of Nemesio Oseguera Cervantes, the leader of the Cártel de Jalisco Nueva Generación (CJNG) who was commonly referred to by his alias “El Mencho”, has once again brought global attention to drug-related violence in Mexico. His death at the hands of the Mexican security forces triggered a wave of retaliatory violence that affected several states.

This situation will undoubtedly occur again. Under Donald Trump, the US government has been ramping up pressure on the Mexican authorities to take stronger action against the cartels that traffic drugs across the border. So now is a good moment to reflect on the main cartels operating in Mexico and the underlying factors that sustain their operations.

For decades, Mexico had three major drug trafficking groups: the Milenio cartel, the Sinaloa cartel and the Golfo cartel. These organisations dominated drug trafficking until the 1980s when the Mexican government, under pressure from the US, intensified its operations against them. This pressure followed the 1985 killing of American Drug Enforcement Administration agent Enrique Camarena by organised crime figures.

But it wasn’t until 2006 that Mexico’s cartel landscape really began to change. That year saw the then-Mexican president, Felipe Calderón, deploy the Mexican army against the cartels in a militarised “war on drugs”. The government’s strategy of targeting senior cartel figures caused these organisations to fragment into smaller groups.

For example, a group of former Mexican special forces commandos who had previously acted as the enforcement arm for the Golfo cartel broke away to form Los Zetas in 2010. Various other factions elsewhere in Mexico also set up their own organisations. These included Beltrán Leyva, La Familia Michoacana, Knights Templar (Caballeros Templarios), CJNG and Guerreros Unidos.

In 2014, following the abduction of 43 student teachers in the Pacific state of Guerrero by Guerreros Unidos, President Enrique Peña Nieto escalated the offensive against Mexico’s cartels. This led to further fragmentation, with some newer organisations such as Santa Rosa de Lima focusing on oil theft. Andrés Manuel López Obrador came to power in 2018 and pressed hard against the Sinaloa cartel.

The detention of senior figures such as Joaquín “El Chapo” Guzmán and Ismael “El Mayo” Zambada caused the Sinaloa cartel to break into two factions: Los Chapitos which is led by El Chapo’s sons and Los Mayos which is headed by El Mayo’s lieutenants. CJNG took advantage of this moment to expand, positioning itself at the centre of Mexican drug trafficking.

The militarised war on drugs has not just caused the number of Mexican drug trafficking organisations to expand, it has also led to a surge in violence. Throughout the 1990s and early 2000s, violence in Mexico was actually declining. But since 2006, when Calderón first deployed the Mexican army against the cartels, homicides have increased from around 10,000 per year to over 30,000.

The rise in violence is also largely a consequence of the deliberate targeting of cartel leaders. Removing leadership produces a sudden succession struggle in an affected organisation, with violence often subsequently employed to prevent or respond to rivals testing the new leadership.

Mexico’s cartel violence is usually highly concentrated, with northern Mexico and the Pacific states experiencing the highest homicide levels. This pattern reflects trafficking routes. Mexico’s northern states are a key corridor for smuggling drugs into the US, while the Pacific coast serves as a major entry point from Asia for the chemicals used to produce fentanyl.

Sustaining cartel operations

The violence perpetrated by the cartels is enabled largely by weapons that are smuggled into Mexico. According to figures published by the US Bureau of Alcohol, Tobacco, Firearms and Explosives, more than half of the weapons seized from criminal groups in Mexico come from the US.

Research shows how close the relationship between US firearms and Mexican cartel violence is. One study from 2019 found that any increase in firearm production in the US increases violence in Mexico. And another, published several years earlier, discovered there was a spike in homicides in Mexico’s northern states when the US government lifted restrictions on the sale of certain assault weapons in 2004.

The Mexican government filed a lawsuit in 2021 that sought to hold American gun makers accountable for their contribution to the rising violence in Mexico. While the lawsuit was rejected unanimously by the US supreme court in 2025, the Mexican authorities have continued to press their US counterparts to take firmer action against arms smuggling from north of the border.

Mexico’s president, Claudia Sheinbaum, made a speech days after El Mencho’s killing in which she asserted that if the US government wants Mexico to prevent drug trafficking, they “have to do their part” and eradicate the flow of weapons.

And, finally, it’s important to recognise that the operations of the Mexican cartels are sustained in large part by drug consumption in the US. Data published by the UN Office on Drugs and Crime suggests that drug seizures, particularly of fentanyl, have increased substantially since 2019.

Until the US takes steps to more effectively reduce demand for drugs among its own citizens, Mexico’s battle against cartel violence will continue.

The Conversation

Raul Zepeda Gil 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.

ref. What you need to know about Mexico’s drug cartels amid escalating violence – https://theconversation.com/what-you-need-to-know-about-mexicos-drug-cartels-amid-escalating-violence-276941

Moulin Rouge! turns 25: how Baz Luhrmann reinvented the movie musical

Source: The Conversation – UK – By Richard Rushton, Professor in Film Studies, Lancaster University

This year marks the 25th anniversary of Moulin Rouge!, Baz Luhrmann’s reinvention of the movie musical. There is little doubt the movie musical was on the decline in the 1980s and 90s. The only real contender during that period was Disney (who released Beauty and the Beast in 1991 and The Lion King in 1994).

The musical was slowly being replaced by what contemporary critics called the “musically oriented film”, starting with 1977’s Saturday Night Fever, then Fame (1981), Flashdance (1983) and Footloose (1984). This trend extended to films whose soundtracks proved irresistible. Think Top Gun (1983), Quentin Tarantino’s bold soundtracks (Pulp Fiction in 1994 and Jackie Brown in 1997), alongside Nora Ephron’s nostalgic throwbacks in Sleepless in Seattle (1989) and You’ve Got Mail (1998).

These poppy soundtracks – full of songs you know but haven’t heard in a while – provided the perfect platform for Luhrmann to introduce a new kind of jukebox musical.

Not only did Moulin Rouge! pack an extraordinary number of songs into its duration – over 20, when a classic musical such as 1934’s Top Hat might contain as few as five tunes – it did so in a way that no musical had ever done before.

The trailer for Moulin Rouge!

Traditional musicals tended to construct their song and dance sequences via long takes while also maintaining a good distance from performers. This was in order to preserve the integrity of the number. It was thought by who? important to capture a dancer’s full body so as to appreciate the athleticism and wholeness of a performance. This was central for Fred Astaire (say in Swing Time, 1936), Gene Kelly (in Singin’ in the Rain, 1952) and even Marylin Monroe (in Gentlemen Prefer Blondes, 1953). The integrity of the performance was everything. Not so for Luhrmann, who introduced cut-up, super-edited song and dance numbers at breakneck speed.

The average shot length in Moulin Rouge! is under two seconds: a very fast pace for the time. While acceptable for an action movie, nothing like this had ever been done in a musical. It is likely that Luhrmann gained inspiration from pop music video culture — the “MTV aesthetic” — that had been de rigueur on TV screens for a good ten to 15 years. He had already borrowed from it in his previous films, Strictly Ballroom (1992) and William Shakespeare’s Romeo + Juliet (1996).

From one world to another

Moulin Rouge! nevertheless borrows one of the main traits of movie musicals. The story of Moulin Rouge! is the story of the attempts of its main characters to go from one world to another.

We find this in many classic musicals. It’s in Dorothy’s dream of leaving Kansas and journeying to Oz, and then in her desire to return home again in The Wizard of Oz (1939). It’s in Maria’s desire to leave the convent in The Sound of Music (1965). Or most emphatically in Tommy’s desire to leave Manhattan and live the rest of his days in a fantasy world in Brigadoon (1954).

In Moulin Rouge!, Christian (Ewan McGregor) wants to leave his current world behind and enter a world in which he is a great writer. Satine (Nicole Kidman), too, desires to leave the world in which she is a dancer at the Moulin Rouge and enter a new world in which she will be a “real” actress on stage in the legitimate theatre.

Your Song from Moulin Rouge!

As happens so often in the musical genre, our characters try to get to a new world by way of song and dance. That is, by putting on a show – what is generally termed a “backstage musical”. When Christian sings Your Song, he is intimating that Satine has opened up a new world for him (“How wonderful life is now you’re in the world”). Satine herself is even more emphatic in singing One Day I’ll Fly Away – and that may be her best way of getting from one world to another.

Do our characters make it to their new worlds? Indeed, Christian does: he becomes a writer and the film we see is his version of the story. But this is not so for Satine – she dies. There certainly are musicals that do not have happy endings, such as West Side Story (1961), Funny Girl (1968) and All that Jazz (1979). But it was was an extraordinarily bold move to chart the demise of the film’s most glamorous performer and biggest star. In this way Luhrmann’s debt may be more akin to opera, such as Puccini’s La Boheme (1869) or Verdi’s La Traviata (1853).

In the end, Moulin Rouge! grounds its stylistic excess in a simple credo: “The greatest thing you’ll ever learn is just to love and be loved in return.” As Satine does not survive to enter the future she imagines, love crosses a different boundary – death itself. Christian’s private grief becomes public art, and the romance endures as story and song. Love does not avert tragedy, but it grants it form, and in doing so allows it to last.

The Conversation

Richard Rushton 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.

ref. Moulin Rouge! turns 25: how Baz Luhrmann reinvented the movie musical – https://theconversation.com/moulin-rouge-turns-25-how-baz-luhrmann-reinvented-the-movie-musical-277575

Lupita Nyong’o revealed she has fibroids – here’s what you need to know about them

Source: The Conversation – UK – By Nicola Tempest, Senior Lecturer, Subspecialist in Reproductive Medicine and Consultant Gynaecologist, University of Liverpool

The actress hopes sharing her story will raise awareness of the condition. Denis Makarenko/ Shutterstock

Academy Award-winning actress Lupita Nyong’o recently shared on Instagram that she has fibroids. The actress revealed that she has had 77 uterine fibroids over the course of her lifetime – the largest of which were the size of an orange. The actress took to social media to share her story in a bid to raise awareness for the common condition.

Fibroids are non-cancerous growths that develop in or around the womb (uterus). They’re thought to affect two in every three women – though many women won’t even realise they have them as they won’t have any symptoms.

Fibroids are made up of muscle and fibrous tissue. Their growth is driven by hormones such as oestrogen and progesterone. They can vary massively in size, from pea-sized to the size of a watermelon. Some women will only have one discrete fibroid – while others, like Nyong’o, will develop numerous fibroids. They’re also sometimes known as uterine myomas or leiomyomas.

Age and ethnicity are the strongest risk factors for fibroids. Approximately 70-80% of women develop fibroids by the age of 50. Those of African ancestry have the highest prevalence and earliest onset of fibroids, with 60% of black women affected by age 35. Fibroids also tend to be larger, more numerous and cause worse symptoms in black women.

Symptoms of fibroids can be many and varied. Heavy periods (menorrhagia) are the most common symptom. Prolonged bleeding (for more than seven days) and bleeding between periods can also be common. Heavy bleeding can also lead to anaemia (low iron), which may result in tiredness, shortness of breath and lightheadedness.

Pain can also occur with fibroids. For some, this pain only happens while they’re on the period or during intercourse, while for others the pelvic pain is constant.

This pain is usually related to the degeneration of the fibroids or pressure from the fibroids pressing against the bladder, rectum or ureters (the tubes that transport urine from the kidneys to the bladder). Pressure symptoms typically include feeling like you need to urinate often or being unable to urinate and bowel dysfunction.

Fibroids can also cause problems when trying to get pregnant. Miscarriage may also occur, due to distortion of the uterine cavity (the place where a pregnancy would implant).

A person points to a medical model of a uterus with fibroids.
Fibroids can cause pain for many women.
Maryna_Auramchuk/ Shutterstock

People with fibroids that become pregnant are also at higher risk of giving birth early, requiring a caesarean section to deliver and having a bleed following delivery.

Treating fibroids

Fibroids usually shrink after the menopause, since levels of oestrogen and progesterone decrease. However, they may still continue to grow in women who take hormone replacement therapy (HRT).

Treatment options for fibroids will depend on a variety of factors, including the sufferer’s symptoms, the size and location of the fibroids and their fertility wishes, as some treatment options can affect a woman’s ability to become pregnant in the future.

Pharmaceutical treatment options can help reduce bleeding (such as tranexamic acid and the combined hormonal contraceptive) or reduce the size of the fibroid by decreasing the amount of hormones present (such as GnRH agonists).

Surgical options can include uterine artery embolisation, which blocks the blood supply to the fibroids and effectively decreases bleeding and shrinks the fibroids, ablation (which removes the lining of the womb) and a myomectomy, in which fibroids are surgically removed.

Some women may also opt for a hysterectomy, where the womb is surgically removed. This is usually done in cases where a woman has large fibroids and severe bleeding. Both ablation and hysterectomy will make pregnancy impossible, so it’s important these options are only considered if you do not wish to have children.

All of these treatment options should help to improve symptoms. However, surgery doesn’t always prevent fibroids from growing back. This is something Nyong’o informed her followers of, saying that despite having 25 fibroids surgically removed, more than 50 are still growing inside her today.

It’s very common for fibroids to return following removal, as the underlying causes remain. At five years after removal, there’s an approximately 50-60% chance of fibroids recurring.

Fibroids are very common. While some women will have no symptoms whatsoever, others may find symptoms to be debilitating. Research to uncover better treatment options for those with fibroids is ongoing, especially looking at non-hormonal treatment options and less invasive surgical options.

The Conversation

Nicola Tempest 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.

ref. Lupita Nyong’o revealed she has fibroids – here’s what you need to know about them – https://theconversation.com/lupita-nyongo-revealed-she-has-fibroids-heres-what-you-need-to-know-about-them-277419

Why some people still believe that aliens shaped ancient civilisations

Source: The Conversation – UK – By Stephan Blum, Research Associate, Institute for Prehistory and Early History and Medieval Archaeology, University of Tübingen

Erich von Däniken proposed that monumental structures such as the pyramids could have been built with help from aliens. Stefan Baumann

Could ancient humans really have built the pyramids without extraterrestrial help? Or do such questions reveal more about modern anxieties than the past itself?

The idea that aliens assisted the builders of ancient monuments was promoted by the Swiss author Erich von Däniken in his bestselling book Chariot of the Gods – published in 1968. Von Däniken died in January 2026, but his vision of ancient astronauts still captivates millions.

The author had pointed to ancient structures such as the pyramids, along with enigmatic ancient artefacts, as supposed evidence that beings from beyond Earth shaped the civilisations of the past.

Though these ideas have been repeatedly debunked, television shows such as the History Channel’s Ancient Aliens continue to air similar narratives.

Erich von Däniken’s theories emerged at a distinct historical moment. They crystallised during the cold war, amid fears of nuclear annihilation, the space race and rapid technological change.

As humans prepared to leave Earth, while simultaneously confronting their own destructive power, the idea of ancient astronauts offered both cosmic reassurance and existential drama. The past became a stage for modern hopes and anxieties.

The reason some people feel able to believe in completely unfounded theories relates to the nature of archaeology itself. The discipline works with fragmentary evidence, layered deposits, and interpretations that rarely yield simple conclusions. Sites such as Giza in Egypt, Göbekli Tepe (a Neolithic settlement in modern Turkey known for its monumental pillars decorated with sculptural reliefs), and Troy – also in Turkey – are not unsolved enigmas but the result of decades of systematic excavation and analysis.

At Giza, archaeologists have uncovered planned worker settlements, bakeries and organised food supply systems, demonstrating how thousands of labourers could construct the pyramids over decades.

Göbekli Tepe shows that its monumental stone pillars were erected by hunter-gatherer communities millennia before the invention of writing – not through alien intervention, but through coordinated labour and ritual innovation. At Troy, successive settlement layers reveal centuries of rebuilding, adaptation and regional exchange rather than a sudden technological anomaly.

Archaeological conclusions are cautious, probabilistic and grounded in material evidence. To outsiders, however, caution can resemble hesitation. Pseudoscience fills that perceived gap with spectacle: aliens built the pyramids; mysterious forces raised Göbekli Tepe; forgotten super-technologies shaped Troy’s walls. Stripped of context, evidence becomes entertainment. Complexity is flattened into insinuation.

A typical “ancient aliens” argument illustrates the pattern: the pyramids are extraordinarily precise. Precision, the claim goes, requires advanced technology; therefore, humans without modern machines could not have built them.

The reasoning sounds logical – but it rests on a false dilemma. What disappears from view is precisely what archaeology studies: logistics, labour
organisation, tool assemblages, accumulated craft knowledge – and small imperfections that reveal human hands at work.

The lure of the extraordinary

Such explanations satisfy a deep psychological impulse. Where once religion explained purpose, science explains process. The “ancient astronauts” hypothesis exploits proportionality bias – the intuition that extraordinary achievements must have extraordinary causes.

Just as medieval legends framed the pyramids as protection against cosmic catastrophe, modern narratives cast humanity as part of a grand design guided by superior beings. Archaeological sites become props in a cosmic drama.

Humans cease to be creators; the past becomes extraordinary because it was “helped”. The appeal is not confined to fringe audiences. Surveys suggest that many people consider extraterrestrial life possible or even likely.

Many scientists agree that, given the vast scale of the universe, such life is statistically plausible. But plausibility is not proof – and it is certainly not evidence for alien intervention in antiquity.

Distrust amplifies the effect. Universities, museums and academic journals are often portrayed as gatekeepers suppressing inconvenient truths. Scientific refutation becomes evidence of conspiracy.

Academic prose – careful, qualified and precise – struggles to compete with dramatic certainty. Questions such as: “How could humans have built this without modern technology?” already contain the insinuation.

Digital media turbocharge the pattern: visually striking claims circulate faster than methodological explanations. Archaeology emphasises gradual change and cumulative knowledge; pseudoscience promises revelation.

Pseudoscientific archaeology is not just a set of beliefs – it is a lucrative industry. Books on ancient astronauts sell millions of copies worldwide. Television franchises generate steady revenue, and leading figures attract audiences in the hundreds of thousands online.

Gobekli Tepe
Göbekli Tepe is the work of coordinated human labour, not of extra-terrestrials.
Matyas Rehak

By contrast, scholarly work circulates in a radically different economy: monographs are printed in small runs and generate little profit. This is not only a battle of ideas but a battle for attention: spectacle is rewarded more visibly than caution.

Von Däniken’s rhetorical genius lay in ambiguity. He rarely made definitive claims, preferring suggestive questions and selective juxtapositions that turned uncertainty into insinuation.

As he once remarked: “Chariots of the Gods was full of speculation – I had 238 question marks. Nobody read the question marks. They said: Mr von Däniken is saying … I did not say – I asked.” The strategy is disarmingly simple: frame speculation as inquiry and criticism as misunderstanding.

Reclaiming the story

The popularity of pseudoscience is not simply ignorance. It reflects the difficulty of interpreting fragmentary evidence, a hunger for meaning, declining institutional trust and the dynamics of digital amplification.

Yet dismissal alone is not enough. Archaeology does more than recover artefacts; it constructs narratives about how humans organised labour, shared beliefs and transformed landscapes. Those narratives are shaped by contemporary questions — and acknowledging this strengthens rather than weakens the discipline.

Debunking alien claims matters. But so does telling richer, more compelling stories about how humans shaped their own past. Archaeology shows that uncertainty is intellectual honesty, that incremental knowledge is cumulative achievement, and that context deepens wonder rather than diminishes it.

Monuments, cities, and human creativity are achievements of our own making, not traces of lost cosmic visitors. Through cooperation, experimentation and resilience, humans created the extraordinary – without any extraterrestrial assistance.

Through rigorous scholarship and compelling storytelling, archaeology shows that the extraordinary was never alien. It was always human.

The Conversation

The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

ref. Why some people still believe that aliens shaped ancient civilisations – https://theconversation.com/why-some-people-still-believe-that-aliens-shaped-ancient-civilisations-277993

‘Sleep divorce’: could separate beds improve your health?

Source: The Conversation – UK – By Laura Boubert, Principal Lecturer in Psychology, University of Westminster

Oleh Veres/Shutterstock

They say love conquers all, but it doesn’t always conquer snoring.

In the US, it’s estimated that 82% of couples share a bed. Sharing a bed with your partner is often seen as an essential part of a romantic relationship. But have you ever wondered whether sleeping apart might actually be better for your health?

Good quality sleep is essential for both physical and mental health. As most adults spend between six and nine hours asleep in every 24-hour period, our sleeping arrangements can have a major effect on wellbeing.

Sleeping arrangements have also evolved over time and across cultures. Until the early 20th century, sleeping together with a partner, children, extended family members or even pets was common. However, the discovery of germs and growing concerns about hygiene led to fears about disease transmission. Sleeping in close proximity began to be seen as a potential health risk, and a new trend emerged for couples to sleep in separate beds or even separate rooms. More recently, we have seen a surge in celebrities announcing their “sleep divorces” from their partners – but are they right?




Read more:
There are benefits to sharing a bed with your pet – as long as you’re scrupulously clean


Sleeping together does appear to bring several benefits. It can strengthen closeness and attachment within a couple and support intimacy. Research suggests it may also have physical effects: couples’ breathing and heart rates can synchronise during sleep, which may contribute to feelings of safety and security. Sleeping together can also reduce stress and increase the production of the hormone oxytocin, sometimes referred to as the “love hormone”.

Couples often report that they sleep better together than when sleeping apart. This has been examined not only through self-reports but also through research using specialist sleep-monitoring methods, including laboratory sleep studies and wearable sleep trackers that measure movement during the night.

When sharing a bed disrupts sleep

However, what happens if your sleep is actually disrupted by your partner rather than improved?

There can be many reasons for this. A partner may snore, get up several times during the night to use the bathroom, read with the light on, or watch television in bed. They might have a sleep condition such as sleep apnoea or restless legs syndrome. Hormonal changes can also play a role, for example menopausal hot flushes or night sweats. Pregnancy, caring for an infant, or different work schedules and shift patterns can also disrupt sleep.

When these disturbances occur frequently, they interfere with fundamental sleep processes, including how quickly you fall asleep (known as sleep onset), how often you wake during the night and how long you remain asleep. Disruption to these processes can have a range of detrimental effects on general physical health.

Poor sleep can impair the immune system, increasing susceptibility to infections such as coughs and colds. It can also disrupt digestion and metabolism, increasing the risk of weight gain and conditions such as diabetes by affecting insulin regulation.

In situations like these, sleeping apart may help. Separate sleeping arrangements allow each person to optimise their own sleep environment. This might include choosing different mattresses or bedding, adjusting light levels, controlling room temperature, or even changing scents and air quality in the bedroom.

Sleeping apart can also support better sleep hygiene. Each partner can adapt their habits around their own sleep patterns, such as going to bed at different times, reading before sleep, or avoiding screens in bed. This behaviour is known to promote better sleep and, in turn, better overall health.

Why relationship quality matters for sleep

But the physical sleep environment is only part of the story. Relationship dynamics also play an important role.

Couples who report being in happy, supportive relationships tend to experience better sleep overall. By contrast, people in unhappy relationships often report poorer sleep quality. Lack of sleep can then worsen emotional regulation, increase anxiety, lower stress tolerance and reduce empathy. These effects can create a negative cycle in which poor sleep contributes to further relationship strain.

Although sleeping in separate beds is sometimes seen as a sign of relationship trouble, this is not necessarily the case. If a partner’s behaviour is consistently disrupting sleep, the health benefits of sleeping separately may outweigh the drawbacks.

Ultimately, whether couples sleep best together or apart depends on both partners and the quality of their relationship. For some couples, sharing a bed strengthens connection and comfort. For others, a “sleep divorce” may simply be a practical way to ensure everyone gets the rest they need.

The Conversation

Laura Boubert 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.

ref. ‘Sleep divorce’: could separate beds improve your health? – https://theconversation.com/sleep-divorce-could-separate-beds-improve-your-health-278055

Hungary’s Viktor Orbán reignites his hostility towards Ukraine as he prepares for April elections

Source: The Conversation – UK – By Marc Roscoe Loustau, Affiliated Fellow at the Institute for Advanced Study, Central European University

Relations between Hungary and Ukraine have deteriorated significantly over the past month. In early March, Hungarian authorities arrested seven Ukrainian bank workers who were transporting millions of US dollars worth of cash and gold through Hungary to Ukraine.

Hungary’s tax authority said they had been detained on suspicion of money laundering, which prompted a furious response from Ukraine. In a post on social media, Ukraine’s foreign minister Andrii Sybiha denounced what he called “state terrorism and racketeering”.

This incident followed an earlier decision by the Hungarian prime minister, Viktor Orbán, to deploy the military to guard power plants after warning that Ukraine planned to disrupt his country’s energy system. Orbán had previously accused Kyiv of holding back Russian oil deliveries through the Druzhba pipeline, which passes through Ukrainian territory.

In these conflicts with Ukraine, Orbán’s eyes are certainly on the home front. Hungarians head to the polls in April for parliamentary elections and, with ordinary people having suffered from high inflation and limited job prospects in recent years, Orbán may well be ginning up international incidents to distract from his poor economic record.

But a deeper dive into the region’s history shows that Orbán has often picked diplomatic fights with neighbouring states, with Ukraine taking the brunt of this campaign.

When the Austro-Hungarian empire collapsed after the first world war, several countries in central Europe inherited ethnic Hungarian communities within their new borders. One of these communities was in Transcarpathia, a region of Czechoslovakia that was taken over by the Soviet Union in 1946. The Hungarian minority there became citizens of independent Ukraine in 1991, along with the rest of Transcarpathia.

A hallmark of Orbán’s nationalist politics since the 1990s has been his willingness to criticise neighbouring countries over their treatment of Hungarian minorities. And after becoming prime minister for a second time in 2010, he fulfilled a longstanding pledge to offer Hungarian citizenship and passports to ethnic Hungarians in surrounding states.

Several years later, in 2014, Orbán then called for for “autonomy” for ethnic Hungarians in Ukraine and has since then kept up a series of complaints about the Ukrainian government’s treatment of the Hungarian minority in Transcarpathia.

Following Russia’s 2014 incursions into eastern Ukraine, for example, Kyiv instituted laws restricting the use of minority languages. These laws were introduced to promote the Ukrainian language and limit Russian.

Orbán complained that the laws violated the rights of Transcarpathia’s Hungarian minority to their own culture and language. He has subsequently used the rationale of defending minority rights to block a variety of measures promoting cooperation between Ukraine and the EU.

Ukraine has been a major focus of Orbán’s campaigns regarding ethnic Hungarian rights. But the country is not alone in being targeted by Budapest. Orbán also referred to southern Slovakia, where there is a large ethnic Hungarian minority, as a “partitioned part” of Hungary in a July 2023 speech.

Orbán’s Russian alliance

It has become complicated for Orbán to maintain his rhetoric of protecting ethnic Hungarian rights as the war in Ukraine has continued and Hungary has drifted further into Russia’s sphere of geopolitical influence. For example, he has more recently muted his criticism of neighbouring countries for their treatment of ethnic Hungarians if they are supportive of Russia.

The Hungarian prime minister initially looked the other way when Slovakia’s government, which has been led by pro-Russia Robert Fico since October 2023, passed a new law in January criminalising speech against a set of post-second world war laws called the “Beneš decrees”. This law has widely been seen as targeting Slovakia’s ethnic Hungarians.

The Beneš decrees were used by Slovakia’s government to deport thousands of Hungarians from the country in the 1940s. While leaders of Slovakia’s Hungarian minority continue to denounce these decrees as a crime against their community, under the new law they could be put in jail for such statements.

Orbán’s initial response was cautious. He pledged to talk with Fico but only once he had a “sufficiently deep understanding” of the situation. Orbán’s opponent in the upcoming election, Peter Magyar, then led a protest in front of the Slovak embassy in Budapest where he denounced the new law. And under pressure, Orbán announced he would appealing the law to the European Commission.

The new law put Orbán in a bind. Should he criticise Slovakia over this assault on the collective rights of ethnic Hungarians and risk sowing discord with a fellow Russian partner? Or should he defend the Slovak government against criticism from Magyar and pay for it at the ballot box?

It’s likely that whoever leads Hungary’s government after the upcoming election will continue to pick fights with neighbouring states over the issue of national minorities. Magyar has signalled he will continue Orbán’s approach, and not only with his protest in front of the Slovakian embassy.

In 2025, he made a point of travelling to Ukraine and Romania to meet with ethnic Hungarians. And he has also consistently demonstrated concern for these minority communities in his campaign speeches.

Given his record of chiding neighbouring state over their treatment of Hungarian minorities, a Magyar win in April will not mean an end to tensions between Hungary and Ukraine. But it could still be a fresh start after years of hostility under Orbán.

The Conversation

Marc Roscoe Loustau 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.

ref. Hungary’s Viktor Orbán reignites his hostility towards Ukraine as he prepares for April elections – https://theconversation.com/hungarys-viktor-orban-reignites-his-hostility-towards-ukraine-as-he-prepares-for-april-elections-277026

Horror won big at the 2026 Oscars – it’s time the genre was taken seriously

Source: The Conversation – UK – By Frazer Lee, Reader in Creative Writing, Brunel University of London

The horror genre rose from the grave to win big at this year’s Oscars, with four films featuring prominently in the awards.

Ryan Coogler’s period vampire movie Sinners was nominated for a record-breaking 16 Oscars, bringing home four golden statues – including the coveted best actor prize for Michael B. Jordan.

Weapons’ Amy Madigan fended off stiff competition to win best supporting actress, and – at the PG-rated end of the horror spectrum – K-Pop Demon Hunters won best animated film and best original song.

Guillermo del Toro’s adaptation of Mary Shelley’s classic novel Frankenstein; Or, The Modern Prometheus shuffled away from the ceremony clutching three Oscars in its cadaverous hands. It won best production design, best costume design, and best make-up and hairstyling out of nine nominations that included best picture and best supporting actor for Australian actor Jacob Elordi.

It would appear that horror is now considered up there with the costume dramas and masterpieces of world cinema that have long been mainstays of film industry awards. But this has not always been the case. Aside from rare recipients such as William Friedkin’s The Exorcist (1973) – which took possession of golden statues for best adapted screenplay and best sound but missed out in all eight of its other nominations – horror has often taken a back seat during awards season.

It seems unfathomable now that Anthony Perkins didn’t receive any Oscar love for his now-iconic role as Norman Bates in Hitchcock’s Psycho (1960). Fans were also horrified, but not in a good way, when Ari Aster’s 2018 occult chiller Hereditary (and its trailblazing performance by lead actress Toni Collette) was completely overlooked by the Academy.

The Exorcist was the first of only a handful of horror features to be nominated for the best picture award. Jaws (1975), The Sixth Sense (1999), Black Swan (2010) and Get Out (2017) were all nominated, and more than worthy potential recipients, but were all snubbed. In 1991 Jonathan Demme’s The Silence of the Lambs won best picture (there’s much debate as to whether the film is a horror or a thriller – let’s just say it’s both), but why the wait for another success story like that of Sinners?

For many, the view that horror is less worthy of mainstream gongs stems from the “video nasty” era when rental shelves at petrol stations across the Western world placed horror tapes on the top shelf alongside more lurid adult titles.

But horror is a very broad church and anyone with a passion for the genre will tell you of their love of everything from gore-fests such as Sam Raimi’s The Evil Dead (1981) to quieter, more atmospheric terrors like Jack Clayton’s The Innocents (1961) and Robert Wise’s The Haunting (1963).

Indie horror is a hotbed of innovation and experimentation and an inclusive place to take risks and have fun. And perhaps one reason for horror’s ascension to the big league of film awards ceremonies is the way in which it is purpose-built to hold a mirror up to society’s problems.

Coralie Fargeat’s The Substance (2024) explored ageing, body image and media manipulation via twin powerhouse performances from Margaret Qualley and Demi Moore. Fargeat was the first woman to be Oscar nominated for writing and directing a horror film, and Moore received a best actress nomination, but both were snubbed on the night.

Jordan Peele’s brilliant and disturbing horror-with-comedy Get Out (2017) took an unflinching look at racism with the Academy awarding it best screenplay. Horror can tackle these big themes using allegorical storytelling, revealing that the scariest monsters of all are often ourselves.

While cheering on the great and good during the Oscars coverage on Sunday night, I was reminded of my own undying love for the genre. I remembered my first ever live book reading at a big horror convention called Horrorfind Weekend in Maryland, US. Tens of thousands of fans were in attendance, lining up for hours for autographs from horror luminaries such as George A. Romero (Night of the Living Dead, 1968) and Tony Todd (Final Destination franchise, 2000s, and Candyman, 1992).

The panel discussions often continued in the bar afterwards and I remember chatting with one of my horror heroes, the writer and filmmaker John Skipp (A Nightmare on Elm Street 5: The Dream Child, 1989). We were talking about how to reach a wider audience with our work and Skipp reminded me, “If you make outsider art, you’ll attract outsider fans.”

Perhaps, this is the key to horror getting the gold standard of approval from awards voters. The more our leaders push us into ever widening margins with their endless stoking of culture wars, the more we become outsiders. We need to face our demons in order to overcome them. Many of us long to be seen, and horror stories see all of us.

The emerging generation of horror filmmakers like Ryan Coogler know this and embed it within their work. To paraphrase the (now Oscar-winning) song Golden from K-Pop Demon Hunters, horror is done hiding, and now it’s shining.

The Conversation

Frazer Lee 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.

ref. Horror won big at the 2026 Oscars – it’s time the genre was taken seriously – https://theconversation.com/horror-won-big-at-the-2026-oscars-its-time-the-genre-was-taken-seriously-278574

Why arthritis in children can threaten eyesight

Source: The Conversation – UK – By Elizabeth Rosser, Associate Professor of Aging, Rheumatology and Regenerative Medicine, UCL

sweet marshmallow/Shutterstock

Arthritis is often associated with older age, but it also affects children. One of the most common forms is juvenile idiopathic arthritis (JIA), an inflammatory condition that causes persistent joint swelling and pain.

For reasons that remain unclear, between 10% and 30% of children with JIA also develop uveitis, an inflammatory disease of the eye. In some cases, this eye inflammation does not respond to treatment and can lead to sight loss.

A recent study from our laboratory shows that immune cells called B cells, best known for producing antibodies, play a previously underappreciated role in driving this process and may point to new treatment approaches.

JIA is diagnosed when a child or young person under 16 develops inflammation in at least one joint for more than six weeks with no clear cause. Around one in 1,000 children in the UK are affected. The condition includes several subtypes, most of which are autoimmune, meaning the immune system mistakenly attacks the body’s own tissues.

Outcomes vary. With treatment, some children experience long periods of remission and may outgrow the condition. For others, inflammation persists into adulthood and can cause joint damage and disability. JIA can also affect organs beyond the joints, including the skin, gut and eyes. When it involves the eye, the condition is known as JIA-associated uveitis.

Much remains unknown about why some children with JIA develop eye inflammation while others do not. It is unclear whether the same immune pathways drive disease in both joints and eyes, or why inflammation most often affects the front of the eye, known as anterior uveitis. In many cases, the condition is silent and painless, allowing damage to accumulate unnoticed. Regular eye screening is therefore essential.

Several risk factors are well established. Girls and children who develop JIA early in life, particularly before the age of six, are more likely to develop uveitis. Children who test positive for antinuclear antibodies are also at increased risk.

Even so, the biological mechanisms linking arthritis and eye disease remain poorly understood, and the role of antibody-producing B cells has received relatively little attention.

To investigate this, our study analysed blood samples from more than 150 children with arthritis. Certain types of B cells were more abundant in those who had developed uveitis than in children with arthritis alone. A distinctive aspect of the research was the opportunity to examine samples taken directly from affected eyes.

In some children, uveitis can lead to cataracts or glaucoma, making surgery necessary to preserve vision. During these procedures, small amounts of biological material that would normally be discarded can be collected for research. Using these samples, we found that activated B cells had migrated into the eyes of children with JIA-associated uveitis.

Laboratory experiments showed that blocking communication between B cells and another type of immune cell, known as T cells, significantly reduced inflammation. The drug used to achieve this is already being tested in clinical trials for multiple sclerosis and lupus, raising the possibility of repurposing it for children with treatment-resistant disease.

The need for new approaches is clear. Currently, one in four children with JIA-associated uveitis do not respond to the only approved biologic therapy, and by age 18 nearly a third have lost some vision in at least one eye.

These findings point to a potential new treatment pathway and highlight a broader issue in medical research. There is often a delay of many years before therapies developed for adults are tested in children, even when the underlying inflammatory mechanisms are similar.

Improving how discoveries are translated into paediatric care could significantly change outcomes for children with arthritis and uveitis. Earlier intervention, targeted therapies and faster access to treatments already being explored in adult disease may help prevent vision loss, and reduce the long-term burden on children and their families.

The Conversation

Elizabeth Rosser received funding from Fight for Sight, Arthritis UK, the Medical Research Foundation, Moorfields Eye Charity, the Lister Institute for Preventive Medicine and the Kennedy Trust for Rheumatology Research for this study. Work for this study was made possible by the CLUSTER consortium (https://www.clusterconsortium.org.uk) and the Childhood Ocular Inflammatory Disease (CHOIR) Biobank.

Beth Jebson 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.

ref. Why arthritis in children can threaten eyesight – https://theconversation.com/why-arthritis-in-children-can-threaten-eyesight-276355

Les microbes qui vivent sur les feuilles : un monde invisible essentiel à la santé des plantes

Source: The Conversation – France (in French) – By Mathilde Bouteiller, Chargée de recherche en microbiologie & biologie moléculaire de l’unité AGHYLE, UniLaSalle

Plant de tomate, feuille de tomate avec du microbiote cultivable et empreinte de feuille sur boîte de Pétri. Fourni par l’auteur

Les humains ne sont pas les seuls à être dotés de microbiotes. Les plantes aussi. Les milliers de microorganismes qui vivent sur leurs feuilles sont encore peu connus, mais pleins de potentiels pour accroître leur croissance ou améliorer leur rendement, ou encore leur résistance au stress.


À l’heure où l’utilisation des pesticides et des engrais de synthèse pose de plus en plus question, des alternatives efficaces doivent être trouvées. Parmi les solutions qui sont à l’étude, l’utilisation de produits d’origine naturelle, aussi appelés biosolutions, montre des résultats prometteurs.

Les biostimulants font partie de ces alternatives. Ils peuvent être de diverses origines et contiennent par exemple des extraits d’algues, des microorganismes, comme des champignons ou des bactéries, des extraits végétaux, des acides aminés… On les applique de multiples manières, en les pulvérisant sur les feuilles, en enrobant les graines ou directement dans le sol.

Ces produits fonctionnent en stimulant les processus biologiques naturels des plantes pour améliorer leur nutrition, leur croissance, leur rendement ou leur résistance au stress. Là où un engrais va apporter directement un élément nutritif (comme l’azote, le phosphore, le potassium) propice à la croissance des plantes et où un pesticide sera utilisé pour éradiquer les agresseurs des plantes, les biostimulants vont, eux, permettre à la plante d’augmenter ses propres capacités.

Quels sont les avantages à utiliser des biostimulants foliaires ?

Il existe ainsi plusieurs avantages à utiliser des traitements foliaires plutôt que des traitements au sol.

Premièrement, ces traitements ont une activité plus rapide puisque la solution va pouvoir agir directement sur le métabolisme de la plante, sans trop dépendre de l’environnement très complexe que représente le sol. De plus, les doses utilisées en traitement foliaire sont bien moins importantes que lors d’une application au sol, ce qui rend ces traitements moins onéreux.

Par ailleurs, il est fréquent d’appliquer ce type de traitement en association avec d’autres traitements foliaires (herbicide, fongicide), dont l’effet négatif semble contrebalancé par l’effet du biostimulant.

Quelle est l’influence des biostimulants sur les microbiotes de la plante ?

Ce qui rend également les biostimulants particulièrement intéressants réside dans leur possibilité d’interagir avec le microbiote des plantes. Car les humains ne sont pas les seuls à vivre aux contacts d’une myriade de bactéries, de champignons, et autres microorganismes, qui exercent des fonctions importantes.

Les organismes présents dans les microbiotes de la plante comprennent :

  • des bactéries (microorganismes unicellulaires sans noyau) ;

  • des archées (microorganismes unicellulaires sans noyau formant un règne à part entière différent des bactéries) ;

  • des champignons pluricellulaires produisant du mycélium ;

  • des champignons unicellulaires (comme les levures) ;

  • des algues (végétaux unicellulaires) et des protistes (cellules unicellulaires non classifiables dans le règne animal, végétal ou fongique) ;

  • des virus et des bactériophages (virus qui attaque exclusivement les bactéries).

Chez les végétaux, ces microorganismes sont notamment présents au niveau des sols, des racines et des parties aériennes (tiges, feuilles, fruits et fleurs).

Les biosolutions ou les produits de lutte chimique vont être directement en contact avec ces microorganismes qui constituent le microbiote de la plante.

Plusieurs études ont déjà montré l’impact des biostimulants sur le microbiote au niveau des racines et du sol. Ces microorganismes du sol et des racines sont regroupés sous le nom de rhizosphère. Des biosolutions appliqués au sol sont, par exemple, capables de modifier les communautés microbiennes du sol, notamment en augmentant l’abondance en champignons mycorhiziens (champignons connus pour améliorer l’acquisition de nutriments par les plantes, qui favoriseraient la croissance et le rendement des cultures).

Malheureusement, à l’heure actuelle, peu d’études sur les microorganismes présents au niveau des parties aériennes des plantes, aussi appelés phyllosphère, sont recensées. Pourtant, nous savons que ces microorganismes exercent une activité globalement positive sur les plantes hôtes et qu’ils sont directement influencés par les produits appliqués sur les feuilles.


Fourni par l’auteur

Au sein de la phyllosphère, les microorganismes sont capables d’interagir entre eux ainsi qu’avec leurs plantes hôtes avec lesquelles ils entretiennent une relation symbiotique, c’est-à-dire une association biologique, durable et réciproquement profitable, entre deux organismes vivants.

De ce fait, ce microbiote joue un rôle important dans le développement et la nutrition des plantes. Par ailleurs, comme cela est observé pour le microbiote cutané chez l’humain, la présence de microorganismes sur la surface des parties aériennes permet à la plante de se protéger et de prévenir de l’attaque d’organismes pathogènes. Une étude montre par exemple que certains membres de la communauté microbienne des feuilles fournissent une protection significative contre un agent pathogène chez l’arabette des dames, une plante à fleur très commune en Europe.

Mais pour mieux comprendre toutes les potentialités des alliances bénéfiques qui se jouent au niveau des feuilles des plantes, point de mystère, il faut mieux les connaître, et les étudier.

Étudier la phyllosphère

Pour étudier les microbiotes, on analyse généralement l’ADN des microorganismes.

La métagénomique est une méthode d’analyse fondée sur la technique de séquençage des ADN (déterminer la séquence des bases de tous les gènes du génome) d’un environnement donné. Avec cette méthode, l’étude des microorganismes prédominants dans un milieu spécifique est possible grâce à l’identification de ces microorganismes, en comparant leurs séquences avec des séquences de microorganismes déjà identifiés dans des bases de données appelées BLAST. Avec la métagénomique, on peut également connaître les fonctions que jouent ces microorganismes. Ces techniques, très à la mode, sont utilisées puisqu’elles présentent l’avantage de ne pas être basées sur la mise en culture de microorganismes parfois très difficile voire impossible.

Cependant, les études basées sur l’ADN ne permettent pas de distinguer l’ADN de microorganismes morts ou vivants et de savoir si ces microorganismes sont actifs. Au sein du laboratoire AGHYLE, le microbiote de la phyllosphère est donc étudié en parallèle par la mise en culture de certains microorganismes sur boîte de Pétri, bien que ces derniers ne représentent que quelques pourcents du microbiote total.

Les bactéries obtenues et isolées de la phyllosphère présentent généralement une grande diversité de couleur, de texture et d’aspect. La coloration permet aux microorganismes de mieux résister aux UV, ce qui est un avantage sélectif, car ils doivent être capables de résister aux rayons du soleil à la différence de ceux de la rhizosphère. Certaines bactéries forment des colonies très mucoïdes (grasses) ce qui les rendent également plus résistantes à la sécheresse.


Fourni par l’auteur

Plusieurs études indiquent que des microorganismes provenant de la phyllosphère présentent des activités bénéfiques pour les plantes. Par exemple, sur la phyllosphère, les bactéries Methylobacterium sont reconnues pour stimuler la croissance des plantes et les protéger des bioagresseurs.

D’autres bactéries isolées de la phyllosphère de la tomate, comme Bacillus velezensis 83, sont également dotées de capacité de stimulation de la croissance des plantes et de protection des cultures.

Au sein du laboratoire, nous avons identifié des bactéries et les champignons isolés de la phyllosphère de la tomate Solanum lycopersicum (variété MicroTom) et du maïs (Zea mays L. variété DATABAZ). En comparant les séquences d’ADN obtenues avec une banque de données internationales (BLAST), nous avons pu identifier le genre et parfois aussi l’espèce de ces microorganismes et vérifier qu’ils s’agissaient bien de microorganismes connus et provenant de la phyllosphère.

Parmi les microorganismes identifiés, plusieurs sont connus dans la littérature et pourraient appartenir aux bactéries ou aux champignons promoteurs de la croissance des plantes et/ou présenter des effets de biocontrôle. D’autres ne sont que partiellement identifiés, et nous ne pouvons donc pas encore savoir s’ils sont bénéfiques ou pathogènes.


Fourni par l’auteur

Bien qu’il soit possible d’utiliser directement des bactéries ou des champignons isolés de l’environnement naturel pour booster la croissance et la protection des plantes, la colonisation et la capacité des microorganismes à fonctionner en champ reste difficile à prévoir.

De plus, le stockage de microorganismes est bien plus compliqué que ne l’est un biostimulant. Dans ce sens, le développement de solutions agissant directement sur les microorganismes déjà présents sur les plantes, reste une alternative prometteuse pour l’agriculture. Ainsi, pour tester des biostimulants de manière peu onéreuse et rapide, nous réalisons au laboratoire des tests in vitro (en boîte de Pétri) sur les microorganismes de la phyllosphère. Le développement des microorganismes est suivi au cours du temps et la morphologie du développement bactérien et mycélien est observée.


Fourni par l’auteur

Dans la figure ci-dessus, on observe l’effet d’un biostimulant foliaire sur un champignon, isolé de la phyllosphère du maïs. Bien que la taille du mycélium ne semble pas impactée, la présence du biostimulant semble affecter le champignon. Mais plusieurs questions restent en suspens : est-ce que ce biostimulant induit la même chose chez tous les microorganismes de la phyllosphère ? Ne va-t-il pas stimuler la croissance d’organismes pathogènes ?

Ces résultats préliminaires offrent des perspectives intéressantes, mais doivent encore être approfondis.

The Conversation

Les premières expérimentations portant sur la phyllosphère ont été initiées dans le cadre des travaux menés au sein de la Chaire Biomes, en partenariat avec l’entreprise Gaïago.

Guillemette Garry ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’a déclaré aucune autre affiliation que son organisme de recherche.

ref. Les microbes qui vivent sur les feuilles : un monde invisible essentiel à la santé des plantes – https://theconversation.com/les-microbes-qui-vivent-sur-les-feuilles-un-monde-invisible-essentiel-a-la-sante-des-plantes-276204